x86: Fix keeping track of AMD C1E

Accomodate the original C1E-aware idle routine to the different times
during boot when the BIOS enables C1E. While at it, remove the synthetic
CPUID flag in favor of a single global setting which denotes C1E status
on the system.

[ hpa: changed c1e_enabled to be a bool; clarified cpu bit 3:21 comment ]

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
LKML-Reference: <20100727165335.GA11630@aftab>
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 553b02f13094..b944f89c4e6e 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -525,8 +525,10 @@ static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
         return (edx & MWAIT_EDX_C1);
 }
 
+bool c1e_detected;
+EXPORT_SYMBOL(c1e_detected);
+
 static cpumask_var_t c1e_mask;
-static int c1e_detected;
 
 void c1e_remove_cpu(int cpu)
 {
@@ -548,12 +550,12 @@ static void c1e_idle(void)
                 u32 lo, hi;
 
                 rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
+
                 if (lo & K8_INTP_C1E_ACTIVE_MASK) {
-                        c1e_detected = 1;
+                        c1e_detected = true;
                         if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
                                 mark_tsc_unstable("TSC halt in AMD C1E");
                         printk(KERN_INFO "System has AMD C1E enabled\n");
-                        set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E);
                 }
         }