drivers/acpi/pci_slot.c

   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
  37 static int check_sta_before_sun;
  38
  39 #define _COMPONENT              ACPI_PCI_COMPONENT
  40 ACPI_MODULE_NAME("pci_slot");
  41
  42 #define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  43
  44 struct 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
  49 static LIST_HEAD(slot_list);
  50 static DEFINE_MUTEX(slot_list_lock);
  51
  52 static int
  53 check_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;
  86 out:
  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  */
  94 static acpi_status
  95 register_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
 141 void 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
 153 void 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
 169 static 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
 177 static 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
 195 void __init acpi_pci_slot_init(void)
 196 {
 197         dmi_check_system(acpi_pci_slot_dmi_table);
 198 }