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Diffstat (limited to '')
| -rw-r--r-- | drivers/pci/pci.c | 6920 |
1 files changed, 6920 insertions, 0 deletions
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c new file mode 100644 index 000000000..5368a3715 --- /dev/null +++ b/drivers/pci/pci.c @@ -0,0 +1,6920 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI Bus Services, see include/linux/pci.h for further explanation. + * + * Copyright 1993 -- 1997 Drew Eckhardt, Frederic Potter, + * David Mosberger-Tang + * + * Copyright 1997 -- 2000 Martin Mares <mj@ucw.cz> + */ + +#include <linux/acpi.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/dmi.h> +#include <linux/init.h> +#include <linux/msi.h> +#include <linux/of.h> +#include <linux/pci.h> +#include <linux/pm.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/string.h> +#include <linux/log2.h> +#include <linux/logic_pio.h> +#include <linux/pm_wakeup.h> +#include <linux/interrupt.h> +#include <linux/device.h> +#include <linux/pm_runtime.h> +#include <linux/pci_hotplug.h> +#include <linux/vmalloc.h> +#include <asm/dma.h> +#include <linux/aer.h> +#include <linux/bitfield.h> +#include "pci.h" + +DEFINE_MUTEX(pci_slot_mutex); + +const char *pci_power_names[] = { + "error", "D0", "D1", "D2", "D3hot", "D3cold", "unknown", +}; +EXPORT_SYMBOL_GPL(pci_power_names); + +#ifdef CONFIG_X86_32 +int isa_dma_bridge_buggy; +EXPORT_SYMBOL(isa_dma_bridge_buggy); +#endif + +int pci_pci_problems; +EXPORT_SYMBOL(pci_pci_problems); + +unsigned int pci_pm_d3hot_delay; + +static void pci_pme_list_scan(struct work_struct *work); + +static LIST_HEAD(pci_pme_list); +static DEFINE_MUTEX(pci_pme_list_mutex); +static DECLARE_DELAYED_WORK(pci_pme_work, pci_pme_list_scan); + +struct pci_pme_device { + struct list_head list; + struct pci_dev *dev; +}; + +#define PME_TIMEOUT 1000 /* How long between PME checks */ + +static void pci_dev_d3_sleep(struct pci_dev *dev) +{ + unsigned int delay_ms = max(dev->d3hot_delay, pci_pm_d3hot_delay); + unsigned int upper; + + if (delay_ms) { + /* Use a 20% upper bound, 1ms minimum */ + upper = max(DIV_ROUND_CLOSEST(delay_ms, 5), 1U); + usleep_range(delay_ms * USEC_PER_MSEC, + (delay_ms + upper) * USEC_PER_MSEC); + } +} + +bool pci_reset_supported(struct pci_dev *dev) +{ + return dev->reset_methods[0] != 0; +} + +#ifdef CONFIG_PCI_DOMAINS +int pci_domains_supported = 1; +#endif + +#define DEFAULT_CARDBUS_IO_SIZE (256) +#define DEFAULT_CARDBUS_MEM_SIZE (64*1024*1024) +/* pci=cbmemsize=nnM,cbiosize=nn can override this */ +unsigned long pci_cardbus_io_size = DEFAULT_CARDBUS_IO_SIZE; +unsigned long pci_cardbus_mem_size = DEFAULT_CARDBUS_MEM_SIZE; + +#define DEFAULT_HOTPLUG_IO_SIZE (256) +#define DEFAULT_HOTPLUG_MMIO_SIZE (2*1024*1024) +#define DEFAULT_HOTPLUG_MMIO_PREF_SIZE (2*1024*1024) +/* hpiosize=nn can override this */ +unsigned long pci_hotplug_io_size = DEFAULT_HOTPLUG_IO_SIZE; +/* + * pci=hpmmiosize=nnM overrides non-prefetchable MMIO size, + * pci=hpmmioprefsize=nnM overrides prefetchable MMIO size; + * pci=hpmemsize=nnM overrides both + */ +unsigned long pci_hotplug_mmio_size = DEFAULT_HOTPLUG_MMIO_SIZE; +unsigned long pci_hotplug_mmio_pref_size = DEFAULT_HOTPLUG_MMIO_PREF_SIZE; + +#define DEFAULT_HOTPLUG_BUS_SIZE 1 +unsigned long pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE; + + +/* PCIe MPS/MRRS strategy; can be overridden by kernel command-line param */ +#ifdef CONFIG_PCIE_BUS_TUNE_OFF +enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_TUNE_OFF; +#elif defined CONFIG_PCIE_BUS_SAFE +enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_SAFE; +#elif defined CONFIG_PCIE_BUS_PERFORMANCE +enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PERFORMANCE; +#elif defined CONFIG_PCIE_BUS_PEER2PEER +enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_PEER2PEER; +#else +enum pcie_bus_config_types pcie_bus_config = PCIE_BUS_DEFAULT; +#endif + +/* + * The default CLS is used if arch didn't set CLS explicitly and not + * all pci devices agree on the same value. Arch can override either + * the dfl or actual value as it sees fit. Don't forget this is + * measured in 32-bit words, not bytes. + */ +u8 pci_dfl_cache_line_size = L1_CACHE_BYTES >> 2; +u8 pci_cache_line_size; + +/* + * If we set up a device for bus mastering, we need to check the latency + * timer as certain BIOSes forget to set it properly. + */ +unsigned int pcibios_max_latency = 255; + +/* If set, the PCIe ARI capability will not be used. */ +static bool pcie_ari_disabled; + +/* If set, the PCIe ATS capability will not be used. */ +static bool pcie_ats_disabled; + +/* If set, the PCI config space of each device is printed during boot. */ +bool pci_early_dump; + +bool pci_ats_disabled(void) +{ + return pcie_ats_disabled; +} +EXPORT_SYMBOL_GPL(pci_ats_disabled); + +/* Disable bridge_d3 for all PCIe ports */ +static bool pci_bridge_d3_disable; +/* Force bridge_d3 for all PCIe ports */ +static bool pci_bridge_d3_force; + +static int __init pcie_port_pm_setup(char *str) +{ + if (!strcmp(str, "off")) + pci_bridge_d3_disable = true; + else if (!strcmp(str, "force")) + pci_bridge_d3_force = true; + return 1; +} +__setup("pcie_port_pm=", pcie_port_pm_setup); + +/** + * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children + * @bus: pointer to PCI bus structure to search + * + * Given a PCI bus, returns the highest PCI bus number present in the set + * including the given PCI bus and its list of child PCI buses. + */ +unsigned char pci_bus_max_busnr(struct pci_bus *bus) +{ + struct pci_bus *tmp; + unsigned char max, n; + + max = bus->busn_res.end; + list_for_each_entry(tmp, &bus->children, node) { + n = pci_bus_max_busnr(tmp); + if (n > max) + max = n; + } + return max; +} +EXPORT_SYMBOL_GPL(pci_bus_max_busnr); + +/** + * pci_status_get_and_clear_errors - return and clear error bits in PCI_STATUS + * @pdev: the PCI device + * + * Returns error bits set in PCI_STATUS and clears them. + */ +int pci_status_get_and_clear_errors(struct pci_dev *pdev) +{ + u16 status; + int ret; + + ret = pci_read_config_word(pdev, PCI_STATUS, &status); + if (ret != PCIBIOS_SUCCESSFUL) + return -EIO; + + status &= PCI_STATUS_ERROR_BITS; + if (status) + pci_write_config_word(pdev, PCI_STATUS, status); + + return status; +} +EXPORT_SYMBOL_GPL(pci_status_get_and_clear_errors); + +#ifdef CONFIG_HAS_IOMEM +static void __iomem *__pci_ioremap_resource(struct pci_dev *pdev, int bar, + bool write_combine) +{ + struct resource *res = &pdev->resource[bar]; + resource_size_t start = res->start; + resource_size_t size = resource_size(res); + + /* + * Make sure the BAR is actually a memory resource, not an IO resource + */ + if (res->flags & IORESOURCE_UNSET || !(res->flags & IORESOURCE_MEM)) { + pci_err(pdev, "can't ioremap BAR %d: %pR\n", bar, res); + return NULL; + } + + if (write_combine) + return ioremap_wc(start, size); + + return ioremap(start, size); +} + +void __iomem *pci_ioremap_bar(struct pci_dev *pdev, int bar) +{ + return __pci_ioremap_resource(pdev, bar, false); +} +EXPORT_SYMBOL_GPL(pci_ioremap_bar); + +void __iomem *pci_ioremap_wc_bar(struct pci_dev *pdev, int bar) +{ + return __pci_ioremap_resource(pdev, bar, true); +} +EXPORT_SYMBOL_GPL(pci_ioremap_wc_bar); +#endif + +/** + * pci_dev_str_match_path - test if a path string matches a device + * @dev: the PCI device to test + * @path: string to match the device against + * @endptr: pointer to the string after the match + * + * Test if a string (typically from a kernel parameter) formatted as a + * path of device/function addresses matches a PCI device. The string must + * be of the form: + * + * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]* + * + * A path for a device can be obtained using 'lspci -t'. Using a path + * is more robust against bus renumbering than using only a single bus, + * device and function address. + * + * Returns 1 if the string matches the device, 0 if it does not and + * a negative error code if it fails to parse the string. + */ +static int pci_dev_str_match_path(struct pci_dev *dev, const char *path, + const char **endptr) +{ + int ret; + unsigned int seg, bus, slot, func; + char *wpath, *p; + char end; + + *endptr = strchrnul(path, ';'); + + wpath = kmemdup_nul(path, *endptr - path, GFP_ATOMIC); + if (!wpath) + return -ENOMEM; + + while (1) { + p = strrchr(wpath, '/'); + if (!p) + break; + ret = sscanf(p, "/%x.%x%c", &slot, &func, &end); + if (ret != 2) { + ret = -EINVAL; + goto free_and_exit; + } + + if (dev->devfn != PCI_DEVFN(slot, func)) { + ret = 0; + goto free_and_exit; + } + + /* + * Note: we don't need to get a reference to the upstream + * bridge because we hold a reference to the top level + * device which should hold a reference to the bridge, + * and so on. + */ + dev = pci_upstream_bridge(dev); + if (!dev) { + ret = 0; + goto free_and_exit; + } + + *p = 0; + } + + ret = sscanf(wpath, "%x:%x:%x.%x%c", &seg, &bus, &slot, + &func, &end); + if (ret != 4) { + seg = 0; + ret = sscanf(wpath, "%x:%x.%x%c", &bus, &slot, &func, &end); + if (ret != 3) { + ret = -EINVAL; + goto free_and_exit; + } + } + + ret = (seg == pci_domain_nr(dev->bus) && + bus == dev->bus->number && + dev->devfn == PCI_DEVFN(slot, func)); + +free_and_exit: + kfree(wpath); + return ret; +} + +/** + * pci_dev_str_match - test if a string matches a device + * @dev: the PCI device to test + * @p: string to match the device against + * @endptr: pointer to the string after the match + * + * Test if a string (typically from a kernel parameter) matches a specified + * PCI device. The string may be of one of the following formats: + * + * [<domain>:]<bus>:<device>.<func>[/<device>.<func>]* + * pci:<vendor>:<device>[:<subvendor>:<subdevice>] + * + * The first format specifies a PCI bus/device/function address which + * may change if new hardware is inserted, if motherboard firmware changes, + * or due to changes caused in kernel parameters. If the domain is + * left unspecified, it is taken to be 0. In order to be robust against + * bus renumbering issues, a path of PCI device/function numbers may be used + * to address the specific device. The path for a device can be determined + * through the use of 'lspci -t'. + * + * The second format matches devices using IDs in the configuration + * space which may match multiple devices in the system. A value of 0 + * for any field will match all devices. (Note: this differs from + * in-kernel code that uses PCI_ANY_ID which is ~0; this is for + * legacy reasons and convenience so users don't have to specify + * FFFFFFFFs on the command line.) + * + * Returns 1 if the string matches the device, 0 if it does not and + * a negative error code if the string cannot be parsed. + */ +static int pci_dev_str_match(struct pci_dev *dev, const char *p, + const char **endptr) +{ + int ret; + int count; + unsigned short vendor, device, subsystem_vendor, subsystem_device; + + if (strncmp(p, "pci:", 4) == 0) { + /* PCI vendor/device (subvendor/subdevice) IDs are specified */ + p += 4; + ret = sscanf(p, "%hx:%hx:%hx:%hx%n", &vendor, &device, + &subsystem_vendor, &subsystem_device, &count); + if (ret != 4) { + ret = sscanf(p, "%hx:%hx%n", &vendor, &device, &count); + if (ret != 2) + return -EINVAL; + + subsystem_vendor = 0; + subsystem_device = 0; + } + + p += count; + + if ((!vendor || vendor == dev->vendor) && + (!device || device == dev->device) && + (!subsystem_vendor || + subsystem_vendor == dev->subsystem_vendor) && + (!subsystem_device || + subsystem_device == dev->subsystem_device)) + goto found; + } else { + /* + * PCI Bus, Device, Function IDs are specified + * (optionally, may include a path of devfns following it) + */ + ret = pci_dev_str_match_path(dev, p, &p); + if (ret < 0) + return ret; + else if (ret) + goto found; + } + + *endptr = p; + return 0; + +found: + *endptr = p; + return 1; +} + +static u8 __pci_find_next_cap_ttl(struct pci_bus *bus, unsigned int devfn, + u8 pos, int cap, int *ttl) +{ + u8 id; + u16 ent; + + pci_bus_read_config_byte(bus, devfn, pos, &pos); + + while ((*ttl)--) { + if (pos < 0x40) + break; + pos &= ~3; + pci_bus_read_config_word(bus, devfn, pos, &ent); + + id = ent & 0xff; + if (id == 0xff) + break; + if (id == cap) + return pos; + pos = (ent >> 8); + } + return 0; +} + +static u8 __pci_find_next_cap(struct pci_bus *bus, unsigned int devfn, + u8 pos, int cap) +{ + int ttl = PCI_FIND_CAP_TTL; + + return __pci_find_next_cap_ttl(bus, devfn, pos, cap, &ttl); +} + +u8 pci_find_next_capability(struct pci_dev *dev, u8 pos, int cap) +{ + return __pci_find_next_cap(dev->bus, dev->devfn, + pos + PCI_CAP_LIST_NEXT, cap); +} +EXPORT_SYMBOL_GPL(pci_find_next_capability); + +static u8 __pci_bus_find_cap_start(struct pci_bus *bus, + unsigned int devfn, u8 hdr_type) +{ + u16 status; + + pci_bus_read_config_word(bus, devfn, PCI_STATUS, &status); + if (!(status & PCI_STATUS_CAP_LIST)) + return 0; + + switch (hdr_type) { + case PCI_HEADER_TYPE_NORMAL: + case PCI_HEADER_TYPE_BRIDGE: + return PCI_CAPABILITY_LIST; + case PCI_HEADER_TYPE_CARDBUS: + return PCI_CB_CAPABILITY_LIST; + } + + return 0; +} + +/** + * pci_find_capability - query for devices' capabilities + * @dev: PCI device to query + * @cap: capability code + * + * Tell if a device supports a given PCI capability. + * Returns the address of the requested capability structure within the + * device's PCI configuration space or 0 in case the device does not + * support it. Possible values for @cap include: + * + * %PCI_CAP_ID_PM Power Management + * %PCI_CAP_ID_AGP Accelerated Graphics Port + * %PCI_CAP_ID_VPD Vital Product Data + * %PCI_CAP_ID_SLOTID Slot Identification + * %PCI_CAP_ID_MSI Message Signalled Interrupts + * %PCI_CAP_ID_CHSWP CompactPCI HotSwap + * %PCI_CAP_ID_PCIX PCI-X + * %PCI_CAP_ID_EXP PCI Express + */ +u8 pci_find_capability(struct pci_dev *dev, int cap) +{ + u8 pos; + + pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); + if (pos) + pos = __pci_find_next_cap(dev->bus, dev->devfn, pos, cap); + + return pos; +} +EXPORT_SYMBOL(pci_find_capability); + +/** + * pci_bus_find_capability - query for devices' capabilities + * @bus: the PCI bus to query + * @devfn: PCI device to query + * @cap: capability code + * + * Like pci_find_capability() but works for PCI devices that do not have a + * pci_dev structure set up yet. + * + * Returns the address of the requested capability structure within the + * device's PCI configuration space or 0 in case the device does not + * support it. + */ +u8 pci_bus_find_capability(struct pci_bus *bus, unsigned int devfn, int cap) +{ + u8 hdr_type, pos; + + pci_bus_read_config_byte(bus, devfn, PCI_HEADER_TYPE, &hdr_type); + + pos = __pci_bus_find_cap_start(bus, devfn, hdr_type & 0x7f); + if (pos) + pos = __pci_find_next_cap(bus, devfn, pos, cap); + + return pos; +} +EXPORT_SYMBOL(pci_bus_find_capability); + +/** + * pci_find_next_ext_capability - Find an extended capability + * @dev: PCI device to query + * @start: address at which to start looking (0 to start at beginning of list) + * @cap: capability code + * + * Returns the address of the next matching extended capability structure + * within the device's PCI configuration space or 0 if the device does + * not support it. Some capabilities can occur several times, e.g., the + * vendor-specific capability, and this provides a way to find them all. + */ +u16 pci_find_next_ext_capability(struct pci_dev *dev, u16 start, int cap) +{ + u32 header; + int ttl; + u16 pos = PCI_CFG_SPACE_SIZE; + + /* minimum 8 bytes per capability */ + ttl = (PCI_CFG_SPACE_EXP_SIZE - PCI_CFG_SPACE_SIZE) / 8; + + if (dev->cfg_size <= PCI_CFG_SPACE_SIZE) + return 0; + + if (start) + pos = start; + + if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) + return 0; + + /* + * If we have no capabilities, this is indicated by cap ID, + * cap version and next pointer all being 0. + */ + if (header == 0) + return 0; + + while (ttl-- > 0) { + if (PCI_EXT_CAP_ID(header) == cap && pos != start) + return pos; + + pos = PCI_EXT_CAP_NEXT(header); + if (pos < PCI_CFG_SPACE_SIZE) + break; + + if (pci_read_config_dword(dev, pos, &header) != PCIBIOS_SUCCESSFUL) + break; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_next_ext_capability); + +/** + * pci_find_ext_capability - Find an extended capability + * @dev: PCI device to query + * @cap: capability code + * + * Returns the address of the requested extended capability structure + * within the device's PCI configuration space or 0 if the device does + * not support it. Possible values for @cap include: + * + * %PCI_EXT_CAP_ID_ERR Advanced Error Reporting + * %PCI_EXT_CAP_ID_VC Virtual Channel + * %PCI_EXT_CAP_ID_DSN Device Serial Number + * %PCI_EXT_CAP_ID_PWR Power Budgeting + */ +u16 pci_find_ext_capability(struct pci_dev *dev, int cap) +{ + return pci_find_next_ext_capability(dev, 0, cap); +} +EXPORT_SYMBOL_GPL(pci_find_ext_capability); + +/** + * pci_get_dsn - Read and return the 8-byte Device Serial Number + * @dev: PCI device to query + * + * Looks up the PCI_EXT_CAP_ID_DSN and reads the 8 bytes of the Device Serial + * Number. + * + * Returns the DSN, or zero if the capability does not exist. + */ +u64 pci_get_dsn(struct pci_dev *dev) +{ + u32 dword; + u64 dsn; + int pos; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DSN); + if (!pos) + return 0; + + /* + * The Device Serial Number is two dwords offset 4 bytes from the + * capability position. The specification says that the first dword is + * the lower half, and the second dword is the upper half. + */ + pos += 4; + pci_read_config_dword(dev, pos, &dword); + dsn = (u64)dword; + pci_read_config_dword(dev, pos + 4, &dword); + dsn |= ((u64)dword) << 32; + + return dsn; +} +EXPORT_SYMBOL_GPL(pci_get_dsn); + +static u8 __pci_find_next_ht_cap(struct pci_dev *dev, u8 pos, int ht_cap) +{ + int rc, ttl = PCI_FIND_CAP_TTL; + u8 cap, mask; + + if (ht_cap == HT_CAPTYPE_SLAVE || ht_cap == HT_CAPTYPE_HOST) + mask = HT_3BIT_CAP_MASK; + else + mask = HT_5BIT_CAP_MASK; + + pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, pos, + PCI_CAP_ID_HT, &ttl); + while (pos) { + rc = pci_read_config_byte(dev, pos + 3, &cap); + if (rc != PCIBIOS_SUCCESSFUL) + return 0; + + if ((cap & mask) == ht_cap) + return pos; + + pos = __pci_find_next_cap_ttl(dev->bus, dev->devfn, + pos + PCI_CAP_LIST_NEXT, + PCI_CAP_ID_HT, &ttl); + } + + return 0; +} + +/** + * pci_find_next_ht_capability - query a device's HyperTransport capabilities + * @dev: PCI device to query + * @pos: Position from which to continue searching + * @ht_cap: HyperTransport capability code + * + * To be used in conjunction with pci_find_ht_capability() to search for + * all capabilities matching @ht_cap. @pos should always be a value returned + * from pci_find_ht_capability(). + * + * NB. To be 100% safe against broken PCI devices, the caller should take + * steps to avoid an infinite loop. + */ +u8 pci_find_next_ht_capability(struct pci_dev *dev, u8 pos, int ht_cap) +{ + return __pci_find_next_ht_cap(dev, pos + PCI_CAP_LIST_NEXT, ht_cap); +} +EXPORT_SYMBOL_GPL(pci_find_next_ht_capability); + +/** + * pci_find_ht_capability - query a device's HyperTransport capabilities + * @dev: PCI device to query + * @ht_cap: HyperTransport capability code + * + * Tell if a device supports a given HyperTransport capability. + * Returns an address within the device's PCI configuration space + * or 0 in case the device does not support the request capability. + * The address points to the PCI capability, of type PCI_CAP_ID_HT, + * which has a HyperTransport capability matching @ht_cap. + */ +u8 pci_find_ht_capability(struct pci_dev *dev, int ht_cap) +{ + u8 pos; + + pos = __pci_bus_find_cap_start(dev->bus, dev->devfn, dev->hdr_type); + if (pos) + pos = __pci_find_next_ht_cap(dev, pos, ht_cap); + + return pos; +} +EXPORT_SYMBOL_GPL(pci_find_ht_capability); + +/** + * pci_find_vsec_capability - Find a vendor-specific extended capability + * @dev: PCI device to query + * @vendor: Vendor ID for which capability is defined + * @cap: Vendor-specific capability ID + * + * If @dev has Vendor ID @vendor, search for a VSEC capability with + * VSEC ID @cap. If found, return the capability offset in + * config space; otherwise return 0. + */ +u16 pci_find_vsec_capability(struct pci_dev *dev, u16 vendor, int cap) +{ + u16 vsec = 0; + u32 header; + int ret; + + if (vendor != dev->vendor) + return 0; + + while ((vsec = pci_find_next_ext_capability(dev, vsec, + PCI_EXT_CAP_ID_VNDR))) { + ret = pci_read_config_dword(dev, vsec + PCI_VNDR_HEADER, &header); + if (ret != PCIBIOS_SUCCESSFUL) + continue; + + if (PCI_VNDR_HEADER_ID(header) == cap) + return vsec; + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_vsec_capability); + +/** + * pci_find_dvsec_capability - Find DVSEC for vendor + * @dev: PCI device to query + * @vendor: Vendor ID to match for the DVSEC + * @dvsec: Designated Vendor-specific capability ID + * + * If DVSEC has Vendor ID @vendor and DVSEC ID @dvsec return the capability + * offset in config space; otherwise return 0. + */ +u16 pci_find_dvsec_capability(struct pci_dev *dev, u16 vendor, u16 dvsec) +{ + int pos; + + pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_DVSEC); + if (!pos) + return 0; + + while (pos) { + u16 v, id; + + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER1, &v); + pci_read_config_word(dev, pos + PCI_DVSEC_HEADER2, &id); + if (vendor == v && dvsec == id) + return pos; + + pos = pci_find_next_ext_capability(dev, pos, PCI_EXT_CAP_ID_DVSEC); + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_find_dvsec_capability); + +/** + * pci_find_parent_resource - return resource region of parent bus of given + * region + * @dev: PCI device structure contains resources to be searched + * @res: child resource record for which parent is sought + * + * For given resource region of given device, return the resource region of + * parent bus the given region is contained in. + */ +struct resource *pci_find_parent_resource(const struct pci_dev *dev, + struct resource *res) +{ + const struct pci_bus *bus = dev->bus; + struct resource *r; + int i; + + pci_bus_for_each_resource(bus, r, i) { + if (!r) + continue; + if (resource_contains(r, res)) { + + /* + * If the window is prefetchable but the BAR is + * not, the allocator made a mistake. + */ + if (r->flags & IORESOURCE_PREFETCH && + !(res->flags & IORESOURCE_PREFETCH)) + return NULL; + + /* + * If we're below a transparent bridge, there may + * be both a positively-decoded aperture and a + * subtractively-decoded region that contain the BAR. + * We want the positively-decoded one, so this depends + * on pci_bus_for_each_resource() giving us those + * first. + */ + return r; + } + } + return NULL; +} +EXPORT_SYMBOL(pci_find_parent_resource); + +/** + * pci_find_resource - Return matching PCI device resource + * @dev: PCI device to query + * @res: Resource to look for + * + * Goes over standard PCI resources (BARs) and checks if the given resource + * is partially or fully contained in any of them. In that case the + * matching resource is returned, %NULL otherwise. + */ +struct resource *pci_find_resource(struct pci_dev *dev, struct resource *res) +{ + int i; + + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + struct resource *r = &dev->resource[i]; + + if (r->start && resource_contains(r, res)) + return r; + } + + return NULL; +} +EXPORT_SYMBOL(pci_find_resource); + +/** + * pci_wait_for_pending - wait for @mask bit(s) to clear in status word @pos + * @dev: the PCI device to operate on + * @pos: config space offset of status word + * @mask: mask of bit(s) to care about in status word + * + * Return 1 when mask bit(s) in status word clear, 0 otherwise. + */ +int pci_wait_for_pending(struct pci_dev *dev, int pos, u16 mask) +{ + int i; + + /* Wait for Transaction Pending bit clean */ + for (i = 0; i < 4; i++) { + u16 status; + if (i) + msleep((1 << (i - 1)) * 100); + + pci_read_config_word(dev, pos, &status); + if (!