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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 *
Alex Chiange4268aa2008-07-17 11:13:32 -06009 * Copyright (C) 2007-2008 Hewlett-Packard Development Company, L.P.
10 * Alex Chiang <achiang@hp.com>
Alex Chiang8344b562008-06-10 15:30:42 -060011 *
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
Matthew Wilcox362b7072008-07-22 12:37:17 -060079check_slot(acpi_handle handle, unsigned long *sun)
Alex Chiang8344b562008-06-10 15:30:42 -060080{
Matthew Wilcox362b7072008-07-22 12:37:17 -060081 int device = -1;
Alex Chiang8344b562008-06-10 15:30:42 -060082 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);
Matthew Wilcox362b7072008-07-22 12:37:17 -060092 if (ACPI_SUCCESS(status) && !(sta & ACPI_STA_DEVICE_PRESENT))
Alex Chiang8344b562008-06-10 15:30:42 -060093 goto out;
Alex Chiang8344b562008-06-10 15:30:42 -060094 }
95
96 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
97 if (ACPI_FAILURE(status)) {
98 dbg("_ADR returned %d on %s\n", status, (char *)buffer.pointer);
Alex Chiang8344b562008-06-10 15:30:42 -060099 goto out;
100 }
101
Alex Chiang8344b562008-06-10 15:30:42 -0600102 /* No _SUN == not a slot == bail */
103 status = acpi_evaluate_integer(handle, "_SUN", NULL, sun);
104 if (ACPI_FAILURE(status)) {
105 dbg("_SUN returned %d on %s\n", status, (char *)buffer.pointer);
Alex Chiang8344b562008-06-10 15:30:42 -0600106 goto out;
107 }
108
Matthew Wilcox362b7072008-07-22 12:37:17 -0600109 device = (adr >> 16) & 0xffff;
Alex Chiang8344b562008-06-10 15:30:42 -0600110out:
111 kfree(buffer.pointer);
Matthew Wilcox362b7072008-07-22 12:37:17 -0600112 return device;
Alex Chiang8344b562008-06-10 15:30:42 -0600113}
114
115struct callback_args {
116 acpi_walk_callback user_function; /* only for walk_p2p_bridge */
117 struct pci_bus *pci_bus;
118 acpi_handle root_handle;
119};
120
121/*
122 * register_slot
123 *
124 * Called once for each SxFy object in the namespace. Don't worry about
125 * calling pci_create_slot multiple times for the same pci_bus:device,
126 * since each subsequent call simply bumps the refcount on the pci_slot.
127 *
128 * The number of calls to pci_destroy_slot from unregister_slot is
129 * symmetrical.
130 */
131static acpi_status
132register_slot(acpi_handle handle, u32 lvl, void *context, void **rv)
133{
134 int device;
135 unsigned long sun;
136 char name[SLOT_NAME_SIZE];
137 struct acpi_pci_slot *slot;
138 struct pci_slot *pci_slot;
139 struct callback_args *parent_context = context;
140 struct pci_bus *pci_bus = parent_context->pci_bus;
141
Matthew Wilcox362b7072008-07-22 12:37:17 -0600142 device = check_slot(handle, &sun);
143 if (device < 0)
Alex Chiang8344b562008-06-10 15:30:42 -0600144 return AE_OK;
145
146 slot = kmalloc(sizeof(*slot), GFP_KERNEL);
147 if (!slot) {
148 err("%s: cannot allocate memory\n", __func__);
149 return AE_OK;
150 }
151
152 snprintf(name, sizeof(name), "%u", (u32)sun);
153 pci_slot = pci_create_slot(pci_bus, device, name);
154 if (IS_ERR(pci_slot)) {
155 err("pci_create_slot returned %ld\n", PTR_ERR(pci_slot));
156 kfree(slot);
Alex Chiange4268aa2008-07-17 11:13:32 -0600157 return AE_OK;
Alex Chiang8344b562008-06-10 15:30:42 -0600158 }
159
160 slot->root_handle = parent_context->root_handle;
161 slot->pci_slot = pci_slot;
162 INIT_LIST_HEAD(&slot->list);
163 mutex_lock(&slot_list_lock);
164 list_add(&slot->list, &slot_list);
165 mutex_unlock(&slot_list_lock);
166
167 dbg("pci_slot: %p, pci_bus: %x, device: %d, name: %s\n",
168 pci_slot, pci_bus->number, device, name);
169
170 return AE_OK;
171}
172
173/*
174 * walk_p2p_bridge - discover and walk p2p bridges
175 * @handle: points to an acpi_pci_root
176 * @context: p2p_bridge_context pointer
177 *
178 * Note that when we call ourselves recursively, we pass a different
179 * value of pci_bus in the child_context.
