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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /arch/x86/pci/intel_mid_pci.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/pci/intel_mid_pci.c')
-rw-r--r-- | arch/x86/pci/intel_mid_pci.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/arch/x86/pci/intel_mid_pci.c b/arch/x86/pci/intel_mid_pci.c new file mode 100644 index 000000000..8edd62206 --- /dev/null +++ b/arch/x86/pci/intel_mid_pci.c @@ -0,0 +1,406 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Intel MID PCI support + * Copyright (c) 2008 Intel Corporation + * Jesse Barnes <jesse.barnes@intel.com> + * + * Moorestown has an interesting PCI implementation: + * - configuration space is memory mapped (as defined by MCFG) + * - Lincroft devices also have a real, type 1 configuration space + * - Early Lincroft silicon has a type 1 access bug that will cause + * a hang if non-existent devices are accessed + * - some devices have the "fixed BAR" capability, which means + * they can't be relocated or modified; check for that during + * BAR sizing + * + * So, we use the MCFG space for all reads and writes, but also send + * Lincroft writes to type 1 space. But only read/write if the device + * actually exists, otherwise return all 1s for reads and bit bucket + * the writes. + */ + +#include <linux/sched.h> +#include <linux/pci.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/dmi.h> +#include <linux/acpi.h> +#include <linux/io.h> +#include <linux/smp.h> + +#include <asm/cpu_device_id.h> +#include <asm/segment.h> +#include <asm/pci_x86.h> +#include <asm/hw_irq.h> +#include <asm/io_apic.h> +#include <asm/intel-family.h> +#include <asm/intel-mid.h> +#include <asm/acpi.h> + +#define PCIE_CAP_OFFSET 0x100 + +/* Quirks for the listed devices */ +#define PCI_DEVICE_ID_INTEL_MRFLD_MMC 0x1190 +#define PCI_DEVICE_ID_INTEL_MRFLD_HSU 0x1191 + +/* Fixed BAR fields */ +#define PCIE_VNDR_CAP_ID_FIXED_BAR 0x00 /* Fixed BAR (TBD) */ +#define PCI_FIXED_BAR_0_SIZE 0x04 +#define PCI_FIXED_BAR_1_SIZE 0x08 +#define PCI_FIXED_BAR_2_SIZE 0x0c +#define PCI_FIXED_BAR_3_SIZE 0x10 +#define PCI_FIXED_BAR_4_SIZE 0x14 +#define PCI_FIXED_BAR_5_SIZE 0x1c + +static int pci_soc_mode; + +/** + * fixed_bar_cap - return the offset of the fixed BAR cap if found + * @bus: PCI bus + * @devfn: device in question + * + * Look for the fixed BAR cap on @bus and @devfn, returning its offset + * if found or 0 otherwise. + */ +static int fixed_bar_cap(struct pci_bus *bus, unsigned int devfn) +{ + int pos; + u32 pcie_cap = 0, cap_data; + + pos = PCIE_CAP_OFFSET; + + if (!raw_pci_ext_ops) + return 0; + + while (pos) { + if (raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, pos, 4, &pcie_cap)) + return 0; + + if (PCI_EXT_CAP_ID(pcie_cap) == 0x0000 || + PCI_EXT_CAP_ID(pcie_cap) == 0xffff) + break; + + if (PCI_EXT_CAP_ID(pcie_cap) == PCI_EXT_CAP_ID_VNDR) { + raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, pos + 4, 4, &cap_data); + if ((cap_data & 0xffff) == PCIE_VNDR_CAP_ID_FIXED_BAR) + return pos; + } + + pos = PCI_EXT_CAP_NEXT(pcie_cap); + } + + return 0; +} + +static int pci_device_update_fixed(struct pci_bus *bus, unsigned int devfn, + int reg, int len, u32 val, int offset) +{ + u32 size; + unsigned int domain, busnum; + int bar = (reg - PCI_BASE_ADDRESS_0) >> 2; + + domain = pci_domain_nr(bus); + busnum = bus->number; + + if (val == ~0 && len == 4) { + unsigned long decode; + + raw_pci_ext_ops->read(domain, busnum, devfn, + offset + 8 + (bar * 4), 4, &size); + + /* Turn the size into a decode pattern for the sizing code */ + if (size) { + decode = size - 1; + decode |= decode >> 1; + decode |= decode >> 2; + decode |= decode >> 4; + decode |= decode >> 8; + decode |= decode >> 16; + decode++; + decode = ~(decode - 1); + } else { + decode = 0; + } + + /* + * If val is all ones, the core code is trying to size the reg, + * so