LXR linux/drivers/acpi/pci

   1/*
   2 *  pci_slot.c - ACPI PCI Slot Driver
   3 *
   4 *  The code here is heavily leveraged from the acpiphp module.
   5 *  Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance.
   6 *  Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code
   7 *  review and fixes.
   8 *
   9 *  Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.
  10 *      Alex Chiang <achiang@hp.com>
  11 *
  12 *  Copyright (C) 2013 Huawei Tech. Co., Ltd.
  13 *      Jiang Liu <jiang.liu@huawei.com>
  14 *
  15 *  This program is free software; you can redistribute it and/or modify it
  16 *  under the terms and conditions of the GNU General Public License,
  17 *  version 2, as published by the Free Software Foundation.
  18 *
  19 *  This program is distributed in the hope that it will be useful, but
  20 *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22 *  General Public License for more details.
  23 */
  24
  25#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  26
  27#include <linux/kernel.h>
  28#include <linux/init.h>
  29#include <linux/slab.h>
  30#include <linux/types.h>
  31#include <linux/list.h>
  32#include <linux/pci.h>
  33#include <linux/acpi.h>
  34#include <linux/dmi.h>
  35#include <linux/pci-acpi.h>
  36
  37static int check_sta_before_sun;
  38
  39#define _COMPONENT              ACPI_PCI_COMPONENT
  40ACPI_MODULE_NAME("pci_slot");
  41
  42#define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  43
  44struct acpi_pci_slot {
  45        struct pci_slot *pci_slot;      /* corresponding pci_slot */
  46        struct list_head list;          /* node in the list of slots */
  47};
  48
  49static LIST_HEAD(slot_list);
  50static DEFINE_MUTEX(slot_list_lock);
  51
  52static int
  53check_slot(acpi_handle handle, unsigned long long *sun)
  54{
  55        int device = -1;
  56        unsigned long long adr, sta;
  57        acpi_status status;
  58        struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  59
  60        acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  61        pr_debug("Checking slot on path: %s\n", (char *)buffer.pointer);
  62
  63        if (check_sta_before_sun) {
  64                /* If SxFy doesn't have _STA, we just assume it's there */
  65                status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  66                if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  67                        goto out;
  68        }
  69
  70        status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  71        if (ACPI_FAILURE(status)) {
  72                pr_debug("_ADR returned %d on %s\n",
  73                         status, (char *)buffer.pointer);
  74                goto out;
  75        }
  76
  77        /* No _SUN == not a slot == bail */
  78        status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
  79        if (ACPI_FAILURE(status)) {
  80                pr_debug("_SUN returned %d on %s\n",
  81                         status, (char *)buffer.pointer);
  82                goto out;
  83        }
  84
  85        device = (adr >> 16) & 0xffff;
  86out:
  87        kfree(buffer.pointer);
  88        return device;
  89}
  90
  91/*
  92 * Check whether handle has an associated slot and create PCI slot if it has.
  93 */
  94static acpi_status
  95register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
  96{
  97        int device;
  98        unsigned long long sun;
  99        char name[SLOT_NAME_SIZE];
 100        struct acpi_pci_slot *slot;
 101        struct pci_slot *pci_slot;
 102        struct pci_bus *pci_bus = context;
 103
 104        device = check_slot(handle, &sun);
 105        if (device < 0)
 106                return AE_OK;
 107
 108        /*
 109         * There may be multiple PCI functions associated with the same slot.
 110         * Check whether PCI slot has already been created for this PCI device.
 111         */
 112        list_for_each_entry(slot, &slot_list, list) {
 113                pci_slot = slot->pci_slot;
 114                if (pci_slot->bus == pci_bus && pci_slot->number == device)
 115                        return AE_OK;
 116        }
 117
 118        slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 119        if (!slot)
 120                return AE_OK;
 121
 122        snprintf(name, sizeof(name), "%llu", sun);
 123        pci_slot = pci_create_slot(pci_bus, device, name, NULL);
 124        if (IS_ERR(pci_slot)) {
 125                pr_err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 126                kfree(slot);
 127                return AE_OK;
 128        }
 129
 130        slot->pci_slot = pci_slot;
 131        list_add(&slot->list, &slot_list);
 132
 133        get_device(&pci_bus->dev);
 134
 135        pr_debug("%p, pci_bus: %x, device: %d, name: %s\n",
 136                 pci_slot, pci_bus->number, device, name);
 137
 138        return AE_OK;
 139}
 140
 141void acpi_pci_slot_enumerate(struct pci_bus *bus)
 142{
 143        acpi_handle handle = ACPI_HANDLE(bus->bridge);
 144
 145        if (handle) {
 146                mutex_lock(&slot_list_lock);
 147                acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 148                                    register_slot, NULL, bus, NULL);
 149                mutex_unlock(&slot_list_lock);
 150        }
 151}
 152
 153void acpi_pci_slot_remove(struct pci_bus *bus)
 154{
 155        struct acpi_pci_slot *slot, *tmp;
 156
 157        mutex_lock(&slot_list_lock);
 158        list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 159                if (slot->pci_slot->bus == bus) {
 160                        list_del(&slot->list);
 161                        pci_destroy_slot(slot->pci_slot);
 162                        put_device(&bus->dev);
 163                        kfree(slot);
 164                }
 165        }
 166        mutex_unlock(&slot_list_lock);
 167}
 168
 169static int do_sta_before_sun(const struct dmi_system_id *d)
 170{
 171        pr_info("%s detected: will evaluate _STA before calling _SUN\n",
 172                d->ident);
 173        check_sta_before_sun = 1;
 174        return 0;
 175}
 176
 177static const struct dmi_system_id acpi_pci_slot_dmi_table[] __initconst = {
 178        /*
 179         * Fujitsu Primequest machines will return 1023 to indicate an
 180         * error if the _SUN method is evaluated on SxFy objects that
 181         * are not present (as indicated by _STA), so for those machines,
 182         * we want to check _STA before evaluating _SUN.
 183         */
 184        {
 185         .callback = do_sta_before_sun,
 186         .ident = "Fujitsu PRIMEQUEST",
 187         .matches = {
 188                DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 189                DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 190                },
 191        },
 192        {}
 193};
 194
 195void __init acpi_pci_slot_init(void)
 196{
 197        dmi_check_system(acpi_pci_slot_dmi_table);
 198}
 199