Linux Audio

Check our new training course

Embedded Linux Audio

Check our new training course
with Creative Commons CC-BY-SA
lecture materials

Bootlin logo

Elixir Cross Referencer

Loading...
  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * This file contains the light-weight system call handlers (fsyscall-handlers).
 *
 * Copyright (C) 2003 Hewlett-Packard Co
 * 	David Mosberger-Tang <davidm@hpl.hp.com>
 *
 * 25-Sep-03 davidm	Implement fsys_rt_sigprocmask().
 * 18-Feb-03 louisk	Implement fsys_gettimeofday().
 * 28-Feb-03 davidm	Fixed several bugs in fsys_gettimeofday().  Tuned it some more,
 *			probably broke it along the way... ;-)
 * 13-Jul-04 clameter   Implement fsys_clock_gettime and revise fsys_gettimeofday to make
 *                      it capable of using memory based clocks without falling back to C code.
 * 08-Feb-07 Fenghua Yu Implement fsys_getcpu.
 *
 */

#include <asm/asmmacro.h>
#include <asm/errno.h>
#include <asm/asm-offsets.h>
#include <asm/percpu.h>
#include <asm/thread_info.h>
#include <asm/sal.h>
#include <asm/signal.h>
#include <asm/unistd.h>

#include "entry.h"
#include <asm/native/inst.h>

/*
 * See Documentation/ia64/fsys.txt for details on fsyscalls.
 *
 * On entry to an fsyscall handler:
 *   r10	= 0 (i.e., defaults to "successful syscall return")
 *   r11	= saved ar.pfs (a user-level value)
 *   r15	= system call number
 *   r16	= "current" task pointer (in normal kernel-mode, this is in r13)
 *   r32-r39	= system call arguments
 *   b6		= return address (a user-level value)
 *   ar.pfs	= previous frame-state (a user-level value)
 *   PSR.be	= cleared to zero (i.e., little-endian byte order is in effect)
 *   all other registers may contain values passed in from user-mode
 *
 * On return from an fsyscall handler:
 *   r11	= saved ar.pfs (as passed into the fsyscall handler)
 *   r15	= system call number (as passed into the fsyscall handler)
 *   r32-r39	= system call arguments (as passed into the fsyscall handler)
 *   b6		= return address (as passed into the fsyscall handler)
 *   ar.pfs	= previous frame-state (as passed into the fsyscall handler)
 */

ENTRY(fsys_ni_syscall)
	.prologue
	.altrp b6
	.body
	mov r8=ENOSYS
	mov r10=-1
	FSYS_RETURN
END(fsys_ni_syscall)

ENTRY(fsys_getpid)
	.prologue
	.altrp b6
	.body
	add r17=IA64_TASK_GROUP_LEADER_OFFSET,r16
	;;
	ld8 r17=[r17]				// r17 = current->group_leader
	add r9=TI_FLAGS+IA64_TASK_SIZE,r16
	;;
	ld4 r9=[r9]
	add r17=IA64_TASK_TGIDLINK_OFFSET,r17
	;;
	and r9=TIF_ALLWORK_MASK,r9
	ld8 r17=[r17]				// r17 = current->group_leader->pids[PIDTYPE_PID].pid
	;;
	add r8=IA64_PID_LEVEL_OFFSET,r17
	;;
	ld4 r8=[r8]				// r8 = pid->level
	add r17=IA64_PID_UPID_OFFSET,r17	// r17 = &pid->numbers[0]
	;;
	shl r8=r8,IA64_UPID_SHIFT
	;;
	add r17=r17,r8				// r17 = &pid->numbers[pid->level]
	;;
	ld4 r8=[r17]				// r8 = pid->numbers[pid->level].nr
	;;
	mov r17=0
	;;
	cmp.ne p8,p0=0,r9
(p8)	br.spnt.many fsys_fallback_syscall
	FSYS_RETURN
END(fsys_getpid)

