blob: 0f3706512686bb32bd6bf40cd6bf2acdc0bdca49 [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
Stephen Hemminger287d19c2008-12-18 09:17:16 -080069
70/**
71 * pci_read_vpd - Read one entry from Vital Product Data
72 * @dev: pci device struct
73 * @pos: offset in vpd space
74 * @count: number of bytes to read
75 * @buf: pointer to where to store result
76 *
77 */
78ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
79{
80 if (!dev->vpd || !dev->vpd->ops)
81 return -ENODEV;
82 return dev->vpd->ops->read(dev, pos, count, buf);
83}
84EXPORT_SYMBOL(pci_read_vpd);
85
86/**
87 * pci_write_vpd - Write entry to Vital Product Data
88 * @dev: pci device struct
89 * @pos: offset in vpd space
Randy Dunlapcffb2fa2009-04-10 15:17:50 -070090 * @count: number of bytes to write
91 * @buf: buffer containing write data
Stephen Hemminger287d19c2008-12-18 09:17:16 -080092 *
93 */
94ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
95{
96 if (!dev->vpd || !dev->vpd->ops)
97 return -ENODEV;
98 return dev->vpd->ops->write(dev, pos, count, buf);
99}
100EXPORT_SYMBOL(pci_write_vpd);
101
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600102/*
103 * The following routines are to prevent the user from accessing PCI config
104 * space when it's unsafe to do so. Some devices require this during BIST and
105 * we're required to prevent it during D-state transitions.
106 *
107 * We have a bit per device to indicate it's blocked and a global wait queue
108 * for callers to sleep on until devices are unblocked.
109 */
110static DECLARE_WAIT_QUEUE_HEAD(pci_ucfg_wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700111
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600112static noinline void pci_wait_ucfg(struct pci_dev *dev)
113{
114 DECLARE_WAITQUEUE(wait, current);
115
116 __add_wait_queue(&pci_ucfg_wait, &wait);
117 do {
118 set_current_state(TASK_UNINTERRUPTIBLE);
119 spin_unlock_irq(&pci_lock);
120 schedule();
121 spin_lock_irq(&pci_lock);
122 } while (dev->block_ucfg_access);
123 __remove_wait_queue(&pci_ucfg_wait, &wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700124}
125
126#define PCI_USER_READ_CONFIG(size,type) \
127int pci_user_read_config_##size \
128 (struct pci_dev *dev, int pos, type *val) \
129{ \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700130 int ret = 0; \
131 u32 data = -1; \
132 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600133 spin_lock_irq(&pci_lock); \
134 if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
135 ret = dev->bus->ops->read(dev->bus, dev->devfn, \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700136 pos, sizeof(type), &data); \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600137 spin_unlock_irq(&pci_lock); \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700138 *val = (type)data; \
139 return ret; \
140}
141
142#define PCI_USER_WRITE_CONFIG(size,type) \
143int pci_user_write_config_##size \
144 (struct pci_dev *dev, int pos, type val) \
145{ \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700146 int ret = -EIO; \
147 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600148 spin_lock_irq(&pci_lock); \
149 if (unlikely(dev->block_ucfg_access)) pci_wait_ucfg(dev); \
150 ret = dev->bus->ops->write(dev->bus, dev->devfn, \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700151 pos, sizeof(type), val); \
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600152 spin_unlock_irq(&pci_lock); \
Brian Kinge04b0ea2005-09-27 01:21:55 -0700153 return ret; \
154}
155
156PCI_USER_READ_CONFIG(byte, u8)
157PCI_USER_READ_CONFIG(word, u16)
158PCI_USER_READ_CONFIG(dword, u32)
159PCI_USER_WRITE_CONFIG(byte, u8)
160PCI_USER_WRITE_CONFIG(word, u16)
161PCI_USER_WRITE_CONFIG(dword, u32)
162
Ben Hutchings94e61082008-03-05 16:52:39 +0000163/* VPD access through PCI 2.2+ VPD capability */
164
165#define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1)
166
167struct pci_vpd_pci22 {
168 struct pci_vpd base;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800169 struct mutex lock;
170 u16 flag;
Ben Hutchings94e61082008-03-05 16:52:39 +0000171 bool busy;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800172 u8 cap;
Ben Hutchings94e61082008-03-05 16:52:39 +0000173};
174
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800175/*
176 * Wait for last operation to complete.
177 * This code has to spin since there is no other notification from the PCI
178 * hardware. Since the VPD is often implemented by serial attachment to an
179 * EEPROM, it may take many milliseconds to complete.
