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#include <linux/of.h>
17#include <linux/of_fdt.h>
18
19#include <asm/page.h>
20#include <asm/rtas.h>
21#include <asm/fadump.h>
22#include <asm/fadump-internal.h>
23
24#include "rtas-fadump.h"
25
26static struct rtas_fadump_mem_struct fdm;
27static const struct rtas_fadump_mem_struct *fdm_active;
28
29static void rtas_fadump_update_config(struct fw_dump *fadump_conf,
30 const struct rtas_fadump_mem_struct *fdm)
31{
32 fadump_conf->boot_mem_dest_addr =
33 be64_to_cpu(fdm->rmr_region.destination_address);
34
35 fadump_conf->fadumphdr_addr = (fadump_conf->boot_mem_dest_addr +
36 fadump_conf->boot_memory_size);
37}
38
39/*
40 * This function is called in the capture kernel to get configuration details
41 * setup in the first kernel and passed to the f/w.
42 */
43static void __init rtas_fadump_get_config(struct fw_dump *fadump_conf,
44 const struct rtas_fadump_mem_struct *fdm)
45{
46 fadump_conf->boot_mem_addr[0] =
47 be64_to_cpu(fdm->rmr_region.source_address);
48 fadump_conf->boot_mem_sz[0] = be64_to_cpu(fdm->rmr_region.source_len);
49 fadump_conf->boot_memory_size = fadump_conf->boot_mem_sz[0];
50
51 fadump_conf->boot_mem_top = fadump_conf->boot_memory_size;
52 fadump_conf->boot_mem_regs_cnt = 1;
53
54 /*
55 * Start address of reserve dump area (permanent reservation) for
56 * re-registering FADump after dump capture.
57 */
58 fadump_conf->reserve_dump_area_start =
59 be64_to_cpu(fdm->cpu_state_data.destination_address);
60
61 rtas_fadump_update_config(fadump_conf, fdm);
62}
63
64static u64 rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf)
65{
66 u64 addr = fadump_conf->reserve_dump_area_start;
67
68 memset(&fdm, 0, sizeof(struct rtas_fadump_mem_struct));
69 addr = addr & PAGE_MASK;
70
71 fdm.header.dump_format_version = cpu_to_be32(0x00000001);
72 fdm.header.dump_num_sections = cpu_to_be16(3);
73 fdm.header.dump_status_flag = 0;
74 fdm.header.offset_first_dump_section =
75 cpu_to_be32((u32)offsetof(struct rtas_fadump_mem_struct,
76 cpu_state_data));
77
78 /*
79 * Fields for disk dump option.
80 * We are not using disk dump option, hence set these fields to 0.
81 */
82 fdm.header.dd_block_size = 0;
83 fdm.header.dd_block_offset = 0;
84 fdm.header.dd_num_blocks = 0;
85 fdm.header.dd_offset_disk_path = 0;
86
87 /* set 0 to disable an automatic dump-reboot. */
88 fdm.header.max_time_auto = 0;
89
90 /* Kernel dump sections */
91 /* cpu state data section. */
92 fdm.cpu_state_data.request_flag =
93 cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
94 fdm.cpu_state_data.source_data_type =
95 cpu_to_be16(RTAS_FADUMP_CPU_STATE_DATA);
96 fdm.cpu_state_data.source_address = 0;
97 fdm.cpu_state_data.source_len =
98 cpu_to_be64(fadump_conf->cpu_state_data_size);
99 fdm.cpu_state_data.destination_address = cpu_to_be64(addr);
100 addr += fadump_conf->cpu_state_data_size;
101
102 /* hpte region section */
103 fdm.hpte_region.request_flag = cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
104 fdm.hpte_region.source_data_type =
105 cpu_to_be16(RTAS_FADUMP_HPTE_REGION);
106 fdm.hpte_region.source_address = 0;
107 fdm.hpte_region.source_len =
108 cpu_to_be64(fadump_conf->hpte_region_size);
109 fdm.hpte_region.destination_address = cpu_to_be64(addr);
110 addr += fadump_conf->hpte_region_size;
111
112 /*
113 * Align boot memory area destination address to page boundary to
114 * be able to mmap read this area in the vmcore.