ENTRY(fsys_set_tid_address)
	.prologue
	.altrp b6
	.body
	add r9=TI_FLAGS+IA64_TASK_SIZE,r16
	add r17=IA64_TASK_TGIDLINK_OFFSET,r16
	;;
	ld4 r9=[r9]
	tnat.z p6,p7=r32		// check argument register for being NaT
	ld8 r17=[r17]				// r17 = current->pids[PIDTYPE_PID].pid
	;;
	and r9=TIF_ALLWORK_MASK,r9
	add r8=IA64_PID_LEVEL_OFFSET,r17
	add r18=IA64_TASK_CLEAR_CHILD_TID_OFFSET,r16
	;;
	ld4 r8=[r8]				// r8 = pid->level
	add r17=IA64_PID_UPID_OFFSET,r17	// r17 = &pid->numbers[0]
	;;
	shl r8=r8,IA64_UPID_SHIFT
	;;
	add r17=r17,r8				// r17 = &pid->numbers[pid->level]
	;;
	ld4 r8=[r17]				// r8 = pid->numbers[pid->level].nr
	;;
	cmp.ne p8,p0=0,r9
	mov r17=-1
	;;
(p6)	st8 [r18]=r32
(p7)	st8 [r18]=r17
(p8)	br.spnt.many fsys_fallback_syscall
	;;
	mov r17=0			// i must not leak kernel bits...
	mov r18=0			// i must not leak kernel bits...
	FSYS_RETURN
END(fsys_set_tid_address)

#if IA64_GTOD_SEQ_OFFSET !=0
#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t
#endif
#if IA64_ITC_JITTER_OFFSET !=0
#error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t
#endif
#define CLOCK_REALTIME 0
#define CLOCK_MONOTONIC 1
#define CLOCK_DIVIDE_BY_1000 0x4000
#define CLOCK_ADD_MONOTONIC 0x8000

ENTRY(fsys_gettimeofday)
	.prologue
	.altrp b6
	.body
	mov r31 = r32
	tnat.nz p6,p0 = r33		// guard against NaT argument
(p6)    br.cond.spnt.few .fail_einval
	mov r30 = CLOCK_DIVIDE_BY_1000
	;;
.gettime:
	// Register map
	// Incoming r31 = pointer to address where to place result
	//          r30 = flags determining how time is processed
	// r2,r3 = temp r4-r7 preserved
	// r8 = result nanoseconds
	// r9 = result seconds
	// r10 = temporary storage for clock difference
	// r11 = preserved: saved ar.pfs
	// r12 = preserved: memory stack
	// r13 = preserved: thread pointer
	// r14 = address of mask / mask value
	// r15 = preserved: system call number
	// r16 = preserved: current task pointer
	// r17 = (not used)
	// r18 = (not used)
	// r19 = address of itc_lastcycle
	// r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence)
	// r21 = address of mmio_ptr
	// r22 = address of wall_time or monotonic_time
	// r23 = address of shift / value
	// r24 = address mult factor / cycle_last value
	// r25 = itc_lastcycle value
	// r26 = address clocksource cycle_last
	// r27 = (not used)
	// r28 = sequence number at the beginning of critcal section
	// r29 = address of itc_jitter
	// r30 = time processing flags / memory address
	// r31 = pointer to result
	// Predicates
	// p6,p7 short term use
	// p8 = timesource ar.itc
	// p9 = timesource mmio64
	// p10 = timesource mmio32 - not used
	// p11 = timesource not to be handled by asm code
	// p12 = memory time source ( = p9 | p10) - not used
	// p13 = do cmpxchg with itc_lastcycle
	// p14 = Divide by 1000
	// p15 = Add monotonic
	//
	// Note that instructions are optimized for McKinley. McKinley can
	// process two bundles simultaneously and therefore we continuously
	// try to feed the CPU two bundles and then a stop.

