x86: UV RTC: Fix early expiry handling

Tune/fix early timer expiry handling and return correct early timeout value
for set_next_event.

Signed-off-by: Dimitri Sivanich <sivanich@sgi.com>
LKML-Reference: <20091014141630.GB11048@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 17 insertions, 12 deletions

diff --git a/arch/x86/kernel/uv_time.c b/arch/x86/kernel/uv_time.c
index 583f11d5c480..ec14889628e0 100644
--- a/arch/x86/kernel/uv_time.c
+++ b/arch/x86/kernel/uv_time.c
@@ -123,7 +123,10 @@ static int uv_setup_intr(int cpu, u64 expires)
         /* Initialize comparator value */
         uv_write_global_mmr64(pnode, UVH_INT_CMPB, expires);
 
-        return (expires < uv_read_rtc(NULL) && !uv_intr_pending(pnode));
+        if (uv_read_rtc(NULL) <= expires)
+                return 0;
+
+        return !uv_intr_pending(pnode);
 }
 
 /*
@@ -223,6 +226,7 @@ static int uv_rtc_set_timer(int cpu, u64 expires)
 
         next_cpu = head->next_cpu;
         *t = expires;
+
         /* Will this one be next to go off? */
         if (next_cpu < 0 || bcpu == next_cpu ||
                         expires < head->cpu[next_cpu].expires) {
@@ -231,7 +235,7 @@ static int uv_rtc_set_timer(int cpu, u64 expires)
                         *t = ULLONG_MAX;
                         uv_rtc_find_next_timer(head, pnode);
                         spin_unlock_irqrestore(&head->lock, flags);
-                        return 1;
+                        return -ETIME;
                 }
         }
 
@@ -244,7 +248,7 @@ static int uv_rtc_set_timer(int cpu, u64 expires)
  *
  * Returns 1 if this timer was pending.
  */
-static int uv_rtc_unset_timer(int cpu)
+static int uv_rtc_unset_timer(int cpu, int force)
 {
         int pnode = uv_cpu_to_pnode(cpu);
         int bid = uv_cpu_to_blade_id(cpu);
@@ -256,14 +260,15 @@ static int uv_rtc_unset_timer(int cpu)
 
         spin_lock_irqsave(&head->lock, flags);
 
-        if (head->next_cpu == bcpu && uv_read_rtc(NULL) >= *t)
+        if ((head->next_cpu == bcpu && uv_read_rtc(NULL) >= *t) || force)
                 rc = 1;
 
-        *t = ULLONG_MAX;
-
-        /* Was the hardware setup for this timer? */
-        if (head->next_cpu == bcpu)
-                uv_rtc_find_next_timer(head, pnode);
+        if (rc) {
+                *t = ULLONG_MAX;
+                /* Was the hardware setup for this timer? */
+                if (head->next_cpu == bcpu)
+                        uv_rtc_find_next_timer(head, pnode);
+        }
 
         spin_unlock_irqrestore(&head->lock, flags);
 
@@ -310,20 +315,20 @@ static void uv_rtc_timer_setup(enum clock_event_mode mode,
                 break;
         case CLOCK_EVT_MODE_UNUSED:
         case CLOCK_EVT_MODE_SHUTDOWN:
-                uv_rtc_unset_timer(ced_cpu);
+                uv_rtc_unset_timer(ced_cpu, 1);
                 break;
         }
 }
 
 static void uv_rtc_interrupt(void)
 {
-        struct clock_event_device *ced = &__get_cpu_var(cpu_ced);
         int cpu = smp_processor_id();
+        struct clock_event_device *ced = &per_cpu(cpu_ced, cpu);
 
         if (!ced || !ced->event_handler)
                 return;
 
-        if (uv_rtc_unset_timer(cpu) != 1)
+        if (uv_rtc_unset_timer(cpu, 0) != 1)
                 return;
 
         ced->event_handler(ced);