[MIPS] time: SMP/NUMA-proofing of IP27 HUB RT timer code.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

1 files changed, 71 insertions, 63 deletions

diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
index d467bf4f6c3f..f5dccf01da11 100644
--- a/arch/mips/sgi-ip27/ip27-timer.c
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -111,8 +111,24 @@ unsigned long read_persistent_clock(void)
         return mktime(year, month, date, hour, min, sec);
 }
 
-static int rt_set_next_event(unsigned long delta,
-                struct clock_event_device *evt)
+static void enable_rt_irq(unsigned int irq)
+{
+}
+
+static void disable_rt_irq(unsigned int irq)
+{
+}
+
+static struct irq_chip rt_irq_type = {
+        .name           = "SN HUB RT timer",
+        .ack            = disable_rt_irq,
+        .mask           = disable_rt_irq,
+        .mask_ack       = disable_rt_irq,
+        .unmask         = enable_rt_irq,
+        .eoi            = enable_rt_irq,
+};
+
+static int rt_next_event(unsigned long delta, struct clock_event_device *evt)
 {
         unsigned int cpu = smp_processor_id();
         int slice = cputoslice(cpu) == 0;
@@ -129,50 +145,24 @@ static void rt_set_mode(enum clock_event_mode mode,
                 struct clock_event_device *evt)
 {
         switch (mode) {
-        case CLOCK_EVT_MODE_PERIODIC:
+        case CLOCK_EVT_MODE_ONESHOT:
                 /* The only mode supported */
                 break;
 
+        case CLOCK_EVT_MODE_PERIODIC:
         case CLOCK_EVT_MODE_UNUSED:
         case CLOCK_EVT_MODE_SHUTDOWN:
-        case CLOCK_EVT_MODE_ONESHOT:
         case CLOCK_EVT_MODE_RESUME:
                 /* Nothing to do  */
                 break;
         }
 }
 
-struct clock_event_device rt_clock_event_device = {
-        .name           = "HUB-RT",
-        .features       = CLOCK_EVT_FEAT_ONESHOT,
-
-        .rating         = 300,
-        .set_next_event = rt_set_next_event,
-        .set_mode       = rt_set_mode,
-};
-
-static void enable_rt_irq(unsigned int irq)
-{
-}
-
-static void disable_rt_irq(unsigned int irq)
-{
-}
-
-static struct irq_chip rt_irq_type = {
-        .name           = "SN HUB RT timer",
-        .ack            = disable_rt_irq,
-        .mask           = disable_rt_irq,
-        .mask_ack       = disable_rt_irq,
-        .unmask         = enable_rt_irq,
-        .eoi            = enable_rt_irq,
-};
-
 unsigned int rt_timer_irq;
 
-static irqreturn_t ip27_rt_timer_interrupt(int irq, void *dev_id)
+static irqreturn_t hub_rt_counter_handler(int irq, void *dev_id)
 {
-        struct clock_event_device *cd = &rt_clock_event_device;
+        struct clock_event_device *cd = dev_id;
         unsigned int cpu = smp_processor_id();
         int slice = cputoslice(cpu) == 0;
 
@@ -182,11 +172,10 @@ static irqreturn_t ip27_rt_timer_interrupt(int irq, void *dev_id)
         return IRQ_HANDLED;
 }
 
-static struct irqaction rt_irqaction = {
-        .handler        = (irq_handler_t) ip27_rt_timer_interrupt,
-        .flags          = IRQF_DISABLED,
-        .mask           = CPU_MASK_NONE,
-        .name           = "timer"
+struct irqaction hub_rt_irqaction = {
+        .handler        = hub_rt_counter_handler,
+        .flags          = IRQF_DISABLED | IRQF_PERCPU,
+        .name           = "hub-rt",
 };
 
 /*
@@ -200,32 +189,48 @@ static struct irqaction rt_irqaction = {
 #define NSEC_PER_CYCLE          800
 #define CYCLES_PER_SEC          (NSEC_PER_SEC / NSEC_PER_CYCLE)
 
