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 */ 60 ENTRY(ia64_execve) 61 /* 62 * Allocate 8 input registers since ptrace() may clobber them 63 */ 64 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8) 65 alloc loc1=ar.pfs,8,2,3,0 66 mov loc0=rp 67 .body 68 mov out0=in0 // filename 69 ;; // stop bit between alloc and call 70 mov out1=in1 // argv 71 mov out2=in2 // envp 72 br.call.sptk.many rp=sys_execve 73 .ret0: 74 cmp4.ge p6,p7=r8,r0 75 mov ar.pfs=loc1 // restore ar.pfs 76 sxt4 r8=r8 // return 64-bit result 77 ;; 78 stf.spill [sp]=f0 79 mov rp=loc0 80 (p6) mov ar.pfs=r0 // clear ar.pfs on success 81 (p7) br.ret.sptk.many rp 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 102 END(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 */ 108 GLOBAL_ENTRY(sys_clone2) 109 /* 110 * Allocate 8 input registers since ptrace() may clobber them 111 */ 112 .prologue ASM_UNW_PRLG_RP|ASM_UNW_PRLG_PFS, ASM_UNW_PRLG_GRSAVE(8) 113 alloc r16=ar.pfs,8,2,6,0 114 DO_SAVE_SWITCH_STACK 115 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 130 END(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 */ 136 GLOBAL_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 158 END(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 */ 166 GLOBAL_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 218 END(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 */ 236 GLOBAL_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 351 END(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 */ 359 GLOBAL_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 451 END(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 */ 459 GLOBAL_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 526 527 strace_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 537 END(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 */ 543 GLOBAL_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 554 END(ia64_strace_leave_kernel) 555 556 ENTRY(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 575 END(call_payload) 576 577 GLOBAL_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 604 END(ia64_ret_from_clone) 605 // fall through 606 GLOBAL_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 612 END(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 */ 659 GLOBAL_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; 688 ia64_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 801 END(ia64_leave_syscall) 802 803 GLOBAL_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 995 rbs_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 ;; 1004 dont_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) 1027 rse_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 ;; 1086 skip_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 = ¤t->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; 1146 ia64_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 1153 END(ia64_leave_kernel) 1154 1155 ENTRY(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 1170 END(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 */ 1176 GLOBAL_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 1186 END(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 */ 1196 GLOBAL_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 1221 END(notify_resume_user) 1222 1223 ENTRY(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 1262 END(sys_rt_sigreturn) 1263 1264 GLOBAL_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 1275 END(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 1282 GLOBAL_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 1302 1: 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 1309 1: 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 1320 END(unw_init_running) 1321 EXPORT_SYMBOL(unw_init_running) 1322 1323 #ifdef CONFIG_FUNCTION_TRACER 1324 #ifdef CONFIG_DYNAMIC_FTRACE 1325 GLOBAL_ENTRY(_mcount) 1326 br ftrace_stub 1327 END(_mcount) 1328 EXPORT_SYMBOL(_mcount) 1329 1330 .here: 1331 br.ret.sptk.many b0 1332 1333 GLOBAL_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 1342 ftrace_patch_gp: 1343 movl gp=__gp 1344 mov b0 = r3 1345 ;; 1346 .global ftrace_call; 1347 ftrace_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 ;; 1372 END(ftrace_caller) 1373 1374 #else 1375 GLOBAL_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 ;; 1403 END(_mcount) 1404 #endif 1405 1406 GLOBAL_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 1419 END(ftrace_stub) 1420 1421 #endif /* CONFIG_FUNCTION_TRACER */ 1422 1423 #define __SYSCALL(nr, entry, nargs) data8 entry 1424 .rodata 1425 .align 8 1426 .globl sys_call_table 1427 sys_call_table: 1428 #include <asm/syscall_table.h> 1429 #undef __SYSCALL 1430