>> 1 /* SPDX-License-Identifier: GPL-2.0 */
1 /* 2 /*
2 * This file is subject to the terms and condi !! 3 * arch/alpha/kernel/entry.S
3 * License. See the file "COPYING" in the mai <<
4 * for more details. <<
5 * 4 *
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf !! 5 * Kernel entry-points.
7 * Copyright (C) 1999, 2000 Silicon Graphics, <<
8 * Copyright (C) 2001 MIPS Technologies, Inc. <<
9 */ 6 */
10 7
11 #include <asm/asm.h> !! 8 #include <asm/asm-offsets.h>
12 #include <asm/asmmacro.h> <<
13 #include <asm/compiler.h> <<
14 #include <asm/irqflags.h> <<
15 #include <asm/regdef.h> <<
16 #include <asm/mipsregs.h> <<
17 #include <asm/stackframe.h> <<
18 #include <asm/isadep.h> <<
19 #include <asm/thread_info.h> 9 #include <asm/thread_info.h>
20 !! 10 #include <asm/pal.h>
21 #ifndef CONFIG_PREEMPTION !! 11 #include <asm/errno.h>
22 #define resume_kernel restore_all !! 12 #include <asm/unistd.h>
23 #else <<
24 #define __ret_from_irq ret_from_exception <<
25 #endif <<
26 13
27 .text 14 .text
28 .align 5 !! 15 .set noat
29 #ifndef CONFIG_PREEMPTION !! 16 .cfi_sections .debug_frame
30 FEXPORT(ret_from_exception) <<
31 local_irq_disable <<
32 b __ret_from_irq <<
33 #endif <<
34 FEXPORT(ret_from_irq) <<
35 LONG_S s0, TI_REGS($28) <<
36 FEXPORT(__ret_from_irq) <<
37 /* <<
38 * We can be coming here from a syscall done i <<
39 * e.g. a failed kernel_execve(). <<
40 */ <<
41 resume_userspace_check: <<
42 LONG_L t0, PT_STATUS(sp) <<
43 andi t0, t0, KU_USER <<
44 beqz t0, resume_kernel <<
45 <<
46 resume_userspace: <<
47 local_irq_disable # make <<
48 # inte <<
49 # betw <<
50 LONG_L a2, TI_FLAGS($28) # curr <<
51 andi t0, a2, _TIF_WORK_MASK # (ign <<
52 bnez t0, work_pending <<
53 j restore_all <<
54 <<
55 #ifdef CONFIG_PREEMPTION <<
56 resume_kernel: <<
57 local_irq_disable <<
58 lw t0, TI_PRE_COUNT($28) <<
59 bnez t0, restore_all <<
60 LONG_L t0, TI_FLAGS($28) <<
61 andi t1, t0, _TIF_NEED_RESCHED <<
62 beqz t1, restore_all <<
63 LONG_L t0, PT_STATUS(sp) <<
64 andi t0, 1 <<
65 beqz t0, restore_all <<
66 PTR_LA ra, restore_all <<
67 j preempt_schedule_irq <<
68 #endif <<
69 17
70 FEXPORT(ret_from_kernel_thread) !! 18 /* Stack offsets. */
71 jal schedule_tail # a0 = !! 19 #define SP_OFF 184
72 move a0, s1 !! 20 #define SWITCH_STACK_SIZE 320
73 jal s0 !! 21
74 j syscall_exit !! 22 .macro CFI_START_OSF_FRAME func
75 !! 23 .align 4
76 FEXPORT(ret_from_fork) !! 24 .globl \func
77 jal schedule_tail # a0 = !! 25 .type \func,@function
78 !! 26 \func:
