cpuswitch.S revision 1.19
1 /* $NetBSD: cpuswitch.S,v 1.19 2002/10/05 13:46:59 bjh21 Exp $ */ 2 3 /* 4 * Copyright (c) 1994-1998 Mark Brinicombe. 5 * Copyright (c) 1994 Brini. 6 * All rights reserved. 7 * 8 * This code is derived from software written for Brini by Mark Brinicombe 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by Brini. 21 * 4. The name of the company nor the name of the author may be used to 22 * endorse or promote products derived from this software without specific 23 * prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY BRINI ``AS IS'' AND ANY EXPRESS OR IMPLIED 26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 28 * IN NO EVENT SHALL BRINI OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * RiscBSD kernel project 38 * 39 * cpuswitch.S 40 * 41 * cpu switching functions 42 * 43 * Created : 15/10/94 44 */ 45 46 #include "opt_armfpe.h" 47 #include "opt_multiprocessor.h" 48 49 #include "assym.h" 50 #include <machine/param.h> 51 #include <machine/cpu.h> 52 #include <machine/frame.h> 53 #include <machine/asm.h> 54 55 #undef IRQdisable 56 #undef IRQenable 57 58 /* 59 * New experimental definitions of IRQdisable and IRQenable 60 * These keep FIQ's enabled since FIQ's are special. 61 */ 62 63 #define IRQdisable \ 64 mrs r14, cpsr ; \ 65 orr r14, r14, #(I32_bit) ; \ 66 msr cpsr_c, r14 ; \ 67 68 #define IRQenable \ 69 mrs r14, cpsr ; \ 70 bic r14, r14, #(I32_bit) ; \ 71 msr cpsr_c, r14 ; \ 72 73 /* 74 * setrunqueue() and remrunqueue() 75 * 76 * Functions to add and remove a process for the run queue. 77 */ 78 79 .text 80 81 .Lwhichqs: 82 .word _C_LABEL(sched_whichqs) 83 84 .Lqs: 85 .word _C_LABEL(sched_qs) 86 87 /* 88 * On entry 89 * r0 = process 90 */ 91 92 ENTRY(setrunqueue) 93 /* 94 * Local register usage 95 * r0 = process 96 * r1 = queue 97 * r2 = &qs[queue] and temp 98 * r3 = temp 99 * r12 = whichqs 100 */ 101 #ifdef DIAGNOSTIC 102 ldr r1, [r0, #(P_BACK)] 103 teq r1, #0x00000000 104 bne .Lsetrunqueue_erg 105 106 ldr r1, [r0, #(P_WCHAN)] 107 teq r1, #0x00000000 108 bne .Lsetrunqueue_erg 109 #endif 110 111 /* Get the priority of the queue */ 112 ldrb r1, [r0, #(P_PRIORITY)] 113 114 /* Indicate that there is a process on this queue */ 115 ldr r12, .Lwhichqs 116 mov r1, r1, lsr #2 117 ldr r2, [r12] 118 mov r3, #0x00000001 119 mov r3, r3, lsl r1 120 orr r2, r2, r3 121 str r2, [r12] 122 123 /* Get the address of the queue */ 124 ldr r2, .Lqs 125 add r1, r2, r1, lsl # 3 126 127 /* Hook the process in */ 128 str r1, [r0, #(P_FORW)] 129 ldr r2, [r1, #(P_BACK)] 130 131 str r0, [r1, #(P_BACK)] 132 #ifdef DIAGNOSTIC 133 teq r2, #0x00000000 134 beq .Lsetrunqueue_erg 135 #endif 136 str r0, [r2, #(P_FORW)] 137 str r2, [r0, #(P_BACK)] 138 139 mov pc, lr 140 141 #ifdef DIAGNOSTIC 142 .Lsetrunqueue_erg: 143 mov r2, r1 144 mov r1, r0 145 add r0, pc, #.Ltext1 - . - 8 146 bl _C_LABEL(printf) 147 148 ldr r2, .Lqs 149 ldr r1, [r2] 150 add r0, pc, #.Ltext2 - . - 8 151 b _C_LABEL(panic) 152 153 .Ltext1: 154 .asciz "setrunqueue : %08x %08x\n" 155 .Ltext2: 156 .asciz "setrunqueue : [qs]=%08x qs=%08x\n" 157 .align 0 158 #endif 159 160 /* 161 * On entry 162 * r0 = process 163 */ 164 165 