1 /*
2 * This file is part of FFmpeg.
3 *
4 * FFmpeg is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * FFmpeg is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General Public
15 * License along with FFmpeg; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18
19 #include "libavutil/cpu.h"
20 #include "libavutil/cpu_internal.h"
21 #include "config.h"
22
23 #define CORE_FLAG(f) \
24 (AV_CPU_FLAG_ ## f * (HAVE_ ## f ## _EXTERNAL || HAVE_ ## f ## _INLINE))
25
26 #define CORE_CPU_FLAGS \
27 (CORE_FLAG(ARMV5TE) | \
28 CORE_FLAG(ARMV6) | \
29 CORE_FLAG(ARMV6T2) | \
30 CORE_FLAG(VFP) | \
31 CORE_FLAG(VFPV3) | \
32 CORE_FLAG(NEON))
33
34 #if defined __linux__ || defined __ANDROID__
35
36 #include <stdint.h>
37 #include <stdio.h>
38 #include <string.h>
39 #include "libavutil/avstring.h"
40
41 #define AT_HWCAP 16
42
43 /* Relevant HWCAP values from kernel headers */
44 #define HWCAP_VFP (1 << 6)
45 #define HWCAP_EDSP (1 << 7)
46 #define HWCAP_THUMBEE (1 << 11)
47 #define HWCAP_NEON (1 << 12)
48 #define HWCAP_VFPv3 (1 << 13)
49 #define HWCAP_TLS (1 << 15)
50
get_hwcap(uint32_t * hwcap)51 static int get_hwcap(uint32_t *hwcap)
52 {
53 struct { uint32_t a_type; uint32_t a_val; } auxv;
54 FILE *f = fopen("/proc/self/auxv", "r");
55 int err = -1;
56
57 if (!f)
58 return -1;
59
60 while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
61 if (auxv.a_type == AT_HWCAP) {
62 *hwcap = auxv.a_val;
63 err = 0;
64 break;
65 }
66 }
67
68 fclose(f);
69 return err;
70 }
71
get_cpuinfo(uint32_t * hwcap)72 static int get_cpuinfo(uint32_t *hwcap)
73 {
74 FILE *f = fopen("/proc/cpuinfo", "r");
75 char buf[200];
76
77 if (!f)
78 return -1;
79
80 *hwcap = 0;
81 while (fgets(buf, sizeof(buf), f)) {
82 if (av_strstart(buf, "Features", NULL)) {
83 if (strstr(buf, " edsp "))
84 *hwcap |= HWCAP_EDSP;
85 if (strstr(buf, " tls "))
86 *hwcap |= HWCAP_TLS;
87 if (strstr(buf, " thumbee "))
88 *hwcap |= HWCAP_THUMBEE;
89 if (strstr(buf, " vfp "))
90 *hwcap |= HWCAP_VFP;
91 if (strstr(buf, " vfpv3 "))
92 *hwcap |= HWCAP_VFPv3;
93 if (strstr(buf, " neon ") || strstr(buf, " asimd "))
94 *hwcap |= HWCAP_NEON;
95 if (strstr(buf, " fp ")) // Listed on 64 bit ARMv8 kernels
96 *hwcap |= HWCAP_VFP | HWCAP_VFPv3;
97 break;
98 }
99 }
100 fclose(f);
101 return 0;
102 }
103
ff_get_cpu_flags_arm(void)104 int ff_get_cpu_flags_arm(void)
105 {
106 int flags = CORE_CPU_FLAGS;
107 uint32_t hwcap;
108
109 if (get_hwcap(&hwcap) < 0)
110 if (get_cpuinfo(&hwcap) < 0)
111 return flags;
112
113 #define check_cap(cap, flag) do { \
114 if (hwcap & HWCAP_ ## cap) \
115 flags |= AV_CPU_FLAG_ ## flag; \
116 } while (0)
117
118 /* No flags explicitly indicate v6 or v6T2 so check others which
119 imply support. */
120 check_cap(EDSP, ARMV5TE);
121 check_cap(TLS, ARMV6);
122 check_cap(THUMBEE, ARMV6T2);
123 check_cap(VFP, VFP);
124 check_cap(VFPv3, VFPV3);
125 check_cap(NEON, NEON);
126
127 /* The v6 checks above are not reliable so let higher flags
128 trickle down. */
129 if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
130 flags |= AV_CPU_FLAG_ARMV6T2;
131 else if (flags & (AV_CPU_FLAG_ARMV6T2 | AV_CPU_FLAG_ARMV6))
132 /* Some functions use the 'setend' instruction which is deprecated on ARMv8
133 * and serializing on some ARMv7 cores. This ensures such functions
134 * are only enabled on ARMv6. */
135 flags |= AV_CPU_FLAG_SETEND;
136
137 if (flags & AV_CPU_FLAG_ARMV6T2)
138 flags |= AV_CPU_FLAG_ARMV6;
139
140 /* set the virtual VFPv2 vector mode flag */
141 if ((flags & AV_CPU_FLAG_VFP) && !(flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON)))
142 flags |= AV_CPU_FLAG_VFP_VM;
143
144 return flags;
145 }
146
147 #else
148
ff_get_cpu_flags_arm(void)149 int ff_get_cpu_flags_arm(void)
150 {
151 return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
152 AV_CPU_FLAG_ARMV6 * HAVE_ARMV6 |
153 AV_CPU_FLAG_ARMV6T2 * HAVE_ARMV6T2 |
154 AV_CPU_FLAG_VFP * HAVE_VFP |
155 AV_CPU_FLAG_VFPV3 * HAVE_VFPV3 |
156 AV_CPU_FLAG_NEON * HAVE_NEON |
157 AV_CPU_FLAG_SETEND * !(HAVE_NEON | HAVE_VFPV3);
158 }
159
160 #endif
161
ff_get_cpu_max_align_arm(void)162 size_t ff_get_cpu_max_align_arm(void)
163 {
164 int flags = av_get_cpu_flags();
165
166 if (flags & AV_CPU_FLAG_NEON)
167 return 16;
168
169 return 8;
170 }
171