ia64/linux-2.6.18-xen.hg

view arch/alpha/kernel/entry.S @ 897:329ea0ccb344

balloon: try harder to balloon up under memory pressure.

Currently if the balloon driver is unable to increase the guest's
reservation it assumes the failure was due to reaching its full
allocation, gives up on the ballooning operation and records the limit
it reached as the "hard limit". The driver will not try again until
the target is set again (even to the same value).

However it is possible that ballooning has in fact failed due to
memory pressure in the host and therefore it is desirable to keep
attempting to reach the target in case memory becomes available. The
most likely scenario is that some guests are ballooning down while
others are ballooning up and therefore there is temporary memory
pressure while things stabilise. You would not expect a well behaved
toolstack to ask a domain to balloon to more than its allocation nor
would you expect it to deliberately over-commit memory by setting
balloon targets which exceed the total host memory.

This patch drops the concept of a hard limit and causes the balloon
driver to retry increasing the reservation on a timer in the same
manner as when decreasing the reservation.

Also if we partially succeed in increasing the reservation
(i.e. receive less pages than we asked for) then we may as well keep
those pages rather than returning them to Xen.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
author Keir Fraser <keir.fraser@citrix.com>
date Fri Jun 05 14:01:20 2009 +0100 (2009-06-05)
parents 831230e53067
children
line source
1 /*
2 * arch/alpha/kernel/entry.S
3 *
4 * Kernel entry-points.
5 */
7 #include <asm/asm-offsets.h>
8 #include <asm/thread_info.h>
9 #include <asm/pal.h>
10 #include <asm/errno.h>
11 #include <asm/unistd.h>
13 .text
14 .set noat
16 /* Stack offsets. */
17 #define SP_OFF 184
18 #define SWITCH_STACK_SIZE 320
20 /*
21 * This defines the normal kernel pt-regs layout.
22 *
23 * regs 9-15 preserved by C code
24 * regs 16-18 saved by PAL-code
25 * regs 29-30 saved and set up by PAL-code
26 * JRP - Save regs 16-18 in a special area of the stack, so that
27 * the palcode-provided values are available to the signal handler.
28 */
30 #define SAVE_ALL \
31 subq $sp, SP_OFF, $sp; \
32 stq $0, 0($sp); \
33 stq $1, 8($sp); \
34 stq $2, 16($sp); \
35 stq $3, 24($sp); \
36 stq $4, 32($sp); \
37 stq $28, 144($sp); \
38 lda $2, alpha_mv; \
39 stq $5, 40($sp); \
40 stq $6, 48($sp); \
41 stq $7, 56($sp); \
42 stq $8, 64($sp); \
43 stq $19, 72($sp); \
44 stq $20, 80($sp); \
45 stq $21, 88($sp); \
46 ldq $2, HAE_CACHE($2); \
47 stq $22, 96($sp); \
48 stq $23, 104($sp); \
49 stq $24, 112($sp); \
50 stq $25, 120($sp); \
51 stq $26, 128($sp); \
52 stq $27, 136($sp); \
53 stq $2, 152($sp); \
54 stq $16, 160($sp); \
55 stq $17, 168($sp); \
56 stq $18, 176($sp)
58 #define RESTORE_ALL \
59 lda $19, alpha_mv; \
60 ldq $0, 0($sp); \
61 ldq $1, 8($sp); \
62 ldq $2, 16($sp); \
63 ldq $3, 24($sp); \
64 ldq $21, 152($sp); \
65 ldq $20, HAE_CACHE($19); \
66 ldq $4, 32($sp); \
67 ldq $5, 40($sp); \
68 ldq $6, 48($sp); \
69 ldq $7, 56($sp); \
70 subq $20, $21, $20; \
71 ldq $8, 64($sp); \
72 beq $20, 99f; \
73 ldq $20, HAE_REG($19); \
74 stq $21, HAE_CACHE($19); \
75 stq $21, 0($20); \
76 ldq $0, 0($sp); \
77 ldq $1, 8($sp); \
78 99:; \
79 ldq $19, 72($sp); \
80 ldq $20, 80($sp); \
81 ldq $21, 88($sp); \
82 ldq $22, 96($sp); \
83 ldq $23, 104($sp); \
84 ldq $24, 112($sp); \
85 ldq $25, 120($sp); \
86 ldq $26, 128($sp); \
87 ldq $27, 136($sp); \
88 ldq $28, 144($sp); \
89 addq $sp, SP_OFF, $sp
91 /*
92 * Non-syscall kernel entry points.
