| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * 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 |
| * |
| * 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/seq_file.h> |
| #include <linux/crash_dump.h> |
| #include <linux/kobject.h> |
| #include <linux/sysfs.h> |
| #include <linux/slab.h> |
| #include <linux/cma.h> |
| #include <linux/hugetlb.h> |
| |
| #include <asm/debugfs.h> |
| #include <asm/page.h> |
| #include <asm/prom.h> |
| #include <asm/fadump.h> |
| #include <asm/fadump-internal.h> |
| #include <asm/setup.h> |
| |
| static struct fw_dump fw_dump; |
| |
| static void __init fadump_reserve_crash_area(u64 base); |
| |
| #ifndef CONFIG_PRESERVE_FA_DUMP |
| static DEFINE_MUTEX(fadump_mutex); |
| struct fadump_mrange_info crash_mrange_info = { "crash", NULL, 0, 0, 0 }; |
| struct fadump_mrange_info reserved_mrange_info = { "reserved", NULL, 0, 0, 0 }; |
| |
| #ifdef CONFIG_CMA |
| static struct cma *fadump_cma; |
| |
| /* |
| * fadump_cma_init() - Initialize CMA area from a fadump reserved memory |
| * |
| * This function initializes CMA area from fadump reserved memory. |
| * The total size of fadump reserved memory covers for boot memory size |
| * + cpu data size + hpte size and metadata. |
| * Initialize only the area equivalent to boot memory size for CMA use. |
| * The reamining portion of fadump reserved memory will be not given |
| * to CMA and pages for thoes will stay reserved. boot memory size is |
| * aligned per CMA requirement to satisy cma_init_reserved_mem() call. |
| * But for some reason even if it fails we still have the memory reservation |
| * with us and we can still continue doing fadump. |
| */ |
| int __init fadump_cma_init(void) |
| { |
| unsigned long long base, size; |
| int rc; |
| |
| if (!fw_dump.fadump_enabled) |
| return 0; |
| |
| /* |
| * Do not use CMA if user has provided fadump=nocma kernel parameter. |
| * Return 1 to continue with fadump old behaviour. |
| */ |
| if (fw_dump.nocma) |
| return 1; |
| |
| base = fw_dump.reserve_dump_area_start; |
| size = fw_dump.boot_memory_size; |
| |
| if (!size) |
| return 0; |
| |
| rc = cma_init_reserved_mem(base, size, 0, "fadump_cma", &fadump_cma); |
| if (rc) { |
| pr_err("Failed to init cma area for firmware-assisted dump,%d\n", rc); |
| /* |
| * Though the CMA init has failed we still have memory |
| * reservation with us. The reserved memory will be |
| * blocked from production system usage. Hence return 1, |
| * so that we can continue with fadump. |
| */ |
| return 1; |
| } |
| |
| /* |
| * So we now have successfully initialized cma area for fadump. |
| */ |
| pr_info("Initialized 0x%lx bytes cma area at %ldMB from 0x%lx " |
| "bytes of memory reserved for firmware-assisted dump\n", |
| cma_get_size(fadump_cma), |
| (unsigned long)cma_get_base(fadump_cma) >> 20, |
| fw_dump.reserve_dump_area_size); |
| return 1; |
| } |
| #else |
| static int __init fadump_cma_init(void) { return 1; } |
| #endif /* CONFIG_CMA */ |
| |
| /* 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) |
| { |
| if (depth != 1) |
| return 0; |
| |
| if (strcmp(uname, "rtas") == 0) { |
| rtas_fadump_dt_scan(&fw_dump, node); |
| return 1; |
| } |
| |
| if (strcmp(uname, "ibm,opal") == 0) { |
| opal_fadump_dt_scan(&fw_dump, node); |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * If fadump is registered, check if the memory provided |
| * falls within boot memory area and reserved memory area. |
| */ |
| int is_fadump_memory_area(u64 addr, unsigned long size) |
| { |
| u64 d_start, d_end; |
| |
| if (!fw_dump.dump_registered) |
| return 0; |
| |
| if (!size) |
| return 0; |
| |
| d_start = fw_dump.reserve_dump_area_start; |
| d_end = d_start + fw_dump.reserve_dump_area_size; |
| if (((addr + size) > d_start) && (addr <= d_end)) |
| return 1; |
| |
| return (addr <= fw_dump.boot_mem_top); |
| } |
| |
| int should_fadump_crash(void) |
| { |
| if (!fw_dump.dump_registered || !fw_dump.fadumphdr_addr) |
| return 0; |
| return 1; |
| } |
| |
| int is_fadump_active(void) |
| { |
| return fw_dump.dump_active; |
| } |
| |
| /* |
| * Returns true, if there are no holes in memory area between d_start to d_end, |
| * false otherwise. |
| */ |
