1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * arch/alpha/kernel/entry.S
4 *
5 * Kernel entry-points.
6 */
7
8 #include <asm/asm-offsets.h>
9 #include <asm/thread_info.h>
10 #include <asm/pal.h>
11 #include <asm/errno.h>
12 #include <asm/unistd.h>
13
14 .text
15 .set noat
16 .cfi_sections .debug_frame
17
18 /* Stack offsets. */
19 #define SP_OFF 184
20 #define SWITCH_STACK_SIZE 64
21
22 .macro CFI_START_OSF_FRAME func
23 .align 4
24 .globl \func
25 .type \func,@function
26 \func:
27 .cfi_startproc simple
28 .cfi_return_column 64
29 .cfi_def_cfa $sp, 48
30 .cfi_rel_offset 64, 8
31 .cfi_rel_offset $gp, 16
32 .cfi_rel_offset $16, 24
33 .cfi_rel_offset $17, 32
34 .cfi_rel_offset $18, 40
35 .endm
36
37 .macro CFI_END_OSF_FRAME func
38 .cfi_endproc
39 .size \func, . - \func
40 .endm
41
42 /*
43 * This defines the normal kernel pt-regs layo
44 *
45 * regs 9-15 preserved by C code
46 * regs 16-18 saved by PAL-code
47 * regs 29-30 saved and set up by PAL-code
48 * JRP - Save regs 16-18 in a special area of
49 * the palcode-provided values are available t
50 */
51
52 .macro SAVE_ALL
53 subq $sp, SP_OFF, $sp
54 .cfi_adjust_cfa_offset SP_OFF
55 stq $0, 0($sp)
56 stq $1, 8($sp)
57 stq $2, 16($sp)
58 stq $3, 24($sp)
59 stq $4, 32($sp)
60 stq $28, 144($sp)
61 .cfi_rel_offset $0, 0
62 .cfi_rel_offset $1, 8
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_S
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 .endm
163
164 .macro UNDO_SWITCH_STACK
165 bsr $1, undo_switch_stack
166 .cfi_restore $9
167 .cfi_restore $10
168 .cfi_restore $11
169 .cfi_restore $12
170 .cfi_restore $13
171 .cfi_restore $14
172 .cfi_restore $15
173 .cfi_adjust_cfa_offset -SWITCH_STACK_
174 .endm
175
176 /*
177 * Non-syscall kernel entry points.
178 */
179
180 CFI_START_OSF_FRAME entInt
181 SAVE_ALL
182 lda $8, 0x3fff
183 lda $26, ret_from_sys_call
184 bic $sp, $8, $8
185 mov $sp, $19
186 jsr $31, do_entInt
187 CFI_END_OSF_FRAME entInt
188
189 CFI_START_OSF_FRAME entArith
190 SAVE_ALL
191 lda $8, 0x3fff
192 lda $26, ret_from_sys_call
193 bic $sp, $8, $8
194 mov $sp, $18
195 jsr $31, do_entArith
196 CFI_END_OSF_FRAME entArith
197
198 CFI_START_OSF_FRAME entMM
199 SAVE_ALL
200 /* save $9 - $15 so the inline exception code
201 subq $sp, 56, $sp
202 .cfi_adjust_cfa_offset 56
203 stq $9, 0($sp)
204 stq $10, 8($sp)
205 stq $11, 16($sp)
206 stq $12, 24($sp)
207 stq $13, 32($sp)
208 stq $14, 40($sp)
209 stq $15, 48($sp)
210 .cfi_rel_offset $9, 0
211 .cfi_rel_offset $10, 8
212 .cfi_rel_offset $11, 16
213 .cfi_rel_offset $12, 24
214 .cfi_rel_offset $13, 32
215 .cfi_rel_offset $14, 40
