1// SPDX-License-Identifier: GPL-2.0-only 2// Copyright (C) 2021-2 ARM Limited. 3// Original author: Mark Brown <broonie@kernel.org> 4// 5// Scalable Matrix Extension ZT context switch test 6// Repeatedly writes unique test patterns into ZT0 7// and reads them back to verify integrity. 8 9#include <asm/unistd.h> 10#include "assembler.h" 11#include "asm-offsets.h" 12#include "sme-inst.h" 13 14.arch_extension sve 15 16#define ZT_SZ 512 17#define ZT_B (ZT_SZ / 8) 18 19// Declare some storage space to shadow ZT register contents and a 20// scratch buffer. 21.pushsection .text 22.data 23.align 4 24ztref: 25 .space ZT_B 26scratch: 27 .space ZT_B 28.popsection 29 30 31// Generate a test pattern for storage in ZT 32// x0: pid 33// x1: generation 34 35// These values are used to construct a 32-bit pattern that is repeated in the 36// scratch buffer as many times as will fit: 37// bits 31:24 generation number (increments once per test_loop) 38// bits 23: 8 pid 39// bits 7: 0 32-bit lane index 40 41function pattern 42 mov w3, wzr 43 bfi w3, w0, #8, #16 // PID 44 bfi w3, w1, #24, #8 // Generation 45 46 ldr x0, =scratch 47 mov w1, #ZT_B / 4 48 490: str w3, [x0], #4 50 add w3, w3, #1 // Lane 51 subs w1, w1, #1 52 b.ne 0b 53 54 ret 55endfunction 56 57// Set up test pattern in a ZT horizontal vector 58// x0: pid 59// x1: generation 60function setup_zt 61 mov x4, x30 62 63 bl pattern // Get pattern in scratch buffer 64 ldr x0, =ztref 65 ldr x1, =scratch 66 mov x2, #ZT_B 67 bl memcpy 68 69 ldr x0, =ztref 70 _ldr_zt 0 // load zt0 from pointer x0 71 72 ret x4 73endfunction 74 75// Trivial memory compare: compare x2 bytes starting at address x0 with 76// bytes starting at address x1. 77// Returns only if all bytes match; otherwise, the program is aborted. 78// Clobbers x0-x5. 79function memcmp 80 cbz x2, 2f 81 82 stp x0, x1, [sp, #-0x20]! 83 str x2, [sp, #0x10] 84 85 mov x5, #0 860: ldrb w3, [x0, x5] 87 ldrb w4, [x1, x5] 88 add x5, x5, #1 89 cmp w3, w4 90 b.ne 1f 91 subs x2, x2, #1 92 b.ne 0b 93 941: ldr x2, [sp, #0x10] 95 ldp x0, x1, [sp], #0x20 96 b.ne barf 97 982: ret 99endfunction 100 101// Verify that a ZT vector matches its shadow in memory, else abort 102// Clobbers x0-x3 103function check_zt 104 mov x3, x30 105 106 ldr x0, =scratch // Poison scratch 107 mov x1, #ZT_B 108 bl memfill_ae 109 110 ldr x0, =scratch 111 _str_zt 0 112 113 ldr x0, =ztref 114 ldr x1, =scratch 115 mov x2, #ZT_B 116 mov x30, x3 117 b memcmp 118endfunction 119 120// Any SME register modified here can cause corruption in the main 121// thread -- but *only* the locations modified here. 122function irritator_handler 123 // Increment the irritation signal count (x23): 124 ldr x0, [x2, #ucontext_regs + 8 * 23] 125 add x0, x0, #1 126 str x0, [x2, #ucontext_regs + 8 * 23] 127 128 // Corrupt some random ZT data 129#if 0 130 adr x0, .text + (irritator_handler - .text) / 16 * 16 131 movi v0.8b, #1 132 movi v9.16b, #2 133 movi v31.8b, #3 134#endif 135 136 ret 137endfunction 138 139function tickle_handler 140 // Increment the signal count (x23): 141 ldr x0, [x2, #ucontext_regs + 8 * 23] 142 add x0, x0, #1 143 str x0, [x2, #ucontext_regs + 8 * 23] 144 145 ret 146endfunction 147 148function terminate_handler 149 mov