[PATCH 1/6] arm64: Add macros to manage processor debug state

[vijay.kilari at gmail.com]

From: Vijaya Kumar K <Vijaya.Kumar at caviumnetworks.com>

Add macros to enable and disable to manage PSTATE.D
for debugging. The macros local_dbg_save and local_dbg_restore
are moved to irqflags.h file

KGDB boot tests fail because of PSTATE.D is masked.
unmask it for debugging support

Signed-off-by: Vijaya Kumar K <Vijaya.Kumar at caviumnetworks.com>
---
 arch/arm64/include/asm/debug-monitors.h |   18 ++----------------
 arch/arm64/include/asm/irqflags.h       |   22 ++++++++++++++++++++++
 arch/arm64/kernel/debug-monitors.c      |    3 ++-
 3 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/include/asm/debug-monitors.h b/arch/arm64/include/asm/debug-monitors.h
index 6231479..bc48880 100644
--- a/arch/arm64/include/asm/debug-monitors.h
+++ b/arch/arm64/include/asm/debug-monitors.h
@@ -43,22 +43,8 @@ enum debug_el {
 #ifndef __ASSEMBLY__
 struct task_struct;
 
-#define local_dbg_save(flags)							\
-	do {									\
-		typecheck(unsigned long, flags);				\
-		asm volatile(							\
-		"mrs	%0, daif			// local_dbg_save\n"	\
-		"msr	daifset, #8"						\
-		: "=r" (flags) : : "memory");					\
-	} while (0)
-
-#define local_dbg_restore(flags)						\
-	do {									\
-		typecheck(unsigned long, flags);				\
-		asm volatile(							\
-		"msr	daif, %0			// local_dbg_restore\n"	\
-		: : "r" (flags) : "memory");					\
-	} while (0)
+#define local_dbg_enable()	asm("msr	daifclr, #8" : : : "memory")
+#define local_dbg_disable()	asm("msr	daifset, #8" : : : "memory")
 
 #define DBG_ARCH_ID_RESERVED	0	/* In case of ptrace ABI updates. */
 
diff --git a/arch/arm64/include/asm/irqflags.h b/arch/arm64/include/asm/irqflags.h
index b2fcfbc..f163b11 100644
--- a/arch/arm64/include/asm/irqflags.h
+++ b/arch/arm64/include/asm/irqflags.h
@@ -90,5 +90,27 @@ static inline int arch_irqs_disabled_flags(unsigned long flags)
 	return flags & PSR_I_BIT;
 }
 
+/*
+ * save and restore debug state
+ */
+static inline unsigned long local_dbg_save(void)
+{
+	unsigned long flags;
+	asm volatile(
+		"mrs	%0, daif		// local_dbg_save"
+		"msr	daifset, #8"
+		: "=r" (flags) : : "memory");
+	return flags;
+}
+
+static inline void local_dbg_restore(unsigned long flags)
+{
+	asm volatile(
+		"msr	daif, %0	// local_dbg_restore"
+		:
+		: "r" (flags)
+		: "memory");
+}
+
 #endif
 #endif
diff --git a/arch/arm64/kernel/debug-monitors.c b/arch/arm64/kernel/debug-monitors.c
index 23586bd..774ad04 100644
--- a/arch/arm64/kernel/debug-monitors.c
+++ b/arch/arm64/kernel/debug-monitors.c
@@ -51,7 +51,7 @@ u8 debug_monitors_arch(void)
 static void mdscr_write(u32 mdscr)
 {
 	unsigned long flags;
-	local_dbg_save(flags);
+	flags = local_dbg_save();
 	asm volatile("msr mdscr_el1, %0" :: "r" (mdscr));
 	local_dbg_restore(flags);
 }
@@ -138,6 +138,7 @@ static void clear_os_lock(void *unused)
 {
 	asm volatile("msr oslar_el1, %0" : : "r" (0));
 	isb();
+	local_dbg_enable();
 }
 
 static int os_lock_notify(struct notifier_block *self,
-- 
1.7.9.5