From 2df173d9e85d9e2c6a8933c63f0c034accff7e0f Mon Sep 17 00:00:00 2001 From: Mahesh Salgaonkar Date: Thu, 16 Feb 2012 01:14:37 +0000 Subject: fadump: Initialize elfcore header and add PT_LOAD program headers. Build the crash memory range list by traversing through system memory during the first kernel before we register for firmware-assisted dump. After the successful dump registration, initialize the elfcore header and populate PT_LOAD program headers with crash memory ranges. The elfcore header is saved in the scratch area within the reserved memory. The scratch area starts at the end of the memory reserved for saving RMR region contents. The scratch area contains fadump crash info structure that contains magic number for fadump validation and physical address where the eflcore header can be found. This structure will also be used to pass some important crash info data to the second kernel which will help second kernel to populate ELF core header with correct data before it gets exported through /proc/vmcore. Since the firmware preserves the entire partition memory at the time of crash the contents of the scratch area will be preserved till second kernel boot. Since the memory dump exported through /proc/vmcore is in ELF format similar to kdump, it will help us to reuse the kdump infrastructure for dump capture and filtering. Unlike phyp dump, userspace tool does not need to refer any sysfs interface while reading /proc/vmcore. NOTE: The current design implementation does not address a possibility of introducing additional fields (in future) to this structure without affecting compatibility. It's on TODO list to come up with better approach to address this. Reserved dump area start => +-------------------------------------+ | CPU state dump data | +-------------------------------------+ | HPTE region data | +-------------------------------------+ | RMR region data | Scratch area start => +-------------------------------------+ | fadump crash info structure { | | magic nummber | +------|---- elfcorehdr_addr | | | } | +----> +-------------------------------------+ | ELF core header | Reserved dump area end => +-------------------------------------+ Signed-off-by: Mahesh Salgaonkar Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/fadump.h | 43 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) (limited to 'arch/powerpc/include/asm/fadump.h') diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h index bbaf278bdccc..9e172a5d53c7 100644 --- a/arch/powerpc/include/asm/fadump.h +++ b/arch/powerpc/include/asm/fadump.h @@ -43,6 +43,12 @@ #define MIN_BOOT_MEM (((RMA_END < (0x1UL << 28)) ? (0x1UL << 28) : RMA_END) \ + (0x1UL << 26)) +#define memblock_num_regions(memblock_type) (memblock.memblock_type.cnt) + +#ifndef ELF_CORE_EFLAGS +#define ELF_CORE_EFLAGS 0 +#endif + /* Firmware provided dump sections */ #define FADUMP_CPU_STATE_DATA 0x0001 #define FADUMP_HPTE_REGION 0x0002 @@ -56,6 +62,9 @@ #define FADUMP_UNREGISTER 2 #define FADUMP_INVALIDATE 3 +/* Dump status flag */ +#define FADUMP_ERROR_FLAG 0x2000 + /* Kernel Dump section info */ struct fadump_section { u32 request_flag; @@ -109,6 +118,7 @@ struct fw_dump { /* cmd line option during boot */ unsigned long reserve_bootvar; + unsigned long fadumphdr_addr; int ibm_configure_kernel_dump; unsigned long fadump_enabled:1; @@ -117,6 +127,39 @@ struct fw_dump { unsigned long dump_registered:1; }; +/* + * Copy the ascii values for first 8 characters from a string into u64 + * variable at their respective indexes. + * e.g. + * The string "FADMPINF" will be converted into 0x4641444d50494e46 + */ +static inline u64 str_to_u64(const char *str) +{ + u64 val = 0; + int i; + + for (i = 0; i < sizeof(val); i++) + val = (*str) ? (val << 8) | *str++ : val << 8; + return val; +} +#define STR_TO_HEX(x) str_to_u64(x) + +#define FADUMP_CRASH_INFO_MAGIC STR_TO_HEX("FADMPINF") + +/* fadump crash info structure */ +struct fadump_crash_info_header { + u64 magic_number; + u64 elfcorehdr_addr; +}; + +/* Crash memory ranges */ +#define INIT_CRASHMEM_RANGES (INIT_MEMBLOCK_REGIONS + 2) + +struct fad_crash_memory_ranges { + unsigned long long base; + unsigned long long size; +}; + extern int early_init_dt_scan_fw_dump(unsigned long node, const char *uname, int depth, void *data); extern int fadump_reserve_mem(void); -- cgit v1.2.3