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