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1// SPDX-License-Identifier: GPL-2.0
2#include <linux/pci.h>
3#include <linux/module.h>
4#include <linux/slab.h>
5#include <linux/ioport.h>
6#include <linux/wait.h>
7
8#include "pci.h"
9
10/*
11 * This interrupt-safe spinlock protects all accesses to PCI
12 * configuration space.
13 */
14
15DEFINE_RAW_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#ifdef CONFIG_PCI_LOCKLESS_CONFIG
28# define pci_lock_config(f) do { (void)(f); } while (0)
29# define pci_unlock_config(f) do { (void)(f); } while (0)
30#else
31# define pci_lock_config(f) raw_spin_lock_irqsave(&pci_lock, f)
32# define pci_unlock_config(f) raw_spin_unlock_irqrestore(&pci_lock, f)
33#endif
34
35#define PCI_OP_READ(size, type, len) \
36int noinline pci_bus_read_config_##size \
37 (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
38{ \
39 int res; \
40 unsigned long flags; \
41 u32 data = 0; \
42 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
43 pci_lock_config(flags); \
44 res = bus->ops->read(bus, devfn, pos, len, &data); \
45 *value = (type)data; \
46 pci_unlock_config(flags); \
47 return res; \
48}
49
50#define PCI_OP_WRITE(size, type, len) \
51int noinline pci_bus_write_config_##size \
52 (struct pci_bus *bus, unsigned int devfn, int pos, type value) \
53{ \
54 int res; \
55 unsigned long flags; \
56 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
57 pci_lock_config(flags); \
58 res = bus->ops->write(bus, devfn, pos, len, value); \
59 pci_unlock_config(flags); \
60 return res; \
61}
62
63PCI_OP_READ(byte, u8, 1)
64PCI_OP_READ(word, u16, 2)
65PCI_OP_READ(dword, u32, 4)
66PCI_OP_WRITE(byte, u8, 1)
67PCI_OP_WRITE(word, u16, 2)
68PCI_OP_WRITE(dword, u32, 4)
69
70EXPORT_SYMBOL(pci_bus_read_config_byte);
71EXPORT_SYMBOL(pci_bus_read_config_word);
72EXPORT_SYMBOL(pci_bus_read_config_dword);
73EXPORT_SYMBOL(pci_bus_write_config_byte);
74EXPORT_SYMBOL(pci_bus_write_config_word);
75EXPORT_SYMBOL(pci_bus_write_config_dword);
76
77int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
78 int where, int size, u32 *val)
79{
80 void __iomem *addr;
81
82 addr = bus->ops->map_bus(bus, devfn, where);
83 if (!addr) {
84 *val = ~0;
85 return PCIBIOS_DEVICE_NOT_FOUND;
86 }
87
88 if (size == 1)
89 *val = readb(addr);
90 else if (size == 2)
91 *val = readw(addr);
92 else
93 *val = readl(addr);
94
95 return PCIBIOS_SUCCESSFUL;
96}
97EXPORT_SYMBOL_GPL(pci_generic_config_read);
98
99int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn,
100 int where, int size, u32 val)
101{
102 void __iomem *addr;
103
104 addr = bus->ops->map_bus(bus, devfn, where);
105 if (!addr)
106 return PCIBIOS_DEVICE_NOT_FOUND;
107
108 if (size == 1)
109 writeb(val, addr);
110 else if (size == 2)
111 writew(val, addr);
112 else
113 writel(val, addr);
114
115 return PCIBIOS_SUCCESSFUL;
116}
117EXPORT_SYMBOL_GPL(pci_generic_config_write);
118
119int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
120 int where, int size, u32 *val)
121{
122 void __iomem *addr;
123
124 addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
125 if (!addr) {
126 *val = ~0;
127 return PCIBIOS_DEVICE_NOT_FOUND;
128 }
129
130 *val = readl(addr);
131
132 if (size <= 2)
133 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
134
135 return PCIBIOS_SUCCESSFUL;
136}
137EXPORT_SYMBOL_GPL(pci_generic_config_read32);
138
139int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
140 int where, int size, u32 val)
141{
142 void __iomem *addr;
143 u32 mask, tmp;
144
145 addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
146 if (!addr)
147 return PCIBIOS_DEVICE_NOT_FOUND;
148
149 if (size == 4) {
150 writel(val, addr);
151 return PCIBIOS_SUCCESSFUL;
152 }
153
154 /*
155 * In general, hardware that supports only 32-bit writes on PCI is
156 * not spec-compliant. For example, software may perform a 16-bit
157 * write. If the hardware only supports 32-bit accesses, we must
158 * do a 32-bit read, merge in the 16 bits we intend to write,
159 * followed by a 32-bit write. If the 16 bits we *don't* intend to
160 * write happen to have any RW1C (write-one-to-clear) bits set, we
161 * just inadvertently cleared something we shouldn't have.
162 */
163 dev_warn_ratelimited(&bus->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x may corrupt adjacent RW1C bits\n",
164 size, pci_domain_nr(bus), bus->number,
165 PCI_SLOT(devfn), PCI_FUNC(devfn), where);
166
167 mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
168 tmp = readl(addr) & mask;
169 tmp |= val << ((where & 0x3) * 8);
170 writel(tmp, addr);
171
172 return PCIBIOS_SUCCESSFUL;
173}
174EXPORT_SYMBOL_GPL(pci_generic_config_write32);
175
176/**
177 * pci_bus_set_ops - Set raw operations of pci bus
178 * @bus: pci bus struct
179 * @ops: new raw operations
180 *
181 * Return previous raw operations
182 */
183struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
184{
185 struct pci_ops *old_ops;
186 unsigned long flags;
187
188 raw_spin_lock_irqsave(&pci_lock, flags);
189 old_ops = bus->ops;
190 bus->ops = ops;
191 raw_spin_unlock_irqrestore(&pci_lock, flags);
192 return old_ops;
193}
194EXPORT_SYMBOL(pci_bus_set_ops);
195
196/*
197 * The following routines are to prevent the user from accessing PCI config
198 * space when it's unsafe to do so. Some devices require this during BIST and
199 * we're required to prevent it during D-state transitions.