| static bool is_fadump_mem_area_contiguous(u64 d_start, u64 d_end) |
| { |
| struct memblock_region *reg; |
| bool ret = false; |
| u64 start, end; |
| |
| for_each_memblock(memory, reg) { |
| start = max_t(u64, d_start, reg->base); |
| end = min_t(u64, d_end, (reg->base + reg->size)); |
| if (d_start < end) { |
| /* Memory hole from d_start to start */ |
| if (start > d_start) |
| break; |
| |
| if (end == d_end) { |
| ret = true; |
| break; |
| } |
| |
| d_start = end + 1; |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Returns true, if there are no holes in boot memory area, |
| * false otherwise. |
| */ |
| bool is_fadump_boot_mem_contiguous(void) |
| { |
| unsigned long d_start, d_end; |
| bool ret = false; |
| int i; |
| |
| for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { |
| d_start = fw_dump.boot_mem_addr[i]; |
| d_end = d_start + fw_dump.boot_mem_sz[i]; |
| |
| ret = is_fadump_mem_area_contiguous(d_start, d_end); |
| if (!ret) |
| break; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Returns true, if there are no holes in reserved memory area, |
| * false otherwise. |
| */ |
| bool is_fadump_reserved_mem_contiguous(void) |
| { |
| u64 d_start, d_end; |
| |
| d_start = fw_dump.reserve_dump_area_start; |
| d_end = d_start + fw_dump.reserve_dump_area_size; |
| return is_fadump_mem_area_contiguous(d_start, d_end); |
| } |
| |
| /* Print firmware assisted dump configurations for debugging purpose. */ |
| static void fadump_show_config(void) |
| { |
| int i; |
| |
| 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); |
| pr_debug(" Boot memory top : %llx\n", fw_dump.boot_mem_top); |
| pr_debug("Boot memory regions cnt: %llx\n", fw_dump.boot_mem_regs_cnt); |
| for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { |
| pr_debug("[%03d] base = %llx, size = %llx\n", i, |
| fw_dump.boot_mem_addr[i], fw_dump.boot_mem_sz[i]); |
| } |
| } |
| |
| /** |
| * 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 u64 fadump_calculate_reserve_size(void) |
| { |
| u64 base, size, bootmem_min; |
| int ret; |
| |
| if (fw_dump.reserve_bootvar) |
| pr_warn("'fadump_reserve_mem=' parameter is deprecated in favor of 'crashkernel=' parameter.\n"); |
| |
| /* |
| * Check if the size is specified through crashkernel= cmdline |
| * option. If yes, then use that but ignore base as fadump reserves |
| * memory at a predefined offset. |
| */ |
| ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(), |
| &size, &base); |
| if (ret == 0 && size > 0) { |
| unsigned long max_size; |
| |
| if (fw_dump.reserve_bootvar) |
| pr_info("Using 'crashkernel=' parameter for memory reservation.\n"); |
| |
| fw_dump.reserve_bootvar = (unsigned long)size; |
| |
| /* |
| * Adjust if the boot memory size specified is above |
| * the upper limit. |
| */ |
| max_size = memblock_phys_mem_size() / MAX_BOOT_MEM_RATIO; |
| if (fw_dump.reserve_bootvar > max_size) { |
| fw_dump.reserve_bootvar = max_size; |
| pr_info("Adjusted boot memory size to %luMB\n", |
| (fw_dump.reserve_bootvar >> 20)); |
| } |
| |
| return fw_dump.reserve_bootvar; |
| } else if (fw_dump.reserve_bootvar) { |
| /* |
| * 'fadump_reserve_mem=' is being used to reserve memory |
| * for firmware-assisted dump. |
| */ |
| return fw_dump.reserve_bootvar; |
| } |
| |
| /* divide by 20 to get 5% of value */ |
| size = memblock_phys_mem_size() / 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; |
| |
| bootmem_min = fw_dump.ops->fadump_get_bootmem_min(); |
| return (size > bootmem_min ? size : bootmem_min); |
| } |
| |
| /* |
| * 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); |
| |
| /* This is to hold kernel metadata on platforms that support it */ |
| size += (fw_dump.ops->fadump_get_metadata_size ? |
| fw_dump.ops->fadump_get_metadata_size() : 0); |
| return size; |
| } |
| |
| static int __init add_boot_mem_region(unsigned long rstart, |
| unsigned long rsize) |
| { |
| int i = fw_dump.boot_mem_regs_cnt++; |
| |
| if (fw_dump.boot_mem_regs_cnt > FADUMP_MAX_MEM_REGS) { |
| fw_dump.boot_mem_regs_cnt = FADUMP_MAX_MEM_REGS; |
| return 0; |
| } |
| |
| pr_debug("Added boot memory range[%d] [%#016lx-%#016lx)\n", |
| i, rstart, (rstart + rsize)); |
| fw_dump.boot_mem_addr[i] = rstart; |
