diff options
Diffstat (limited to 'arch/mips/kernel/sync-r4k.c')
| -rw-r--r-- | arch/mips/kernel/sync-r4k.c | 32 |
1 files changed, 8 insertions, 24 deletions
diff --git a/arch/mips/kernel/sync-r4k.c b/arch/mips/kernel/sync-r4k.c index 2242bdd43..4472a7f98 100644 --- a/arch/mips/kernel/sync-r4k.c +++ b/arch/mips/kernel/sync-r4k.c @@ -17,35 +17,23 @@ #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 * the master and slaves each set their cycle counters to a known @@ -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) |