93 */
95 .align 4
96 .globl entInt
97 .ent entInt
98 entInt:
99 SAVE_ALL
100 lda $8, 0x3fff
101 lda $26, ret_from_sys_call
102 bic $sp, $8, $8
103 mov $sp, $19
104 jsr $31, do_entInt
105 .end entInt
107 .align 4
108 .globl entArith
109 .ent entArith
110 entArith:
111 SAVE_ALL
112 lda $8, 0x3fff
113 lda $26, ret_from_sys_call
114 bic $sp, $8, $8
115 mov $sp, $18
116 jsr $31, do_entArith
117 .end entArith
119 .align 4
120 .globl entMM
121 .ent entMM
122 entMM:
123 SAVE_ALL
124 /* save $9 - $15 so the inline exception code can manipulate them. */
125 subq $sp, 56, $sp
126 stq $9, 0($sp)
127 stq $10, 8($sp)
128 stq $11, 16($sp)
129 stq $12, 24($sp)
130 stq $13, 32($sp)
131 stq $14, 40($sp)
132 stq $15, 48($sp)
133 addq $sp, 56, $19
134 /* handle the fault */
135 lda $8, 0x3fff
136 bic $sp, $8, $8
137 jsr $26, do_page_fault
138 /* reload the registers after the exception code played. */
139 ldq $9, 0($sp)
140 ldq $10, 8($sp)
141 ldq $11, 16($sp)
142 ldq $12, 24($sp)
143 ldq $13, 32($sp)
144 ldq $14, 40($sp)
145 ldq $15, 48($sp)
146 addq $sp, 56, $sp
147 /* finish up the syscall as normal. */
148 br ret_from_sys_call
149 .end entMM
151 .align 4
152 .globl entIF
153 .ent entIF
154 entIF:
155 SAVE_ALL
156 lda $8, 0x3fff
157 lda $26, ret_from_sys_call
158 bic $sp, $8, $8
159 mov $sp, $17
160 jsr $31, do_entIF
161 .end entIF
163 .align 4
164 .globl entUna
165 .ent entUna
166 entUna:
167 lda $sp, -256($sp)
168 stq $0, 0($sp)
169 ldq $0, 256($sp) /* get PS */
170 stq $1, 8($sp)
171 stq $2, 16($sp)
172 stq $3, 24($sp)
173 and $0, 8, $0 /* user mode? */
174 stq $4, 32($sp)
175 bne $0, entUnaUser /* yup -> do user-level unaligned fault */
176 stq $5, 40($sp)
177 stq $6, 48($sp)
178 stq $7, 56($sp)
179 stq $8, 64($sp)
180 stq $9, 72($sp)
181 stq $10, 80($sp)
182 stq $11, 88($sp)
183 stq $12, 96($sp)
184 stq $13, 104($sp)
185 stq $14, 112($sp)
186 stq $15, 120($sp)
187 /* 16-18 PAL-saved */
188 stq $19, 152($sp)
189 stq $20, 160($sp)
190 stq $21, 168($sp)
191 stq $22, 176($sp)
192 stq $23, 184($sp)
193 stq $24, 192($sp)
194 stq $25, 200($sp)
195 stq $26, 208($sp)
196 stq $27, 216($sp)
197 stq $28, 224($sp)
198 mov $sp, $19
199 stq $gp, 232($sp)
200 lda $8, 0x3fff
201 stq $31, 248($sp)
202 bic $sp, $8, $8
203 jsr $26, do_entUna
204 ldq $0, 0($sp)
205 ldq $1, 8($sp)
206 ldq $2, 16($sp)
207 ldq $3, 24($sp)
208 ldq $4, 32($sp)
209 ldq $5, 40($sp)
210 ldq $6, 48($sp)
211 ldq $7, 56($sp)
212 ldq $8, 64($sp)
213 ldq $9, 72($sp)
214 ldq $10, 80($sp)
215 ldq $11, 88($sp)
216 ldq $12, 96($sp)
217 ldq $13, 104($sp)
218 ldq $14, 112($sp)
219 ldq $15, 120($sp)
220 /* 16-18 PAL-saved */
221 ldq $19, 152($sp)
222 ldq $20, 160($sp)
223 ldq $21, 168($sp)
224 ldq $22, 176($sp)
