| blob | a87cbf889ff479f635df3d42af731f80e32e8e64 |
1 /*
2 * linux/arch/arm/kernel/entry-armv.S
3 *
4 * Copyright (C) 1996,1997,1998 Russell King.
5 * ARM700 fix by Matthew Godbolt (linux-user@willothewisp.demon.co.uk)
6 * nommu support by Hyok S. Choi (hyok.choi@samsung.com)
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * Low-level vector interface routines
13 *
14 * Note: there is a StrongARM bug in the STMIA rn, {regs}^ instruction
15 * that causes it to save wrong values... Be aware!
16 */
18 #include <asm/memory.h>
19 #include <asm/glue-df.h>
20 #include <asm/glue-pf.h>
21 #include <asm/vfpmacros.h>
22 #include <mach/entry-macro.S>
23 #include <asm/thread_notify.h>
24 #include <asm/unwind.h>
25 #include <asm/unistd.h>
26 #include <asm/tls.h>
28 #include "entry-header.S"
29 #include <asm/entry-macro-multi.S>
31 /*
32 * Interrupt handling.
33 */
34 .macro irq_handler
35 #ifdef CONFIG_MULTI_IRQ_HANDLER
36 ldr r1, =handle_arch_irq
37 mov r0, sp
38 ldr r1, [r1]
39 adr lr, BSYM(9997f)
40 teq r1, #0
41 movne pc, r1
42 #endif
43 arch_irq_handler_default
44 9997:
45 .endm
47 .macro pabt_helper
48 @ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
49 #ifdef MULTI_PABORT
50 ldr ip, .LCprocfns
51 mov lr, pc
52 ldr pc, [ip, #PROCESSOR_PABT_FUNC]
53 #else
54 bl CPU_PABORT_HANDLER
55 #endif
56 .endm
58 .macro dabt_helper
60 @
61 @ Call the processor-specific abort handler:
62 @
63 @ r2 - pt_regs
64 @ r4 - aborted context pc
65 @ r5 - aborted context psr
66 @
67 @ The abort handler must return the aborted address in r0, and
68 @ the fault status register in r1. r9 must be preserved.
69 @
70 #ifdef MULTI_DABORT
71 ldr ip, .LCprocfns
72 mov lr, pc
73 ldr pc, [ip, #PROCESSOR_DABT_FUNC]
74 #else
75 bl CPU_DABORT_HANDLER
76 #endif
77 .endm
79 #ifdef CONFIG_KPROBES
80 .section .kprobes.text,"ax",%progbits
81 #else
82 .text
83 #endif
85 /*
86 * Invalid mode handlers
87 */
88 .macro inv_entry, reason
89 sub sp, sp, #S_FRAME_SIZE
90 ARM( stmib sp, {r1 - lr} )
91 THUMB( stmia sp, {r0 - r12} )
92 THUMB( str sp, [sp, #S_SP] )
93 THUMB( str lr, [sp, #S_LR] )
94 mov r1, #\reason
95 .endm
97 __pabt_invalid:
98 inv_entry BAD_PREFETCH
99 b common_invalid
100 ENDPROC(__pabt_invalid)
102 __dabt_invalid:
103 inv_entry BAD_DATA
104 b common_invalid
105 ENDPROC(__dabt_invalid)
107 __irq_invalid:
108 inv_entry BAD_IRQ
109 b common_invalid
110 ENDPROC(__irq_invalid)
112 __und_invalid:
113 inv_entry BAD_UNDEFINSTR
115 @
116 @ XXX fall through to common_invalid
117 @
119 @
120 @ common_invalid - generic code for failed exception (re-entrant version of handlers)
121 @
122 common_invalid:
123 zero_fp
125 ldmia r0, {r4 - r6}
126 add r0, sp, #S_PC @ here for interlock avoidance
127 mov r7, #-1 @ "" "" "" ""
128 str r4, [sp] @ save preserved r0
129 stmia r0, {r5 - r7} @ lr_<exception>,
130 @ cpsr_<exception>, "old_r0"
132 mov r0, sp
133 b bad_mode
134 ENDPROC(__und_invalid)
136 /*
137 * SVC mode handlers
138 */
140 #if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
141 #define SPFIX(code...) code
142 #else
143 #define SPFIX(code...)