79 FEXPORT(syscall_exit) !! 27 .cfi_startproc simple
80 #ifdef CONFIG_DEBUG_RSEQ !! 28 .cfi_return_column 64
81 move a0, sp !! 29 .cfi_def_cfa $sp, 48
82 jal rseq_syscall !! 30 .cfi_rel_offset 64, 8
83 #endif !! 31 .cfi_rel_offset $gp, 16
84 local_irq_disable # make !! 32 .cfi_rel_offset $16, 24
85 # sign !! 33 .cfi_rel_offset $17, 32
86 # samp !! 34 .cfi_rel_offset $18, 40
87 LONG_L a2, TI_FLAGS($28) # curr !! 35 .endm
88 li t0, _TIF_ALLWORK_MASK !! 36
89 and t0, a2, t0 !! 37 .macro CFI_END_OSF_FRAME func
90 bnez t0, syscall_exit_work !! 38 .cfi_endproc
91 !! 39 .size \func, . - \func
92 restore_all: # rest !! 40 .endm
93 .set noat !! 41
94 RESTORE_TEMP !! 42 /*
95 RESTORE_AT !! 43 * This defines the normal kernel pt-regs layout.
96 RESTORE_STATIC !! 44 *
97 restore_partial: # restore part !! 45 * regs 9-15 preserved by C code
98 #ifdef CONFIG_TRACE_IRQFLAGS !! 46 * regs 16-18 saved by PAL-code
99 SAVE_STATIC !! 47 * regs 29-30 saved and set up by PAL-code
100 SAVE_AT !! 48 * JRP - Save regs 16-18 in a special area of the stack, so that
101 SAVE_TEMP !! 49 * the palcode-provided values are available to the signal handler.
102 LONG_L v0, PT_STATUS(sp) !! 50 */
103 #if defined(CONFIG_CPU_R3000) !! 51
104 and v0, ST0_IEP !! 52 .macro SAVE_ALL
105 #else !! 53 subq $sp, SP_OFF, $sp
106 and v0, ST0_IE !! 54 .cfi_adjust_cfa_offset SP_OFF
107 #endif !! 55 stq $0, 0($sp)
108 beqz v0, 1f !! 56 stq $1, 8($sp)
109 jal trace_hardirqs_on !! 57 stq $2, 16($sp)
110 b 2f !! 58 stq $3, 24($sp)
111 1: jal trace_hardirqs_off !! 59 stq $4, 32($sp)
112 2: !! 60 stq $28, 144($sp)
113 RESTORE_TEMP !! 61 .cfi_rel_offset $0, 0
114 RESTORE_AT !! 62 .cfi_rel_offset $1, 8
115 RESTORE_STATIC !! 63 .cfi_rel_offset $2, 16
>> 64 .cfi_rel_offset $3, 24
>> 65 .cfi_rel_offset $4, 32
>> 66 .cfi_rel_offset $28, 144
>> 67 lda $2, alpha_mv
>> 68 stq $5, 40($sp)
>> 69 stq $6, 48($sp)
>> 70 stq $7, 56($sp)
>> 71 stq $8, 64($sp)
>> 72 stq $19, 72($sp)
>> 73 stq $20, 80($sp)
>> 74 stq $21, 88($sp)
>> 75 ldq $2, HAE_CACHE($2)
>> 76 stq $22, 96($sp)
>> 77 stq $23, 104($sp)
>> 78 stq $24, 112($sp)
>> 79 stq $25, 120($sp)
>> 80 stq $26, 128($sp)
>> 81 stq $27, 136($sp)
>> 82 stq $2, 152($sp)
>> 83 stq $16, 160($sp)
>> 84 stq $17, 168($sp)
>> 85 stq $18, 176($sp)
>> 86 .cfi_rel_offset $5, 40
>> 87 .cfi_rel_offset $6, 48
>> 88 .cfi_rel_offset $7, 56
>> 89 .cfi_rel_offset $8, 64
>> 90 .cfi_rel_offset $19, 72
>> 91 .cfi_rel_offset $20, 80
>> 92 .cfi_rel_offset $21, 88
>> 93 .cfi_rel_offset $22, 96
>> 94 .cfi_rel_offset $23, 104
>> 95 .cfi_rel_offset $24, 112
>> 96 .cfi_rel_offset $25, 120
>> 97 .cfi_rel_offset $26, 128
>> 98 .cfi_rel_offset $27, 136
>> 99 .endm
>> 100
>> 101 .macro RESTORE_ALL
>> 102 lda $19, alpha_mv
>> 103 ldq $0, 0($sp)
>> 104 ldq $1, 8($sp)
>> 105 ldq $2, 16($sp)
>> 106 ldq $3, 24($sp)
>> 107 ldq $21, 152($sp)
>> 108 ldq $20, HAE_CACHE($19)
>> 109 ldq $4, 32($sp)
>> 110 ldq $5, 40($sp)
>> 111 ldq $6, 48($sp)
>> 112 ldq $7, 56($sp)
>> 113 subq $20, $21, $20
>> 114 ldq $8, 64($sp)
>> 115 beq $20, 99f
>> 116 ldq $20, HAE_REG($19)
>> 117 stq $21, HAE_CACHE($19)
>> 118 stq $21, 0($20)
>> 119 99: ldq $19, 72($sp)
>> 120 ldq $20, 80($sp)
>> 121 ldq $21, 88($sp)
>> 122 ldq $22, 96($sp)
>> 123 ldq $23, 104($sp)
>> 124 ldq $24, 112($sp)
>> 125 ldq $25, 120($sp)
>> 126 ldq $26, 128($sp)
>> 127 ldq $27, 136($sp)
>> 128 ldq $28, 144($sp)
>> 129 addq $sp, SP_OFF, $sp
>> 130 .cfi_restore $0
>> 131 .cfi_restore $1
>> 132 .cfi_restore $2
>> 133 .cfi_restore $3
>> 134 .cfi_restore $4
>> 135 .cfi_restore $5
>> 136 .cfi_restore $6
>> 137 .cfi_restore $7
>> 138 .cfi_restore $8
>> 139 .cfi_restore $19
>> 140 .cfi_restore $20
>> 141 .cfi_restore $21
>> 142 .cfi_restore $22
>> 143 .cfi_restore $23
>> 144 .cfi_restore $24
>> 145 .cfi_restore $25
>> 146 .cfi_restore $26
>> 147 .cfi_restore $27
>> 148 .cfi_restore $28
>> 149 .cfi_adjust_cfa_offset -SP_OFF
>> 150 .endm
>> 151
>> 152 .macro DO_SWITCH_STACK
>> 153 bsr $1, do_switch_stack
>> 154 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 155 .cfi_rel_offset $9, 0
>> 156 .cfi_rel_offset $10, 8
>> 157 .cfi_rel_offset $11, 16
>> 158 .cfi_rel_offset $12, 24
>> 159 .cfi_rel_offset $13, 32
>> 160 .cfi_rel_offset $14, 40
>> 161 .cfi_rel_offset $15, 48
>> 162 /* We don't really care about the FP registers for debugging. */
>> 163 .endm
>> 164
>> 165 .macro UNDO_SWITCH_STACK
>> 166 bsr $1, undo_switch_stack
>> 167 .cfi_restore $9
>> 168 .cfi_restore $10
>> 169 .cfi_restore $11
>> 170 .cfi_restore $12
>> 171 .cfi_restore $13
>> 172 .cfi_restore $14
>> 173 .cfi_restore $15
>> 174 .cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
>> 175 .endm
>> 176
>> 177 /*
>> 178 * Non-syscall kernel entry points.