ENTRY(remrunqueue) 166 /* 167 * Local register usage 168 * r0 = oldproc 169 * r1 = queue 170 * r2 = &qs[queue] and scratch 171 * r3 = scratch 172 * r12 = whichqs 173 */ 174 175 /* Get the priority of the queue */ 176 ldrb r1, [r0, #(P_PRIORITY)] 177 mov r1, r1, lsr #2 178 179 /* Unhook the process */ 180 ldr r2, [r0, #(P_FORW)] 181 ldr r3, [r0, #(P_BACK)] 182 183 str r3, [r2, #(P_BACK)] 184 str r2, [r3, #(P_FORW)] 185 186 /* If the queue is now empty clear the queue not empty flag */ 187 teq r2, r3 188 189 /* This could be reworked to avoid the use of r4 */ 190 ldreq r12, .Lwhichqs 191 moveq r3, #0x00000001 192 ldreq r2, [r12] 193 moveq r3, r3, lsl r1 194 biceq r2, r2, r3 195 streq r2, [r12] 196 197 /* Remove the back pointer for the process */ 198 mov r1, #0x00000000 199 str r1, [r0, #(P_BACK)] 200 201 mov pc, lr 202 203 204 /* 205 * cpuswitch() 206 * 207 * preforms a process context switch. 208 * This function has several entry points 209 */ 210 211 #ifdef MULTIPROCESSOR 212 .Lcpu_info_store: 213 .word _C_LABEL(cpu_info_store) 214 .Lcurproc: 215 /* FIXME: This is bogus in the general case. */ 216 .word _C_LABEL(cpu_info_store) + CI_CURPROC 217 #else 218 .Lcurproc: 219 .word _C_LABEL(curproc) 220 #endif 221 222 .Lcurpcb: 223 .word _C_LABEL(curpcb) 224 225 .Lwant_resched: 226 .word _C_LABEL(want_resched) 227 228 .Lcpufuncs: 229 .word _C_LABEL(cpufuncs) 230 231 .data 232 .global _C_LABEL(curpcb) 233 _C_LABEL(curpcb): 234 .word 0x00000000 235 .text 236 237 .Lblock_userspace_access: 238 .word _C_LABEL(block_userspace_access) 239 240 .Lcpu_do_powersave: 241 .word _C_LABEL(cpu_do_powersave) 242 243 /* 244 * Idle loop, exercised while waiting for a process to wake up. 245 * 246 * NOTE: When we jump back to .Lswitch_search, we must have a 247 * pointer to whichqs in r7, which is what it is when we arrive 248 * here. 249 */ 250 /* LINTSTUB: Ignore */ 251 ASENTRY_NP(idle) 252 #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) 253 bl _C_LABEL(sched_unlock_idle) 254 #endif 255 ldr r3, .Lcpu_do_powersave 256 257 /* Enable interrupts */ 258 IRQenable 259 260 /* If we don't want to sleep, use a simpler loop. */ 261 ldr r3, [r3] /* r3 = cpu_do_powersave */ 262 teq r3, #0 263 bne 2f 264 265 /* Non-powersave idle. */ 266 1: /* should maybe do uvm pageidlezero stuff here */ 267 ldr r3, [r7] /* r3 = whichqs */ 268 teq r3, #0x00000000 269 bne .Lswitch_search 270 b 1b 271 272 2: /* Powersave idle. */ 273 ldr r4, .Lcpufuncs 274 3: ldr r3, [r7] /* r3 = whichqs */ 275 teq r3, #0x00000000 276 bne .Lswitch_search 277 278 /* if saving power, don't want to pageidlezero */ 279 mov r0, #0 280 add lr, pc, #3b - . - 8 281 ldr pc, [r4, #(CF_SLEEP)] 282 /* loops back around */ 283 284 285 /* 286 * Find a new process to run, save the current context and 287 * load the new context 288 */ 289 290 ENTRY(cpu_switch) 291 /* 292 * Local register usage. Some of these registers are out of date. 293 * r1 = oldproc 294 * r2 = spl level 295 * r3 = whichqs 296 * r4 = queue 297 * r5 = &qs[queue] 298 * r6 = newproc 299 * r7 = scratch 300 */ 301 stmfd sp!, {r4-r7, lr} 302 303 /* 304 * Get the current process and indicate that there