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