144 #endif
146 .macro svc_entry, stack_hole=0
147 UNWIND(.fnstart )
148 UNWIND(.save {r0 - pc} )
149 sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
150 #ifdef CONFIG_THUMB2_KERNEL
151 SPFIX( str r0, [sp] ) @ temporarily saved
152 SPFIX( mov r0, sp )
153 SPFIX( tst r0, #4 ) @ test original stack alignment
154 SPFIX( ldr r0, [sp] ) @ restored
155 #else
156 SPFIX( tst sp, #4 )
157 #endif
158 SPFIX( subeq sp, sp, #4 )
159 stmia sp, {r1 - r12}
161 ldmia r0, {r3 - r5}
162 add r7, sp, #S_SP - 4 @ here for interlock avoidance
163 mov r6, #-1 @ "" "" "" ""
164 add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
165 SPFIX( addeq r2, r2, #4 )
166 str r3, [sp, #-4]! @ save the "real" r0 copied
167 @ from the exception stack
169 mov r3, lr
171 @
172 @ We are now ready to fill in the remaining blanks on the stack:
173 @
174 @ r2 - sp_svc
175 @ r3 - lr_svc
176 @ r4 - lr_<exception>, already fixed up for correct return/restart
177 @ r5 - spsr_<exception>
178 @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
179 @
180 stmia r7, {r2 - r6}
182 #ifdef CONFIG_TRACE_IRQFLAGS
183 bl trace_hardirqs_off
184 #endif
185 .endm
187 .align 5
188 __dabt_svc:
189 svc_entry
190 mov r2, sp
191 dabt_helper
193 @
194 @ IRQs off again before pulling preserved data off the stack
195 @
196 disable_irq_notrace
198 #ifdef CONFIG_TRACE_IRQFLAGS
199 tst r5, #PSR_I_BIT
200 bleq trace_hardirqs_on
201 tst r5, #PSR_I_BIT
202 blne trace_hardirqs_off
203 #endif
204 svc_exit r5 @ return from exception
205 UNWIND(.fnend )
206 ENDPROC(__dabt_svc)
208 .align 5
209 __irq_svc:
210 svc_entry
211 irq_handler
213 #ifdef CONFIG_PREEMPT
214 get_thread_info tsk
215 ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
216 ldr r0, [tsk, #TI_FLAGS] @ get flags
217 teq r8, #0 @ if preempt count != 0
218 movne r0, #0 @ force flags to 0
219 tst r0, #_TIF_NEED_RESCHED
220 blne svc_preempt
221 #endif
223 #ifdef CONFIG_TRACE_IRQFLAGS
224 @ The parent context IRQs must have been enabled to get here in
225 @ the first place, so there's no point checking the PSR I bit.
226 bl trace_hardirqs_on
227 #endif
228 svc_exit r5 @ return from exception
229 UNWIND(.fnend )
230 ENDPROC(__irq_svc)
232 .ltorg
234 #ifdef CONFIG_PREEMPT
235 svc_preempt:
236 mov r8, lr
237 1: bl preempt_schedule_irq @ irq en/disable is done inside
238 ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
239 tst r0, #_TIF_NEED_RESCHED
240 moveq pc, r8 @ go again
241 b 1b
242 #endif
244 .align 5
245 __und_svc:
246 #ifdef CONFIG_KPROBES
247 @ If a kprobe is about to simulate a "stmdb sp..." instruction,
248 @ it obviously needs free stack space which then will belong to
249 @ the saved context.
250 svc_entry 64
251 #else
252 svc_entry
253 #endif
254 @
255 @ call emulation code, which returns using r9 if it has emulated
256 @ the instruction, or the more conventional lr if we are to treat
257 @ this as a real undefined instruction
258 @
259 @ r0 - instruction
260 @
261 #ifndef CONFIG_THUMB2_KERNEL
262 ldr r0, [r4, #-4]
263 #else
264 ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
265 and r9, r0, #0xf800
266 cmp r9, #0xe800 @ 32-bit instruction if xx >= 0
267 ldrhhs r9, [r4] @ bottom 16 bits
268 orrhs r0, r9, r0, lsl #16
269 #endif
270 adr r9, BSYM(1f)
271 mov r2, r4
272 bl call_fpe
274 mov r0, sp @ struct pt_regs *regs
275 bl do_undefinstr
277 @
278 @ IRQs off again before pulling preserved data off the stack
279 @
280 1: disable_irq_notrace
282 @
283 @ restore SPSR and restart the instruction
284 @
285 ldr r5, [sp, #S_PSR] @ Get SVC cpsr
286 #ifdef CONFIG_TRACE_IRQFLAGS
287 tst r5, #PSR_I_BIT
288 bleq trace_hardirqs_on
289 tst r5, #PSR_I_BIT
290 blne trace_hardirqs_off
291 #endif