(status & mask)) + return 1; + } + + return 0; +} + +static int pci_acs_enable; + +/** + * pci_request_acs - ask for ACS to be enabled if supported + */ +void pci_request_acs(void) +{ + pci_acs_enable = 1; +} + +static const char *disable_acs_redir_param; + +/** + * pci_disable_acs_redir - disable ACS redirect capabilities + * @dev: the PCI device + * + * For only devices specified in the disable_acs_redir parameter. + */ +static void pci_disable_acs_redir(struct pci_dev *dev) +{ + int ret = 0; + const char *p; + int pos; + u16 ctrl; + + if (!disable_acs_redir_param) + return; + + p = disable_acs_redir_param; + while (*p) { + ret = pci_dev_str_match(dev, p, &p); + if (ret < 0) { + pr_info_once("PCI: Can't parse disable_acs_redir parameter: %s\n", + disable_acs_redir_param); + + break; + } else if (ret == 1) { + /* Found a match */ + break; + } + + if (*p != ';' && *p != ',') { + /* End of param or invalid format */ + break; + } + p++; + } + + if (ret != 1) + return; + + if (!pci_dev_specific_disable_acs_redir(dev)) + return; + + pos = dev->acs_cap; + if (!pos) { + pci_warn(dev, "cannot disable ACS redirect for this hardware as it does not have ACS capabilities\n"); + return; + } + + pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl); + + /* P2P Request & Completion Redirect */ + ctrl &= ~(PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_EC); + + pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); + + pci_info(dev, "disabled ACS redirect\n"); +} + +/** + * pci_std_enable_acs - enable ACS on devices using standard ACS capabilities + * @dev: the PCI device + */ +static void pci_std_enable_acs(struct pci_dev *dev) +{ + int pos; + u16 cap; + u16 ctrl; + + pos = dev->acs_cap; + if (!pos) + return; + + pci_read_config_word(dev, pos + PCI_ACS_CAP, &cap); + pci_read_config_word(dev, pos + PCI_ACS_CTRL, &ctrl); + + /* Source Validation */ + ctrl |= (cap & PCI_ACS_SV); + + /* P2P Request Redirect */ + ctrl |= (cap & PCI_ACS_RR); + + /* P2P Completion Redirect */ + ctrl |= (cap & PCI_ACS_CR); + + /* Upstream Forwarding */ + ctrl |= (cap & PCI_ACS_UF); + + /* Enable Translation Blocking for external devices and noats */ + if (pci_ats_disabled() || dev->external_facing || dev->untrusted) + ctrl |= (cap & PCI_ACS_TB); + + pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl); +} + +/** + * pci_enable_acs - enable ACS if hardware support it + * @dev: the PCI device + */ +static void pci_enable_acs(struct pci_dev *dev) +{ + if (!pci_acs_enable) + goto disable_acs_redir; + + if (!pci_dev_specific_enable_acs(dev)) + goto disable_acs_redir; + + pci_std_enable_acs(dev); + +disable_acs_redir: + /* + * Note: pci_disable_acs_redir() must be called even if ACS was not + * enabled by the kernel because it may have been enabled by + * platform firmware. So if we are told to disable it, we should + * always disable it after setting the kernel's default + * preferences. + */ + pci_disable_acs_redir(dev); +} + +/** + * pci_restore_bars - restore a device's BAR values (e.g. after wake-up) + * @dev: PCI device to have its BARs restored + * + * Restore the BAR values for a given device, so as to make it + * accessible by its driver. + */ +static void pci_restore_bars(struct pci_dev *dev) +{ + int i; + + for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) + pci_update_resource(dev, i); +} + +static inline bool platform_pci_power_manageable(struct pci_dev *dev) +{ + if (pci_use_mid_pm()) + return true; + + return acpi_pci_power_manageable(dev); +} + +static inline int platform_pci_set_power_state(struct pci_dev *dev, + pci_power_t t) +{ + if (pci_use_mid_pm()) + return mid_pci_set_power_state(dev, t); + + return acpi_pci_set_power_state(dev, t); +} + +static inline pci_power_t platform_pci_get_power_state(struct pci_dev *dev) +{ + if (pci_use_mid_pm()) + return mid_pci_get_power_state(dev); + + return acpi_pci_get_power_state(dev); +} + +static inline void platform_pci_refresh_power_state(struct pci_dev *dev) +{ + if (!pci_use_mid_pm()) + acpi_pci_refresh_power_state(dev); +} + +static inline pci_power_t platform_pci_choose_state(struct pci_dev *dev) +{ + if (pci_use_mid_pm()) + return PCI_POWER_ERROR; + + return acpi_pci_choose_state(dev); +} + +static inline int platform_pci_set_wakeup(struct pci_dev *dev, bool enable) +{ + if (pci_use_mid_pm()) + return PCI_POWER_ERROR; + + return acpi_pci_wakeup(dev, enable); +} + +static inline bool platform_pci_need_resume(struct pci_dev *dev) +{ + if (pci_use_mid_pm()) + return false; + + return acpi_pci_need_resume(dev); +} + +static inline bool platform_pci_bridge_d3(struct pci_dev *dev) +{ + if (pci_use_mid_pm()) + return false; + + return acpi_pci_bridge_d3(dev); +} + +/** + * pci_update_current_state - Read power state of given device and cache it + * @dev: PCI device to handle. + * @state: State to cache in case the device doesn't have the PM capability + * + * The power state is read from the PMCSR register, which however is + * inaccessible in D3cold. The platform firmware is therefore queried first + * to detect accessibility of the register. In case the platform firmware + * reports an incorrect state or the device isn't power manageable by the + * platform at all, we try to detect D3cold by testing accessibility of the + * vendor ID in config space. + */ +void pci_update_current_state(struct pci_dev *dev, pci_power_t state) +{ + if (platform_pci_get_power_state(dev) == PCI_D3cold) { + dev->current_state = PCI_D3cold; + } else if (dev->pm_cap) { + u16 pmcsr; + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + if (PCI_POSSIBLE_ERROR(pmcsr)) { + dev->current_state = PCI_D3cold; + return; + } + dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK; + } else { + dev->current_state = state; + } +} + +/** + * pci_refresh_power_state - Refresh the given device's power state data + * @dev: Target PCI device. + * + * Ask the platform to refresh the devices power state information and invoke + * pci_update_current_state() to update its current PCI power state. + */ +void pci_refresh_power_state(struct pci_dev *dev) +{ + platform_pci_refresh_power_state(dev); + pci_update_current_state(dev, dev->current_state); +} + +/** + * pci_platform_power_transition - Use platform to change device power state + * @dev: PCI device to handle. + * @state: State to put the device into. + */ +int pci_platform_power_transition(struct pci_dev *dev, pci_power_t state) +{ + int error; + + error = platform_pci_set_power_state(dev, state); + if (!error) + pci_update_current_state(dev, state); + else if (!dev->pm_cap) /* Fall back to PCI_D0 */ + dev->current_state = PCI_D0; + + return error; +} +EXPORT_SYMBOL_GPL(pci_platform_power_transition); + +static int pci_resume_one(struct pci_dev *pci_dev, void *ign) +{ + pm_request_resume(&pci_dev->dev); + return 0; +} + +/** + * pci_resume_bus - Walk given bus and runtime resume devices on it + * @bus: Top bus of the subtree to walk. + */ +void pci_resume_bus(struct pci_bus *bus) +{ + if (bus) + pci_walk_bus(bus, pci_resume_one, NULL); +} + +static int pci_dev_wait(struct pci_dev *dev, char *reset_type, int timeout) +{ + int delay = 1; + u32 id; + + /* + * After reset, the device should not silently discard config + * requests, but it may still indicate that it needs more time by + * responding to them with CRS completions. The Root Port will + * generally synthesize ~0 (PCI_ERROR_RESPONSE) data to complete + * the read (except when CRS SV is enabled and the read was for the + * Vendor ID; in that case it synthesizes 0x0001 data). + * + * Wait for the device to return a non-CRS completion. Read the + * Command register instead of Vendor ID so we don't have to + * contend with the CRS SV value. + */ + pci_read_config_dword(dev, PCI_COMMAND, &id); + while (PCI_POSSIBLE_ERROR(id)) { + if (delay > timeout) { + pci_warn(dev, "not ready %dms after %s; giving up\n", + delay - 1, reset_type); + return -ENOTTY; + } + + if (delay > PCI_RESET_WAIT) + pci_info(dev, "not ready %dms after %s; waiting\n", + delay - 1, reset_type); + + msleep(delay); + delay *= 2; + pci_read_config_dword(dev, PCI_COMMAND, &id); + } + + if (delay > PCI_RESET_WAIT) + pci_info(dev, "ready %dms after %s\n", delay - 1, + reset_type); + + return 0; +} + +/** + * pci_power_up - Put the given device into D0 + * @dev: PCI device to power up + * + * On success, return 0 or 1, depending on whether or not it is necessary to + * restore the device's BARs subsequently (1 is returned in that case). + * + * On failure, return a negative error code. Always return failure if @dev + * lacks a Power Management Capability, even if the platform was able to + * put the device in D0 via non-PCI means. + */ +int pci_power_up(struct pci_dev *dev) +{ + bool need_restore; + pci_power_t state; + u16 pmcsr; + + platform_pci_set_power_state(dev, PCI_D0); + + if (!dev->pm_cap) { + state = platform_pci_get_power_state(dev); + if (state == PCI_UNKNOWN) + dev->current_state = PCI_D0; + else + dev->current_state = state; + + return -EIO; + } + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + if (PCI_POSSIBLE_ERROR(pmcsr)) { + pci_err(dev, "Unable to change power state from %s to D0, device inaccessible\n", + pci_power_name(dev->current_state)); + dev->current_state = PCI_D3cold; + return -EIO; + } + + state = pmcsr & PCI_PM_CTRL_STATE_MASK; + + need_restore = (state == PCI_D3hot || dev->current_state >= PCI_D3hot) && + !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET); + + if (state == PCI_D0) + goto end; + + /* + * Force the entire word to 0. This doesn't affect PME_Status, disables + * PME_En, and sets PowerState to 0. + */ + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, 0); + + /* Mandatory transition delays; see PCI PM 1.2. */ + if (state == PCI_D3hot) + pci_dev_d3_sleep(dev); + else if (state == PCI_D2) + udelay(PCI_PM_D2_DELAY); + +end: + dev->current_state = PCI_D0; + if (need_restore) + return 1; + + return 0; +} + +/** + * pci_set_full_power_state - Put a PCI device into D0 and update its state + * @dev: PCI device to power up + * + * Call pci_power_up() to put @dev into D0, read from its PCI_PM_CTRL register + * to confirm the state change, restore its BARs if they might be lost and + * reconfigure ASPM in acordance with the new power state. + * + * If pci_restore_state() is going to be called right after a power state change + * to D0, it is more efficient to use pci_power_up() directly instead of this + * function. + */ +static int pci_set_full_power_state(struct pci_dev *dev) +{ + u16 pmcsr; + int ret; + + ret = pci_power_up(dev); + if (ret < 0) { + if (dev->current_state == PCI_D0) + return 0; + + return ret; + } + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK; + if (dev->current_state != PCI_D0) { + pci_info_ratelimited(dev, "Refused to change power state from %s to D0\n", + pci_power_name(dev->current_state)); + } else if (ret > 0) { + /* + * According to section 5.4.1 of the "PCI BUS POWER MANAGEMENT + * INTERFACE SPECIFICATION, REV. 1.2", a device transitioning + * from D3hot to D0 _may_ perform an internal reset, thereby + * going to "D0 Uninitialized" rather than "D0 Initialized". + * For example, at least some versions of the 3c905B and the + * 3c556B exhibit this behaviour. + * + * At least some laptop BIOSen (e.g. the Thinkpad T21) leave + * devices in a D3hot state at boot. Consequently, we need to + * restore at least the BARs so that the device will be + * accessible to its driver. + */ + pci_restore_bars(dev); + } + + if (dev->bus->self) + pcie_aspm_pm_state_change(dev->bus->self); + + return 0; +} + +/** + * __pci_dev_set_current_state - Set current state of a PCI device + * @dev: Device to handle + * @data: pointer to state to be set + */ +static int __pci_dev_set_current_state(struct pci_dev *dev, void *data) +{ + pci_power_t state = *(pci_power_t *)data; + + dev->current_state = state; + return 0; +} + +/** + * pci_bus_set_current_state - Walk given bus and set current state of devices + * @bus: Top bus of the subtree to walk. + * @state: state to be set + */ +void pci_bus_set_current_state(struct pci_bus *bus, pci_power_t state) +{ + if (bus) + pci_walk_bus(bus, __pci_dev_set_current_state, &state); +} + +/** + * pci_set_low_power_state - Put a PCI device into a low-power state. + * @dev: PCI device to handle. + * @state: PCI power state (D1, D2, D3hot) to put the device into. + * + * Use the device's PCI_PM_CTRL register to put it into a low-power state. + * + * RETURN VALUE: + * -EINVAL if the requested state is invalid. + * -EIO if device does not support PCI PM or its PM capabilities register has a + * wrong version, or device doesn't support the requested state. + * 0 if device already is in the requested state. + * 0 if device's power state has been successfully changed. + */ +static int pci_set_low_power_state(struct pci_dev *dev, pci_power_t state) +{ + u16 pmcsr; + + if (!dev->pm_cap) + return -EIO; + + /* + * Validate transition: We can enter D0 from any state, but if + * we're already in a low-power state, we can only go deeper. E.g., + * we can go from D1 to D3, but we can't go directly from D3 to D1; + * we'd have to go from D3 to D0, then to D1. + */ + if (dev->current_state <= PCI_D3cold && dev->current_state > state) { + pci_dbg(dev, "Invalid power transition (from %s to %s)\n", + pci_power_name(dev->current_state), + pci_power_name(state)); + return -EINVAL; + } + + /* Check if this device supports the desired state */ + if ((state == PCI_D1 && !dev->d1_support) + || (state == PCI_D2 && !dev->d2_support)) + return -EIO; + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + if (PCI_POSSIBLE_ERROR(pmcsr)) { + pci_err(dev, "Unable to change power state from %s to %s, device inaccessible\n", + pci_power_name(dev->current_state), + pci_power_name(state)); + dev->current_state = PCI_D3cold; + return -EIO; + } + + pmcsr &= ~PCI_PM_CTRL_STATE_MASK; + pmcsr |= state; + + /* Enter specified state */ + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); + + /* Mandatory power management transition delays; see PCI PM 1.2. */ + if (state == PCI_D3hot) + pci_dev_d3_sleep(dev); + else if (state == PCI_D2) + udelay(PCI_PM_D2_DELAY); + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + dev->current_state = pmcsr & PCI_PM_CTRL_STATE_MASK; + if (dev->current_state != state) + pci_info_ratelimited(dev, "Refused to change power state from %s to %s\n", + pci_power_name(dev->current_state), + pci_power_name(state)); + + if (dev->bus->self) + pcie_aspm_pm_state_change(dev->bus->self); + + return 0; +} + +/** + * pci_set_power_state - Set the power state of a PCI device + * @dev: PCI device to handle. + * @state: PCI power state (D0, D1, D2, D3hot) to put the device into. + * + * Transition a device to a new power state, using the platform firmware and/or + * the device's PCI PM registers. + * + * RETURN VALUE: + * -EINVAL if the requested state is invalid. + * -EIO if device does not support PCI PM or its PM capabilities register has a + * wrong version, or device doesn't support the requested state. + * 0 if the transition is to D1 or D2 but D1 and D2 are not supported. + * 0 if device already is in the requested state. + * 0 if the transition is to D3 but D3 is not supported. + * 0 if device's power state has been successfully changed. + */ +int pci_set_power_state(struct pci_dev *dev, pci_power_t state) +{ + int error; + + /* Bound the state we're entering */ + if (state > PCI_D3cold) + state = PCI_D3cold; + else if (state < PCI_D0) + state = PCI_D0; + else if ((state == PCI_D1 || state == PCI_D2) && pci_no_d1d2(dev)) + + /* + * If the device or the parent bridge do not support PCI + * PM, ignore the request if we're doing anything other + * than putting it into D0 (which would only happen on + * boot). + */ + return 0; + + /* Check if we're already there */ + if (dev->current_state == state) + return 0; + + if (state == PCI_D0) + return pci_set_full_power_state(dev); + + /* + * This device is quirked not to be put into D3, so don't put it in + * D3 + */ + if (state >= PCI_D3hot && (dev->dev_flags & PCI_DEV_FLAGS_NO_D3)) + return 0; + + if (state == PCI_D3cold) { + /* + * To put the device in D3cold, put it into D3hot in the native + * way, then put it into D3cold using platform ops. + */ + error = pci_set_low_power_state(dev, PCI_D3hot); + + if (pci_platform_power_transition(dev, PCI_D3cold)) + return error; + + /* Powering off a bridge may power off the whole hierarchy */ + if (dev->current_state == PCI_D3cold) + pci_bus_set_current_state(dev->subordinate, PCI_D3cold); + } else { + error = pci_set_low_power_state(dev, state); + + if (pci_platform_power_transition(dev, state)) + return error; + } + + return 0; +} +EXPORT_SYMBOL(pci_set_power_state); + +#define PCI_EXP_SAVE_REGS 7 + +static struct pci_cap_saved_state *_pci_find_saved_cap(struct pci_dev *pci_dev, + u16 cap, bool extended) +{ + struct pci_cap_saved_state *tmp; + + hlist_for_each_entry(tmp, &pci_dev->saved_cap_space, next) { + if (tmp->cap.cap_extended == extended && tmp->cap.cap_nr == cap) + return tmp; + } + return NULL; +} + +struct pci_cap_saved_state *pci_find_saved_cap(struct pci_dev *dev, char cap) +{ + return _pci_find_saved_cap(dev, cap, false); +} + +struct pci_cap_saved_state *pci_find_saved_ext_cap(struct pci_dev *dev, u16 cap) +{ + return _pci_find_saved_cap(dev, cap, true); +} + +static int pci_save_pcie_state(struct pci_dev *dev) +{ + int i = 0; + struct pci_cap_saved_state *save_state; + u16 *cap; + + if (!pci_is_pcie(dev)) + return 0; + + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); + if (!save_state) { + pci_err(dev, "buffer not found in %s\n", __func__); + return -ENOMEM; + } + + cap = (u16 *)&save_state->cap.data[0]; + pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_LNKCTL, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_SLTCTL, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_RTCTL, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_DEVCTL2, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_LNKCTL2, &cap[i++]); + pcie_capability_read_word(dev, PCI_EXP_SLTCTL2, &cap[i++]); + + return 0; +} + +void pci_bridge_reconfigure_ltr(struct pci_dev *dev) +{ +#ifdef CONFIG_PCIEASPM + struct pci_dev *bridge; + u32 ctl; + + bridge = pci_upstream_bridge(dev); + if (bridge && bridge->ltr_path) { + pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, &ctl); + if (!(ctl & PCI_EXP_DEVCTL2_LTR_EN)) { + pci_dbg(bridge, "re-enabling LTR\n"); + pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_LTR_EN); + } + } +#endif +} + +static void pci_restore_pcie_state(struct pci_dev *dev) +{ + int i = 0; + struct pci_cap_saved_state *save_state; + u16 *cap; + + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_EXP); + if (!save_state) + return; + + /* + * Downstream ports reset the LTR enable bit when link goes down. + * Check and re-configure the bit here before restoring device. + * PCIe r5.0, sec 7.5.3.16. + */ + pci_bridge_reconfigure_ltr(dev); + + cap = (u16 *)&save_state->cap.data[0]; + pcie_capability_write_word(dev, PCI_EXP_DEVCTL, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_LNKCTL, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_SLTCTL, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_RTCTL, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_DEVCTL2, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_LNKCTL2, cap[i++]); + pcie_capability_write_word(dev, PCI_EXP_SLTCTL2, cap[i++]); +} + +static int pci_save_pcix_state(struct pci_dev *dev) +{ + int pos; + struct pci_cap_saved_state *save_state; + + pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!pos) + return 0; + + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX); + if (!save_state) { + pci_err(dev, "buffer not found in %s\n", __func__); + return -ENOMEM; + } + + pci_read_config_word(dev, pos + PCI_X_CMD, + (u16 *)save_state->cap.data); + + return 0; +} + +static void pci_restore_pcix_state(struct pci_dev *dev) +{ + int i = 0, pos; + struct pci_cap_saved_state *save_state; + u16 *cap; + + save_state = pci_find_saved_cap(dev, PCI_CAP_ID_PCIX); + pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!save_state || !pos) + return; + cap = (u16 *)&save_state->cap.data[0]; + + pci_write_config_word(dev, pos + PCI_X_CMD, cap[i++]); +} + +static void pci_save_ltr_state(struct pci_dev *dev) +{ + int ltr; + struct pci_cap_saved_state *save_state; + u32 *cap; + + if (!pci_is_pcie(dev)) + return; + + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!ltr) + return; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state) { + pci_err(dev, "no suspend buffer for LTR; ASPM issues possible after resume\n"); + return; + } + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_read_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, cap); +} + +static void pci_restore_ltr_state(struct pci_dev *dev) +{ + struct pci_cap_saved_state *save_state; + int ltr; + u32 *cap; + + save_state = pci_find_saved_ext_cap(dev, PCI_EXT_CAP_ID_LTR); + ltr = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_LTR); + if (!save_state || !ltr) + return; + + /* Some broken devices only support dword access to LTR */ + cap = &save_state->cap.data[0]; + pci_write_config_dword(dev, ltr + PCI_LTR_MAX_SNOOP_LAT, *cap); +} + +/** + * pci_save_state - save the PCI configuration space of a device before + * suspending + * @dev: PCI device that we're dealing with + */ +int pci_save_state(struct pci_dev *dev) +{ + int i; + /* XXX: 100% dword access ok here? */ + for (i = 0; i < 16; i++) { + pci_read_config_dword(dev, i * 4, &dev->saved_config_space[i]); + pci_dbg(dev, "saving config space at offset %#x (reading %#x)\n", + i * 4, dev->saved_config_space[i]); + } + dev->state_saved = true; + + i = pci_save_pcie_state(dev); + if (i != 0) + return i; + + i = pci_save_pcix_state(dev); + if (i != 0) + return i; + + pci_save_ltr_state(dev); + pci_save_dpc_state(dev); + pci_save_aer_state(dev); + pci_save_ptm_state(dev); + return pci_save_vc_state(dev); +} +EXPORT_SYMBOL(pci_save_state); + +static void pci_restore_config_dword(struct pci_dev *pdev, int offset, + u32 saved_val, int retry, bool force) +{ + u32 val; + + pci_read_config_dword(pdev, offset, &val); + if (!force && val == saved_val) + return; + + for (;;) { + pci_dbg(pdev, "restoring config space at offset %#x (was %#x, writing %#x)\n", + offset, val, saved_val); + pci_write_config_dword(pdev, offset, saved_val); + if (retry-- <= 0) + return; + + pci_read_config_dword(pdev, offset, &val); + if (val == saved_val) + return; + + mdelay(1); + } +} + +static void pci_restore_config_space_range(struct pci_dev *pdev, + int start, int end, int retry, + bool force) +{ + int index; + + for (index = end; index >= start; index--) + pci_restore_config_dword(pdev, 4 * index, + pdev->saved_config_space[index], + retry, force); +} + +static void pci_restore_config_space(struct