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v3.5.6
  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
 70/**
 71 * pci_bus_set_ops - Set raw operations of pci bus
 72 * @bus:	pci bus struct
 73 * @ops:	new raw operations
 74 *
 75 * Return previous raw operations
 76 */
 77struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
 78{
 79	struct pci_ops *old_ops;
 80	unsigned long flags;
 81
 82	raw_spin_lock_irqsave(&pci_lock, flags);
 83	old_ops = bus->ops;
 84	bus->ops = ops;
 85	raw_spin_unlock_irqrestore(&pci_lock, flags);
 86	return old_ops;
 87}
 88EXPORT_SYMBOL(pci_bus_set_ops);
 89
 90/**
 91 * pci_read_vpd - Read one entry from Vital Product Data
 92 * @dev:	pci device struct
 93 * @pos:	offset in vpd space
 94 * @count:	number of bytes to read
 95 * @buf:	pointer to where to store result
 96 *
 97 */
 98ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
 99{
100	if (!dev->vpd || !dev->vpd->ops)
101		return -ENODEV;
102	return dev->vpd->ops->read(dev, pos, count, buf);
103}
104EXPORT_SYMBOL(pci_read_vpd);
105
106/**
107 * pci_write_vpd - Write entry to Vital Product Data
108 * @dev:	pci device struct
109 * @pos:	offset in vpd space
110 * @count:	number of bytes to write
111 * @buf:	buffer containing write data
112 *
113 */
114ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
115{
116	if (!dev->vpd || !dev->vpd->ops)
117		return -ENODEV;
118	return dev->vpd->ops->write(dev, pos, count, buf);
119}
120EXPORT_SYMBOL(pci_write_vpd);
121
122/*
123 * The following routines are to prevent the user from accessing PCI config
124 * space when it's unsafe to do so.  Some devices require this during BIST and
125 * we're required to prevent it during D-state transitions.
126 *
127 * We have a bit per device to indicate it's blocked and a global wait queue
128 * for callers to sleep on until devices are unblocked.
129 */
130static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
131
132static noinline void pci_wait_cfg(struct pci_dev *dev)
133{
134	DECLARE_WAITQUEUE(wait, current);
135
136	__add_wait_queue(&pci_cfg_wait, &wait);
137	do {
138		set_current_state(TASK_UNINTERRUPTIBLE);
139		raw_spin_unlock_irq(&pci_lock);
140		schedule();
141		raw_spin_lock_irq(&pci_lock);
142	} while (dev->block_cfg_access);
143	__remove_wait_queue(&pci_cfg_wait, &wait);
144}
145
146/* Returns 0 on success, negative values indicate error. */
147#define PCI_USER_READ_CONFIG(size,type)					\
148int pci_user_read_config_##size						\
149	(struct pci_dev *dev, int pos, type *val)			\
150{									\
151	int ret = 0;							\
152	u32 data = -1;							\
153	if (PCI_##size##_BAD)						\
154		return -EINVAL;						\
155	raw_spin_lock_irq(&pci_lock);				\
156	if (unlikely(dev->block_cfg_access))				\
157		pci_wait_cfg(dev);					\
158	ret = dev->bus->ops->read(dev->bus, dev->devfn,			\
159					pos, sizeof(type), &data);	\
160	raw_spin_unlock_irq(&pci_lock);				\
161	*val = (type)data;						\
162	if (ret > 0)							\
163		ret = -EINVAL;						\
164	return ret;							\
165}
 
166
167/* Returns 0 on success, negative values indicate error. */
168#define PCI_USER_WRITE_CONFIG(size,type)				\
169int pci_user_write_config_##size					\
170	(struct pci_dev *dev, int pos, type val)			\
171{									\
172	int ret = -EIO;							\
173	if (PCI_##size##_BAD)						\
174		return -EINVAL;						\
175	raw_spin_lock_irq(&pci_lock);				\
176	if (unlikely(dev->block_cfg_access))				\
177		pci_wait_cfg(dev);					\
178	ret = dev->bus->ops->write(dev->bus, dev->devfn,		\
179					pos, sizeof(type), val);	\
180	raw_spin_unlock_irq(&pci_lock);				\
181	if (ret > 0)							\
182		ret = -EINVAL;						\
183	return ret;							\
184}
 
185
186PCI_USER_READ_CONFIG(byte, u8)
187PCI_USER_READ_CONFIG(word, u16)
188PCI_USER_READ_CONFIG(dword, u32)
189PCI_USER_WRITE_CONFIG(byte, u8)
190PCI_USER_WRITE_CONFIG(word, u16)
191PCI_USER_WRITE_CONFIG(dword, u32)
192
193/* VPD access through PCI 2.2+ VPD capability */
194
195#define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1)
196
197struct pci_vpd_pci22 {
198	struct pci_vpd base;
199	struct mutex lock;
200	u16	flag;
201	bool	busy;
202	u8	cap;
203};
204
205/*
206 * Wait for last operation to complete.
