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 "smu_v11_0_i2c.h"
29 
30 #define EEPROM_I2C_TARGET_ADDR 0xA0
31 
32 /*
33  * The 2 macros bellow represent the actual size in bytes that
34  * those entities occupy in the EEPROM memory.
35  * EEPROM_TABLE_RECORD_SIZE is different than sizeof(eeprom_table_record) which
36  * uses uint64 to store 6b fields such as retired_page.
37  */
38 #define EEPROM_TABLE_HEADER_SIZE 20
39 #define EEPROM_TABLE_RECORD_SIZE 24
40 
41 #define EEPROM_ADDRESS_SIZE 0x2
42 
43 /* Table hdr is 'AMDR' */
44 #define EEPROM_TABLE_HDR_VAL 0x414d4452
45 #define EEPROM_TABLE_VER 0x00010000
46 
47 /* Assume 2 Mbit size */
48 #define EEPROM_SIZE_BYTES 256000
49 #define EEPROM_PAGE__SIZE_BYTES 256
50 #define EEPROM_HDR_START 0
51 #define EEPROM_RECORD_START (EEPROM_HDR_START + EEPROM_TABLE_HEADER_SIZE)
52 #define EEPROM_MAX_RECORD_NUM ((EEPROM_SIZE_BYTES - EEPROM_TABLE_HEADER_SIZE) / EEPROM_TABLE_RECORD_SIZE)
53 #define EEPROM_ADDR_MSB_MASK GENMASK(17, 8)
54 
55 #define to_amdgpu_device(x) (container_of(x, struct amdgpu_ras, eeprom_control))->adev
56 
57 static void __encode_table_header_to_buff(struct amdgpu_ras_eeprom_table_header *hdr,
58 					  unsigned char *buff)
59 {
60 	uint32_t *pp = (uint32_t *) buff;
61 
62 	pp[0] = cpu_to_le32(hdr->header);
63 	pp[1] = cpu_to_le32(hdr->version);
64 	pp[2] = cpu_to_le32(hdr->first_rec_offset);
65 	pp[3] = cpu_to_le32(hdr->tbl_size);
66 	pp[4] = cpu_to_le32(hdr->checksum);
67 }
68 
69 static void __decode_table_header_from_buff(struct amdgpu_ras_eeprom_table_header *hdr,
70 					  unsigned char *buff)
71 {
72 	uint32_t *pp = (uint32_t *)buff;
73 
74 	hdr->header 	      = le32_to_cpu(pp[0]);
75 	hdr->version 	      = le32_to_cpu(pp[1]);
76 	hdr->first_rec_offset = le32_to_cpu(pp[2]);
77 	hdr->tbl_size 	      = le32_to_cpu(pp[3]);
78 	hdr->checksum 	      = le32_to_cpu(pp[4]);
79 }
80 
81 static int __update_table_header(struct amdgpu_ras_eeprom_control *control,
82 				 unsigned char *buff)
83 {
84 	int ret = 0;
85 	struct i2c_msg msg = {
86 			.addr	= EEPROM_I2C_TARGET_ADDR,
87 			.flags	= 0,
88 			.len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE,
89 			.buf	= buff,
90 	};
91 
92 
93 	*(uint16_t *)buff = EEPROM_HDR_START;
94 	__encode_table_header_to_buff(&control->tbl_hdr, buff + EEPROM_ADDRESS_SIZE);
95 
96 	ret = i2c_transfer(&control->eeprom_accessor, &msg, 1);
97 	if (ret < 1)
98 		DRM_ERROR("Failed to write EEPROM table header, ret:%d", ret);
99 
100 	return ret;
101 }
102 
103 static uint32_t  __calc_hdr_byte_sum(struct amdgpu_ras_eeprom_control *control);
104 
105 int amdgpu_ras_eeprom_init(struct amdgpu_ras_eeprom_control *control)
106 {
107 	int ret = 0;
108 	struct amdgpu_device *adev = to_amdgpu_device(control);
109 	unsigned char buff[EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE] = { 0 };
110 	struct amdgpu_ras_eeprom_table_header *hdr = &control->tbl_hdr;
111 	struct i2c_msg msg = {
112 			.addr	= EEPROM_I2C_TARGET_ADDR,
113 			.flags	= I2C_M_RD,