225 ldq $23, 184($sp)
226 ldq $24, 192($sp)
227 ldq $25, 200($sp)
228 ldq $26, 208($sp)
229 ldq $27, 216($sp)
230 ldq $28, 224($sp)
231 ldq $gp, 232($sp)
232 lda $sp, 256($sp)
233 call_pal PAL_rti
234 .end entUna
236 .align 4
237 .ent entUnaUser
238 entUnaUser:
239 ldq $0, 0($sp) /* restore original $0 */
240 lda $sp, 256($sp) /* pop entUna's stack frame */
241 SAVE_ALL /* setup normal kernel stack */
242 lda $sp, -56($sp)
243 stq $9, 0($sp)
244 stq $10, 8($sp)
245 stq $11, 16($sp)
246 stq $12, 24($sp)
247 stq $13, 32($sp)
248 stq $14, 40($sp)
249 stq $15, 48($sp)
250 lda $8, 0x3fff
251 addq $sp, 56, $19
252 bic $sp, $8, $8
253 jsr $26, do_entUnaUser
254 ldq $9, 0($sp)
255 ldq $10, 8($sp)
256 ldq $11, 16($sp)
257 ldq $12, 24($sp)
258 ldq $13, 32($sp)
259 ldq $14, 40($sp)
260 ldq $15, 48($sp)
261 lda $sp, 56($sp)
262 br ret_from_sys_call
263 .end entUnaUser
265 .align 4
266 .globl entDbg
267 .ent entDbg
268 entDbg:
269 SAVE_ALL
270 lda $8, 0x3fff
271 lda $26, ret_from_sys_call
272 bic $sp, $8, $8
273 mov $sp, $16
274 jsr $31, do_entDbg
275 .end entDbg
277 /*
278 * The system call entry point is special. Most importantly, it looks
279 * like a function call to userspace as far as clobbered registers. We
280 * do preserve the argument registers (for syscall restarts) and $26
281 * (for leaf syscall functions).
282 *
283 * So much for theory. We don't take advantage of this yet.
284 *
285 * Note that a0-a2 are not saved by PALcode as with the other entry points.
286 */
288 .align 4
289 .globl entSys
290 .globl ret_from_sys_call
291 .ent entSys
292 entSys:
293 SAVE_ALL
294 lda $8, 0x3fff
295 bic $sp, $8, $8
296 lda $4, NR_SYSCALLS($31)
297 stq $16, SP_OFF+24($sp)
298 lda $5, sys_call_table
299 lda $27, sys_ni_syscall
300 cmpult $0, $4, $4
301 ldl $3, TI_FLAGS($8)
302 stq $17, SP_OFF+32($sp)
303 s8addq $0, $5, $5
304 stq $18, SP_OFF+40($sp)
305 blbs $3, strace
306 beq $4, 1f
307 ldq $27, 0($5)
308 1: jsr $26, ($27), alpha_ni_syscall
309 ldgp $gp, 0($26)
310 blt $0, $syscall_error /* the call failed */
311 stq $0, 0($sp)
312 stq $31, 72($sp) /* a3=0 => no error */
314 .align 4
315 ret_from_sys_call:
316 cmovne $26, 0, $19 /* $19 = 0 => non-restartable */
317 ldq $0, SP_OFF($sp)
318 and $0, 8, $0
319 beq $0, restore_all
320 ret_from_reschedule:
321 /* Make sure need_resched and sigpending don't change between
322 sampling and the rti. */
323 lda $16, 7
324 call_pal PAL_swpipl
325 ldl $5, TI_FLAGS($8)
326 and $5, _TIF_WORK_MASK, $2
327 bne $5, work_pending
328 restore_all:
329 RESTORE_ALL
330 call_pal PAL_rti
332 .align 3
333 $syscall_error:
334 /*
335 * Some system calls (e.g., ptrace) can return arbitrary
336 * values which might normally be mistaken as error numbers.
