diff options
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/Makefile | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/fadump.c | 246 | ||||
| -rw-r--r-- | arch/powerpc/kernel/prom.c | 15 |
3 files changed, 261 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index ee728e433aa2..391bf7e1ba2f 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_IBMVIO) += vio.o obj-$(CONFIG_IBMEBUS) += ibmebus.o obj-$(CONFIG_GENERIC_TBSYNC) += smp-tbsync.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o +obj-$(CONFIG_FA_DUMP) += fadump.o ifeq ($(CONFIG_PPC32),y) obj-$(CONFIG_E500) += idle_e500.o endif diff --git a/arch/powerpc/kernel/fadump.c b/arch/powerpc/kernel/fadump.c new file mode 100644 index 000000000000..deb276a9ce71 --- /dev/null +++ b/arch/powerpc/kernel/fadump.c @@ -0,0 +1,246 @@ +/* + * Firmware Assisted dump: A robust mechanism to get reliable kernel crash + * dump with assistance from firmware. This approach does not use kexec, + * instead firmware assists in booting the kdump kernel while preserving + * memory contents. The most of the code implementation has been adapted + * from phyp assisted dump implementation written by Linas Vepstas and + * Manish Ahuja + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * Copyright 2011 IBM Corporation + * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> + */ + +#undef DEBUG +#define pr_fmt(fmt) "fadump: " fmt + +#include <linux/string.h> +#include <linux/memblock.h> + +#include <asm/page.h> +#include <asm/prom.h> +#include <asm/rtas.h> +#include <asm/fadump.h> + +static struct fw_dump fw_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) +{ + __be32 *sections; + int i, num_sections; + unsigned long size; + const int *token; + + if (depth != 1 || strcmp(uname, "rtas") != 0) + return 0; + + /* + * Check if Firmware Assisted dump is supported. if yes, check + * if dump has been initiated on last reboot. + */ + token = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump", NULL); + if (!token) + return 0; + + fw_dump.fadump_supported = 1; + fw_dump.ibm_configure_kernel_dump = *token; + + /* + * The 'ibm,kernel-dump' rtas node is present only if there is + * dump data waiting for us. + */ + if (of_get_flat_dt_prop(node, "ibm,kernel-dump", NULL)) + fw_dump.dump_active = 1; + + /* Get the sizes required to store dump data for the firmware provided + * dump sections. + * For each dump section type supported, a 32bit cell which defines + * the ID of a supported section followed by two 32 bit cells which + * gives teh size of the section in bytes. + */ + sections = of_get_flat_dt_prop(node, "ibm,configure-kernel-dump-sizes", + &size); + + if (!sections) + return 0; + + num_sections = size / (3 * sizeof(u32)); + + for (i = 0; i < num_sections; i++, sections += 3) { + u32 type = (u32)of_read_number(sections, 1); + + switch (type) { + case FADUMP_CPU_STATE_DATA: + fw_dump.cpu_state_data_size = + of_read_ulong(§ions[1], 2); + break; + case FADUMP_HPTE_REGION: + fw_dump.hpte_region_size = + of_read_ulong(§ions[1], 2); + break; + } + } + return 1; +} + +/** + * fadump_calculate_reserve_size(): reserve variable boot area 5% of System RAM + * + * Function to find the largest memory size we need to reserve during early + * boot process. This will be the size of the memory that is required for a + * kernel to boot successfully. + * + * This function has been taken from phyp-assisted dump feature implementation. + * + * returns larger of 256MB or 5% rounded down to multiples of 256MB. + * + * TODO: Come up with better approach to find out more accurate memory size + * that is required for a kernel to boot successfully. + * + */ +static inline unsigned long fadump_calculate_reserve_size(void) +{ + unsigned long size; + + /* + * Check if the size is specified through fadump_reserve_mem= cmdline + * option. If yes, then use that. + */ + if (fw_dump.reserve_bootvar) + return fw_dump.reserve_bootvar; + + /* divide by 20 to get 5% of value */ + size = memblock_end_of_DRAM() / 20; + + /* round it down in multiples of 256 */ + size = size & ~0x0FFFFFFFUL; + + /* Truncate to memory_limit. We don't want to over reserve the memory.