[PATCH v3 10/11] powerpc: Add new set of soft_enabled_ functions

[Madhavan Srinivasan <maddy@linux.vnet.ibm.com>]

To support disabling and enabling of irq with PMI, set of
new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore()
functions are added. And powerpc_local_irq_save() implemented,
by adding a new soft_enabled manipulation function soft_enabled_or_return().
Local_irq_pmu_* macros are provided to access these powerpc_local_irq_pmu*
functions which includes trace_hardirqs_on|off() to match what we
have in include/linux/irqflags.h.

Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
---
 arch/powerpc/include/asm/hw_irq.h | 62 ++++++++++++++++++++++++++++++++++++++-
 arch/powerpc/kernel/irq.c         |  4 +++
 2 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/hw_irq.h b/arch/powerpc/include/asm/hw_irq.h
index ac9a17ea1d66..7be90b73a943 100644
--- a/arch/powerpc/include/asm/hw_irq.h
+++ b/arch/powerpc/include/asm/hw_irq.h
@@ -90,6 +90,20 @@ static inline notrace unsigned long soft_enabled_set_return(unsigned long enable
 	return flags;
 }
 
+static inline notrace unsigned long soft_enabled_or_return(unsigned long enable)
+{
+	unsigned long flags, zero;
+
+	asm volatile(
+		"mr %1,%3; lbz %0,%2(13); or %1,%0,%1; stb %1,%2(13)"
+		: "=r" (flags), "=&r"(zero)
+		: "i" (offsetof(struct paca_struct, soft_enabled)),\
+		 "r" (enable)
+		: "memory");
+
+	return flags;
+}
+
 static inline unsigned long arch_local_save_flags(void)
 {
 	return soft_enabled_return();
@@ -114,7 +128,7 @@ static inline unsigned long arch_local_irq_save(void)
 
 static inline bool arch_irqs_disabled_flags(unsigned long flags)
 {
-	return flags == IRQ_DISABLE_MASK_LINUX;
+	return flags & IRQ_DISABLE_MASK_LINUX;
 }
 
 static inline bool arch_irqs_disabled(void)
@@ -122,6 +136,52 @@ static inline bool arch_irqs_disabled(void)
 	return arch_irqs_disabled_flags(arch_local_save_flags());
 }
 
+/*
+ * To support disabling and enabling of irq with PMI, set of
+ * new powerpc_local_irq_pmu_save() and powerpc_local_irq_restore()
+ * functions are added. These macros are implemented using generic
+ * linux local_irq_* code from include/linux/irqflags.h.
+ */
+#define raw_local_irq_pmu_save(flags)					\
+	do {								\
+		typecheck(unsigned long, flags);			\
+		flags = soft_enabled_or_return(IRQ_DISABLE_MASK_LINUX | \
+				IRQ_DISABLE_MASK_PMU);			\
+	} while(0)
+
+#define raw_local_irq_pmu_restore(flags)				\
+	do {								\
+		typecheck(unsigned long, flags);			\
+		arch_local_irq_restore(flags);				\
+	} while(0)
+
+#ifdef CONFIG_TRACE_IRQFLAGS
+#define powerpc_local_irq_pmu_save(flags)			\
+	 do {							\
+		raw_local_irq_pmu_save(flags);			\
+		trace_hardirqs_off();				\
+	} while(0)
+#define powerpc_local_irq_pmu_restore(flags)			\
+	do {							\
+		if (raw_irqs_disabled_flags(flags)) {		\
+			raw_local_irq_pmu_restore(flags);	\
+			trace_hardirqs_off();			\
+		} else {					\
+			trace_hardirqs_on();			\
+			raw_local_irq_pmu_restore(flags);	\
+		}						\
+	} while(0)
+#else
+#define powerpc_local_irq_pmu_save(flags)			\
+	do {							\
+		raw_local_irq_pmu_save(flags);			\
+	} while(0)
+#define powerpc_local_irq_pmu_restore(flags)			\
+	do {							\
+		raw_local_irq_pmu_restore(flags);		\
+	} while (0)
+#endif  /* CONFIG_TRACE_IRQFLAGS */
+
 #ifdef CONFIG_PPC_BOOK3E
 #define __hard_irq_enable()	asm volatile("wrteei 1" : : : "memory")
 #define __hard_irq_disable()	asm volatile("wrteei 0" : : : "memory")
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c
index 299b55071612..9010f996e238 100644
--- a/arch/powerpc/kernel/irq.c
+++ b/arch/powerpc/kernel/irq.c
@@ -227,6 +227,10 @@ notrace void arch_local_irq_restore(unsigned long en)
 	unsigned char irq_happened;
 	unsigned int replay;
 
+#ifdef CONFIG_IRQ_DEBUG_SUPPORT
+	WARN_ON(en & local_paca->soft_enabled & ~IRQ_DISABLE_MASK_LINUX);
+#endif
+
 	/* Write the new soft-enabled value */
 	soft_enabled_set(en);
 
-- 
2.7.4