diff options
author | Hari Bathini <hbathini@linux.ibm.com> | 2019-09-11 20:19:44 +0530 |
---|---|---|
committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-09-14 00:04:42 +1000 |
commit | f35120115b767c49ad8de56dd78c86540a14df5b (patch) | |
tree | 34ef1731a14dcb61b9dd9eede645b93738538ae8 /arch/powerpc/platforms/pseries/rtas-fadump.c | |
parent | 8255da95e54519bb74638c2448ac17f4b34fe6f5 (diff) | |
download | linux-stable-f35120115b767c49ad8de56dd78c86540a14df5b.tar.gz linux-stable-f35120115b767c49ad8de56dd78c86540a14df5b.tar.bz2 linux-stable-f35120115b767c49ad8de56dd78c86540a14df5b.zip |
pseries/fadump: move out platform specific support from generic code
Move code that supports processing the crash'ed kernel's memory
preserved by firmware to platform specific callback functions.
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/156821337690.5656.13050665924800177744.stgit@hbathini.in.ibm.com
Diffstat (limited to 'arch/powerpc/platforms/pseries/rtas-fadump.c')
-rw-r--r-- | arch/powerpc/platforms/pseries/rtas-fadump.c | 263 |
1 files changed, 260 insertions, 3 deletions
diff --git a/arch/powerpc/platforms/pseries/rtas-fadump.c b/arch/powerpc/platforms/pseries/rtas-fadump.c index a11e3c2458d2..bf1e8fc549b5 100644 --- a/arch/powerpc/platforms/pseries/rtas-fadump.c +++ b/arch/powerpc/platforms/pseries/rtas-fadump.c @@ -23,6 +23,7 @@ #include "rtas-fadump.h" static struct rtas_fadump_mem_struct fdm; +static const struct rtas_fadump_mem_struct *fdm_active; static void rtas_fadump_update_config(struct fw_dump *fadump_conf, const struct rtas_fadump_mem_struct *fdm) @@ -34,6 +35,25 @@ static void rtas_fadump_update_config(struct fw_dump *fadump_conf, fadump_conf->boot_memory_size); } +/* + * This function is called in the capture kernel to get configuration details + * setup in the first kernel and passed to the f/w. + */ +static void rtas_fadump_get_config(struct fw_dump *fadump_conf, + const struct rtas_fadump_mem_struct *fdm) +{ + fadump_conf->boot_memory_size = be64_to_cpu(fdm->rmr_region.source_len); + + /* + * Start address of reserve dump area (permanent reservation) for + * re-registering FADump after dump capture. + */ + fadump_conf->reserve_dump_area_start = + be64_to_cpu(fdm->cpu_state_data.destination_address); + + rtas_fadump_update_config(fadump_conf, fdm); +} + static u64 rtas_fadump_init_mem_struct(struct fw_dump *fadump_conf) { u64 addr = fadump_conf->reserve_dump_area_start; @@ -171,7 +191,183 @@ static int rtas_fadump_unregister(struct fw_dump *fadump_conf) static int rtas_fadump_invalidate(struct fw_dump *fadump_conf) { - return -EIO; + unsigned int wait_time; + int rc; + + /* TODO: Add upper time limit for the delay */ + do { + rc = rtas_call(fadump_conf->ibm_configure_kernel_dump, 3, 1, + NULL, FADUMP_INVALIDATE, fdm_active, + sizeof(struct rtas_fadump_mem_struct)); + + wait_time = rtas_busy_delay_time(rc); + if (wait_time) + mdelay(wait_time); + } while (wait_time); + + if (rc) { + pr_err("Failed to invalidate - unexpected error (%d).\n", rc); + return -EIO; + } + + fadump_conf->dump_active = 0; + fdm_active = NULL; + return 0; +} + +#define RTAS_FADUMP_GPR_MASK 0xffffff0000000000 +static inline int rtas_fadump_gpr_index(u64 id) +{ + char str[3]; + int i = -1; + + if ((id & RTAS_FADUMP_GPR_MASK) == fadump_str_to_u64("GPR")) { + /* get the digits at the end */ + id &= ~RTAS_FADUMP_GPR_MASK; + id >>= 24; + str[2] = '\0'; + str[1] = id & 0xff; + str[0] = (id >> 8) & 0xff; + if (kstrtoint(str, 10, &i)) + i = -EINVAL; + if (i > 31) + i = -1; + } + return i; +} + +void rtas_fadump_set_regval(struct pt_regs *regs, u64 