Merge branch 'acpica' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux...
[sfrench/cifs-2.6.git] / arch / x86 / oprofile / nmi_int.c
index 3347f696edc77d4692f7b0b0fdb774677b573cfa..b28d2f1253bbc927731afa08022fdef21a598a24 100644 (file)
@@ -31,8 +31,9 @@ static struct op_x86_model_spec *model;
 static DEFINE_PER_CPU(struct op_msrs, cpu_msrs);
 static DEFINE_PER_CPU(unsigned long, saved_lvtpc);
 
-/* 0 == registered but off, 1 == registered and on */
-static int nmi_enabled = 0;
+/* must be protected with get_online_cpus()/put_online_cpus(): */
+static int nmi_enabled;
+static int ctr_running;
 
 struct op_counter_config counter_config[OP_MAX_COUNTER];
 
@@ -61,12 +62,16 @@ static int profile_exceptions_notify(struct notifier_block *self,
 {
        struct die_args *args = (struct die_args *)data;
        int ret = NOTIFY_DONE;
-       int cpu = smp_processor_id();
 
        switch (val) {
        case DIE_NMI:
        case DIE_NMI_IPI:
-               model->check_ctrs(args->regs, &per_cpu(cpu_msrs, cpu));
+               if (ctr_running)
+                       model->check_ctrs(args->regs, &__get_cpu_var(cpu_msrs));
+               else if (!nmi_enabled)
+                       break;
+               else
+                       model->stop(&__get_cpu_var(cpu_msrs));
                ret = NOTIFY_STOP;
                break;
        default:
@@ -95,24 +100,36 @@ static void nmi_cpu_save_registers(struct op_msrs *msrs)
 static void nmi_cpu_start(void *dummy)
 {
        struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
-       model->start(msrs);
+       if (!msrs->controls)
+               WARN_ON_ONCE(1);
+       else
+               model->start(msrs);
 }
 
 static int nmi_start(void)
 {
+       get_online_cpus();
        on_each_cpu(nmi_cpu_start, NULL, 1);
+       ctr_running = 1;
+       put_online_cpus();
        return 0;
 }
 
 static void nmi_cpu_stop(void *dummy)
 {
        struct op_msrs const *msrs = &__get_cpu_var(cpu_msrs);
-       model->stop(msrs);
+       if (!msrs->controls)
+               WARN_ON_ONCE(1);
+       else
+               model->stop(msrs);
 }
 
 static void nmi_stop(void)
 {
+       get_online_cpus();
        on_each_cpu(nmi_cpu_stop, NULL, 1);
+       ctr_running = 0;
+       put_online_cpus();
 }
 
 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
@@ -159,7 +176,7 @@ static int nmi_setup_mux(void)
 
        for_each_possible_cpu(i) {
                per_cpu(cpu_msrs, i).multiplex =
-                       kmalloc(multiplex_size, GFP_KERNEL);
+                       kzalloc(multiplex_size, GFP_KERNEL);
                if (!per_cpu(cpu_msrs, i).multiplex)
                        return 0;
        }
@@ -179,7 +196,6 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
                if (counter_config[i].enabled) {
                        multiplex[i].saved = -(u64)counter_config[i].count;
                } else {
-                       multiplex[i].addr  = 0;
                        multiplex[i].saved = 0;
                }
        }
@@ -189,25 +205,27 @@ static void nmi_cpu_setup_mux(int cpu, struct op_msrs const * const msrs)
 
 static void nmi_cpu_save_mpx_registers(struct op_msrs *msrs)
 {
+       struct op_msr *counters = msrs->counters;
        struct op_msr *multiplex = msrs->multiplex;
        int i;
 
        for (i = 0; i < model->num_counters; ++i) {
                int virt = op_x86_phys_to_virt(i);
-               if (multiplex[virt].addr)
-                       rdmsrl(multiplex[virt].addr, multiplex[virt].saved);
+               if (counters[i].addr)
+                       rdmsrl(counters[i].addr, multiplex[virt].saved);
        }
 }
 
 static void nmi_cpu_restore_mpx_registers(struct op_msrs *msrs)
 {
+       struct op_msr *counters = msrs->counters;
        struct op_msr *multiplex = msrs->multiplex;
        int i;
 
        for (i = 0; i < model->num_counters; ++i) {
                int virt = op_x86_phys_to_virt(i);
-               if (multiplex[virt].addr)
-                       wrmsrl(multiplex[virt].addr, multiplex[virt].saved);
+               if (counters[i].addr)
+                       wrmsrl(counters[i].addr, multiplex[virt].saved);
        }
 }
 
