From: Hari Bathini <hbath...@linux.vnet.ibm.com> Firmware provides architected register state data at the time of crash. Process this data and build CPU notes to append to ELF core.
Signed-off-by: Hari Bathini <hbath...@linux.vnet.ibm.com> Signed-off-by: Vasant Hegde <hegdevas...@linux.vnet.ibm.com> --- arch/powerpc/kernel/fadump-common.h | 4 + arch/powerpc/platforms/powernv/opal-fadump.c | 198 ++++++++++++++++++++++++-- arch/powerpc/platforms/powernv/opal-fadump.h | 39 +++++ 3 files changed, 229 insertions(+), 12 deletions(-) diff --git a/arch/powerpc/kernel/fadump-common.h b/arch/powerpc/kernel/fadump-common.h index 7107cf2..fc408b0 100644 --- a/arch/powerpc/kernel/fadump-common.h +++ b/arch/powerpc/kernel/fadump-common.h @@ -98,7 +98,11 @@ struct fw_dump { /* cmd line option during boot */ unsigned long reserve_bootvar; + unsigned long cpu_state_destination_addr; + unsigned long cpu_state_data_version; + unsigned long cpu_state_entry_size; unsigned long cpu_state_data_size; + unsigned long hpte_region_size; unsigned long boot_mem_dest_addr; diff --git a/arch/powerpc/platforms/powernv/opal-fadump.c b/arch/powerpc/platforms/powernv/opal-fadump.c index f75b861..9a32a7f 100644 --- a/arch/powerpc/platforms/powernv/opal-fadump.c +++ b/arch/powerpc/platforms/powernv/opal-fadump.c @@ -23,6 +23,7 @@ #include "opal-fadump.h" static const struct opal_fadump_mem_struct *opal_fdm_active; +static const struct opal_mpipl_fadump *opal_cpu_metadata; static struct opal_fadump_mem_struct *opal_fdm; static int opal_fadump_unregister(struct fw_dump *fadump_conf); @@ -282,15 +283,122 @@ static void opal_fadump_cleanup(struct fw_dump *fadump_conf) pr_warn("Could not reset (%llu) kernel metadata tag!\n", ret); } +static inline void opal_fadump_set_regval_regnum(struct pt_regs *regs, + u32 reg_type, u32 reg_num, + u64 reg_val) +{ + if (reg_type == HDAT_FADUMP_REG_TYPE_GPR) { + if (reg_num < 32) + regs->gpr[reg_num] = reg_val; + return; + } + + switch (reg_num) { + case SPRN_CTR: + regs->ctr = reg_val; + break; + case SPRN_LR: + regs->link = reg_val; + break; + case SPRN_XER: + regs->xer = reg_val; + break; + case SPRN_DAR: + regs->dar = reg_val; + break; + case SPRN_DSISR: + regs->dsisr = reg_val; + break; + case HDAT_FADUMP_REG_ID_NIP: + regs->nip = reg_val; + break; + case HDAT_FADUMP_REG_ID_MSR: + regs->msr = reg_val; + break; + case HDAT_FADUMP_REG_ID_CCR: + regs->ccr = reg_val; + break; + } +} + +static inline void opal_fadump_read_regs(char *bufp, unsigned int regs_cnt, + unsigned int reg_entry_size, + struct pt_regs *regs) +{ + int i; + struct hdat_fadump_reg_entry *reg_entry; + + memset(regs, 0, sizeof(struct pt_regs)); + + for (i = 0; i < regs_cnt; i++, bufp += reg_entry_size) { + reg_entry = (struct hdat_fadump_reg_entry *)bufp; + opal_fadump_set_regval_regnum(regs, + be32_to_cpu(reg_entry->reg_type), + be32_to_cpu(reg_entry->reg_num), + be64_to_cpu(reg_entry->reg_val)); + } +} + +static inline bool __init is_thread_core_inactive(u8 core_state) +{ + bool is_inactive = false; + + if (core_state == HDAT_FADUMP_CORE_INACTIVE) + is_inactive = true; + + return is_inactive; +} + /* * Convert CPU state data saved at the time of crash into ELF notes. + * + * Each register entry is of 16 bytes, A numerical identifier along with + * a GPR/SPR flag in the first 8 bytes and the register value in the next + * 8 bytes. For more details refer to F/W documentation. */ static int __init opal_fadump_build_cpu_notes(struct fw_dump *fadump_conf) { u32 num_cpus, *note_buf; struct fadump_crash_info_header *fdh = NULL; + struct hdat_fadump_thread_hdr *thdr; + unsigned long addr; + u32 thread_pir; + char *bufp; + struct pt_regs regs; + unsigned int size_of_each_thread; + unsigned int regs_offset, regs_cnt, reg_esize; + int i; + + fadump_conf->cpu_state_entry_size = + be32_to_cpu(opal_cpu_metadata->cpu_data_size); + fadump_conf->cpu_state_destination_addr = + be64_to_cpu(opal_cpu_metadata->region[0].dest); + fadump_conf->cpu_state_data_size = + be64_to_cpu(opal_cpu_metadata->region[0].size); + + if ((fadump_conf->cpu_state_destination_addr == 0) || + (fadump_conf->cpu_state_entry_size == 0)) { + pr_err("CPU state data not available for processing!