reg_id, u64 reg_val) +{ + int i; + + i = rtas_fadump_gpr_index(reg_id); + if (i >= 0) + regs->gpr[i] = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("NIA")) + regs->nip = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("MSR")) + regs->msr = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("CTR")) + regs->ctr = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("LR")) + regs->link = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("XER")) + regs->xer = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("CR")) + regs->ccr = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("DAR")) + regs->dar = (unsigned long)reg_val; + else if (reg_id == fadump_str_to_u64("DSISR")) + regs->dsisr = (unsigned long)reg_val; +} + +static struct rtas_fadump_reg_entry* +rtas_fadump_read_regs(struct rtas_fadump_reg_entry *reg_entry, + struct pt_regs *regs) +{ + memset(regs, 0, sizeof(struct pt_regs)); + + while (be64_to_cpu(reg_entry->reg_id) != fadump_str_to_u64("CPUEND")) { + rtas_fadump_set_regval(regs, be64_to_cpu(reg_entry->reg_id), + be64_to_cpu(reg_entry->reg_value)); + reg_entry++; + } + reg_entry++; + return reg_entry; +} + +/* + * Read CPU state dump data and convert it into ELF notes. + * The CPU dump starts with magic number "REGSAVE". NumCpusOffset should be + * used to access the data to allow for additional fields to be added without + * affecting compatibility. Each list of registers for a CPU starts with + * "CPUSTRT" and ends with "CPUEND". Each register entry is of 16 bytes, + * 8 Byte ASCII identifier and 8 Byte register value. The register entry + * with identifier "CPUSTRT" and "CPUEND" contains 4 byte cpu id as part + * of register value. For more details refer to PAPR document. + * + * Only for the crashing cpu we ignore the CPU dump data and get exact + * state from fadump crash info structure populated by first kernel at the + * time of crash. + */ +static int __init rtas_fadump_build_cpu_notes(struct fw_dump *fadump_conf) +{ + struct rtas_fadump_reg_save_area_header *reg_header; + struct fadump_crash_info_header *fdh = NULL; + struct rtas_fadump_reg_entry *reg_entry; + u32 num_cpus, *note_buf; + int i, rc = 0, cpu = 0; + struct pt_regs regs; + unsigned long addr; + void *vaddr; + + addr = be64_to_cpu(fdm_active->cpu_state_data.destination_address); + vaddr = __va(addr); + + reg_header = vaddr; + if (be64_to_cpu(reg_header->magic_number) != + fadump_str_to_u64("REGSAVE")) { + pr_err("Unable to read register save area.\n"); + return -ENOENT; + } + + pr_debug("--------CPU State Data------------\n"); + pr_debug("Magic Number: %llx\n", be64_to_cpu(reg_header->magic_number)); + pr_debug("NumCpuOffset: %x\n", be32_to_cpu(reg_header->num_cpu_offset)); + + vaddr += be32_to_cpu(reg_header->num_cpu_offset); + num_cpus = be32_to_cpu(*((__be32 *)(vaddr))); + pr_debug("NumCpus : %u\n", num_cpus); + vaddr += sizeof(u32); + reg_entry = (struct rtas_fadump_reg_entry *)vaddr; + + rc = fadump_setup_cpu_notes_buf(num_cpus); + if (rc != 0) + return rc; + + note_buf = (u32 *)fadump_conf->cpu_notes_buf_vaddr; + + if (fadump_conf->fadumphdr_addr) + fdh = __va(fadump_conf->fadumphdr_addr); + + for (i = 0; i < num_cpus; i++) { + if (be64_to_cpu(reg_entry->reg_id) != + fadump_str_to_u64("CPUSTRT")) { + pr_err("Unable to read CPU state data\n"); + rc = -ENOENT; + goto error_out; + } + /* Lower 4 bytes of reg_value contains logical cpu id */ + cpu = (be64_to_cpu(reg_entry->reg_value) & + RTAS_FADUMP_CPU_ID_MASK); + if (fdh && !cpumask_test_cpu(cpu, &fdh->online_mask)) { + RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry); + continue; + } + pr_debug("Reading register data for cpu %d...