| blob | 2ac92633150009fc283747c010e1745fcb7b6b9e |
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * arch/ia64/kernel/entry.S
4 *
5 * Kernel entry points.
6 *
7 * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
8 * David Mosberger-Tang <davidm@hpl.hp.com>
9 * Copyright (C) 1999, 2002-2003
10 * Asit Mallick <Asit.K.Mallick@intel.com>
11 * Don Dugger <Don.Dugger@intel.com>
12 * Suresh Siddha <suresh.b.siddha@intel.com>
13 * Fenghua Yu <fenghua.yu@intel.com>
14 * Copyright (C) 1999 VA Linux Systems
15 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
16 */
17 /*
18 * ia64_switch_to now places correct virtual mapping in in TR2 for
19 * kernel stack. This allows us to handle interrupts without changing
20 * to physical mode.
21 *
22 * Jonathan Nicklin <nicklin@missioncriticallinux.com>
23 * Patrick O'Rourke <orourke@missioncriticallinux.com>
24 * 11/07/2000
25 */
26 /*
27 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
28 * VA Linux Systems Japan K.K.
29 * pv_ops.
30 */
31 /*
32 * Global (preserved) predicate usage on syscall entry/exit path:
33 *
34 * pKStk: See entry.h.
35 * pUStk: See entry.h.
36 * pSys: See entry.h.
37 * pNonSys: !pSys
38 */
41 #include <asm/asmmacro.h>
42 #include <asm/cache.h>
43 #include <asm/errno.h>
44 #include <asm/kregs.h>
45 #include <asm/asm-offsets.h>
46 #include <asm/pgtable.h>
47 #include <asm/percpu.h>
48 #include <asm/processor.h>
49 #include <asm/thread_info.h>
50 #include <asm/unistd.h>
51 #include <asm/ftrace.h>
52 #include <asm/export.h>
54 #include "minstate.h"
56 /*
57 * execve() is special because in case of success, we need to
58 * setup a null register window frame.
59 */
60 ENTRY(ia64_execve)
61 /*
62 * Allocate 8 input registers since ptrace() may clobber them
63 */
64 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
65 alloc loc1=ar.pfs,8,2,3,0
66 mov loc0=rp
67 .body
68 mov out0=in0 // filename
69 ;; // stop bit between alloc and call
70 mov out1=in1 // argv
71 mov out2=in2 // envp
72 br.call.sptk.many rp=sys_execve
73 .ret0:
74 cmp4.ge p6,p7=r8,r0
75 mov ar.pfs=loc1 // restore ar.pfs
76 sxt4 r8=r8 // return 64-bit result
77 ;;
78 stf.spill [sp]=f0
79 mov rp=loc0
80 (p6) mov ar.pfs=r0 // clear ar.pfs on success
81 (p7) br.ret.sptk.many rp
83 /*
84 * In theory, we'd have to zap this state only to prevent leaking of
85 * security sensitive state (e.g., if current->mm->dumpable is zero). However,
86 * this executes in less than 20 cycles even on Itanium, so it's not worth
87 * optimizing for...).
88 */
89 mov ar.unat=0; mov ar.lc=0
90 mov r4=0; mov f2=f0; mov b1=r0
91 mov r5=0; mov f3=f0; mov b2=r0
92 mov r6=0; mov f4=f0; mov b3=r0
93 mov r7=0; mov f5=f0; mov b4=r0
94 ldf.fill f12=[sp]; mov f13=f0; mov b5=r0
95 ldf.fill f14=[sp]; ldf.fill f15=[sp]; mov f16=f0
96 ldf.fill f17=[sp]; ldf.fill f18=[sp]; mov f19=f0
97 ldf.fill f20=[sp]; ldf.fill f21=[sp]; mov f22=f0
98 ldf.fill f23=[sp]; ldf.fill f24=[sp]; mov f25=f0
99 ldf.fill f26=[sp]; ldf.fill f27=[sp]; mov f28=f0
100 ldf.fill f29=[sp]; ldf.fill f30=[sp]; mov f31=f0
101 br.ret.sptk.many rp
102 END(ia64_execve)
104 /*
105 * sys_clone2(u64 flags, u64 ustack_base, u64 ustack_size, u64 parent_tidptr, u64 child_tidptr,
106 * u64 tls)
107 */
108 GLOBAL_ENTRY(sys_clone2)
109 /*
110 * Allocate 8 input registers since ptrace() may clobber them
111 */
112 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
113 alloc r16=ar.pfs,8,2,6,0
114 DO_SAVE_SWITCH_STACK
115 adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
116 mov loc0=rp
117 mov loc1=r16 // save ar.pfs across do_fork
118 .body
119 mov out1=in1
120 mov out2=in2
121 tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
122 mov out3=in3 // parent_tidptr: valid only w/CLONE_PARENT_SETTID
123 ;;
124 (p6) st8 [r2]=in5 // store TLS in r16 for copy_thread()
125 mov out4=in4 // child_tidptr: valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
126 mov out0=in0 // out0 = clone_flags
127 br.call.sptk.many rp=do_fork
128 .ret1: .restore sp
129 adds sp=IA64_SWITCH_STACK_SIZE,sp // pop the switch stack
130 mov ar.pfs=loc1
131 mov rp=loc0
132 br.ret.sptk.many rp
133 END(sys_clone2)
135 /*
136 * sys_clone(u64 flags, u64 ustack_base, u64 parent_tidptr, u64 child_tidptr, u64 tls)
137 * Deprecated. Use sys_clone2() instead.
138 */
139 GLOBAL_ENTRY(sys_clone)
140 /*
141 * Allocate 8 input registers since ptrace() may clobber them
142 */
143 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
144 alloc r16=ar.pfs,8,2,6,0
145 DO_SAVE_SWITCH_STACK
146 adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
147 mov loc0=rp
148 mov loc1=r16 // save ar.pfs across do_fork
149 .body
150 mov out1=in1
151 mov out2=16 // stacksize (compensates for 16-byte scratch area)
152 tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
153 mov out3=in2 // parent_tidptr: valid only w/CLONE_PARENT_SETTID
154 ;;
155 (p6) st8 [r2]=in4 // store TLS in r13 (tp)
156 mov out4=in3 // child_tidptr: valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
157 mov out0=in0 // out0 = clone_flags
158 br.call.sptk.many rp=do_fork
159 .ret2: .restore sp
160 adds sp=IA64_SWITCH_STACK_SIZE,sp // pop the switch stack
161 mov ar.pfs=loc1
162 mov rp=loc0
163 br.ret.sptk.many rp
164 END(sys_clone)
166 /*
167 * prev_task <- ia64_switch_to(struct task_struct *next)
168 * With Ingo's new scheduler, interrupts are disabled when this routine gets
169 * called. The code starting at .map relies on this. The rest of the code
170 * doesn't care about the interrupt masking status.
171 */
172 GLOBAL_ENTRY(ia64_switch_to)
173 .prologue
174 alloc r16=ar.pfs,1,0,0,0
175 DO_SAVE_SWITCH_STACK
176 .body
178 adds r22=IA64_TASK_THREAD_KSP_OFFSET,r13
179 movl r25=init_task
180 mov r27=IA64_KR(CURRENT_STACK)
181 adds r21=IA64_TASK_THREAD_KSP_OFFSET,in0
182 dep r20=0,in0,61,3 // physical address of "next"
183 ;;
184 st8 [r22]=sp // save kernel stack pointer of old task
185 shr.u r26=r20,IA64_GRANULE_SHIFT
186 cmp.eq p7,p6=r25,in0
187 ;;
188 /*
189 * If we've already mapped this task's page, we can skip doing it again.
