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v6.2
   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 */
  39
  40
  41#include <linux/pgtable.h>
  42#include <asm/asmmacro.h>
  43#include <asm/cache.h>
  44#include <asm/errno.h>
  45#include <asm/kregs.h>
  46#include <asm/asm-offsets.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>
  53
  54#include "minstate.h"
  55
  56	/*
  57	 * execve() is special because in case of success, we need to
  58	 * setup a null register window frame.
  59	 */
  60ENTRY(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
  82
  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
 102END(ia64_execve)
 103
 104/*
 105 * sys_clone2(u64 flags, u64 ustack_base, u64 ustack_size, u64 parent_tidptr, u64 child_tidptr,
 106 *	      u64 tls)
 107 */
 108GLOBAL_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	mov loc0=rp
 116	mov loc1=r16                             // save ar.pfs across ia64_clone
 117	.body
 118	mov out0=in0
 119	mov out1=in1
 120	mov out2=in2
 121	mov out3=in3
 122	mov out4=in4
 123	mov out5=in5
 124	br.call.sptk.many rp=ia64_clone
 
 
 
 125.ret1:	.restore sp
 126	adds sp=IA64_SWITCH_STACK_SIZE,sp	// pop the switch stack
 127	mov ar.pfs=loc1
 128	mov rp=loc0
 129	br.ret.sptk.many rp
 130END(sys_clone2)
 131
 132/*
 133 * sys_clone(u64 flags, u64 ustack_base, u64 parent_tidptr, u64 child_tidptr, u64 tls)
 134 *	Deprecated.  Use sys_clone2() instead.
 135 */
 136GLOBAL_ENTRY(sys_clone)
 137	/*
 138	 * Allocate 8 input registers since ptrace() may clobber them
 139	 */
 140	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
 141	alloc r16=ar.pfs,8,2,6,0
 142	DO_SAVE_SWITCH_STACK
 
 143	mov loc0=rp
 144	mov loc1=r16                             // save ar.pfs across ia64_clone
 145	.body
 146	mov out0=in0
 147	mov out1=in1
 148	mov out2=16				// stacksize (compensates for 16-byte scratch area)
 149	mov out3=in3
 150	mov out4=in4
 151	mov out5=in5
 152	br.call.sptk.many rp=ia64_clone
 
 
 
 153.ret2:	.restore sp
 154	adds sp=IA64_SWITCH_STACK_SIZE,sp	// pop the switch stack
 155	mov ar.pfs=loc1
 156	mov rp=loc0
 157	br.ret.sptk.many rp
 158END(sys_clone)
 159
 160/*
 161 * prev_task <- ia64_switch_to(struct task_struct *next)
 162 *	With Ingo's new scheduler, interrupts are disabled when this routine gets
 163 *	called.  The code starting at .map relies on this.  The rest of the code
 164 *	doesn't care about the interrupt masking status.
 165 */
 166GLOBAL_ENTRY(ia64_switch_to)
 167	.prologue
 168	alloc r16=ar.pfs,1,0,0,0
 169	DO_SAVE_SWITCH_STACK
 170	.body
 171
 172	adds r22=IA64_TASK_THREAD_KSP_OFFSET,r13
 173	movl r25=init_task
 174	mov r27=IA64_KR(CURRENT_STACK)
 175	adds r21=IA64_TASK_THREAD_KSP_OFFSET,in0
 176	dep r20=0,in0,61,3		// physical address of "next"
 177	;;
 178	st8 [r22]=sp			// save kernel stack pointer of old task
 179	shr.u r26=r20,IA64_GRANULE_SHIFT
 180	cmp.eq p7,p6=r25,in0
 181	;;
 182	/*
 183	 * If we've already mapped this task's page, we can skip doing it again.
 184	 */
 185(p6)	cmp.eq p7,p6=r26,r27
 186(p6)	br.cond.dpnt .map
 187	;;
 188.done:
 189	ld8 sp=[r21]			// load kernel stack pointer of new task
 190	MOV_TO_KR(CURRENT, in0, r8, r9)		// update "current" application register
 191	mov r8=r13			// return pointer to previously running task
 192	mov r13=in0			// set "current" pointer
 193	;;
 194	DO_LOAD_SWITCH_STACK
 195
 196#ifdef CONFIG_SMP
 197	sync.i				// ensure "fc"s done by this CPU are visible on other CPUs
 198#endif
 199	br.ret.sptk.many rp		// boogie on out in new context
 200
 201.map:
 202	RSM_PSR_IC(r25)			// interrupts (psr.i) are already disabled here
 203	movl r25=PAGE_KERNEL
 204	;;
 205	srlz.d
 206	or r23=r25,r20			// construct PA | page properties
 207	mov r25=IA64_GRANULE_SHIFT<<2
 208	;;
 209	MOV_TO_ITIR(p0, r25, r8)
 210	MOV_TO_IFA(in0, r8)		// VA of next task...
 211	;;
 212	mov r25=IA64_TR_CURRENT_STACK
 213	MOV_TO_KR(CURRENT_STACK, r26, r8, r9)	// remember last page we mapped...
 214	;;
 215	itr.d dtr[r25]=r23		// wire in new mapping...
 216	SSM_PSR_IC_AND_SRLZ_D(r8, r9)	// reenable the psr.ic bit
 217	br.cond.sptk .done
 218END(ia64_switch_to)
 219
 220/*
 221 * Note that interrupts are enabled during save_switch_stack and load_switch_stack.  This
 222 * means that we may get an interrupt with "sp" pointing to the new kernel stack while
 223 * ar.bspstore is still pointing to the old kernel backing store area.  Since ar.rsc,
 224 * ar.rnat, ar.bsp, and ar.bspstore are all preserved by interrupts, this is not a
 225 * problem.  Also, we don't need to specify unwind information for preserved registers
 226 * that are not modified in save_switch_stack as the right unwind information is already
 227 * specified at the call-site of save_switch_stack.
 228 */
 229
 230/*
 231 * save_switch_stack:
 232 *	- r16 holds ar.pfs
 233 *	- b7 holds address to return to
 234 *	- rp (b0) holds return address to save
 235 */
 236GLOBAL_ENTRY(save_switch_stack)
 237	.prologue
 238	.altrp b7
 239	flushrs			// flush dirty regs to backing store (must be first in insn group)
 240	.save @priunat,r17
 241	mov r17=ar.unat		// preserve caller's
 242	.body
 243#ifdef CONFIG_ITANIUM
 244	adds r2=16+128,sp
 245	adds r3=16+64,sp
 246	adds r14=SW(R4)+16,sp
 247	;;
 248	st8.spill [r14]=r4,16		// spill r4
 249	lfetch.fault.excl.nt1 [r3],128
 250	;;
 251	lfetch.fault.excl.nt1 [r2],128
 252	lfetch.fault.excl.nt1 [r3],128
 253	;;
 254	lfetch.fault.excl [r2]
 255	lfetch.fault.excl [r3]
 256	adds r15=SW(R5)+16,sp
 257#else
 258	add r2=16+3*128,sp
 259	add r3=16,sp
 260	add r14=SW(R4)+16,sp
 261	;;
 262	st8.spill [r14]=r4,SW(R6)-SW(R4)	// spill r4 and prefetch offset 0x1c0
 263	lfetch.fault.excl.nt1 [r3],128	//		prefetch offset 0x010
 264	;;
 265	lfetch.fault.excl.nt1 [r3],128	//		prefetch offset 0x090
 266	lfetch.fault.excl.nt1 [r2],128	//		prefetch offset 0x190
 267	;;
 268	lfetch.fault.excl.nt1 [r3]	//		prefetch offset 0x110
 269	lfetch.fault.excl.nt1 [r2]	//		prefetch offset 0x210
 270	adds r15=SW(R5)+16,sp
 271#endif
 272	;;
 273	st8.spill [r15]=r5,SW(R7)-SW(R5)	// spill r5
 274	mov.m ar.rsc=0			// put RSE in mode: enforced lazy, little endian, pl 0
 275	add r2=SW(F2)+16,sp		// r2 = &sw->f2
 276	;;
 277	st8.spill [r14]=r6,SW(B0)-SW(R6)	// spill r6
 278	mov.m r18=ar.fpsr		// preserve fpsr
 279	add r3=SW(F3)+16,sp		// r3 = &sw->f3
 280	;;
 281	stf.spill [r2]=f2,32
 282	mov.m r19=ar.rnat
 283	mov r21=b0
 284
 285	stf.spill [r3]=f3,32
 286	st8.spill [r15]=r7,SW(B2)-SW(R7)	// spill r7
 287	mov r22=b1
 288	;;
 289	// since we're done with the spills, read and save ar.unat:
 290	mov.m r29=ar.unat
 291	mov.m r20=ar.bspstore
 292	mov r23=b2
 293	stf.spill [r2]=f4,32
 294	stf.spill [r3]=f5,32
 295	mov r24=b3
 296	;;
 297	st8 [r14]=r21,SW(B1)-SW(B0)		// save b0
 298	st8 [r15]=r23,SW(B3)-SW(B2)		// save b2
 299	mov r25=b4
 300	mov r26=b5
 301	;;
 302	st8 [r14]=r22,SW(B4)-SW(B1)		// save b1
 303	st8 [r15]=r24,SW(AR_PFS)-SW(B3)		// save b3
 304	mov r21=ar.lc		// I-unit
 305	stf.spill [r2]=f12,32
 306	stf.spill [r3]=f13,32
 307	;;
 308	st8 [r14]=r25,SW(B5)-SW(B4)		// save b4
 309	st8 [r15]=r16,SW(AR_LC)-SW(AR_PFS)	// save ar.pfs
 310	stf.spill [r2]=f14,32
 311	stf.spill [r3]=f15,32
 312	;;
 313	st8 [r14]=r26				// save b5
 314	st8 [r15]=r21				// save ar.lc
 315	stf.spill [r2]=f16,32
 316	stf.spill [r3]=f17,32
 317	;;
 318	stf.spill [r2]=f18,32
 319	stf.spill [r3]=f19,32
 320	;;
 321	stf.spill [r2]=f20,32
 322	stf.spill [r3]=f21,32
 323	;;
 324	stf.spill [r2]=f22,32
 325	stf.spill [r3]=f23,32
 326	;;
 327	stf.spill [r2]=f24,32
 328	stf.spill [r3]=f25,32
 329	;;
 330	stf.spill [r2]=f26,32
 331	stf.spill [r3]=f27,32
 332	;;
 333	stf.spill [r2]=f28,32
 334	stf.spill [r3]=f29,32
 335	;;
 336	stf.spill [r2]=f30,SW(AR_UNAT)-SW(F30)
 337	stf.spill [r3]=f31,SW(PR)-SW(F31)
 338	add r14=SW(CALLER_UNAT)+16,sp
 339	;;
 340	st8 [r2]=r29,SW(AR_RNAT)-SW(AR_UNAT)	// save ar.unat
 341	st8 [r14]=r17,SW(AR_FPSR)-SW(CALLER_UNAT) // save caller_unat
 342	mov r21=pr
 343	;;
 344	st8 [r2]=r19,SW(AR_BSPSTORE)-SW(AR_RNAT) // save ar.rnat
 345	st8 [r3]=r21				// save predicate registers
 346	;;
 347	st8 [r2]=r20				// save ar.bspstore
 348	st8 [r14]=r18				// save fpsr
 349	mov ar.rsc=3		// put RSE back into eager mode, pl 0
 350	br.cond.sptk.many b7
 351END(save_switch_stack)
 352
 353/*
 354 * load_switch_stack:
 355 *	- "invala" MUST be done at call site (normally in DO_LOAD_SWITCH_STACK)
 356 *	- b7 holds address to return to
 357 *	- must not touch r8-r11
 358 */
 359GLOBAL_ENTRY(load_switch_stack)
 360	.prologue
 361	.altrp b7
 362
 363	.body
 364	lfetch.fault.nt1 [sp]
 365	adds r2=SW(AR_BSPSTORE)+16,sp
 366	adds r3=SW(AR_UNAT)+16,sp
 367	mov ar.rsc=0						// put RSE into enforced lazy mode
 368	adds r14=SW(CALLER_UNAT)+16,sp
 369	adds r15=SW(AR_FPSR)+16,sp
 370	;;
 371	ld8 r27=[r2],(SW(B0)-SW(AR_BSPSTORE))	// bspstore
 372	ld8 r29=[r3],(SW(B1)-SW(AR_UNAT))	// unat
 373	;;
 374	ld8 r21=[r2],16		// restore b0
 375	ld8 r22=[r3],16		// restore b1
 376	;;
 377	ld8 r23=[r2],16		// restore b2
 378	ld8 r24=[r3],16		// restore b3
 379	;;
 380	ld8 r25=[r2],16		// restore b4
 381	ld8 r26=[r3],16		// restore b5
 382	;;
 383	ld8 r16=[r2],(SW(PR)-SW(AR_PFS))	// ar.pfs
 384	ld8 r17=[r3],(SW(AR_RNAT)-SW(AR_LC))	// ar.lc
 385	;;
 386	ld8 r28=[r2]		// restore pr
 387	ld8 r30=[r3]		// restore rnat
 388	;;
 389	ld8 r18=[r14],16	// restore caller's unat
 390	ld8 r19=[r15],24	// restore fpsr
 391	;;
 392	ldf.fill f2=[r14],32
 393	ldf.fill f3=[r15],32
 394	;;
 395	ldf.fill f4=[r14],32
 396	ldf.fill f5=[r15],32
 397	;;
 398	ldf.fill f12=[r14],32
 399	ldf.fill f13=[r15],32
 400	;;
 401	ldf.fill f14=[r14],32
 402	ldf.fill f15=[r15],32
 403	;;
 404	ldf.fill f16=[r14],32
 405	ldf.fill f17=[r15],32
 406	;;
 407	ldf.fill f18=[r14],32
 408	ldf.fill f19=[r15],32
 409	mov b0=r21
 410	;;
 411	ldf.fill f20=[r14],32
 412	ldf.fill f21=[r15],32
 413	mov b1=r22
 414	;;
 415	ldf.fill f22=[r14],32
 416	ldf.fill f23=[r15],32
 417	mov b2=r23
 418	;;
 419	mov ar.bspstore=r27
 420	mov ar.unat=r29		// establish unat holding the NaT bits for r4-r7
 421	mov b3=r24
 422	;;
 423	ldf.fill f24=[r14],32
 424	ldf.fill f25=[r15],32
 425	mov b4=r25
 426	;;
 427	ldf.fill f26=[r14],32
 428	ldf.fill f27=[r15],32
 429	mov b5=r26
 430	;;
 431	ldf.fill f28=[r14],32
 432	ldf.fill f29=[r15],32
 433	mov ar.pfs=r16
 434	;;
 435	ldf.fill f30=[r14],32
 436	ldf.fill f31=[r15],24
 437	mov ar.lc=r17
 438	;;
 439	ld8.fill r4=[r14],16
 440	ld8.fill r5=[r15],16
 441	mov pr=r28,-1
 442	;;
 443	ld8.fill r6=[r14],16
 444	ld8.fill r7=[r15],16
 445
 446	mov ar.unat=r18				// restore caller's unat
 447	mov ar.rnat=r30				// must restore after bspstore but before rsc!
 448	mov ar.fpsr=r19				// restore fpsr
 449	mov ar.rsc=3				// put RSE back into eager mode, pl 0
 450	br.cond.sptk.many b7
 451END(load_switch_stack)
 452
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 453	/*
 454	 * Invoke a system call, but do some tracing before and after the call.
 455	 * We MUST preserve the current register frame throughout this routine
 456	 * because some system calls (such as ia64_execve) directly
 457	 * manipulate ar.pfs.
 458	 */
 459GLOBAL_ENTRY(ia64_trace_syscall)
 460	PT_REGS_UNWIND_INFO(0)
 461	/*
 462	 * We need to preserve the scratch registers f6-f11 in case the system
 463	 * call is sigreturn.
