xref: /linux/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c (revision 920c293af8d01942caa10300ad97eabf778e8598)
1 /*
2  * Copyright 2019 Advanced Micro Devices, Inc.
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
17  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
18  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20  * OTHER DEALINGS IN THE SOFTWARE.
21  *
22  */
23 
24 #include "amdgpu_ras_eeprom.h"
25 #include "amdgpu.h"
26 #include "amdgpu_ras.h"
27 #include <linux/bits.h>
28 #include "atom.h"
29 #include "amdgpu_atomfirmware.h"
30 
31 #define EEPROM_I2C_TARGET_ADDR_VEGA20		0xA0
32 #define EEPROM_I2C_TARGET_ADDR_ARCTURUS		0xA8
33 #define EEPROM_I2C_TARGET_ADDR_ARCTURUS_D342	0xA0
34 #define EEPROM_I2C_TARGET_ADDR_SIENNA_CICHLID   0xA0
35 #define EEPROM_I2C_TARGET_ADDR_ALDEBARAN        0xA0
36 
37 /*
38  * The 2 macros bellow represent the actual size in bytes that
39  * those entities occupy in the EEPROM memory.
40  * EEPROM_TABLE_RECORD_SIZE is different than sizeof(eeprom_table_record) which
41  * uses uint64 to store 6b fields such as retired_page.
42  */
43 #define EEPROM_TABLE_HEADER_SIZE 20
44 #define EEPROM_TABLE_RECORD_SIZE 24
45 
46 #define EEPROM_ADDRESS_SIZE 0x2
47 
48 /* Table hdr is 'AMDR' */
49 #define EEPROM_TABLE_HDR_VAL 0x414d4452
50 #define EEPROM_TABLE_VER 0x00010000
51 
52 /* Bad GPU tag ‘BADG’ */
53 #define EEPROM_TABLE_HDR_BAD 0x42414447
54 
55 /* Assume 2 Mbit size */
56 #define EEPROM_SIZE_BYTES 256000
57 #define EEPROM_PAGE__SIZE_BYTES 256
58 #define EEPROM_HDR_START 0
59 #define EEPROM_RECORD_START (EEPROM_HDR_START + EEPROM_TABLE_HEADER_SIZE)
60 #define EEPROM_MAX_RECORD_NUM ((EEPROM_SIZE_BYTES - EEPROM_TABLE_HEADER_SIZE) / EEPROM_TABLE_RECORD_SIZE)
61 #define EEPROM_ADDR_MSB_MASK GENMASK(17, 8)
62 
63 #define to_amdgpu_device(x) (container_of(x, struct amdgpu_ras, eeprom_control))->adev
64 
65 static bool __is_ras_eeprom_supported(struct amdgpu_device *adev)
66 {
67 	if ((adev->asic_type == CHIP_VEGA20) ||
68 	    (adev->asic_type == CHIP_ARCTURUS) ||
69 	    (adev->asic_type == CHIP_SIENNA_CICHLID) ||
70 	    (adev->asic_type == CHIP_ALDEBARAN))
71 		return true;
72 
73 	return false;
74 }
75 
76 static bool __get_eeprom_i2c_addr_arct(struct amdgpu_device *adev,
77 				       uint16_t *i2c_addr)
78 {
79 	struct atom_context *atom_ctx = adev->mode_info.atom_context;
80 
81 	if (!i2c_addr || !atom_ctx)
82 		return false;
83 
84 	if (strnstr(atom_ctx->vbios_version,
85 	            "D342",
86 		    sizeof(atom_ctx->vbios_version)))
87 		*i2c_addr = EEPROM_I2C_TARGET_ADDR_ARCTURUS_D342;
88 	else
89 		*i2c_addr = EEPROM_I2C_TARGET_ADDR_ARCTURUS;
90 
91 	return true;
92 }
93 
94 static bool __get_eeprom_i2c_addr(struct amdgpu_device *adev,
95 				  uint16_t *i2c_addr)
96 {
97 	if (!i2c_addr)
98 		return false;
99 
100 	if (amdgpu_atomfirmware_ras_rom_addr(adev, (uint8_t*)i2c_addr))
101 		return true;
102 
103 	switch (adev->asic_type) {
104 	case CHIP_VEGA20:
105 		*i2c_addr = EEPROM_I2C_TARGET_ADDR_VEGA20;
106 		break;
107 
108 	case CHIP_ARCTURUS:
109 		return __get_eeprom_i2c_addr_arct(adev, i2c_addr);
110 
111 	case CHIP_SIENNA_CICHLID:
112 		*i2c_addr = EEPROM_I2C_TARGET_ADDR_SIENNA_CICHLID;
