/* EINA - EFL data type library
 * Copyright (C) 2007-2008 Jorge Luis Zapata Muga
 *
 * This 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.
 *
 * This 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 this library;
 * if not, see <http://www.gnu.org/licenses/>.
 */

#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#ifdef EFL_HAVE_THREADS
# ifdef _WIN32
#  define WIN32_LEAN_AND_MEAN
#  include <windows.h>
# elif defined (__sun) || defined(__GNU__) || defined(__CYGWIN__)
#  include <unistd.h>
# elif defined (__FreeBSD__) || defined (__OpenBSD__) || \
   defined (__NetBSD__) || defined (__DragonFly__) || defined (__MacOSX__) || \
   (defined (__MACH__) && defined (__APPLE__))
#  include <unistd.h>
#  include <sys/param.h>
#  include <sys/sysctl.h>
# elif defined (__linux__) || defined(__GLIBC__)
#  include <sched.h>
# endif
# include <pthread.h>

# define TH_MAX 32
#endif

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>

#include "eina_log.h"
#include "eina_cpu.h"

#if defined(HAVE_SYS_AUXV_H) && defined(HAVE_ASM_HWCAP_H) && (defined(__arm__) || defined(__aarch64__)) && defined(__linux__)
# include <sys/auxv.h>
# include <asm/hwcap.h>
#endif

/*============================================================================*
*                                  Local                                     *
*============================================================================*/

static void _eina_page_size(void);

/* FIXME this ifdefs should be replaced */
#if defined(__i386__) || defined(__x86_64__)
/* We save ebx and restore it to be PIC compatible */
static inline void _x86_cpuid(int op, int *a, int *b, int *c, int *d)
{
   __asm__ volatile (
#if defined(__x86_64__)
      "pushq %%rbx      \n\t" /* save %ebx */
#else
      "pushl %%ebx      \n\t" /* save %ebx */
#endif
      "cpuid            \n\t"
      "movl %%ebx, %1   \n\t" /* save what cpuid just put in %ebx */
#if defined(__x86_64__)
      "popq %%rbx       \n\t" /* restore the old %ebx */
#else
      "popl %%ebx       \n\t" /* restore the old %ebx */
#endif
      : "=a" (*a), "=r" (*b), "=c" (*c), "=d" (*d)
      : "a" (op)
      : "cc");
}

static
void _x86_simd(Eina_Cpu_Features *features)
{
   int a, b, c, d;

   _x86_cpuid(1, &a, &b, &c, &d);
   /*
    * edx
    * 18 = PN (Processor Number)
    * 19 = CLFlush (Cache Line Flush)
    * 23 = MMX
    * 25 = SSE
    * 26 = SSE2
    * 28 = HTT (Hyper Threading)
    * ecx
    * 0 = SSE3
    * 9 = SSSE3
    * 19 = SSE4.1
    * 20 = SSE4.2
    */
   if ((d >> 23) & 1)
      *features |= EINA_CPU_MMX;

   if ((d >> 25) & 1)
      *features |= EINA_CPU_SSE;

   if ((d >> 26) & 1)
      *features |= EINA_CPU_SSE2;

   if (c & 1)
      *features |= EINA_CPU_SSE3;

   if ((c >> 9) & 1)
      *features |= EINA_CPU_SSSE3;

   if ((c >> 19) & 1)
      *features |= EINA_CPU_SSE41;

   if ((c >> 20) & 1)
      *features |= EINA_CPU_SSE42;
}
#endif

#if defined(HAVE_SYS_AUXV_H) && defined(HAVE_ASM_HWCAP_H) && (defined(__arm__) || defined(__aarch64__)) && defined(__linux__)
static void
_arm_cpu_features(Eina_Cpu_Features *features)
{
   unsigned long aux = getauxval(AT_HWCAP);
# if defined(__aarch64__)
   *features |= EINA_CPU_NEON;
# endif
# ifdef HWCAP_NEON
   if (aux & HWCAP_NEON) *features |= EINA_CPU_NEON;
# endif
# ifdef HWCAP_SVE
   if (aux & HWCAP_SVE) *features |= EINA_CPU_SVE;
# endif
}
#endif

#if defined(HAVE_SYS_AUXV_H) && defined(HAVE_ASM_HWCAP_H) && (defined(__POWERPC__) && defined(__VEC__)) && defined(__linux__)
static void
_ppc_cpu_features(Eina_Cpu_Features *features)
{
# ifdef PPC_FEATURE_HAS_ALTIVEC
   unsigned long aux = getauxval(AT_HWCAP);
   if (aux & PPC_FEATURE_HAS_ALTIVEC) *features |= EINA_CPU_ALTIVEC;
# endif
}
#endif

