Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel...

[pandora-kernel.git] / arch / x86 / kernel / cpu / intel.c

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 879666f..1366c7c 100644 (file)
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -47,6 +47,27 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
                (c->x86 == 0x6 && c->x86_model >= 0x0e))
                set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
 
+       /*
+        * Atom erratum AAE44/AAF40/AAG38/AAH41:
+        *
+        * A race condition between speculative fetches and invalidating
+        * a large page.  This is worked around in microcode, but we
+        * need the microcode to have already been loaded... so if it is
+        * not, recommend a BIOS update and disable large pages.
+        */
+       if (c->x86 == 6 && c->x86_model == 0x1c && c->x86_mask <= 2) {
+               u32 ucode, junk;
+
+               wrmsr(MSR_IA32_UCODE_REV, 0, 0);
+               sync_core();
+               rdmsr(MSR_IA32_UCODE_REV, junk, ucode);
+
+               if (ucode < 0x20e) {
+                       printk(KERN_WARNING "Atom PSE erratum detected, BIOS microcode update recommended\n");
+                       clear_cpu_cap(c, X86_FEATURE_PSE);
+               }
+       }
+
 #ifdef CONFIG_X86_64
        set_cpu_cap(c, X86_FEATURE_SYSENTER32);
 #else
@@ -70,7 +91,8 @@ static void __cpuinit early_init_intel(struct cpuinfo_x86 *c)
        if (c->x86_power & (1 << 8)) {
                set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
                set_cpu_cap(c, X86_FEATURE_NONSTOP_TSC);
-               sched_clock_stable = 1;
+               if (!check_tsc_unstable())
+                       sched_clock_stable = 1;
        }
 
        /*