115 */
116 addr = PAGE_ALIGN(addr);
117
118 /* RMA region section */
119 fdm.rmr_region.request_flag = cpu_to_be32(RTAS_FADUMP_REQUEST_FLAG);
120 fdm.rmr_region.source_data_type =
121 cpu_to_be16(RTAS_FADUMP_REAL_MODE_REGION);
122 fdm.rmr_region.source_address = cpu_to_be64(0);
123 fdm.rmr_region.source_len = cpu_to_be64(fadump_conf->boot_memory_size);
124 fdm.rmr_region.destination_address = cpu_to_be64(addr);
125 addr += fadump_conf->boot_memory_size;
126
127 rtas_fadump_update_config(fadump_conf, fdm: &fdm);
128
129 return addr;
130}
131
132static u64 rtas_fadump_get_bootmem_min(void)
133{
134 return RTAS_FADUMP_MIN_BOOT_MEM;
135}
136
137static int rtas_fadump_register(struct fw_dump *fadump_conf)
138{
139 unsigned int wait_time;
140 int rc, err = -EIO;
141
142 /* TODO: Add upper time limit for the delay */
143 do {
144 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
145 NULL, FADUMP_REGISTER, &fdm,
146 sizeof(struct rtas_fadump_mem_struct));
147
148 wait_time = rtas_busy_delay_time(rc);
149 if (wait_time)
150 mdelay(wait_time);
151
152 } while (wait_time);
153
154 switch (rc) {
155 case 0:
156 pr_info("Registration is successful!\n");
157 fadump_conf->dump_registered = 1;
158 err = 0;
159 break;
160 case -1:
161 pr_err("Failed to register. Hardware Error(%d).\n", rc);
162 break;
163 case -3:
164 if (!is_fadump_boot_mem_contiguous())
165 pr_err("Can't have holes in boot memory area.\n");
166 else if (!is_fadump_reserved_mem_contiguous())
167 pr_err("Can't have holes in reserved memory area.\n");
168
169 pr_err("Failed to register. Parameter Error(%d).\n", rc);
170 err = -EINVAL;
171 break;
172 case -9:
173 pr_err("Already registered!\n");
174 fadump_conf->dump_registered = 1;
175 err = -EEXIST;
176 break;
177 default:
178 pr_err("Failed to register. Unknown Error(%d).\n", rc);
179 break;
180 }
181
182 return err;
183}
184
185static int rtas_fadump_unregister(struct fw_dump *fadump_conf)
186{
187 unsigned int wait_time;
188 int rc;
189
190 /* TODO: Add upper time limit for the delay */
191 do {
192 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
193 NULL, FADUMP_UNREGISTER, &fdm,
194 sizeof(struct rtas_fadump_mem_struct));
195
196 wait_time = rtas_busy_delay_time(rc);
197 if (wait_time)
198 mdelay(wait_time);
199 } while (wait_time);
200
201 if (rc) {
202 pr_err("Failed to un-register - unexpected error(%d).\n", rc);
203 return -EIO;
204 }
205
206 fadump_conf->dump_registered = 0;
207 return 0;
208}
209
210static int rtas_fadump_invalidate(struct fw_dump *fadump_conf)
211{
212 unsigned int wait_time;
213 int rc;
214
215 /* TODO: Add upper time limit for the delay */
216 do {
217 rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1,
218 NULL, FADUMP_INVALIDATE, fdm_active,
219 sizeof(struct rtas_fadump_mem_struct));
220
221 wait_time = rtas_busy_delay_time(rc);
222 if (wait_time)
223 mdelay(wait_time);
224 } while (wait_time);
225
226 if (rc) {
227 pr_err("Failed to invalidate - unexpected error (%d).\n", rc);
228 return -EIO;
229 }
230
231 fadump_conf->dump_active = 0;
232 fdm_active = NULL;
233 return 0;
234}
235
236#define RTAS_FADUMP_GPR_MASK 0xffffff0000000000
237static inline int rtas_fadump_gpr_index(u64 id)
238{