207 * This code has to spin since there is no other notification from the PCI
208 * hardware. Since the VPD is often implemented by serial attachment to an
209 * EEPROM, it may take many milliseconds to complete.
210 *
211 * Returns 0 on success, negative values indicate error.
212 */
213static int pci_vpd_pci22_wait(struct pci_dev *dev)
214{
215	struct pci_vpd_pci22 *vpd =
216		container_of(dev->vpd, struct pci_vpd_pci22, base);
217	unsigned long timeout = jiffies + HZ/20 + 2;
218	u16 status;
219	int ret;
220
221	if (!vpd->busy)
222		return 0;
223
224	for (;;) {
225		ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
226						&status);
227		if (ret < 0)
228			return ret;
229
230		if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
231			vpd->busy = false;
232			return 0;
233		}
234
235		if (time_after(jiffies, timeout)) {
236			dev_printk(KERN_DEBUG, &dev->dev,
237				   "vpd r/w failed.  This is likely a firmware "
238				   "bug on this device.  Contact the card "
239				   "vendor for a firmware update.");
240			return -ETIMEDOUT;
241		}
242		if (fatal_signal_pending(current))
243			return -EINTR;
244		if (!cond_resched())
245			udelay(10);
246	}
247}
248
249static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
250				  void *arg)
251{
252	struct pci_vpd_pci22 *vpd =
253		container_of(dev->vpd, struct pci_vpd_pci22, base);
254	int ret;
255	loff_t end = pos + count;
256	u8 *buf = arg;
257
258	if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
259		return -EINVAL;
260
261	if (mutex_lock_killable(&vpd->lock))
262		return -EINTR;
263
264	ret = pci_vpd_pci22_wait(dev);
265	if (ret < 0)
266		goto out;
267
268	while (pos < end) {
269		u32 val;
270		unsigned int i, skip;
271
272		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
273						 pos & ~3);
274		if (ret < 0)
275			break;
276		vpd->busy = true;
277		vpd->flag = PCI_VPD_ADDR_F;
278		ret = pci_vpd_pci22_wait(dev);
279		if (ret < 0)
280			break;
281
282		ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
283		if (ret < 0)
284			break;
285
286		skip = pos & 3;
287		for (i = 0;  i < sizeof(u32); i++) {
288			if (i >= skip) {
289				*buf++ = val;
290				if (++pos == end)
291					break;
292			}
293			val >>= 8;
294		}
295	}
296out:
297	mutex_unlock(&vpd->lock);
298	return ret ? ret : count;
299}
300
301static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count,
302				   const void *arg)
303{
304	struct pci_vpd_pci22 *vpd =
305		container_of(dev->vpd, struct pci_vpd_pci22, base);
306	const u8 *buf = arg;
307	loff_t end = pos + count;
308	int ret = 0;
309
310	if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
311		return -EINVAL;
312
313	if (mutex_lock_killable(&vpd->lock))
314		return -EINTR;
315
316	ret = pci_vpd_pci22_wait(dev);
317	if (ret < 0)
318		goto out;
319
320	while (pos < end) {
321		u32 val;
322
323		val = *buf++;
324		val |= *buf++ << 8;
325		val |= *buf++ << 16;
326		val |= *buf++ << 24;
327
328		ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
329		if (ret < 0)
330			break;
331		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
332						 pos | PCI_VPD_ADDR_F);
333		if (ret < 0)
334			break;
335
336		vpd->busy = true;
337		vpd->flag = 0;
338		ret = pci_vpd_pci22_wait(dev);
339		if (ret < 0)
340			break;
341
342		pos += sizeof(u32);
343	}
344out:
345	mutex_unlock(&vpd->lock);
346	return ret ? ret : count;
347}
348
349static void pci_vpd_pci22_release(struct pci_dev *dev)
350{
351	kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
352}
353
354static const struct pci_vpd_ops pci_vpd_pci22_ops = {
355	.read = pci_vpd_pci22_read,
356	.write = pci_vpd_pci22_write,
357	.release = pci_vpd_pci22_release,
358};
359
360int pci_vpd_pci22_init(struct pci_dev *dev)
361{
362	struct pci_vpd_pci22 *vpd;
363	u8 cap;
364
365	cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
366	if (!cap)
367		return -ENODEV;
368	vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
369	if (!vpd)
370		return -ENOMEM;
371
372	vpd->base.len = PCI_VPD_PCI22_SIZE;
373	vpd->base.ops = &pci_vpd_pci22_ops;
374	mutex_init(&vpd->lock);
375	vpd->cap = cap;
376	vpd->busy = false;
377	dev->vpd = &vpd->base;
378	return 0;
379}
380
381/**
382 * pci_vpd_truncate - Set available Vital Product Data size
383 * @dev:	pci device struct
384 * @size:	available memory in bytes
385 *
386 * Adjust size of available VPD area.
