diff options
Diffstat (limited to 'arch/powerpc/kernel/fadump.c')
| -rw-r--r-- | arch/powerpc/kernel/fadump.c | 1878 |
1 files changed, 1878 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c new file mode 100644 index 000000000..7f79c9aea --- /dev/null +++ b/arch/powerpc/kernel/fadump.c @@ -0,0 +1,1878 @@ +// 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 <linux/debugfs.h> +#include <linux/of.h> +#include <linux/of_fdt.h> + +#include <asm/page.h> +#include <asm/fadump.h> +#include <asm/fadump-internal.h> +#include <asm/setup.h> +#include <asm/interrupt.h> +#include <asm/prom.h> + +/* + * The CPU who acquired the lock to trigger the fadump crash should + * wait for other CPUs to enter. + * + * The timeout is in milliseconds. + */ +#define CRASH_TIMEOUT 500 + +static struct fw_dump fw_dump; + +static void __init fadump_reserve_crash_area(u64 base); + +#ifndef CONFIG_PRESERVE_FA_DUMP + +static struct kobject *fadump_kobj; + +static atomic_t cpus_in_fadump; +static DEFINE_MUTEX(fadump_mutex); + +#define RESERVED_RNGS_SZ 16384 /* 16K - 128 entries */ +#define RESERVED_RNGS_CNT (RESERVED_RNGS_SZ / \ + sizeof(struct fadump_memory_range)) +static struct fadump_memory_range rngs[RESERVED_RNGS_CNT]; +static struct fadump_mrange_info +reserved_mrange_info = { "reserved", rngs, RESERVED_RNGS_SZ, 0, RESERVED_RNGS_CNT, true }; + +static void __init early_init_dt_scan_reserved_ranges(unsigned long node); + +#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 remaining portion of fadump reserved memory will be not given + * to CMA and pages for those 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. + */ +void __init fadump_cma_init(void) +{ + unsigned long long base, size, end; + int rc; + + if (!fw_dump.fadump_supported || !fw_dump.fadump_enabled || + fw_dump.dump_active) + return; + /* + * Do not use CMA if user has provided fadump=nocma kernel parameter. + */ + if (fw_dump.nocma || !fw_dump.boot_memory_size) + return; + + /* + * [base, end) should be reserved during early init in + * fadump_reserve_mem(). No need to check this here as + * cma_init_reserved_mem() already checks for overlap. + * Here we give the aligned chunk of this reserved memory to CMA. + */ + base = fw_dump.reserve_dump_area_start; + size = fw_dump.boot_memory_size; + end = base + size; + + base = ALIGN(base, CMA_MIN_ALIGNMENT_BYTES); + end = ALIGN_DOWN(end, CMA_MIN_ALIGNMENT_BYTES); + size = end - base; + + if (end <= base) { + pr_warn("%s: Too less memory to give to CMA\n", __func__); + return; + } + + 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; + } + + /* + * If CMA activation fails, keep the pages reserved, instead of + * exposing them to buddy allocator. Same as 'fadump=nocma' case. + */ + cma_reserve_pages_on_error(fadump_cma); + + /* + * So we now have successfully initialized cma area for fadump. + */ + pr_info("Initialized [0x%llx, %luMB] cma area from [0x%lx, %luMB] " + "bytes of memory reserved for firmware-assisted dump\n", + cma_get_base(fadump_cma), cma_get_size(fadump_cma) >> 20, + fw_dump.reserve_dump_area_start, + fw_dump.boot_memory_size >> 20); + return; +} +#endif /* CONFIG_CMA */ + +/* + * Additional parameters meant for capture kernel are placed in a dedicated area. + * If this is capture kernel boot, append these parameters to bootargs. + */ +void __init fadump_append_bootargs(void) +{ + char *append_args; + size_t len; + + if (!fw_dump.dump_active || !fw_dump.param_area_supported || !fw_dump.param_area) + return; + + if (fw_dump.param_area < fw_dump.boot_mem_top) { + if (memblock_reserve(fw_dump.param_area, COMMAND_LINE_SIZE)) { + pr_warn("WARNING: Can't use additional parameters area!\n"); + fw_dump.param_area = 0; + return; + } + } + + append_args = (char *)fw_dump.param_area; + len = strlen(boot_command_line); + + /* + * Too late to fail even if cmdline size exceeds. Truncate additional parameters + * to cmdline size and proceed anyway. + */ + if (len + strlen(append_args) >= COMMAND_LINE_SIZE - 1) + pr_warn("WARNING: Appending parameters exceeds cmdline size. Truncating!