Messages in this thread Patch in this message | | | Date | Sun, 31 Aug 2008 15:58:28 +0200 | From | Krzysztof Helt <> | Subject | [PATCH] x86: amd k6-2 mtrr not detected fix |
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From: Krzysztof Helt <krzysztof.h1@wp.pl>
The AMD K6-2 cpus have 2 mtrr registers which are not detected by the latest Linux kernel. The mtrr capability is not reported through the cpuid on these cpus. This fools early detection function [mtrr_bp_init()] as the mtrr capability bit is set later in the init_amd() function. Fix it by setting the K6 mtrr capability bit just before the check in mtrr_bp_init(). The added condition is copied from the init_amd().
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> ---
It seems that the same problem affects Cyrix and Centaur/VIA cpus. Can some x86 guy inspect the mtrr initialization code ?
arch/x86/kernel/cpu/mtrr/main.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c index 58ac5d3..4bef914 100644 --- a/arch/x86/kernel/cpu/mtrr/main.c +++ b/arch/x86/kernel/cpu/mtrr/main.c @@ -1612,6 +1612,12 @@ void __init mtrr_bp_init(void) } else { switch (boot_cpu_data.x86_vendor) { case X86_VENDOR_AMD: + if (boot_cpu_data.x86_model == 13 || + boot_cpu_data.x86_model == 9 || + (boot_cpu_data.x86_model == 8 && + boot_cpu_data.x86_mask >= 8)) + set_cpu_cap(&boot_cpu_data, + X86_FEATURE_K6_MTRR); if (cpu_has_k6_mtrr) { /* Pre-Athlon (K6) AMD CPU MTRRs */ mtrr_if = mtrr_ops[X86_VENDOR_AMD]; -- 1.5.2.2
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