	add r2 = TI_FLAGS+IA64_TASK_SIZE,r16
	tnat.nz p6,p0 = r31		// guard against Nat argument
(p6)	br.cond.spnt.few .fail_einval
	movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address
	;;
	ld4 r2 = [r2]			// process work pending flags
	movl r29 = itc_jitter_data	// itc_jitter
	add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20	// wall_time
	add r21 = IA64_CLKSRC_MMIO_OFFSET,r20
	mov pr = r30,0xc000	// Set predicates according to function
	;;
	and r2 = TIF_ALLWORK_MASK,r2
	add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29
(p15)	add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20	// monotonic_time
	;;
	add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20	// clksrc_cycle_last
	cmp.ne p6, p0 = 0, r2	// Fallback if work is scheduled
(p6)	br.cond.spnt.many fsys_fallback_syscall
	;;
	// Begin critical section
.time_redo:
	ld4.acq r28 = [r20]	// gtod_lock.sequence, Must take first
	;;
	and r28 = ~1,r28	// And make sequence even to force retry if odd
	;;
	ld8 r30 = [r21]		// clocksource->mmio_ptr
	add r24 = IA64_CLKSRC_MULT_OFFSET,r20
	ld4 r2 = [r29]		// itc_jitter value
	add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20
	add r14 = IA64_CLKSRC_MASK_OFFSET,r20
	;;
	ld4 r3 = [r24]		// clocksource mult value
	ld8 r14 = [r14]         // clocksource mask value
	cmp.eq p8,p9 = 0,r30	// use cpu timer if no mmio_ptr
	;;
	setf.sig f7 = r3	// Setup for mult scaling of counter
(p8)	cmp.ne p13,p0 = r2,r0	// need itc_jitter compensation, set p13
	ld4 r23 = [r23]		// clocksource shift value
	ld8 r24 = [r26]		// get clksrc_cycle_last value
(p9)	cmp.eq p13,p0 = 0,r30	// if mmio_ptr, clear p13 jitter control
	;;
	.pred.rel.mutex p8,p9
	MOV_FROM_ITC(p8, p6, r2, r10)	// CPU_TIMER. 36 clocks latency!!!
(p9)	ld8 r2 = [r30]		// MMIO_TIMER. Could also have latency issues..
(p13)	ld8 r25 = [r19]		// get itc_lastcycle value
	ld8 r9 = [r22],IA64_TIMESPEC_TV_NSEC_OFFSET	// tv_sec
	;;
	ld8 r8 = [r22],-IA64_TIMESPEC_TV_NSEC_OFFSET	// tv_nsec
(p13)	sub r3 = r25,r2		// Diff needed before comparison (thanks davidm)
	;;
(p13)	cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared
	sub r10 = r2,r24	// current_cycle - last_cycle
	;;
(p6)	sub r10 = r25,r24	// time we got was less than last_cycle
(p7)	mov ar.ccv = r25	// more than last_cycle. Prep for cmpxchg
	;;
(p7)	cmpxchg8.rel r3 = [r19],r2,ar.ccv
	;;
(p7)	cmp.ne p7,p0 = r25,r3	// if cmpxchg not successful
	;;
(p7)	sub r10 = r3,r24	// then use new last_cycle instead
	;;
	and r10 = r10,r14	// Apply mask
	;;
	setf.sig f8 = r10
	nop.i 123
	;;
	// fault check takes 5 cycles and we have spare time
EX(.fail_efault, probe.w.fault r31, 3)
	xmpy.l f8 = f8,f7	// nsec_per_cyc*(counter-last_counter)
	;;
	getf.sig r2 = f8
	mf
	;;
	ld4 r10 = [r20]		// gtod_lock.sequence
	shr.u r2 = r2,r23	// shift by factor
	;;
	add r8 = r8,r2		// Add xtime.nsecs
	cmp4.ne p7,p0 = r28,r10
(p7)	br.cond.dpnt.few .time_redo	// sequence number changed, redo
	// End critical section.
	// Now r8=tv->tv_nsec and r9=tv->tv_sec
	mov r10 = r0
	movl r2 = 1000000000
	add r23 = IA64_TIMESPEC_TV_NSEC_OFFSET, r31
(p14)	movl r3 = 2361183241434822607	// Prep for / 1000 hack
	;;
.time_normalize:
	mov r21 = r8
	cmp.ge p6,p0 = r8,r2
(p14)	shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time
	;;
(p14)	setf.sig f8 = r20
(p6)	sub r8 = r8,r2
(p6)	add r9 = 1,r9		// two nops before the branch.
(p14)	setf.sig f7 = r3	// Chances for repeats are 1 in 10000 for gettod
(p6)	br.cond.dpnt.few .time_normalize
	;;
	// Divided by 8 though shift. Now divide by 125
	// The compiler was able to do that with a multiply
	// and a shift and we do the same
EX(.fail_efault, probe.w.fault r23, 3)	// This also costs 5 cycles
(p14)	xmpy.hu f8 = f8, f7		// xmpy has 5 cycles latency so use it
	;;
(p14)	getf.sig r2 = f8
	;;
	mov r8 = r0
(p14)	shr.u r21 = r2, 4
	;;
EX(.fail_efault, st8 [r31] = r9)
EX(.fail_efault, st8 [r23] = r21)
	FSYS_RETURN
.fail_einval:
	mov r8 = EINVAL
	mov r10 = -1
	FSYS_RETURN
.fail_efault:
	mov r8 = EFAULT
	mov r10 = -1
	FSYS_RETURN
END(fsys_gettimeofday)