292 svc_exit r5 @ return from exception
293 UNWIND(.fnend )
294 ENDPROC(__und_svc)
296 .align 5
297 __pabt_svc:
298 svc_entry
299 mov r2, sp @ regs
300 pabt_helper
302 @
303 @ IRQs off again before pulling preserved data off the stack
304 @
305 disable_irq_notrace
307 #ifdef CONFIG_TRACE_IRQFLAGS
308 tst r5, #PSR_I_BIT
309 bleq trace_hardirqs_on
310 tst r5, #PSR_I_BIT
311 blne trace_hardirqs_off
312 #endif
313 svc_exit r5 @ return from exception
314 UNWIND(.fnend )
315 ENDPROC(__pabt_svc)
317 .align 5
318 .LCcralign:
319 .word cr_alignment
320 #ifdef MULTI_DABORT
321 .LCprocfns:
322 .word processor
323 #endif
324 .LCfp:
325 .word fp_enter
327 /*
328 * User mode handlers
329 *
330 * EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
331 */
333 #if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
334 #error "sizeof(struct pt_regs) must be a multiple of 8"
335 #endif
337 .macro usr_entry
338 UNWIND(.fnstart )
339 UNWIND(.cantunwind ) @ don't unwind the user space
340 sub sp, sp, #S_FRAME_SIZE
341 ARM( stmib sp, {r1 - r12} )
342 THUMB( stmia sp, {r0 - r12} )
344 ldmia r0, {r3 - r5}
345 add r0, sp, #S_PC @ here for interlock avoidance
346 mov r6, #-1 @ "" "" "" ""
348 str r3, [sp] @ save the "real" r0 copied
349 @ from the exception stack
351 @
352 @ We are now ready to fill in the remaining blanks on the stack:
353 @
354 @ r4 - lr_<exception>, already fixed up for correct return/restart
355 @ r5 - spsr_<exception>
356 @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
357 @
358 @ Also, separately save sp_usr and lr_usr
359 @
360 stmia r0, {r4 - r6}
361 ARM( stmdb r0, {sp, lr}^ )
362 THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
364 @
365 @ Enable the alignment trap while in kernel mode
366 @
367 alignment_trap r0
369 @
370 @ Clear FP to mark the first stack frame
371 @
372 zero_fp
374 #ifdef CONFIG_IRQSOFF_TRACER
375 bl trace_hardirqs_off
376 #endif
377 .endm
379 .macro kuser_cmpxchg_check
380 #if !defined(CONFIG_CPU_32v6K) && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
381 #ifndef CONFIG_MMU
382 #warning "NPTL on non MMU needs fixing"
383 #else
384 @ Make sure our user space atomic helper is restarted
385 @ if it was interrupted in a critical region. Here we
386 @ perform a quick test inline since it should be false
387 @ 99.9999% of the time. The rest is done out of line.
388 cmp r4, #TASK_SIZE
389 blhs kuser_cmpxchg64_fixup
390 #endif
391 #endif
392 .endm
394 .align 5
395 __dabt_usr:
396 usr_entry
397 kuser_cmpxchg_check
398 mov r2, sp
399 dabt_helper
400 b ret_from_exception
401 UNWIND(.fnend )
402 ENDPROC(__dabt_usr)
404 .align 5
405 __irq_usr:
406 usr_entry
407 kuser_cmpxchg_check
408 irq_handler
409 get_thread_info tsk
410 mov why, #0
411 b ret_to_user_from_irq
412 UNWIND(.fnend )
413 ENDPROC(__irq_usr)
415 .ltorg
417 .align 5
418 __und_usr:
419 usr_entry
421 mov r2, r4
422 mov r3, r5
424 @
425 @ fall through to the emulation code, which returns using r9 if
426 @ it has emulated the instruction, or the more conventional lr
427 @ if we are to treat this as a real undefined instruction
428 @
429 @ r0 - instruction
430 @
431 adr r9, BSYM(ret_from_exception)
432 adr lr, BSYM(__und_usr_unknown)
433 tst r3, #PSR_T_BIT @ Thumb mode?
434 itet eq @ explicit IT needed for the 1f label
435 subeq r4, r2, #4 @ ARM instr at LR - 4
436 subne r4, r2, #2 @ Thumb instr at LR - 2
437 1: ldreqt r0, [r4]
438 #ifdef CONFIG_CPU_ENDIAN_BE8
439 reveq r0, r0 @ little endian instruction
440 #endif
441 beq call_fpe
442 @ Thumb instruction
443 #if __LINUX_ARM_ARCH__ >= 7
444 2:
445 ARM( ldrht r5, [r4], #2 )
446 THUMB( ldrht r5, [r4] )
447 THUMB( add r4, r4, #2 )
448 and r0, r5, #0xf800 @ mask bits 111x x... .... ....
