X-Git-Url: http://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fcpuid%2Fcpuid.c;h=153f52d4a4ad513b7898095f880d2777d44d9b5e;hp=cab887b16f9236c83148c9aee9ca6b1f91636e1d;hb=7cfb44d46f1e316b8342698d4f51a9e9b38808a6;hpb=55b3c66cb086067c9e1f41ef149cfd34bac86028

diff --git a/ccan/cpuid/cpuid.c b/ccan/cpuid/cpuid.c
index cab887b1..153f52d4 100644
--- a/ccan/cpuid/cpuid.c
+++ b/ccan/cpuid/cpuid.c
@@ -90,31 +90,19 @@ 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,
 	 * but we store the value of EAX into ret since GCC uses EAX
 	 * as the return register for every C function.  That's a double
 	 * operation, but there's no other way to do this unless doing this
-	 * function entirely in assembly.  */
-
-	/* This check is to make sure that the compiler is actually compiling
+	 * function entirely in assembly.
+	 *
+	 * The following assembly code has been shamelessly stolen from:
+	 * 	http://wiki.osdev.org/CPUID
+	 * and converted to work with AT&T syntax.
+	 *
+	 * This check is to make sure that the compiler is actually compiling
 	 * for 64-bit.
 	 *
 	 * The compiler can be 32-bit and the system 64-bit so the 
@@ -173,14 +161,22 @@ bool cpuid_test_feature(cpuid_t feature)
 
 bool cpuid_has_feature(int feature, bool extended)
 {
-	uint32_t eax, ebx, ecx, edx;
+	uint32_t eax, ebx, ecx, edx, i;
 
 	if (!extended)
 		___cpuid(CPU_PROCINFO_AND_FEATUREBITS, &eax, &ebx, &ecx, &edx);
 	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[] = {
@@ -213,8 +209,6 @@ cputype_t cpuid_get_cpu_type(void)
 		uint32_t i;
 
 		___cpuid(CPU_VENDORID, &i, &u.bufu32[0], &u.bufu32[2], &u.bufu32[1]);
-		u.buf[12] = '\0';
-
 		for (i = 0; i < sizeof(cpuids) / sizeof(cpuids[0]); ++i) {
 			if (strncmp(cpuids[i], u.buf, 12) == 0) {
 				cputype = (cputype_t)i;
@@ -256,9 +250,16 @@ 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();
@@ -312,4 +313,3 @@ void cpuid(cpuid_t info, uint32_t *buf)
 }
 
 #endif
-