--- /dev/null
+// 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/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;
+
+/*
+ * 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 *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 fill_prstatus(struct elf_prstatus *prstatus, int pir,
+ struct pt_regs *regs)
+{
+ memset(prstatus, 0, sizeof(struct elf_prstatus));
+ elf_core_copy_kernel_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->pr_pid = cpu_to_be32(100 + pir);
+ prstatus->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->pr_cursig = cpu_to_be16(sig);
+ }
+}
+
+static Elf64_Word *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");
+
+ /* 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(opal_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)",
+ MAX_PT_LOAD_CNT, idx);
+ 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 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/core\n");
+ opalcore_cleanup();
+ return rc;
+ }
+
+ /* Set OPAL core file size */
+ opal_core_attr.size = oc_conf->opalcore_size;
+
+ /* Export OPAL core sysfs file */
+ rc = sysfs_create_bin_file(opal_kobj, &opal_core_attr);
+ if (rc != 0) {
+ pr_err("Failed to export /sys/firmware/opal/core\n");
+ opalcore_cleanup();
+ return rc;
+ }
+
+ return 0;
+}
+fs_initcall(opalcore_init);
projects / openwrt / staging / blogic.git / commitdiff