 464	 */
 465	adds r16=PT(F6)+16,sp
 466	adds r17=PT(F7)+16,sp
 467	;;
 468 	stf.spill [r16]=f6,32
 469 	stf.spill [r17]=f7,32
 470	;;
 471 	stf.spill [r16]=f8,32
 472 	stf.spill [r17]=f9,32
 473	;;
 474 	stf.spill [r16]=f10
 475 	stf.spill [r17]=f11
 476	br.call.sptk.many rp=syscall_trace_enter // give parent a chance to catch syscall args
 477	cmp.lt p6,p0=r8,r0			// check tracehook
 478	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 479	adds r3=PT(R10)+16,sp			// r3 = &pt_regs.r10
 480	mov r10=0
 481(p6)	br.cond.sptk strace_error		// syscall failed ->
 482	adds r16=PT(F6)+16,sp
 483	adds r17=PT(F7)+16,sp
 484	;;
 485	ldf.fill f6=[r16],32
 486	ldf.fill f7=[r17],32
 487	;;
 488	ldf.fill f8=[r16],32
 489	ldf.fill f9=[r17],32
 490	;;
 491	ldf.fill f10=[r16]
 492	ldf.fill f11=[r17]
 493	// the syscall number may have changed, so re-load it and re-calculate the
 494	// syscall entry-point:
 495	adds r15=PT(R15)+16,sp			// r15 = &pt_regs.r15 (syscall #)
 496	;;
 497	ld8 r15=[r15]
 498	mov r3=NR_syscalls - 1
 499	;;
 500	adds r15=-1024,r15
 501	movl r16=sys_call_table
 502	;;
 503	shladd r20=r15,3,r16			// r20 = sys_call_table + 8*(syscall-1024)
 504	cmp.leu p6,p7=r15,r3
 505	;;
 506(p6)	ld8 r20=[r20]				// load address of syscall entry point
 507(p7)	movl r20=sys_ni_syscall
 508	;;
 509	mov b6=r20
 510	br.call.sptk.many rp=b6			// do the syscall
 511.strace_check_retval:
 512	cmp.lt p6,p0=r8,r0			// syscall failed?
 513	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 514	adds r3=PT(R10)+16,sp			// r3 = &pt_regs.r10
 515	mov r10=0
 516(p6)	br.cond.sptk strace_error		// syscall failed ->
 517	;;					// avoid RAW on r10
 518.strace_save_retval:
 519.mem.offset 0,0; st8.spill [r2]=r8		// store return value in slot for r8
 520.mem.offset 8,0; st8.spill [r3]=r10		// clear error indication in slot for r10
 521	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
 522.ret3:
 523(pUStk)	cmp.eq.unc p6,p0=r0,r0			// p6 <- pUStk
 524(pUStk)	rsm psr.i				// disable interrupts
 525	br.cond.sptk ia64_work_pending_syscall_end
 526
 527strace_error:
 528	ld8 r3=[r2]				// load pt_regs.r8
 529	sub r9=0,r8				// negate return value to get errno value
 530	;;
 531	cmp.ne p6,p0=r3,r0			// is pt_regs.r8!=0?
 532	adds r3=16,r2				// r3=&pt_regs.r10
 533	;;
 534(p6)	mov r10=-1
 535(p6)	mov r8=r9
 536	br.cond.sptk .strace_save_retval
 537END(ia64_trace_syscall)
 538
 539	/*
 540	 * When traced and returning from sigreturn, we invoke syscall_trace but then
 541	 * go straight to ia64_leave_kernel rather than ia64_leave_syscall.
 542	 */
 543GLOBAL_ENTRY(ia64_strace_leave_kernel)
 544	PT_REGS_UNWIND_INFO(0)
 545{	/*
 546	 * Some versions of gas generate bad unwind info if the first instruction of a
 547	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
 548	 */
 549	nop.m 0
 550	nop.i 0
 551	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
 552}
 553.ret4:	br.cond.sptk ia64_leave_kernel
 554END(ia64_strace_leave_kernel)
 555
 556ENTRY(call_payload)
 557	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0)
 558	/* call the kernel_thread payload; fn is in r4, arg - in r5 */
 559	alloc loc1=ar.pfs,0,3,1,0
 560	mov loc0=rp
 561	mov loc2=gp
 562	mov out0=r5		// arg
 563	ld8 r14 = [r4], 8	// fn.address
 564	;;
 565	mov b6 = r14
 566	ld8 gp = [r4]		// fn.gp
 567	;;
 568	br.call.sptk.many rp=b6	// fn(arg)
 569.ret12:	mov gp=loc2
 570	mov rp=loc0
 571	mov ar.pfs=loc1
 572	/* ... and if it has returned, we are going to userland */
 573	cmp.ne pKStk,pUStk=r0,r0
 574	br.ret.sptk.many rp
 575END(call_payload)
 576
 577GLOBAL_ENTRY(ia64_ret_from_clone)
 578	PT_REGS_UNWIND_INFO(0)
 579{	/*
 580	 * Some versions of gas generate bad unwind info if the first instruction of a
 581	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
 582	 */
 583	nop.m 0
 584	nop.i 0
 585	/*
 586	 * We need to call schedule_tail() to complete the scheduling process.
 587	 * Called by ia64_switch_to() after ia64_clone()->copy_thread().  r8 contains the
 588	 * address of the previously executing task.
 589	 */
 590	br.call.sptk.many rp=ia64_invoke_schedule_tail
 591}
 592.ret8:
 593(pKStk)	br.call.sptk.many rp=call_payload
 594	adds r2=TI_FLAGS+IA64_TASK_SIZE,r13
 595	;;
 596	ld4 r2=[r2]
 597	;;
 598	mov r8=0
 599	and r2=_TIF_SYSCALL_TRACEAUDIT,r2
 600	;;
 601	cmp.ne p6,p0=r2,r0
 602(p6)	br.cond.spnt .strace_check_retval
 603	;;					// added stop bits to prevent r8 dependency
 604END(ia64_ret_from_clone)
 605	// fall through
 606GLOBAL_ENTRY(ia64_ret_from_syscall)
 607	PT_REGS_UNWIND_INFO(0)
 608	cmp.ge p6,p7=r8,r0			// syscall executed successfully?
 609	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 610	mov r10=r0				// clear error indication in r10
 611(p7)	br.cond.spnt handle_syscall_error	// handle potential syscall failure
 612END(ia64_ret_from_syscall)
 613	// fall through
 614
 615/*
 616 * ia64_leave_syscall(): Same as ia64_leave_kernel, except that it doesn't
 617 *	need to switch to bank 0 and doesn't restore the scratch registers.
 618 *	To avoid leaking kernel bits, the scratch registers are set to
 619 *	the following known-to-be-safe values:
 620 *
 621 *		  r1: restored (global pointer)
 622 *		  r2: cleared
 623 *		  r3: 1 (when returning to user-level)
 624 *	      r8-r11: restored (syscall return value(s))
 625 *		 r12: restored (user-level stack pointer)
 626 *		 r13: restored (user-level thread pointer)
 627 *		 r14: set to __kernel_syscall_via_epc
 628 *		 r15: restored (syscall #)
 629 *	     r16-r17: cleared
 630 *		 r18: user-level b6
 631 *		 r19: cleared
 632 *		 r20: user-level ar.fpsr
 633 *		 r21: user-level b0
 634 *		 r22: cleared
 635 *		 r23: user-level ar.bspstore
 636 *		 r24: user-level ar.rnat
 637 *		 r25: user-level ar.unat
 638 *		 r26: user-level ar.pfs
 639 *		 r27: user-level ar.rsc
 640 *		 r28: user-level ip
 641 *		 r29: user-level psr
 642 *		 r30: user-level cfm
 643 *		 r31: user-level pr
 644 *	      f6-f11: cleared
 645 *		  pr: restored (user-level pr)
 646 *		  b0: restored (user-level rp)
 647 *	          b6: restored
 648 *		  b7: set to __kernel_syscall_via_epc
 649 *	     ar.unat: restored (user-level ar.unat)
 650 *	      ar.pfs: restored (user-level ar.pfs)
 651 *	      ar.rsc: restored (user-level ar.rsc)
 652 *	     ar.rnat: restored (user-level ar.rnat)
 653 *	 ar.bspstore: restored (user-level ar.bspstore)
 654 *	     ar.fpsr: restored (user-level ar.fpsr)
 655 *	      ar.ccv: cleared
 656 *	      ar.csd: cleared
 657 *	      ar.ssd: cleared
 658 */
 659GLOBAL_ENTRY(ia64_leave_syscall)
 660	PT_REGS_UNWIND_INFO(0)
 661	/*
 662	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
 663	 * user- or fsys-mode, hence we disable interrupts early on.
 664	 *
 665	 * p6 controls whether current_thread_info()->flags needs to be check for
 666	 * extra work.  We always check for extra work when returning to user-level.
 667	 * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count
 668	 * is 0.  After extra work processing has been completed, execution
 669	 * resumes at ia64_work_processed_syscall with p6 set to 1 if the extra-work-check
 670	 * needs to be redone.
 671	 */
 672#ifdef CONFIG_PREEMPTION
 673	RSM_PSR_I(p0, r2, r18)			// disable interrupts
 674	cmp.eq pLvSys,p0=r0,r0			// pLvSys=1: leave from syscall
 675(pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
 676	;;
 677	.pred.rel.mutex pUStk,pKStk
 678(pKStk) ld4 r21=[r20]			// r21 <- preempt_count
 679(pUStk)	mov r21=0			// r21 <- 0
 680	;;
 681	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
 682#else /* !CONFIG_PREEMPTION */
 683	RSM_PSR_I(pUStk, r2, r18)
 684	cmp.eq pLvSys,p0=r0,r0		// pLvSys=1: leave from syscall
 685(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
 686#endif
 687.global ia64_work_processed_syscall;
 688ia64_work_processed_syscall:
 689#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 690	adds r2=PT(LOADRS)+16,r12
 691	MOV_FROM_ITC(pUStk, p9, r22, r19)	// fetch time at leave
 692	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
 693	;;
 694(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
 695	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
 696	adds r3=PT(AR_BSPSTORE)+16,r12		// deferred
 697	;;
 698#else
 699	adds r2=PT(LOADRS)+16,r12
 700	adds r3=PT(AR_BSPSTORE)+16,r12
 701	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
 702	;;
 703(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
 704	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
 705	nop.i 0
 706	;;
 707#endif
 708	mov r16=ar.bsp				// M2  get existing backing store pointer
 709	ld8 r18=[r2],PT(R9)-PT(B6)		// load b6
 710(p6)	and r15=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
 711	;;
 712	ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)	// load ar.bspstore (may be garbage)
 713(p6)	cmp4.ne.unc p6,p0=r15, r0		// any special work pending?
 714(p6)	br.cond.spnt .work_pending_syscall
 715	;;
 716	// start restoring the state saved on the kernel stack (struct pt_regs):
 717	ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
 718	ld8 r11=[r3],PT(CR_IIP)-PT(R11)
 719(pNonSys) break 0		//      bug check: we shouldn't be here if pNonSys is TRUE!
 720	;;
 721	invala			// M0|1 invalidate ALAT
 722	RSM_PSR_I_IC(r28, r29, r30)	// M2   turn off interrupts and interruption collection
 723	cmp.eq p9,p0=r0,r0	// A    set p9 to indicate that we should restore cr.ifs
 724
 725	ld8 r29=[r2],16		// M0|1 load cr.ipsr
 726	ld8 r28=[r3],16		// M0|1 load cr.iip
 727#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 728(pUStk) add r14=TI_AC_LEAVE+IA64_TASK_SIZE,r13
 729	;;
 730	ld8 r30=[r2],16		// M0|1 load cr.ifs
 731	ld8 r25=[r3],16		// M0|1 load ar.unat
 732(pUStk) add r15=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
 733	;;
 734#else
 735	mov r22=r0		// A    clear r22
 736	;;
 737	ld8 r30=[r2],16		// M0|1 load cr.ifs
 738	ld8 r25=[r3],16		// M0|1 load ar.unat
 739(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
 740	;;
 741#endif
 742	ld8 r26=[r2],PT(B0)-PT(AR_PFS)	// M0|1 load ar.pfs
 743	MOV_FROM_PSR(pKStk, r22, r21)	// M2   read PSR now that interrupts are disabled
 744	nop 0
 745	;;
 746	ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
 747	ld8 r27=[r3],PT(PR)-PT(AR_RSC)	// M0|1 load ar.rsc
 748	mov f6=f0			// F    clear f6
 749	;;
 750	ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT)	// M0|1 load ar.rnat (may be garbage)
 751	ld8 r31=[r3],PT(R1)-PT(PR)		// M0|1 load predicates
 752	mov f7=f0				// F    clear f7
 753	;;
 754	ld8 r20=[r2],PT(R12)-PT(AR_FPSR)	// M0|1 load ar.fpsr
 755	ld8.fill r1=[r3],16			// M0|1 load r1
 756(pUStk) mov r17=1				// A
 757	;;
 758#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 759(pUStk) st1 [r15]=r17				// M2|3
 760#else
 761(pUStk) st1 [r14]=r17				// M2|3
 762#endif
 763	ld8.fill r13=[r3],16			// M0|1
 764	mov f8=f0				// F    clear f8
 765	;;
 766	ld8.fill r12=[r2]			// M0|1 restore r12 (sp)
 767	ld8.fill r15=[r3]			// M0|1 restore r15
 768	mov b6=r18				// I0   restore b6
 769
 770	LOAD_PHYS_STACK_REG_SIZE(r17)
 771	mov f9=f0					// F    clear f9
 772(pKStk) br.cond.dpnt.many skip_rbs_switch		// B
 773
 774	srlz.d				// M0   ensure interruption collection is off (for cover)
 775	shr.u r18=r19,16		// I0|1 get byte size of existing "dirty" partition
 776	COVER				// B    add current frame into dirty partition & set cr.ifs
 777	;;
 778#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 779	mov r19=ar.bsp			// M2   get new backing store pointer
 780	st8 [r14]=r22			// M	save time at leave
 781	mov f10=f0			// F    clear f10
 782
 783	mov r22=r0			// A	clear r22
 784	movl r14=__kernel_syscall_via_epc // X
 785	;;
 786#else
 787	mov r19=ar.bsp			// M2   get new backing store pointer
 788	mov f10=f0			// F    clear f10
 789
 790	nop.m 0
 791	movl r14=__kernel_syscall_via_epc // X
 792	;;
 793#endif
 794	mov.m ar.csd=r0			// M2   clear ar.csd
 795	mov.m ar.ccv=r0			// M2   clear ar.ccv
 796	mov b7=r14			// I0   clear b7 (hint with __kernel_syscall_via_epc)
 797
 798	mov.m ar.ssd=r0			// M2   clear ar.ssd
 799	mov f11=f0			// F    clear f11
 800	br.cond.sptk.many rbs_switch	// B
 801END(ia64_leave_syscall)
 802
 803GLOBAL_ENTRY(ia64_leave_kernel)
 804	PT_REGS_UNWIND_INFO(0)
 805	/*
 806	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
 807	 * user- or fsys-mode, hence we disable interrupts early on.
 808	 *
 809	 * p6 controls whether current_thread_info()->flags needs to be check for
 810	 * extra work.  We always check for extra work when returning to user-level.
 811	 * With CONFIG_PREEMPTION, we also check for extra work when the preempt_count
 812	 * is 0.  After extra work processing has been completed, execution
 813	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
 814	 * needs to be redone.
 815	 */
 816#ifdef CONFIG_PREEMPTION
 817	RSM_PSR_I(p0, r17, r31)			// disable interrupts
 818	cmp.eq p0,pLvSys=r0,r0			// pLvSys=0: leave from kernel
 819(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
 820	;;
 821	.pred.rel.mutex pUStk,pKStk
 822(pKStk)	ld4 r21=[r20]			// r21 <- preempt_count
 823(pUStk)	mov r21=0			// r21 <- 0
 824	;;
 825	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
 826#else
 827	RSM_PSR_I(pUStk, r17, r31)
 828	cmp.eq p0,pLvSys=r0,r0		// pLvSys=0: leave from kernel
 829(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
 830#endif
 831.work_processed_kernel:
 832	adds r17=TI_FLAGS+IA64_TASK_SIZE,r13
 833	;;
 834(p6)	ld4 r31=[r17]				// load current_thread_info()->flags
 835	adds r21=PT(PR)+16,r12
 836	;;
 837
 838	lfetch [r21],PT(CR_IPSR)-PT(PR)
 839	adds r2=PT(B6)+16,r12
 840	adds r3=PT(R16)+16,r12
 841	;;
 842	lfetch [r21]
 843	ld8 r28=[r2],8		// load b6
 844	adds r29=PT(R24)+16,r12
 845
 846	ld8.fill r16=[r3],PT(AR_CSD)-PT(R16)
 847	adds r30=PT(AR_CCV)+16,r12
 848(p6)	and r19=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
 849	;;
 850	ld8.fill r24=[r29]
 851	ld8 r15=[r30]		// load ar.ccv
 852(p6)	cmp4.ne.unc p6,p0=r19, r0		// any special work pending?
