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/* hwf-s390x.c - Detect hardware features - s390x/zSeries part
* Copyright (C) 2020 Jussi Kivilinna <jussi.kivilinna@iki.fi>
*
* 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
*/
#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 (__s390x__)
# error Module build for wrong CPU.
#endif
#undef HAVE_STFLE
#ifdef HAVE_GCC_INLINE_ASM_S390X
# define HAVE_STFLE 1
#endif
#ifndef AT_HWCAP
# define AT_HWCAP 16
#endif
#ifndef HWCAP_S390_STFLE
# define HWCAP_S390_STFLE 4
#endif
#ifndef HWCAP_S390_VXRS
# define HWCAP_S390_VXRS 2048
#endif
struct feature_map_s
{
unsigned int facilities_bit;
unsigned int hwcap_flag;
unsigned int hwf_flag;
};
static const struct feature_map_s s390x_features[] =
{
{ 17, 0, HWF_S390X_MSA },
{ 77, 0, HWF_S390X_MSA_4 },
{ 146, 0, HWF_S390X_MSA_8 },
#ifdef HAVE_GCC_INLINE_ASM_S390X_VX
{ 129, HWCAP_S390_VXRS, HWF_S390X_VX },
#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 facilities_s
{
u64 bits[3];
};
static int
get_hwcap(unsigned int *hwcap)
{
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;
if (hwcap_initialized)
{
*hwcap = stored_hwcap;
return 0;
}
#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 (hwcap_initialized && stored_hwcap)
{
*hwcap = stored_hwcap;
return 0;
}
#endif
f = fopen("/proc/self/auxv", "r");
if (!f)
{
*hwcap = stored_hwcap;
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 (hwcap_initialized)
err = 0;
fclose(f);
*hwcap = stored_hwcap;
return err;
}
#endif
#ifdef HAVE_STFLE
static void
get_stfle(struct facilities_s *out)
{
static int stfle_initialized = 0;
static struct facilities_s stored_facilities;
if (!stfle_initialized)
{
register unsigned long reg0 asm("0") = DIM(stored_facilities.bits) - 1;
asm ("stfle %1\n\t"
: "+d" (reg0),
"=Q" (stored_facilities.bits[0])
:
: "cc", "memory");
stfle_initialized = 1;
}
*out = stored_facilities;
}
#endif
static unsigned int
detect_s390x_features(void)
{
struct facilities_s facilities = { { 0, } };
unsigned int hwcap = 0;
unsigned int features = 0;
unsigned int i;
#if defined (HAS_SYS_AT_HWCAP)
if (get_hwcap(&hwcap) < 0)
return features;
#endif
if ((hwcap & HWCAP_S390_STFLE) == 0)
return features;
#ifdef HAVE_STFLE
get_stfle(&facilities);
#endif
for (i = 0; i < DIM(s390x_features); i++)
{
if (s390x_features[i].hwcap_flag == 0 ||
(s390x_features[i].hwcap_flag & hwcap))
{
unsigned int idx = s390x_features[i].facilities_bit;
unsigned int u64_idx = idx / 64;
unsigned int u64_bit = 63 - (idx % 64);
if (facilities.bits[u64_idx] & (U64_C(1) << u64_bit))
features |= s390x_features[i].hwf_flag;
}
}
return features;
}
unsigned int
_gcry_hwf_detect_s390x (void)
{
unsigned int ret = 0;
ret |= detect_s390x_features ();
return ret;
}