387 */
388int pci_vpd_truncate(struct pci_dev *dev, size_t size)
389{
390	if (!dev->vpd)
391		return -EINVAL;
392
393	/* limited by the access method */
394	if (size > dev->vpd->len)
395		return -EINVAL;
396
397	dev->vpd->len = size;
398	if (dev->vpd->attr)
399		dev->vpd->attr->size = size;
400
401	return 0;
402}
403EXPORT_SYMBOL(pci_vpd_truncate);
404
405/**
406 * pci_cfg_access_lock - Lock PCI config reads/writes
407 * @dev:	pci device struct
408 *
409 * When access is locked, any userspace reads or writes to config
410 * space and concurrent lock requests will sleep until access is
411 * allowed via pci_cfg_access_unlocked again.
412 */
413void pci_cfg_access_lock(struct pci_dev *dev)
414{
415	might_sleep();
416
417	raw_spin_lock_irq(&pci_lock);
418	if (dev->block_cfg_access)
419		pci_wait_cfg(dev);
420	dev->block_cfg_access = 1;
421	raw_spin_unlock_irq(&pci_lock);
422}
423EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
424
425/**
426 * pci_cfg_access_trylock - try to lock PCI config reads/writes
427 * @dev:	pci device struct
428 *
429 * Same as pci_cfg_access_lock, but will return 0 if access is
430 * already locked, 1 otherwise. This function can be used from
431 * atomic contexts.
432 */
433bool pci_cfg_access_trylock(struct pci_dev *dev)
434{
435	unsigned long flags;
436	bool locked = true;
437
438	raw_spin_lock_irqsave(&pci_lock, flags);
439	if (dev->block_cfg_access)
440		locked = false;
441	else
442		dev->block_cfg_access = 1;
443	raw_spin_unlock_irqrestore(&pci_lock, flags);
444
445	return locked;
446}
447EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
448
449/**
450 * pci_cfg_access_unlock - Unlock PCI config reads/writes
451 * @dev:	pci device struct
452 *
453 * This function allows PCI config accesses to resume.
454 */
455void pci_cfg_access_unlock(struct pci_dev *dev)
456{
457	unsigned long flags;
458
459	raw_spin_lock_irqsave(&pci_lock, flags);
460
461	/* This indicates a problem in the caller, but we don't need
462	 * to kill them, unlike a double-block above. */
463	WARN_ON(!dev->block_cfg_access);
464
465	dev->block_cfg_access = 0;
466	wake_up_all(&pci_cfg_wait);
467	raw_spin_unlock_irqrestore(&pci_lock, flags);
468}
469EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
v3.15
  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
 70/**
 71 * pci_bus_set_ops - Set raw operations of pci bus
 72 * @bus:	pci bus struct
 73 * @ops:	new raw operations
 74 *
 75 * Return previous raw operations
 76 */
 77struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops)
 78{
 79	struct pci_ops *old_ops;
 80	unsigned long flags;
 81
 82	raw_spin_lock_irqsave(&pci_lock, flags);
 83	old_ops = bus->ops;
 84	bus->ops = ops;
 85	raw_spin_unlock_irqrestore(&pci_lock, flags);
 86	return old_ops;
 87}
 88EXPORT_SYMBOL(pci_bus_set_ops);
 89
 90/**
 91 * pci_read_vpd - Read one entry from Vital Product Data
 92 * @dev:	pci device struct
 93 * @pos:	offset in vpd space
 94 * @count:	number of bytes to read
 95 * @buf:	pointer to where to store result
 96 *
 97 */
 98ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
 99{
100	if (!dev->vpd || !dev->vpd->ops)
101		return -ENODEV;
102	return dev->vpd->ops->read(dev, pos, count, buf);
103}
104EXPORT_SYMBOL(pci_read_vpd);
105
106/**
107 * pci_write_vpd - Write entry to Vital Product Data
108 * @dev:	pci device struct
109 * @pos:	offset in vpd space
110 * @count:	number of bytes to write
111 * @buf:	buffer containing write data
112 *
113 */
114ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
115{
116	if (!dev->vpd || !dev->vpd->ops)
117		return -ENODEV;
118	return dev->vpd->ops->write(dev, pos, count, buf);
119}
120EXPORT_SYMBOL(pci_write_vpd);
121
122/*
123 * The following routines are to prevent the user from accessing PCI config
124 * space when it's unsafe to do so.  Some devices require this during BIST and
125 * we're required to prevent it during D-state transitions.
