x86/oprofile: Add function has_mux() to check multiplexing support
The check is used to prevent running multiplexing code for models not
supporting multiplexing. Before, the code was running but without
effect.
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 82ee2951..dca7240 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -124,6 +124,11 @@
static DEFINE_PER_CPU(int, switch_index);
+static inline int has_mux(void)
+{
+ return !!model->switch_ctrl;
+}
+
inline int op_x86_phys_to_virt(int phys)
{
return __get_cpu_var(switch_index) + phys;
@@ -132,6 +137,10 @@
static void nmi_shutdown_mux(void)
{
int i;
+
+ if (!has_mux())
+ return;
+
for_each_possible_cpu(i) {
kfree(per_cpu(cpu_msrs, i).multiplex);
per_cpu(cpu_msrs, i).multiplex = NULL;
@@ -144,12 +153,17 @@
size_t multiplex_size =
sizeof(struct op_msr) * model->num_virt_counters;
int i;
+
+ if (!has_mux())
+ return 1;
+
for_each_possible_cpu(i) {
per_cpu(cpu_msrs, i).multiplex =
kmalloc(multiplex_size, GFP_KERNEL);
if (!per_cpu(cpu_msrs, i).multiplex)
return 0;
}
+
return 1;
}
@@ -158,6 +172,9 @@
int i;
struct op_msr *multiplex = msrs->multiplex;
+ if (!has_mux())
+ return;
+
for (i = 0; i < model->num_virt_counters; ++i) {
if (counter_config[i].enabled) {
multiplex[i].saved = -(u64)counter_config[i].count;
@@ -229,7 +246,7 @@
static int nmi_switch_event(void)
{
- if (!model->switch_ctrl)
+ if (!has_mux())
return -ENOSYS; /* not implemented */
if (nmi_multiplex_on() < 0)
return -EINVAL; /* not necessary */