hwf: add detection of PowerPC hardware features

* src/Makefile.am: PowerPC hardware detection.
* src/g10lib.h: Likewise.
* src/hwf-common.h: Likewise.
* src/hwf-ppc.c: Likewise.
* src/hwfeatures.c: Likewise.
* configure.ac: Likewise.
--

GnuPG-bug-id: 4529
[jk: split PowerPC HW features to separate patch, from
 https://lists.gnupg.org/pipermail/gcrypt-devel/2019-July/004769.html]
[jk: disable __builtin_cpu_supports usage for now]
Signed-off-by: Jussi Kivilinna <jussi.kivilinna@iki.fi>

6 files changed, 266 insertions, 8 deletions

diff --git a/configure.ac b/configure.ac
index e8c8cd39..6980f381 100644
--- a/configure.ac
+++ b/configure.ac
@@ -669,6 +669,14 @@ AC_ARG_ENABLE(arm-crypto-support,
 	      armcryptosupport=$enableval,armcryptosupport=yes)
 AC_MSG_RESULT($armcryptosupport)
 
+# Implementation of the --disable-ppc-crypto-support switch.
+AC_MSG_CHECKING([whether PPC crypto support is requested])
+AC_ARG_ENABLE(ppc-crypto-support,
+              AC_HELP_STRING([--disable-ppc-crypto-support],
+                 [Disable support for the PPC crypto instructions introduced in POWER 8 (PowerISA 2.07)]),
+              ppccryptosupport=$enableval,ppccryptosupport=yes)
+AC_MSG_RESULT($ppccryptosupport)
+
 # Implementation of the --disable-O-flag-munging switch.
 AC_MSG_CHECKING([whether a -O flag munging is requested])
 AC_ARG_ENABLE([O-flag-munging],
@@ -1267,6 +1275,9 @@ if test "$mpi_cpu_arch" != "arm" ; then
    fi
 fi
 
+if test "$mpi_cpu_arch" != "ppc"; then
+   ppccryptosupport="n/a"
+fi
 
 #############################################
 ####                                     ####
@@ -2107,6 +2118,10 @@ if test x"$armcryptosupport" = xyes ; then
   AC_DEFINE(ENABLE_ARM_CRYPTO_SUPPORT,1,
             [Enable support for ARMv8 Crypto Extension instructions.])
 fi
+if test x"$ppccryptosupport" = xyes ; then
+  AC_DEFINE(ENABLE_PPC_CRYPTO_SUPPORT,1,
+            [Enable support for POWER 8 (PowerISA 2.07) crypto extension.])
+fi
 if test x"$jentsupport" = xyes ; then
   AC_DEFINE(ENABLE_JENT_SUPPORT, 1,
             [Enable support for the jitter entropy collector.])
@@ -2687,6 +2702,7 @@ case "$mpi_cpu_arch" in
         ;;
      ppc)
         AC_DEFINE(HAVE_CPU_ARCH_PPC, 1,   [Defined for PPC platforms])
+        GCRYPT_HWF_MODULES="libgcrypt_la-hwf-ppc.lo"
         ;;
      arm)
         AC_DEFINE(HAVE_CPU_ARCH_ARM, 1,   [Defined for ARM platforms])
@@ -2788,6 +2804,7 @@ GCRY_MSG_SHOW([Try using Intel AVX:      ],[$avxsupport])
 GCRY_MSG_SHOW([Try using Intel AVX2:     ],[$avx2support])
 GCRY_MSG_SHOW([Try using ARM NEON:       ],[$neonsupport])
 GCRY_MSG_SHOW([Try using ARMv8 crypto:   ],[$armcryptosupport])
+GCRY_MSG_SHOW([Try using PPC crypto:     ],[$ppccryptosupport])
 GCRY_MSG_SHOW([],[])
 
 if test "x${gpg_config_script_warn}" != x; then
diff --git a/src/Makefile.am b/src/Makefile.am
index 82d6e8a0..5d347a2a 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -66,7 +66,7 @@ libgcrypt_la_SOURCES = \
 	hmac256.c hmac256.h context.c context.h \
 	ec-context.h
 
-EXTRA_libgcrypt_la_SOURCES = hwf-x86.c hwf-arm.c
+EXTRA_libgcrypt_la_SOURCES = hwf-x86.c hwf-arm.c hwf-ppc.c
 gcrypt_hwf_modules = @GCRYPT_HWF_MODULES@
 
 
diff --git a/src/g10lib.h b/src/g10lib.h
index 694c2d83..41e18c13 100644
--- a/src/g10lib.h
+++ b/src/g10lib.h
@@ -236,7 +236,7 @@ char **_gcry_strtokenize (const char *string, const char *delim);
 #define HWF_ARM_SHA2            (1 << 20)
 #define HWF_ARM_PMULL           (1 << 21)
 