126 *
127 * We have a bit per device to indicate it's blocked and a global wait queue
128 * for callers to sleep on until devices are unblocked.
129 */
130static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait);
131
132static noinline void pci_wait_cfg(struct pci_dev *dev)
133{
134	DECLARE_WAITQUEUE(wait, current);
135
136	__add_wait_queue(&pci_cfg_wait, &wait);
137	do {
138		set_current_state(TASK_UNINTERRUPTIBLE);
139		raw_spin_unlock_irq(&pci_lock);
140		schedule();
141		raw_spin_lock_irq(&pci_lock);
142	} while (dev->block_cfg_access);
143	__remove_wait_queue(&pci_cfg_wait, &wait);
144}
145
146/* Returns 0 on success, negative values indicate error. */
147#define PCI_USER_READ_CONFIG(size,type)					\
148int pci_user_read_config_##size						\
149	(struct pci_dev *dev, int pos, type *val)			\
150{									\
151	int ret = 0;							\
152	u32 data = -1;							\
153	if (PCI_##size##_BAD)						\
154		return -EINVAL;						\
155	raw_spin_lock_irq(&pci_lock);				\
156	if (unlikely(dev->block_cfg_access))				\
157		pci_wait_cfg(dev);					\
158	ret = dev->bus->ops->read(dev->bus, dev->devfn,			\
159					pos, sizeof(type), &data);	\
160	raw_spin_unlock_irq(&pci_lock);				\
161	*val = (type)data;						\
162	if (ret > 0)							\
163		ret = -EINVAL;						\
164	return ret;							\
165}									\
166EXPORT_SYMBOL_GPL(pci_user_read_config_##size);
167
168/* Returns 0 on success, negative values indicate error. */
169#define PCI_USER_WRITE_CONFIG(size,type)				\
170int pci_user_write_config_##size					\
171	(struct pci_dev *dev, int pos, type val)			\
172{									\
173	int ret = -EIO;							\
174	if (PCI_##size##_BAD)						\
175		return -EINVAL;						\
176	raw_spin_lock_irq(&pci_lock);				\
177	if (unlikely(dev->block_cfg_access))				\
178		pci_wait_cfg(dev);					\
179	ret = dev->bus->ops->write(dev->bus, dev->devfn,		\
180					pos, sizeof(type), val);	\
181	raw_spin_unlock_irq(&pci_lock);				\
182	if (ret > 0)							\
183		ret = -EINVAL;						\
184	return ret;							\
185}									\
186EXPORT_SYMBOL_GPL(pci_user_write_config_##size);
187
188PCI_USER_READ_CONFIG(byte, u8)
189PCI_USER_READ_CONFIG(word, u16)
190PCI_USER_READ_CONFIG(dword, u32)
191PCI_USER_WRITE_CONFIG(byte, u8)
192PCI_USER_WRITE_CONFIG(word, u16)
193PCI_USER_WRITE_CONFIG(dword, u32)
194
195/* VPD access through PCI 2.2+ VPD capability */
196
197#define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1)
198
199struct pci_vpd_pci22 {
200	struct pci_vpd base;
201	struct mutex lock;
202	u16	flag;
203	bool	busy;
204	u8	cap;
205};
206
207/*
208 * Wait for last operation to complete.
