MIPS/Loongson-3: Convert oprofile to hotplug state machine

Install the callbacks via the state machine and let the core invoke
the callbacks on the already online CPUs.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <rric@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mips@linux-mips.org
Cc: oprofile-list@lists.sf.net
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160713153337.054827168@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

2 files changed, 15 insertions, 21 deletions

diff --git a/arch/mips/oprofile/op_model_loongson3.c b/arch/mips/oprofile/op_model_loongson3.c
index 8bcf7fc40f0d..85f3ee4ab456 100644
--- a/arch/mips/oprofile/op_model_loongson3.c
+++ b/arch/mips/oprofile/op_model_loongson3.c
@@ -168,33 +168,26 @@ static int loongson3_perfcount_handler(void)
         return handled;
 }
 
-static int loongson3_cpu_callback(struct notifier_block *nfb,
-        unsigned long action, void *hcpu)
+static int loongson3_starting_cpu(unsigned int cpu)
 {
-        switch (action) {
-        case CPU_STARTING:
-        case CPU_STARTING_FROZEN:
-                write_c0_perflo1(reg.control1);
-                write_c0_perflo2(reg.control2);
-                break;
-        case CPU_DYING:
-        case CPU_DYING_FROZEN:
-                write_c0_perflo1(0xc0000000);
-                write_c0_perflo2(0x40000000);
-                break;
-        }
-
-        return NOTIFY_OK;
+        write_c0_perflo1(reg.control1);
+        write_c0_perflo2(reg.control2);
+        return 0;
 }
 
-static struct notifier_block loongson3_notifier_block = {
-        .notifier_call = loongson3_cpu_callback
-};
+static int loongson3_dying_cpu(unsigned int cpu)
+{
+        write_c0_perflo1(0xc0000000);
+        write_c0_perflo2(0x40000000);
+        return 0;
+}
 
 static int __init loongson3_init(void)
 {
         on_each_cpu(reset_counters, NULL, 1);
-        register_hotcpu_notifier(&loongson3_notifier_block);
+        cpuhp_setup_state_nocalls(CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
+                                  "AP_MIPS_OP_LOONGSON3_STARTING",
+                                  loongson3_starting_cpu, loongson3_dying_cpu);
         save_perf_irq = perf_irq;
         perf_irq = loongson3_perfcount_handler;
 
@@ -204,7 +197,7 @@ static int __init loongson3_init(void)
 static void loongson3_exit(void)
 {
         on_each_cpu(reset_counters, NULL, 1);
-        unregister_hotcpu_notifier(&loongson3_notifier_block);
+        cpuhp_remove_state_nocalls(CPUHP_AP_MIPS_OP_LOONGSON3_STARTING);
         perf_irq = save_perf_irq;
 }
 
diff --git a/include/linux/cpuhotplug.h b/include/linux/cpuhotplug.h
index 4c02b52dc77f..ad26e353a5c0 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -35,6 +35,7 @@ enum cpuhp_state {
         CPUHP_AP_PERF_X86_CSTATE_STARTING,
         CPUHP_AP_PERF_XTENSA_STARTING,
         CPUHP_AP_PERF_METAG_STARTING,
+        CPUHP_AP_MIPS_OP_LOONGSON3_STARTING,
         CPUHP_AP_ARM_VFP_STARTING,
         CPUHP_AP_PERF_ARM_STARTING,
         CPUHP_AP_ARM_L2X0_STARTING,