pci_dev *pdev) +{ + if (pdev->hdr_type == PCI_HEADER_TYPE_NORMAL) { + pci_restore_config_space_range(pdev, 10, 15, 0, false); + /* Restore BARs before the command register. */ + pci_restore_config_space_range(pdev, 4, 9, 10, false); + pci_restore_config_space_range(pdev, 0, 3, 0, false); + } else if (pdev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + pci_restore_config_space_range(pdev, 12, 15, 0, false); + + /* + * Force rewriting of prefetch registers to avoid S3 resume + * issues on Intel PCI bridges that occur when these + * registers are not explicitly written. + */ + pci_restore_config_space_range(pdev, 9, 11, 0, true); + pci_restore_config_space_range(pdev, 0, 8, 0, false); + } else { + pci_restore_config_space_range(pdev, 0, 15, 0, false); + } +} + +static void pci_restore_rebar_state(struct pci_dev *pdev) +{ + unsigned int pos, nbars, i; + u32 ctrl; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); + if (!pos) + return; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> + PCI_REBAR_CTRL_NBAR_SHIFT; + + for (i = 0; i < nbars; i++, pos += 8) { + struct resource *res; + int bar_idx, size; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; + res = pdev->resource + bar_idx; + size = pci_rebar_bytes_to_size(resource_size(res)); + ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; + ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; + pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); + } +} + +/** + * pci_restore_state - Restore the saved state of a PCI device + * @dev: PCI device that we're dealing with + */ +void pci_restore_state(struct pci_dev *dev) +{ + if (!dev->state_saved) + return; + + /* + * Restore max latencies (in the LTR capability) before enabling + * LTR itself (in the PCIe capability). + */ + pci_restore_ltr_state(dev); + + pci_restore_pcie_state(dev); + pci_restore_pasid_state(dev); + pci_restore_pri_state(dev); + pci_restore_ats_state(dev); + pci_restore_vc_state(dev); + pci_restore_rebar_state(dev); + pci_restore_dpc_state(dev); + pci_restore_ptm_state(dev); + + pci_aer_clear_status(dev); + pci_restore_aer_state(dev); + + pci_restore_config_space(dev); + + pci_restore_pcix_state(dev); + pci_restore_msi_state(dev); + + /* Restore ACS and IOV configuration state */ + pci_enable_acs(dev); + pci_restore_iov_state(dev); + + dev->state_saved = false; +} +EXPORT_SYMBOL(pci_restore_state); + +struct pci_saved_state { + u32 config_space[16]; + struct pci_cap_saved_data cap[]; +}; + +/** + * pci_store_saved_state - Allocate and return an opaque struct containing + * the device saved state. + * @dev: PCI device that we're dealing with + * + * Return NULL if no state or error. + */ +struct pci_saved_state *pci_store_saved_state(struct pci_dev *dev) +{ + struct pci_saved_state *state; + struct pci_cap_saved_state *tmp; + struct pci_cap_saved_data *cap; + size_t size; + + if (!dev->state_saved) + return NULL; + + size = sizeof(*state) + sizeof(struct pci_cap_saved_data); + + hlist_for_each_entry(tmp, &dev->saved_cap_space, next) + size += sizeof(struct pci_cap_saved_data) + tmp->cap.size; + + state = kzalloc(size, GFP_KERNEL); + if (!state) + return NULL; + + memcpy(state->config_space, dev->saved_config_space, + sizeof(state->config_space)); + + cap = state->cap; + hlist_for_each_entry(tmp, &dev->saved_cap_space, next) { + size_t len = sizeof(struct pci_cap_saved_data) + tmp->cap.size; + memcpy(cap, &tmp->cap, len); + cap = (struct pci_cap_saved_data *)((u8 *)cap + len); + } + /* Empty cap_save terminates list */ + + return state; +} +EXPORT_SYMBOL_GPL(pci_store_saved_state); + +/** + * pci_load_saved_state - Reload the provided save state into struct pci_dev. + * @dev: PCI device that we're dealing with + * @state: Saved state returned from pci_store_saved_state() + */ +int pci_load_saved_state(struct pci_dev *dev, + struct pci_saved_state *state) +{ + struct pci_cap_saved_data *cap; + + dev->state_saved = false; + + if (!state) + return 0; + + memcpy(dev->saved_config_space, state->config_space, + sizeof(state->config_space)); + + cap = state->cap; + while (cap->size) { + struct pci_cap_saved_state *tmp; + + tmp = _pci_find_saved_cap(dev, cap->cap_nr, cap->cap_extended); + if (!tmp || tmp->cap.size != cap->size) + return -EINVAL; + + memcpy(tmp->cap.data, cap->data, tmp->cap.size); + cap = (struct pci_cap_saved_data *)((u8 *)cap + + sizeof(struct pci_cap_saved_data) + cap->size); + } + + dev->state_saved = true; + return 0; +} +EXPORT_SYMBOL_GPL(pci_load_saved_state); + +/** + * pci_load_and_free_saved_state - Reload the save state pointed to by state, + * and free the memory allocated for it. + * @dev: PCI device that we're dealing with + * @state: Pointer to saved state returned from pci_store_saved_state() + */ +int pci_load_and_free_saved_state(struct pci_dev *dev, + struct pci_saved_state **state) +{ + int ret = pci_load_saved_state(dev, *state); + kfree(*state); + *state = NULL; + return ret; +} +EXPORT_SYMBOL_GPL(pci_load_and_free_saved_state); + +int __weak pcibios_enable_device(struct pci_dev *dev, int bars) +{ + return pci_enable_resources(dev, bars); +} + +static int do_pci_enable_device(struct pci_dev *dev, int bars) +{ + int err; + struct pci_dev *bridge; + u16 cmd; + u8 pin; + + err = pci_set_power_state(dev, PCI_D0); + if (err < 0 && err != -EIO) + return err; + + bridge = pci_upstream_bridge(dev); + if (bridge) + pcie_aspm_powersave_config_link(bridge); + + err = pcibios_enable_device(dev, bars); + if (err < 0) + return err; + pci_fixup_device(pci_fixup_enable, dev); + + if (dev->msi_enabled || dev->msix_enabled) + return 0; + + pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &pin); + if (pin) { + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_INTX_DISABLE) + pci_write_config_word(dev, PCI_COMMAND, + cmd & ~PCI_COMMAND_INTX_DISABLE); + } + + return 0; +} + +/** + * pci_reenable_device - Resume abandoned device + * @dev: PCI device to be resumed + * + * NOTE: This function is a backend of pci_default_resume() and is not supposed + * to be called by normal code, write proper resume handler and use it instead. + */ +int pci_reenable_device(struct pci_dev *dev) +{ + if (pci_is_enabled(dev)) + return do_pci_enable_device(dev, (1 << PCI_NUM_RESOURCES) - 1); + return 0; +} +EXPORT_SYMBOL(pci_reenable_device); + +static void pci_enable_bridge(struct pci_dev *dev) +{ + struct pci_dev *bridge; + int retval; + + bridge = pci_upstream_bridge(dev); + if (bridge) + pci_enable_bridge(bridge); + + if (pci_is_enabled(dev)) { + if (!dev->is_busmaster) + pci_set_master(dev); + return; + } + + retval = pci_enable_device(dev); + if (retval) + pci_err(dev, "Error enabling bridge (%d), continuing\n", + retval); + pci_set_master(dev); +} + +static int pci_enable_device_flags(struct pci_dev *dev, unsigned long flags) +{ + struct pci_dev *bridge; + int err; + int i, bars = 0; + + /* + * Power state could be unknown at this point, either due to a fresh + * boot or a device removal call. So get the current power state + * so that things like MSI message writing will behave as expected + * (e.g. if the device really is in D0 at enable time). + */ + pci_update_current_state(dev, dev->current_state); + + if (atomic_inc_return(&dev->enable_cnt) > 1) + return 0; /* already enabled */ + + bridge = pci_upstream_bridge(dev); + if (bridge) + pci_enable_bridge(bridge); + + /* only skip sriov related */ + for (i = 0; i <= PCI_ROM_RESOURCE; i++) + if (dev->resource[i].flags & flags) + bars |= (1 << i); + for (i = PCI_BRIDGE_RESOURCES; i < DEVICE_COUNT_RESOURCE; i++) + if (dev->resource[i].flags & flags) + bars |= (1 << i); + + err = do_pci_enable_device(dev, bars); + if (err < 0) + atomic_dec(&dev->enable_cnt); + return err; +} + +/** + * pci_enable_device_io - Initialize a device for use with IO space + * @dev: PCI device to be initialized + * + * Initialize device before it's used by a driver. Ask low-level code + * to enable I/O resources. Wake up the device if it was suspended. + * Beware, this function can fail. + */ +int pci_enable_device_io(struct pci_dev *dev) +{ + return pci_enable_device_flags(dev, IORESOURCE_IO); +} +EXPORT_SYMBOL(pci_enable_device_io); + +/** + * pci_enable_device_mem - Initialize a device for use with Memory space + * @dev: PCI device to be initialized + * + * Initialize device before it's used by a driver. Ask low-level code + * to enable Memory resources. Wake up the device if it was suspended. + * Beware, this function can fail. + */ +int pci_enable_device_mem(struct pci_dev *dev) +{ + return pci_enable_device_flags(dev, IORESOURCE_MEM); +} +EXPORT_SYMBOL(pci_enable_device_mem); + +/** + * pci_enable_device - Initialize device before it's used by a driver. + * @dev: PCI device to be initialized + * + * Initialize device before it's used by a driver. Ask low-level code + * to enable I/O and memory. Wake up the device if it was suspended. + * Beware, this function can fail. + * + * Note we don't actually enable the device many times if we call + * this function repeatedly (we just increment the count). + */ +int pci_enable_device(struct pci_dev *dev) +{ + return pci_enable_device_flags(dev, IORESOURCE_MEM | IORESOURCE_IO); +} +EXPORT_SYMBOL(pci_enable_device); + +/* + * Managed PCI resources. This manages device on/off, INTx/MSI/MSI-X + * on/off and BAR regions. pci_dev itself records MSI/MSI-X status, so + * there's no need to track it separately. pci_devres is initialized + * when a device is enabled using managed PCI device enable interface. + */ +struct pci_devres { + unsigned int enabled:1; + unsigned int pinned:1; + unsigned int orig_intx:1; + unsigned int restore_intx:1; + unsigned int mwi:1; + u32 region_mask; +}; + +static void pcim_release(struct device *gendev, void *res) +{ + struct pci_dev *dev = to_pci_dev(gendev); + struct pci_devres *this = res; + int i; + + for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) + if (this->region_mask & (1 << i)) + pci_release_region(dev, i); + + if (this->mwi) + pci_clear_mwi(dev); + + if (this->restore_intx) + pci_intx(dev, this->orig_intx); + + if (this->enabled && !this->pinned) + pci_disable_device(dev); +} + +static struct pci_devres *get_pci_dr(struct pci_dev *pdev) +{ + struct pci_devres *dr, *new_dr; + + dr = devres_find(&pdev->dev, pcim_release, NULL, NULL); + if (dr) + return dr; + + new_dr = devres_alloc(pcim_release, sizeof(*new_dr), GFP_KERNEL); + if (!new_dr) + return NULL; + return devres_get(&pdev->dev, new_dr, NULL, NULL); +} + +static struct pci_devres *find_pci_dr(struct pci_dev *pdev) +{ + if (pci_is_managed(pdev)) + return devres_find(&pdev->dev, pcim_release, NULL, NULL); + return NULL; +} + +/** + * pcim_enable_device - Managed pci_enable_device() + * @pdev: PCI device to be initialized + * + * Managed pci_enable_device(). + */ +int pcim_enable_device(struct pci_dev *pdev) +{ + struct pci_devres *dr; + int rc; + + dr = get_pci_dr(pdev); + if (unlikely(!dr)) + return -ENOMEM; + if (dr->enabled) + return 0; + + rc = pci_enable_device(pdev); + if (!rc) { + pdev->is_managed = 1; + dr->enabled = 1; + } + return rc; +} +EXPORT_SYMBOL(pcim_enable_device); + +/** + * pcim_pin_device - Pin managed PCI device + * @pdev: PCI device to pin + * + * Pin managed PCI device @pdev. Pinned device won't be disabled on + * driver detach. @pdev must have been enabled with + * pcim_enable_device(). + */ +void pcim_pin_device(struct pci_dev *pdev) +{ + struct pci_devres *dr; + + dr = find_pci_dr(pdev); + WARN_ON(!dr || !dr->enabled); + if (dr) + dr->pinned = 1; +} +EXPORT_SYMBOL(pcim_pin_device); + +/* + * pcibios_device_add - provide arch specific hooks when adding device dev + * @dev: the PCI device being added + * + * Permits the platform to provide architecture specific functionality when + * devices are added. This is the default implementation. Architecture + * implementations can override this. + */ +int __weak pcibios_device_add(struct pci_dev *dev) +{ + return 0; +} + +/** + * pcibios_release_device - provide arch specific hooks when releasing + * device dev + * @dev: the PCI device being released + * + * Permits the platform to provide architecture specific functionality when + * devices are released. This is the default implementation. Architecture + * implementations can override this. + */ +void __weak pcibios_release_device(struct pci_dev *dev) {} + +/** + * pcibios_disable_device - disable arch specific PCI resources for device dev + * @dev: the PCI device to disable + * + * Disables architecture specific PCI resources for the device. This + * is the default implementation. Architecture implementations can + * override this. + */ +void __weak pcibios_disable_device(struct pci_dev *dev) {} + +/** + * pcibios_penalize_isa_irq - penalize an ISA IRQ + * @irq: ISA IRQ to penalize + * @active: IRQ active or not + * + * Permits the platform to provide architecture-specific functionality when + * penalizing ISA IRQs. This is the default implementation. Architecture + * implementations can override this. + */ +void __weak pcibios_penalize_isa_irq(int irq, int active) {} + +static void do_pci_disable_device(struct pci_dev *dev) +{ + u16 pci_command; + + pci_read_config_word(dev, PCI_COMMAND, &pci_command); + if (pci_command & PCI_COMMAND_MASTER) { + pci_command &= ~PCI_COMMAND_MASTER; + pci_write_config_word(dev, PCI_COMMAND, pci_command); + } + + pcibios_disable_device(dev); +} + +/** + * pci_disable_enabled_device - Disable device without updating enable_cnt + * @dev: PCI device to disable + * + * NOTE: This function is a backend of PCI power management routines and is + * not supposed to be called drivers. + */ +void pci_disable_enabled_device(struct pci_dev *dev) +{ + if (pci_is_enabled(dev)) + do_pci_disable_device(dev); +} + +/** + * pci_disable_device - Disable PCI device after use + * @dev: PCI device to be disabled + * + * Signal to the system that the PCI device is not in use by the system + * anymore. This only involves disabling PCI bus-mastering, if active. + * + * Note we don't actually disable the device until all callers of + * pci_enable_device() have called pci_disable_device(). + */ +void pci_disable_device(struct pci_dev *dev) +{ + struct pci_devres *dr; + + dr = find_pci_dr(dev); + if (dr) + dr->enabled = 0; + + dev_WARN_ONCE(&dev->dev, atomic_read(&dev->enable_cnt) <= 0, + "disabling already-disabled device"); + + if (atomic_dec_return(&dev->enable_cnt) != 0) + return; + + do_pci_disable_device(dev); + + dev->is_busmaster = 0; +} +EXPORT_SYMBOL(pci_disable_device); + +/** + * pcibios_set_pcie_reset_state - set reset state for device dev + * @dev: the PCIe device reset + * @state: Reset state to enter into + * + * Set the PCIe reset state for the device. This is the default + * implementation. Architecture implementations can override this. + */ +int __weak pcibios_set_pcie_reset_state(struct pci_dev *dev, + enum pcie_reset_state state) +{ + return -EINVAL; +} + +/** + * pci_set_pcie_reset_state - set reset state for device dev + * @dev: the PCIe device reset + * @state: Reset state to enter into + * + * Sets the PCI reset state for the device. + */ +int pci_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +{ + return pcibios_set_pcie_reset_state(dev, state); +} +EXPORT_SYMBOL_GPL(pci_set_pcie_reset_state); + +#ifdef CONFIG_PCIEAER +void pcie_clear_device_status(struct pci_dev *dev) +{ + u16 sta; + + pcie_capability_read_word(dev, PCI_EXP_DEVSTA, &sta); + pcie_capability_write_word(dev, PCI_EXP_DEVSTA, sta); +} +#endif + +/** + * pcie_clear_root_pme_status - Clear root port PME interrupt status. + * @dev: PCIe root port or event collector. + */ +void pcie_clear_root_pme_status(struct pci_dev *dev) +{ + pcie_capability_set_dword(dev, PCI_EXP_RTSTA, PCI_EXP_RTSTA_PME); +} + +/** + * pci_check_pme_status - Check if given device has generated PME. + * @dev: Device to check. + * + * Check the PME status of the device and if set, clear it and clear PME enable + * (if set). Return 'true' if PME status and PME enable were both set or + * 'false' otherwise. + */ +bool pci_check_pme_status(struct pci_dev *dev) +{ + int pmcsr_pos; + u16 pmcsr; + bool ret = false; + + if (!dev->pm_cap) + return false; + + pmcsr_pos = dev->pm_cap + PCI_PM_CTRL; + pci_read_config_word(dev, pmcsr_pos, &pmcsr); + if (!(pmcsr & PCI_PM_CTRL_PME_STATUS)) + return false; + + /* Clear PME status. */ + pmcsr |= PCI_PM_CTRL_PME_STATUS; + if (pmcsr & PCI_PM_CTRL_PME_ENABLE) { + /* Disable PME to avoid interrupt flood. */ + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + ret = true; + } + + pci_write_config_word(dev, pmcsr_pos, pmcsr); + + return ret; +} + +/** + * pci_pme_wakeup - Wake up a PCI device if its PME Status bit is set. + * @dev: Device to handle. + * @pme_poll_reset: Whether or not to reset the device's pme_poll flag. + * + * Check if @dev has generated PME and queue a resume request for it in that + * case. + */ +static int pci_pme_wakeup(struct pci_dev *dev, void *pme_poll_reset) +{ + if (pme_poll_reset && dev->pme_poll) + dev->pme_poll = false; + + if (pci_check_pme_status(dev)) { + pci_wakeup_event(dev); + pm_request_resume(&dev->dev); + } + return 0; +} + +/** + * pci_pme_wakeup_bus - Walk given bus and wake up devices on it, if necessary. + * @bus: Top bus of the subtree to walk. + */ +void pci_pme_wakeup_bus(struct pci_bus *bus) +{ + if (bus) + pci_walk_bus(bus, pci_pme_wakeup, (void *)true); +} + + +/** + * pci_pme_capable - check the capability of PCI device to generate PME# + * @dev: PCI device to handle. + * @state: PCI state from which device will issue PME#. + */ +bool pci_pme_capable(struct pci_dev *dev, pci_power_t state) +{ + if (!dev->pm_cap) + return false; + + return !!(dev->pme_support & (1 << state)); +} +EXPORT_SYMBOL(pci_pme_capable); + +static void pci_pme_list_scan(struct work_struct *work) +{ + struct pci_pme_device *pme_dev, *n; + + mutex_lock(&pci_pme_list_mutex); + list_for_each_entry_safe(pme_dev, n, &pci_pme_list, list) { + if (pme_dev->dev->pme_poll) { + struct pci_dev *bridge; + + bridge = pme_dev->dev->bus->self; + /* + * If bridge is in low power state, the + * configuration space of subordinate devices + * may be not accessible + */ + if (bridge && bridge->current_state != PCI_D0) + continue; + /* + * If the device is in D3cold it should not be + * polled either. + */ + if (pme_dev->dev->current_state == PCI_D3cold) + continue; + + pci_pme_wakeup(pme_dev->dev, NULL); + } else { + list_del(&pme_dev->list); + kfree(pme_dev); + } + } + if (!list_empty(&pci_pme_list)) + queue_delayed_work(system_freezable_wq, &pci_pme_work, + msecs_to_jiffies(PME_TIMEOUT)); + mutex_unlock(&pci_pme_list_mutex); +} + +static void __pci_pme_active(struct pci_dev *dev, bool enable) +{ + u16 pmcsr; + + if (!dev->pme_support) + return; + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + /* Clear PME_Status by writing 1 to it and enable PME# */ + pmcsr |= PCI_PM_CTRL_PME_STATUS | PCI_PM_CTRL_PME_ENABLE; + if (!enable) + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); +} + +/** + * pci_pme_restore - Restore PME configuration after config space restore. + * @dev: PCI device to update. + */ +void pci_pme_restore(struct pci_dev *dev) +{ + u16 pmcsr; + + if (!dev->pme_support) + return; + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + if (dev->wakeup_prepared) { + pmcsr |= PCI_PM_CTRL_PME_ENABLE; + pmcsr &= ~PCI_PM_CTRL_PME_STATUS; + } else { + pmcsr &= ~PCI_PM_CTRL_PME_ENABLE; + pmcsr |= PCI_PM_CTRL_PME_STATUS; + } + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, pmcsr); +} + +/** + * pci_pme_active - enable or disable PCI device's PME# function + * @dev: PCI device to handle. + * @enable: 'true' to enable PME# generation; 'false' to disable it. + * + * The caller must verify that the device is capable of generating PME# before + * calling this function with @enable equal to 'true'. + */ +void pci_pme_active(struct pci_dev *dev, bool enable) +{ + __pci_pme_active(dev, enable); + + /* + * PCI (as opposed to PCIe) PME requires that the device have + * its PME# line hooked up correctly. Not all hardware vendors + * do this, so the PME never gets delivered and the device + * remains asleep. The easiest way around this is to + * periodically walk the list of suspended devices and check + * whether any have their PME flag set. The assumption is that + * we'll wake up often enough anyway that this won't be a huge + * hit, and the power savings from the devices will still be a + * win. + * + * Although PCIe uses in-band PME message instead of PME# line + * to report PME, PME does not work for some PCIe devices in + * reality. For example, there are devices that set their PME + * status bits, but don't really bother to send a PME message; + * there are PCI Express Root Ports that don't bother to + * trigger interrupts when they receive PME messages from the + * devices below. So PME poll is used for PCIe devices too. + */ + + if (dev->pme_poll) { + struct pci_pme_device *pme_dev; + if (enable) { + pme_dev = kmalloc(sizeof(struct pci_pme_device), + GFP_KERNEL); + if (!pme_dev) { + pci_warn(dev, "can't enable PME#\n"); + return; + } + pme_dev->dev = dev; + mutex_lock(&pci_pme_list_mutex); + list_add(&pme_dev->list, &pci_pme_list); + if (list_is_singular(&pci_pme_list)) + queue_delayed_work(system_freezable_wq, + &pci_pme_work, + msecs_to_jiffies(PME_TIMEOUT)); + mutex_unlock(&pci_pme_list_mutex); + } else { + mutex_lock(&pci_pme_list_mutex); + list_for_each_entry(pme_dev, &pci_pme_list, list) { + if (pme_dev->dev == dev) { + list_del(&pme_dev->list); + kfree(pme_dev); + break; + } + } + mutex_unlock(&pci_pme_list_mutex); + } + } + + pci_dbg(dev, "PME# %s\n", enable ? "enabled" : "disabled"); +} +EXPORT_SYMBOL(pci_pme_active); + +/** + * __pci_enable_wake - enable PCI device as wakeup event source + * @dev: PCI device affected + * @state: PCI state from which device will issue wakeup events + * @enable: True to enable event generation; false to disable + * + * This enables the device as a wakeup event source, or disables it. + * When such events involves platform-specific hooks, those hooks are + * called automatically by this routine. + * + * Devices with legacy power management (no standard PCI PM capabilities) + * always require such platform hooks. + * + * RETURN VALUE: + * 0 is returned on success + * -EINVAL is returned if device is not supposed to wake up the system + * Error code depending on the platform is returned if both the platform and + * the native mechanism fail to enable the generation of wake-up events + */ +static int __pci_enable_wake(struct pci_dev *dev, pci_power_t state, bool enable) +{ + int ret = 0; + + /* + * Bridges that are not power-manageable directly only signal + * wakeup on behalf of subordinate devices which is set up + * elsewhere, so skip them. However, bridges that are + * power-manageable may signal wakeup for themselves (for example, + * on a hotplug event) and they need to be covered here. + */ + if (!pci_power_manageable(dev)) + return 0; + + /* Don't do the same thing twice in a row for one device. */ + if (!!enable == !!dev->wakeup_prepared) + return 0; + + /* + * According to "PCI System Architecture" 4th ed. by Tom Shanley & Don + * Anderson we should be doing PME# wake enable followed by ACPI wake + * enable. To disable wake-up we call the platform first, for symmetry. + */ + + if (enable) { + int error; + + /* + * Enable PME signaling if the device can signal PME from + * D3cold regardless of whether or not it can signal PME from + * the current target state, because that will allow it to + * signal PME when the hierarchy above it goes into D3cold and + * the device itself ends up in D3cold as a result of that. + */ + if (pci_pme_capable(dev, state) || pci_pme_capable(dev, PCI_D3cold)) + pci_pme_active(dev, true); + else + ret = 1; + error = platform_pci_set_wakeup(dev, true); + if (ret) + ret = error; + if (!ret) + dev->wakeup_prepared = true; + } else { + platform_pci_set_wakeup(dev, false); + pci_pme_active(dev, false); + dev->wakeup_prepared = false; + } + + return ret; +} + +/** + * pci_enable_wake - change wakeup settings for a PCI device + * @pci_dev: Target device + * @state: PCI state from which device will issue wakeup events + * @enable: Whether or not to enable event generation + * + * If @enable is set, check device_may_wakeup() for the device before calling + * __pci_enable_wake() for it. + */ +int pci_enable_wake(struct pci_dev *pci_dev, pci_power_t state, bool enable) +{ + if (enable && !device_may_wakeup(&pci_dev->dev)) + return -EINVAL; + + return __pci_enable_wake(pci_dev, state, enable); +} +EXPORT_SYMBOL(pci_enable_wake); + +/** + * pci_wake_from_d3 - enable/disable device to wake up from D3_hot or D3_cold + * @dev: PCI device to prepare + * @enable: True to enable wake-up event generation; false to disable + * + * Many drivers want the device to wake up the system from D3_hot or D3_cold + * and this function allows them to set that up cleanly - pci_enable_wake() + * should not be called twice in a row to enable wake-up due to PCI PM vs ACPI + * ordering constraints. + * + * This function only returns error code if the device is not allowed to wake + * up the system from sleep or it is not capable of generating PME# from both + * D3_hot and D3_cold and the platform is unable to enable wake-up power for it. + */ +int pci_wake_from_d3(struct pci_dev *dev, bool enable) +{ + return pci_pme_capable(dev, PCI_D3cold) ? + pci_enable_wake(dev, PCI_D3cold, enable) : + pci_enable_wake(dev, PCI_D3hot, enable); +} +EXPORT_SYMBOL(pci_wake_from_d3); + +/** + * pci_target_state - find an appropriate low power state for a given PCI dev + * @dev: PCI device + * @wakeup: Whether or not wakeup functionality will be enabled for the device. + * + * Use underlying platform code to find a supported low power state for @dev. + * If the platform can't manage @dev, return the deepest state from which it + * can generate wake events, based on any available PME info. + */ +static pci_power_t pci_target_state(struct pci_dev *dev, bool wakeup) +{ + if (platform_pci_power_manageable(dev)) { + /* + * Call the platform to find the target state for the device. + */ + pci_power_t state = platform_pci_choose_state(dev); + + switch (state) { + case PCI_POWER_ERROR: + case PCI_UNKNOWN: + return PCI_D3hot; + + case PCI_D1: + case PCI_D2: + if (pci_no_d1d2(dev)) + return PCI_D3hot; + } + + return state; + } + + /* + * If the device is in D3cold even though it's not power-manageable by + * the platform, it may have been powered down by non-standard means. + * Best to let it slumber. + */ + if (dev->current_state == PCI_D3cold) + return PCI_D3cold; + else if (!dev->pm_cap) + return PCI_D0; + + if (wakeup && dev->pme_support) { + pci_power_t state = PCI_D3hot; + + /* + * Find the deepest state from which the device can generate + * PME#. + */ + while (state && !