 853	;;
 854	ld8 r29=[r2],16		// load b7
 855	ld8 r30=[r3],16		// load ar.csd
 856(p6)	br.cond.spnt .work_pending
 857	;;
 858	ld8 r31=[r2],16		// load ar.ssd
 859	ld8.fill r8=[r3],16
 860	;;
 861	ld8.fill r9=[r2],16
 862	ld8.fill r10=[r3],PT(R17)-PT(R10)
 863	;;
 864	ld8.fill r11=[r2],PT(R18)-PT(R11)
 865	ld8.fill r17=[r3],16
 866	;;
 867	ld8.fill r18=[r2],16
 868	ld8.fill r19=[r3],16
 869	;;
 870	ld8.fill r20=[r2],16
 871	ld8.fill r21=[r3],16
 872	mov ar.csd=r30
 873	mov ar.ssd=r31
 874	;;
 875	RSM_PSR_I_IC(r23, r22, r25)	// initiate turning off of interrupt and interruption collection
 876	invala			// invalidate ALAT
 877	;;
 878	ld8.fill r22=[r2],24
 879	ld8.fill r23=[r3],24
 880	mov b6=r28
 881	;;
 882	ld8.fill r25=[r2],16
 883	ld8.fill r26=[r3],16
 884	mov b7=r29
 885	;;
 886	ld8.fill r27=[r2],16
 887	ld8.fill r28=[r3],16
 888	;;
 889	ld8.fill r29=[r2],16
 890	ld8.fill r30=[r3],24
 891	;;
 892	ld8.fill r31=[r2],PT(F9)-PT(R31)
 893	adds r3=PT(F10)-PT(F6),r3
 894	;;
 895	ldf.fill f9=[r2],PT(F6)-PT(F9)
 896	ldf.fill f10=[r3],PT(F8)-PT(F10)
 897	;;
 898	ldf.fill f6=[r2],PT(F7)-PT(F6)
 899	;;
 900	ldf.fill f7=[r2],PT(F11)-PT(F7)
 901	ldf.fill f8=[r3],32
 902	;;
 903	srlz.d	// ensure that inter. collection is off (VHPT is don't care, since text is pinned)
 904	mov ar.ccv=r15
 905	;;
 906	ldf.fill f11=[r2]
 907	BSW_0(r2, r3, r15)	// switch back to bank 0 (no stop bit required beforehand...)
 908	;;
 909(pUStk)	mov r18=IA64_KR(CURRENT)// M2 (12 cycle read latency)
 910	adds r16=PT(CR_IPSR)+16,r12
 911	adds r17=PT(CR_IIP)+16,r12
 912
 913#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 914	.pred.rel.mutex pUStk,pKStk
 915	MOV_FROM_PSR(pKStk, r22, r29)	// M2 read PSR now that interrupts are disabled
 916	MOV_FROM_ITC(pUStk, p9, r22, r29)	// M  fetch time at leave
 917	nop.i 0
 918	;;
 919#else
 920	MOV_FROM_PSR(pKStk, r22, r29)	// M2 read PSR now that interrupts are disabled
 921	nop.i 0
 922	nop.i 0
 923	;;
 924#endif
 925	ld8 r29=[r16],16	// load cr.ipsr
 926	ld8 r28=[r17],16	// load cr.iip
 927	;;
 928	ld8 r30=[r16],16	// load cr.ifs
 929	ld8 r25=[r17],16	// load ar.unat
 930	;;
 931	ld8 r26=[r16],16	// load ar.pfs
 932	ld8 r27=[r17],16	// load ar.rsc
 933	cmp.eq p9,p0=r0,r0	// set p9 to indicate that we should restore cr.ifs
 934	;;
 935	ld8 r24=[r16],16	// load ar.rnat (may be garbage)
 936	ld8 r23=[r17],16	// load ar.bspstore (may be garbage)
 937	;;
 938	ld8 r31=[r16],16	// load predicates
 939	ld8 r21=[r17],16	// load b0
 940	;;
 941	ld8 r19=[r16],16	// load ar.rsc value for "loadrs"
 942	ld8.fill r1=[r17],16	// load r1
 943	;;
 944	ld8.fill r12=[r16],16
 945	ld8.fill r13=[r17],16
 946#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 947(pUStk)	adds r3=TI_AC_LEAVE+IA64_TASK_SIZE,r18
 948#else
 949(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
 950#endif
 951	;;
 952	ld8 r20=[r16],16	// ar.fpsr
 953	ld8.fill r15=[r17],16
 954#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 955(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18	// deferred
 956#endif
 957	;;
 958	ld8.fill r14=[r16],16
 959	ld8.fill r2=[r17]
 960(pUStk)	mov r17=1
 961	;;
 962#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 963	//  mmi_ :  ld8 st1 shr;;         mmi_ : st8 st1 shr;;
 964	//  mib  :  mov add br        ->  mib  : ld8 add br
 965	//  bbb_ :  br  nop cover;;       mbb_ : mov br  cover;;
 966	//
 967	//  no one require bsp in r16 if (pKStk) branch is selected.
 968(pUStk)	st8 [r3]=r22		// save time at leave
 969(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
 970	shr.u r18=r19,16	// get byte size of existing "dirty" partition
 971	;;
 972	ld8.fill r3=[r16]	// deferred
 973	LOAD_PHYS_STACK_REG_SIZE(r17)
 974(pKStk)	br.cond.dpnt skip_rbs_switch
 975	mov r16=ar.bsp		// get existing backing store pointer
 976#else
 977	ld8.fill r3=[r16]
 978(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
 979	shr.u r18=r19,16	// get byte size of existing "dirty" partition
 980	;;
 981	mov r16=ar.bsp		// get existing backing store pointer
 982	LOAD_PHYS_STACK_REG_SIZE(r17)
 983(pKStk)	br.cond.dpnt skip_rbs_switch
 984#endif
 985
 986	/*
 987	 * Restore user backing store.
 988	 *
 989	 * NOTE: alloc, loadrs, and cover can't be predicated.
 990	 */
 991(pNonSys) br.cond.dpnt dont_preserve_current_frame
 992	COVER				// add current frame into dirty partition and set cr.ifs
 993	;;
 994	mov r19=ar.bsp			// get new backing store pointer
 995rbs_switch:
 996	sub r16=r16,r18			// krbs = old bsp - size of dirty partition
 997	cmp.ne p9,p0=r0,r0		// clear p9 to skip restore of cr.ifs
 998	;;
 999	sub r19=r19,r16			// calculate total byte size of dirty partition
1000	add r18=64,r18			// don't force in0-in7 into memory...
1001	;;
1002	shl r19=r19,16			// shift size of dirty partition into loadrs position
1003	;;
1004dont_preserve_current_frame:
1005	/*
1006	 * To prevent leaking bits between the kernel and user-space,
1007	 * we must clear the stacked registers in the "invalid" partition here.
1008	 * Not pretty, but at least it's fast (3.34 registers/cycle on Itanium,
1009	 * 5 registers/cycle on McKinley).
1010	 */
1011#	define pRecurse	p6
1012#	define pReturn	p7
1013#ifdef CONFIG_ITANIUM
1014#	define Nregs	10
1015#else
1016#	define Nregs	14
1017#endif
1018	alloc loc0=ar.pfs,2,Nregs-2,2,0
1019	shr.u loc1=r18,9		// RNaTslots <= floor(dirtySize / (64*8))
1020	sub r17=r17,r18			// r17 = (physStackedSize + 8) - dirtySize
1021	;;
1022	mov ar.rsc=r19			// load ar.rsc to be used for "loadrs"
1023	shladd in0=loc1,3,r17
1024	mov in1=0
1025	;;
1026	TEXT_ALIGN(32)
1027rse_clear_invalid:
1028#ifdef CONFIG_ITANIUM
1029	// cycle 0
1030 { .mii
1031	alloc loc0=ar.pfs,2,Nregs-2,2,0
1032	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
1033	add out0=-Nregs*8,in0
1034}{ .mfb
1035	add out1=1,in1			// increment recursion count
1036	nop.f 0
1037	nop.b 0				// can't do br.call here because of alloc (WAW on CFM)
1038	;;
1039}{ .mfi	// cycle 1
1040	mov loc1=0
1041	nop.f 0
1042	mov loc2=0
1043}{ .mib
1044	mov loc3=0
1045	mov loc4=0
1046(pRecurse) br.call.sptk.many b0=rse_clear_invalid
1047
1048}{ .mfi	// cycle 2
1049	mov loc5=0
1050	nop.f 0
1051	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
1052}{ .mib
1053	mov loc6=0
1054	mov loc7=0
1055(pReturn) br.ret.sptk.many b0
1056}
1057#else /* !CONFIG_ITANIUM */
1058	alloc loc0=ar.pfs,2,Nregs-2,2,0
1059	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
1060	add out0=-Nregs*8,in0
1061	add out1=1,in1			// increment recursion count
1062	mov loc1=0
1063	mov loc2=0
1064	;;
1065	mov loc3=0
1066	mov loc4=0
1067	mov loc5=0
1068	mov loc6=0
1069	mov loc7=0
1070(pRecurse) br.call.dptk.few b0=rse_clear_invalid
1071	;;
1072	mov loc8=0
1073	mov loc9=0
1074	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
1075	mov loc10=0
1076	mov loc11=0
1077(pReturn) br.ret.dptk.many b0
1078#endif /* !CONFIG_ITANIUM */
1079#	undef pRecurse
1080#	undef pReturn
1081	;;
1082	alloc r17=ar.pfs,0,0,0,0	// drop current register frame
1083	;;
1084	loadrs
1085	;;
1086skip_rbs_switch:
1087	mov ar.unat=r25		// M2
1088(pKStk)	extr.u r22=r22,21,1	// I0 extract current value of psr.pp from r22
1089(pLvSys)mov r19=r0		// A  clear r19 for leave_syscall, no-op otherwise
1090	;;
1091(pUStk)	mov ar.bspstore=r23	// M2
1092(pKStk)	dep r29=r22,r29,21,1	// I0 update ipsr.pp with psr.pp
1093(pLvSys)mov r16=r0		// A  clear r16 for leave_syscall, no-op otherwise
1094	;;
1095	MOV_TO_IPSR(p0, r29, r25)	// M2
1096	mov ar.pfs=r26		// I0
1097(pLvSys)mov r17=r0		// A  clear r17 for leave_syscall, no-op otherwise
1098
1099	MOV_TO_IFS(p9, r30, r25)// M2
1100	mov b0=r21		// I0
1101(pLvSys)mov r18=r0		// A  clear r18 for leave_syscall, no-op otherwise
1102
1103	mov ar.fpsr=r20		// M2
1104	MOV_TO_IIP(r28, r25)	// M2
1105	nop 0
1106	;;
1107(pUStk)	mov ar.rnat=r24		// M2 must happen with RSE in lazy mode
1108	nop 0
1109(pLvSys)mov r2=r0
1110
1111	mov ar.rsc=r27		// M2
1112	mov pr=r31,-1		// I0
1113	RFI			// B
1114
1115	/*
1116	 * On entry:
1117	 *	r20 = &current->thread_info->pre_count (if CONFIG_PREEMPTION)
1118	 *	r31 = current->thread_info->flags
1119	 * On exit:
1120	 *	p6 = TRUE if work-pending-check needs to be redone
1121	 *
1122	 * Interrupts are disabled on entry, reenabled depend on work, and
1123	 * disabled on exit.
1124	 */
1125.work_pending_syscall:
1126	add r2=-8,r2
1127	add r3=-8,r3
1128	;;
1129	st8 [r2]=r8
1130	st8 [r3]=r10
1131.work_pending:
1132	tbit.z p6,p0=r31,TIF_NEED_RESCHED	// is resched not needed?
1133(p6)	br.cond.sptk.few .notify
1134	br.call.spnt.many rp=preempt_schedule_irq
1135.ret9:	cmp.eq p6,p0=r0,r0	// p6 <- 1 (re-check)
1136(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
1137	br.cond.sptk.many .work_processed_kernel
1138
1139.notify:
1140(pUStk)	br.call.spnt.many rp=notify_resume_user
1141.ret10:	cmp.ne p6,p0=r0,r0	// p6 <- 0 (don't re-check)
1142(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
1143	br.cond.sptk.many .work_processed_kernel
1144
1145.global ia64_work_pending_syscall_end;
1146ia64_work_pending_syscall_end:
1147	adds r2=PT(R8)+16,r12
1148	adds r3=PT(R10)+16,r12
1149	;;
1150	ld8 r8=[r2]
1151	ld8 r10=[r3]
1152	br.cond.sptk.many ia64_work_processed_syscall
1153END(ia64_leave_kernel)
1154
1155ENTRY(handle_syscall_error)
1156	/*
1157	 * Some system calls (e.g., ptrace, mmap) can return arbitrary values which could
1158	 * lead us to mistake a negative return value as a failed syscall.  Those syscall
1159	 * must deposit a non-zero value in pt_regs.r8 to indicate an error.  If
1160	 * pt_regs.r8 is zero, we assume that the call completed successfully.
1161	 */
1162	PT_REGS_UNWIND_INFO(0)
1163	ld8 r3=[r2]		// load pt_regs.r8
1164	;;
1165	cmp.eq p6,p7=r3,r0	// is pt_regs.r8==0?
1166	;;
1167(p7)	mov r10=-1
1168(p7)	sub r8=0,r8		// negate return value to get errno
1169	br.cond.sptk ia64_leave_syscall
1170END(handle_syscall_error)
1171
1172	/*
1173	 * Invoke schedule_tail(task) while preserving in0-in7, which may be needed
1174	 * in case a system call gets restarted.
1175	 */
1176GLOBAL_ENTRY(ia64_invoke_schedule_tail)
1177	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1178	alloc loc1=ar.pfs,8,2,1,0
1179	mov loc0=rp
1180	mov out0=r8				// Address of previous task
1181	;;
1182	br.call.sptk.many rp=schedule_tail
1183.ret11:	mov ar.pfs=loc1
1184	mov rp=loc0
1185	br.ret.sptk.many rp
1186END(ia64_invoke_schedule_tail)
1187
1188	/*
1189	 * Setup stack and call do_notify_resume_user(), keeping interrupts
1190	 * disabled.
1191	 *
1192	 * Note that pSys and pNonSys need to be set up by the caller.
1193	 * We declare 8 input registers so the system call args get preserved,
1194	 * in case we need to restart a system call.
1195	 */
1196GLOBAL_ENTRY(notify_resume_user)
1197	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1198	alloc loc1=ar.pfs,8,2,3,0 // preserve all eight input regs in case of syscall restart!
1199	mov r9=ar.unat
1200	mov loc0=rp				// save return address
1201	mov out0=0				// there is no "oldset"
1202	adds out1=8,sp				// out1=&sigscratch->ar_pfs
1203(pSys)	mov out2=1				// out2==1 => we're in a syscall
1204	;;
1205(pNonSys) mov out2=0				// out2==0 => not a syscall
1206	.fframe 16
1207	.spillsp ar.unat, 16
1208	st8 [sp]=r9,-16				// allocate space for ar.unat and save it
1209	st8 [out1]=loc1,-8			// save ar.pfs, out1=&sigscratch
1210	.body
1211	br.call.sptk.many rp=do_notify_resume_user
1212.ret15:	.restore sp
1213	adds sp=16,sp				// pop scratch stack space
1214	;;
1215	ld8 r9=[sp]				// load new unat from sigscratch->scratch_unat
1216	mov rp=loc0
1217	;;
1218	mov ar.unat=r9
1219	mov ar.pfs=loc1
1220	br.ret.sptk.many rp
1221END(notify_resume_user)
1222
1223ENTRY(sys_rt_sigreturn)
1224	PT_REGS_UNWIND_INFO(0)
1225	/*
1226	 * Allocate 8 input registers since ptrace() may clobber them
1227	 */
1228	alloc r2=ar.pfs,8,0,1,0
1229	.prologue
1230	PT_REGS_SAVES(16)
1231	adds sp=-16,sp
1232	.body
1233	cmp.eq pNonSys,pSys=r0,r0		// sigreturn isn't a normal syscall...
1234	;;
1235	/*
1236	 * leave_kernel() restores f6-f11 from pt_regs, but since the streamlined
1237	 * syscall-entry path does not save them we save them here instead.  Note: we
1238	 * don't need to save any other registers that are not saved by the stream-lined
1239	 * syscall path, because restore_sigcontext() restores them.