190 */
191 (p6) cmp.eq p7,p6=r26,r27
192 (p6) br.cond.dpnt .map
193 ;;
194 .done:
195 ld8 sp=[r21] // load kernel stack pointer of new task
196 MOV_TO_KR(CURRENT, in0, r8, r9) // update "current" application register
197 mov r8=r13 // return pointer to previously running task
198 mov r13=in0 // set "current" pointer
199 ;;
200 DO_LOAD_SWITCH_STACK
202 #ifdef CONFIG_SMP
203 sync.i // ensure "fc"s done by this CPU are visible on other CPUs
204 #endif
205 br.ret.sptk.many rp // boogie on out in new context
207 .map:
208 RSM_PSR_IC(r25) // interrupts (psr.i) are already disabled here
209 movl r25=PAGE_KERNEL
210 ;;
211 srlz.d
212 or r23=r25,r20 // construct PA | page properties
213 mov r25=IA64_GRANULE_SHIFT<<2
214 ;;
215 MOV_TO_ITIR(p0, r25, r8)
216 MOV_TO_IFA(in0, r8) // VA of next task...
217 ;;
218 mov r25=IA64_TR_CURRENT_STACK
219 MOV_TO_KR(CURRENT_STACK, r26, r8, r9) // remember last page we mapped...
220 ;;
221 itr.d dtr[r25]=r23 // wire in new mapping...
222 SSM_PSR_IC_AND_SRLZ_D(r8, r9) // reenable the psr.ic bit
223 br.cond.sptk .done
224 END(ia64_switch_to)
226 /*
227 * Note that interrupts are enabled during save_switch_stack and load_switch_stack. This
228 * means that we may get an interrupt with "sp" pointing to the new kernel stack while
229 * ar.bspstore is still pointing to the old kernel backing store area. Since ar.rsc,
230 * ar.rnat, ar.bsp, and ar.bspstore are all preserved by interrupts, this is not a
231 * problem. Also, we don't need to specify unwind information for preserved registers
232 * that are not modified in save_switch_stack as the right unwind information is already
233 * specified at the call-site of save_switch_stack.
234 */
236 /*
237 * save_switch_stack:
238 * - r16 holds ar.pfs
239 * - b7 holds address to return to
240 * - rp (b0) holds return address to save
241 */
242 GLOBAL_ENTRY(save_switch_stack)
243 .prologue
244 .altrp b7
245 flushrs // flush dirty regs to backing store (must be first in insn group)
246 .save @priunat,r17
247 mov r17=ar.unat // preserve caller's
248 .body
249 #ifdef CONFIG_ITANIUM
250 adds r2=16+128,sp
251 adds r3=16+64,sp
252 adds r14=SW(R4)+16,sp
253 ;;
254 st8.spill [r14]=r4,16 // spill r4
255 lfetch.fault.excl.nt1 [r3],128
256 ;;
257 lfetch.fault.excl.nt1 [r2],128
258 lfetch.fault.excl.nt1 [r3],128
259 ;;
260 lfetch.fault.excl [r2]
261 lfetch.fault.excl [r3]
262 adds r15=SW(R5)+16,sp
263 #else
264 add r2=16+3*128,sp
265 add r3=16,sp
266 add r14=SW(R4)+16,sp
267 ;;
268 st8.spill [r14]=r4,SW(R6)-SW(R4) // spill r4 and prefetch offset 0x1c0
269 lfetch.fault.excl.nt1 [r3],128 // prefetch offset 0x010
270 ;;
271 lfetch.fault.excl.nt1 [r3],128 // prefetch offset 0x090
272 lfetch.fault.excl.nt1 [r2],128 // prefetch offset 0x190
273 ;;
274 lfetch.fault.excl.nt1 [r3] // prefetch offset 0x110
275 lfetch.fault.excl.nt1 [r2] // prefetch offset 0x210
276 adds r15=SW(R5)+16,sp
277 #endif
278 ;;
279 st8.spill [r15]=r5,SW(R7)-SW(R5) // spill r5
280 mov.m ar.rsc=0 // put RSE in mode: enforced lazy, little endian, pl 0
281 add r2=SW(F2)+16,sp // r2 = &sw->f2
282 ;;
283 st8.spill [r14]=r6,SW(B0)-SW(R6) // spill r6
284 mov.m r18=ar.fpsr // preserve fpsr
285 add r3=SW(F3)+16,sp // r3 = &sw->f3
286 ;;
287 stf.spill [r2]=f2,32
288 mov.m r19=ar.rnat
289 mov r21=b0
291 stf.spill [r3]=f3,32
292 st8.spill [r15]=r7,SW(B2)-SW(R7) // spill r7
293 mov r22=b1
294 ;;
295 // since we're done with the spills, read and save ar.unat:
296 mov.m r29=ar.unat
297 mov.m r20=ar.bspstore
298 mov r23=b2
299 stf.spill [r2]=f4,32
300 stf.spill [r3]=f5,32
301 mov r24=b3
302 ;;
303 st8 [r14]=r21,SW(B1)-SW(B0) // save b0
304 st8 [r15]=r23,SW(B3)-SW(B2) // save b2
305 mov r25=b4
306 mov r26=b5
307 ;;
308 st8 [r14]=r22,SW(B4)-SW(B1) // save b1
309 st8 [r15]=r24,SW(AR_PFS)-SW(B3) // save b3
310 mov r21=ar.lc // I-unit
311 stf.spill [r2]=f12,32
312 stf.spill [r3]=f13,32
313 ;;
314 st8 [r14]=r25,SW(B5)-SW(B4) // save b4
315 st8 [r15]=r16,SW(AR_LC)-SW(AR_PFS) // save ar.pfs
316 stf.spill [r2]=f14,32
317 stf.spill [r3]=f15,32
318 ;;
319 st8 [r14]=r26 // save b5
320 st8 [r15]=r21 // save ar.lc
321 stf.spill [r2]=f16,32
322 stf.spill [r3]=f17,32
323 ;;
324 stf.spill [r2]=f18,32
325 stf.spill [r3]=f19,32
326 ;;
327 stf.spill [r2]=f20,32
328 stf.spill [r3]=f21,32
329 ;;
330 stf.spill [r2]=f22,32
331 stf.spill [r3]=f23,32
332 ;;
333 stf.spill [r2]=f24,32
334 stf.spill [r3]=f25,32
335 ;;
336 stf.spill [r2]=f26,32
337 stf.spill [r3]=f27,32
338 ;;
339 stf.spill [r2]=f28,32
340 stf.spill [r3]=f29,32
341 ;;
342 stf.spill [r2]=f30,SW(AR_UNAT)-SW(F30)
343 stf.spill [r3]=f31,SW(PR)-SW(F31)
344 add r14=SW(CALLER_UNAT)+16,sp
345 ;;
346 st8 [r2]=r29,SW(AR_RNAT)-SW(AR_UNAT) // save ar.unat
347 st8 [r14]=r17,SW(AR_FPSR)-SW(CALLER_UNAT) // save caller_unat
348 mov r21=pr
349 ;;
350 st8 [r2]=r19,SW(AR_BSPSTORE)-SW(AR_RNAT) // save ar.rnat
351 st8 [r3]=r21 // save predicate registers
352 ;;
353 st8 [r2]=r20 // save ar.bspstore
354 st8 [r14]=r18 // save fpsr
355 mov ar.rsc=3 // put RSE back into eager mode, pl 0
356 br.cond.sptk.many b7
357 END(save_switch_stack)
359 /*
360 * load_switch_stack:
361 * - "invala" MUST be done at call site (normally in DO_LOAD_SWITCH_STACK)