113 		break;
114 
115 	case CHIP_ALDEBARAN:
116 		*i2c_addr = EEPROM_I2C_TARGET_ADDR_ALDEBARAN;
117 		break;
118 
119 	default:
120 		return false;
121 	}
122 
123 	return true;
124 }
125 
126 static void __encode_table_header_to_buff(struct amdgpu_ras_eeprom_table_header *hdr,
127 					  unsigned char *buff)
128 {
129 	uint32_t *pp = (uint32_t *) buff;
130 
131 	pp[0] = cpu_to_le32(hdr->header);
132 	pp[1] = cpu_to_le32(hdr->version);
133 	pp[2] = cpu_to_le32(hdr->first_rec_offset);
134 	pp[3] = cpu_to_le32(hdr->tbl_size);
135 	pp[4] = cpu_to_le32(hdr->checksum);
136 }
137 
138 static void __decode_table_header_from_buff(struct amdgpu_ras_eeprom_table_header *hdr,
139 					  unsigned char *buff)
140 {
141 	uint32_t *pp = (uint32_t *)buff;
142 
143 	hdr->header	      = le32_to_cpu(pp[0]);
144 	hdr->version	      = le32_to_cpu(pp[1]);
145 	hdr->first_rec_offset = le32_to_cpu(pp[2]);
146 	hdr->tbl_size	      = le32_to_cpu(pp[3]);
147 	hdr->checksum	      = le32_to_cpu(pp[4]);
148 }
149 
150 static int __update_table_header(struct amdgpu_ras_eeprom_control *control,
151 				 unsigned char *buff)
152 {
153 	int ret = 0;
154 	struct amdgpu_device *adev = to_amdgpu_device(control);
155 	struct i2c_msg msg = {
156 			.addr	= 0,
157 			.flags	= 0,
158 			.len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE,
159 			.buf	= buff,
160 	};
161 
162 
163 	*(uint16_t *)buff = EEPROM_HDR_START;
164 	__encode_table_header_to_buff(&control->tbl_hdr, buff + EEPROM_ADDRESS_SIZE);
165 
166 	msg.addr = control->i2c_address;
167 
168 	/* i2c may be unstable in gpu reset */
169 	down_read(&adev->reset_sem);
170 	ret = i2c_transfer(&adev->pm.smu_i2c, &msg, 1);
171 	up_read(&adev->reset_sem);
172 
173 	if (ret < 1)
174 		DRM_ERROR("Failed to write EEPROM table header, ret:%d", ret);
175 
176 	return ret;
177 }
178 
179 static uint32_t  __calc_hdr_byte_sum(struct amdgpu_ras_eeprom_control *control)
180 {
181 	int i;
182 	uint32_t tbl_sum = 0;
183 
184 	/* Header checksum, skip checksum field in the calculation */
185 	for (i = 0; i < sizeof(control->tbl_hdr) - sizeof(control->tbl_hdr.checksum); i++)
186 		tbl_sum += *(((unsigned char *)&control->tbl_hdr) + i);
187 
188 	return tbl_sum;
189 }
190 
191 static uint32_t  __calc_recs_byte_sum(struct eeprom_table_record *records,
192 				      int num)
193 {
194 	int i, j;
195 	uint32_t tbl_sum = 0;
196 
197 	/* Records checksum */
198 	for (i = 0; i < num; i++) {
199 		struct eeprom_table_record *record = &records[i];
200 
201 		for (j = 0; j < sizeof(*record); j++) {
202 			tbl_sum += *(((unsigned char *)record) + j);
203 		}
204 	}
205 
206 	return tbl_sum;
207 }
208 
209 static inline uint32_t  __calc_tbl_byte_sum(struct amdgpu_ras_eeprom_control *control,
210 				  struct eeprom_table_record *records, int num)
211 {
212 	return __calc_hdr_byte_sum(control) + __calc_recs_byte_sum(records, num);
213 }
214 
215 /* Checksum = 256 -((sum of all table entries) mod 256) */
216 static void __update_tbl_checksum(struct amdgpu_ras_eeprom_control *control,
217 				  struct eeprom_table_record *records, int num,
218 				  uint32_t old_hdr_byte_sum)
219 {
220 	/*
221 	 * This will update the table sum with new records.