1240	 */
1241	adds r16=PT(F6)+32,sp
1242	adds r17=PT(F7)+32,sp
1243	;;
1244 	stf.spill [r16]=f6,32
1245 	stf.spill [r17]=f7,32
1246	;;
1247 	stf.spill [r16]=f8,32
1248 	stf.spill [r17]=f9,32
1249	;;
1250 	stf.spill [r16]=f10
1251 	stf.spill [r17]=f11
1252	adds out0=16,sp				// out0 = &sigscratch
1253	br.call.sptk.many rp=ia64_rt_sigreturn
1254.ret19:	.restore sp,0
1255	adds sp=16,sp
1256	;;
1257	ld8 r9=[sp]				// load new ar.unat
1258	mov.sptk b7=r8,ia64_leave_kernel
1259	;;
1260	mov ar.unat=r9
1261	br.many b7
1262END(sys_rt_sigreturn)
1263
1264GLOBAL_ENTRY(ia64_prepare_handle_unaligned)
1265	.prologue
1266	/*
1267	 * r16 = fake ar.pfs, we simply need to make sure privilege is still 0
1268	 */
1269	mov r16=r0
1270	DO_SAVE_SWITCH_STACK
1271	br.call.sptk.many rp=ia64_handle_unaligned	// stack frame setup in ivt
1272.ret21:	.body
1273	DO_LOAD_SWITCH_STACK
1274	br.cond.sptk.many rp				// goes to ia64_leave_kernel
1275END(ia64_prepare_handle_unaligned)
1276
1277	//
1278	// unw_init_running(void (*callback)(info, arg), void *arg)
1279	//
1280#	define EXTRA_FRAME_SIZE	((UNW_FRAME_INFO_SIZE+15)&~15)
1281
1282GLOBAL_ENTRY(unw_init_running)
1283	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1284	alloc loc1=ar.pfs,2,3,3,0
1285	;;
1286	ld8 loc2=[in0],8
1287	mov loc0=rp
1288	mov r16=loc1
1289	DO_SAVE_SWITCH_STACK
1290	.body
1291
1292	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1293	.fframe IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE
1294	SWITCH_STACK_SAVES(EXTRA_FRAME_SIZE)
1295	adds sp=-EXTRA_FRAME_SIZE,sp
1296	.body
1297	;;
1298	adds out0=16,sp				// &info
1299	mov out1=r13				// current
1300	adds out2=16+EXTRA_FRAME_SIZE,sp	// &switch_stack
1301	br.call.sptk.many rp=unw_init_frame_info
13021:	adds out0=16,sp				// &info
1303	mov b6=loc2
1304	mov loc2=gp				// save gp across indirect function call
1305	;;
1306	ld8 gp=[in0]
1307	mov out1=in1				// arg
1308	br.call.sptk.many rp=b6			// invoke the callback function
13091:	mov gp=loc2				// restore gp
1310
1311	// For now, we don't allow changing registers from within
1312	// unw_init_running; if we ever want to allow that, we'd
1313	// have to do a load_switch_stack here:
1314	.restore sp
1315	adds sp=IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE,sp
1316
1317	mov ar.pfs=loc1
1318	mov rp=loc0
1319	br.ret.sptk.many rp
1320END(unw_init_running)
1321EXPORT_SYMBOL(unw_init_running)
1322
1323#ifdef CONFIG_FUNCTION_TRACER
1324#ifdef CONFIG_DYNAMIC_FTRACE
1325GLOBAL_ENTRY(_mcount)
1326	br ftrace_stub
1327END(_mcount)
1328EXPORT_SYMBOL(_mcount)
1329
1330.here:
1331	br.ret.sptk.many b0
1332
1333GLOBAL_ENTRY(ftrace_caller)
1334	alloc out0 = ar.pfs, 8, 0, 4, 0
1335	mov out3 = r0
1336	;;
1337	mov out2 = b0
1338	add r3 = 0x20, r3
1339	mov out1 = r1;
1340	br.call.sptk.many b0 = ftrace_patch_gp
1341	//this might be called from module, so we must patch gp
1342ftrace_patch_gp:
1343	movl gp=__gp
1344	mov b0 = r3
1345	;;
1346.global ftrace_call;
1347ftrace_call:
1348{
1349	.mlx
1350	nop.m 0x0
1351	movl r3 = .here;;
1352}
1353	alloc loc0 = ar.pfs, 4, 4, 2, 0
1354	;;
1355	mov loc1 = b0
1356	mov out0 = b0
1357	mov loc2 = r8
1358	mov loc3 = r15
1359	;;
1360	adds out0 = -MCOUNT_INSN_SIZE, out0
1361	mov out1 = in2
1362	mov b6 = r3
1363
1364	br.call.sptk.many b0 = b6
1365	;;
1366	mov ar.pfs = loc0
1367	mov b0 = loc1
1368	mov r8 = loc2
1369	mov r15 = loc3
1370	br ftrace_stub
1371	;;
1372END(ftrace_caller)
1373
1374#else
1375GLOBAL_ENTRY(_mcount)
1376	movl r2 = ftrace_stub
1377	movl r3 = ftrace_trace_function;;
1378	ld8 r3 = [r3];;
1379	ld8 r3 = [r3];;
1380	cmp.eq p7,p0 = r2, r3
1381(p7)	br.sptk.many ftrace_stub
1382	;;
1383
1384	alloc loc0 = ar.pfs, 4, 4, 2, 0
1385	;;
1386	mov loc1 = b0
1387	mov out0 = b0
1388	mov loc2 = r8
1389	mov loc3 = r15
1390	;;
1391	adds out0 = -MCOUNT_INSN_SIZE, out0
1392	mov out1 = in2
1393	mov b6 = r3
1394
1395	br.call.sptk.many b0 = b6
1396	;;
1397	mov ar.pfs = loc0
1398	mov b0 = loc1
1399	mov r8 = loc2
1400	mov r15 = loc3
1401	br ftrace_stub
1402	;;
1403END(_mcount)
1404#endif
1405
1406GLOBAL_ENTRY(ftrace_stub)
1407	mov r3 = b0
1408	movl r2 = _mcount_ret_helper
1409	;;
1410	mov b6 = r2
1411	mov b7 = r3
1412	br.ret.sptk.many b6
1413
1414_mcount_ret_helper:
1415	mov b0 = r42
1416	mov r1 = r41
1417	mov ar.pfs = r40
1418	br b7
1419END(ftrace_stub)
1420
1421#endif /* CONFIG_FUNCTION_TRACER */
1422
1423#define __SYSCALL(nr, entry) data8 entry
1424	.rodata
1425	.align 8
1426	.globl sys_call_table
1427sys_call_table:
1428#include <asm/syscall_table.h>
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
v4.10.11
 
   1/*
   2 * arch/ia64/kernel/entry.S
   3 *
   4 * Kernel entry points.
   5 *
   6 * Copyright (C) 1998-2003, 2005 Hewlett-Packard Co
   7 *	David Mosberger-Tang <davidm@hpl.hp.com>
   8 * Copyright (C) 1999, 2002-2003
   9 *	Asit Mallick <Asit.K.Mallick@intel.com>
  10 * 	Don Dugger <Don.Dugger@intel.com>
  11 *	Suresh Siddha <suresh.b.siddha@intel.com>
  12 *	Fenghua Yu <fenghua.yu@intel.com>
  13 * Copyright (C) 1999 VA Linux Systems
  14 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
  15 */
  16/*
  17 * ia64_switch_to now places correct virtual mapping in in TR2 for
  18 * kernel stack. This allows us to handle interrupts without changing
  19 * to physical mode.
  20 *
  21 * Jonathan Nicklin	<nicklin@missioncriticallinux.com>
  22 * Patrick O'Rourke	<orourke@missioncriticallinux.com>
  23 * 11/07/2000
  24 */
  25/*
  26 * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp>
  27 *                    VA Linux Systems Japan K.K.
  28 *                    pv_ops.
  29 */
  30/*
  31 * Global (preserved) predicate usage on syscall entry/exit path:
  32 *
  33 *	pKStk:		See entry.h.
  34 *	pUStk:		See entry.h.
  35 *	pSys:		See entry.h.
  36 *	pNonSys:	!pSys
  37 */
  38
  39
 
  40#include <asm/asmmacro.h>
  41#include <asm/cache.h>
  42#include <asm/errno.h>
  43#include <asm/kregs.h>
  44#include <asm/asm-offsets.h>
  45#include <asm/pgtable.h>
  46#include <asm/percpu.h>
  47#include <asm/processor.h>
  48#include <asm/thread_info.h>
  49#include <asm/unistd.h>
  50#include <asm/ftrace.h>
  51#include <asm/export.h>
  52
  53#include "minstate.h"
  54
  55	/*
  56	 * execve() is special because in case of success, we need to
  57	 * setup a null register window frame.
  58	 */
  59ENTRY(ia64_execve)
  60	/*
  61	 * Allocate 8 input registers since ptrace() may clobber them
  62	 */
  63	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
  64	alloc loc1=ar.pfs,8,2,3,0
  65	mov loc0=rp
  66	.body
  67	mov out0=in0			// filename
  68	;;				// stop bit between alloc and call
  69	mov out1=in1			// argv
  70	mov out2=in2			// envp
  71	br.call.sptk.many rp=sys_execve
  72.ret0:
  73	cmp4.ge p6,p7=r8,r0
  74	mov ar.pfs=loc1			// restore ar.pfs
  75	sxt4 r8=r8			// return 64-bit result
  76	;;
  77	stf.spill [sp]=f0
  78	mov rp=loc0
  79(p6)	mov ar.pfs=r0			// clear ar.pfs on success
  80(p7)	br.ret.sptk.many rp
  81
  82	/*
  83	 * In theory, we'd have to zap this state only to prevent leaking of
  84	 * security sensitive state (e.g., if current->mm->dumpable is zero).  However,
  85	 * this executes in less than 20 cycles even on Itanium, so it's not worth
  86	 * optimizing for...).
  87	 */
  88	mov ar.unat=0; 		mov ar.lc=0
  89	mov r4=0;		mov f2=f0;		mov b1=r0
  90	mov r5=0;		mov f3=f0;		mov b2=r0
  91	mov r6=0;		mov f4=f0;		mov b3=r0
  92	mov r7=0;		mov f5=f0;		mov b4=r0
  93	ldf.fill f12=[sp];	mov f13=f0;		mov b5=r0
  94	ldf.fill f14=[sp];	ldf.fill f15=[sp];	mov f16=f0
  95	ldf.fill f17=[sp];	ldf.fill f18=[sp];	mov f19=f0
  96	ldf.fill f20=[sp];	ldf.fill f21=[sp];	mov f22=f0
  97	ldf.fill f23=[sp];	ldf.fill f24=[sp];	mov f25=f0
  98	ldf.fill f26=[sp];	ldf.fill f27=[sp];	mov f28=f0
  99	ldf.fill f29=[sp];	ldf.fill f30=[sp];	mov f31=f0
 100	br.ret.sptk.many rp
 101END(ia64_execve)
 102
 103/*
 104 * sys_clone2(u64 flags, u64 ustack_base, u64 ustack_size, u64 parent_tidptr, u64 child_tidptr,
 105 *	      u64 tls)
 106 */
 107GLOBAL_ENTRY(sys_clone2)
 108	/*
 109	 * Allocate 8 input registers since ptrace() may clobber them
 110	 */
 111	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
 112	alloc r16=ar.pfs,8,2,6,0
 113	DO_SAVE_SWITCH_STACK
 114	adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
 115	mov loc0=rp
 116	mov loc1=r16				// save ar.pfs across do_fork
 117	.body
 
 118	mov out1=in1
 119	mov out2=in2
 120	tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
 121	mov out3=in3	// parent_tidptr: valid only w/CLONE_PARENT_SETTID
 122	;;
 123(p6)	st8 [r2]=in5				// store TLS in r16 for copy_thread()
 124	mov out4=in4	// child_tidptr:  valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
 125	mov out0=in0				// out0 = clone_flags
 126	br.call.sptk.many rp=do_fork
 127.ret1:	.restore sp
 128	adds sp=IA64_SWITCH_STACK_SIZE,sp	// pop the switch stack
 129	mov ar.pfs=loc1
 130	mov rp=loc0
 131	br.ret.sptk.many rp
 132END(sys_clone2)
 133
 134/*
 135 * sys_clone(u64 flags, u64 ustack_base, u64 parent_tidptr, u64 child_tidptr, u64 tls)
 136 *	Deprecated.  Use sys_clone2() instead.
 137 */
 138GLOBAL_ENTRY(sys_clone)
 139	/*
 140	 * Allocate 8 input registers since ptrace() may clobber them
 141	 */
 142	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
 143	alloc r16=ar.pfs,8,2,6,0
 144	DO_SAVE_SWITCH_STACK
 145	adds r2=PT(R16)+IA64_SWITCH_STACK_SIZE+16,sp
 146	mov loc0=rp
 147	mov loc1=r16				// save ar.pfs across do_fork
 148	.body
 
 149	mov out1=in1
 150	mov out2=16				// stacksize (compensates for 16-byte scratch area)
 151	tbit.nz p6,p0=in0,CLONE_SETTLS_BIT
 152	mov out3=in2	// parent_tidptr: valid only w/CLONE_PARENT_SETTID
 153	;;
 154(p6)	st8 [r2]=in4				// store TLS in r13 (tp)
 155	mov out4=in3	// child_tidptr:  valid only w/CLONE_CHILD_SETTID or CLONE_CHILD_CLEARTID
 156	mov out0=in0				// out0 = clone_flags
 157	br.call.sptk.many rp=do_fork
 158.ret2:	.restore sp
 159	adds sp=IA64_SWITCH_STACK_SIZE,sp	// pop the switch stack
 160	mov ar.pfs=loc1
 161	mov rp=loc0
 162	br.ret.sptk.many rp
 163END(sys_clone)
 164
 165/*
 166 * prev_task <- ia64_switch_to(struct task_struct *next)
 167 *	With Ingo's new scheduler, interrupts are disabled when this routine gets
 168 *	called.  The code starting at .map relies on this.  The rest of the code
 169 *	doesn't care about the interrupt masking status.
 170 */
 171GLOBAL_ENTRY(ia64_switch_to)
 172	.prologue
 173	alloc r16=ar.pfs,1,0,0,0
 174	DO_SAVE_SWITCH_STACK
 175	.body
 176
 177	adds r22=IA64_TASK_THREAD_KSP_OFFSET,r13
 178	movl r25=init_task
 179	mov r27=IA64_KR(CURRENT_STACK)
 180	adds r21=IA64_TASK_THREAD_KSP_OFFSET,in0
 181	dep r20=0,in0,61,3		// physical address of "next"
 182	;;
 183	st8 [r22]=sp			// save kernel stack pointer of old task
 184	shr.u r26=r20,IA64_GRANULE_SHIFT
 185	cmp.eq p7,p6=r25,in0
 186	;;
 187	/*
 188	 * If we've already mapped this task's page, we can skip doing it again.
 189	 */
 190(p6)	cmp.eq p7,p6=r26,r27
 191(p6)	br.cond.dpnt .map
 192	;;
 193.done:
 194	ld8 sp=[r21]			// load kernel stack pointer of new task
 195	MOV_TO_KR(CURRENT, in0, r8, r9)		// update "current" application register
 196	mov r8=r13			// return pointer to previously running task
 197	mov r13=in0			// set "current" pointer
 198	;;
 199	DO_LOAD_SWITCH_STACK
 200
 201#ifdef CONFIG_SMP
 202	sync.i				// ensure "fc"s done by this CPU are visible on other CPUs
 203#endif
 204	br.ret.sptk.many rp		// boogie on out in new context
 205
 206.map:
 207	RSM_PSR_IC(r25)			// interrupts (psr.i) are already disabled here
 208	movl r25=PAGE_KERNEL
 209	;;
 210	srlz.d
 211	or r23=r25,r20			// construct PA | page properties
 212	mov r25=IA64_GRANULE_SHIFT<<2
 213	;;
 214	MOV_TO_ITIR(p0, r25, r8)
 215	MOV_TO_IFA(in0, r8)		// VA of next task...
 216	;;
 217	mov r25=IA64_TR_CURRENT_STACK
 218	MOV_TO_KR(CURRENT_STACK, r26, r8, r9)	// remember last page we mapped...
 219	;;
 220	itr.d dtr[r25]=r23		// wire in new mapping...