\n"); + return -ENODEV; + } + + size_of_each_thread = fadump_conf->cpu_state_entry_size; + num_cpus = (fadump_conf->cpu_state_data_size / size_of_each_thread); + + addr = fadump_conf->cpu_state_destination_addr; + bufp = __va(addr); + + /* + * Offset for register entries, entry size and registers count is + * duplicated in every thread header in keeping with HDAT format. + * Use these values from the first thread header. + */ + thdr = (struct hdat_fadump_thread_hdr *)bufp; + regs_offset = (offsetof(struct hdat_fadump_thread_hdr, offset) + + be32_to_cpu(thdr->offset)); + reg_esize = be32_to_cpu(thdr->esize); + regs_cnt = be32_to_cpu(thdr->ecnt); - num_cpus = 1; /* Allocate buffer to hold cpu crash notes. */ fadump_conf->cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); fadump_conf->cpu_notes_buf_size = @@ -309,10 +417,53 @@ static int __init opal_fadump_build_cpu_notes(struct fw_dump *fadump_conf) if (fadump_conf->fadumphdr_addr) fdh = __va(fadump_conf->fadumphdr_addr); - if (fdh && (fdh->crashing_cpu != FADUMP_CPU_UNKNOWN)) { - note_buf = fadump_regs_to_elf_notes(note_buf, &(fdh->regs)); - final_note(note_buf); + pr_debug("--------CPU State Data------------\n"); + pr_debug("NumCpus : %u\n", num_cpus); + pr_debug("\tOffset: %u, Entry size: %u, Cnt: %u\n", + regs_offset, reg_esize, regs_cnt); + + for (i = 0; i < num_cpus; i++, bufp += size_of_each_thread) { + thdr = (struct hdat_fadump_thread_hdr *)bufp; + + thread_pir = be32_to_cpu(thdr->pir); + pr_debug("%04d) PIR: 0x%x, core state: 0x%02x\n", + (i + 1), thread_pir, thdr->core_state); + + /* + * Register state data of MAX cores is provided by firmware, + * but some of this cores may not be active. So, while + * processing register state data, check core state and + * skip threads that belong to inactive cores. + */ + if (is_thread_core_inactive(thdr->core_state)) + continue; + + /* + * If this is kernel initiated crash, crashing_cpu would be set + * appropriately and register data of the crashing CPU saved by + * crashing kernel. Add this saved register data of crashing CPU + * to elf notes and populate the pt_regs for the remaining CPUs + * from register state data provided by firmware. + */ + if (fdh && (fdh->crashing_cpu == thread_pir)) { + note_buf = fadump_regs_to_elf_notes(note_buf, + &fdh->regs); + pr_debug("Crashing CPU PIR: 0x%x - R1 : 0x%lx, NIP : 0x%lx\n", + fdh->crashing_cpu, fdh->regs.gpr[1], + fdh->regs.nip); + continue; + } + + opal_fadump_read_regs((bufp + regs_offset), regs_cnt, + reg_esize, ®s); + note_buf = fadump_regs_to_elf_notes(note_buf, ®s); + pr_debug("CPU PIR: 0x%x - R1 : 0x%lx, NIP : 0x%lx\n", + thread_pir, regs.gpr[1], regs.nip); + } + final_note(note_buf); + + if (fdh) { pr_debug("Updating elfcore header (%llx) with cpu notes\n", fdh->elfcorehdr_addr); fadump_update_elfcore_header(fadump_conf, @@ -327,7 +478,8 @@ static int __init opal_fadump_process(struct fw_dump *fadump_conf) struct fadump_crash_info_header *fdh; int rc = 0; - if (!opal_fdm_active || !fadump_conf->fadumphdr_addr) + if (!opal_fdm_active || !opal_cpu_metadata || + !fadump_conf->fadumphdr_addr) return -EINVAL; /* Validate the fadump crash info header */ @@ -337,13 +489,6 @@ static int __init