449 cmp r0, #0xe800 @ 32bit instruction if xx != 0
450 blo __und_usr_unknown
451 3: ldrht r0, [r4]
452 add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
453 orr r0, r0, r5, lsl #16
454 #else
455 b __und_usr_unknown
456 #endif
457 UNWIND(.fnend )
458 ENDPROC(__und_usr)
460 @
461 @ fallthrough to call_fpe
462 @
464 /*
465 * The out of line fixup for the ldrt above.
466 */
467 .pushsection .fixup, "ax"
468 4: mov pc, r9
469 .popsection
470 .pushsection __ex_table,"a"
471 .long 1b, 4b
472 #if __LINUX_ARM_ARCH__ >= 7
473 .long 2b, 4b
474 .long 3b, 4b
475 #endif
476 .popsection
478 /*
479 * Check whether the instruction is a co-processor instruction.
480 * If yes, we need to call the relevant co-processor handler.
481 *
482 * Note that we don't do a full check here for the co-processor
483 * instructions; all instructions with bit 27 set are well
484 * defined. The only instructions that should fault are the
485 * co-processor instructions. However, we have to watch out
486 * for the ARM6/ARM7 SWI bug.
487 *
488 * NEON is a special case that has to be handled here. Not all
489 * NEON instructions are co-processor instructions, so we have
490 * to make a special case of checking for them. Plus, there's
491 * five groups of them, so we have a table of mask/opcode pairs
492 * to check against, and if any match then we branch off into the
493 * NEON handler code.
494 *
495 * Emulators may wish to make use of the following registers:
496 * r0 = instruction opcode.
497 * r2 = PC+4
498 * r9 = normal "successful" return address
499 * r10 = this threads thread_info structure.
500 * lr = unrecognised instruction return address
501 */
502 @
503 @ Fall-through from Thumb-2 __und_usr
504 @
505 #ifdef CONFIG_NEON
506 adr r6, .LCneon_thumb_opcodes
507 b 2f
508 #endif
509 call_fpe:
510 #ifdef CONFIG_NEON
511 adr r6, .LCneon_arm_opcodes
512 2:
513 ldr r7, [r6], #4 @ mask value
514 cmp r7, #0 @ end mask?
515 beq 1f
516 and r8, r0, r7
517 ldr r7, [r6], #4 @ opcode bits matching in mask
518 cmp r8, r7 @ NEON instruction?
519 bne 2b
520 get_thread_info r10
521 mov r7, #1
522 strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used
523 strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used
524 b do_vfp @ let VFP handler handle this
525 1:
526 #endif
527 tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
528 tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2
529 #if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710)
530 and r8, r0, #0x0f000000 @ mask out op-code bits
531 teqne r8, #0x0f000000 @ SWI (ARM6/7 bug)?
532 #endif
533 moveq pc, lr
534 get_thread_info r10 @ get current thread
535 and r8, r0, #0x00000f00 @ mask out CP number
536 THUMB( lsr r8, r8, #8 )
537 mov r7, #1
538 add r6, r10, #TI_USED_CP
539 ARM( strb r7, [r6, r8, lsr #8] ) @ set appropriate used_cp[]
540 THUMB( strb r7, [r6, r8] ) @ set appropriate used_cp[]
541 #ifdef CONFIG_IWMMXT
542 @ Test if we need to give access to iWMMXt coprocessors
543 ldr r5, [r10, #TI_FLAGS]
544 rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
545 movcss r7, r5, lsr #(TIF_USING_IWMMXT + 1)
546 bcs iwmmxt_task_enable
547 #endif
548 ARM( add pc, pc, r8, lsr #6 )
549 THUMB( lsl r8, r8, #2 )
550 THUMB( add pc, r8 )
551 nop
553 movw_pc lr @ CP#0
554 W(b) do_fpe @ CP#1 (FPE)
555 W(b) do_fpe @ CP#2 (FPE)
556 movw_pc lr @ CP#3
557 #ifdef CONFIG_CRUNCH
558 b crunch_task_enable @ CP#4 (MaverickCrunch)
559 b crunch_task_enable @ CP#5 (MaverickCrunch)
560 b crunch_task_enable @ CP#6 (MaverickCrunch)
561 #else
562 movw_pc lr @ CP#4
563 movw_pc lr @ CP#5
564 movw_pc lr @ CP#6
565 #endif
566 movw_pc lr @ CP#7
567 movw_pc lr @ CP#8
568 movw_pc lr @ CP#9
569 #ifdef CONFIG_VFP
570 W(b) do_vfp @ CP#10 (VFP)
571 W(b) do_vfp @ CP#11 (VFP)
572 #else
573 movw_pc lr @ CP#10 (VFP)
