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
check_slot(acpi_handle handle,unsigned long long * sun)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
register_slot(acpi_handle handle,u32 lvl,void * context,void ** rv)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
acpi_pci_slot_enumerate(struct pci_bus * bus)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
acpi_pci_slot_remove(struct pci_bus * bus)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
do_sta_before_sun(const struct dmi_system_id * d)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
acpi_pci_slot_init(void)187 void __init acpi_pci_slot_init(void)
188 {
189 dmi_check_system(acpi_pci_slot_dmi_table);
190 }
191