 221	SSM_PSR_IC_AND_SRLZ_D(r8, r9)	// reenable the psr.ic bit
 222	br.cond.sptk .done
 223END(ia64_switch_to)
 224
 225/*
 226 * Note that interrupts are enabled during save_switch_stack and load_switch_stack.  This
 227 * means that we may get an interrupt with "sp" pointing to the new kernel stack while
 228 * ar.bspstore is still pointing to the old kernel backing store area.  Since ar.rsc,
 229 * ar.rnat, ar.bsp, and ar.bspstore are all preserved by interrupts, this is not a
 230 * problem.  Also, we don't need to specify unwind information for preserved registers
 231 * that are not modified in save_switch_stack as the right unwind information is already
 232 * specified at the call-site of save_switch_stack.
 233 */
 234
 235/*
 236 * save_switch_stack:
 237 *	- r16 holds ar.pfs
 238 *	- b7 holds address to return to
 239 *	- rp (b0) holds return address to save
 240 */
 241GLOBAL_ENTRY(save_switch_stack)
 242	.prologue
 243	.altrp b7
 244	flushrs			// flush dirty regs to backing store (must be first in insn group)
 245	.save @priunat,r17
 246	mov r17=ar.unat		// preserve caller's
 247	.body
 248#ifdef CONFIG_ITANIUM
 249	adds r2=16+128,sp
 250	adds r3=16+64,sp
 251	adds r14=SW(R4)+16,sp
 252	;;
 253	st8.spill [r14]=r4,16		// spill r4
 254	lfetch.fault.excl.nt1 [r3],128
 255	;;
 256	lfetch.fault.excl.nt1 [r2],128
 257	lfetch.fault.excl.nt1 [r3],128
 258	;;
 259	lfetch.fault.excl [r2]
 260	lfetch.fault.excl [r3]
 261	adds r15=SW(R5)+16,sp
 262#else
 263	add r2=16+3*128,sp
 264	add r3=16,sp
 265	add r14=SW(R4)+16,sp
 266	;;
 267	st8.spill [r14]=r4,SW(R6)-SW(R4)	// spill r4 and prefetch offset 0x1c0
 268	lfetch.fault.excl.nt1 [r3],128	//		prefetch offset 0x010
 269	;;
 270	lfetch.fault.excl.nt1 [r3],128	//		prefetch offset 0x090
 271	lfetch.fault.excl.nt1 [r2],128	//		prefetch offset 0x190
 272	;;
 273	lfetch.fault.excl.nt1 [r3]	//		prefetch offset 0x110
 274	lfetch.fault.excl.nt1 [r2]	//		prefetch offset 0x210
 275	adds r15=SW(R5)+16,sp
 276#endif
 277	;;
 278	st8.spill [r15]=r5,SW(R7)-SW(R5)	// spill r5
 279	mov.m ar.rsc=0			// put RSE in mode: enforced lazy, little endian, pl 0
 280	add r2=SW(F2)+16,sp		// r2 = &sw->f2
 281	;;
 282	st8.spill [r14]=r6,SW(B0)-SW(R6)	// spill r6
 283	mov.m r18=ar.fpsr		// preserve fpsr
 284	add r3=SW(F3)+16,sp		// r3 = &sw->f3
 285	;;
 286	stf.spill [r2]=f2,32
 287	mov.m r19=ar.rnat
 288	mov r21=b0
 289
 290	stf.spill [r3]=f3,32
 291	st8.spill [r15]=r7,SW(B2)-SW(R7)	// spill r7
 292	mov r22=b1
 293	;;
 294	// since we're done with the spills, read and save ar.unat:
 295	mov.m r29=ar.unat
 296	mov.m r20=ar.bspstore
 297	mov r23=b2
 298	stf.spill [r2]=f4,32
 299	stf.spill [r3]=f5,32
 300	mov r24=b3
 301	;;
 302	st8 [r14]=r21,SW(B1)-SW(B0)		// save b0
 303	st8 [r15]=r23,SW(B3)-SW(B2)		// save b2
 304	mov r25=b4
 305	mov r26=b5
 306	;;
 307	st8 [r14]=r22,SW(B4)-SW(B1)		// save b1
 308	st8 [r15]=r24,SW(AR_PFS)-SW(B3)		// save b3
 309	mov r21=ar.lc		// I-unit
 310	stf.spill [r2]=f12,32
 311	stf.spill [r3]=f13,32
 312	;;
 313	st8 [r14]=r25,SW(B5)-SW(B4)		// save b4
 314	st8 [r15]=r16,SW(AR_LC)-SW(AR_PFS)	// save ar.pfs
 315	stf.spill [r2]=f14,32
 316	stf.spill [r3]=f15,32
 317	;;
 318	st8 [r14]=r26				// save b5
 319	st8 [r15]=r21				// save ar.lc
 320	stf.spill [r2]=f16,32
 321	stf.spill [r3]=f17,32
 322	;;
 323	stf.spill [r2]=f18,32
 324	stf.spill [r3]=f19,32
 325	;;
 326	stf.spill [r2]=f20,32
 327	stf.spill [r3]=f21,32
 328	;;
 329	stf.spill [r2]=f22,32
 330	stf.spill [r3]=f23,32
 331	;;
 332	stf.spill [r2]=f24,32
 333	stf.spill [r3]=f25,32
 334	;;
 335	stf.spill [r2]=f26,32
 336	stf.spill [r3]=f27,32
 337	;;
 338	stf.spill [r2]=f28,32
 339	stf.spill [r3]=f29,32
 340	;;
 341	stf.spill [r2]=f30,SW(AR_UNAT)-SW(F30)
 342	stf.spill [r3]=f31,SW(PR)-SW(F31)
 343	add r14=SW(CALLER_UNAT)+16,sp
 344	;;
 345	st8 [r2]=r29,SW(AR_RNAT)-SW(AR_UNAT)	// save ar.unat
 346	st8 [r14]=r17,SW(AR_FPSR)-SW(CALLER_UNAT) // save caller_unat
 347	mov r21=pr
 348	;;
 349	st8 [r2]=r19,SW(AR_BSPSTORE)-SW(AR_RNAT) // save ar.rnat
 350	st8 [r3]=r21				// save predicate registers
 351	;;
 352	st8 [r2]=r20				// save ar.bspstore
 353	st8 [r14]=r18				// save fpsr
 354	mov ar.rsc=3		// put RSE back into eager mode, pl 0
 355	br.cond.sptk.many b7
 356END(save_switch_stack)
 357
 358/*
 359 * load_switch_stack:
 360 *	- "invala" MUST be done at call site (normally in DO_LOAD_SWITCH_STACK)
 361 *	- b7 holds address to return to
 362 *	- must not touch r8-r11
 363 */
 364GLOBAL_ENTRY(load_switch_stack)
 365	.prologue
 366	.altrp b7
 367
 368	.body
 369	lfetch.fault.nt1 [sp]
 370	adds r2=SW(AR_BSPSTORE)+16,sp
 371	adds r3=SW(AR_UNAT)+16,sp
 372	mov ar.rsc=0						// put RSE into enforced lazy mode
 373	adds r14=SW(CALLER_UNAT)+16,sp
 374	adds r15=SW(AR_FPSR)+16,sp
 375	;;
 376	ld8 r27=[r2],(SW(B0)-SW(AR_BSPSTORE))	// bspstore
 377	ld8 r29=[r3],(SW(B1)-SW(AR_UNAT))	// unat
 378	;;
 379	ld8 r21=[r2],16		// restore b0
 380	ld8 r22=[r3],16		// restore b1
 381	;;
 382	ld8 r23=[r2],16		// restore b2
 383	ld8 r24=[r3],16		// restore b3
 384	;;
 385	ld8 r25=[r2],16		// restore b4
 386	ld8 r26=[r3],16		// restore b5
 387	;;
 388	ld8 r16=[r2],(SW(PR)-SW(AR_PFS))	// ar.pfs
 389	ld8 r17=[r3],(SW(AR_RNAT)-SW(AR_LC))	// ar.lc
 390	;;
 391	ld8 r28=[r2]		// restore pr
 392	ld8 r30=[r3]		// restore rnat
 393	;;
 394	ld8 r18=[r14],16	// restore caller's unat
 395	ld8 r19=[r15],24	// restore fpsr
 396	;;
 397	ldf.fill f2=[r14],32
 398	ldf.fill f3=[r15],32
 399	;;
 400	ldf.fill f4=[r14],32
 401	ldf.fill f5=[r15],32
 402	;;
 403	ldf.fill f12=[r14],32
 404	ldf.fill f13=[r15],32
 405	;;
 406	ldf.fill f14=[r14],32
 407	ldf.fill f15=[r15],32
 408	;;
 409	ldf.fill f16=[r14],32
 410	ldf.fill f17=[r15],32
 411	;;
 412	ldf.fill f18=[r14],32
 413	ldf.fill f19=[r15],32
 414	mov b0=r21
 415	;;
 416	ldf.fill f20=[r14],32
 417	ldf.fill f21=[r15],32
 418	mov b1=r22
 419	;;
 420	ldf.fill f22=[r14],32
 421	ldf.fill f23=[r15],32
 422	mov b2=r23
 423	;;
 424	mov ar.bspstore=r27
 425	mov ar.unat=r29		// establish unat holding the NaT bits for r4-r7
 426	mov b3=r24
 427	;;
 428	ldf.fill f24=[r14],32
 429	ldf.fill f25=[r15],32
 430	mov b4=r25
 431	;;
 432	ldf.fill f26=[r14],32
 433	ldf.fill f27=[r15],32
 434	mov b5=r26
 435	;;
 436	ldf.fill f28=[r14],32
 437	ldf.fill f29=[r15],32
 438	mov ar.pfs=r16
 439	;;
 440	ldf.fill f30=[r14],32
 441	ldf.fill f31=[r15],24
 442	mov ar.lc=r17
 443	;;
 444	ld8.fill r4=[r14],16
 445	ld8.fill r5=[r15],16
 446	mov pr=r28,-1
 447	;;
 448	ld8.fill r6=[r14],16
 449	ld8.fill r7=[r15],16
 450
 451	mov ar.unat=r18				// restore caller's unat
 452	mov ar.rnat=r30				// must restore after bspstore but before rsc!
 453	mov ar.fpsr=r19				// restore fpsr
 454	mov ar.rsc=3				// put RSE back into eager mode, pl 0
 455	br.cond.sptk.many b7
 456END(load_switch_stack)
 457
 458GLOBAL_ENTRY(prefetch_stack)
 459	add r14 = -IA64_SWITCH_STACK_SIZE, sp
 460	add r15 = IA64_TASK_THREAD_KSP_OFFSET, in0
 461	;;
 462	ld8 r16 = [r15]				// load next's stack pointer
 463	lfetch.fault.excl [r14], 128
 464	;;
 465	lfetch.fault.excl [r14], 128
 466	lfetch.fault [r16], 128
 467	;;
 468	lfetch.fault.excl [r14], 128
 469	lfetch.fault [r16], 128
 470	;;
 471	lfetch.fault.excl [r14], 128
 472	lfetch.fault [r16], 128
 473	;;
 474	lfetch.fault.excl [r14], 128
 475	lfetch.fault [r16], 128
 476	;;
 477	lfetch.fault [r16], 128
 478	br.ret.sptk.many rp
 479END(prefetch_stack)
 480
 481	/*
 482	 * Invoke a system call, but do some tracing before and after the call.
 483	 * We MUST preserve the current register frame throughout this routine
 484	 * because some system calls (such as ia64_execve) directly
 485	 * manipulate ar.pfs.
 486	 */
 487GLOBAL_ENTRY(ia64_trace_syscall)
 488	PT_REGS_UNWIND_INFO(0)
 489	/*
 490	 * We need to preserve the scratch registers f6-f11 in case the system
 491	 * call is sigreturn.
 492	 */
 493	adds r16=PT(F6)+16,sp
 494	adds r17=PT(F7)+16,sp
 495	;;
 496 	stf.spill [r16]=f6,32
 497 	stf.spill [r17]=f7,32
 498	;;
 499 	stf.spill [r16]=f8,32
 500 	stf.spill [r17]=f9,32
 501	;;
 502 	stf.spill [r16]=f10
 503 	stf.spill [r17]=f11
 504	br.call.sptk.many rp=syscall_trace_enter // give parent a chance to catch syscall args
 505	cmp.lt p6,p0=r8,r0			// check tracehook
 506	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 507	adds r3=PT(R10)+16,sp			// r3 = &pt_regs.r10
 508	mov r10=0
 509(p6)	br.cond.sptk strace_error		// syscall failed ->
 510	adds r16=PT(F6)+16,sp
 511	adds r17=PT(F7)+16,sp
 512	;;
 513	ldf.fill f6=[r16],32
 514	ldf.fill f7=[r17],32
 515	;;
 516	ldf.fill f8=[r16],32
 517	ldf.fill f9=[r17],32
 518	;;
 519	ldf.fill f10=[r16]
 520	ldf.fill f11=[r17]
 521	// the syscall number may have changed, so re-load it and re-calculate the
 522	// syscall entry-point:
 523	adds r15=PT(R15)+16,sp			// r15 = &pt_regs.r15 (syscall #)
 524	;;
 525	ld8 r15=[r15]
 526	mov r3=NR_syscalls - 1
 527	;;
 528	adds r15=-1024,r15
 529	movl r16=sys_call_table
 530	;;
 531	shladd r20=r15,3,r16			// r20 = sys_call_table + 8*(syscall-1024)
 532	cmp.leu p6,p7=r15,r3
 533	;;
 534(p6)	ld8 r20=[r20]				// load address of syscall entry point
 535(p7)	movl r20=sys_ni_syscall
 536	;;
 537	mov b6=r20
 538	br.call.sptk.many rp=b6			// do the syscall
 539.strace_check_retval:
 540	cmp.lt p6,p0=r8,r0			// syscall failed?
 541	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 542	adds r3=PT(R10)+16,sp			// r3 = &pt_regs.r10
 543	mov r10=0
 544(p6)	br.cond.sptk strace_error		// syscall failed ->
 545	;;					// avoid RAW on r10
 546.strace_save_retval:
 547.mem.offset 0,0; st8.spill [r2]=r8		// store return value in slot for r8
 548.mem.offset 8,0; st8.spill [r3]=r10		// clear error indication in slot for r10
 549	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
 550.ret3:
 551(pUStk)	cmp.eq.unc p6,p0=r0,r0			// p6 <- pUStk
 552(pUStk)	rsm psr.i				// disable interrupts
 553	br.cond.sptk ia64_work_pending_syscall_end
 554
 555strace_error:
 556	ld8 r3=[r2]				// load pt_regs.r8
 557	sub r9=0,r8				// negate return value to get errno value
 558	;;
 559	cmp.ne p6,p0=r3,r0			// is pt_regs.r8!=0?
 560	adds r3=16,r2				// r3=&pt_regs.r10
 561	;;
 562(p6)	mov r10=-1
 563(p6)	mov r8=r9
 564	br.cond.sptk .strace_save_retval
 565END(ia64_trace_syscall)
 566
 567	/*
 568	 * When traced and returning from sigreturn, we invoke syscall_trace but then
 569	 * go straight to ia64_leave_kernel rather than ia64_leave_syscall.
 570	 */
 571GLOBAL_ENTRY(ia64_strace_leave_kernel)
 572	PT_REGS_UNWIND_INFO(0)
 573{	/*
 574	 * Some versions of gas generate bad unwind info if the first instruction of a
 575	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
 576	 */
 577	nop.m 0
 578	nop.i 0
 579	br.call.sptk.many rp=syscall_trace_leave // give parent a chance to catch return value
 580}
 581.ret4:	br.cond.sptk ia64_leave_kernel
 582END(ia64_strace_leave_kernel)
 583
 584ENTRY(call_payload)
 585	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(0)
 586	/* call the kernel_thread payload; fn is in r4, arg - in r5 */
 587	alloc loc1=ar.pfs,0,3,1,0
 588	mov loc0=rp
 589	mov loc2=gp
 590	mov out0=r5		// arg
 591	ld8 r14 = [r4], 8	// fn.address
 592	;;
 593	mov b6 = r14
 594	ld8 gp = [r4]		// fn.gp
 595	;;
 596	br.call.sptk.many rp=b6	// fn(arg)
 597.ret12:	mov gp=loc2
 598	mov rp=loc0
 599	mov ar.pfs=loc1
 600	/* ... and if it has returned, we are going to userland */
 601	cmp.ne pKStk,pUStk=r0,r0
 602	br.ret.sptk.many rp
 603END(call_payload)
 604
 605GLOBAL_ENTRY(ia64_ret_from_clone)
 606	PT_REGS_UNWIND_INFO(0)
 607{	/*
 608	 * Some versions of gas generate bad unwind info if the first instruction of a
 609	 * procedure doesn't go into the first slot of a bundle.  This is a workaround.
