blob: 39bb96b413ef1b696eae53d6239c2d3a29bbd20e [file] [log] [blame]
Ben Hutchings94e61082008-03-05 16:52:39 +00001#include <linux/delay.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07002#include <linux/pci.h>
3#include <linux/module.h>
Al Virof6a57032006-10-18 01:47:25 -04004#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07005#include <linux/ioport.h>
Matthew Wilcox7ea7e982006-10-19 09:41:28 -06006#include <linux/wait.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007
Adrian Bunk48b19142005-11-06 01:45:08 +01008#include "pci.h"
9
Linus Torvalds1da177e2005-04-16 15:20:36 -070010/*
11 * This interrupt-safe spinlock protects all accesses to PCI
12 * configuration space.
13 */
14
15static DEFINE_SPINLOCK(pci_lock);
16
17/*
18 * Wrappers for all PCI configuration access functions. They just check
19 * alignment, do locking and call the low-level functions pointed to
20 * by pci_dev->ops.
21 */
22
23#define PCI_byte_BAD 0
24#define PCI_word_BAD (pos & 1)
25#define PCI_dword_BAD (pos & 3)
26
27#define PCI_OP_READ(size,type,len) \
28int pci_bus_read_config_##size \
29 (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
30{ \
31 int res; \
32 unsigned long flags; \
33 u32 data = 0; \
34 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
35 spin_lock_irqsave(&pci_lock, flags); \
36 res = bus->ops->read(bus, devfn, pos, len, &data); \
37 *value = (type)data; \
38 spin_unlock_irqrestore(&pci_lock, flags); \
39 return res; \
40}
41
42#define PCI_OP_WRITE(size,type,len) \
43int pci_bus_write_config_##size \
44 (struct pci_bus *bus, unsigned int devfn, int pos, type value) \
45{ \
46 int res; \
47 unsigned long flags; \
48 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
49 spin_lock_irqsave(&pci_lock, flags); \
50 res = bus->ops->write(bus, devfn, pos, len, value); \
51 spin_unlock_irqrestore(&pci_lock, flags); \
52 return res; \
53}
54
55PCI_OP_READ(byte, u8, 1)
56PCI_OP_READ(word, u16, 2)
57PCI_OP_READ(dword, u32, 4)
58PCI_OP_WRITE(byte, u8, 1)
59PCI_OP_WRITE(word, u16, 2)
60PCI_OP_WRITE(dword, u32, 4)
61
62EXPORT_SYMBOL(pci_bus_read_config_byte);
63EXPORT_SYMBOL(pci_bus_read_config_word);
64EXPORT_SYMBOL(pci_bus_read_config_dword);
65EXPORT_SYMBOL(pci_bus_write_config_byte);
66EXPORT_SYMBOL(pci_bus_write_config_word);
67EXPORT_SYMBOL(pci_bus_write_config_dword);
Brian Kinge04b0ea2005-09-27 01:21:55 -070068
Matthew Wilcox7ea7e982006-10-19 09:41:28 -060069/*
70 * The following routines are to prevent the user from accessing PCI config
71 * space when it's unsafe to do so. Some devices require this during BIST and
72 * we're required to prevent it during D-state transitions.
73 *
74 * We have a bit per device to indicate it's blocked and a global wait queue
75 * for callers to sleep on until devices are unblocked.