ENTRY(fsys_clock_gettime)
	.prologue
	.altrp b6
	.body
	cmp4.ltu p6, p0 = CLOCK_MONOTONIC, r32
	// Fallback if this is not CLOCK_REALTIME or CLOCK_MONOTONIC
(p6)	br.spnt.few fsys_fallback_syscall
	mov r31 = r33
	shl r30 = r32,15
	br.many .gettime
END(fsys_clock_gettime)

/*
 * fsys_getcpu doesn't use the third parameter in this implementation. It reads
 * current_thread_info()->cpu and corresponding node in cpu_to_node_map.
 */
ENTRY(fsys_getcpu)
	.prologue
	.altrp b6
	.body
	;;
	add r2=TI_FLAGS+IA64_TASK_SIZE,r16
	tnat.nz p6,p0 = r32			// guard against NaT argument
	add r3=TI_CPU+IA64_TASK_SIZE,r16
	;;
	ld4 r3=[r3]				// M r3 = thread_info->cpu
	ld4 r2=[r2]				// M r2 = thread_info->flags
(p6)    br.cond.spnt.few .fail_einval		// B
	;;
	tnat.nz p7,p0 = r33			// I guard against NaT argument
(p7)    br.cond.spnt.few .fail_einval		// B
	;;
	cmp.ne p6,p0=r32,r0
	cmp.ne p7,p0=r33,r0
	;;
#ifdef CONFIG_NUMA
	movl r17=cpu_to_node_map
	;;
EX(.fail_efault, (p6) probe.w.fault r32, 3)		// M This takes 5 cycles
EX(.fail_efault, (p7) probe.w.fault r33, 3)		// M This takes 5 cycles
	shladd r18=r3,1,r17
	;;
	ld2 r20=[r18]				// r20 = cpu_to_node_map[cpu]
	and r2 = TIF_ALLWORK_MASK,r2
	;;
	cmp.ne p8,p0=0,r2
(p8)	br.spnt.many fsys_fallback_syscall
	;;
	;;
EX(.fail_efault, (p6) st4 [r32] = r3)
EX(.fail_efault, (p7) st2 [r33] = r20)
	mov r8=0
	;;
#else
EX(.fail_efault, (p6) probe.w.fault r32, 3)		// M This takes 5 cycles
EX(.fail_efault, (p7) probe.w.fault r33, 3)		// M This takes 5 cycles
	and r2 = TIF_ALLWORK_MASK,r2
	;;
	cmp.ne p8,p0=0,r2
(p8)	br.spnt.many fsys_fallback_syscall
	;;
EX(.fail_efault, (p6) st4 [r32] = r3)
EX(.fail_efault, (p7) st2 [r33] = r0)
	mov r8=0
	;;
#endif
	FSYS_RETURN
END(fsys_getcpu)