| fw_dump.boot_mem_sz[i] = rsize; |
| return 1; |
| } |
| |
| /* |
| * Firmware usually has a hard limit on the data it can copy per region. |
| * Honour that by splitting a memory range into multiple regions. |
| */ |
| static int __init add_boot_mem_regions(unsigned long mstart, |
| unsigned long msize) |
| { |
| unsigned long rstart, rsize, max_size; |
| int ret = 1; |
| |
| rstart = mstart; |
| max_size = fw_dump.max_copy_size ? fw_dump.max_copy_size : msize; |
| while (msize) { |
| if (msize > max_size) |
| rsize = max_size; |
| else |
| rsize = msize; |
| |
| ret = add_boot_mem_region(rstart, rsize); |
| if (!ret) |
| break; |
| |
| msize -= rsize; |
| rstart += rsize; |
| } |
| |
| return ret; |
| } |
| |
| static int __init fadump_get_boot_mem_regions(void) |
| { |
| unsigned long base, size, cur_size, hole_size, last_end; |
| unsigned long mem_size = fw_dump.boot_memory_size; |
| struct memblock_region *reg; |
| int ret = 1; |
| |
| fw_dump.boot_mem_regs_cnt = 0; |
| |
| last_end = 0; |
| hole_size = 0; |
| cur_size = 0; |
| for_each_memblock(memory, reg) { |
| base = reg->base; |
| size = reg->size; |
| hole_size += (base - last_end); |
| |
| if ((cur_size + size) >= mem_size) { |
| size = (mem_size - cur_size); |
| ret = add_boot_mem_regions(base, size); |
| break; |
| } |
| |
| mem_size -= size; |
| cur_size += size; |
| ret = add_boot_mem_regions(base, size); |
| if (!ret) |
| break; |
| |
| last_end = base + size; |
| } |
| fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size); |
| |
| return ret; |
| } |
| |
| int __init fadump_reserve_mem(void) |
| { |
| u64 base, size, mem_boundary, bootmem_min, align = PAGE_SIZE; |
| bool is_memblock_bottom_up = memblock_bottom_up(); |
| int ret = 1; |
| |
| if (!fw_dump.fadump_enabled) |
| return 0; |
| |
| if (!fw_dump.fadump_supported) { |
| pr_info("Firmware-Assisted Dump is not supported on this hardware\n"); |
| goto error_out; |
| } |
| |
| /* |
| * Initialize boot memory size |
| * If dump is active then we have already calculated the size during |
| * first kernel. |
| */ |
| if (!fw_dump.dump_active) { |
| fw_dump.boot_memory_size = |
| PAGE_ALIGN(fadump_calculate_reserve_size()); |
| #ifdef CONFIG_CMA |
| if (!fw_dump.nocma) { |
| align = FADUMP_CMA_ALIGNMENT; |
| fw_dump.boot_memory_size = |
| ALIGN(fw_dump.boot_memory_size, align); |
| } |
| #endif |
| |
| bootmem_min = fw_dump.ops->fadump_get_bootmem_min(); |
| if (fw_dump.boot_memory_size < bootmem_min) { |
| pr_err("Can't enable fadump with boot memory size (0x%lx) less than 0x%llx\n", |
| fw_dump.boot_memory_size, bootmem_min); |
| goto error_out; |
| } |
| |
| if (!fadump_get_boot_mem_regions()) { |
| pr_err("Too many holes in boot memory area to enable fadump\n"); |
| goto error_out; |
| } |
| } |
| |
| /* |
| * 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", memory_limit); |
| } |
| if (memory_limit) |
| mem_boundary = memory_limit; |
| else |
| mem_boundary = memblock_end_of_DRAM(); |
| |
| base = fw_dump.boot_mem_top; |
| size = get_fadump_area_size(); |
| fw_dump.reserve_dump_area_size = size; |
| if (fw_dump.dump_active) { |
| pr_info("Firmware-assisted dump is active.\n"); |
| |
| #ifdef CONFIG_HUGETLB_PAGE |
| /* |
| * FADump capture kernel doesn't care much about hugepages. |
| * In fact, handling hugepages in capture kernel is asking for |
| * trouble. So, disable HugeTLB support when fadump is active. |
| */ |
| hugetlb_disabled = true; |
| #endif |
| /* |
| * 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 |
| * can be released for general use by invalidating fadump. |
| */ |
| fadump_reserve_crash_area(base); |
| |
| pr_debug("fadumphdr_addr = %#016lx\n", fw_dump.fadumphdr_addr); |
| pr_debug("Reserve dump area start address: 0x%lx\n", |
| fw_dump.reserve_dump_area_start); |
| } else { |
| /* |
| * Reserve memory at an offset closer to bottom of the RAM to |
| * minimize the impact of memory hot-remove operation. |
| */ |
| memblock_set_bottom_up(true); |
| base = memblock_find_in_range(base, mem_boundary, size, align); |
| |
| /* Restore the previous allocation mode */ |
| memblock_set_bottom_up(is_memblock_bottom_up); |
| |
| if (!base) { |
