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author | Yinghai Lu <yhlu.kernel@gmail.com> | 2008-09-14 02:33:15 -0700 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-09-14 14:09:13 +0200 |
commit | aef93c8bd506a78983d91cd576a97fee6e934ac1 (patch) | |
tree | ecefbd11687673a0c5234450a421beef29adb214 /arch/x86/kernel/cpu/common.c | |
parent | e38e05a85828dac23540cd007df5f20985388afc (diff) | |
download | op-kernel-dev-aef93c8bd506a78983d91cd576a97fee6e934ac1.zip op-kernel-dev-aef93c8bd506a78983d91cd576a97fee6e934ac1.tar.gz |
x86: identify_cpu_without_cpuid v2
Krzysztof found some old cyrix cpu where an mtrr-alike cpu feature was
not detected properly.
this one is based on Krzysztof' patch, and we call ->c_identify() in
early_identify_cpu.
need to call c_identify() for cpus without cpuid even earlier ...
v2: Krzysztof point out need to give cyrix another chance about cpuid
checking again, after ->c_identify() enables cpuid for it
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
-rw-r--r-- | arch/x86/kernel/cpu/common.c | 57 |
1 files changed, 40 insertions, 17 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 9a57106c..f5f25b8 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -485,6 +485,33 @@ static void __cpuinit get_cpu_cap(struct cpuinfo_x86 *c) c->x86_power = cpuid_edx(0x80000007); } + +static void __cpuinit identify_cpu_without_cpuid(struct cpuinfo_x86 *c) +{ +#ifdef CONFIG_X86_32 + int i; + + /* + * First of all, decide if this is a 486 or higher + * It's a 486 if we can modify the AC flag + */ + if (flag_is_changeable_p(X86_EFLAGS_AC)) + c->x86 = 4; + else + c->x86 = 3; + + for (i = 0; i < X86_VENDOR_NUM; i++) + if (cpu_devs[i] && cpu_devs[i]->c_identify) { + c->x86_vendor_id[0] = 0; + cpu_devs[i]->c_identify(c); + if (c->x86_vendor_id[0]) { + get_cpu_vendor(c); + break; + } + } +#endif +} + /* * Do minimum CPU detection early. * Fields really needed: vendor, cpuid_level, family, model, mask, @@ -503,13 +530,16 @@ static void __init early_identify_cpu(struct cpuinfo_x86 *c) #endif c->x86_cache_alignment = c->x86_clflush_size; - if (!have_cpuid_p()) - return; - memset(&c->x86_capability, 0, sizeof c->x86_capability); - c->extended_cpuid_level = 0; + if (!have_cpuid_p()) + identify_cpu_without_cpuid(c); + + /* cyrix could have cpuid enabled via c_identify()*/ + if (!have_cpuid()) + return; + cpu_detect(c); get_cpu_vendor(c); @@ -583,10 +613,14 @@ static void __cpuinit detect_nopl(struct cpuinfo_x86 *c) static void __cpuinit generic_identify(struct cpuinfo_x86 *c) { + c->extended_cpuid_level = 0; + if (!have_cpuid_p()) - return; + identify_cpu_without_cpuid(c); - c->extended_cpuid_level = 0; + /* cyrix could have cpuid enabled via c_identify()*/ + if (!have_cpuid()) + return; cpu_detect(c); @@ -639,17 +673,6 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) c->x86_cache_alignment = c->x86_clflush_size; memset(&c->x86_capability, 0, sizeof c->x86_capability); - if (!have_cpuid_p()) { - /* - * First of all, decide if this is a 486 or higher - * It's a 486 if we can modify the AC flag - */ - if (flag_is_changeable_p(X86_EFLAGS_AC)) - c->x86 = 4; - else - c->x86 = 3; - } - generic_identify(c); if (this_cpu->c_identify) |