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Alex Chiang8344b562008-06-10 15:30:42 -06001/*
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 Alex Chiang <achiang@hp.com>
10 * Copyright (C) 2007 Hewlett-Packard Development Company, L.P.
11 *
12 * This program is free software; you can redistribute it and/or modify it
13 * under the terms and conditions of the GNU General Public License,
14 * version 2, as published by the Free Software Foundation.
15 *
16 * This program is distributed in the hope that it will be useful, but
17 * WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
19 * General Public License for more details.
20 *
21 * You should have received a copy of the GNU General Public License along
22 * with this program; if not, write to the Free Software Foundation, Inc.,
23 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/init.h>
29#include <linux/types.h>
30#include <linux/pci.h>
31#include <linux/acpi.h>
32#include <acpi/acpi_bus.h>
33#include <acpi/acpi_drivers.h>
34
35static int debug;
36static int check_sta_before_sun;
37
38#define DRIVER_VERSION "0.1"
39#define DRIVER_AUTHOR "Alex Chiang <achiang@hp.com>"
40#define DRIVER_DESC "ACPI PCI Slot Detection Driver"
41MODULE_AUTHOR(DRIVER_AUTHOR);
42MODULE_DESCRIPTION(DRIVER_DESC);
43MODULE_LICENSE("GPL");
44MODULE_PARM_DESC(debug, "Debugging mode enabled or not");
45module_param(debug, bool, 0644);
46
47#define _COMPONENT ACPI_PCI_COMPONENT
48ACPI_MODULE_NAME("pci_slot");
49
50#define MY_NAME "pci_slot"
51#define err(format, arg...) printk(KERN_ERR "%s: " format , MY_NAME , ## arg)
52#define info(format, arg...) printk(KERN_INFO "%s: " format , MY_NAME , ## arg)
53#define dbg(format, arg...) \
54 do { \
55 if (debug) \
56 printk(KERN_DEBUG "%s: " format, \
57 MY_NAME , ## arg); \
58 } while (0)
59
60#define SLOT_NAME_SIZE 20 /* Inspired by #define in acpiphp.h */
61
62struct acpi_pci_slot {
63 acpi_handle root_handle; /* handle of the root bridge */
64 struct pci_slot *pci_slot; /* corresponding pci_slot */
65 struct list_head list; /* node in the list of slots */
66};
67
68static int acpi_pci_slot_add(acpi_handle handle);
69static void acpi_pci_slot_remove(acpi_handle handle);
70
71static LIST_HEAD(slot_list);
72static DEFINE_MUTEX(slot_list_lock);
73static struct acpi_pci_driver acpi_pci_slot_driver = {
74 .add = acpi_pci_slot_add,
75 .remove = acpi_pci_slot_remove,
76};
77
78static int
79check_slot(acpi_handle handle, int *device, unsigned long *sun)
80{
81 int retval = 0;
82 unsigned long adr, sta;
83 acpi_status status;
84 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
85
86 acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer);
87 dbg("Checking slot on path: %s\n", (char *)buffer.pointer);
88
89 if (check_sta_before_sun) {
90 /* If SxFy doesn't have _STA, we just assume it's there */
91 status = acpi_evaluate_integer(handle, "_STA", NULL, &sta);
92 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT)) {
93 retval = -1;
94 goto out;
95 }
96 }
97
98 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
99 if (ACPI_FAILURE(status)) {
100 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
101 retval = -1;
102 goto out;
103 }
104
105 *device = (adr >> 16) & 0xffff;
106
107 /* No _SUN == not a slot == bail */
108 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
109 if (ACPI_FAILURE(status)) {
110 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
111 retval = -1;
112 goto out;
113 }
114
115out:
116 kfree(buffer.pointer);
117 return retval;
118}
119
120struct callback_args {
121 acpi_walk_callback user_function; /* only for walk_p2p_bridge */
122 struct pci_bus *pci_bus;
123 acpi_handle root_handle;
124};
125
126/*
127 * register_slot
128 *
129 * Called once for each SxFy object in the namespace. Don't worry about
130 * calling pci_create_slot multiple times for the same pci_bus:device,
131 * since each subsequent call simply bumps the refcount on the pci_slot.
132 *
133 * The number of calls to pci_destroy_slot from unregister_slot is
134 * symmetrical.
135 */
136static acpi_status
137register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
138{
139 int device;
140 unsigned long sun;
141 char name[SLOT_NAME_SIZE];
142 struct acpi_pci_slot *slot;
143 struct pci_slot *pci_slot;
144 struct callback_args *parent_context = context;
145 struct pci_bus *pci_bus = parent_context->pci_bus;
146
147 if (check_slot(handle, &device, &sun))
148 return AE_OK;
149
150 slot = kmalloc(sizeof(*slot), GFP_KERNEL);
151 if (!slot) {
152 err("%s: cannot allocate memory\n", __func__);
153 return AE_OK;
154 }
155
156 snprintf(name, sizeof(name), "%u", (u32)sun);
157 pci_slot = pci_create_slot(pci_bus, device, name);
158 if (IS_ERR(pci_slot)) {
159 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
160 kfree(slot);
161 }
162
163 slot->root_handle = parent_context->root_handle;
164 slot->pci_slot = pci_slot;
165 INIT_LIST_HEAD(&slot->list);
166 mutex_lock(&slot_list_lock);
167 list_add(&slot->list, &slot_list);
168 mutex_unlock(&slot_list_lock);
169
170 dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
171 pci_slot, pci_bus->number, device, name);
172
173 return AE_OK;
174}
175
176/*
177 * walk_p2p_bridge - discover and walk p2p bridges
178 * @handle: points to an acpi_pci_root
179 * @context: p2p_bridge_context pointer
180 *
181 * Note that when we call ourselves recursively, we pass a different
182 * value of pci_bus in the child_context.
