x86: Fix keeping track of AMD C1E
Michal Schmidt [Tue, 27 Jul 2010 16:53:35 +0000 (18:53 +0200)]
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>

arch/x86/include/asm/acpi.h
arch/x86/include/asm/cpufeature.h
arch/x86/include/asm/processor.h
arch/x86/kernel/process.c
drivers/acpi/processor_idle.c

index aa2c39d..92091de 100644 (file)
@@ -134,7 +134,7 @@ static inline unsigned int acpi_processor_cstate_check(unsigned int max_cstate)
            boot_cpu_data.x86_model <= 0x05 &&
            boot_cpu_data.x86_mask < 0x0A)
                return 1;
-       else if (boot_cpu_has(X86_FEATURE_AMDC1E))
+       else if (c1e_detected)
                return 1;
        else
                return max_cstate;
index 817aa31..0b205b8 100644 (file)
@@ -89,7 +89,7 @@
 #define X86_FEATURE_LFENCE_RDTSC (3*32+18) /* "" Lfence synchronizes RDTSC */
 #define X86_FEATURE_11AP       (3*32+19) /* "" Bad local APIC aka 11AP */
 #define X86_FEATURE_NOPL       (3*32+20) /* The NOPL (0F 1F) instructions */
-#define X86_FEATURE_AMDC1E     (3*32+21) /* AMD C1E detected */
+                                         /* 21 available, was AMD_C1E */
 #define X86_FEATURE_XTOPOLOGY  (3*32+22) /* cpu topology enum extensions */
 #define X86_FEATURE_TSC_RELIABLE (3*32+23) /* TSC is known to be reliable */
 #define X86_FEATURE_NONSTOP_TSC        (3*32+24) /* TSC does not stop in C states */
index d85637b..325b7bd 100644 (file)
@@ -762,6 +762,7 @@ extern void init_c1e_mask(void);
 extern unsigned long           boot_option_idle_override;
 extern unsigned long           idle_halt;
 extern unsigned long           idle_nomwait;
+extern bool                    c1e_detected;
 
 /*
  * on systems with caches, caches must be flashed as the absolute
index 553b02f..b944f89 100644 (file)
@@ -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);
                }
        }
 
index e9a8026..eead3f5 100644 (file)
@@ -164,7 +164,7 @@ static void lapic_timer_check_state(int state, struct acpi_processor *pr,
        if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
                return;
 
-       if (boot_cpu_has(X86_FEATURE_AMDC1E))
+       if (c1e_detected)
                type = ACPI_STATE_C1;
 
        /*