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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, see <http://www.gnu.org/licenses/>.
19 ***/
20 
21 #ifdef HAVE_CONFIG_H
22 #include <config.h>
23 #endif
24 
25 #include <stdint.h>
26 #include <sys/types.h>
27 #include <fcntl.h>
28 
29 #include <pulse/xmalloc.h>
30 #include <pulsecore/core-util.h>
31 #include <pulsecore/log.h>
32 
33 #include "cpu-arm.h"
34 
35 #if defined (__arm__) && defined (__linux__)
36 
37 #define MAX_BUFFER 4096
38 static char *
get_cpuinfo_line(char * cpuinfo,const char * tag)39 get_cpuinfo_line(char *cpuinfo, const char *tag) {
40     char *line, *end, *colon;
41 
42     if (!(line = strstr(cpuinfo, tag)))
43         return NULL;
44 
45     if (!(end = strchr(line, '\n')))
46         return NULL;
47 
48     if (!(colon = strchr(line, ':')))
49         return NULL;
50 
51     if (++colon >= end)
52         return NULL;
53 
54     return pa_xstrndup(colon, end - colon);
55 }
56 
get_cpuinfo(void)57 static char *get_cpuinfo(void) {
58     char *cpuinfo;
59     int n, fd;
60 
61     cpuinfo = pa_xmalloc(MAX_BUFFER);
62 
63     if ((fd = pa_open_cloexec("/proc/cpuinfo", O_RDONLY, 0)) < 0) {
64         pa_xfree(cpuinfo);
65         return NULL;
66     }
67 
68     if ((n = pa_read(fd, cpuinfo, MAX_BUFFER-1, NULL)) < 0) {
69         pa_xfree(cpuinfo);
70         pa_close(fd);
71         return NULL;
72     }
73     cpuinfo[n] = 0;
74     pa_close(fd);
75 
76     return cpuinfo;
77 }
78 #endif /* defined (__arm__) && defined (__linux__) */
79 
pa_cpu_get_arm_flags(pa_cpu_arm_flag_t * flags)80 void pa_cpu_get_arm_flags(pa_cpu_arm_flag_t *flags) {
81 #if defined (__arm__) && defined (__linux__)
82     char *cpuinfo, *line;
83     int arch, part;
84 
85     /* We need to read the CPU flags from /proc/cpuinfo because there is no user
86      * space support to get the CPU features. This only works on linux AFAIK. */
87     if (!(cpuinfo = get_cpuinfo())) {
88         pa_log("Can't read cpuinfo");
89         return;
90     }
91 
92     *flags = 0;
93 
94     /* get the CPU architecture */
95     if ((line = get_cpuinfo_line(cpuinfo, "CPU architecture"))) {
96         arch = strtoul(line, NULL, 0);
97         if (arch >= 6)
98             *flags |= PA_CPU_ARM_V6;
99         if (arch >= 7)
100             *flags |= PA_CPU_ARM_V7;
101 
102         pa_xfree(line);
103     }
104 
105     /* get the CPU features */
106     if ((line = get_cpuinfo_line(cpuinfo, "Features"))) {
107         const char *state = NULL;
108         char *current;
109 
110         while ((current = pa_split_spaces(line, &state))) {
111             if (pa_streq(current, "vfp"))
112                 *flags |= PA_CPU_ARM_VFP;
113             else if (pa_streq(current, "edsp"))
114                 *flags |= PA_CPU_ARM_EDSP;
115             else if (pa_streq(current, "neon"))
116                 *flags |= PA_CPU_ARM_NEON;
117             else if (pa_streq(current, "vfpv3"))
118                 *flags |= PA_CPU_ARM_VFPV3;
119 
120             pa_xfree(current);
121         }
122         pa_xfree(line);
123     }
124 
125     /* get the CPU part number */
126     if ((line = get_cpuinfo_line(cpuinfo, "CPU part"))) {
127         part = strtoul(line, NULL, 0);
128         if (part == 0xc08)
129             *flags |= PA_CPU_ARM_CORTEX_A8;
130         pa_xfree(line);
131     }
132     pa_xfree(cpuinfo);
133 
134     pa_log_info("CPU flags: %s%s%s%s%s%s%s",
135           (*flags & PA_CPU_ARM_V6) ? "V6 " : "",
136           (*flags & PA_CPU_ARM_V7) ? "V7 " : "",
137           (*flags & PA_CPU_ARM_VFP) ? "VFP " : "",
138           (*flags & PA_CPU_ARM_EDSP) ? "EDSP " : "",
139           (*flags & PA_CPU_ARM_NEON) ? "NEON " : "",
140           (*flags & PA_CPU_ARM_VFPV3) ? "VFPV3 " : "",
141           (*flags & PA_CPU_ARM_CORTEX_A8) ? "Cortex-A8 " : "");
142 #endif
143 }
144 
pa_cpu_init_arm(pa_cpu_arm_flag_t * flags)145 bool pa_cpu_init_arm(pa_cpu_arm_flag_t *flags) {
146 #if defined (__arm__)
147 #if defined (__linux__)
148     pa_cpu_get_arm_flags(flags);
149 
150     if (*flags & PA_CPU_ARM_V6)
151         pa_volume_func_init_arm(*flags);
152 
153 #ifdef HAVE_NEON
154     if (*flags & PA_CPU_ARM_NEON) {
155         pa_convert_func_init_neon(*flags);
156         pa_mix_func_init_neon(*flags);
157         pa_remap_func_init_neon(*flags);
158     }
159 #endif
160 
161     return true;
162 
163 #else /* defined (__linux__) */
164     pa_log("Reading ARM CPU features not yet supported on this OS");
165 #endif /* defined (__linux__) */
166 
167 #else /* defined (__arm__) */
168     return false;
169 #endif /* defined (__arm__) */
170 }
171