sparc64: Initial hw perf counter support.

Only supports one simple counter and only UltraSPARC-IIIi chips.
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/nmi.h

@@ -7,4 +7,7 @@ extern void nmi_adjust_hz(unsigned int new_hz);
 
 extern atomic_t nmi_active;
 
+extern void start_nmi_watchdog(void *unused);
+extern void stop_nmi_watchdog(void *unused);
+
 #endif /* __NMI_H */

arch/sparc/include/asm/perf_counter.h

@@ -5,4 +5,10 @@ extern void set_perf_counter_pending(void);
 
 #define	PERF_COUNTER_INDEX_OFFSET	0
 
+#ifdef CONFIG_PERF_COUNTERS
+extern void init_hw_perf_counters(void);
+#else
+static inline void init_hw_perf_counters(void)	{ }
+#endif
+
 #endif

arch/sparc/kernel/Makefile

@@ -103,3 +103,6 @@ obj-$(CONFIG_SUN_LDOMS) += ldc.o vio.o viohs.o ds.o
 obj-$(CONFIG_AUDIT)     += audit.o
 audit--$(CONFIG_AUDIT)  := compat_audit.o
 obj-$(CONFIG_COMPAT)    += $(audit--y)
+
+pc--$(CONFIG_PERF_COUNTERS) := perf_counter.o
+obj-$(CONFIG_SPARC64)	+= $(pc--y)

arch/sparc/kernel/nmi.c

@@ -19,6 +19,7 @@
 #include <linux/delay.h>
 #include <linux/smp.h>
 
+#include <asm/perf_counter.h>
 #include <asm/ptrace.h>
 #include <asm/local.h>
 #include <asm/pcr.h>
@@ -156,7 +157,7 @@ static void report_broken_nmi(int cpu, int *prev_nmi_count)
 	atomic_dec(&nmi_active);
 }
 
-static void stop_nmi_watchdog(void *unused)
+void stop_nmi_watchdog(void *unused)
 {
 	pcr_ops->write(PCR_PIC_PRIV);
 	__get_cpu_var(wd_enabled) = 0;
@@ -210,7 +211,7 @@ error:
 	return err;
 }
 
-static void start_nmi_watchdog(void *unused)
+void start_nmi_watchdog(void *unused)
 {
 	__get_cpu_var(wd_enabled) = 1;
 	atomic_inc(&nmi_active);
@@ -263,6 +264,9 @@ int __init nmi_init(void)
 			atomic_set(&nmi_active, -1);
 		}
 	}
+	if (!err)
+		init_hw_perf_counters();
+
 	return err;
 }