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Diffstat (limited to 'arch/i386/oprofile/nmi_int.c')
-rw-r--r--arch/i386/oprofile/nmi_int.c88
1 files changed, 59 insertions, 29 deletions
diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c
index 5f8dc8a..3700eef 100644
--- a/arch/i386/oprofile/nmi_int.c
+++ b/arch/i386/oprofile/nmi_int.c
@@ -17,14 +17,15 @@
#include <asm/nmi.h>
#include <asm/msr.h>
#include <asm/apic.h>
+#include <asm/kdebug.h>
#include "op_counter.h"
#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 int nmi_start(void);
static void nmi_stop(void);
@@ -82,13 +83,24 @@ static void exit_driverfs(void)
#define exit_driverfs() do { } while (0)
#endif /* CONFIG_PM */
-
-static int nmi_callback(struct pt_regs * regs, int cpu)
+static int profile_exceptions_notify(struct notifier_block *self,
+ unsigned long val, void *data)
{
- return model->check_ctrs(regs, &cpu_msrs[cpu]);
+ struct die_args *args = (struct die_args *)data;
+ int ret = NOTIFY_DONE;
+ int cpu = smp_processor_id();
+
+ switch(val) {
+ case DIE_NMI:
+ if (model->check_ctrs(args->regs, &cpu_msrs[cpu]))
+ ret = NOTIFY_STOP;
+ break;
+ default:
+ break;
+ }
+ return ret;
}
-
-
+
static void nmi_cpu_save_registers(struct op_msrs * msrs)
{
unsigned int const nr_ctrs = model->num_counters;
@@ -98,15 +110,19 @@ static void nmi_cpu_save_registers(struct op_msrs * msrs)
unsigned int i;
for (i = 0; i < nr_ctrs; ++i) {
- rdmsr(counters[i].addr,
- counters[i].saved.low,
- counters[i].saved.high);
+ if (counters[i].addr){
+ rdmsr(counters[i].addr,
+ counters[i].saved.low,
+ counters[i].saved.high);
+ }
}
for (i = 0; i < nr_ctrls; ++i) {
- rdmsr(controls[i].addr,
- controls[i].saved.low,
- controls[i].saved.high);
+ if (controls[i].addr){
+ rdmsr(controls[i].addr,
+ controls[i].saved.low,
+ controls[i].saved.high);
+ }
}
}
@@ -170,27 +186,29 @@ static void nmi_cpu_setup(void * dummy)
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
+static struct notifier_block profile_exceptions_nb = {
+ .notifier_call = profile_exceptions_notify,
+ .next = NULL,
+ .priority = 0
+};
static int nmi_setup(void)
{
+ int err=0;
+
if (!allocate_msrs())
return -ENOMEM;
- /* We walk a thin line between law and rape here.
- * We need to be careful to install our NMI handler
- * without actually triggering any NMIs as this will
- * break the core code horrifically.
- */
- if (reserve_lapic_nmi() < 0) {
+ if ((err = register_die_notifier(&profile_exceptions_nb))){
free_msrs();
- return -EBUSY;
+ return err;
}
+
/* We need to serialize save and setup for HT because the subset
* of msrs are distinct for save and setup operations
*/
on_each_cpu(nmi_save_registers, NULL, 0, 1);
on_each_cpu(nmi_cpu_setup, NULL, 0, 1);
- set_nmi_callback(nmi_callback);
nmi_enabled = 1;
return 0;
}
@@ -205,15 +223,19 @@ static void nmi_restore_registers(struct op_msrs * msrs)
unsigned int i;
for (i = 0; i < nr_ctrls; ++i) {
- wrmsr(controls[i].addr,
- controls[i].saved.low,
- controls[i].saved.high);
+ if (controls[i].addr){
+ wrmsr(controls[i].addr,
+ controls[i].saved.low,
+ controls[i].saved.high);
+ }
}
for (i = 0; i < nr_ctrs; ++i) {
- wrmsr(counters[i].addr,
- counters[i].saved.low,
- counters[i].saved.high);
+ if (counters[i].addr){
+ wrmsr(counters[i].addr,
+ counters[i].saved.low,
+ counters[i].saved.high);
+ }
}
}
@@ -234,6 +256,7 @@ static void nmi_cpu_shutdown(void * dummy)
apic_write(APIC_LVTPC, saved_lvtpc[cpu]);
apic_write(APIC_LVTERR, v);
nmi_restore_registers(msrs);
+ model->shutdown(msrs);
}
@@ -241,8 +264,7 @@ static void nmi_shutdown(void)
{
nmi_enabled = 0;
on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1);
- unset_nmi_callback();
- release_lapic_nmi();
+ unregister_die_notifier(&profile_exceptions_nb);
free_msrs();
}
@@ -284,6 +306,14 @@ static int nmi_create_files(struct super_block * sb, struct dentry * root)
struct dentry * dir;
char buf[4];
+ /* quick little hack to _not_ expose a counter if it is not
+ * available for use. This should protect userspace app.
+ * NOTE: assumes 1:1 mapping here (that counters are organized
+ * sequentially in their struct assignment).
+ */
+ if (unlikely(!avail_to_resrv_perfctr_nmi_bit(i)))
+ continue;
+
snprintf(buf, sizeof(buf), "%d", i);
dir = oprofilefs_mkdir(sb, root, buf);
oprofilefs_create_ulong(sb, dir, "enabled", &counter_config[i].enabled);
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