\n"); + + pr_debug("Cmdline: %s\n", boot_command_line); + snprintf(boot_command_line + len, COMMAND_LINE_SIZE - len, " %s", append_args); + pr_info("Updated cmdline: %s\n", boot_command_line); +} + +/* 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 == 0) { + early_init_dt_scan_reserved_ranges(node); + return 0; + } + + 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) +{ + phys_addr_t reg_start, reg_end; + bool ret = false; + u64 i, start, end; + + for_each_mem_range(i, ®_start, ®_end) { + start = max_t(u64, d_start, reg_start); + end = min_t(u64, d_end, reg_end); + 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 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 __init 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", str_yes_no(fw_dump.fadump_enabled)); + pr_debug("Dump Active : %s\n", str_yes_no(fw_dump.dump_active)); + 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 __init 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, NULL, NULL, NULL); + 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 __init get_fadump_area_size(void) +{ + unsigned long size = 0; + + size += fw_dump.cpu_state_data_size; + size += fw_dump.hpte_region_size; + /* + * Account for pagesize alignment of boot memory area destination address. + * This faciliates in mmap reading of first kernel's memory. + */ + size = PAGE_ALIGN(size); + size += fw_dump.boot_memory_size; + size += sizeof(struct fadump_crash_info_header); + + /* 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 max_boot_mem_rgns = fw_dump.ops->fadump_max_boot_mem_rgns(); + int i = fw_dump.boot_mem_regs_cnt++; + + if (fw_dump.boot_mem_regs_cnt > max_boot_mem_rgns) { + fw_dump.boot_mem_regs_cnt = max_boot_mem_rgns; + 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 size, cur_size, hole_size, last_end; + unsigned long mem_size = fw_dump.boot_memory_size; + phys_addr_t reg_start, reg_end; + int ret = 1; + u64 i; + + fw_dump.boot_mem_regs_cnt = 0; + + last_end = 0; + hole_size = 0; + cur_size = 0; + for_each_mem_range(i, ®_start, ®_end) { + size = reg_end - reg_start; + hole_size += (reg_start - last_end); + + if ((cur_size + size) >= mem_size) { + size = (mem_size - cur_size); + ret = add_boot_mem_regions(reg_start, size); + break; + } + + mem_size -= size; + cur_size += size; + ret = add_boot_mem_regions(reg_start, size); + if (!ret) + break; + + last_end = reg_end; + } + fw_dump.boot_mem_top = PAGE_ALIGN(fw_dump.boot_memory_size + hole_size); + + return ret; +} + +/* + * Returns true, if the given range overlaps with reserved memory ranges + * starting at idx. Also, updates idx to index of overlapping memory range + * with the given memory range. + * False, otherwise. + */ +static bool __init overlaps_reserved_ranges(u64 base, u64 end, int *idx) +{ + bool ret = false; + int i; + + for (i = *idx; i < reserved_mrange_info.mem_range_cnt; i++) { + u64 rbase = reserved_mrange_info.mem_ranges[i].base; + u64 rend = rbase + reserved_mrange_info.mem_ranges[i].size; + + if (end <= rbase) + break; + + if ((end > rbase) && (base < rend)) { + *idx = i; + ret = true; + break; + } + } + + return ret; +} + +/* + * Locate a suitable memory area to reserve memory for FADump. While at it, + * lookup reserved-ranges & avoid overlap with them, as they are used by F/W. + */ +static u64 __init fadump_locate_reserve_mem(u64 base, u64 size) +{ + struct fadump_memory_range *mrngs; + phys_addr_t mstart, mend; + int idx = 0; + u64 i, ret = 0; + + mrngs = reserved_mrange_info.mem_ranges; + for_each_free_mem_range(i, NUMA_NO_NODE, MEMBLOCK_NONE, + &mstart, &mend, NULL) { + pr_debug("%llu) mstart: %llx, mend: %llx, base: %llx\n", + i, mstart, mend, base); + + if (mstart > base) + base = PAGE_ALIGN(mstart); + + while ((mend > base) && ((mend - base) >= size)) { + if (!overlaps_reserved_ranges(base, base+size, &idx)) { + ret = base; + goto out; + } + + base = mrngs[idx].base + mrngs[idx].size; + base = PAGE_ALIGN(base); + } + } + +out: + return ret; +} + +int __init fadump_reserve_mem(void) +{ + u64 base, size, mem_boundary, bootmem_min; + 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()); + + 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; + } + } + + 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. + */ + base = fadump_locate_reserve_mem(base, size); + + if (!base || (base + size > mem_boundary)) { + 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)); + } + + return ret; +error_out: + fw_dump.fadump_enabled = 0; + fw_dump.reserve_dump_area_size = 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) +{ + unsigned int msecs; + struct fadump_crash_info_header *fdh = NULL; + int old_cpu, this_cpu; + /* Do not include first CPU */ + unsigned int ncpus = num_online_cpus() - 1; + + 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 its 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) { + atomic_inc(&cpus_in_fadump); + + /* + * 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->cpu_mask = *cpu_online_mask; + + /* + * If we came in via system reset, wait a while for the secondary + * CPUs to enter. + */ + if (TRAP(&(fdh->regs)) == INTERRUPT_SYSTEM_RESET) { + msecs = CRASH_TIMEOUT; + while ((atomic_read(&cpus_in_fadump) < ncpus) && (--msecs > 0)) + mdelay(1); + } + + fw_dump.ops->fadump_trigger(fdh, str); +} + +u32 *__init 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_regs(&prstatus.pr_reg, regs); + buf = append_elf_note(buf, NN_PRSTATUS, NT_PRSTATUS, + &prstatus, sizeof(prstatus)); + return buf; +} + +void __init fadump_update_elfcore_header(char *bufp) +{ + struct elf_phdr *phdr; + + 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 *__init fadump_alloc_buffer(unsigned long size) +{ + return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO); +} + +static void fadump_free_buffer(unsigned long vaddr, unsigned long size) +{ + free_pages_exact((void *)vaddr, size); +} + +s32 __init 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) +{ + if (mrange_info->is_static) { + mrange_info->mem_range_cnt = 0; + return; + } + + kfree(mrange_info->mem_ranges); + memset((void *)((u64)mrange_info + RNG_NAME_SZ), 0, + (sizeof(struct fadump_mrange_info) - RNG_NAME_SZ)); +} + +/* + * 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; + + /* + * Boot memory area needs separate PT_LOAD segment(s) as it + * is moved to a different location at the time of crash. + * So, fold only if the region is not boot memory area. + */ + if ((start + size) == base && start >= fw_dump.boot_mem_top) + 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; + + if (mrange_info->is_static) { + pr_err("Reached array size limit for %s memory ranges\n", + mrange_info->name); + return -ENOSPC; + } + + 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_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 (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2)) + elf->e_flags = 2; + else if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V1)) + elf->e_flags = 1; + else + elf->e_flags = 0; + + 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; +} + +/* + * 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 void __init populate_elf_pt_load(struct elf_phdr *phdr, u64 start, + u64 size, unsigned long long offset) +{ + phdr->p_align = 0; + phdr->p_memsz = size; + phdr->p_filesz = size; + phdr->p_paddr = start; + phdr->p_offset = offset; + phdr->p_type = PT_LOAD; + phdr->p_flags = PF_R|PF_W|PF_X; + phdr->p_vaddr = (unsigned long)__va(start); +} + +static void __init fadump_populate_elfcorehdr(struct fadump_crash_info_header *fdh) +{ + char *bufp; + struct elfhdr *elf; + struct elf_phdr *phdr; + u64 boot_mem_dest_offset; + unsigned long long i, ra_start, ra_end, ra_size, mstart, mend; + + bufp = (char *) fw_dump.elfcorehdr_addr; + fadump_init_elfcore_header(bufp); + elf = (struct elfhdr *)bufp; + bufp += sizeof(struct elfhdr); + + /* + * Set up ELF PT_NOTE, a placeholder for CPU notes information. + * The notes info will be populated later by platform-specific code. + * 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; + /* Increment number of program headers. */ + (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 = phdr->p_offset = fdh->vmcoreinfo_raddr; + phdr->p_memsz = phdr->p_filesz = fdh->vmcoreinfo_size; + /* Increment number of program headers. */ + (elf->e_phnum)++; + + /* + * Setup PT_LOAD sections. first include boot memory regions + * and then add rest of the memory regions. + */ + boot_mem_dest_offset = fw_dump.boot_mem_dest_addr; + for (i = 0; i < fw_dump.boot_mem_regs_cnt; i++) { + phdr = (struct elf_phdr *)bufp; + bufp += sizeof(struct elf_phdr); + populate_elf_pt_load(phdr, fw_dump.boot_mem_addr[i], + fw_dump.boot_mem_sz[i], + boot_mem_dest_offset); + /* Increment number of program headers. */ + (elf->e_phnum)++; + boot_mem_dest_offset += fw_dump.boot_mem_sz[i]; + } + + /* Memory reserved for fadump in first kernel */ + ra_start = fw_dump.reserve_dump_area_start; + ra_size = get_fadump_area_size(); + ra_end = ra_start + ra_size; + + phdr = (struct elf_phdr *)bufp; + for_each_mem_range(i, &mstart, &mend) { + /* Boot memory regions already added, skip them now */ + if (mstart < fw_dump.boot_mem_top) { + if (mend > fw_dump.boot_mem_top) + mstart = fw_dump.boot_mem_top; + else + continue; + } + + /* Handle memblock regions overlaps with fadump reserved area */ + if ((ra_start < mend) && (ra_end > mstart)) { + if ((mstart < ra_start) && (mend > ra_end)) { + populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart); + /* Increment number of program headers. */ + (elf->e_phnum)++; + bufp += sizeof(struct elf_phdr); + phdr = (struct elf_phdr *)bufp; + populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end); + } else if (mstart < ra_start) { + populate_elf_pt_load(phdr, mstart, ra_start - mstart, mstart); + } else if (ra_end < mend) { + populate_elf_pt_load(phdr, ra_end, mend - ra_end, ra_end); + } + } else { + /* No overlap with fadump reserved memory region */ + populate_elf_pt_load(phdr, mstart, mend - mstart, mstart); + } + + /* Increment number of program headers. */ + (elf->e_phnum)++; + bufp += sizeof(struct elf_phdr); + phdr = (struct elf_phdr *) bufp; + } +} + +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->version = FADUMP_HEADER_VERSION; + /* We will set the crashing cpu id in crash_fadump() during crash. */ + fdh->crashing_cpu = FADUMP_CPU_UNKNOWN; + + /* + * The physical address and size of vmcoreinfo are required in the + * second kernel to prepare elfcorehdr. + */ + fdh->vmcoreinfo_raddr = fadump_relocate(paddr_vmcoreinfo_note()); + fdh->vmcoreinfo_size = VMCOREINFO_NOTE_SIZE; + + + fdh->pt_regs_sz = sizeof(struct pt_regs); + /* + * When LPAR is terminated by PYHP, ensure all possible CPUs' + * register data is processed while exporting the vmcore. + */ + fdh->cpu_mask = *cpu_possible_mask; + fdh->cpu_mask_sz = sizeof(struct cpumask); + + return addr; +} + +static int register_fadump(void) +{ + unsigned long addr; + + /* + * If no memory is reserved then we can not register for firmware- + * assisted dump. + */ + if (!fw_dump.reserve_dump_area_size) + return -ENODEV; + + addr = fw_dump.fadumphdr_addr; + + /* Initialize fadump crash info header. */ + addr = init_fadump_header(addr); + + /* 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); + } + + 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) +{ + unsigned long reg_spfn, reg_epfn; + u64 tstart, tend, spfn, epfn; + int i; + + spfn = PHYS_PFN(start); + epfn = PHYS_PFN(end); + + for_each_mem_pfn_range(i, MAX_NUMNODES, ®_spfn, ®_epfn, NULL) { + tstart = max_t(u64, spfn, reg_spfn); + tend = min_t(u64, epfn, reg_epfn); + + 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; + 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) + swap(mem_ranges[idx], mem_ranges[i]); + } + + /* 