239 char str[3];
240 int i = -1;
241
242 if ((id & RTAS_FADUMP_GPR_MASK) == fadump_str_to_u64("GPR")) {
243 /* get the digits at the end */
244 id &= ~RTAS_FADUMP_GPR_MASK;
245 id >>= 24;
246 str[2] = '\0';
247 str[1] = id & 0xff;
248 str[0] = (id >> 8) & 0xff;
249 if (kstrtoint(s: str, base: 10, res: &i))
250 i = -EINVAL;
251 if (i > 31)
252 i = -1;
253 }
254 return i;
255}
256
257static void __init rtas_fadump_set_regval(struct pt_regs *regs, u64 reg_id, u64 reg_val)
258{
259 int i;
260
261 i = rtas_fadump_gpr_index(id: reg_id);
262 if (i >= 0)
263 regs->gpr[i] = (unsigned long)reg_val;
264 else if (reg_id == fadump_str_to_u64("NIA"))
265 regs->nip = (unsigned long)reg_val;
266 else if (reg_id == fadump_str_to_u64("MSR"))
267 regs->msr = (unsigned long)reg_val;
268 else if (reg_id == fadump_str_to_u64("CTR"))
269 regs->ctr = (unsigned long)reg_val;
270 else if (reg_id == fadump_str_to_u64("LR"))
271 regs->link = (unsigned long)reg_val;
272 else if (reg_id == fadump_str_to_u64("XER"))
273 regs->xer = (unsigned long)reg_val;
274 else if (reg_id == fadump_str_to_u64("CR"))
275 regs->ccr = (unsigned long)reg_val;
276 else if (reg_id == fadump_str_to_u64("DAR"))
277 regs->dar = (unsigned long)reg_val;
278 else if (reg_id == fadump_str_to_u64("DSISR"))
279 regs->dsisr = (unsigned long)reg_val;
280}
281
282static struct rtas_fadump_reg_entry* __init
283rtas_fadump_read_regs(struct rtas_fadump_reg_entry *reg_entry,
284 struct pt_regs *regs)
285{
286 memset(regs, 0, sizeof(struct pt_regs));
287
288 while (be64_to_cpu(reg_entry->reg_id) != fadump_str_to_u64("CPUEND")) {
289 rtas_fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id),
290 be64_to_cpu(reg_entry->reg_value));
291 reg_entry++;
292 }
293 reg_entry++;
294 return reg_entry;
295}
296
297/*
298 * Read CPU state dump data and convert it into ELF notes.
299 * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be
300 * used to access the data to allow for additional fields to be added without
301 * affecting compatibility. Each list of registers for a CPU starts with
302 * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes,
303 * 8 Byte ASCII identifier and 8 Byte register value. The register entry
304 * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part
305 * of register value. For more details refer to PAPR document.
306 *
307 * Only for the crashing cpu we ignore the CPU dump data and get exact
308 * state from fadump crash info structure populated by first kernel at the
309 * time of crash.
310 */
311static int __init rtas_fadump_build_cpu_notes(struct fw_dump *fadump_conf)
312{
313 struct rtas_fadump_reg_save_area_header *reg_header;
314 struct fadump_crash_info_header *fdh = NULL;
315 struct rtas_fadump_reg_entry *reg_entry;
316 u32 num_cpus, *note_buf;
317 int i, rc = 0, cpu = 0;
318 struct pt_regs regs;
319 unsigned long addr;
320 void *vaddr;
321
322 addr = be64_to_cpu(fdm_active->cpu_state_data.destination_address);
323 vaddr = __va(addr);
324
325 reg_header = vaddr;
326 if (be64_to_cpu(reg_header->magic_number) !=
327 fadump_str_to_u64("REGSAVE")) {
328 pr_err("Unable to read register save area.\n");
329 return -ENOENT;
330 }
331
332 pr_debug("--------CPU State Data------------\n");