>> 179 */
>> 180
>> 181 CFI_START_OSF_FRAME entInt
>> 182 SAVE_ALL
>> 183 lda $8, 0x3fff
>> 184 lda $26, ret_from_sys_call
>> 185 bic $sp, $8, $8
>> 186 mov $sp, $19
>> 187 jsr $31, do_entInt
>> 188 CFI_END_OSF_FRAME entInt
>> 189
>> 190 CFI_START_OSF_FRAME entArith
>> 191 SAVE_ALL
>> 192 lda $8, 0x3fff
>> 193 lda $26, ret_from_sys_call
>> 194 bic $sp, $8, $8
>> 195 mov $sp, $18
>> 196 jsr $31, do_entArith
>> 197 CFI_END_OSF_FRAME entArith
>> 198
>> 199 CFI_START_OSF_FRAME entMM
>> 200 SAVE_ALL
>> 201 /* save $9 - $15 so the inline exception code can manipulate them. */
>> 202 subq $sp, 56, $sp
>> 203 .cfi_adjust_cfa_offset 56
>> 204 stq $9, 0($sp)
>> 205 stq $10, 8($sp)
>> 206 stq $11, 16($sp)
>> 207 stq $12, 24($sp)
>> 208 stq $13, 32($sp)
>> 209 stq $14, 40($sp)
>> 210 stq $15, 48($sp)
>> 211 .cfi_rel_offset $9, 0
>> 212 .cfi_rel_offset $10, 8
>> 213 .cfi_rel_offset $11, 16
>> 214 .cfi_rel_offset $12, 24
>> 215 .cfi_rel_offset $13, 32
>> 216 .cfi_rel_offset $14, 40
>> 217 .cfi_rel_offset $15, 48
>> 218 addq $sp, 56, $19
>> 219 /* handle the fault */
>> 220 lda $8, 0x3fff
>> 221 bic $sp, $8, $8
>> 222 jsr $26, do_page_fault
>> 223 /* reload the registers after the exception code played. */
>> 224 ldq $9, 0($sp)
>> 225 ldq $10, 8($sp)
>> 226 ldq $11, 16($sp)
>> 227 ldq $12, 24($sp)
>> 228 ldq $13, 32($sp)
>> 229 ldq $14, 40($sp)
>> 230 ldq $15, 48($sp)
>> 231 addq $sp, 56, $sp
>> 232 .cfi_restore $9
>> 233 .cfi_restore $10
>> 234 .cfi_restore $11
>> 235 .cfi_restore $12
>> 236 .cfi_restore $13
>> 237 .cfi_restore $14
>> 238 .cfi_restore $15
>> 239 .cfi_adjust_cfa_offset -56
>> 240 /* finish up the syscall as normal. */
>> 241 br ret_from_sys_call
>> 242 CFI_END_OSF_FRAME entMM
>> 243
>> 244 CFI_START_OSF_FRAME entIF
>> 245 SAVE_ALL
>> 246 lda $8, 0x3fff
>> 247 lda $26, ret_from_sys_call
>> 248 bic $sp, $8, $8
>> 249 mov $sp, $17
>> 250 jsr $31, do_entIF
>> 251 CFI_END_OSF_FRAME entIF
>> 252
>> 253 CFI_START_OSF_FRAME entUna
>> 254 lda $sp, -256($sp)
>> 255 .cfi_adjust_cfa_offset 256
>> 256 stq $0, 0($sp)
>> 257 .cfi_rel_offset $0, 0
>> 258 .cfi_remember_state
>> 259 ldq $0, 256($sp) /* get PS */
>> 260 stq $1, 8($sp)
>> 261 stq $2, 16($sp)
>> 262 stq $3, 24($sp)
>> 263 and $0, 8, $0 /* user mode? */
>> 264 stq $4, 32($sp)
>> 265 bne $0, entUnaUser /* yup -> do user-level unaligned fault */
>> 266 stq $5, 40($sp)
>> 267 stq $6, 48($sp)
>> 268 stq $7, 56($sp)
>> 269 stq $8, 64($sp)
>> 270 stq $9, 72($sp)
>> 271 stq $10, 80($sp)
>> 272 stq $11, 88($sp)
>> 273 stq $12, 96($sp)
>> 274 stq $13, 104($sp)
>> 275 stq $14, 112($sp)
>> 276 stq $15, 120($sp)
>> 277 /* 16-18 PAL-saved */
>> 278 stq $19, 152($sp)
>> 279 stq $20, 160($sp)
>> 280 stq $21, 168($sp)
>> 281 stq $22, 176($sp)
>> 282 stq $23, 184($sp)
>> 283 stq $24, 192($sp)
>> 284 stq $25, 200($sp)
>> 285 stq $26, 208($sp)
>> 286 stq $27, 216($sp)
>> 287 stq $28, 224($sp)
>> 288 mov $sp, $19
>> 289 stq $gp, 232($sp)
>> 290 .cfi_rel_offset $1, 1*8
>> 291 .cfi_rel_offset $2, 2*8
>> 292 .cfi_rel_offset $3, 3*8
>> 293 .cfi_rel_offset $4, 4*8
>> 294 .cfi_rel_offset $5, 5*8
>> 295 .cfi_rel_offset $6, 6*8
