diff options
Diffstat (limited to '')
-rw-r--r-- | arch/powerpc/platforms/powernv/opal-core.c | 663 |
1 files changed, 663 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/powernv/opal-core.c b/arch/powerpc/platforms/powernv/opal-core.c new file mode 100644 index 000000000..bb7657115 --- /dev/null +++ b/arch/powerpc/platforms/powernv/opal-core.c @@ -0,0 +1,663 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Interface for exporting the OPAL ELF core. + * Heavily inspired from fs/proc/vmcore.c + * + * Copyright 2019, Hari Bathini, IBM Corporation. + */ + +#define pr_fmt(fmt) "opal core: " fmt + +#include <linux/memblock.h> +#include <linux/uaccess.h> +#include <linux/proc_fs.h> +#include <linux/elf.h> +#include <linux/elfcore.h> +#include <linux/kobject.h> +#include <linux/sysfs.h> +#include <linux/slab.h> +#include <linux/crash_core.h> +#include <linux/of.h> + +#include <asm/page.h> +#include <asm/opal.h> +#include <asm/fadump-internal.h> + +#include "opal-fadump.h" + +#define MAX_PT_LOAD_CNT 8 + +/* NT_AUXV note related info */ +#define AUXV_CNT 1 +#define AUXV_DESC_SZ (((2 * AUXV_CNT) + 1) * sizeof(Elf64_Off)) + +struct opalcore_config { + u32 num_cpus; + /* PIR value of crashing CPU */ + u32 crashing_cpu; + + /* CPU state data info from F/W */ + u64 cpu_state_destination_vaddr; + u64 cpu_state_data_size; + u64 cpu_state_entry_size; + + /* OPAL memory to be exported as PT_LOAD segments */ + u64 ptload_addr[MAX_PT_LOAD_CNT]; + u64 ptload_size[MAX_PT_LOAD_CNT]; + u64 ptload_cnt; + + /* Pointer to the first PT_LOAD in the ELF core file */ + Elf64_Phdr *ptload_phdr; + + /* Total size of opalcore file. */ + size_t opalcore_size; + + /* Buffer for all the ELF core headers and the PT_NOTE */ + size_t opalcorebuf_sz; + char *opalcorebuf; + + /* NT_AUXV buffer */ + char auxv_buf[AUXV_DESC_SZ]; +}; + +struct opalcore { + struct list_head list; + u64 paddr; + size_t size; + loff_t offset; +}; + +static LIST_HEAD(opalcore_list); +static struct opalcore_config *oc_conf; +static const struct opal_mpipl_fadump *opalc_metadata; +static const struct opal_mpipl_fadump *opalc_cpu_metadata; +static struct kobject *mpipl_kobj; + +/* + * Set crashing CPU's signal to SIGUSR1. if the kernel is triggered + * by kernel, SIGTERM otherwise. + */ +bool kernel_initiated; + +static struct opalcore * __init get_new_element(void) +{ + return kzalloc(sizeof(struct opalcore), GFP_KERNEL); +} + +static inline int is_opalcore_usable(void) +{ + return (oc_conf && oc_conf->opalcorebuf != NULL) ? 1 : 0; +} + +static Elf64_Word *__init append_elf64_note(Elf64_Word *buf, char *name, + u32 type, void *data, + size_t data_len) +{ + Elf64_Nhdr *note = (Elf64_Nhdr *)buf; + Elf64_Word namesz = strlen(name) + 1; + + note->n_namesz = cpu_to_be32(namesz); + note->n_descsz = cpu_to_be32(data_len); + note->n_type = cpu_to_be32(type); + buf += DIV_ROUND_UP(sizeof(*note), sizeof(Elf64_Word)); + memcpy(buf, name, namesz); + buf += DIV_ROUND_UP(namesz, sizeof(Elf64_Word)); + memcpy(buf, data, data_len); + buf += DIV_ROUND_UP(data_len, sizeof(Elf64_Word)); + + return buf; +} + +static void __init fill_prstatus(struct elf_prstatus *prstatus, int pir, + struct pt_regs *regs) +{ + memset(prstatus, 0, sizeof(struct elf_prstatus)); + elf_core_copy_regs(&(prstatus->pr_reg), regs); + + /* + * Overload PID with PIR value. + * As a PIR value could also be '0', add an offset of '100' + * to every PIR to avoid misinterpretations in GDB. + */ + prstatus->common.pr_pid = cpu_to_be32(100 + pir); + prstatus->common.pr_ppid = cpu_to_be32(1); + + /* + * Indicate SIGUSR1 for crash initiated from kernel. + * SIGTERM otherwise. + */ + if (pir == oc_conf->crashing_cpu) { + short sig; + + sig = kernel_initiated ? SIGUSR1 : SIGTERM; + prstatus->common.pr_cursig = cpu_to_be16(sig); + } +} + +static Elf64_Word *__init auxv_to_elf64_notes(Elf64_Word *buf, + u64 opal_boot_entry) +{ + Elf64_Off *bufp = (Elf64_Off *)oc_conf->auxv_buf; + int idx = 0; + + memset(bufp, 0, AUXV_DESC_SZ); + + /* Entry point of OPAL */ + bufp[idx++] = cpu_to_be64(AT_ENTRY); + bufp[idx++] = cpu_to_be64(opal_boot_entry); + + /* end of vector */ + bufp[idx++] = cpu_to_be64(AT_NULL); + + buf = append_elf64_note(buf, CRASH_CORE_NOTE_NAME, NT_AUXV, + oc_conf->auxv_buf, AUXV_DESC_SZ); + return buf; +} + +/* + * Read from the ELF header and then the crash dump. + * Returns number of bytes read on success, -errno on failure. + */ +static ssize_t read_opalcore(struct file *file, struct kobject *kobj, + struct bin_attribute *bin_attr, char *to, + loff_t pos, size_t count) +{ + struct opalcore *m; + ssize_t tsz, avail; + loff_t tpos = pos; + + if (pos >= oc_conf->opalcore_size) + return 0; + + /* Adjust count if it goes beyond opalcore size */ + avail = oc_conf->opalcore_size - pos; + if (count > avail) + count = avail; + + if (count == 0) + return 0; + + /* Read ELF core header and/or PT_NOTE segment */ + if (tpos < oc_conf->opalcorebuf_sz) { + tsz = min_t(size_t, oc_conf->opalcorebuf_sz - tpos, count); + memcpy(to, oc_conf->opalcorebuf + tpos, tsz); + to += tsz; + tpos += tsz; + count -= tsz; + } + + list_for_each_entry(m, &opalcore_list, list) { + /* nothing more to read here */ + if (count == 0) + break; + + if (tpos < m->offset + m->size) { + void *addr; + + tsz = min_t(size_t, m->offset + m->size - tpos, count); + addr = (void *)(m->paddr + tpos - m->offset); + memcpy(to, __va(addr), tsz); + to += tsz; + tpos += tsz; + count -= tsz; + } + } + + return (tpos - pos); +} + +static struct bin_attribute opal_core_attr = { + .attr = {.name = "core", .mode = 0400}, + .read = read_opalcore +}; + +/* + * Read CPU state dump data and convert it 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 Elf64_Word * __init opalcore_append_cpu_notes(Elf64_Word *buf) +{ + u32 thread_pir, size_per_thread, regs_offset, regs_cnt, reg_esize; + struct hdat_fadump_thread_hdr *thdr; + struct elf_prstatus prstatus; + Elf64_Word *first_cpu_note; + struct pt_regs regs; + char *bufp; + int i; + + size_per_thread = oc_conf->cpu_state_entry_size; + bufp = __va(oc_conf->cpu_state_destination_vaddr); + + /* + * 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); + + pr_debug("--------CPU State Data------------\n"); + pr_debug("NumCpus : %u\n", oc_conf->num_cpus); + pr_debug("\tOffset: %u, Entry size: %u, Cnt: %u\n", + regs_offset, reg_esize, regs_cnt); + + /* + * Skip past the first CPU note. Fill this note with the + * crashing CPU's prstatus. + */ + first_cpu_note = buf; + buf = append_elf64_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, + &prstatus, sizeof(prstatus)); + + for (i = 0; i < oc_conf->num_cpus; i++, bufp += size_per_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, 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 (thdr->core_state == HDAT_FADUMP_CORE_INACTIVE) + continue; + + opal_fadump_read_regs((bufp + regs_offset), regs_cnt, + reg_esize, false, ®s); + + pr_debug("PIR 0x%x - R1 : 0x%llx, NIP : 