222 	 *
223 	 * TODO: What happens when the EEPROM table is to be wrapped around
224 	 * and old records from start will get overridden.
225 	 */
226 
227 	/* need to recalculate updated header byte sum */
228 	control->tbl_byte_sum -= old_hdr_byte_sum;
229 	control->tbl_byte_sum += __calc_tbl_byte_sum(control, records, num);
230 
231 	control->tbl_hdr.checksum = 256 - (control->tbl_byte_sum % 256);
232 }
233 
234 /* table sum mod 256 + checksum must equals 256 */
235 static bool __validate_tbl_checksum(struct amdgpu_ras_eeprom_control *control,
236 			    struct eeprom_table_record *records, int num)
237 {
238 	control->tbl_byte_sum = __calc_tbl_byte_sum(control, records, num);
239 
240 	if (control->tbl_hdr.checksum + (control->tbl_byte_sum % 256) != 256) {
241 		DRM_WARN("Checksum mismatch, checksum: %u ", control->tbl_hdr.checksum);
242 		return false;
243 	}
244 
245 	return true;
246 }
247 
248 static int amdgpu_ras_eeprom_correct_header_tag(
249 				struct amdgpu_ras_eeprom_control *control,
250 				uint32_t header)
251 {
252 	unsigned char buff[EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE];
253 	struct amdgpu_ras_eeprom_table_header *hdr = &control->tbl_hdr;
254 	int ret = 0;
255 
256 	memset(buff, 0, EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE);
257 
258 	mutex_lock(&control->tbl_mutex);
259 	hdr->header = header;
260 	ret = __update_table_header(control, buff);
261 	mutex_unlock(&control->tbl_mutex);
262 
263 	return ret;
264 }
265 
266 int amdgpu_ras_eeprom_reset_table(struct amdgpu_ras_eeprom_control *control)
267 {
268 	unsigned char buff[EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE] = { 0 };
269 	struct amdgpu_ras_eeprom_table_header *hdr = &control->tbl_hdr;
270 	int ret = 0;
271 
272 	mutex_lock(&control->tbl_mutex);
273 
274 	hdr->header = EEPROM_TABLE_HDR_VAL;
275 	hdr->version = EEPROM_TABLE_VER;
276 	hdr->first_rec_offset = EEPROM_RECORD_START;
277 	hdr->tbl_size = EEPROM_TABLE_HEADER_SIZE;
278 
279 	control->tbl_byte_sum = 0;
280 	__update_tbl_checksum(control, NULL, 0, 0);
281 	control->next_addr = EEPROM_RECORD_START;
282 
283 	ret = __update_table_header(control, buff);
284 
285 	mutex_unlock(&control->tbl_mutex);
286 
287 	return ret;
288 
289 }
290 
291 int amdgpu_ras_eeprom_init(struct amdgpu_ras_eeprom_control *control,
292 			bool *exceed_err_limit)
293 {
294 	int ret = 0;
295 	struct amdgpu_device *adev = to_amdgpu_device(control);
296 	unsigned char buff[EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE] = { 0 };
297 	struct amdgpu_ras_eeprom_table_header *hdr = &control->tbl_hdr;
298 	struct amdgpu_ras *ras = amdgpu_ras_get_context(adev);
299 	struct i2c_msg msg = {
300 			.addr	= 0,
301 			.flags	= I2C_M_RD,
302 			.len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE,
303 			.buf	= buff,
304 	};
305 
306 	*exceed_err_limit = false;
307 
308 	if (!__is_ras_eeprom_supported(adev))
309 		return 0;
310 
311 	/* Verify i2c adapter is initialized */
312 	if (!adev->pm.smu_i2c.algo)
313 		return -ENOENT;
314 
315 	if (!__get_eeprom_i2c_addr(adev, &control->i2c_address))
316 		return -EINVAL;
317 
318 	mutex_init(&control->tbl_mutex);
319 
320 	msg.addr = control->i2c_address;
321 	/* Read/Create table header from EEPROM address 0 */
322 	ret = i2c_transfer(&adev->pm.smu_i2c, &msg, 1);
323 	if (ret < 1) {
324 		DRM_ERROR("Failed to read EEPROM table header, ret:%d", ret);
325 		return ret;
326 	}
327 
328 	__decode_table_header_from_buff(hdr, &buff[2]);
329 
330 	if (hdr->header == EEPROM_TABLE_HDR_VAL) {
