Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus

[linux-drm-fsl-dcu.git] / arch / mips / kernel / sync-r4k.c

diff --git a/arch/mips/kernel/sync-r4k.c b/arch/mips/kernel/sync-r4k.c
index 2242bdd4370eb19851ff5a31540a02c65fa26498..4472a7f985776ad78a6e032a333cacd5bb2c7415 100644 (file)
--- a/arch/mips/kernel/sync-r4k.c
+++ b/arch/mips/kernel/sync-r4k.c
@@ -17,34 +17,22 @@
 #include <asm/barrier.h>
 #include <asm/mipsregs.h>
 
-static atomic_t count_start_flag = ATOMIC_INIT(0);
+static unsigned int initcount = 0;
 static atomic_t count_count_start = ATOMIC_INIT(0);
 static atomic_t count_count_stop = ATOMIC_INIT(0);
-static atomic_t count_reference = ATOMIC_INIT(0);
 
 #define COUNTON 100
-#define NR_LOOPS 5
+#define NR_LOOPS 3
 
 void synchronise_count_master(int cpu)
 {
        int i;
        unsigned long flags;
-       unsigned int initcount;
 
        printk(KERN_INFO "Synchronize counters for CPU %u: ", cpu);
 
        local_irq_save(flags);
 
-       /*
-        * Notify the slaves that it's time to start
-        */
-       atomic_set(&count_reference, read_c0_count());
-       atomic_set(&count_start_flag, cpu);
-       smp_wmb();
-
-       /* Count will be initialised to current timer for all CPU's */
-       initcount = read_c0_count();
-
        /*
         * We loop a few times to get a primed instruction cache,
         * then the last pass is more or less synchronised and
@@ -63,9 +51,13 @@ void synchronise_count_master(int cpu)
                atomic_set(&count_count_stop, 0);
                smp_wmb();
 
-               /* this lets the slaves write their count register */
+               /* Let the slave writes its count register */
                atomic_inc(&count_count_start);
 
+               /* Count will be initialised to current timer */
+               if (i == 1)
+                       initcount = read_c0_count();
+
                /*
                 * Everyone initialises count in the last loop:
                 */
@@ -73,7 +65,7 @@ void synchronise_count_master(int cpu)
                        write_c0_count(initcount);
 
                /*
-                * Wait for all slaves to leave the synchronization point:
+                * Wait for slave to leave the synchronization point:
                 */
                while (atomic_read(&count_count_stop) != 1)
                        mb();
@@ -83,7 +75,6 @@ void synchronise_count_master(int cpu)
        }
        /* Arrange for an interrupt in a short while */
        write_c0_compare(read_c0_count() + COUNTON);
-       atomic_set(&count_start_flag, 0);
 
        local_irq_restore(flags);
 
@@ -98,19 +89,12 @@ void synchronise_count_master(int cpu)
 void synchronise_count_slave(int cpu)
 {
        int i;
-       unsigned int initcount;
 
        /*
         * Not every cpu is online at the time this gets called,
         * so we first wait for the master to say everyone is ready
         */
 
-       while (atomic_read(&count_start_flag) != cpu)
-               mb();
-
-       /* Count will be initialised to next expire for all CPU's */
-       initcount = atomic_read(&count_reference);
-
        for (i = 0; i < NR_LOOPS; i++) {
                atomic_inc(&count_count_start);
                while (atomic_read(&count_count_start) != 2)