opal_fadump_process(struct fw_dump *fadump_conf) return -EINVAL; } - /* - * TODO: To build cpu notes, find a way to map PIR to logical id. - * Also, we may need different method for pseries and powernv. - * The currently booted kernel could have a different PIR to - * logical id mapping. So, try saving info of previous kernel's - * paca to get the right PIR to logical id mapping. - */ rc = opal_fadump_build_cpu_notes(fadump_conf); if (rc) return rc; @@ -397,6 +542,14 @@ static void opal_fadump_trigger(struct fadump_crash_info_header *fdh, { int rc; + /* + * Unlike on pSeries platform, logical CPU number is not provided + * with architected register state data. So, store the crashing + * CPU's PIR instead to plug the appropriate register data for + * crashing CPU in the vmcore file. + */ + fdh->crashing_cpu = (u32)mfspr(SPRN_PIR); + rc = opal_cec_reboot2(OPAL_REBOOT_MPIPL, msg); if (rc == OPAL_UNSUPPORTED) { pr_emerg("Reboot type %d not supported.\n", @@ -449,6 +602,7 @@ int __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, ulong node) u64 addr = 0; s64 ret; const struct opal_fadump_mem_struct *r_opal_fdm_active; + const struct opal_mpipl_fadump *r_opal_cpu_metadata; ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_KERNEL, &addr); if ((ret != OPAL_SUCCESS) || !addr) { @@ -473,6 +627,26 @@ int __init opal_fadump_dt_scan(struct fw_dump *fadump_conf, ulong node) return 1; } + ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &addr); + if ((ret != OPAL_SUCCESS) || !addr) { + pr_err("Failed to get CPU metadata (%lld)\n", ret); + return 1; + } + + addr = be64_to_cpu(addr); + pr_debug("CPU metadata addr: %llx\n", addr); + + opal_cpu_metadata = __va(addr); + r_opal_cpu_metadata = (void *)addr; + fadump_conf->cpu_state_data_version = + be32_to_cpu(r_opal_cpu_metadata->cpu_data_version); + if (fadump_conf->cpu_state_data_version != + HDAT_FADUMP_CPU_DATA_VERSION) { + pr_err("CPU data format version (%lu) mismatch!\n", + fadump_conf->cpu_state_data_version); + return 1; + } + pr_info("Firmware-assisted dump is active.\n"); fadump_conf->dump_active = 1; opal_fadump_get_config(fadump_conf, r_opal_fdm_active); diff --git a/arch/powerpc/platforms/powernv/opal-fadump.h b/arch/powerpc/platforms/powernv/opal-fadump.h index 19cac1f..ce4c522 100644 --- a/arch/powerpc/platforms/powernv/opal-fadump.h +++ b/arch/powerpc/platforms/powernv/opal-fadump.h @@ -30,4 +30,43 @@ struct opal_fadump_mem_struct { struct opal_mpipl_region rgn[OPAL_FADUMP_MAX_MEM_REGS]; } __attribute__((packed)); +/* + * CPU state data is provided by f/w. Below are the definitions + * provided in HDAT spec. Refer to latest HDAT specification for + * any update to this format. + */ + +#define HDAT_FADUMP_CPU_DATA_VERSION 1 + +#define HDAT_FADUMP_CORE_INACTIVE (0x0F) + +/* HDAT thread header for register entries */ +struct hdat_fadump_thread_hdr { + __be32 pir; + /* 0x00 - 0x0F - The corresponding stop state of the core */ + u8 core_state; + u8 reserved[3]; + + __be32 offset; /* Offset to Register Entries array */ + __be32 ecnt; /* Number of entries */ + __be32 esize; /* Alloc size of each array entry in bytes */ + __be32 eactsz; /* Actual size of each array entry in bytes */ +} __attribute__((packed)); + +/* Register types populated by f/w */ +#define HDAT_FADUMP_REG_TYPE_GPR 0x01 +#define HDAT_FADUMP_REG_TYPE_SPR 0x02 + +/* ID numbers used by f/w while populating certain registers */ +#define HDAT_FADUMP_REG_ID_NIP 0x7D0 +#define HDAT_FADUMP_REG_ID_MSR 0x7D1 +#define HDAT_FADUMP_REG_ID_CCR 0x7D2 + +/* HDAT register entry. */ +struct hdat_fadump_reg_entry { + __be32 reg_type; + __be32 reg_num; + __be64 reg_val; +} __attribute__((packed)); + #endif /* __PPC64_OPAL_FA_DUMP_H__ */