331 		control->num_recs = (hdr->tbl_size - EEPROM_TABLE_HEADER_SIZE) /
332 				    EEPROM_TABLE_RECORD_SIZE;
333 		control->tbl_byte_sum = __calc_hdr_byte_sum(control);
334 		control->next_addr = EEPROM_RECORD_START;
335 
336 		DRM_DEBUG_DRIVER("Found existing EEPROM table with %d records",
337 				 control->num_recs);
338 
339 	} else if ((hdr->header == EEPROM_TABLE_HDR_BAD) &&
340 			(amdgpu_bad_page_threshold != 0)) {
341 		if (ras->bad_page_cnt_threshold > control->num_recs) {
342 			dev_info(adev->dev, "Using one valid bigger bad page "
343 				"threshold and correcting eeprom header tag.\n");
344 			ret = amdgpu_ras_eeprom_correct_header_tag(control,
345 							EEPROM_TABLE_HDR_VAL);
346 		} else {
347 			*exceed_err_limit = true;
348 			dev_err(adev->dev, "Exceeding the bad_page_threshold parameter, "
349 				"disabling the GPU.\n");
350 		}
351 	} else {
352 		DRM_INFO("Creating new EEPROM table");
353 
354 		ret = amdgpu_ras_eeprom_reset_table(control);
355 	}
356 
357 	return ret == 1 ? 0 : -EIO;
358 }
359 
360 static void __encode_table_record_to_buff(struct amdgpu_ras_eeprom_control *control,
361 					  struct eeprom_table_record *record,
362 					  unsigned char *buff)
363 {
364 	__le64 tmp = 0;
365 	int i = 0;
366 
367 	/* Next are all record fields according to EEPROM page spec in LE foramt */
368 	buff[i++] = record->err_type;
369 
370 	buff[i++] = record->bank;
371 
372 	tmp = cpu_to_le64(record->ts);
373 	memcpy(buff + i, &tmp, 8);
374 	i += 8;
375 
376 	tmp = cpu_to_le64((record->offset & 0xffffffffffff));
377 	memcpy(buff + i, &tmp, 6);
378 	i += 6;
379 
380 	buff[i++] = record->mem_channel;
381 	buff[i++] = record->mcumc_id;
382 
383 	tmp = cpu_to_le64((record->retired_page & 0xffffffffffff));
384 	memcpy(buff + i, &tmp, 6);
385 }
386 
387 static void __decode_table_record_from_buff(struct amdgpu_ras_eeprom_control *control,
388 					    struct eeprom_table_record *record,
389 					    unsigned char *buff)
390 {
391 	__le64 tmp = 0;
392 	int i =  0;
393 
394 	/* Next are all record fields according to EEPROM page spec in LE foramt */
395 	record->err_type = buff[i++];
396 
397 	record->bank = buff[i++];
398 
399 	memcpy(&tmp, buff + i, 8);
400 	record->ts = le64_to_cpu(tmp);
401 	i += 8;
402 
403 	memcpy(&tmp, buff + i, 6);
404 	record->offset = (le64_to_cpu(tmp) & 0xffffffffffff);
405 	i += 6;
406 
407 	record->mem_channel = buff[i++];
408 	record->mcumc_id = buff[i++];
409 
410 	memcpy(&tmp, buff + i,  6);
411 	record->retired_page = (le64_to_cpu(tmp) & 0xffffffffffff);
412 }
413 
414 /*
415  * When reaching end of EEPROM memory jump back to 0 record address
416  * When next record access will go beyond EEPROM page boundary modify bits A17/A8
417  * in I2C selector to go to next page
418  */
419 static uint32_t __correct_eeprom_dest_address(uint32_t curr_address)
420 {
421 	uint32_t next_address = curr_address + EEPROM_TABLE_RECORD_SIZE;
422 
423 	/* When all EEPROM memory used jump back to 0 address */
424 	if (next_address > EEPROM_SIZE_BYTES) {
425 		DRM_INFO("Reached end of EEPROM memory, jumping to 0 "
426 			 "and overriding old record");
427 		return EEPROM_RECORD_START;
428 	}
429 
430 	/*
431 	 * To check if we overflow page boundary  compare next address with
432 	 * current and see if bits 17/8 of the EEPROM address will change
433 	 * If they do start from the next 256b page
434 	 *
435 	 * https://www.st.com/resource/en/datasheet/m24m02-dr.pdf sec. 5.1.2
436 	 */
