[PATCH v3] ARM: hw_breakpoint: Add ARMv8 support

[Christopher Covington]

Add the trivial support necessary to get hardware breakpoints
working for GDB on ARMv8 simulators running in AArch32 mode.

Acked-by: Will Deacon <will.deacon@xxxxxxx>
Signed-off-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
---

 v3: assume for now that ARMv9 and later will update FSR

 v2: modify debug_exception_updates_fsr

 arch/arm/include/asm/hw_breakpoint.h | 1 +
 arch/arm/kernel/hw_breakpoint.c      | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/hw_breakpoint.h b/arch/arm/include/asm/hw_breakpoint.h
index eef55ea..8e427c7 100644
--- a/arch/arm/include/asm/hw_breakpoint.h
+++ b/arch/arm/include/asm/hw_breakpoint.h
@@ -51,6 +51,7 @@ static inline void decode_ctrl_reg(u32 reg,
 #define ARM_DEBUG_ARCH_V7_ECP14	3
 #define ARM_DEBUG_ARCH_V7_MM	4
 #define ARM_DEBUG_ARCH_V7_1	5
+#define ARM_DEBUG_ARCH_V8	6
 
 /* Breakpoint */
 #define ARM_BREAKPOINT_EXECUTE	0
diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoint.c
index 3d44660..9da35c6 100644
--- a/arch/arm/kernel/hw_breakpoint.c
+++ b/arch/arm/kernel/hw_breakpoint.c
@@ -167,7 +167,7 @@ static int debug_arch_supported(void)
 /* Can we determine the watchpoint access type from the fsr? */
 static int debug_exception_updates_fsr(void)
 {
-	return 0;
+	return get_debug_arch() >= ARM_DEBUG_ARCH_V8;
 }
 
 /* Determine number of WRP registers available. */
@@ -257,6 +257,7 @@ static int enable_monitor_mode(void)
 		break;
 	case ARM_DEBUG_ARCH_V7_ECP14:
 	case ARM_DEBUG_ARCH_V7_1:
+	case ARM_DEBUG_ARCH_V8:
 		ARM_DBG_WRITE(c0, c2, 2, (dscr | ARM_DSCR_MDBGEN));
 		isb();
 		break;
-- 
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