200 *
201 * We have a bit per device to indicate it's blocked and a global wait queue
202 * for callers to sleep on until devices are unblocked.
203 */
204static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
205
206static noinline void pci_wait_cfg(struct pci_dev *dev)
207 __must_hold(&pci_lock)
208{
209 do {
210 raw_spin_unlock_irq(&pci_lock);
211 wait_event(pci_cfg_wait, !dev->block_cfg_access);
212 raw_spin_lock_irq(&pci_lock);
213 } while (dev->block_cfg_access);
214}
215
216/* Returns 0 on success, negative values indicate error. */
217#define PCI_USER_READ_CONFIG(size, type) \
218int pci_user_read_config_##size \
219 (struct pci_dev *dev, int pos, type *val) \
220{ \
221 int ret = PCIBIOS_SUCCESSFUL; \
222 u32 data = -1; \
223 if (PCI_##size##_BAD) \
224 return -EINVAL; \
225 raw_spin_lock_irq(&pci_lock); \
226 if (unlikely(dev->block_cfg_access)) \
227 pci_wait_cfg(dev); \
228 ret = dev->bus->ops->read(dev->bus, dev->devfn, \
229 pos, sizeof(type), &data); \
230 raw_spin_unlock_irq(&pci_lock); \
231 *val = (type)data; \
232 return pcibios_err_to_errno(ret); \
233} \
234EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
235
236/* Returns 0 on success, negative values indicate error. */
237#define PCI_USER_WRITE_CONFIG(size, type) \
238int pci_user_write_config_##size \
239 (struct pci_dev *dev, int pos, type val) \
240{ \
241 int ret = PCIBIOS_SUCCESSFUL; \
242 if (PCI_##size##_BAD) \
243 return -EINVAL; \
244 raw_spin_lock_irq(&pci_lock); \
245 if (unlikely(dev->block_cfg_access)) \
246 pci_wait_cfg(dev); \
247 ret = dev->bus->ops->write(dev->bus, dev->devfn, \
248 pos, sizeof(type), val); \
249 raw_spin_unlock_irq(&pci_lock); \
250 return pcibios_err_to_errno(ret); \
251} \
252EXPORT_SYMBOL_GPL(pci_user_write_config_##size);
253
254PCI_USER_READ_CONFIG(byte, u8)
255PCI_USER_READ_CONFIG(word, u16)
256PCI_USER_READ_CONFIG(dword, u32)
257PCI_USER_WRITE_CONFIG(byte, u8)
258PCI_USER_WRITE_CONFIG(word, u16)
259PCI_USER_WRITE_CONFIG(dword, u32)
260
261/**
262 * pci_cfg_access_lock - Lock PCI config reads/writes
263 * @dev: pci device struct
264 *
265 * When access is locked, any userspace reads or writes to config
266 * space and concurrent lock requests will sleep until access is
267 * allowed via pci_cfg_access_unlock() again.
268 */
269void pci_cfg_access_lock(struct pci_dev *dev)
270{
271 might_sleep();
272
273 raw_spin_lock_irq(&pci_lock);
274 if (dev->block_cfg_access)
275 pci_wait_cfg(dev);
276 dev->block_cfg_access = 1;
277 raw_spin_unlock_irq(&pci_lock);
278}
279EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
280
281/**
282 * pci_cfg_access_trylock - try to lock PCI config reads/writes
283 * @dev: pci device struct
284 *
285 * Same as pci_cfg_access_lock, but will return 0 if access is
286 * already locked, 1 otherwise. This function can be used from
287 * atomic contexts.
288 */
289bool pci_cfg_access_trylock(struct pci_dev *dev)
290{
291 unsigned long flags;
292 bool locked = true;
293
294 raw_spin_lock_irqsave(&pci_lock, flags);
295 if (dev->block_cfg_access)
296 locked = false;
297 else
298 dev->block_cfg_access = 1;
299 raw_spin_unlock_irqrestore(&pci_lock, flags);
300
301 return locked;
302}
303EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
304
305/**
306 * pci_cfg_access_unlock - Unlock PCI config reads/writes
307 * @dev: pci device struct
308 *
309 * This function allows PCI config accesses to resume.
310 */
311void pci_cfg_access_unlock(struct pci_dev *dev)
312{
313 unsigned long flags;
314
315 raw_spin_lock_irqsave(&pci_lock, flags);
316
317 /*
318 * This indicates a problem in the caller, but we don't need
319 * to kill them, unlike a double-block above.
