1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Firmware-Assisted Dump support on POWERVM platform.
4 *
5 * Copyright 2011, Mahesh Salgaonkar, IBM Corporation.
6 * Copyright 2019, Hari Bathini, IBM Corporation.
7 */
8
9 #define pr_fmt(fmt) "rtas fadump: " fmt
10
11 #include <linux/string.h>
12 #include <linux/memblock.h>
13 #include <linux/delay.h>
14 #include <linux/seq_file.h>
15 #include <linux/crash_dump.h>
16
17 #include <asm/page.h>
18 #include <asm/prom.h>
19 #include <asm/rtas.h>
20 #include <asm/fadump.h>
21 #include <asm/fadump-internal.h>
22
23 #include "rtas-fadump.h"
24
25 static struct rtas_fadump_mem_struct fdm;
26 static const struct rtas_fadump_mem_struct *fdm_active;
27
rtas_fadump_update_config(struct fw_dump * fadump_conf,const struct rtas_fadump_mem_struct * fdm)28 static void rtas_fadump_update_config(struct fw_dump *fadump_conf,
29 const struct rtas_fadump_mem_struct *fdm)
30 {
31 fadump_conf->boot_mem_dest_addr =
32 be64_to_cpu(fdm->rmr_region.destination_address);
33
34 fadump_conf->fadumphdr_addr = (fadump_conf->boot_mem_dest_addr +
35 fadump_conf->boot_memory_size);
36 }
37
38 /*
39 * This function is called in the capture kernel to get configuration details
40 * setup in the first kernel and passed to the f/w.
41 */
rtas_fadump_get_config(struct fw_dump * fadump_conf,const struct rtas_fadump_mem_struct * fdm)42 static void rtas_fadump_get_config(struct fw_dump *fadump_conf,
43 const struct rtas_fadump_mem_struct *fdm)
44 {
45 fadump_conf->boot_mem_addr[0] =
46 be64_to_cpu(fdm->rmr_region.source_address);
47 fadump_conf->boot_mem_sz[0] = be64_to_cpu(fdm->rmr_region.source_len);
48 fadump_conf->boot_memory_size = fadump_conf->boot_mem_sz[0];
49
50 fadump_conf->boot_mem_top = fadump_conf->boot_memory_size;
51 fadump_conf->boot_mem_regs_cnt = 1;
52
53 /*
54 * Start address of reserve dump area (permanent reservation) for
55 * re-registering FADump after dump capture.
56 */
57 fadump_conf->reserve_dump_area_start =
58 be64_to_cpu(fdm->cpu_state_data.destination_address);
59
60 rtas_fadump_update_config(fadump_conf, fdm);
61 }
62
rtas_fadump_init_mem_struct(struct fw_dump * fadump_conf)63 static u64 rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf)
64 {
65 u64 addr = fadump_conf->reserve_dump_area_start;
66
67 memset(&fdm, 0, sizeof(struct rtas_fadump_mem_struct));
68 addr = addr & PAGE_MASK;
69
70 fdm.header.dump_format_version = cpu_to_be32(0x00000001);
71 fdm.header.dump_num_sections = cpu_to_be16(3);
72 fdm.header.dump_status_flag = 0;
73 fdm.header.offset_first_dump_section =
74 cpu_to_be32((u32)offsetof(struct rtas_fadump_mem_struct,
75 cpu_state_data));
76
77 /*
78 * Fields for disk dump option.
79 * We are not using disk dump option, hence set these fields to 0.