337 * Those functions must zero $0 (v0) directly in the stack
338 * frame to indicate that a negative return value wasn't an
339 * error number..
340 */
341 ldq $19, 0($sp) /* old syscall nr (zero if success) */
342 beq $19, $ret_success
344 ldq $20, 72($sp) /* .. and this a3 */
345 subq $31, $0, $0 /* with error in v0 */
346 addq $31, 1, $1 /* set a3 for errno return */
347 stq $0, 0($sp)
348 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
349 stq $1, 72($sp) /* a3 for return */
350 br ret_from_sys_call
352 $ret_success:
353 stq $0, 0($sp)
354 stq $31, 72($sp) /* a3=0 => no error */
355 br ret_from_sys_call
356 .end entSys
358 /*
359 * Do all cleanup when returning from all interrupts and system calls.
360 *
361 * Arguments:
362 * $5: TI_FLAGS.
363 * $8: current.
364 * $19: The old syscall number, or zero if this is not a return
365 * from a syscall that errored and is possibly restartable.
366 * $20: Error indication.
367 */
369 .align 4
370 .ent work_pending
371 work_pending:
372 and $5, _TIF_NEED_RESCHED, $2
373 beq $2, $work_notifysig
375 $work_resched:
376 subq $sp, 16, $sp
377 stq $19, 0($sp) /* save syscall nr */
378 stq $20, 8($sp) /* and error indication (a3) */
379 jsr $26, schedule
380 ldq $19, 0($sp)
381 ldq $20, 8($sp)
382 addq $sp, 16, $sp
383 /* Make sure need_resched and sigpending don't change between
384 sampling and the rti. */
385 lda $16, 7
386 call_pal PAL_swpipl
387 ldl $5, TI_FLAGS($8)
388 and $5, _TIF_WORK_MASK, $2
389 beq $2, restore_all
390 and $5, _TIF_NEED_RESCHED, $2
391 bne $2, $work_resched
393 $work_notifysig:
394 mov $sp, $17
395 br $1, do_switch_stack
396 mov $5, $21
397 mov $sp, $18
398 mov $31, $16
399 jsr $26, do_notify_resume
400 bsr $1, undo_switch_stack
401 br restore_all
402 .end work_pending
404 /*
405 * PTRACE syscall handler
406 */
408 .align 4
409 .ent strace
410 strace:
411 /* set up signal stack, call syscall_trace */
412 bsr $1, do_switch_stack
413 jsr $26, syscall_trace
414 bsr $1, undo_switch_stack
416 /* get the system call number and the arguments back.. */
417 ldq $0, 0($sp)
418 ldq $16, SP_OFF+24($sp)
419 ldq $17, SP_OFF+32($sp)
420 ldq $18, SP_OFF+40($sp)
421 ldq $19, 72($sp)
422 ldq $20, 80($sp)
423 ldq $21, 88($sp)
425 /* get the system call pointer.. */
426 lda $1, NR_SYSCALLS($31)
427 lda $2, sys_call_table
428 lda $27, alpha_ni_syscall
429 cmpult $0, $1, $1
430 s8addq $0, $2, $2
431 beq $1, 1f
432 ldq $27, 0($2)
433 1: jsr $26, ($27), sys_gettimeofday
434 ldgp $gp, 0($26)
436 /* check return.. */
437 blt $0, $strace_error /* the call failed */
438 stq $31, 72($sp) /* a3=0 => no error */
439 $strace_success:
440 stq $0, 0($sp) /* save return value */
442 bsr $1, do_switch_stack
443 jsr $26, syscall_trace
444 bsr $1, undo_switch_stack
445 br $31, ret_from_sys_call
447 .align 3
448 $strace_error:
449 ldq $19, 0($sp) /* old syscall nr (zero if success) */
450 beq $19, $strace_success
451 ldq $20, 72($sp) /* .. and this a3 */
453 subq $31, $0, $0 /* with error in v0 */
454 addq $31, 1, $1 /* set a3 for errno return */
455 stq $0, 0($sp)
456 stq $1, 72($sp) /* a3 for return */
458 bsr $1, do_switch_stack
459 mov $19, $9 /* save old syscall number */
460 mov $20, $10 /* save old a3 */
461 jsr $26, syscall_trace
462 mov $9, $19
463 mov $10, $20
464 bsr $1, undo_switch_stack
466 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
467 br ret_from_sys_call
468 .end strace
470 /*
471 * Save and restore the switch stack -- aka the balance of the user context.
