1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ 2 /* 3 * Copyright (C) 2012 ARM Ltd. 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 * This program 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 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. If not, see <http://www.gnu.org/licenses/>. 16 */ 17 #ifndef _UAPI__ASM_SIGCONTEXT_H 18 #define _UAPI__ASM_SIGCONTEXT_H 19 20 #ifndef __ASSEMBLY__ 21 22 #include <linux/types.h> 23 24 /* 25 * Signal context structure - contains all info to do with the state 26 * before the signal handler was invoked. 27 */ 28 struct sigcontext { 29 __u64 fault_address; 30 /* AArch64 registers */ 31 __u64 regs[31]; 32 __u64 sp; 33 __u64 pc; 34 __u64 pstate; 35 /* 4K reserved for FP/SIMD state and future expansion */ 36 __u8 __reserved[4096] __attribute__((__aligned__(16))); 37 }; 38 39 /* 40 * Allocation of __reserved[]: 41 * (Note: records do not necessarily occur in the order shown here.) 42 * 43 * size description 44 * 45 * 0x210 fpsimd_context 46 * 0x10 esr_context 47 * 0x8a0 sve_context (vl <= 64) (optional) 48 * 0x20 extra_context (optional) 49 * 0x10 terminator (null _aarch64_ctx) 50 * 51 * 0x510 (reserved for future allocation) 52 * 53 * New records that can exceed this space need to be opt-in for userspace, so 54 * that an expanded signal frame is not generated unexpectedly. The mechanism 55 * for opting in will depend on the extension that generates each new record. 56 * The above table documents the maximum set and sizes of records than can be 57 * generated when userspace does not opt in for any such extension. 58 */ 59 60 /* 61 * Header to be used at the beginning of structures extending the user 62 * context. Such structures must be placed after the rt_sigframe on the stack 63 * and be 16-byte aligned. The last structure must be a dummy one with the 64 * magic and size set to 0. 65 */ 66 struct _aarch64_ctx { 67 __u32 magic; 68 __u32 size; 69 }; 70 71 #define FPSIMD_MAGIC 0x46508001 72 73 struct fpsimd_context { 74 struct _aarch64_ctx head; 75 __u32 fpsr; 76 __u32 fpcr; 77 __uint128_t vregs[32]; 78 }; 79 80 /* ESR_EL1 context */ 81 #define ESR_MAGIC 0x45535201 82 83 struct esr_context { 84 struct _aarch64_ctx head; 85 __u64 esr; 86 }; 87 88 /* 89 * extra_context: describes extra space in the signal frame for 90 * additional structures that don't fit in sigcontext.__reserved[]. 91 * 92 * Note: 93 * 94 * 1) fpsimd_context, esr_context and extra_context must be placed in 95 * sigcontext.__reserved[] if present. They cannot be placed in the 96 * extra space. Any other record can be placed either in the extra 97 * space or in sigcontext.__reserved[], unless otherwise specified in 98 * this file. 99 * 100 * 2) There must not be more than one extra_context. 101 * 102 * 3) If extra_context is present, it must be followed immediately in 103 * sigcontext.__reserved[] by the terminating null _aarch64_ctx. 104 * 105 * 4) The extra space to which datap points must start at the first 106 * 16-byte aligned address immediately after the terminating null 107 * _aarch64_ctx that follows the extra_context structure in 108 * __reserved[]. The extra space may overrun the end of __reserved[], 109 * as indicated by a sufficiently large value for the size field. 110 * 111 * 5) The extra space must itself be terminated with a null 112 * _aarch64_ctx. 113 */ 114 #define EXTRA_MAGIC 0x45585401 115 116 struct extra_context { 117 struct _aarch64_ctx head; 118 __u64 datap; /* 16-byte aligned pointer to extra space cast to __u64 */ 119 __u32 size; /* size in bytes of the extra space */ 120 __u32 __reserved[3]; 121 }; 122 123 #define SVE_MAGIC 0x53564501 124 125 struct sve_context { 126 struct _aarch64_ctx head; 127 __u16 vl; 128 __u16 __reserved[3]; 129 }; 130 131 #endif /* !__ASSEMBLY__ */ 132 133 /* 134 * The SVE architecture leaves space for future expansion of the 135 * vector length beyond its initial architectural limit of 2048 bits 136 * (16 quadwords). 