209 * This code has to spin since there is no other notification from the PCI
210 * hardware. Since the VPD is often implemented by serial attachment to an
211 * EEPROM, it may take many milliseconds to complete.
212 *
213 * Returns 0 on success, negative values indicate error.
214 */
215static int pci_vpd_pci22_wait(struct pci_dev *dev)
216{
217	struct pci_vpd_pci22 *vpd =
218		container_of(dev->vpd, struct pci_vpd_pci22, base);
219	unsigned long timeout = jiffies + HZ/20 + 2;
220	u16 status;
221	int ret;
222
223	if (!vpd->busy)
224		return 0;
225
226	for (;;) {
227		ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
228						&status);
229		if (ret < 0)
230			return ret;
231
232		if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
233			vpd->busy = false;
234			return 0;
235		}
236
237		if (time_after(jiffies, timeout)) {
238			dev_printk(KERN_DEBUG, &dev->dev,
239				   "vpd r/w failed.  This is likely a firmware "
240				   "bug on this device.  Contact the card "
241				   "vendor for a firmware update.");
242			return -ETIMEDOUT;
243		}
244		if (fatal_signal_pending(current))
245			return -EINTR;
246		if (!cond_resched())
247			udelay(10);
248	}
249}
250
251static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
252				  void *arg)
253{
254	struct pci_vpd_pci22 *vpd =
255		container_of(dev->vpd, struct pci_vpd_pci22, base);
256	int ret;
257	loff_t end = pos + count;
258	u8 *buf = arg;
259
260	if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
261		return -EINVAL;
262
263	if (mutex_lock_killable(&vpd->lock))
264		return -EINTR;
265
266	ret = pci_vpd_pci22_wait(dev);
267	if (ret < 0)
268		goto out;
269
270	while (pos < end) {
271		u32 val;
272		unsigned int i, skip;
273
274		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
275						 pos & ~3);
276		if (ret < 0)
277			break;
278		vpd->busy = true;
279		vpd->flag = PCI_VPD_ADDR_F;
280		ret = pci_vpd_pci22_wait(dev);
281		if (ret < 0)
282			break;
283
284		ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
285		if (ret < 0)
286			break;
287
288		skip = pos & 3;
289		for (i = 0;  i < sizeof(u32); i++) {
290			if (i >= skip) {
291				*buf++ = val;
292				if (++pos == end)
293					break;
294			}
295			val >>= 8;
296		}
297	}
298out:
299	mutex_unlock(&vpd->lock);
300	return ret ? ret : count;
301}
302
303static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count,
304				   const void *arg)
305{
306	struct pci_vpd_pci22 *vpd =
307		container_of(dev->vpd, struct pci_vpd_pci22, base);
308	const u8 *buf = arg;
309	loff_t end = pos + count;
310	int ret = 0;
311
312	if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
313		return -EINVAL;
314
315	if (mutex_lock_killable(&vpd->lock))
316		return -EINTR;
317
318	ret = pci_vpd_pci22_wait(dev);
319	if (ret < 0)
320		goto out;
321
322	while (pos < end) {
323		u32 val;
324
325		val = *buf++;
326		val |= *buf++ << 8;
327		val |= *buf++ << 16;
328		val |= *buf++ << 24;
329
330		ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
331		if (ret < 0)
332			break;
333		ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
334						 pos | PCI_VPD_ADDR_F);
335		if (ret < 0)
336			break;
337
338		vpd->busy = true;
339		vpd->flag = 0;
340		ret = pci_vpd_pci22_wait(dev);
341		if (ret < 0)
342			break;
343
344		pos += sizeof(u32);
345	}
346out:
347	mutex_unlock(&vpd->lock);
348	return ret ? ret : count;
349}
350
351static void pci_vpd_pci22_release(struct pci_dev *dev)
352{
353	kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
354}
355
356static const struct pci_vpd_ops pci_vpd_pci22_ops = {
357	.read = pci_vpd_pci22_read,
358	.write = pci_vpd_pci22_write,
359	.release = pci_vpd_pci22_release,
360};
361
362int pci_vpd_pci22_init(struct pci_dev *dev)
363{
364	struct pci_vpd_pci22 *vpd;
365	u8 cap;
366
367	cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
368	if (!cap)
369		return -ENODEV;
370	vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
371	if (!vpd)
372		return -ENOMEM;
373
374	vpd->base.len = PCI_VPD_PCI22_SIZE;
375	vpd->base.ops = &pci_vpd_pci22_ops;
376	mutex_init(&vpd->lock);
377	vpd->cap = cap;
378	vpd->busy = false;
379	dev->vpd = &vpd->base;
380	return 0;
381}
382
383/**
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
384 * pci_cfg_access_lock - Lock PCI config reads/writes
385 * @dev:	pci device struct
386 *
387 * When access is locked, any userspace reads or writes to config
388 * space and concurrent lock requests will sleep until access is
389 * allowed via pci_cfg_access_unlocked again.