472 */
474 .align 4
475 .ent do_switch_stack
476 do_switch_stack:
477 lda $sp, -SWITCH_STACK_SIZE($sp)
478 stq $9, 0($sp)
479 stq $10, 8($sp)
480 stq $11, 16($sp)
481 stq $12, 24($sp)
482 stq $13, 32($sp)
483 stq $14, 40($sp)
484 stq $15, 48($sp)
485 stq $26, 56($sp)
486 stt $f0, 64($sp)
487 stt $f1, 72($sp)
488 stt $f2, 80($sp)
489 stt $f3, 88($sp)
490 stt $f4, 96($sp)
491 stt $f5, 104($sp)
492 stt $f6, 112($sp)
493 stt $f7, 120($sp)
494 stt $f8, 128($sp)
495 stt $f9, 136($sp)
496 stt $f10, 144($sp)
497 stt $f11, 152($sp)
498 stt $f12, 160($sp)
499 stt $f13, 168($sp)
500 stt $f14, 176($sp)
501 stt $f15, 184($sp)
502 stt $f16, 192($sp)
503 stt $f17, 200($sp)
504 stt $f18, 208($sp)
505 stt $f19, 216($sp)
506 stt $f20, 224($sp)
507 stt $f21, 232($sp)
508 stt $f22, 240($sp)
509 stt $f23, 248($sp)
510 stt $f24, 256($sp)
511 stt $f25, 264($sp)
512 stt $f26, 272($sp)
513 stt $f27, 280($sp)
514 mf_fpcr $f0 # get fpcr
515 stt $f28, 288($sp)
516 stt $f29, 296($sp)
517 stt $f30, 304($sp)
518 stt $f0, 312($sp) # save fpcr in slot of $f31
519 ldt $f0, 64($sp) # dont let "do_switch_stack" change fp state.
520 ret $31, ($1), 1
521 .end do_switch_stack
523 .align 4
524 .ent undo_switch_stack
525 undo_switch_stack:
526 ldq $9, 0($sp)
527 ldq $10, 8($sp)
528 ldq $11, 16($sp)
529 ldq $12, 24($sp)
530 ldq $13, 32($sp)
531 ldq $14, 40($sp)
532 ldq $15, 48($sp)
533 ldq $26, 56($sp)
534 ldt $f30, 312($sp) # get saved fpcr
535 ldt $f0, 64($sp)
536 ldt $f1, 72($sp)
537 ldt $f2, 80($sp)
538 ldt $f3, 88($sp)
539 mt_fpcr $f30 # install saved fpcr
540 ldt $f4, 96($sp)
541 ldt $f5, 104($sp)
542 ldt $f6, 112($sp)
543 ldt $f7, 120($sp)
544 ldt $f8, 128($sp)
545 ldt $f9, 136($sp)
546 ldt $f10, 144($sp)
547 ldt $f11, 152($sp)
548 ldt $f12, 160($sp)
549 ldt $f13, 168($sp)
550 ldt $f14, 176($sp)
551 ldt $f15, 184($sp)
552 ldt $f16, 192($sp)
553 ldt $f17, 200($sp)
554 ldt $f18, 208($sp)
555 ldt $f19, 216($sp)
556 ldt $f20, 224($sp)
557 ldt $f21, 232($sp)
558 ldt $f22, 240($sp)
559 ldt $f23, 248($sp)
560 ldt $f24, 256($sp)
561 ldt $f25, 264($sp)
562 ldt $f26, 272($sp)
563 ldt $f27, 280($sp)
564 ldt $f28, 288($sp)
565 ldt $f29, 296($sp)
566 ldt $f30, 304($sp)
567 lda $sp, SWITCH_STACK_SIZE($sp)
568 ret $31, ($1), 1
569 .end undo_switch_stack
571 /*
572 * The meat of the context switch code.