>> 296 .cfi_rel_offset $7, 7*8
>> 297 .cfi_rel_offset $8, 8*8
>> 298 .cfi_rel_offset $9, 9*8
>> 299 .cfi_rel_offset $10, 10*8
>> 300 .cfi_rel_offset $11, 11*8
>> 301 .cfi_rel_offset $12, 12*8
>> 302 .cfi_rel_offset $13, 13*8
>> 303 .cfi_rel_offset $14, 14*8
>> 304 .cfi_rel_offset $15, 15*8
>> 305 .cfi_rel_offset $19, 19*8
>> 306 .cfi_rel_offset $20, 20*8
>> 307 .cfi_rel_offset $21, 21*8
>> 308 .cfi_rel_offset $22, 22*8
>> 309 .cfi_rel_offset $23, 23*8
>> 310 .cfi_rel_offset $24, 24*8
>> 311 .cfi_rel_offset $25, 25*8
>> 312 .cfi_rel_offset $26, 26*8
>> 313 .cfi_rel_offset $27, 27*8
>> 314 .cfi_rel_offset $28, 28*8
>> 315 .cfi_rel_offset $29, 29*8
>> 316 lda $8, 0x3fff
>> 317 stq $31, 248($sp)
>> 318 bic $sp, $8, $8
>> 319 jsr $26, do_entUna
>> 320 ldq $0, 0($sp)
>> 321 ldq $1, 8($sp)
>> 322 ldq $2, 16($sp)
>> 323 ldq $3, 24($sp)
>> 324 ldq $4, 32($sp)
>> 325 ldq $5, 40($sp)
>> 326 ldq $6, 48($sp)
>> 327 ldq $7, 56($sp)
>> 328 ldq $8, 64($sp)
>> 329 ldq $9, 72($sp)
>> 330 ldq $10, 80($sp)
>> 331 ldq $11, 88($sp)
>> 332 ldq $12, 96($sp)
>> 333 ldq $13, 104($sp)
>> 334 ldq $14, 112($sp)
>> 335 ldq $15, 120($sp)
>> 336 /* 16-18 PAL-saved */
>> 337 ldq $19, 152($sp)
>> 338 ldq $20, 160($sp)
>> 339 ldq $21, 168($sp)
>> 340 ldq $22, 176($sp)
>> 341 ldq $23, 184($sp)
>> 342 ldq $24, 192($sp)
>> 343 ldq $25, 200($sp)
>> 344 ldq $26, 208($sp)
>> 345 ldq $27, 216($sp)
>> 346 ldq $28, 224($sp)
>> 347 ldq $gp, 232($sp)
>> 348 lda $sp, 256($sp)
>> 349 .cfi_restore $1
>> 350 .cfi_restore $2
>> 351 .cfi_restore $3
>> 352 .cfi_restore $4
>> 353 .cfi_restore $5
>> 354 .cfi_restore $6
>> 355 .cfi_restore $7
>> 356 .cfi_restore $8
>> 357 .cfi_restore $9
>> 358 .cfi_restore $10
>> 359 .cfi_restore $11
>> 360 .cfi_restore $12
>> 361 .cfi_restore $13
>> 362 .cfi_restore $14
>> 363 .cfi_restore $15
>> 364 .cfi_restore $19
>> 365 .cfi_restore $20
>> 366 .cfi_restore $21
>> 367 .cfi_restore $22
>> 368 .cfi_restore $23
>> 369 .cfi_restore $24
>> 370 .cfi_restore $25
>> 371 .cfi_restore $26
>> 372 .cfi_restore $27
>> 373 .cfi_restore $28
>> 374 .cfi_restore $29
>> 375 .cfi_adjust_cfa_offset -256
>> 376 call_pal PAL_rti
>> 377
>> 378 .align 4
>> 379 entUnaUser:
>> 380 .cfi_restore_state
>> 381 ldq $0, 0($sp) /* restore original $0 */
>> 382 lda $sp, 256($sp) /* pop entUna's stack frame */
>> 383 .cfi_restore $0
>> 384 .cfi_adjust_cfa_offset -256
>> 385 SAVE_ALL /* setup normal kernel stack */
>> 386 lda $sp, -56($sp)
>> 387 .cfi_adjust_cfa_offset 56
>> 388 stq $9, 0($sp)
>> 389 stq $10, 8($sp)
>> 390 stq $11, 16($sp)
>> 391 stq $12, 24($sp)
>> 392 stq $13, 32($sp)
>> 393 stq $14, 40($sp)
>> 394 stq $15, 48($sp)
>> 395 .cfi_rel_offset $9, 0
>> 396 .cfi_rel_offset $10, 8
>> 397 .cfi_rel_offset $11, 16
>> 398 .cfi_rel_offset $12, 24
>> 399 .cfi_rel_offset $13, 32
>> 400 .cfi_rel_offset $14, 40
>> 401 .cfi_rel_offset $15, 48
>> 402 lda $8, 0x3fff
>> 403 addq $sp, 56, $19
>> 404 bic $sp, $8, $8
>> 405 jsr $26, do_entUnaUser
>> 406 ldq $9, 0($sp)
>> 407 ldq $10, 8($sp)
>> 408 ldq $11, 16($sp)
>> 409 ldq $12, 24($sp)
>> 410 ldq $13, 32($sp)
>> 411 ldq $14, 40($sp)
>> 412 ldq $15, 48($sp)