 610	 */
 611	nop.m 0
 612	nop.i 0
 613	/*
 614	 * We need to call schedule_tail() to complete the scheduling process.
 615	 * Called by ia64_switch_to() after do_fork()->copy_thread().  r8 contains the
 616	 * address of the previously executing task.
 617	 */
 618	br.call.sptk.many rp=ia64_invoke_schedule_tail
 619}
 620.ret8:
 621(pKStk)	br.call.sptk.many rp=call_payload
 622	adds r2=TI_FLAGS+IA64_TASK_SIZE,r13
 623	;;
 624	ld4 r2=[r2]
 625	;;
 626	mov r8=0
 627	and r2=_TIF_SYSCALL_TRACEAUDIT,r2
 628	;;
 629	cmp.ne p6,p0=r2,r0
 630(p6)	br.cond.spnt .strace_check_retval
 631	;;					// added stop bits to prevent r8 dependency
 632END(ia64_ret_from_clone)
 633	// fall through
 634GLOBAL_ENTRY(ia64_ret_from_syscall)
 635	PT_REGS_UNWIND_INFO(0)
 636	cmp.ge p6,p7=r8,r0			// syscall executed successfully?
 637	adds r2=PT(R8)+16,sp			// r2 = &pt_regs.r8
 638	mov r10=r0				// clear error indication in r10
 639(p7)	br.cond.spnt handle_syscall_error	// handle potential syscall failure
 640END(ia64_ret_from_syscall)
 641	// fall through
 642
 643/*
 644 * ia64_leave_syscall(): Same as ia64_leave_kernel, except that it doesn't
 645 *	need to switch to bank 0 and doesn't restore the scratch registers.
 646 *	To avoid leaking kernel bits, the scratch registers are set to
 647 *	the following known-to-be-safe values:
 648 *
 649 *		  r1: restored (global pointer)
 650 *		  r2: cleared
 651 *		  r3: 1 (when returning to user-level)
 652 *	      r8-r11: restored (syscall return value(s))
 653 *		 r12: restored (user-level stack pointer)
 654 *		 r13: restored (user-level thread pointer)
 655 *		 r14: set to __kernel_syscall_via_epc
 656 *		 r15: restored (syscall #)
 657 *	     r16-r17: cleared
 658 *		 r18: user-level b6
 659 *		 r19: cleared
 660 *		 r20: user-level ar.fpsr
 661 *		 r21: user-level b0
 662 *		 r22: cleared
 663 *		 r23: user-level ar.bspstore
 664 *		 r24: user-level ar.rnat
 665 *		 r25: user-level ar.unat
 666 *		 r26: user-level ar.pfs
 667 *		 r27: user-level ar.rsc
 668 *		 r28: user-level ip
 669 *		 r29: user-level psr
 670 *		 r30: user-level cfm
 671 *		 r31: user-level pr
 672 *	      f6-f11: cleared
 673 *		  pr: restored (user-level pr)
 674 *		  b0: restored (user-level rp)
 675 *	          b6: restored
 676 *		  b7: set to __kernel_syscall_via_epc
 677 *	     ar.unat: restored (user-level ar.unat)
 678 *	      ar.pfs: restored (user-level ar.pfs)
 679 *	      ar.rsc: restored (user-level ar.rsc)
 680 *	     ar.rnat: restored (user-level ar.rnat)
 681 *	 ar.bspstore: restored (user-level ar.bspstore)
 682 *	     ar.fpsr: restored (user-level ar.fpsr)
 683 *	      ar.ccv: cleared
 684 *	      ar.csd: cleared
 685 *	      ar.ssd: cleared
 686 */
 687GLOBAL_ENTRY(ia64_leave_syscall)
 688	PT_REGS_UNWIND_INFO(0)
 689	/*
 690	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
 691	 * user- or fsys-mode, hence we disable interrupts early on.
 692	 *
 693	 * p6 controls whether current_thread_info()->flags needs to be check for
 694	 * extra work.  We always check for extra work when returning to user-level.
 695	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
 696	 * is 0.  After extra work processing has been completed, execution
 697	 * resumes at ia64_work_processed_syscall with p6 set to 1 if the extra-work-check
 698	 * needs to be redone.
 699	 */
 700#ifdef CONFIG_PREEMPT
 701	RSM_PSR_I(p0, r2, r18)			// disable interrupts
 702	cmp.eq pLvSys,p0=r0,r0			// pLvSys=1: leave from syscall
 703(pKStk) adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
 704	;;
 705	.pred.rel.mutex pUStk,pKStk
 706(pKStk) ld4 r21=[r20]			// r21 <- preempt_count
 707(pUStk)	mov r21=0			// r21 <- 0
 708	;;
 709	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
 710#else /* !CONFIG_PREEMPT */
 711	RSM_PSR_I(pUStk, r2, r18)
 712	cmp.eq pLvSys,p0=r0,r0		// pLvSys=1: leave from syscall
 713(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
 714#endif
 715.global ia64_work_processed_syscall;
 716ia64_work_processed_syscall:
 717#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 718	adds r2=PT(LOADRS)+16,r12
 719	MOV_FROM_ITC(pUStk, p9, r22, r19)	// fetch time at leave
 720	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
 721	;;
 722(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
 723	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
 724	adds r3=PT(AR_BSPSTORE)+16,r12		// deferred
 725	;;
 726#else
 727	adds r2=PT(LOADRS)+16,r12
 728	adds r3=PT(AR_BSPSTORE)+16,r12
 729	adds r18=TI_FLAGS+IA64_TASK_SIZE,r13
 730	;;
 731(p6)	ld4 r31=[r18]				// load current_thread_info()->flags
 732	ld8 r19=[r2],PT(B6)-PT(LOADRS)		// load ar.rsc value for "loadrs"
 733	nop.i 0
 734	;;
 735#endif
 736	mov r16=ar.bsp				// M2  get existing backing store pointer
 737	ld8 r18=[r2],PT(R9)-PT(B6)		// load b6
 738(p6)	and r15=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
 739	;;
 740	ld8 r23=[r3],PT(R11)-PT(AR_BSPSTORE)	// load ar.bspstore (may be garbage)
 741(p6)	cmp4.ne.unc p6,p0=r15, r0		// any special work pending?
 742(p6)	br.cond.spnt .work_pending_syscall
 743	;;
 744	// start restoring the state saved on the kernel stack (struct pt_regs):
 745	ld8 r9=[r2],PT(CR_IPSR)-PT(R9)
 746	ld8 r11=[r3],PT(CR_IIP)-PT(R11)
 747(pNonSys) break 0		//      bug check: we shouldn't be here if pNonSys is TRUE!
 748	;;
 749	invala			// M0|1 invalidate ALAT
 750	RSM_PSR_I_IC(r28, r29, r30)	// M2   turn off interrupts and interruption collection
 751	cmp.eq p9,p0=r0,r0	// A    set p9 to indicate that we should restore cr.ifs
 752
 753	ld8 r29=[r2],16		// M0|1 load cr.ipsr
 754	ld8 r28=[r3],16		// M0|1 load cr.iip
 755#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 756(pUStk) add r14=TI_AC_LEAVE+IA64_TASK_SIZE,r13
 757	;;
 758	ld8 r30=[r2],16		// M0|1 load cr.ifs
 759	ld8 r25=[r3],16		// M0|1 load ar.unat
 760(pUStk) add r15=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
 761	;;
 762#else
 763	mov r22=r0		// A    clear r22
 764	;;
 765	ld8 r30=[r2],16		// M0|1 load cr.ifs
 766	ld8 r25=[r3],16		// M0|1 load ar.unat
 767(pUStk) add r14=IA64_TASK_THREAD_ON_USTACK_OFFSET,r13
 768	;;
 769#endif
 770	ld8 r26=[r2],PT(B0)-PT(AR_PFS)	// M0|1 load ar.pfs
 771	MOV_FROM_PSR(pKStk, r22, r21)	// M2   read PSR now that interrupts are disabled
 772	nop 0
 773	;;
 774	ld8 r21=[r2],PT(AR_RNAT)-PT(B0) // M0|1 load b0
 775	ld8 r27=[r3],PT(PR)-PT(AR_RSC)	// M0|1 load ar.rsc
 776	mov f6=f0			// F    clear f6
 777	;;
 778	ld8 r24=[r2],PT(AR_FPSR)-PT(AR_RNAT)	// M0|1 load ar.rnat (may be garbage)
 779	ld8 r31=[r3],PT(R1)-PT(PR)		// M0|1 load predicates
 780	mov f7=f0				// F    clear f7
 781	;;
 782	ld8 r20=[r2],PT(R12)-PT(AR_FPSR)	// M0|1 load ar.fpsr
 783	ld8.fill r1=[r3],16			// M0|1 load r1
 784(pUStk) mov r17=1				// A
 785	;;
 786#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 787(pUStk) st1 [r15]=r17				// M2|3
 788#else
 789(pUStk) st1 [r14]=r17				// M2|3
 790#endif
 791	ld8.fill r13=[r3],16			// M0|1
 792	mov f8=f0				// F    clear f8
 793	;;
 794	ld8.fill r12=[r2]			// M0|1 restore r12 (sp)
 795	ld8.fill r15=[r3]			// M0|1 restore r15
 796	mov b6=r18				// I0   restore b6
 797
 798	LOAD_PHYS_STACK_REG_SIZE(r17)
 799	mov f9=f0					// F    clear f9
 800(pKStk) br.cond.dpnt.many skip_rbs_switch		// B
 801
 802	srlz.d				// M0   ensure interruption collection is off (for cover)
 803	shr.u r18=r19,16		// I0|1 get byte size of existing "dirty" partition
 804	COVER				// B    add current frame into dirty partition & set cr.ifs
 805	;;
 806#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 807	mov r19=ar.bsp			// M2   get new backing store pointer
 808	st8 [r14]=r22			// M	save time at leave
 809	mov f10=f0			// F    clear f10
 810
 811	mov r22=r0			// A	clear r22
 812	movl r14=__kernel_syscall_via_epc // X
 813	;;
 814#else
 815	mov r19=ar.bsp			// M2   get new backing store pointer
 816	mov f10=f0			// F    clear f10
 817
 818	nop.m 0
 819	movl r14=__kernel_syscall_via_epc // X
 820	;;
 821#endif
 822	mov.m ar.csd=r0			// M2   clear ar.csd
 823	mov.m ar.ccv=r0			// M2   clear ar.ccv
 824	mov b7=r14			// I0   clear b7 (hint with __kernel_syscall_via_epc)
 825
 826	mov.m ar.ssd=r0			// M2   clear ar.ssd
 827	mov f11=f0			// F    clear f11
 828	br.cond.sptk.many rbs_switch	// B
 829END(ia64_leave_syscall)
 830
 831GLOBAL_ENTRY(ia64_leave_kernel)
 832	PT_REGS_UNWIND_INFO(0)
 833	/*
 834	 * work.need_resched etc. mustn't get changed by this CPU before it returns to
 835	 * user- or fsys-mode, hence we disable interrupts early on.
 836	 *
 837	 * p6 controls whether current_thread_info()->flags needs to be check for
 838	 * extra work.  We always check for extra work when returning to user-level.
 839	 * With CONFIG_PREEMPT, we also check for extra work when the preempt_count
 840	 * is 0.  After extra work processing has been completed, execution
 841	 * resumes at .work_processed_syscall with p6 set to 1 if the extra-work-check
 842	 * needs to be redone.
 843	 */
 844#ifdef CONFIG_PREEMPT
 845	RSM_PSR_I(p0, r17, r31)			// disable interrupts
 846	cmp.eq p0,pLvSys=r0,r0			// pLvSys=0: leave from kernel
 847(pKStk)	adds r20=TI_PRE_COUNT+IA64_TASK_SIZE,r13
 848	;;
 849	.pred.rel.mutex pUStk,pKStk
 850(pKStk)	ld4 r21=[r20]			// r21 <- preempt_count
 851(pUStk)	mov r21=0			// r21 <- 0
 852	;;
 853	cmp.eq p6,p0=r21,r0		// p6 <- pUStk || (preempt_count == 0)
 854#else
 855	RSM_PSR_I(pUStk, r17, r31)
 856	cmp.eq p0,pLvSys=r0,r0		// pLvSys=0: leave from kernel
 857(pUStk)	cmp.eq.unc p6,p0=r0,r0		// p6 <- pUStk
 858#endif
 859.work_processed_kernel:
 860	adds r17=TI_FLAGS+IA64_TASK_SIZE,r13
 861	;;
 862(p6)	ld4 r31=[r17]				// load current_thread_info()->flags
 863	adds r21=PT(PR)+16,r12
 864	;;
 865
 866	lfetch [r21],PT(CR_IPSR)-PT(PR)
 867	adds r2=PT(B6)+16,r12
 868	adds r3=PT(R16)+16,r12
 869	;;
 870	lfetch [r21]
 871	ld8 r28=[r2],8		// load b6
 872	adds r29=PT(R24)+16,r12
 873
 874	ld8.fill r16=[r3],PT(AR_CSD)-PT(R16)
 875	adds r30=PT(AR_CCV)+16,r12
 876(p6)	and r19=TIF_WORK_MASK,r31		// any work other than TIF_SYSCALL_TRACE?
 877	;;
 878	ld8.fill r24=[r29]
 879	ld8 r15=[r30]		// load ar.ccv
 880(p6)	cmp4.ne.unc p6,p0=r19, r0		// any special work pending?
 881	;;
 882	ld8 r29=[r2],16		// load b7
 883	ld8 r30=[r3],16		// load ar.csd
 884(p6)	br.cond.spnt .work_pending
 885	;;
 886	ld8 r31=[r2],16		// load ar.ssd
 887	ld8.fill r8=[r3],16
 888	;;
 889	ld8.fill r9=[r2],16
 890	ld8.fill r10=[r3],PT(R17)-PT(R10)
 891	;;
 892	ld8.fill r11=[r2],PT(R18)-PT(R11)
 893	ld8.fill r17=[r3],16
 894	;;
 895	ld8.fill r18=[r2],16
 896	ld8.fill r19=[r3],16
 897	;;
 898	ld8.fill r20=[r2],16
 899	ld8.fill r21=[r3],16
 900	mov ar.csd=r30
 901	mov ar.ssd=r31
 902	;;
 903	RSM_PSR_I_IC(r23, r22, r25)	// initiate turning off of interrupt and interruption collection
 904	invala			// invalidate ALAT
 905	;;
 906	ld8.fill r22=[r2],24
 907	ld8.fill r23=[r3],24
 908	mov b6=r28
 909	;;
 910	ld8.fill r25=[r2],16
 911	ld8.fill r26=[r3],16
 912	mov b7=r29
 913	;;
 914	ld8.fill r27=[r2],16
 915	ld8.fill r28=[r3],16
 916	;;
 917	ld8.fill r29=[r2],16
 918	ld8.fill r30=[r3],24
 919	;;
 920	ld8.fill r31=[r2],PT(F9)-PT(R31)
 921	adds r3=PT(F10)-PT(F6),r3
 922	;;
 923	ldf.fill f9=[r2],PT(F6)-PT(F9)
 924	ldf.fill f10=[r3],PT(F8)-PT(F10)
 925	;;
 926	ldf.fill f6=[r2],PT(F7)-PT(F6)
 927	;;
 928	ldf.fill f7=[r2],PT(F11)-PT(F7)
 929	ldf.fill f8=[r3],32
 930	;;
 931	srlz.d	// ensure that inter. collection is off (VHPT is don't care, since text is pinned)
 932	mov ar.ccv=r15
 933	;;
 934	ldf.fill f11=[r2]
 935	BSW_0(r2, r3, r15)	// switch back to bank 0 (no stop bit required beforehand...)
 936	;;
 937(pUStk)	mov r18=IA64_KR(CURRENT)// M2 (12 cycle read latency)
 938	adds r16=PT(CR_IPSR)+16,r12
 939	adds r17=PT(CR_IIP)+16,r12
 940
 941#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 942	.pred.rel.mutex pUStk,pKStk
 943	MOV_FROM_PSR(pKStk, r22, r29)	// M2 read PSR now that interrupts are disabled
 944	MOV_FROM_ITC(pUStk, p9, r22, r29)	// M  fetch time at leave
 945	nop.i 0
 946	;;
 947#else
 948	MOV_FROM_PSR(pKStk, r22, r29)	// M2 read PSR now that interrupts are disabled
 949	nop.i 0
 950	nop.i 0
 951	;;
 952#endif
 953	ld8 r29=[r16],16	// load cr.ipsr
 954	ld8 r28=[r17],16	// load cr.iip
 955	;;
 956	ld8 r30=[r16],16	// load cr.ifs
 957	ld8 r25=[r17],16	// load ar.unat
 958	;;
 959	ld8 r26=[r16],16	// load ar.pfs
 960	ld8 r27=[r17],16	// load ar.rsc
 961	cmp.eq p9,p0=r0,r0	// set p9 to indicate that we should restore cr.ifs
 962	;;
 963	ld8 r24=[r16],16	// load ar.rnat (may be garbage)
 964	ld8 r23=[r17],16	// load ar.bspstore (may be garbage)
 965	;;
 966	ld8 r31=[r16],16	// load predicates
 967	ld8 r21=[r17],16	// load b0
 968	;;
 969	ld8 r19=[r16],16	// load ar.rsc value for "loadrs"
 970	ld8.fill r1=[r17],16	// load r1
 971	;;
 972	ld8.fill r12=[r16],16
 973	ld8.fill r13=[r17],16
 974#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 975(pUStk)	adds r3=TI_AC_LEAVE+IA64_TASK_SIZE,r18
 976#else
 977(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18
 978#endif
 979	;;
 980	ld8 r20=[r16],16	// ar.fpsr
 981	ld8.fill r15=[r17],16
 982#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 983(pUStk)	adds r18=IA64_TASK_THREAD_ON_USTACK_OFFSET,r18	// deferred
 984#endif
 985	;;
 986	ld8.fill r14=[r16],16
 987	ld8.fill r2=[r17]
 988(pUStk)	mov r17=1
 989	;;
 990#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
 991	//  mmi_ :  ld8 st1 shr;;         mmi_ : st8 st1 shr;;
 992	//  mib  :  mov add br        ->  mib  : ld8 add br
 993	//  bbb_ :  br  nop cover;;       mbb_ : mov br  cover;;
 994	//
 995	//  no one require bsp in r16 if (pKStk) branch is selected.
