From: Andrew Cooper Date: Thu, 11 Feb 2016 15:40:47 +0000 (+0100) Subject: x86: drop X86_FEATURE_3DNOW_ALT X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~1771^2~10 X-Git-Url: https://dgit.raspbian.org/%22http://www.example.com/cgi/%22/%22http:/www.example.com/cgi/%22?a=commitdiff_plain;h=51bd4bbdfdbaa02acdcc2b058f3caf1e815898d7;p=xen.git x86: drop X86_FEATURE_3DNOW_ALT Introducing an X86_FEATURE aliased value turns out to complicate automatic processing of the feature list. Drop X86_FEATURE_3DNOW_ALT and use X86_FEATURE_PBE, extending the comment accordingly. Signed-off-by: Andrew Cooper Acked-by: Jan Beulich --- diff --git a/xen/arch/x86/cpu/amd.c b/xen/arch/x86/cpu/amd.c index 8ec841b3e9..1ac44e00ff 100644 --- a/xen/arch/x86/cpu/amd.c +++ b/xen/arch/x86/cpu/amd.c @@ -440,9 +440,12 @@ static void init_amd(struct cpuinfo_x86 *c) wrmsrl(MSR_K7_HWCR, value); } - /* Bit 31 in normal CPUID used for nonstandard 3DNow ID; - 3DNow is IDd by bit 31 in extended CPUID (1*32+31) anyway */ - __clear_bit(X86_FEATURE_3DNOW_ALT, c->x86_capability); + /* + * Some AMD CPUs duplicate the 3DNow bit in base and extended CPUID + * leaves. Unfortunately, this aliases PBE on Intel CPUs. Clobber the + * alias, leaving 3DNow in the extended leaf. + */ + __clear_bit(X86_FEATURE_PBE, c->x86_capability); if (c->x86 == 0xf && c->x86_model < 0x14 && cpu_has(c, X86_FEATURE_LAHF_LM)) { diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h index 23f9fb206f..65830397e2 100644 --- a/xen/include/asm-x86/cpufeature.h +++ b/xen/include/asm-x86/cpufeature.h @@ -45,7 +45,6 @@ #define X86_FEATURE_ACC (0*32+29) /* Automatic clock control */ #define X86_FEATURE_IA64 (0*32+30) /* IA-64 processor */ #define X86_FEATURE_PBE (0*32+31) /* Pending Break Enable */ -#define X86_FEATURE_3DNOW_ALT (0*32+31) /* AMD nonstandard 3DNow (Aliases PBE) */ /* AMD-defined CPU features, CPUID level 0x80000001, word 1 */ /* Don't duplicate feature flags which are redundant with Intel! */