ENTRY(fsys_fallback_syscall)
	.prologue
	.altrp b6
	.body
	/*
	 * We only get here from light-weight syscall handlers.  Thus, we already
	 * know that r15 contains a valid syscall number.  No need to re-check.
	 */
	adds r17=-1024,r15
	movl r14=sys_call_table
	;;
	RSM_PSR_I(p0, r26, r27)
	shladd r18=r17,3,r14
	;;
	ld8 r18=[r18]				// load normal (heavy-weight) syscall entry-point
	MOV_FROM_PSR(p0, r29, r26)		// read psr (12 cyc load latency)
	mov r27=ar.rsc
	mov r21=ar.fpsr
	mov r26=ar.pfs
END(fsys_fallback_syscall)
	/* FALL THROUGH */
GLOBAL_ENTRY(fsys_bubble_down)
	.prologue
	.altrp b6
	.body
	/*
	 * We get here for syscalls that don't have a lightweight
	 * handler.  For those, we need to bubble down into the kernel
	 * and that requires setting up a minimal pt_regs structure,
	 * and initializing the CPU state more or less as if an
	 * interruption had occurred.  To make syscall-restarts work,
	 * we setup pt_regs such that cr_iip points to the second
	 * instruction in syscall_via_break.  Decrementing the IP
	 * hence will restart the syscall via break and not
	 * decrementing IP will return us to the caller, as usual.
	 * Note that we preserve the value of psr.pp rather than
	 * initializing it from dcr.pp.  This makes it possible to
	 * distinguish fsyscall execution from other privileged
	 * execution.
	 *
	 * On entry:
	 *	- normal fsyscall handler register usage, except
	 *	  that we also have:
	 *	- r18: address of syscall entry point
	 *	- r21: ar.fpsr
	 *	- r26: ar.pfs
	 *	- r27: ar.rsc
	 *	- r29: psr
	 *
	 * We used to clear some PSR bits here but that requires slow
	 * serialization.  Fortuntely, that isn't really necessary.
	 * The rationale is as follows: we used to clear bits
	 * ~PSR_PRESERVED_BITS in PSR.L.  Since
	 * PSR_PRESERVED_BITS==PSR.{UP,MFL,MFH,PK,DT,PP,SP,RT,IC}, we
	 * ended up clearing PSR.{BE,AC,I,DFL,DFH,DI,DB,SI,TB}.
	 * However,
	 *
	 * PSR.BE : already is turned off in __kernel_syscall_via_epc()
	 * PSR.AC : don't care (kernel normally turns PSR.AC on)
	 * PSR.I  : already turned off by the time fsys_bubble_down gets
	 *	    invoked
	 * PSR.DFL: always 0 (kernel never turns it on)
	 * PSR.DFH: don't care --- kernel never touches f32-f127 on its own
	 *	    initiative
	 * PSR.DI : always 0 (kernel never turns it on)
	 * PSR.SI : always 0 (kernel never turns it on)
	 * PSR.DB : don't care --- kernel never enables kernel-level
	 *	    breakpoints
	 * PSR.TB : must be 0 already; if it wasn't zero on entry to
	 *          __kernel_syscall_via_epc, the branch to fsys_bubble_down
	 *          will trigger a taken branch; the taken-trap-handler then
	 *          converts the syscall into a break-based system-call.
	 */
	/*
	 * Reading psr.l gives us only bits 0-31, psr.it, and psr.mc.
	 * The rest we have to synthesize.
	 */
#	define PSR_ONE_BITS		((3 << IA64_PSR_CPL0_BIT)	\
					 | (0x1 << IA64_PSR_RI_BIT)	\
					 | IA64_PSR_BN | IA64_PSR_I)

	invala					// M0|1
	movl r14=ia64_ret_from_syscall		// X

	nop.m 0
	movl r28=__kernel_syscall_via_break	// X	create cr.iip
	;;

