Merge branch 'mpi-master' into wip-k-fmlpwip-k-fmlp

Conflicts:
	litmus/sched_cedf.c

1 files changed, 9 insertions, 34 deletions

diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
index 8c9a43daf80f..9e9b60d969dc 100644
--- a/arch/blackfin/kernel/time-ts.c
+++ b/arch/blackfin/kernel/time-ts.c
@@ -23,29 +23,6 @@
 #include <asm/gptimers.h>
 #include <asm/nmi.h>
 
-/* Accelerators for sched_clock()
- * convert from cycles(64bits) => nanoseconds (64bits)
- *  basic equation:
- *              ns = cycles / (freq / ns_per_sec)
- *              ns = cycles * (ns_per_sec / freq)
- *              ns = cycles * (10^9 / (cpu_khz * 10^3))
- *              ns = cycles * (10^6 / cpu_khz)
- *
- *      Then we use scaling math (suggested by george@mvista.com) to get:
- *              ns = cycles * (10^6 * SC / cpu_khz) / SC
- *              ns = cycles * cyc2ns_scale / SC
- *
- *      And since SC is a constant power of two, we can convert the div
- *  into a shift.
- *
- *  We can use khz divisor instead of mhz to keep a better precision, since
- *  cyc2ns_scale is limited to 10^6 * 2^10, which fits in 32 bits.
- *  (mathieu.desnoyers@polymtl.ca)
- *
- *                      -johnstul@us.ibm.com "math is hard, lets go shopping!"
- */
-
-#define CYC2NS_SCALE_FACTOR 10 /* 2^10, carefully chosen */
 
 #if defined(CONFIG_CYCLES_CLOCKSOURCE)
 
@@ -63,7 +40,6 @@ static struct clocksource bfin_cs_cycles = {
         .rating         = 400,
         .read           = bfin_read_cycles,
         .mask           = CLOCKSOURCE_MASK(64),
-        .shift          = CYC2NS_SCALE_FACTOR,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
@@ -75,10 +51,7 @@ static inline unsigned long long bfin_cs_cycles_sched_clock(void)
 
 static int __init bfin_cs_cycles_init(void)
 {
-        bfin_cs_cycles.mult = \
-                clocksource_hz2mult(get_cclk(), bfin_cs_cycles.shift);
-
-        if (clocksource_register(&bfin_cs_cycles))
+        if (clocksource_register_hz(&bfin_cs_cycles, get_cclk()))
                 panic("failed to register clocksource");
 
         return 0;
@@ -111,7 +84,6 @@ static struct clocksource bfin_cs_gptimer0 = {
         .rating         = 350,
         .read           = bfin_read_gptimer0,
         .mask           = CLOCKSOURCE_MASK(32),
-        .shift          = CYC2NS_SCALE_FACTOR,
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
@@ -125,10 +97,7 @@ static int __init bfin_cs_gptimer0_init(void)
 {
         setup_gptimer0();
 
-        bfin_cs_gptimer0.mult = \
-                clocksource_hz2mult(get_sclk(), bfin_cs_gptimer0.shift);
-
-        if (clocksource_register(&bfin_cs_gptimer0))
+        if (clocksource_register_hz(&bfin_cs_gptimer0, get_sclk()))
                 panic("failed to register clocksource");
 
         return 0;
@@ -206,8 +175,14 @@ irqreturn_t bfin_gptmr0_interrupt(int irq, void *dev_id)
 {
         struct clock_event_device *evt = dev_id;
         smp_mb();
-        evt->event_handler(evt);
+        /*
+         * We want to ACK before we handle so that we can handle smaller timer
+         * intervals.  This way if the timer expires again while we're handling
+         * things, we're more likely to see that 2nd int rather than swallowing
+         * it by ACKing the int at the end of this handler.
+         */
         bfin_gptmr0_ack();
+        evt->event_handler(evt);
         return IRQ_HANDLED;
 }