(dev->pme_support & (1 << state))) + state--; + + if (state) + return state; + else if (dev->pme_support & 1) + return PCI_D0; + } + + return PCI_D3hot; +} + +/** + * pci_prepare_to_sleep - prepare PCI device for system-wide transition + * into a sleep state + * @dev: Device to handle. + * + * Choose the power state appropriate for the device depending on whether + * it can wake up the system and/or is power manageable by the platform + * (PCI_D3hot is the default) and put the device into that state. + */ +int pci_prepare_to_sleep(struct pci_dev *dev) +{ + bool wakeup = device_may_wakeup(&dev->dev); + pci_power_t target_state = pci_target_state(dev, wakeup); + int error; + + if (target_state == PCI_POWER_ERROR) + return -EIO; + + pci_enable_wake(dev, target_state, wakeup); + + error = pci_set_power_state(dev, target_state); + + if (error) + pci_enable_wake(dev, target_state, false); + + return error; +} +EXPORT_SYMBOL(pci_prepare_to_sleep); + +/** + * pci_back_from_sleep - turn PCI device on during system-wide transition + * into working state + * @dev: Device to handle. + * + * Disable device's system wake-up capability and put it into D0. + */ +int pci_back_from_sleep(struct pci_dev *dev) +{ + int ret = pci_set_power_state(dev, PCI_D0); + + if (ret) + return ret; + + pci_enable_wake(dev, PCI_D0, false); + return 0; +} +EXPORT_SYMBOL(pci_back_from_sleep); + +/** + * pci_finish_runtime_suspend - Carry out PCI-specific part of runtime suspend. + * @dev: PCI device being suspended. + * + * Prepare @dev to generate wake-up events at run time and put it into a low + * power state. + */ +int pci_finish_runtime_suspend(struct pci_dev *dev) +{ + pci_power_t target_state; + int error; + + target_state = pci_target_state(dev, device_can_wakeup(&dev->dev)); + if (target_state == PCI_POWER_ERROR) + return -EIO; + + __pci_enable_wake(dev, target_state, pci_dev_run_wake(dev)); + + error = pci_set_power_state(dev, target_state); + + if (error) + pci_enable_wake(dev, target_state, false); + + return error; +} + +/** + * pci_dev_run_wake - Check if device can generate run-time wake-up events. + * @dev: Device to check. + * + * Return true if the device itself is capable of generating wake-up events + * (through the platform or using the native PCIe PME) or if the device supports + * PME and one of its upstream bridges can generate wake-up events. + */ +bool pci_dev_run_wake(struct pci_dev *dev) +{ + struct pci_bus *bus = dev->bus; + + if (!dev->pme_support) + return false; + + /* PME-capable in principle, but not from the target power state */ + if (!pci_pme_capable(dev, pci_target_state(dev, true))) + return false; + + if (device_can_wakeup(&dev->dev)) + return true; + + while (bus->parent) { + struct pci_dev *bridge = bus->self; + + if (device_can_wakeup(&bridge->dev)) + return true; + + bus = bus->parent; + } + + /* We have reached the root bus. */ + if (bus->bridge) + return device_can_wakeup(bus->bridge); + + return false; +} +EXPORT_SYMBOL_GPL(pci_dev_run_wake); + +/** + * pci_dev_need_resume - Check if it is necessary to resume the device. + * @pci_dev: Device to check. + * + * Return 'true' if the device is not runtime-suspended or it has to be + * reconfigured due to wakeup settings difference between system and runtime + * suspend, or the current power state of it is not suitable for the upcoming + * (system-wide) transition. + */ +bool pci_dev_need_resume(struct pci_dev *pci_dev) +{ + struct device *dev = &pci_dev->dev; + pci_power_t target_state; + + if (!pm_runtime_suspended(dev) || platform_pci_need_resume(pci_dev)) + return true; + + target_state = pci_target_state(pci_dev, device_may_wakeup(dev)); + + /* + * If the earlier platform check has not triggered, D3cold is just power + * removal on top of D3hot, so no need to resume the device in that + * case. + */ + return target_state != pci_dev->current_state && + target_state != PCI_D3cold && + pci_dev->current_state != PCI_D3hot; +} + +/** + * pci_dev_adjust_pme - Adjust PME setting for a suspended device. + * @pci_dev: Device to check. + * + * If the device is suspended and it is not configured for system wakeup, + * disable PME for it to prevent it from waking up the system unnecessarily. + * + * Note that if the device's power state is D3cold and the platform check in + * pci_dev_need_resume() has not triggered, the device's configuration need not + * be changed. + */ +void pci_dev_adjust_pme(struct pci_dev *pci_dev) +{ + struct device *dev = &pci_dev->dev; + + spin_lock_irq(&dev->power.lock); + + if (pm_runtime_suspended(dev) && !device_may_wakeup(dev) && + pci_dev->current_state < PCI_D3cold) + __pci_pme_active(pci_dev, false); + + spin_unlock_irq(&dev->power.lock); +} + +/** + * pci_dev_complete_resume - Finalize resume from system sleep for a device. + * @pci_dev: Device to handle. + * + * If the device is runtime suspended and wakeup-capable, enable PME for it as + * it might have been disabled during the prepare phase of system suspend if + * the device was not configured for system wakeup. + */ +void pci_dev_complete_resume(struct pci_dev *pci_dev) +{ + struct device *dev = &pci_dev->dev; + + if (!pci_dev_run_wake(pci_dev)) + return; + + spin_lock_irq(&dev->power.lock); + + if (pm_runtime_suspended(dev) && pci_dev->current_state < PCI_D3cold) + __pci_pme_active(pci_dev, true); + + spin_unlock_irq(&dev->power.lock); +} + +/** + * pci_choose_state - Choose the power state of a PCI device. + * @dev: Target PCI device. + * @state: Target state for the whole system. + * + * Returns PCI power state suitable for @dev and @state. + */ +pci_power_t pci_choose_state(struct pci_dev *dev, pm_message_t state) +{ + if (state.event == PM_EVENT_ON) + return PCI_D0; + + return pci_target_state(dev, false); +} +EXPORT_SYMBOL(pci_choose_state); + +void pci_config_pm_runtime_get(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + if (parent) + pm_runtime_get_sync(parent); + pm_runtime_get_noresume(dev); + /* + * pdev->current_state is set to PCI_D3cold during suspending, + * so wait until suspending completes + */ + pm_runtime_barrier(dev); + /* + * Only need to resume devices in D3cold, because config + * registers are still accessible for devices suspended but + * not in D3cold. + */ + if (pdev->current_state == PCI_D3cold) + pm_runtime_resume(dev); +} + +void pci_config_pm_runtime_put(struct pci_dev *pdev) +{ + struct device *dev = &pdev->dev; + struct device *parent = dev->parent; + + pm_runtime_put(dev); + if (parent) + pm_runtime_put_sync(parent); +} + +static const struct dmi_system_id bridge_d3_blacklist[] = { +#ifdef CONFIG_X86 + { + /* + * Gigabyte X299 root port is not marked as hotplug capable + * which allows Linux to power manage it. However, this + * confuses the BIOS SMI handler so don't power manage root + * ports on that system. + */ + .ident = "X299 DESIGNARE EX-CF", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "Gigabyte Technology Co., Ltd."), + DMI_MATCH(DMI_BOARD_NAME, "X299 DESIGNARE EX-CF"), + }, + }, + { + /* + * Downstream device is not accessible after putting a root port + * into D3cold and back into D0 on Elo Continental Z2 board + */ + .ident = "Elo Continental Z2", + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "Elo Touch Solutions"), + DMI_MATCH(DMI_BOARD_NAME, "Geminilake"), + DMI_MATCH(DMI_BOARD_VERSION, "Continental Z2"), + }, + }, +#endif + { } +}; + +/** + * pci_bridge_d3_possible - Is it possible to put the bridge into D3 + * @bridge: Bridge to check + * + * This function checks if it is possible to move the bridge to D3. + * Currently we only allow D3 for recent enough PCIe ports and Thunderbolt. + */ +bool pci_bridge_d3_possible(struct pci_dev *bridge) +{ + if (!pci_is_pcie(bridge)) + return false; + + switch (pci_pcie_type(bridge)) { + case PCI_EXP_TYPE_ROOT_PORT: + case PCI_EXP_TYPE_UPSTREAM: + case PCI_EXP_TYPE_DOWNSTREAM: + if (pci_bridge_d3_disable) + return false; + + /* + * Hotplug ports handled by firmware in System Management Mode + * may not be put into D3 by the OS (Thunderbolt on non-Macs). + */ + if (bridge->is_hotplug_bridge && !pciehp_is_native(bridge)) + return false; + + if (pci_bridge_d3_force) + return true; + + /* Even the oldest 2010 Thunderbolt controller supports D3. */ + if (bridge->is_thunderbolt) + return true; + + /* Platform might know better if the bridge supports D3 */ + if (platform_pci_bridge_d3(bridge)) + return true; + + /* + * Hotplug ports handled natively by the OS were not validated + * by vendors for runtime D3 at least until 2018 because there + * was no OS support. + */ + if (bridge->is_hotplug_bridge) + return false; + + if (dmi_check_system(bridge_d3_blacklist)) + return false; + + /* + * It should be safe to put PCIe ports from 2015 or newer + * to D3. + */ + if (dmi_get_bios_year() >= 2015) + return true; + break; + } + + return false; +} + +static int pci_dev_check_d3cold(struct pci_dev *dev, void *data) +{ + bool *d3cold_ok = data; + + if (/* The device needs to be allowed to go D3cold ... */ + dev->no_d3cold || !dev->d3cold_allowed || + + /* ... and if it is wakeup capable to do so from D3cold. */ + (device_may_wakeup(&dev->dev) && + !pci_pme_capable(dev, PCI_D3cold)) || + + /* If it is a bridge it must be allowed to go to D3. */ + !pci_power_manageable(dev)) + + *d3cold_ok = false; + + return !*d3cold_ok; +} + +/* + * pci_bridge_d3_update - Update bridge D3 capabilities + * @dev: PCI device which is changed + * + * Update upstream bridge PM capabilities accordingly depending on if the + * device PM configuration was changed or the device is being removed. The + * change is also propagated upstream. + */ +void pci_bridge_d3_update(struct pci_dev *dev) +{ + bool remove = !device_is_registered(&dev->dev); + struct pci_dev *bridge; + bool d3cold_ok = true; + + bridge = pci_upstream_bridge(dev); + if (!bridge || !pci_bridge_d3_possible(bridge)) + return; + + /* + * If D3 is currently allowed for the bridge, removing one of its + * children won't change that. + */ + if (remove && bridge->bridge_d3) + return; + + /* + * If D3 is currently allowed for the bridge and a child is added or + * changed, disallowance of D3 can only be caused by that child, so + * we only need to check that single device, not any of its siblings. + * + * If D3 is currently not allowed for the bridge, checking the device + * first may allow us to skip checking its siblings. + */ + if (!remove) + pci_dev_check_d3cold(dev, &d3cold_ok); + + /* + * If D3 is currently not allowed for the bridge, this may be caused + * either by the device being changed/removed or any of its siblings, + * so we need to go through all children to find out if one of them + * continues to block D3. + */ + if (d3cold_ok && !bridge->bridge_d3) + pci_walk_bus(bridge->subordinate, pci_dev_check_d3cold, + &d3cold_ok); + + if (bridge->bridge_d3 != d3cold_ok) { + bridge->bridge_d3 = d3cold_ok; + /* Propagate change to upstream bridges */ + pci_bridge_d3_update(bridge); + } +} + +/** + * pci_d3cold_enable - Enable D3cold for device + * @dev: PCI device to handle + * + * This function can be used in drivers to enable D3cold from the device + * they handle. It also updates upstream PCI bridge PM capabilities + * accordingly. + */ +void pci_d3cold_enable(struct pci_dev *dev) +{ + if (dev->no_d3cold) { + dev->no_d3cold = false; + pci_bridge_d3_update(dev); + } +} +EXPORT_SYMBOL_GPL(pci_d3cold_enable); + +/** + * pci_d3cold_disable - Disable D3cold for device + * @dev: PCI device to handle + * + * This function can be used in drivers to disable D3cold from the device + * they handle. It also updates upstream PCI bridge PM capabilities + * accordingly. + */ +void pci_d3cold_disable(struct pci_dev *dev) +{ + if (!dev->no_d3cold) { + dev->no_d3cold = true; + pci_bridge_d3_update(dev); + } +} +EXPORT_SYMBOL_GPL(pci_d3cold_disable); + +/** + * pci_pm_init - Initialize PM functions of given PCI device + * @dev: PCI device to handle. + */ +void pci_pm_init(struct pci_dev *dev) +{ + int pm; + u16 status; + u16 pmc; + + pm_runtime_forbid(&dev->dev); + pm_runtime_set_active(&dev->dev); + pm_runtime_enable(&dev->dev); + device_enable_async_suspend(&dev->dev); + dev->wakeup_prepared = false; + + dev->pm_cap = 0; + dev->pme_support = 0; + + /* find PCI PM capability in list */ + pm = pci_find_capability(dev, PCI_CAP_ID_PM); + if (!pm) + return; + /* Check device's ability to generate PME# */ + pci_read_config_word(dev, pm + PCI_PM_PMC, &pmc); + + if ((pmc & PCI_PM_CAP_VER_MASK) > 3) { + pci_err(dev, "unsupported PM cap regs version (%u)\n", + pmc & PCI_PM_CAP_VER_MASK); + return; + } + + dev->pm_cap = pm; + dev->d3hot_delay = PCI_PM_D3HOT_WAIT; + dev->d3cold_delay = PCI_PM_D3COLD_WAIT; + dev->bridge_d3 = pci_bridge_d3_possible(dev); + dev->d3cold_allowed = true; + + dev->d1_support = false; + dev->d2_support = false; + if (!pci_no_d1d2(dev)) { + if (pmc & PCI_PM_CAP_D1) + dev->d1_support = true; + if (pmc & PCI_PM_CAP_D2) + dev->d2_support = true; + + if (dev->d1_support || dev->d2_support) + pci_info(dev, "supports%s%s\n", + dev->d1_support ? " D1" : "", + dev->d2_support ? " D2" : ""); + } + + pmc &= PCI_PM_CAP_PME_MASK; + if (pmc) { + pci_info(dev, "PME# supported from%s%s%s%s%s\n", + (pmc & PCI_PM_CAP_PME_D0) ? " D0" : "", + (pmc & PCI_PM_CAP_PME_D1) ? " D1" : "", + (pmc & PCI_PM_CAP_PME_D2) ? " D2" : "", + (pmc & PCI_PM_CAP_PME_D3hot) ? " D3hot" : "", + (pmc & PCI_PM_CAP_PME_D3cold) ? " D3cold" : ""); + dev->pme_support = pmc >> PCI_PM_CAP_PME_SHIFT; + dev->pme_poll = true; + /* + * Make device's PM flags reflect the wake-up capability, but + * let the user space enable it to wake up the system as needed. + */ + device_set_wakeup_capable(&dev->dev, true); + /* Disable the PME# generation functionality */ + pci_pme_active(dev, false); + } + + pci_read_config_word(dev, PCI_STATUS, &status); + if (status & PCI_STATUS_IMM_READY) + dev->imm_ready = 1; +} + +static unsigned long pci_ea_flags(struct pci_dev *dev, u8 prop) +{ + unsigned long flags = IORESOURCE_PCI_FIXED | IORESOURCE_PCI_EA_BEI; + + switch (prop) { + case PCI_EA_P_MEM: + case PCI_EA_P_VF_MEM: + flags |= IORESOURCE_MEM; + break; + case PCI_EA_P_MEM_PREFETCH: + case PCI_EA_P_VF_MEM_PREFETCH: + flags |= IORESOURCE_MEM | IORESOURCE_PREFETCH; + break; + case PCI_EA_P_IO: + flags |= IORESOURCE_IO; + break; + default: + return 0; + } + + return flags; +} + +static struct resource *pci_ea_get_resource(struct pci_dev *dev, u8 bei, + u8 prop) +{ + if (bei <= PCI_EA_BEI_BAR5 && prop <= PCI_EA_P_IO) + return &dev->resource[bei]; +#ifdef CONFIG_PCI_IOV + else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5 && + (prop == PCI_EA_P_VF_MEM || prop == PCI_EA_P_VF_MEM_PREFETCH)) + return &dev->resource[PCI_IOV_RESOURCES + + bei - PCI_EA_BEI_VF_BAR0]; +#endif + else if (bei == PCI_EA_BEI_ROM) + return &dev->resource[PCI_ROM_RESOURCE]; + else + return NULL; +} + +/* Read an Enhanced Allocation (EA) entry */ +static int pci_ea_read(struct pci_dev *dev, int offset) +{ + struct resource *res; + int ent_size, ent_offset = offset; + resource_size_t start, end; + unsigned long flags; + u32 dw0, bei, base, max_offset; + u8 prop; + bool support_64 = (sizeof(resource_size_t) >= 8); + + pci_read_config_dword(dev, ent_offset, &dw0); + ent_offset += 4; + + /* Entry size field indicates DWORDs after 1st */ + ent_size = ((dw0 & PCI_EA_ES) + 1) << 2; + + if (!(dw0 & PCI_EA_ENABLE)) /* Entry not enabled */ + goto out; + + bei = (dw0 & PCI_EA_BEI) >> 4; + prop = (dw0 & PCI_EA_PP) >> 8; + + /* + * If the Property is in the reserved range, try the Secondary + * Property instead. + */ + if (prop > PCI_EA_P_BRIDGE_IO && prop < PCI_EA_P_MEM_RESERVED) + prop = (dw0 & PCI_EA_SP) >> 16; + if (prop > PCI_EA_P_BRIDGE_IO) + goto out; + + res = pci_ea_get_resource(dev, bei, prop); + if (!res) { + pci_err(dev, "Unsupported EA entry BEI: %u\n", bei); + goto out; + } + + flags = pci_ea_flags(dev, prop); + if (!flags) { + pci_err(dev, "Unsupported EA properties: %#x\n", prop); + goto out; + } + + /* Read Base */ + pci_read_config_dword(dev, ent_offset, &base); + start = (base & PCI_EA_FIELD_MASK); + ent_offset += 4; + + /* Read MaxOffset */ + pci_read_config_dword(dev, ent_offset, &max_offset); + ent_offset += 4; + + /* Read Base MSBs (if 64-bit entry) */ + if (base & PCI_EA_IS_64) { + u32 base_upper; + + pci_read_config_dword(dev, ent_offset, &base_upper); + ent_offset += 4; + + flags |= IORESOURCE_MEM_64; + + /* entry starts above 32-bit boundary, can't use */ + if (!support_64 && base_upper) + goto out; + + if (support_64) + start |= ((u64)base_upper << 32); + } + + end = start + (max_offset | 0x03); + + /* Read MaxOffset MSBs (if 64-bit entry) */ + if (max_offset & PCI_EA_IS_64) { + u32 max_offset_upper; + + pci_read_config_dword(dev, ent_offset, &max_offset_upper); + ent_offset += 4; + + flags |= IORESOURCE_MEM_64; + + /* entry too big, can't use */ + if (!support_64 && max_offset_upper) + goto out; + + if (support_64) + end += ((u64)max_offset_upper << 32); + } + + if (end < start) { + pci_err(dev, "EA Entry crosses address boundary\n"); + goto out; + } + + if (ent_size != ent_offset - offset) { + pci_err(dev, "EA Entry Size (%d) does not match length read (%d)\n", + ent_size, ent_offset - offset); + goto out; + } + + res->name = pci_name(dev); + res->start = start; + res->end = end; + res->flags = flags; + + if (bei <= PCI_EA_BEI_BAR5) + pci_info(dev, "BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n", + bei, res, prop); + else if (bei == PCI_EA_BEI_ROM) + pci_info(dev, "ROM: %pR (from Enhanced Allocation, properties %#02x)\n", + res, prop); + else if (bei >= PCI_EA_BEI_VF_BAR0 && bei <= PCI_EA_BEI_VF_BAR5) + pci_info(dev, "VF BAR %d: %pR (from Enhanced Allocation, properties %#02x)\n", + bei - PCI_EA_BEI_VF_BAR0, res, prop); + else + pci_info(dev, "BEI %d res: %pR (from Enhanced Allocation, properties %#02x)\n", + bei, res, prop); + +out: + return offset + ent_size; +} + +/* Enhanced Allocation Initialization */ +void pci_ea_init(struct pci_dev *dev) +{ + int ea; + u8 num_ent; + int offset; + int i; + + /* find PCI EA capability in list */ + ea = pci_find_capability(dev, PCI_CAP_ID_EA); + if (!ea) + return; + + /* determine the number of entries */ + pci_bus_read_config_byte(dev->bus, dev->devfn, ea + PCI_EA_NUM_ENT, + &num_ent); + num_ent &= PCI_EA_NUM_ENT_MASK; + + offset = ea + PCI_EA_FIRST_ENT; + + /* Skip DWORD 2 for type 1 functions */ + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) + offset += 4; + + /* parse each EA entry */ + for (i = 0; i < num_ent; ++i) + offset = pci_ea_read(dev, offset); +} + +static void pci_add_saved_cap(struct pci_dev *pci_dev, + struct pci_cap_saved_state *new_cap) +{ + hlist_add_head(&new_cap->next, &pci_dev->saved_cap_space); +} + +/** + * _pci_add_cap_save_buffer - allocate buffer for saving given + * capability registers + * @dev: the PCI device + * @cap: the capability to allocate the buffer for + * @extended: Standard or Extended capability ID + * @size: requested size of the buffer + */ +static int _pci_add_cap_save_buffer(struct pci_dev *dev, u16 cap, + bool extended, unsigned int size) +{ + int pos; + struct pci_cap_saved_state *save_state; + + if (extended) + pos = pci_find_ext_capability(dev, cap); + else + pos = pci_find_capability(dev, cap); + + if (!pos) + return 0; + + save_state = kzalloc(sizeof(*save_state) + size, GFP_KERNEL); + if (!save_state) + return -ENOMEM; + + save_state->cap.cap_nr = cap; + save_state->cap.cap_extended = extended; + save_state->cap.size = size; + pci_add_saved_cap(dev, save_state); + + return 0; +} + +int pci_add_cap_save_buffer(struct pci_dev *dev, char cap, unsigned int size) +{ + return _pci_add_cap_save_buffer(dev, cap, false, size); +} + +int pci_add_ext_cap_save_buffer(struct pci_dev *dev, u16 cap, unsigned int size) +{ + return _pci_add_cap_save_buffer(dev, cap, true, size); +} + +/** + * pci_allocate_cap_save_buffers - allocate buffers for saving capabilities + * @dev: the PCI device + */ +void pci_allocate_cap_save_buffers(struct pci_dev *dev) +{ + int error; + + error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_EXP, + PCI_EXP_SAVE_REGS * sizeof(u16)); + if (error) + pci_err(dev, "unable to preallocate PCI Express save buffer\n"); + + error = pci_add_cap_save_buffer(dev, PCI_CAP_ID_PCIX, sizeof(u16)); + if (error) + pci_err(dev, "unable to preallocate PCI-X save buffer\n"); + + error = pci_add_ext_cap_save_buffer(dev, PCI_EXT_CAP_ID_LTR, + 2 * sizeof(u16)); + if (error) + pci_err(dev, "unable to allocate suspend buffer for LTR\n"); + + pci_allocate_vc_save_buffers(dev); +} + +void pci_free_cap_save_buffers(struct pci_dev *dev) +{ + struct pci_cap_saved_state *tmp; + struct hlist_node *n; + + hlist_for_each_entry_safe(tmp, n, &dev->saved_cap_space, next) + kfree(tmp); +} + +/** + * pci_configure_ari - enable or disable ARI forwarding + * @dev: the PCI device + * + * If @dev and its upstream bridge both support ARI, enable ARI in the + * bridge. Otherwise, disable ARI in the bridge. + */ +void pci_configure_ari(struct pci_dev *dev) +{ + u32 cap; + struct pci_dev *bridge; + + if (pcie_ari_disabled || !pci_is_pcie(dev) || dev->devfn) + return; + + bridge = dev->bus->self; + if (!bridge) + return; + + pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap); + if (!