update the mmconfig space with the real size. + * + * Note: this assumes the fixed size we got is a power of two. + */ + return raw_pci_ext_ops->write(domain, busnum, devfn, reg, 4, + decode); + } + + /* This is some other kind of BAR write, so just do it. */ + return raw_pci_ext_ops->write(domain, busnum, devfn, reg, len, val); +} + +/** + * type1_access_ok - check whether to use type 1 + * @bus: bus number + * @devfn: device & function in question + * @reg: configuration register offset + * + * If the bus is on a Lincroft chip and it exists, or is not on a Lincroft at + * all, the we can go ahead with any reads & writes. If it's on a Lincroft, + * but doesn't exist, avoid the access altogether to keep the chip from + * hanging. + */ +static bool type1_access_ok(unsigned int bus, unsigned int devfn, int reg) +{ + /* + * This is a workaround for A0 LNC bug where PCI status register does + * not have new CAP bit set. can not be written by SW either. + * + * PCI header type in real LNC indicates a single function device, this + * will prevent probing other devices under the same function in PCI + * shim. Therefore, use the header type in shim instead. + */ + if (reg >= 0x100 || reg == PCI_STATUS || reg == PCI_HEADER_TYPE) + return false; + if (bus == 0 && (devfn == PCI_DEVFN(2, 0) + || devfn == PCI_DEVFN(0, 0) + || devfn == PCI_DEVFN(3, 0))) + return true; + return false; /* Langwell on others */ +} + +static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, + int size, u32 *value) +{ + if (type1_access_ok(bus->number, devfn, where)) + return pci_direct_conf1.read(pci_domain_nr(bus), bus->number, + devfn, where, size, value); + return raw_pci_ext_ops->read(pci_domain_nr(bus), bus->number, + devfn, where, size, value); +} + +static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, + int size, u32 value) +{ + int offset; + + /* + * On MRST, there is no PCI ROM BAR, this will cause a subsequent read + * to ROM BAR return 0 then being ignored. + */ + if (where == PCI_ROM_ADDRESS) + return 0; + + /* + * Devices with fixed BARs need special handling: + * - BAR sizing code will save, write ~0, read size, restore + * - so writes to fixed BARs need special handling + * - other writes to fixed BAR devices should go through mmconfig + */ + offset = fixed_bar_cap(bus, devfn); + if (offset && + (where >= PCI_BASE_ADDRESS_0 && where <= PCI_BASE_ADDRESS_5)) { + return pci_device_update_fixed(bus, devfn, where, size, value, + offset); + } + + /* + * On Moorestown update both real & mmconfig space + * Note: early Lincroft silicon can't handle type 1 accesses to + * non-existent devices, so just eat the write in that case. + */ + if (type1_access_ok(bus->number, devfn, where)) + return pci_direct_conf1.write(pci_domain_nr(bus), bus->number, + devfn, where, size, value); + return raw_pci_ext_ops->write(pci_domain_nr(bus), bus->number, devfn, + where, size, value); +} + +static const struct x86_cpu_id intel_mid_cpu_ids[] = { + X86_MATCH_INTEL_FAM6_MODEL(ATOM_SILVERMONT_MID, NULL), + {} +}; + +static int intel_mid_pci_irq_enable(struct pci_dev *dev) +{ + const struct x86_cpu_id *id; + struct irq_alloc_info info; + bool polarity_low; + u16 model = 0; + int ret; + u8 gsi; + + if (dev->irq_managed && dev->irq > 0) + return 0; + + ret = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi); + if (ret < 0) { + dev_warn(&dev->dev, "Failed to read interrupt line: %d\n", ret); + return ret; + } + + id = x86_match_cpu(intel_mid_cpu_ids); + if (id) + model = id->model; + + switch (model) { + case INTEL_FAM6_ATOM_SILVERMONT_MID: + polarity_low = false; + + /* Special treatment for IRQ0 */ + if (gsi == 0) { + /* + * Skip HS UART common registers device since it has + * IRQ0 assigned and not used by the kernel. + */ + if (dev->device == PCI_DEVICE_ID_INTEL_MRFLD_HSU) + return -EBUSY; + /* + * TNG has IRQ0 assigned to eMMC controller. But