is no longer 305 * a valid process (curproc = 0). Zero the current PCB pointer 306 * while we're at it. 307 */ 308 ldr r7, .Lcurproc 309 ldr r6, .Lcurpcb 310 mov r0, #0x00000000 311 ldr r1, [r7] /* r1 = curproc */ 312 str r0, [r7] /* curproc = NULL */ 313 str r0, [r6] /* curpcb = NULL */ 314 315 /* stash the old proc while we call functions */ 316 mov r5, r1 317 318 #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) 319 /* release the sched_lock before handling interrupts */ 320 bl _C_LABEL(sched_unlock_idle) 321 #endif 322 323 /* Lower the spl level to spl0 and get the current spl level. */ 324 #ifdef __NEWINTR 325 mov r0, #(IPL_NONE) 326 bl _C_LABEL(_spllower) 327 #else /* ! __NEWINTR */ 328 #ifdef spl0 329 mov r0, #(_SPL_0) 330 bl _C_LABEL(splx) 331 #else 332 bl _C_LABEL(spl0) 333 #endif /* spl0 */ 334 #endif /* __NEWINTR */ 335 336 /* Push the old spl level onto the stack */ 337 str r0, [sp, #-0x0004]! 338 339 /* First phase : find a new process */ 340 341 ldr r7, .Lwhichqs 342 343 /* rem: r5 = old proc */ 344 /* rem: r7 = &whichqs */ 345 346 .Lswitch_search: 347 IRQdisable 348 #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) 349 bl _C_LABEL(sched_lock_idle) 350 #endif 351 352 /* Do we have any active queues */ 353 ldr r3, [r7] 354 355 /* If not we must idle until we do. */ 356 teq r3, #0x00000000 357 beq _ASM_LABEL(idle) 358 359 /* put old proc back in r1 */ 360 mov r1, r5 361 362 /* rem: r1 = old proc */ 363 /* rem: r3 = whichqs */ 364 /* rem: interrupts are disabled */ 365 366 /* 367 * We have found an active queue. Currently we do not know which queue 368 * is active just that one of them is. 369 */ 370 /* this is the ffs algorithm devised by d.seal and posted to 371 * comp.sys.arm on 16 Feb 1994. 372 */ 373 rsb r5, r3, #0 374 ands r0, r3, r5 375 376 adr r5, .Lcpu_switch_ffs_table 377 378 /* X = R0 */ 379 orr r4, r0, r0, lsl #4 /* r4 = X * 0x11 */ 380 orr r4, r4, r4, lsl #6 /* r4 = X * 0x451 */ 381 rsb r4, r4, r4, lsl #16 /* r4 = X * 0x0450fbaf */ 382 383 /* used further down, saves SA stall */ 384 ldr r6, .Lqs 385 386 /* now lookup in table indexed on top 6 bits of a4 */ 387 ldrb r4, [ r5, r4, lsr #26 ] 388 389 /* rem: r0 = bit mask of chosen queue (1 << r4) */ 390 /* rem: r1 = old proc */ 391 /* rem: r3 = whichqs */ 392 /* rem: r4 = queue number */ 393 /* rem: interrupts are disabled */ 394 395 /* Get the address of the queue (&qs[queue]) */ 396 add r5, r6, r4, lsl #3 397 398 /* 399 * Get the process from the queue and place the next process in 400 * the queue at the head. This basically unlinks the process at 401 * the head of the queue. 402 */ 403 ldr r6, [r5, #(P_FORW)] 404 405 /* rem: r6 = new process */ 406 ldr r7, [r6, #(P_FORW)] 407 str r7, [r5, #(P_FORW)] 408 409 /* 410 * Test to see if the queue is now empty. If the head of the queue 411 * points to the queue itself then there are no more processes in 412 * the queue. We can therefore clear the queue not empty flag held 413 * in r3. 