76 */
77static DECLARE_WAIT_QUEUE_HEAD(pci_ucfg_wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -070078
Matthew Wilcox7ea7e982006-10-19 09:41:28 -060079static noinline void pci_wait_ucfg(struct pci_dev *dev)
80{
81 DECLARE_WAITQUEUE(wait, current);
82
83 __add_wait_queue(&pci_ucfg_wait, &wait);
84 do {
85 set_current_state(TASK_UNINTERRUPTIBLE);
86 spin_unlock_irq(&pci_lock);
87 schedule();
88 spin_lock_irq(&pci_lock);
89 } while (dev->block_ucfg_access);
90 __remove_wait_queue(&pci_ucfg_wait, &wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -070091}
92
93#define PCI_USER_READ_CONFIG(size,type) \
94int pci_user_read_config_##size \
95 (struct pci_dev *dev, int pos, type *val) \
96{ \
Brian Kinge04b0ea2005-09-27 01:21:55 -070097 int ret = 0; \
98 u32 data = -1; \
99 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600100 spin_lock_irq(&pci_lock); \
101 if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
102 ret = dev->bus->ops->read(dev->bus, dev->devfn, \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700103 pos, sizeof(type), &data); \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600104 spin_unlock_irq(&pci_lock); \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700105 *val = (type)data; \
106 return ret; \
107}
108
109#define PCI_USER_WRITE_CONFIG(size,type) \
110int pci_user_write_config_##size \
111 (struct pci_dev *dev, int pos, type val) \
112{ \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700113 int ret = -EIO; \
114 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600115 spin_lock_irq(&pci_lock); \
116 if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
117 ret = dev->bus->ops->write(dev->bus, dev->devfn, \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700118 pos, sizeof(type), val); \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600119 spin_unlock_irq(&pci_lock); \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700120 return ret; \
121}
122
123PCI_USER_READ_CONFIG(byte, u8)
124PCI_USER_READ_CONFIG(word, u16)
125PCI_USER_READ_CONFIG(dword, u32)
126PCI_USER_WRITE_CONFIG(byte, u8)
127PCI_USER_WRITE_CONFIG(word, u16)
128PCI_USER_WRITE_CONFIG(dword, u32)
129
Ben Hutchings94e61082008-03-05 16:52:39 +0000130/* VPD access through PCI 2.2+ VPD capability */
131
132#define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1)
133
134struct pci_vpd_pci22 {
135 struct pci_vpd base;
136 spinlock_t lock; /* controls access to hardware and the flags */
137 u8 cap;
138 bool busy;
139 bool flag; /* value of F bit to wait for */
140};
141
142/* Wait for last operation to complete */
143static int pci_vpd_pci22_wait(struct pci_dev *dev)
144{
145 struct pci_vpd_pci22 *vpd =
146 container_of(dev->vpd, struct pci_vpd_pci22, base);
147 u16 flag, status;
148 int wait;
149 int ret;
150
151 if (!vpd->busy)
152 return 0;
153
154 flag = vpd->flag ? PCI_VPD_ADDR_F : 0;
155 wait = vpd->flag ? 10 : 1000; /* read: 100 us; write: 10 ms */
156 for (;;) {
157 ret = pci_user_read_config_word(dev,
158 vpd->cap + PCI_VPD_ADDR,
159 &status);
160 if (ret < 0)
161 return ret;
162 if ((status & PCI_VPD_ADDR_F) == flag) {
163 vpd->busy = false;
164 return 0;
165 }
166 if (wait-- == 0)
167 return -ETIMEDOUT;
168 udelay(10);
169 }
170}
171
172static int pci_vpd_pci22_read(struct pci_dev *dev, int pos, int size,
173 char *buf)
174{
175 struct pci_vpd_pci22 *vpd =
176 container_of(dev->vpd, struct pci_vpd_pci22, base);
177 u32 val;
178 int ret;
179 int begin, end, i;
180
Benjamin Li99cb2332008-07-02 10:59:04 -0700181 if (pos < 0 || pos > vpd->base.len || size > vpd->base.len - pos)
Ben Hutchings94e61082008-03-05 16:52:39 +0000182 return -EINVAL;
183 if (size == 0)
184 return 0;
185
186 spin_lock_irq(&vpd->lock);
187 ret = pci_vpd_pci22_wait(dev);
188 if (ret < 0)
189 goto out;
190 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
191 pos & ~3);
192 if (ret < 0)
193 goto out;
194 vpd->busy = true;
195 vpd->flag = 1;
196 ret = pci_vpd_pci22_wait(dev);
197 if (ret < 0)
198 goto out;
199 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA,
200 &val);
201out:
202 spin_unlock_irq(&vpd->lock);
203 if (ret < 0)
204 return ret;
205
206 /* Convert to bytes */
207 begin = pos & 3;
208 end = min(4, begin + size);
209 for (i = 0; i < end; ++i) {
210 if (i >= begin)
