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Commit b5e8acf6 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
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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: default avatarIngo Molnar <mingo@elte.hu>
parent b0f3f28e

arch/x86/kernel/cpu/perf_counter.c

+2 −14
Original line number Diff line number Diff line
@@ -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");