cpuid: cache processor brand string

[ccan] / ccan / cpuid / cpuid.c

diff --git a/ccan/cpuid/cpuid.c b/ccan/cpuid/cpuid.c
index cab887b16f9236c83148c9aee9ca6b1f91636e1d..1a09c5e666cb9457041bb0ae524fdd579677c07d 100644 (file)
--- a/ccan/cpuid/cpuid.c
+++ b/ccan/cpuid/cpuid.c
@@ -90,22 +90,6 @@ static struct {
        { CEF_XOP,              1 << 11,        false }
 };
 
-static bool has_feature(int feature, uint32_t ecx, uint32_t edx)
-{
-       int i;
-
-       for (i = 0; i < sizeof(features) / sizeof(features[0]); ++i) {
-               if (features[i].feature == feature) {
-                       if (features[i].use_edx)
-                               return (edx & features[i].mask);
-                       else
-                               return (ecx & features[i].mask);
-               }
-       }
-
-       return false;
-}
-
 bool cpuid_is_supported(void)
 {
        /* The following assembly code uses EAX as the return value,
@@ -180,7 +164,15 @@ bool cpuid_has_feature(int feature, bool extended)
        else
                ___cpuid(CPU_EXTENDED_PROC_INFO_FEATURE_BITS, &eax, &ebx, &ecx, &edx);
 
-       return has_feature(feature, ecx, edx);
+       for (i = 0; i < sizeof(features) / sizeof(features[0]); ++i) {
+               if (features[i].feature == feature) {
+                       if (features[i].use_edx)
+                               return (edx & features[i].mask);
+                       else
+                               return (ecx & features[i].mask);
+               }
+       }
+       return false;
 }
 
 static const char *const cpuids[] = {
@@ -256,9 +248,16 @@ void cpuid(cpuid_t info, uint32_t *buf)
                return;
 
        if (info == CPU_PROC_BRAND_STRING) {
-               ___cpuid(CPU_PROC_BRAND_STRING,           &buf[0], &buf[1], &buf[2],  &buf[3]);
-               ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL0, &buf[4], &buf[5], &buf[6],  &buf[7]);
-               ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL1, &buf[8], &buf[9], &buf[10], &buf[11]);
+               static char cached[48] = { 0 };
+               if (cached[0] == '\0') {
+                       ___cpuid(CPU_PROC_BRAND_STRING,           &buf[0], &buf[1], &buf[2],  &buf[3]);
+                       ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL0, &buf[4], &buf[5], &buf[6],  &buf[7]);
+                       ___cpuid(CPU_PROC_BRAND_STRING_INTERNAL1, &buf[8], &buf[9], &buf[10], &buf[11]);
+
+                       memcpy(cached, buf, sizeof cached);
+               } else
+                       buf = (uint32_t *)cached;
+
                return;
        } else if (info == CPU_HIGHEST_EXTENDED_FUNCTION_SUPPORTED) {
                *buf = cpuid_highest_ext_func_supported();