[tip:smp/hotplug] watchdog/octeon: Convert to hotplug state machine

From: tip-bot for Sebastian Andrzej Siewior
Date: Mon Nov 21 2016 - 10:51:45 EST


Commit-ID: 883fa6da66effbada2b1c26ebb752166083e50bf
Gitweb: http://git.kernel.org/tip/883fa6da66effbada2b1c26ebb752166083e50bf
Author: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
AuthorDate: Thu, 17 Nov 2016 19:35:32 +0100
Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Mon, 21 Nov 2016 16:37:07 +0100

watchdog/octeon: 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@xxxxxxxxxxxxx>
Cc: Wim Van Sebroeck <wim@xxxxxxxxx>
Cc: rt@xxxxxxxxxxxxxx
Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
Cc: linux-watchdog@xxxxxxxxxxxxxxx
Link: http://lkml.kernel.org/r/20161117183541.8588-12-bigeasy@xxxxxxxxxxxxx
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

---
drivers/watchdog/octeon-wdt-main.c | 62 +++++++++-----------------------------
1 file changed, 15 insertions(+), 47 deletions(-)

diff --git a/drivers/watchdog/octeon-wdt-main.c b/drivers/watchdog/octeon-wdt-main.c
index b55981f..529182d 100644
--- a/drivers/watchdog/octeon-wdt-main.c
+++ b/drivers/watchdog/octeon-wdt-main.c
@@ -374,7 +374,7 @@ void octeon_wdt_nmi_stage3(u64 reg[32])
octeon_wdt_write_string("*** Chip soft reset soon ***\r\n");
}

-static void octeon_wdt_disable_interrupt(int cpu)
+static int octeon_wdt_cpu_pre_down(unsigned int cpu)
{
unsigned int core;
unsigned int irq;
@@ -392,9 +392,10 @@ static void octeon_wdt_disable_interrupt(int cpu)
cvmx_write_csr(CVMX_CIU_WDOGX(core), ciu_wdog.u64);

free_irq(irq, octeon_wdt_poke_irq);
+ return 0;
}

-static void octeon_wdt_setup_interrupt(int cpu)
+static int octeon_wdt_cpu_online(unsigned int cpu)
{
unsigned int core;
unsigned int irq;
@@ -424,25 +425,8 @@ static void octeon_wdt_setup_interrupt(int cpu)
ciu_wdog.s.len = timeout_cnt;
ciu_wdog.s.mode = 3; /* 3 = Interrupt + NMI + Soft-Reset */
cvmx_write_csr(CVMX_CIU_WDOGX(core), ciu_wdog.u64);
-}

-static int octeon_wdt_cpu_callback(struct notifier_block *nfb,
- unsigned long action, void *hcpu)
-{
- unsigned int cpu = (unsigned long)hcpu;
-
- switch (action & ~CPU_TASKS_FROZEN) {
- case CPU_DOWN_PREPARE:
- octeon_wdt_disable_interrupt(cpu);
- break;
- case CPU_ONLINE:
- case CPU_DOWN_FAILED:
- octeon_wdt_setup_interrupt(cpu);
- break;
- default:
- break;
- }
- return NOTIFY_OK;
+ return 0;
}

static int octeon_wdt_ping(struct watchdog_device __always_unused *wdog)
@@ -531,10 +515,6 @@ static int octeon_wdt_stop(struct watchdog_device *wdog)
return 0;
}

-static struct notifier_block octeon_wdt_cpu_notifier = {
- .notifier_call = octeon_wdt_cpu_callback,
-};
-
static const struct watchdog_info octeon_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "OCTEON",
@@ -553,6 +533,7 @@ static struct watchdog_device octeon_wdt = {
.ops = &octeon_wdt_ops,
};

+static enum cpuhp_state octeon_wdt_online;
/**
* Module/ driver initialization.
*
@@ -562,7 +543,6 @@ static int __init octeon_wdt_init(void)
{
int i;
int ret;
- int cpu;
u64 *ptr;

/*
@@ -610,14 +590,16 @@ static int __init octeon_wdt_init(void)

cpumask_clear(&irq_enabled_cpus);

- cpu_notifier_register_begin();
- for_each_online_cpu(cpu)
- octeon_wdt_setup_interrupt(cpu);
-
- __register_hotcpu_notifier(&octeon_wdt_cpu_notifier);
- cpu_notifier_register_done();
-
+ ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "watchdog/octeon:online",
+ octeon_wdt_cpu_online, octeon_wdt_cpu_pre_down);
+ if (ret < 0)
+ goto err;
+ octeon_wdt_online = ret;
return 0;
+err:
+ cvmx_write_csr(CVMX_MIO_BOOT_LOC_CFGX(0), 0);
+ watchdog_unregister_device(&octeon_wdt);
+ return ret;
}

/**
@@ -625,22 +607,8 @@ static int __init octeon_wdt_init(void)
*/
static void __exit octeon_wdt_cleanup(void)
{
- int cpu;
-
watchdog_unregister_device(&octeon_wdt);
-
- cpu_notifier_register_begin();
- __unregister_hotcpu_notifier(&octeon_wdt_cpu_notifier);
-
- for_each_online_cpu(cpu) {
- int core = cpu2core(cpu);
- /* Disable the watchdog */
- cvmx_write_csr(CVMX_CIU_WDOGX(core), 0);
- /* Free the interrupt handler */
- free_irq(OCTEON_IRQ_WDOG0 + core, octeon_wdt_poke_irq);
- }
-
- cpu_notifier_register_done();
+ cpuhp_remove_state(octeon_wdt_online);

/*
* Disable the boot-bus memory, the code it points to is soon