From: Andrew Cooper Date: Tue, 3 Nov 2015 17:15:58 +0000 (+0100) Subject: x86: query for paddr_bits in early_cpu_detect() X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~2305^2 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=32b31c17da1ba0da970cd182a8865ac20fabd0fa;p=xen.git x86: query for paddr_bits in early_cpu_detect() It is __read_mostly, so repeatedly writing to it is suboptiomal. As the MTRRs have already been set up, nothing good will come from its value changing across CPUs. Signed-off-by: Andrew Cooper Reviewed-by: Konrad Rzeszutek Wilk --- diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index 02f25046fd..ac8a2582fd 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -207,6 +207,9 @@ static void __init early_cpu_detect(void) /* Leaf 0x1 capabilities filled in early for Xen. */ c->x86_capability[cpufeat_word(X86_FEATURE_FPU)] = cap0; c->x86_capability[cpufeat_word(X86_FEATURE_XMM3)] = cap4; + + if ( cpuid_eax(0x80000000) >= 0x80000008 ) + paddr_bits = cpuid_eax(0x80000008) & 0xff; } static void __cpuinit generic_identify(struct cpuinfo_x86 *c) @@ -254,8 +257,6 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c) } if ( c->extended_cpuid_level >= 0x80000004 ) get_model_name(c); /* Default name */ - if ( c->extended_cpuid_level >= 0x80000008 ) - paddr_bits = cpuid_eax(0x80000008) & 0xff; } /* Might lift BIOS max_leaf=3 limit. */