0x%llx\n", thread_pir, + be64_to_cpu(regs.gpr[1]), be64_to_cpu(regs.nip)); + fill_prstatus(&prstatus, thread_pir, ®s); + + if (thread_pir != oc_conf->crashing_cpu) { + buf = append_elf64_note(buf, CRASH_CORE_NOTE_NAME, + NT_PRSTATUS, &prstatus, + sizeof(prstatus)); + } else { + /* + * Add crashing CPU as the first NT_PRSTATUS note for + * GDB to process the core file appropriately. + */ + append_elf64_note(first_cpu_note, CRASH_CORE_NOTE_NAME, + NT_PRSTATUS, &prstatus, + sizeof(prstatus)); + } + } + + return buf; +} + +static int __init create_opalcore(void) +{ + u64 opal_boot_entry, opal_base_addr, paddr; + u32 hdr_size, cpu_notes_size, count; + struct device_node *dn; + struct opalcore *new; + loff_t opalcore_off; + struct page *page; + Elf64_Phdr *phdr; + Elf64_Ehdr *elf; + int i, ret; + char *bufp; + + /* Get size of header & CPU notes for OPAL core */ + hdr_size = (sizeof(Elf64_Ehdr) + + ((oc_conf->ptload_cnt + 1) * sizeof(Elf64_Phdr))); + cpu_notes_size = ((oc_conf->num_cpus * (CRASH_CORE_NOTE_HEAD_BYTES + + CRASH_CORE_NOTE_NAME_BYTES + + CRASH_CORE_NOTE_DESC_BYTES)) + + (CRASH_CORE_NOTE_HEAD_BYTES + + CRASH_CORE_NOTE_NAME_BYTES + AUXV_DESC_SZ)); + + /* Allocate buffer to setup OPAL core */ + oc_conf->opalcorebuf_sz = PAGE_ALIGN(hdr_size + cpu_notes_size); + oc_conf->opalcorebuf = alloc_pages_exact(oc_conf->opalcorebuf_sz, + GFP_KERNEL | __GFP_ZERO); + if (!oc_conf->opalcorebuf) { + pr_err("Not enough memory to setup OPAL core (size: %lu)\n", + oc_conf->opalcorebuf_sz); + oc_conf->opalcorebuf_sz = 0; + return -ENOMEM; + } + count = oc_conf->opalcorebuf_sz / PAGE_SIZE; + page = virt_to_page(oc_conf->opalcorebuf); + for (i = 0; i < count; i++) + mark_page_reserved(page + i); + + pr_debug("opalcorebuf = 0x%llx\n", (u64)oc_conf->opalcorebuf); + + /* Read OPAL related device-tree entries */ + dn = of_find_node_by_name(NULL, "ibm,opal"); + if (dn) { + ret = of_property_read_u64(dn, "opal-base-address", + &opal_base_addr); + pr_debug("opal-base-address: %llx\n", opal_base_addr); + ret |= of_property_read_u64(dn, "opal-boot-address", + &opal_boot_entry); + pr_debug("opal-boot-address: %llx\n", opal_boot_entry); + } + if (!dn || ret) + pr_warn("WARNING: Failed to read OPAL base & entry values\n"); + + of_node_put(dn); + + /* Use count to keep track of the program headers */ + count = 0; + + bufp = oc_conf->opalcorebuf; + elf = (Elf64_Ehdr *)bufp; + bufp += sizeof(Elf64_Ehdr); + memcpy(elf->e_ident, ELFMAG, SELFMAG); + elf->e_ident[EI_CLASS] = ELF_CLASS; + elf->e_ident[EI_DATA] = ELFDATA2MSB; + elf->e_ident[EI_VERSION] = EV_CURRENT; + elf->e_ident[EI_OSABI] = ELF_OSABI; + memset(elf->e_ident+EI_PAD, 0, EI_NIDENT-EI_PAD); + elf->e_type = cpu_to_be16(ET_CORE); + elf->e_machine = cpu_to_be16(ELF_ARCH); + elf->e_version = cpu_to_be32(EV_CURRENT); + elf->e_entry = 0; + elf->e_phoff = cpu_to_be64(sizeof(Elf64_Ehdr)); + elf->e_shoff = 0; + elf->e_flags = 0; + + elf->e_ehsize = cpu_to_be16(sizeof(Elf64_Ehdr)); + elf->e_phentsize = cpu_to_be16(sizeof(Elf64_Phdr)); + elf->e_phnum = 0; + elf->e_shentsize = 0; + elf->e_shnum = 0; + elf->e_shstrndx = 0; + + phdr = (Elf64_Phdr *)bufp; + bufp += sizeof(Elf64_Phdr); + phdr->p_type = cpu_to_be32(PT_NOTE); + phdr->p_flags = 0; + phdr->p_align = 0; + phdr->p_paddr = phdr->p_vaddr = 0; + phdr->p_offset = cpu_to_be64(hdr_size); + phdr->p_filesz = phdr->p_memsz = cpu_to_be64(cpu_notes_size); + count++; + + opalcore_off = oc_conf->opalcorebuf_sz; + oc_conf->ptload_phdr = (Elf64_Phdr *)bufp; + paddr = 0; + for (i = 0; i < oc_conf->ptload_cnt; i++) { + phdr = (Elf64_Phdr *)bufp; + bufp += sizeof(Elf64_Phdr); + phdr->p_type = cpu_to_be32(PT_LOAD); + phdr->p_flags = cpu_to_be32(PF_R|PF_W|PF_X); + phdr->p_align = 0; + + new = get_new_element(); + if (!new) + return -ENOMEM; + new->paddr = oc_conf->ptload_addr[i]; + new->size = oc_conf->ptload_size[i]; + new->offset = opalcore_off; + list_add_tail(&new->list, &opalcore_list); + + phdr->p_paddr = cpu_to_be64(paddr); + phdr->p_vaddr = cpu_to_be64(opal_base_addr + paddr); + phdr->p_filesz = phdr->p_memsz = + cpu_to_be64(oc_conf->ptload_size[i]); + phdr->p_offset = cpu_to_be64(opalcore_off); + + count++; + opalcore_off += oc_conf->ptload_size[i]; + paddr += oc_conf->ptload_size[i]; + } + + elf->e_phnum = cpu_to_be16(count); + + bufp = (char *)opalcore_append_cpu_notes((Elf64_Word *)bufp); + bufp = (char *)auxv_to_elf64_notes((Elf64_Word *)bufp, opal_boot_entry); + + oc_conf->opalcore_size = opalcore_off; + return 0; +} + +static void opalcore_cleanup(void) +{ + if (oc_conf == NULL) + return; + + /* Remove OPAL core sysfs file */ + sysfs_remove_bin_file(mpipl_kobj, &opal_core_attr); + oc_conf->ptload_phdr = NULL; + oc_conf->ptload_cnt = 0; + + /* free the buffer used for setting up OPAL core */ + if (oc_conf->opalcorebuf) { + void *end = (void *)((u64)oc_conf->opalcorebuf + + oc_conf->opalcorebuf_sz); + + free_reserved_area(oc_conf->opalcorebuf, end, -1, NULL); + oc_conf->opalcorebuf = NULL; + oc_conf->opalcorebuf_sz = 0; + } + + kfree(oc_conf); + oc_conf = NULL; +} +__exitcall(opalcore_cleanup); + +static void __init opalcore_config_init(void) +{ + u32 idx, cpu_data_version; + struct device_node *np; + const __be32 *prop; + u64 addr = 0; + int i, ret; + + np = of_find_node_by_path("/ibm,opal/dump"); + if (np == NULL) + return; + + if (!of_device_is_compatible(np, "ibm,opal-dump")) { + pr_warn("Support missing for this f/w version!\n"); + return; + } + + /* Check if dump has been initiated on last reboot */ + prop = of_get_property(np, "mpipl-boot", NULL); + if (!prop) { + of_node_put(np); + return; + } + + /* Get OPAL metadata */ + ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_OPAL, &addr); + if ((ret != OPAL_SUCCESS) || !addr) { + pr_err("Failed to get OPAL metadata (%d)\n", ret); + goto error_out; + } + + addr = be64_to_cpu(addr); + pr_debug("OPAL metadata addr: %llx\n", addr); + opalc_metadata = __va(addr); + + /* Get OPAL CPU metadata */ + ret = opal_mpipl_query_tag(OPAL_MPIPL_TAG_CPU, &addr); + if ((ret != OPAL_SUCCESS) || !addr) { + pr_err("Failed to get OPAL CPU metadata (%d)\n", ret); + goto error_out; + } + + addr = be64_to_cpu(addr); + pr_debug("CPU metadata addr: %llx\n", addr); + opalc_cpu_metadata = __va(addr); + + /* Allocate memory for config buffer */ + oc_conf = kzalloc(sizeof(struct opalcore_config), GFP_KERNEL); + if (oc_conf == NULL) + goto error_out; + + /* Parse OPAL metadata */ + if (opalc_metadata->version != OPAL_MPIPL_VERSION) { + pr_warn("Supported OPAL metadata version: %u, found: %u!\n", + OPAL_MPIPL_VERSION, opalc_metadata->version); + pr_warn("WARNING: F/W using newer OPAL metadata format!!