>> 413 lda $sp, 56($sp)
>> 414 .cfi_restore $9
>> 415 .cfi_restore $10
>> 416 .cfi_restore $11
>> 417 .cfi_restore $12
>> 418 .cfi_restore $13
>> 419 .cfi_restore $14
>> 420 .cfi_restore $15
>> 421 .cfi_adjust_cfa_offset -56
>> 422 br ret_from_sys_call
>> 423 CFI_END_OSF_FRAME entUna
>> 424
>> 425 CFI_START_OSF_FRAME entDbg
>> 426 SAVE_ALL
>> 427 lda $8, 0x3fff
>> 428 lda $26, ret_from_sys_call
>> 429 bic $sp, $8, $8
>> 430 mov $sp, $16
>> 431 jsr $31, do_entDbg
>> 432 CFI_END_OSF_FRAME entDbg
>> 433
>> 434 /*
>> 435 * The system call entry point is special. Most importantly, it looks
>> 436 * like a function call to userspace as far as clobbered registers. We
>> 437 * do preserve the argument registers (for syscall restarts) and $26
>> 438 * (for leaf syscall functions).
>> 439 *
>> 440 * So much for theory. We don't take advantage of this yet.
>> 441 *
>> 442 * Note that a0-a2 are not saved by PALcode as with the other entry points.
>> 443 */
>> 444
>> 445 .align 4
>> 446 .globl entSys
>> 447 .type entSys, @function
>> 448 .cfi_startproc simple
>> 449 .cfi_return_column 64
>> 450 .cfi_def_cfa $sp, 48
>> 451 .cfi_rel_offset 64, 8
>> 452 .cfi_rel_offset $gp, 16
>> 453 entSys:
>> 454 SAVE_ALL
>> 455 lda $8, 0x3fff
>> 456 bic $sp, $8, $8
>> 457 lda $4, NR_SYSCALLS($31)
>> 458 stq $16, SP_OFF+24($sp)
>> 459 lda $5, sys_call_table
>> 460 lda $27, sys_ni_syscall
>> 461 cmpult $0, $4, $4
>> 462 ldl $3, TI_FLAGS($8)
>> 463 stq $17, SP_OFF+32($sp)
>> 464 s8addq $0, $5, $5
>> 465 stq $18, SP_OFF+40($sp)
>> 466 .cfi_rel_offset $16, SP_OFF+24
>> 467 .cfi_rel_offset $17, SP_OFF+32
>> 468 .cfi_rel_offset $18, SP_OFF+40
>> 469 #ifdef CONFIG_AUDITSYSCALL
>> 470 lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
>> 471 and $3, $6, $3
116 #endif 472 #endif
117 RESTORE_SOME !! 473 bne $3, strace
118 RESTORE_SP_AND_RET !! 474 beq $4, 1f
119 .set at !! 475 ldq $27, 0($5)
>> 476 1: jsr $26, ($27), alpha_ni_syscall
>> 477 ldgp $gp, 0($26)
>> 478 blt $0, $syscall_error /* the call failed */
>> 479 stq $0, 0($sp)
>> 480 stq $31, 72($sp) /* a3=0 => no error */
>> 481
>> 482 .align 4
>> 483 .globl ret_from_sys_call
>> 484 ret_from_sys_call:
>> 485 cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
>> 486 ldq $0, SP_OFF($sp)
>> 487 and $0, 8, $0
>> 488 beq $0, ret_to_kernel
>> 489 ret_to_user:
>> 490 /* Make sure need_resched and sigpending don't change between
>> 491 sampling and the rti. */
>> 492 lda $16, 7
>> 493 call_pal PAL_swpipl
>> 494 ldl $17, TI_FLAGS($8)
>> 495 and $17, _TIF_WORK_MASK, $2
>> 496 bne $2, work_pending
>> 497 restore_all:
>> 498 .cfi_remember_state
>> 499 RESTORE_ALL
>> 500 call_pal PAL_rti
>> 501
>> 502 ret_to_kernel:
>> 503 .cfi_restore_state
>> 504 lda $16, 7
>> 505 call_pal PAL_swpipl
>> 506 br restore_all
>> 507
>> 508 .align 3
>> 509 $syscall_error:
>> 510 /*
>> 511 * Some system calls (e.g., ptrace) can return arbitrary
>> 512 * values which might normally be mistaken as error numbers.
>> 513 * Those functions must zero $0 (v0) directly in the stack
>> 514 * frame to indicate that a negative return value wasn't an
>> 515 * error number..