320 */
321 WARN_ON(!dev->block_cfg_access);
322
323 dev->block_cfg_access = 0;
324 raw_spin_unlock_irqrestore(&pci_lock, flags);
325
326 wake_up_all(&pci_cfg_wait);
327}
328EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
329
330static inline int pcie_cap_version(const struct pci_dev *dev)
331{
332 return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS;
333}
334
335bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
336{
337 int type = pci_pcie_type(dev);
338
339 return type == PCI_EXP_TYPE_ENDPOINT ||
340 type == PCI_EXP_TYPE_LEG_END ||
341 type == PCI_EXP_TYPE_ROOT_PORT ||
342 type == PCI_EXP_TYPE_UPSTREAM ||
343 type == PCI_EXP_TYPE_DOWNSTREAM ||
344 type == PCI_EXP_TYPE_PCI_BRIDGE ||
345 type == PCI_EXP_TYPE_PCIE_BRIDGE;
346}
347
348static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
349{
350 return pcie_downstream_port(dev) &&
351 pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT;
352}
353
354bool pcie_cap_has_rtctl(const struct pci_dev *dev)
355{
356 int type = pci_pcie_type(dev);
357
358 return type == PCI_EXP_TYPE_ROOT_PORT ||
359 type == PCI_EXP_TYPE_RC_EC;
360}
361
362static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
363{
364 if (!pci_is_pcie(dev))
365 return false;
366
367 switch (pos) {
368 case PCI_EXP_FLAGS:
369 return true;
370 case PCI_EXP_DEVCAP:
371 case PCI_EXP_DEVCTL:
372 case PCI_EXP_DEVSTA:
373 return true;
374 case PCI_EXP_LNKCAP:
375 case PCI_EXP_LNKCTL:
376 case PCI_EXP_LNKSTA:
377 return pcie_cap_has_lnkctl(dev);
378 case PCI_EXP_SLTCAP:
379 case PCI_EXP_SLTCTL:
380 case PCI_EXP_SLTSTA:
381 return pcie_cap_has_sltctl(dev);
382 case PCI_EXP_RTCTL:
383 case PCI_EXP_RTCAP:
384 case PCI_EXP_RTSTA:
385 return pcie_cap_has_rtctl(dev);
386 case PCI_EXP_DEVCAP2:
387 case PCI_EXP_DEVCTL2:
388 case PCI_EXP_LNKCAP2:
389 case PCI_EXP_LNKCTL2:
390 case PCI_EXP_LNKSTA2:
391 return pcie_cap_version(dev) > 1;
392 default:
393 return false;
394 }
395}
396
397/*
398 * Note that these accessor functions are only for the "PCI Express
399 * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the
400 * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)
401 */
402int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
403{
404 int ret;
405
406 *val = 0;
407 if (pos & 1)
408 return PCIBIOS_BAD_REGISTER_NUMBER;
409
410 if (pcie_capability_reg_implemented(dev, pos)) {
411 ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
412 /*
413 * Reset *val to 0 if pci_read_config_word() fails, it may
414 * have been written as 0xFFFF if hardware error happens
415 * during pci_read_config_word().
416 */
417 if (ret)
418 *val = 0;
419 return ret;
420 }
421
422 /*
423 * For Functions that do not implement the Slot Capabilities,
424 * Slot Status, and Slot Control registers, these spaces must
425 * be hardwired to 0b, with the exception of the Presence Detect
426 * State bit in the Slot Status register of Downstream Ports,
427 * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8)
428 */
429 if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
430 pos == PCI_EXP_SLTSTA)
431 *val = PCI_EXP_SLTSTA_PDS;
432
433 return 0;
434}
435EXPORT_SYMBOL(pcie_capability_read_word);
436
437int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
438{
439 int ret;
440
441 *val = 0;
442 if (pos & 3)
443 return PCIBIOS_BAD_REGISTER_NUMBER;
444
445 if (pcie_capability_reg_implemented(dev, pos)) {
446 ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
447 /*
448 * Reset *val to 0 if pci_read_config_dword() fails, it may
449 * have been written as 0xFFFFFFFF if hardware error happens
450 * during pci_read_config_dword().
451 */
452 if (ret)
453 *val = 0;
454 return ret;
455 }
456
457 if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
458 pos == PCI_EXP_SLTSTA)
459 *val = PCI_EXP_SLTSTA_PDS;
460
461 return 0;
462}
463EXPORT_SYMBOL(pcie_capability_read_dword);
464
465int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val)
466{
467 if (pos & 1)
468 return PCIBIOS_BAD_REGISTER_NUMBER;
469
470 if (!pcie_capability_reg_implemented(dev, pos))
471 return 0;
472
473 return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val);
474}
475EXPORT_SYMBOL(pcie_capability_write_word);
476
477int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val)
478{
479 if (pos & 3)
480 return PCIBIOS_BAD_REGISTER_NUMBER;
481
482 if (!pcie_capability_reg_implemented(dev, pos))
483 return 0;
484
485 return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val);
486}
487EXPORT_SYMBOL(pcie_capability_write_dword);
488
489int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos,
490 u16 clear, u16 set)
491{
492 int ret;
493 u16 val;
494
495 ret = pcie_capability_read_word(dev, pos, &val);
496 if (!ret) {
497 val &= ~clear;
498 val |= set;
499 ret = pcie_capability_write_word(dev, pos, val);
500 }
501
502 return ret;
503}
504EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
505
506int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
507 u32 clear, u32 set)
508{
509 int ret;
510 u32 val;
511
512 ret = pcie_capability_read_dword(dev, pos, &val);
513 if (!ret) {
514 val &= ~clear;
515 val |= set;
516 ret = pcie_capability_write_dword(dev, pos, val);
517 }
518
519 return ret;
520}
521EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);
522
523int pci_read_config_byte(const struct pci_dev *dev, int where, u8 *val)
524{
525 if (pci_dev_is_disconnected(dev)) {
526 *val = ~0;
527 return PCIBIOS_DEVICE_NOT_FOUND;
528 }
529 return pci_bus_read_config_byte(dev->bus, dev->devfn, where, val);
530}
531EXPORT_SYMBOL(pci_read_config_byte);
532
