diff options
Diffstat (limited to 'arch/mips/cavium-octeon/csrc-octeon.c')
| -rw-r--r-- | arch/mips/cavium-octeon/csrc-octeon.c | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/mips/cavium-octeon/csrc-octeon.c b/arch/mips/cavium-octeon/csrc-octeon.c index 96110f217dcd..0bf4bbe04ae2 100644 --- a/arch/mips/cavium-octeon/csrc-octeon.c +++ b/arch/mips/cavium-octeon/csrc-octeon.c @@ -50,6 +50,38 @@ static struct clocksource clocksource_mips = { .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +unsigned long long notrace sched_clock(void) +{ + /* 64-bit arithmatic can overflow, so use 128-bit. */ +#if (__GNUC__ < 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ <= 3)) + u64 t1, t2, t3; + unsigned long long rv; + u64 mult = clocksource_mips.mult; + u64 shift = clocksource_mips.shift; + u64 cnt = read_c0_cvmcount(); + + asm ( + "dmultu\t%[cnt],%[mult]\n\t" + "nor\t%[t1],$0,%[shift]\n\t" + "mfhi\t%[t2]\n\t" + "mflo\t%[t3]\n\t" + "dsll\t%[t2],%[t2],1\n\t" + "dsrlv\t%[rv],%[t3],%[shift]\n\t" + "dsllv\t%[t1],%[t2],%[t1]\n\t" + "or\t%[rv],%[t1],%[rv]\n\t" + : [rv] "=&r" (rv), [t1] "=&r" (t1), [t2] "=&r" (t2), [t3] "=&r" (t3) + : [cnt] "r" (cnt), [mult] "r" (mult), [shift] "r" (shift) + : "hi", "lo"); + return rv; +#else + /* GCC > 4.3 do it the easy way. */ + unsigned int __attribute__((mode(TI))) t; + t = read_c0_cvmcount(); + t = t * clocksource_mips.mult; + return (unsigned long long)(t >> clocksource_mips.shift); +#endif +} + void __init plat_time_init(void) { clocksource_mips.rating = 300; |