\n"); + } + + oc_conf->ptload_cnt = 0; + idx = be32_to_cpu(opalc_metadata->region_cnt); + if (idx > MAX_PT_LOAD_CNT) { + pr_warn("WARNING: OPAL regions count (%d) adjusted to limit (%d)", + idx, MAX_PT_LOAD_CNT); + idx = MAX_PT_LOAD_CNT; + } + for (i = 0; i < idx; i++) { + oc_conf->ptload_addr[oc_conf->ptload_cnt] = + be64_to_cpu(opalc_metadata->region[i].dest); + oc_conf->ptload_size[oc_conf->ptload_cnt++] = + be64_to_cpu(opalc_metadata->region[i].size); + } + oc_conf->ptload_cnt = i; + oc_conf->crashing_cpu = be32_to_cpu(opalc_metadata->crashing_pir); + + if (!oc_conf->ptload_cnt) { + pr_err("OPAL memory regions not found\n"); + goto error_out; + } + + /* Parse OPAL CPU metadata */ + cpu_data_version = be32_to_cpu(opalc_cpu_metadata->cpu_data_version); + if (cpu_data_version != HDAT_FADUMP_CPU_DATA_VER) { + pr_warn("Supported CPU data version: %u, found: %u!\n", + HDAT_FADUMP_CPU_DATA_VER, cpu_data_version); + pr_warn("WARNING: F/W using newer CPU state data format!!\n"); + } + + addr = be64_to_cpu(opalc_cpu_metadata->region[0].dest); + if (!addr) { + pr_err("CPU state data not found!\n"); + goto error_out; + } + oc_conf->cpu_state_destination_vaddr = (u64)__va(addr); + + oc_conf->cpu_state_data_size = + be64_to_cpu(opalc_cpu_metadata->region[0].size); + oc_conf->cpu_state_entry_size = + be32_to_cpu(opalc_cpu_metadata->cpu_data_size); + + if ((oc_conf->cpu_state_entry_size == 0) || + (oc_conf->cpu_state_entry_size > oc_conf->cpu_state_data_size)) { + pr_err("CPU state data is invalid.\n"); + goto error_out; + } + oc_conf->num_cpus = (oc_conf->cpu_state_data_size / + oc_conf->cpu_state_entry_size); + + of_node_put(np); + return; + +error_out: + pr_err("Could not export /sys/firmware/opal/core\n"); + opalcore_cleanup(); + of_node_put(np); +} + +static ssize_t release_core_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int input = -1; + + if (kstrtoint(buf, 0, &input)) + return -EINVAL; + + if (input == 1) { + if (oc_conf == NULL) { + pr_err("'/sys/firmware/opal/core' file not accessible!\n"); + return -EPERM; + } + + /* + * Take away '/sys/firmware/opal/core' and release all memory + * used for exporting this file. + */ + opalcore_cleanup(); + } else + return -EINVAL; + + return count; +} + +static struct kobj_attribute opalcore_rel_attr = __ATTR_WO(release_core); + +static struct attribute *mpipl_attr[] = { + &opalcore_rel_attr.attr, + NULL, +}; + +static struct bin_attribute *mpipl_bin_attr[] = { + &opal_core_attr, + NULL, + +}; + +static const struct attribute_group mpipl_group = { + .attrs = mpipl_attr, + .bin_attrs = mpipl_bin_attr, +}; + +static int __init opalcore_init(void) +{ + int rc = -1; + + opalcore_config_init(); + + if (oc_conf == NULL) + return rc; + + create_opalcore(); + + /* + * If oc_conf->opalcorebuf= is set in the 2nd kernel, + * then capture the dump. + */ + if (!(is_opalcore_usable())) { + pr_err("Failed to export /sys/firmware/opal/mpipl/core\n"); + opalcore_cleanup(); + return rc; + } + + /* Set OPAL core file size */ + opal_core_attr.size = oc_conf->opalcore_size; + + mpipl_kobj = kobject_create_and_add("mpipl", opal_kobj); + if (!mpipl_kobj) { + pr_err("unable to create mpipl kobject\n"); + return -ENOMEM; + } + + /* Export OPAL core sysfs file */ + rc = sysfs_create_group(mpipl_kobj, &mpipl_group); + if (rc) { + pr_err("mpipl sysfs group creation failed (%d)", rc); + opalcore_cleanup(); + return rc; + } + /* The /sys/firmware/opal/core is moved to /sys/firmware/opal/mpipl/ + * directory, need to create symlink at old location to maintain + * backward compatibility. + */ + rc = compat_only_sysfs_link_entry_to_kobj(opal_kobj, mpipl_kobj, + "core", NULL); + if (rc) { + pr_err("unable to create core symlink (%d)\n", rc); + return rc; + } + + return 0; +} +fs_initcall(opalcore_init); |