Krzysztof found some old cyrix cpu mtrr etc cpu feature was not detected
this one is based on Krzysztof' patch, and call c_identify in early_identify_cpu.
need to call c_identify() for cpus without cpuid earlier...
v2: Krzysztof point out need to give cyrix another chance about cpuid checking again
after c_identify enable cpuid for it
Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Cc: Krzysztof Helt <krzysztof.h1@wp.pl>
---
arch/x86/kernel/cpu/common.c | 57 ++++++++++++++++++++++++++++++-------------
1 file changed, 40 insertions(+), 17 deletions(-)
Index: linux-2.6/arch/x86/kernel/cpu/common.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/common.c
+++ linux-2.6/arch/x86/kernel/cpu/common.c
@@ -485,6 +485,33 @@ static void __cpuinit get_cpu_cap(struct
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(st
#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
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(struc
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)
--