 996(pUStk)	st8 [r3]=r22		// save time at leave
 997(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
 998	shr.u r18=r19,16	// get byte size of existing "dirty" partition
 999	;;
1000	ld8.fill r3=[r16]	// deferred
1001	LOAD_PHYS_STACK_REG_SIZE(r17)
1002(pKStk)	br.cond.dpnt skip_rbs_switch
1003	mov r16=ar.bsp		// get existing backing store pointer
1004#else
1005	ld8.fill r3=[r16]
1006(pUStk)	st1 [r18]=r17		// restore current->thread.on_ustack
1007	shr.u r18=r19,16	// get byte size of existing "dirty" partition
1008	;;
1009	mov r16=ar.bsp		// get existing backing store pointer
1010	LOAD_PHYS_STACK_REG_SIZE(r17)
1011(pKStk)	br.cond.dpnt skip_rbs_switch
1012#endif
1013
1014	/*
1015	 * Restore user backing store.
1016	 *
1017	 * NOTE: alloc, loadrs, and cover can't be predicated.
1018	 */
1019(pNonSys) br.cond.dpnt dont_preserve_current_frame
1020	COVER				// add current frame into dirty partition and set cr.ifs
1021	;;
1022	mov r19=ar.bsp			// get new backing store pointer
1023rbs_switch:
1024	sub r16=r16,r18			// krbs = old bsp - size of dirty partition
1025	cmp.ne p9,p0=r0,r0		// clear p9 to skip restore of cr.ifs
1026	;;
1027	sub r19=r19,r16			// calculate total byte size of dirty partition
1028	add r18=64,r18			// don't force in0-in7 into memory...
1029	;;
1030	shl r19=r19,16			// shift size of dirty partition into loadrs position
1031	;;
1032dont_preserve_current_frame:
1033	/*
1034	 * To prevent leaking bits between the kernel and user-space,
1035	 * we must clear the stacked registers in the "invalid" partition here.
1036	 * Not pretty, but at least it's fast (3.34 registers/cycle on Itanium,
1037	 * 5 registers/cycle on McKinley).
1038	 */
1039#	define pRecurse	p6
1040#	define pReturn	p7
1041#ifdef CONFIG_ITANIUM
1042#	define Nregs	10
1043#else
1044#	define Nregs	14
1045#endif
1046	alloc loc0=ar.pfs,2,Nregs-2,2,0
1047	shr.u loc1=r18,9		// RNaTslots <= floor(dirtySize / (64*8))
1048	sub r17=r17,r18			// r17 = (physStackedSize + 8) - dirtySize
1049	;;
1050	mov ar.rsc=r19			// load ar.rsc to be used for "loadrs"
1051	shladd in0=loc1,3,r17
1052	mov in1=0
1053	;;
1054	TEXT_ALIGN(32)
1055rse_clear_invalid:
1056#ifdef CONFIG_ITANIUM
1057	// cycle 0
1058 { .mii
1059	alloc loc0=ar.pfs,2,Nregs-2,2,0
1060	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
1061	add out0=-Nregs*8,in0
1062}{ .mfb
1063	add out1=1,in1			// increment recursion count
1064	nop.f 0
1065	nop.b 0				// can't do br.call here because of alloc (WAW on CFM)
1066	;;
1067}{ .mfi	// cycle 1
1068	mov loc1=0
1069	nop.f 0
1070	mov loc2=0
1071}{ .mib
1072	mov loc3=0
1073	mov loc4=0
1074(pRecurse) br.call.sptk.many b0=rse_clear_invalid
1075
1076}{ .mfi	// cycle 2
1077	mov loc5=0
1078	nop.f 0
1079	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
1080}{ .mib
1081	mov loc6=0
1082	mov loc7=0
1083(pReturn) br.ret.sptk.many b0
1084}
1085#else /* !CONFIG_ITANIUM */
1086	alloc loc0=ar.pfs,2,Nregs-2,2,0
1087	cmp.lt pRecurse,p0=Nregs*8,in0	// if more than Nregs regs left to clear, (re)curse
1088	add out0=-Nregs*8,in0
1089	add out1=1,in1			// increment recursion count
1090	mov loc1=0
1091	mov loc2=0
1092	;;
1093	mov loc3=0
1094	mov loc4=0
1095	mov loc5=0
1096	mov loc6=0
1097	mov loc7=0
1098(pRecurse) br.call.dptk.few b0=rse_clear_invalid
1099	;;
1100	mov loc8=0
1101	mov loc9=0
1102	cmp.ne pReturn,p0=r0,in1	// if recursion count != 0, we need to do a br.ret
1103	mov loc10=0
1104	mov loc11=0
1105(pReturn) br.ret.dptk.many b0
1106#endif /* !CONFIG_ITANIUM */
1107#	undef pRecurse
1108#	undef pReturn
1109	;;
1110	alloc r17=ar.pfs,0,0,0,0	// drop current register frame
1111	;;
1112	loadrs
1113	;;
1114skip_rbs_switch:
1115	mov ar.unat=r25		// M2
1116(pKStk)	extr.u r22=r22,21,1	// I0 extract current value of psr.pp from r22
1117(pLvSys)mov r19=r0		// A  clear r19 for leave_syscall, no-op otherwise
1118	;;
1119(pUStk)	mov ar.bspstore=r23	// M2
1120(pKStk)	dep r29=r22,r29,21,1	// I0 update ipsr.pp with psr.pp
1121(pLvSys)mov r16=r0		// A  clear r16 for leave_syscall, no-op otherwise
1122	;;
1123	MOV_TO_IPSR(p0, r29, r25)	// M2
1124	mov ar.pfs=r26		// I0
1125(pLvSys)mov r17=r0		// A  clear r17 for leave_syscall, no-op otherwise
1126
1127	MOV_TO_IFS(p9, r30, r25)// M2
1128	mov b0=r21		// I0
1129(pLvSys)mov r18=r0		// A  clear r18 for leave_syscall, no-op otherwise
1130
1131	mov ar.fpsr=r20		// M2
1132	MOV_TO_IIP(r28, r25)	// M2
1133	nop 0
1134	;;
1135(pUStk)	mov ar.rnat=r24		// M2 must happen with RSE in lazy mode
1136	nop 0
1137(pLvSys)mov r2=r0
1138
1139	mov ar.rsc=r27		// M2
1140	mov pr=r31,-1		// I0
1141	RFI			// B
1142
1143	/*
1144	 * On entry:
1145	 *	r20 = &current->thread_info->pre_count (if CONFIG_PREEMPT)
1146	 *	r31 = current->thread_info->flags
1147	 * On exit:
1148	 *	p6 = TRUE if work-pending-check needs to be redone
1149	 *
1150	 * Interrupts are disabled on entry, reenabled depend on work, and
1151	 * disabled on exit.
1152	 */
1153.work_pending_syscall:
1154	add r2=-8,r2
1155	add r3=-8,r3
1156	;;
1157	st8 [r2]=r8
1158	st8 [r3]=r10
1159.work_pending:
1160	tbit.z p6,p0=r31,TIF_NEED_RESCHED	// is resched not needed?
1161(p6)	br.cond.sptk.few .notify
1162	br.call.spnt.many rp=preempt_schedule_irq
1163.ret9:	cmp.eq p6,p0=r0,r0	// p6 <- 1 (re-check)
1164(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
1165	br.cond.sptk.many .work_processed_kernel
1166
1167.notify:
1168(pUStk)	br.call.spnt.many rp=notify_resume_user
1169.ret10:	cmp.ne p6,p0=r0,r0	// p6 <- 0 (don't re-check)
1170(pLvSys)br.cond.sptk.few  ia64_work_pending_syscall_end
1171	br.cond.sptk.many .work_processed_kernel
1172
1173.global ia64_work_pending_syscall_end;
1174ia64_work_pending_syscall_end:
1175	adds r2=PT(R8)+16,r12
1176	adds r3=PT(R10)+16,r12
1177	;;
1178	ld8 r8=[r2]
1179	ld8 r10=[r3]
1180	br.cond.sptk.many ia64_work_processed_syscall
1181END(ia64_leave_kernel)
1182
1183ENTRY(handle_syscall_error)
1184	/*
1185	 * Some system calls (e.g., ptrace, mmap) can return arbitrary values which could
1186	 * lead us to mistake a negative return value as a failed syscall.  Those syscall
1187	 * must deposit a non-zero value in pt_regs.r8 to indicate an error.  If
1188	 * pt_regs.r8 is zero, we assume that the call completed successfully.
1189	 */
1190	PT_REGS_UNWIND_INFO(0)
1191	ld8 r3=[r2]		// load pt_regs.r8
1192	;;
1193	cmp.eq p6,p7=r3,r0	// is pt_regs.r8==0?
1194	;;
1195(p7)	mov r10=-1
1196(p7)	sub r8=0,r8		// negate return value to get errno
1197	br.cond.sptk ia64_leave_syscall
1198END(handle_syscall_error)
1199
1200	/*
1201	 * Invoke schedule_tail(task) while preserving in0-in7, which may be needed
1202	 * in case a system call gets restarted.
1203	 */
1204GLOBAL_ENTRY(ia64_invoke_schedule_tail)
1205	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1206	alloc loc1=ar.pfs,8,2,1,0
1207	mov loc0=rp
1208	mov out0=r8				// Address of previous task
1209	;;
1210	br.call.sptk.many rp=schedule_tail
1211.ret11:	mov ar.pfs=loc1
1212	mov rp=loc0
1213	br.ret.sptk.many rp
1214END(ia64_invoke_schedule_tail)
1215
1216	/*
1217	 * Setup stack and call do_notify_resume_user(), keeping interrupts
1218	 * disabled.
1219	 *
1220	 * Note that pSys and pNonSys need to be set up by the caller.
1221	 * We declare 8 input registers so the system call args get preserved,
1222	 * in case we need to restart a system call.
1223	 */
1224GLOBAL_ENTRY(notify_resume_user)
1225	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8)
1226	alloc loc1=ar.pfs,8,2,3,0 // preserve all eight input regs in case of syscall restart!
1227	mov r9=ar.unat
1228	mov loc0=rp				// save return address
1229	mov out0=0				// there is no "oldset"
1230	adds out1=8,sp				// out1=&sigscratch->ar_pfs
1231(pSys)	mov out2=1				// out2==1 => we're in a syscall
1232	;;
1233(pNonSys) mov out2=0				// out2==0 => not a syscall
1234	.fframe 16
1235	.spillsp ar.unat, 16
1236	st8 [sp]=r9,-16				// allocate space for ar.unat and save it
1237	st8 [out1]=loc1,-8			// save ar.pfs, out1=&sigscratch
1238	.body
1239	br.call.sptk.many rp=do_notify_resume_user
1240.ret15:	.restore sp
1241	adds sp=16,sp				// pop scratch stack space
1242	;;
1243	ld8 r9=[sp]				// load new unat from sigscratch->scratch_unat
1244	mov rp=loc0
1245	;;
1246	mov ar.unat=r9
1247	mov ar.pfs=loc1
1248	br.ret.sptk.many rp
1249END(notify_resume_user)
1250
1251ENTRY(sys_rt_sigreturn)
1252	PT_REGS_UNWIND_INFO(0)
1253	/*
1254	 * Allocate 8 input registers since ptrace() may clobber them
1255	 */
1256	alloc r2=ar.pfs,8,0,1,0
1257	.prologue
1258	PT_REGS_SAVES(16)
1259	adds sp=-16,sp
1260	.body
1261	cmp.eq pNonSys,pSys=r0,r0		// sigreturn isn't a normal syscall...
1262	;;
1263	/*
1264	 * leave_kernel() restores f6-f11 from pt_regs, but since the streamlined
1265	 * syscall-entry path does not save them we save them here instead.  Note: we
1266	 * don't need to save any other registers that are not saved by the stream-lined
1267	 * syscall path, because restore_sigcontext() restores them.
