diff options
Diffstat (limited to 'arch/powerpc/kernel/fadump.c')
| -rw-r--r-- | arch/powerpc/kernel/fadump.c | 1315 |
1 files changed, 1315 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c new file mode 100644 index 0000000..cfe7a38 --- /dev/null +++ b/arch/powerpc/kernel/fadump.c @@ -0,0 +1,1315 @@ +/* + * Firmware Assisted dump: A robust mechanism to get reliable kernel crash + * dump with assistance from firmware. This approach does not use kexec, + * instead firmware assists in booting the kdump kernel while preserving + * memory contents. The most of the code implementation has been adapted + * from phyp assisted dump implementation written by Linas Vepstas and + * Manish Ahuja + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright 2011 IBM Corporation + * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> + */ + +#undef DEBUG +#define pr_fmt(fmt) "fadump: " fmt + +#include <linux/string.h> +#include <linux/memblock.h> +#include <linux/delay.h> +#include <linux/debugfs.h> +#include <linux/seq_file.h> +#include <linux/crash_dump.h> +#include <linux/kobject.h> +#include <linux/sysfs.h> + +#include <asm/page.h> +#include <asm/prom.h> +#include <asm/rtas.h> +#include <asm/fadump.h> + +static struct fw_dump fw_dump; +static struct fadump_mem_struct fdm; +static const struct fadump_mem_struct *fdm_active; + +static DEFINE_MUTEX(fadump_mutex); +struct fad_crash_memory_ranges crash_memory_ranges[INIT_CRASHMEM_RANGES]; +int crash_mem_ranges; + +/* Scan the Firmware Assisted dump configuration details. */ +int __init early_init_dt_scan_fw_dump(unsigned long node, + const char *uname, int depth, void *data) +{ + __be32 *sections; + int i, num_sections; + unsigned long size; + const int *token; + + if (depth != 1 || strcmp(uname, "rtas") != 0) + return 0; + + /* + * Check if Firmware Assisted dump is supported. if yes, check + * if dump has been initiated on last reboot. + */ + token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); + if (!token) + return 0; + + fw_dump.fadump_supported = 1; + fw_dump.ibm_configure_kernel_dump = *token; + + /* + * 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) + fw_dump.dump_active = 1; + + /* 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 + * the ID of a supported section followed by two 32 bit cells which + * gives teh size of the section in bytes. + */ + sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", + &size); + + if (!sections) + return 0; + + num_sections = size / (3 * sizeof(u32)); + + for (i = 0; i < num_sections; i++, sections += 3) { + u32 type = (u32)of_read_number(sections, 1); + + switch (type) { + case FADUMP_CPU_STATE_DATA: + fw_dump.cpu_state_data_size = + of_read_ulong(§ions[1], 2); + break; + case FADUMP_HPTE_REGION: + fw_dump.hpte_region_size = + of_read_ulong(§ions[1], 2); + break; + } + } + return 1; +} + +int is_fadump_active(void) +{ + return fw_dump.dump_active; +} + +/* Print firmware assisted dump configurations for debugging purpose. */ +static void fadump_show_config(void) +{ + pr_debug("Support for firmware-assisted dump (fadump): %s\n", + (fw_dump.fadump_supported ? "present" : "no support")); + + if (!fw_dump.fadump_supported) + return; + + pr_debug("Fadump enabled : %s\n", + (fw_dump.fadump_enabled ? "yes" : "no")); + pr_debug("Dump Active : %s\n", + (fw_dump.dump_active ? "yes" : "no")); + pr_debug("Dump section sizes:\n"); + pr_debug(" CPU state data size: %lx\n", fw_dump.cpu_state_data_size); + pr_debug(" HPTE region size : %lx\n", fw_dump.hpte_region_size); + pr_debug("Boot memory size : %lx\n", fw_dump.boot_memory_size); +} + +static unsigned long init_fadump_mem_struct(struct fadump_mem_struct *fdm, + unsigned long addr) +{ + if (!fdm) + return 0; + + memset(fdm, 0, sizeof(struct fadump_mem_struct)); + addr = addr & PAGE_MASK; + + fdm->header.dump_format_version = 0x00000001; + fdm->header.dump_num_sections = 3; + fdm->header.dump_status_flag = 0; + fdm->header.offset_first_dump_section = + (u32)offsetof(struct fadump_mem_struct, cpu_state_data); + + /* + * Fields for disk dump option. + * We are not using disk dump option, hence set these fields to 0. + */ + fdm->header.dd_block_size = 0; + fdm->header.dd_block_offset = 0; + fdm->header.dd_num_blocks = 0; + fdm->header.dd_offset_disk_path = 0; + + /* set 0 to disable an automatic dump-reboot. */ + fdm->header.max_time_auto = 0; + + /* Kernel dump sections */ + /* cpu state data section. */ + fdm->cpu_state_data.request_flag = FADUMP_REQUEST_FLAG; + fdm->cpu_state_data.source_data_type = FADUMP_CPU_STATE_DATA; + fdm->cpu_state_data.source_address = 0; + fdm->cpu_state_data.source_len = fw_dump.cpu_state_data_size; + fdm->cpu_state_data.destination_address = addr; + addr += fw_dump.cpu_state_data_size; + + /* hpte region section */ + fdm->hpte_region.request_flag = FADUMP_REQUEST_FLAG; + fdm->hpte_region.source_data_type = FADUMP_HPTE_REGION; + fdm->hpte_region.source_address = 0; + fdm->hpte_region.source_len = fw_dump.hpte_region_size; + fdm->hpte_region.destination_address = addr; + addr += fw_dump.hpte_region_size; + + /* RMA region section */ + fdm->rmr_region.request_flag = FADUMP_REQUEST_FLAG; + fdm->rmr_region.source_data_type = FADUMP_REAL_MODE_REGION; + fdm->rmr_region.source_address = RMA_START; + fdm->rmr_region.source_len = fw_dump.boot_memory_size; + fdm->rmr_region.destination_address = addr; + addr += fw_dump.boot_memory_size; + + return addr; +} + +/** + * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM + * + * Function to find the largest memory size we need to reserve during early + * boot process. This will be the size of the memory that is required for a + * kernel to boot successfully. + * + * This function has been taken from phyp-assisted dump feature implementation. + * + * returns larger of 256MB or 5% rounded down to multiples of 256MB. + * + * TODO: Come up with better approach to find out more accurate memory size + * that is required for a kernel to boot successfully. + * + */ +static inline unsigned long fadump_calculate_reserve_size(void) +{ + unsigned long size; + + /* + * Check if the size is specified through fadump_reserve_mem= cmdline + * option. If yes, then use that. + */ + if (fw_dump.reserve_bootvar) + return fw_dump.reserve_bootvar; + + /* divide by 20 to get 5% of value */ + size = memblock_end_of_DRAM() / 20; + + /* round it down in multiples of 256 */ + size = size & ~0x0FFFFFFFUL; + + /* Truncate to memory_limit. We don't want to over reserve the memory.*/ + if (memory_limit && size > memory_limit) + size = memory_limit; + + return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); +} + +/* + * Calculate the total memory size required to be reserved for + * firmware-assisted dump registration. + */ +static unsigned long get_fadump_area_size(void) +{ + unsigned long size = 0; + + size += fw_dump.cpu_state_data_size; + size += fw_dump.hpte_region_size; + size += fw_dump.boot_memory_size; + size += sizeof(struct fadump_crash_info_header); + size += sizeof(struct elfhdr); /* ELF core header.*/ + size += sizeof(struct elf_phdr); /* place holder for cpu notes */ + /* Program headers for crash memory regions. */ + size += sizeof(struct elf_phdr) * (memblock_num_regions(memory) + 2); + + size = PAGE_ALIGN(size); + return size; +} + +int __init fadump_reserve_mem(void) +{ + unsigned long base, size, memory_boundary; + + if (!fw_dump.fadump_enabled) + return 0; + + if (!fw_dump.fadump_supported) { + printk(KERN_INFO "Firmware-assisted dump is not supported on" + " this hardware\n"); + fw_dump.fadump_enabled = 0; + return 0; + } + /* + * Initialize boot memory size + * If dump is active then we have already calculated the size during + * first kernel. + */ + if (fdm_active) + fw_dump.boot_memory_size = fdm_active->rmr_region.source_len; + else + fw_dump.boot_memory_size = fadump_calculate_reserve_size(); + + /* + * Calculate the memory boundary. + * If memory_limit is less than actual memory boundary then reserve + * the memory for fadump beyond the memory_limit and adjust the + * memory_limit accordingly, so that the running kernel can run with + * specified memory_limit. + */ + if (memory_limit && memory_limit < memblock_end_of_DRAM()) { + size = get_fadump_area_size(); + if ((memory_limit + size) < memblock_end_of_DRAM()) + memory_limit += size; + else + memory_limit = memblock_end_of_DRAM(); + printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" + " dump, now %#016llx\n", + (unsigned long long)memory_limit); + } + if (memory_limit) + memory_boundary = memory_limit; + else + memory_boundary = memblock_end_of_DRAM(); + + if (fw_dump.dump_active) { + printk(KERN_INFO "Firmware-assisted dump is active.