(cap & PCI_EXP_DEVCAP2_ARI)) + return; + + if (pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI)) { + pcie_capability_set_word(bridge, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_ARI); + bridge->ari_enabled = 1; + } else { + pcie_capability_clear_word(bridge, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_ARI); + bridge->ari_enabled = 0; + } +} + +static bool pci_acs_flags_enabled(struct pci_dev *pdev, u16 acs_flags) +{ + int pos; + u16 cap, ctrl; + + pos = pdev->acs_cap; + if (!pos) + return false; + + /* + * Except for egress control, capabilities are either required + * or only required if controllable. Features missing from the + * capability field can therefore be assumed as hard-wired enabled. + */ + pci_read_config_word(pdev, pos + PCI_ACS_CAP, &cap); + acs_flags &= (cap | PCI_ACS_EC); + + pci_read_config_word(pdev, pos + PCI_ACS_CTRL, &ctrl); + return (ctrl & acs_flags) == acs_flags; +} + +/** + * pci_acs_enabled - test ACS against required flags for a given device + * @pdev: device to test + * @acs_flags: required PCI ACS flags + * + * Return true if the device supports the provided flags. Automatically + * filters out flags that are not implemented on multifunction devices. + * + * Note that this interface checks the effective ACS capabilities of the + * device rather than the actual capabilities. For instance, most single + * function endpoints are not required to support ACS because they have no + * opportunity for peer-to-peer access. We therefore return 'true' + * regardless of whether the device exposes an ACS capability. This makes + * it much easier for callers of this function to ignore the actual type + * or topology of the device when testing ACS support. + */ +bool pci_acs_enabled(struct pci_dev *pdev, u16 acs_flags) +{ + int ret; + + ret = pci_dev_specific_acs_enabled(pdev, acs_flags); + if (ret >= 0) + return ret > 0; + + /* + * Conventional PCI and PCI-X devices never support ACS, either + * effectively or actually. The shared bus topology implies that + * any device on the bus can receive or snoop DMA. + */ + if (!pci_is_pcie(pdev)) + return false; + + switch (pci_pcie_type(pdev)) { + /* + * PCI/X-to-PCIe bridges are not specifically mentioned by the spec, + * but since their primary interface is PCI/X, we conservatively + * handle them as we would a non-PCIe device. + */ + case PCI_EXP_TYPE_PCIE_BRIDGE: + /* + * PCIe 3.0, 6.12.1 excludes ACS on these devices. "ACS is never + * applicable... must never implement an ACS Extended Capability...". + * This seems arbitrary, but we take a conservative interpretation + * of this statement. + */ + case PCI_EXP_TYPE_PCI_BRIDGE: + case PCI_EXP_TYPE_RC_EC: + return false; + /* + * PCIe 3.0, 6.12.1.1 specifies that downstream and root ports should + * implement ACS in order to indicate their peer-to-peer capabilities, + * regardless of whether they are single- or multi-function devices. + */ + case PCI_EXP_TYPE_DOWNSTREAM: + case PCI_EXP_TYPE_ROOT_PORT: + return pci_acs_flags_enabled(pdev, acs_flags); + /* + * PCIe 3.0, 6.12.1.2 specifies ACS capabilities that should be + * implemented by the remaining PCIe types to indicate peer-to-peer + * capabilities, but only when they are part of a multifunction + * device. The footnote for section 6.12 indicates the specific + * PCIe types included here. + */ + case PCI_EXP_TYPE_ENDPOINT: + case PCI_EXP_TYPE_UPSTREAM: + case PCI_EXP_TYPE_LEG_END: + case PCI_EXP_TYPE_RC_END: + if (!pdev->multifunction) + break; + + return pci_acs_flags_enabled(pdev, acs_flags); + } + + /* + * PCIe 3.0, 6.12.1.3 specifies no ACS capabilities are applicable + * to single function devices with the exception of downstream ports. + */ + return true; +} + +/** + * pci_acs_path_enabled - test ACS flags from start to end in a hierarchy + * @start: starting downstream device + * @end: ending upstream device or NULL to search to the root bus + * @acs_flags: required flags + * + * Walk up a device tree from start to end testing PCI ACS support. If + * any step along the way does not support the required flags, return false. + */ +bool pci_acs_path_enabled(struct pci_dev *start, + struct pci_dev *end, u16 acs_flags) +{ + struct pci_dev *pdev, *parent = start; + + do { + pdev = parent; + + if (!pci_acs_enabled(pdev, acs_flags)) + return false; + + if (pci_is_root_bus(pdev->bus)) + return (end == NULL); + + parent = pdev->bus->self; + } while (pdev != end); + + return true; +} + +/** + * pci_acs_init - Initialize ACS if hardware supports it + * @dev: the PCI device + */ +void pci_acs_init(struct pci_dev *dev) +{ + dev->acs_cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ACS); + + /* + * Attempt to enable ACS regardless of capability because some Root + * Ports (e.g. those quirked with *_intel_pch_acs_*) do not have + * the standard ACS capability but still support ACS via those + * quirks. + */ + pci_enable_acs(dev); +} + +/** + * pci_rebar_find_pos - find position of resize ctrl reg for BAR + * @pdev: PCI device + * @bar: BAR to find + * + * Helper to find the position of the ctrl register for a BAR. + * Returns -ENOTSUPP if resizable BARs are not supported at all. + * Returns -ENOENT if no ctrl register for the BAR could be found. + */ +static int pci_rebar_find_pos(struct pci_dev *pdev, int bar) +{ + unsigned int pos, nbars, i; + u32 ctrl; + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_REBAR); + if (!pos) + return -ENOTSUPP; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + nbars = (ctrl & PCI_REBAR_CTRL_NBAR_MASK) >> + PCI_REBAR_CTRL_NBAR_SHIFT; + + for (i = 0; i < nbars; i++, pos += 8) { + int bar_idx; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + bar_idx = ctrl & PCI_REBAR_CTRL_BAR_IDX; + if (bar_idx == bar) + return pos; + } + + return -ENOENT; +} + +/** + * pci_rebar_get_possible_sizes - get possible sizes for BAR + * @pdev: PCI device + * @bar: BAR to query + * + * Get the possible sizes of a resizable BAR as bitmask defined in the spec + * (bit 0=1MB, bit 19=512GB). Returns 0 if BAR isn't resizable. + */ +u32 pci_rebar_get_possible_sizes(struct pci_dev *pdev, int bar) +{ + int pos; + u32 cap; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return 0; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CAP, &cap); + cap = FIELD_GET(PCI_REBAR_CAP_SIZES, cap); + + /* Sapphire RX 5600 XT Pulse has an invalid cap dword for BAR 0 */ + if (pdev->vendor == PCI_VENDOR_ID_ATI && pdev->device == 0x731f && + bar == 0 && cap == 0x700) + return 0x3f00; + + return cap; +} +EXPORT_SYMBOL(pci_rebar_get_possible_sizes); + +/** + * pci_rebar_get_current_size - get the current size of a BAR + * @pdev: PCI device + * @bar: BAR to set size to + * + * Read the size of a BAR from the resizable BAR config. + * Returns size if found or negative error code. + */ +int pci_rebar_get_current_size(struct pci_dev *pdev, int bar) +{ + int pos; + u32 ctrl; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return pos; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + return (ctrl & PCI_REBAR_CTRL_BAR_SIZE) >> PCI_REBAR_CTRL_BAR_SHIFT; +} + +/** + * pci_rebar_set_size - set a new size for a BAR + * @pdev: PCI device + * @bar: BAR to set size to + * @size: new size as defined in the spec (0=1MB, 19=512GB) + * + * Set the new size of a BAR as defined in the spec. + * Returns zero if resizing was successful, error code otherwise. + */ +int pci_rebar_set_size(struct pci_dev *pdev, int bar, int size) +{ + int pos; + u32 ctrl; + + pos = pci_rebar_find_pos(pdev, bar); + if (pos < 0) + return pos; + + pci_read_config_dword(pdev, pos + PCI_REBAR_CTRL, &ctrl); + ctrl &= ~PCI_REBAR_CTRL_BAR_SIZE; + ctrl |= size << PCI_REBAR_CTRL_BAR_SHIFT; + pci_write_config_dword(pdev, pos + PCI_REBAR_CTRL, ctrl); + return 0; +} + +/** + * pci_enable_atomic_ops_to_root - enable AtomicOp requests to root port + * @dev: the PCI device + * @cap_mask: mask of desired AtomicOp sizes, including one or more of: + * PCI_EXP_DEVCAP2_ATOMIC_COMP32 + * PCI_EXP_DEVCAP2_ATOMIC_COMP64 + * PCI_EXP_DEVCAP2_ATOMIC_COMP128 + * + * Return 0 if all upstream bridges support AtomicOp routing, egress + * blocking is disabled on all upstream ports, and the root port supports + * the requested completion capabilities (32-bit, 64-bit and/or 128-bit + * AtomicOp completion), or negative otherwise. + */ +int pci_enable_atomic_ops_to_root(struct pci_dev *dev, u32 cap_mask) +{ + struct pci_bus *bus = dev->bus; + struct pci_dev *bridge; + u32 cap, ctl2; + + /* + * Per PCIe r5.0, sec 9.3.5.10, the AtomicOp Requester Enable bit + * in Device Control 2 is reserved in VFs and the PF value applies + * to all associated VFs. + */ + if (dev->is_virtfn) + return -EINVAL; + + if (!pci_is_pcie(dev)) + return -EINVAL; + + /* + * Per PCIe r4.0, sec 6.15, endpoints and root ports may be + * AtomicOp requesters. For now, we only support endpoints as + * requesters and root ports as completers. No endpoints as + * completers, and no peer-to-peer. + */ + + switch (pci_pcie_type(dev)) { + case PCI_EXP_TYPE_ENDPOINT: + case PCI_EXP_TYPE_LEG_END: + case PCI_EXP_TYPE_RC_END: + break; + default: + return -EINVAL; + } + + while (bus->parent) { + bridge = bus->self; + + pcie_capability_read_dword(bridge, PCI_EXP_DEVCAP2, &cap); + + switch (pci_pcie_type(bridge)) { + /* Ensure switch ports support AtomicOp routing */ + case PCI_EXP_TYPE_UPSTREAM: + case PCI_EXP_TYPE_DOWNSTREAM: + if (!(cap & PCI_EXP_DEVCAP2_ATOMIC_ROUTE)) + return -EINVAL; + break; + + /* Ensure root port supports all the sizes we care about */ + case PCI_EXP_TYPE_ROOT_PORT: + if ((cap & cap_mask) != cap_mask) + return -EINVAL; + break; + } + + /* Ensure upstream ports don't block AtomicOps on egress */ + if (pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM) { + pcie_capability_read_dword(bridge, PCI_EXP_DEVCTL2, + &ctl2); + if (ctl2 & PCI_EXP_DEVCTL2_ATOMIC_EGRESS_BLOCK) + return -EINVAL; + } + + bus = bus->parent; + } + + pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, + PCI_EXP_DEVCTL2_ATOMIC_REQ); + return 0; +} +EXPORT_SYMBOL(pci_enable_atomic_ops_to_root); + +/** + * pci_swizzle_interrupt_pin - swizzle INTx for device behind bridge + * @dev: the PCI device + * @pin: the INTx pin (1=INTA, 2=INTB, 3=INTC, 4=INTD) + * + * Perform INTx swizzling for a device behind one level of bridge. This is + * required by section 9.1 of the PCI-to-PCI bridge specification for devices + * behind bridges on add-in cards. For devices with ARI enabled, the slot + * number is always 0 (see the Implementation Note in section 2.2.8.1 of + * the PCI Express Base Specification, Revision 2.1) + */ +u8 pci_swizzle_interrupt_pin(const struct pci_dev *dev, u8 pin) +{ + int slot; + + if (pci_ari_enabled(dev->bus)) + slot = 0; + else + slot = PCI_SLOT(dev->devfn); + + return (((pin - 1) + slot) % 4) + 1; +} + +int pci_get_interrupt_pin(struct pci_dev *dev, struct pci_dev **bridge) +{ + u8 pin; + + pin = dev->pin; + if (!pin) + return -1; + + while (!pci_is_root_bus(dev->bus)) { + pin = pci_swizzle_interrupt_pin(dev, pin); + dev = dev->bus->self; + } + *bridge = dev; + return pin; +} + +/** + * pci_common_swizzle - swizzle INTx all the way to root bridge + * @dev: the PCI device + * @pinp: pointer to the INTx pin value (1=INTA, 2=INTB, 3=INTD, 4=INTD) + * + * Perform INTx swizzling for a device. This traverses through all PCI-to-PCI + * bridges all the way up to a PCI root bus. + */ +u8 pci_common_swizzle(struct pci_dev *dev, u8 *pinp) +{ + u8 pin = *pinp; + + while (!pci_is_root_bus(dev->bus)) { + pin = pci_swizzle_interrupt_pin(dev, pin); + dev = dev->bus->self; + } + *pinp = pin; + return PCI_SLOT(dev->devfn); +} +EXPORT_SYMBOL_GPL(pci_common_swizzle); + +/** + * pci_release_region - Release a PCI bar + * @pdev: PCI device whose resources were previously reserved by + * pci_request_region() + * @bar: BAR to release + * + * Releases the PCI I/O and memory resources previously reserved by a + * successful call to pci_request_region(). Call this function only + * after all use of the PCI regions has ceased. + */ +void pci_release_region(struct pci_dev *pdev, int bar) +{ + struct pci_devres *dr; + + if (pci_resource_len(pdev, bar) == 0) + return; + if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) + release_region(pci_resource_start(pdev, bar), + pci_resource_len(pdev, bar)); + else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) + release_mem_region(pci_resource_start(pdev, bar), + pci_resource_len(pdev, bar)); + + dr = find_pci_dr(pdev); + if (dr) + dr->region_mask &= ~(1 << bar); +} +EXPORT_SYMBOL(pci_release_region); + +/** + * __pci_request_region - Reserved PCI I/O and memory resource + * @pdev: PCI device whose resources are to be reserved + * @bar: BAR to be reserved + * @res_name: Name to be associated with resource. + * @exclusive: whether the region access is exclusive or not + * + * Mark the PCI region associated with PCI device @pdev BAR @bar as + * being reserved by owner @res_name. Do not access any + * address inside the PCI regions unless this call returns + * successfully. + * + * If @exclusive is set, then the region is marked so that userspace + * is explicitly not allowed to map the resource via /dev/mem or + * sysfs MMIO access. + * + * Returns 0 on success, or %EBUSY on error. A warning + * message is also printed on failure. + */ +static int __pci_request_region(struct pci_dev *pdev, int bar, + const char *res_name, int exclusive) +{ + struct pci_devres *dr; + + if (pci_resource_len(pdev, bar) == 0) + return 0; + + if (pci_resource_flags(pdev, bar) & IORESOURCE_IO) { + if (!request_region(pci_resource_start(pdev, bar), + pci_resource_len(pdev, bar), res_name)) + goto err_out; + } else if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM) { + if (!__request_mem_region(pci_resource_start(pdev, bar), + pci_resource_len(pdev, bar), res_name, + exclusive)) + goto err_out; + } + + dr = find_pci_dr(pdev); + if (dr) + dr->region_mask |= 1 << bar; + + return 0; + +err_out: + pci_warn(pdev, "BAR %d: can't reserve %pR\n", bar, + &pdev->resource[bar]); + return -EBUSY; +} + +/** + * pci_request_region - Reserve PCI I/O and memory resource + * @pdev: PCI device whose resources are to be reserved + * @bar: BAR to be reserved + * @res_name: Name to be associated with resource + * + * Mark the PCI region associated with PCI device @pdev BAR @bar as + * being reserved by owner @res_name. Do not access any + * address inside the PCI regions unless this call returns + * successfully. + * + * Returns 0 on success, or %EBUSY on error. A warning + * message is also printed on failure. + */ +int pci_request_region(struct pci_dev *pdev, int bar, const char *res_name) +{ + return __pci_request_region(pdev, bar, res_name, 0); +} +EXPORT_SYMBOL(pci_request_region); + +/** + * pci_release_selected_regions - Release selected PCI I/O and memory resources + * @pdev: PCI device whose resources were previously reserved + * @bars: Bitmask of BARs to be released + * + * Release selected PCI I/O and memory resources previously reserved. + * Call this function only after all use of the PCI regions has ceased. + */ +void pci_release_selected_regions(struct pci_dev *pdev, int bars) +{ + int i; + + for (i = 0; i < PCI_STD_NUM_BARS; i++) + if (bars & (1 << i)) + pci_release_region(pdev, i); +} +EXPORT_SYMBOL(pci_release_selected_regions); + +static int __pci_request_selected_regions(struct pci_dev *pdev, int bars, + const char *res_name, int excl) +{ + int i; + + for (i = 0; i < PCI_STD_NUM_BARS; i++) + if (bars & (1 << i)) + if (__pci_request_region(pdev, i, res_name, excl)) + goto err_out; + return 0; + +err_out: + while (--i >= 0) + if (bars & (1 << i)) + pci_release_region(pdev, i); + + return -EBUSY; +} + + +/** + * pci_request_selected_regions - Reserve selected PCI I/O and memory resources + * @pdev: PCI device whose resources are to be reserved + * @bars: Bitmask of BARs to be requested + * @res_name: Name to be associated with resource + */ +int pci_request_selected_regions(struct pci_dev *pdev, int bars, + const char *res_name) +{ + return __pci_request_selected_regions(pdev, bars, res_name, 0); +} +EXPORT_SYMBOL(pci_request_selected_regions); + +int pci_request_selected_regions_exclusive(struct pci_dev *pdev, int bars, + const char *res_name) +{ + return __pci_request_selected_regions(pdev, bars, res_name, + IORESOURCE_EXCLUSIVE); +} +EXPORT_SYMBOL(pci_request_selected_regions_exclusive); + +/** + * pci_release_regions - Release reserved PCI I/O and memory resources + * @pdev: PCI device whose resources were previously reserved by + * pci_request_regions() + * + * Releases all PCI I/O and memory resources previously reserved by a + * successful call to pci_request_regions(). Call this function only + * after all use of the PCI regions has ceased. + */ + +void pci_release_regions(struct pci_dev *pdev) +{ + pci_release_selected_regions(pdev, (1 << PCI_STD_NUM_BARS) - 1); +} +EXPORT_SYMBOL(pci_release_regions); + +/** + * pci_request_regions - Reserve PCI I/O and memory resources + * @pdev: PCI device whose resources are to be reserved + * @res_name: Name to be associated with resource. + * + * Mark all PCI regions associated with PCI device @pdev as + * being reserved by owner @res_name. Do not access any + * address inside the PCI regions unless this call returns + * successfully. + * + * Returns 0 on success, or %EBUSY on error. A warning + * message is also printed on failure. + */ +int pci_request_regions(struct pci_dev *pdev, const char *res_name) +{ + return pci_request_selected_regions(pdev, + ((1 << PCI_STD_NUM_BARS) - 1), res_name); +} +EXPORT_SYMBOL(pci_request_regions); + +/** + * pci_request_regions_exclusive - Reserve PCI I/O and memory resources + * @pdev: PCI device whose resources are to be reserved + * @res_name: Name to be associated with resource. + * + * Mark all PCI regions associated with PCI device @pdev as being reserved + * by owner @res_name. Do not access any address inside the PCI regions + * unless this call returns successfully. + * + * pci_request_regions_exclusive() will mark the region so that /dev/mem + * and the sysfs MMIO access will not be allowed. + * + * Returns 0 on success, or %EBUSY on error. A warning message is also + * printed on failure. + */ +int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) +{ + return pci_request_selected_regions_exclusive(pdev, + ((1 << PCI_STD_NUM_BARS) - 1), res_name); +} +EXPORT_SYMBOL(pci_request_regions_exclusive); + +/* + * Record the PCI IO range (expressed as CPU physical address + size). + * Return a negative value if an error has occurred, zero otherwise + */ +int pci_register_io_range(struct fwnode_handle *fwnode, phys_addr_t addr, + resource_size_t size) +{ + int ret = 0; +#ifdef PCI_IOBASE + struct logic_pio_hwaddr *range; + + if (!size || addr + size < addr) + return -EINVAL; + + range = kzalloc(sizeof(*range), GFP_ATOMIC); + if (!range) + return -ENOMEM; + + range->fwnode = fwnode; + range->size = size; + range->hw_start = addr; + range->flags = LOGIC_PIO_CPU_MMIO; + + ret = logic_pio_register_range(range); + if (ret) + kfree(range); + + /* Ignore duplicates due to deferred probing */ + if (ret == -EEXIST) + ret = 0; +#endif + + return ret; +} + +phys_addr_t pci_pio_to_address(unsigned long pio) +{ + phys_addr_t address = (phys_addr_t)OF_BAD_ADDR; + +#ifdef PCI_IOBASE + if (pio >= MMIO_UPPER_LIMIT) + return address; + + address = logic_pio_to_hwaddr(pio); +#endif + + return address; +} +EXPORT_SYMBOL_GPL(pci_pio_to_address); + +unsigned long __weak pci_address_to_pio(phys_addr_t address) +{ +#ifdef PCI_IOBASE + return logic_pio_trans_cpuaddr(address); +#else + if (address > IO_SPACE_LIMIT) + return (unsigned long)-1; + + return (unsigned long) address; +#endif +} + +/** + * pci_remap_iospace - Remap the memory mapped I/O space + * @res: Resource describing the I/O space + * @phys_addr: physical address of range to be mapped + * + * Remap the memory mapped I/O space described by the @res and the CPU + * physical address @phys_addr into virtual address space. Only + * architectures that have memory mapped IO functions defined (and the + * PCI_IOBASE value defined) should call this function. + */ +#ifndef pci_remap_iospace +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) +{ +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; + + if (!