source/libs/pixman/pixman-src/pixman/pixman-ppc.c

   1 /*
   2  * Copyright © 2000 SuSE, Inc.
   3  * Copyright © 2007 Red Hat, Inc.
   4  *
   5  * Permission to use, copy, modify, distribute, and sell this software and its
   6  * documentation for any purpose is hereby granted without fee, provided that
   7  * the above copyright notice appear in all copies and that both that
   8  * copyright notice and this permission notice appear in supporting
   9  * documentation, and that the name of SuSE not be used in advertising or
  10  * publicity pertaining to distribution of the software without specific,
  11  * written prior permission.  SuSE makes no representations about the
  12  * suitability of this software for any purpose.  It is provided "as is"
  13  * without express or implied warranty.
  14  *
  15  * SuSE DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
  16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL SuSE
  17  * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  18  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
  19  * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
  20  * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  21  */
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include "pixman-private.h"
  27
  28 #ifdef USE_VMX
  29
  30 /* The CPU detection code needs to be in a file not compiled with
  31  * "-maltivec -mabi=altivec", as gcc would try to save vector register
  32  * across function calls causing SIGILL on cpus without Altivec/vmx.
  33  */
  34 #ifdef __APPLE__
  35 #include <sys/sysctl.h>
  36
  37 static pixman_bool_t
  38 pixman_have_vmx (void)
  39 {
  40     int error, have_vmx;
  41     size_t length = sizeof(have_vmx);
  42
  43     error = sysctlbyname ("hw.optional.altivec", &have_vmx, &length, NULL, 0);
  44
  45     if (error)
  46         return FALSE;
  47
  48     return have_vmx;
  49 }
  50
  51 #elif defined (__OpenBSD__)
  52 #include <sys/param.h>
  53 #include <sys/sysctl.h>
  54 #include <machine/cpu.h>
  55
  56 static pixman_bool_t
  57 pixman_have_vmx (void)
  58 {
  59     int error, have_vmx;
  60     int mib[2] = { CTL_MACHDEP, CPU_ALTIVEC };
  61     size_t length = sizeof(have_vmx);
  62
  63     error = sysctl (mib, 2, &have_vmx, &length, NULL, 0);
  64
  65     if (error != 0)
  66         return FALSE;
  67
  68     return have_vmx;
  69 }
  70
  71 #elif defined (__linux__)
  72
  73 #include <sys/types.h>
  74 #include <sys/stat.h>
  75 #include <fcntl.h>
  76 #include <unistd.h>
  77 #include <stdio.h>
  78 #include <linux/auxvec.h>
  79 #include <asm/cputable.h>
  80
  81 static pixman_bool_t
  82 pixman_have_vmx (void)
  83 {
  84     int have_vmx = FALSE;
  85     int fd;
  86     struct
  87     {
  88         unsigned long type;
  89         unsigned long value;
  90     } aux;
  91
  92     fd = open ("/proc/self/auxv", O_RDONLY);
  93     if (fd >= 0)
  94     {
  95         while (read (fd, &aux, sizeof (aux)) == sizeof (aux))
  96         {
  97             if (aux.type == AT_HWCAP && (aux.value & PPC_FEATURE_HAS_ALTIVEC))
  98             {
  99                 have_vmx = TRUE;
 100                 break;
 101             }
 102         }
 103
 104         close (fd);
 105     }
 106
 107     return have_vmx;
 108 }
 109
 110 #else /* !__APPLE__ && !__OpenBSD__ && !__linux__ */
 111 #include <signal.h>
 112 #include <setjmp.h>
 113
 114 static jmp_buf jump_env;
 115
 116 static void
 117 vmx_test (int        sig,
 118           siginfo_t *si,
 119           void *     unused)
 120 {
 121     longjmp (jump_env, 1);
 122 }
 123
 124 static pixman_bool_t
 125 pixman_have_vmx (void)
 126 {
 127     struct sigaction sa, osa;
 128     int jmp_result;
 129
 130     sa.sa_flags = SA_SIGINFO;
 131     sigemptyset (&sa.sa_mask);
 132     sa.sa_sigaction = vmx_test;
 133     sigaction (SIGILL, &sa, &osa);
 134     jmp_result = setjmp (jump_env);
 135     if (jmp_result == 0)
 136     {
 137         asm volatile ( "vor 0, 0, 0" );
 138     }
 139     sigaction (SIGILL, &osa, NULL);
 140     return (jmp_result == 0);
 141 }
 142
 143 #endif /* __APPLE__ */
 144 #endif /* USE_VMX */
 145
 146 pixman_implementation_t *
 147 _pixman_ppc_get_implementations (pixman_implementation_t *imp)
 148 {
 149 #ifdef USE_VMX
 150     if (!_pixman_disabled ("vmx") && pixman_have_vmx ())
 151         imp = _pixman_implementation_create_vmx (imp);
 152 #endif
 153
 154     return imp;
 155 }