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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>
hifive-unleashed-5.1
Yinghai Lu 2008-09-14 02:33:15 -07:00 committed by Ingo Molnar
parent e38e05a858
commit aef93c8bd5
1 changed files with 41 additions and 18 deletions
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59
arch/x86/kernel/cpu/common.c
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@ -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);
@ -583,11 +613,15 @@ static void __cpuinit detect_nopl(struct cpuinfo_x86 *c)
static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
{
if (!have_cpuid_p())
return;
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);
@ -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)