573 */
575 .align 4
576 .globl alpha_switch_to
577 .ent alpha_switch_to
578 alpha_switch_to:
579 .prologue 0
580 bsr $1, do_switch_stack
581 call_pal PAL_swpctx
582 lda $8, 0x3fff
583 bsr $1, undo_switch_stack
584 bic $sp, $8, $8
585 mov $17, $0
586 ret
587 .end alpha_switch_to
589 /*
590 * New processes begin life here.
591 */
593 .globl ret_from_fork
594 .align 4
595 .ent ret_from_fork
596 ret_from_fork:
597 lda $26, ret_from_sys_call
598 mov $17, $16
599 jmp $31, schedule_tail
600 .end ret_from_fork
602 /*
603 * kernel_thread(fn, arg, clone_flags)
604 */
605 .align 4
606 .globl kernel_thread
607 .ent kernel_thread
608 kernel_thread:
609 /* We can be called from a module. */
610 ldgp $gp, 0($27)
611 .prologue 1
612 subq $sp, SP_OFF+6*8, $sp
613 br $1, 2f /* load start address */
615 /* We've now "returned" from a fake system call. */
616 unop
617 blt $0, 1f /* error? */
618 ldi $1, 0x3fff
619 beq $20, 1f /* parent or child? */
621 bic $sp, $1, $8 /* in child. */
622 jsr $26, ($27)
623 ldgp $gp, 0($26)
624 mov $0, $16
625 mov $31, $26
626 jmp $31, sys_exit
628 1: ret /* in parent. */
630 .align 4
631 2: /* Fake a system call stack frame, as we can't do system calls
632 from kernel space. Note that we store FN and ARG as they
633 need to be set up in the child for the call. Also store $8
634 and $26 for use in the parent. */
635 stq $31, SP_OFF($sp) /* ps */
636 stq $1, SP_OFF+8($sp) /* pc */
637 stq $gp, SP_OFF+16($sp) /* gp */
638 stq $16, 136($sp) /* $27; FN for child */
639 stq $17, SP_OFF+24($sp) /* $16; ARG for child */
640 stq $8, 64($sp) /* $8 */
641 stq $26, 128($sp) /* $26 */
642 /* Avoid the HAE being gratuitously wrong, to avoid restoring it. */
643 ldq $2, alpha_mv+HAE_CACHE
644 stq $2, 152($sp) /* HAE */
646 /* Shuffle FLAGS to the front; add CLONE_VM. */
647 ldi $1, CLONE_VM|CLONE_UNTRACED
648 or $18, $1, $16
649 bsr $26, sys_clone
651 /* We don't actually care for a3 success widgetry in the kernel.
652 Not for positive errno values. */
653 stq $0, 0($sp) /* $0 */
654 br restore_all
655 .end kernel_thread
657 /*
658 * execve(path, argv, envp)
659 */
660 .align 4
661 .globl execve
662 .ent execve
663 execve:
664 /* We can be called from a module. */
665 ldgp $gp, 0($27)
666 lda $sp, -(32+SIZEOF_PT_REGS+8)($sp)
667 .frame $sp, 32+SIZEOF_PT_REGS+8, $26, 0
668 stq $26, 0($sp)
669 stq $16, 8($sp)
670 stq $17, 16($sp)
671 stq $18, 24($sp)
672 .prologue 1
674 lda $16, 32($sp)
675 lda $17, 0
676 lda $18, SIZEOF_PT_REGS
677 bsr $26, memset !samegp
679 /* Avoid the HAE being gratuitously wrong, which would cause us
680 to do the whole turn off interrupts thing and restore it. */
681 ldq $2, alpha_mv+HAE_CACHE
682 stq $2, 152+32($sp)
684 ldq $16, 8($sp)
685 ldq $17, 16($sp)
686 ldq $18, 24($sp)
687 lda $19, 32($sp)
688 bsr $26, do_execve !samegp
690 ldq $26, 0($sp)
691 bne $0, 1f /* error! */
693 /* Move the temporary pt_regs struct from its current location
694 to the top of the kernel stack frame. See copy_thread for
695 details for a normal process. */
696 lda $16, 0x4000 - SIZEOF_PT_REGS($8)
697 lda $17, 32($sp)
698 lda $18, SIZEOF_PT_REGS
699 bsr $26, memmove !samegp
701 /* Take that over as our new stack frame and visit userland! */
702 lda $sp, 0x4000 - SIZEOF_PT_REGS($8)
703 br $31, ret_from_sys_call
705 1: lda $sp, 32+SIZEOF_PT_REGS+8($sp)
706 ret
707 .end execve
710 /*
711 * Special system calls. Most of these are special in that they either
712 * have to play switch_stack games or in some way use the pt_regs struct.
