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