183 */
184static acpi_status
185walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
186{
187 int device, function;
188 unsigned long adr;
189 acpi_status status;
190 acpi_handle dummy_handle;
191 acpi_walk_callback user_function;
192
193 struct pci_dev *dev;
194 struct pci_bus *pci_bus;
195 struct callback_args child_context;
196 struct callback_args *parent_context = context;
197
198 pci_bus = parent_context->pci_bus;
199 user_function = parent_context->user_function;
200
201 status = acpi_get_handle(handle, "_ADR", &dummy_handle);
202 if (ACPI_FAILURE(status))
203 return AE_OK;
204
205 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
206 if (ACPI_FAILURE(status))
207 return AE_OK;
208
209 device = (adr >> 16) & 0xffff;
210 function = adr & 0xffff;
211
212 dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
213 if (!dev || !dev->subordinate)
214 goto out;
215
216 child_context.pci_bus = dev->subordinate;
217 child_context.user_function = user_function;
218 child_context.root_handle = parent_context->root_handle;
219
220 dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
221 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
222 user_function, &child_context, NULL);
223 if (ACPI_FAILURE(status))
224 goto out;
225
226 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
227 walk_p2p_bridge, &child_context, NULL);
228out:
229 pci_dev_put(dev);
230 return AE_OK;
231}
232
233/*
234 * walk_root_bridge - generic root bridge walker
235 * @handle: points to an acpi_pci_root
236 * @user_function: user callback for slot objects
237 *
238 * Call user_function for all objects underneath this root bridge.
239 * Walk p2p bridges underneath us and call user_function on those too.
240 */
241static int
242walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
243{
244 int seg, bus;
245 unsigned long tmp;
246 acpi_status status;
247 acpi_handle dummy_handle;
248 struct pci_bus *pci_bus;
249 struct callback_args context;
250
251 /* If the bridge doesn't have _STA, we assume it is always there */
252 status = acpi_get_handle(handle, "_STA", &dummy_handle);
253 if (ACPI_SUCCESS(status)) {
254 status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
255 if (ACPI_FAILURE(status)) {
256 info("%s: _STA evaluation failure\n", __func__);
257 return 0;
258 }
259 if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
260 /* don't register this object */
261 return 0;
262 }
263
264 status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
265 seg = ACPI_SUCCESS(status) ? tmp : 0;
266
267 status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
268 bus = ACPI_SUCCESS(status) ? tmp : 0;
269
270 pci_bus = pci_find_bus(seg, bus);
271 if (!pci_bus)
272 return 0;
273
274 context.pci_bus = pci_bus;
275 context.user_function = user_function;
276 context.root_handle = handle;
277
278 dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
279 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
280 user_function, &context, NULL);
281 if (ACPI_FAILURE(status))
282 return status;
283
284 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
285 walk_p2p_bridge, &context, NULL);
286 if (ACPI_FAILURE(status))
287 err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
288
289 return status;
290}
291
292/*
293 * acpi_pci_slot_add
294 * @handle: points to an acpi_pci_root
295 */
296static int
297acpi_pci_slot_add(acpi_handle handle)
298{
299 acpi_status status;
300
301 status = walk_root_bridge(handle, register_slot);
302 if (ACPI_FAILURE(status))
303 err("%s: register_slot failure - %d\n", __func__, status);
304
305 return status;
306}
307
308/*
309 * acpi_pci_slot_remove
310 * @handle: points to an acpi_pci_root
311 */
312static void
313acpi_pci_slot_remove(acpi_handle handle)
314{
315 struct acpi_pci_slot *slot, *tmp;
316
317 mutex_lock(&slot_list_lock);
318 list_for_each_entry_safe(slot, tmp, &slot_list, list) {
319 if (slot->root_handle == handle) {
320 list_del(&slot->list);
321 pci_destroy_slot(slot->pci_slot);
322 kfree(slot);
323 }
324 }
325 mutex_unlock(&slot_list_lock);
326}
327
328static int do_sta_before_sun(const struct dmi_system_id *d)
329{
330 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
331 check_sta_before_sun = 1;
332 return 0;
333}
334
335static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
336 /*
337 * Fujitsu Primequest machines will return 1023 to indicate an
338 * error if the _SUN method is evaluated on SxFy objects that
339 * are not present (as indicated by _STA), so for those machines,
340 * we want to check _STA before evaluating _SUN.
341 */
342 {
343 .callback = do_sta_before_sun,
344 .ident = "Fujitsu PRIMEQUEST",
345 .matches = {
346 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
347 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
348 },
349 },
350 {}
351};
352
353static int __init
354acpi_pci_slot_init(void)
355{
356 dmi_check_system(acpi_pci_slot_dmi_table);
357 acpi_pci_register_driver(&acpi_pci_slot_driver);
358 return 0;
359}
360
361static void __exit
362acpi_pci_slot_exit(void)
363{
364 acpi_pci_unregister_driver(&acpi_pci_slot_driver);
365}
366
367module_init(acpi_pci_slot_init);
368module_exit(acpi_pci_slot_exit);