114 			.len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_HEADER_SIZE,
115 			.buf	= buff,
116 	};
117 
118 	mutex_init(&control->tbl_mutex);
119 
120 	switch (adev->asic_type) {
121 	case CHIP_VEGA20:
122 		ret = smu_v11_0_i2c_eeprom_control_init(&control->eeprom_accessor);
123 		break;
124 
125 	default:
126 		return 0;
127 	}
128 
129 	if (ret) {
130 		DRM_ERROR("Failed to init I2C controller, ret:%d", ret);
131 		return ret;
132 	}
133 
134 	/* Read/Create table header from EEPROM address 0 */
135 	ret = i2c_transfer(&control->eeprom_accessor, &msg, 1);
136 	if (ret < 1) {
137 		DRM_ERROR("Failed to read EEPROM table header, ret:%d", ret);
138 		return ret;
139 	}
140 
141 	__decode_table_header_from_buff(hdr, &buff[2]);
142 
143 	if (hdr->header == EEPROM_TABLE_HDR_VAL) {
144 		control->num_recs = (hdr->tbl_size - EEPROM_TABLE_HEADER_SIZE) /
145 				    EEPROM_TABLE_RECORD_SIZE;
146 		DRM_DEBUG_DRIVER("Found existing EEPROM table with %d records",
147 				 control->num_recs);
148 
149 	} else {
150 		DRM_INFO("Creating new EEPROM table");
151 
152 		hdr->header = EEPROM_TABLE_HDR_VAL;
153 		hdr->version = EEPROM_TABLE_VER;
154 		hdr->first_rec_offset = EEPROM_RECORD_START;
155 		hdr->tbl_size = EEPROM_TABLE_HEADER_SIZE;
156 
157 		adev->psp.ras.ras->eeprom_control.tbl_byte_sum =
158 				__calc_hdr_byte_sum(&adev->psp.ras.ras->eeprom_control);
159 		ret = __update_table_header(control, buff);
160 	}
161 
162 	/* Start inserting records from here */
163 	adev->psp.ras.ras->eeprom_control.next_addr = EEPROM_RECORD_START;
164 
165 	return ret == 1 ? 0 : -EIO;
166 }
167 
168 void amdgpu_ras_eeprom_fini(struct amdgpu_ras_eeprom_control *control)
169 {
170 	struct amdgpu_device *adev = to_amdgpu_device(control);
171 
172 	switch (adev->asic_type) {
173 	case CHIP_VEGA20:
174 		smu_v11_0_i2c_eeprom_control_fini(&control->eeprom_accessor);
175 		break;
176 
177 	default:
178 		return;
179 	}
180 }
181 
182 static void __encode_table_record_to_buff(struct amdgpu_ras_eeprom_control *control,
183 					  struct eeprom_table_record *record,
184 					  unsigned char *buff)
185 {
186 	__le64 tmp = 0;
187 	int i = 0;
188 
189 	/* Next are all record fields according to EEPROM page spec in LE foramt */
190 	buff[i++] = record->err_type;
191 
192 	buff[i++] = record->bank;
193 
194 	tmp = cpu_to_le64(record->ts);
195 	memcpy(buff + i, &tmp, 8);
196 	i += 8;
197 
198 	tmp = cpu_to_le64((record->offset & 0xffffffffffff));
199 	memcpy(buff + i, &tmp, 6);
200 	i += 6;
201 
202 	buff[i++] = record->mem_channel;
203 	buff[i++] = record->mcumc_id;
204 
205 	tmp = cpu_to_le64((record->retired_page & 0xffffffffffff));
206 	memcpy(buff + i, &tmp, 6);
207 }
208 
209 static void __decode_table_record_from_buff(struct amdgpu_ras_eeprom_control *control,
210 					    struct eeprom_table_record *record,
211 					    unsigned char *buff)
212 {
213 	__le64 tmp = 0;
214 	int i =  0;
215 
216 	/* Next are all record fields according to EEPROM page spec in LE foramt */
217 	record->err_type = buff[i++];
218 