-
+#define HWF_PPC_VCRYPTO         (1 << 22)
 
 gpg_err_code_t _gcry_disable_hw_feature (const char *name);
 void _gcry_detect_hw_features (void);
diff --git a/src/hwf-common.h b/src/hwf-common.h
index 8f156b56..76f346e9 100644
--- a/src/hwf-common.h
+++ b/src/hwf-common.h
@@ -22,6 +22,6 @@
 
 unsigned int _gcry_hwf_detect_x86 (void);
 unsigned int _gcry_hwf_detect_arm (void);
-
+unsigned int _gcry_hwf_detect_ppc (void);
 
 #endif /*HWF_COMMON_H*/
diff --git a/src/hwf-ppc.c b/src/hwf-ppc.c
new file mode 100644
index 00000000..1bf2edf7
--- /dev/null
+++ b/src/hwf-ppc.c
@@ -0,0 +1,234 @@
+/* hwf-ppc.c - Detect hardware features - PPC part
+ * Copyright (C) 2013,2019 Jussi Kivilinna <jussi.kivilinna@iki.fi>
+ * Copyright (C) 2019 Shawn Landden <shawn@git.icu>
+ *
+ * This file is part of Libgcrypt.
+ *
+ * Libgcrypt is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as
+ * published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * Libgcrypt is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <errno.h>
+#if defined(HAVE_SYS_AUXV_H) && (defined(HAVE_GETAUXVAL) || \
+    defined(HAVE_ELF_AUX_INFO))
+#include <sys/auxv.h>
+#endif
+
+#include "g10lib.h"
+#include "hwf-common.h"
+
+#if !defined (__powerpc__) && !defined (__powerpc64__)
+# error Module build for wrong CPU.
+#endif
+
+
+#if defined(HAVE_SYS_AUXV_H) && defined(HAVE_ELF_AUX_INFO) && \
+    !defined(HAVE_GETAUXVAL) && defined(AT_HWCAP)
+#define HAVE_GETAUXVAL
+static unsigned long getauxval(unsigned long type)
+{
+  unsigned long auxval = 0;
+  int err;
+
+  /* FreeBSD provides 'elf_aux_info' function that does the same as
+   * 'getauxval' on Linux. */
+
+  err = elf_aux_info (type, &auxval, sizeof(auxval));
+  if (err)
+    {
+      errno = err;
+      auxval = 0;
+    }
+
+  return auxval;
+}
+#endif
+
+
+#undef HAS_SYS_AT_HWCAP
+#if defined(__linux__) || \
+    (defined(HAVE_SYS_AUXV_H) && defined(HAVE_GETAUXVAL))
+#define HAS_SYS_AT_HWCAP 1
+
+struct feature_map_s
+  {
+    unsigned int hwcap_flag;
+    unsigned int hwcap2_flag;
+    const char *feature_match;
+    unsigned int hwf_flag;
+  };
+
+#if defined(__powerpc__) || defined(__powerpc64__)
+
+/* Note: These macros have same values on Linux and FreeBSD. */
+#ifndef AT_HWCAP
+# define AT_HWCAP      16
+#endif
+#ifndef AT_HWCAP2
+# define AT_HWCAP2     26
+#endif
+
+#ifndef PPC_FEATURE2_VEC_CRYPTO
+# define PPC_FEATURE2_VEC_CRYPTO    0x02000000
+#endif
+
+static const struct feature_map_s ppc_features[] =
+  {
+#ifdef ENABLE_PPC_CRYPTO_SUPPORT
+    { 0, PPC_FEATURE2_VEC_CRYPTO, " crypto", HWF_PPC_VCRYPTO },
+#endif
+  };
+#endif
+
+static int
+get_hwcap(unsigned int *hwcap, unsigned int *hwcap2)
+{
+  struct { unsigned long a_type; unsigned long a_val; } auxv;
+  FILE *f;
+  int err = -1;
+  static int hwcap_initialized = 0;
+  static unsigned int stored_hwcap = 0;
+  static unsigned int stored_hwcap2 = 0;
+
+  if (hwcap_initialized)
+    {
+      *hwcap = stored_hwcap;
+      *hwcap2 = stored_hwcap2;
+      return 0;
+    }
+
+#if 0 // TODO: configure.ac detection for __builtin_cpu_supports
+#if defined(__GLIBC__) && defined(__GNUC__)
+#if __GNUC__ >= 6
+  /* Returns 0 if glibc support doesn't exist, so we can
+   * only trust positive results. This function will need updating
+   * if we ever need more than one cpu feature.
+   */
+  // TODO: fix, false if ENABLE_PPC_CRYPTO_SUPPORT
+  if (sizeof(ppc_features)/sizeof(ppc_features[0]) == 0) {
+    if (__builtin_cpu_supports("vcrypto")) {
+      stored_hwcap = 0;
