code.delx.au - pulseaudio/blob - src/pulsecore/cpu-arm.c

   1 /***
   2   This file is part of PulseAudio.
   3
   4   Copyright 2004-2006 Lennart Poettering
   5   Copyright 2009 Wim Taymans <wim.taymans@collabora.co.uk>
   6
   7   PulseAudio is free software; you can redistribute it and/or modify
   8   it under the terms of the GNU Lesser General Public License as published
   9   by the Free Software Foundation; either version 2.1 of the License,
  10   or (at your option) any later version.
  11
  12   PulseAudio is distributed in the hope that it will be useful, but
  13   WITHOUT ANY WARRANTY; without even the implied warranty of
  14   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  15   General Public License for more details.
  16
  17   You should have received a copy of the GNU Lesser General Public License
  18   along with PulseAudio; if not, write to the Free Software
  19   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  20   USA.
  21 ***/
  22
  23 #ifdef HAVE_CONFIG_H
  24 #include <config.h>
  25 #endif
  26
  27 #include <stdint.h>
  28 #include <sys/types.h>
  29 #include <sys/stat.h>
  30 #include <fcntl.h>
  31
  32 #include <pulse/xmalloc.h>
  33 #include <pulsecore/log.h>
  34
  35 #include "cpu-arm.h"
  36
  37 #if defined (__arm__) && defined (__linux__)
  38
  39 #define MAX_BUFFER  4096
  40 static char *
  41 get_cpuinfo_line (char *cpuinfo, const char *tag) {
  42     char *line, *end, *colon;
  43
  44     if (!(line = strstr (cpuinfo, tag)))
  45         return NULL;
  46
  47     if (!(end = strchr (line, '\n')))
  48         return NULL;
  49
  50     if (!(colon = strchr (line, ':')))
  51         return NULL;
  52
  53     if (++colon >= end)
  54         return NULL;
  55
  56     return pa_xstrndup (colon, end - colon);
  57 }
  58
  59 static char *get_cpuinfo(void) {
  60     char *cpuinfo;
  61     int n, fd;
  62
  63     cpuinfo = pa_xmalloc(MAX_BUFFER);
  64
  65     if ((fd = open("/proc/cpuinfo", O_RDONLY)) < 0) {
  66         pa_xfree(cpuinfo);
  67         return NULL;
  68     }
  69
  70     if ((n = pa_read(fd, cpuinfo, MAX_BUFFER-1)) < 0) {
  71         pa_xfree(cpuinfo);
  72         pa_close(fd);
  73         return NULL;
  74     }
  75     cpuinfo[n] = 0;
  76     pa_close(fd);
  77
  78     return cpuinfo;
  79 }
  80 #endif /* defined (__arm__) && defined (__linux__) */
  81
  82 void pa_cpu_init_arm (void) {
  83 #if defined (__arm__)
  84 #if defined (__linux__)
  85     char *cpuinfo, *line;
  86     int arch;
  87     pa_cpu_arm_flag_t flags = 0;
  88
  89     /* We need to read the CPU flags from /proc/cpuinfo because there is no user
  90      * space support to get the CPU features. This only works on linux AFAIK. */
  91     if (!(cpuinfo = get_cpuinfo ())) {
  92         pa_log ("Can't read cpuinfo");
  93         return;
  94     }
  95
  96     /* get the CPU architecture */
  97     if ((line = get_cpuinfo_line (cpuinfo, "CPU architecture"))) {
  98         arch = strtoul (line, NULL, 0);
  99         if (arch >= 6)
 100             flags |= PA_CPU_ARM_V6;
 101         if (arch >= 7)
 102             flags |= PA_CPU_ARM_V7;
 103
 104         pa_xfree(line);
 105     }
 106     /* get the CPU features */
 107     if ((line = get_cpuinfo_line (cpuinfo, "Features"))) {
 108         char *state = NULL, *current;
 109
 110         while ((current = pa_split_spaces (line, &state))) {
 111             if (!strcmp (current, "vfp"))
 112                 flags |= PA_CPU_ARM_VFP;
 113             else if (!strcmp (current, "edsp"))
 114                 flags |= PA_CPU_ARM_EDSP;
 115             else if (!strcmp (current, "neon"))
 116                 flags |= PA_CPU_ARM_NEON;
 117             else if (!strcmp (current, "vfpv3"))
 118                 flags |= PA_CPU_ARM_VFPV3;
 119
 120             pa_xfree(current);
 121         }
 122     }
 123     pa_xfree(cpuinfo);
 124
 125     pa_log_info ("CPU flags: %s%s%s%s%s%s",
 126           (flags & PA_CPU_ARM_V6) ? "V6 " : "",
 127           (flags & PA_CPU_ARM_V7) ? "V7 " : "",
 128           (flags & PA_CPU_ARM_VFP) ? "VFP " : "",
 129           (flags & PA_CPU_ARM_EDSP) ? "EDSP " : "",
 130           (flags & PA_CPU_ARM_NEON) ? "NEON " : "",
 131           (flags & PA_CPU_ARM_VFPV3) ? "VFPV3 " : "");
 132 #else /* defined (__linux__) */
 133     pa_log ("ARM cpu features not yet supported on this OS");
 134 #endif /* defined (__linux__) */
 135
 136     if (flags & PA_CPU_ARM_V6)
 137         pa_volume_func_init_arm (flags);
 138 #endif /* defined (__arm__) */
 139 }