\n"); + /* + * If last boot has crashed then reserve all the memory + * above boot_memory_size so that we don't touch it until + * dump is written to disk by userspace tool. This memory + * will be released for general use once the dump is saved. + */ + base = fw_dump.boot_memory_size; + size = memory_boundary - base; + memblock_reserve(base, size); + printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " + "for saving crash dump\n", + (unsigned long)(size >> 20), + (unsigned long)(base >> 20)); + + fw_dump.fadumphdr_addr = + fdm_active->rmr_region.destination_address + + fdm_active->rmr_region.source_len; + pr_debug("fadumphdr_addr = %p\n", + (void *) fw_dump.fadumphdr_addr); + } else { + /* Reserve the memory at the top of memory. */ + size = get_fadump_area_size(); + base = memory_boundary - size; + memblock_reserve(base, size); + printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " + "for firmware-assisted dump\n", + (unsigned long)(size >> 20), + (unsigned long)(base >> 20)); + } + fw_dump.reserve_dump_area_start = base; + fw_dump.reserve_dump_area_size = size; + return 1; +} + +/* Look for fadump= cmdline option. */ +static int __init early_fadump_param(char *p) +{ + if (!p) + return 1; + + if (strncmp(p, "on", 2) == 0) + fw_dump.fadump_enabled = 1; + else if (strncmp(p, "off", 3) == 0) + fw_dump.fadump_enabled = 0; + + return 0; +} +early_param("fadump", early_fadump_param); + +/* Look for fadump_reserve_mem= cmdline option */ +static int __init early_fadump_reserve_mem(char *p) +{ + if (p) + fw_dump.reserve_bootvar = memparse(p, &p); + return 0; +} +early_param("fadump_reserve_mem", early_fadump_reserve_mem); + +static void register_fw_dump(struct fadump_mem_struct *fdm) +{ + int rc; + unsigned int wait_time; + + pr_debug("Registering for firmware-assisted kernel dump...\n"); + + /* TODO: Add upper time limit for the delay */ + do { + rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, + FADUMP_REGISTER, fdm, + sizeof(struct fadump_mem_struct)); + + wait_time = rtas_busy_delay_time(rc); + if (wait_time) + mdelay(wait_time); + + } while (wait_time); + + switch (rc) { + case -1: + printk(KERN_ERR "Failed to register firmware-assisted kernel" + " dump. Hardware Error(%d).\n", rc); + break; + case -3: + printk(KERN_ERR "Failed to register firmware-assisted kernel" + " dump. Parameter Error(%d).\n", rc); + break; + case -9: + printk(KERN_ERR "firmware-assisted kernel dump is already " + " registered."); + fw_dump.dump_registered = 1; + break; + case 0: + printk(KERN_INFO "firmware-assisted kernel dump registration" + " is successful\n"); + fw_dump.dump_registered = 1; + break; + } +} + +void crash_fadump(struct pt_regs *regs, const char *str) +{ + struct fadump_crash_info_header *fdh = NULL; + + if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) + return; + + fdh = __va(fw_dump.fadumphdr_addr); + crashing_cpu = smp_processor_id(); + fdh->crashing_cpu = crashing_cpu; + crash_save_vmcoreinfo(); + + if (regs) + fdh->regs = *regs; + else + ppc_save_regs(&fdh->regs); + + fdh->cpu_online_mask = *cpu_online_mask; + + /* Call ibm,os-term rtas call to trigger firmware assisted dump */ + rtas_os_term((char *)str); +} + +#define GPR_MASK 0xffffff0000000000 +static inline int fadump_gpr_index(u64 id) +{ + int i = -1; + char str[3]; + + if ((id & GPR_MASK) == REG_ID("GPR")) { + /* get the digits at the end */ + id &= ~GPR_MASK; + id >>= 24; + str[2] = '\0'; + str[1] = id & 0xff; + str[0] = (id >> 8) & 0xff; + sscanf(str, "%d", &i); + if (i > 31) + i = -1; + } + return i; +} + +static inline void fadump_set_regval(struct pt_regs *regs, u64 reg_id, + u64 reg_val) +{ + int i; + + i = fadump_gpr_index(reg_id); + if (i >= 0) + regs->gpr[i] = (unsigned long)reg_val; + else if (reg_id == REG_ID("NIA")) + regs->nip = (unsigned long)reg_val; + else if (reg_id == REG_ID("MSR")) + regs->msr = (unsigned long)reg_val; + else if (reg_id == REG_ID("CTR")) + regs->ctr = (unsigned long)reg_val; + else if (reg_id == REG_ID("LR")) + regs->link = (unsigned long)reg_val; + else if (reg_id == REG_ID("XER")) + regs->xer = (unsigned long)reg_val; + else if (reg_id == REG_ID("CR")) + regs->ccr = (unsigned long)reg_val; + else if (reg_id == REG_ID("DAR")) + regs->dar = (unsigned long)reg_val; + else if (reg_id == REG_ID("DSISR")) + regs->dsisr = (unsigned