1 //===-- LinuxPTraceDefines_arm64sve.h ------------------------- -*- C++ -*-===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H 10 #define LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H 11 12 #include <cstdint> 13 14 namespace lldb_private { 15 namespace sve { 16 17 /* 18 * The SVE architecture leaves space for future expansion of the 19 * vector length beyond its initial architectural limit of 2048 bits 20 * (16 quadwords). 21 * 22 * See <Linux kernel source tree>/Documentation/arm64/sve.rst for a description 23 * of the vl/vq terminology. 24 */ 25 26 const uint16_t vq_bytes = 16; /* number of bytes per quadword */ 27 28 const uint16_t vq_min = 1; 29 const uint16_t vq_max = 512; 30 31 const uint16_t vl_min = vq_min * vq_bytes; 32 const uint16_t vl_max = vq_max * vq_bytes; 33 34 const uint16_t num_of_zregs = 32; 35 const uint16_t num_of_pregs = 16; 36 37 inline uint16_t vl_valid(uint16_t vl) { 38 return (vl % vq_bytes == 0 && vl >= vl_min && vl <= vl_max); 39 } 40 41 inline uint16_t vq_from_vl(uint16_t vl) { return vl / vq_bytes; } 42 inline uint16_t vl_from_vq(uint16_t vq) { return vq * vq_bytes; } 43 44 /* A new signal frame record sve_context encodes the SVE Registers on signal 45 * delivery. sve_context struct definition may be included in asm/sigcontext.h. 46 * We define sve_context_size which will be used by LLDB sve helper functions. 47 * More information on sve_context can be found in Linux kernel source tree at 48 * Documentation/arm64/sve.rst. 49 */ 50 51 const uint16_t sve_context_size = 16; 52 53 /* 54 * If the SVE registers are currently live for the thread at signal delivery, 55 * sve_context.head.size >= 56 * SigContextSize(vq_from_vl(sve_context.vl)) 57 * and the register data may be accessed using the Sig*() functions. 58 * 59 * If sve_context.head.size < 60 * SigContextSize(vq_from_vl(sve_context.vl)), 61 * the SVE registers were not live for the thread and no register data 62 * is included: in this case, the Sig*() functions should not be 63 * used except for this check. 64 * 65 * The same convention applies when returning from a signal: a caller 66 * will need to remove or resize the sve_context block if it wants to 67 * make the SVE registers live when they were previously non-live or 68 * vice-versa. This may require the caller to allocate fresh 69 * memory and/or move other context blocks in the signal frame. 70 * 71 * Changing the vector length during signal return is not permitted: 72 * sve_context.vl must equal the thread's current vector length when 73 * doing a sigreturn. 74 * 75 * 76 * Note: for all these functions, the "vq" argument denotes the SVE 77 * vector length in quadwords (i.e., units of 128 bits). 78 * 79 * The correct way to obtain vq is to use vq_from_vl(vl). The 80 * result is valid if and only if vl_valid(vl) is true. This is 81 * guaranteed for a struct sve_context written by the kernel. 82 * 83 * 84 * Additional functions describe the contents and layout of the payload. 