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 void __init early_init_dt_scan_reserved_ranges(unsigned long node) +{ + const __be32 *prop; + int len, ret = -1; + unsigned long i; + + /* reserved-ranges already scanned */ + if (reserved_mrange_info.mem_range_cnt != 0) + return; + + prop = of_get_flat_dt_prop(node, "reserved-ranges", &len); + if (!prop) + return; + + /* + * 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; + } + } + } + + /* Compact reserved ranges */ + sort_and_merge_mem_ranges(&reserved_mrange_info); +} + +/* + * 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; + + ra_start = fw_dump.reserve_dump_area_start; + ra_end = ra_start + fw_dump.reserve_dump_area_size; + + /* + * If reserved ranges array limit is hit, overwrite the last reserved + * memory range with reserved dump area to ensure it is excluded from + * the memory being released (reused for next FADump registration). + */ + if (reserved_mrange_info.mem_range_cnt == + reserved_mrange_info.max_mem_ranges) + reserved_mrange_info.mem_range_cnt--; + + ret = fadump_add_mem_range(&reserved_mrange_info, ra_start, ra_end); + if (ret != 0) + 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_free_elfcorehdr_buf(void) +{ + if (fw_dump.elfcorehdr_addr == 0 || fw_dump.elfcorehdr_size == 0) + return; + + /* + * Before freeing the memory of `elfcorehdr`, reset the global + * `elfcorehdr_addr` to prevent modules like `vmcore` from accessing + * invalid memory. + */ + elfcorehdr_addr = ELFCORE_ADDR_ERR; + fadump_free_buffer(fw_dump.elfcorehdr_addr, fw_dump.elfcorehdr_size); + fw_dump.elfcorehdr_addr = 0; + fw_dump.elfcorehdr_size = 0; +} + +static void fadump_invalidate_release_mem(void) +{ + scoped_guard(mutex, &fadump_mutex) { + if (!fw_dump.dump_active) + return; + fadump_cleanup(); + } + + fadump_free_elfcorehdr_buf(); + 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 release_mem_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; +} + +/* Release the reserved memory and disable the FADump */ +static void __init unregister_fadump(void) +{ + fadump_cleanup(); + fadump_release_memory(fw_dump.reserve_dump_area_start, + fw_dump.reserve_dump_area_size); + fw_dump.fadump_enabled = 0; + kobject_put(fadump_kobj); +} + +static ssize_t enabled_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%d\n", fw_dump.fadump_enabled); +} + +/* + * /sys/kernel/fadump/hotplug_ready sysfs node returns 1, which inidcates + * to usersapce that fadump re-registration is not required on memory + * hotplug events. + */ +static ssize_t hotplug_ready_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%d\n", 1); +} + +static ssize_t mem_reserved_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%ld\n", fw_dump.reserve_dump_area_size); +} + +static ssize_t registered_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%d\n", fw_dump.dump_registered); +} + +static ssize_t bootargs_append_show(struct kobject *kobj, + struct kobj_attribute *attr, + char *buf) +{ + return sysfs_emit(buf, "%s\n", (char *)__va(fw_dump.param_area)); +} + +static ssize_t bootargs_append_store(struct kobject *kobj, + struct kobj_attribute *attr, + const char *buf, size_t count) +{ + char *params; + + if (!fw_dump.fadump_enabled || fw_dump.dump_active) + return -EPERM; + + if (count >= COMMAND_LINE_SIZE) + return -EINVAL; + + /* + * Fail here instead of handling this scenario with + * some silly workaround in capture kernel. + */ + if (saved_command_line_len + count >= COMMAND_LINE_SIZE) { + pr_err("Appending parameters exceeds cmdline size!