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authorThomas Gleixner <tglx@linutronix.de>2008-09-22 19:02:25 +0200
committerThomas Gleixner <tglx@linutronix.de>2008-09-23 11:38:53 +0200
commita8d6829044901a67732904be5f1eacdf8539604f (patch)
tree9540f55fd2beb716a5dda0146e3e742c5a48e380
parent27ce4cb4a0c7cf59b9a9952266883862f2e4c99f (diff)
x86: prevent C-states hang on AMD C1E enabled machines
Impact: System hang when AMD C1E machines switch into C2/C3 AMD C1E enabled systems do not work with normal ACPI C-states even if the BIOS is advertising them. Limit the C-states to C1 for the ACPI processor idle code. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--arch/x86/kernel/process.c1
-rw-r--r--include/asm-x86/acpi.h2
-rw-r--r--include/asm-x86/cpufeature.h1
3 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
index 2e2247117f6..d8c2a299bfe 100644
--- a/arch/x86/kernel/process.c
+++ b/arch/x86/kernel/process.c
@@ -272,6 +272,7 @@ static void c1e_idle(void)
c1e_detected = 1;
mark_tsc_unstable("TSC halt in C1E");
printk(KERN_INFO "System has C1E enabled\n");
+ set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E);
}
}
diff --git a/include/asm-x86/acpi.h b/include/asm-x86/acpi.h
index 635d764dc13..35d1743b57a 100644
--- a/include/asm-x86/acpi.h
+++ b/include/asm-x86/acpi.h
@@ -140,6 +140,8 @@ 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))
+ return 1;
else
return max_cstate;
}
diff --git a/include/asm-x86/cpufeature.h b/include/asm-x86/cpufeature.h
index 9489283a4bc..cfcfb0a806b 100644
--- a/include/asm-x86/cpufeature.h
+++ b/include/asm-x86/cpufeature.h
@@ -81,6 +81,7 @@
#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 */
/* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
#define X86_FEATURE_XMM3 (4*32+ 0) /* Streaming SIMD Extensions-3 */