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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>
hifive-unleashed-5.1
Thomas Gleixner 2008-09-22 19:02:25 +02:00
parent 27ce4cb4a0
commit a8d6829044
3 changed files with 4 additions and 0 deletions
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1
arch/x86/kernel/process.c
View File

@ -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);
}
}

2
include/asm-x86/acpi.h
View File

@ -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;
}

1
include/asm-x86/cpufeature.h
View File

@ -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 */