1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * PCI VPD support
4 *
5 * Copyright (C) 2010 Broadcom Corporation.
6 */
7
8 #include <linux/pci.h>
9 #include <linux/delay.h>
10 #include <linux/export.h>
11 #include <linux/sched/signal.h>
12 #include <asm/unaligned.h>
13 #include "pci.h"
14
15 #define PCI_VPD_LRDT_TAG_SIZE 3
16 #define PCI_VPD_SRDT_LEN_MASK 0x07
17 #define PCI_VPD_SRDT_TAG_SIZE 1
18 #define PCI_VPD_STIN_END 0x0f
19 #define PCI_VPD_INFO_FLD_HDR_SIZE 3
20
pci_vpd_lrdt_size(const u8 * lrdt)21 static u16 pci_vpd_lrdt_size(const u8 *lrdt)
22 {
23 return get_unaligned_le16(lrdt + 1);
24 }
25
pci_vpd_srdt_tag(const u8 * srdt)26 static u8 pci_vpd_srdt_tag(const u8 *srdt)
27 {
28 return *srdt >> 3;
29 }
30
pci_vpd_srdt_size(const u8 * srdt)31 static u8 pci_vpd_srdt_size(const u8 *srdt)
32 {
33 return *srdt & PCI_VPD_SRDT_LEN_MASK;
34 }
35
pci_vpd_info_field_size(const u8 * info_field)36 static u8 pci_vpd_info_field_size(const u8 *info_field)
37 {
38 return info_field[2];
39 }
40
41 /* VPD access through PCI 2.2+ VPD capability */
42
pci_get_func0_dev(struct pci_dev * dev)43 static struct pci_dev *pci_get_func0_dev(struct pci_dev *dev)
44 {
45 return pci_get_slot(dev->bus, PCI_DEVFN(PCI_SLOT(dev->devfn), 0));
46 }
47
48 #define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1)
49 #define PCI_VPD_SZ_INVALID UINT_MAX
50
51 /**
52 * pci_vpd_size - determine actual size of Vital Product Data
53 * @dev: pci device struct
54 */
pci_vpd_size(struct pci_dev * dev)55 static size_t pci_vpd_size(struct pci_dev *dev)
56 {
57 size_t off = 0, size;
58 unsigned char tag, header[1+2]; /* 1 byte tag, 2 bytes length */
59
60 while (pci_read_vpd_any(dev, off, 1, header) == 1) {
61 size = 0;
62
63 if (off == 0 && (header[0] == 0x00 || header[0] == 0xff))
64 goto error;
65
66 if (header[0] & PCI_VPD_LRDT) {
67 /* Large Resource Data Type Tag */
68 if (pci_read_vpd_any(dev, off + 1, 2, &header[1]) != 2) {
69 pci_warn(dev, "failed VPD read at offset %zu\n",
70 off + 1);
71 return off ?: PCI_VPD_SZ_INVALID;
72 }
73 size = pci_vpd_lrdt_size(header);
74 if (off + size > PCI_VPD_MAX_SIZE)
75 goto error;
76
77 off += PCI_VPD_LRDT_TAG_SIZE + size;
78 } else {
79 /* Short Resource Data Type Tag */
80 tag = pci_vpd_srdt_tag(header);
81 size = pci_vpd_srdt_size(header);
82 if (off + size > PCI_VPD_MAX_SIZE)
83 goto error;
84
85 off += PCI_VPD_SRDT_TAG_SIZE + size;
86 if (tag == PCI_VPD_STIN_END) /* End tag descriptor */
87 return off;
88 }
89 }
90 return off;
91
92 error:
93 pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset %zu%s\n",
94 header[0], size, off, off == 0 ?
95 "; assume missing optional EEPROM" : "");
96 return off ?: PCI_VPD_SZ_INVALID;
97 }
98
pci_vpd_available(struct pci_dev * dev,bool check_size)99 static bool pci_vpd_available(struct pci_dev *dev, bool check_size)
100 {
101 struct pci_vpd *vpd = &dev->vpd;
102
103 if (!vpd->cap)
104 return false;
105
106 if (vpd->len == 0 && check_size) {
107 vpd->len = pci_vpd_size(dev);
108 if (vpd->len == PCI_VPD_SZ_INVALID) {
109 vpd->cap = 0;
110 return false;
111 }
112 }
113
114 return true;
115 }
116
117 /*
118 * Wait for last operation to complete.