219 	record->bank = buff[i++];
220 
221 	memcpy(&tmp, buff + i, 8);
222 	record->ts = le64_to_cpu(tmp);
223 	i += 8;
224 
225 	memcpy(&tmp, buff + i, 6);
226 	record->offset = (le64_to_cpu(tmp) & 0xffffffffffff);
227 	i += 6;
228 
229 	buff[i++] = record->mem_channel;
230 	buff[i++] = record->mcumc_id;
231 
232 	memcpy(&tmp, buff + i,  6);
233 	record->retired_page = (le64_to_cpu(tmp) & 0xffffffffffff);
234 }
235 
236 /*
237  * When reaching end of EEPROM memory jump back to 0 record address
238  * When next record access will go beyond EEPROM page boundary modify bits A17/A8
239  * in I2C selector to go to next page
240  */
241 static uint32_t __correct_eeprom_dest_address(uint32_t curr_address)
242 {
243 	uint32_t next_address = curr_address + EEPROM_TABLE_RECORD_SIZE;
244 
245 	/* When all EEPROM memory used jump back to 0 address */
246 	if (next_address > EEPROM_SIZE_BYTES) {
247 		DRM_INFO("Reached end of EEPROM memory, jumping to 0 "
248 			 "and overriding old record");
249 		return EEPROM_RECORD_START;
250 	}
251 
252 	/*
253 	 * To check if we overflow page boundary  compare next address with
254 	 * current and see if bits 17/8 of the EEPROM address will change
255 	 * If they do start from the next 256b page
256 	 *
257 	 * https://www.st.com/resource/en/datasheet/m24m02-dr.pdf sec. 5.1.2
258 	 */
259 	if ((curr_address & EEPROM_ADDR_MSB_MASK) != (next_address & EEPROM_ADDR_MSB_MASK)) {
260 		DRM_DEBUG_DRIVER("Reached end of EEPROM memory page, jumping to next: %lx",
261 				(next_address & EEPROM_ADDR_MSB_MASK));
262 
263 		return  (next_address & EEPROM_ADDR_MSB_MASK);
264 	}
265 
266 	return curr_address;
267 }
268 
269 
270 static uint32_t  __calc_hdr_byte_sum(struct amdgpu_ras_eeprom_control *control)
271 {
272 	int i;
273 	uint32_t tbl_sum = 0;
274 
275 	/* Header checksum, skip checksum field in the calculation */
276 	for (i = 0; i < sizeof(control->tbl_hdr) - sizeof(control->tbl_hdr.checksum); i++)
277 		tbl_sum += *(((unsigned char *)&control->tbl_hdr) + i);
278 
279 	return tbl_sum;
280 }
281 
282 static uint32_t  __calc_recs_byte_sum(struct eeprom_table_record *records,
283 				      int num)
284 {
285 	int i, j;
286 	uint32_t tbl_sum = 0;
287 
288 	/* Records checksum */
289 	for (i = 0; i < num; i++) {
290 		struct eeprom_table_record *record = &records[i];
291 
292 		for (j = 0; j < sizeof(*record); j++) {
293 			tbl_sum += *(((unsigned char *)record) + j);
294 		}
295 	}
296 
297 	return tbl_sum;
298 }
299 
300 static inline uint32_t  __calc_tbl_byte_sum(struct amdgpu_ras_eeprom_control *control,
301 				  struct eeprom_table_record *records, int num)
302 {
303 	return __calc_hdr_byte_sum(control) + __calc_recs_byte_sum(records, num);
304 }
305 
306 /* Checksum = 256 -((sum of all table entries) mod 256) */
307 static void __update_tbl_checksum(struct amdgpu_ras_eeprom_control *control,
308 				  struct eeprom_table_record *records, int num,
309 				  uint32_t old_hdr_byte_sum)
310 {
311 	/*
312 	 * This will update the table sum with new records.