533int pci_read_config_word(const struct pci_dev *dev, int where, u16 *val)
534{
535 if (pci_dev_is_disconnected(dev)) {
536 *val = ~0;
537 return PCIBIOS_DEVICE_NOT_FOUND;
538 }
539 return pci_bus_read_config_word(dev->bus, dev->devfn, where, val);
540}
541EXPORT_SYMBOL(pci_read_config_word);
542
543int pci_read_config_dword(const struct pci_dev *dev, int where,
544 u32 *val)
545{
546 if (pci_dev_is_disconnected(dev)) {
547 *val = ~0;
548 return PCIBIOS_DEVICE_NOT_FOUND;
549 }
550 return pci_bus_read_config_dword(dev->bus, dev->devfn, where, val);
551}
552EXPORT_SYMBOL(pci_read_config_dword);
553
554int pci_write_config_byte(const struct pci_dev *dev, int where, u8 val)
555{
556 if (pci_dev_is_disconnected(dev))
557 return PCIBIOS_DEVICE_NOT_FOUND;
558 return pci_bus_write_config_byte(dev->bus, dev->devfn, where, val);
559}
560EXPORT_SYMBOL(pci_write_config_byte);
561
562int pci_write_config_word(const struct pci_dev *dev, int where, u16 val)
563{
564 if (pci_dev_is_disconnected(dev))
565 return PCIBIOS_DEVICE_NOT_FOUND;
566 return pci_bus_write_config_word(dev->bus, dev->devfn, where, val);
567}
568EXPORT_SYMBOL(pci_write_config_word);
569
570int pci_write_config_dword(const struct pci_dev *dev, int where,
571 u32 val)
572{
573 if (pci_dev_is_disconnected(dev))
574 return PCIBIOS_DEVICE_NOT_FOUND;
575 return pci_bus_write_config_dword(dev->bus, dev->devfn, where, val);
576}
577EXPORT_SYMBOL(pci_write_config_dword);
1#include <linux/delay.h>
2#include <linux/pci.h>
3#include <linux/module.h>
4#include <linux/sched.h>
5#include <linux/slab.h>
6#include <linux/ioport.h>
7#include <linux/wait.h>
8
9#include "pci.h"
10
11/*
12 * This interrupt-safe spinlock protects all accesses to PCI
13 * configuration space.
14 */
15
16DEFINE_RAW_SPINLOCK(pci_lock);
17
18/*
19 * Wrappers for all PCI configuration access functions. They just check
20 * alignment, do locking and call the low-level functions pointed to
21 * by pci_dev->ops.
22 */
23
24#define PCI_byte_BAD 0
25#define PCI_word_BAD (pos & 1)
26#define PCI_dword_BAD (pos & 3)
27
28#define PCI_OP_READ(size, type, len) \
29int pci_bus_read_config_##size \
30 (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \
31{ \
32 int res; \
33 unsigned long flags; \
34 u32 data = 0; \
35 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
36 raw_spin_lock_irqsave(&pci_lock, flags); \
37 res = bus->ops->read(bus, devfn, pos, len, &data); \
38 *value = (type)data; \
39 raw_spin_unlock_irqrestore(&pci_lock, flags); \
40 return res; \
41}
42
43#define PCI_OP_WRITE(size, type, len) \
44int pci_bus_write_config_##size \
45 (struct pci_bus *bus, unsigned int devfn, int pos, type value) \
46{ \
47 int res; \
48 unsigned long flags; \
49 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
50 raw_spin_lock_irqsave(&pci_lock, flags); \
51 res = bus->ops->write(bus, devfn, pos, len, value); \
52 raw_spin_unlock_irqrestore(&pci_lock, flags); \
53 return res; \
54}
55
56PCI_OP_READ(byte, u8, 1)
57PCI_OP_READ(word, u16, 2)
58PCI_OP_READ(dword, u32, 4)
59PCI_OP_WRITE(byte, u8, 1)
60PCI_OP_WRITE(word, u16, 2)
61PCI_OP_WRITE(dword, u32, 4)
62
63EXPORT_SYMBOL(pci_bus_read_config_byte);
64EXPORT_SYMBOL(pci_bus_read_config_word);
65EXPORT_SYMBOL(pci_bus_read_config_dword);
66EXPORT_SYMBOL(pci_bus_write_config_byte);
67EXPORT_SYMBOL(pci_bus_write_config_word);
68EXPORT_SYMBOL(pci_bus_write_config_dword);
69
70int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn,
71 int where, int size, u32 *val)
72{
73 void __iomem *addr;
74
75 addr = bus->ops->map_bus(bus, devfn, where);
76 if (!addr) {
77 *val = ~0;
78 return PCIBIOS_DEVICE_NOT_FOUND;
79 }
80
81 if (size == 1)
82 *val = readb(addr);
83 else if (size == 2)
84 *val = readw(addr);
85 else
86 *val = readl(addr);
87
88 return PCIBIOS_SUCCESSFUL;
89}
90EXPORT_SYMBOL_GPL(pci_generic_config_read);
91
92int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn,
93 int where, int size, u32 val)
94{
95 void __iomem *addr;
96
97 addr = bus->ops->map_bus(bus, devfn, where);
98 if (!addr)
99 return PCIBIOS_DEVICE_NOT_FOUND;
100
101 if (size == 1)
102 writeb(val, addr);
103 else if (size == 2)
104 writew(val, addr);
105 else
106 writel(val, addr);
107
108 return PCIBIOS_SUCCESSFUL;
109}
110EXPORT_SYMBOL_GPL(pci_generic_config_write);
111
112int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn,
113 int where, int size, u32 *val)
114{
115 void __iomem *addr;
116
117 addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
118 if (!addr) {
119 *val = ~0;
120 return PCIBIOS_DEVICE_NOT_FOUND;
121 }
122
123 *val = readl(addr);
124
125 if (size <= 2)
126 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1);
127
128 return PCIBIOS_SUCCESSFUL;
129}
130EXPORT_SYMBOL_GPL(pci_generic_config_read32);
131
132int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn,
133 int where, int size, u32 val)
134{
135 void __iomem *addr;
136 u32 mask, tmp;
137
138 addr = bus->ops->map_bus(bus, devfn, where & ~0x3);
139 if (!addr)
140 return PCIBIOS_DEVICE_NOT_FOUND;
141
142 if (size == 4) {
143 writel(val, addr);
144 return PCIBIOS_SUCCESSFUL;
145 }
146
147 /*
148 * In general, hardware that supports only 32-bit writes on PCI is
149 * not spec-compliant. For example, software may perform a 16-bit
150 * write. If the hardware only supports 32-bit accesses, we must
151 * do a 32-bit read, merge in the 16 bits we intend to write,
152 * followed by a 32-bit write. If the 16 bits we *don't* intend to
153 * write happen to have any RW1C (write-one-to-clear) bits set, we
154 * just inadvertently cleared something we shouldn't have.