80 */
81 fdm.header.dd_block_size = 0;
82 fdm.header.dd_block_offset = 0;
83 fdm.header.dd_num_blocks = 0;
84 fdm.header.dd_offset_disk_path = 0;
85
86 /* set 0 to disable an automatic dump-reboot. */
87 fdm.header.max_time_auto = 0;
88
89 /* Kernel dump sections */
90 /* cpu state data section. */
91 fdm.cpu_state_data.request_flag =
92 cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
93 fdm.cpu_state_data.source_data_type =
94 cpu_to_be16(RTAS_FADUMP_CPU_STATE_DATA);
95 fdm.cpu_state_data.source_address = 0;
96 fdm.cpu_state_data.source_len =
97 cpu_to_be64(fadump_conf->cpu_state_data_size);
98 fdm.cpu_state_data.destination_address = cpu_to_be64(addr);
99 addr += fadump_conf->cpu_state_data_size;
100
101 /* hpte region section */
102 fdm.hpte_region.request_flag = cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
103 fdm.hpte_region.source_data_type =
104 cpu_to_be16(RTAS_FADUMP_HPTE_REGION);
105 fdm.hpte_region.source_address = 0;
106 fdm.hpte_region.source_len =
107 cpu_to_be64(fadump_conf->hpte_region_size);
108 fdm.hpte_region.destination_address = cpu_to_be64(addr);
109 addr += fadump_conf->hpte_region_size;
110
111 /* RMA region section */
112 fdm.rmr_region.request_flag = cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
113 fdm.rmr_region.source_data_type =
114 cpu_to_be16(RTAS_FADUMP_REAL_MODE_REGION);
115 fdm.rmr_region.source_address = cpu_to_be64(0);
116 fdm.rmr_region.source_len = cpu_to_be64(fadump_conf->boot_memory_size);
117 fdm.rmr_region.destination_address = cpu_to_be64(addr);
118 addr += fadump_conf->boot_memory_size;
119
120 rtas_fadump_update_config(fadump_conf, &fdm);
121
122 return addr;
123 }
124
rtas_fadump_get_bootmem_min(void)125 static u64 rtas_fadump_get_bootmem_min(void)
126 {
127 return RTAS_FADUMP_MIN_BOOT_MEM;
128 }
129
rtas_fadump_register(struct fw_dump * fadump_conf)130 static int rtas_fadump_register(struct fw_dump *fadump_conf)
131 {
132 unsigned int wait_time;
133 int rc, err = -EIO;
134
135 /* TODO: Add upper time limit for the delay */
136 do {
137 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
138 NULL, FADUMP_REGISTER, &fdm,
139 sizeof(struct rtas_fadump_mem_struct));
140
141 wait_time = rtas_busy_delay_time(rc);
142 if (wait_time)
143 mdelay(wait_time);
144
145 } while (wait_time);
146
147 switch (rc) {
148 case 0:
149 pr_info("Registration is successful!\n");
150 fadump_conf->dump_registered = 1;
151 err = 0;
152 break;
153 case -1:
154 pr_err("Failed to register. Hardware Error(%d).\n", rc);
155 break;
156 case -3:
157 if (!is_fadump_boot_mem_contiguous())
158 pr_err("Can't have holes in boot memory area.\n");
159 else if (!is_fadump_reserved_mem_contiguous())
160 pr_err("Can't have holes in reserved memory area.\n");
161
162 pr_err("Failed to register. Parameter Error(%d).\n", rc);
163 err = -EINVAL;
164 break;
165 case -9:
166 pr_err("Already registered!\n");
167 fadump_conf->dump_registered = 1;
168 err = -EEXIST;
169 break;
170 default:
171 pr_err("Failed to register. Unknown Error(%d).\n", rc);
172 break;
173 }
174
175 return err;
176 }
177
rtas_fadump_unregister(struct fw_dump * fadump_conf)178 static int rtas_fadump_unregister(struct fw_dump *fadump_conf)
179 {
180 unsigned int wait_time;
181 int rc;
182
183 /* TODO: Add upper time limit for the delay */
184 do {
185 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
186 NULL, FADUMP_UNREGISTER, &fdm,
187 sizeof(struct rtas_fadump_mem_struct));
188
189 wait_time = rtas_busy_delay_time(rc);
190 if (wait_time)
191 mdelay(wait_time);
192 } while (wait_time);
193
194 if (rc) {