333 pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number));
334 pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset));
335
336 vaddr += be32_to_cpu(reg_header->num_cpu_offset);
337 num_cpus = be32_to_cpu(*((__be32 *)(vaddr)));
338 pr_debug("NumCpus : %u\n", num_cpus);
339 vaddr += sizeof(u32);
340 reg_entry = (struct rtas_fadump_reg_entry *)vaddr;
341
342 rc = fadump_setup_cpu_notes_buf(num_cpus);
343 if (rc != 0)
344 return rc;
345
346 note_buf = (u32 *)fadump_conf->cpu_notes_buf_vaddr;
347
348 if (fadump_conf->fadumphdr_addr)
349 fdh = __va(fadump_conf->fadumphdr_addr);
350
351 for (i = 0; i < num_cpus; i++) {
352 if (be64_to_cpu(reg_entry->reg_id) !=
353 fadump_str_to_u64("CPUSTRT")) {
354 pr_err("Unable to read CPU state data\n");
355 rc = -ENOENT;
356 goto error_out;
357 }
358 /* Lower 4 bytes of reg_value contains logical cpu id */
359 cpu = (be64_to_cpu(reg_entry->reg_value) &
360 RTAS_FADUMP_CPU_ID_MASK);
361 if (fdh && !cpumask_test_cpu(cpu, cpumask: &fdh->cpu_mask)) {
362 RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
363 continue;
364 }
365 pr_debug("Reading register data for cpu %d...\n", cpu);
366 if (fdh && fdh->crashing_cpu == cpu) {
367 regs = fdh->regs;
368 note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
369 RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry);
370 } else {
371 reg_entry++;
372 reg_entry = rtas_fadump_read_regs(reg_entry, regs: &regs);
373 note_buf = fadump_regs_to_elf_notes(note_buf, &regs);
374 }
375 }
376 final_note(buf: note_buf);
377
378 if (fdh) {
379 pr_debug("Updating elfcore header (%llx) with cpu notes\n",
380 fdh->elfcorehdr_addr);
381 fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr));
382 }
383 return 0;
384
385error_out:
386 fadump_free_cpu_notes_buf();
387 return rc;
388
389}
390
391/*
392 * Validate and process the dump data stored by firmware before exporting
393 * it through '/proc/vmcore'.
394 */
395static int __init rtas_fadump_process(struct fw_dump *fadump_conf)
396{
397 struct fadump_crash_info_header *fdh;
398 int rc = 0;
399
400 if (!fdm_active || !fadump_conf->fadumphdr_addr)
401 return -EINVAL;
402
403 /* Check if the dump data is valid. */
404 if ((be16_to_cpu(fdm_active->header.dump_status_flag) ==
405 RTAS_FADUMP_ERROR_FLAG) ||
406 (fdm_active->cpu_state_data.error_flags != 0) ||
407 (fdm_active->rmr_region.error_flags != 0)) {
408 pr_err("Dump taken by platform is not valid\n");
409 return -EINVAL;
410 }
411 if ((fdm_active->rmr_region.bytes_dumped !=
412 fdm_active->rmr_region.source_len) ||
413 !fdm_active->cpu_state_data.bytes_dumped) {
414 pr_err("Dump taken by platform is incomplete\n");
415 return -EINVAL;
416 }
417
418 /* Validate the fadump crash info header */
419 fdh = __va(fadump_conf->fadumphdr_addr);
420 if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) {
421 pr_err("Crash info header is not valid.\n");
422 return -EINVAL;
423 }
424
425 rc = rtas_fadump_build_cpu_notes(fadump_conf);
426 if (rc)
427 return rc;
428
429 /*
430 * We are done validating dump info and elfcore header is now ready
431 * to be exported. set elfcorehdr_addr so that vmcore module will
432 * export the elfcore header through '/proc/vmcore'.