(res->flags & IORESOURCE_IO)) + return -EINVAL; + + if (res->end > IO_SPACE_LIMIT) + return -EINVAL; + + return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr, + pgprot_device(PAGE_KERNEL)); +#else + /* + * This architecture does not have memory mapped I/O space, + * so this function should never be called + */ + WARN_ONCE(1, "This architecture does not support memory mapped I/O\n"); + return -ENODEV; +#endif +} +EXPORT_SYMBOL(pci_remap_iospace); +#endif + +/** + * pci_unmap_iospace - Unmap the memory mapped I/O space + * @res: resource to be unmapped + * + * Unmap the CPU virtual address @res from virtual address space. Only + * architectures that have memory mapped IO functions defined (and the + * PCI_IOBASE value defined) should call this function. + */ +void pci_unmap_iospace(struct resource *res) +{ +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; + + vunmap_range(vaddr, vaddr + resource_size(res)); +#endif +} +EXPORT_SYMBOL(pci_unmap_iospace); + +static void devm_pci_unmap_iospace(struct device *dev, void *ptr) +{ + struct resource **res = ptr; + + pci_unmap_iospace(*res); +} + +/** + * devm_pci_remap_iospace - Managed pci_remap_iospace() + * @dev: Generic device to remap IO address for + * @res: Resource describing the I/O space + * @phys_addr: physical address of range to be mapped + * + * Managed pci_remap_iospace(). Map is automatically unmapped on driver + * detach. + */ +int devm_pci_remap_iospace(struct device *dev, const struct resource *res, + phys_addr_t phys_addr) +{ + const struct resource **ptr; + int error; + + ptr = devres_alloc(devm_pci_unmap_iospace, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return -ENOMEM; + + error = pci_remap_iospace(res, phys_addr); + if (error) { + devres_free(ptr); + } else { + *ptr = res; + devres_add(dev, ptr); + } + + return error; +} +EXPORT_SYMBOL(devm_pci_remap_iospace); + +/** + * devm_pci_remap_cfgspace - Managed pci_remap_cfgspace() + * @dev: Generic device to remap IO address for + * @offset: Resource address to map + * @size: Size of map + * + * Managed pci_remap_cfgspace(). Map is automatically unmapped on driver + * detach. + */ +void __iomem *devm_pci_remap_cfgspace(struct device *dev, + resource_size_t offset, + resource_size_t size) +{ + void __iomem **ptr, *addr; + + ptr = devres_alloc(devm_ioremap_release, sizeof(*ptr), GFP_KERNEL); + if (!ptr) + return NULL; + + addr = pci_remap_cfgspace(offset, size); + if (addr) { + *ptr = addr; + devres_add(dev, ptr); + } else + devres_free(ptr); + + return addr; +} +EXPORT_SYMBOL(devm_pci_remap_cfgspace); + +/** + * devm_pci_remap_cfg_resource - check, request region and ioremap cfg resource + * @dev: generic device to handle the resource for + * @res: configuration space resource to be handled + * + * Checks that a resource is a valid memory region, requests the memory + * region and ioremaps with pci_remap_cfgspace() API that ensures the + * proper PCI configuration space memory attributes are guaranteed. + * + * All operations are managed and will be undone on driver detach. + * + * Returns a pointer to the remapped memory or an ERR_PTR() encoded error code + * on failure. Usage example:: + * + * res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + * base = devm_pci_remap_cfg_resource(&pdev->dev, res); + * if (IS_ERR(base)) + * return PTR_ERR(base); + */ +void __iomem *devm_pci_remap_cfg_resource(struct device *dev, + struct resource *res) +{ + resource_size_t size; + const char *name; + void __iomem *dest_ptr; + + BUG_ON(!dev); + + if (!res || resource_type(res) != IORESOURCE_MEM) { + dev_err(dev, "invalid resource\n"); + return IOMEM_ERR_PTR(-EINVAL); + } + + size = resource_size(res); + + if (res->name) + name = devm_kasprintf(dev, GFP_KERNEL, "%s %s", dev_name(dev), + res->name); + else + name = devm_kstrdup(dev, dev_name(dev), GFP_KERNEL); + if (!name) + return IOMEM_ERR_PTR(-ENOMEM); + + if (!devm_request_mem_region(dev, res->start, size, name)) { + dev_err(dev, "can't request region for resource %pR\n", res); + return IOMEM_ERR_PTR(-EBUSY); + } + + dest_ptr = devm_pci_remap_cfgspace(dev, res->start, size); + if (!dest_ptr) { + dev_err(dev, "ioremap failed for resource %pR\n", res); + devm_release_mem_region(dev, res->start, size); + dest_ptr = IOMEM_ERR_PTR(-ENOMEM); + } + + return dest_ptr; +} +EXPORT_SYMBOL(devm_pci_remap_cfg_resource); + +static void __pci_set_master(struct pci_dev *dev, bool enable) +{ + u16 old_cmd, cmd; + + pci_read_config_word(dev, PCI_COMMAND, &old_cmd); + if (enable) + cmd = old_cmd | PCI_COMMAND_MASTER; + else + cmd = old_cmd & ~PCI_COMMAND_MASTER; + if (cmd != old_cmd) { + pci_dbg(dev, "%s bus mastering\n", + enable ? "enabling" : "disabling"); + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + dev->is_busmaster = enable; +} + +/** + * pcibios_setup - process "pci=" kernel boot arguments + * @str: string used to pass in "pci=" kernel boot arguments + * + * Process kernel boot arguments. This is the default implementation. + * Architecture specific implementations can override this as necessary. + */ +char * __weak __init pcibios_setup(char *str) +{ + return str; +} + +/** + * pcibios_set_master - enable PCI bus-mastering for device dev + * @dev: the PCI device to enable + * + * Enables PCI bus-mastering for the device. This is the default + * implementation. Architecture specific implementations can override + * this if necessary. + */ +void __weak pcibios_set_master(struct pci_dev *dev) +{ + u8 lat; + + /* The latency timer doesn't apply to PCIe (either Type 0 or Type 1) */ + if (pci_is_pcie(dev)) + return; + + pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat); + if (lat < 16) + lat = (64 <= pcibios_max_latency) ? 64 : pcibios_max_latency; + else if (lat > pcibios_max_latency) + lat = pcibios_max_latency; + else + return; + + pci_write_config_byte(dev, PCI_LATENCY_TIMER, lat); +} + +/** + * pci_set_master - enables bus-mastering for device dev + * @dev: the PCI device to enable + * + * Enables bus-mastering on the device and calls pcibios_set_master() + * to do the needed arch specific settings. + */ +void pci_set_master(struct pci_dev *dev) +{ + __pci_set_master(dev, true); + pcibios_set_master(dev); +} +EXPORT_SYMBOL(pci_set_master); + +/** + * pci_clear_master - disables bus-mastering for device dev + * @dev: the PCI device to disable + */ +void pci_clear_master(struct pci_dev *dev) +{ + __pci_set_master(dev, false); +} +EXPORT_SYMBOL(pci_clear_master); + +/** + * pci_set_cacheline_size - ensure the CACHE_LINE_SIZE register is programmed + * @dev: the PCI device for which MWI is to be enabled + * + * Helper function for pci_set_mwi. + * Originally copied from drivers/net/acenic.c. + * Copyright 1998-2001 by Jes Sorensen, <jes@trained-monkey.org>. + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int pci_set_cacheline_size(struct pci_dev *dev) +{ + u8 cacheline_size; + + if (!pci_cache_line_size) + return -EINVAL; + + /* Validate current setting: the PCI_CACHE_LINE_SIZE must be + equal to or multiple of the right value. */ + pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size); + if (cacheline_size >= pci_cache_line_size && + (cacheline_size % pci_cache_line_size) == 0) + return 0; + + /* Write the correct value. */ + pci_write_config_byte(dev, PCI_CACHE_LINE_SIZE, pci_cache_line_size); + /* Read it back. */ + pci_read_config_byte(dev, PCI_CACHE_LINE_SIZE, &cacheline_size); + if (cacheline_size == pci_cache_line_size) + return 0; + + pci_dbg(dev, "cache line size of %d is not supported\n", + pci_cache_line_size << 2); + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(pci_set_cacheline_size); + +/** + * pci_set_mwi - enables memory-write-invalidate PCI transaction + * @dev: the PCI device for which MWI is enabled + * + * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND. + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int pci_set_mwi(struct pci_dev *dev) +{ +#ifdef PCI_DISABLE_MWI + return 0; +#else + int rc; + u16 cmd; + + rc = pci_set_cacheline_size(dev); + if (rc) + return rc; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (!(cmd & PCI_COMMAND_INVALIDATE)) { + pci_dbg(dev, "enabling Mem-Wr-Inval\n"); + cmd |= PCI_COMMAND_INVALIDATE; + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + return 0; +#endif +} +EXPORT_SYMBOL(pci_set_mwi); + +/** + * pcim_set_mwi - a device-managed pci_set_mwi() + * @dev: the PCI device for which MWI is enabled + * + * Managed pci_set_mwi(). + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int pcim_set_mwi(struct pci_dev *dev) +{ + struct pci_devres *dr; + + dr = find_pci_dr(dev); + if (!dr) + return -ENOMEM; + + dr->mwi = 1; + return pci_set_mwi(dev); +} +EXPORT_SYMBOL(pcim_set_mwi); + +/** + * pci_try_set_mwi - enables memory-write-invalidate PCI transaction + * @dev: the PCI device for which MWI is enabled + * + * Enables the Memory-Write-Invalidate transaction in %PCI_COMMAND. + * Callers are not required to check the return value. + * + * RETURNS: An appropriate -ERRNO error value on error, or zero for success. + */ +int pci_try_set_mwi(struct pci_dev *dev) +{ +#ifdef PCI_DISABLE_MWI + return 0; +#else + return pci_set_mwi(dev); +#endif +} +EXPORT_SYMBOL(pci_try_set_mwi); + +/** + * pci_clear_mwi - disables Memory-Write-Invalidate for device dev + * @dev: the PCI device to disable + * + * Disables PCI Memory-Write-Invalidate transaction on the device + */ +void pci_clear_mwi(struct pci_dev *dev) +{ +#ifndef PCI_DISABLE_MWI + u16 cmd; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_INVALIDATE) { + cmd &= ~PCI_COMMAND_INVALIDATE; + pci_write_config_word(dev, PCI_COMMAND, cmd); + } +#endif +} +EXPORT_SYMBOL(pci_clear_mwi); + +/** + * pci_disable_parity - disable parity checking for device + * @dev: the PCI device to operate on + * + * Disable parity checking for device @dev + */ +void pci_disable_parity(struct pci_dev *dev) +{ + u16 cmd; + + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (cmd & PCI_COMMAND_PARITY) { + cmd &= ~PCI_COMMAND_PARITY; + pci_write_config_word(dev, PCI_COMMAND, cmd); + } +} + +/** + * pci_intx - enables/disables PCI INTx for device dev + * @pdev: the PCI device to operate on + * @enable: boolean: whether to enable or disable PCI INTx + * + * Enables/disables PCI INTx for device @pdev + */ +void pci_intx(struct pci_dev *pdev, int enable) +{ + u16 pci_command, new; + + pci_read_config_word(pdev, PCI_COMMAND, &pci_command); + + if (enable) + new = pci_command & ~PCI_COMMAND_INTX_DISABLE; + else + new = pci_command | PCI_COMMAND_INTX_DISABLE; + + if (new != pci_command) { + struct pci_devres *dr; + + pci_write_config_word(pdev, PCI_COMMAND, new); + + dr = find_pci_dr(pdev); + if (dr && !dr->restore_intx) { + dr->restore_intx = 1; + dr->orig_intx = !enable; + } + } +} +EXPORT_SYMBOL_GPL(pci_intx); + +static bool pci_check_and_set_intx_mask(struct pci_dev *dev, bool mask) +{ + struct pci_bus *bus = dev->bus; + bool mask_updated = true; + u32 cmd_status_dword; + u16 origcmd, newcmd; + unsigned long flags; + bool irq_pending; + + /* + * We do a single dword read to retrieve both command and status. + * Document assumptions that make this possible. + */ + BUILD_BUG_ON(PCI_COMMAND % 4); + BUILD_BUG_ON(PCI_COMMAND + 2 != PCI_STATUS); + + raw_spin_lock_irqsave(&pci_lock, flags); + + bus->ops->read(bus, dev->devfn, PCI_COMMAND, 4, &cmd_status_dword); + + irq_pending = (cmd_status_dword >> 16) & PCI_STATUS_INTERRUPT; + + /* + * Check interrupt status register to see whether our device + * triggered the interrupt (when masking) or the next IRQ is + * already pending (when unmasking). + */ + if (mask != irq_pending) { + mask_updated = false; + goto done; + } + + origcmd = cmd_status_dword; + newcmd = origcmd & ~PCI_COMMAND_INTX_DISABLE; + if (mask) + newcmd |= PCI_COMMAND_INTX_DISABLE; + if (newcmd != origcmd) + bus->ops->write(bus, dev->devfn, PCI_COMMAND, 2, newcmd); + +done: + raw_spin_unlock_irqrestore(&pci_lock, flags); + + return mask_updated; +} + +/** + * pci_check_and_mask_intx - mask INTx on pending interrupt + * @dev: the PCI device to operate on + * + * Check if the device dev has its INTx line asserted, mask it and return + * true in that case. False is returned if no interrupt was pending. + */ +bool pci_check_and_mask_intx(struct pci_dev *dev) +{ + return pci_check_and_set_intx_mask(dev, true); +} +EXPORT_SYMBOL_GPL(pci_check_and_mask_intx); + +/** + * pci_check_and_unmask_intx - unmask INTx if no interrupt is pending + * @dev: the PCI device to operate on + * + * Check if the device dev has its INTx line asserted, unmask it if not and + * return true. False is returned and the mask remains active if there was + * still an interrupt pending. + */ +bool pci_check_and_unmask_intx(struct pci_dev *dev) +{ + return pci_check_and_set_intx_mask(dev, false); +} +EXPORT_SYMBOL_GPL(pci_check_and_unmask_intx); + +/** + * pci_wait_for_pending_transaction - wait for pending transaction + * @dev: the PCI device to operate on + * + * Return 0 if transaction is pending 1 otherwise. + */ +int pci_wait_for_pending_transaction(struct pci_dev *dev) +{ + if (!pci_is_pcie(dev)) + return 1; + + return pci_wait_for_pending(dev, pci_pcie_cap(dev) + PCI_EXP_DEVSTA, + PCI_EXP_DEVSTA_TRPND); +} +EXPORT_SYMBOL(pci_wait_for_pending_transaction); + +/** + * pcie_flr - initiate a PCIe function level reset + * @dev: device to reset + * + * Initiate a function level reset unconditionally on @dev without + * checking any flags and DEVCAP + */ +int pcie_flr(struct pci_dev *dev) +{ + if (!pci_wait_for_pending_transaction(dev)) + pci_err(dev, "timed out waiting for pending transaction; performing function level reset anyway\n"); + + pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_BCR_FLR); + + if (dev->imm_ready) + return 0; + + /* + * Per PCIe r4.0, sec 6.6.2, a device must complete an FLR within + * 100ms, but may silently discard requests while the FLR is in + * progress. Wait 100ms before trying to access the device. + */ + msleep(100); + + return pci_dev_wait(dev, "FLR", PCIE_RESET_READY_POLL_MS); +} +EXPORT_SYMBOL_GPL(pcie_flr); + +/** + * pcie_reset_flr - initiate a PCIe function level reset + * @dev: device to reset + * @probe: if true, return 0 if device can be reset this way + * + * Initiate a function level reset on @dev. + */ +int pcie_reset_flr(struct pci_dev *dev, bool probe) +{ + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) + return -ENOTTY; + + if (!(dev->devcap & PCI_EXP_DEVCAP_FLR)) + return -ENOTTY; + + if (probe) + return 0; + + return pcie_flr(dev); +} +EXPORT_SYMBOL_GPL(pcie_reset_flr); + +static int pci_af_flr(struct pci_dev *dev, bool probe) +{ + int pos; + u8 cap; + + pos = pci_find_capability(dev, PCI_CAP_ID_AF); + if (!pos) + return -ENOTTY; + + if (dev->dev_flags & PCI_DEV_FLAGS_NO_FLR_RESET) + return -ENOTTY; + + pci_read_config_byte(dev, pos + PCI_AF_CAP, &cap); + if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR)) + return -ENOTTY; + + if (probe) + return 0; + + /* + * Wait for Transaction Pending bit to clear. A word-aligned test + * is used, so we use the control offset rather than status and shift + * the test bit to match. + */ + if (!pci_wait_for_pending(dev, pos + PCI_AF_CTRL, + PCI_AF_STATUS_TP << 8)) + pci_err(dev, "timed out waiting for pending transaction; performing AF function level reset anyway\n"); + + pci_write_config_byte(dev, pos + PCI_AF_CTRL, PCI_AF_CTRL_FLR); + + if (dev->imm_ready) + return 0; + + /* + * Per Advanced Capabilities for Conventional PCI ECN, 13 April 2006, + * updated 27 July 2006; a device must complete an FLR within + * 100ms, but may silently discard requests while the FLR is in + * progress. Wait 100ms before trying to access the device. + */ + msleep(100); + + return pci_dev_wait(dev, "AF_FLR", PCIE_RESET_READY_POLL_MS); +} + +/** + * pci_pm_reset - Put device into PCI_D3 and back into PCI_D0. + * @dev: Device to reset. + * @probe: if true, return 0 if the device can be reset this way. + * + * If @dev supports native PCI PM and its PCI_PM_CTRL_NO_SOFT_RESET flag is + * unset, it will be reinitialized internally when going from PCI_D3hot to + * PCI_D0. If that's the case and the device is not in a low-power state + * already, force it into PCI_D3hot and back to PCI_D0, causing it to be reset. + * + * NOTE: This causes the caller to sleep for twice the device power transition + * cooldown period, which for the D0->D3hot and D3hot->D0 transitions is 10 ms + * by default (i.e. unless the @dev's d3hot_delay field has a different value). + * Moreover, only devices in D0 can be reset by this function. + */ +static int pci_pm_reset(struct pci_dev *dev, bool probe) +{ + u16 csr; + + if (!dev->pm_cap || dev->dev_flags & PCI_DEV_FLAGS_NO_PM_RESET) + return -ENOTTY; + + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &csr); + if (csr & PCI_PM_CTRL_NO_SOFT_RESET) + return -ENOTTY; + + if (probe) + return 0; + + if (dev->current_state != PCI_D0) + return -EINVAL; + + csr &= ~PCI_PM_CTRL_STATE_MASK; + csr |= PCI_D3hot; + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr); + pci_dev_d3_sleep(dev); + + csr &= ~PCI_PM_CTRL_STATE_MASK; + csr |= PCI_D0; + pci_write_config_word(dev, dev->pm_cap + PCI_PM_CTRL, csr); + pci_dev_d3_sleep(dev); + + return pci_dev_wait(dev, "PM D3hot->D0", PCIE_RESET_READY_POLL_MS); +} + +/** + * pcie_wait_for_link_delay - Wait until link is active or inactive + * @pdev: Bridge device + * @active: waiting for active or inactive? + * @delay: Delay to wait after link has become active (in ms) + * + * Use this to wait till link becomes active or inactive. + */ +static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, + int delay) +{ + int timeout = 1000; + bool ret; + u16 lnk_status; + + /* + * Some controllers might not implement link active reporting. In this + * case, we wait for 1000 ms + any delay requested by the caller. + */ + if (!pdev->link_active_reporting) { + msleep(timeout + delay); + return true; + } + + /* + * PCIe r4.0 sec 6.6.1, a component must enter LTSSM Detect within 20ms, + * after which we should expect an link active if the reset was + * successful. If so, software must wait a minimum 100ms before sending + * configuration requests to devices downstream this port. + * + * If the link fails to activate, either the device was physically + * removed or the link is permanently failed. + */ + if (active) + msleep(20); + for (;;) { + pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); + ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); + if (ret == active) + break; + if (timeout <= 0) + break; + msleep(10); + timeout -= 10; + } + if (active && ret) + msleep(delay); + + return ret == active; +} + +/** + * pcie_wait_for_link - Wait until link is active or inactive + * @pdev: Bridge device + * @active: waiting for active or inactive? + * + * Use this to wait till link becomes active or inactive. + */ +bool pcie_wait_for_link(struct pci_dev *pdev, bool active) +{ + return pcie_wait_for_link_delay(pdev, active, 100); +} + +/* + * Find maximum D3cold delay required by all the devices on the bus. The + * spec says 100 ms, but firmware can lower it and we allow drivers to + * increase it as well. + * + * Called with @pci_bus_sem locked for reading. + */ +static int pci_bus_max_d3cold_delay(const struct pci_bus *bus) +{ + const struct pci_dev *pdev; + int min_delay = 100; + int max_delay = 0; + + list_for_each_entry(pdev, &bus->devices, bus_list) { + if (pdev->d3cold_delay < min_delay) + min_delay = pdev->d3cold_delay; + if (pdev->d3cold_delay > max_delay) + max_delay = pdev->d3cold_delay; + } + + return max(min_delay, max_delay); +} + +/** + * pci_bridge_wait_for_secondary_bus - Wait for secondary bus to be accessible + * @dev: PCI bridge + * @reset_type: reset type in human-readable form + * @timeout: maximum time to wait for devices on secondary bus (milliseconds) + * + * Handle necessary delays before access to the devices on the secondary + * side of the bridge are permitted after D3cold to D0 transition + * or Conventional Reset. + * + * For PCIe this means the delays in PCIe 5.0 section 6.6.1. For + * conventional PCI it means Tpvrh + Trhfa specified in PCI 3.0 section + * 4.3.2. + * + * Return 0 on success or -ENOTTY if the first device on the secondary bus + * failed to become accessible. + */ +int pci_bridge_wait_for_secondary_bus(struct pci_dev *dev, char *reset_type, + int timeout) +{ + struct pci_dev *child; + int delay; + + if (pci_dev_is_disconnected(dev)) + return 0; + + if (!pci_is_bridge(dev)) + return 0; + + down_read(&pci_bus_sem); + + /* + * We only deal with devices that are present currently on the bus. + * For any hot-added devices the access delay is handled in pciehp + * board_added(). In case of ACPI hotplug the firmware is expected + * to configure the devices before OS is notified. + */ + if (!dev->subordinate || list_empty(&dev->subordinate->devices)) { + up_read(&pci_bus_sem); + return 0; + } + + /* Take d3cold_delay requirements into account */ + delay = pci_bus_max_d3cold_delay(dev->subordinate); + if (!delay) { + up_read(&pci_bus_sem); + return 0; + } + + child = list_first_entry(&dev->subordinate->devices, struct pci_dev, + bus_list); + up_read(&pci_bus_sem); + + /* + * Conventional PCI and PCI-X we need to wait Tpvrh + Trhfa before + * accessing the device after reset (that is 1000 ms + 100 ms). + */ + if (!pci_is_pcie(dev)) { + pci_dbg(dev, "waiting %d ms for secondary bus\n", 1000 + delay); + msleep(1000 + delay); + return 0; + } + + /* + * For PCIe downstream and root ports that do not support speeds + * greater than 5 GT/s need to wait minimum 100 ms. For higher + * speeds (gen3) we need to wait first for the data link layer to + * become active. + * + * However, 100 ms is the minimum and the PCIe spec says the + * software must allow at least 1s before it can determine that the + * device that did not respond is a broken device. There is + * evidence that 100 ms is not always enough, for example certain + * Titan Ridge xHCI controller does not always respond to + * configuration requests if we only wait for 100 ms (see + * https://bugzilla.kernel.org/show_bug.cgi?id=203885). + * + * Therefore we wait for 100 ms and check for the device presence + * until the timeout expires. + */ + if (!pcie_downstream_port(dev)) + return 0; + + if (pcie_get_speed_cap(dev) <= PCIE_SPEED_5_0GT) { + pci_dbg(dev, "waiting %d ms for downstream link\n", delay); + msleep(delay); + } else { + pci_dbg(dev, "waiting %d ms for downstream link, after activation\n", + delay); + if (!pcie_wait_for_link_delay(dev, true, delay)) { + /* Did not train, no need to wait any further */ + pci_info(dev, "Data Link Layer Link Active not set in 1000 msec\n"); + return -ENOTTY; + } + } + + return pci_dev_wait(child, reset_type, timeout - delay); +} + +void pci_reset_secondary_bus(struct pci_dev *dev) +{ + u16 ctrl; + + pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &ctrl); + ctrl |= PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); + + /* + * PCI spec v3.0 7.6.4.2 requires minimum Trst of 1ms. Double + * this to 2ms to ensure that we meet the minimum requirement. + */ + msleep(2); + + ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET; + pci_write_config_word(dev, PCI_BRIDGE_CONTROL, ctrl); +} + +void __weak pcibios_reset_secondary_bus(struct pci_dev *dev) +{ + pci_reset_secondary_bus(dev); +} + +/** + * pci_bridge_secondary_bus_reset - Reset the secondary bus on a PCI bridge. + * @dev: Bridge device + * + * Use the bridge control register to assert reset on the secondary bus. + * Devices on the secondary bus are left in power-on state. + */ +int pci_bridge_secondary_bus_reset(struct pci_dev *dev) +{ + pcibios_reset_secondary_bus(dev); + + return pci_bridge_wait_for_secondary_bus(dev, "bus reset", + PCIE_RESET_READY_POLL_MS); +} +EXPORT_SYMBOL_GPL(pci_bridge_secondary_bus_reset); + +static int pci_parent_bus_reset(struct pci_dev *dev, bool probe) +{ + struct pci_dev *pdev; + + if (pci_is_root_bus(dev->bus) || dev->subordinate || + !dev->bus->self || dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) + return -ENOTTY; + + list_for_each_entry(pdev, &dev->bus->devices, bus_list) + if (pdev != dev) + return -ENOTTY; + + if (probe) + return 0; + + return pci_bridge_secondary_bus_reset(dev->bus->self); +} + +static int pci_reset_hotplug_slot(struct hotplug_slot *hotplug, bool probe) +{ + int rc = -ENOTTY; + + if (!hotplug || !try_module_get(hotplug->owner)) + return rc; + + if (hotplug->ops->reset_slot) + rc = hotplug->ops->reset_slot(hotplug, probe); + + module_put(hotplug->owner); + + return rc; +} + +static int pci_dev_reset_slot_function(struct pci_dev *dev, bool probe) +{ + if (dev->multifunction || dev->subordinate || !dev->slot || + dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET) + return -ENOTTY; + + return pci_reset_hotplug_slot(dev->slot->hotplug, probe); +} + +static int pci_reset_bus_function(struct pci_dev *dev, bool probe) +{ + int rc; + + rc = pci_dev_reset_slot_function(dev, probe); + if (rc != -ENOTTY) + return rc; + return pci_parent_bus_reset(dev, probe); +} + +void pci_dev_lock(struct pci_dev *dev) +{ + /* block PM suspend, driver