| blob | e2550500486d497c8455165b37916f2eb4974cd5 |
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 <linux/init.h>
20 #include <asm/assembler.h>
21 #include <asm/memory.h>
22 #include <asm/glue-df.h>
23 #include <asm/glue-pf.h>
24 #include <asm/vfpmacros.h>
25 #ifndef CONFIG_MULTI_IRQ_HANDLER
26 #include <mach/entry-macro.S>
27 #endif
28 #include <asm/thread_notify.h>
29 #include <asm/unwind.h>
30 #include <asm/unistd.h>
31 #include <asm/tls.h>
32 #include <asm/system_info.h>
34 #include "entry-header.S"
35 #include <asm/entry-macro-multi.S>
36 #include <asm/probes.h>
38 /*
39 * Interrupt handling.
40 */
41 .macro irq_handler
42 #ifdef CONFIG_MULTI_IRQ_HANDLER
43 ldr r1, =handle_arch_irq
44 mov r0, sp
45 badr lr, 9997f
46 ldr pc, [r1]
47 #else
48 arch_irq_handler_default
49 #endif
50 9997:
51 .endm
53 .macro pabt_helper
54 @ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
55 #ifdef MULTI_PABORT
56 ldr ip, .LCprocfns
57 mov lr, pc
58 ldr pc, [ip, #PROCESSOR_PABT_FUNC]
59 #else
60 bl CPU_PABORT_HANDLER
61 #endif
62 .endm
64 .macro dabt_helper
66 @
67 @ Call the processor-specific abort handler:
68 @
69 @ r2 - pt_regs
70 @ r4 - aborted context pc
71 @ r5 - aborted context psr
72 @
73 @ The abort handler must return the aborted address in r0, and
74 @ the fault status register in r1. r9 must be preserved.
75 @
76 #ifdef MULTI_DABORT
77 ldr ip, .LCprocfns
78 mov lr, pc
79 ldr pc, [ip, #PROCESSOR_DABT_FUNC]
80 #else
81 bl CPU_DABORT_HANDLER
82 #endif
83 .endm
85 #ifdef CONFIG_KPROBES
86 .section .kprobes.text,"ax",%progbits
87 #else
88 .text
89 #endif
91 /*
92 * Invalid mode handlers
93 */
94 .macro inv_entry, reason
95 sub sp, sp, #S_FRAME_SIZE
96 ARM( stmib sp, {r1 - lr} )
97 THUMB( stmia sp, {r0 - r12} )
98 THUMB( str sp, [sp, #S_SP] )
99 THUMB( str lr, [sp, #S_LR] )
100 mov r1, #\reason
101 .endm
103 __pabt_invalid:
104 inv_entry BAD_PREFETCH
105 b common_invalid
106 ENDPROC(__pabt_invalid)
108 __dabt_invalid:
109 inv_entry BAD_DATA
110 b common_invalid
111 ENDPROC(__dabt_invalid)
113 __irq_invalid:
114 inv_entry BAD_IRQ
115 b common_invalid
116 ENDPROC(__irq_invalid)
118 __und_invalid:
119 inv_entry BAD_UNDEFINSTR
121 @
122 @ XXX fall through to common_invalid
123 @
125 @
126 @ common_invalid - generic code for failed exception (re-entrant version of handlers)
127 @
128 common_invalid:
129 zero_fp
131 ldmia r0, {r4 - r6}
132 add r0, sp, #S_PC @ here for interlock avoidance
133 mov r7, #-1 @ "" "" "" ""
134 str r4, [sp] @ save preserved r0
135 stmia r0, {r5 - r7} @ lr_<exception>,
136 @ cpsr_<exception>, "old_r0"
138 mov r0, sp
139 b bad_mode
140 ENDPROC(__und_invalid)
142 /*
143 * SVC mode handlers
144 */
146 #if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
147 #define SPFIX(code...) code
148 #else
149 #define SPFIX(code...)