-static void __init ip27_rt_clock_event_init(void)
+static DEFINE_PER_CPU(struct clock_event_device, hub_rt_clockevent);
+static DEFINE_PER_CPU(char [11], hub_rt_name);
+
+static void __cpuinit hub_rt_clock_event_init(void)
 {
-        struct clock_event_device *cd = &rt_clock_event_device;
         unsigned int cpu = smp_processor_id();
-        int irq = allocate_irqno();
-
-        if (irq < 0)
-                panic("Can't allocate interrupt number for timer interrupt");
-
-        rt_timer_irq = irq;
-
+        struct clock_event_device *cd = &per_cpu(hub_rt_clockevent, cpu);
+        unsigned char *name = per_cpu(hub_rt_name, cpu);
+        int irq = rt_timer_irq;
+
+        sprintf(name, "hub-rt %d", cpu);
+        cd->name                = "HUB-RT",
+        cd->features            = CLOCK_EVT_FEAT_ONESHOT,
+        clockevent_set_clock(cd, CYCLES_PER_SEC);
+        cd->max_delta_ns        = clockevent_delta2ns(0xfffffffffffff, cd);
+        cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
+        cd->rating              = 200,
         cd->irq                 = irq,
         cd->cpumask             = cpumask_of_cpu(cpu),
-
-        /*
-         * Calculate the min / max delta
-         */
-        cd->mult                =
-                div_sc((unsigned long) CYCLES_PER_SEC, NSEC_PER_SEC, 32);
-        cd->shift               = 32;
-        cd->max_delta_ns        = clockevent_delta2ns(0x7fffffff, cd);
-        cd->min_delta_ns        = clockevent_delta2ns(0x300, cd);
+        cd->rating              = 300,
+        cd->set_next_event      = rt_next_event,
+        cd->set_mode            = rt_set_mode,
         clockevents_register_device(cd);
+}
+
+static void __init hub_rt_clock_event_global_init(void)
+{
+        unsigned int irq;
+
+        do {
+                smp_wmb();
+                irq = rt_timer_irq;
+                if (irq)
+                        break;
+
+                irq = allocate_irqno();
+                if (irq < 0)
+                        panic("Allocation of irq number for timer failed");
+        } while (xchg(&rt_timer_irq, irq));
 
         set_irq_chip_and_handler(irq, &rt_irq_type, handle_percpu_irq);
-        setup_irq(irq, &rt_irqaction);
+        setup_irq(irq, &hub_rt_irqaction);
 }
 
 static cycle_t hub_rt_read(void)
@@ -233,27 +238,29 @@ static cycle_t hub_rt_read(void)
         return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 }
 
-struct clocksource ht_rt_clocksource = {
+struct clocksource hub_rt_clocksource = {
         .name   = "HUB-RT",
         .rating = 200,
         .read   = hub_rt_read,
         .mask   = CLOCKSOURCE_MASK(52),
-        .shift  = 32,
         .flags  = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
-static void __init ip27_rt_clocksource_init(void)
+static void __init hub_rt_clocksource_init(void)
 {
-        clocksource_register(&ht_rt_clocksource);
+        struct clocksource *cs = &hub_rt_clocksource;
+
+        clocksource_set_clock(cs, CYCLES_PER_SEC);
+        clocksource_register(cs);
 }
 
 void __init plat_time_init(void)
 {
-        ip27_rt_clock_event_init();
-        ip27_rt_clocksource_init();
+        hub_rt_clocksource_init();
+        hub_rt_clock_event_global_init();
 }
 
-void __init cpu_time_init(void)
+void __cpuinit cpu_time_init(void)
 {
         lboard_t *board;
         klcpu_t *cpu;
@@ -271,6 +278,7 @@ void __init cpu_time_init(void)
 
         printk("CPU %d clock is %dMHz.\n", smp_processor_id(), cpu->cpu_speed);
 
+        hub_rt_clock_event_init();
         set_c0_status(SRB_TIMOCLK);
 }