313 	 *
314 	 * TODO: What happens when the EEPROM table is to be wrapped around
315 	 * and old records from start will get overridden.
316 	 */
317 
318 	/* need to recalculate updated header byte sum */
319 	control->tbl_byte_sum -= old_hdr_byte_sum;
320 	control->tbl_byte_sum += __calc_tbl_byte_sum(control, records, num);
321 
322 	control->tbl_hdr.checksum = 256 - (control->tbl_byte_sum % 256);
323 }
324 
325 /* table sum mod 256 + checksum must equals 256 */
326 static bool __validate_tbl_checksum(struct amdgpu_ras_eeprom_control *control,
327 			    struct eeprom_table_record *records, int num)
328 {
329 	control->tbl_byte_sum = __calc_tbl_byte_sum(control, records, num);
330 
331 	if (control->tbl_hdr.checksum + (control->tbl_byte_sum % 256) != 256) {
332 		DRM_WARN("Checksum mismatch, checksum: %u ", control->tbl_hdr.checksum);
333 		return false;
334 	}
335 
336 	return true;
337 }
338 
339 int amdgpu_ras_eeprom_process_recods(struct amdgpu_ras_eeprom_control *control,
340 					    struct eeprom_table_record *records,
341 					    bool write,
342 					    int num)
343 {
344 	int i, ret = 0;
345 	struct i2c_msg *msgs;
346 	unsigned char *buffs;
347 	struct amdgpu_device *adev = to_amdgpu_device(control);
348 
349 	if (adev->asic_type != CHIP_VEGA20)
350 		return 0;
351 
352 	buffs = kcalloc(num, EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE,
353 			 GFP_KERNEL);
354 	if (!buffs)
355 		return -ENOMEM;
356 
357 	mutex_lock(&control->tbl_mutex);
358 
359 	msgs = kcalloc(num, sizeof(*msgs), GFP_KERNEL);
360 	if (!msgs) {
361 		ret = -ENOMEM;
362 		goto free_buff;
363 	}
364 
365 	/* In case of overflow just start from beginning to not lose newest records */
366 	if (write && (control->next_addr + EEPROM_TABLE_RECORD_SIZE * num > EEPROM_SIZE_BYTES))
367 		control->next_addr = EEPROM_RECORD_START;
368 
369 
370 	/*
371 	 * TODO Currently makes EEPROM writes for each record, this creates
372 	 * internal fragmentation. Optimized the code to do full page write of
373 	 * 256b
374 	 */
375 	for (i = 0; i < num; i++) {
376 		unsigned char *buff = &buffs[i * (EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE)];
377 		struct eeprom_table_record *record = &records[i];
378 		struct i2c_msg *msg = &msgs[i];
379 
380 		control->next_addr = __correct_eeprom_dest_address(control->next_addr);
381 
382 		/*
383 		 * Update bits 16,17 of EEPROM address in I2C address by setting them
384 		 * to bits 1,2 of Device address byte
385 		 */
386 		msg->addr = EEPROM_I2C_TARGET_ADDR |
387 			       ((control->next_addr & EEPROM_ADDR_MSB_MASK) >> 15);
388 		msg->flags	= write ? 0 : I2C_M_RD;
389 		msg->len	= EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE;
390 		msg->buf	= buff;
391 
392 		/* Insert the EEPROM dest addess, bits 0-15 */
393 		buff[0] = ((control->next_addr >> 8) & 0xff);
394 		buff[1] = (control->next_addr & 0xff);
395 
396 		/* EEPROM table content is stored in LE format */
