x86: fix resume (S2R) broken by Intel microcode module, on A110L

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / microcode_intel.c

diff --git a/arch/x86/kernel/microcode_intel.c b/arch/x86/kernel/microcode_intel.c
index 622dc4a217848d1c8d16941796a4f82f868fc967..a8e62792d171c6c63645582441b3d9482fffcbac 100644 (file)
--- a/arch/x86/kernel/microcode_intel.c
+++ b/arch/x86/kernel/microcode_intel.c
@@ -155,6 +155,7 @@ static DEFINE_SPINLOCK(microcode_update_lock);
 static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
 {
        struct cpuinfo_x86 *c = &cpu_data(cpu_num);
+       unsigned long flags;
        unsigned int val[2];
 
        memset(csig, 0, sizeof(*csig));
@@ -174,11 +175,16 @@ static int collect_cpu_info(int cpu_num, struct cpu_signature *csig)
                csig->pf = 1 << ((val[1] >> 18) & 7);
        }
 
+       /* serialize access to the physical write to MSR 0x79 */
+       spin_lock_irqsave(&microcode_update_lock, flags);
+
        wrmsr(MSR_IA32_UCODE_REV, 0, 0);
        /* see notes above for revision 1.07.  Apparent chip bug */
        sync_core();
        /* get the current revision from MSR 0x8B */
        rdmsr(MSR_IA32_UCODE_REV, val[0], csig->rev);
+       spin_unlock_irqrestore(&microcode_update_lock, flags);
+
        pr_debug("microcode: collect_cpu_info : sig=0x%x, pf=0x%x, rev=0x%x\n",
                        csig->sig, csig->pf, csig->rev);