216 .cfi_rel_offset $15, 48
217 addq $sp, 56, $19
218 /* handle the fault */
219 lda $8, 0x3fff
220 bic $sp, $8, $8
221 jsr $26, do_page_fault
222 /* reload the registers after the exception co
223 ldq $9, 0($sp)
224 ldq $10, 8($sp)
225 ldq $11, 16($sp)
226 ldq $12, 24($sp)
227 ldq $13, 32($sp)
228 ldq $14, 40($sp)
229 ldq $15, 48($sp)
230 addq $sp, 56, $sp
231 .cfi_restore $9
232 .cfi_restore $10
233 .cfi_restore $11
234 .cfi_restore $12
235 .cfi_restore $13
236 .cfi_restore $14
237 .cfi_restore $15
238 .cfi_adjust_cfa_offset -56
239 /* finish up the syscall as normal. */
240 br ret_from_sys_call
241 CFI_END_OSF_FRAME entMM
242
243 CFI_START_OSF_FRAME entIF
244 SAVE_ALL
245 lda $8, 0x3fff
246 lda $26, ret_from_sys_call
247 bic $sp, $8, $8
248 mov $sp, $17
249 jsr $31, do_entIF
250 CFI_END_OSF_FRAME entIF
251
252 CFI_START_OSF_FRAME entUna
253 lda $sp, -256($sp)
254 .cfi_adjust_cfa_offset 256
255 stq $0, 0($sp)
256 .cfi_rel_offset $0, 0
257 .cfi_remember_state
258 ldq $0, 256($sp) /* get PS */
259 stq $1, 8($sp)
260 stq $2, 16($sp)
261 stq $3, 24($sp)
262 and $0, 8, $0 /* use
263 stq $4, 32($sp)
264 bne $0, entUnaUser /* yup -> do u
265 stq $5, 40($sp)
266 stq $6, 48($sp)
267 stq $7, 56($sp)
268 stq $8, 64($sp)
269 stq $9, 72($sp)
270 stq $10, 80($sp)
271 stq $11, 88($sp)
272 stq $12, 96($sp)
273 stq $13, 104($sp)
274 stq $14, 112($sp)
275 stq $15, 120($sp)
276 /* 16-18 PAL-saved */
277 stq $19, 152($sp)
278 stq $20, 160($sp)
279 stq $21, 168($sp)
280 stq $22, 176($sp)
281 stq $23, 184($sp)
282 stq $24, 192($sp)
283 stq $25, 200($sp)
284 stq $26, 208($sp)
285 stq $27, 216($sp)
286 stq $28, 224($sp)
287 mov $sp, $19
288 stq $gp, 232($sp)
289 .cfi_rel_offset $1, 1*8
290 .cfi_rel_offset $2, 2*8
291 .cfi_rel_offset $3, 3*8
292 .cfi_rel_offset $4, 4*8
293 .cfi_rel_offset $5, 5*8
294 .cfi_rel_offset $6, 6*8
295 .cfi_rel_offset $7, 7*8
296 .cfi_rel_offset $8, 8*8
297 .cfi_rel_offset $9, 9*8
298 .cfi_rel_offset $10, 10*8
299 .cfi_rel_offset $11, 11*8
300 .cfi_rel_offset $12, 12*8
301 .cfi_rel_offset $13, 13*8
302 .cfi_rel_offset $14, 14*8
303 .cfi_rel_offset $15, 15*8
304 .cfi_rel_offset $19, 19*8
305 .cfi_rel_offset $20, 20*8
306 .cfi_rel_offset $21, 21*8
307 .cfi_rel_offset $22, 22*8
308 .cfi_rel_offset $23, 23*8
309 .cfi_rel_offset $24, 24*8
310 .cfi_rel_offset $25, 25*8
311 .cfi_rel_offset $26, 26*8
312 .cfi_rel_offset $27, 27*8
313 .cfi_rel_offset $28, 28*8
314 .cfi_rel_offset $29, 29*8
315 lda $8, 0x3fff
316 stq $31, 248($sp)
317 bic $sp, $8, $8
318 jsr $26, do_entUna
319 ldq $0, 0($sp)
320 ldq $1, 8($sp)
321 ldq $2, 16($sp)
322 ldq $3, 24($sp)