@@ -251,7 +269,10 @@ static int nmi_switch_event(void)
        if (nmi_multiplex_on() < 0)
                return -EINVAL;         /* not necessary */
 
-       on_each_cpu(nmi_cpu_switch, NULL, 1);
+       get_online_cpus();
+       if (ctr_running)
+               on_each_cpu(nmi_cpu_switch, NULL, 1);
+       put_online_cpus();
 
        return 0;
 }
@@ -294,6 +315,7 @@ static void free_msrs(void)
                kfree(per_cpu(cpu_msrs, i).controls);
                per_cpu(cpu_msrs, i).controls = NULL;
        }
+       nmi_shutdown_mux();
 }
 
 static int allocate_msrs(void)
@@ -303,17 +325,24 @@ static int allocate_msrs(void)
 
        int i;
        for_each_possible_cpu(i) {
-               per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
+               per_cpu(cpu_msrs, i).counters = kzalloc(counters_size,
                                                        GFP_KERNEL);
                if (!per_cpu(cpu_msrs, i).counters)
-                       return 0;
-               per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
+                       goto fail;
+               per_cpu(cpu_msrs, i).controls = kzalloc(controls_size,
                                                        GFP_KERNEL);
                if (!per_cpu(cpu_msrs, i).controls)
-                       return 0;
+                       goto fail;
        }
 
+       if (!nmi_setup_mux())
+               goto fail;
+
        return 1;
+
+fail:
+       free_msrs();
+       return 0;
 }
 
 static void nmi_cpu_setup(void *dummy)
@@ -335,49 +364,6 @@ static struct notifier_block profile_exceptions_nb = {
        .priority = 2
 };
 
-static int nmi_setup(void)
-{
-       int err = 0;
-       int cpu;
-
-       if (!allocate_msrs())
-               err = -ENOMEM;
-       else if (!nmi_setup_mux())
-               err = -ENOMEM;
-       else
-               err = register_die_notifier(&profile_exceptions_nb);
-
-       if (err) {
-               free_msrs();
-               nmi_shutdown_mux();
-               return err;
-       }
-
-       /* We need to serialize save and setup for HT because the subset
-        * of msrs are distinct for save and setup operations
-        */
-
-       /* Assume saved/restored counters are the same on all CPUs */
-       model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
-       for_each_possible_cpu(cpu) {
-               if (!cpu)
-                       continue;
-
-               memcpy(per_cpu(cpu_msrs, cpu).counters,
-                      per_cpu(cpu_msrs, 0).counters,
-                      sizeof(struct op_msr) * model->num_counters);
-
-               memcpy(per_cpu(cpu_msrs, cpu).controls,
-                      per_cpu(cpu_msrs, 0).controls,
-                      sizeof(struct op_msr) * model->num_controls);
-
-               mux_clone(cpu);
-       }
-       on_each_cpu(nmi_cpu_setup, NULL, 1);
-       nmi_enabled = 1;
-       return 0;
-}
-
 static void nmi_cpu_restore_registers(struct op_msrs *msrs)
 {
        struct op_msr *counters = msrs->counters;
@@ -411,20 +397,24 @@ static void nmi_cpu_shutdown(void *dummy)
        apic_write(APIC_LVTPC, per_cpu(saved_lvtpc, cpu));
        apic_write(APIC_LVTERR, v);
        nmi_cpu_restore_registers(msrs);
+       if (model->cpu_down)
+               model->cpu_down();
 }
 
-static void nmi_shutdown(void)
+static void nmi_cpu_up(void *dummy)
 {
-       struct op_msrs *msrs;
+       if (nmi_enabled)
+               nmi_cpu_setup(dummy);
+       if (ctr_running)
+               nmi_cpu_start(dummy);
+}
 