there + * are also other devices with bogus PCI configuration + * that have IRQ0 assigned. This check ensures that + * eMMC gets it. The rest of devices still could be + * enabled without interrupt line being allocated. + */ + if (dev->device != PCI_DEVICE_ID_INTEL_MRFLD_MMC) + return 0; + } + break; + default: + polarity_low = true; + break; + } + + ioapic_set_alloc_attr(&info, dev_to_node(&dev->dev), 1, polarity_low); + + /* + * MRST only have IOAPIC, the PCI irq lines are 1:1 mapped to + * IOAPIC RTE entries, so we just enable RTE for the device. + */ + ret = mp_map_gsi_to_irq(gsi, IOAPIC_MAP_ALLOC, &info); + if (ret < 0) + return ret; + + dev->irq = ret; + dev->irq_managed = 1; + + return 0; +} + +static void intel_mid_pci_irq_disable(struct pci_dev *dev) +{ + if (!mp_should_keep_irq(&dev->dev) && dev->irq_managed && + dev->irq > 0) { + mp_unmap_irq(dev->irq); + dev->irq_managed = 0; + } +} + +static const struct pci_ops intel_mid_pci_ops __initconst = { + .read = pci_read, + .write = pci_write, +}; + +/** + * intel_mid_pci_init - installs intel_mid_pci_ops + * + * Moorestown has an interesting PCI implementation (see above). + * Called when the early platform detection installs it. + */ +int __init intel_mid_pci_init(void) +{ + pr_info("Intel MID platform detected, using MID PCI ops\n"); + pci_mmcfg_late_init(); + pcibios_enable_irq = intel_mid_pci_irq_enable; + pcibios_disable_irq = intel_mid_pci_irq_disable; + pci_root_ops = intel_mid_pci_ops; + pci_soc_mode = 1; + /* Continue with standard init */ + acpi_noirq_set(); + return 1; +} + +/* + * Langwell devices are not true PCI devices; they are not subject to 10 ms + * d3 to d0 delay required by PCI spec. + */ +static void pci_d3delay_fixup(struct pci_dev *dev) +{ + /* + * PCI fixups are effectively decided compile time. If we have a dual + * SoC/non-SoC kernel we don't want to mangle d3 on non-SoC devices. + */ + if (!pci_soc_mode) + return; + /* + * True PCI devices in Lincroft should allow type 1 access, the rest + * are Langwell fake PCI devices. + */ + if (type1_access_ok(dev->bus->number, dev->devfn, PCI_DEVICE_ID)) + return; + dev->d3hot_delay = 0; +} +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_d3delay_fixup); + +static void mid_power_off_one_device(struct pci_dev *dev) +{ + u16 pmcsr; + + /* + * Update current state first, otherwise PCI core enforces PCI_D0 in + * pci_set_power_state() for devices which status was PCI_UNKNOWN. + */ + pci_read_config_word(dev, dev->pm_cap + PCI_PM_CTRL, &pmcsr); + dev->current_state = (pci_power_t __force)(pmcsr & PCI_PM_CTRL_STATE_MASK); + + pci_set_power_state(dev, PCI_D3hot); +} + +static void mid_power_off_devices(struct pci_dev *dev) +{ + int id; + + if (!pci_soc_mode) + return; + + id = intel_mid_pwr_get_lss_id(dev); + if (id < 0) + return; + + /* + * This sets only PMCSR bits. The actual power off will happen in + * arch/x86/platform/intel-mid/pwr.c. + */ + mid_power_off_one_device(dev); +} + +DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, mid_power_off_devices); + +/* + * Langwell devices reside at fixed offsets, don't try to move them. + */ +static void pci_fixed_bar_fixup(struct pci_dev *dev) +{ + unsigned long offset; + u32 size; + int i; + + if (!pci_soc_mode) + return; + + /* Must have extended configuration space */ + if (dev->cfg_size < PCIE_CAP_OFFSET + 4) + return; + + /* Fixup the BAR sizes for fixed BAR devices and make them unmoveable */ + offset = fixed_bar_cap(dev->bus, dev->devfn); + if (!offset || PCI_DEVFN(2, 0) == dev->devfn || + PCI_DEVFN(2, 2) == dev->devfn) + return; + + for (i = 0; i < PCI_STD_NUM_BARS; i++) { + pci_read_config_dword(dev, offset + 8 + (i * 4), &size); + dev->resource[i].end = dev->resource[i].start + size - 1; + dev->resource[i].flags |= IORESOURCE_PCI_FIXED; + } +} +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, pci_fixed_bar_fixup); |