\n"); + return -ENOSPC; + } + + params = __va(fw_dump.param_area); + strscpy_pad(params, buf, COMMAND_LINE_SIZE); + /* Remove newline character at the end. */ + if (params[count-1] == '\n') + params[count-1] = '\0'; + + return count; +} + +static ssize_t registered_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 release_attr = __ATTR_WO(release_mem); +static struct kobj_attribute enable_attr = __ATTR_RO(enabled); +static struct kobj_attribute register_attr = __ATTR_RW(registered); +static struct kobj_attribute mem_reserved_attr = __ATTR_RO(mem_reserved); +static struct kobj_attribute hotplug_ready_attr = __ATTR_RO(hotplug_ready); +static struct kobj_attribute bootargs_append_attr = __ATTR_RW(bootargs_append); + +static struct attribute *fadump_attrs[] = { + &enable_attr.attr, + ®ister_attr.attr, + &mem_reserved_attr.attr, + &hotplug_ready_attr.attr, + NULL, +}; + +ATTRIBUTE_GROUPS(fadump); + +DEFINE_SHOW_ATTRIBUTE(fadump_region); + +static void __init fadump_init_files(void) +{ + int rc = 0; + + fadump_kobj = kobject_create_and_add("fadump", kernel_kobj); + if (!fadump_kobj) { + pr_err("failed to create fadump kobject\n"); + return; + } + + if (fw_dump.param_area) { + rc = sysfs_create_file(fadump_kobj, &bootargs_append_attr.attr); + if (rc) + pr_err("unable to create bootargs_append sysfs file (%d)\n", rc); + } + + debugfs_create_file("fadump_region", 0444, arch_debugfs_dir, NULL, + &fadump_region_fops); + + if (fw_dump.dump_active) { + rc = sysfs_create_file(fadump_kobj, &release_attr.attr); + if (rc) + pr_err("unable to create release_mem sysfs file (%d)\n", + rc); + } + + rc = sysfs_create_groups(fadump_kobj, fadump_groups); + if (rc) { + pr_err("sysfs group creation failed (%d), unregistering FADump", + rc); + unregister_fadump(); + return; + } + + /* + * The FADump sysfs are moved from kernel_kobj to fadump_kobj need to + * create symlink at old location to maintain backward compatibility. + * + * - fadump_enabled -> fadump/enabled + * - fadump_registered -> fadump/registered + * - fadump_release_mem -> fadump/release_mem + */ + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, + "enabled", "fadump_enabled"); + if (rc) { + pr_err("unable to create fadump_enabled symlink (%d)", rc); + return; + } + + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, fadump_kobj, + "registered", + "fadump_registered"); + if (rc) { + pr_err("unable to create fadump_registered symlink (%d)", rc); + sysfs_remove_link(kernel_kobj, "fadump_enabled"); + return; + } + + if (fw_dump.dump_active) { + rc = compat_only_sysfs_link_entry_to_kobj(kernel_kobj, + fadump_kobj, + "release_mem", + "fadump_release_mem"); + if (rc) + pr_err("unable to create fadump_release_mem symlink (%d)", + rc); + } + return; +} + +static int __init fadump_setup_elfcorehdr_buf(void) +{ + int elf_phdr_cnt; + unsigned long elfcorehdr_size; + + /* + * Program header for CPU notes comes first, followed by one for + * vmcoreinfo, and the remaining program headers correspond to + * memory regions. + */ + elf_phdr_cnt = 2 + fw_dump.boot_mem_regs_cnt + memblock_num_regions(memory); + elfcorehdr_size = sizeof(struct elfhdr) + (elf_phdr_cnt * sizeof(struct elf_phdr)); + elfcorehdr_size = PAGE_ALIGN(elfcorehdr_size); + + fw_dump.elfcorehdr_addr = (u64)fadump_alloc_buffer(elfcorehdr_size); + if (!fw_dump.elfcorehdr_addr) { + pr_err("Failed to allocate %lu bytes for elfcorehdr\n", + elfcorehdr_size); + return -ENOMEM; + } + fw_dump.elfcorehdr_size = elfcorehdr_size; + return 0; +} + +/* + * Check if the fadump header of crashed kernel is compatible with fadump kernel. + * + * It checks the magic number, endianness, and size of non-primitive type + * members of fadump header to ensure safe dump collection. + */ +static bool __init is_fadump_header_compatible(struct fadump_crash_info_header *fdh) +{ + if (fdh->magic_number == FADUMP_CRASH_INFO_MAGIC_OLD) { + pr_err("Old magic number, can't process the dump.\n"); + return false; + } + + if (fdh->magic_number != FADUMP_CRASH_INFO_MAGIC) { + if (fdh->magic_number == swab64(FADUMP_CRASH_INFO_MAGIC)) + pr_err("Endianness mismatch between the crashed and fadump kernels.\n"); + else + pr_err("Fadump header is corrupted.