long)reg_val; +} + +static struct fadump_reg_entry* +fadump_read_registers(struct fadump_reg_entry *reg_entry, struct pt_regs *regs) +{ + memset(regs, 0, sizeof(struct pt_regs)); + + while (reg_entry->reg_id != REG_ID("CPUEND")) { + fadump_set_regval(regs, reg_entry->reg_id, + reg_entry->reg_value); + reg_entry++; + } + reg_entry++; + return reg_entry; +} + +static u32 *fadump_append_elf_note(u32 *buf, char *name, unsigned type, + void *data, size_t data_len) +{ + struct elf_note note; + + note.n_namesz = strlen(name) + 1; + note.n_descsz = data_len; + note.n_type = type; + memcpy(buf, ¬e, sizeof(note)); + buf += (sizeof(note) + 3)/4; + memcpy(buf, name, note.n_namesz); + buf += (note.n_namesz + 3)/4; + memcpy(buf, data, note.n_descsz); + buf += (note.n_descsz + 3)/4; + + return buf; +} + +static void fadump_final_note(u32 *buf) +{ + struct elf_note note; + + note.n_namesz = 0; + note.n_descsz = 0; + note.n_type = 0; + memcpy(buf, ¬e, sizeof(note)); +} + +static u32 *fadump_regs_to_elf_notes(u32 *buf, struct pt_regs *regs) +{ + struct elf_prstatus prstatus; + + memset(&prstatus, 0, sizeof(prstatus)); + /* + * FIXME: How do i get PID? Do I really need it? + * prstatus.pr_pid = ???? + */ + elf_core_copy_kernel_regs(&prstatus.pr_reg, regs); + buf = fadump_append_elf_note(buf, KEXEC_CORE_NOTE_NAME, NT_PRSTATUS, + &prstatus, sizeof(prstatus)); + return buf; +} + +static void fadump_update_elfcore_header(char *bufp) +{ + struct elfhdr *elf; + struct elf_phdr *phdr; + + elf = (struct elfhdr *)bufp; + bufp += sizeof(struct elfhdr); + + /* First note is a place holder for cpu notes info. */ + phdr = (struct elf_phdr *)bufp; + + if (phdr->p_type == PT_NOTE) { + phdr->p_paddr = fw_dump.cpu_notes_buf; + phdr->p_offset = phdr->p_paddr; + phdr->p_filesz = fw_dump.cpu_notes_buf_size; + phdr->p_memsz = fw_dump.cpu_notes_buf_size; + } + return; +} + +static void *fadump_cpu_notes_buf_alloc(unsigned long size) +{ + void *vaddr; + struct page *page; + unsigned long order, count, i; + + order = get_order(size); + vaddr = (void *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, order); + if (!vaddr) + return NULL; + + count = 1 << order; + page = virt_to_page(vaddr); + for (i = 0; i < count; i++) + SetPageReserved(page + i); + return vaddr; +} + +static void fadump_cpu_notes_buf_free(unsigned long vaddr, unsigned long size) +{ + struct page *page; + unsigned long order, count, i; + + order = get_order(size); + count = 1 << order; + page = virt_to_page(vaddr); + for (i = 0; i < count; i++) + ClearPageReserved(page + i); + __free_pages(page, order); +} + +/* + * 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 fadump_build_cpu_notes(const struct fadump_mem_struct *fdm) +{ + struct fadump_reg_save_area_header *reg_header; + struct fadump_reg_entry *reg_entry; + struct fadump_crash_info_header *fdh = NULL; + void *vaddr; + unsigned long addr; + u32 num_cpus, *note_buf; + struct pt_regs regs; + int i, rc = 0, cpu = 0; + + if (!fdm->cpu_state_data.bytes_dumped) + return -EINVAL; + + addr = fdm->cpu_state_data.destination_address; + vaddr = __va(addr); + + reg_header = vaddr; + if (reg_header->magic_number != REGSAVE_AREA_MAGIC) { + printk(KERN_ERR "Unable to read register save area.\n"); + return -ENOENT; + } + pr_debug("--------CPU State Data------------\n"); + pr_debug("Magic Number: %llx\n", reg_header->magic_number); + pr_debug("NumCpuOffset: %x\n", reg_header->num_cpu_offset); + + vaddr += reg_header->num_cpu_offset; + num_cpus = *((u32 *)(vaddr)); + pr_debug("NumCpus : %u\n", num_cpus); + vaddr += sizeof(u32); + reg_entry = (struct fadump_reg_entry *)vaddr; + + /* Allocate buffer to hold cpu crash notes. */ + fw_dump.cpu_notes_buf_size = num_cpus * sizeof(note_buf_t); + fw_dump.cpu_notes_buf_size = PAGE_ALIGN(fw_dump.cpu_notes_buf_size); + note_buf = fadump_cpu_notes_buf_alloc(fw_dump.cpu_notes_buf_size); + if (!note_buf) { + printk(KERN_ERR "Failed to allocate 0x%lx bytes for " + "cpu notes buffer\n", fw_dump.cpu_notes_buf_size); + return -ENOMEM; + } + fw_dump.cpu_notes_buf = __pa(note_buf); + + pr_debug("Allocated buffer for cpu notes of size %ld at %p\n", + (num_cpus * sizeof(note_buf_t)), note_buf); + + if (fw_dump.fadumphdr_addr) + fdh = __va(fw_dump.fadumphdr_addr); + + for (i = 0; i < num_cpus; i++) { + if (reg_entry->reg_id != REG_ID("CPUSTRT")) { + printk(KERN_ERR "Unable to read CPU state data\n"); + rc = -ENOENT; + goto error_out; + } + /* Lower 4 bytes of reg_value contains logical cpu id */ + cpu = reg_entry->reg_value & FADUMP_CPU_ID_MASK; + if (!cpumask_test_cpu(cpu, &fdh->cpu_online_mask)) { + 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); + SKIP_TO_NEXT_CPU(reg_entry); + } else { + reg_entry++; + reg_entry = fadump_read_registers(reg_entry, ®s); + note_buf = fadump_regs_to_elf_notes(note_buf, ®s); + } + } + fadump_final_note(note_buf); + + pr_debug("Updating elfcore header (%llx) with cpu notes\n", + fdh->elfcorehdr_addr); + fadump_update_elfcore_header((char *)__va(fdh->elfcorehdr_addr)); + return 0; + +error_out: + fadump_cpu_notes_buf_free((unsigned long)__va(fw_dump.cpu_notes_buf), + fw_dump.cpu_notes_buf_size); + fw_dump.cpu_notes_buf = 0; + fw_dump.cpu_notes_buf_size = 0; + return rc; + +} + +/* + * Validate and process the dump data stored by firmware before exporting + * it through '/proc/vmcore'. + */ +static int __init process_fadump(const struct fadump_mem_struct *fdm_active) +{ + struct fadump_crash_info_header *fdh; + int rc = 0; + + if (!fdm_active || !fw_dump.fadumphdr_addr) + return -EINVAL; + + /* Check if the dump data is valid. */ + if ((fdm_active->header.dump_status_flag == FADUMP_ERROR_FLAG) || + (fdm_active->cpu_state_data.error_flags != 0) || + (fdm_active->rmr_region.error_flags != 0)) { + printk(KERN_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) { + printk(KERN_ERR "Dump taken by platform is incomplete\n"); + return -EINVAL; + } + + /* Validate the fadump crash info header */ + fdh = __va(fw_dump.fadumphdr_addr); + if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { + printk(KERN_ERR "Crash info header is not valid.\n"); + return -EINVAL; + } + + rc = fadump_build_cpu_notes(fdm_active); + 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 inline void fadump_add_crash_memory(unsigned long long base, + unsigned long long end) +{ + if (base == end) + return; + + pr_debug("crash_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", + crash_mem_ranges, base, end - 1, (end - base)); + crash_memory_ranges[crash_mem_ranges].base = base; + crash_memory_ranges[crash_mem_ranges].size = end - base; + crash_mem_ranges++; +} + +static void fadump_exclude_reserved_area(unsigned long long start, + unsigned long long end) +{ + unsigned long long ra_start, ra_end; + + ra_start = fw_dump.reserve_dump_area_start; + ra_end = ra_start + fw_dump.reserve_dump_area_size; + + if ((ra_start < end) && (ra_end > start)) { + if ((start < ra_start) && (end > ra_end)) { + fadump_add_crash_memory(start, ra_start); + fadump_add_crash_memory(ra_end, end); + } else if (start < ra_start) { + fadump_add_crash_memory(start, ra_start); + } else if (ra_end < end) { + fadump_add_crash_memory(ra_end, end); + } + } else + fadump_add_crash_memory(start, end); +} + +static int fadump_init_elfcore_header(char *bufp) +{ + struct elfhdr *elf; + + elf = (struct elfhdr *) bufp; + bufp += sizeof(struct elfhdr); + memcpy(elf->e_ident, ELFMAG, SELFMAG); + elf->e_ident[EI_CLASS] = ELF_CLASS; + elf->e_ident[EI_DATA] = ELF_DATA; + 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 = ET_CORE; + elf->e_machine = ELF_ARCH; + elf->e_version = EV_CURRENT; + elf->e_entry = 0; + elf->e_phoff = sizeof(struct elfhdr); + elf->e_shoff = 0; + elf->e_flags = ELF_CORE_EFLAGS; + elf->e_ehsize = sizeof(struct elfhdr); + elf->e_phentsize = sizeof(struct elf_phdr); + elf->e_phnum = 0; + elf->e_shentsize = 0; + elf->e_shnum = 0; + elf->e_shstrndx = 0; + + return 0; +} + +/* + * Traverse through memblock structure and setup crash memory ranges. These + * ranges will be used create PT_LOAD program headers in elfcore header. + */ +static void fadump_setup_crash_memory_ranges(void) +{ + struct memblock_region *reg; + unsigned long long start, end; + + pr_debug("Setup crash memory ranges.