211 *buf++ = val;
212 val >>= 8;
213 }
214 return end - begin;
215}
216
217static int pci_vpd_pci22_write(struct pci_dev *dev, int pos, int size,
218 const char *buf)
219{
220 struct pci_vpd_pci22 *vpd =
221 container_of(dev->vpd, struct pci_vpd_pci22, base);
222 u32 val;
223 int ret;
224
Benjamin Li99cb2332008-07-02 10:59:04 -0700225 if (pos < 0 || pos > vpd->base.len || pos & 3 ||
226 size > vpd->base.len - pos || size < 4)
Ben Hutchings94e61082008-03-05 16:52:39 +0000227 return -EINVAL;
228
229 val = (u8) *buf++;
230 val |= ((u8) *buf++) << 8;
231 val |= ((u8) *buf++) << 16;
232 val |= ((u32)(u8) *buf++) << 24;
233
234 spin_lock_irq(&vpd->lock);
235 ret = pci_vpd_pci22_wait(dev);
236 if (ret < 0)
237 goto out;
238 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA,
239 val);
240 if (ret < 0)
241 goto out;
242 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
243 pos | PCI_VPD_ADDR_F);
244 if (ret < 0)
245 goto out;
246 vpd->busy = true;
247 vpd->flag = 0;
248 ret = pci_vpd_pci22_wait(dev);
249out:
250 spin_unlock_irq(&vpd->lock);
251 if (ret < 0)
252 return ret;
253
254 return 4;
255}
256
Ben Hutchings94e61082008-03-05 16:52:39 +0000257static void pci_vpd_pci22_release(struct pci_dev *dev)
258{
259 kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
260}
261
262static struct pci_vpd_ops pci_vpd_pci22_ops = {
263 .read = pci_vpd_pci22_read,
264 .write = pci_vpd_pci22_write,
Ben Hutchings94e61082008-03-05 16:52:39 +0000265 .release = pci_vpd_pci22_release,
266};
267
268int pci_vpd_pci22_init(struct pci_dev *dev)
269{
270 struct pci_vpd_pci22 *vpd;
271 u8 cap;
272
273 cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
274 if (!cap)
275 return -ENODEV;
276 vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
277 if (!vpd)
278 return -ENOMEM;
279
Benjamin Li99cb2332008-07-02 10:59:04 -0700280 vpd->base.len = PCI_VPD_PCI22_SIZE;
Ben Hutchings94e61082008-03-05 16:52:39 +0000281 vpd->base.ops = &pci_vpd_pci22_ops;
282 spin_lock_init(&vpd->lock);
283 vpd->cap = cap;
284 vpd->busy = false;
285 dev->vpd = &vpd->base;
286 return 0;
287}
288
Brian Kinge04b0ea2005-09-27 01:21:55 -0700289/**
290 * pci_block_user_cfg_access - Block userspace PCI config reads/writes
291 * @dev: pci device struct
292 *
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600293 * When user access is blocked, any reads or writes to config space will
294 * sleep until access is unblocked again. We don't allow nesting of
295 * block/unblock calls.
296 */
Brian Kinge04b0ea2005-09-27 01:21:55 -0700297void pci_block_user_cfg_access(struct pci_dev *dev)
298{
299 unsigned long flags;
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600300 int was_blocked;
Brian Kinge04b0ea2005-09-27 01:21:55 -0700301
Brian Kinge04b0ea2005-09-27 01:21:55 -0700302 spin_lock_irqsave(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600303 was_blocked = dev->block_ucfg_access;
Brian Kinge04b0ea2005-09-27 01:21:55 -0700304 dev->block_ucfg_access = 1;
305 spin_unlock_irqrestore(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600306
307 /* If we BUG() inside the pci_lock, we're guaranteed to hose
308 * the machine */
309 BUG_ON(was_blocked);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700310}
311EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
312
313/**
314 * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
315 * @dev: pci device struct
316 *
317 * This function allows userspace PCI config accesses to resume.
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600318 */
Brian Kinge04b0ea2005-09-27 01:21:55 -0700319void pci_unblock_user_cfg_access(struct pci_dev *dev)
320{
321 unsigned long flags;
322
Brian Kinge04b0ea2005-09-27 01:21:55 -0700323 spin_lock_irqsave(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600324
325 /* This indicates a problem in the caller, but we don't need
326 * to kill them, unlike a double-block above. */
327 WARN_ON(!dev->block_ucfg_access);
328
Brian Kinge04b0ea2005-09-27 01:21:55 -0700329 dev->block_ucfg_access = 0;
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600330 wake_up_all(&pci_ucfg_wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700331 spin_unlock_irqrestore(&pci_lock, flags);
332}
333EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);