fadump: Convert firmware-assisted cpu state dump data into elf notes.
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>
diff --git a/arch/powerpc/include/asm/fadump.h b/arch/powerpc/include/asm/fadump.h
index 9e172a5..6768195 100644
--- a/arch/powerpc/include/asm/fadump.h
+++ b/arch/powerpc/include/asm/fadump.h
@@ -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 @@
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 @@
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 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