155 */
156 dev_warn_ratelimited(&bus->dev, "%d-byte config write to %04x:%02x:%02x.%d offset %#x may corrupt adjacent RW1C bits\n",
157 size, pci_domain_nr(bus), bus->number,
158 PCI_SLOT(devfn), PCI_FUNC(devfn), where);
159
160 mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8));
161 tmp = readl(addr) & mask;
162 tmp |= val << ((where & 0x3) * 8);
163 writel(tmp, addr);
164
165 return PCIBIOS_SUCCESSFUL;
166}
167EXPORT_SYMBOL_GPL(pci_generic_config_write32);
168
169/**
170 * pci_bus_set_ops - Set raw operations of pci bus
171 * @bus: pci bus struct
172 * @ops: new raw operations
173 *
174 * Return previous raw operations
175 */
176struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
177{
178 struct pci_ops *old_ops;
179 unsigned long flags;
180
181 raw_spin_lock_irqsave(&pci_lock, flags);
182 old_ops = bus->ops;
183 bus->ops = ops;
184 raw_spin_unlock_irqrestore(&pci_lock, flags);
185 return old_ops;
186}
187EXPORT_SYMBOL(pci_bus_set_ops);
188
189/*
190 * The following routines are to prevent the user from accessing PCI config
191 * space when it's unsafe to do so. Some devices require this during BIST and
192 * we're required to prevent it during D-state transitions.
193 *
194 * We have a bit per device to indicate it's blocked and a global wait queue
195 * for callers to sleep on until devices are unblocked.
196 */
197static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
198
199static noinline void pci_wait_cfg(struct pci_dev *dev)
200{
201 DECLARE_WAITQUEUE(wait, current);
202
203 __add_wait_queue(&pci_cfg_wait, &wait);
204 do {
205 set_current_state(TASK_UNINTERRUPTIBLE);
206 raw_spin_unlock_irq(&pci_lock);
207 schedule();
208 raw_spin_lock_irq(&pci_lock);
209 } while (dev->block_cfg_access);
210 __remove_wait_queue(&pci_cfg_wait, &wait);
211}
212
213/* Returns 0 on success, negative values indicate error. */
214#define PCI_USER_READ_CONFIG(size, type) \
215int pci_user_read_config_##size \
216 (struct pci_dev *dev, int pos, type *val) \
217{ \
218 int ret = PCIBIOS_SUCCESSFUL; \
219 u32 data = -1; \
220 if (PCI_##size##_BAD) \
221 return -EINVAL; \
222 raw_spin_lock_irq(&pci_lock); \
223 if (unlikely(dev->block_cfg_access)) \
224 pci_wait_cfg(dev); \
225 ret = dev->bus->ops->read(dev->bus, dev->devfn, \
226 pos, sizeof(type), &data); \
227 raw_spin_unlock_irq(&pci_lock); \
228 *val = (type)data; \
229 return pcibios_err_to_errno(ret); \
230} \
231EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
232
233/* Returns 0 on success, negative values indicate error. */
234#define PCI_USER_WRITE_CONFIG(size, type) \
235int pci_user_write_config_##size \
236 (struct pci_dev *dev, int pos, type val) \
237{ \
238 int ret = PCIBIOS_SUCCESSFUL; \
239 if (PCI_##size##_BAD) \
240 return -EINVAL; \
241 raw_spin_lock_irq(&pci_lock); \
242 if (unlikely(dev->block_cfg_access)) \
243 pci_wait_cfg(dev); \
244 ret = dev->bus->ops->write(dev->bus, dev->devfn, \
245 pos, sizeof(type), val); \
246 raw_spin_unlock_irq(&pci_lock); \
247 return pcibios_err_to_errno(ret); \
248} \
249EXPORT_SYMBOL_GPL(pci_user_write_config_##size);
250
251PCI_USER_READ_CONFIG(byte, u8)
252PCI_USER_READ_CONFIG(word, u16)
253PCI_USER_READ_CONFIG(dword, u32)
254PCI_USER_WRITE_CONFIG(byte, u8)
255PCI_USER_WRITE_CONFIG(word, u16)
256PCI_USER_WRITE_CONFIG(dword, u32)
257
258/* VPD access through PCI 2.2+ VPD capability */
259
260/**
261 * pci_read_vpd - Read one entry from Vital Product Data
262 * @dev: pci device struct
263 * @pos: offset in vpd space
264 * @count: number of bytes to read
265 * @buf: pointer to where to store result
266 */
267ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
268{
269 if (!dev->vpd || !dev->vpd->ops)
270 return -ENODEV;
271 return dev->vpd->ops->read(dev, pos, count, buf);
272}
273EXPORT_SYMBOL(pci_read_vpd);
274
275/**
276 * pci_write_vpd - Write entry to Vital Product Data
277 * @dev: pci device struct
278 * @pos: offset in vpd space
279 * @count: number of bytes to write
280 * @buf: buffer containing write data
281 */
282ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
283{
284 if (!dev->vpd || !dev->vpd->ops)
285 return -ENODEV;
286 return dev->vpd->ops->write(dev, pos, count, buf);
287}
288EXPORT_SYMBOL(pci_write_vpd);
289
290/**
291 * pci_set_vpd_size - Set size of Vital Product Data space
292 * @dev: pci device struct
293 * @len: size of vpd space
294 */
295int pci_set_vpd_size(struct pci_dev *dev, size_t len)
296{