\n"); + + return false; + } + + /* + * Dump collection is not safe if the size of non-primitive type members + * of the fadump header do not match between crashed and fadump kernel. + */ + if (fdh->pt_regs_sz != sizeof(struct pt_regs) || + fdh->cpu_mask_sz != sizeof(struct cpumask)) { + pr_err("Fadump header size mismatch.\n"); + return false; + } + + return true; +} + +static void __init fadump_process(void) +{ + struct fadump_crash_info_header *fdh; + + fdh = (struct fadump_crash_info_header *) __va(fw_dump.fadumphdr_addr); + if (!fdh) { + pr_err("Crash info header is empty.\n"); + goto err_out; + } + + /* Avoid processing the dump if fadump header isn't compatible */ + if (!is_fadump_header_compatible(fdh)) + goto err_out; + + /* Allocate buffer for elfcorehdr */ + if (fadump_setup_elfcorehdr_buf()) + goto err_out; + + fadump_populate_elfcorehdr(fdh); + + /* Let platform update the CPU notes in elfcorehdr */ + if (fw_dump.ops->fadump_process(&fw_dump) < 0) + goto err_out; + + /* + * elfcorehdr is now ready to be exported. + * + * set elfcorehdr_addr so that vmcore module will export the + * elfcorehdr through '/proc/vmcore'. + */ + elfcorehdr_addr = virt_to_phys((void *)fw_dump.elfcorehdr_addr); + return; + +err_out: + fadump_invalidate_release_mem(); +} + +/* + * Reserve memory to store additional parameters to be passed + * for fadump/capture kernel. + */ +void __init fadump_setup_param_area(void) +{ + phys_addr_t range_start, range_end; + + if (!fw_dump.fadump_enabled) + return; + + if (!fw_dump.param_area_supported || fw_dump.dump_active) + return; + + /* This memory can't be used by PFW or bootloader as it is shared across kernels */ + if (early_radix_enabled()) { + /* + * Anywhere in the upper half should be good enough as all memory + * is accessible in real mode. + */ + range_start = memblock_end_of_DRAM() / 2; + range_end = memblock_end_of_DRAM(); + } else { + /* + * Memory range for passing additional parameters for HASH MMU + * must meet the following conditions: + * 1. The first memory block size must be higher than the + * minimum RMA (MIN_RMA) size. Bootloader can use memory + * upto RMA size. So it should be avoided. + * 2. The range should be between MIN_RMA and RMA size (ppc64_rma_size) + * 3. It must not overlap with the fadump reserved area. + */ + if (ppc64_rma_size < MIN_RMA) + return; + + range_start = MIN_RMA; + range_end = min(ppc64_rma_size, fw_dump.boot_mem_top); + } + + fw_dump.param_area = memblock_phys_alloc_range(COMMAND_LINE_SIZE, + COMMAND_LINE_SIZE, + range_start, + range_end); + if (!fw_dump.param_area) { + pr_warn("WARNING: Could not setup area to pass additional parameters!\n"); + return; + } + + memset((void *)fw_dump.param_area, 0, COMMAND_LINE_SIZE); +} + +/* + * Prepare for firmware-assisted dump. + */ +int __init setup_fadump(void) +{ + if (!fw_dump.fadump_supported) + return 0; + + fadump_init_files(); + fadump_show_config(); + + if (!fw_dump.fadump_enabled) + return 1; + + /* + * If dump data is available then see if it is valid and prepare for + * saving it to the disk. + */ + if (fw_dump.dump_active) { + fadump_process(); + } + /* Initialize the kernel dump memory structure and register with f/w */ + else if (fw_dump.reserve_dump_area_size) { + fw_dump.ops->fadump_init_mem_struct(&fw_dump); + register_fadump(); + } + + /* + * In case of panic, fadump is triggered via ppc_panic_event() + * panic notifier. Setting crash_kexec_post_notifiers to 'true' + * lets panic() function take crash friendly path before panic + * notifiers are invoked. + */ + crash_kexec_post_notifiers = true; + + return 1; +} +/* + * Use subsys_initcall_sync() here because there is dependency with + * crash_save_vmcoreinfo_init(), which must run first to ensure vmcoreinfo initialization + * is done before registering with f/w. + */ +subsys_initcall_sync(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) +{ + u64 i, mstart, mend, msize; + + for_each_mem_range(i, &mstart, &mend) { + msize = mend - mstart; + + 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); + } +} |