362 * - b7 holds address to return to
363 * - must not touch r8-r11
364 */
365 GLOBAL_ENTRY(load_switch_stack)
366 .prologue
367 .altrp b7
369 .body
370 lfetch.fault.nt1 [sp]
371 adds r2=SW(AR_BSPSTORE)+16,sp
372 adds r3=SW(AR_UNAT)+16,sp
373 mov ar.rsc=0 // put RSE into enforced lazy mode
374 adds r14=SW(CALLER_UNAT)+16,sp
375 adds r15=SW(AR_FPSR)+16,sp
376 ;;
377 ld8 r27=[r2],(SW(B0)-SW(AR_BSPSTORE)) // bspstore
378 ld8 r29=[r3],(SW(B1)-SW(AR_UNAT)) // unat
379 ;;
380 ld8 r21=[r2],16 // restore b0
381 ld8 r22=[r3],16 // restore b1
382 ;;
383 ld8 r23=[r2],16 // restore b2
384 ld8 r24=[r3],16 // restore b3
385 ;;
386 ld8 r25=[r2],16 // restore b4
387 ld8 r26=[r3],16 // restore b5
388 ;;
389 ld8 r16=[r2],(SW(PR)-SW(AR_PFS)) // ar.pfs
390 ld8 r17=[r3],(SW(AR_RNAT)-SW(AR_LC)) // ar.lc
391 ;;
392 ld8 r28=[r2] // restore pr
393 ld8 r30=[r3] // restore rnat
394 ;;
395 ld8 r18=[r14],16 // restore caller's unat
396 ld8 r19=[r15],24 // restore fpsr
397 ;;
398 ldf.fill f2=[r14],32
399 ldf.fill f3=[r15],32
400 ;;
401 ldf.fill f4=[r14],32
402 ldf.fill f5=[r15],32
403 ;;
404 ldf.fill f12=[r14],32
405 ldf.fill f13=[r15],32
406 ;;
407 ldf.fill f14=[r14],32
408 ldf.fill f15=[r15],32
409 ;;
410 ldf.fill f16=[r14],32
411 ldf.fill f17=[r15],32
412 ;;
413 ldf.fill f18=[r14],32
414 ldf.fill f19=[r15],32
415 mov b0=r21
416 ;;
417 ldf.fill f20=[r14],32
418 ldf.fill f21=[r15],32
419 mov b1=r22
420 ;;
421 ldf.fill f22=[r14],32
422 ldf.fill f23=[r15],32
423 mov b2=r23
424 ;;
425 mov ar.bspstore=r27
426 mov ar.unat=r29 // establish unat holding the NaT bits for r4-r7
427 mov b3=r24
428 ;;
429 ldf.fill f24=[r14],32
430 ldf.fill f25=[r15],32
431 mov b4=r25
432 ;;
433 ldf.fill f26=[r14],32
434 ldf.fill f27=[r15],32
435 mov b5=r26
436 ;;
437 ldf.fill f28=[r14],32
438 ldf.fill f29=[r15],32
439 mov ar.pfs=r16
440 ;;
441 ldf.fill f30=[r14],32
442 ldf.fill f31=[r15],24
443 mov ar.lc=r17
444 ;;
445 ld8.fill r4=[r14],16
446 ld8.fill r5=[r15],16
447 mov pr=r28,-1
448 ;;
449 ld8.fill r6=[r14],16
450 ld8.fill r7=[r15],16
452 mov ar.unat=r18 // restore caller's unat
453 mov ar.rnat=r30 // must restore after bspstore but before rsc!
454 mov ar.fpsr=r19 // restore fpsr
455 mov ar.rsc=3 // put RSE back into eager mode, pl 0
456 br.cond.sptk.many b7
457 END(load_switch_stack)
459 /*
460 * Invoke a system call, but do some tracing before and after the call.
461 * We MUST preserve the current register frame throughout this routine
462 * because some system calls (such as ia64_execve) directly
463 * manipulate ar.pfs.
464 */
465 GLOBAL_ENTRY(ia64_trace_syscall)
466 PT_REGS_UNWIND_INFO(0)
467 /*
468 * We need to preserve the scratch registers f6-f11 in case the system
469 * call is sigreturn.
470 */
471 adds r16=PT(F6)+16,sp
472 adds r17=PT(F7)+16,sp
473 ;;
474 stf.spill [r16]=f6,32
475 stf.spill [r17]=f7,32
476 ;;
477 stf.spill [r16]=f8,32
478 stf.spill [r17]=f9,32
479 ;;
480 stf.spill [r16]=f10
481 stf.spill [r17]=f11
482 br.call.sptk.many rp=syscall_trace_enter // give parent a chance to catch syscall args
483 cmp.lt p6,p0=r8,r0 // check tracehook
484 adds r2=PT(R8)+16,sp // r2 = &pt_regs.r8
485 adds r3=PT(R10)+16,sp // r3 = &pt_regs.r10
486 mov r10=0
487 (p6) br.cond.sptk strace_error // syscall failed ->
488 adds r16=PT(F6)+16,sp
489 adds r17=PT(F7)+16,sp
490 ;;
491 ldf.fill f6=[r16],32
492 ldf.fill f7=[r17],32
493 ;;
494 ldf.fill f8=[r16],32
495 ldf.fill f9=[r17],32
496 ;;
497 ldf.fill f10=[r16]
498 ldf.fill f11=[r17]
499 // the syscall number may have changed, so re-load it and re-calculate the
500 // syscall entry-point:
501 adds r15=PT(R15)+16,sp // r15 = &pt_regs.r15 (syscall #)
502 ;;
503 ld8 r15=[r15]
504 mov r3=NR_syscalls - 1
505 ;;
506 adds r15=-1024,r15
507 movl r16=sys_call_table
508 ;;
509 shladd r20=r15,3,r16 // r20 = sys_call_table + 8*(syscall-1024)
510 cmp.leu p6,p7=r15,r3
511 ;;
512 (p6) ld8 r20=[r20] // load address of syscall entry point
513 (p7) movl r20=sys_ni_syscall
514 ;;
515 mov b6=r20
516 br.call.sptk.many rp=b6 // do the syscall
517 .strace_check_retval:
518 cmp.lt p6,p0=r8,r0 // syscall failed?
519 adds r2=PT(R8)+16,sp // r2 = &pt_regs.r8
520 adds r3=PT(R10)+16,sp // r3 = &pt_regs.r10
521 mov r10=0
522 (p6) br.cond.sptk strace_error // syscall failed ->
523 ;; // avoid RAW on r10
524 .strace_save_retval:
525 .mem.offset 0,0; st8.spill [r2]=r8 // store return value in slot for r8
526 .mem.offset 8,0; st8.spill [r3]=r10 // clear error indication in slot for r10
527 br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
528 .ret3:
529 (pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk
530 (pUStk) rsm psr.i // disable interrupts
531 br.cond.sptk ia64_work_pending_syscall_end
533 strace_error:
534 ld8 r3=[r2] // load pt_regs.r8
535 sub r9=0,r8 // negate return value to get errno value
536 ;;
537 cmp.ne p6,p0=r3,r0 // is pt_regs.r8!=0?
538 adds r3=16,r2 // r3=&pt_regs.r10
539 ;;
540 (p6) mov r10=-1
541 (p6) mov r8=r9
542 br.cond.sptk .strace_save_retval
543 END(ia64_trace_syscall)
545 /*
546 * When traced and returning from sigreturn, we invoke syscall_trace but then
547 * go straight to ia64_leave_kernel rather than ia64_leave_syscall.