574 movw_pc lr @ CP#11 (VFP)
575 #endif
576 movw_pc lr @ CP#12
577 movw_pc lr @ CP#13
578 movw_pc lr @ CP#14 (Debug)
579 movw_pc lr @ CP#15 (Control)
581 #ifdef CONFIG_NEON
582 .align 6
584 .LCneon_arm_opcodes:
585 .word 0xfe000000 @ mask
586 .word 0xf2000000 @ opcode
588 .word 0xff100000 @ mask
589 .word 0xf4000000 @ opcode
591 .word 0x00000000 @ mask
592 .word 0x00000000 @ opcode
594 .LCneon_thumb_opcodes:
595 .word 0xef000000 @ mask
596 .word 0xef000000 @ opcode
598 .word 0xff100000 @ mask
599 .word 0xf9000000 @ opcode
601 .word 0x00000000 @ mask
602 .word 0x00000000 @ opcode
603 #endif
605 do_fpe:
606 enable_irq
607 ldr r4, .LCfp
608 add r10, r10, #TI_FPSTATE @ r10 = workspace
609 ldr pc, [r4] @ Call FP module USR entry point
611 /*
612 * The FP module is called with these registers set:
613 * r0 = instruction
614 * r2 = PC+4
615 * r9 = normal "successful" return address
616 * r10 = FP workspace
617 * lr = unrecognised FP instruction return address
618 */
620 .pushsection .data
621 ENTRY(fp_enter)
622 .word no_fp
623 .popsection
625 ENTRY(no_fp)
626 mov pc, lr
627 ENDPROC(no_fp)
629 __und_usr_unknown:
630 enable_irq
631 mov r0, sp
632 adr lr, BSYM(ret_from_exception)
633 b do_undefinstr
634 ENDPROC(__und_usr_unknown)
636 .align 5
637 __pabt_usr:
638 usr_entry
639 mov r2, sp @ regs
640 pabt_helper
641 UNWIND(.fnend )
642 /* fall through */
643 /*
644 * This is the return code to user mode for abort handlers
645 */
646 ENTRY(ret_from_exception)
647 UNWIND(.fnstart )
648 UNWIND(.cantunwind )
649 get_thread_info tsk
650 mov why, #0
651 b ret_to_user
652 UNWIND(.fnend )
653 ENDPROC(__pabt_usr)
654 ENDPROC(ret_from_exception)
656 /*
657 * Register switch for ARMv3 and ARMv4 processors
658 * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
659 * previous and next are guaranteed not to be the same.
660 */
661 ENTRY(__switch_to)
662 UNWIND(.fnstart )
663 UNWIND(.cantunwind )
664 add ip, r1, #TI_CPU_SAVE
665 ldr r3, [r2, #TI_TP_VALUE]
666 ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
667 THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
668 THUMB( str sp, [ip], #4 )
669 THUMB( str lr, [ip], #4 )
670 #ifdef CONFIG_CPU_USE_DOMAINS
671 ldr r6, [r2, #TI_CPU_DOMAIN]
672 #endif
673 set_tls r3, r4, r5
674 #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
675 ldr r7, [r2, #TI_TASK]
676 ldr r8, =__stack_chk_guard
677 ldr r7, [r7, #TSK_STACK_CANARY]
678 #endif
679 #ifdef CONFIG_CPU_USE_DOMAINS
680 mcr p15, 0, r6, c3, c0, 0 @ Set domain register
681 #endif
682 mov r5, r0
683 add r4, r2, #TI_CPU_SAVE
684 ldr r0, =thread_notify_head
685 mov r1, #THREAD_NOTIFY_SWITCH
686 bl atomic_notifier_call_chain
687 #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
688 str r7, [r8]
689 #endif
690 THUMB( mov ip, r4 )
691 mov r0, r5
692 ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
693 THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
694 THUMB( ldr sp, [ip], #4 )
695 THUMB( ldr pc, [ip] )
696 UNWIND(.fnend )
697 ENDPROC(__switch_to)
699 __INIT
701 /*
702 * User helpers.
703 *
704 * Each segment is 32-byte aligned and will be moved to the top of the high
705 * vector page. New segments (if ever needed) must be added in front of
706 * existing ones. This mechanism should be used only for things that are
707 * really small and justified, and not be abused freely.
708 *
709 * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
710 */
711 THUMB( .arm )
713 .macro usr_ret, reg
714 #ifdef CONFIG_ARM_THUMB
715 bx \reg
716 #else
717 mov pc, \reg
718 #endif
719 .endm
721 .align 5
722 .globl __kuser_helper_start
723 __kuser_helper_start:
725 /*
726 * Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular
727 * kuser "slots", therefore 0xffff0f80 is not used as a valid entry point.
