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 <fcntl.h>
  30
  31 #include <pulse/xmalloc.h>
  32 #include <pulsecore/core-util.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 = pa_open_cloexec("/proc/cpuinfo", O_RDONLY, 0)) < 0) {
  66         pa_xfree(cpuinfo);
  67         return NULL;
  68     }
  69
  70     if ((n = pa_read(fd, cpuinfo, MAX_BUFFER-1, NULL)) < 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 pa_bool_t pa_cpu_init_arm(pa_cpu_arm_flag_t *flags) {
  83 #if defined (__arm__)
  84 #if defined (__linux__)
  85     char *cpuinfo, *line;
  86     int arch;
  87
  88     /* We need to read the CPU flags from /proc/cpuinfo because there is no user
  89      * space support to get the CPU features. This only works on linux AFAIK. */
  90     if (!(cpuinfo = get_cpuinfo())) {
  91         pa_log("Can't read cpuinfo");
  92         return;
  93     }
  94
  95     *flags = 0;
  96
  97     /* get the CPU architecture */
  98     if ((line = get_cpuinfo_line(cpuinfo, "CPU architecture"))) {
  99         arch = strtoul(line, NULL, 0);
 100         if (arch >= 6)
 101             *flags |= PA_CPU_ARM_V6;
 102         if (arch >= 7)
 103             *flags |= PA_CPU_ARM_V7;
 104
 105         pa_xfree(line);
 106     }
 107     /* get the CPU features */
 108     if ((line = get_cpuinfo_line(cpuinfo, "Features"))) {
 109         const char *state = NULL;
 110         char *current;
 111
 112         while ((current = pa_split_spaces(line, &state))) {
 113             if (!strcmp(current, "vfp"))
 114                 *flags |= PA_CPU_ARM_VFP;
 115             else if (!strcmp(current, "edsp"))
 116                 *flags |= PA_CPU_ARM_EDSP;
 117             else if (!strcmp(current, "neon"))
 118                 *flags |= PA_CPU_ARM_NEON;
 119             else if (!strcmp(current, "vfpv3"))
 120                 *flags |= PA_CPU_ARM_VFPV3;
 121
 122             pa_xfree(current);
 123         }
 124     }
 125     pa_xfree(cpuinfo);
 126
 127     pa_log_info("CPU flags: %s%s%s%s%s%s",
 128           (*flags & PA_CPU_ARM_V6) ? "V6 " : "",
 129           (*flags & PA_CPU_ARM_V7) ? "V7 " : "",
 130           (*flags & PA_CPU_ARM_VFP) ? "VFP " : "",
 131           (*flags & PA_CPU_ARM_EDSP) ? "EDSP " : "",
 132           (*flags & PA_CPU_ARM_NEON) ? "NEON " : "",
 133           (*flags & PA_CPU_ARM_VFPV3) ? "VFPV3 " : "");
 134
 135     if (*flags & PA_CPU_ARM_V6)
 136         pa_volume_func_init_arm(*flags);
 137
 138     return TRUE;
 139
 140 #else /* defined (__linux__) */
 141     pa_log ("ARM cpu features not yet supported on this OS");
 142 #endif /* defined (__linux__) */
 143
 144 #else /* defined (__arm__) */
 145     return FALSE;
 146 #endif /* defined (__arm__) */
 147 }