	mov r2=r16				// A    get task addr to addl-addressable register
	adds r16=IA64_TASK_THREAD_ON_USTACK_OFFSET,r16 // A
	mov r31=pr				// I0   save pr (2 cyc)
	;;
	st1 [r16]=r0				// M2|3 clear current->thread.on_ustack flag
	addl r22=IA64_RBS_OFFSET,r2		// A    compute base of RBS
	add r3=TI_FLAGS+IA64_TASK_SIZE,r2	// A
	;;
	ld4 r3=[r3]				// M0|1 r3 = current_thread_info()->flags
	lfetch.fault.excl.nt1 [r22]		// M0|1 prefetch register backing-store
	nop.i 0
	;;
	mov ar.rsc=0				// M2   set enforced lazy mode, pl 0, LE, loadrs=0
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
	MOV_FROM_ITC(p0, p6, r30, r23)		// M    get cycle for accounting
#else
	nop.m 0
#endif
	nop.i 0
	;;
	mov r23=ar.bspstore			// M2 (12 cyc) save ar.bspstore
	mov.m r24=ar.rnat			// M2 (5 cyc) read ar.rnat (dual-issues!)
	nop.i 0
	;;
	mov ar.bspstore=r22			// M2 (6 cyc) switch to kernel RBS
	movl r8=PSR_ONE_BITS			// X
	;;
	mov r25=ar.unat				// M2 (5 cyc) save ar.unat
	mov r19=b6				// I0   save b6 (2 cyc)
	mov r20=r1				// A    save caller's gp in r20
	;;
	or r29=r8,r29				// A    construct cr.ipsr value to save
	mov b6=r18				// I0   copy syscall entry-point to b6 (7 cyc)
	addl r1=IA64_STK_OFFSET-IA64_PT_REGS_SIZE,r2 // A compute base of memory stack

	mov r18=ar.bsp				// M2   save (kernel) ar.bsp (12 cyc)
	cmp.ne pKStk,pUStk=r0,r0		// A    set pKStk <- 0, pUStk <- 1
	br.call.sptk.many b7=ia64_syscall_setup	// B
	;;
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
	// mov.m r30=ar.itc is called in advance
	add r16=TI_AC_STAMP+IA64_TASK_SIZE,r2
	add r17=TI_AC_LEAVE+IA64_TASK_SIZE,r2
	;;
	ld8 r18=[r16],TI_AC_STIME-TI_AC_STAMP	// time at last check in kernel
	ld8 r19=[r17],TI_AC_UTIME-TI_AC_LEAVE	// time at leave kernel
	;;
	ld8 r20=[r16],TI_AC_STAMP-TI_AC_STIME	// cumulated stime
	ld8 r21=[r17]				// cumulated utime
	sub r22=r19,r18				// stime before leave kernel
	;;
	st8 [r16]=r30,TI_AC_STIME-TI_AC_STAMP	// update stamp
	sub r18=r30,r19				// elapsed time in user mode
	;;
	add r20=r20,r22				// sum stime
	add r21=r21,r18				// sum utime
	;;
	st8 [r16]=r20				// update stime
	st8 [r17]=r21				// update utime
	;;
#endif
	mov ar.rsc=0x3				// M2   set eager mode, pl 0, LE, loadrs=0
	mov rp=r14				// I0   set the real return addr
	and r3=_TIF_SYSCALL_TRACEAUDIT,r3	// A
	;;
	SSM_PSR_I(p0, p6, r22)			// M2   we're on kernel stacks now, reenable irqs
	cmp.eq p8,p0=r3,r0			// A
(p10)	br.cond.spnt.many ia64_ret_from_syscall	// B    return if bad call-frame or r15 is a NaT

	nop.m 0
(p8)	br.call.sptk.many b6=b6			// B    (ignore return address)
	br.cond.spnt ia64_trace_syscall		// B
END(fsys_bubble_down)