>> 516 */
>> 517 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 518 beq $18, $ret_success
>> 519
>> 520 ldq $19, 72($sp) /* .. and this a3 */
>> 521 subq $31, $0, $0 /* with error in v0 */
>> 522 addq $31, 1, $1 /* set a3 for errno return */
>> 523 stq $0, 0($sp)
>> 524 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
>> 525 stq $1, 72($sp) /* a3 for return */
>> 526 br ret_from_sys_call
>> 527
>> 528 $ret_success:
>> 529 stq $0, 0($sp)
>> 530 stq $31, 72($sp) /* a3=0 => no error */
>> 531 br ret_from_sys_call
120 532
>> 533 /*
>> 534 * Do all cleanup when returning from all interrupts and system calls.
>> 535 *
>> 536 * Arguments:
>> 537 * $8: current.
>> 538 * $17: TI_FLAGS.
>> 539 * $18: The old syscall number, or zero if this is not a return
>> 540 * from a syscall that errored and is possibly restartable.
>> 541 * $19: The old a3 value
>> 542 */
>> 543
>> 544 .align 4
>> 545 .type work_pending, @function
121 work_pending: 546 work_pending:
122 andi t0, a2, _TIF_NEED_RESCHED # a2 !! 547 and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING, $2
123 beqz t0, work_notifysig !! 548 bne $2, $work_notifysig
124 work_resched: <<
125 TRACE_IRQS_OFF <<
126 jal schedule <<
127 <<
128 local_irq_disable # make <<
129 # sign <<
130 # samp <<
131 LONG_L a2, TI_FLAGS($28) <<
132 andi t0, a2, _TIF_WORK_MASK # is t <<
133 # othe <<
134 beqz t0, restore_all <<
135 andi t0, a2, _TIF_NEED_RESCHED <<
136 bnez t0, work_resched <<
137 <<
138 work_notifysig: # deal <<
139 # noti <<
140 move a0, sp <<
141 li a1, 0 <<
142 jal do_notify_resume # a2 a <<
143 j resume_userspace_check <<
144 <<
145 FEXPORT(syscall_exit_partial) <<
146 #ifdef CONFIG_DEBUG_RSEQ <<
147 move a0, sp <<
148 jal rseq_syscall <<
149 #endif <<
150 local_irq_disable # make <<
151 # chan <<
152 LONG_L a2, TI_FLAGS($28) # curr <<
153 li t0, _TIF_ALLWORK_MASK <<
154 and t0, a2 <<
155 beqz t0, restore_partial <<
156 SAVE_STATIC <<
157 syscall_exit_work: <<
158 LONG_L t0, PT_STATUS(sp) <<
159 andi t0, t0, KU_USER <<
160 beqz t0, resume_kernel <<
161 li t0, _TIF_WORK_SYSCALL_EXIT <<
162 and t0, a2 # a2 i <<
163 beqz t0, work_pending # trac <<
164 local_irq_enable # coul <<
165 # call <<
166 TRACE_IRQS_ON <<
167 move a0, sp <<
168 jal syscall_trace_leave <<
169 b resume_userspace <<
170 549
171 #if defined(CONFIG_CPU_MIPSR2) || defined(CONF !! 550 $work_resched:
172 defined(CONFIG_CPU_MIPSR6) || defined(CONF !! 551 /*
>> 552 * We can get here only if we returned from syscall without SIGPENDING
>> 553 * or got through work_notifysig already. Either case means no syscall
>> 554 * restarts for us, so let $18 and $19 burn.
>> 555 */
>> 556 jsr $26, schedule
>> 557 mov 0, $18
>> 558 br ret_to_user
>> 559
>> 560 $work_notifysig:
>> 561 mov $sp, $16
>> 562 DO_SWITCH_STACK
>> 563 jsr $26, do_work_pending
>> 564 UNDO_SWITCH_STACK
>> 565 br restore_all
173 566
174 /* 567 /*
175 * MIPS32R2 Instruction Hazard Barrier - must !! 568 * PTRACE syscall handler
176 * !! 569 */
177 * For C code use the inline version named ins !! 570
>> 571 .align 4
>> 572 .type strace, @function
>> 573 strace:
>> 574 /* set up signal stack, call syscall_trace */
>> 575 DO_SWITCH_STACK
>> 576 jsr $26, syscall_trace_enter /* returns the syscall number */
>> 577 UNDO_SWITCH_STACK
>> 578
>> 579 /* get the arguments back.. */
>> 580 ldq $16, SP_OFF+24($sp)
>> 581 ldq $17, SP_OFF+32($sp)
>> 582 ldq $18, SP_OFF+40($sp)
>> 583 ldq $19, 72($sp)
>> 584 ldq $20, 80($sp)
>> 585 ldq $21, 88($sp)
>> 586
>> 587 /* get the system call pointer.. */
>> 588 lda $1, NR_SYSCALLS($31)
>> 589 lda $2, sys_call_table
>> 590 lda $27, alpha_ni_syscall
>> 591 cmpult $0, $1, $1
>> 592 s8addq $0, $2, $2
>> 593 beq $1, 1f
>> 594 ldq $27, 0($2)
>> 595 1: jsr $26, ($27), sys_gettimeofday
>> 596 ret_from_straced:
>> 597 ldgp $gp, 0($26)
>> 598
>> 599 /* check return.. */
>> 600 blt $0, $strace_error /* the call failed */
>> 601 stq $31, 72($sp) /* a3=0 => no error */
>> 602 $strace_success:
>> 603 stq $0, 0($sp) /* save return value */
>> 604
>> 605 DO_SWITCH_STACK
>> 606 jsr $26, syscall_trace_leave
>> 607 UNDO_SWITCH_STACK
>> 608 br $31, ret_from_sys_call
>> 609
>> 610 .align 3
>> 611 $strace_error:
>> 612 ldq $18, 0($sp) /* old syscall nr (zero if success) */
>> 613 beq $18, $strace_success
>> 614 ldq $19, 72($sp) /* .. and this a3 */
>> 615
>> 616 subq $31, $0, $0 /* with error in v0 */
>> 617 addq $31, 1, $1 /* set a3 for errno return */
>> 618 stq $0, 0($sp)
>> 619 stq $1, 72($sp) /* a3 for return */
>> 620
>> 621 DO_SWITCH_STACK
>> 622 mov $18, $9 /* save old syscall number */
>> 623 mov $19, $10 /* save old a3 */
>> 624 jsr $26, syscall_trace_leave
>> 625 mov $9, $18
>> 626 mov $10, $19
>> 627 UNDO_SWITCH_STACK
>> 628
>> 629 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
>> 630 br ret_from_sys_call
>> 631 CFI_END_OSF_FRAME entSys
>> 632
>> 633 /*
>> 634 * Save and restore the switch stack -- aka the balance of the user context.
