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  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  27  */
  28
  29 #include <linux/kernel.h>
  30 #include <linux/module.h>
  31 #include <linux/init.h>
  32 #include <linux/slab.h>
  33 #include <linux/types.h>
  34 #include <linux/list.h>
  35 #include <linux/pci.h>
  36 #include <linux/acpi.h>
  37 #include <linux/dmi.h>
  38
  39 static bool debug;
  40 static int check_sta_before_sun;
  41
  42 #define DRIVER_VERSION  "0.1"
  43 #define DRIVER_AUTHOR   "Alex Chiang <achiang@hp.com>"
  44 #define DRIVER_DESC     "ACPI PCI Slot Detection Driver"
  45 MODULE_AUTHOR(DRIVER_AUTHOR);
  46 MODULE_DESCRIPTION(DRIVER_DESC);
  47 MODULE_LICENSE("GPL");
  48 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  49 module_param(debug, bool, 0644);
  50
  51 #define _COMPONENT              ACPI_PCI_COMPONENT
  52 ACPI_MODULE_NAME("pci_slot");
  53
  54 #define MY_NAME "pci_slot"
  55 #define err(format, arg...) pr_err("%s: " format , MY_NAME , ## arg)
  56 #define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
  57 #define dbg(format, arg...)                                     \
  58         do {                                                    \
  59                 if (debug)                                      \
  60                         pr_debug("%s: " format, MY_NAME , ## arg); \
  61         } while (0)
  62
  63 #define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  64
  65 struct acpi_pci_slot {
  66         struct pci_slot *pci_slot;      /* corresponding pci_slot */
  67         struct list_head list;          /* node in the list of slots */
  68 };
  69
  70 static LIST_HEAD(slot_list);
  71 static DEFINE_MUTEX(slot_list_lock);
  72
  73 static int
  74 check_slot(acpi_handle handle, unsigned long long *sun)
  75 {
  76         int device = -1;
  77         unsigned long long adr, sta;
  78         acpi_status status;
  79         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  80
  81         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  82         dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
  83
  84         if (check_sta_before_sun) {
  85                 /* If SxFy doesn't have _STA, we just assume it's there */
  86                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  87                 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  88                         goto out;
  89         }
  90
  91         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  92         if (ACPI_FAILURE(status)) {
  93                 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
  94                 goto out;
  95         }
  96
  97         /* No _SUN == not a slot == bail */
  98         status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
  99         if (ACPI_FAILURE(status)) {
 100                 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
 101                 goto out;
 102         }
 103
 104         device = (adr >> 16) & 0xffff;
 105 out:
 106         kfree(buffer.pointer);
 107         return device;
 108 }
 109
 110 /*
 111  * Check whether handle has an associated slot and create PCI slot if it has.
 112  */
 113 static acpi_status
 114 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 115 {
 116         int device;
 117         unsigned long long sun;
 118         char name[SLOT_NAME_SIZE];
 119         struct acpi_pci_slot *slot;
 120         struct pci_slot *pci_slot;
 121         struct pci_bus *pci_bus = context;
 122
 123         device = check_slot(handle, &sun);
 124         if (device < 0)
 125                 return AE_OK;
 126
 127         /*
 128          * There may be multiple PCI functions associated with the same slot.
 129          * Check whether PCI slot has already been created for this PCI device.
 130          */
 131         list_for_each_entry(slot, &slot_list, list) {
 132                 pci_slot = slot->pci_slot;
 133                 if (pci_slot->bus == pci_bus && pci_slot->number == device)
 134                         return AE_OK;
 135         }
 136
 137         slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 138         if (!slot) {
 139                 err("%s: cannot allocate memory\n", __func__);
 140                 return AE_OK;
 141         }
 142
 143         snprintf(name, sizeof(name), "%llu", sun);
 144         pci_slot = pci_create_slot(pci_bus, device, name, NULL);
 145         if (IS_ERR(pci_slot)) {
 146                 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 147                 kfree(slot);
 148                 return AE_OK;
 149         }
 150
 151         slot->pci_slot = pci_slot;
 152         list_add(&slot->list, &slot_list);
 153
 154         get_device(&pci_bus->dev);
 155
 156         dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
 157                 pci_slot, pci_bus->number, device, name);
 158
 159         return AE_OK;
 160 }
 161
 162 void acpi_pci_slot_enumerate(struct pci_bus *bus)
 163 {
 164         acpi_handle handle = ACPI_HANDLE(bus->bridge);
 165
 166         if (handle) {
 167                 mutex_lock(&slot_list_lock);
 168                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 169                                     register_slot, NULL, bus, NULL);
 170                 mutex_unlock(&slot_list_lock);
 171         }
 172 }
 173
 174 void acpi_pci_slot_remove(struct pci_bus *bus)
 175 {
 176         struct acpi_pci_slot *slot, *tmp;
 177
 178         mutex_lock(&slot_list_lock);
 179         list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 180                 if (slot->pci_slot->bus == bus) {
 181                         list_del(&slot->list);
 182                         pci_destroy_slot(slot->pci_slot);
 183                         put_device(&bus->dev);
 184                         kfree(slot);
 185                 }
 186         }
 187         mutex_unlock(&slot_list_lock);
 188 }
 189
 190 static int do_sta_before_sun(const struct dmi_system_id *d)
 191 {
 192         info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 193         check_sta_before_sun = 1;
 194         return 0;
 195 }
 196
 197 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 198         /*
 199          * Fujitsu Primequest machines will return 1023 to indicate an
 200          * error if the _SUN method is evaluated on SxFy objects that
 201          * are not present (as indicated by _STA), so for those machines,
 202          * we want to check _STA before evaluating _SUN.
 203          */
 204         {
 205          .callback = do_sta_before_sun,
 206          .ident = "Fujitsu PRIMEQUEST",
 207          .matches = {
 208                 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 209                 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 210                 },
 211         },
 212         {}
 213 };
 214
 215 void __init acpi_pci_slot_init(void)
 216 {
 217         dmi_check_system(acpi_pci_slot_dmi_table);
 218 }