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 #if HAVE_GETAUXVAL
42 #include <sys/auxv.h>
43 #endif
44
45 #define AT_HWCAP 16
46
47 /* Relevant HWCAP values from kernel headers */
48 #define HWCAP_VFP (1 << 6)
49 #define HWCAP_EDSP (1 << 7)
50 #define HWCAP_THUMBEE (1 << 11)
51 #define HWCAP_NEON (1 << 12)
52 #define HWCAP_VFPv3 (1 << 13)
53 #define HWCAP_TLS (1 << 15)
54
get_auxval(uint32_t *hwcap)55 static int get_auxval(uint32_t *hwcap)
56 {
57 #if HAVE_GETAUXVAL
58 unsigned long ret = getauxval(AT_HWCAP);
59 if (ret == 0)
60 return -1;
61 *hwcap = ret;
62 return 0;
63 #else
64 return -1;
65 #endif
66 }
67
get_hwcap(uint32_t *hwcap)68 static int get_hwcap(uint32_t *hwcap)
69 {
70 struct { uint32_t a_type; uint32_t a_val; } auxv;
71 FILE *f = fopen("/proc/self/auxv", "r");
72 int err = -1;
73
74 if (!f)
75 return -1;
76
77 while (fread(&auxv, sizeof(auxv), 1, f) > 0) {
78 if (auxv.a_type == AT_HWCAP) {
79 *hwcap = auxv.a_val;
80 err = 0;
81 break;
82 }
83 }
84
85 fclose(f);
86 return err;
87 }
88
get_cpuinfo(uint32_t *hwcap)89 static int get_cpuinfo(uint32_t *hwcap)
90 {
91 FILE *f = fopen("/proc/cpuinfo", "r");
92 char buf[200];
93
94 if (!f)
95 return -1;
96
97 *hwcap = 0;
98 while (fgets(buf, sizeof(buf), f)) {
99 if (av_strstart(buf, "Features", NULL)) {
100 if (strstr(buf, " edsp "))
101 *hwcap |= HWCAP_EDSP;
102 if (strstr(buf, " tls "))
103 *hwcap |= HWCAP_TLS;
104 if (strstr(buf, " thumbee "))
105 *hwcap |= HWCAP_THUMBEE;
106 if (strstr(buf, " vfp "))
107 *hwcap |= HWCAP_VFP;
108 if (strstr(buf, " vfpv3 "))
109 *hwcap |= HWCAP_VFPv3;
110 if (strstr(buf, " neon ") || strstr(buf, " asimd "))
111 *hwcap |= HWCAP_NEON;
112 if (strstr(buf, " fp ")) // Listed on 64 bit ARMv8 kernels
113 *hwcap |= HWCAP_VFP | HWCAP_VFPv3;
114 break;
115 }
116 }
117 fclose(f);
118 return 0;
119 }
120
ff_get_cpu_flags_arm(void)121 int ff_get_cpu_flags_arm(void)
122 {
123 int flags = CORE_CPU_FLAGS;
124 uint32_t hwcap;
125
126 if (get_auxval(&hwcap) < 0)
127 if (get_hwcap(&hwcap) < 0)
128 if (get_cpuinfo(&hwcap) < 0)
129 return flags;
130
131 #define check_cap(cap, flag) do { \
132 if (hwcap & HWCAP_ ## cap) \
133 flags |= AV_CPU_FLAG_ ## flag; \
134 } while (0)
135
136 /* No flags explicitly indicate v6 or v6T2 so check others which
137 imply support. */
138 check_cap(EDSP, ARMV5TE);
139 check_cap(TLS, ARMV6);
140 check_cap(THUMBEE, ARMV6T2);
141 check_cap(VFP, VFP);
142 check_cap(VFPv3, VFPV3);
143 check_cap(NEON, NEON);
144
145 /* The v6 checks above are not reliable so let higher flags
146 trickle down. */
147 if (flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON))
148 flags |= AV_CPU_FLAG_ARMV6T2;
149 else if (flags & (AV_CPU_FLAG_ARMV6T2 | AV_CPU_FLAG_ARMV6))
150 /* Some functions use the 'setend' instruction which is deprecated on ARMv8
151 * and serializing on some ARMv7 cores. This ensures such functions
152 * are only enabled on ARMv6. */
153 flags |= AV_CPU_FLAG_SETEND;
154
155 if (flags & AV_CPU_FLAG_ARMV6T2)
156 flags |= AV_CPU_FLAG_ARMV6;
157
158 /* set the virtual VFPv2 vector mode flag */
159 if ((flags & AV_CPU_FLAG_VFP) && !(flags & (AV_CPU_FLAG_VFPV3 | AV_CPU_FLAG_NEON)))
160 flags |= AV_CPU_FLAG_VFP_VM;
161
162 return flags;
163 }
164
165 #else
166
ff_get_cpu_flags_arm(void)167 int ff_get_cpu_flags_arm(void)
168 {
169 return AV_CPU_FLAG_ARMV5TE * HAVE_ARMV5TE |
170 AV_CPU_FLAG_ARMV6 * HAVE_ARMV6 |
171 AV_CPU_FLAG_ARMV6T2 * HAVE_ARMV6T2 |
172 AV_CPU_FLAG_VFP * HAVE_VFP |
173 AV_CPU_FLAG_VFPV3 * HAVE_VFPV3 |
174 AV_CPU_FLAG_NEON * HAVE_NEON |
175 AV_CPU_FLAG_SETEND * !(HAVE_NEON | HAVE_VFPV3);
176 }
177
178 #endif
179
ff_get_cpu_max_align_arm(void)180 size_t ff_get_cpu_max_align_arm(void)
181 {
182 int flags = av_get_cpu_flags();
183
184 if (flags & AV_CPU_FLAG_NEON)
185 return 16;
186
187 return 8;
188 }
189