297 if (!dev->vpd || !dev->vpd->ops)
298 return -ENODEV;
299 return dev->vpd->ops->set_size(dev, len);
300}
301EXPORT_SYMBOL(pci_set_vpd_size);
302
303#define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
304
305/**
306 * pci_vpd_size - determine actual size of Vital Product Data
307 * @dev: pci device struct
308 * @old_size: current assumed size, also maximum allowed size
309 */
310static size_t pci_vpd_size(struct pci_dev *dev, size_t old_size)
311{
312 size_t off = 0;
313 unsigned char header[1+2]; /* 1 byte tag, 2 bytes length */
314
315 while (off < old_size &&
316 pci_read_vpd(dev, off, 1, header) == 1) {
317 unsigned char tag;
318
319 if (header[0] & PCI_VPD_LRDT) {
320 /* Large Resource Data Type Tag */
321 tag = pci_vpd_lrdt_tag(header);
322 /* Only read length from known tag items */
323 if ((tag == PCI_VPD_LTIN_ID_STRING) ||
324 (tag == PCI_VPD_LTIN_RO_DATA) ||
325 (tag == PCI_VPD_LTIN_RW_DATA)) {
326 if (pci_read_vpd(dev, off+1, 2,
327 &header[1]) != 2) {
328 dev_warn(&dev->dev,
329 "invalid large VPD tag %02x size at offset %zu",
330 tag, off + 1);
331 return 0;
332 }
333 off += PCI_VPD_LRDT_TAG_SIZE +
334 pci_vpd_lrdt_size(header);
335 }
336 } else {
337 /* Short Resource Data Type Tag */
338 off += PCI_VPD_SRDT_TAG_SIZE +
339 pci_vpd_srdt_size(header);
340 tag = pci_vpd_srdt_tag(header);
341 }
342
343 if (tag == PCI_VPD_STIN_END) /* End tag descriptor */
344 return off;
345
346 if ((tag != PCI_VPD_LTIN_ID_STRING) &&
347 (tag != PCI_VPD_LTIN_RO_DATA) &&
348 (tag != PCI_VPD_LTIN_RW_DATA)) {
349 dev_warn(&dev->dev,
350 "invalid %s VPD tag %02x at offset %zu",
351 (header[0] & PCI_VPD_LRDT) ? "large" : "short",
352 tag, off);
353 return 0;
354 }
355 }
356 return 0;
357}
358
359/*
360 * Wait for last operation to complete.
361 * This code has to spin since there is no other notification from the PCI
362 * hardware. Since the VPD is often implemented by serial attachment to an
363 * EEPROM, it may take many milliseconds to complete.
364 *
365 * Returns 0 on success, negative values indicate error.
366 */
367static int pci_vpd_wait(struct pci_dev *dev)
368{
369 struct pci_vpd *vpd = dev->vpd;
370 unsigned long timeout = jiffies + msecs_to_jiffies(50);
371 unsigned long max_sleep = 16;
372 u16 status;
373 int ret;
374
375 if (!vpd->busy)
376 return 0;
377
378 while (time_before(jiffies, timeout)) {
379 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
380 &status);
381 if (ret < 0)
382 return ret;
383
384 if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
385 vpd->busy = 0;
386 return 0;
387 }
388
389 if (fatal_signal_pending(current))
390 return -EINTR;
391
392 usleep_range(10, max_sleep);
393 if (max_sleep < 1024)
394 max_sleep *= 2;
395 }
396
397 dev_warn(&dev->dev, "VPD access failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update\n");
398 return -ETIMEDOUT;
399}
400
401static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
402 void *arg)
403{
404 struct pci_vpd *vpd = dev->vpd;
405 int ret;
406 loff_t end = pos + count;
407 u8 *buf = arg;
408
409 if (pos < 0)
410 return -EINVAL;
411
412 if (!vpd->valid) {
413 vpd->valid = 1;
414 vpd->len = pci_vpd_size(dev, vpd->len);
415 }
416
417 if (vpd->len == 0)
418 return -EIO;
419
420 if (pos > vpd->len)
421 return 0;
422
423 if (end > vpd->len) {
424 end = vpd->len;
425 count = end - pos;
426 }
427
428 if (mutex_lock_killable(&vpd->lock))
429 return -EINTR;
430
431 ret = pci_vpd_wait(dev);
432 if (ret < 0)
433 goto out;
434
435 while (pos < end) {
436 u32 val;
437 unsigned int i, skip;
438
439 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
440 pos & ~3);
441 if (ret < 0)
442 break;
443 vpd->busy = 1;
444 vpd->flag = PCI_VPD_ADDR_F;
445 ret = pci_vpd_wait(dev);
446 if (ret < 0)
447 break;
448
449 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
450 if (ret < 0)
451 break;
452
453 skip = pos & 3;
454 for (i = 0; i < sizeof(u32); i++) {
455 if (i >= skip) {
456 *buf++ = val;
457 if (++pos == end)
458 break;
459 }
460 val >>= 8;
461 }
462 }
463out:
464 mutex_unlock(&vpd->lock);
465 return ret ? ret : count;
466}
467
468static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
469 const void *arg)
470{
471 struct pci_vpd *vpd = dev->vpd;
472 const u8 *buf = arg;
473 loff_t end = pos + count;
474 int ret = 0;
475
476 if (pos < 0 || (pos & 3) || (count & 3))
477 return -EINVAL;
478
479 if (!vpd->valid) {
480 vpd->valid = 1;
481 vpd->len = pci_vpd_size(dev, vpd->len);