180 */
181static acpi_status
182walk_p2p_bridge(acpi_handle handle, u32 lvl, void *context, void **rv)
183{
184 int device, function;
185 unsigned long adr;
186 acpi_status status;
187 acpi_handle dummy_handle;
188 acpi_walk_callback user_function;
189
190 struct pci_dev *dev;
191 struct pci_bus *pci_bus;
192 struct callback_args child_context;
193 struct callback_args *parent_context = context;
194
195 pci_bus = parent_context->pci_bus;
196 user_function = parent_context->user_function;
197
198 status = acpi_get_handle(handle, "_ADR", &dummy_handle);
199 if (ACPI_FAILURE(status))
200 return AE_OK;
201
202 status = acpi_evaluate_integer(handle, "_ADR", NULL, &adr);
203 if (ACPI_FAILURE(status))
204 return AE_OK;
205
206 device = (adr >> 16) & 0xffff;
207 function = adr & 0xffff;
208
209 dev = pci_get_slot(pci_bus, PCI_DEVFN(device, function));
210 if (!dev || !dev->subordinate)
211 goto out;
212
213 child_context.pci_bus = dev->subordinate;
214 child_context.user_function = user_function;
215 child_context.root_handle = parent_context->root_handle;
216
217 dbg("p2p bridge walk, pci_bus = %x\n", dev->subordinate->number);
218 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
219 user_function, &child_context, NULL);
220 if (ACPI_FAILURE(status))
221 goto out;
222
223 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
224 walk_p2p_bridge, &child_context, NULL);
225out:
226 pci_dev_put(dev);
227 return AE_OK;
228}
229
230/*
231 * walk_root_bridge - generic root bridge walker
232 * @handle: points to an acpi_pci_root
233 * @user_function: user callback for slot objects
234 *
235 * Call user_function for all objects underneath this root bridge.
236 * Walk p2p bridges underneath us and call user_function on those too.
237 */
238static int
239walk_root_bridge(acpi_handle handle, acpi_walk_callback user_function)
240{
241 int seg, bus;
242 unsigned long tmp;
243 acpi_status status;
244 acpi_handle dummy_handle;
245 struct pci_bus *pci_bus;
246 struct callback_args context;
247
248 /* If the bridge doesn't have _STA, we assume it is always there */
249 status = acpi_get_handle(handle, "_STA", &dummy_handle);
250 if (ACPI_SUCCESS(status)) {
251 status = acpi_evaluate_integer(handle, "_STA", NULL, &tmp);
252 if (ACPI_FAILURE(status)) {
253 info("%s: _STA evaluation failure\n", __func__);
254 return 0;
255 }
256 if ((tmp & ACPI_STA_DEVICE_FUNCTIONING) == 0)
257 /* don't register this object */
258 return 0;
259 }
260
261 status = acpi_evaluate_integer(handle, "_SEG", NULL, &tmp);
262 seg = ACPI_SUCCESS(status) ? tmp : 0;
263
264 status = acpi_evaluate_integer(handle, "_BBN", NULL, &tmp);
265 bus = ACPI_SUCCESS(status) ? tmp : 0;
266
267 pci_bus = pci_find_bus(seg, bus);
268 if (!pci_bus)
269 return 0;
270
271 context.pci_bus = pci_bus;
272 context.user_function = user_function;
273 context.root_handle = handle;
274
275 dbg("root bridge walk, pci_bus = %x\n", pci_bus->number);
276 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
277 user_function, &context, NULL);
278 if (ACPI_FAILURE(status))
279 return status;
280
281 status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, (u32)1,
282 walk_p2p_bridge, &context, NULL);
283 if (ACPI_FAILURE(status))
284 err("%s: walk_p2p_bridge failure - %d\n", __func__, status);
285
286 return status;
287}
288
289/*
290 * acpi_pci_slot_add
291 * @handle: points to an acpi_pci_root
292 */
293static int
294acpi_pci_slot_add(acpi_handle handle)
295{
296 acpi_status status;
297
298 status = walk_root_bridge(handle, register_slot);
299 if (ACPI_FAILURE(status))
300 err("%s: register_slot failure - %d\n", __func__, status);
301
302 return status;
303}
304
305/*
306 * acpi_pci_slot_remove
307 * @handle: points to an acpi_pci_root
308 */
309static void
310acpi_pci_slot_remove(acpi_handle handle)
311{
312 struct acpi_pci_slot *slot, *tmp;
313
314 mutex_lock(&slot_list_lock);
315 list_for_each_entry_safe(slot, tmp, &slot_list, list) {
316 if (slot->root_handle == handle) {
317 list_del(&slot->list);
318 pci_destroy_slot(slot->pci_slot);
319 kfree(slot);
320 }
321 }
322 mutex_unlock(&slot_list_lock);
323}
324
325static int do_sta_before_sun(const struct dmi_system_id *d)
326{
327 info("%s detected: will evaluate _STA before calling _SUN\n", d->ident);
328 check_sta_before_sun = 1;
329 return 0;
330}
331
332static struct dmi_system_id acpi_pci_slot_dmi_table[] __initdata = {
333 /*
334 * Fujitsu Primequest machines will return 1023 to indicate an
335 * error if the _SUN method is evaluated on SxFy objects that
336 * are not present (as indicated by _STA), so for those machines,
337 * we want to check _STA before evaluating _SUN.
338 */
339 {
340 .callback = do_sta_before_sun,
341 .ident = "Fujitsu PRIMEQUEST",
342 .matches = {
343 DMI_MATCH(DMI_BIOS_VENDOR, "FUJITSU LIMITED"),
344 DMI_MATCH(DMI_BIOS_VERSION, "PRIMEQUEST"),
345 },
346 },
347 {}
348};
349
350static int __init
351acpi_pci_slot_init(void)
352{
353 dmi_check_system(acpi_pci_slot_dmi_table);
354 acpi_pci_register_driver(&acpi_pci_slot_driver);
355 return 0;
356}
357
358static void __exit
359acpi_pci_slot_exit(void)
360{
361 acpi_pci_unregister_driver(&acpi_pci_slot_driver);
362}
363
364module_init(acpi_pci_slot_init);
365module_exit(acpi_pci_slot_exit);