xref: /netbsd-src/crypto/external/bsd/openssl/dist/crypto/armcap.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*
2  * Copyright 2011-2017 The OpenSSL Project Authors. All Rights Reserved.
3  *
4  * Licensed under the OpenSSL license (the "License").  You may not use
5  * this file except in compliance with the License.  You can obtain a copy
6  * in the file LICENSE in the source distribution or at
7  * https://www.openssl.org/source/license.html
8  */
9 
10 #include <stdio.h>
11 #include <stdlib.h>
12 #include <string.h>
13 #include <setjmp.h>
14 #include <signal.h>
15 #include <openssl/crypto.h>
16 
17 #include "arm_arch.h"
18 
19 unsigned int OPENSSL_armcap_P = 0;
20 
21 #if __ARM_MAX_ARCH__<7
22 void OPENSSL_cpuid_setup(void)
23 {
24 }
25 
26 unsigned long OPENSSL_rdtsc(void)
27 {
28     return 0;
29 }
30 #else
31 static sigset_t all_masked;
32 
33 static sigjmp_buf ill_jmp;
34 static void ill_handler(int sig)
35 {
36     siglongjmp(ill_jmp, sig);
37 }
38 
39 /*
40  * Following subroutines could have been inlined, but it's not all
41  * ARM compilers support inline assembler...
42  */
43 #if __ARM_MAX_ARCH__>=7
44 void _armv7_neon_probe(void);
45 void _armv8_aes_probe(void);
46 void _armv8_sha1_probe(void);
47 void _armv8_sha256_probe(void);
48 void _armv8_pmull_probe(void);
49 unsigned long _armv7_tick(void);
50 #endif
51 
52 unsigned long OPENSSL_rdtsc(void)
53 {
54 #if __ARM_MAX_ARCH__>=7
55     if (OPENSSL_armcap_P & ARMV7_TICK)
56         return _armv7_tick();
57     else
58 #endif
59         return 0;
60 }
61 
62 # if defined(__GNUC__) && __GNUC__>=2
63 void OPENSSL_cpuid_setup(void) __attribute__ ((constructor));
64 # endif
65 /*
66  * Use a weak reference to getauxval() so we can use it if it is available but
67  * don't break the build if it is not.
68  */
69 # if defined(__GNUC__) && __GNUC__>=2 && defined(__ELF__)
70 extern unsigned long getauxval(unsigned long type) __attribute__ ((weak));
71 # else
72 static unsigned long (*getauxval) (unsigned long) = NULL;
73 # endif
74 
75 /*
76  * ARM puts the feature bits for Crypto Extensions in AT_HWCAP2, whereas
77  * AArch64 used AT_HWCAP.
78  */
79 # if defined(__arm__) || defined (__arm)
80 #  define HWCAP                  16
81                                   /* AT_HWCAP */
82 #  define HWCAP_NEON             (1 << 12)
83 
84 #  define HWCAP_CE               26
85                                   /* AT_HWCAP2 */
86 #  define HWCAP_CE_AES           (1 << 0)
87 #  define HWCAP_CE_PMULL         (1 << 1)
88 #  define HWCAP_CE_SHA1          (1 << 2)
89 #  define HWCAP_CE_SHA256        (1 << 3)
90 # elif defined(__aarch64__)
91 #  define HWCAP                  16
92                                   /* AT_HWCAP */
93 #  define HWCAP_NEON             (1 << 1)
94 
95 #  define HWCAP_CE               HWCAP
96 #  define HWCAP_CE_AES           (1 << 3)
97 #  define HWCAP_CE_PMULL         (1 << 4)
98 #  define HWCAP_CE_SHA1          (1 << 5)
99 #  define HWCAP_CE_SHA256        (1 << 6)
100 # endif
101 
102 void OPENSSL_cpuid_setup(void)
103 {
104     char *e;
105     struct sigaction ill_oact, ill_act;
106     sigset_t oset;
107     static int trigger = 0;
108 
109     if (trigger)
110         return;
111     trigger = 1;
112 
113     if ((e = getenv("OPENSSL_armcap"))) {
114         OPENSSL_armcap_P = (unsigned int)strtoul(e, NULL, 0);
115         return;
116     }
117 
118 # if defined(__APPLE__) && !defined(__aarch64__)
119     /*
120      * Capability probing by catching SIGILL appears to be problematic
121      * on iOS. But since Apple universe is "monocultural", it's actually
122      * possible to simply set pre-defined processor capability mask.
123      */
124     if (1) {
125         OPENSSL_armcap_P = ARMV7_NEON;
126         return;
127     }
128     /*
129      * One could do same even for __aarch64__ iOS builds. It's not done
130      * exclusively for reasons of keeping code unified across platforms.
131      * Unified code works because it never triggers SIGILL on Apple
132      * devices...
133      */
134 # endif
135 
136     sigfillset(&all_masked);
137     sigdelset(&all_masked, SIGILL);
138     sigdelset(&all_masked, SIGTRAP);
139     sigdelset(&all_masked, SIGFPE);
140     sigdelset(&all_masked, SIGBUS);
141     sigdelset(&all_masked, SIGSEGV);
142 
143     OPENSSL_armcap_P = 0;
144 
145     memset(&ill_act, 0, sizeof(ill_act));
146     ill_act.sa_handler = ill_handler;
147     ill_act.sa_mask = all_masked;
148 
149     sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
150     sigaction(SIGILL, &ill_act, &ill_oact);
151 
152 #if __ARM_MAX_ARCH__>=7
153     if (getauxval != NULL) {
154         if (getauxval(HWCAP) & HWCAP_NEON) {
155             unsigned long hwcap = getauxval(HWCAP_CE);
156 
157             OPENSSL_armcap_P |= ARMV7_NEON;
158 
159             if (hwcap & HWCAP_CE_AES)
160                 OPENSSL_armcap_P |= ARMV8_AES;
161 
162             if (hwcap & HWCAP_CE_PMULL)
163                 OPENSSL_armcap_P |= ARMV8_PMULL;
164 
165             if (hwcap & HWCAP_CE_SHA1)
166                 OPENSSL_armcap_P |= ARMV8_SHA1;
167 
168             if (hwcap & HWCAP_CE_SHA256)
169                 OPENSSL_armcap_P |= ARMV8_SHA256;
170         }
171     } else if (sigsetjmp(ill_jmp, 1) == 0) {
172         _armv7_neon_probe();
173         OPENSSL_armcap_P |= ARMV7_NEON;
174         if (sigsetjmp(ill_jmp, 1) == 0) {
175             _armv8_pmull_probe();
176             OPENSSL_armcap_P |= ARMV8_PMULL | ARMV8_AES;
177         } else if (sigsetjmp(ill_jmp, 1) == 0) {
178             _armv8_aes_probe();
179             OPENSSL_armcap_P |= ARMV8_AES;
180         }
181         if (sigsetjmp(ill_jmp, 1) == 0) {
182             _armv8_sha1_probe();
183             OPENSSL_armcap_P |= ARMV8_SHA1;
184         }
185         if (sigsetjmp(ill_jmp, 1) == 0) {
186             _armv8_sha256_probe();
187             OPENSSL_armcap_P |= ARMV8_SHA256;
188         }
189     }
190     if (sigsetjmp(ill_jmp, 1) == 0) {
191         _armv7_tick();
192         OPENSSL_armcap_P |= ARMV7_TICK;
193     }
194 #endif
195 
196     sigaction(SIGILL, &ill_oact, NULL);
197     sigprocmask(SIG_SETMASK, &oset, NULL);
198 }
199 #endif
200