x86/PAT: Fix Xorg regression on CPUs that don't support PAT

[sfrench/cifs-2.6.git] / arch / x86 / mm / pat.c

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index 9b78685b66e663c80ec3a68986a39024fd372b3c..83a59a67757a77b46f7b7788074294a3a3c8a10c 100644 (file)
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -65,9 +65,11 @@ static int __init nopat(char *str)
 }
 early_param("nopat", nopat);
 
+static bool __read_mostly __pat_initialized = false;
+
 bool pat_enabled(void)
 {
-       return !!__pat_enabled;
+       return __pat_initialized;
 }
 EXPORT_SYMBOL_GPL(pat_enabled);
 
@@ -225,13 +227,14 @@ static void pat_bsp_init(u64 pat)
        }
 
        wrmsrl(MSR_IA32_CR_PAT, pat);
+       __pat_initialized = true;
 
        __init_cache_modes(pat);
 }
 
 static void pat_ap_init(u64 pat)
 {
-       if (!boot_cpu_has(X86_FEATURE_PAT)) {
+       if (!this_cpu_has(X86_FEATURE_PAT)) {
                /*
                 * If this happens we are on a secondary CPU, but switched to
                 * PAT on the boot CPU. We have no way to undo PAT.
@@ -306,7 +309,7 @@ void pat_init(void)
        u64 pat;
        struct cpuinfo_x86 *c = &boot_cpu_data;
 
-       if (!pat_enabled()) {
+       if (!__pat_enabled) {
                init_cache_modes();
                return;
        }