390 */
391void pci_cfg_access_lock(struct pci_dev *dev)
392{
393	might_sleep();
394
395	raw_spin_lock_irq(&pci_lock);
396	if (dev->block_cfg_access)
397		pci_wait_cfg(dev);
398	dev->block_cfg_access = 1;
399	raw_spin_unlock_irq(&pci_lock);
400}
401EXPORT_SYMBOL_GPL(pci_cfg_access_lock);
402
403/**
404 * pci_cfg_access_trylock - try to lock PCI config reads/writes
405 * @dev:	pci device struct
406 *
407 * Same as pci_cfg_access_lock, but will return 0 if access is
408 * already locked, 1 otherwise. This function can be used from
409 * atomic contexts.
410 */
411bool pci_cfg_access_trylock(struct pci_dev *dev)
412{
413	unsigned long flags;
414	bool locked = true;
415
416	raw_spin_lock_irqsave(&pci_lock, flags);
417	if (dev->block_cfg_access)
418		locked = false;
419	else
420		dev->block_cfg_access = 1;
421	raw_spin_unlock_irqrestore(&pci_lock, flags);
422
423	return locked;
424}
425EXPORT_SYMBOL_GPL(pci_cfg_access_trylock);
426
427/**
428 * pci_cfg_access_unlock - Unlock PCI config reads/writes
429 * @dev:	pci device struct
430 *
431 * This function allows PCI config accesses to resume.
432 */
433void pci_cfg_access_unlock(struct pci_dev *dev)
434{
435	unsigned long flags;
436
437	raw_spin_lock_irqsave(&pci_lock, flags);
438
439	/* This indicates a problem in the caller, but we don't need
440	 * to kill them, unlike a double-block above. */
441	WARN_ON(!dev->block_cfg_access);
442
443	dev->block_cfg_access = 0;
444	wake_up_all(&pci_cfg_wait);
445	raw_spin_unlock_irqrestore(&pci_lock, flags);
446}
447EXPORT_SYMBOL_GPL(pci_cfg_access_unlock);
448
449static inline int pcie_cap_version(const struct pci_dev *dev)
450{
451	return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS;
452}
453
454static inline bool pcie_cap_has_lnkctl(const struct pci_dev *dev)
455{
456	int type = pci_pcie_type(dev);
457
458	return type == PCI_EXP_TYPE_ENDPOINT ||
459	       type == PCI_EXP_TYPE_LEG_END ||
460	       type == PCI_EXP_TYPE_ROOT_PORT ||
461	       type == PCI_EXP_TYPE_UPSTREAM ||
462	       type == PCI_EXP_TYPE_DOWNSTREAM ||
463	       type == PCI_EXP_TYPE_PCI_BRIDGE ||
464	       type == PCI_EXP_TYPE_PCIE_BRIDGE;
465}
466
467static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev)
468{
469	int type = pci_pcie_type(dev);
470
471	return (type == PCI_EXP_TYPE_ROOT_PORT ||
472		type == PCI_EXP_TYPE_DOWNSTREAM) &&
473	       pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT;
474}
475
476static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev)
477{
478	int type = pci_pcie_type(dev);
479
480	return type == PCI_EXP_TYPE_ROOT_PORT ||
481	       type == PCI_EXP_TYPE_RC_EC;
482}
483
484static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos)
485{
486	if (!pci_is_pcie(dev))
487		return false;
488
489	switch (pos) {
490	case PCI_EXP_FLAGS:
491		return true;
492	case PCI_EXP_DEVCAP:
493	case PCI_EXP_DEVCTL:
494	case PCI_EXP_DEVSTA:
495		return true;
496	case PCI_EXP_LNKCAP:
497	case PCI_EXP_LNKCTL:
498	case PCI_EXP_LNKSTA:
499		return pcie_cap_has_lnkctl(dev);
500	case PCI_EXP_SLTCAP:
501	case PCI_EXP_SLTCTL:
502	case PCI_EXP_SLTSTA:
503		return pcie_cap_has_sltctl(dev);
504	case PCI_EXP_RTCTL:
505	case PCI_EXP_RTCAP:
506	case PCI_EXP_RTSTA:
507		return pcie_cap_has_rtctl(dev);
508	case PCI_EXP_DEVCAP2:
509	case PCI_EXP_DEVCTL2:
510	case PCI_EXP_LNKCAP2:
511	case PCI_EXP_LNKCTL2:
512	case PCI_EXP_LNKSTA2:
513		return pcie_cap_version(dev) > 1;
514	default:
515		return false;
516	}
517}
518
519/*
520 * Note that these accessor functions are only for the "PCI Express
521 * Capability" (see PCIe spec r3.0, sec 7.8).  They do not apply to the
522 * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.)