-       nmi_enabled = 0;
-       on_each_cpu(nmi_cpu_shutdown, NULL, 1);
-       unregister_die_notifier(&profile_exceptions_nb);
-       nmi_shutdown_mux();
-       msrs = &get_cpu_var(cpu_msrs);
-       model->shutdown(msrs);
-       free_msrs();
-       put_cpu_var(cpu_msrs);
+static void nmi_cpu_down(void *dummy)
+{
+       if (ctr_running)
+               nmi_cpu_stop(dummy);
+       if (nmi_enabled)
+               nmi_cpu_shutdown(dummy);
 }
 
 static int nmi_create_files(struct super_block *sb, struct dentry *root)
@@ -456,7 +446,6 @@ static int nmi_create_files(struct super_block *sb, struct dentry *root)
        return 0;
 }
 
-#ifdef CONFIG_SMP
 static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
                                 void *data)
 {
@@ -464,10 +453,10 @@ static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
        switch (action) {
        case CPU_DOWN_FAILED:
        case CPU_ONLINE:
-               smp_call_function_single(cpu, nmi_cpu_start, NULL, 0);
+               smp_call_function_single(cpu, nmi_cpu_up, NULL, 0);
                break;
        case CPU_DOWN_PREPARE:
-               smp_call_function_single(cpu, nmi_cpu_stop, NULL, 1);
+               smp_call_function_single(cpu, nmi_cpu_down, NULL, 1);
                break;
        }
        return NOTIFY_DONE;
@@ -476,7 +465,75 @@ static int oprofile_cpu_notifier(struct notifier_block *b, unsigned long action,
 static struct notifier_block oprofile_cpu_nb = {
        .notifier_call = oprofile_cpu_notifier
 };
-#endif
+
+static int nmi_setup(void)
+{
+       int err = 0;
+       int cpu;
+
+       if (!allocate_msrs())
+               return -ENOMEM;
+
+       /* We need to serialize save and setup for HT because the subset
+        * of msrs are distinct for save and setup operations
+        */
+
+       /* Assume saved/restored counters are the same on all CPUs */
+       err = model->fill_in_addresses(&per_cpu(cpu_msrs, 0));
+       if (err)
+               goto fail;
+
+       for_each_possible_cpu(cpu) {
+               if (!cpu)
+                       continue;
+
+               memcpy(per_cpu(cpu_msrs, cpu).counters,
+                      per_cpu(cpu_msrs, 0).counters,
+                      sizeof(struct op_msr) * model->num_counters);
+
+               memcpy(per_cpu(cpu_msrs, cpu).controls,
+                      per_cpu(cpu_msrs, 0).controls,
+                      sizeof(struct op_msr) * model->num_controls);
+
+               mux_clone(cpu);
+       }
+
+       nmi_enabled = 0;
+       ctr_running = 0;
+       barrier();
+       err = register_die_notifier(&profile_exceptions_nb);
+       if (err)
+               goto fail;
+
+       get_online_cpus();
+       register_cpu_notifier(&oprofile_cpu_nb);
+       on_each_cpu(nmi_cpu_setup, NULL, 1);
+       nmi_enabled = 1;
+       put_online_cpus();
+
+       return 0;
+fail:
+       free_msrs();
+       return err;
+}
+
+static void nmi_shutdown(void)
+{
+       struct op_msrs *msrs;
+
+       get_online_cpus();
+       unregister_cpu_notifier(&oprofile_cpu_nb);
+       on_each_cpu(nmi_cpu_shutdown, NULL, 1);
+       nmi_enabled = 0;
+       ctr_running = 0;
+       put_online_cpus();
+       barrier();
+       unregister_die_notifier(&profile_exceptions_nb);
+       msrs = &get_cpu_var(cpu_msrs);
+       model->shutdown(msrs);
+       free_msrs();
+       put_cpu_var(cpu_msrs);
+}
 
 #ifdef CONFIG_PM
 
@@ -686,9 +743,6 @@ int __init op_nmi_init(struct oprofile_operations *ops)
                return -ENODEV;
        }
 
-#ifdef CONFIG_SMP
-       register_cpu_notifier(&oprofile_cpu_nb);
-#endif
        /* default values, can be overwritten by model */
        ops->create_files       = nmi_create_files;
        ops->setup              = nmi_setup;
@@ -715,12 +769,6 @@ int __init op_nmi_init(struct oprofile_operations *ops)
 
 void op_nmi_exit(void)
 {
-       if (using_nmi) {
+       if (using_nmi)
                exit_sysfs();
-#ifdef CONFIG_SMP
-               unregister_cpu_notifier(&oprofile_cpu_nb);
-#endif
-       }
-       if (model->exit)
-               model->exit();
 }