713 */
714 .align 4
715 .globl sys_fork
716 .ent sys_fork
717 sys_fork:
718 .prologue 0
719 mov $sp, $21
720 bsr $1, do_switch_stack
721 bis $31, SIGCHLD, $16
722 mov $31, $17
723 mov $31, $18
724 mov $31, $19
725 mov $31, $20
726 jsr $26, alpha_clone
727 bsr $1, undo_switch_stack
728 ret
729 .end sys_fork
731 .align 4
732 .globl sys_clone
733 .ent sys_clone
734 sys_clone:
735 .prologue 0
736 mov $sp, $21
737 bsr $1, do_switch_stack
738 /* $16, $17, $18, $19, $20 come from the user. */
739 jsr $26, alpha_clone
740 bsr $1, undo_switch_stack
741 ret
742 .end sys_clone
744 .align 4
745 .globl sys_vfork
746 .ent sys_vfork
747 sys_vfork:
748 .prologue 0
749 mov $sp, $16
750 bsr $1, do_switch_stack
751 jsr $26, alpha_vfork
752 bsr $1, undo_switch_stack
753 ret
754 .end sys_vfork
756 .align 4
757 .globl sys_sigreturn
758 .ent sys_sigreturn
759 sys_sigreturn:
760 .prologue 0
761 mov $sp, $17
762 lda $18, -SWITCH_STACK_SIZE($sp)
763 lda $sp, -SWITCH_STACK_SIZE($sp)
764 jsr $26, do_sigreturn
765 br $1, undo_switch_stack
766 br ret_from_sys_call
767 .end sys_sigreturn
769 .align 4
770 .globl sys_rt_sigreturn
771 .ent sys_rt_sigreturn
772 sys_rt_sigreturn:
773 .prologue 0
774 mov $sp, $17
775 lda $18, -SWITCH_STACK_SIZE($sp)
776 lda $sp, -SWITCH_STACK_SIZE($sp)
777 jsr $26, do_rt_sigreturn
778 br $1, undo_switch_stack
779 br ret_from_sys_call
780 .end sys_rt_sigreturn
782 .align 4
783 .globl sys_sigsuspend
784 .ent sys_sigsuspend
785 sys_sigsuspend:
786 .prologue 0
787 mov $sp, $17
788 br $1, do_switch_stack
789 mov $sp, $18
790 subq $sp, 16, $sp
791 stq $26, 0($sp)
792 jsr $26, do_sigsuspend
793 ldq $26, 0($sp)
794 lda $sp, SWITCH_STACK_SIZE+16($sp)
795 ret
796 .end sys_sigsuspend
798 .align 4
799 .globl sys_rt_sigsuspend
800 .ent sys_rt_sigsuspend
801 sys_rt_sigsuspend:
802 .prologue 0
803 mov $sp, $18
804 br $1, do_switch_stack
805 mov $sp, $19
806 subq $sp, 16, $sp
807 stq $26, 0($sp)
808 jsr $26, do_rt_sigsuspend
809 ldq $26, 0($sp)
810 lda $sp, SWITCH_STACK_SIZE+16($sp)
811 ret
812 .end sys_rt_sigsuspend
814 .align 4
815 .globl sys_sethae
816 .ent sys_sethae
817 sys_sethae:
818 .prologue 0
819 stq $16, 152($sp)
820 ret
821 .end sys_sethae
823 .align 4
824 .globl osf_getpriority
825 .ent osf_getpriority
826 osf_getpriority:
827 lda $sp, -16($sp)
828 stq $26, 0($sp)
829 .prologue 0
831 jsr $26, sys_getpriority
833 ldq $26, 0($sp)
834 blt $0, 1f
836 /* Return value is the unbiased priority, i.e. 20 - prio.