85 * For each, Sig*Offset(args) is the start offset relative to 86 * the start of struct sve_context, and Sig*Size(args) is the 87 * size in bytes: 88 * 89 * x type description 90 * - ---- ----------- 91 * REGS the entire SVE context 92 * 93 * ZREGS __uint128_t[num_of_zregs][vq] all Z-registers 94 * ZREG __uint128_t[vq] individual Z-register Zn 95 * 96 * PREGS uint16_t[num_of_pregs][vq] all P-registers 97 * PREG uint16_t[vq] individual P-register Pn 98 * 99 * FFR uint16_t[vq] first-fault status register 100 * 101 * Additional data might be appended in the future. 102 */ 103 104 inline uint16_t SigZRegSize(uint16_t vq) { return vq * vq_bytes; } 105 inline uint16_t SigPRegSize(uint16_t vq) { return vq * vq_bytes / 8; } 106 inline uint16_t SigFFRSize(uint16_t vq) { return SigPRegSize(vq); } 107 108 inline uint32_t SigRegsOffset() { 109 return (sve_context_size + vq_bytes - 1) / vq_bytes * vq_bytes; 110 } 111 112 inline uint32_t SigZRegsOffset() { return SigRegsOffset(); } 113 114 inline uint32_t SigZRegOffset(uint16_t vq, uint16_t n) { 115 return SigRegsOffset() + SigZRegSize(vq) * n; 116 } 117 118 inline uint32_t SigZRegsSize(uint16_t vq) { 119 return SigZRegOffset(vq, num_of_zregs) - SigRegsOffset(); 120 } 121 122 inline uint32_t SigPRegsOffset(uint16_t vq) { 123 return SigRegsOffset() + SigZRegsSize(vq); 124 } 125 126 inline uint32_t SigPRegOffset(uint16_t vq, uint16_t n) { 127 return SigPRegsOffset(vq) + SigPRegSize(vq) * n; 128 } 129 130 inline uint32_t SigpRegsSize(uint16_t vq) { 131 return SigPRegOffset(vq, num_of_pregs) - SigPRegsOffset(vq); 132 } 133 134 inline uint32_t SigFFROffset(uint16_t vq) { 135 return SigPRegsOffset(vq) + SigpRegsSize(vq); 136 } 137 138 inline uint32_t SigRegsSize(uint16_t vq) { 139 return SigFFROffset(vq) + SigFFRSize(vq) - SigRegsOffset(); 140 } 141 142 inline uint32_t SVESigContextSize(uint16_t vq) { 143 return SigRegsOffset() + SigRegsSize(vq); 144 } 145 146 struct user_sve_header { 147 uint32_t size; /* total meaningful regset content in bytes */ 148 uint32_t max_size; /* maxmium possible size for this thread */ 149 uint16_t vl; /* current vector length */ 150 uint16_t max_vl; /* maximum possible vector length */ 151 uint16_t flags; 152 uint16_t reserved; 153 }; 154 155 /* Definitions for user_sve_header.flags: */ 156 const uint16_t ptrace_regs_mask = 1 << 0; 157 const uint16_t ptrace_regs_fpsimd = 0; 158 const uint16_t ptrace_regs_sve = ptrace_regs_mask; 159 160 /* 161 * The remainder of the SVE state follows struct user_sve_header. The 162 * total size of the SVE state (including header) depends on the 163 * metadata in the header: PTraceSize(vq, flags) gives the total size 164 * of the state in bytes, including the header. 165 * 166 * Refer to <asm/sigcontext.h> for details of how to pass the correct 167 * "vq" argument to these macros. 168 */ 169 170 /* Offset from the start of struct user_sve_header to the register data */ 171 inline uint16_t PTraceRegsOffset() { 172 return (sizeof(struct user_sve_header) + vq_bytes - 1) / vq_bytes * vq_bytes; 173 } 174 175 /* 176 * The register data content and layout depends on the value of the 177 * flags field. 178 */ 179 180 /* 181 * (flags & ptrace_regs_mask) == ptrace_regs_fpsimd case: 182 * 183 * The payload starts at offset PTraceFPSIMDOffset, and is of type 184 * struct user_fpsimd_state. Additional data might be appended in the 185 * future: use PTraceFPSIMDSize(vq, flags) to compute the total size. 186 * PTraceFPSIMDSize(vq, flags) will never be less than 187 * sizeof(struct user_fpsimd_state). 