X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=crc%2Fcrc32c-intel.c;h=6e810a28f93608dfafcaac4bb6dec03bea526554;hp=cec5ad5dec9d5d88ec7498133f2915ae0c1bd146;hb=58dc28f4e56cba465cc56b9f81065862b1e98548;hpb=419484b934222e589f0b718e9494b045df176167

diff --git a/crc/crc32c-intel.c b/crc/crc32c-intel.c
index cec5ad5d..6e810a28 100644
--- a/crc/crc32c-intel.c
+++ b/crc/crc32c-intel.c
@@ -1,4 +1,3 @@
-#include <inttypes.h>
 #include "crc32c.h"
 
 /*
@@ -12,7 +11,9 @@
  * Volume 2A: Instruction Set Reference, A-M
  */
 
-#ifdef ARCH_HAVE_SSE
+bool crc32c_intel_available = false;
+
+#ifdef ARCH_HAVE_SSE4_2
 
 #if BITS_PER_LONG == 64
 #define REX_PRE "0x48, "
@@ -22,8 +23,10 @@
 #define SCALE_F 4
 #endif
 
-uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data,
-				 unsigned long length)
+static bool crc32c_probed;
+
+static uint32_t crc32c_intel_le_hw_byte(uint32_t crc, unsigned char const *data,
+					unsigned long length)
 {
 	while (length--) {
 		__asm__ __volatile__(
@@ -68,5 +71,17 @@ uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
 	return crc;
 }
 
-#endif /* ARCH_HAVE_SSE */
+void crc32c_intel_probe(void)
+{
+	if (!crc32c_probed) {
+		unsigned int eax, ebx, ecx = 0, edx;
+
+		eax = 1;
+
+		do_cpuid(&eax, &ebx, &ecx, &edx);
+		crc32c_intel_available = (ecx & (1 << 20)) != 0;
+		crc32c_probed = true;
+	}
+}
 
+#endif /* ARCH_HAVE_SSE4_2 */