\n", cpu); + if (fdh && fdh->crashing_cpu == cpu) { + regs = fdh->regs; + note_buf = fadump_regs_to_elf_notes(note_buf, ®s); + RTAS_FADUMP_SKIP_TO_NEXT_CPU(reg_entry); + } else { + reg_entry++; + reg_entry = rtas_fadump_read_regs(reg_entry, ®s); + note_buf = fadump_regs_to_elf_notes(note_buf, ®s); + } + } + final_note(note_buf); + + if (fdh) { + pr_debug("Updating elfcore header (%llx) with cpu notes\n", + fdh->elfcorehdr_addr); + fadump_update_elfcore_header(__va(fdh->elfcorehdr_addr)); + } + return 0; + +error_out: + fadump_free_cpu_notes_buf(); + return rc; + } /* @@ -180,14 +376,58 @@ static int rtas_fadump_invalidate(struct fw_dump *fadump_conf) */ static int __init rtas_fadump_process(struct fw_dump *fadump_conf) { - return -EINVAL; + struct fadump_crash_info_header *fdh; + int rc = 0; + + if (!fdm_active || !fadump_conf->fadumphdr_addr) + return -EINVAL; + + /* Check if the dump data is valid. */ + if ((be16_to_cpu(fdm_active->header.dump_status_flag) == + RTAS_FADUMP_ERROR_FLAG) || + (fdm_active->cpu_state_data.error_flags != 0) || + (fdm_active->rmr_region.error_flags != 0)) { + pr_err("Dump taken by platform is not valid\n"); + return -EINVAL; + } + if ((fdm_active->rmr_region.bytes_dumped != + fdm_active->rmr_region.source_len) || + !fdm_active->cpu_state_data.bytes_dumped) { + pr_err("Dump taken by platform is incomplete\n"); + return -EINVAL; + } + + /* Validate the fadump crash info header */ + fdh = __va(fadump_conf->fadumphdr_addr); + if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { + pr_err("Crash info header is not valid.\n"); + return -EINVAL; + } + + rc = rtas_fadump_build_cpu_notes(fadump_conf); + if (rc) + return rc; + + /* + * We are done validating dump info and elfcore header is now ready + * to be exported. set elfcorehdr_addr so that vmcore module will + * export the elfcore header through '/proc/vmcore'. + */ + elfcorehdr_addr = fdh->elfcorehdr_addr; + + return 0; } static void rtas_fadump_region_show(struct fw_dump *fadump_conf, struct seq_file *m) { - const struct rtas_fadump_mem_struct *fdm_ptr = &fdm; const struct rtas_fadump_section *cpu_data_section; + const struct rtas_fadump_mem_struct *fdm_ptr; + + if (fdm_active) + fdm_ptr = fdm_active; + else + fdm_ptr = &fdm; cpu_data_section = &(fdm_ptr->cpu_state_data); seq_printf(m, "CPU :[%#016llx-%#016llx] %#llx bytes, Dumped: %#llx\n", @@ -210,6 +450,12 @@ static void rtas_fadump_region_show(struct fw_dump *fadump_conf, seq_printf(m, "Size: %#llx, Dumped: %#llx bytes\n", be64_to_cpu(fdm_ptr->rmr_region.source_len), be64_to_cpu(fdm_ptr->rmr_region.bytes_dumped)); + + /* Dump is active. Show reserved area start address. */ + if (fdm_active) { + seq_printf(m, "\nMemory above %#016lx is reserved for saving crash dump\n", + fadump_conf->reserve_dump_area_start); + } } static void rtas_fadump_trigger(struct fadump_crash_info_header *fdh, @@ -247,6 +493,17 @@ void __init rtas_fadump_dt_scan(struct fw_dump *fadump_conf, u64 node) fadump_conf->ops = &rtas_fadump_ops; fadump_conf->fadump_supported = 1; + /* + * The 'ibm,kernel-dump' rtas node is present only if there is + * dump data waiting for us. + */ + fdm_active = of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL); + if (fdm_active) { + pr_info("Firmware-assisted dump is active.\n"); + fadump_conf->dump_active = 1; + rtas_fadump_get_config(fadump_conf, (void *)__pa(fdm_active)); + } + /* Get the sizes required to store dump data for the firmware provided * dump sections. * For each dump section type supported, a 32bit cell which defines |