From b5e8acf66ff5db707c7e08df49fdf6b415878442 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Thu, 5 Mar 2009 20:34:21 +0100 Subject: perfcounters: IRQ and NMI support on AMD CPUs, fix The BKGD suggests that counter width on AMD CPUs is 48 for all existing models (it certainly is for mine). Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_counter.c | 16 ++-------------- 1 file changed, 2 insertions(+), 14 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/perf_counter.c b/arch/x86/kernel/cpu/perf_counter.c index 6ebe9abf6aef..f5853718d4d3 100644 --- a/arch/x86/kernel/cpu/perf_counter.c +++ b/arch/x86/kernel/cpu/perf_counter.c @@ -959,20 +959,8 @@ static struct pmc_x86_ops *pmc_amd_init(void) nr_counters_generic = 4; nr_counters_fixed = 0; - counter_value_mask = ~0ULL; - - rdmsrl(MSR_K7_PERFCTR0, old); - wrmsrl(MSR_K7_PERFCTR0, counter_value_mask); - /* - * read the truncated mask - */ - rdmsrl(MSR_K7_PERFCTR0, counter_value_mask); - wrmsrl(MSR_K7_PERFCTR0, old); - - bits = 32 + fls(counter_value_mask >> 32); - if (bits == 32) - bits = fls((u32)counter_value_mask); - counter_value_bits = bits; + counter_value_mask = 0x0000FFFFFFFFFFFFULL; + counter_value_bits = 48; pr_info("AMD Performance Monitoring support detected.\n"); -- cgit v1.2.2