437 	if ((curr_address & EEPROM_ADDR_MSB_MASK) != (next_address & EEPROM_ADDR_MSB_MASK)) {
438 		DRM_DEBUG_DRIVER("Reached end of EEPROM memory page, jumping to next: %lx",
439 				(next_address & EEPROM_ADDR_MSB_MASK));
440 
441 		return  (next_address & EEPROM_ADDR_MSB_MASK);
442 	}
443 
444 	return curr_address;
445 }
446 
447 bool amdgpu_ras_eeprom_check_err_threshold(struct amdgpu_device *adev)
448 {
449 	struct amdgpu_ras *con = amdgpu_ras_get_context(adev);
450 
451 	if (!__is_ras_eeprom_supported(adev))
452 		return false;
453 
454 	/* skip check eeprom table for VEGA20 Gaming */
455 	if (!con)
456 		return false;
457 	else
458 		if (!(con->features & BIT(AMDGPU_RAS_BLOCK__UMC)))
459 			return false;
460 
461 	if (con->eeprom_control.tbl_hdr.header == EEPROM_TABLE_HDR_BAD) {
462 		dev_warn(adev->dev, "This GPU is in BAD status.");
463 		dev_warn(adev->dev, "Please retire it or setting one bigger "
464 				"threshold value when reloading driver.\n");
465 		return true;
466 	}
467 
468 	return false;
469 }
470 
471 int amdgpu_ras_eeprom_process_recods(struct amdgpu_ras_eeprom_control *control,
472 					    struct eeprom_table_record *records,
473 					    bool write,
474 					    int num)
475 {
476 	int i, ret = 0;
477 	struct i2c_msg *msgs, *msg;
478 	unsigned char *buffs, *buff;
479 	struct eeprom_table_record *record;
480 	struct amdgpu_device *adev = to_amdgpu_device(control);
481 	struct amdgpu_ras *ras = amdgpu_ras_get_context(adev);
482 
483 	if (!__is_ras_eeprom_supported(adev))
484 		return 0;
485 
486 	buffs = kcalloc(num, EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE,
487 			 GFP_KERNEL);
488 	if (!buffs)
489 		return -ENOMEM;
490 
491 	mutex_lock(&control->tbl_mutex);
492 
493 	msgs = kcalloc(num, sizeof(*msgs), GFP_KERNEL);
494 	if (!msgs) {
495 		ret = -ENOMEM;
496 		goto free_buff;
497 	}
498 
499 	/*
500 	 * If saved bad pages number exceeds the bad page threshold for
501 	 * the whole VRAM, update table header to mark the BAD GPU tag
502 	 * and schedule one ras recovery after eeprom write is done,
503 	 * this can avoid the missing for latest records.
504 	 *
505 	 * This new header will be picked up and checked in the bootup
506 	 * by ras recovery, which may break bootup process to notify
507 	 * user this GPU is in bad state and to retire such GPU for
508 	 * further check.
509 	 */
510 	if (write && (amdgpu_bad_page_threshold != 0) &&
511 		((control->num_recs + num) >= ras->bad_page_cnt_threshold)) {
512 		dev_warn(adev->dev,
513 			"Saved bad pages(%d) reaches threshold value(%d).\n",
514 			control->num_recs + num, ras->bad_page_cnt_threshold);
515 		control->tbl_hdr.header = EEPROM_TABLE_HDR_BAD;
516 	}
517 
518 	/* In case of overflow just start from beginning to not lose newest records */
519 	if (write && (control->next_addr + EEPROM_TABLE_RECORD_SIZE * num > EEPROM_SIZE_BYTES))
520 		control->next_addr = EEPROM_RECORD_START;
521 
522 	/*
523 	 * TODO Currently makes EEPROM writes for each record, this creates
524 	 * internal fragmentation. Optimized the code to do full page write of
525 	 * 256b
526 	 */
527 	for (i = 0; i < num; i++) {
528 		buff = &buffs[i * (EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE)];
529 		record = &records[i];
530 		msg = &msgs[i];
531 
532 		control->next_addr = __correct_eeprom_dest_address(control->next_addr);
533 
534 		/*
535 		 * Update bits 16,17 of EEPROM address in I2C address by setting them
536 		 * to bits 1,2 of Device address byte
537 		 */
538 		msg->addr = control->i2c_address |
