/* Get system parameters, e.g. cache information.  S390/S390x version.

   Copyright (C) 2015-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library 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.

   The GNU C Library 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 the GNU C Library.  If not, see

   <http://www.gnu.org/licenses/>.  */

#include <unistd.h>

#include <dl-procinfo.h>

static long int linux_sysconf (int name);

/* Possible arguments for get_cache_info.

   The values are reflecting the level/attribute/type indications

   of ecag-instruction (extract cpu attribue).  */

#define CACHE_LEVEL_MAX        8

#define CACHE_ATTR_LINESIZE    1

#define CACHE_ATTR_SIZE        2

#define CACHE_ATTR_ASSOC       3

#define CACHE_TYPE_DATA        0

#define CACHE_TYPE_INSTRUCTION 1

static long

get_cache_info (int level, int attr, int type)

{

  unsigned long int val;

  unsigned int cmd;

  unsigned long int arg;

  /* Check arguments.  */

  if (level < 1 || level > CACHE_LEVEL_MAX

      || attr < CACHE_ATTR_LINESIZE || attr > CACHE_ATTR_ASSOC

      || type < CACHE_TYPE_DATA || type > CACHE_TYPE_INSTRUCTION)

    return 0L;

  /* Check if ecag-instruction is available.

     ecag - extract CPU attribute (only in zarch; arch >= z10; in as 2.24)  */

  if (!(GLRO (dl_hwcap) & HWCAP_S390_STFLE)

#if !defined __s390x__

      || !(GLRO (dl_hwcap) & HWCAP_S390_ZARCH)

      || !(GLRO (dl_hwcap) & HWCAP_S390_HIGH_GPRS)

#endif /* !__s390x__ */

      )

    {

      /* stfle (or zarch, high-gprs on s390-32) is not available.

	 We are on an old machine. Return 256byte for LINESIZE for L1 d/i-cache,

	 otherwise 0.  */

      if (level == 1 && attr == CACHE_ATTR_LINESIZE)

	return 256L;

      else

	return 0L;

    }

  /* Store facility list and check for z10.

     (see ifunc-resolver for details)  */

  register unsigned long reg0 __asm__("0") = 0;

#ifdef __s390x__

  unsigned long stfle_bits;

# define STFLE_Z10_MASK (1UL << (63 - 34))

#else

  unsigned long long stfle_bits;

# define STFLE_Z10_MASK (1ULL << (63 - 34))

#endif /* !__s390x__ */

  __asm__ __volatile__(".machine push"        "\n\t"

		       ".machinemode \"zarch_nohighgprs\"\n\t"

		       ".machine \"z9-109\""  "\n\t"

		       "stfle %0"             "\n\t"

		       ".machine pop"         "\n"

		       : "=QS" (stfle_bits), "+d" (reg0)

		       : : "cc");

  if (!(stfle_bits & STFLE_Z10_MASK))

    {

      /* We are at least on a z9 machine.

	 Return 256byte for LINESIZE for L1 d/i-cache,

	 otherwise 0.  */

      if (level == 1 && attr == CACHE_ATTR_LINESIZE)

	return 256L;

      else

	return 0L;

    }

  /* Check cache topology, if cache is available at this level.  */

  arg = (CACHE_LEVEL_MAX - level) * 8;

  __asm__ __volatile__ (".machine push\n\t"

			".machine \"z10\"\n\t"

			".machinemode \"zarch_nohighgprs\"\n\t"

			"ecag %0,%%r0,0\n\t"   /* returns 64bit unsigned integer.  */

			"srlg %0,%0,0(%1)\n\t" /* right align 8bit cache info field.  */

			".machine pop"

			: "=&d" (val)

			: "a" (arg)

			);

  val &= 0xCUL; /* Extract cache scope information from cache topology summary.

		   (bits 4-5 of 8bit-field; 00 means cache does not exist).  */

  if (val == 0)

    return 0L;

  /* Get cache information for level, attribute and type.  */

  cmd = (attr << 4) | ((level - 1) << 1) | type;

  __asm__ __volatile__ (".machine push\n\t"

			".machine \"z10\"\n\t"

			".machinemode \"zarch_nohighgprs\"\n\t"

			"ecag %0,%%r0,0(%1)\n\t"

			".machine pop"

			: "=d" (val)

			: "a" (cmd)

			);

  return val;

}

long int

__sysconf (int name)

{

  if (name >= _SC_LEVEL1_ICACHE_SIZE && name <= _SC_LEVEL4_CACHE_LINESIZE)

    {

      int level;

      int attr;

      int type;

      switch (name)

	{

	case _SC_LEVEL1_ICACHE_SIZE:

	  level = 1;

	  attr = CACHE_ATTR_SIZE;

	  type = CACHE_TYPE_INSTRUCTION;

	  break;

	case _SC_LEVEL1_ICACHE_ASSOC:

	  level = 1;

	  attr = CACHE_ATTR_ASSOC;

	  type = CACHE_TYPE_INSTRUCTION;

	  break;

	case _SC_LEVEL1_ICACHE_LINESIZE:

	  level = 1;

	  attr = CACHE_ATTR_LINESIZE;

	  type = CACHE_TYPE_INSTRUCTION;

	  break;

	case _SC_LEVEL1_DCACHE_SIZE:

	  level = 1;

	  attr = CACHE_ATTR_SIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL1_DCACHE_ASSOC:

	  level = 1;

	  attr = CACHE_ATTR_ASSOC;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL1_DCACHE_LINESIZE:

	  level = 1;

	  attr = CACHE_ATTR_LINESIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL2_CACHE_SIZE:

	  level = 2;

	  attr = CACHE_ATTR_SIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL2_CACHE_ASSOC:

	  level = 2;

	  attr = CACHE_ATTR_ASSOC;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL2_CACHE_LINESIZE:

	  level = 2;

	  attr = CACHE_ATTR_LINESIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL3_CACHE_SIZE:

	  level = 3;

	  attr = CACHE_ATTR_SIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL3_CACHE_ASSOC:

	  level = 3;

	  attr = CACHE_ATTR_ASSOC;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL3_CACHE_LINESIZE:

	  level = 3;

	  attr = CACHE_ATTR_LINESIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL4_CACHE_SIZE:

	  level = 4;

	  attr = CACHE_ATTR_SIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL4_CACHE_ASSOC:

	  level = 4;

	  attr = CACHE_ATTR_ASSOC;

	  type = CACHE_TYPE_DATA;

	  break;

	case _SC_LEVEL4_CACHE_LINESIZE:

	  level = 4;

	  attr = CACHE_ATTR_LINESIZE;

	  type = CACHE_TYPE_DATA;

	  break;

	default:

	  level = 0;

	  attr = 0;

	  type = 0;

	  break;

	}

      return get_cache_info (level, attr, type);

    }

  return linux_sysconf (name);

}

/* Now the generic Linux version.  */

#undef __sysconf

#define __sysconf static linux_sysconf

#include <sysdeps/unix/sysv/linux/sysconf.c>