probe, etc. */ + device_lock(&dev->dev); + pci_cfg_access_lock(dev); +} +EXPORT_SYMBOL_GPL(pci_dev_lock); + +/* Return 1 on successful lock, 0 on contention */ +int pci_dev_trylock(struct pci_dev *dev) +{ + if (device_trylock(&dev->dev)) { + if (pci_cfg_access_trylock(dev)) + return 1; + device_unlock(&dev->dev); + } + + return 0; +} +EXPORT_SYMBOL_GPL(pci_dev_trylock); + +void pci_dev_unlock(struct pci_dev *dev) +{ + pci_cfg_access_unlock(dev); + device_unlock(&dev->dev); +} +EXPORT_SYMBOL_GPL(pci_dev_unlock); + +static void pci_dev_save_and_disable(struct pci_dev *dev) +{ + const struct pci_error_handlers *err_handler = + dev->driver ? dev->driver->err_handler : NULL; + + /* + * dev->driver->err_handler->reset_prepare() is protected against + * races with ->remove() by the device lock, which must be held by + * the caller. + */ + if (err_handler && err_handler->reset_prepare) + err_handler->reset_prepare(dev); + + /* + * Wake-up device prior to save. PM registers default to D0 after + * reset and a simple register restore doesn't reliably return + * to a non-D0 state anyway. + */ + pci_set_power_state(dev, PCI_D0); + + pci_save_state(dev); + /* + * Disable the device by clearing the Command register, except for + * INTx-disable which is set. This not only disables MMIO and I/O port + * BARs, but also prevents the device from being Bus Master, preventing + * DMA from the device including MSI/MSI-X interrupts. For PCI 2.3 + * compliant devices, INTx-disable prevents legacy interrupts. + */ + pci_write_config_word(dev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); +} + +static void pci_dev_restore(struct pci_dev *dev) +{ + const struct pci_error_handlers *err_handler = + dev->driver ? dev->driver->err_handler : NULL; + + pci_restore_state(dev); + + /* + * dev->driver->err_handler->reset_done() is protected against + * races with ->remove() by the device lock, which must be held by + * the caller. + */ + if (err_handler && err_handler->reset_done) + err_handler->reset_done(dev); +} + +/* dev->reset_methods[] is a 0-terminated list of indices into this array */ +static const struct pci_reset_fn_method pci_reset_fn_methods[] = { + { }, + { pci_dev_specific_reset, .name = "device_specific" }, + { pci_dev_acpi_reset, .name = "acpi" }, + { pcie_reset_flr, .name = "flr" }, + { pci_af_flr, .name = "af_flr" }, + { pci_pm_reset, .name = "pm" }, + { pci_reset_bus_function, .name = "bus" }, +}; + +static ssize_t reset_method_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct pci_dev *pdev = to_pci_dev(dev); + ssize_t len = 0; + int i, m; + + for (i = 0; i < PCI_NUM_RESET_METHODS; i++) { + m = pdev->reset_methods[i]; + if (!m) + break; + + len += sysfs_emit_at(buf, len, "%s%s", len ? " " : "", + pci_reset_fn_methods[m].name); + } + + if (len) + len += sysfs_emit_at(buf, len, "\n"); + + return len; +} + +static int reset_method_lookup(const char *name) +{ + int m; + + for (m = 1; m < PCI_NUM_RESET_METHODS; m++) { + if (sysfs_streq(name, pci_reset_fn_methods[m].name)) + return m; + } + + return 0; /* not found */ +} + +static ssize_t reset_method_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pci_dev *pdev = to_pci_dev(dev); + char *options, *name; + int m, n; + u8 reset_methods[PCI_NUM_RESET_METHODS] = { 0 }; + + if (sysfs_streq(buf, "")) { + pdev->reset_methods[0] = 0; + pci_warn(pdev, "All device reset methods disabled by user"); + return count; + } + + if (sysfs_streq(buf, "default")) { + pci_init_reset_methods(pdev); + return count; + } + + options = kstrndup(buf, count, GFP_KERNEL); + if (!options) + return -ENOMEM; + + n = 0; + while ((name = strsep(&options, " ")) != NULL) { + if (sysfs_streq(name, "")) + continue; + + name = strim(name); + + m = reset_method_lookup(name); + if (!m) { + pci_err(pdev, "Invalid reset method '%s'", name); + goto error; + } + + if (pci_reset_fn_methods[m].reset_fn(pdev, PCI_RESET_PROBE)) { + pci_err(pdev, "Unsupported reset method '%s'", name); + goto error; + } + + if (n == PCI_NUM_RESET_METHODS - 1) { + pci_err(pdev, "Too many reset methods\n"); + goto error; + } + + reset_methods[n++] = m; + } + + reset_methods[n] = 0; + + /* Warn if dev-specific supported but not highest priority */ + if (pci_reset_fn_methods[1].reset_fn(pdev, PCI_RESET_PROBE) == 0 && + reset_methods[0] != 1) + pci_warn(pdev, "Device-specific reset disabled/de-prioritized by user"); + memcpy(pdev->reset_methods, reset_methods, sizeof(pdev->reset_methods)); + kfree(options); + return count; + +error: + /* Leave previous methods unchanged */ + kfree(options); + return -EINVAL; +} +static DEVICE_ATTR_RW(reset_method); + +static struct attribute *pci_dev_reset_method_attrs[] = { + &dev_attr_reset_method.attr, + NULL, +}; + +static umode_t pci_dev_reset_method_attr_is_visible(struct kobject *kobj, + struct attribute *a, int n) +{ + struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); + + if (!pci_reset_supported(pdev)) + return 0; + + return a->mode; +} + +const struct attribute_group pci_dev_reset_method_attr_group = { + .attrs = pci_dev_reset_method_attrs, + .is_visible = pci_dev_reset_method_attr_is_visible, +}; + +/** + * __pci_reset_function_locked - reset a PCI device function while holding + * the @dev mutex lock. + * @dev: PCI device to reset + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be responsive + * to PCI config space in order to use this function. + * + * The device function is presumed to be unused and the caller is holding + * the device mutex lock when this function is called. + * + * Resetting the device will make the contents of PCI configuration space + * random, so any caller of this must be prepared to reinitialise the + * device including MSI, bus mastering, BARs, decoding IO and memory spaces, + * etc. + * + * Returns 0 if the device function was successfully reset or negative if the + * device doesn't support resetting a single function. + */ +int __pci_reset_function_locked(struct pci_dev *dev) +{ + int i, m, rc; + + might_sleep(); + + /* + * A reset method returns -ENOTTY if it doesn't support this device and + * we should try the next method. + * + * If it returns 0 (success), we're finished. If it returns any other + * error, we're also finished: this indicates that further reset + * mechanisms might be broken on the device. + */ + for (i = 0; i < PCI_NUM_RESET_METHODS; i++) { + m = dev->reset_methods[i]; + if (!m) + return -ENOTTY; + + rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_DO_RESET); + if (!rc) + return 0; + if (rc != -ENOTTY) + return rc; + } + + return -ENOTTY; +} +EXPORT_SYMBOL_GPL(__pci_reset_function_locked); + +/** + * pci_init_reset_methods - check whether device can be safely reset + * and store supported reset mechanisms. + * @dev: PCI device to check for reset mechanisms + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be in D0-D3hot + * state. + * + * Stores reset mechanisms supported by device in reset_methods byte array + * which is a member of struct pci_dev. + */ +void pci_init_reset_methods(struct pci_dev *dev) +{ + int m, i, rc; + + BUILD_BUG_ON(ARRAY_SIZE(pci_reset_fn_methods) != PCI_NUM_RESET_METHODS); + + might_sleep(); + + i = 0; + for (m = 1; m < PCI_NUM_RESET_METHODS; m++) { + rc = pci_reset_fn_methods[m].reset_fn(dev, PCI_RESET_PROBE); + if (!rc) + dev->reset_methods[i++] = m; + else if (rc != -ENOTTY) + break; + } + + dev->reset_methods[i] = 0; +} + +/** + * pci_reset_function - quiesce and reset a PCI device function + * @dev: PCI device to reset + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be responsive + * to PCI config space in order to use this function. + * + * This function does not just reset the PCI portion of a device, but + * clears all the state associated with the device. This function differs + * from __pci_reset_function_locked() in that it saves and restores device state + * over the reset and takes the PCI device lock. + * + * Returns 0 if the device function was successfully reset or negative if the + * device doesn't support resetting a single function. + */ +int pci_reset_function(struct pci_dev *dev) +{ + int rc; + + if (!pci_reset_supported(dev)) + return -ENOTTY; + + pci_dev_lock(dev); + pci_dev_save_and_disable(dev); + + rc = __pci_reset_function_locked(dev); + + pci_dev_restore(dev); + pci_dev_unlock(dev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_function); + +/** + * pci_reset_function_locked - quiesce and reset a PCI device function + * @dev: PCI device to reset + * + * Some devices allow an individual function to be reset without affecting + * other functions in the same device. The PCI device must be responsive + * to PCI config space in order to use this function. + * + * This function does not just reset the PCI portion of a device, but + * clears all the state associated with the device. This function differs + * from __pci_reset_function_locked() in that it saves and restores device state + * over the reset. It also differs from pci_reset_function() in that it + * requires the PCI device lock to be held. + * + * Returns 0 if the device function was successfully reset or negative if the + * device doesn't support resetting a single function. + */ +int pci_reset_function_locked(struct pci_dev *dev) +{ + int rc; + + if (!pci_reset_supported(dev)) + return -ENOTTY; + + pci_dev_save_and_disable(dev); + + rc = __pci_reset_function_locked(dev); + + pci_dev_restore(dev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_reset_function_locked); + +/** + * pci_try_reset_function - quiesce and reset a PCI device function + * @dev: PCI device to reset + * + * Same as above, except return -EAGAIN if unable to lock device. + */ +int pci_try_reset_function(struct pci_dev *dev) +{ + int rc; + + if (!pci_reset_supported(dev)) + return -ENOTTY; + + if (!pci_dev_trylock(dev)) + return -EAGAIN; + + pci_dev_save_and_disable(dev); + rc = __pci_reset_function_locked(dev); + pci_dev_restore(dev); + pci_dev_unlock(dev); + + return rc; +} +EXPORT_SYMBOL_GPL(pci_try_reset_function); + +/* Do any devices on or below this bus prevent a bus reset? */ +static bool pci_bus_resetable(struct pci_bus *bus) +{ + struct pci_dev *dev; + + + if (bus->self && (bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) + return false; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || + (dev->subordinate && !pci_bus_resetable(dev->subordinate))) + return false; + } + + return true; +} + +/* Lock devices from the top of the tree down */ +static void pci_bus_lock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_bus_unlock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Return 1 on successful lock, 0 on contention */ +static int pci_bus_trylock(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + if (!pci_dev_trylock(dev)) + goto unlock; + if (dev->subordinate) { + if (!pci_bus_trylock(dev->subordinate)) { + pci_dev_unlock(dev); + goto unlock; + } + } + } + return 1; + +unlock: + list_for_each_entry_continue_reverse(dev, &bus->devices, bus_list) { + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } + return 0; +} + +/* Do any devices on or below this slot prevent a bus reset? */ +static bool pci_slot_resetable(struct pci_slot *slot) +{ + struct pci_dev *dev; + + if (slot->bus->self && + (slot->bus->self->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET)) + return false; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (dev->dev_flags & PCI_DEV_FLAGS_NO_BUS_RESET || + (dev->subordinate && !pci_bus_resetable(dev->subordinate))) + return false; + } + + return true; +} + +/* Lock devices from the top of the tree down */ +static void pci_slot_lock(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_lock(dev); + if (dev->subordinate) + pci_bus_lock(dev->subordinate); + } +} + +/* Unlock devices from the bottom of the tree up */ +static void pci_slot_unlock(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } +} + +/* Return 1 on successful lock, 0 on contention */ +static int pci_slot_trylock(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (!pci_dev_trylock(dev)) + goto unlock; + if (dev->subordinate) { + if (!pci_bus_trylock(dev->subordinate)) { + pci_dev_unlock(dev); + goto unlock; + } + } + } + return 1; + +unlock: + list_for_each_entry_continue_reverse(dev, + &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + if (dev->subordinate) + pci_bus_unlock(dev->subordinate); + pci_dev_unlock(dev); + } + return 0; +} + +/* + * Save and disable devices from the top of the tree down while holding + * the @dev mutex lock for the entire tree. + */ +static void pci_bus_save_and_disable_locked(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable_locked(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down while holding @dev mutex lock + * for the entire tree. Parent bridges need to be restored before we can + * get to subordinate devices. + */ +static void pci_bus_restore_locked(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore_locked(dev->subordinate); + } +} + +/* + * Save and disable devices from the top of the tree down while holding + * the @dev mutex lock for the entire tree. + */ +static void pci_slot_save_and_disable_locked(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_save_and_disable(dev); + if (dev->subordinate) + pci_bus_save_and_disable_locked(dev->subordinate); + } +} + +/* + * Restore devices from top of the tree down while holding @dev mutex lock + * for the entire tree. Parent bridges need to be restored before we can + * get to subordinate devices. + */ +static void pci_slot_restore_locked(struct pci_slot *slot) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &slot->bus->devices, bus_list) { + if (!dev->slot || dev->slot != slot) + continue; + pci_dev_restore(dev); + if (dev->subordinate) + pci_bus_restore_locked(dev->subordinate); + } +} + +static int pci_slot_reset(struct pci_slot *slot, bool probe) +{ + int rc; + + if (!slot || !pci_slot_resetable(slot)) + return -ENOTTY; + + if (!probe) + pci_slot_lock(slot); + + might_sleep(); + + rc = pci_reset_hotplug_slot(slot->hotplug, probe); + + if (!probe) + pci_slot_unlock(slot); + + return rc; +} + +/** + * pci_probe_reset_slot - probe whether a PCI slot can be reset + * @slot: PCI slot to probe + * + * Return 0 if slot can be reset, negative if a slot reset is not supported. + */ +int pci_probe_reset_slot(struct pci_slot *slot) +{ + return pci_slot_reset(slot, PCI_RESET_PROBE); +} +EXPORT_SYMBOL_GPL(pci_probe_reset_slot); + +/** + * __pci_reset_slot - Try to reset a PCI slot + * @slot: PCI slot to reset + * + * A PCI bus may host multiple slots, each slot may support a reset mechanism + * independent of other slots. For instance, some slots may support slot power + * control. In the case of a 1:1 bus to slot architecture, this function may + * wrap the bus reset to avoid spurious slot related events such as hotplug. + * Generally a slot reset should be attempted before a bus reset. All of the + * function of the slot and any subordinate buses behind the slot are reset + * through this function. PCI config space of all devices in the slot and + * behind the slot is saved before and restored after reset. + * + * Same as above except return -EAGAIN if the slot cannot be locked + */ +static int __pci_reset_slot(struct pci_slot *slot) +{ + int rc; + + rc = pci_slot_reset(slot, PCI_RESET_PROBE); + if (rc) + return rc; + + if (pci_slot_trylock(slot)) { + pci_slot_save_and_disable_locked(slot); + might_sleep(); + rc = pci_reset_hotplug_slot(slot->hotplug, PCI_RESET_DO_RESET); + pci_slot_restore_locked(slot); + pci_slot_unlock(slot); + } else + rc = -EAGAIN; + + return rc; +} + +static int pci_bus_reset(struct pci_bus *bus, bool probe) +{ + int ret; + + if (!bus->self || !pci_bus_resetable(bus)) + return -ENOTTY; + + if (probe) + return 0; + + pci_bus_lock(bus); + + might_sleep(); + + ret = pci_bridge_secondary_bus_reset(bus->self); + + pci_bus_unlock(bus); + + return ret; +} + +/** + * pci_bus_error_reset - reset the bridge's subordinate bus + * @bridge: The parent device that connects to the bus to reset + * + * This function will first try to reset the slots on this bus if the method is + * available. If slot reset fails or is not available, this will fall back to a + * secondary bus reset. + */ +int pci_bus_error_reset(struct pci_dev *bridge) +{ + struct pci_bus *bus = bridge->subordinate; + struct pci_slot *slot; + + if (!bus) + return -ENOTTY; + + mutex_lock(&pci_slot_mutex); + if (list_empty(&bus->slots)) + goto bus_reset; + + list_for_each_entry(slot, &bus->slots, list) + if (pci_probe_reset_slot(slot)) + goto bus_reset; + + list_for_each_entry(slot, &bus->slots, list) + if (pci_slot_reset(slot, PCI_RESET_DO_RESET)) + goto bus_reset; + + mutex_unlock(&pci_slot_mutex); + return 0; +bus_reset: + mutex_unlock(&pci_slot_mutex); + return pci_bus_reset(bridge->subordinate, PCI_RESET_DO_RESET); +} + +/** + * pci_probe_reset_bus - probe whether a PCI bus can be reset + * @bus: PCI bus to probe + * + * Return 0 if bus can be reset, negative if a bus reset is not supported. + */ +int pci_probe_reset_bus(struct pci_bus *bus) +{ + return pci_bus_reset(bus, PCI_RESET_PROBE); +} +EXPORT_SYMBOL_GPL(pci_probe_reset_bus); + +/** + * __pci_reset_bus - Try to reset a PCI bus + * @bus: top level PCI bus to reset + * + * Same as above except return -EAGAIN if the bus cannot be locked + */ +static int __pci_reset_bus(struct pci_bus *bus) +{ + int rc; + + rc = pci_bus_reset(bus, PCI_RESET_PROBE); + if (rc) + return rc; + + if (pci_bus_trylock(bus)) { + pci_bus_save_and_disable_locked(bus); + might_sleep(); + rc = pci_bridge_secondary_bus_reset(bus->self); + pci_bus_restore_locked(bus); + pci_bus_unlock(bus); + } else + rc = -EAGAIN; + + return rc; +} + +/** + * pci_reset_bus - Try to reset a PCI bus + * @pdev: top level PCI device to reset via slot/bus + * + * Same as above except return -EAGAIN if the bus cannot be locked + */ +int pci_reset_bus(struct pci_dev *pdev) +{ + return (!pci_probe_reset_slot(pdev->slot)) ? + __pci_reset_slot(pdev->slot) : __pci_reset_bus(pdev->bus); +} +EXPORT_SYMBOL_GPL(pci_reset_bus); + +/** + * pcix_get_max_mmrbc - get PCI-X maximum designed memory read byte count + * @dev: PCI device to query + * + * Returns mmrbc: maximum designed memory read count in bytes or + * appropriate error value. + */ +int pcix_get_max_mmrbc(struct pci_dev *dev) +{ + int cap; + u32 stat; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + return -EINVAL; + + if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat)) + return -EINVAL; + + return 512 << ((stat & PCI_X_STATUS_MAX_READ) >> 21); +} +EXPORT_SYMBOL(pcix_get_max_mmrbc); + +/** + * pcix_get_mmrbc - get PCI-X maximum memory read byte count + * @dev: PCI device to query + * + * Returns mmrbc: maximum memory read count in bytes or appropriate error + * value. + */ +int pcix_get_mmrbc(struct pci_dev *dev) +{ + int cap; + u16 cmd; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + return -EINVAL; + + if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd)) + return -EINVAL; + + return 512 << ((cmd & PCI_X_CMD_MAX_READ) >> 2); +} +EXPORT_SYMBOL(pcix_get_mmrbc); + +/** + * pcix_set_mmrbc - set PCI-X maximum memory read byte count + * @dev: PCI device to query + * @mmrbc: maximum memory read count in bytes + * valid values are 512, 1024, 2048, 4096 + * + * If possible sets maximum memory read byte count, some bridges have errata + * that prevent this. + */ +int pcix_set_mmrbc(struct pci_dev *dev, int mmrbc) +{ + int cap; + u32 stat, v, o; + u16 cmd; + + if (mmrbc < 512 || mmrbc > 4096 || !is_power_of_2(mmrbc)) + return -EINVAL; + + v = ffs(mmrbc) - 10; + + cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); + if (!cap) + return -EINVAL; + + if (pci_read_config_dword(dev, cap + PCI_X_STATUS, &stat)) + return -EINVAL; + + if (v > (stat & PCI_X_STATUS_MAX_READ) >> 21) + return -E2BIG; + + if (pci_read_config_word(dev, cap + PCI_X_CMD, &cmd)) + return -EINVAL; + + o = (cmd & PCI_X_CMD_MAX_READ) >> 2; + if (o != v) { + if (v > o && (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_MMRBC)) + return -EIO; + + cmd &= ~PCI_X_CMD_MAX_READ; + cmd |= v << 2; + if (pci_write_config_word(dev, cap + PCI_X_CMD, cmd)) + return -EIO; + } + return 0; +} +EXPORT_SYMBOL(pcix_set_mmrbc); + +/** + * pcie_get_readrq - get PCI Express read request size + * @dev: PCI device to query + * + * Returns maximum memory read request in bytes or appropriate error value. + */ +int pcie_get_readrq(struct pci_dev *dev) +{ + u16 ctl; + + pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); + + return 128 << ((ctl & PCI_EXP_DEVCTL_READRQ) >> 12); +} +EXPORT_SYMBOL(pcie_get_readrq); + +/** + * pcie_set_readrq - set PCI Express maximum memory read request + * @dev: PCI device to query + * @rq: maximum memory read count in bytes + * valid values are 128, 256, 512, 1024, 2048, 4096 + * + * If possible sets maximum memory read request in bytes + */ +int pcie_set_readrq(struct pci_dev *dev, int rq) +{ + u16 v; + int ret; + struct pci_host_bridge *bridge = pci_find_host_bridge(dev->bus); + + if (rq < 128 || rq > 4096 || !is_power_of_2(rq)) + return -EINVAL; + + /* + * If using the "performance" PCIe config, we clamp the read rq + * size to the max packet size to keep the host bridge from + * generating requests larger than we can cope with. + */ + if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { + int mps = pcie_get_mps(dev); + + if (mps < rq) + rq = mps; + } + + v = (ffs(rq) - 8) << 12; + + if (bridge->no_inc_mrrs) { + int max_mrrs = pcie_get_readrq(dev); + + if (rq > max_mrrs) { + pci_info(dev, "can't set Max_Read_Request_Size to %d; max is %d\n", rq, max_mrrs); + return -EINVAL; + } + } + + ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_READRQ, v); + + return pcibios_err_to_errno(ret); +} +EXPORT_SYMBOL(pcie_set_readrq); + +/** + * pcie_get_mps - get PCI Express maximum payload size + * @dev: PCI device to query + * + * Returns maximum payload size in bytes + */ +int pcie_get_mps(struct pci_dev *dev) +{ + u16 ctl; + + pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); + + return 128 << ((ctl & PCI_EXP_DEVCTL_PAYLOAD) >> 5); +} +EXPORT_SYMBOL(pcie_get_mps); + +/** + * pcie_set_mps - set PCI Express maximum payload size + * @dev: PCI device to query + * @mps: maximum payload size in bytes + * valid values are 128, 256, 512, 1024, 2048, 4096 + * + * If possible sets maximum payload size + */ +int pcie_set_mps(struct pci_dev *dev, int mps) +{ + u16 v; + int ret; + + if (mps < 128 || mps > 4096 || !is_power_of_2(mps)) + return -EINVAL; + + v = ffs(mps) - 8; + if (v > dev->pcie_mpss) + return -EINVAL; + v <<= 5; + + ret = pcie_capability_clear_and_set_word(dev, PCI_EXP_DEVCTL, + PCI_EXP_DEVCTL_PAYLOAD, v); + + return pcibios_err_to_errno(ret); +} +EXPORT_SYMBOL(pcie_set_mps); + +/** + * pcie_bandwidth_available - determine minimum link settings of a PCIe + * device and its bandwidth limitation + * @dev: PCI device to query + * @limiting_dev: storage for device causing the bandwidth limitation + * @speed: storage for speed of limiting device + * @width: storage for width of limiting device + * + * Walk up the PCI device chain and find the point where the minimum + * bandwidth is available. Return the bandwidth available there and (if + * limiting_dev, speed, and width pointers are supplied) information about + * that point. The bandwidth returned is in Mb/s, i.e., megabits/second of + * raw