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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 <bigeasy@linutronix.de>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20160818125731.27256-14-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
This commit is contained in:
Sebastian Andrzej Siewior 2016-08-18 14:57:28 +02:00 committed by Thomas Gleixner
parent dfc616d8b3
commit e8483b578b
1 changed files with 12 additions and 58 deletions
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70
drivers/bus/mips_cdmm.c
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@ -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);