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Commit 130951cc authored by Andi Kleen's avatar Andi Kleen Committed by Linus Torvalds
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[PATCH] x86_64: Support constant TSC feature in future AMD CPUs. 



Based on the documentation recently posted by Richard Brunner.

Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 2765130b

arch/x86_64/kernel/setup.c

+6 −0
Original line number Diff line number Diff line
@@ -910,6 +910,10 @@ static int __init init_amd(struct cpuinfo_x86 *c) 
	} 

	display_cacheinfo(c);



	/* c->x86_power is 8000_0007 edx. Bit 8 is constant TSC */

	if (c->x86_power & (1<<8))

		set_bit(X86_FEATURE_CONSTANT_TSC, &c->x86_capability);



	if (c->extended_cpuid_level >= 0x80000008) {

		c->x86_max_cores = (cpuid_ecx(0x80000008) & 0xff) + 1;

		if (c->x86_max_cores & (c->x86_max_cores - 1))
@@ -1268,6 +1272,8 @@ static int show_cpuinfo(struct seq_file *m, void *v) 
		"ttp",  /* thermal trip */

		"tm",

		"stc"

		"?",

		"constant_tsc",

	};