323 ldq $4, 32($sp)
324 ldq $5, 40($sp)
325 ldq $6, 48($sp)
326 ldq $7, 56($sp)
327 ldq $8, 64($sp)
328 ldq $9, 72($sp)
329 ldq $10, 80($sp)
330 ldq $11, 88($sp)
331 ldq $12, 96($sp)
332 ldq $13, 104($sp)
333 ldq $14, 112($sp)
334 ldq $15, 120($sp)
335 /* 16-18 PAL-saved */
336 ldq $19, 152($sp)
337 ldq $20, 160($sp)
338 ldq $21, 168($sp)
339 ldq $22, 176($sp)
340 ldq $23, 184($sp)
341 ldq $24, 192($sp)
342 ldq $25, 200($sp)
343 ldq $26, 208($sp)
344 ldq $27, 216($sp)
345 ldq $28, 224($sp)
346 ldq $gp, 232($sp)
347 lda $sp, 256($sp)
348 .cfi_restore $1
349 .cfi_restore $2
350 .cfi_restore $3
351 .cfi_restore $4
352 .cfi_restore $5
353 .cfi_restore $6
354 .cfi_restore $7
355 .cfi_restore $8
356 .cfi_restore $9
357 .cfi_restore $10
358 .cfi_restore $11
359 .cfi_restore $12
360 .cfi_restore $13
361 .cfi_restore $14
362 .cfi_restore $15
363 .cfi_restore $19
364 .cfi_restore $20
365 .cfi_restore $21
366 .cfi_restore $22
367 .cfi_restore $23
368 .cfi_restore $24
369 .cfi_restore $25
370 .cfi_restore $26
371 .cfi_restore $27
372 .cfi_restore $28
373 .cfi_restore $29
374 .cfi_adjust_cfa_offset -256
375 call_pal PAL_rti
376
377 .align 4
378 entUnaUser:
379 .cfi_restore_state
380 ldq $0, 0($sp) /* restore ori
381 lda $sp, 256($sp) /* pop entUna'
382 .cfi_restore $0
383 .cfi_adjust_cfa_offset -256
384 SAVE_ALL /* setup norma
385 lda $sp, -56($sp)
386 .cfi_adjust_cfa_offset 56
387 stq $9, 0($sp)
388 stq $10, 8($sp)
389 stq $11, 16($sp)
390 stq $12, 24($sp)
391 stq $13, 32($sp)
392 stq $14, 40($sp)
393 stq $15, 48($sp)
394 .cfi_rel_offset $9, 0
395 .cfi_rel_offset $10, 8
396 .cfi_rel_offset $11, 16
397 .cfi_rel_offset $12, 24
398 .cfi_rel_offset $13, 32
399 .cfi_rel_offset $14, 40
400 .cfi_rel_offset $15, 48
401 lda $8, 0x3fff
402 addq $sp, 56, $19
403 bic $sp, $8, $8
404 jsr $26, do_entUnaUser
405 ldq $9, 0($sp)
406 ldq $10, 8($sp)
407 ldq $11, 16($sp)
408 ldq $12, 24($sp)
409 ldq $13, 32($sp)
410 ldq $14, 40($sp)
411 ldq $15, 48($sp)
412 lda $sp, 56($sp)
413 .cfi_restore $9
414 .cfi_restore $10
415 .cfi_restore $11
416 .cfi_restore $12
417 .cfi_restore $13
418 .cfi_restore $14
419 .cfi_restore $15
420 .cfi_adjust_cfa_offset -56
421 br ret_from_sys_call
422 CFI_END_OSF_FRAME entUna
423
424 CFI_START_OSF_FRAME entDbg
425 SAVE_ALL
426 lda $8, 0x3fff
427 lda $26, ret_from_sys_call
428 bic $sp, $8, $8
429 mov $sp, $16
430 jsr $31, do_entDbg
431 CFI_END_OSF_FRAME entDbg
432
433 /*
434 * The system call entry point is special. Mo
435 * like a function call to userspace as far as
436 * do preserve the argument registers (for sys
437 * (for leaf syscall functions).
