From e8483b578b229774382a95891439b2ebd9c92fc5 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Thu, 18 Aug 2016 14:57:28 +0200 Subject: [PATCH] MIPS/BUS/CDMM: Convert 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: Sebastian Andrzej Siewior Cc: James Hogan Cc: Peter Zijlstra Cc: Ralf Baechle Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20160818125731.27256-14-bigeasy@linutronix.de Signed-off-by: Thomas Gleixner --- drivers/bus/mips_cdmm.c | 70 +++++++---------------------------------- 1 file changed, 12 insertions(+), 58 deletions(-) diff --git a/drivers/bus/mips_cdmm.c b/drivers/bus/mips_cdmm.c index cad49bc38b3e..1b14256376d2 100644 --- a/drivers/bus/mips_cdmm.c +++ b/drivers/bus/mips_cdmm.c @@ -596,19 +596,20 @@ BUILD_PERDEV_HELPER(cpu_down) /* int mips_cdmm_cpu_down_helper(...) */ BUILD_PERDEV_HELPER(cpu_up) /* int mips_cdmm_cpu_up_helper(...) */ /** - * mips_cdmm_bus_down() - Tear down the CDMM bus. - * @data: Pointer to unsigned int CPU number. + * mips_cdmm_cpu_down_prep() - Callback for CPUHP DOWN_PREP: + * Tear down the CDMM bus. + * @cpu: unsigned int CPU number. * * This function is executed on the hotplugged CPU and calls the CDMM * driver cpu_down callback for all devices on that CPU. */ -static long mips_cdmm_bus_down(void *data) +static int mips_cdmm_cpu_down_prep(unsigned int cpu) { struct mips_cdmm_bus *bus; long ret; /* Inform all the devices on the bus */ - ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, data, + ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, mips_cdmm_cpu_down_helper); /* @@ -623,8 +624,8 @@ static long mips_cdmm_bus_down(void *data) } /** - * mips_cdmm_bus_up() - Bring up the CDMM bus. - * @data: Pointer to unsigned int CPU number. + * mips_cdmm_cpu_online() - Callback for CPUHP ONLINE: Bring up the CDMM bus. + * @cpu: unsigned int CPU number. * * This work_on_cpu callback function is executed on a given CPU to discover * CDMM devices on that CPU, or to call the CDMM driver cpu_up callback for all @@ -634,7 +635,7 @@ static long mips_cdmm_bus_down(void *data) * initialisation. When CPUs are brought online the function is * invoked directly on the hotplugged CPU. */ -static long mips_cdmm_bus_up(void *data) +static int mips_cdmm_cpu_online(unsigned int cpu) { struct mips_cdmm_bus *bus; long ret; @@ -651,50 +652,12 @@ static long mips_cdmm_bus_up(void *data) mips_cdmm_bus_discover(bus); else /* Inform all the devices on the bus */ - ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, data, + ret = bus_for_each_dev(&mips_cdmm_bustype, NULL, &cpu, mips_cdmm_cpu_up_helper); return ret; } -/** - * mips_cdmm_cpu_notify() - Take action when a CPU is going online or offline. - * @nb: CPU notifier block . - * @action: Event that has taken place (CPU_*). - * @data: CPU number. - * - * This notifier is used to keep the CDMM buses updated as CPUs are offlined and - * onlined. When CPUs go offline or come back online, so does their CDMM bus, so - * devices must be informed. Also when CPUs come online for the first time the - * devices on the CDMM bus need discovering. - * - * Returns: NOTIFY_OK if event was used. - * NOTIFY_DONE if we didn't care. - */ -static int mips_cdmm_cpu_notify(struct notifier_block *nb, - unsigned long action, void *data) -{ - unsigned int cpu = (unsigned int)data; - - switch (action & ~CPU_TASKS_FROZEN) { - case CPU_ONLINE: - case CPU_DOWN_FAILED: - mips_cdmm_bus_up(&cpu); - break; - case CPU_DOWN_PREPARE: - mips_cdmm_bus_down(&cpu); - break; - default: - return NOTIFY_DONE; - } - - return NOTIFY_OK; -} - -static struct notifier_block mips_cdmm_cpu_nb = { - .notifier_call = mips_cdmm_cpu_notify, -}; - /** * mips_cdmm_init() - Initialise CDMM bus. * @@ -703,7 +666,6 @@ static struct notifier_block mips_cdmm_cpu_nb = { */ static int __init mips_cdmm_init(void) { - unsigned int cpu; int ret; /* Register the bus */ @@ -712,19 +674,11 @@ static int __init mips_cdmm_init(void) return ret; /* We want to be notified about new CPUs */ - ret = register_cpu_notifier(&mips_cdmm_cpu_nb); - if (ret) { + ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "bus/cdmm:online", + mips_cdmm_cpu_online, mips_cdmm_cpu_down_prep); + if (ret < 0) pr_warn("cdmm: Failed to register CPU notifier\n"); - goto out; - } - /* Discover devices on CDMM of online CPUs */ - for_each_online_cpu(cpu) - work_on_cpu(cpu, mips_cdmm_bus_up, &cpu); - - return 0; -out: - bus_unregister(&mips_cdmm_bustype); return ret; } subsys_initcall(mips_cdmm_init);