728 */
730 __kuser_cmpxchg64: @ 0xffff0f60
732 #if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
734 /*
735 * Poor you. No fast solution possible...
736 * The kernel itself must perform the operation.
737 * A special ghost syscall is used for that (see traps.c).
738 */
739 stmfd sp!, {r7, lr}
740 ldr r7, 1f @ it's 20 bits
741 swi __ARM_NR_cmpxchg64
742 ldmfd sp!, {r7, pc}
743 1: .word __ARM_NR_cmpxchg64
745 #elif defined(CONFIG_CPU_32v6K)
747 stmfd sp!, {r4, r5, r6, r7}
748 ldrd r4, r5, [r0] @ load old val
749 ldrd r6, r7, [r1] @ load new val
750 smp_dmb arm
751 1: ldrexd r0, r1, [r2] @ load current val
752 eors r3, r0, r4 @ compare with oldval (1)
753 eoreqs r3, r1, r5 @ compare with oldval (2)
754 strexdeq r3, r6, r7, [r2] @ store newval if eq
755 teqeq r3, #1 @ success?
756 beq 1b @ if no then retry
757 smp_dmb arm
758 rsbs r0, r3, #0 @ set returned val and C flag
759 ldmfd sp!, {r4, r5, r6, r7}
760 bx lr
762 #elif !defined(CONFIG_SMP)
764 #ifdef CONFIG_MMU
766 /*
767 * The only thing that can break atomicity in this cmpxchg64
768 * implementation is either an IRQ or a data abort exception
769 * causing another process/thread to be scheduled in the middle of
770 * the critical sequence. The same strategy as for cmpxchg is used.
771 */
772 stmfd sp!, {r4, r5, r6, lr}
773 ldmia r0, {r4, r5} @ load old val
774 ldmia r1, {r6, lr} @ load new val
775 1: ldmia r2, {r0, r1} @ load current val
776 eors r3, r0, r4 @ compare with oldval (1)
777 eoreqs r3, r1, r5 @ compare with oldval (2)
778 2: stmeqia r2, {r6, lr} @ store newval if eq
779 rsbs r0, r3, #0 @ set return val and C flag
780 ldmfd sp!, {r4, r5, r6, pc}
782 .text
783 kuser_cmpxchg64_fixup:
784 @ Called from kuser_cmpxchg_fixup.
785 @ r4 = address of interrupted insn (must be preserved).
786 @ sp = saved regs. r7 and r8 are clobbered.
787 @ 1b = first critical insn, 2b = last critical insn.
788 @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
789 mov r7, #0xffff0fff
790 sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
791 subs r8, r4, r7
792 rsbcss r8, r8, #(2b - 1b)
793 strcs r7, [sp, #S_PC]
794 #if __LINUX_ARM_ARCH__ < 6
795 bcc kuser_cmpxchg32_fixup
796 #endif
797 mov pc, lr
798 .previous
800 #else
801 #warning "NPTL on non MMU needs fixing"
802 mov r0, #-1
803 adds r0, r0, #0
804 usr_ret lr
805 #endif
807 #else
808 #error "incoherent kernel configuration"
809 #endif
811 /* pad to next slot */
812 .rept (16 - (. - __kuser_cmpxchg64)/4)
813 .word 0
814 .endr
816 .align 5
818 __kuser_memory_barrier: @ 0xffff0fa0
819 smp_dmb arm
820 usr_ret lr
822 .align 5
824 __kuser_cmpxchg: @ 0xffff0fc0
826 #if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
828 /*
829 * Poor you. No fast solution possible...
830 * The kernel itself must perform the operation.
831 * A special ghost syscall is used for that (see traps.c).
832 */
833 stmfd sp!, {r7, lr}
834 ldr r7, 1f @ it's 20 bits
835 swi __ARM_NR_cmpxchg
836 ldmfd sp!, {r7, pc}
837 1: .word __ARM_NR_cmpxchg
839 #elif __LINUX_ARM_ARCH__ < 6
841 #ifdef CONFIG_MMU
843 /*
844 * The only thing that can break atomicity in this cmpxchg
845 * implementation is either an IRQ or a data abort exception
846 * causing another process/thread to be scheduled in the middle
847 * of the critical sequence. To prevent this, code is added to
848 * the IRQ and data abort exception handlers to set the pc back
849 * to the beginning of the critical section if it is found to be
850 * within that critical section (see kuser_cmpxchg_fixup).
851 */
852 1: ldr r3, [r2] @ load current val
853 subs r3, r3, r0 @ compare with oldval
854 2: streq r1, [r2] @ store newval if eq
855 rsbs r0, r3, #0 @ set return val and C flag
856 usr_ret lr
858 .text
859 kuser_cmpxchg32_fixup:
860 @ Called from kuser_cmpxchg_check macro.