bandwidth. + */ +u32 pcie_bandwidth_available(struct pci_dev *dev, struct pci_dev **limiting_dev, + enum pci_bus_speed *speed, + enum pcie_link_width *width) +{ + u16 lnksta; + enum pci_bus_speed next_speed; + enum pcie_link_width next_width; + u32 bw, next_bw; + + if (speed) + *speed = PCI_SPEED_UNKNOWN; + if (width) + *width = PCIE_LNK_WIDTH_UNKNOWN; + + bw = 0; + + while (dev) { + pcie_capability_read_word(dev, PCI_EXP_LNKSTA, &lnksta); + + next_speed = pcie_link_speed[lnksta & PCI_EXP_LNKSTA_CLS]; + next_width = FIELD_GET(PCI_EXP_LNKSTA_NLW, lnksta); + + next_bw = next_width * PCIE_SPEED2MBS_ENC(next_speed); + + /* Check if current device limits the total bandwidth */ + if (!bw || next_bw <= bw) { + bw = next_bw; + + if (limiting_dev) + *limiting_dev = dev; + if (speed) + *speed = next_speed; + if (width) + *width = next_width; + } + + dev = pci_upstream_bridge(dev); + } + + return bw; +} +EXPORT_SYMBOL(pcie_bandwidth_available); + +/** + * pcie_get_speed_cap - query for the PCI device's link speed capability + * @dev: PCI device to query + * + * Query the PCI device speed capability. Return the maximum link speed + * supported by the device. + */ +enum pci_bus_speed pcie_get_speed_cap(struct pci_dev *dev) +{ + u32 lnkcap2, lnkcap; + + /* + * Link Capabilities 2 was added in PCIe r3.0, sec 7.8.18. The + * implementation note there recommends using the Supported Link + * Speeds Vector in Link Capabilities 2 when supported. + * + * Without Link Capabilities 2, i.e., prior to PCIe r3.0, software + * should use the Supported Link Speeds field in Link Capabilities, + * where only 2.5 GT/s and 5.0 GT/s speeds were defined. + */ + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP2, &lnkcap2); + + /* PCIe r3.0-compliant */ + if (lnkcap2) + return PCIE_LNKCAP2_SLS2SPEED(lnkcap2); + + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_5_0GB) + return PCIE_SPEED_5_0GT; + else if ((lnkcap & PCI_EXP_LNKCAP_SLS) == PCI_EXP_LNKCAP_SLS_2_5GB) + return PCIE_SPEED_2_5GT; + + return PCI_SPEED_UNKNOWN; +} +EXPORT_SYMBOL(pcie_get_speed_cap); + +/** + * pcie_get_width_cap - query for the PCI device's link width capability + * @dev: PCI device to query + * + * Query the PCI device width capability. Return the maximum link width + * supported by the device. + */ +enum pcie_link_width pcie_get_width_cap(struct pci_dev *dev) +{ + u32 lnkcap; + + pcie_capability_read_dword(dev, PCI_EXP_LNKCAP, &lnkcap); + if (lnkcap) + return FIELD_GET(PCI_EXP_LNKCAP_MLW, lnkcap); + + return PCIE_LNK_WIDTH_UNKNOWN; +} +EXPORT_SYMBOL(pcie_get_width_cap); + +/** + * pcie_bandwidth_capable - calculate a PCI device's link bandwidth capability + * @dev: PCI device + * @speed: storage for link speed + * @width: storage for link width + * + * Calculate a PCI device's link bandwidth by querying for its link speed + * and width, multiplying them, and applying encoding overhead. The result + * is in Mb/s, i.e., megabits/second of raw bandwidth. + */ +u32 pcie_bandwidth_capable(struct pci_dev *dev, enum pci_bus_speed *speed, + enum pcie_link_width *width) +{ + *speed = pcie_get_speed_cap(dev); + *width = pcie_get_width_cap(dev); + + if (*speed == PCI_SPEED_UNKNOWN || *width == PCIE_LNK_WIDTH_UNKNOWN) + return 0; + + return *width * PCIE_SPEED2MBS_ENC(*speed); +} + +/** + * __pcie_print_link_status - Report the PCI device's link speed and width + * @dev: PCI device to query + * @verbose: Print info even when enough bandwidth is available + * + * If the available bandwidth at the device is less than the device is + * capable of, report the device's maximum possible bandwidth and the + * upstream link that limits its performance. If @verbose, always print + * the available bandwidth, even if the device isn't constrained. + */ +void __pcie_print_link_status(struct pci_dev *dev, bool verbose) +{ + enum pcie_link_width width, width_cap; + enum pci_bus_speed speed, speed_cap; + struct pci_dev *limiting_dev = NULL; + u32 bw_avail, bw_cap; + + bw_cap = pcie_bandwidth_capable(dev, &speed_cap, &width_cap); + bw_avail = pcie_bandwidth_available(dev, &limiting_dev, &speed, &width); + + if (bw_avail >= bw_cap && verbose) + pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth (%s x%d link)\n", + bw_cap / 1000, bw_cap % 1000, + pci_speed_string(speed_cap), width_cap); + else if (bw_avail < bw_cap) + pci_info(dev, "%u.%03u Gb/s available PCIe bandwidth, limited by %s x%d link at %s (capable of %u.%03u Gb/s with %s x%d link)\n", + bw_avail / 1000, bw_avail % 1000, + pci_speed_string(speed), width, + limiting_dev ? pci_name(limiting_dev) : "<unknown>", + bw_cap / 1000, bw_cap % 1000, + pci_speed_string(speed_cap), width_cap); +} + +/** + * pcie_print_link_status - Report the PCI device's link speed and width + * @dev: PCI device to query + * + * Report the available bandwidth at the device. + */ +void pcie_print_link_status(struct pci_dev *dev) +{ + __pcie_print_link_status(dev, true); +} +EXPORT_SYMBOL(pcie_print_link_status); + +/** + * pci_select_bars - Make BAR mask from the type of resource + * @dev: the PCI device for which BAR mask is made + * @flags: resource type mask to be selected + * + * This helper routine makes bar mask from the type of resource. + */ +int pci_select_bars(struct pci_dev *dev, unsigned long flags) +{ + int i, bars = 0; + for (i = 0; i < PCI_NUM_RESOURCES; i++) + if (pci_resource_flags(dev, i) & flags) + bars |= (1 << i); + return bars; +} +EXPORT_SYMBOL(pci_select_bars); + +/* Some architectures require additional programming to enable VGA */ +static arch_set_vga_state_t arch_set_vga_state; + +void __init pci_register_set_vga_state(arch_set_vga_state_t func) +{ + arch_set_vga_state = func; /* NULL disables */ +} + +static int pci_set_vga_state_arch(struct pci_dev *dev, bool decode, + unsigned int command_bits, u32 flags) +{ + if (arch_set_vga_state) + return arch_set_vga_state(dev, decode, command_bits, + flags); + return 0; +} + +/** + * pci_set_vga_state - set VGA decode state on device and parents if requested + * @dev: the PCI device + * @decode: true = enable decoding, false = disable decoding + * @command_bits: PCI_COMMAND_IO and/or PCI_COMMAND_MEMORY + * @flags: traverse ancestors and change bridges + * CHANGE_BRIDGE_ONLY / CHANGE_BRIDGE + */ +int pci_set_vga_state(struct pci_dev *dev, bool decode, + unsigned int command_bits, u32 flags) +{ + struct pci_bus *bus; + struct pci_dev *bridge; + u16 cmd; + int rc; + + WARN_ON((flags & PCI_VGA_STATE_CHANGE_DECODES) && (command_bits & ~(PCI_COMMAND_IO|PCI_COMMAND_MEMORY))); + + /* ARCH specific VGA enables */ + rc = pci_set_vga_state_arch(dev, decode, command_bits, flags); + if (rc) + return rc; + + if (flags & PCI_VGA_STATE_CHANGE_DECODES) { + pci_read_config_word(dev, PCI_COMMAND, &cmd); + if (decode) + cmd |= command_bits; + else + cmd &= ~command_bits; + pci_write_config_word(dev, PCI_COMMAND, cmd); + } + + if (!(flags & PCI_VGA_STATE_CHANGE_BRIDGE)) + return 0; + + bus = dev->bus; + while (bus) { + bridge = bus->self; + if (bridge) { + pci_read_config_word(bridge, PCI_BRIDGE_CONTROL, + &cmd); + if (decode) + cmd |= PCI_BRIDGE_CTL_VGA; + else + cmd &= ~PCI_BRIDGE_CTL_VGA; + pci_write_config_word(bridge, PCI_BRIDGE_CONTROL, + cmd); + } + bus = bus->parent; + } + return 0; +} + +#ifdef CONFIG_ACPI +bool pci_pr3_present(struct pci_dev *pdev) +{ + struct acpi_device *adev; + + if (acpi_disabled) + return false; + + adev = ACPI_COMPANION(&pdev->dev); + if (!adev) + return false; + + return adev->power.flags.power_resources && + acpi_has_method(adev->handle, "_PR3"); +} +EXPORT_SYMBOL_GPL(pci_pr3_present); +#endif + +/** + * pci_add_dma_alias - Add a DMA devfn alias for a device + * @dev: the PCI device for which alias is added + * @devfn_from: alias slot and function + * @nr_devfns: number of subsequent devfns to alias + * + * This helper encodes an 8-bit devfn as a bit number in dma_alias_mask + * which is used to program permissible bus-devfn source addresses for DMA + * requests in an IOMMU. These aliases factor into IOMMU group creation + * and are useful for devices generating DMA requests beyond or different + * from their logical bus-devfn. Examples include device quirks where the + * device simply uses the wrong devfn, as well as non-transparent bridges + * where the alias may be a proxy for devices in another domain. + * + * IOMMU group creation is performed during device discovery or addition, + * prior to any potential DMA mapping and therefore prior to driver probing + * (especially for userspace assigned devices where IOMMU group definition + * cannot be left as a userspace activity). DMA aliases should therefore + * be configured via quirks, such as the PCI fixup header quirk. + */ +void pci_add_dma_alias(struct pci_dev *dev, u8 devfn_from, + unsigned int nr_devfns) +{ + int devfn_to; + + nr_devfns = min(nr_devfns, (unsigned int)MAX_NR_DEVFNS - devfn_from); + devfn_to = devfn_from + nr_devfns - 1; + + if (!dev->dma_alias_mask) + dev->dma_alias_mask = bitmap_zalloc(MAX_NR_DEVFNS, GFP_KERNEL); + if (!dev->dma_alias_mask) { + pci_warn(dev, "Unable to allocate DMA alias mask\n"); + return; + } + + bitmap_set(dev->dma_alias_mask, devfn_from, nr_devfns); + + if (nr_devfns == 1) + pci_info(dev, "Enabling fixed DMA alias to %02x.%d\n", + PCI_SLOT(devfn_from), PCI_FUNC(devfn_from)); + else if (nr_devfns > 1) + pci_info(dev, "Enabling fixed DMA alias for devfn range from %02x.%d to %02x.%d\n", + PCI_SLOT(devfn_from), PCI_FUNC(devfn_from), + PCI_SLOT(devfn_to), PCI_FUNC(devfn_to)); +} + +bool pci_devs_are_dma_aliases(struct pci_dev *dev1, struct pci_dev *dev2) +{ + return (dev1->dma_alias_mask && + test_bit(dev2->devfn, dev1->dma_alias_mask)) || + (dev2->dma_alias_mask && + test_bit(dev1->devfn, dev2->dma_alias_mask)) || + pci_real_dma_dev(dev1) == dev2 || + pci_real_dma_dev(dev2) == dev1; +} + +bool pci_device_is_present(struct pci_dev *pdev) +{ + u32 v; + + /* Check PF if pdev is a VF, since VF Vendor/Device IDs are 0xffff */ + pdev = pci_physfn(pdev); + if (pci_dev_is_disconnected(pdev)) + return false; + return pci_bus_read_dev_vendor_id(pdev->bus, pdev->devfn, &v, 0); +} +EXPORT_SYMBOL_GPL(pci_device_is_present); + +void pci_ignore_hotplug(struct pci_dev *dev) +{ + struct pci_dev *bridge = dev->bus->self; + + dev->ignore_hotplug = 1; + /* Propagate the "ignore hotplug" setting to the parent bridge. */ + if (bridge) + bridge->ignore_hotplug = 1; +} +EXPORT_SYMBOL_GPL(pci_ignore_hotplug); + +/** + * pci_real_dma_dev - Get PCI DMA device for PCI device + * @dev: the PCI device that may have a PCI DMA alias + * + * Permits the platform to provide architecture-specific functionality to + * devices needing to alias DMA to another PCI device on another PCI bus. If + * the PCI device is on the same bus, it is recommended to use + * pci_add_dma_alias(). This is the default implementation. Architecture + * implementations can override this. + */ +struct pci_dev __weak *pci_real_dma_dev(struct pci_dev *dev) +{ + return dev; +} + +resource_size_t __weak pcibios_default_alignment(void) +{ + return 0; +} + +/* + * Arches that don't want to expose struct resource to userland as-is in + * sysfs and /proc can implement their own pci_resource_to_user(). + */ +void __weak pci_resource_to_user(const struct pci_dev *dev, int bar, + const struct resource *rsrc, + resource_size_t *start, resource_size_t *end) +{ + *start = rsrc->start; + *end = rsrc->end; +} + +static char *resource_alignment_param; +static DEFINE_SPINLOCK(resource_alignment_lock); + +/** + * pci_specified_resource_alignment - get resource alignment specified by user. + * @dev: the PCI device to get + * @resize: whether or not to change resources' size when reassigning alignment + * + * RETURNS: Resource alignment if it is specified. + * Zero if it is not specified. + */ +static resource_size_t pci_specified_resource_alignment(struct pci_dev *dev, + bool *resize) +{ + int align_order, count; + resource_size_t align = pcibios_default_alignment(); + const char *p; + int ret; + + spin_lock(&resource_alignment_lock); + p = resource_alignment_param; + if (!p || !*p) + goto out; + if (pci_has_flag(PCI_PROBE_ONLY)) { + align = 0; + pr_info_once("PCI: Ignoring requested alignments (PCI_PROBE_ONLY)\n"); + goto out; + } + + while (*p) { + count = 0; + if (sscanf(p, "%d%n", &align_order, &count) == 1 && + p[count] == '@') { + p += count + 1; + if (align_order > 63) { + pr_err("PCI: Invalid requested alignment (order %d)\n", + align_order); + align_order = PAGE_SHIFT; + } + } else { + align_order = PAGE_SHIFT; + } + + ret = pci_dev_str_match(dev, p, &p); + if (ret == 1) { + *resize = true; + align = 1ULL << align_order; + break; + } else if (ret < 0) { + pr_err("PCI: Can't parse resource_alignment parameter: %s\n", + p); + break; + } + + if (*p != ';' && *p != ',') { + /* End of param or invalid format */ + break; + } + p++; + } +out: + spin_unlock(&resource_alignment_lock); + return align; +} + +static void pci_request_resource_alignment(struct pci_dev *dev, int bar, + resource_size_t align, bool resize) +{ + struct resource *r = &dev->resource[bar]; + resource_size_t size; + + if (!(r->flags & IORESOURCE_MEM)) + return; + + if (r->flags & IORESOURCE_PCI_FIXED) { + pci_info(dev, "BAR%d %pR: ignoring requested alignment %#llx\n", + bar, r, (unsigned long long)align); + return; + } + + size = resource_size(r); + if (size >= align) + return; + + /* + * Increase the alignment of the resource. There are two ways we + * can do this: + * + * 1) Increase the size of the resource. BARs are aligned on their + * size, so when we reallocate space for this resource, we'll + * allocate it with the larger alignment. This also prevents + * assignment of any other BARs inside the alignment region, so + * if we're requesting page alignment, this means no other BARs + * will share the page. + * + * The disadvantage is that this makes the resource larger than + * the hardware BAR, which may break drivers that compute things + * based on the resource size, e.g., to find registers at a + * fixed offset before the end of the BAR. + * + * 2) Retain the resource size, but use IORESOURCE_STARTALIGN and + * set r->start to the desired alignment. By itself this + * doesn't prevent other BARs being put inside the alignment + * region, but if we realign *every* resource of every device in + * the system, none of them will share an alignment region. + * + * When the user has requested alignment for only some devices via + * the "pci=resource_alignment" argument, "resize" is true and we + * use the first method. Otherwise we assume we're aligning all + * devices and we use the second. + */ + + pci_info(dev, "BAR%d %pR: requesting alignment to %#llx\n", + bar, r, (unsigned long long)align); + + if (resize) { + r->start = 0; + r->end = align - 1; + } else { + r->flags &= ~IORESOURCE_SIZEALIGN; + r->flags |= IORESOURCE_STARTALIGN; + r->start = align; + r->end = r->start + size - 1; + } + r->flags |= IORESOURCE_UNSET; +} + +/* + * This function disables memory decoding and releases memory resources + * of the device specified by kernel's boot parameter 'pci=resource_alignment='. + * It also rounds up size to specified alignment. + * Later on, the kernel will assign page-aligned memory resource back + * to the device. + */ +void pci_reassigndev_resource_alignment(struct pci_dev *dev) +{ + int i; + struct resource *r; + resource_size_t align; + u16 command; + bool resize = false; + + /* + * VF BARs are read-only zero according to SR-IOV spec r1.1, sec + * 3.4.1.11. Their resources are allocated from the space + * described by the VF BARx register in the PF's SR-IOV capability. + * We can't influence their alignment here. + */ + if (dev->is_virtfn) + return; + + /* check if specified PCI is target device to reassign */ + align = pci_specified_resource_alignment(dev, &resize); + if (!align) + return; + + if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL && + (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) { + pci_warn(dev, "Can't reassign resources to host bridge\n"); + return; + } + + pci_read_config_word(dev, PCI_COMMAND, &command); + command &= ~PCI_COMMAND_MEMORY; + pci_write_config_word(dev, PCI_COMMAND, command); + + for (i = 0; i <= PCI_ROM_RESOURCE; i++) + pci_request_resource_alignment(dev, i, align, resize); + + /* + * Need to disable bridge's resource window, + * to enable the kernel to reassign new resource + * window later on. + */ + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) { + r = &dev->resource[i]; + if (!(r->flags & IORESOURCE_MEM)) + continue; + r->flags |= IORESOURCE_UNSET; + r->end = resource_size(r) - 1; + r->start = 0; + } + pci_disable_bridge_window(dev); + } +} + +static ssize_t resource_alignment_show(struct bus_type *bus, char *buf) +{ + size_t count = 0; + + spin_lock(&resource_alignment_lock); + if (resource_alignment_param) + count = sysfs_emit(buf, "%s\n", resource_alignment_param); + spin_unlock(&resource_alignment_lock); + + return count; +} + +static ssize_t resource_alignment_store(struct bus_type *bus, + const char *buf, size_t count) +{ + char *param, *old, *end; + + if (count >= (PAGE_SIZE - 1)) + return -EINVAL; + + param = kstrndup(buf, count, GFP_KERNEL); + if (!param) + return -ENOMEM; + + end = strchr(param, '\n'); + if (end) + *end = '\0'; + + spin_lock(&resource_alignment_lock); + old = resource_alignment_param; + if (strlen(param)) { + resource_alignment_param = param; + } else { + kfree(param); + resource_alignment_param = NULL; + } + spin_unlock(&resource_alignment_lock); + + kfree(old); + + return count; +} + +static BUS_ATTR_RW(resource_alignment); + +static int __init pci_resource_alignment_sysfs_init(void) +{ + return bus_create_file(&pci_bus_type, + &bus_attr_resource_alignment); +} +late_initcall(pci_resource_alignment_sysfs_init); + +static void pci_no_domains(void) +{ +#ifdef CONFIG_PCI_DOMAINS + pci_domains_supported = 0; +#endif +} + +#ifdef CONFIG_PCI_DOMAINS_GENERIC +static atomic_t __domain_nr = ATOMIC_INIT(-1); + +static int pci_get_new_domain_nr(void) +{ + return atomic_inc_return(&__domain_nr); +} + +static int of_pci_bus_find_domain_nr(struct device *parent) +{ + static int use_dt_domains = -1; + int domain = -1; + + if (parent) + domain = of_get_pci_domain_nr(parent->of_node); + + /* + * Check DT domain and use_dt_domains values. + * + * If DT domain property is valid (domain >= 0) and + * use_dt_domains != 0, the DT assignment is valid since this means + * we have not previously allocated a domain number by using + * pci_get_new_domain_nr(); we should also update use_dt_domains to + * 1, to indicate that we have just assigned a domain number from + * DT. + * + * If DT domain property value is not valid (ie domain < 0), and we + * have not previously assigned a domain number from DT + * (use_dt_domains != 1) we should assign a domain number by + * using the: + * + * pci_get_new_domain_nr() + * + * API and update the use_dt_domains value to keep track of method we + * are using to assign domain numbers (use_dt_domains = 0). + * + * All other combinations imply we have a platform that is trying + * to mix domain numbers obtained from DT and pci_get_new_domain_nr(), + * which is a recipe for domain mishandling and it is prevented by + * invalidating the domain value (domain = -1) and printing a + * corresponding error. + */ + if (domain >= 0 && use_dt_domains) { + use_dt_domains = 1; + } else if (domain < 0 && use_dt_domains != 1) { + use_dt_domains = 0; + domain = pci_get_new_domain_nr(); + } else { + if (parent) + pr_err("Node %pOF has ", parent->of_node); + pr_err("Inconsistent \"linux,pci-domain\" property in DT\n"); + domain = -1; + } + + return domain; +} + +int pci_bus_find_domain_nr(struct pci_bus *bus, struct device *parent) +{ + return acpi_disabled ? of_pci_bus_find_domain_nr(parent) : + acpi_pci_bus_find_domain_nr(bus); +} +#endif + +/** + * pci_ext_cfg_avail - can we access extended PCI config space? + * + * Returns 1 if we can access PCI extended config space (offsets + * greater than 0xff). This is the default implementation. Architecture + * implementations can override this. + */ +int __weak pci_ext_cfg_avail(void) +{ + return 1; +} + +void __weak pci_fixup_cardbus(struct pci_bus *bus) +{ +} +EXPORT_SYMBOL(pci_fixup_cardbus); + +static int __init pci_setup(char *str) +{ + while (str) { + char *k = strchr(str, ','); + if (k) + *k++ = 0; + if (*str && (str = pcibios_setup(str)) && *str) { + if (!strcmp(str, "nomsi")) { + pci_no_msi(); + } else if (!strncmp(str, "noats", 5)) { + pr_info("PCIe: ATS is disabled\n"); + pcie_ats_disabled = true; + } else if (!strcmp(str, "noaer")) { + pci_no_aer(); + } else if (!strcmp(str, "earlydump")) { + pci_early_dump = true; + } else if (!strncmp(str, "realloc=", 8)) { + pci_realloc_get_opt(str + 8); + } else if (!strncmp(str, "realloc", 7)) { + pci_realloc_get_opt("on"); + } else if (!strcmp(str, "nodomains")) { + pci_no_domains(); + } else if (!strncmp(str, "noari", 5)) { + pcie_ari_disabled = true; + } else if (!strncmp(str, "cbiosize=", 9)) { + pci_cardbus_io_size = memparse(str + 9, &str); + } else if (!strncmp(str, "cbmemsize=", 10)) { + pci_cardbus_mem_size = memparse(str + 10, &str); + } else if (!strncmp(str, "resource_alignment=", 19)) { + resource_alignment_param = str + 19; + } else if (!strncmp(str, "ecrc=", 5)) { + pcie_ecrc_get_policy(str + 5); + } else if (!strncmp(str, "hpiosize=", 9)) { + pci_hotplug_io_size = memparse(str + 9, &str); + } else if (!strncmp(str, "hpmmiosize=", 11)) { + pci_hotplug_mmio_size = memparse(str + 11, &str); + } else if (!strncmp(str, "hpmmioprefsize=", 15)) { + pci_hotplug_mmio_pref_size = memparse(str + 15, &str); + } else if (!strncmp(str, "hpmemsize=", 10)) { + pci_hotplug_mmio_size = memparse(str + 10, &str); + pci_hotplug_mmio_pref_size = pci_hotplug_mmio_size; + } else if (!strncmp(str, "hpbussize=", 10)) { + pci_hotplug_bus_size = + simple_strtoul(str + 10, &str, 0); + if (pci_hotplug_bus_size > 0xff) + pci_hotplug_bus_size = DEFAULT_HOTPLUG_BUS_SIZE; + } else if (!strncmp(str, "pcie_bus_tune_off", 17)) { + pcie_bus_config = PCIE_BUS_TUNE_OFF; + } else if (!strncmp(str, "pcie_bus_safe", 13)) { + pcie_bus_config = PCIE_BUS_SAFE; + } else if (!strncmp(str, "pcie_bus_perf", 13)) { + pcie_bus_config = PCIE_BUS_PERFORMANCE; + } else if (!strncmp(str, "pcie_bus_peer2peer", 18)) { + pcie_bus_config = PCIE_BUS_PEER2PEER; + } else if (!strncmp(str, "pcie_scan_all", 13)) { + pci_add_flags(PCI_SCAN_ALL_PCIE_DEVS); + } else if (!strncmp(str, "disable_acs_redir=", 18)) { + disable_acs_redir_param = str + 18; + } else { + pr_err("PCI: Unknown option `%s'\n", str); + } + } + str = k; + } + return 0; +} +early_param("pci", pci_setup); + +/* + * 'resource_alignment_param' and 'disable_acs_redir_param' are initialized + * in pci_setup(), above, to point to data in the __initdata section which + * will be freed after the init sequence is complete. We can't allocate memory + * in pci_setup() because some architectures do not have any memory allocation + * service available during an early_param() call. So we allocate memory and + * copy the variable here before the init section is freed. + * + */ +static int __init pci_realloc_setup_params(void) +{ + resource_alignment_param = kstrdup(resource_alignment_param, + GFP_KERNEL); + disable_acs_redir_param = kstrdup(disable_acs_redir_param, GFP_KERNEL); + + return 0; +} +pure_initcall(pci_realloc_setup_params); |