548 */
549 GLOBAL_ENTRY(ia64_strace_leave_kernel)
550 PT_REGS_UNWIND_INFO(0)
551 { /*
552 * Some versions of gas generate bad unwind info if the first instruction of a
553 * procedure doesn't go into the first slot of a bundle. This is a workaround.
554 */
555 nop.m 0
556 nop.i 0
557 br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
558 }
559 .ret4: br.cond.sptk ia64_leave_kernel
560 END(ia64_strace_leave_kernel)
562 ENTRY(call_payload)
563 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0)
564 /* call the kernel_thread payload; fn is in r4, arg - in r5 */
565 alloc loc1=ar.pfs,0,3,1,0
566 mov loc0=rp
567 mov loc2=gp
568 mov out0=r5 // arg
569 ld8 r14 = [r4], 8 // fn.address
570 ;;
571 mov b6 = r14
572 ld8 gp = [r4] // fn.gp
573 ;;
574 br.call.sptk.many rp=b6 // fn(arg)
575 .ret12: mov gp=loc2
576 mov rp=loc0
577 mov ar.pfs=loc1
578 /* ... and if it has returned, we are going to userland */
579 cmp.ne pKStk,pUStk=r0,r0
580 br.ret.sptk.many rp
581 END(call_payload)
583 GLOBAL_ENTRY(ia64_ret_from_clone)
584 PT_REGS_UNWIND_INFO(0)
585 { /*
586 * Some versions of gas generate bad unwind info if the first instruction of a
587 * procedure doesn't go into the first slot of a bundle. This is a workaround.
588 */
589 nop.m 0
590 nop.i 0
591 /*
592 * We need to call schedule_tail() to complete the scheduling process.
593 * Called by ia64_switch_to() after do_fork()->copy_thread(). r8 contains the
594 * address of the previously executing task.
595 */
596 br.call.sptk.many rp=ia64_invoke_schedule_tail
597 }
598 .ret8:
599 (pKStk) br.call.sptk.many rp=call_payload
600 adds r2=TI_FLAGS+IA64_TASK_SIZE,r13
601 ;;
602 ld4 r2=[r2]
603 ;;
604 mov r8=0
605 and r2=_TIF_SYSCALL_TRACEAUDIT,r2
606 ;;
607 cmp.ne p6,p0=r2,r0
608 (p6) br.cond.spnt .strace_check_retval
609 ;; // added stop bits to prevent r8 dependency
610 END(ia64_ret_from_clone)
611 // fall through
612 GLOBAL_ENTRY(ia64_ret_from_syscall)
613 PT_REGS_UNWIND_INFO(0)
614 cmp.ge p6,p7=r8,r0 // syscall executed successfully?
615 adds r2=PT(R8)+16,sp // r2 = &pt_regs.r8
616 mov r10=r0 // clear error indication in r10
617 (p7) br.cond.spnt handle_syscall_error // handle potential syscall failure
618 END(ia64_ret_from_syscall)
619 // fall through
621 /*
622 * ia64_leave_syscall(): Same as ia64_leave_kernel, except that it doesn't
623 * need to switch to bank 0 and doesn't restore the scratch registers.
624 * To avoid leaking kernel bits, the scratch registers are set to
625 * the following known-to-be-safe values:
626 *
627 * r1: restored (global pointer)
628 * r2: cleared
629 * r3: 1 (when returning to user-level)
630 * r8-r11: restored (syscall return value(s))
631 * r12: restored (user-level stack pointer)
632 * r13: restored (user-level thread pointer)
633 * r14: set to __kernel_syscall_via_epc
634 * r15: restored (syscall #)
635 * r16-r17: cleared
636 * r18: user-level b6
637 * r19: cleared
638 * r20: user-level ar.fpsr
639 * r21: user-level b0
640 * r22: cleared
641 * r23: user-level ar.bspstore
642 * r24: user-level ar.rnat
643 * r25: user-level ar.unat
644 * r26: user-level ar.pfs
645 * r27: user-level ar.rsc
646 * r28: user-level ip
647 * r29: user-level psr
648 * r30: user-level cfm
649 * r31: user-level pr
650 * f6-f11: cleared
651 * pr: restored (user-level pr)
652 * b0: restored (user-level rp)
653 * b6: restored
654 * b7: set to __kernel_syscall_via_epc
655 * ar.unat: restored (user-level ar.unat)
656 * ar.pfs: restored (user-level ar.pfs)
657 * ar.rsc: restored (user-level ar.rsc)
658 * ar.rnat: restored (user-level ar.rnat)
659 * ar.bspstore: restored (user-level ar.bspstore)
660 * ar.fpsr: restored (user-level ar.fpsr)
661 * ar.ccv: cleared
662 * ar.csd: cleared
663 * ar.ssd: cleared
664 */
665 GLOBAL_ENTRY(ia64_leave_syscall)
666 PT_REGS_UNWIND_INFO(0)
667 /*
668 * work.need_resched etc. mustn't get changed by this CPU before it returns to
669 * user- or fsys-mode, hence we disable interrupts early on.
670 *
671 * p6 controls whether current_thread_info()->flags needs to be check for
672 * extra work. We always check for extra work when returning to user-level.
673 * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count
674 * is 0. After extra work processing has been completed, execution
675 * resumes at ia64_work_processed_syscall with p6 set to 1 if the extra-work-check
676 * needs to be redone.
677 */
678 #ifdef CONFIG_PREEMPTION
679 RSM_PSR_I(p0, r2, r18) // disable interrupts
680 cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall
681 (pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
682 ;;
683 .pred.rel.mutex pUStk,pKStk
684 (pKStk) ld4 r21=[r20] // r21 <- preempt_count
685 (pUStk) mov r21=0 // r21 <- 0
686 ;;
687 cmp.eq p6,p0=r21,r0 // p6 <- pUStk || (preempt_count == 0)
688 #else /* !CONFIG_PREEMPTION */
689 RSM_PSR_I(pUStk, r2, r18)
690 cmp.eq pLvSys,p0=r0,r0 // pLvSys=1: leave from syscall
691 (pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk
692 #endif
693 .global ia64_work_processed_syscall;
694 ia64_work_processed_syscall:
695 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
696 adds r2=PT(LOADRS)+16,r12
697 MOV_FROM_ITC(pUStk, p9, r22, r19) // fetch time at leave
698 adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
699 ;;
700 (p6) ld4 r31=[r18] // load current_thread_info()->flags
701 ld8 r19=[r2],PT(B6)-PT(LOADRS) // load ar.rsc value for "loadrs"
702 adds r3=PT(AR_BSPSTORE)+16,r12 // deferred
703 ;;
704 #else
705 adds r2=PT(LOADRS)+16,r12
706 adds r3=PT(AR_BSPSTORE)+16,r12
707 adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
708 ;;
709 (p6) ld4 r31=[r18] // load current_thread_info()->flags
710 ld8 r19=[r2],PT(B6)-PT(LOADRS) // load ar.rsc value for "loadrs"
711 nop.i 0
712 ;;
713 #endif
714 mov r16=ar.bsp // M2 get existing backing store pointer
715 ld8 r18=[r2],PT(R9)-PT(B6) // load b6
716 (p6) and r15=TIF_WORK_MASK,r31 // any work other than TIF_SYSCALL_TRACE?
717 ;;
718 ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE) // load ar.bspstore (may be garbage)
719 (p6) cmp4.ne.unc p6,p0=r15, r0 // any special work pending?