119 * This code has to spin since there is no other notification from the PCI
120 * hardware. Since the VPD is often implemented by serial attachment to an
121 * EEPROM, it may take many milliseconds to complete.
122 * @set: if true wait for flag to be set, else wait for it to be cleared
123 *
124 * Returns 0 on success, negative values indicate error.
125 */
pci_vpd_wait(struct pci_dev * dev,bool set)126 static int pci_vpd_wait(struct pci_dev *dev, bool set)
127 {
128 struct pci_vpd *vpd = &dev->vpd;
129 unsigned long timeout = jiffies + msecs_to_jiffies(125);
130 unsigned long max_sleep = 16;
131 u16 status;
132 int ret;
133
134 do {
135 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR,
136 &status);
137 if (ret < 0)
138 return ret;
139
140 if (!!(status & PCI_VPD_ADDR_F) == set)
141 return 0;
142
143 if (time_after(jiffies, timeout))
144 break;
145
146 usleep_range(10, max_sleep);
147 if (max_sleep < 1024)
148 max_sleep *= 2;
149 } while (true);
150
151 pci_warn(dev, "VPD access failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update\n");
152 return -ETIMEDOUT;
153 }
154
pci_vpd_read(struct pci_dev * dev,loff_t pos,size_t count,void * arg,bool check_size)155 static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count,
156 void *arg, bool check_size)
157 {
158 struct pci_vpd *vpd = &dev->vpd;
159 unsigned int max_len;
160 int ret = 0;
161 loff_t end = pos + count;
162 u8 *buf = arg;
163
164 if (!pci_vpd_available(dev, check_size))
165 return -ENODEV;
166
167 if (pos < 0)
168 return -EINVAL;
169
170 max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE;
171
172 if (pos >= max_len)
173 return 0;
174
175 if (end > max_len) {
176 end = max_len;
177 count = end - pos;
178 }
179
180 if (mutex_lock_killable(&vpd->lock))
181 return -EINTR;
182
183 while (pos < end) {
184 u32 val;
185 unsigned int i, skip;
186
187 if (fatal_signal_pending(current)) {
188 ret = -EINTR;
189 break;
190 }
191
192 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
193 pos & ~3);
194 if (ret < 0)
195 break;
196 ret = pci_vpd_wait(dev, true);
197 if (ret < 0)
198 break;
199
200 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val);
201 if (ret < 0)
202 break;
203
204 skip = pos & 3;
205 for (i = 0; i < sizeof(u32); i++) {
206 if (i >= skip) {
207 *buf++ = val;
208 if (++pos == end)
209 break;
210 }
211 val >>= 8;
212 }
213 }
214
215 mutex_unlock(&vpd->lock);
216 return ret ? ret : count;
217 }
218
pci_vpd_write(struct pci_dev * dev,loff_t pos,size_t count,const void * arg,bool check_size)219 static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count,
220 const void *arg, bool check_size)
221 {
222 struct pci_vpd *vpd = &dev->vpd;
223 unsigned int max_len;
224 const u8 *buf = arg;
225 loff_t end = pos + count;
226 int ret = 0;
227
228 if (!pci_vpd_available(dev, check_size))
229 return -ENODEV;
230
231 if (pos < 0 || (pos & 3) || (count & 3))
232 return -EINVAL;
233
234 max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE;
235
236 if (end > max_len)
237 return -EINVAL;
238
239 if (mutex_lock_killable(&vpd->lock))
240 return -EINTR;
241
242 while (pos < end) {
243 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA,
244 get_unaligned_le32(buf));
245 if (ret < 0)
246 break;
247 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR,
248 pos | PCI_VPD_ADDR_F);
249 if (ret < 0)
250 break;
251
252 ret = pci_vpd_wait(dev, false);
253 if (ret < 0)
254 break;
255
256 buf += sizeof(u32);
257 pos += sizeof(u32);
258 }
259
260 mutex_unlock(&vpd->lock);
261 return ret ? ret : count;
262 }
263
pci_vpd_init(struct pci_dev * dev)264 void pci_vpd_init(struct pci_dev *dev)
265 {
266 if (dev->vpd.len == PCI_VPD_SZ_INVALID)
267 return;
268
269 dev->vpd.cap = pci_find_capability(dev, PCI_CAP_ID_VPD);
270 mutex_init(&dev->vpd.lock);
271 }
272