195 pr_err("Failed to un-register - unexpected error(%d).\n", rc);
196 return -EIO;
197 }
198
199 fadump_conf->dump_registered = 0;
200 return 0;
201 }
202
rtas_fadump_invalidate(struct fw_dump * fadump_conf)203 static int rtas_fadump_invalidate(struct fw_dump *fadump_conf)
204 {
205 unsigned int wait_time;
206 int rc;
207
208 /* TODO: Add upper time limit for the delay */
209 do {
210 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
211 NULL, FADUMP_INVALIDATE, fdm_active,
212 sizeof(struct rtas_fadump_mem_struct));
213
214 wait_time = rtas_busy_delay_time(rc);
215 if (wait_time)
216 mdelay(wait_time);
217 } while (wait_time);
218
219 if (rc) {
220 pr_err("Failed to invalidate - unexpected error (%d).\n", rc);
221 return -EIO;
222 }
223
224 fadump_conf->dump_active = 0;
225 fdm_active = NULL;
226 return 0;
227 }
228
229 #define RTAS_FADUMP_GPR_MASK 0xffffff0000000000
rtas_fadump_gpr_index(u64 id)230 static inline int rtas_fadump_gpr_index(u64 id)
231 {
232 char str[3];
233 int i = -1;
234
235 if ((id & RTAS_FADUMP_GPR_MASK) == fadump_str_to_u64("GPR")) {
236 /* get the digits at the end */
237 id &= ~RTAS_FADUMP_GPR_MASK;
238 id >>= 24;
239 str[2] = '\0';
240 str[1] = id & 0xff;
241 str[0] = (id >> 8) & 0xff;
242 if (kstrtoint(str, 10, &i))
243 i = -EINVAL;
244 if (i > 31)
245 i = -1;
246 }
247 return i;
248 }
249
rtas_fadump_set_regval(struct pt_regs * regs,u64 reg_id,u64 reg_val)250 void rtas_fadump_set_regval(struct pt_regs *regs, u64 reg_id, u64 reg_val)
251 {
252 int i;
253
254 i = rtas_fadump_gpr_index(reg_id);
255 if (i >= 0)
256 regs->gpr[i] = (unsigned long)reg_val;
257 else if (reg_id == fadump_str_to_u64("NIA"))
258 regs->nip = (unsigned long)reg_val;
259 else if (reg_id == fadump_str_to_u64("MSR"))
260 regs->msr = (unsigned long)reg_val;
261 else if (reg_id == fadump_str_to_u64("CTR"))
262 regs->ctr = (unsigned long)reg_val;
263 else if (reg_id == fadump_str_to_u64("LR"))
264 regs->link = (unsigned long)reg_val;
265 else if (reg_id == fadump_str_to_u64("XER"))
266 regs->xer = (unsigned long)reg_val;
267 else if (reg_id == fadump_str_to_u64("CR"))
268 regs->ccr = (unsigned long)reg_val;
269 else if (reg_id == fadump_str_to_u64("DAR"))
270 regs->dar = (unsigned long)reg_val;
271 else if (reg_id == fadump_str_to_u64("DSISR"))
272 regs->dsisr = (unsigned long)reg_val;
273 }
274
275 static struct rtas_fadump_reg_entry*
rtas_fadump_read_regs(struct rtas_fadump_reg_entry * reg_entry,struct pt_regs * regs)276 rtas_fadump_read_regs(struct rtas_fadump_reg_entry *reg_entry,
277 struct pt_regs *regs)
278 {
279 memset(regs, 0, sizeof(struct pt_regs));
280
281 while (be64_to_cpu(reg_entry->reg_id) != fadump_str_to_u64("CPUEND")) {
282 rtas_fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
283 be64_to_cpu(reg_entry->reg_value));
284 reg_entry++;
285 }
286 reg_entry++;
287 return reg_entry;
288 }
289
290 /*
291 * Read CPU state dump data and convert it into ELF notes.
292 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
293 * used to access the data to allow for additional fields to be added without
294 * affecting compatibility. Each list of registers for a CPU starts with
295 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
296 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
297 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
298 * of register value. For more details refer to PAPR document.
299 *
300 * Only for the crashing cpu we ignore the CPU dump data and get exact
301 * state from fadump crash info structure populated by first kernel at the
302 * time of crash.
