X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=crc%2Fcrc32c-intel.c;h=9a2cefdedcaf288fa5a302c952f21410353b88ea;hp=969a037f942d24e9509b11217fd3123e01658aea;hb=3d2d14bcb844e72809192311369a642c5d415472;hpb=2f68124f26e54233db41b462a257dabc48e5c32b

diff --git a/crc/crc32c-intel.c b/crc/crc32c-intel.c
index 969a037f..9a2cefde 100644
--- a/crc/crc32c-intel.c
+++ b/crc/crc32c-intel.c
@@ -1,10 +1,3 @@
-#include <inttypes.h>
-#include <string.h>
-#include <unistd.h>
-#include <stdlib.h>
-#include <signal.h>
-#include <sys/types.h>
-#include <sys/wait.h>
 #include "crc32c.h"
 
 /*
@@ -18,6 +11,8 @@
  * Volume 2A: Instruction Set Reference, A-M
  */
 
+bool crc32c_intel_available = false;
+
 #ifdef ARCH_HAVE_SSE4_2
 
 #if BITS_PER_LONG == 64
@@ -28,8 +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__(
@@ -74,30 +71,17 @@ uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
 	return crc;
 }
 
-static void do_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx,
-		     unsigned int *edx)
+void crc32c_intel_probe(void)
 {
-	int id = *eax;
+	if (!crc32c_probed) {
+		unsigned int eax, ebx, ecx = 0, edx;
 
-	asm("movl %4, %%eax;"
-	    "cpuid;"
-	    "movl %%eax, %0;"
-	    "movl %%ebx, %1;"
-	    "movl %%ecx, %2;"
-	    "movl %%edx, %3;"
-		: "=r" (*eax), "=r" (*ebx), "=r" (*ecx), "=r" (*edx)
-		: "r" (id)
-		: "eax", "ebx", "ecx", "edx");
-}
+		eax = 1;
 
-int crc32c_intel_works(void)
-{
-	unsigned int eax, ebx, ecx, edx;
-
-	eax = 1;
-
-	do_cpuid(&eax, &ebx, &ecx, &edx);
-	return (ecx & (1 << 20)) != 0;
+		do_cpuid(&eax, &ebx, &ecx, &edx);
+		crc32c_intel_available = (ecx & (1 << 20)) != 0;
+		crc32c_probed = true;
+	}
 }
 
 #endif /* ARCH_HAVE_SSE */