| pr_err("Failed to find memory chunk for reservation!\n"); |
| goto error_out; |
| } |
| fw_dump.reserve_dump_area_start = base; |
| |
| /* |
| * Calculate the kernel metadata address and register it with |
| * f/w if the platform supports. |
| */ |
| if (fw_dump.ops->fadump_setup_metadata && |
| (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)) |
| goto error_out; |
| |
| if (memblock_reserve(base, size)) { |
| pr_err("Failed to reserve memory!\n"); |
| goto error_out; |
| } |
| |
| pr_info("Reserved %lldMB of memory at %#016llx (System RAM: %lldMB)\n", |
| (size >> 20), base, (memblock_phys_mem_size() >> 20)); |
| |
| ret = fadump_cma_init(); |
| } |
| |
| return ret; |
| error_out: |
| fw_dump.fadump_enabled = 0; |
| return 0; |
| } |
| |
| /* 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; |
| else if (strncmp(p, "nocma", 5) == 0) { |
| fw_dump.fadump_enabled = 1; |
| fw_dump.nocma = 1; |
| } |
| |
| return 0; |
| } |
| early_param("fadump", early_fadump_param); |
| |
| /* |
| * Look for fadump_reserve_mem= cmdline option |
| * TODO: Remove references to 'fadump_reserve_mem=' parameter, |
| * the sooner 'crashkernel=' parameter is accustomed to. |
| */ |
| 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); |
| |
| void crash_fadump(struct pt_regs *regs, const char *str) |
| { |
| struct fadump_crash_info_header *fdh = NULL; |
| int old_cpu, this_cpu; |
| |
| if (!should_fadump_crash()) |
| return; |
| |
| /* |
| * old_cpu == -1 means this is the first CPU which has come here, |
| * go ahead and trigger fadump. |
| * |
| * old_cpu != -1 means some other CPU has already on it's way |
| * to trigger fadump, just keep looping here. |
| */ |
| this_cpu = smp_processor_id(); |
| old_cpu = cmpxchg(&crashing_cpu, -1, this_cpu); |
| |
| if (old_cpu != -1) { |
| /* |
| * We can't loop here indefinitely. Wait as long as fadump |
| * is in force. If we race with fadump un-registration this |
| * loop will break and then we go down to normal panic path |
| * and reboot. If fadump is in force the first crashing |
| * cpu will definitely trigger fadump. |
| */ |
| while (fw_dump.dump_registered) |
| cpu_relax(); |
| return; |
| } |
| |
| fdh = __va(fw_dump.fadumphdr_addr); |
| fdh->crashing_cpu = crashing_cpu; |
| crash_save_vmcoreinfo(); |
| |
| if (regs) |
| fdh->regs = *regs; |
| else |
| ppc_save_regs(&fdh->regs); |
| |
| fdh->online_mask = *cpu_online_mask; |
| |
| fw_dump.ops->fadump_trigger(fdh, str); |
| } |
| |
| 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 = append_elf_note(buf, CRASH_CORE_NOTE_NAME, NT_PRSTATUS, |
| &prstatus, sizeof(prstatus)); |
| return buf; |
| } |
| |
| 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 = __pa(fw_dump.cpu_notes_buf_vaddr); |
| 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_alloc_buffer(unsigned long size) |
| { |
| unsigned long count, i; |
| struct page *page; |
| void *vaddr; |
| |
| vaddr = alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); |
| if (!vaddr) |
| return NULL; |
| |
| count = PAGE_ALIGN(size) / PAGE_SIZE; |
| page = virt_to_page(vaddr); |
| for (i = 0; i < count; i++) |
| mark_page_reserved(page + i); |
| return vaddr; |
| } |
| |
| static void fadump_free_buffer(unsigned long vaddr, unsigned long size) |
| { |
| free_reserved_area((void *)vaddr, (void *)(vaddr + size), -1, NULL); |
| } |
| |
| s32 fadump_setup_cpu_notes_buf(u32 num_cpus) |
| { |
| /* 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); |
| fw_dump.cpu_notes_buf_vaddr = |
| (unsigned long)fadump_alloc_buffer(fw_dump.cpu_notes_buf_size); |
| if (!fw_dump.cpu_notes_buf_vaddr) { |
| pr_err("Failed to allocate %ld bytes for CPU notes buffer\n", |
| fw_dump.cpu_notes_buf_size); |
| return -ENOMEM; |
| } |
| |
| pr_debug("Allocated buffer for cpu notes of size %ld at 0x%lx\n", |
| fw_dump.cpu_notes_buf_size, |
| fw_dump.cpu_notes_buf_vaddr); |
| return 0; |
| } |
| |
| void fadump_free_cpu_notes_buf(void) |
| { |
| if (!fw_dump.cpu_notes_buf_vaddr) |
| return; |
| |
| fadump_free_buffer(fw_dump.cpu_notes_buf_vaddr, |
| fw_dump.cpu_notes_buf_size); |
| fw_dump.cpu_notes_buf_vaddr = 0; |
| fw_dump.cpu_notes_buf_size = 0; |
| } |
| |
| static void fadump_free_mem_ranges(struct fadump_mrange_info *mrange_info) |
