diff options
Diffstat (limited to 'drivers/acpi/pci_slot.c')
| -rw-r--r-- | drivers/acpi/pci_slot.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/drivers/acpi/pci_slot.c b/drivers/acpi/pci_slot.c new file mode 100644 index 000000000..d6cb2c27a --- /dev/null +++ b/drivers/acpi/pci_slot.c @@ -0,0 +1,187 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * pci_slot.c - ACPI PCI Slot Driver + * + * The code here is heavily leveraged from the acpiphp module. + * Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance. + * Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code + * review and fixes. + * + * Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P. + * Alex Chiang <achiang@hp.com> + * + * Copyright (C) 2013 Huawei Tech. Co., Ltd. + * Jiang Liu <jiang.liu@huawei.com> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/list.h> +#include <linux/pci.h> +#include <linux/acpi.h> +#include <linux/dmi.h> +#include <linux/pci-acpi.h> + +static int check_sta_before_sun; + +#define SLOT_NAME_SIZE 21 /* Inspired by #define in acpiphp.h */ + +struct acpi_pci_slot { + struct pci_slot *pci_slot; /* corresponding pci_slot */ + struct list_head list; /* node in the list of slots */ +}; + +static LIST_HEAD(slot_list); +static DEFINE_MUTEX(slot_list_lock); + +static int +check_slot(acpi_handle handle, unsigned long long *sun) +{ + int device = -1; + unsigned long long adr, sta; + acpi_status status; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + + acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); + pr_debug("Checking slot on path: %s\n", (char *)buffer.pointer); + + if (check_sta_before_sun) { + /* If SxFy doesn't have _STA, we just assume it's there */ + status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); + if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) + goto out; + } + + status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr); + if (ACPI_FAILURE(status)) { + pr_debug("_ADR returned %d on %s\n", + status, (char *)buffer.pointer); + goto out; + } + + /* No _SUN == not a slot == bail */ + status = acpi_evaluate_integer(handle, "_SUN", NULL, sun); + if (ACPI_FAILURE(status)) { + pr_debug("_SUN returned %d on %s\n", + status, (char *)buffer.pointer); + goto out; + } + + device = (adr >> 16) & 0xffff; +out: + kfree(buffer.pointer); + return device; +} + +/* + * Check whether handle has an associated slot and create PCI slot if it has. + */ +static acpi_status +register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) +{ + int device; + unsigned long long sun; + char name[SLOT_NAME_SIZE]; + struct acpi_pci_slot *slot; + struct pci_slot *pci_slot; + struct pci_bus *pci_bus = context; + + device = check_slot(handle, &sun); + if (device < 0) + return AE_OK; + + /* + * There may be multiple PCI functions associated with the same slot. + * Check whether PCI slot has already been created for this PCI device. + */ + list_for_each_entry(slot, &slot_list, list) { + pci_slot = slot->pci_slot; + if (pci_slot->bus == pci_bus && pci_slot->number == device) + return AE_OK; + } + + slot = kmalloc(sizeof(*slot), GFP_KERNEL); + if (!slot) + return AE_OK; + + snprintf(name, sizeof(name), "%llu", sun); + pci_slot = pci_create_slot(pci_bus, device, name, NULL); + if (IS_ERR(pci_slot)) { + pr_err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot)); + kfree(slot); + return AE_OK; + } + + slot->pci_slot = pci_slot; + list_add(&slot->list, &slot_list); + + get_device(&pci_bus->dev); + + pr_debug("%p, pci_bus: %x, device: %d, name: %s\n", + pci_slot, pci_bus->number, device, name); + + return AE_OK; +} + +void acpi_pci_slot_enumerate(struct pci_bus *bus) +{ + acpi_handle handle = ACPI_HANDLE(bus->bridge); + + if (handle) { + mutex_lock(&slot_list_lock); + acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, + register_slot, NULL, bus, NULL); + mutex_unlock(&slot_list_lock); + } +} + +void acpi_pci_slot_remove(struct pci_bus *bus) +{ + struct acpi_pci_slot *slot, *tmp; + + mutex_lock(&slot_list_lock); + list_for_each_entry_safe(slot, tmp, &slot_list, list) { + if (slot->pci_slot->bus == bus) { + list_del(&slot->list); + pci_destroy_slot(slot->pci_slot); + put_device(&bus->dev); + kfree(slot); + } + } + mutex_unlock(&slot_list_lock); +} + +static int do_sta_before_sun(const struct dmi_system_id *d) +{ + pr_info("%s detected: will evaluate _STA before calling _SUN\n", + d->ident); + check_sta_before_sun = 1; + return 0; +} + +static const struct dmi_system_id acpi_pci_slot_dmi_table[] __initconst = { + /* + * Fujitsu Primequest machines will return 1023 to indicate an + * error if the _SUN method is evaluated on SxFy objects that + * are not present (as indicated by _STA), so for those machines, + * we want to check _STA before evaluating _SUN. + */ + { + .callback = do_sta_before_sun, + .ident = "Fujitsu PRIMEQUEST", + .matches = { + DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), + DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), + }, + }, + {} +}; + +void __init acpi_pci_slot_init(void) +{ + dmi_check_system(acpi_pci_slot_dmi_table); +} |