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