303 */
rtas_fadump_build_cpu_notes(struct fw_dump * fadump_conf)304 static int __init rtas_fadump_build_cpu_notes(struct fw_dump *fadump_conf)
305 {
306 struct rtas_fadump_reg_save_area_header *reg_header;
307 struct fadump_crash_info_header *fdh = NULL;
308 struct rtas_fadump_reg_entry *reg_entry;
309 u32 num_cpus, *note_buf;
310 int i, rc = 0, cpu = 0;
311 struct pt_regs regs;
312 unsigned long addr;
313 void *vaddr;
314
315 addr = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
316 vaddr = __va(addr);
317
318 reg_header = vaddr;
319 if (be64_to_cpu(reg_header->magic_number) !=
320 fadump_str_to_u64("REGSAVE")) {
321 pr_err("Unable to read register save area.\n");
322 return -ENOENT;
323 }
324
325 pr_debug("--------CPU State Data------------\n");
326 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
327 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
328
329 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
330 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
331 pr_debug("NumCpus : %u\n", num_cpus);
332 vaddr += sizeof(u32);
333 reg_entry = (struct rtas_fadump_reg_entry *)vaddr;
334
335 rc = fadump_setup_cpu_notes_buf(num_cpus);
336 if (rc != 0)
337 return rc;
338
339 note_buf = (u32 *)fadump_conf->cpu_notes_buf_vaddr;
340
341 if (fadump_conf->fadumphdr_addr)
342 fdh = __va(fadump_conf->fadumphdr_addr);
343
344 for (i = 0; i < num_cpus; i++) {
345 if (be64_to_cpu(reg_entry->reg_id) !=
346 fadump_str_to_u64("CPUSTRT")) {
347 pr_err("Unable to read CPU state data\n");
348 rc = -ENOENT;
349 goto error_out;
350 }
351 /* Lower 4 bytes of reg_value contains logical cpu id */
352 cpu = (be64_to_cpu(reg_entry->reg_value) &
353 RTAS_FADUMP_CPU_ID_MASK);
354 if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) {
355 RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
356 continue;
357 }
358 pr_debug("Reading register data for cpu %d...\n", cpu);
359 if (fdh && fdh->crashing_cpu == cpu) {
360 regs = fdh->regs;
361 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
362 RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
363 } else {
364 reg_entry++;
365 reg_entry = rtas_fadump_read_regs(reg_entry, ®s);
366 note_buf = fadump_regs_to_elf_notes(note_buf, ®s);
367 }
368 }
369 final_note(note_buf);
370
371 if (fdh) {
372 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
373 fdh->elfcorehdr_addr);
374 fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr));
375 }
376 return 0;
377
378 error_out:
379 fadump_free_cpu_notes_buf();
380 return rc;
381
382 }
383
384 /*
385 * Validate and process the dump data stored by firmware before exporting
386 * it through '/proc/vmcore'.
387 */
rtas_fadump_process(struct fw_dump * fadump_conf)388 static int __init rtas_fadump_process(struct fw_dump *fadump_conf)
389 {
390 struct fadump_crash_info_header *fdh;
391 int rc = 0;
392
393 if (!fdm_active || !fadump_conf->fadumphdr_addr)
394 return -EINVAL;
395
396 /* Check if the dump data is valid. */
397 if ((be16_to_cpu(fdm_active->header.dump_status_flag) ==
398 RTAS_FADUMP_ERROR_FLAG) ||
399 (fdm_active->cpu_state_data.error_flags != 0) ||
400 (fdm_active->rmr_region.error_flags != 0)) {
401 pr_err("Dump taken by platform is not valid\n");
402 return -EINVAL;
403 }
404 if ((fdm_active->rmr_region.bytes_dumped !=
405 fdm_active->rmr_region.source_len) ||
406 !fdm_active->cpu_state_data.bytes_dumped) {
407 pr_err("Dump taken by platform is incomplete\n");
408 return -EINVAL;
409 }
410
411 /* Validate the fadump crash info header */
412 fdh = __va(fadump_conf->fadumphdr_addr);
413 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
414 pr_err("Crash info header is not valid.\n");
415 return -EINVAL;
416 }
417
418 rc = rtas_fadump_build_cpu_notes(fadump_conf);
419 if (rc)
420 return rc;
421
422 /*
423 * We are done validating dump info and elfcore header is now ready
424 * to be exported. set elfcorehdr_addr so that vmcore module will
425 * export the elfcore header through '/proc/vmcore'.