| { |
| kfree(mrange_info->mem_ranges); |
| mrange_info->mem_ranges = NULL; |
| mrange_info->mem_ranges_sz = 0; |
| mrange_info->max_mem_ranges = 0; |
| } |
| |
| /* |
| * Allocate or reallocate mem_ranges array in incremental units |
| * of PAGE_SIZE. |
| */ |
| static int fadump_alloc_mem_ranges(struct fadump_mrange_info *mrange_info) |
| { |
| struct fadump_memory_range *new_array; |
| u64 new_size; |
| |
| new_size = mrange_info->mem_ranges_sz + PAGE_SIZE; |
| pr_debug("Allocating %llu bytes of memory for %s memory ranges\n", |
| new_size, mrange_info->name); |
| |
| new_array = krealloc(mrange_info->mem_ranges, new_size, GFP_KERNEL); |
| if (new_array == NULL) { |
| pr_err("Insufficient memory for setting up %s memory ranges\n", |
| mrange_info->name); |
| fadump_free_mem_ranges(mrange_info); |
| return -ENOMEM; |
| } |
| |
| mrange_info->mem_ranges = new_array; |
| mrange_info->mem_ranges_sz = new_size; |
| mrange_info->max_mem_ranges = (new_size / |
| sizeof(struct fadump_memory_range)); |
| return 0; |
| } |
| |
| static inline int fadump_add_mem_range(struct fadump_mrange_info *mrange_info, |
| u64 base, u64 end) |
| { |
| struct fadump_memory_range *mem_ranges = mrange_info->mem_ranges; |
| bool is_adjacent = false; |
| u64 start, size; |
| |
| if (base == end) |
| return 0; |
| |
| /* |
| * Fold adjacent memory ranges to bring down the memory ranges/ |
| * PT_LOAD segments count. |
| */ |
| if (mrange_info->mem_range_cnt) { |
| start = mem_ranges[mrange_info->mem_range_cnt - 1].base; |
| size = mem_ranges[mrange_info->mem_range_cnt - 1].size; |
| |
| if ((start + size) == base) |
| is_adjacent = true; |
| } |
| if (!is_adjacent) { |
| /* resize the array on reaching the limit */ |
| if (mrange_info->mem_range_cnt == mrange_info->max_mem_ranges) { |
| int ret; |
| |
| ret = fadump_alloc_mem_ranges(mrange_info); |
| if (ret) |
| return ret; |
| |
| /* Update to the new resized array */ |
| mem_ranges = mrange_info->mem_ranges; |
| } |
| |
| start = base; |
| mem_ranges[mrange_info->mem_range_cnt].base = start; |
| mrange_info->mem_range_cnt++; |
| } |
| |
| mem_ranges[mrange_info->mem_range_cnt - 1].size = (end - start); |
| pr_debug("%s_memory_range[%d] [%#016llx-%#016llx], %#llx bytes\n", |
| mrange_info->name, (mrange_info->mem_range_cnt - 1), |
| start, end - 1, (end - start)); |
| return 0; |
| } |
| |
| static int fadump_exclude_reserved_area(u64 start, u64 end) |
| { |
| u64 ra_start, ra_end; |
| int ret = 0; |
| |
| 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)) { |
| ret = fadump_add_mem_range(&crash_mrange_info, |
| start, ra_start); |
| if (ret) |
| return ret; |
| |
| ret = fadump_add_mem_range(&crash_mrange_info, |
| ra_end, end); |
| } else if (start < ra_start) { |
| ret = fadump_add_mem_range(&crash_mrange_info, |
| start, ra_start); |
| } else if (ra_end < end) { |
| ret = fadump_add_mem_range(&crash_mrange_info, |
| ra_end, end); |
| } |
| } else |
| ret = fadump_add_mem_range(&crash_mrange_info, start, end); |
| |
| return ret; |
| } |
| |
| 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; |
| #if defined(_CALL_ELF) |
| elf->e_flags = _CALL_ELF; |
| #else |
| elf->e_flags = 0; |
| #endif |
| 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 int fadump_setup_crash_memory_ranges(void) |
| { |
| struct memblock_region *reg; |
| u64 start, end; |
| int i, ret; |
| |
| pr_debug("Setup crash memory ranges.\n"); |
| crash_mrange_info.mem_range_cnt = 0; |
| |
| /* |
| * Boot memory region(s) registered with firmware are moved to |
| * different location at the time of crash. Create separate program |
| * header(s) for this memory chunk(s) with the correct offset. |
| */ |
| for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { |
| start = fw_dump.boot_mem_addr[i]; |
| end = start + fw_dump.boot_mem_sz[i]; |
| ret = fadump_add_mem_range(&crash_mrange_info, start, end); |
| if (ret) |
| return ret; |
| } |
| |
| for_each_memblock(memory, reg) { |
| start = (u64)reg->base; |
| end = start + (u64)reg->size; |
| |
| /* |
| * skip the memory chunk that is already added |
| * (0 through boot_memory_top). |
| */ |
| if (start < fw_dump.boot_mem_top) { |