188 */ 189 190 const uint32_t ptrace_fpsimd_offset = PTraceRegsOffset(); 191 192 /* Return size of struct user_fpsimd_state from asm/ptrace.h */ 193 inline uint32_t PTraceFPSIMDSize(uint16_t vq, uint16_t flags) { return 528; } 194 195 /* 196 * (flags & ptrace_regs_mask) == ptrace_regs_sve case: 197 * 198 * The payload starts at offset PTraceSVEOffset, and is of size 199 * PTraceSVESize(vq, flags). 200 * 201 * Additional functions describe the contents and layout of the payload. 202 * For each, PTrace*X*Offset(args) is the start offset relative to 203 * the start of struct user_sve_header, and PTrace*X*Size(args) is 204 * the size in bytes: 205 * 206 * x type description 207 * - ---- ----------- 208 * ZREGS \ 209 * ZREG | 210 * PREGS | refer to <asm/sigcontext.h> 211 * PREG | 212 * FFR / 213 * 214 * FPSR uint32_t FPSR 215 * FPCR uint32_t FPCR 216 * 217 * Additional data might be appended in the future. 218 */ 219 220 inline uint32_t PTraceZRegSize(uint16_t vq) { return SigZRegSize(vq); } 221 222 inline uint32_t PTracePRegSize(uint16_t vq) { return SigPRegSize(vq); } 223 224 inline uint32_t PTraceFFRSize(uint16_t vq) { return SigFFRSize(vq); } 225 226 const uint32_t fpsr_size = sizeof(uint32_t); 227 const uint32_t fpcr_size = sizeof(uint32_t); 228 229 inline uint32_t SigToPTrace(uint32_t offset) { 230 return offset - SigRegsOffset() + PTraceRegsOffset(); 231 } 232 233 const uint32_t ptrace_sve_offset = PTraceRegsOffset(); 234 235 inline uint32_t PTraceZRegsOffset(uint16_t vq) { 236 return SigToPTrace(SigZRegsOffset()); 237 } 238 239 inline uint32_t PTraceZRegOffset(uint16_t vq, uint16_t n) { 240 return SigToPTrace(SigZRegOffset(vq, n)); 241 } 242 243 inline uint32_t PTraceZRegsSize(uint16_t vq) { 244 return PTraceZRegOffset(vq, num_of_zregs) - SigToPTrace(SigRegsOffset()); 245 } 246 247 inline uint32_t PTracePRegsOffset(uint16_t vq) { 248 return SigToPTrace(SigPRegsOffset(vq)); 249 } 250 251 inline uint32_t PTracePRegOffset(uint16_t vq, uint16_t n) { 252 return SigToPTrace(SigPRegOffset(vq, n)); 253 } 254 255 inline uint32_t PTracePRegsSize(uint16_t vq) { 256 return PTracePRegOffset(vq, num_of_pregs) - PTracePRegsOffset(vq); 257 } 258 259 inline uint32_t PTraceFFROffset(uint16_t vq) { 260 return SigToPTrace(SigFFROffset(vq)); 261 } 262 263 inline uint32_t PTraceFPSROffset(uint16_t vq) { 264 return (PTraceFFROffset(vq) + PTraceFFRSize(vq) + (vq_bytes - 1)) / vq_bytes * 265 vq_bytes; 266 } 267 268 inline uint32_t PTraceFPCROffset(uint16_t vq) { 269 return PTraceFPSROffset(vq) + fpsr_size; 270 } 271 272 /* 273 * Any future extension appended after FPCR must be aligned to the next 274 * 128-bit boundary. 275 */ 276 277 inline uint32_t PTraceSVESize(uint16_t vq, uint16_t flags) { 278 return (PTraceFPCROffset(vq) + fpcr_size - ptrace_sve_offset + vq_bytes - 1) / 279 vq_bytes * vq_bytes; 280 } 281 282 inline uint32_t PTraceSize(uint16_t vq, uint16_t flags) { 283 return (flags & ptrace_regs_mask) == ptrace_regs_sve 284 ? ptrace_sve_offset + PTraceSVESize(vq, flags) 285 : ptrace_fpsimd_offset + PTraceFPSIMDSize(vq, flags); 286 } 287 288 } // namespace SVE 289 } // namespace lldb_private 290 291 #endif // LLDB_SOURCE_PLUGINS_PROCESS_UTILITY_LINUXPTRACEDEFINES_ARM64SVE_H 292