539 			        ((control->next_addr & EEPROM_ADDR_MSB_MASK) >> 15);
540 		msg->flags	= write ? 0 : I2C_M_RD;
541 		msg->len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE;
542 		msg->buf	= buff;
543 
544 		/* Insert the EEPROM dest addess, bits 0-15 */
545 		buff[0] = ((control->next_addr >> 8) & 0xff);
546 		buff[1] = (control->next_addr & 0xff);
547 
548 		/* EEPROM table content is stored in LE format */
549 		if (write)
550 			__encode_table_record_to_buff(control, record, buff + EEPROM_ADDRESS_SIZE);
551 
552 		/*
553 		 * The destination EEPROM address might need to be corrected to account
554 		 * for page or entire memory wrapping
555 		 */
556 		control->next_addr += EEPROM_TABLE_RECORD_SIZE;
557 	}
558 
559 	/* i2c may be unstable in gpu reset */
560 	down_read(&adev->reset_sem);
561 	ret = i2c_transfer(&adev->pm.smu_i2c, msgs, num);
562 	up_read(&adev->reset_sem);
563 
564 	if (ret < 1) {
565 		DRM_ERROR("Failed to process EEPROM table records, ret:%d", ret);
566 
567 		/* TODO Restore prev next EEPROM address ? */
568 		goto free_msgs;
569 	}
570 
571 
572 	if (!write) {
573 		for (i = 0; i < num; i++) {
574 			buff = &buffs[i*(EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE)];
575 			record = &records[i];
576 
577 			__decode_table_record_from_buff(control, record, buff + EEPROM_ADDRESS_SIZE);
578 		}
579 	}
580 
581 	if (write) {
582 		uint32_t old_hdr_byte_sum = __calc_hdr_byte_sum(control);
583 
584 		/*
585 		 * Update table header with size and CRC and account for table
586 		 * wrap around where the assumption is that we treat it as empty
587 		 * table
588 		 *
589 		 * TODO - Check the assumption is correct
590 		 */
591 		control->num_recs += num;
592 		control->num_recs %= EEPROM_MAX_RECORD_NUM;
593 		control->tbl_hdr.tbl_size += EEPROM_TABLE_RECORD_SIZE * num;
594 		if (control->tbl_hdr.tbl_size > EEPROM_SIZE_BYTES)
595 			control->tbl_hdr.tbl_size = EEPROM_TABLE_HEADER_SIZE +
596 			control->num_recs * EEPROM_TABLE_RECORD_SIZE;
597 
598 		__update_tbl_checksum(control, records, num, old_hdr_byte_sum);
599 
600 		__update_table_header(control, buffs);
601 	} else if (!__validate_tbl_checksum(control, records, num)) {
602 		DRM_WARN("EEPROM Table checksum mismatch!");
603 		/* TODO Uncomment when EEPROM read/write is relliable */
604 		/* ret = -EIO; */
605 	}
606 
607 free_msgs:
608 	kfree(msgs);
609 
610 free_buff:
611 	kfree(buffs);
612 
613 	mutex_unlock(&control->tbl_mutex);
614 
615 	return ret == num ? 0 : -EIO;
616 }
617 
618 inline uint32_t amdgpu_ras_eeprom_get_record_max_length(void)
619 {
620 	return EEPROM_MAX_RECORD_NUM;
621 }
622 
623 /* Used for testing if bugs encountered */
624 #if 0
625 void amdgpu_ras_eeprom_test(struct amdgpu_ras_eeprom_control *control)
626 {
627 	int i;
628 	struct eeprom_table_record *recs = kcalloc(1, sizeof(*recs), GFP_KERNEL);
629 
630 	if (!recs)
631 		return;
632 
633 	for (i = 0; i < 1 ; i++) {
634 		recs[i].address = 0xdeadbeef;
635 		recs[i].retired_page = i;
636 	}
637 
638 	if (!amdgpu_ras_eeprom_process_recods(control, recs, true, 1)) {
639 
640 		memset(recs, 0, sizeof(*recs) * 1);
641 
642 		control->next_addr = EEPROM_RECORD_START;
643 
644 		if (!amdgpu_ras_eeprom_process_recods(control, recs, false, 1)) {
645 			for (i = 0; i < 1; i++)
646 				DRM_INFO("rec.address :0x%llx, rec.retired_page :%llu",
647 					 recs[i].address, recs[i].retired_page);
648 		} else
649 			DRM_ERROR("Failed in reading from table");
650 
651 	} else
652 		DRM_ERROR("Failed in writing to table");
653 }
654 #endif
655