1 files changed, 92 insertions, 8 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 287513a09819..2a65fe7680ab 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -23,12 +23,18 @@
 #include "op_counter.h"
 #include "op_x86_model.h"
 
+DEFINE_PER_CPU(int, switch_index);
+
 static struct op_x86_model_spec const *model;
 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);
+static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs);
+static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs);
+static void nmi_cpu_stop(void *dummy);
+static void nmi_cpu_start(void *dummy);
 
 /* 0 == registered but off, 1 == registered and on */
 static int nmi_enabled = 0;
@@ -81,6 +87,47 @@ static void exit_sysfs(void)
 #define exit_sysfs() do { } while (0)
 #endif /* CONFIG_PM */
 
+static void nmi_cpu_switch(void *dummy)
+{
+        int cpu = smp_processor_id();
+        int si = per_cpu(switch_index, cpu);
+        struct op_msrs *msrs = &per_cpu(cpu_msrs, cpu);
+
+        nmi_cpu_stop(NULL);
+        nmi_cpu_save_mpx_registers(msrs);
+
+        /* move to next set */
+        si += model->num_hardware_counters;
+        if ((si > model->num_counters) || (counter_config[si].count == 0))
+                per_cpu(switch_index, smp_processor_id()) = 0;
+        else
+                per_cpu(switch_index, smp_processor_id()) = si;
+
+        nmi_cpu_restore_mpx_registers(msrs);
+        model->setup_ctrs(msrs);
+        nmi_cpu_start(NULL);
+}
+
+/*
+ * Quick check to see if multiplexing is necessary.
+ * The check should be sufficient since counters are used
+ * in ordre.
+ */
+static int nmi_multiplex_on(void)
+{
+        return counter_config[model->num_hardware_counters].count ? 0 : -EINVAL;
+}
+
+static int nmi_switch_event(void)
+{
+        if (nmi_multiplex_on() < 0)
+                return -EINVAL;
+
+        on_each_cpu(nmi_cpu_switch, NULL, 0, 1);
+
+        return 0;
+}
+
 static int profile_exceptions_notify(struct notifier_block *self,
                                      unsigned long val, void *data)
 {
@@ -144,11 +191,10 @@ static void free_msrs(void)
 
 static int allocate_msrs(void)
 {
-        int success = 1;
+        int i, success = 1;
         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
 
-        int i;
         for_each_possible_cpu(i) {
                 per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
                                                                 GFP_KERNEL);
@@ -156,8 +202,8 @@ static int allocate_msrs(void)
                         success = 0;
                         break;
                 }
-                per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
-                                                                GFP_KERNEL);
+                per_cpu(cpu_msrs, i).controls =
+                                kmalloc(controls_size, GFP_KERNEL);
                 if (!per_cpu(cpu_msrs, i).controls) {
                         success = 0;
                         break;
@@ -201,7 +247,8 @@ static int nmi_setup(void)
                 return err;
         }
 
-        /* We need to serialize save and setup for HT because the subset
+        /*
+         * We need to serialize save and setup for HT because the subset
          * of msrs are distinct for save and setup operations
          */
 
@@ -217,7 +264,6 @@ static int nmi_setup(void)
                                 per_cpu(cpu_msrs, 0).controls,
                                 sizeof(struct op_msr) * model->num_controls);
                 }
-
         }
         on_each_cpu(nmi_save_registers, NULL, 1);
         on_each_cpu(nmi_cpu_setup, NULL, 1);
@@ -225,7 +271,41 @@ static int nmi_setup(void)
         return 0;
 }
 
-static void nmi_restore_registers(struct op_msrs *msrs)
+static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
+{
+        unsigned int si = __get_cpu_var(switch_index);
+        unsigned int const nr_ctrs = model->num_hardware_counters;
+        struct op_msr *counters = &msrs->counters[si];
+        unsigned int i;
+
+        for (i = 0; i < nr_ctrs; ++i) {
+                int offset = i + si;
+                if (counters[offset].addr) {
+                        rdmsr(counters[offset].addr,
+                                counters[offset].multiplex.low,
+                                counters[offset].multiplex.high);
+                }
+        }
+}
+
+static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
+{
+        unsigned int si = __get_cpu_var(switch_index);
+        unsigned int const nr_ctrs = model->num_hardware_counters;
+        struct op_msr *counters = &msrs->counters[si];
+        unsigned int i;
+
+        for (i = 0; i < nr_ctrs; ++i) {
+                int offset = i + si;
+                if (counters[offset].addr) {
+                        wrmsr(counters[offset].addr,
+                                counters[offset].multiplex.low,
+                                counters[offset].multiplex.high);
+                }
+        }
+}
+
+static void nmi_cpu_restore_registers(struct op_msrs *msrs)
 {
         unsigned int const nr_ctrs = model->num_counters;
         unsigned int const nr_ctrls = model->num_controls;
@@ -265,7 +345,8 @@ static void nmi_cpu_shutdown(void *dummy)
         apic_write(APIC_LVTERR, v | APIC_LVT_MASKED);
         apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
         apic_write(APIC_LVTERR, v);
-        nmi_restore_registers(msrs);
+        nmi_cpu_restore_registers(msrs);
+        __get_cpu_var(switch_index) = 0;
 }
 
 static void nmi_shutdown(void)
@@ -328,6 +409,7 @@ static int nmi_create_files(struct super_block *sb, struct dentry *root)
                 oprofilefs_create_ulong(sb, dir, "unit_mask", &counter_config[i].unit_mask);
                 oprofilefs_create_ulong(sb, dir, "kernel", &counter_config[i].kernel);
                 oprofilefs_create_ulong(sb, dir, "user", &counter_config[i].user);
+                counter_config[i].save_count_low = 0;
         }
 
         return 0;
@@ -469,12 +551,14 @@ int __init op_nmi_init(struct oprofile_operations *ops)
         }
 
         /* default values, can be overwritten by model */
+        __get_cpu_var(switch_index) = 0;
         ops->create_files = nmi_create_files;
         ops->setup = nmi_setup;
         ops->shutdown = nmi_shutdown;
         ops->start = nmi_start;
         ops->stop = nmi_stop;
         ops->cpu_type = cpu_type;
+        ops->switch_events = nmi_switch_event;
 
         if (model->init)
                 ret = model->init(ops);