861 @ r4 = address of interrupted insn (must be preserved).
862 @ sp = saved regs. r7 and r8 are clobbered.
863 @ 1b = first critical insn, 2b = last critical insn.
864 @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
865 mov r7, #0xffff0fff
866 sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
867 subs r8, r4, r7
868 rsbcss r8, r8, #(2b - 1b)
869 strcs r7, [sp, #S_PC]
870 mov pc, lr
871 .previous
873 #else
874 #warning "NPTL on non MMU needs fixing"
875 mov r0, #-1
876 adds r0, r0, #0
877 usr_ret lr
878 #endif
880 #else
882 smp_dmb arm
883 1: ldrex r3, [r2]
884 subs r3, r3, r0
885 strexeq r3, r1, [r2]
886 teqeq r3, #1
887 beq 1b
888 rsbs r0, r3, #0
889 /* beware -- each __kuser slot must be 8 instructions max */
890 ALT_SMP(b __kuser_memory_barrier)
891 ALT_UP(usr_ret lr)
893 #endif
895 .align 5
897 __kuser_get_tls: @ 0xffff0fe0
898 ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
899 usr_ret lr
900 mrc p15, 0, r0, c13, c0, 3 @ 0xffff0fe8 hardware TLS code
901 .rep 4
902 .word 0 @ 0xffff0ff0 software TLS value, then
903 .endr @ pad up to __kuser_helper_version
905 __kuser_helper_version: @ 0xffff0ffc
906 .word ((__kuser_helper_end - __kuser_helper_start) >> 5)
908 .globl __kuser_helper_end
909 __kuser_helper_end:
911 THUMB( .thumb )
913 /*
914 * Vector stubs.
915 *
916 * This code is copied to 0xffff0200 so we can use branches in the
917 * vectors, rather than ldr's. Note that this code must not
918 * exceed 0x300 bytes.
919 *
920 * Common stub entry macro:
921 * Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
922 *
923 * SP points to a minimal amount of processor-private memory, the address
924 * of which is copied into r0 for the mode specific abort handler.
925 */
926 .macro vector_stub, name, mode, correction=0
927 .align 5
929 vector_\name:
930 .if \correction
931 sub lr, lr, #\correction
932 .endif
934 @
935 @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
936 @ (parent CPSR)
937 @
938 stmia sp, {r0, lr} @ save r0, lr
939 mrs lr, spsr
940 str lr, [sp, #8] @ save spsr
942 @
943 @ Prepare for SVC32 mode. IRQs remain disabled.
944 @
945 mrs r0, cpsr
946 eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
947 msr spsr_cxsf, r0
949 @
950 @ the branch table must immediately follow this code
951 @
952 and lr, lr, #0x0f
953 THUMB( adr r0, 1f )
954 THUMB( ldr lr, [r0, lr, lsl #2] )
955 mov r0, sp
956 ARM( ldr lr, [pc, lr, lsl #2] )
957 movs pc, lr @ branch to handler in SVC mode
958 ENDPROC(vector_\name)
960 .align 2
961 @ handler addresses follow this label
962 1:
963 .endm
965 .globl __stubs_start
966 __stubs_start:
967 /*
968 * Interrupt dispatcher
969 */
970 vector_stub irq, IRQ_MODE, 4
972 .long __irq_usr @ 0 (USR_26 / USR_32)
973 .long __irq_invalid @ 1 (FIQ_26 / FIQ_32)
974 .long __irq_invalid @ 2 (IRQ_26 / IRQ_32)
975 .long __irq_svc @ 3 (SVC_26 / SVC_32)
976 .long __irq_invalid @ 4
977 .long __irq_invalid @ 5
978 .long __irq_invalid @ 6
979 .long __irq_invalid @ 7
980 .long __irq_invalid @ 8
981 .long __irq_invalid @ 9
982 .long __irq_invalid @ a
983 .long __irq_invalid @ b
984 .long __irq_invalid @ c
985 .long __irq_invalid @ d
986 .long __irq_invalid @ e
987 .long __irq_invalid @ f
989 /*
990 * Data abort dispatcher
991 * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
992 */
993 vector_stub dabt, ABT_MODE, 8
995 .long __dabt_usr @ 0 (USR_26 / USR_32)
996 .long __dabt_invalid @ 1 (FIQ_26 / FIQ_32)
997 .long __dabt_invalid @ 2 (IRQ_26 / IRQ_32)
998 .long __dabt_svc @ 3 (SVC_26 / SVC_32)
999 .long __dabt_invalid @ 4
1000 .long __dabt_invalid @ 5
1001 .long __dabt_invalid @ 6
1002 .long __dabt_invalid @ 7
