diff options
Diffstat (limited to 'arch/x86/kernel/uv_time.c')
| -rw-r--r-- | arch/x86/kernel/uv_time.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/arch/x86/kernel/uv_time.c b/arch/x86/kernel/uv_time.c index 3c84aa001c1..56e421bc379 100644 --- a/arch/x86/kernel/uv_time.c +++ b/arch/x86/kernel/uv_time.c @@ -19,6 +19,7 @@ * Copyright (c) Dimitri Sivanich */ #include <linux/clockchips.h> +#include <linux/slab.h> #include <asm/uv/uv_mmrs.h> #include <asm/uv/uv_hub.h> @@ -282,10 +283,21 @@ static int uv_rtc_unset_timer(int cpu, int force) /* * Read the RTC. + * + * Starting with HUB rev 2.0, the UV RTC register is replicated across all + * cachelines of it's own page. This allows faster simultaneous reads + * from a given socket. */ static cycle_t uv_read_rtc(struct clocksource *cs) { - return (cycle_t)uv_read_local_mmr(UVH_RTC); + unsigned long offset; + + if (uv_get_min_hub_revision_id() == 1) + offset = 0; + else + offset = (uv_blade_processor_id() * L1_CACHE_BYTES) % PAGE_SIZE; + + return (cycle_t)uv_read_local_mmr(UVH_RTC | offset); } /* |