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From: Michal Schmidt on 13 Jul 2010 15:20
c1e_mask is redundant. The information about activated timer broadcast for
AMD C1E is kept in the CPU feature flags.

Signed-off-by: Michal Schmidt <mschmidt(a)redhat.com>
---

arch/x86/include/asm/cpufeature.h | 2 +-
arch/x86/include/asm/idle.h | 2 --
arch/x86/include/asm/processor.h | 1 -
arch/x86/kernel/cpu/common.c | 1 -
arch/x86/kernel/process.c | 25 +++++++++----------------
arch/x86/kernel/smpboot.c | 1 -
6 files changed, 10 insertions(+), 22 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index 4681459..d826f48 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -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 */
+#define X86_FEATURE_AMDC1E (3*32+21) /* Broken APIC timer in 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 */
diff --git a/arch/x86/include/asm/idle.h b/arch/x86/include/asm/idle.h
index 38d8737..1ef7da2 100644
--- a/arch/x86/include/asm/idle.h
+++ b/arch/x86/include/asm/idle.h
@@ -16,6 +16,4 @@ static inline void enter_idle(void) { }
static inline void exit_idle(void) { }
#endif /* CONFIG_X86_64 */

-void c1e_remove_cpu(int cpu);
-
#endif /* _ASM_X86_IDLE_H */
diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 7e5c6a6..c5e29a9 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -757,7 +757,6 @@ static inline void __sti_mwait(unsigned long eax, unsigned long ecx)
extern void mwait_idle_with_hints(unsigned long eax, unsigned long ecx);

extern void select_idle_routine(const struct cpuinfo_x86 *c);
-extern void init_c1e_mask(void);

extern unsigned long boot_option_idle_override;
extern unsigned long idle_halt;
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 68e4a6f..7be2fbf 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -864,7 +864,6 @@ static void vgetcpu_set_mode(void)
void __init identify_boot_cpu(void)
{
identify_cpu(&boot_cpu_data);
- init_c1e_mask();
#ifdef CONFIG_X86_32
sysenter_setup();
enable_sep_cpu();
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index f3520a8..cfe109d 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -561,15 +561,8 @@ no_c1e_idle:
return 0;
}

-static cpumask_var_t c1e_mask;
static int c1e_detected;

-void c1e_remove_cpu(int cpu)
-{
- if (c1e_mask != NULL)
- cpumask_clear_cpu(cpu, c1e_mask);
-}
-
/*
* C1E aware idle routine. We check for C1E active in the interrupt
* pending message MSR. If we detect C1E, then we handle it the same
@@ -596,8 +589,7 @@ static void c1e_idle(void)
if (c1e_detected) {
int cpu = smp_processor_id();

- if (!cpumask_test_cpu(cpu, c1e_mask)) {
- cpumask_set_cpu(cpu, c1e_mask);
+ if (!cpu_has(&current_cpu_data, X86_FEATURE_AMDC1E)) {
/*
* Force broadcast so ACPI can not interfere.
*/
@@ -630,6 +622,14 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
" performance may degrade.\n");
}
#endif
+ if (c1e_detected) {
+ /*
+ * Broadcast can't have been activated on this CPU yet.
+ * Clear the flag to let c1e_idle() do it.
+ */
+ clear_cpu_cap(&current_cpu_data, X86_FEATURE_AMDC1E);
+ }
+
if (pm_idle)
return;

@@ -646,13 +646,6 @@ void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
pm_idle = default_idle;
}

-void __init init_c1e_mask(void)
-{
- /* If we're using c1e_idle, we need to allocate c1e_mask. */
- if (pm_idle == c1e_idle)
- zalloc_cpumask_var(&c1e_mask, GFP_KERNEL);
-}
-
static int __init idle_setup(char *str)
{
if (!str)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index c4f33b2..dd647bb 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1355,7 +1355,6 @@ void play_dead_common(void)
idle_task_exit();
reset_lazy_tlbstate();
irq_ctx_exit(raw_smp_processor_id());
- c1e_remove_cpu(raw_smp_processor_id());

mb();
/* Ack it */

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Prev: [PATCH 1/2] x86: fix keeping track of AMD C1E
Next: trivial: clear the comment on parameters for ext2_xattr_set