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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * pci_slot.c - ACPI PCI Slot Driver4 *5 * The code here is heavily leveraged from the acpiphp module.6 * Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.7 * Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code8 * review and fixes.9 *10 * Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.11 * Alex Chiang <achiang@hp.com>12 *13 * Copyright (C) 2013 Huawei Tech. Co., Ltd.14 * Jiang Liu <jiang.liu@huawei.com>15 */16 17#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt18 19#include <linux/kernel.h>20#include <linux/init.h>21#include <linux/slab.h>22#include <linux/types.h>23#include <linux/list.h>24#include <linux/pci.h>25#include <linux/acpi.h>26#include <linux/dmi.h>27#include <linux/pci-acpi.h>28 29static int check_sta_before_sun;30 31#define SLOT_NAME_SIZE 21 /* Inspired by #define in acpiphp.h */32 33struct acpi_pci_slot {34 struct pci_slot *pci_slot; /* corresponding pci_slot */35 struct list_head list; /* node in the list of slots */36};37 38static LIST_HEAD(slot_list);39static DEFINE_MUTEX(slot_list_lock);40 41static int42check_slot(acpi_handle handle, unsigned long long *sun)43{44 int device = -1;45 unsigned long long adr, sta;46 acpi_status status;47 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };48 49 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);50 pr_debug("Checking slot on path: %s\n", (char *)buffer.pointer);51 52 if (check_sta_before_sun) {53 /* If SxFy doesn't have _STA, we just assume it's there */54 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);55 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))56 goto out;57 }58 59 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);60 if (ACPI_FAILURE(status)) {61 pr_debug("_ADR returned %d on %s\n",62 status, (char *)buffer.pointer);63 goto out;64 }65 66 /* No _SUN == not a slot == bail */67 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);68 if (ACPI_FAILURE(status)) {69 pr_debug("_SUN returned %d on %s\n",70 status, (char *)buffer.pointer);71 goto out;72 }73 74 device = (adr >> 16) & 0xffff;75out:76 kfree(buffer.pointer);77 return device;78}79 80/*81 * Check whether handle has an associated slot and create PCI slot if it has.82 */83static acpi_status84register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)85{86 int device;87 unsigned long long sun;88 char name[SLOT_NAME_SIZE];89 struct acpi_pci_slot *slot;90 struct pci_slot *pci_slot;91 struct pci_bus *pci_bus = context;92 93 device = check_slot(handle, &sun);94 if (device < 0)95 return AE_OK;96 97 /*98 * There may be multiple PCI functions associated with the same slot.99 * Check whether PCI slot has already been created for this PCI device.100 */101 list_for_each_entry(slot, &slot_list, list) {102 pci_slot = slot->pci_slot;103 if (pci_slot->bus == pci_bus && pci_slot->number == device)104 return AE_OK;105 }106 107 slot = kmalloc(sizeof(*slot), GFP_KERNEL);108 if (!slot)109 return AE_OK;110 111 snprintf(name, sizeof(name), "%llu", sun);112 pci_slot = pci_create_slot(pci_bus, device, name, NULL);113 if (IS_ERR(pci_slot)) {114 pr_err("pci_create_slot returned %pe\n", pci_slot);115 kfree(slot);116 return AE_OK;117 }118 119 slot->pci_slot = pci_slot;120 list_add(&slot->list, &slot_list);121 122 get_device(&pci_bus->dev);123 124 pr_debug("%p, pci_bus: %x, device: %d, name: %s\n",125 pci_slot, pci_bus->number, device, name);126 127 return AE_OK;128}129 130void acpi_pci_slot_enumerate(struct pci_bus *bus)131{132 acpi_handle handle = ACPI_HANDLE(bus->bridge);133 134 if (handle) {135 mutex_lock(&slot_list_lock);136 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,137 register_slot, NULL, bus, NULL);138 mutex_unlock(&slot_list_lock);139 }140}141 142void acpi_pci_slot_remove(struct pci_bus *bus)143{144 struct acpi_pci_slot *slot, *tmp;145 146 mutex_lock(&slot_list_lock);147 list_for_each_entry_safe(slot, tmp, &slot_list, list) {148 if (slot->pci_slot->bus == bus) {149 list_del(&slot->list);150 pci_destroy_slot(slot->pci_slot);151 put_device(&bus->dev);152 kfree(slot);153 }154 }155 mutex_unlock(&slot_list_lock);156}157 158static int do_sta_before_sun(const struct dmi_system_id *d)159{160 pr_info("%s detected: will evaluate _STA before calling _SUN\n",161 d->ident);162 check_sta_before_sun = 1;163 return 0;164}165 166static const struct dmi_system_id acpi_pci_slot_dmi_table[] __initconst = {167 /*168 * Fujitsu Primequest machines will return 1023 to indicate an169 * error if the _SUN method is evaluated on SxFy objects that170 * are not present (as indicated by _STA), so for those machines,171 * we want to check _STA before evaluating _SUN.172 */173 {174 .callback = do_sta_before_sun,175 .ident = "Fujitsu PRIMEQUEST",176 .matches = {177 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),178 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),179 },180 },181 {}182};183 184void __init acpi_pci_slot_init(void)185{186 dmi_check_system(acpi_pci_slot_dmi_table);187}188