1268	 */
1269	adds r16=PT(F6)+32,sp
1270	adds r17=PT(F7)+32,sp
1271	;;
1272 	stf.spill [r16]=f6,32
1273 	stf.spill [r17]=f7,32
1274	;;
1275 	stf.spill [r16]=f8,32
1276 	stf.spill [r17]=f9,32
1277	;;
1278 	stf.spill [r16]=f10
1279 	stf.spill [r17]=f11
1280	adds out0=16,sp				// out0 = &sigscratch
1281	br.call.sptk.many rp=ia64_rt_sigreturn
1282.ret19:	.restore sp,0
1283	adds sp=16,sp
1284	;;
1285	ld8 r9=[sp]				// load new ar.unat
1286	mov.sptk b7=r8,ia64_leave_kernel
1287	;;
1288	mov ar.unat=r9
1289	br.many b7
1290END(sys_rt_sigreturn)
1291
1292GLOBAL_ENTRY(ia64_prepare_handle_unaligned)
1293	.prologue
1294	/*
1295	 * r16 = fake ar.pfs, we simply need to make sure privilege is still 0
1296	 */
1297	mov r16=r0
1298	DO_SAVE_SWITCH_STACK
1299	br.call.sptk.many rp=ia64_handle_unaligned	// stack frame setup in ivt
1300.ret21:	.body
1301	DO_LOAD_SWITCH_STACK
1302	br.cond.sptk.many rp				// goes to ia64_leave_kernel
1303END(ia64_prepare_handle_unaligned)
1304
1305	//
1306	// unw_init_running(void (*callback)(info, arg), void *arg)
1307	//
1308#	define EXTRA_FRAME_SIZE	((UNW_FRAME_INFO_SIZE+15)&~15)
1309
1310GLOBAL_ENTRY(unw_init_running)
1311	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1312	alloc loc1=ar.pfs,2,3,3,0
1313	;;
1314	ld8 loc2=[in0],8
1315	mov loc0=rp
1316	mov r16=loc1
1317	DO_SAVE_SWITCH_STACK
1318	.body
1319
1320	.prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(2)
1321	.fframe IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE
1322	SWITCH_STACK_SAVES(EXTRA_FRAME_SIZE)
1323	adds sp=-EXTRA_FRAME_SIZE,sp
1324	.body
1325	;;
1326	adds out0=16,sp				// &info
1327	mov out1=r13				// current
1328	adds out2=16+EXTRA_FRAME_SIZE,sp	// &switch_stack
1329	br.call.sptk.many rp=unw_init_frame_info
13301:	adds out0=16,sp				// &info
1331	mov b6=loc2
1332	mov loc2=gp				// save gp across indirect function call
1333	;;
1334	ld8 gp=[in0]
1335	mov out1=in1				// arg
1336	br.call.sptk.many rp=b6			// invoke the callback function
13371:	mov gp=loc2				// restore gp
1338
1339	// For now, we don't allow changing registers from within
1340	// unw_init_running; if we ever want to allow that, we'd
1341	// have to do a load_switch_stack here:
1342	.restore sp
1343	adds sp=IA64_SWITCH_STACK_SIZE+EXTRA_FRAME_SIZE,sp
1344
1345	mov ar.pfs=loc1
1346	mov rp=loc0
1347	br.ret.sptk.many rp
1348END(unw_init_running)
1349EXPORT_SYMBOL(unw_init_running)
1350
1351#ifdef CONFIG_FUNCTION_TRACER
1352#ifdef CONFIG_DYNAMIC_FTRACE
1353GLOBAL_ENTRY(_mcount)
1354	br ftrace_stub
1355END(_mcount)
1356EXPORT_SYMBOL(_mcount)
1357
1358.here:
1359	br.ret.sptk.many b0
1360
1361GLOBAL_ENTRY(ftrace_caller)
1362	alloc out0 = ar.pfs, 8, 0, 4, 0
1363	mov out3 = r0
1364	;;
1365	mov out2 = b0
1366	add r3 = 0x20, r3
1367	mov out1 = r1;
1368	br.call.sptk.many b0 = ftrace_patch_gp
1369	//this might be called from module, so we must patch gp
1370ftrace_patch_gp:
1371	movl gp=__gp
1372	mov b0 = r3
1373	;;
1374.global ftrace_call;
1375ftrace_call:
1376{
1377	.mlx
1378	nop.m 0x0
1379	movl r3 = .here;;
1380}
1381	alloc loc0 = ar.pfs, 4, 4, 2, 0
1382	;;
1383	mov loc1 = b0
1384	mov out0 = b0
1385	mov loc2 = r8
1386	mov loc3 = r15
1387	;;
1388	adds out0 = -MCOUNT_INSN_SIZE, out0
1389	mov out1 = in2
1390	mov b6 = r3
1391
1392	br.call.sptk.many b0 = b6
1393	;;
1394	mov ar.pfs = loc0
1395	mov b0 = loc1
1396	mov r8 = loc2
1397	mov r15 = loc3
1398	br ftrace_stub
1399	;;
1400END(ftrace_caller)
1401
1402#else
1403GLOBAL_ENTRY(_mcount)
1404	movl r2 = ftrace_stub
1405	movl r3 = ftrace_trace_function;;
1406	ld8 r3 = [r3];;
1407	ld8 r3 = [r3];;
1408	cmp.eq p7,p0 = r2, r3
1409(p7)	br.sptk.many ftrace_stub
1410	;;
1411
1412	alloc loc0 = ar.pfs, 4, 4, 2, 0
1413	;;
1414	mov loc1 = b0
1415	mov out0 = b0
1416	mov loc2 = r8
1417	mov loc3 = r15
1418	;;
1419	adds out0 = -MCOUNT_INSN_SIZE, out0
1420	mov out1 = in2
1421	mov b6 = r3
1422
1423	br.call.sptk.many b0 = b6
1424	;;
1425	mov ar.pfs = loc0
1426	mov b0 = loc1
1427	mov r8 = loc2
1428	mov r15 = loc3
1429	br ftrace_stub
1430	;;
1431END(_mcount)
1432#endif
1433
1434GLOBAL_ENTRY(ftrace_stub)
1435	mov r3 = b0
1436	movl r2 = _mcount_ret_helper
1437	;;
1438	mov b6 = r2
1439	mov b7 = r3
1440	br.ret.sptk.many b6
1441
1442_mcount_ret_helper:
1443	mov b0 = r42
1444	mov r1 = r41
1445	mov ar.pfs = r40
1446	br b7
1447END(ftrace_stub)
1448
1449#endif /* CONFIG_FUNCTION_TRACER */
1450
 
1451	.rodata
1452	.align 8
1453	.globl sys_call_table
1454sys_call_table:
1455	data8 sys_ni_syscall		//  This must be sys_ni_syscall!  See ivt.S.
1456	data8 sys_exit				// 1025
1457	data8 sys_read
1458	data8 sys_write
1459	data8 sys_open
1460	data8 sys_close
1461	data8 sys_creat				// 1030
1462	data8 sys_link
1463	data8 sys_unlink
1464	data8 ia64_execve
1465	data8 sys_chdir
1466	data8 sys_fchdir			// 1035
1467	data8 sys_utimes
1468	data8 sys_mknod
1469	data8 sys_chmod
1470	data8 sys_chown
1471	data8 sys_lseek				// 1040
1472	data8 sys_getpid
1473	data8 sys_getppid
1474	data8 sys_mount
1475	data8 sys_umount
1476	data8 sys_setuid			// 1045
1477	data8 sys_getuid
1478	data8 sys_geteuid
1479	data8 sys_ptrace
1480	data8 sys_access
1481	data8 sys_sync				// 1050
1482	data8 sys_fsync
1483	data8 sys_fdatasync
1484	data8 sys_kill
1485	data8 sys_rename
1486	data8 sys_mkdir				// 1055
1487	data8 sys_rmdir
1488	data8 sys_dup
1489	data8 sys_ia64_pipe
1490	data8 sys_times
1491	data8 ia64_brk				// 1060
1492	data8 sys_setgid
1493	data8 sys_getgid
1494	data8 sys_getegid
1495	data8 sys_acct
1496	data8 sys_ioctl				// 1065
1497	data8 sys_fcntl
1498	data8 sys_umask
1499	data8 sys_chroot
1500	data8 sys_ustat
1501	data8 sys_dup2				// 1070
1502	data8 sys_setreuid
1503	data8 sys_setregid
1504	data8 sys_getresuid
1505	data8 sys_setresuid
1506	data8 sys_getresgid			// 1075
1507	data8 sys_setresgid
1508	data8 sys_getgroups
1509	data8 sys_setgroups
1510	data8 sys_getpgid
1511	data8 sys_setpgid			// 1080
1512	data8 sys_setsid
1513	data8 sys_getsid
1514	data8 sys_sethostname
1515	data8 sys_setrlimit
1516	data8 sys_getrlimit			// 1085
1517	data8 sys_getrusage
1518	data8 sys_gettimeofday
1519	data8 sys_settimeofday
1520	data8 sys_select
1521	data8 sys_poll				// 1090
1522	data8 sys_symlink
1523	data8 sys_readlink
1524	data8 sys_uselib
1525	data8 sys_swapon
1526	data8 sys_swapoff			// 1095
1527	data8 sys_reboot
1528	data8 sys_truncate
1529	data8 sys_ftruncate
1530	data8 sys_fchmod
1531	data8 sys_fchown			// 1100
1532	data8 ia64_getpriority
1533	data8 sys_setpriority
1534	data8 sys_statfs
1535	data8 sys_fstatfs
1536	data8 sys_gettid			// 1105
1537	data8 sys_semget
1538	data8 sys_semop
1539	data8 sys_semctl
1540	data8 sys_msgget
1541	data8 sys_msgsnd			// 1110
1542	data8 sys_msgrcv
1543	data8 sys_msgctl
1544	data8 sys_shmget
1545	data8 sys_shmat
1546	data8 sys_shmdt				// 1115
1547	data8 sys_shmctl
1548	data8 sys_syslog
1549	data8 sys_setitimer
1550	data8 sys_getitimer
1551	data8 sys_ni_syscall			// 1120		/* was: ia64_oldstat */
1552	data8 sys_ni_syscall					/* was: ia64_oldlstat */
1553	data8 sys_ni_syscall					/* was: ia64_oldfstat */
1554	data8 sys_vhangup
1555	data8 sys_lchown
1556	data8 sys_remap_file_pages		// 1125
1557	data8 sys_wait4
1558	data8 sys_sysinfo
1559	data8 sys_clone
1560	data8 sys_setdomainname
1561	data8 sys_newuname			// 1130
1562	data8 sys_adjtimex
1563	data8 sys_ni_syscall					/* was: ia64_create_module */
1564	data8 sys_init_module
1565	data8 sys_delete_module
1566	data8 sys_ni_syscall			// 1135		/* was: sys_get_kernel_syms */
1567	data8 sys_ni_syscall					/* was: sys_query_module */
1568	data8 sys_quotactl
1569	data8 sys_bdflush
1570	data8 sys_sysfs
1571	data8 sys_personality			// 1140
1572	data8 sys_ni_syscall		// sys_afs_syscall
1573	data8 sys_setfsuid
1574	data8 sys_setfsgid
1575	data8 sys_getdents
1576	data8 sys_flock				// 1145
1577	data8 sys_readv
1578	data8 sys_writev
1579	data8 sys_pread64
1580	data8 sys_pwrite64
1581	data8 sys_sysctl			// 1150
1582	data8 sys_mmap
1583	data8 sys_munmap
1584	data8 sys_mlock
1585	data8 sys_mlockall
1586	data8 sys_mprotect			// 1155
1587	data8 ia64_mremap
1588	data8 sys_msync
1589	data8 sys_munlock
1590	data8 sys_munlockall
1591	data8 sys_sched_getparam		// 1160
1592	data8 sys_sched_setparam
1593	data8 sys_sched_getscheduler
1594	data8 sys_sched_setscheduler
1595	data8 sys_sched_yield
1596	data8 sys_sched_get_priority_max	// 1165
1597	data8 sys_sched_get_priority_min
1598	data8 sys_sched_rr_get_interval
1599	data8 sys_nanosleep
1600	data8 sys_ni_syscall			// old nfsservctl
1601	data8 sys_prctl				// 1170
1602	data8 sys_getpagesize
1603	data8 sys_mmap2
1604	data8 sys_pciconfig_read
1605	data8 sys_pciconfig_write
1606	data8 sys_perfmonctl			// 1175
1607	data8 sys_sigaltstack
1608	data8 sys_rt_sigaction
1609	data8 sys_rt_sigpending
1610	data8 sys_rt_sigprocmask
1611	data8 sys_rt_sigqueueinfo		// 1180
1612	data8 sys_rt_sigreturn
1613	data8 sys_rt_sigsuspend
1614	data8 sys_rt_sigtimedwait
1615	data8 sys_getcwd
1616	data8 sys_capget			// 1185
1617	data8 sys_capset
1618	data8 sys_sendfile64
1619	data8 sys_ni_syscall		// sys_getpmsg (STREAMS)
1620	data8 sys_ni_syscall		// sys_putpmsg (STREAMS)
1621	data8 sys_socket			// 1190
1622	data8 sys_bind
1623	data8 sys_connect
1624	data8 sys_listen
1625	data8 sys_accept
1626	data8 sys_getsockname			// 1195
1627	data8 sys_getpeername
1628	data8 sys_socketpair
1629	data8 sys_send
1630	data8 sys_sendto
1631	data8 sys_recv				// 1200
1632	data8 sys_recvfrom
1633	data8 sys_shutdown
1634	data8 sys_setsockopt
1635	data8 sys_getsockopt
1636	data8 sys_sendmsg			// 1205
1637	data8 sys_recvmsg
1638	data8 sys_pivot_root
1639	data8 sys_mincore
1640	data8 sys_madvise
1641	data8 sys_newstat			// 1210
1642	data8 sys_newlstat
1643	data8 sys_newfstat
1644	data8 sys_clone2
1645	data8 sys_getdents64
1646	data8 sys_getunwind			// 1215
1647	data8 sys_readahead
1648	data8 sys_setxattr
1649	data8 sys_lsetxattr
1650	data8 sys_fsetxattr
1651	data8 sys_getxattr			// 1220
1652	data8 sys_lgetxattr
1653	data8 sys_fgetxattr
1654	data8 sys_listxattr
1655	data8 sys_llistxattr
1656	data8 sys_flistxattr			// 1225
1657	data8 sys_removexattr
1658	data8 sys_lremovexattr
1659	data8 sys_fremovexattr
1660	data8 sys_tkill
1661	data8 sys_futex				// 1230
1662	data8 sys_sched_setaffinity
1663	data8 sys_sched_getaffinity
1664	data8 sys_set_tid_address
1665	data8 sys_fadvise64_64
1666	data8 sys_tgkill 			// 1235
1667	data8 sys_exit_group
1668	data8 sys_lookup_dcookie
1669	data8 sys_io_setup
1670	data8 sys_io_destroy
1671	data8 sys_io_getevents			// 1240
1672	data8 sys_io_submit
1673	data8 sys_io_cancel
1674	data8 sys_epoll_create
1675	data8 sys_epoll_ctl
1676	data8 sys_epoll_wait			// 1245
1677	data8 sys_restart_syscall
1678	data8 sys_semtimedop
1679	data8 sys_timer_create
1680	data8 sys_timer_settime
1681	data8 sys_timer_gettime			// 1250
1682	data8 sys_timer_getoverrun
1683	data8 sys_timer_delete
1684	data8 sys_clock_settime
1685	data8 sys_clock_gettime
1686	data8 sys_clock_getres			// 1255
1687	data8 sys_clock_nanosleep
1688	data8 sys_fstatfs64
1689	data8 sys_statfs64
1690	data8 sys_mbind
1691	data8 sys_get_mempolicy			// 1260
1692	data8 sys_set_mempolicy
1693	data8 sys_mq_open
1694	data8 sys_mq_unlink
1695	data8 sys_mq_timedsend
1696	data8 sys_mq_timedreceive		// 1265
1697	data8 sys_mq_notify
1698	data8 sys_mq_getsetattr
1699	data8 sys_kexec_load
1700	data8 sys_ni_syscall			// reserved for vserver
1701	data8 sys_waitid			// 1270
1702	data8 sys_add_key
1703	data8 sys_request_key
1704	data8 sys_keyctl
1705	data8 sys_ioprio_set
1706	data8 sys_ioprio_get			// 1275
1707	data8 sys_move_pages
1708	data8 sys_inotify_init
1709	data8 sys_inotify_add_watch
1710	data8 sys_inotify_rm_watch
1711	data8 sys_migrate_pages			// 1280
1712	data8 sys_openat
1713	data8 sys_mkdirat
1714	data8 sys_mknodat
1715	data8 sys_fchownat
1716	data8 sys_futimesat			// 1285
1717	data8 sys_newfstatat
1718	data8 sys_unlinkat
1719	data8 sys_renameat
1720	data8 sys_linkat
1721	data8 sys_symlinkat			// 1290
1722	data8 sys_readlinkat
1723	data8 sys_fchmodat
1724	data8 sys_faccessat
1725	data8 sys_pselect6
1726	data8 sys_ppoll				// 1295
1727	data8 sys_unshare
1728	data8 sys_splice
1729	data8 sys_set_robust_list
1730	data8 sys_get_robust_list
1731	data8 sys_sync_file_range		// 1300
1732	data8 sys_tee
1733	data8 sys_vmsplice
1734	data8 sys_fallocate
1735	data8 sys_getcpu
1736	data8 sys_epoll_pwait			// 1305
1737	data8 sys_utimensat
1738	data8 sys_signalfd
1739	data8 sys_ni_syscall
1740	data8 sys_eventfd
1741	data8 sys_timerfd_create		// 1310
1742	data8 sys_timerfd_settime
1743	data8 sys_timerfd_gettime
1744	data8 sys_signalfd4
1745	data8 sys_eventfd2
1746	data8 sys_epoll_create1			// 1315
1747	data8 sys_dup3
1748	data8 sys_pipe2
1749	data8 sys_inotify_init1
1750	data8 sys_preadv
1751	data8 sys_pwritev			// 1320
1752	data8 sys_rt_tgsigqueueinfo
1753	data8 sys_recvmmsg
1754	data8 sys_fanotify_init
1755	data8 sys_fanotify_mark
1756	data8 sys_prlimit64			// 1325
1757	data8 sys_name_to_handle_at
1758	data8 sys_open_by_handle_at
1759	data8 sys_clock_adjtime
1760	data8 sys_syncfs
1761	data8 sys_setns				// 1330
1762	data8 sys_sendmmsg
1763	data8 sys_process_vm_readv
1764	data8 sys_process_vm_writev
1765	data8 sys_accept4
1766	data8 sys_finit_module			// 1335
1767	data8 sys_sched_setattr
1768	data8 sys_sched_getattr
1769	data8 sys_renameat2
1770	data8 sys_getrandom
1771	data8 sys_memfd_create			// 1340
1772	data8 sys_bpf
1773	data8 sys_execveat
1774	data8 sys_userfaultfd
1775	data8 sys_membarrier
1776	data8 sys_kcmp				// 1345
1777	data8 sys_mlock2
1778	data8 sys_copy_file_range
1779	data8 sys_preadv2
1780	data8 sys_pwritev2
1781
1782	.org sys_call_table + 8*NR_syscalls	// guard against failures to increase NR_syscalls