x86/oprofile: Implement multiplexing setup/shutdown functions

This patch implements nmi_setup_mux() and nmi_shutdown_mux() functions
to setup/shutdown multiplexing. Multiplexing code in nmi_int.c is now
much more separated.

Signed-off-by: Robert Richter <robert.richter@amd.com>

1 files changed, 40 insertions, 36 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 02b57b8d0e61..674fa37d1502 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -106,9 +106,35 @@ inline int op_x86_phys_to_virt(int phys)
         return __get_cpu_var(switch_index) + phys;
 }
 
+static void nmi_shutdown_mux(void)
+{
+        int i;
+        for_each_possible_cpu(i) {
+                kfree(per_cpu(cpu_msrs, i).multiplex);
+                per_cpu(cpu_msrs, i).multiplex = NULL;
+                per_cpu(switch_index, i) = 0;
+        }
+}
+
+static int nmi_setup_mux(void)
+{
+        size_t multiplex_size =
+                sizeof(struct op_msr) * model->num_virt_counters;
+        int i;
+        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;
+}
+
 #else
 
 inline int op_x86_phys_to_virt(int phys) { return phys; }
+static inline void nmi_shutdown_mux(void) { }
+static inline int nmi_setup_mux(void) { return 1; }
 
 #endif
 
@@ -120,51 +146,27 @@ static void free_msrs(void)
                 per_cpu(cpu_msrs, i).counters = NULL;
                 kfree(per_cpu(cpu_msrs, i).controls);
                 per_cpu(cpu_msrs, i).controls = NULL;
-
-#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
-                kfree(per_cpu(cpu_msrs, i).multiplex);
-                per_cpu(cpu_msrs, i).multiplex = NULL;
-#endif
         }
 }
 
 static int allocate_msrs(void)
 {
-        int success = 1;
         size_t controls_size = sizeof(struct op_msr) * model->num_controls;
         size_t counters_size = sizeof(struct op_msr) * model->num_counters;
-#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
-        size_t multiplex_size = sizeof(struct op_msr) * model->num_virt_counters;
-#endif
 
         int i;
         for_each_possible_cpu(i) {
                 per_cpu(cpu_msrs, i).counters = kmalloc(counters_size,
-                                                                GFP_KERNEL);
-                if (!per_cpu(cpu_msrs, i).counters) {
-                        success = 0;
-                        break;
-                }
+                                                        GFP_KERNEL);
+                if (!per_cpu(cpu_msrs, i).counters)
+                        return 0;
                 per_cpu(cpu_msrs, i).controls = kmalloc(controls_size,
-                                                                GFP_KERNEL);
-                if (!per_cpu(cpu_msrs, i).controls) {
-                        success = 0;
-                        break;
-                }
-#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
-                per_cpu(cpu_msrs, i).multiplex =
-                                kmalloc(multiplex_size, GFP_KERNEL);
-                if (!per_cpu(cpu_msrs, i).multiplex) {
-                        success = 0;
-                        break;
-                }
-#endif
+                                                        GFP_KERNEL);
+                if (!per_cpu(cpu_msrs, i).controls)
+                        return 0;
         }
 
-        if (!success)
-                free_msrs();
-
-        return success;
+        return 1;
 }
 
 #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
@@ -218,11 +220,15 @@ static int nmi_setup(void)
         int cpu;
 
         if (!allocate_msrs())
-                return -ENOMEM;
+                err = -ENOMEM;
+        else if (!nmi_setup_mux())
+                err = -ENOMEM;
+        else
+                err = register_die_notifier(&profile_exceptions_nb);
 
-        err = register_die_notifier(&profile_exceptions_nb);
         if (err) {
                 free_msrs();
+                nmi_shutdown_mux();
                 return err;
         }
 
@@ -314,9 +320,6 @@ 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);
-#ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX
-        per_cpu(switch_index, cpu) = 0;
-#endif
 }
 
 static void nmi_shutdown(void)
@@ -326,6 +329,7 @@ static void nmi_shutdown(void)
         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();