837 This does result in negative return values, so signal
838 no error by writing into the R0 slot. */
839 lda $1, 20
840 stq $31, 16($sp)
841 subl $1, $0, $0
842 unop
844 1: lda $sp, 16($sp)
845 ret
846 .end osf_getpriority
848 .align 4
849 .globl sys_getxuid
850 .ent sys_getxuid
851 sys_getxuid:
852 .prologue 0
853 ldq $2, TI_TASK($8)
854 ldl $0, TASK_UID($2)
855 ldl $1, TASK_EUID($2)
856 stq $1, 80($sp)
857 ret
858 .end sys_getxuid
860 .align 4
861 .globl sys_getxgid
862 .ent sys_getxgid
863 sys_getxgid:
864 .prologue 0
865 ldq $2, TI_TASK($8)
866 ldl $0, TASK_GID($2)
867 ldl $1, TASK_EGID($2)
868 stq $1, 80($sp)
869 ret
870 .end sys_getxgid
872 .align 4
873 .globl sys_getxpid
874 .ent sys_getxpid
875 sys_getxpid:
876 .prologue 0
877 ldq $2, TI_TASK($8)
879 /* See linux/kernel/timer.c sys_getppid for discussion
880 about this loop. */
881 ldq $3, TASK_GROUP_LEADER($2)
882 ldq $4, TASK_REAL_PARENT($3)
883 ldl $0, TASK_TGID($2)
884 1: ldl $1, TASK_TGID($4)
885 #ifdef CONFIG_SMP
886 mov $4, $5
887 mb
888 ldq $3, TASK_GROUP_LEADER($2)
889 ldq $4, TASK_REAL_PARENT($3)
890 cmpeq $4, $5, $5
891 beq $5, 1b
892 #endif
893 stq $1, 80($sp)
894 ret
895 .end sys_getxpid
897 .align 4
898 .globl sys_pipe
899 .ent sys_pipe
900 sys_pipe:
901 lda $sp, -16($sp)
902 stq $26, 0($sp)
903 .prologue 0
905 lda $16, 8($sp)
906 jsr $26, do_pipe
908 ldq $26, 0($sp)
909 bne $0, 1f
911 /* The return values are in $0 and $20. */
912 ldl $1, 12($sp)
913 ldl $0, 8($sp)
915 stq $1, 80+16($sp)
916 1: lda $sp, 16($sp)
917 ret
918 .end sys_pipe
920 .align 4
921 .globl sys_ptrace
922 .ent sys_ptrace
923 sys_ptrace:
924 .prologue 0
925 mov $sp, $20
926 jmp $31, do_sys_ptrace
927 .end sys_ptrace
929 .align 4
930 .globl sys_execve
931 .ent sys_execve
932 sys_execve:
933 .prologue 0
934 mov $sp, $19
935 jmp $31, do_sys_execve
936 .end sys_execve
938 .align 4
939 .globl osf_sigprocmask
940 .ent osf_sigprocmask
941 osf_sigprocmask:
942 .prologue 0
943 mov $sp, $18
944 jmp $31, do_osf_sigprocmask
945 .end osf_sigprocmask
947 .align 4
948 .globl alpha_ni_syscall
949 .ent alpha_ni_syscall
950 alpha_ni_syscall:
951 .prologue 0
952 /* Special because it also implements overflow handling via
953 syscall number 0. And if you recall, zero is a special
954 trigger for "not an error". Store large non-zero there. */
955 lda $0, -ENOSYS
956 unop
957 stq $0, 0($sp)
958 ret
959 .end alpha_ni_syscall