482 }
483
484 if (vpd->len == 0)
485 return -EIO;
486
487 if (end > vpd->len)
488 return -EINVAL;
489
490 if (mutex_lock_killable(&vpd->lock))
491 return -EINTR;
492
493 ret = pci_vpd_wait(dev);
494 if (ret < 0)
495 goto out;
496
497 while (pos < end) {
498 u32 val;
499
500 val = *buf++;
501 val |= *buf++ << 8;
502 val |= *buf++ << 16;
503 val |= *buf++ << 24;
504
505 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
506 if (ret < 0)
507 break;
508 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
509 pos | PCI_VPD_ADDR_F);
510 if (ret < 0)
511 break;
512
513 vpd->busy = 1;
514 vpd->flag = 0;
515 ret = pci_vpd_wait(dev);
516 if (ret < 0)
517 break;
518
519 pos += sizeof(u32);
520 }
521out:
522 mutex_unlock(&vpd->lock);
523 return ret ? ret : count;
524}
525
526static int pci_vpd_set_size(struct pci_dev *dev, size_t len)
527{
528 struct pci_vpd *vpd = dev->vpd;
529
530 if (len == 0 || len > PCI_VPD_MAX_SIZE)
531 return -EIO;
532
533 vpd->valid = 1;
534 vpd->len = len;
535
536 return 0;
537}
538
539static const struct pci_vpd_ops pci_vpd_ops = {
540 .read = pci_vpd_read,
541 .write = pci_vpd_write,
542 .set_size = pci_vpd_set_size,
543};
544
545static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count,
546 void *arg)
547{
548 struct pci_dev *tdev = pci_get_slot(dev->bus,
549 PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
550 ssize_t ret;
551
552 if (!tdev)
553 return -ENODEV;
554
555 ret = pci_read_vpd(tdev, pos, count, arg);
556 pci_dev_put(tdev);
557 return ret;
558}
559
560static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count,
561 const void *arg)
562{
563 struct pci_dev *tdev = pci_get_slot(dev->bus,
564 PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
565 ssize_t ret;
566
567 if (!tdev)
568 return -ENODEV;
569
570 ret = pci_write_vpd(tdev, pos, count, arg);
571 pci_dev_put(tdev);
572 return ret;
573}
574
575static int pci_vpd_f0_set_size(struct pci_dev *dev, size_t len)
576{
577 struct pci_dev *tdev = pci_get_slot(dev->bus,
578 PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
579 int ret;
580
581 if (!tdev)
582 return -ENODEV;
583
584 ret = pci_set_vpd_size(tdev, len);
585 pci_dev_put(tdev);
586 return ret;
587}
588
589static const struct pci_vpd_ops pci_vpd_f0_ops = {
590 .read = pci_vpd_f0_read,
591 .write = pci_vpd_f0_write,
592 .set_size = pci_vpd_f0_set_size,
593};
594
595int pci_vpd_init(struct pci_dev *dev)
596{
597 struct pci_vpd *vpd;
598 u8 cap;
599
600 cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
601 if (!cap)
602 return -ENODEV;
603
604 vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
605 if (!vpd)
606 return -ENOMEM;
607
608 vpd->len = PCI_VPD_MAX_SIZE;
609 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0)
610 vpd->ops = &pci_vpd_f0_ops;
611 else
612 vpd->ops = &pci_vpd_ops;
613 mutex_init(&vpd->lock);
614 vpd->cap = cap;
615 vpd->busy = 0;
616 vpd->valid = 0;
617 dev->vpd = vpd;
618 return 0;
619}
620
621void pci_vpd_release(struct pci_dev *dev)
622{
623 kfree(dev->vpd);
624}
625
626/**
627 * pci_cfg_access_lock - Lock PCI config reads/writes
628 * @dev: pci device struct
629 *
630 * When access is locked, any userspace reads or writes to config
631 * space and concurrent lock requests will sleep until access is
632 * allowed via pci_cfg_access_unlocked again.
633 */
634void pci_cfg_access_lock(struct pci_dev *dev)
635{
636 might_sleep();
637
638 raw_spin_lock_irq(&pci_lock);
639 if (dev->block_cfg_access)
640 pci_wait_cfg(dev);
641 dev->block_cfg_access = 1;
642 raw_spin_unlock_irq(&pci_lock);
643}
644EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
645
646/**
647 * pci_cfg_access_trylock - try to lock PCI config reads/writes
648 * @dev: pci device struct
649 *
650 * Same as pci_cfg_access_lock, but will return 0 if access is
651 * already locked, 1 otherwise. This function can be used from
652 * atomic contexts.
653 */
654bool pci_cfg_access_trylock(struct pci_dev *dev)
655{
656 unsigned long flags;
657 bool locked = true;
658
659 raw_spin_lock_irqsave(&pci_lock, flags);
660 if (dev->block_cfg_access)
661 locked = false;
662 else
663 dev->block_cfg_access = 1;
664 raw_spin_unlock_irqrestore(&pci_lock, flags);
665
666 return locked;
667}
668EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
669
670/**
671 * pci_cfg_access_unlock - Unlock PCI config reads/writes
672 * @dev: pci device struct
673 *
674 * This function allows PCI config accesses to resume.