180 */
Ben Hutchings94e61082008-03-05 16:52:39 +0000181static int pci_vpd_pci22_wait(struct pci_dev *dev)
182{
183 struct pci_vpd_pci22 *vpd =
184 container_of(dev->vpd, struct pci_vpd_pci22, base);
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800185 unsigned long timeout = jiffies + HZ/20 + 2;
186 u16 status;
Ben Hutchings94e61082008-03-05 16:52:39 +0000187 int ret;
188
189 if (!vpd->busy)
190 return 0;
191
Ben Hutchings94e61082008-03-05 16:52:39 +0000192 for (;;) {
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800193 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
Ben Hutchings94e61082008-03-05 16:52:39 +0000194 &status);
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800195 if (ret)
Ben Hutchings94e61082008-03-05 16:52:39 +0000196 return ret;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800197
198 if ((status & PCI_VPD_ADDR_F) == vpd->flag) {
Ben Hutchings94e61082008-03-05 16:52:39 +0000199 vpd->busy = false;
200 return 0;
201 }
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800202
203 if (time_after(jiffies, timeout))
Ben Hutchings94e61082008-03-05 16:52:39 +0000204 return -ETIMEDOUT;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800205 if (fatal_signal_pending(current))
206 return -EINTR;
207 if (!cond_resched())
208 udelay(10);
Ben Hutchings94e61082008-03-05 16:52:39 +0000209 }
210}
211
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800212static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count,
213 void *arg)
Ben Hutchings94e61082008-03-05 16:52:39 +0000214{
215 struct pci_vpd_pci22 *vpd =
216 container_of(dev->vpd, struct pci_vpd_pci22, base);
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800217 int ret;
218 loff_t end = pos + count;
219 u8 *buf = arg;
Ben Hutchings94e61082008-03-05 16:52:39 +0000220
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800221 if (pos < 0 || pos > vpd->base.len || end > vpd->base.len)
Ben Hutchings94e61082008-03-05 16:52:39 +0000222 return -EINVAL;
Ben Hutchings94e61082008-03-05 16:52:39 +0000223
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800224 if (mutex_lock_killable(&vpd->lock))
225 return -EINTR;
226
Ben Hutchings94e61082008-03-05 16:52:39 +0000227 ret = pci_vpd_pci22_wait(dev);
228 if (ret < 0)
229 goto out;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800230
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800231 while (pos < end) {
232 u32 val;
233 unsigned int i, skip;
234
235 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
236 pos & ~3);
237 if (ret < 0)
238 break;
239 vpd->busy = true;
240 vpd->flag = PCI_VPD_ADDR_F;
241 ret = pci_vpd_pci22_wait(dev);
242 if (ret < 0)
243 break;
244
245 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
246 if (ret < 0)
247 break;
248
249 skip = pos & 3;
250 for (i = 0; i < sizeof(u32); i++) {
251 if (i >= skip) {
252 *buf++ = val;
253 if (++pos == end)
254 break;
255 }
256 val >>= 8;
257 }
258 }
Ben Hutchings94e61082008-03-05 16:52:39 +0000259out:
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800260 mutex_unlock(&vpd->lock);
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800261 return ret ? ret : count;
Ben Hutchings94e61082008-03-05 16:52:39 +0000262}
263
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800264static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count,
265 const void *arg)
Ben Hutchings94e61082008-03-05 16:52:39 +0000266{
267 struct pci_vpd_pci22 *vpd =
268 container_of(dev->vpd, struct pci_vpd_pci22, base);
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800269 const u8 *buf = arg;
270 loff_t end = pos + count;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800271 int ret = 0;
Ben Hutchings94e61082008-03-05 16:52:39 +0000272
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800273 if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len)
Ben Hutchings94e61082008-03-05 16:52:39 +0000274 return -EINVAL;
275
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800276 if (mutex_lock_killable(&vpd->lock))
277 return -EINTR;
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800278
Ben Hutchings94e61082008-03-05 16:52:39 +0000279 ret = pci_vpd_pci22_wait(dev);
280 if (ret < 0)
281 goto out;
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800282
283 while (pos < end) {
284 u32 val;
285
286 val = *buf++;
287 val |= *buf++ << 8;
288 val |= *buf++ << 16;
289 val |= *buf++ << 24;
290
291 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val);
292 if (ret < 0)
293 break;
294 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