vpd_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)273 static ssize_t vpd_read(struct file *filp, struct kobject *kobj,
274 struct bin_attribute *bin_attr, char *buf, loff_t off,
275 size_t count)
276 {
277 struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
278
279 return pci_read_vpd(dev, off, count, buf);
280 }
281
vpd_write(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t off,size_t count)282 static ssize_t vpd_write(struct file *filp, struct kobject *kobj,
283 struct bin_attribute *bin_attr, char *buf, loff_t off,
284 size_t count)
285 {
286 struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj));
287
288 return pci_write_vpd(dev, off, count, buf);
289 }
290 static BIN_ATTR(vpd, 0600, vpd_read, vpd_write, 0);
291
292 static struct bin_attribute *vpd_attrs[] = {
293 &bin_attr_vpd,
294 NULL,
295 };
296
vpd_attr_is_visible(struct kobject * kobj,struct bin_attribute * a,int n)297 static umode_t vpd_attr_is_visible(struct kobject *kobj,
298 struct bin_attribute *a, int n)
299 {
300 struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
301
302 if (!pdev->vpd.cap)
303 return 0;
304
305 return a->attr.mode;
306 }
307
308 const struct attribute_group pci_dev_vpd_attr_group = {
309 .bin_attrs = vpd_attrs,
310 .is_bin_visible = vpd_attr_is_visible,
311 };
312
pci_vpd_alloc(struct pci_dev * dev,unsigned int * size)313 void *pci_vpd_alloc(struct pci_dev *dev, unsigned int *size)
314 {
315 unsigned int len;
316 void *buf;
317 int cnt;
318
319 if (!pci_vpd_available(dev, true))
320 return ERR_PTR(-ENODEV);
321
322 len = dev->vpd.len;
323 buf = kmalloc(len, GFP_KERNEL);
324 if (!buf)
325 return ERR_PTR(-ENOMEM);
326
327 cnt = pci_read_vpd(dev, 0, len, buf);
328 if (cnt != len) {
329 kfree(buf);
330 return ERR_PTR(-EIO);
331 }
332
333 if (size)
334 *size = len;
335
336 return buf;
337 }
338 EXPORT_SYMBOL_GPL(pci_vpd_alloc);
339
pci_vpd_find_tag(const u8 * buf,unsigned int len,u8 rdt,unsigned int * size)340 static int pci_vpd_find_tag(const u8 *buf, unsigned int len, u8 rdt, unsigned int *size)
341 {
342 int i = 0;
343
344 /* look for LRDT tags only, end tag is the only SRDT tag */
345 while (i + PCI_VPD_LRDT_TAG_SIZE <= len && buf[i] & PCI_VPD_LRDT) {
346 unsigned int lrdt_len = pci_vpd_lrdt_size(buf + i);
347 u8 tag = buf[i];
348
349 i += PCI_VPD_LRDT_TAG_SIZE;
350 if (tag == rdt) {
351 if (i + lrdt_len > len)
352 lrdt_len = len - i;
353 if (size)
354 *size = lrdt_len;
355 return i;
356 }
357
358 i += lrdt_len;
359 }
360
361 return -ENOENT;
362 }
363
pci_vpd_find_id_string(const u8 * buf,unsigned int len,unsigned int * size)364 int pci_vpd_find_id_string(const u8 *buf, unsigned int len, unsigned int *size)
365 {
366 return pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_ID_STRING, size);
367 }
368 EXPORT_SYMBOL_GPL(pci_vpd_find_id_string);
369
pci_vpd_find_info_keyword(const u8 * buf,unsigned int off,unsigned int len,const char * kw)370 static int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off,
371 unsigned int len, const char *kw)
372 {
373 int i;
374
375 for (i = off; i + PCI_VPD_INFO_FLD_HDR_SIZE <= off + len;) {
376 if (buf[i + 0] == kw[0] &&
377 buf[i + 1] == kw[1])
378 return i;
379
380 i += PCI_VPD_INFO_FLD_HDR_SIZE +
381 pci_vpd_info_field_size(&buf[i]);
382 }
383
384 return -ENOENT;
385 }
386
__pci_read_vpd(struct pci_dev * dev,loff_t pos,size_t count,void * buf,bool check_size)387 static ssize_t __pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf,
388 bool check_size)
389 {
390 ssize_t ret;
391
392 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
393 dev = pci_get_func0_dev(dev);
394 if (!dev)
395 return -ENODEV;
396
397 ret = pci_vpd_read(dev, pos, count, buf, check_size);
398 pci_dev_put(dev);
399 return ret;
400 }
401
402 return pci_vpd_read(dev, pos, count, buf, check_size);
