diff options
author | Marc Zyngier <marc.zyngier@arm.com> | 2011-01-14 15:32:36 +0000 |
---|---|---|
committer | Marc Zyngier <marc.zyngier@arm.com> | 2012-04-27 13:35:33 +0100 |
commit | 3f61c80eb7dff0fb35beb8068852d3fc902315a6 (patch) | |
tree | 33f1285e1bac944b3279993b14cbfc196abf570e /arch/arm/kernel/arch_timer.c | |
parent | 022c03a2d650c641fa0f94dbc9d9ff77f8057678 (diff) | |
download | linux-3f61c80eb7dff0fb35beb8068852d3fc902315a6.tar.bz2 |
ARM: architected timers: Add A15 specific sched_clock implementation
Provide an A15 sched_clock implementation using the virtual counter,
which is thought to be more useful than the physical one in a
virtualised environment, as it can offset the time spent in another
VM or the hypervisor.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kernel/arch_timer.c')
-rw-r--r-- | arch/arm/kernel/arch_timer.c | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c index bb9a8b45bffa..dd907048f571 100644 --- a/arch/arm/kernel/arch_timer.c +++ b/arch/arm/kernel/arch_timer.c @@ -23,6 +23,7 @@ #include <asm/localtimer.h> #include <asm/arch_timer.h> #include <asm/system_info.h> +#include <asm/sched_clock.h> static unsigned long arch_timer_rate; static int arch_timer_ppi; @@ -204,6 +205,18 @@ static inline cycle_t arch_counter_get_cntvct(void) return ((cycle_t) cvalh << 32) | cvall; } +static u32 notrace arch_counter_get_cntvct32(void) +{ + cycle_t cntvct = arch_counter_get_cntvct(); + + /* + * The sched_clock infrastructure only knows about counters + * with at most 32bits. Forget about the upper 24 bits for the + * time being... + */ + return (u32)(cntvct & (u32)~0); +} + static cycle_t arch_counter_read(struct clocksource *cs) { return arch_counter_get_cntpct(); @@ -286,3 +299,15 @@ out_free: return err; } + +int __init arch_timer_sched_clock_init(void) +{ + int err; + + err = arch_timer_available(); + if (err) + return err; + + setup_sched_clock(arch_counter_get_cntvct32, 32, arch_timer_rate); + return 0; +} |