	.rodata
	.align 8
	.globl fsyscall_table

	data8 fsys_bubble_down
fsyscall_table:
	data8 fsys_ni_syscall
	data8 0				// exit			// 1025
	data8 0				// read
	data8 0				// write
	data8 0				// open
	data8 0				// close
	data8 0				// creat		// 1030
	data8 0				// link
	data8 0				// unlink
	data8 0				// execve
	data8 0				// chdir
	data8 0				// fchdir		// 1035
	data8 0				// utimes
	data8 0				// mknod
	data8 0				// chmod
	data8 0				// chown
	data8 0				// lseek		// 1040
	data8 fsys_getpid		// getpid
	data8 0				// getppid
	data8 0				// mount
	data8 0				// umount
	data8 0				// setuid		// 1045
	data8 0				// getuid
	data8 0				// geteuid
	data8 0				// ptrace
	data8 0				// access
	data8 0				// sync			// 1050
	data8 0				// fsync
	data8 0				// fdatasync
	data8 0				// kill
	data8 0				// rename
	data8 0				// mkdir		// 1055
	data8 0				// rmdir
	data8 0				// dup
	data8 0				// pipe
	data8 0				// times
	data8 0				// brk			// 1060
	data8 0				// setgid
	data8 0				// getgid
	data8 0				// getegid
	data8 0				// acct
	data8 0				// ioctl		// 1065
	data8 0				// fcntl
	data8 0				// umask
	data8 0				// chroot
	data8 0				// ustat
	data8 0				// dup2			// 1070
	data8 0				// setreuid
	data8 0				// setregid
	data8 0				// getresuid
	data8 0				// setresuid
	data8 0				// getresgid		// 1075
	data8 0				// setresgid
	data8 0				// getgroups
	data8 0				// setgroups
	data8 0				// getpgid
	data8 0				// setpgid		// 1080
	data8 0				// setsid
	data8 0				// getsid
	data8 0				// sethostname
	data8 0				// setrlimit
	data8 0				// getrlimit		// 1085
	data8 0				// getrusage
	data8 fsys_gettimeofday		// gettimeofday
	data8 0				// settimeofday
	data8 0				// select
	data8 0				// poll			// 1090
	data8 0				// symlink
	data8 0				// readlink
	data8 0				// uselib
	data8 0				// swapon
	data8 0				// swapoff		// 1095
	data8 0				// reboot
	data8 0				// truncate
	data8 0				// ftruncate
	data8 0				// fchmod
	data8 0				// fchown		// 1100
	data8 0				// getpriority
	data8 0				// setpriority
	data8 0				// statfs
	data8 0				// fstatfs
	data8 0				// gettid		// 1105
	data8 0				// semget
	data8 0				// semop
	data8 0				// semctl
	data8 0				// msgget
	data8 0				// msgsnd		// 1110
	data8 0				// msgrcv
	data8 0				// msgctl
	data8 0				// shmget
	data8 0				// shmat
	data8 0				// shmdt		// 1115
	data8 0				// shmctl
	data8 0				// syslog
	data8 0				// setitimer
	data8 0				// getitimer
	data8 0					 		// 1120
	data8 0
	data8 0
	data8 0				// vhangup
	data8 0				// lchown
	data8 0				// remap_file_pages	// 1125
	data8 0				// wait4
	data8 0				// sysinfo
	data8 0				// clone
	data8 0				// setdomainname
	data8 0				// newuname		// 1130
	data8 0				// adjtimex
	data8 0
	data8 0				// init_module
	data8 0				// delete_module
	data8 0							// 1135
	data8 0
	data8 0				// quotactl
	data8 0				// bdflush
	data8 0				// sysfs
	data8 0				// personality		// 1140
	data8 0				// afs_syscall
	data8 0				// setfsuid
	data8 0				// setfsgid
	data8 0				// getdents
	data8 0				// flock		// 1145
	data8 0				// readv
	data8 0				// writev
	data8 0				// pread64
	data8 0				// pwrite64
	data8 0				// sysctl		// 1150
	data8 0				// mmap
	data8 0				// munmap
	data8 0				// mlock
	data8 0				// mlockall
	data8 0				// mprotect		// 1155
	data8 0				// mremap
	data8 0				// msync
	data8 0				// munlock
	data8 0				// munlockall
	data8 0				// sched_getparam	// 1160
	data8 0				// sched_setparam
	data8 0				// sched_getscheduler
	data8 0				// sched_setscheduler
	data8 0				// sched_yield
	data8 0				// sched_get_priority_max	// 1165
	data8 0				// sched_get_priority_min
	data8 0				// sched_rr_get_interval
	data8 0				// nanosleep
	data8 0				// nfsservctl
	data8 0				// prctl		// 1170
