x86/oprofile: Implement op_x86_virt_to_phys()

This patch implements a common x86 function to convert virtual counter
numbers to physical.
Signed-off-by: Robert Richter <robert.richter@amd.com>

arch/x86/oprofile/nmi_int.c

@@ -129,6 +129,11 @@ inline int op_x86_phys_to_virt(int phys)
 	return __get_cpu_var(switch_index) + phys;
 }
 
+inline int op_x86_virt_to_phys(int virt)
+{
+	return virt % model->num_counters;
+}
+
 static void nmi_shutdown_mux(void)
 {
 	int i;
@@ -270,6 +275,7 @@ static void mux_clone(int cpu)
 #else
 
 inline int op_x86_phys_to_virt(int phys) { return phys; }
+inline int op_x86_virt_to_phys(int virt) { return virt; }
 static inline void nmi_shutdown_mux(void) { }
 static inline int nmi_setup_mux(void) { return 1; }
 static inline void

arch/x86/oprofile/op_model_amd.c

@@ -81,7 +81,7 @@ static void op_mux_fill_in_addresses(struct op_msrs * const msrs)
 	int i;
 
 	for (i = 0; i < NUM_VIRT_COUNTERS; i++) {
-		int hw_counter = i % NUM_COUNTERS;
+		int hw_counter = op_x86_virt_to_phys(i);
 		if (reserve_perfctr_nmi(MSR_K7_PERFCTR0 + i))
 			msrs->multiplex[i].addr = MSR_K7_PERFCTR0 + hw_counter;
 		else

arch/x86/oprofile/op_x86_model.h

@@ -60,6 +60,7 @@ struct op_counter_config;
 extern u64 op_x86_get_ctrl(struct op_x86_model_spec const *model,
 			   struct op_counter_config *counter_config);
 extern int op_x86_phys_to_virt(int phys);
+extern int op_x86_virt_to_phys(int virt);
 
 extern struct op_x86_model_spec op_ppro_spec;
 extern struct op_x86_model_spec op_p4_spec;