1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * pci_slot.c - ACPI PCI Slot Driver 4 * 5 * The code here is heavily leveraged from the acpiphp module. 6 * Thanks to Matthew Wilcox <matthew@wil.cx> for much guidance. 7 * Thanks to Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com> for code 8 * review and fixes. 9 * 10 * Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P. 11 * Alex Chiang <achiang@hp.com> 12 * 13 * Copyright (C) 2013 Huawei Tech. Co., Ltd. 14 * Jiang Liu <jiang.liu@huawei.com> 15 */ 16 17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 18 19 #include <linux/kernel.h> 20 #include <linux/init.h> 21 #include <linux/slab.h> 22 #include <linux/types.h> 23 #include <linux/list.h> 24 #include <linux/pci.h> 25 #include <linux/acpi.h> 26 #include <linux/dmi.h> 27 #include <linux/pci-acpi.h> 28 29 static int check_sta_before_sun; 30 31 #define _COMPONENT ACPI_PCI_COMPONENT 32 ACPI_MODULE_NAME("pci_slot"); 33 34 #define SLOT_NAME_SIZE 21 /* Inspired by #define in acpiphp.h */ 35 36 struct acpi_pci_slot { 37 struct pci_slot *pci_slot; /* corresponding pci_slot */ 38 struct list_head list; /* node in the list of slots */ 39 }; 40 41 static LIST_HEAD(slot_list); 42 static DEFINE_MUTEX(slot_list_lock); 43 44 static int 45 check_slot(acpi_handle handle, unsigned long long *sun) 46 { 47 int device = -1; 48 unsigned long long adr, sta; 49 acpi_status status; 50 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; 51 52 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer); 53 pr_debug("Checking slot on path: %s\n", (char *)buffer.pointer); 54 55 if (check_sta_before_sun) { 56 /* If SxFy doesn't have _STA, we just assume it's there */ 57 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta); 58 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) 59 goto out; 60 } 61 62 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr); 63 if (ACPI_FAILURE(status)) { 64 pr_debug("_ADR returned %d on %s\n", 65 status, (char *)buffer.pointer); 66 goto out; 67 } 68 69 /* No _SUN == not a slot == bail */ 70 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun); 71 if (ACPI_FAILURE(status)) { 72 pr_debug("_SUN returned %d on %s\n", 73 status, (char *)buffer.pointer); 74 goto out; 75 } 76 77 device = (adr >> 16) & 0xffff; 78 out: 79 kfree(buffer.pointer); 80 return device; 81 } 82 83 /* 84 * Check whether handle has an associated slot and create PCI slot if it has. 85 */ 86 static acpi_status 87 register_slot(acpi_handle handle, u32 lvl, void *context, void **rv) 88 { 89 int device; 90 unsigned long long sun; 91 char name[SLOT_NAME_SIZE]; 92 struct acpi_pci_slot *slot; 93 struct pci_slot *pci_slot; 94 struct pci_bus *pci_bus = context; 95 96 device = check_slot(handle, &sun); 97 if (device < 0) 98 return AE_OK; 99 100 /* 101 * There may be multiple PCI functions associated with the same slot. 102 * Check whether PCI slot has already been created for this PCI device. 103 */ 104 list_for_each_entry(slot, &slot_list, list) { 105 pci_slot = slot->pci_slot; 106 if (pci_slot->bus == pci_bus && pci_slot->number == device) 107 return AE_OK; 108 } 109 110 slot = kmalloc(sizeof(*slot), GFP_KERNEL); 111 if (!slot) 112 return AE_OK; 113 114 snprintf(name, sizeof(name), "%llu", sun); 115 pci_slot = pci_create_slot(pci_bus, device, name, NULL); 116 if (IS_ERR(pci_slot)) { 117 pr_err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot)); 118 kfree(slot); 119 return AE_OK; 120 } 121 122 slot->pci_slot = pci_slot; 123 list_add(&slot->list, &slot_list); 124 125 get_device(&pci_bus->dev); 126 127 pr_debug("%p, pci_bus: %x, device: %d, name: %s\n", 128 pci_slot, pci_bus->number, device, name); 129 130 return AE_OK; 131 } 132 133 void acpi_pci_slot_enumerate(struct pci_bus *bus) 134 { 135 acpi_handle handle = ACPI_HANDLE(bus->bridge); 136 137 if (handle) { 138 mutex_lock(&slot_list_lock); 139 acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, 140 register_slot, NULL, bus, NULL); 141 mutex_unlock(&slot_list_lock); 142 } 143 } 144 145 void acpi_pci_slot_remove(struct pci_bus *bus) 146 { 147 struct acpi_pci_slot *slot, *tmp; 148 149 mutex_lock(&slot_list_lock); 150 list_for_each_entry_safe(slot, tmp, &slot_list, list) { 151 if (slot->pci_slot->bus == bus) { 152 list_del(&slot->list); 153 pci_destroy_slot(slot->pci_slot); 154 put_device(&bus->dev); 155 kfree(slot); 156 } 157 } 158 mutex_unlock(&slot_list_lock); 159 } 160 161 static int do_sta_before_sun(const struct dmi_system_id *d) 162 { 163 pr_info("%s detected: will evaluate _STA before calling _SUN\n", 164 d->ident); 165 check_sta_before_sun = 1; 166 return 0; 167 } 168 169 static const struct dmi_system_id acpi_pci_slot_dmi_table[] __initconst = { 170 /* 171 * Fujitsu Primequest machines will return 1023 to indicate an 172 * error if the _SUN method is evaluated on SxFy objects that 173 * are not present (as indicated by _STA), so for those machines, 174 * we want to check _STA before evaluating _SUN. 175 */ 176 { 177 .callback = do_sta_before_sun, 178 .ident = "Fujitsu PRIMEQUEST", 179 .matches = { 180 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"), 181 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"), 182 }, 183 }, 184 {} 185 }; 186 187 void __init acpi_pci_slot_init(void) 188 { 189 dmi_check_system(acpi_pci_slot_dmi_table); 190 } 191