x86: oprofile: remove NR_CPUS arrays in arch/x86/oprofile/nmi_int.c

Change the following arrays sized by NR_CPUS to be PERCPU variables:

	static struct op_msrs cpu_msrs[NR_CPUS];
	static unsigned long saved_lvtpc[NR_CPUS];

Also some minor complaints from checkpatch.pl fixed.

Based on:
	git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
	git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86.git

All changes were transparent except for:

 static void nmi_shutdown(void)
 {
+	struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 	nmi_enabled = 0;
 	on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
 	unregister_die_notifier(&profile_exceptions_nb);
-	model->shutdown(cpu_msrs);
+	model->shutdown(msrs);
 	free_msrs();
 }

The existing code passed a reference to cpu 0's instance of struct op_msrs
to model->shutdown, whilst the other functions are passed a reference to
<this cpu's> instance of a struct op_msrs.  This seemed to be a bug to me
even though as long as cpu 0 and <this cpu> are of the same type it would
have the same effect...?

Cc: Philippe Elie <phil.el@wanadoo.fr>
Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 27 insertions, 22 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 1f11cf0a307f..cc48d3fde545 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -23,8 +23,8 @@
 #include "op_x86_model.h"
 
 static struct op_x86_model_spec const *model;
-static struct op_msrs cpu_msrs[NR_CPUS];
-static unsigned long saved_lvtpc[NR_CPUS];
+static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
+static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
 
 static int nmi_start(void);
 static void nmi_stop(void);
@@ -89,7 +89,7 @@ static int profile_exceptions_notify(struct notifier_block *self,
 
         switch (val) {
         case DIE_NMI:
-                if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
+                if (model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu)))
                         ret = NOTIFY_STOP;
                 break;
         default:
@@ -126,7 +126,7 @@ static void nmi_cpu_save_registers(struct op_msrs *msrs)
 static void nmi_save_registers(void *dummy)
 {
         int cpu = smp_processor_id();
-        struct op_msrs *msrs = &cpu_msrs[cpu];
+        struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
         nmi_cpu_save_registers(msrs);
 }
 
@@ -134,10 +134,10 @@ static void free_msrs(void)
 {
         int i;
         for_each_possible_cpu(i) {
-                kfree(cpu_msrs[i].counters);
-                cpu_msrs[i].counters = NULL;
-                kfree(cpu_msrs[i].controls);
-                cpu_msrs[i].controls = NULL;
+                kfree(per_cpu(cpu_msrs, i).counters);
+                per_cpu(cpu_msrs, i).counters = NULL;
+                kfree(per_cpu(cpu_msrs, i).controls);
+                per_cpu(cpu_msrs, i).controls = NULL;
         }
 }
 
@@ -149,13 +149,15 @@ static int allocate_msrs(void)
 
         int i;
         for_each_possible_cpu(i) {
-                cpu_msrs[i].counters = kmalloc(counters_size, GFP_KERNEL);
-                if (!cpu_msrs[i].counters) {
+                per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
+                                                                GFP_KERNEL);
+                if (!per_cpu(cpu_msrs, i).counters) {
                         success = 0;
                         break;
                 }
-                cpu_msrs[i].controls = kmalloc(controls_size, GFP_KERNEL);
-                if (!cpu_msrs[i].controls) {
+                per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
+                                                                GFP_KERNEL);
+                if (!per_cpu(cpu_msrs, i).controls) {
                         success = 0;
                         break;
                 }
@@ -170,11 +172,11 @@ static int allocate_msrs(void)
 static void nmi_cpu_setup(void *dummy)
 {
         int cpu = smp_processor_id();
-        struct op_msrs *msrs = &cpu_msrs[cpu];
+        struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
         spin_lock(&oprofilefs_lock);
         model->setup_ctrs(msrs);
         spin_unlock(&oprofilefs_lock);
-        saved_lvtpc[cpu] = apic_read(APIC_LVTPC);
+        per_cpu(saved_lvtpc, cpu) = apic_read(APIC_LVTPC);
         apic_write(APIC_LVTPC, APIC_DM_NMI);
 }
 
@@ -203,13 +205,15 @@ static int nmi_setup(void)
          */
 
         /* Assume saved/restored counters are the same on all CPUs */
-        model->fill_in_addresses(&cpu_msrs[0]);
+        model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
         for_each_possible_cpu(cpu) {
                 if (cpu != 0) {
-                        memcpy(cpu_msrs[cpu].counters, cpu_msrs[0].counters,
+                        memcpy(per_cpu(cpu_msrs, cpu).counters,
+                                per_cpu(cpu_msrs, 0).counters,
                                 sizeof(struct op_msr) * model->num_counters);
 
-                        memcpy(cpu_msrs[cpu].controls, cpu_msrs[0].controls,
+                        memcpy(per_cpu(cpu_msrs, cpu).controls,
+                                per_cpu(cpu_msrs, 0).controls,
                                 sizeof(struct op_msr) * model->num_controls);
                 }
 
@@ -249,7 +253,7 @@ static void nmi_cpu_shutdown(void *dummy)
 {
         unsigned int v;
         int cpu = smp_processor_id();
-        struct op_msrs *msrs = &cpu_msrs[cpu];
+        struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
 
         /* restoring APIC_LVTPC can trigger an apic error because the delivery
          * mode and vector nr combination can be illegal. That's by design: on
@@ -258,23 +262,24 @@ static void nmi_cpu_shutdown(void *dummy)
          */
         v = apic_read(APIC_LVTERR);
         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
-        apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
+        apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
         apic_write(APIC_LVTERR, v);
         nmi_restore_registers(msrs);
 }
 
 static void nmi_shutdown(void)
 {
+        struct op_msrs *msrs = &__get_cpu_var(cpu_msrs);
         nmi_enabled = 0;
         on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
         unregister_die_notifier(&profile_exceptions_nb);
-        model->shutdown(cpu_msrs);
+        model->shutdown(msrs);
         free_msrs();
 }
 
 static void nmi_cpu_start(void *dummy)
 {
-        struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+        struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
         model->start(msrs);
 }
 
@@ -286,7 +291,7 @@ static int nmi_start(void)
 
 static void nmi_cpu_stop(void *dummy)
 {
-        struct op_msrs const *msrs = &cpu_msrs[smp_processor_id()];
+        struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
         model->stop(msrs);
 }