arm64: Provide read/write fault information in compat signal handlers

For AArch32, bit 11 (WnR) of the FSR/ESR register is set when the fault
was caused by a write access and applications like Qemu rely on such
information being provided in sigcontext. This patch introduces the
ESR_EL1 tracking for the arm64 kernel faults and sets bit 11 accordingly
in compat sigcontext.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/include/asm/esr.h b/arch/arm64/include/asm/esr.h
index c4a7f94..72674f4 100644
--- a/arch/arm64/include/asm/esr.h
+++ b/arch/arm64/include/asm/esr.h
@@ -18,9 +18,11 @@
 #ifndef __ASM_ESR_H
 #define __ASM_ESR_H
 
-#define ESR_EL1_EC_SHIFT	(26)
-#define ESR_EL1_IL		(1U << 25)
+#define ESR_EL1_WRITE		(1 << 6)
+#define ESR_EL1_CM		(1 << 8)
+#define ESR_EL1_IL		(1 << 25)
 
+#define ESR_EL1_EC_SHIFT	(26)
 #define ESR_EL1_EC_UNKNOWN	(0x00)
 #define ESR_EL1_EC_WFI		(0x01)
 #define ESR_EL1_EC_CP15_32	(0x03)
diff --git a/arch/arm64/include/asm/processor.h b/arch/arm64/include/asm/processor.h
index 45b20cd..34de2a8 100644
--- a/arch/arm64/include/asm/processor.h
+++ b/arch/arm64/include/asm/processor.h
@@ -79,6 +79,7 @@
 	unsigned long		tp_value;
 	struct fpsimd_state	fpsimd_state;
 	unsigned long		fault_address;	/* fault info */
+	unsigned long		fault_code;	/* ESR_EL1 value */
 	struct debug_info	debug;		/* debugging */
 };