675 */
676void pci_cfg_access_unlock(struct pci_dev *dev)
677{
678 unsigned long flags;
679
680 raw_spin_lock_irqsave(&pci_lock, flags);
681
682 /* This indicates a problem in the caller, but we don't need
683 * to kill them, unlike a double-block above. */
684 WARN_ON(!dev->block_cfg_access);
685
686 dev->block_cfg_access = 0;
687 wake_up_all(&pci_cfg_wait);
688 raw_spin_unlock_irqrestore(&pci_lock, flags);
689}
690EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
691
692static inline int pcie_cap_version(const struct pci_dev *dev)
693{
694 return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS;
695}
696
697static bool pcie_downstream_port(const struct pci_dev *dev)
698{
699 int type = pci_pcie_type(dev);
700
701 return type == PCI_EXP_TYPE_ROOT_PORT ||
702 type == PCI_EXP_TYPE_DOWNSTREAM;
703}
704
705bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
706{
707 int type = pci_pcie_type(dev);
708
709 return type == PCI_EXP_TYPE_ENDPOINT ||
710 type == PCI_EXP_TYPE_LEG_END ||
711 type == PCI_EXP_TYPE_ROOT_PORT ||
712 type == PCI_EXP_TYPE_UPSTREAM ||
713 type == PCI_EXP_TYPE_DOWNSTREAM ||
714 type == PCI_EXP_TYPE_PCI_BRIDGE ||
715 type == PCI_EXP_TYPE_PCIE_BRIDGE;
716}
717
718static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
719{
720 return pcie_downstream_port(dev) &&
721 pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT;
722}
723
724static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
725{
726 int type = pci_pcie_type(dev);
727
728 return type == PCI_EXP_TYPE_ROOT_PORT ||
729 type == PCI_EXP_TYPE_RC_EC;
730}
731
732static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
733{
734 if (!pci_is_pcie(dev))
735 return false;
736
737 switch (pos) {
738 case PCI_EXP_FLAGS:
739 return true;
740 case PCI_EXP_DEVCAP:
741 case PCI_EXP_DEVCTL:
742 case PCI_EXP_DEVSTA:
743 return true;
744 case PCI_EXP_LNKCAP:
745 case PCI_EXP_LNKCTL:
746 case PCI_EXP_LNKSTA:
747 return pcie_cap_has_lnkctl(dev);
748 case PCI_EXP_SLTCAP:
749 case PCI_EXP_SLTCTL:
750 case PCI_EXP_SLTSTA:
751 return pcie_cap_has_sltctl(dev);
752 case PCI_EXP_RTCTL:
753 case PCI_EXP_RTCAP:
754 case PCI_EXP_RTSTA:
755 return pcie_cap_has_rtctl(dev);
756 case PCI_EXP_DEVCAP2:
757 case PCI_EXP_DEVCTL2:
758 case PCI_EXP_LNKCAP2:
759 case PCI_EXP_LNKCTL2:
760 case PCI_EXP_LNKSTA2:
761 return pcie_cap_version(dev) > 1;
762 default:
763 return false;
764 }
765}
766
767/*
768 * Note that these accessor functions are only for the "PCI Express
769 * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the
770 * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)
771 */
772int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
773{
774 int ret;
775
776 *val = 0;
777 if (pos & 1)
778 return -EINVAL;
779
780 if (pcie_capability_reg_implemented(dev, pos)) {
781 ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
782 /*
783 * Reset *val to 0 if pci_read_config_word() fails, it may
784 * have been written as 0xFFFF if hardware error happens
785 * during pci_read_config_word().
786 */
787 if (ret)
788 *val = 0;
789 return ret;
790 }
791
792 /*
793 * For Functions that do not implement the Slot Capabilities,
794 * Slot Status, and Slot Control registers, these spaces must
795 * be hardwired to 0b, with the exception of the Presence Detect
796 * State bit in the Slot Status register of Downstream Ports,
797 * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8)
798 */
799 if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
800 pos == PCI_EXP_SLTSTA)
801 *val = PCI_EXP_SLTSTA_PDS;
802
803 return 0;
804}
805EXPORT_SYMBOL(pcie_capability_read_word);
806
807int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
808{
809 int ret;
810
811 *val = 0;
812 if (pos & 3)
813 return -EINVAL;
814
815 if (pcie_capability_reg_implemented(dev, pos)) {
816 ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
817 /*
818 * Reset *val to 0 if pci_read_config_dword() fails, it may
819 * have been written as 0xFFFFFFFF if hardware error happens
820 * during pci_read_config_dword().
821 */
822 if (ret)
823 *val = 0;
824 return ret;
825 }
826
827 if (pci_is_pcie(dev) && pcie_downstream_port(dev) &&
828 pos == PCI_EXP_SLTSTA)
829 *val = PCI_EXP_SLTSTA_PDS;
830
831 return 0;
832}
833EXPORT_SYMBOL(pcie_capability_read_dword);
834
835int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val)
836{
837 if (pos & 1)
838 return -EINVAL;
839
840 if (!pcie_capability_reg_implemented(dev, pos))
841 return 0;
842
843 return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val);
844}
845EXPORT_SYMBOL(pcie_capability_write_word);
846
847int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val)
848{
849 if (pos & 3)
850 return -EINVAL;
851
852 if (!pcie_capability_reg_implemented(dev, pos))
853 return 0;
854
855 return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val);
856}
857EXPORT_SYMBOL(pcie_capability_write_dword);
858
859int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos,
860 u16 clear, u16 set)
861{
862 int ret;
863 u16 val;
864
865 ret = pcie_capability_read_word(dev, pos, &val);
866 if (!ret) {
867 val &= ~clear;
868 val |= set;
869 ret = pcie_capability_write_word(dev, pos, val);
870 }
871
872 return ret;
873}
874EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
875
876int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
877 u32 clear, u32 set)
878{
879 int ret;
880 u32 val;
881
882 ret = pcie_capability_read_dword(dev, pos, &val);
883 if (!ret) {
884 val &= ~clear;
885 val |= set;
886 ret = pcie_capability_write_dword(dev, pos, val);
887 }
888
889 return ret;
890}
891EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);