403 }
404
405 /**
406 * pci_read_vpd - Read one entry from Vital Product Data
407 * @dev: PCI device struct
408 * @pos: offset in VPD space
409 * @count: number of bytes to read
410 * @buf: pointer to where to store result
411 */
pci_read_vpd(struct pci_dev * dev,loff_t pos,size_t count,void * buf)412 ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
413 {
414 return __pci_read_vpd(dev, pos, count, buf, true);
415 }
416 EXPORT_SYMBOL(pci_read_vpd);
417
418 /* Same, but allow to access any address */
pci_read_vpd_any(struct pci_dev * dev,loff_t pos,size_t count,void * buf)419 ssize_t pci_read_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, void *buf)
420 {
421 return __pci_read_vpd(dev, pos, count, buf, false);
422 }
423 EXPORT_SYMBOL(pci_read_vpd_any);
424
__pci_write_vpd(struct pci_dev * dev,loff_t pos,size_t count,const void * buf,bool check_size)425 static ssize_t __pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count,
426 const void *buf, bool check_size)
427 {
428 ssize_t ret;
429
430 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) {
431 dev = pci_get_func0_dev(dev);
432 if (!dev)
433 return -ENODEV;
434
435 ret = pci_vpd_write(dev, pos, count, buf, check_size);
436 pci_dev_put(dev);
437 return ret;
438 }
439
440 return pci_vpd_write(dev, pos, count, buf, check_size);
441 }
442
443 /**
444 * pci_write_vpd - Write entry to Vital Product Data
445 * @dev: PCI device struct
446 * @pos: offset in VPD space
447 * @count: number of bytes to write
448 * @buf: buffer containing write data
449 */
pci_write_vpd(struct pci_dev * dev,loff_t pos,size_t count,const void * buf)450 ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
451 {
452 return __pci_write_vpd(dev, pos, count, buf, true);
453 }
454 EXPORT_SYMBOL(pci_write_vpd);
455
456 /* Same, but allow to access any address */
pci_write_vpd_any(struct pci_dev * dev,loff_t pos,size_t count,const void * buf)457 ssize_t pci_write_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, const void *buf)
458 {
459 return __pci_write_vpd(dev, pos, count, buf, false);
460 }
461 EXPORT_SYMBOL(pci_write_vpd_any);
462
pci_vpd_find_ro_info_keyword(const void * buf,unsigned int len,const char * kw,unsigned int * size)463 int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len,
464 const char *kw, unsigned int *size)
465 {
466 int ro_start, infokw_start;
467 unsigned int ro_len, infokw_size;
468
469 ro_start = pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_RO_DATA, &ro_len);
470 if (ro_start < 0)
471 return ro_start;
472
473 infokw_start = pci_vpd_find_info_keyword(buf, ro_start, ro_len, kw);
474 if (infokw_start < 0)
475 return infokw_start;
476
477 infokw_size = pci_vpd_info_field_size(buf + infokw_start);
478 infokw_start += PCI_VPD_INFO_FLD_HDR_SIZE;
479
480 if (infokw_start + infokw_size > len)
481 return -EINVAL;
482
483 if (size)
484 *size = infokw_size;
485
486 return infokw_start;
487 }
488 EXPORT_SYMBOL_GPL(pci_vpd_find_ro_info_keyword);
489
pci_vpd_check_csum(const void * buf,unsigned int len)490 int pci_vpd_check_csum(const void *buf, unsigned int len)
491 {
492 const u8 *vpd = buf;
493 unsigned int size;
494 u8 csum = 0;
495 int rv_start;
496
497 rv_start = pci_vpd_find_ro_info_keyword(buf, len, PCI_VPD_RO_KEYWORD_CHKSUM, &size);
498 if (rv_start == -ENOENT) /* no checksum in VPD */
499 return 1;
500 else if (rv_start < 0)
501 return rv_start;
502
503 if (!size)
504 return -EINVAL;
505
506 while (rv_start >= 0)
507 csum += vpd[rv_start--];
508
509 return csum ? -EILSEQ : 0;
510 }
511 EXPORT_SYMBOL_GPL(pci_vpd_check_csum);
512
513 #ifdef CONFIG_PCI_QUIRKS
514 /*
515 * Quirk non-zero PCI functions to route VPD access through function 0 for
516 * devices that share VPD resources between functions. The functions are
517 * expected to be identical devices.