>> 635 */
>> 636
>> 637 .align 4
>> 638 .type do_switch_stack, @function
>> 639 .cfi_startproc simple
>> 640 .cfi_return_column 64
>> 641 .cfi_def_cfa $sp, 0
>> 642 .cfi_register 64, $1
>> 643 do_switch_stack:
>> 644 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 645 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 646 stq $9, 0($sp)
>> 647 stq $10, 8($sp)
>> 648 stq $11, 16($sp)
>> 649 stq $12, 24($sp)
>> 650 stq $13, 32($sp)
>> 651 stq $14, 40($sp)
>> 652 stq $15, 48($sp)
>> 653 stq $26, 56($sp)
>> 654 stt $f0, 64($sp)
>> 655 stt $f1, 72($sp)
>> 656 stt $f2, 80($sp)
>> 657 stt $f3, 88($sp)
>> 658 stt $f4, 96($sp)
>> 659 stt $f5, 104($sp)
>> 660 stt $f6, 112($sp)
>> 661 stt $f7, 120($sp)
>> 662 stt $f8, 128($sp)
>> 663 stt $f9, 136($sp)
>> 664 stt $f10, 144($sp)
>> 665 stt $f11, 152($sp)
>> 666 stt $f12, 160($sp)
>> 667 stt $f13, 168($sp)
>> 668 stt $f14, 176($sp)
>> 669 stt $f15, 184($sp)
>> 670 stt $f16, 192($sp)
>> 671 stt $f17, 200($sp)
>> 672 stt $f18, 208($sp)
>> 673 stt $f19, 216($sp)
>> 674 stt $f20, 224($sp)
>> 675 stt $f21, 232($sp)
>> 676 stt $f22, 240($sp)
>> 677 stt $f23, 248($sp)
>> 678 stt $f24, 256($sp)
>> 679 stt $f25, 264($sp)
>> 680 stt $f26, 272($sp)
>> 681 stt $f27, 280($sp)
>> 682 mf_fpcr $f0 # get fpcr
>> 683 stt $f28, 288($sp)
>> 684 stt $f29, 296($sp)
>> 685 stt $f30, 304($sp)
>> 686 stt $f0, 312($sp) # save fpcr in slot of $f31
>> 687 ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
>> 688 ret $31, ($1), 1
>> 689 .cfi_endproc
>> 690 .size do_switch_stack, .-do_switch_stack
>> 691
>> 692 .align 4
>> 693 .type undo_switch_stack, @function
>> 694 .cfi_startproc simple
>> 695 .cfi_def_cfa $sp, 0
>> 696 .cfi_register 64, $1
>> 697 undo_switch_stack:
>> 698 ldq $9, 0($sp)
>> 699 ldq $10, 8($sp)
>> 700 ldq $11, 16($sp)
>> 701 ldq $12, 24($sp)
>> 702 ldq $13, 32($sp)
>> 703 ldq $14, 40($sp)
>> 704 ldq $15, 48($sp)
>> 705 ldq $26, 56($sp)
>> 706 ldt $f30, 312($sp) # get saved fpcr
>> 707 ldt $f0, 64($sp)
>> 708 ldt $f1, 72($sp)
>> 709 ldt $f2, 80($sp)
>> 710 ldt $f3, 88($sp)
>> 711 mt_fpcr $f30 # install saved fpcr
>> 712 ldt $f4, 96($sp)
>> 713 ldt $f5, 104($sp)
>> 714 ldt $f6, 112($sp)
>> 715 ldt $f7, 120($sp)
>> 716 ldt $f8, 128($sp)
>> 717 ldt $f9, 136($sp)
>> 718 ldt $f10, 144($sp)
>> 719 ldt $f11, 152($sp)
>> 720 ldt $f12, 160($sp)
>> 721 ldt $f13, 168($sp)
>> 722 ldt $f14, 176($sp)
>> 723 ldt $f15, 184($sp)
>> 724 ldt $f16, 192($sp)
>> 725 ldt $f17, 200($sp)
>> 726 ldt $f18, 208($sp)
>> 727 ldt $f19, 216($sp)
>> 728 ldt $f20, 224($sp)
>> 729 ldt $f21, 232($sp)
>> 730 ldt $f22, 240($sp)
>> 731 ldt $f23, 248($sp)
>> 732 ldt $f24, 256($sp)
>> 733 ldt $f25, 264($sp)
>> 734 ldt $f26, 272($sp)
>> 735 ldt $f27, 280($sp)
>> 736 ldt $f28, 288($sp)
>> 737 ldt $f29, 296($sp)
>> 738 ldt $f30, 304($sp)
>> 739 lda $sp, SWITCH_STACK_SIZE($sp)
>> 740 ret $31, ($1), 1
>> 741 .cfi_endproc
>> 742 .size undo_switch_stack, .-undo_switch_stack
>> 743
>> 744 /*
>> 745 * The meat of the context switch code.