433 */
434 elfcorehdr_addr = fdh->elfcorehdr_addr;
435
436 return 0;
437}
438
439static void rtas_fadump_region_show(struct fw_dump *fadump_conf,
440 struct seq_file *m)
441{
442 const struct rtas_fadump_section *cpu_data_section;
443 const struct rtas_fadump_mem_struct *fdm_ptr;
444
445 if (fdm_active)
446 fdm_ptr = fdm_active;
447 else
448 fdm_ptr = &fdm;
449
450 cpu_data_section = &(fdm_ptr->cpu_state_data);
451 seq_printf(m, fmt: "CPU :[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n",
452 be64_to_cpu(cpu_data_section->destination_address),
453 be64_to_cpu(cpu_data_section->destination_address) +
454 be64_to_cpu(cpu_data_section->source_len) - 1,
455 be64_to_cpu(cpu_data_section->source_len),
456 be64_to_cpu(cpu_data_section->bytes_dumped));
457
458 seq_printf(m, fmt: "HPTE:[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n",
459 be64_to_cpu(fdm_ptr->hpte_region.destination_address),
460 be64_to_cpu(fdm_ptr->hpte_region.destination_address) +
461 be64_to_cpu(fdm_ptr->hpte_region.source_len) - 1,
462 be64_to_cpu(fdm_ptr->hpte_region.source_len),
463 be64_to_cpu(fdm_ptr->hpte_region.bytes_dumped));
464
465 seq_printf(m, fmt: "DUMP: Src: %#016llx, Dest: %#016llx, ",
466 be64_to_cpu(fdm_ptr->rmr_region.source_address),
467 be64_to_cpu(fdm_ptr->rmr_region.destination_address));
468 seq_printf(m, fmt: "Size: %#llx, Dumped: %#llx bytes\n",
469 be64_to_cpu(fdm_ptr->rmr_region.source_len),
470 be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped));
471
472 /* Dump is active. Show preserved area start address. */
473 if (fdm_active) {
474 seq_printf(m, fmt: "\nMemory above %#016llx is reserved for saving crash dump\n",
475 fadump_conf->boot_mem_top);
476 }
477}
478
479static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh,
480 const char *msg)
481{
482 /* Call ibm,os-term rtas call to trigger firmware assisted dump */
483 rtas_os_term((char *)msg);
484}
485
486static struct fadump_ops rtas_fadump_ops = {
487 .fadump_init_mem_struct = rtas_fadump_init_mem_struct,
488 .fadump_get_bootmem_min = rtas_fadump_get_bootmem_min,
489 .fadump_register = rtas_fadump_register,
490 .fadump_unregister = rtas_fadump_unregister,
491 .fadump_invalidate = rtas_fadump_invalidate,
492 .fadump_process = rtas_fadump_process,
493 .fadump_region_show = rtas_fadump_region_show,
494 .fadump_trigger = rtas_fadump_trigger,
495};
496
497void __init rtas_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node)
498{
499 int i, size, num_sections;
500 const __be32 *sections;
501 const __be32 *token;
502
503 /*
504 * Check if Firmware Assisted dump is supported. if yes, check
505 * if dump has been initiated on last reboot.
506 */
507 token = of_get_flat_dt_prop(node, name: "ibm,configure-kernel-dump", NULL);
508 if (!token)
509 return;
510
511 fadump_conf->ibm_configure_kernel_dump = be32_to_cpu(*token);
512 fadump_conf->ops = &rtas_fadump_ops;
513 fadump_conf->fadump_supported = 1;
514
515 /* Firmware supports 64-bit value for size, align it to pagesize. */
516 fadump_conf->max_copy_size = ALIGN_DOWN(U64_MAX, PAGE_SIZE);
517
518 /*
519 * The 'ibm,kernel-dump' rtas node is present only if there is
520 * dump data waiting for us.
521 */
522 fdm_active = of_get_flat_dt_prop(node, name: "ibm,kernel-dump", NULL);
523 if (fdm_active) {
524 pr_info("Firmware-assisted dump is active.\n");
525 fadump_conf->dump_active = 1;
526 rtas_fadump_get_config(fadump_conf, fdm: (void *)__pa(fdm_active));
527 }
528
529 /* Get the sizes required to store dump data for the firmware provided
530 * dump sections.
531 * For each dump section type supported, a 32bit cell which defines
532 * the ID of a supported section followed by two 32 bit cells which
533 * gives the size of the section in bytes.
534 */
535 sections = of_get_flat_dt_prop(node, name: "ibm,configure-kernel-dump-sizes",
536 size: &size);
537
538 if (!sections)
539 return;
540
541 num_sections = size / (3 * sizeof(u32));
542
543 for (i = 0; i < num_sections; i++, sections += 3) {
544 u32 type = (u32)of_read_number(cell: sections, size: 1);
545
546 switch (type) {
547 case RTAS_FADUMP_CPU_STATE_DATA:
548 fadump_conf->cpu_state_data_size =
549 of_read_ulong(cell: &sections[1], size: 2);
550 break;
551 case RTAS_FADUMP_HPTE_REGION:
552 fadump_conf->hpte_region_size =
553 of_read_ulong(cell: &sections[1], size: 2);
554 break;
555 }
556 }
557}
558

source code of linux/arch/powerpc/platforms/pseries/rtas-fadump.c