X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/dc2adc883524babe0ebec62d8f85372ef18bfd7a..6c0946ef1f1fa9b75b8c6d65ea0554ff4e1ec4eb:/base/dispatch.c?ds=sidebyside

diff --git a/base/dispatch.c b/base/dispatch.c
index bda7f88e..50c842e1 100644
--- a/base/dispatch.c
+++ b/base/dispatch.c
@@ -56,6 +56,8 @@ 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; };
@@ -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");
   }
@@ -139,6 +145,7 @@ static int rdrand_works_p(unsigned op)
 
   switch (op) {
     case OP_RDRAND: what = "RDRAND"; break;
+    case OP_RDSEED: what = "RDSEED"; break;
     default: assert(!"unexpected op");
   }
 
@@ -527,6 +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)					\