>> 746 */
>> 747
>> 748 .align 4
>> 749 .globl alpha_switch_to
>> 750 .type alpha_switch_to, @function
>> 751 .cfi_startproc
>> 752 alpha_switch_to:
>> 753 DO_SWITCH_STACK
>> 754 call_pal PAL_swpctx
>> 755 lda $8, 0x3fff
>> 756 UNDO_SWITCH_STACK
>> 757 bic $sp, $8, $8
>> 758 mov $17, $0
>> 759 ret
>> 760 .cfi_endproc
>> 761 .size alpha_switch_to, .-alpha_switch_to
>> 762
>> 763 /*
>> 764 * New processes begin life here.
>> 765 */
>> 766
>> 767 .globl ret_from_fork
>> 768 .align 4
>> 769 .ent ret_from_fork
>> 770 ret_from_fork:
>> 771 lda $26, ret_from_sys_call
>> 772 mov $17, $16
>> 773 jmp $31, schedule_tail
>> 774 .end ret_from_fork
>> 775
>> 776 /*
>> 777 * ... and new kernel threads - here
>> 778 */
>> 779 .align 4
>> 780 .globl ret_from_kernel_thread
>> 781 .ent ret_from_kernel_thread
>> 782 ret_from_kernel_thread:
>> 783 mov $17, $16
>> 784 jsr $26, schedule_tail
>> 785 mov $9, $27
>> 786 mov $10, $16
>> 787 jsr $26, ($9)
>> 788 br $31, ret_to_user
>> 789 .end ret_from_kernel_thread
>> 790
>> 791
>> 792 /*
>> 793 * Special system calls. Most of these are special in that they either
>> 794 * have to play switch_stack games or in some way use the pt_regs struct.
178 */ 795 */
179 LEAF(mips_ihb) <<
180 .set MIPS_ISA_LEVEL_RAW <<
181 jr.hb ra <<
182 nop <<
183 END(mips_ihb) <<
184 796
185 #endif /* CONFIG_CPU_MIPSR2 - CONFIG_CPU_MIPSR !! 797 .macro fork_like name
>> 798 .align 4
>> 799 .globl alpha_\name
>> 800 .ent alpha_\name
>> 801 alpha_\name:
>> 802 .prologue 0
>> 803 bsr $1, do_switch_stack
>> 804 jsr $26, sys_\name
>> 805 ldq $26, 56($sp)
>> 806 lda $sp, SWITCH_STACK_SIZE($sp)
>> 807 ret
>> 808 .end alpha_\name
>> 809 .endm
>> 810
>> 811 fork_like fork
>> 812 fork_like vfork
>> 813 fork_like clone
>> 814
>> 815 .align 4
>> 816 .globl sys_sigreturn
>> 817 .ent sys_sigreturn
>> 818 sys_sigreturn:
>> 819 .prologue 0
>> 820 lda $9, ret_from_straced
>> 821 cmpult $26, $9, $9
>> 822 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 823 jsr $26, do_sigreturn
>> 824 bne $9, 1f
>> 825 jsr $26, syscall_trace_leave
>> 826 1: br $1, undo_switch_stack
>> 827 br ret_from_sys_call
>> 828 .end sys_sigreturn
>> 829
>> 830 .align 4
>> 831 .globl sys_rt_sigreturn
>> 832 .ent sys_rt_sigreturn
>> 833 sys_rt_sigreturn:
>> 834 .prologue 0
>> 835 lda $9, ret_from_straced
>> 836 cmpult $26, $9, $9
>> 837 lda $sp, -SWITCH_STACK_SIZE($sp)
>> 838 jsr $26, do_rt_sigreturn
>> 839 bne $9, 1f
>> 840 jsr $26, syscall_trace_leave
>> 841 1: br $1, undo_switch_stack
>> 842 br ret_from_sys_call
>> 843 .end sys_rt_sigreturn
>> 844
>> 845 .align 4
>> 846 .globl alpha_ni_syscall
>> 847 .ent alpha_ni_syscall
>> 848 alpha_ni_syscall:
>> 849 .prologue 0
>> 850 /* Special because it also implements overflow handling via
>> 851 syscall number 0. And if you recall, zero is a special
>> 852 trigger for "not an error". Store large non-zero there. */
>> 853 lda $0, -ENOSYS
>> 854 unop
>> 855 stq $0, 0($sp)
>> 856 ret
>> 857 .end alpha_ni_syscall
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