295 pos | PCI_VPD_ADDR_F);
296 if (ret < 0)
297 break;
298
299 vpd->busy = true;
300 vpd->flag = 0;
301 ret = pci_vpd_pci22_wait(dev);
302
303 pos += sizeof(u32);
304 }
Ben Hutchings94e61082008-03-05 16:52:39 +0000305out:
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800306 mutex_unlock(&vpd->lock);
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800307 return ret ? ret : count;
Ben Hutchings94e61082008-03-05 16:52:39 +0000308}
309
Ben Hutchings94e61082008-03-05 16:52:39 +0000310static void pci_vpd_pci22_release(struct pci_dev *dev)
311{
312 kfree(container_of(dev->vpd, struct pci_vpd_pci22, base));
313}
314
Stephen Hemminger287d19c2008-12-18 09:17:16 -0800315static const struct pci_vpd_ops pci_vpd_pci22_ops = {
Ben Hutchings94e61082008-03-05 16:52:39 +0000316 .read = pci_vpd_pci22_read,
317 .write = pci_vpd_pci22_write,
Ben Hutchings94e61082008-03-05 16:52:39 +0000318 .release = pci_vpd_pci22_release,
319};
320
321int pci_vpd_pci22_init(struct pci_dev *dev)
322{
323 struct pci_vpd_pci22 *vpd;
324 u8 cap;
325
326 cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
327 if (!cap)
328 return -ENODEV;
329 vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC);
330 if (!vpd)
331 return -ENOMEM;
332
Benjamin Li99cb233d2008-07-02 10:59:04 -0700333 vpd->base.len = PCI_VPD_PCI22_SIZE;
Ben Hutchings94e61082008-03-05 16:52:39 +0000334 vpd->base.ops = &pci_vpd_pci22_ops;
Stephen Hemminger1120f8b2008-12-18 09:17:16 -0800335 mutex_init(&vpd->lock);
Ben Hutchings94e61082008-03-05 16:52:39 +0000336 vpd->cap = cap;
337 vpd->busy = false;
338 dev->vpd = &vpd->base;
339 return 0;
340}
341
Brian Kinge04b0ea2005-09-27 01:21:55 -0700342/**
Stephen Hemmingerdb567942008-12-18 09:17:16 -0800343 * pci_vpd_truncate - Set available Vital Product Data size
344 * @dev: pci device struct
345 * @size: available memory in bytes
346 *
347 * Adjust size of available VPD area.
348 */
349int pci_vpd_truncate(struct pci_dev *dev, size_t size)
350{
351 if (!dev->vpd)
352 return -EINVAL;
353
354 /* limited by the access method */
355 if (size > dev->vpd->len)
356 return -EINVAL;
357
358 dev->vpd->len = size;
Anton Vorontsovd407e322009-04-01 02:23:41 +0400359 if (dev->vpd->attr)
360 dev->vpd->attr->size = size;
Stephen Hemmingerdb567942008-12-18 09:17:16 -0800361
362 return 0;
363}
364EXPORT_SYMBOL(pci_vpd_truncate);
365
366/**
Brian Kinge04b0ea2005-09-27 01:21:55 -0700367 * pci_block_user_cfg_access - Block userspace PCI config reads/writes
368 * @dev: pci device struct
369 *
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600370 * When user access is blocked, any reads or writes to config space will
371 * sleep until access is unblocked again. We don't allow nesting of
372 * block/unblock calls.
373 */
Brian Kinge04b0ea2005-09-27 01:21:55 -0700374void pci_block_user_cfg_access(struct pci_dev *dev)
375{
376 unsigned long flags;
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600377 int was_blocked;
Brian Kinge04b0ea2005-09-27 01:21:55 -0700378
Brian Kinge04b0ea2005-09-27 01:21:55 -0700379 spin_lock_irqsave(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600380 was_blocked = dev->block_ucfg_access;
Brian Kinge04b0ea2005-09-27 01:21:55 -0700381 dev->block_ucfg_access = 1;
382 spin_unlock_irqrestore(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600383
384 /* If we BUG() inside the pci_lock, we're guaranteed to hose
385 * the machine */
386 BUG_ON(was_blocked);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700387}
388EXPORT_SYMBOL_GPL(pci_block_user_cfg_access);
389
390/**
391 * pci_unblock_user_cfg_access - Unblock userspace PCI config reads/writes
392 * @dev: pci device struct
393 *
394 * This function allows userspace PCI config accesses to resume.
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600395 */
Brian Kinge04b0ea2005-09-27 01:21:55 -0700396void pci_unblock_user_cfg_access(struct pci_dev *dev)
397{
398 unsigned long flags;
399
Brian Kinge04b0ea2005-09-27 01:21:55 -0700400 spin_lock_irqsave(&pci_lock, flags);
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600401
402 /* This indicates a problem in the caller, but we don't need
403 * to kill them, unlike a double-block above. */
404 WARN_ON(!dev->block_ucfg_access);
405
Brian Kinge04b0ea2005-09-27 01:21:55 -0700406 dev->block_ucfg_access = 0;
Matthew Wilcox7ea7e982006-10-19 09:41:28 -0600407 wake_up_all(&pci_ucfg_wait);
Brian Kinge04b0ea2005-09-27 01:21:55 -0700408 spin_unlock_irqrestore(&pci_lock, flags);
409}
410EXPORT_SYMBOL_GPL(pci_unblock_user_cfg_access);