| if (end > fw_dump.boot_mem_top) |
| start = fw_dump.boot_mem_top; |
| else |
| continue; |
| } |
| |
| /* add this range excluding the reserved dump area. */ |
| ret = fadump_exclude_reserved_area(start, end); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * 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) |
| { |
| unsigned long raddr, rstart, rend, rlast, hole_size; |
| int i; |
| |
| hole_size = 0; |
| rlast = 0; |
| raddr = paddr; |
| for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { |
| rstart = fw_dump.boot_mem_addr[i]; |
| rend = rstart + fw_dump.boot_mem_sz[i]; |
| hole_size += (rstart - rlast); |
| |
| if (paddr >= rstart && paddr < rend) { |
| raddr += fw_dump.boot_mem_dest_addr - hole_size; |
| break; |
| } |
| |
| rlast = rend; |
| } |
| |
| pr_debug("vmcoreinfo: paddr = 0x%lx, raddr = 0x%lx\n", paddr, raddr); |
| return raddr; |
| } |
| |
| static int fadump_create_elfcore_headers(char *bufp) |
| { |
| unsigned long long raddr, offset; |
| struct elf_phdr *phdr; |
| struct elfhdr *elf; |
| int i, j; |
| |
| 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 = phdr->p_filesz = VMCOREINFO_NOTE_SIZE; |
| |
| /* Increment number of program headers. */ |
| (elf->e_phnum)++; |
| |
| /* setup PT_LOAD sections. */ |
| j = 0; |
| offset = 0; |
| raddr = fw_dump.boot_mem_addr[0]; |
| for (i = 0; i < crash_mrange_info.mem_range_cnt; i++) { |
| u64 mbase, msize; |
| |
| mbase = crash_mrange_info.mem_ranges[i].base; |
| msize = crash_mrange_info.mem_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 == raddr) { |
| /* |
| * The entire real memory region will be moved by |
| * firmware to the specified destination_address. |
| * Hence set the correct offset. |
| */ |
| phdr->p_offset = fw_dump.boot_mem_dest_addr + offset; |
| if (j < (fw_dump.boot_mem_regs_cnt - 1)) { |
| offset += fw_dump.boot_mem_sz[j]; |
| raddr = fw_dump.boot_mem_addr[++j]; |
| } |
| } |
| |
| 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; |
| |
| 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 = FADUMP_CPU_UNKNOWN; |
| |
| return addr; |
| } |
| |
| static int register_fadump(void) |
| { |
| unsigned long addr; |
| void *vaddr; |
| int ret; |
| |
| /* |
| * If no memory is reserved then we can not register for firmware- |
| * assisted dump. |
| */ |
| if (!fw_dump.reserve_dump_area_size) |
| return -ENODEV; |
| |
| ret = fadump_setup_crash_memory_ranges(); |
| if (ret) |
| return ret; |
| |
| addr = fw_dump.fadumphdr_addr; |
| |
| /* 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. */ |
| pr_debug("Registering for firmware-assisted kernel dump...\n"); |
| return fw_dump.ops->fadump_register(&fw_dump); |
| } |
| |
| void fadump_cleanup(void) |
| { |
| if (!fw_dump.fadump_supported) |
| return; |
| |
| /* Invalidate the registration only if dump is active. */ |
| if (fw_dump.dump_active) { |
| pr_debug("Invalidating firmware-assisted dump registration\n"); |
| fw_dump.ops->fadump_invalidate(&fw_dump); |
| } else if (fw_dump.dump_registered) { |
| /* Un-register Firmware-assisted dump if it was registered. */ |
| fw_dump.ops->fadump_unregister(&fw_dump); |
| fadump_free_mem_ranges(&crash_mrange_info); |
| } |
| |
| if (fw_dump.ops->fadump_cleanup) |
| fw_dump.ops->fadump_cleanup(&fw_dump); |
| } |
| |
| static void fadump_free_reserved_memory(unsigned long start_pfn, |
| unsigned long end_pfn) |
| { |
| unsigned long pfn; |
| unsigned long time_limit = jiffies + HZ; |
| |
| pr_info("freeing reserved memory (0x%llx - 0x%llx)\n", |
| PFN_PHYS(start_pfn), PFN_PHYS(end_pfn)); |
| |
| for (pfn = start_pfn; pfn < end_pfn; pfn++) { |
| free_reserved_page(pfn_to_page(pfn)); |
| |
| if (time_after(jiffies, time_limit)) { |
| cond_resched(); |
| time_limit = jiffies + HZ; |
| } |
| } |
| } |
| |
| /* |
| * Skip memory holes and free memory that was actually reserved. |
| */ |
| static void fadump_release_reserved_area(u64 start, u64 end) |
| { |
| u64 tstart, tend, spfn, epfn; |
| struct memblock_region *reg; |
| |
| spfn = PHYS_PFN(start); |
| epfn = PHYS_PFN(end); |
| for_each_memblock(memory, reg) { |
| tstart = max_t(u64, spfn, memblock_region_memory_base_pfn(reg)); |
| tend = min_t(u64, epfn, memblock_region_memory_end_pfn(reg)); |
