powerpc/64s: Add new set of irq_soft_mask_ functions for PMI masking

To support soft-masking of the performance monitor interrupt, a 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 irq_soft_mask manipulation function
irq_soft_mask_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>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/hw_irq.h

@@ -115,6 +115,24 @@ static inline notrace unsigned long irq_soft_mask_set_return(unsigned long mask)
 	return flags;
 }
 
+static inline notrace unsigned long irq_soft_mask_or_return(unsigned long mask)
+{
+	unsigned long flags, tmp;
+
+	asm volatile(
+		"lbz %0,%2(13); or %1,%0,%3; stb %1,%2(13)"
+		: "=&r" (flags), "=r" (tmp)
+		: "i" (offsetof(struct paca_struct, irq_soft_mask)),
+		  "r" (mask)
+		: "memory");
+
+#ifdef CONFIG_PPC_IRQ_SOFT_MASK_DEBUG
+	WARN_ON((mask | flags) && !((mask | flags) & IRQS_DISABLED));
+#endif
+
+	return flags;
+}
+
 static inline unsigned long arch_local_save_flags(void)
 {
 	return irq_soft_mask_return();
@@ -147,6 +165,55 @@ static inline bool arch_irqs_disabled(void)
 	return arch_irqs_disabled_flags(arch_local_save_flags());
 }
 
+#ifdef CONFIG_PPC_BOOK3S
+/*
+ * 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 = irq_soft_mask_or_return(IRQS_DISABLED |	\
+				IRQS_PMI_DISABLED);			\
+	} 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 */
+
+#endif /* CONFIG_PPC_BOOK3S */
+
 #ifdef CONFIG_PPC_BOOK3E
 #define __hard_irq_enable()	asm volatile("wrteei 1" : : : "memory")
 #define __hard_irq_disable()	asm volatile("wrteei 0" : : : "memory")