+      stored_hwcap2 = PPC_FEATURE2_VEC_CRYPTO;
+	    hwcap_initialized = 1;
+      return 0;
+    }
+  }
+#endif
+#endif
+#endif
+
+#if defined(HAVE_SYS_AUXV_H) && defined(HAVE_GETAUXVAL)
+  errno = 0;
+  auxv.a_val = getauxval (AT_HWCAP);
+  if (errno == 0)
+    {
+      stored_hwcap |= auxv.a_val;
+      hwcap_initialized = 1;
+    }
+
+  if (AT_HWCAP2 >= 0)
+    {
+      errno = 0;
+      auxv.a_val = getauxval (AT_HWCAP2);
+      if (errno == 0)
+	{
+	  stored_hwcap2 |= auxv.a_val;
+	  hwcap_initialized = 1;
+	}
+    }
+
+  if (hwcap_initialized && (stored_hwcap || stored_hwcap2))
+    {
+      *hwcap = stored_hwcap;
+      *hwcap2 = stored_hwcap2;
+      return 0;
+    }
+#endif
+
+  f = fopen("/proc/self/auxv", "r");
+  if (!f)
+    {
+      *hwcap = stored_hwcap;
+      *hwcap2 = stored_hwcap2;
+      return -1;
+    }
+
+  while (fread(&auxv, sizeof(auxv), 1, f) > 0)
+    {
+      if (auxv.a_type == AT_HWCAP)
+        {
+          stored_hwcap |= auxv.a_val;
+          hwcap_initialized = 1;
+        }
+
+      if (auxv.a_type == AT_HWCAP2)
+        {
+          stored_hwcap2 |= auxv.a_val;
+          hwcap_initialized = 1;
+        }
+    }
+
+  if (hwcap_initialized)
+      err = 0;
+
+  fclose(f);
+  *hwcap = stored_hwcap;
+  *hwcap2 = stored_hwcap2;
+  return err;
+}
+
+static unsigned int
+detect_ppc_at_hwcap(void)
+{
+  unsigned int hwcap;
+  unsigned int hwcap2;
+  unsigned int features = 0;
+  unsigned int i;
+
+  if (get_hwcap(&hwcap, &hwcap2) < 0)
+      return features;
+
+  for (i = 0; i < DIM(ppc_features); i++)
+    {
+      if (hwcap & ppc_features[i].hwcap_flag)
+        features |= ppc_features[i].hwf_flag;
+
+      if (hwcap2 & ppc_features[i].hwcap2_flag)
+        features |= ppc_features[i].hwf_flag;
+    }
+
+  return features;
+}
+
+#endif
+
+unsigned int
+_gcry_hwf_detect_ppc (void)
+{
+  unsigned int ret = 0;
+  unsigned int broken_hwfs = 0;
+
+#if defined (HAS_SYS_AT_HWCAP)
+  ret |= detect_ppc_at_hwcap ();
+#endif
+
+  ret &= ~broken_hwfs;
+
+  return ret;
+}
diff --git a/src/hwfeatures.c b/src/hwfeatures.c
index e0816694..fe513753 100644
--- a/src/hwfeatures.c
+++ b/src/hwfeatures.c
@@ -42,6 +42,7 @@ static struct
   const char *desc;
 } hwflist[] =
   {
+#if defined(HAVE_CPU_ARCH_X86)
     { HWF_PADLOCK_RNG,         "padlock-rng" },
     { HWF_PADLOCK_AES,         "padlock-aes" },
     { HWF_PADLOCK_SHA,         "padlock-sha" },
@@ -59,11 +60,15 @@ static struct
     { HWF_INTEL_FAST_VPGATHER, "intel-fast-vpgather" },
     { HWF_INTEL_RDTSC,         "intel-rdtsc" },
     { HWF_INTEL_SHAEXT,        "intel-shaext" },
+#elif defined(HAVE_CPU_ARCH_ARM)
     { HWF_ARM_NEON,            "arm-neon" },
     { HWF_ARM_AES,             "arm-aes" },
     { HWF_ARM_SHA1,            "arm-sha1" },
     { HWF_ARM_SHA2,            "arm-sha2" },
-    { HWF_ARM_PMULL,           "arm-pmull" }
+    { HWF_ARM_PMULL,           "arm-pmull" },
+#elif defined(HAVE_CPU_ARCH_PPC)
+    { HWF_PPC_VCRYPTO,         "ppc-crypto" },
+#endif
   };
 
 /* A bit vector with the hardware features which shall not be used.
@@ -208,12 +213,14 @@ _gcry_detect_hw_features (void)
   {
     hw_features = _gcry_hwf_detect_x86 ();
   }
-#endif /* HAVE_CPU_ARCH_X86 */
-#if defined (HAVE_CPU_ARCH_ARM)
+#elif defined (HAVE_CPU_ARCH_ARM)
   {
     hw_features = _gcry_hwf_detect_arm ();
   }
-#endif /* HAVE_CPU_ARCH_ARM */
-
+#elif defined (HAVE_CPU_ARCH_PPC)
+  {
+    hw_features = _gcry_hwf_detect_ppc ();
+  }
+#endif
   hw_features &= ~disabled_hw_features;
 }