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      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 <pixman-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__) || defined(__NetBSD__)
     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 (__FreeBSD__)
     72 #include <machine/cpu.h>
     73 #include <sys/auxv.h>
     74 
     75 static pixman_bool_t
     76 pixman_have_vmx (void)
     77 {
     78 
     79     unsigned long cpufeatures;
     80     int have_vmx;
     81 
     82     if (elf_aux_info(AT_HWCAP, &cpufeatures, sizeof(cpufeatures)))
     83     return FALSE;
     84 
     85     have_vmx = cpufeatures & PPC_FEATURE_HAS_ALTIVEC;
     86     return have_vmx;
     87 }
     88 
     89 #elif defined (__linux__)
     90 
     91 #include <sys/types.h>
     92 #include <sys/stat.h>
     93 #include <fcntl.h>
     94 #include <unistd.h>
     95 #include <stdio.h>
     96 #include <linux/auxvec.h>
     97 #include <asm/cputable.h>
     98 
     99 static pixman_bool_t
    100 pixman_have_vmx (void)
    101 {
    102     int have_vmx = FALSE;
    103     int fd;
    104     struct
    105     {
    106 	unsigned long type;
    107 	unsigned long value;
    108     } aux;
    109 
    110     fd = open ("/proc/self/auxv", O_RDONLY);
    111     if (fd >= 0)
    112     {
    113 	while (read (fd, &aux, sizeof (aux)) == sizeof (aux))
    114 	{
    115 	    if (aux.type == AT_HWCAP && (aux.value & PPC_FEATURE_HAS_ALTIVEC))
    116 	    {
    117 		have_vmx = TRUE;
    118 		break;
    119 	    }
    120 	}
    121 
    122 	close (fd);
    123     }
    124 
    125     return have_vmx;
    126 }
    127 
    128 #else /* !__APPLE__ && !__OpenBSD__ && !__linux__ */
    129 #include <signal.h>
    130 #include <setjmp.h>
    131 
    132 static jmp_buf jump_env;
    133 
    134 static void
    135 vmx_test (int        sig,
    136 	  siginfo_t *si,
    137 	  void *     unused)
    138 {
    139     longjmp (jump_env, 1);
    140 }
    141 
    142 static pixman_bool_t
    143 pixman_have_vmx (void)
    144 {
    145     struct sigaction sa, osa;
    146     int jmp_result;
    147 
    148     sa.sa_flags = SA_SIGINFO;
    149     sigemptyset (&sa.sa_mask);
    150     sa.sa_sigaction = vmx_test;
    151     sigaction (SIGILL, &sa, &osa);
    152     jmp_result = setjmp (jump_env);
    153     if (jmp_result == 0)
    154     {
    155 	asm volatile ( "vor 0, 0, 0" );
    156     }
    157     sigaction (SIGILL, &osa, NULL);
    158     return (jmp_result == 0);
    159 }
    160 
    161 #endif /* __APPLE__ */
    162 #endif /* USE_VMX */
    163 
    164 pixman_implementation_t *
    165 _pixman_ppc_get_implementations (pixman_implementation_t *imp)
    166 {
    167 #ifdef USE_VMX
    168     if (!_pixman_disabled ("vmx") && pixman_have_vmx ())
    169 	imp = _pixman_implementation_create_vmx (imp);
    170 #endif
    171 
    172     return imp;
    173 }
    174