minor fixes, use cpuid detection from mirage-crypto (detect_cpu_featu…

…res) also in mirage-crypto-entropy (entropy_cpu_stubs)

config/cfg.ml

@@ -8,7 +8,7 @@ let _ =
   in
   let accelerate_flags =
     match arch with
-    | "x86_64" -> [ "-DACCELERATE"; "-mssse3"; "-maes"; "-mpclmul" ]
+    | "x86_64" | "amd64" -> [ "-DACCELERATE"; "-mssse3"; "-maes"; "-mpclmul" ]
     | _ -> []
   in
   let ent_flags =

src/dune

@@ -3,11 +3,12 @@
   (public_name mirage-crypto)
   (libraries cstruct)
   (private_modules ccm cipher_block cipher_stream hash native uncommon)
-  (c_names misc misc_sse
+  (c_names detect_cpu_features
+           misc misc_sse
            md5 sha1 sha256 sha512 hash_stubs
            aes_generic aes_aesni ghash_generic ghash_pclmul
            des_generic
-           entropy_cpu_stubs detect_cpu_features)
+           entropy_cpu_stubs)
   (c_flags (:standard) (:include cflags.sexp)))
 
 (include_subdirs unqualified)

src/native/detect_cpu_features.c

@@ -1,6 +1,6 @@
 #include "mirage_crypto.h"
 
-#ifdef __mc_ACCELERATE__
+#if defined (__i386__) || defined (__x86_64__)
 
 #include <cpuid.h>
 
@@ -10,23 +10,30 @@ CAMLprim value
 mc_detect_cpu_features (__unit ()) {
   unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
 
-  if (__get_cpuid(1, &eax, &ebx, &ecx, &edx))
-  {
+  if (__get_cpuid(1, &eax, &ebx, &ecx, &edx)) {
     if (ecx & bit_PCLMUL)
       mc_detected_cpu_features.pclmul = 1;
     if (ecx & bit_SSSE3)
       mc_detected_cpu_features.ssse3 = 1;
     if (ecx & bit_AES)
       mc_detected_cpu_features.aesni = 1;
+    if (ecx & bit_RDRND)
+      mc_detected_cpu_features.rdrand = 1;
   }
+
+  if (__get_cpuid_count(7, 0, &eax, &ebx, &ecx, &edx)) {
+    if (ebx & bit_RDSEED)
+      mc_detected_cpu_features.rdseed = 1;
+  }
+
   return Val_unit;
 }
 
-#else /* __mc_ACCELERATE__ */
+#else /* i386 || x86_64 */
 
 CAMLprim value
 mc_detect_cpu_features (__unit ()) {
   return Val_unit;
 }
 
-#endif /* __mc_ACCELERATE__ */
+#endif /* i386 || x86_64 */

src/native/entropy_cpu_stubs.c

@@ -10,12 +10,6 @@
 #define __x86__
 
 #include <x86intrin.h>
-#include <cpuid.h>
-
-/* because clang... */
-#if !defined(bit_RDSEED)
-#define bit_RDSEED 0x00040000
-#endif
 
 #if defined (__x86_64__)
 #define random_t unsigned long long
@@ -40,6 +34,7 @@ static inline uint32_t read_virtual_count () {
   return c_lo;
 }
 #endif /* arm */
+
 #if defined (__aarch64__)
 #define	isb()		__asm __volatile("isb" : : : "memory")
 static inline uint64_t read_virtual_count(void)
@@ -63,35 +58,25 @@ static enum cpu_rng_t __cpu_rng = RNG_NONE;
 
 static void detect () {
 #if defined (__x86__)
-
-  unsigned int sig, eax, ebx, ecx, edx;
-  int max = __get_cpuid_max (0, &sig);
   random_t r = 0;
 
-  if (max < 1) return;
-
-  if (sig == signature_INTEL_ebx || sig == signature_AMD_ebx) {
-    __cpuid (1, eax, ebx, ecx, edx);
-    if (ecx & bit_RDRND)
-      /* AMD Ryzen 3000 bug where RDRAND always returns -1
-         https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/ */
-      for (int i = 0; i < RETRIES; i++)
-        if (_rdrand_step(&r) == 1 && r != (random_t) (-1)) {
-          __cpu_rng = RNG_RDRAND;
-          break;
-        }
-    if (max > 7) {
-      __cpuid_count (7, 0, eax, ebx, ecx, edx);
-      if (ebx & bit_RDSEED)
-        /* RDSEED could return -1 as well, thus we test it here as well
-           https://www.reddit.com/r/Amd/comments/cmza34/agesa_1003_abb_fixes_rdrandrdseed/ */
-        for (int i = 0; i < RETRIES; i++)
-          if (_rdseed_step(&r) == 1 && r != (random_t) (-1)) {
-            __cpu_rng = RNG_RDSEED;
-            break;
-          }
-    }
-  }
+  if (mc_detected_cpu_features.rdrand)
+    /* AMD Ryzen 3000 bug where RDRAND always returns -1
+       https://arstechnica.com/gadgets/2019/10/how-a-months-old-amd-microcode-bug-destroyed-my-weekend/ */
+    for (int i = 0; i < RETRIES; i++)
+      if (_rdrand_step(&r) == 1 && r != (random_t) (-1)) {
+        __cpu_rng = RNG_RDRAND;
+        break;
+      }
+
+  if (mc_detected_cpu_features.rdseed)
+    /* RDSEED could return -1, thus we test it here
+       https://www.reddit.com/r/Amd/comments/cmza34/agesa_1003_abb_fixes_rdrandrdseed/ */
+    for (int i = 0; i < RETRIES; i++)
+      if (_rdseed_step(&r) == 1 && r != (random_t) (-1)) {
+        __cpu_rng = RNG_RDSEED;
+        break;
+      }
 #endif
 }
 

src/native/mirage_crypto.h

@@ -12,17 +12,23 @@
 #define __mc_ACCELERATE__
 #endif
 
-#ifdef __mc_ACCELERATE__
+#if defined (__i386__) || defined (__x86_64__)
 
 struct _mc_cpu_features {
   int aesni;
   int pclmul;
   int ssse3;
+  int rdrand;
+  int rdseed;
 };
 
 /* Supported accelerations */
 extern struct _mc_cpu_features mc_detected_cpu_features;
 
+#endif /* __i386__ || __x86_64__ */
+
+#ifdef __mc_ACCELERATE__
+
 #define _mc_switch_accel(FEATURE, GENERIC_CALL, ACCELERATED_CALL) \
   if (!(mc_detected_cpu_features.FEATURE)) { GENERIC_CALL; } \
   else { ACCELERATED_CALL; }