414 */ 415 416 teq r5, r7 417 biceq r3, r3, r0 418 419 /* rem: r0 = bit mask of chosen queue (1 << r4) - NOT NEEDED AN MORE */ 420 421 /* Fix the back pointer for the process now at the head of the queue. */ 422 ldr r0, [r6, #(P_BACK)] 423 str r0, [r7, #(P_BACK)] 424 425 /* Update the RAM copy of the queue not empty flags word. */ 426 ldr r7, .Lwhichqs 427 str r3, [r7] 428 429 /* rem: r1 = old proc */ 430 /* rem: r3 = whichqs - NOT NEEDED ANY MORE */ 431 /* rem: r4 = queue number - NOT NEEDED ANY MORE */ 432 /* rem: r6 = new process */ 433 /* rem: interrupts are disabled */ 434 435 /* Clear the want_resched flag */ 436 ldr r7, .Lwant_resched 437 mov r0, #0x00000000 438 str r0, [r7] 439 440 /* 441 * Clear the back pointer of the process we have removed from 442 * the head of the queue. The new process is isolated now. 443 */ 444 str r0, [r6, #(P_BACK)] 445 446 #if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) 447 /* 448 * unlock the sched_lock, but leave interrupts off, for now. 449 */ 450 mov r7, r1 451 bl _C_LABEL(sched_unlock_idle) 452 mov r1, r7 453 #endif 454 455 #ifdef MULTIPROCESSOR 456 /* XXX use curcpu() */ 457 ldr r0, .Lcpu_info_store 458 str r0, [r6, #(P_CPU)] 459 #else 460 /* p->p_cpu initialized in fork1() for single-processor */ 461 #endif 462 463 /* Process is now on a processor. */ 464 mov r0, #SONPROC /* p->p_stat = SONPROC */ 465 strb r0, [r6, #(P_STAT)] 466 467 /* We have a new curproc now so make a note it */ 468 ldr r7, .Lcurproc 469 str r6, [r7] 470 471 /* Hook in a new pcb */ 472 ldr r7, .Lcurpcb 473 ldr r0, [r6, #(P_ADDR)] 474 str r0, [r7] 475 476 /* At this point we can allow IRQ's again. */ 477 IRQenable 478 479 /* rem: r1 = old proc */ 480 /* rem: r6 = new process */ 481 /* rem: interrupts are enabled */ 482 483 /* 484 * If the new process is the same as the process that called 485 * cpu_switch() then we do not need to save and restore any 486 * contexts. This means we can make a quick exit. 487 * The test is simple if curproc on entry (now in r1) is the 488 * same as the proc removed from the queue we can jump to the exit. 489 */ 490 teq r1, r6 491 beq .Lswitch_return 492 493 /* Remember the old process in r0 */ 494 mov r0, r1 495 496 /* 497 * If the curproc on entry to cpu_switch was zero then the 498 * process that called it was exiting. This means that we do 499 * not need to save the current context. Instead we can jump 500 * straight to restoring the context for the new process. 501 */ 502 teq r0, #0x00000000 503 beq .Lswitch_exited 504 505 /* rem: r0 = old proc */ 506 /* rem: r6 = new process */ 507 /* rem: interrupts are enabled */ 508 509 /* Stage two : Save old context */ 510 511 /* Get the user structure for the old process. */ 512 ldr r1, [r0, #(P_ADDR)] 513 514 /* Save all the registers in the old process's pcb */ 515 add r7, r1, #(PCB_R8) 516 stmia r7, {r8-r13} 517 518 /* 519 * This can be optimised... We know we want to go from SVC32 520 * mode to UND32 mode 521 */ 522 mrs r3, cpsr 523 bic r2, r3, #(PSR_MODE) 524 orr r2, r2, #(PSR_UND32_MODE | I32_bit) 525 msr cpsr_c, r2 526 527 str sp, [r1, #(PCB_UND_SP)] 528 529 msr cpsr_c, r3 /* Restore the old mode */ 530 531 /* rem: r0 = old proc */ 532 /* rem: r1 = old pcb */ 533 /* rem: r6 = new process */ 534 /* rem: interrupts are enabled */ 535 536 /* What else needs to be saved Only FPA stuff when that is supported */ 537 538 /* r1 now free! */ 539 540 /* Third phase : restore saved context */ 541 542 /* rem: r0 = old proc */ 543 /* rem: r6 = new process */ 544 /* rem: interrupts are enabled */ 545 546 /* 547 * Don't allow user space access between the purge and the switch. 