523 */
524int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val)
525{
526	int ret;
527
528	*val = 0;
529	if (pos & 1)
530		return -EINVAL;
531
532	if (pcie_capability_reg_implemented(dev, pos)) {
533		ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val);
534		/*
535		 * Reset *val to 0 if pci_read_config_word() fails, it may
536		 * have been written as 0xFFFF if hardware error happens
537		 * during pci_read_config_word().
538		 */
539		if (ret)
540			*val = 0;
541		return ret;
542	}
543
544	/*
545	 * For Functions that do not implement the Slot Capabilities,
546	 * Slot Status, and Slot Control registers, these spaces must
547	 * be hardwired to 0b, with the exception of the Presence Detect
548	 * State bit in the Slot Status register of Downstream Ports,
549	 * which must be hardwired to 1b.  (PCIe Base Spec 3.0, sec 7.8)
550	 */
551	if (pci_is_pcie(dev) && pos == PCI_EXP_SLTSTA &&
552		 pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) {
553		*val = PCI_EXP_SLTSTA_PDS;
554	}
555
556	return 0;
557}
558EXPORT_SYMBOL(pcie_capability_read_word);
559
560int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val)
561{
562	int ret;
563
564	*val = 0;
565	if (pos & 3)
566		return -EINVAL;
567
568	if (pcie_capability_reg_implemented(dev, pos)) {
569		ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val);
570		/*
571		 * Reset *val to 0 if pci_read_config_dword() fails, it may
572		 * have been written as 0xFFFFFFFF if hardware error happens
573		 * during pci_read_config_dword().
574		 */
575		if (ret)
576			*val = 0;
577		return ret;
578	}
579
580	if (pci_is_pcie(dev) && pos == PCI_EXP_SLTCTL &&
581		 pci_pcie_type(dev) == PCI_EXP_TYPE_DOWNSTREAM) {
582		*val = PCI_EXP_SLTSTA_PDS;
583	}
584
585	return 0;
586}
587EXPORT_SYMBOL(pcie_capability_read_dword);
588
589int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val)
590{
591	if (pos & 1)
592		return -EINVAL;
593
594	if (!pcie_capability_reg_implemented(dev, pos))
595		return 0;
596
597	return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val);
598}
599EXPORT_SYMBOL(pcie_capability_write_word);
600
601int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val)
602{
603	if (pos & 3)
604		return -EINVAL;
605
606	if (!pcie_capability_reg_implemented(dev, pos))
607		return 0;
608
609	return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val);
610}
611EXPORT_SYMBOL(pcie_capability_write_dword);
612
613int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos,
614				       u16 clear, u16 set)
615{
616	int ret;
617	u16 val;
618
619	ret = pcie_capability_read_word(dev, pos, &val);
620	if (!ret) {
621		val &= ~clear;
622		val |= set;
623		ret = pcie_capability_write_word(dev, pos, val);
624	}
625
626	return ret;
627}
628EXPORT_SYMBOL(pcie_capability_clear_and_set_word);
629
630int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos,
631					u32 clear, u32 set)
632{
633	int ret;
634	u32 val;
635
636	ret = pcie_capability_read_dword(dev, pos, &val);
637	if (!ret) {
638		val &= ~clear;
639		val |= set;
640		ret = pcie_capability_write_dword(dev, pos, val);
641	}
642
643	return ret;
644}
645EXPORT_SYMBOL(pcie_capability_clear_and_set_dword);