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 #include <linux/pci-acpi.h>
  39
  40 static bool debug;
  41 static int check_sta_before_sun;
  42
  43 #define DRIVER_VERSION  "0.1"
  44 #define DRIVER_AUTHOR   "Alex Chiang <achiang@hp.com>"
  45 #define DRIVER_DESC     "ACPI PCI Slot Detection Driver"
  46 MODULE_AUTHOR(DRIVER_AUTHOR);
  47 MODULE_DESCRIPTION(DRIVER_DESC);
  48 MODULE_LICENSE("GPL");
  49 MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
  50 module_param(debug, bool, 0644);
  51
  52 #define _COMPONENT              ACPI_PCI_COMPONENT
  53 ACPI_MODULE_NAME("pci_slot");
  54
  55 #define MY_NAME "pci_slot"
  56 #define err(format, arg...) pr_err("%s: " format , MY_NAME , ## arg)
  57 #define info(format, arg...) pr_info("%s: " format , MY_NAME , ## arg)
  58 #define dbg(format, arg...)                                     \
  59         do {                                                    \
  60                 if (debug)                                      \
  61                         pr_debug("%s: " format, MY_NAME , ## arg); \
  62         } while (0)
  63
  64 #define SLOT_NAME_SIZE 21               /* Inspired by #define in acpiphp.h */
  65
  66 struct acpi_pci_slot {
  67         struct pci_slot *pci_slot;      /* corresponding pci_slot */
  68         struct list_head list;          /* node in the list of slots */
  69 };
  70
  71 static LIST_HEAD(slot_list);
  72 static DEFINE_MUTEX(slot_list_lock);
  73
  74 static int
  75 check_slot(acpi_handle handle, unsigned long long *sun)
  76 {
  77         int device = -1;
  78         unsigned long long adr, sta;
  79         acpi_status status;
  80         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
  81
  82         acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
  83         dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
  84
  85         if (check_sta_before_sun) {
  86                 /* If SxFy doesn't have _STA, we just assume it's there */
  87                 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
  88                 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
  89                         goto out;
  90         }
  91
  92         status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
  93         if (ACPI_FAILURE(status)) {
  94                 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
  95                 goto out;
  96         }
  97
  98         /* No _SUN == not a slot == bail */
  99         status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
 100         if (ACPI_FAILURE(status)) {
 101                 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
 102                 goto out;
 103         }
 104
 105         device = (adr >> 16) & 0xffff;
 106 out:
 107         kfree(buffer.pointer);
 108         return device;
 109 }
 110
 111 /*
 112  * Check whether handle has an associated slot and create PCI slot if it has.
 113  */
 114 static acpi_status
 115 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
 116 {
 117         int device;
 118         unsigned long long sun;
 119         char name[SLOT_NAME_SIZE];
 120         struct acpi_pci_slot *slot;
 121         struct pci_slot *pci_slot;
 122         struct pci_bus *pci_bus = context;
 123
 124         device = check_slot(handle, &sun);
 125         if (device < 0)
 126                 return AE_OK;
 127
 128         /*
 129          * There may be multiple PCI functions associated with the same slot.
 130          * Check whether PCI slot has already been created for this PCI device.
 131          */
 132         list_for_each_entry(slot, &slot_list, list) {
 133                 pci_slot = slot->pci_slot;
 134                 if (pci_slot->bus == pci_bus && pci_slot->number == device)
 135                         return AE_OK;
 136         }
 137
 138         slot = kmalloc(sizeof(*slot), GFP_KERNEL);
 139         if (!slot) {
 140                 err("%s: cannot allocate memory\n", __func__);
 141                 return AE_OK;
 142         }
 143
 144         snprintf(name, sizeof(name), "%llu", sun);
 145         pci_slot = pci_create_slot(pci_bus, device, name, NULL);
 146         if (IS_ERR(pci_slot)) {
 147                 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
 148                 kfree(slot);
 149                 return AE_OK;
 150         }
 151
 152         slot->pci_slot = pci_slot;
 153         list_add(&slot->list, &slot_list);
 154
 155         get_device(&pci_bus->dev);
 156
 157         dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
 158                 pci_slot, pci_bus->number, device, name);
 159
 160         return AE_OK;
 161 }
 162
 163 void acpi_pci_slot_enumerate(struct pci_bus *bus)
 164 {
 165         acpi_handle handle = ACPI_HANDLE(bus->bridge);
 166
 167         if (handle) {
 168                 mutex_lock(&slot_list_lock);
 169                 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1,
 170                                     register_slot, NULL, bus, NULL);
 171                 mutex_unlock(&slot_list_lock);
 172         }
 173 }
 174
 175 void acpi_pci_slot_remove(struct pci_bus *bus)
 176 {
 177         struct acpi_pci_slot *slot, *tmp;
 178
 179         mutex_lock(&slot_list_lock);
 180         list_for_each_entry_safe(slot, tmp, &slot_list, list) {
 181                 if (slot->pci_slot->bus == bus) {
 182                         list_del(&slot->list);
 183                         pci_destroy_slot(slot->pci_slot);
 184                         put_device(&bus->dev);
 185                         kfree(slot);
 186                 }
 187         }
 188         mutex_unlock(&slot_list_lock);
 189 }
 190
 191 static int do_sta_before_sun(const struct dmi_system_id *d)
 192 {
 193         info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
 194         check_sta_before_sun = 1;
 195         return 0;
 196 }
 197
 198 static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
 199         /*
 200          * Fujitsu Primequest machines will return 1023 to indicate an
 201          * error if the _SUN method is evaluated on SxFy objects that
 202          * are not present (as indicated by _STA), so for those machines,
 203          * we want to check _STA before evaluating _SUN.
 204          */
 205         {
 206          .callback = do_sta_before_sun,
 207          .ident = "Fujitsu PRIMEQUEST",
 208          .matches = {
 209                 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
 210                 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
 211                 },
 212         },
 213         {}
 214 };
 215
 216 void __init acpi_pci_slot_init(void)
 217 {
 218         dmi_check_system(acpi_pci_slot_dmi_table);
 219 }