Add Curve25519 support.

[libgcrypt.git] / src / hwf-x86.c

diff --git a/src/hwf-x86.c b/src/hwf-x86.c
index b50b4b0..399952c 100644 (file)
--- a/src/hwf-x86.c
+++ b/src/hwf-x86.c
@@ -77,11 +77,12 @@ get_cpuid(unsigned int in, unsigned int *eax, unsigned int *ebx,
 
   asm volatile
     ("pushl %%ebx\n\t"           /* Save GOT register.  */
+     "movl %1, %%ebx\n\t"
      "cpuid\n\t"
      "movl %%ebx, %1\n\t"
      "popl %%ebx\n\t"            /* Restore GOT register. */
-     : "=a" (regs[0]), "=r" (regs[1]), "=c" (regs[2]), "=d" (regs[3])
-     : "0" (in)
+     : "=a" (regs[0]), "=D" (regs[1]), "=c" (regs[2]), "=d" (regs[3])
+     : "0" (in), "1" (0), "2" (0), "3" (0)
      : "cc"
      );
 
@@ -94,6 +95,23 @@ get_cpuid(unsigned int in, unsigned int *eax, unsigned int *ebx,
   if (edx)
     *edx = regs[3];
 }
+
+#if defined(ENABLE_AVX_SUPPORT) || defined(ENABLE_AVX2_SUPPORT)
+static unsigned int
+get_xgetbv(void)
+{
+  unsigned int t_eax, t_edx;
+
+  asm volatile
+    ("xgetbv\n\t"
+     : "=a" (t_eax), "=d" (t_edx)
+     : "c" (0)
+    );
+
+  return t_eax;
+}
+#endif /* ENABLE_AVX_SUPPORT || ENABLE_AVX2_SUPPORT */
+
 #endif /* i386 && GNUC */
 
 
@@ -115,7 +133,7 @@ get_cpuid(unsigned int in, unsigned int *eax, unsigned int *ebx,
   asm volatile
     ("cpuid\n\t"
      : "=a" (regs[0]), "=b" (regs[1]), "=c" (regs[2]), "=d" (regs[3])
-     : "0" (in)
+     : "0" (in), "1" (0), "2" (0), "3" (0)
      : "cc"
      );
 
@@ -128,6 +146,23 @@ get_cpuid(unsigned int in, unsigned int *eax, unsigned int *ebx,
   if (edx)
     *edx = regs[3];
 }
+
+#if defined(ENABLE_AVX_SUPPORT) || defined(ENABLE_AVX2_SUPPORT)
+static unsigned int
+get_xgetbv(void)
+{
+  unsigned int t_eax, t_edx;
+
+  asm volatile
+    ("xgetbv\n\t"
+     : "=a" (t_eax), "=d" (t_edx)
+     : "c" (0)
+    );
+
+  return t_eax;
+}
+#endif /* ENABLE_AVX_SUPPORT || ENABLE_AVX2_SUPPORT */
+
 #endif /* x86-64 && GNUC */
 
 
@@ -137,12 +172,16 @@ detect_x86_gnuc (void)
 {
   char vendor_id[12+1];
   unsigned int features;
+  unsigned int os_supports_avx_avx2_registers = 0;
+  unsigned int max_cpuid_level;
   unsigned int result = 0;
 
+  (void)os_supports_avx_avx2_registers;
+
   if (!is_cpuid_available())
     return 0;
 
-  get_cpuid(0, NULL,
+  get_cpuid(0, &max_cpuid_level,
             (unsigned int *)&vendor_id[0],
             (unsigned int *)&vendor_id[8],
             (unsigned int *)&vendor_id[4]);
@@ -187,6 +226,7 @@ detect_x86_gnuc (void)
   else if (!strcmp (vendor_id, "GenuineIntel"))
     {
       /* This is an Intel CPU.  */
+      result |= HWF_INTEL_CPU;
     }
   else if (!strcmp (vendor_id, "AuthenticAMD"))
     {
@@ -199,17 +239,61 @@ detect_x86_gnuc (void)
   /* Get CPU info and Intel feature flags (ECX).  */
   get_cpuid(1, NULL, NULL, &features, NULL);
 
+#ifdef ENABLE_PCLMUL_SUPPORT
+  /* Test bit 1 for PCLMUL.  */
+  if (features & 0x00000002)
+     result |= HWF_INTEL_PCLMUL;
+#endif
+  /* Test bit 9 for SSSE3.  */
+  if (features & 0x00000200)
+     result |= HWF_INTEL_SSSE3;
 #ifdef ENABLE_AESNI_SUPPORT
   /* Test bit 25 for AES-NI.  */
   if (features & 0x02000000)
      result |= HWF_INTEL_AESNI;
 #endif /*ENABLE_AESNI_SUPPORT*/
+#if defined(ENABLE_AVX_SUPPORT) || defined(ENABLE_AVX2_SUPPORT)
+  /* Test bit 27 for OSXSAVE (required for AVX/AVX2).  */
+  if (features & 0x08000000)
+    {
+      /* Check that OS has enabled both XMM and YMM state support.  */
+      if ((get_xgetbv() & 0x6) == 0x6)
+        os_supports_avx_avx2_registers = 1;
+    }
+#endif
+#ifdef ENABLE_AVX_SUPPORT
+  /* Test bit 28 for AVX.  */
+  if (features & 0x10000000)
+    if (os_supports_avx_avx2_registers)
+      result |= HWF_INTEL_AVX;
+#endif /*ENABLE_AVX_SUPPORT*/
 #ifdef ENABLE_DRNG_SUPPORT
   /* Test bit 30 for RDRAND.  */
   if (features & 0x40000000)
      result |= HWF_INTEL_RDRAND;
 #endif /*ENABLE_DRNG_SUPPORT*/
 
+  /* Check additional Intel feature flags.  Early Intel P5 processors report
+   * too high max_cpuid_level, so don't check level 7 if processor does not
+   * support SSE3 (as cpuid:7 contains only features for newer processors).
+   * Source: http://www.sandpile.org/x86/cpuid.htm  */
+  if (max_cpuid_level >= 7 && (features & 0x00000001))
+    {
+      /* Get CPUID:7 contains further Intel feature flags. */
+      get_cpuid(7, NULL, &features, NULL, NULL);
+
+      /* Test bit 8 for BMI2.  */
+      if (features & 0x00000100)
+          result |= HWF_INTEL_BMI2;
+
+#ifdef ENABLE_AVX2_SUPPORT
+      /* Test bit 5 for AVX2.  */
+      if (features & 0x00000020)
+        if (os_supports_avx_avx2_registers)
+          result |= HWF_INTEL_AVX2;
+#endif /*ENABLE_AVX_SUPPORT*/
+    }
+
   return result;
 }
 #endif /* HAS_X86_CPUID */