1 /* Copyright (c) 2023, Google Inc.
2 *
3 * Permission to use, copy, modify, and/or distribute this software for any
4 * purpose with or without fee is hereby granted, provided that the above
5 * copyright notice and this permission notice appear in all copies.
6 *
7 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
8 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
9 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
10 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
11 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
12 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
13 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
14
15 #include "internal.h"
16
17 // While Arm system registers are normally not available to userspace, FreeBSD
18 // expects userspace to simply read them. It traps the reads and fills in CPU
19 // capabilities.
20 #if defined(OPENSSL_AARCH64) && !defined(OPENSSL_STATIC_ARMCAP) && \
21 (defined(ANDROID_BAREMETAL) || defined(OPENSSL_FREEBSD))
22
23 #include <openssl/arm_arch.h>
24
25 #define ID_AA64PFR0_EL1_ADVSIMD 5
26
27 #define ID_AA64ISAR0_EL1_AES 1
28 #define ID_AA64ISAR0_EL1_SHA1 2
29 #define ID_AA64ISAR0_EL1_SHA2 3
30
31 #define NBITS_ID_FIELD 4
32
33 #define READ_SYSREG(name) \
34 ({ \
35 uint64_t _r; \
36 __asm__("mrs %0, " name : "=r"(_r)); \
37 _r; \
38 })
39
get_id_field(uint64_t reg,unsigned field)40 static unsigned get_id_field(uint64_t reg, unsigned field) {
41 return (reg >> (field * NBITS_ID_FIELD)) & ((1 << NBITS_ID_FIELD) - 1);
42 }
43
get_signed_id_field(uint64_t reg,unsigned field)44 static int get_signed_id_field(uint64_t reg, unsigned field) {
45 unsigned value = get_id_field(reg, field);
46 if (value & (1 << (NBITS_ID_FIELD - 1))) {
47 return (int)(value | (UINT64_MAX << NBITS_ID_FIELD));
48 } else {
49 return (int)value;
50 }
51 }
52
read_armcap(void)53 static uint32_t read_armcap(void) {
54 uint32_t armcap = ARMV7_NEON;
55
56 uint64_t id_aa64pfr0_el1 = READ_SYSREG("id_aa64pfr0_el1");
57
58 if (get_signed_id_field(id_aa64pfr0_el1, ID_AA64PFR0_EL1_ADVSIMD) < 0) {
59 // If AdvSIMD ("NEON") is missing, don't report other features either.
60 // This matches OpenSSL.
61 return 0;
62 }
63
64 uint64_t id_aa64isar0_el1 = READ_SYSREG("id_aa64isar0_el1");
65
66 unsigned aes = get_id_field(id_aa64isar0_el1, ID_AA64ISAR0_EL1_AES);
67 if (aes > 0) {
68 armcap |= ARMV8_AES;
69 }
70 if (aes > 1) {
71 armcap |= ARMV8_PMULL;
72 }
73
74 unsigned sha1 = get_id_field(id_aa64isar0_el1, ID_AA64ISAR0_EL1_SHA1);
75 if (sha1 > 0) {
76 armcap |= ARMV8_SHA1;
77 }
78
79 unsigned sha2 = get_id_field(id_aa64isar0_el1, ID_AA64ISAR0_EL1_SHA2);
80 if (sha2 > 0) {
81 armcap |= ARMV8_SHA256;
82 }
83 if (sha2 > 1) {
84 armcap |= ARMV8_SHA512;
85 }
86
87 return armcap;
88 }
89
OPENSSL_cpuid_setup(void)90 void OPENSSL_cpuid_setup(void) { OPENSSL_armcap_P |= read_armcap(); }
91
92 #endif // OPENSSL_AARCH64 && !OPENSSL_STATIC_ARMCAP &&
93 // (ANDROID_BAREMETAL || OPENSSL_FREEBSD)
94