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-rw-r--r--arch/x86/include/asm/cpufeatures.h1
-rw-r--r--arch/x86/kernel/cpu/scattered.c1
-rw-r--r--drivers/cpufreq/amd-pstate.c9
3 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 3c7434329661..6c128d463a14 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -470,6 +470,7 @@
#define X86_FEATURE_BHI_CTRL (21*32+ 2) /* "" BHI_DIS_S HW control available */
#define X86_FEATURE_CLEAR_BHB_HW (21*32+ 3) /* "" BHI_DIS_S HW control enabled */
#define X86_FEATURE_CLEAR_BHB_LOOP_ON_VMEXIT (21*32+ 4) /* "" Clear branch history at vmexit using SW loop */
+#define X86_FEATURE_FAST_CPPC (21*32 + 5) /* "" AMD Fast CPPC */
/*
* BUG word(s)
diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index af5aa2c754c2..c84c30188fdf 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -45,6 +45,7 @@ static const struct cpuid_bit cpuid_bits[] = {
{ X86_FEATURE_HW_PSTATE, CPUID_EDX, 7, 0x80000007, 0 },
{ X86_FEATURE_CPB, CPUID_EDX, 9, 0x80000007, 0 },
{ X86_FEATURE_PROC_FEEDBACK, CPUID_EDX, 11, 0x80000007, 0 },
+ { X86_FEATURE_FAST_CPPC, CPUID_EDX, 15, 0x80000007, 0 },
{ X86_FEATURE_MBA, CPUID_EBX, 6, 0x80000008, 0 },
{ X86_FEATURE_SMBA, CPUID_EBX, 2, 0x80000020, 0 },
{ X86_FEATURE_BMEC, CPUID_EBX, 3, 0x80000020, 0 },
diff --git a/drivers/cpufreq/amd-pstate.c b/drivers/cpufreq/amd-pstate.c
index 9ad62dbe8bfb..fda8f86c90e0 100644
--- a/drivers/cpufreq/amd-pstate.c
+++ b/drivers/cpufreq/amd-pstate.c
@@ -51,6 +51,7 @@
#define AMD_PSTATE_TRANSITION_LATENCY 20000
#define AMD_PSTATE_TRANSITION_DELAY 1000
+#define AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY 600
#define CPPC_HIGHEST_PERF_PERFORMANCE 196
#define CPPC_HIGHEST_PERF_DEFAULT 166
@@ -849,8 +850,12 @@ static u32 amd_pstate_get_transition_delay_us(unsigned int cpu)
u32 transition_delay_ns;
transition_delay_ns = cppc_get_transition_latency(cpu);
- if (transition_delay_ns == CPUFREQ_ETERNAL)
- return AMD_PSTATE_TRANSITION_DELAY;
+ if (transition_delay_ns == CPUFREQ_ETERNAL) {
+ if (cpu_feature_enabled(X86_FEATURE_FAST_CPPC))
+ return AMD_PSTATE_FAST_CPPC_TRANSITION_DELAY;
+ else
+ return AMD_PSTATE_TRANSITION_DELAY;
+ }
return transition_delay_ns / NSEC_PER_USEC;
}