720 (p6) br.cond.spnt .work_pending_syscall
721 ;;
722 // start restoring the state saved on the kernel stack (struct pt_regs):
723 ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
724 ld8 r11=[r3],PT(CR_IIP)-PT(R11)
725 (pNonSys) break 0 // bug check: we shouldn't be here if pNonSys is TRUE!
726 ;;
727 invala // M0|1 invalidate ALAT
728 RSM_PSR_I_IC(r28, r29, r30) // M2 turn off interrupts and interruption collection
729 cmp.eq p9,p0=r0,r0 // A set p9 to indicate that we should restore cr.ifs
731 ld8 r29=[r2],16 // M0|1 load cr.ipsr
732 ld8 r28=[r3],16 // M0|1 load cr.iip
733 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
734 (pUStk) add r14=TI_AC_LEAVE+IA64_TASK_SIZE,r13
735 ;;
736 ld8 r30=[r2],16 // M0|1 load cr.ifs
737 ld8 r25=[r3],16 // M0|1 load ar.unat
738 (pUStk) add r15=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
739 ;;
740 #else
741 mov r22=r0 // A clear r22
742 ;;
743 ld8 r30=[r2],16 // M0|1 load cr.ifs
744 ld8 r25=[r3],16 // M0|1 load ar.unat
745 (pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
746 ;;
747 #endif
748 ld8 r26=[r2],PT(B0)-PT(AR_PFS) // M0|1 load ar.pfs
749 MOV_FROM_PSR(pKStk, r22, r21) // M2 read PSR now that interrupts are disabled
750 nop 0
751 ;;
752 ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
753 ld8 r27=[r3],PT(PR)-PT(AR_RSC) // M0|1 load ar.rsc
754 mov f6=f0 // F clear f6
755 ;;
756 ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT) // M0|1 load ar.rnat (may be garbage)
757 ld8 r31=[r3],PT(R1)-PT(PR) // M0|1 load predicates
758 mov f7=f0 // F clear f7
759 ;;
760 ld8 r20=[r2],PT(R12)-PT(AR_FPSR) // M0|1 load ar.fpsr
761 ld8.fill r1=[r3],16 // M0|1 load r1
762 (pUStk) mov r17=1 // A
763 ;;
764 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
765 (pUStk) st1 [r15]=r17 // M2|3
766 #else
767 (pUStk) st1 [r14]=r17 // M2|3
768 #endif
769 ld8.fill r13=[r3],16 // M0|1
770 mov f8=f0 // F clear f8
771 ;;
772 ld8.fill r12=[r2] // M0|1 restore r12 (sp)
773 ld8.fill r15=[r3] // M0|1 restore r15
774 mov b6=r18 // I0 restore b6
776 LOAD_PHYS_STACK_REG_SIZE(r17)
777 mov f9=f0 // F clear f9
778 (pKStk) br.cond.dpnt.many skip_rbs_switch // B
780 srlz.d // M0 ensure interruption collection is off (for cover)
781 shr.u r18=r19,16 // I0|1 get byte size of existing "dirty" partition
782 COVER // B add current frame into dirty partition & set cr.ifs
783 ;;
784 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
785 mov r19=ar.bsp // M2 get new backing store pointer
786 st8 [r14]=r22 // M save time at leave
787 mov f10=f0 // F clear f10
789 mov r22=r0 // A clear r22
790 movl r14=__kernel_syscall_via_epc // X
791 ;;
792 #else
793 mov r19=ar.bsp // M2 get new backing store pointer
794 mov f10=f0 // F clear f10
796 nop.m 0
797 movl r14=__kernel_syscall_via_epc // X
798 ;;
799 #endif
800 mov.m ar.csd=r0 // M2 clear ar.csd
801 mov.m ar.ccv=r0 // M2 clear ar.ccv
802 mov b7=r14 // I0 clear b7 (hint with __kernel_syscall_via_epc)
804 mov.m ar.ssd=r0 // M2 clear ar.ssd
805 mov f11=f0 // F clear f11
806 br.cond.sptk.many rbs_switch // B
807 END(ia64_leave_syscall)
809 GLOBAL_ENTRY(ia64_leave_kernel)
810 PT_REGS_UNWIND_INFO(0)
811 /*
812 * work.need_resched etc. mustn't get changed by this CPU before it returns to
813 * user- or fsys-mode, hence we disable interrupts early on.
814 *
815 * p6 controls whether current_thread_info()->flags needs to be check for
816 * extra work. We always check for extra work when returning to user-level.
817 * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count
818 * is 0. After extra work processing has been completed, execution
819 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
820 * needs to be redone.
821 */
822 #ifdef CONFIG_PREEMPTION
823 RSM_PSR_I(p0, r17, r31) // disable interrupts
824 cmp.eq p0,pLvSys=r0,r0 // pLvSys=0: leave from kernel
825 (pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
826 ;;
827 .pred.rel.mutex pUStk,pKStk
828 (pKStk) ld4 r21=[r20] // r21 <- preempt_count
829 (pUStk) mov r21=0 // r21 <- 0
830 ;;
831 cmp.eq p6,p0=r21,r0 // p6 <- pUStk || (preempt_count == 0)
832 #else
833 RSM_PSR_I(pUStk, r17, r31)
834 cmp.eq p0,pLvSys=r0,r0 // pLvSys=0: leave from kernel
835 (pUStk) cmp.eq.unc p6,p0=r0,r0 // p6 <- pUStk
836 #endif
837 .work_processed_kernel:
838 adds r17=TI_FLAGS+IA64_TASK_SIZE,r13
839 ;;
840 (p6) ld4 r31=[r17] // load current_thread_info()->flags
841 adds r21=PT(PR)+16,r12
842 ;;
844 lfetch [r21],PT(CR_IPSR)-PT(PR)
845 adds r2=PT(B6)+16,r12
846 adds r3=PT(R16)+16,r12
847 ;;
848 lfetch [r21]
849 ld8 r28=[r2],8 // load b6
850 adds r29=PT(R24)+16,r12
852 ld8.fill r16=[r3],PT(AR_CSD)-PT(R16)
853 adds r30=PT(AR_CCV)+16,r12
854 (p6) and r19=TIF_WORK_MASK,r31 // any work other than TIF_SYSCALL_TRACE?
855 ;;
856 ld8.fill r24=[r29]
857 ld8 r15=[r30] // load ar.ccv
858 (p6) cmp4.ne.unc p6,p0=r19, r0 // any special work pending?