548 */ 549 ldr r3, .Lblock_userspace_access 550 mov r1, #0x00000001 551 mov r2, #0x00000000 552 str r1, [r3] 553 554 stmfd sp!, {r0-r3} 555 ldr r1, .Lcpufuncs 556 add lr, pc, #.Lcs_cache_purged - . - 8 557 ldr pc, [r1, #CF_IDCACHE_WBINV_ALL] 558 559 .Lcs_cache_purged: 560 ldmfd sp!, {r0-r3} 561 562 .Lcs_cache_purge_skipped: 563 /* At this point we need to kill IRQ's again. */ 564 IRQdisable 565 566 /* 567 * Interrupts are disabled so we can allow user space accesses again 568 * as none will occur until interrupts are re-enabled after the 569 * switch. 570 */ 571 str r2, [r3] 572 573 /* Get the user structure for the new process in r1 */ 574 ldr r1, [r6, #(P_ADDR)] 575 576 /* Get the pagedir physical address for the process. */ 577 ldr r0, [r1, #(PCB_PAGEDIR)] 578 579 /* Switch the memory to the new process */ 580 ldr r3, .Lcpufuncs 581 add lr, pc, #.Lcs_context_switched - . - 8 582 ldr pc, [r3, #CF_CONTEXT_SWITCH] 583 584 .Lcs_context_switched: 585 /* 586 * This can be optimised... We know we want to go from SVC32 587 * mode to UND32 mode 588 */ 589 mrs r3, cpsr 590 bic r2, r3, #(PSR_MODE) 591 orr r2, r2, #(PSR_UND32_MODE) 592 msr cpsr_c, r2 593 594 ldr sp, [r1, #(PCB_UND_SP)] 595 596 msr cpsr_c, r3 /* Restore the old mode */ 597 598 /* Restore all the save registers */ 599 add r7, r1, #PCB_R8 600 ldmia r7, {r8-r13} 601 602 mov r7, r1 /* preserve PCB pointer */ 603 604 #ifdef ARMFPE 605 add r0, r1, #(USER_SIZE) & 0x00ff 606 add r0, r0, #(USER_SIZE) & 0xff00 607 bl _C_LABEL(arm_fpe_core_changecontext) 608 #endif 609 610 /* We can enable interrupts again */ 611 IRQenable 612 613 /* rem: r6 = new proc */ 614 /* rem: r7 = new PCB */ 615 616 /* 617 * Check for restartable atomic sequences (RAS). 618 */ 619 620 ldr r2, [r6, #(P_NRAS)] 621 ldr r4, [r7, #(PCB_TF)] /* r4 = trapframe (used below) */ 622 teq r2, #0 /* p->p_nras == 0? */ 623 bne .Lswitch_do_ras /* no, check for one */ 624 625 .Lswitch_return: 626 627 /* Get the spl level from the stack and update the current spl level */ 628 ldr r0, [sp], #0x0004 629 bl _C_LABEL(splx) 630 631 /* cpu_switch returns the proc it switched to. */ 632 mov r0, r6 633 634 /* 635 * Pull the registers that got pushed when either savectx() or 636 * cpu_switch() was called and return. 637 */ 638 ldmfd sp!, {r4-r7, pc} 639 640 .Lswitch_do_ras: 641 ldr r1, [r4, #(TF_PC)] /* second ras_lookup() arg */ 642 mov r0, r6 /* first ras_lookup() arg */ 643 bl _C_LABEL(ras_lookup) 644 cmn r0, #1 /* -1 means "not in a RAS" */ 645 strne r0, [r4, #(TF_PC)] 646 b .Lswitch_return 647 648 .Lswitch_exited: 649 /* 650 * We skip the cache purge because switch_exit() already did 651 * it. Load up registers the way Lcs_cache_purge_skipped 652 * expects. Userspace access already blocked in switch_exit(). 