[Xen-devel] [PATCH v5 2/9] x86/intel_pstate: APERF/MPERF feature detect

[Wei Wang <wei.w.wang@xxxxxxxxx>]

Add support to detect the APERF/MPERF feature. Also, remove the identical
code in cpufreq.c and powernow.c. This patch is independent of the
earlier patches.

Signed-off-by: Wei Wang <wei.w.wang@xxxxxxxxx>
---
 xen/arch/x86/acpi/cpufreq/cpufreq.c  | 6 ++----
 xen/arch/x86/acpi/cpufreq/powernow.c | 6 ++----
 xen/arch/x86/cpu/common.c            | 4 ++++
 xen/include/asm-x86/cpufeature.h     | 5 +++++
 4 files changed, 13 insertions(+), 8 deletions(-)

 changes in v5:
 1) define macros for 0x1 and CPUID leaf5;
 2) add a statement stating that this patch is independent of the
    previous ones.

diff --git a/xen/arch/x86/acpi/cpufreq/cpufreq.c 
b/xen/arch/x86/acpi/cpufreq/cpufreq.c
index ef79f77..8494fa0 100644
--- a/xen/arch/x86/acpi/cpufreq/cpufreq.c
+++ b/xen/arch/x86/acpi/cpufreq/cpufreq.c
@@ -50,7 +50,6 @@ enum {
 };
 
 #define INTEL_MSR_RANGE         (0xffffull)
-#define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
 
 struct acpi_cpufreq_data *cpufreq_drv_data[NR_CPUS];
 
@@ -351,10 +350,9 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 static void feature_detect(void *info)
 {
     struct cpufreq_policy *policy = info;
-    unsigned int eax, ecx;
+    unsigned int eax;
 
-    ecx = cpuid_ecx(6);
-    if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY) {
+    if ( cpu_has_aperfmperf ) {
         policy->aperf_mperf = 1;
         acpi_cpufreq_driver.getavg = get_measured_perf;
     }
diff --git a/xen/arch/x86/acpi/cpufreq/powernow.c 
b/xen/arch/x86/acpi/cpufreq/powernow.c
index 4de6f8d..d11da1a 100644
--- a/xen/arch/x86/acpi/cpufreq/powernow.c
+++ b/xen/arch/x86/acpi/cpufreq/powernow.c
@@ -37,7 +37,6 @@
 #include <acpi/acpi.h>
 #include <acpi/cpufreq/cpufreq.h>
 
-#define CPUID_6_ECX_APERFMPERF_CAPABILITY       (0x1)
 #define CPUID_FREQ_VOLT_CAPABILITIES    0x80000007
 #define CPB_CAPABLE             0x00000200
 #define USE_HW_PSTATE           0x00000080
@@ -211,10 +210,9 @@ static int powernow_cpufreq_verify(struct cpufreq_policy 
*policy)
 static void feature_detect(void *info)
 {
     struct cpufreq_policy *policy = info;
-    unsigned int ecx, edx;
+    unsigned int edx;
 
-    ecx = cpuid_ecx(6);
-    if (ecx & CPUID_6_ECX_APERFMPERF_CAPABILITY) {
+    if ( cpu_has_aperfmperf ) {
         policy->aperf_mperf = 1;
         powernow_cpufreq_driver.getavg = get_measured_perf;
     }
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c
index 35ef21b..5224d10 100644
--- a/xen/arch/x86/cpu/common.c
+++ b/xen/arch/x86/cpu/common.c
@@ -239,6 +239,10 @@ static void __cpuinit generic_identify(struct cpuinfo_x86 
*c)
        if ( cpu_has(c, X86_FEATURE_CLFLSH) )
                c->x86_clflush_size = ((ebx >> 8) & 0xff) * 8;
 
+       if ( (c->cpuid_level > CPUID_PM_LEAF) &&
+               (cpuid_ecx(CPUID_PM_LEAF) & CPUID6_ECX_APERFMPERF_CAPABILITY) )
+               set_bit(X86_FEATURE_APERFMPERF, c->x86_capability);
+
        /* AMD-defined flags: level 0x80000001 */
        c->extended_cpuid_level = cpuid_eax(0x80000000);
        if ( (c->extended_cpuid_level & 0xffff0000) == 0x80000000 ) {
diff --git a/xen/include/asm-x86/cpufeature.h b/xen/include/asm-x86/cpufeature.h
index 9a01563..d5f532b 100644
--- a/xen/include/asm-x86/cpufeature.h
+++ b/xen/include/asm-x86/cpufeature.h
@@ -69,6 +69,7 @@
 #define X86_FEATURE_XTOPOLOGY    (3*32+13) /* cpu topology enum extensions */
 #define X86_FEATURE_CPUID_FAULTING (3*32+14) /* cpuid faulting */
 #define X86_FEATURE_CLFLUSH_MONITOR (3*32+15) /* clflush reqd with monitor */
+#define X86_FEATURE_APERFMPERF (3*32+28) /* APERFMPERF */
 
 /* Intel-defined CPU features, CPUID level 0x00000001 (ecx), word 4 */
 #define X86_FEATURE_XMM3       (4*32+ 0) /* Streaming SIMD Extensions-3 */
@@ -165,6 +166,9 @@
 #define CPUID5_ECX_EXTENSIONS_SUPPORTED 0x1
 #define CPUID5_ECX_INTERRUPT_BREAK      0x2
 
+#define CPUID_PM_LEAF                    6
+#define CPUID6_ECX_APERFMPERF_CAPABILITY 0x1
+
 #define cpu_has_vme            0
 #define cpu_has_de             1
 #define cpu_has_pse            1
@@ -190,6 +194,7 @@
 #define cpu_has_page1gb                boot_cpu_has(X86_FEATURE_PAGE1GB)
 #define cpu_has_efer           1
 #define cpu_has_fsgsbase       boot_cpu_has(X86_FEATURE_FSGSBASE)
+#define cpu_has_aperfmperf      boot_cpu_has(X86_FEATURE_APERFMPERF)
 
 #define cpu_has_smep            boot_cpu_has(X86_FEATURE_SMEP)
 #define cpu_has_smap            boot_cpu_has(X86_FEATURE_SMAP)
-- 
1.9.1


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