oprofile/x86: make AMD IBS hotplug capable

Current IBS code is not hotplug capable. An offline cpu might not be
initialized or deinitialized properly. This patch fixes this by
removing on_each_cpu() functions. The IBS init/deinit code is executed
in the per-cpu functions model->setup_ctrs() and model->cpu_down()
which are also called by hotplug notifiers. model->cpu_down() replaces
model->exit() that became obsolete.

Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Robert Richter <robert.richter@amd.com>

3 files changed, 19 insertions, 41 deletions

diff --git a/arch/x86/oprofile/nmi_int.c b/arch/x86/oprofile/nmi_int.c
index 2a086726cad1..b28d2f1253bb 100644
--- a/arch/x86/oprofile/nmi_int.c
+++ b/arch/x86/oprofile/nmi_int.c
@@ -397,6 +397,8 @@ 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_cpu_up(void *dummy)
@@ -769,6 +771,4 @@ void op_nmi_exit(void)
 {
         if (using_nmi)
                 exit_sysfs();
-        if (model->exit)
-                model->exit();
 }
diff --git a/arch/x86/oprofile/op_model_amd.c b/arch/x86/oprofile/op_model_amd.c
index 384c52410480..b67a6b5aa8d4 100644
--- a/arch/x86/oprofile/op_model_amd.c
+++ b/arch/x86/oprofile/op_model_amd.c
@@ -374,6 +374,15 @@ static void op_amd_setup_ctrs(struct op_x86_model_spec const *model,
                 val |= op_x86_get_ctrl(model, &counter_config[virt]);
                 wrmsrl(msrs->controls[i].addr, val);
         }
+
+        if (ibs_caps)
+                setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_NMI, 0);
+}
+
+static void op_amd_cpu_shutdown(void)
+{
+        if (ibs_caps)
+                setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_FIX, 1);
 }
 
 static int op_amd_check_ctrs(struct pt_regs * const regs,
@@ -436,28 +445,16 @@ static void op_amd_stop(struct op_msrs const * const msrs)
         op_amd_stop_ibs();
 }
 
-static u8 ibs_eilvt_off;
-
-static inline void apic_init_ibs_nmi_per_cpu(void *arg)
-{
-        ibs_eilvt_off = setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_NMI, 0);
-}
-
-static inline void apic_clear_ibs_nmi_per_cpu(void *arg)
-{
-        setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_FIX, 1);
-}
-
-static int init_ibs_nmi(void)
+static int __init_ibs_nmi(void)
 {
 #define IBSCTL_LVTOFFSETVAL             (1 << 8)
 #define IBSCTL                          0x1cc
         struct pci_dev *cpu_cfg;
         int nodes;
         u32 value = 0;
+        u8 ibs_eilvt_off;
 
-        /* per CPU setup */
-        on_each_cpu(apic_init_ibs_nmi_per_cpu, NULL, 1);
+        ibs_eilvt_off = setup_APIC_eilvt_ibs(0, APIC_EILVT_MSG_FIX, 1);
 
         nodes = 0;
         cpu_cfg = NULL;
@@ -487,21 +484,15 @@ static int init_ibs_nmi(void)
         return 0;
 }
 
-/* uninitialize the APIC for the IBS interrupts if needed */
-static void clear_ibs_nmi(void)
-{
-        on_each_cpu(apic_clear_ibs_nmi_per_cpu, NULL, 1);
-}
-
 /* initialize the APIC for the IBS interrupts if available */
-static void ibs_init(void)
+static void init_ibs(void)
 {
         ibs_caps = get_ibs_caps();
 
         if (!ibs_caps)
                 return;
 
-        if (init_ibs_nmi()) {
+        if (__init_ibs_nmi()) {
                 ibs_caps = 0;
                 return;
         }
@@ -510,14 +501,6 @@ static void ibs_init(void)
                (unsigned)ibs_caps);
 }
 
-static void ibs_exit(void)
-{
-        if (!ibs_caps)
-                return;
-
-        clear_ibs_nmi();
-}
-
 static int (*create_arch_files)(struct super_block *sb, struct dentry *root);
 
 static int setup_ibs_files(struct super_block *sb, struct dentry *root)
@@ -566,17 +549,12 @@ static int setup_ibs_files(struct super_block *sb, struct dentry *root)
 
 static int op_amd_init(struct oprofile_operations *ops)
 {
-        ibs_init();
+        init_ibs();
         create_arch_files = ops->create_files;
         ops->create_files = setup_ibs_files;
         return 0;
 }
 
-static void op_amd_exit(void)
-{
-        ibs_exit();
-}
-
 struct op_x86_model_spec op_amd_spec = {
         .num_counters           = NUM_COUNTERS,
         .num_controls           = NUM_COUNTERS,
@@ -584,9 +562,9 @@ struct op_x86_model_spec op_amd_spec = {
         .reserved               = MSR_AMD_EVENTSEL_RESERVED,
         .event_mask             = OP_EVENT_MASK,
         .init                   = op_amd_init,
-        .exit                   = op_amd_exit,
         .fill_in_addresses      = &op_amd_fill_in_addresses,
         .setup_ctrs             = &op_amd_setup_ctrs,
+        .cpu_down               = &op_amd_cpu_shutdown,
         .check_ctrs             = &op_amd_check_ctrs,
         .start                  = &op_amd_start,
         .stop                   = &op_amd_stop,
diff --git a/arch/x86/oprofile/op_x86_model.h b/arch/x86/oprofile/op_x86_model.h
index 551401398fba..89017fa1fd63 100644
--- a/arch/x86/oprofile/op_x86_model.h
+++ b/arch/x86/oprofile/op_x86_model.h
@@ -40,10 +40,10 @@ struct op_x86_model_spec {
         u64             reserved;
         u16             event_mask;
         int             (*init)(struct oprofile_operations *ops);
-        void            (*exit)(void);
         int             (*fill_in_addresses)(struct op_msrs * const msrs);
         void            (*setup_ctrs)(struct op_x86_model_spec const *model,
                                       struct op_msrs const * const msrs);
+        void            (*cpu_down)(void);
         int             (*check_ctrs)(struct pt_regs * const regs,
                                       struct op_msrs const * const msrs);
         void            (*start)(struct op_msrs const * const msrs);