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fadump: Convert firmware-assisted cpu state dump data into elf notes.

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When registered for firmware assisted dump on powerpc, firmware preserves
the registers for the active CPUs during a system crash. This patch reads
the cpu register data stored in Firmware-assisted dump format (except for
crashing cpu) and converts it into elf notes and updates the PT_NOTE program
header accordingly. The exact register state for crashing cpu is saved to
fadump crash info structure in scratch area during crash_fadump() and read
during second kernel boot.

Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Mahesh Salgaonkar
2012-02-16 01:14:45 +00:00
committed by Benjamin Herrenschmidt
parent 2df173d9e8
commit ebaeb5ae24
4 changed files with 365 additions and 2 deletions
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44
arch/powerpc/include/asm/fadump.h
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@@ -65,6 +65,18 @@
/* Dump status flag */
#define FADUMP_ERROR_FLAG 0x2000
#define FADUMP_CPU_ID_MASK ((1UL << 32) - 1)
#define CPU_UNKNOWN (~((u32)0))
/* Utility macros */
#define SKIP_TO_NEXT_CPU(reg_entry) \
({ \
while (reg_entry->reg_id != REG_ID("CPUEND")) \
reg_entry++; \
reg_entry++; \
})
/* Kernel Dump section info */
struct fadump_section {
u32 request_flag;
@@ -119,6 +131,9 @@ struct fw_dump {
unsigned long reserve_bootvar;
unsigned long fadumphdr_addr;
unsigned long cpu_notes_buf;
unsigned long cpu_notes_buf_size;
int ibm_configure_kernel_dump;
unsigned long fadump_enabled:1;
@@ -143,13 +158,40 @@ static inline u64 str_to_u64(const char *str)
return val;
}
#define STR_TO_HEX(x) str_to_u64(x)
#define REG_ID(x) str_to_u64(x)
#define FADUMP_CRASH_INFO_MAGIC STR_TO_HEX("FADMPINF")
#define REGSAVE_AREA_MAGIC STR_TO_HEX("REGSAVE")
/* The firmware-assisted dump format.
*
* The register save area is an area in the partition's memory used to preserve
* the register contents (CPU state data) for the active CPUs during a firmware
* assisted dump. The dump format contains register save area header followed
* by register entries. Each list of registers for a CPU starts with
* "CPUSTRT" and ends with "CPUEND".
*/
/* Register save area header. */
struct fadump_reg_save_area_header {
u64 magic_number;
u32 version;
u32 num_cpu_offset;
};
/* Register entry. */
struct fadump_reg_entry {
u64 reg_id;
u64 reg_value;
};
/* fadump crash info structure */
struct fadump_crash_info_header {
u64 magic_number;
u64 elfcorehdr_addr;
u32 crashing_cpu;
struct pt_regs regs;
struct cpumask cpu_online_mask;
};
/* Crash memory ranges */
@@ -165,7 +207,9 @@ extern int early_init_dt_scan_fw_dump(unsigned long node,
extern int fadump_reserve_mem(void);
extern int setup_fadump(void);
extern int is_fadump_active(void);
extern void crash_fadump(struct pt_regs *, const char *);
#else /* CONFIG_FA_DUMP */
static inline int is_fadump_active(void) { return 0; }
static inline void crash_fadump(struct pt_regs *regs, const char *str) { }
#endif
#endif