Discussion:
[patch V2 50/67] MIPS/Loongson-3: Convert oprofile to hotplug state machine
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Anna-Maria Gleixner
2016-07-13 17:16:53 UTC
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Raw Message
From: Richard Cochran <***@linutronix.de>

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

Signed-off-by: Richard Cochran <***@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <***@linutronix.de>
Acked-by: Ralf Baechle <***@linux-mips.org>
Cc: Linus Torvalds <***@linux-foundation.org>
Cc: Peter Zijlstra <***@infradead.org>
Cc: Robert Richter <***@kernel.org>
Cc: Thomas Gleixner <***@linutronix.de>
Cc: linux-***@linux-mips.org
Cc: oprofile-***@lists.sf.net
Signed-off-by: Anna-Maria Gleixner <anna-***@linutronix.de>
---
arch/mips/oprofile/op_model_loongson3.c | 35 +++++++++++++--------------------
include/linux/cpuhotplug.h | 1 +
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 8bcf7fc..85f3ee4 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 f986963..18dbf7b 100644
--- a/include/linux/cpuhotplug.h
+++ b/include/linux/cpuhotplug.h
@@ -36,6 +36,7 @@ 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,
--
2.8.1
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