w21, w0 150 mov x20, x2 151 152 puts "Terminated by signal " 153 mov w0, w21 154 bl putdec 155 puts ", no error, iterations=" 156 ldr x0, [x20, #ucontext_regs + 8 * 22] 157 bl putdec 158 puts ", signals=" 159 ldr x0, [x20, #ucontext_regs + 8 * 23] 160 bl putdecn 161 162 mov x0, #0 163 mov x8, #__NR_exit 164 svc #0 165endfunction 166 167// w0: signal number 168// x1: sa_action 169// w2: sa_flags 170// Clobbers x0-x6,x8 171function setsignal 172 str x30, [sp, #-((sa_sz + 15) / 16 * 16 + 16)]! 173 174 mov w4, w0 175 mov x5, x1 176 mov w6, w2 177 178 add x0, sp, #16 179 mov x1, #sa_sz 180 bl memclr 181 182 mov w0, w4 183 add x1, sp, #16 184 str w6, [x1, #sa_flags] 185 str x5, [x1, #sa_handler] 186 mov x2, #0 187 mov x3, #sa_mask_sz 188 mov x8, #__NR_rt_sigaction 189 svc #0 190 191 cbz w0, 1f 192 193 puts "sigaction failure\n" 194 b .Labort 195 1961: ldr x30, [sp], #((sa_sz + 15) / 16 * 16 + 16) 197 ret 198endfunction 199 200// Main program entry point 201.globl _start 202function _start 203 mov x23, #0 // signal count 204 205 mov w0, #SIGINT 206 adr x1, terminate_handler 207 mov w2, #SA_SIGINFO 208 bl setsignal 209 210 mov w0, #SIGTERM 211 adr x1, terminate_handler 212 mov w2, #SA_SIGINFO 213 bl setsignal 214 215 mov w0, #SIGUSR1 216 adr x1, irritator_handler 217 mov w2, #SA_SIGINFO 218 orr w2, w2, #SA_NODEFER 219 bl setsignal 220 221 mov w0, #SIGUSR2 222 adr x1, tickle_handler 223 mov w2, #SA_SIGINFO 224 orr w2, w2, #SA_NODEFER 225 bl setsignal 226 227 smstart_za 228 229 // Obtain our PID, to ensure test pattern uniqueness between processes 230 mov x8, #__NR_getpid 231 svc #0 232 mov x20, x0 233 234 puts "PID:\t" 235 mov x0, x20 236 bl putdecn 237 238 mov x22, #0 // generation number, increments per iteration 239.Ltest_loop: 240 mov x0, x20 241 mov x1, x22 242 bl setup_zt 243 244 mov x8, #__NR_sched_yield // Encourage preemption 245 svc #0 246 247 mrs x0, S3_3_C4_C2_2 // SVCR should have ZA=1,SM=0 248 and x1, x0, #3 249 cmp x1, #2 250 b.ne svcr_barf 251 252 bl check_zt 253 254 add x22, x22, #1 // Everything still working 255 b .Ltest_loop 256 257.Labort: 258 mov x0, #0 259 mov x1, #SIGABRT 260 mov x8, #__NR_kill 261 svc #0 262endfunction 263 264function barf 265// fpsimd.c acitivty log dump hack 266// ldr w0, =0xdeadc0de 267// mov w8, #__NR_exit 268// svc #0 269// end hack 270 271 mrs x13, S3_3_C4_C2_2 272 smstop 273 mov x10, x0 // expected data 274 mov x11, x1 // actual data 275 mov x12, x2 // data size 276 277 puts "Mismatch: PID=" 278 mov x0, x20 279 bl putdec 280 puts ", iteration=" 281 mov x0, x22 282 bl putdec 283 puts "\tExpected [" 284 mov x0, x10 285 mov x1, x12 286 bl dumphex 287 puts "]\n\tGot [" 288 mov x0, x11 289 mov x1, x12 290 bl dumphex 291 puts "]\n" 292 puts "\tSVCR: " 293 mov x0, x13 294 bl putdecn 295 296 mov x8, #__NR_getpid 297 svc #0 298// fpsimd.c acitivty log dump hack 299// ldr w0, =0xdeadc0de 300// mov w8, #__NR_exit 301// svc #0 302// ^ end of hack 303 mov x1, #SIGABRT 304 mov x8, #__NR_kill 305 svc #0 306// mov x8, #__NR_exit 307// mov x1, #1 308// svc #0 309endfunction 310 311function svcr_barf 312 mov x10, x0 313 314 puts "Bad SVCR: " 315 mov x0, x10 316 bl putdecn 317 318 mov x8, #__NR_exit 319 mov x1, #1 320 svc #0 321endfunction 322