\n"); + crash_mem_ranges = 0; + /* + * add the first memory chunk (RMA_START through boot_memory_size) as + * a separate memory chunk. The reason is, at the time crash firmware + * will move the content of this memory chunk to different location + * specified during fadump registration. We need to create a separate + * program header for this chunk with the correct offset. + */ + fadump_add_crash_memory(RMA_START, fw_dump.boot_memory_size); + + for_each_memblock(memory, reg) { + start = (unsigned long long)reg->base; + end = start + (unsigned long long)reg->size; + if (start == RMA_START && end >= fw_dump.boot_memory_size) + start = fw_dump.boot_memory_size; + + /* add this range excluding the reserved dump area. */ + fadump_exclude_reserved_area(start, end); + } +} + +/* + * If the given physical address falls within the boot memory region then + * return the relocated address that points to the dump region reserved + * for saving initial boot memory contents. + */ +static inline unsigned long fadump_relocate(unsigned long paddr) +{ + if (paddr > RMA_START && paddr < fw_dump.boot_memory_size) + return fdm.rmr_region.destination_address + paddr; + else + return paddr; +} + +static int fadump_create_elfcore_headers(char *bufp) +{ + struct elfhdr *elf; + struct elf_phdr *phdr; + int i; + + fadump_init_elfcore_header(bufp); + elf = (struct elfhdr *)bufp; + bufp += sizeof(struct elfhdr); + + /* + * setup ELF PT_NOTE, place holder for cpu notes info. The notes info + * will be populated during second kernel boot after crash. Hence + * this PT_NOTE will always be the first elf note. + * + * NOTE: Any new ELF note addition should be placed after this note. + */ + phdr = (struct elf_phdr *)bufp; + bufp += sizeof(struct elf_phdr); + phdr->p_type = PT_NOTE; + phdr->p_flags = 0; + phdr->p_vaddr = 0; + phdr->p_align = 0; + + phdr->p_offset = 0; + phdr->p_paddr = 0; + phdr->p_filesz = 0; + phdr->p_memsz = 0; + + (elf->e_phnum)++; + + /* setup ELF PT_NOTE for vmcoreinfo */ + phdr = (struct elf_phdr *)bufp; + bufp += sizeof(struct elf_phdr); + phdr->p_type = PT_NOTE; + phdr->p_flags = 0; + phdr->p_vaddr = 0; + phdr->p_align = 0; + + phdr->p_paddr = fadump_relocate(paddr_vmcoreinfo_note()); + phdr->p_offset = phdr->p_paddr; + phdr->p_memsz = vmcoreinfo_max_size; + phdr->p_filesz = vmcoreinfo_max_size; + + /* Increment number of program headers. */ + (elf->e_phnum)++; + + /* setup PT_LOAD sections. */ + + for (i = 0; i < crash_mem_ranges; i++) { + unsigned long long mbase, msize; + mbase = crash_memory_ranges[i].base; + msize = crash_memory_ranges[i].size; + + if (!msize) + continue; + + phdr = (struct elf_phdr *)bufp; + bufp += sizeof(struct elf_phdr); + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_offset = mbase; + + if (mbase == RMA_START) { + /* + * The entire RMA region will be moved by firmware + * to the specified destination_address. Hence set + * the correct offset. + */ + phdr->p_offset = fdm.rmr_region.destination_address; + } + + phdr->p_paddr = mbase; + phdr->p_vaddr = (unsigned long)__va(mbase); + phdr->p_filesz = msize; + phdr->p_memsz = msize; + phdr->p_align = 0; + + /* Increment number of program headers. */ + (elf->e_phnum)++; + } + return 0; +} + +static unsigned long init_fadump_header(unsigned long addr) +{ + struct fadump_crash_info_header *fdh; + + if (!addr) + return 0; + + fw_dump.fadumphdr_addr = addr; + fdh = __va(addr); + addr += sizeof(struct fadump_crash_info_header); + + memset(fdh, 0, sizeof(struct fadump_crash_info_header)); + fdh->magic_number = FADUMP_CRASH_INFO_MAGIC; + fdh->elfcorehdr_addr = addr; + /* We will set the crashing cpu id in crash_fadump() during crash. */ + fdh->crashing_cpu = CPU_UNKNOWN; + + return addr; +} + +static void register_fadump(void) +{ + unsigned long addr; + void *vaddr; + + /* + * If no memory is reserved then we can not register for firmware- + * assisted dump. + */ + if (!fw_dump.reserve_dump_area_size) + return; + + fadump_setup_crash_memory_ranges(); + + addr = fdm.rmr_region.destination_address + fdm.rmr_region.source_len; + /* Initialize fadump crash info header. */ + addr = init_fadump_header(addr); + vaddr = __va(addr); + + pr_debug("Creating ELF core headers at %#016lx\n", addr); + fadump_create_elfcore_headers(vaddr); + + /* register the future kernel dump with firmware. */ + register_fw_dump(&fdm); +} + +static int fadump_unregister_dump(struct fadump_mem_struct *fdm) +{ + int rc = 0; + unsigned int wait_time; + + pr_debug("Un-register firmware-assisted dump\n"); + + /* TODO: Add upper time limit for the delay */ + do { + rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, + FADUMP_UNREGISTER, fdm, + sizeof(struct fadump_mem_struct)); + + wait_time = rtas_busy_delay_time(rc); + if (wait_time) + mdelay(wait_time); + } while (wait_time); + + if (rc) { + printk(KERN_ERR "Failed to un-register firmware-assisted dump." + " unexpected error(%d).