X-Git-Url: https://git.kernel.dk/?a=blobdiff_plain;f=crc%2Fcrc32c-intel.c;h=77d6df411973510298342d79e190db4b3a447ffa;hb=refs%2Ftags%2Ffio-1.41.6;hp=cec5ad5dec9d5d88ec7498133f2915ae0c1bd146;hpb=419484b934222e589f0b718e9494b045df176167;p=fio.git

diff --git a/crc/crc32c-intel.c b/crc/crc32c-intel.c
index cec5ad5d..77d6df41 100644
--- a/crc/crc32c-intel.c
+++ b/crc/crc32c-intel.c
@@ -1,4 +1,10 @@
 #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"
 
 /*
@@ -68,5 +74,30 @@ uint32_t crc32c_intel(unsigned char const *data, unsigned long length)
 	return crc;
 }
 
-#endif /* ARCH_HAVE_SSE */
+static void do_cpuid(unsigned int *eax, unsigned int *ebx, unsigned int *ecx,
+		     unsigned int *edx)
+{
+	int id = *eax;
+
+	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");
+}
+
+int crc32c_intel_works(void)
+{
+	unsigned int eax, ebx, ecx, edx;
+
+	eax = 1;
 
+	do_cpuid(&eax, &ebx, &ecx, &edx);
+	return (ecx & (1 << 20)) != 0;
+}
+
+#endif /* ARCH_HAVE_SSE */