137 * 138 * See linux/Documentation/arm64/sve.txt for a description of the VL/VQ 139 * terminology. 140 */ 141 #define SVE_VQ_BYTES 16 /* number of bytes per quadword */ 142 143 #define SVE_VQ_MIN 1 144 #define SVE_VQ_MAX 512 145 146 #define SVE_VL_MIN (SVE_VQ_MIN * SVE_VQ_BYTES) 147 #define SVE_VL_MAX (SVE_VQ_MAX * SVE_VQ_BYTES) 148 149 #define SVE_NUM_ZREGS 32 150 #define SVE_NUM_PREGS 16 151 152 #define sve_vl_valid(vl) \ 153 ((vl) % SVE_VQ_BYTES == 0 && (vl) >= SVE_VL_MIN && (vl) <= SVE_VL_MAX) 154 #define sve_vq_from_vl(vl) ((vl) / SVE_VQ_BYTES) 155 #define sve_vl_from_vq(vq) ((vq) * SVE_VQ_BYTES) 156 157 /* 158 * If the SVE registers are currently live for the thread at signal delivery, 159 * sve_context.head.size >= 160 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)) 161 * and the register data may be accessed using the SVE_SIG_*() macros. 162 * 163 * If sve_context.head.size < 164 * SVE_SIG_CONTEXT_SIZE(sve_vq_from_vl(sve_context.vl)), 165 * the SVE registers were not live for the thread and no register data 166 * is included: in this case, the SVE_SIG_*() macros should not be 167 * used except for this check. 168 * 169 * The same convention applies when returning from a signal: a caller 170 * will need to remove or resize the sve_context block if it wants to 171 * make the SVE registers live when they were previously non-live or 172 * vice-versa. This may require the the caller to allocate fresh 173 * memory and/or move other context blocks in the signal frame. 174 * 175 * Changing the vector length during signal return is not permitted: 176 * sve_context.vl must equal the thread's current vector length when 177 * doing a sigreturn. 178 * 179 * 180 * Note: for all these macros, the "vq" argument denotes the SVE 181 * vector length in quadwords (i.e., units of 128 bits). 182 * 183 * The correct way to obtain vq is to use sve_vq_from_vl(vl). The 184 * result is valid if and only if sve_vl_valid(vl) is true. This is 185 * guaranteed for a struct sve_context written by the kernel. 186 * 187 * 188 * Additional macros describe the contents and layout of the payload. 189 * For each, SVE_SIG_x_OFFSET(args) is the start offset relative to 190 * the start of struct sve_context, and SVE_SIG_x_SIZE(args) is the 191 * size in bytes: 192 * 193 * x type description 194 * - ---- ----------- 195 * REGS the entire SVE context 196 * 197 * ZREGS __uint128_t[SVE_NUM_ZREGS][vq] all Z-registers 198 * ZREG __uint128_t[vq] individual Z-register Zn 199 * 200 * PREGS uint16_t[SVE_NUM_PREGS][vq] all P-registers 201 * PREG uint16_t[vq] individual P-register Pn 202 * 203 * FFR uint16_t[vq] first-fault status register 204 * 205 * Additional data might be appended in the future. 206 */ 207 208 #define SVE_SIG_ZREG_SIZE(vq) ((__u32)(vq) * SVE_VQ_BYTES) 209 #define SVE_SIG_PREG_SIZE(vq) ((__u32)(vq) * (SVE_VQ_BYTES / 8)) 210 #define SVE_SIG_FFR_SIZE(vq) SVE_SIG_PREG_SIZE(vq) 211 212 #define SVE_SIG_REGS_OFFSET \ 213 ((sizeof(struct sve_context) + (SVE_VQ_BYTES - 1)) \ 214 / SVE_VQ_BYTES * SVE_VQ_BYTES) 215 216 #define SVE_SIG_ZREGS_OFFSET SVE_SIG_REGS_OFFSET 217 #define SVE_SIG_ZREG_OFFSET(vq, n) \ 218 (SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREG_SIZE(vq) * (n)) 219 #define SVE_SIG_ZREGS_SIZE(vq) \ 220 (SVE_SIG_ZREG_OFFSET(vq, SVE_NUM_ZREGS) - SVE_SIG_ZREGS_OFFSET) 221 222 #define SVE_SIG_PREGS_OFFSET(vq) \ 223 (SVE_SIG_ZREGS_OFFSET + SVE_SIG_ZREGS_SIZE(vq)) 224 #define SVE_SIG_PREG_OFFSET(vq, n) \ 225 (SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREG_SIZE(vq) * (n)) 226 #define SVE_SIG_PREGS_SIZE(vq) \ 227 (SVE_SIG_PREG_OFFSET(vq, SVE_NUM_PREGS) - SVE_SIG_PREGS_OFFSET(vq)) 228 229 #define SVE_SIG_FFR_OFFSET(vq) \ 230 (SVE_SIG_PREGS_OFFSET(vq) + SVE_SIG_PREGS_SIZE(vq)) 231 232 #define SVE_SIG_REGS_SIZE(vq) \ 233 (SVE_SIG_FFR_OFFSET(vq) + SVE_SIG_FFR_SIZE(vq) - SVE_SIG_REGS_OFFSET) 234 235 #define SVE_SIG_CONTEXT_SIZE(vq) (SVE_SIG_REGS_OFFSET + SVE_SIG_REGS_SIZE(vq)) 236 237 238 #endif /* _UAPI__ASM_SIGCONTEXT_H */ 239
