diff options
Diffstat (limited to 'arch/arm/mach-versatile')
| -rw-r--r-- | arch/arm/mach-versatile/core.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c index dcc2ca3dcde..57196947559 100644 --- a/arch/arm/mach-versatile/core.c +++ b/arch/arm/mach-versatile/core.c @@ -27,6 +27,7 @@ #include <linux/amba/bus.h> #include <linux/amba/clcd.h> +#include <asm/cnt32_to_63.h> #include <asm/system.h> #include <asm/hardware.h> #include <asm/io.h> @@ -228,14 +229,19 @@ void __init versatile_map_io(void) /* * This is the Versatile sched_clock implementation. This has - * a resolution of 41.7ns, and a maximum value of about 179s. + * a resolution of 41.7ns, and a maximum value of about 35583 days. + * + * The return value is guaranteed to be monotonic in that range as + * long as there is always less than 89 seconds between successive + * calls to this function. */ unsigned long long sched_clock(void) { - unsigned long long v; + unsigned long long v = cnt32_to_63(readl(VERSATILE_REFCOUNTER)); - v = (unsigned long long)readl(VERSATILE_REFCOUNTER) * 125; - do_div(v, 3); + /* the <<1 gets rid of the cnt_32_to_63 top bit saving on a bic insn */ + v *= 125<<1; + do_div(v, 3<<1); return v; } |