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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 <mingo@elte.hu>
This commit is contained in:
Peter Zijlstra 2009-03-05 20:34:21 +01:00 committed by Ingo Molnar
parent b0f3f28e0f
commit b5e8acf66f
1 changed files with 2 additions and 14 deletions
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16
arch/x86/kernel/cpu/perf_counter.c
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@ -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");