X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/0ed9f882cdf9d0b4428459f7d5496610d53ca4c9..1519ef6617fd7351bd40026b9eeb47c7f7f42234:/base/dispatch.c

diff --git a/base/dispatch.c b/base/dispatch.c
index 7652f323..309be5c3 100644
--- a/base/dispatch.c
+++ b/base/dispatch.c
@@ -56,12 +56,14 @@ enum {
 #  define CPUID1C_AVX (1u << 28)
 #  define CPUID1C_RDRAND (1u << 30)
 
+  CPUID_7_0_B,				/* eax = 7, ecx = 0 => ebx&?? */
+#  define CPUID70B_RDSEED (1u << 18)
 };
 
 struct cpuid { unsigned a, b, c, d; };
 extern int dispatch_x86ish_cpuid(struct cpuid *, unsigned a, unsigned c);
 extern int dispatch_x86ish_xmmregisters_p(void);
-extern int dispatch_x86ish_rdrand(unsigned *);
+extern int dispatch_x86ish_rdrand(unsigned op, unsigned *);
 
 static void cpuid(struct cpuid *cc, unsigned a, unsigned c)
 {
@@ -99,6 +101,10 @@ static int cpuid_feature_p(unsigned leaf, unsigned bits)
       if (cpuid_maxleaf() < 1) return (0);
       cpuid(&c, 1, 0); r = c.c;
       break;
+    case CPUID_7_0_B:
+      if (cpuid_maxleaf() < 7) return (0);
+      cpuid(&c, 7, 0); r = c.b;
+      break;
     default:
       assert(!"unknown cpuid leaf");
   }
@@ -130,28 +136,37 @@ static int xmm_registers_available_p(void)
  *		that it's already been verified to be safe to issue.
  */
 
-static int rdrand_works_p(void)
+enum { OP_RDRAND, OP_RDSEED };
+
+static int rdrand_works_p(unsigned op)
 {
   unsigned ref, x, i;
+  const char *what;
+
+  switch (op) {
+    case OP_RDRAND: what = "RDRAND"; break;
+    case OP_RDSEED: what = "RDSEED"; break;
+    default: assert(!"unexpected op");
+  }
 
   /* Check that it doesn't always give the same answer.  Try four times: this
    * will fail with probability %$2^{-128}$% with a truly random generator,
    * which seems fair enough.
    */
-  if (dispatch_x86ish_rdrand(&ref)) goto fail;
+  if (dispatch_x86ish_rdrand(op, &ref)) goto fail;
   for (i = 0; i < 4; i++) {
-    if (dispatch_x86ish_rdrand(&x)) goto fail;
+    if (dispatch_x86ish_rdrand(op, &x)) goto fail;
     if (x != ref) goto not_stuck;
   }
-  dispatch_debug("RDRAND always returns 0x%08x!", ref);
+  dispatch_debug("%s always returns 0x%08x!", what, ref);
   return (0);
 
 not_stuck:
-  dispatch_debug("RDRAND instruction looks plausible");
+  dispatch_debug("%s instruction looks plausible", what);
   return (1);
 
 fail:
-  dispatch_debug("RDRAND instruction fails too often");
+  dispatch_debug("%s instruction fails too often", what);
   return (0);
 }
 
@@ -505,11 +520,11 @@ int cpu_feature_p(int feat)
 		 cpuid_feature_p(CPUID_1_D, CPUID1D_SSE2) &&
 		 xmm_registers_available_p());
     CASE_CPUFEAT(X86_AESNI, "x86:aesni",
-		 cpuid_feature_p(CPUID_1_D, CPUID1C_AESNI) &&
+		 cpuid_feature_p(CPUID_1_C, CPUID1C_AESNI) &&
 		 xmm_registers_available_p());
     CASE_CPUFEAT(X86_RDRAND, "x86:rdrand",
 		 cpuid_feature_p(CPUID_1_C, CPUID1C_RDRAND) &&
-		 rdrand_works_p());
+		 rdrand_works_p(OP_RDRAND));
     CASE_CPUFEAT(X86_AVX, "x86:avx",
 		 cpuid_feature_p(CPUID_1_C, CPUID1C_AVX) &&
 		 xmm_registers_available_p());
@@ -519,6 +534,9 @@ int cpu_feature_p(int feat)
     CASE_CPUFEAT(X86_PCLMUL, "x86:pclmul",
 		 cpuid_feature_p(CPUID_1_C, CPUID1C_PCLMUL) &&
 		 xmm_registers_available_p());
+    CASE_CPUFEAT(X86_RDSEED, "x86:rdseed",
+		 cpuid_feature_p(CPUID_7_0_B, CPUID70B_RDSEED) &&
+		 rdrand_works_p(OP_RDSEED));
 #endif
 #ifdef CAPMAP
 #  define FEATP__CASE(feat, tok)					\