\n", rc); + return rc; + } + fw_dump.dump_registered = 0; + return 0; +} + +static int fadump_invalidate_dump(struct fadump_mem_struct *fdm) +{ + int rc = 0; + unsigned int wait_time; + + pr_debug("Invalidating firmware-assisted dump registration\n"); + + /* TODO: Add upper time limit for the delay */ + do { + rc = rtas_call(fw_dump.ibm_configure_kernel_dump, 3, 1, NULL, + FADUMP_INVALIDATE, fdm, + sizeof(struct fadump_mem_struct)); + + wait_time = rtas_busy_delay_time(rc); + if (wait_time) + mdelay(wait_time); + } while (wait_time); + + if (rc) { + printk(KERN_ERR "Failed to invalidate firmware-assisted dump " + "rgistration. unexpected error(%d).\n", rc); + return rc; + } + fw_dump.dump_active = 0; + fdm_active = NULL; + return 0; +} + +void fadump_cleanup(void) +{ + /* Invalidate the registration only if dump is active. */ + if (fw_dump.dump_active) { + init_fadump_mem_struct(&fdm, + fdm_active->cpu_state_data.destination_address); + fadump_invalidate_dump(&fdm); + } +} + +/* + * Release the memory that was reserved in early boot to preserve the memory + * contents. The released memory will be available for general use. + */ +static void fadump_release_memory(unsigned long begin, unsigned long end) +{ + unsigned long addr; + unsigned long ra_start, ra_end; + + ra_start = fw_dump.reserve_dump_area_start; + ra_end = ra_start + fw_dump.reserve_dump_area_size; + + for (addr = begin; addr < end; addr += PAGE_SIZE) { + /* + * exclude the dump reserve area. Will reuse it for next + * fadump registration. + */ + if (addr <= ra_end && ((addr + PAGE_SIZE) > ra_start)) + continue; + + ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT)); + init_page_count(pfn_to_page(addr >> PAGE_SHIFT)); + free_page((unsigned long)__va(addr)); + totalram_pages++; + } +} + +static void fadump_invalidate_release_mem(void) +{ + unsigned long reserved_area_start, reserved_area_end; + unsigned long destination_address; + + mutex_lock(&fadump_mutex); + if (!fw_dump.dump_active) { + mutex_unlock(&fadump_mutex); + return; + } + + destination_address = fdm_active->cpu_state_data.destination_address; + fadump_cleanup(); + mutex_unlock(&fadump_mutex); + + /* + * Save the current reserved memory bounds we will require them + * later for releasing the memory for general use. + */ + reserved_area_start = fw_dump.reserve_dump_area_start; + reserved_area_end = reserved_area_start + + fw_dump.reserve_dump_area_size; + /* + * Setup reserve_dump_area_start and its size so that we can + * reuse this reserved memory for Re-registration. + */ + fw_dump.reserve_dump_area_start = destination_address; + fw_dump.reserve_dump_area_size = get_fadump_area_size(); + + fadump_release_memory(reserved_area_start, reserved_area_end); + if (fw_dump.cpu_notes_buf) { + fadump_cpu_notes_buf_free( + (unsigned long)__va(fw_dump.cpu_notes_buf), + fw_dump.cpu_notes_buf_size); + fw_dump.cpu_notes_buf = 0; + fw_dump.cpu_notes_buf_size = 0; + } + /* Initialize the kernel dump memory structure for FAD registration. */ + init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); +} + +static ssize_t fadump_release_memory_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + if (!fw_dump.dump_active) + return -EPERM; + + if (buf[0] == '1') { + /* + * Take away the '/proc/vmcore'. We are releasing the dump + * memory, hence it will not be valid anymore. + */ + vmcore_cleanup(); + fadump_invalidate_release_mem(); + + } else + return -EINVAL; + return count; +} + +static ssize_t fadump_enabled_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", fw_dump.fadump_enabled); +} + +static ssize_t fadump_register_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sprintf(buf, "%d\n", fw_dump.dump_registered); +} + +static ssize_t fadump_register_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + int ret = 0; + + if (!fw_dump.fadump_enabled || fdm_active) + return -EPERM; + + mutex_lock(&fadump_mutex); + + switch (buf[0]) { + case '0': + if (fw_dump.dump_registered == 0) { + ret = -EINVAL; + goto unlock_out; + } + /* Un-register Firmware-assisted dump */ + fadump_unregister_dump(&fdm); + break; + case '1': + if (fw_dump.dump_registered == 1) { + ret = -EINVAL; + goto