/*============================================================================*
*                                 Global                                     *
*============================================================================*/

/*============================================================================*
*                                   API                                      *
*============================================================================*/

/* FIXME the features checks should be called when this function is called?
 * or make it static by doing eina_cpu_init() and return a local var
 */
EINA_API Eina_Cpu_Features eina_cpu_features = 0;

Eina_Bool
eina_cpu_init(void)
{
#if defined(__i386__) || defined(__x86_64__)
   _x86_simd(&eina_cpu_features);
#elif defined(HAVE_SYS_AUXV_H) && defined(HAVE_ASM_HWCAP_H) && (defined(__arm__) || defined(__aarch64__)) && defined(__linux__)
   _arm_cpu_features(&eina_cpu_features);
#endif

   // Figure out the page size for this system
   _eina_page_size();

   return EINA_TRUE;
}

Eina_Bool
eina_cpu_shutdown(void)
{
   return EINA_TRUE;
}

/**
 *
 * @return
 */
EINA_API Eina_Cpu_Features eina_cpu_features_get(void)
{
   return eina_cpu_features;
}

static int _cpu_count = -1;

static int
_eina_cpu_count_internal(void)
{
#ifdef EFL_HAVE_THREADS

# if   defined (_WIN32)
   SYSTEM_INFO sysinfo;

   GetSystemInfo(&sysinfo);
   return sysinfo.dwNumberOfProcessors;

# elif defined (__sun) || defined(__GNU__) || defined(__CYGWIN__)
   /*
    * _SC_NPROCESSORS_ONLN: number of processors that are online, that
                            is available when sysconf is called. The number
                            of cpu can change by admins.
    * _SC_NPROCESSORS_CONF: maximum number of processors that are available
                            to the current OS instance. That number can be
                            change after a reboot.
    * _SC_NPROCESSORS_MAX : maximum number of processors that are on the
                            motherboard.
    */
   return sysconf(_SC_NPROCESSORS_ONLN);

# elif defined (__FreeBSD__) || defined (__OpenBSD__) || \
   defined (__NetBSD__) || defined (__DragonFly__) || defined (__MacOSX__) || \
   (defined (__MACH__) && defined (__APPLE__))

   int mib[4];
   int cpus;
   size_t len = sizeof(cpus);

   mib[0] = CTL_HW;
#ifdef HW_AVAILCPU
   mib[1] = HW_AVAILCPU;
#else
   mib[1] = HW_NCPU;
#endif
   sysctl(mib, 2, &cpus, &len, NULL, 0);
   if (cpus < 1)
      cpus = 1;

   return cpus;

# elif defined (__linux__) || defined(__GLIBC__)
   cpu_set_t cpu;
   int i;
   static int cpus = 0;

   if (cpus != 0)
      return cpus;

   CPU_ZERO(&cpu);
   if (sched_getaffinity(0, sizeof(cpu), &cpu) != 0)
     {
        fprintf(stderr, "[Eina] could not get cpu affinity: %s\n",
                strerror(errno));
        return 1;
     }

   for (i = 0; i < TH_MAX; i++)
     {
        if (CPU_ISSET(i, &cpu))
           cpus++;
     }
   return cpus;

# else
#  error "eina_cpu_count() error: Platform not supported"
# endif
#else
   return 1;
#endif
}

static int _page_size = 0;

static void
_eina_page_size(void)
{
#ifdef _WIN32
   SYSTEM_INFO si;

   GetSystemInfo(&si);

   _page_size = (int)si.dwPageSize;
#elif defined _SC_PAGESIZE
   _page_size = (int)sysconf(_SC_PAGESIZE);
#elif defined _SC_PAGE_SIZE
   _page_size = (int)sysconf(_SC_PAGE_SIZE);
#elif defined HAVE_GETPAGESIZE
   _page_size = getpagesize();
#else
# warn "Falling back to a safe default page size (4K) !"
   _page_size = 4096;
#endif
   if (_page_size < 1)
     {
        EINA_LOG_ERR("system reported weird value for PAGESIZE, assuming 4096.");
        _page_size = 4096;
     }
}

EINA_API int eina_cpu_page_size(void)
{
   if (_page_size == 0) _eina_page_size();
   return _page_size;
}

EINA_API int eina_cpu_count(void)
{
   return _cpu_count;
}

void eina_cpu_count_internal(void)
{
   if (getenv("EINA_CPU_FAKE"))
     _cpu_count = atoi(getenv("EINA_CPU_FAKE"));
   else
     _cpu_count = _eina_cpu_count_internal();
}