859 ;;
860 ld8 r29=[r2],16 // load b7
861 ld8 r30=[r3],16 // load ar.csd
862 (p6) br.cond.spnt .work_pending
863 ;;
864 ld8 r31=[r2],16 // load ar.ssd
865 ld8.fill r8=[r3],16
866 ;;
867 ld8.fill r9=[r2],16
868 ld8.fill r10=[r3],PT(R17)-PT(R10)
869 ;;
870 ld8.fill r11=[r2],PT(R18)-PT(R11)
871 ld8.fill r17=[r3],16
872 ;;
873 ld8.fill r18=[r2],16
874 ld8.fill r19=[r3],16
875 ;;
876 ld8.fill r20=[r2],16
877 ld8.fill r21=[r3],16
878 mov ar.csd=r30
879 mov ar.ssd=r31
880 ;;
881 RSM_PSR_I_IC(r23, r22, r25) // initiate turning off of interrupt and interruption collection
882 invala // invalidate ALAT
883 ;;
884 ld8.fill r22=[r2],24
885 ld8.fill r23=[r3],24
886 mov b6=r28
887 ;;
888 ld8.fill r25=[r2],16
889 ld8.fill r26=[r3],16
890 mov b7=r29
891 ;;
892 ld8.fill r27=[r2],16
893 ld8.fill r28=[r3],16
894 ;;
895 ld8.fill r29=[r2],16
896 ld8.fill r30=[r3],24
897 ;;
898 ld8.fill r31=[r2],PT(F9)-PT(R31)
899 adds r3=PT(F10)-PT(F6),r3
900 ;;
901 ldf.fill f9=[r2],PT(F6)-PT(F9)
902 ldf.fill f10=[r3],PT(F8)-PT(F10)
903 ;;
904 ldf.fill f6=[r2],PT(F7)-PT(F6)
905 ;;
906 ldf.fill f7=[r2],PT(F11)-PT(F7)
907 ldf.fill f8=[r3],32
908 ;;
909 srlz.d // ensure that inter. collection is off (VHPT is don't care, since text is pinned)
910 mov ar.ccv=r15
911 ;;
912 ldf.fill f11=[r2]
913 BSW_0(r2, r3, r15) // switch back to bank 0 (no stop bit required beforehand...)
914 ;;
915 (pUStk) mov r18=IA64_KR(CURRENT)// M2 (12 cycle read latency)
916 adds r16=PT(CR_IPSR)+16,r12
917 adds r17=PT(CR_IIP)+16,r12
919 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
920 .pred.rel.mutex pUStk,pKStk
921 MOV_FROM_PSR(pKStk, r22, r29) // M2 read PSR now that interrupts are disabled
922 MOV_FROM_ITC(pUStk, p9, r22, r29) // M fetch time at leave
923 nop.i 0
924 ;;
925 #else
926 MOV_FROM_PSR(pKStk, r22, r29) // M2 read PSR now that interrupts are disabled
927 nop.i 0
928 nop.i 0
929 ;;
930 #endif
931 ld8 r29=[r16],16 // load cr.ipsr
932 ld8 r28=[r17],16 // load cr.iip
933 ;;
934 ld8 r30=[r16],16 // load cr.ifs
935 ld8 r25=[r17],16 // load ar.unat
936 ;;
937 ld8 r26=[r16],16 // load ar.pfs
938 ld8 r27=[r17],16 // load ar.rsc
939 cmp.eq p9,p0=r0,r0 // set p9 to indicate that we should restore cr.ifs
940 ;;
941 ld8 r24=[r16],16 // load ar.rnat (may be garbage)
942 ld8 r23=[r17],16 // load ar.bspstore (may be garbage)
943 ;;
944 ld8 r31=[r16],16 // load predicates
945 ld8 r21=[r17],16 // load b0
946 ;;
947 ld8 r19=[r16],16 // load ar.rsc value for "loadrs"
948 ld8.fill r1=[r17],16 // load r1
949 ;;
950 ld8.fill r12=[r16],16
951 ld8.fill r13=[r17],16
952 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
953 (pUStk) adds r3=TI_AC_LEAVE+IA64_TASK_SIZE,r18
954 #else
955 (pUStk) adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
956 #endif
957 ;;
958 ld8 r20=[r16],16 // ar.fpsr
959 ld8.fill r15=[r17],16
960 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
961 (pUStk) adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18 // deferred
962 #endif
963 ;;
964 ld8.fill r14=[r16],16
965 ld8.fill r2=[r17]
966 (pUStk) mov r17=1
967 ;;
968 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
969 // mmi_ : ld8 st1 shr;; mmi_ : st8 st1 shr;;
970 // mib : mov add br -> mib : ld8 add br
971 // bbb_ : br nop cover;; mbb_ : mov br cover;;
972 //
973 // no one require bsp in r16 if (pKStk) branch is selected.
974 (pUStk) st8 [r3]=r22 // save time at leave
975 (pUStk) st1 [r18]=r17 // restore current->thread.on_ustack
976 shr.u r18=r19,16 // get byte size of existing "dirty" partition
977 ;;
978 ld8.fill r3=[r16] // deferred
979 LOAD_PHYS_STACK_REG_SIZE(r17)
980 (pKStk) br.cond.dpnt skip_rbs_switch
981 mov r16=ar.bsp // get existing backing store pointer
982 #else
983 ld8.fill r3=[r16]
984 (pUStk) st1 [r18]=r17 // restore current->thread.on_ustack
985 shr.u r18=r19,16 // get byte size of existing "dirty" partition
986 ;;
987 mov r16=ar.bsp // get existing backing store pointer
988 LOAD_PHYS_STACK_REG_SIZE(r17)
989 (pKStk) br.cond.dpnt skip_rbs_switch
990 #endif
992 /*
993 * Restore user backing store.
994 *
995 * NOTE: alloc, loadrs, and cover can't be predicated.
996 */
997 (pNonSys) br.cond.dpnt dont_preserve_current_frame
998 COVER // add current frame into dirty partition and set cr.ifs
999 ;;
1000 mov r19=ar.bsp // get new backing store pointer
1001 rbs_switch:
1002 sub r16=r16,r18 // krbs = old bsp - size of dirty partition
1003 cmp.ne p9,p0=r0,r0 // clear p9 to skip restore of cr.ifs
1004 ;;
1005 sub r19=r19,r16 // calculate total byte size of dirty partition
1006 add r18=64,r18 // don't force in0-in7 into memory...
1007 ;;
1008 shl r19=r19,16 // shift size of dirty partition into loadrs position
1009 ;;
1010 dont_preserve_current_frame:
1011 /*
1012 * To prevent leaking bits between the kernel and user-space,
1013 * we must clear the stacked registers in the "invalid" partition here.
1014 * Not pretty, but at least it's fast (3.34 registers/cycle on Itanium,
1015 * 5 registers/cycle on McKinley).