unlock_out; + } + /* Register Firmware-assisted dump */ + register_fadump(); + break; + default: + ret = -EINVAL; + break; + } + +unlock_out: + mutex_unlock(&fadump_mutex); + return ret < 0 ? ret : count; +} + +static int fadump_region_show(struct seq_file *m, void *private) +{ + const struct fadump_mem_struct *fdm_ptr; + + if (!fw_dump.fadump_enabled) + return 0; + + mutex_lock(&fadump_mutex); + if (fdm_active) + fdm_ptr = fdm_active; + else { + mutex_unlock(&fadump_mutex); + fdm_ptr = &fdm; + } + + seq_printf(m, + "CPU : [%#016llx-%#016llx] %#llx bytes, " + "Dumped: %#llx\n", + fdm_ptr->cpu_state_data.destination_address, + fdm_ptr->cpu_state_data.destination_address + + fdm_ptr->cpu_state_data.source_len - 1, + fdm_ptr->cpu_state_data.source_len, + fdm_ptr->cpu_state_data.bytes_dumped); + seq_printf(m, + "HPTE: [%#016llx-%#016llx] %#llx bytes, " + "Dumped: %#llx\n", + fdm_ptr->hpte_region.destination_address, + fdm_ptr->hpte_region.destination_address + + fdm_ptr->hpte_region.source_len - 1, + fdm_ptr->hpte_region.source_len, + fdm_ptr->hpte_region.bytes_dumped); + seq_printf(m, + "DUMP: [%#016llx-%#016llx] %#llx bytes, " + "Dumped: %#llx\n", + fdm_ptr->rmr_region.destination_address, + fdm_ptr->rmr_region.destination_address + + fdm_ptr->rmr_region.source_len - 1, + fdm_ptr->rmr_region.source_len, + fdm_ptr->rmr_region.bytes_dumped); + + if (!fdm_active || + (fw_dump.reserve_dump_area_start == + fdm_ptr->cpu_state_data.destination_address)) + goto out; + + /* Dump is active. Show reserved memory region. */ + seq_printf(m, + " : [%#016llx-%#016llx] %#llx bytes, " + "Dumped: %#llx\n", + (unsigned long long)fw_dump.reserve_dump_area_start, + fdm_ptr->cpu_state_data.destination_address - 1, + fdm_ptr->cpu_state_data.destination_address - + fw_dump.reserve_dump_area_start, + fdm_ptr->cpu_state_data.destination_address - + fw_dump.reserve_dump_area_start); +out: + if (fdm_active) + mutex_unlock(&fadump_mutex); + return 0; +} + +static struct kobj_attribute fadump_release_attr = __ATTR(fadump_release_mem, + 0200, NULL, + fadump_release_memory_store); +static struct kobj_attribute fadump_attr = __ATTR(fadump_enabled, + 0444, fadump_enabled_show, + NULL); +static struct kobj_attribute fadump_register_attr = __ATTR(fadump_registered, + 0644, fadump_register_show, + fadump_register_store); + +static int fadump_region_open(struct inode *inode, struct file *file) +{ + return single_open(file, fadump_region_show, inode->i_private); +} + +static const struct file_operations fadump_region_fops = { + .open = fadump_region_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void fadump_init_files(void) +{ + struct dentry *debugfs_file; + int rc = 0; + + rc = sysfs_create_file(kernel_kobj, &fadump_attr.attr); + if (rc) + printk(KERN_ERR "fadump: unable to create sysfs file" + " fadump_enabled (%d)\n", rc); + + rc = sysfs_create_file(kernel_kobj, &fadump_register_attr.attr); + if (rc) + printk(KERN_ERR "fadump: unable to create sysfs file" + " fadump_registered (%d)\n", rc); + + debugfs_file = debugfs_create_file("fadump_region", 0444, + powerpc_debugfs_root, NULL, + &fadump_region_fops); + if (!debugfs_file) + printk(KERN_ERR "fadump: unable to create debugfs file" + " fadump_region\n"); + + if (fw_dump.dump_active) { + rc = sysfs_create_file(kernel_kobj, &fadump_release_attr.attr); + if (rc) + printk(KERN_ERR "fadump: unable to create sysfs file" + " fadump_release_mem (%d)\n", rc); + } + return; +} + +/* + * Prepare for firmware-assisted dump. + */ +int __init setup_fadump(void) +{ + if (!fw_dump.fadump_enabled) + return 0; + + if (!fw_dump.fadump_supported) { + printk(KERN_ERR "Firmware-assisted dump is not supported on" + " this hardware\n"); + return 0; + } + + fadump_show_config(); + /* + * If dump data is available then see if it is valid and prepare for + * saving it to the disk. + */ + if (fw_dump.dump_active) { + /* + * if dump process fails then invalidate the registration + * and release memory before proceeding for re-registration. + */ + if (process_fadump(fdm_active) < 0) + fadump_invalidate_release_mem(); + } + /* Initialize the kernel dump memory structure for FAD registration. */ + else if (fw_dump.reserve_dump_area_size) + init_fadump_mem_struct(&fdm, fw_dump.reserve_dump_area_start); + fadump_init_files(); + + return 1; +} +subsys_initcall(setup_fadump); |