518 */
quirk_f0_vpd_link(struct pci_dev * dev)519 static void quirk_f0_vpd_link(struct pci_dev *dev)
520 {
521 struct pci_dev *f0;
522
523 if (!PCI_FUNC(dev->devfn))
524 return;
525
526 f0 = pci_get_func0_dev(dev);
527 if (!f0)
528 return;
529
530 if (f0->vpd.cap && dev->class == f0->class &&
531 dev->vendor == f0->vendor && dev->device == f0->device)
532 dev->dev_flags |= PCI_DEV_FLAGS_VPD_REF_F0;
533
534 pci_dev_put(f0);
535 }
536 DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID,
537 PCI_CLASS_NETWORK_ETHERNET, 8, quirk_f0_vpd_link);
538
539 /*
540 * If a device follows the VPD format spec, the PCI core will not read or
541 * write past the VPD End Tag. But some vendors do not follow the VPD
542 * format spec, so we can't tell how much data is safe to access. Devices
543 * may behave unpredictably if we access too much. Blacklist these devices
544 * so we don't touch VPD at all.
545 */
quirk_blacklist_vpd(struct pci_dev * dev)546 static void quirk_blacklist_vpd(struct pci_dev *dev)
547 {
548 dev->vpd.len = PCI_VPD_SZ_INVALID;
549 pci_warn(dev, FW_BUG "disabling VPD access (can't determine size of non-standard VPD format)\n");
550 }
551 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd);
552 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd);
553 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd);
554 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd);
555 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd);
556 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd);
557 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd);
558 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd);
559 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd);
560 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd);
561 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd);
562 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID, quirk_blacklist_vpd);
563 /*
564 * The Amazon Annapurna Labs 0x0031 device id is reused for other non Root Port
565 * device types, so the quirk is registered for the PCI_CLASS_BRIDGE_PCI class.
566 */
567 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031,
568 PCI_CLASS_BRIDGE_PCI, 8, quirk_blacklist_vpd);
569
quirk_chelsio_extend_vpd(struct pci_dev * dev)570 static void quirk_chelsio_extend_vpd(struct pci_dev *dev)
571 {
572 int chip = (dev->device & 0xf000) >> 12;
573 int func = (dev->device & 0x0f00) >> 8;
574 int prod = (dev->device & 0x00ff) >> 0;
575
576 /*
577 * If this is a T3-based adapter, there's a 1KB VPD area at offset
578 * 0xc00 which contains the preferred VPD values. If this is a T4 or
579 * later based adapter, the special VPD is at offset 0x400 for the
580 * Physical Functions (the SR-IOV Virtual Functions have no VPD
581 * Capabilities). The PCI VPD Access core routines will normally
582 * compute the size of the VPD by parsing the VPD Data Structure at
583 * offset 0x000. This will result in silent failures when attempting
584 * to accesses these other VPD areas which are beyond those computed
585 * limits.
586 */
587 if (chip == 0x0 && prod >= 0x20)
588 dev->vpd.len = 8192;
589 else if (chip >= 0x4 && func < 0x8)
590 dev->vpd.len = 2048;
591 }
592
593 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID,
594 quirk_chelsio_extend_vpd);
595
596 #endif
597