Commit | Line | Data |
---|---|---|
94e61088 | 1 | #include <linux/delay.h> |
1da177e4 LT |
2 | #include <linux/pci.h> |
3 | #include <linux/module.h> | |
f6a57033 | 4 | #include <linux/sched.h> |
1da177e4 | 5 | #include <linux/ioport.h> |
7ea7e98f | 6 | #include <linux/wait.h> |
1da177e4 | 7 | |
48b19148 AB |
8 | #include "pci.h" |
9 | ||
1da177e4 LT |
10 | /* |
11 | * This interrupt-safe spinlock protects all accesses to PCI | |
12 | * configuration space. | |
13 | */ | |
14 | ||
15 | static 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) \ | |
28 | int 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) \ | |
43 | int 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 | ||
55 | PCI_OP_READ(byte, u8, 1) | |
56 | PCI_OP_READ(word, u16, 2) | |
57 | PCI_OP_READ(dword, u32, 4) | |
58 | PCI_OP_WRITE(byte, u8, 1) | |
59 | PCI_OP_WRITE(word, u16, 2) | |
60 | PCI_OP_WRITE(dword, u32, 4) | |
61 | ||
62 | EXPORT_SYMBOL(pci_bus_read_config_byte); | |
63 | EXPORT_SYMBOL(pci_bus_read_config_word); | |
64 | EXPORT_SYMBOL(pci_bus_read_config_dword); | |
65 | EXPORT_SYMBOL(pci_bus_write_config_byte); | |
66 | EXPORT_SYMBOL(pci_bus_write_config_word); | |
67 | EXPORT_SYMBOL(pci_bus_write_config_dword); | |
e04b0ea2 | 68 | |
7ea7e98f MW |
69 | /* |
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 | */ | |
77 | static DECLARE_WAIT_QUEUE_HEAD(pci_ucfg_wait); | |
e04b0ea2 | 78 | |
7ea7e98f MW |
79 | static 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); | |
e04b0ea2 BK |
91 | } |
92 | ||
93 | #define PCI_USER_READ_CONFIG(size,type) \ | |
94 | int pci_user_read_config_##size \ | |
95 | (struct pci_dev *dev, int pos, type *val) \ | |
96 | { \ | |
e04b0ea2 BK |
97 | int ret = 0; \ |
98 | u32 data = -1; \ | |
99 | if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ | |
7ea7e98f MW |
100 | 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, \ | |
e04b0ea2 | 103 | pos, sizeof(type), &data); \ |
7ea7e98f | 104 | spin_unlock_irq(&pci_lock); \ |
e04b0ea2 BK |
105 | *val = (type)data; \ |
106 | return ret; \ | |
107 | } | |
108 | ||
109 | #define PCI_USER_WRITE_CONFIG(size,type) \ | |
110 | int pci_user_write_config_##size \ | |
111 | (struct pci_dev *dev, int pos, type val) \ | |
112 | { \ | |
e04b0ea2 BK |
113 | int ret = -EIO; \ |
114 | if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ | |
7ea7e98f MW |
115 | 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, \ | |
e04b0ea2 | 118 | pos, sizeof(type), val); \ |
7ea7e98f | 119 | spin_unlock_irq(&pci_lock); \ |
e04b0ea2 BK |
120 | return ret; \ |
121 | } | |
122 | ||
123 | PCI_USER_READ_CONFIG(byte, u8) | |
124 | PCI_USER_READ_CONFIG(word, u16) | |
125 | PCI_USER_READ_CONFIG(dword, u32) | |
126 | PCI_USER_WRITE_CONFIG(byte, u8) | |
127 | PCI_USER_WRITE_CONFIG(word, u16) | |
128 | PCI_USER_WRITE_CONFIG(dword, u32) | |
129 | ||
94e61088 BH |
130 | /* VPD access through PCI 2.2+ VPD capability */ |
131 | ||
132 | #define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1) | |
133 | ||
134 | struct pci_vpd_pci22 { | |
135 | struct pci_vpd base; | |
1120f8b8 SH |
136 | struct mutex lock; |
137 | u16 flag; | |
94e61088 | 138 | bool busy; |
1120f8b8 | 139 | u8 cap; |
94e61088 BH |
140 | }; |
141 | ||
1120f8b8 SH |
142 | /* |
143 | * Wait for last operation to complete. | |
144 | * This code has to spin since there is no other notification from the PCI | |