| if (tstart < tend) { |
| fadump_free_reserved_memory(tstart, tend); |
| |
| if (tend == epfn) |
| break; |
| |
| spfn = tend; |
| } |
| } |
| } |
| |
| /* |
| * Sort the mem ranges in-place and merge adjacent ranges |
| * to minimize the memory ranges count. |
| */ |
| static void sort_and_merge_mem_ranges(struct fadump_mrange_info *mrange_info) |
| { |
| struct fadump_memory_range *mem_ranges; |
| struct fadump_memory_range tmp_range; |
| u64 base, size; |
| int i, j, idx; |
| |
| if (!reserved_mrange_info.mem_range_cnt) |
| return; |
| |
| /* Sort the memory ranges */ |
| mem_ranges = mrange_info->mem_ranges; |
| for (i = 0; i < mrange_info->mem_range_cnt; i++) { |
| idx = i; |
| for (j = (i + 1); j < mrange_info->mem_range_cnt; j++) { |
| if (mem_ranges[idx].base > mem_ranges[j].base) |
| idx = j; |
| } |
| if (idx != i) { |
| tmp_range = mem_ranges[idx]; |
| mem_ranges[idx] = mem_ranges[i]; |
| mem_ranges[i] = tmp_range; |
| } |
| } |
| |
| /* Merge adjacent reserved ranges */ |
| idx = 0; |
| for (i = 1; i < mrange_info->mem_range_cnt; i++) { |
| base = mem_ranges[i-1].base; |
| size = mem_ranges[i-1].size; |
| if (mem_ranges[i].base == (base + size)) |
| mem_ranges[idx].size += mem_ranges[i].size; |
| else { |
| idx++; |
| if (i == idx) |
| continue; |
| |
| mem_ranges[idx] = mem_ranges[i]; |
| } |
| } |
| mrange_info->mem_range_cnt = idx + 1; |
| } |
| |
| /* |
| * Scan reserved-ranges to consider them while reserving/releasing |
| * memory for FADump. |
| */ |
| static inline int fadump_scan_reserved_mem_ranges(void) |
| { |
| struct device_node *root; |
| const __be32 *prop; |
| int len, ret = -1; |
| unsigned long i; |
| |
| root = of_find_node_by_path("/"); |
| if (!root) |
| return ret; |
| |
| prop = of_get_property(root, "reserved-ranges", &len); |
| if (!prop) |
| return ret; |
| |
| /* |
| * Each reserved range is an (address,size) pair, 2 cells each, |
| * totalling 4 cells per range. |
| */ |
| for (i = 0; i < len / (sizeof(*prop) * 4); i++) { |
| u64 base, size; |
| |
| base = of_read_number(prop + (i * 4) + 0, 2); |
| size = of_read_number(prop + (i * 4) + 2, 2); |
| |
| if (size) { |
| ret = fadump_add_mem_range(&reserved_mrange_info, |
| base, base + size); |
| if (ret < 0) { |
| pr_warn("some reserved ranges are ignored!\n"); |
| break; |
| } |
| } |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Release the memory that was reserved during early boot to preserve the |
| * crash'ed kernel's memory contents except reserved dump area (permanent |
| * reservation) and reserved ranges used by F/W. The released memory will |
| * be available for general use. |
| */ |
| static void fadump_release_memory(u64 begin, u64 end) |
| { |
| u64 ra_start, ra_end, tstart; |
| int i, ret; |
| |
| fadump_scan_reserved_mem_ranges(); |
| |
| ra_start = fw_dump.reserve_dump_area_start; |
| ra_end = ra_start + fw_dump.reserve_dump_area_size; |
| |
| /* |
| * Add reserved dump area to reserved ranges list |
| * and exclude all these ranges while releasing memory. |
| */ |
| ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end); |
| if (ret != 0) { |
| /* |
| * Not enough memory to setup reserved ranges but the system is |
| * running shortage of memory. So, release all the memory except |
| * Reserved dump area (reused for next fadump registration). |
| */ |
| if (begin < ra_end && end > ra_start) { |
| if (begin < ra_start) |
| fadump_release_reserved_area(begin, ra_start); |
| if (end > ra_end) |
| fadump_release_reserved_area(ra_end, end); |
| } else |
| fadump_release_reserved_area(begin, end); |
| |
| return; |
| } |
| |
| /* Get the reserved ranges list in order first. */ |
| sort_and_merge_mem_ranges(&reserved_mrange_info); |
| |
| /* Exclude reserved ranges and release remaining memory */ |
| tstart = begin; |
| for (i = 0; i < reserved_mrange_info.mem_range_cnt; i++) { |
| ra_start = reserved_mrange_info.mem_ranges[i].base; |
| ra_end = ra_start + reserved_mrange_info.mem_ranges[i].size; |
| |
| if (tstart >= ra_end) |
| continue; |
| |
| if (tstart < ra_start) |
| fadump_release_reserved_area(tstart, ra_start); |
| tstart = ra_end; |
| } |
| |
| if (tstart < end) |
| fadump_release_reserved_area(tstart, end); |