1003 .long __dabt_invalid @ 8
1004 .long __dabt_invalid @ 9
1005 .long __dabt_invalid @ a
1006 .long __dabt_invalid @ b
1007 .long __dabt_invalid @ c
1008 .long __dabt_invalid @ d
1009 .long __dabt_invalid @ e
1010 .long __dabt_invalid @ f
1012 /*
1013 * Prefetch abort dispatcher
1014 * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
1015 */
1016 vector_stub pabt, ABT_MODE, 4
1018 .long __pabt_usr @ 0 (USR_26 / USR_32)
1019 .long __pabt_invalid @ 1 (FIQ_26 / FIQ_32)
1020 .long __pabt_invalid @ 2 (IRQ_26 / IRQ_32)
1021 .long __pabt_svc @ 3 (SVC_26 / SVC_32)
1022 .long __pabt_invalid @ 4
1023 .long __pabt_invalid @ 5
1024 .long __pabt_invalid @ 6
1025 .long __pabt_invalid @ 7
1026 .long __pabt_invalid @ 8
1027 .long __pabt_invalid @ 9
1028 .long __pabt_invalid @ a
1029 .long __pabt_invalid @ b
1030 .long __pabt_invalid @ c
1031 .long __pabt_invalid @ d
1032 .long __pabt_invalid @ e
1033 .long __pabt_invalid @ f
1035 /*
1036 * Undef instr entry dispatcher
1037 * Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
1038 */
1039 vector_stub und, UND_MODE
1041 .long __und_usr @ 0 (USR_26 / USR_32)
1042 .long __und_invalid @ 1 (FIQ_26 / FIQ_32)
1043 .long __und_invalid @ 2 (IRQ_26 / IRQ_32)
1044 .long __und_svc @ 3 (SVC_26 / SVC_32)
1045 .long __und_invalid @ 4
1046 .long __und_invalid @ 5
1047 .long __und_invalid @ 6
1048 .long __und_invalid @ 7
1049 .long __und_invalid @ 8
1050 .long __und_invalid @ 9
1051 .long __und_invalid @ a
1052 .long __und_invalid @ b
1053 .long __und_invalid @ c
1054 .long __und_invalid @ d
1055 .long __und_invalid @ e
1056 .long __und_invalid @ f
1058 .align 5
1060 /*=============================================================================
1061 * Undefined FIQs
1062 *-----------------------------------------------------------------------------
1063 * Enter in FIQ mode, spsr = ANY CPSR, lr = ANY PC
1064 * MUST PRESERVE SVC SPSR, but need to switch to SVC mode to show our msg.
1065 * Basically to switch modes, we *HAVE* to clobber one register... brain
1066 * damage alert! I don't think that we can execute any code in here in any
1067 * other mode than FIQ... Ok you can switch to another mode, but you can't
1068 * get out of that mode without clobbering one register.
1069 */
1070 vector_fiq:
1071 disable_fiq
1072 subs pc, lr, #4
1074 /*=============================================================================
1075 * Address exception handler
1076 *-----------------------------------------------------------------------------
1077 * These aren't too critical.
1078 * (they're not supposed to happen, and won't happen in 32-bit data mode).
1079 */
1081 vector_addrexcptn:
1082 b vector_addrexcptn
1084 /*
1085 * We group all the following data together to optimise
1086 * for CPUs with separate I & D caches.
1087 */
1088 .align 5
1090 .LCvswi:
1091 .word vector_swi
1093 .globl __stubs_end
1094 __stubs_end:
1096 .equ stubs_offset, __vectors_start + 0x200 - __stubs_start
1098 .globl __vectors_start
1099 __vectors_start:
1100 ARM( swi SYS_ERROR0 )
1101 THUMB( svc #0 )
1102 THUMB( nop )
1103 W(b) vector_und + stubs_offset
1104 W(ldr) pc, .LCvswi + stubs_offset
1105 W(b) vector_pabt + stubs_offset
1106 W(b) vector_dabt + stubs_offset
1107 W(b) vector_addrexcptn + stubs_offset
1108 W(b) vector_irq + stubs_offset
1109 W(b) vector_fiq + stubs_offset
1111 .globl __vectors_end
1112 __vectors_end:
1114 .data
1116 .globl cr_alignment
1117 .globl cr_no_alignment
1118 cr_alignment:
1119 .space 4
1120 cr_no_alignment:
1121 .space 4
1123 #ifdef CONFIG_MULTI_IRQ_HANDLER
1124 .globl handle_arch_irq
1125 handle_arch_irq:
1126 .space 4
1127 #endif