145 | * hardware. Since the VPD is often implemented by serial attachment to an | |
146 | * EEPROM, it may take many milliseconds to complete. | |
147 | */ | |
94e61088 BH |
148 | static int pci_vpd_pci22_wait(struct pci_dev *dev) |
149 | { | |
150 | struct pci_vpd_pci22 *vpd = | |
151 | container_of(dev->vpd, struct pci_vpd_pci22, base); | |
1120f8b8 SH |
152 | unsigned long timeout = jiffies + HZ/20 + 2; |
153 | u16 status; | |
94e61088 BH |
154 | int ret; |
155 | ||
156 | if (!vpd->busy) | |
157 | return 0; | |
158 | ||
94e61088 | 159 | for (;;) { |
1120f8b8 | 160 | ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR, |
94e61088 | 161 | &status); |
1120f8b8 | 162 | if (ret) |
94e61088 | 163 | return ret; |
1120f8b8 SH |
164 | |
165 | if ((status & PCI_VPD_ADDR_F) == vpd->flag) { | |
94e61088 BH |
166 | vpd->busy = false; |
167 | return 0; | |
168 | } | |
1120f8b8 SH |
169 | |
170 | if (time_after(jiffies, timeout)) | |
94e61088 | 171 | return -ETIMEDOUT; |
1120f8b8 SH |
172 | if (fatal_signal_pending(current)) |
173 | return -EINTR; | |
174 | if (!cond_resched()) | |
175 | udelay(10); | |
94e61088 BH |
176 | } |
177 | } | |
178 | ||
179 | static int pci_vpd_pci22_read(struct pci_dev *dev, int pos, int size, | |
180 | char *buf) | |
181 | { | |
182 | struct pci_vpd_pci22 *vpd = | |
183 | container_of(dev->vpd, struct pci_vpd_pci22, base); | |
184 | u32 val; | |
1120f8b8 | 185 | int ret = 0; |
94e61088 BH |
186 | int begin, end, i; |
187 | ||
99cb233d | 188 | if (pos < 0 || pos > vpd->base.len || size > vpd->base.len - pos) |
94e61088 BH |
189 | return -EINVAL; |
190 | if (size == 0) | |
191 | return 0; | |
192 | ||
1120f8b8 SH |
193 | if (mutex_lock_killable(&vpd->lock)) |
194 | return -EINTR; | |
195 | ||
94e61088 BH |
196 | ret = pci_vpd_pci22_wait(dev); |
197 | if (ret < 0) | |
198 | goto out; | |
199 | ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, | |
200 | pos & ~3); | |
201 | if (ret < 0) | |
202 | goto out; | |
1120f8b8 | 203 | |
94e61088 | 204 | vpd->busy = true; |
1120f8b8 | 205 | vpd->flag = PCI_VPD_ADDR_F; |
94e61088 BH |
206 | ret = pci_vpd_pci22_wait(dev); |
207 | if (ret < 0) | |
208 | goto out; | |
209 | ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, | |
210 | &val); | |
211 | out: | |
1120f8b8 | 212 | mutex_unlock(&vpd->lock); |
94e61088 BH |
213 | if (ret < 0) |
214 | return ret; | |
215 | ||
216 | /* Convert to bytes */ | |
217 | begin = pos & 3; | |
218 | end = min(4, begin + size); | |
219 | for (i = 0; i < end; ++i) { | |
220 | if (i >= begin) | |
221 | *buf++ = val; | |
222 | val >>= 8; | |
223 | } | |
224 | return end - begin; | |
225 | } | |
226 | ||
227 | static int pci_vpd_pci22_write(struct pci_dev *dev, int pos, int size, | |
228 | const char *buf) | |
229 | { | |
230 | struct pci_vpd_pci22 *vpd = | |
231 | container_of(dev->vpd, struct pci_vpd_pci22, base); | |
232 | u32 val; | |
1120f8b8 | 233 | int ret = 0; |
94e61088 | 234 | |
99cb233d BL |
235 | if (pos < 0 || pos > vpd->base.len || pos & 3 || |
236 | size > vpd->base.len - pos || size < 4) | |
94e61088 BH |
237 | return -EINVAL; |
238 | ||
239 | val = (u8) *buf++; | |
240 | val |= ((u8) *buf++) << 8; | |
241 | val |= ((u8) *buf++) << 16; | |
242 | val |= ((u32)(u8) *buf++) << 24; | |
243 | ||
1120f8b8 SH |
244 | if (mutex_lock_killable(&vpd->lock)) |
245 | return -EINTR; | |
94e61088 BH |
246 | ret = pci_vpd_pci22_wait(dev); |
247 | if (ret < 0) | |
248 | goto out; | |