438 *
439 * So much for theory. We don't take advantag
440 *
441 * Note that a0-a2 are not saved by PALcode as
442 */
443
444 .align 4
445 .globl entSys
446 .type entSys, @function
447 .cfi_startproc simple
448 .cfi_return_column 64
449 .cfi_def_cfa $sp, 48
450 .cfi_rel_offset 64, 8
451 .cfi_rel_offset $gp, 16
452 entSys:
453 SAVE_ALL
454 lda $8, 0x3fff
455 bic $sp, $8, $8
456 lda $4, NR_syscalls($31)
457 stq $16, SP_OFF+24($sp)
458 lda $5, sys_call_table
459 lda $27, sys_ni_syscall
460 cmpult $0, $4, $4
461 ldl $3, TI_FLAGS($8)
462 stq $17, SP_OFF+32($sp)
463 s8addq $0, $5, $5
464 stq $18, SP_OFF+40($sp)
465 .cfi_rel_offset $16, SP_OFF+24
466 .cfi_rel_offset $17, SP_OFF+32
467 .cfi_rel_offset $18, SP_OFF+40
468 #ifdef CONFIG_AUDITSYSCALL
469 lda $6, _TIF_SYSCALL_TRACE | _TIF_
470 and $3, $6, $3
471 bne $3, strace
472 #else
473 blbs $3, strace /* che
474 #endif
475 beq $4, 1f
476 ldq $27, 0($5)
477 1: jsr $26, ($27), sys_ni_syscall
478 ldgp $gp, 0($26)
479 blt $0, $syscall_error /* the
480 $ret_success:
481 stq $0, 0($sp)
482 stq $31, 72($sp) /* a3=
483
484 .align 4
485 .globl ret_from_sys_call
486 ret_from_sys_call:
487 cmovne $26, 0, $18 /* $18
488 ldq $0, SP_OFF($sp)
489 and $0, 8, $0
490 beq $0, ret_to_kernel
491 ret_to_user:
492 /* Make sure need_resched and sigpendi
493 sampling and the rti. */
494 lda $16, 7
495 call_pal PAL_swpipl
496 ldl $17, TI_FLAGS($8)
497 and $17, _TIF_WORK_MASK, $2
498 bne $2, work_pending
499 restore_all:
500 ldl $2, TI_STATUS($8)
501 and $2, TS_SAVED_FP | TS_RESTORE_F
502 bne $3, restore_fpu
503 restore_other:
504 .cfi_remember_state
505 RESTORE_ALL
506 call_pal PAL_rti
507
508 ret_to_kernel:
509 .cfi_restore_state
510 lda $16, 7
511 call_pal PAL_swpipl
512 br restore_other
513
514 .align 3
515 $syscall_error:
516 /*
517 * Some system calls (e.g., ptrace) ca
518 * values which might normally be mist
519 * Those functions must zero $0 (v0) d
520 * frame to indicate that a negative r
521 * error number..
522 */
523 ldq $18, 0($sp) /* old syscall
524 beq $18, $ret_success
525
526 ldq $19, 72($sp) /* .. and this
527 subq $31, $0, $0 /* with error
528 addq $31, 1, $1 /* set a3 for
529 stq $0, 0($sp)
530 mov $31, $26 /* tell "ret_f
531 stq $1, 72($sp) /* a3 for retu
532 br ret_from_sys_call
533
534 /*
535 * Do all cleanup when returning from all inte
536 *
537 * Arguments:
538 * $8: current.
539 * $17: TI_FLAGS.
540 * $18: The old syscall number, or zero i
541 * from a syscall that errored and i
542 * $19: The old a3 value
543 */
544
545 .align 4
546 .type work_pending, @function
547 work_pending:
548 and $17, _TIF_NOTIFY_RESUME | _TIF
549 bne $2, $work_notifysig
550
551 $work_resched:
552 /*
553 * We can get here only if we returned
554 * or got through work_notifysig alrea
555 * restarts for us, so let $18 and $19
556 */
557 jsr $26, schedule
558 mov 0, $18
559 br ret_to_user
560
561 $work_notifysig:
562 mov $sp, $16
563 DO_SWITCH_STACK
564 jsr $26, do_work_pending
565 UNDO_SWITCH_STACK
566 br restore_all
567
568 /*
569 * PTRACE syscall handler
570 */
571
572 .align 4
573 .type strace, @function
574 strace:
575 /* set up signal stack, call syscall_t
576 // NB: if anyone adds preemption, this
577 ldl $1, TI_STATUS($8)
578 and $1, TS_SAVED_FP, $3
579 or $1, TS_SAVED_FP, $2
580 bne $3, 1f
581 stl $2, TI_STATUS($8)
582 bsr $26, __save_fpu
583 1:
584 DO_SWITCH_STACK
585 jsr $26, syscall_trace_enter /* re