| } |
| |
| static void fadump_invalidate_release_mem(void) |
| { |
| mutex_lock(&fadump_mutex); |
| if (!fw_dump.dump_active) { |
| mutex_unlock(&fadump_mutex); |
| return; |
| } |
| |
| fadump_cleanup(); |
| mutex_unlock(&fadump_mutex); |
| |
| fadump_release_memory(fw_dump.boot_mem_top, memblock_end_of_DRAM()); |
| fadump_free_cpu_notes_buf(); |
| |
| /* |
| * Setup kernel metadata and initialize the kernel dump |
| * memory structure for FADump re-registration. |
| */ |
| if (fw_dump.ops->fadump_setup_metadata && |
| (fw_dump.ops->fadump_setup_metadata(&fw_dump) < 0)) |
| pr_warn("Failed to setup kernel metadata!\n"); |
| fw_dump.ops->fadump_init_mem_struct(&fw_dump); |
| } |
| |
| static ssize_t fadump_release_memory_store(struct kobject *kobj, |
| struct kobj_attribute *attr, |
| const char *buf, size_t count) |
| { |
| int input = -1; |
| |
| if (!fw_dump.dump_active) |
| return -EPERM; |
| |
| if (kstrtoint(buf, 0, &input)) |
| return -EINVAL; |
| |
| if (input == 1) { |
| /* |
| * Take away the '/proc/vmcore'. We are releasing the dump |
| * memory, hence it will not be valid anymore. |
| */ |
| #ifdef CONFIG_PROC_VMCORE |
| vmcore_cleanup(); |
| #endif |
| 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; |
| int input = -1; |
| |
| if (!fw_dump.fadump_enabled || fw_dump.dump_active) |
| return -EPERM; |
| |
| if (kstrtoint(buf, 0, &input)) |
| return -EINVAL; |
| |
| mutex_lock(&fadump_mutex); |
| |
| switch (input) { |
| case 0: |
| if (fw_dump.dump_registered == 0) { |
| goto unlock_out; |
| } |
| |
| /* Un-register Firmware-assisted dump */ |
| pr_debug("Un-register firmware-assisted dump\n"); |
| fw_dump.ops->fadump_unregister(&fw_dump); |
| break; |
| case 1: |
| if (fw_dump.dump_registered == 1) { |
| /* Un-register Firmware-assisted dump */ |
| fw_dump.ops->fadump_unregister(&fw_dump); |
| } |
| /* Register Firmware-assisted dump */ |
| ret = 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) |
| { |
| if (!fw_dump.fadump_enabled) |
| return 0; |
| |
| mutex_lock(&fadump_mutex); |
| fw_dump.ops->fadump_region_show(&fw_dump, m); |
| 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); |
| |
| DEFINE_SHOW_ATTRIBUTE(fadump_region); |
| |
| 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 (fw_dump.ops->fadump_process(&fw_dump) < 0) |
| fadump_invalidate_release_mem(); |
| } |
| /* Initialize the kernel dump memory structure for FAD registration. */ |
| else if (fw_dump.reserve_dump_area_size) |
| fw_dump.ops->fadump_init_mem_struct(&fw_dump); |
| |
| fadump_init_files(); |
| |
| return 1; |
| } |
| subsys_initcall(setup_fadump); |
| #else /* !CONFIG_PRESERVE_FA_DUMP */ |
| |
| /* 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) |
| { |
| if ((depth != 1) || (strcmp(uname, "ibm,opal") != 0)) |
| return 0; |
| |
| opal_fadump_dt_scan(&fw_dump, node); |
| return 1; |
| } |
| |
| /* |
| * When dump is active but PRESERVE_FA_DUMP is enabled on the kernel, |
| * preserve crash data. The subsequent memory preserving kernel boot |
| * is likely to process this crash data. |
| */ |
| int __init fadump_reserve_mem(void) |
| { |
| if (fw_dump.dump_active) { |
| /* |
| * If last boot has crashed then reserve all the memory |
| * above boot memory to preserve crash data. |
| */ |
| pr_info("Preserving crash data for processing in next boot.\n"); |
| fadump_reserve_crash_area(fw_dump.boot_mem_top); |
| } else |
| pr_debug("FADump-aware kernel..\n"); |
| |
| return 1; |
| } |
| #endif /* CONFIG_PRESERVE_FA_DUMP */ |
| |
| /* Preserve everything above the base address */ |
| static void __init fadump_reserve_crash_area(u64 base) |
| { |
| struct memblock_region *reg; |
| u64 mstart, msize; |
| |
| for_each_memblock(memory, reg) { |
| mstart = reg->base; |
| msize = reg->size; |
| |
| if ((mstart + msize) < base) |
| continue; |
| |
| if (mstart < base) { |
| msize -= (base - mstart); |
| mstart = base; |
| } |
| |
| pr_info("Reserving %lluMB of memory at %#016llx for preserving crash data", |
| (msize >> 20), mstart); |
| memblock_reserve(mstart, msize); |
| } |
| } |
| |
| unsigned long __init arch_reserved_kernel_pages(void) |
| { |
| return memblock_reserved_size() / PAGE_SIZE; |
| } |