249 | ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, | |
250 | val); | |
251 | if (ret < 0) | |
252 | goto out; | |
253 | ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, | |
254 | pos | PCI_VPD_ADDR_F); | |
255 | if (ret < 0) | |
256 | goto out; | |
257 | vpd->busy = true; | |
258 | vpd->flag = 0; | |
259 | ret = pci_vpd_pci22_wait(dev); | |
260 | out: | |
1120f8b8 | 261 | mutex_unlock(&vpd->lock); |
94e61088 BH |
262 | if (ret < 0) |
263 | return ret; | |
264 | ||
265 | return 4; | |
266 | } | |
267 | ||
94e61088 BH |
268 | static void pci_vpd_pci22_release(struct pci_dev *dev) |
269 | { | |
270 | kfree(container_of(dev->vpd, struct pci_vpd_pci22, base)); | |
271 | } | |
272 | ||
273 | static struct pci_vpd_ops pci_vpd_pci22_ops = { | |
274 | .read = pci_vpd_pci22_read, | |
275 | .write = pci_vpd_pci22_write, | |
94e61088 BH |
276 | .release = pci_vpd_pci22_release, |
277 | }; | |
278 | ||
279 | int pci_vpd_pci22_init(struct pci_dev *dev) | |
280 | { | |
281 | struct pci_vpd_pci22 *vpd; | |
282 | u8 cap; | |
283 | ||
284 | cap = pci_find_capability(dev, PCI_CAP_ID_VPD); | |
285 | if (!cap) | |
286 | return -ENODEV; | |
287 | vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC); | |
288 | if (!vpd) | |
289 | return -ENOMEM; | |
290 | ||
99cb233d | 291 | vpd->base.len = PCI_VPD_PCI22_SIZE; |
94e61088 | 292 | vpd->base.ops = &pci_vpd_pci22_ops; |
1120f8b8 | 293 | mutex_init(&vpd->lock); |
94e61088 BH |
294 | vpd->cap = cap; |
295 | vpd->busy = false; | |
296 | dev->vpd = &vpd->base; | |
297 | return 0; | |
298 | } | |
299 | ||
e04b0ea2 BK |
300 | /** |
301 | * pci_block_user_cfg_access - Block userspace PCI config reads/writes | |
302 | * @dev: pci device struct | |
303 | * | |
7ea7e98f MW |
304 | * When user access is blocked, any reads or writes to config space will |
305 | * sleep until access is unblocked again. We don't allow nesting of | |
306 | * block/unblock calls. | |
307 | */ | |
e04b0ea2 BK |
308 | void pci_block_user_cfg_access(struct pci_dev *dev) |
309 | { | |
310 | unsigned long flags; | |
7ea7e98f | 311 | int was_blocked; |
e04b0ea2 | 312 | |
e04b0ea2 | 313 | spin_lock_irqsave(&pci_lock, flags); |
7ea7e98f | 314 | was_blocked = dev->block_ucfg_access; |
e04b0ea2 BK |
315 | dev->block_ucfg_access = 1; |
316 | spin_unlock_irqrestore(&pci_lock, flags); | |
7ea7e98f MW |
317 | |
318 | /* If we BUG() inside the pci_lock, we're guaranteed to hose | |
319 | * the machine */ | |
320 | BUG_ON(was_blocked); | |
e04b0ea2 BK |
321 | } |
322 | EXPORT_SYMBOL_GPL(pci_block_user_cfg_access); | |
323 | ||
324 | /** | |
325 | * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes | |
326 | * @dev: pci device struct | |
327 | * | |
328 | * This function allows userspace PCI config accesses to resume. | |
7ea7e98f | 329 | */ |
e04b0ea2 BK |
330 | void pci_unblock_user_cfg_access(struct pci_dev *dev) |
331 | { | |
332 | unsigned long flags; | |
333 | ||
e04b0ea2 | 334 | spin_lock_irqsave(&pci_lock, flags); |
7ea7e98f MW |
335 | |
336 | /* This indicates a problem in the caller, but we don't need | |
337 | * to kill them, unlike a double-block above. */ | |
338 | WARN_ON(!dev->block_ucfg_access); | |
339 | ||
e04b0ea2 | 340 | dev->block_ucfg_access = 0; |
7ea7e98f | 341 | wake_up_all(&pci_ucfg_wait); |
e04b0ea2 BK |
342 | spin_unlock_irqrestore(&pci_lock, flags); |
343 | } | |
344 | EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access); |