653 */ 654 ldr r3, .Lblock_userspace_access 655 mov r2, #0x00000000 656 b .Lcs_cache_purge_skipped 657 658 /* 659 * void switch_exit(struct proc *p, struct proc *p0); 660 * Switch to proc0's saved context and deallocate the address space and kernel 661 * stack for p. Then jump into cpu_switch(), as if we were in proc0 all along. 662 */ 663 664 /* LINTSTUB: Func: void switch_exit(struct proc *p, struct proc *p0) */ 665 ENTRY(switch_exit) 666 /* 667 * r0 = proc 668 * r1 = proc0 669 */ 670 671 mov r3, r0 672 673 /* In case we fault */ 674 ldr r0, .Lcurproc 675 mov r2, #0x00000000 676 str r2, [r0] 677 678 /* ldr r0, .Lcurpcb 679 str r2, [r0]*/ 680 681 /* 682 * Don't allow user space access between the purge and the switch. 683 */ 684 ldr r0, .Lblock_userspace_access 685 mov r2, #0x00000001 686 str r2, [r0] 687 688 /* Switch to proc0 context */ 689 690 stmfd sp!, {r0-r3} 691 692 ldr r0, .Lcpufuncs 693 add lr, pc, #.Lse_cache_purged - . - 8 694 ldr pc, [r0, #CF_IDCACHE_WBINV_ALL] 695 696 .Lse_cache_purged: 697 ldmfd sp!, {r0-r3} 698 699 IRQdisable 700 701 ldr r2, [r1, #(P_ADDR)] 702 ldr r0, [r2, #(PCB_PAGEDIR)] 703 704 /* Switch the memory to the new process */ 705 ldr r4, .Lcpufuncs 706 add lr, pc, #.Lse_context_switched - . - 8 707 ldr pc, [r4, #CF_CONTEXT_SWITCH] 708 709 .Lse_context_switched: 710 /* Restore all the save registers */ 711 add r7, r2, #PCB_R8 712 ldmia r7, {r8-r13} 713 714 /* This is not really needed ! */ 715 /* Yes it is for the su and fu routines */ 716 ldr r0, .Lcurpcb 717 str r2, [r0] 718 719 IRQenable 720 721 /* str r3, [sp, #-0x0004]!*/ 722 723 /* 724 * Schedule the vmspace and stack to be freed. 725 */ 726 mov r0, r3 /* exit2(p) */ 727 bl _C_LABEL(exit2) 728 729 /* Paranoia */ 730 ldr r1, .Lcurproc 731 mov r0, #0x00000000 732 str r0, [r1] 733 734 ldr r7, .Lwhichqs /* r7 = &whichqs */ 735 mov r5, #0x00000000 /* r5 = old proc = NULL */ 736 b .Lswitch_search 737 738 /* LINTSTUB: Func: void savectx(struct pcb *pcb) */ 739 ENTRY(savectx) 740 /* 741 * r0 = pcb 742 */ 743 744 /* Push registers.*/ 745 stmfd sp!, {r4-r7, lr} 746 747 /* Store all the registers in the process's pcb */ 748 add r2, r0, #(PCB_R8) 749 stmia r2, {r8-r13} 750 751 /* Pull the regs of the stack */ 752 ldmfd sp!, {r4-r7, pc} 753 754 ENTRY(proc_trampoline) 755 #ifdef MULTIPROCESSOR 756 bl _C_LABEL(proc_trampoline_mp) 757 #endif 758 add lr, pc, #(.Ltrampoline_return - . - 8) 759 mov r0, r5 760 mov r1, sp 761 mov pc, r4 762 763 .Ltrampoline_return: 764 /* Kill irq's */ 765 mrs r0, cpsr 766 orr r0, r0, #(I32_bit) 767 msr cpsr_c, r0 768 769 PULLFRAME 770 771 movs pc, lr /* Exit */ 772 773 .type .Lcpu_switch_ffs_table, _ASM_TYPE_OBJECT; 774 .Lcpu_switch_ffs_table: 775 /* same as ffs table but all nums are -1 from that */ 776 /* 0 1 2 3 4 5 6 7 */ 777 .byte 0, 0, 1, 12, 2, 6, 0, 13 /* 0- 7 */ 778 .byte 3, 0, 7, 0, 0, 0, 0, 14 /* 8-15 */ 779 .byte 10, 4, 0, 0, 8, 0, 0, 25 /* 16-23 */ 780 .byte 0, 0, 0, 0, 0, 21, 27, 15 /* 24-31 */ 781 .byte 31, 11, 5, 0, 0, 0, 0, 0 /* 32-39 */ 782 .byte 9, 0, 0, 24, 0, 0, 20, 26 /* 40-47 */ 783 .byte 30, 0, 0, 0, 0, 23, 0, 19 /* 48-55 */ 784 .byte 29, 0, 22, 18, 28, 17, 16, 0 /* 56-63 */ 785 786 /* End of cpuswitch.S */ 787
Indexes created Tue Oct 21 19:09:51 GMT 2025