1016 */
1017 # define pRecurse p6
1018 # define pReturn p7
1019 #ifdef CONFIG_ITANIUM
1020 # define Nregs 10
1021 #else
1022 # define Nregs 14
1023 #endif
1024 alloc loc0=ar.pfs,2,Nregs-2,2,0
1025 shr.u loc1=r18,9 // RNaTslots <= floor(dirtySize / (64*8))
1026 sub r17=r17,r18 // r17 = (physStackedSize + 8) - dirtySize
1027 ;;
1028 mov ar.rsc=r19 // load ar.rsc to be used for "loadrs"
1029 shladd in0=loc1,3,r17
1030 mov in1=0
1031 ;;
1032 TEXT_ALIGN(32)
1033 rse_clear_invalid:
1034 #ifdef CONFIG_ITANIUM
1035 // cycle 0
1036 { .mii
1037 alloc loc0=ar.pfs,2,Nregs-2,2,0
1038 cmp.lt pRecurse,p0=Nregs*8,in0 // if more than Nregs regs left to clear, (re)curse
1039 add out0=-Nregs*8,in0
1040 }{ .mfb
1041 add out1=1,in1 // increment recursion count
1042 nop.f 0
1043 nop.b 0 // can't do br.call here because of alloc (WAW on CFM)
1044 ;;
1045 }{ .mfi // cycle 1
1046 mov loc1=0
1047 nop.f 0
1048 mov loc2=0
1049 }{ .mib
1050 mov loc3=0
1051 mov loc4=0
1052 (pRecurse) br.call.sptk.many b0=rse_clear_invalid
1054 }{ .mfi // cycle 2
1055 mov loc5=0
1056 nop.f 0
1057 cmp.ne pReturn,p0=r0,in1 // if recursion count != 0, we need to do a br.ret
1058 }{ .mib
1059 mov loc6=0
1060 mov loc7=0
1061 (pReturn) br.ret.sptk.many b0
1062 }
1063 #else /* !CONFIG_ITANIUM */
1064 alloc loc0=ar.pfs,2,Nregs-2,2,0
1065 cmp.lt pRecurse,p0=Nregs*8,in0 // if more than Nregs regs left to clear, (re)curse
1066 add out0=-Nregs*8,in0
1067 add out1=1,in1 // increment recursion count
1068 mov loc1=0
1069 mov loc2=0
1070 ;;
1071 mov loc3=0
1072 mov loc4=0
1073 mov loc5=0
1074 mov loc6=0
1075 mov loc7=0
1076 (pRecurse) br.call.dptk.few b0=rse_clear_invalid
1077 ;;
1078 mov loc8=0
1079 mov loc9=0
1080 cmp.ne pReturn,p0=r0,in1 // if recursion count != 0, we need to do a br.ret
1081 mov loc10=0
1082 mov loc11=0
1083 (pReturn) br.ret.dptk.many b0
1084 #endif /* !CONFIG_ITANIUM */
1085 # undef pRecurse
1086 # undef pReturn
1087 ;;
1088 alloc r17=ar.pfs,0,0,0,0 // drop current register frame
1089 ;;
1090 loadrs
1091 ;;
1092 skip_rbs_switch:
1093 mov ar.unat=r25 // M2
1094 (pKStk) extr.u r22=r22,21,1 // I0 extract current value of psr.pp from r22
1095 (pLvSys)mov r19=r0 // A clear r19 for leave_syscall, no-op otherwise
1096 ;;
1097 (pUStk) mov ar.bspstore=r23 // M2
1098 (pKStk) dep r29=r22,r29,21,1 // I0 update ipsr.pp with psr.pp
1099 (pLvSys)mov r16=r0 // A clear r16 for leave_syscall, no-op otherwise
1100 ;;
1101 MOV_TO_IPSR(p0, r29, r25) // M2
1102 mov ar.pfs=r26 // I0
1103 (pLvSys)mov r17=r0 // A clear r17 for leave_syscall, no-op otherwise
1105 MOV_TO_IFS(p9, r30, r25)// M2
1106 mov b0=r21 // I0
1107 (pLvSys)mov r18=r0 // A clear r18 for leave_syscall, no-op otherwise
1109 mov ar.fpsr=r20 // M2
1110 MOV_TO_IIP(r28, r25) // M2
1111 nop 0
1112 ;;
1113 (pUStk) mov ar.rnat=r24 // M2 must happen with RSE in lazy mode
1114 nop 0
1115 (pLvSys)mov r2=r0
1117 mov ar.rsc=r27 // M2
1118 mov pr=r31,-1 // I0
1119 RFI // B
1121 /*
1122 * On entry:
1123 * r20 = ¤t->thread_info->pre_count (if CONFIG_PREEMPTION)
1124 * r31 = current->thread_info->flags
1125 * On exit:
1126 * p6 = TRUE if work-pending-check needs to be redone
1127 *
1128 * Interrupts are disabled on entry, reenabled depend on work, and
1129 * disabled on exit.
1130 */
1131 .work_pending_syscall:
1132 add r2=-8,r2
1133 add r3=-8,r3
1134 ;;
1135 st8 [r2]=r8
1136 st8 [r3]=r10
1137 .work_pending:
1138 tbit.z p6,p0=r31,TIF_NEED_RESCHED // is resched not needed?
1139 (p6) br.cond.sptk.few .notify
1140 br.call.spnt.many rp=preempt_schedule_irq
1141 .ret9: cmp.eq p6,p0=r0,r0 // p6 <- 1 (re-check)
1142 (pLvSys)br.cond.sptk.few ia64_work_pending_syscall_end
1143 br.cond.sptk.many .work_processed_kernel
1145 .notify:
1146 (pUStk) br.call.spnt.many rp=notify_resume_user
1147 .ret10: cmp.ne p6,p0=r0,r0 // p6 <- 0 (don't re-check)
1148 (pLvSys)br.cond.sptk.few ia64_work_pending_syscall_end
1149 br.cond.sptk.many .work_processed_kernel
1151 .global ia64_work_pending_syscall_end;
1152 ia64_work_pending_syscall_end:
1153 adds r2=PT(R8)+16,r12
1154 adds r3=PT(R10)+16,r12
1155 ;;
1156 ld8 r8=[r2]
1157 ld8 r10=[r3]
1158 br.cond.sptk.many ia64_work_processed_syscall
1159 END(ia64_leave_kernel)
1161 ENTRY(handle_syscall_error)
1162 /*
1163 * Some system calls (e.g., ptrace, mmap) can return arbitrary values which could
1164 * lead us to mistake a negative return value as a failed syscall. Those syscall
1165 * must deposit a non-zero value in pt_regs.r8 to indicate an error. If
1166 * pt_regs.r8 is zero, we assume that the call completed successfully.
1167 */
1168 PT_REGS_UNWIND_INFO(0)
1169 ld8 r3=[r2] // load pt_regs.r8
1170 ;;
1171 cmp.eq p6,p7=r3,r0 // is pt_regs.r8==0?
1172 ;;
1173 (p7) mov r10=-1
1174 (p7) sub r8=0,r8 // negate return value to get errno
1175 br.cond.sptk ia64_leave_syscall
1176 END(handle_syscall_error)
1178 /*
1179 * Invoke schedule_tail(task) while preserving in0-in7, which may be needed
1180 * in case a system call gets restarted.
1181 */
1182 GLOBAL_ENTRY(ia64_invoke_schedule_tail)
1183 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1184 alloc loc1=ar.pfs,8,2,1,0
1185 mov loc0=rp
1186 mov out0=r8 // Address of previous task
1187 ;;
1188 br.call.sptk.many rp=schedule_tail
1189 .ret11: mov ar.pfs=loc1
1190 mov rp=loc0
1191 br.ret.sptk.many rp
1192 END(ia64_invoke_schedule_tail)
1194 /*
1195 * Setup stack and call do_notify_resume_user(), keeping interrupts
1196 * disabled.
1197 *
1198 * Note that pSys and pNonSys need to be set up by the caller.
1199 * We declare 8 input registers so the system call args get preserved,
1200 * in case we need to restart a system call.
1201 */
1202 GLOBAL_ENTRY(notify_resume_user)
1203 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1204 alloc loc1=ar.pfs,8,2,3,0 // preserve all eight input regs in case of syscall restart!
1205 mov r9=ar.unat
1206 mov loc0=rp // save return address
1207 mov out0=0 // there is no "oldset"
1208 adds out1=8,sp // out1=&sigscratch->ar_pfs
1209 (pSys) mov out2=1 // out2==1 => we're in a syscall
1210 ;;
1211 (pNonSys) mov out2=0 // out2==0 => not a syscall
1212 .fframe 16
1213 .spillsp ar.unat, 16
1214 st8 [sp]=r9,-16 // allocate space for ar.unat and save it
1215 st8 [out1]=loc1,-8 // save ar.pfs, out1=&sigscratch
1216 .body
1217 br.call.sptk.many rp=do_notify_resume_user
1218 .ret15: .restore sp
1219 adds sp=16,sp // pop scratch stack space
1220 ;;
1221 ld8 r9=[sp] // load new unat from sigscratch->scratch_unat
1222 mov rp=loc0
1223 ;;
1224 mov ar.unat=r9
1225 mov ar.pfs=loc1
1226 br.ret.sptk.many rp
1227 END(notify_resume_user)
1229 ENTRY(sys_rt_sigreturn)
1230 PT_REGS_UNWIND_INFO(0)
1231 /*
1232 * Allocate 8 input registers since ptrace() may clobber them
1233 */
1234 alloc r2=ar.pfs,8,0,1,0
1235 .prologue
1236 PT_REGS_SAVES(16)
1237 adds sp=-16,sp
1238 .body
1239 cmp.eq pNonSys,pSys=r0,r0 // sigreturn isn't a normal syscall...