586 UNDO_SWITCH_STACK
587
588 /* get the arguments back.. */
589 ldq $16, SP_OFF+24($sp)
590 ldq $17, SP_OFF+32($sp)
591 ldq $18, SP_OFF+40($sp)
592 ldq $19, 72($sp)
593 ldq $20, 80($sp)
594 ldq $21, 88($sp)
595
596 /* get the system call pointer.. */
597 lda $1, NR_syscalls($31)
598 lda $2, sys_call_table
599 lda $27, sys_ni_syscall
600 cmpult $0, $1, $1
601 s8addq $0, $2, $2
602 beq $1, 1f
603 ldq $27, 0($2)
604 1: jsr $26, ($27), sys_gettimeofday
605 ret_from_straced:
606 ldgp $gp, 0($26)
607
608 /* check return.. */
609 blt $0, $strace_error /* the
610 $strace_success:
611 stq $31, 72($sp) /* a3=
612 stq $0, 0($sp) /* sav
613
614 DO_SWITCH_STACK
615 jsr $26, syscall_trace_leave
616 UNDO_SWITCH_STACK
617 br $31, ret_from_sys_call
618
619 .align 3
620 $strace_error:
621 ldq $18, 0($sp) /* old syscall
622 beq $18, $strace_success
623 ldq $19, 72($sp) /* .. and this
624
625 subq $31, $0, $0 /* with error
626 addq $31, 1, $1 /* set a3 for
627 stq $0, 0($sp)
628 stq $1, 72($sp) /* a3 for retu
629
630 DO_SWITCH_STACK
631 mov $18, $9 /* save old sy
632 mov $19, $10 /* save old a3
633 jsr $26, syscall_trace_leave
634 mov $9, $18
635 mov $10, $19
636 UNDO_SWITCH_STACK
637
638 mov $31, $26 /* tell "ret_f
639 br ret_from_sys_call
640 CFI_END_OSF_FRAME entSys
641
642 /*
643 * Save and restore the switch stack -- aka th
644 */
645
646 .align 4
647 .type do_switch_stack, @function
648 .cfi_startproc simple
649 .cfi_return_column 64
650 .cfi_def_cfa $sp, 0
651 .cfi_register 64, $1
652 do_switch_stack:
653 lda $sp, -SWITCH_STACK_SIZE($sp)
654 .cfi_adjust_cfa_offset SWITCH_STACK_S
655 stq $9, 0($sp)
656 stq $10, 8($sp)
657 stq $11, 16($sp)
658 stq $12, 24($sp)
659 stq $13, 32($sp)
660 stq $14, 40($sp)
661 stq $15, 48($sp)
662 stq $26, 56($sp)
663 ret $31, ($1), 1
664 .cfi_endproc
665 .size do_switch_stack, .-do_switch_s
666
667 .align 4
668 .type undo_switch_stack, @function
669 .cfi_startproc simple
670 .cfi_def_cfa $sp, 0
671 .cfi_register 64, $1
672 undo_switch_stack:
673 ldq $9, 0($sp)
674 ldq $10, 8($sp)
675 ldq $11, 16($sp)
676 ldq $12, 24($sp)
677 ldq $13, 32($sp)
678 ldq $14, 40($sp)
679 ldq $15, 48($sp)
680 ldq $26, 56($sp)
681 lda $sp, SWITCH_STACK_SIZE($sp)
682 ret $31, ($1), 1
683 .cfi_endproc
684 .size undo_switch_stack, .-undo_swit
685
686 #define FR(n) n * 8 + TI_FP($8)
687 .align 4
688 .globl __save_fpu
689 .type __save_fpu, @function
690 __save_fpu:
691 #define V(n) stt $f##n, FR(n)
692 V( 0); V( 1); V( 2); V( 3)
693 V( 4); V( 5); V( 6); V( 7)
694 V( 8); V( 9); V(10); V(11)
695 V(12); V(13); V(14); V(15)
696 V(16); V(17); V(18); V(19)
697 V(20); V(21); V(22); V(23)
698 V(24); V(25); V(26); V(27)
699 mf_fpcr $f0 # get fpcr
700 V(28); V(29); V(30)
701 stt $f0, FR(31) # save fpcr in
702 ldt $f0, FR(0) # don't let "_
703 ret
704 #undef V
705 .size __save_fpu, .-__save_fpu
706
707 .align 4
708 restore_fpu:
709 and $3, TS_RESTORE_FP, $3
710 bic $2, TS_SAVED_FP | TS_RESTORE_F
711 beq $3, 1f
712 #define V(n) ldt $f##n, FR(n)
713 ldt $f30, FR(31) # get saved fp
714 V( 0); V( 1); V( 2); V( 3)
715 mt_fpcr $f30 # install save
716 V( 4); V( 5); V( 6); V( 7)
717 V( 8); V( 9); V(10); V(11)
718 V(12); V(13); V(14); V(15)
719 V(16); V(17); V(18); V(19)
720 V(20); V(21); V(22); V(23)
721 V(24); V(25); V(26); V(27)
722 V(28); V(29); V(30)
723 1: stl $2, TI_STATUS($8)
724 br restore_other
725 #undef V
726
727
728 /*
729 * The meat of the context switch code.