*/ + if (memory_limit && size > memory_limit) + size = memory_limit; + + return (size > MIN_BOOT_MEM ? size : MIN_BOOT_MEM); +} + +/* + * Calculate the total memory size required to be reserved for + * firmware-assisted dump registration. + */ +static unsigned long get_fadump_area_size(void) +{ + unsigned long size = 0; + + size += fw_dump.cpu_state_data_size; + size += fw_dump.hpte_region_size; + size += fw_dump.boot_memory_size; + + size = PAGE_ALIGN(size); + return size; +} + +int __init fadump_reserve_mem(void) +{ + unsigned long base, size, memory_boundary; + + if (!fw_dump.fadump_enabled) + return 0; + + if (!fw_dump.fadump_supported) { + printk(KERN_INFO "Firmware-assisted dump is not supported on" + " this hardware\n"); + fw_dump.fadump_enabled = 0; + return 0; + } + /* Initialize boot memory size */ + fw_dump.boot_memory_size = fadump_calculate_reserve_size(); + + /* + * Calculate the memory boundary. + * If memory_limit is less than actual memory boundary then reserve + * the memory for fadump beyond the memory_limit and adjust the + * memory_limit accordingly, so that the running kernel can run with + * specified memory_limit. + */ + if (memory_limit && memory_limit < memblock_end_of_DRAM()) { + size = get_fadump_area_size(); + if ((memory_limit + size) < memblock_end_of_DRAM()) + memory_limit += size; + else + memory_limit = memblock_end_of_DRAM(); + printk(KERN_INFO "Adjusted memory_limit for firmware-assisted" + " dump, now %#016llx\n", + (unsigned long long)memory_limit); + } + if (memory_limit) + memory_boundary = memory_limit; + else + memory_boundary = memblock_end_of_DRAM(); + + if (fw_dump.dump_active) { + printk(KERN_INFO "Firmware-assisted dump is active.\n"); + /* + * If last boot has crashed then reserve all the memory + * above boot_memory_size so that we don't touch it until + * dump is written to disk by userspace tool. This memory + * will be released for general use once the dump is saved. + */ + base = fw_dump.boot_memory_size; + size = memory_boundary - base; + memblock_reserve(base, size); + printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " + "for saving crash dump\n", + (unsigned long)(size >> 20), + (unsigned long)(base >> 20)); + } else { + /* Reserve the memory at the top of memory. */ + size = get_fadump_area_size(); + base = memory_boundary - size; + memblock_reserve(base, size); + printk(KERN_INFO "Reserved %ldMB of memory at %ldMB " + "for firmware-assisted dump\n", + (unsigned long)(size >> 20), + (unsigned long)(base >> 20)); + } + fw_dump.reserve_dump_area_start = base; + fw_dump.reserve_dump_area_size = size; + return 1; +} + +/* Look for fadump= cmdline option. */ +static int __init early_fadump_param(char *p) +{ + if (!p) + return 1; + + if (strncmp(p, "on", 2) == 0) + fw_dump.fadump_enabled = 1; + else if (strncmp(p, "off", 3) == 0) + fw_dump.fadump_enabled = 0; + + return 0; +} +early_param("fadump", early_fadump_param); + +/* Look for fadump_reserve_mem= cmdline option */ +static int __init early_fadump_reserve_mem(char *p) +{ + if (p) + fw_dump.reserve_bootvar = memparse(p, &p); + return 0; +} +early_param("fadump_reserve_mem", early_fadump_reserve_mem); diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c index abe405dab34d..70222b35cfc5 100644 --- a/arch/powerpc/kernel/prom.c +++ b/arch/powerpc/kernel/prom.c @@ -55,6 +55,7 @@ #include <asm/phyp_dump.h> #include <asm/kexec.h> #include <asm/opal.h> +#include <asm/fadump.h> #include <mm/mmu_decl.h> @@ -719,6 +720,11 @@ void __init early_init_devtree(void *params) of_scan_flat_dt(early_init_dt_scan_phyp_dump, NULL); #endif +#ifdef CONFIG_FA_DUMP + /* scan tree to see if dump is active during last boot */ + of_scan_flat_dt(early_init_dt_scan_fw_dump, NULL); +#endif + /* Pre-initialize the cmd_line with the content of boot_commmand_line, * which will be empty except when the content of the variable has * been overriden by a bootloading mechanism. This happens typically @@ -750,7 +756,14 @@ void __init early_init_devtree(void *params) if (PHYSICAL_START > MEMORY_START) memblock_reserve(MEMORY_START, 0x8000); reserve_kdump_trampoline(); - reserve_crashkernel(); +#ifdef CONFIG_FA_DUMP + /* + * If we fail to reserve memory for firmware-assisted dump then + * fallback to kexec based kdump. + */ + if (fadump_reserve_mem() == 0) +#endif + reserve_crashkernel(); early_reserve_mem(); phyp_dump_reserve_mem(); |