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authorAndreas Herrmann <andreas.herrmann3@amd.com>2008-06-10 16:05:18 +0200
committerIngo Molnar <mingo@elte.hu>2008-06-12 10:14:22 +0200
commit97cfab6ac4ddfda0d722393bbf46cc40bc332107 (patch)
tree699f95483b968bfad891bca59ad46f74949543bc
parentee863ba7ab3d3ed8a9585d378aae69d1e3e9f1b4 (diff)
x86: PAT: fix ambiguous paranoia check in pat_init()
Starting with commit 8d4a4300854f3971502e81dacd930704cb88f606 (x86: cleanup PAT cpu validation) the PAT CPU feature flag is not cleared anymore. Now the error message "PAT enabled, but CPU feature cleared" in pat_init() is misleading. Furthermore the current code does not check for existence of the PAT CPU feature flag if a CPU is whitelisted in validate_pat_support. This patch clears pat_wc_enabled if boot CPU has no PAT feature flag and adapts the paranoia check. Signed-off-by: Andreas Herrmann <andreas.herrmann3@amd.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--arch/x86/kernel/cpu/addon_cpuid_features.c7
-rw-r--r--arch/x86/mm/pat.c11
2 files changed, 10 insertions, 8 deletions
diff --git a/arch/x86/kernel/cpu/addon_cpuid_features.c b/arch/x86/kernel/cpu/addon_cpuid_features.c
index 0fbd06241e0..2df461f06a5 100644
--- a/arch/x86/kernel/cpu/addon_cpuid_features.c
+++ b/arch/x86/kernel/cpu/addon_cpuid_features.c
@@ -53,6 +53,9 @@ void __cpuinit init_scattered_cpuid_features(struct cpuinfo_x86 *c)
#ifdef CONFIG_X86_PAT
void __cpuinit validate_pat_support(struct cpuinfo_x86 *c)
{
+ if (!cpu_has_pat)
+ pat_disable("PAT not supported by CPU.");
+
switch (c->x86_vendor) {
case X86_VENDOR_INTEL:
if (c->x86 == 0xF || (c->x86 == 6 && c->x86_model >= 15))
@@ -64,8 +67,6 @@ void __cpuinit validate_pat_support(struct cpuinfo_x86 *c)
return;
}
- pat_disable(cpu_has_pat ?
- "PAT disabled. Not yet verified on this CPU type." :
- "PAT not supported by CPU.");
+ pat_disable("PAT disabled. Not yet verified on this CPU type.");
}
#endif
diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 320d644a810..65105b1195a 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -76,14 +76,15 @@ void pat_init(void)
return;
/* Paranoia check. */
- if (!cpu_has_pat) {
- printk(KERN_ERR "PAT enabled, but CPU feature cleared\n");
+ if (!cpu_has_pat && boot_pat_state) {
/*
- * Panic if this happens on the secondary CPU, and we
+ * If this happens we are on a secondary CPU, but
* switched to PAT on the boot CPU. We have no way to
* undo PAT.
- */
- BUG_ON(boot_pat_state);
+ */
+ printk(KERN_ERR "PAT enabled, "
+ "but not supported by secondary CPU\n");
+ BUG();
}
/* Set PWT to Write-Combining. All other bits stay the same */