730 */
731 .align 4
732 .globl alpha_switch_to
733 .type alpha_switch_to, @function
734 .cfi_startproc
735 alpha_switch_to:
736 DO_SWITCH_STACK
737 ldl $1, TI_STATUS($8)
738 and $1, TS_RESTORE_FP, $3
739 bne $3, 1f
740 or $1, TS_RESTORE_FP | TS_SAVED_F
741 and $1, TS_SAVED_FP, $3
742 stl $2, TI_STATUS($8)
743 bne $3, 1f
744 bsr $26, __save_fpu
745 1:
746 call_pal PAL_swpctx
747 lda $8, 0x3fff
748 UNDO_SWITCH_STACK
749 bic $sp, $8, $8
750 mov $17, $0
751 ret
752 .cfi_endproc
753 .size alpha_switch_to, .-alpha_switc
754
755 /*
756 * New processes begin life here.
757 */
758
759 .globl ret_from_fork
760 .align 4
761 .ent ret_from_fork
762 ret_from_fork:
763 lda $26, ret_to_user
764 mov $17, $16
765 jmp $31, schedule_tail
766 .end ret_from_fork
767
768 /*
769 * ... and new kernel threads - here
770 */
771 .align 4
772 .globl ret_from_kernel_thread
773 .ent ret_from_kernel_thread
774 ret_from_kernel_thread:
775 mov $17, $16
776 jsr $26, schedule_tail
777 mov $9, $27
778 mov $10, $16
779 jsr $26, ($9)
780 br $31, ret_to_user
781 .end ret_from_kernel_thread
782
783
784 /*
785 * Special system calls. Most of these are sp
786 * have to play switch_stack games.
787 */
788
789 .macro fork_like name
790 .align 4
791 .globl alpha_\name
792 .ent alpha_\name
793 alpha_\name:
794 .prologue 0
795 bsr $1, do_switch_stack
796 // NB: if anyone adds preemption, this
797 ldl $1, TI_STATUS($8)
798 and $1, TS_SAVED_FP, $3
799 or $1, TS_SAVED_FP, $2
800 bne $3, 1f
801 stl $2, TI_STATUS($8)
802 bsr $26, __save_fpu
803 1:
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 fork_like clone3
815
816 .macro sigreturn_like name
817 .align 4
818 .globl sys_\name
819 .ent sys_\name
820 sys_\name:
821 .prologue 0
822 lda $9, ret_from_straced
823 cmpult $26, $9, $9
824 lda $sp, -SWITCH_STACK_SIZE($sp)
825 jsr $26, do_\name
826 bne $9, 1f
827 jsr $26, syscall_trace_leave
828 1: br $1, undo_switch_stack
829 br ret_from_sys_call
830 .end sys_\name
831 .endm
832
833 sigreturn_like sigreturn
834 sigreturn_like rt_sigreturn
835
836 .align 4
837 .globl alpha_syscall_zero
838 .ent alpha_syscall_zero
839 alpha_syscall_zero:
840 .prologue 0
841 /* Special because it needs to do some
842 force_successful_syscall_return().
843 syscall number for that, zero meani
844 That works nicely, but for real sys
845 make sure that this logics doesn't
846 Store a non-zero there - -ENOSYS we
847 for our return value will do just f
848 */
849 lda $0, -ENOSYS
850 unop
851 stq $0, 0($sp)
852 ret
853 .end alpha_syscall_zero
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