426 */
427 elfcorehdr_addr = fdh->elfcorehdr_addr;
428
429 return 0;
430 }
431
rtas_fadump_region_show(struct fw_dump * fadump_conf,struct seq_file * m)432 static void rtas_fadump_region_show(struct fw_dump *fadump_conf,
433 struct seq_file *m)
434 {
435 const struct rtas_fadump_section *cpu_data_section;
436 const struct rtas_fadump_mem_struct *fdm_ptr;
437
438 if (fdm_active)
439 fdm_ptr = fdm_active;
440 else
441 fdm_ptr = &fdm;
442
443 cpu_data_section = &(fdm_ptr->cpu_state_data);
444 seq_printf(m, "CPU :[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n",
445 be64_to_cpu(cpu_data_section->destination_address),
446 be64_to_cpu(cpu_data_section->destination_address) +
447 be64_to_cpu(cpu_data_section->source_len) - 1,
448 be64_to_cpu(cpu_data_section->source_len),
449 be64_to_cpu(cpu_data_section->bytes_dumped));
450
451 seq_printf(m, "HPTE:[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n",
452 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
453 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
454 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
455 be64_to_cpu(fdm_ptr->hpte_region.source_len),
456 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
457
458 seq_printf(m, "DUMP: Src: %#016llx, Dest: %#016llx, ",
459 be64_to_cpu(fdm_ptr->rmr_region.source_address),
460 be64_to_cpu(fdm_ptr->rmr_region.destination_address));
461 seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n",
462 be64_to_cpu(fdm_ptr->rmr_region.source_len),
463 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
464
465 /* Dump is active. Show reserved area start address. */
466 if (fdm_active) {
467 seq_printf(m, "\nMemory above %#016lx is reserved for saving crash dump\n",
468 fadump_conf->reserve_dump_area_start);
469 }
470 }
471
rtas_fadump_trigger(struct fadump_crash_info_header * fdh,const char * msg)472 static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh,
473 const char *msg)
474 {
475 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
476 rtas_os_term((char *)msg);
477 }
478
479 static struct fadump_ops rtas_fadump_ops = {
480 .fadump_init_mem_struct = rtas_fadump_init_mem_struct,
481 .fadump_get_bootmem_min = rtas_fadump_get_bootmem_min,
482 .fadump_register = rtas_fadump_register,
483 .fadump_unregister = rtas_fadump_unregister,
484 .fadump_invalidate = rtas_fadump_invalidate,
485 .fadump_process = rtas_fadump_process,
486 .fadump_region_show = rtas_fadump_region_show,
487 .fadump_trigger = rtas_fadump_trigger,
488 };
489
rtas_fadump_dt_scan(struct fw_dump * fadump_conf,u64 node)490 void __init rtas_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
491 {
492 int i, size, num_sections;
493 const __be32 *sections;
494 const __be32 *token;
495
496 /*
497 * Check if Firmware Assisted dump is supported. if yes, check
498 * if dump has been initiated on last reboot.
499 */
500 token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL);
501 if (!token)
502 return;
503
504 fadump_conf->ibm_configure_kernel_dump = be32_to_cpu(*token);
505 fadump_conf->ops = &rtas_fadump_ops;
506 fadump_conf->fadump_supported = 1;
507
508 /* Firmware supports 64-bit value for size, align it to pagesize. */
509 fadump_conf->max_copy_size = _ALIGN_DOWN(U64_MAX, PAGE_SIZE);
510
511 /*
512 * The 'ibm,kernel-dump' rtas node is present only if there is
513 * dump data waiting for us.
514 */
515 fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL);
516 if (fdm_active) {
517 pr_info("Firmware-assisted dump is active.\n");
518 fadump_conf->dump_active = 1;
519 rtas_fadump_get_config(fadump_conf, (void *)__pa(fdm_active));
520 }
521
522 /* Get the sizes required to store dump data for the firmware provided
523 * dump sections.
524 * For each dump section type supported, a 32bit cell which defines
525 * the ID of a supported section followed by two 32 bit cells which
526 * gives the size of the section in bytes.
527 */
528 sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes",
529 &size);
530
531 if (!sections)
532 return;
533
534 num_sections = size / (3 * sizeof(u32));
535
536 for (i = 0; i < num_sections; i++, sections += 3) {
537 u32 type = (u32)of_read_number(sections, 1);
538
539 switch (type) {
540 case RTAS_FADUMP_CPU_STATE_DATA:
541 fadump_conf->cpu_state_data_size =
542 of_read_ulong(§ions[1], 2);
543 break;
544 case RTAS_FADUMP_HPTE_REGION:
545 fadump_conf->hpte_region_size =
546 of_read_ulong(§ions[1], 2);
547 break;
548 }
549 }
550 }
551