	data8 0				// getpagesize
	data8 0				// mmap2
	data8 0				// pciconfig_read
	data8 0				// pciconfig_write
	data8 0				// perfmonctl		// 1175
	data8 0				// sigaltstack
	data8 0				// rt_sigaction
	data8 0				// rt_sigpending
	data8 0				// rt_sigprocmask
	data8 0				// rt_sigqueueinfo	// 1180
	data8 0				// rt_sigreturn
	data8 0				// rt_sigsuspend
	data8 0				// rt_sigtimedwait
	data8 0				// getcwd
	data8 0				// capget		// 1185
	data8 0				// capset
	data8 0				// sendfile
	data8 0
	data8 0
	data8 0				// socket		// 1190
	data8 0				// bind
	data8 0				// connect
	data8 0				// listen
	data8 0				// accept
	data8 0				// getsockname		// 1195
	data8 0				// getpeername
	data8 0				// socketpair
	data8 0				// send
	data8 0				// sendto
	data8 0				// recv			// 1200
	data8 0				// recvfrom
	data8 0				// shutdown
	data8 0				// setsockopt
	data8 0				// getsockopt
	data8 0				// sendmsg		// 1205
	data8 0				// recvmsg
	data8 0				// pivot_root
	data8 0				// mincore
	data8 0				// madvise
	data8 0				// newstat		// 1210
	data8 0				// newlstat
	data8 0				// newfstat
	data8 0				// clone2
	data8 0				// getdents64
	data8 0				// getunwind		// 1215
	data8 0				// readahead
	data8 0				// setxattr
	data8 0				// lsetxattr
	data8 0				// fsetxattr
	data8 0				// getxattr		// 1220
	data8 0				// lgetxattr
	data8 0				// fgetxattr
	data8 0				// listxattr
	data8 0				// llistxattr
	data8 0				// flistxattr		// 1225
	data8 0				// removexattr
	data8 0				// lremovexattr
	data8 0				// fremovexattr
	data8 0				// tkill
	data8 0				// futex		// 1230
	data8 0				// sched_setaffinity
	data8 0				// sched_getaffinity
	data8 fsys_set_tid_address	// set_tid_address
	data8 0				// fadvise64_64
	data8 0				// tgkill		// 1235
	data8 0				// exit_group
	data8 0				// lookup_dcookie
	data8 0				// io_setup
	data8 0				// io_destroy
	data8 0				// io_getevents		// 1240
	data8 0				// io_submit
	data8 0				// io_cancel
	data8 0				// epoll_create
	data8 0				// epoll_ctl
	data8 0				// epoll_wait		// 1245
	data8 0				// restart_syscall
	data8 0				// semtimedop
	data8 0				// timer_create
	data8 0				// timer_settime
	data8 0				// timer_gettime 	// 1250
	data8 0				// timer_getoverrun
	data8 0				// timer_delete
	data8 0				// clock_settime
	data8 fsys_clock_gettime	// clock_gettime
	data8 0				// clock_getres		// 1255
	data8 0				// clock_nanosleep
	data8 0				// fstatfs64
	data8 0				// statfs64
	data8 0				// mbind
	data8 0				// get_mempolicy	// 1260
	data8 0				// set_mempolicy
	data8 0				// mq_open
	data8 0				// mq_unlink
	data8 0				// mq_timedsend
	data8 0				// mq_timedreceive	// 1265
	data8 0				// mq_notify
	data8 0				// mq_getsetattr
	data8 0				// kexec_load
	data8 0				// vserver
	data8 0				// waitid		// 1270
	data8 0				// add_key
	data8 0				// request_key
	data8 0				// keyctl
	data8 0				// ioprio_set
	data8 0				// ioprio_get		// 1275
	data8 0				// move_pages
	data8 0				// inotify_init
	data8 0				// inotify_add_watch
	data8 0				// inotify_rm_watch
	data8 0				// migrate_pages	// 1280
	data8 0				// openat
	data8 0				// mkdirat
	data8 0				// mknodat
	data8 0				// fchownat
	data8 0				// futimesat		// 1285
	data8 0				// newfstatat
	data8 0				// unlinkat
	data8 0				// renameat
	data8 0				// linkat
	data8 0				// symlinkat		// 1290
	data8 0				// readlinkat
	data8 0				// fchmodat
	data8 0				// faccessat
	data8 0
	data8 0							// 1295
	data8 0				// unshare
	data8 0				// splice
	data8 0				// set_robust_list
	data8 0				// get_robust_list
	data8 0				// sync_file_range	// 1300
	data8 0				// tee
	data8 0				// vmsplice
	data8 0
	data8 fsys_getcpu		// getcpu		// 1304

	// fill in zeros for the remaining entries
	.zero:
	.space fsyscall_table + 8*NR_syscalls - .zero, 0