397 		if (write)
398 			__encode_table_record_to_buff(control, record, buff + EEPROM_ADDRESS_SIZE);
399 
400 		/*
401 		 * The destination EEPROM address might need to be corrected to account
402 		 * for page or entire memory wrapping
403 		 */
404 		control->next_addr += EEPROM_TABLE_RECORD_SIZE;
405 	}
406 
407 	ret = i2c_transfer(&control->eeprom_accessor, msgs, num);
408 	if (ret < 1) {
409 		DRM_ERROR("Failed to process EEPROM table records, ret:%d", ret);
410 
411 		/* TODO Restore prev next EEPROM address ? */
412 		goto free_msgs;
413 	}
414 
415 
416 	if (!write) {
417 		for (i = 0; i < num; i++) {
418 			unsigned char *buff = &buffs[i*(EEPROM_ADDRESS_SIZE + EEPROM_TABLE_RECORD_SIZE)];
419 			struct eeprom_table_record *record = &records[i];
420 
421 			__decode_table_record_from_buff(control, record, buff + EEPROM_ADDRESS_SIZE);
422 		}
423 	}
424 
425 	if (write) {
426 		uint32_t old_hdr_byte_sum = __calc_hdr_byte_sum(control);
427 
428 		/*
429 		 * Update table header with size and CRC and account for table
430 		 * wrap around where the assumption is that we treat it as empty
431 		 * table
432 		 *
433 		 * TODO - Check the assumption is correct
434 		 */
435 		control->num_recs += num;
436 		control->num_recs %= EEPROM_MAX_RECORD_NUM;
437 		control->tbl_hdr.tbl_size += EEPROM_TABLE_RECORD_SIZE * num;
438 		if (control->tbl_hdr.tbl_size > EEPROM_SIZE_BYTES)
439 			control->tbl_hdr.tbl_size = EEPROM_TABLE_HEADER_SIZE +
440 			control->num_recs * EEPROM_TABLE_RECORD_SIZE;
441 
442 		__update_tbl_checksum(control, records, num, old_hdr_byte_sum);
443 
444 		__update_table_header(control, buffs);
445 	} else if (!__validate_tbl_checksum(control, records, num)) {
446 		DRM_WARN("EEPROM Table checksum mismatch!");
447 		/* TODO Uncomment when EEPROM read/write is relliable */
448 		/* ret = -EIO; */
449 	}
450 
451 free_msgs:
452 	kfree(msgs);
453 
454 free_buff:
455 	kfree(buffs);
456 
457 	mutex_unlock(&control->tbl_mutex);
458 
459 	return ret == num ? 0 : -EIO;
460 }
461 
462 /* Used for testing if bugs encountered */
463 #if 0
464 void amdgpu_ras_eeprom_test(struct amdgpu_ras_eeprom_control *control)
465 {
466 	int i;
467 	struct eeprom_table_record *recs = kcalloc(1, sizeof(*recs), GFP_KERNEL);
468 
469 	if (!recs)
470 		return;
471 
472 	for (i = 0; i < 1 ; i++) {
473 		recs[i].address = 0xdeadbeef;
474 		recs[i].retired_page = i;
475 	}
476 
477 	if (!amdgpu_ras_eeprom_process_recods(control, recs, true, 1)) {
478 
479 		memset(recs, 0, sizeof(*recs) * 1);
480 
481 		control->next_addr = EEPROM_RECORD_START;
482 
483 		if (!amdgpu_ras_eeprom_process_recods(control, recs, false, 1)) {
484 			for (i = 0; i < 1; i++)
485 				DRM_INFO("rec.address :0x%llx, rec.retired_page :%llu",
486 					 recs[i].address, recs[i].retired_page);
487 		} else
488 			DRM_ERROR("Failed in reading from table");
489 
490 	} else
491 		DRM_ERROR("Failed in writing to table");
492 }
493 #endif
494