[PATCH] x86: pat cpu feature bit setting for known cpus

From: Yinghai Lu
Date: Tue Mar 25 2008 - 02:22:27 EST


[PATCH] x86: pat cpu feature bit setting for known cpus

Signed-off-by: Yinghai Lu <yhlu.kernel@xxxxxxxxx>

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index eb94460..b186047 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -309,6 +309,19 @@ static void __cpuinit early_get_cap(struct cpuinfo_x86 *c)

}

+ clear_cpu_cap(c, X86_FEATURE_PAT);
+
+ switch (c->x86_vendor) {
+ case X86_VENDOR_AMD:
+ if (c->x86 >= 0xf && c->x86 <= 0x11)
+ set_cpu_cap(c, X86_FEATURE_PAT);
+ break;
+ case X86_VENDOR_INTEL:
+ if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
+ set_cpu_cap(c, X86_FEATURE_PAT);
+ break;
+ }
+
}

/*
@@ -397,6 +410,18 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 *c)
init_scattered_cpuid_features(c);
}

+ clear_cpu_cap(c, X86_FEATURE_PAT);
+
+ switch (c->x86_vendor) {
+ case X86_VENDOR_AMD:
+ if (c->x86 >= 0xf && c->x86 <= 0x11)
+ set_cpu_cap(c, X86_FEATURE_PAT);
+ break;
+ case X86_VENDOR_INTEL:
+ if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
+ set_cpu_cap(c, X86_FEATURE_PAT);
+ break;
+ }
}

static void __cpuinit squash_the_stupid_serial_number(struct cpuinfo_x86 *c)
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 3f1dc97..ddaaaaa 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -979,12 +979,19 @@ static void __cpuinit early_identify_cpu(struct cpuinfo_x86 *c)
if (c->extended_cpuid_level >= 0x80000007)
c->x86_power = cpuid_edx(0x80000007);

+
+ clear_cpu_cap(c, X86_FEATURE_PAT);
+
switch (c->x86_vendor) {
case X86_VENDOR_AMD:
early_init_amd(c);
+ if (c->x86 >= 0xf && c->x86 <= 0x11)
+ set_cpu_cap(c, X86_FEATURE_PAT);
break;
case X86_VENDOR_INTEL:
early_init_intel(c);
+ if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
+ set_cpu_cap(c, X86_FEATURE_PAT);
break;
}

--- a/arch/x86/mm/pat.c 2008-03-24 23:10:32.000000000 -0700
+++ b/arch/x86/mm/pat.c 2008-03-24 23:11:38.000000000 -0700
@@ -42,19 +42,8 @@
if (!pat_wc_enabled)
return 0;

- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- (boot_cpu_data.x86 == 0xF ||
- (boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model >= 15))) {
- if (cpu_has_pat) {
- return 1;
- }
- }
- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
- boot_cpu_data.x86 >= 0xf && boot_cpu_data.x86 <= 0x11) {
- if (cpu_has_pat) {
- return 1;
- }
- }
+ if (cpu_has_pat)
+ return 1;

pat_wc_enabled = 0;
printk(KERN_INFO "CPU and/or kernel does not support PAT.\n");
--
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