1240 ;;
1241 /*
1242 * leave_kernel() restores f6-f11 from pt_regs, but since the streamlined
1243 * syscall-entry path does not save them we save them here instead. Note: we
1244 * don't need to save any other registers that are not saved by the stream-lined
1245 * syscall path, because restore_sigcontext() restores them.
1246 */
1247 adds r16=PT(F6)+32,sp
1248 adds r17=PT(F7)+32,sp
1249 ;;
1250 stf.spill [r16]=f6,32
1251 stf.spill [r17]=f7,32
1252 ;;
1253 stf.spill [r16]=f8,32
1254 stf.spill [r17]=f9,32
1255 ;;
1256 stf.spill [r16]=f10
1257 stf.spill [r17]=f11
1258 adds out0=16,sp // out0 = &sigscratch
1259 br.call.sptk.many rp=ia64_rt_sigreturn
1260 .ret19: .restore sp,0
1261 adds sp=16,sp
1262 ;;
1263 ld8 r9=[sp] // load new ar.unat
1264 mov.sptk b7=r8,ia64_leave_kernel
1265 ;;
1266 mov ar.unat=r9
1267 br.many b7
1268 END(sys_rt_sigreturn)
1270 GLOBAL_ENTRY(ia64_prepare_handle_unaligned)
1271 .prologue
1272 /*
1273 * r16 = fake ar.pfs, we simply need to make sure privilege is still 0
1274 */
1275 mov r16=r0
1276 DO_SAVE_SWITCH_STACK
1277 br.call.sptk.many rp=ia64_handle_unaligned // stack frame setup in ivt
1278 .ret21: .body
1279 DO_LOAD_SWITCH_STACK
1280 br.cond.sptk.many rp // goes to ia64_leave_kernel
1281 END(ia64_prepare_handle_unaligned)
1283 //
1284 // unw_init_running(void (*callback)(info, arg), void *arg)
1285 //
1286 # define EXTRA_FRAME_SIZE ((UNW_FRAME_INFO_SIZE+15)&~15)
1288 GLOBAL_ENTRY(unw_init_running)
1289 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1290 alloc loc1=ar.pfs,2,3,3,0
1291 ;;
1292 ld8 loc2=[in0],8
1293 mov loc0=rp
1294 mov r16=loc1
1295 DO_SAVE_SWITCH_STACK
1296 .body
1298 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1299 .fframe IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE
1300 SWITCH_STACK_SAVES(EXTRA_FRAME_SIZE)
1301 adds sp=-EXTRA_FRAME_SIZE,sp
1302 .body
1303 ;;
1304 adds out0=16,sp // &info
1305 mov out1=r13 // current
1306 adds out2=16+EXTRA_FRAME_SIZE,sp // &switch_stack
1307 br.call.sptk.many rp=unw_init_frame_info
1308 1: adds out0=16,sp // &info
1309 mov b6=loc2
1310 mov loc2=gp // save gp across indirect function call
1311 ;;
1312 ld8 gp=[in0]
1313 mov out1=in1 // arg
1314 br.call.sptk.many rp=b6 // invoke the callback function
1315 1: mov gp=loc2 // restore gp
1317 // For now, we don't allow changing registers from within
1318 // unw_init_running; if we ever want to allow that, we'd
1319 // have to do a load_switch_stack here:
1320 .restore sp
1321 adds sp=IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE,sp
1323 mov ar.pfs=loc1
1324 mov rp=loc0
1325 br.ret.sptk.many rp
1326 END(unw_init_running)
1327 EXPORT_SYMBOL(unw_init_running)
1329 #ifdef CONFIG_FUNCTION_TRACER
1330 #ifdef CONFIG_DYNAMIC_FTRACE
1331 GLOBAL_ENTRY(_mcount)
1332 br ftrace_stub
1333 END(_mcount)
1334 EXPORT_SYMBOL(_mcount)
1336 .here:
1337 br.ret.sptk.many b0
1339 GLOBAL_ENTRY(ftrace_caller)
1340 alloc out0 = ar.pfs, 8, 0, 4, 0
1341 mov out3 = r0
1342 ;;
1343 mov out2 = b0
1344 add r3 = 0x20, r3
1345 mov out1 = r1;
1346 br.call.sptk.many b0 = ftrace_patch_gp
1347 //this might be called from module, so we must patch gp
1348 ftrace_patch_gp:
1349 movl gp=__gp
1350 mov b0 = r3
1351 ;;
1352 .global ftrace_call;
1353 ftrace_call:
1354 {
1355 .mlx
1356 nop.m 0x0
1357 movl r3 = .here;;
1358 }
1359 alloc loc0 = ar.pfs, 4, 4, 2, 0
1360 ;;
1361 mov loc1 = b0
1362 mov out0 = b0
1363 mov loc2 = r8
1364 mov loc3 = r15
1365 ;;
1366 adds out0 = -MCOUNT_INSN_SIZE, out0
1367 mov out1 = in2
1368 mov b6 = r3
1370 br.call.sptk.many b0 = b6
1371 ;;
1372 mov ar.pfs = loc0
1373 mov b0 = loc1
1374 mov r8 = loc2
1375 mov r15 = loc3
1376 br ftrace_stub
1377 ;;
1378 END(ftrace_caller)
1380 #else
1381 GLOBAL_ENTRY(_mcount)
1382 movl r2 = ftrace_stub
1383 movl r3 = ftrace_trace_function;;
1384 ld8 r3 = [r3];;
1385 ld8 r3 = [r3];;
1386 cmp.eq p7,p0 = r2, r3
1387 (p7) br.sptk.many ftrace_stub
1388 ;;
1390 alloc loc0 = ar.pfs, 4, 4, 2, 0
1391 ;;
1392 mov loc1 = b0
1393 mov out0 = b0
1394 mov loc2 = r8
1395 mov loc3 = r15
1396 ;;
1397 adds out0 = -MCOUNT_INSN_SIZE, out0
1398 mov out1 = in2
1399 mov b6 = r3
1401 br.call.sptk.many b0 = b6
1402 ;;
1403 mov ar.pfs = loc0
1404 mov b0 = loc1
1405 mov r8 = loc2
1406 mov r15 = loc3
1407 br ftrace_stub
1408 ;;
1409 END(_mcount)
1410 #endif
1412 GLOBAL_ENTRY(ftrace_stub)
1413 mov r3 = b0
1414 movl r2 = _mcount_ret_helper
1415 ;;
1416 mov b6 = r2
1417 mov b7 = r3
1418 br.ret.sptk.many b6
1420 _mcount_ret_helper:
1421 mov b0 = r42
1422 mov r1 = r41
1423 mov ar.pfs = r40
1424 br b7
1425 END(ftrace_stub)
1427 #endif /* CONFIG_FUNCTION_TRACER */
1429 #define __SYSCALL(nr, entry, nargs) data8 entry
1430 .rodata
1431 .align 8
1432 .globl sys_call_table
1433 sys_call_table:
1434 #include <asm/syscall_table.h>
1435 #undef __SYSCALL