150 #endif
152 .macro svc_entry, stack_hole=0, trace=1, uaccess=1
153 UNWIND(.fnstart )
154 UNWIND(.save {r0 - pc} )
155 sub sp, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
156 #ifdef CONFIG_THUMB2_KERNEL
157 SPFIX( str r0, [sp] ) @ temporarily saved
158 SPFIX( mov r0, sp )
159 SPFIX( tst r0, #4 ) @ test original stack alignment
160 SPFIX( ldr r0, [sp] ) @ restored
161 #else
162 SPFIX( tst sp, #4 )
163 #endif
164 SPFIX( subeq sp, sp, #4 )
165 stmia sp, {r1 - r12}
167 ldmia r0, {r3 - r5}
168 add r7, sp, #S_SP - 4 @ here for interlock avoidance
169 mov r6, #-1 @ "" "" "" ""
170 add r2, sp, #(S_FRAME_SIZE + 8 + \stack_hole - 4)
171 SPFIX( addeq r2, r2, #4 )
172 str r3, [sp, #-4]! @ save the "real" r0 copied
173 @ from the exception stack
175 mov r3, lr
177 @
178 @ We are now ready to fill in the remaining blanks on the stack:
179 @
180 @ r2 - sp_svc
181 @ r3 - lr_svc
182 @ r4 - lr_<exception>, already fixed up for correct return/restart
183 @ r5 - spsr_<exception>
184 @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
185 @
186 stmia r7, {r2 - r6}
188 uaccess_save r0
189 .if \uaccess
190 uaccess_disable r0
191 .endif
193 .if \trace
194 #ifdef CONFIG_TRACE_IRQFLAGS
195 bl trace_hardirqs_off
196 #endif
197 .endif
198 .endm
200 .align 5
201 __dabt_svc:
202 svc_entry uaccess=0
203 mov r2, sp
204 dabt_helper
205 THUMB( ldr r5, [sp, #S_PSR] ) @ potentially updated CPSR
206 svc_exit r5 @ return from exception
207 UNWIND(.fnend )
208 ENDPROC(__dabt_svc)
210 .align 5
211 __irq_svc:
212 svc_entry
213 irq_handler
215 #ifdef CONFIG_PREEMPT
216 get_thread_info tsk
217 ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
218 ldr r0, [tsk, #TI_FLAGS] @ get flags
219 teq r8, #0 @ if preempt count != 0
220 movne r0, #0 @ force flags to 0
221 tst r0, #_TIF_NEED_RESCHED
222 blne svc_preempt
223 #endif
225 svc_exit r5, irq = 1 @ return from exception
226 UNWIND(.fnend )
227 ENDPROC(__irq_svc)
229 .ltorg
231 #ifdef CONFIG_PREEMPT
232 svc_preempt:
233 mov r8, lr
234 1: bl preempt_schedule_irq @ irq en/disable is done inside
235 ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
236 tst r0, #_TIF_NEED_RESCHED
237 reteq r8 @ go again
238 b 1b
239 #endif
241 __und_fault:
242 @ Correct the PC such that it is pointing at the instruction
243 @ which caused the fault. If the faulting instruction was ARM
244 @ the PC will be pointing at the next instruction, and have to
245 @ subtract 4. Otherwise, it is Thumb, and the PC will be
246 @ pointing at the second half of the Thumb instruction. We
247 @ have to subtract 2.
248 ldr r2, [r0, #S_PC]
249 sub r2, r2, r1
250 str r2, [r0, #S_PC]
251 b do_undefinstr
252 ENDPROC(__und_fault)
254 .align 5
255 __und_svc:
256 #ifdef CONFIG_KPROBES
257 @ If a kprobe is about to simulate a "stmdb sp..." instruction,
258 @ it obviously needs free stack space which then will belong to
259 @ the saved context.
260 svc_entry MAX_STACK_SIZE
261 #else
262 svc_entry
263 #endif
264 @
265 @ call emulation code, which returns using r9 if it has emulated
266 @ the instruction, or the more conventional lr if we are to treat
267 @ this as a real undefined instruction
268 @
269 @ r0 - instruction
270 @
271 #ifndef CONFIG_THUMB2_KERNEL
272 ldr r0, [r4, #-4]
273 #else
274 mov r1, #2
275 ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
276 cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
277 blo __und_svc_fault
278 ldrh r9, [r4] @ bottom 16 bits
279 add r4, r4, #2
280 str r4, [sp, #S_PC]
281 orr r0, r9, r0, lsl #16
282 #endif
283 badr r9, __und_svc_finish
284 mov r2, r4
285 bl call_fpe
287 mov r1, #4 @ PC correction to apply
288 __und_svc_fault:
289 mov r0, sp @ struct pt_regs *regs
290 bl __und_fault
292 __und_svc_finish:
293 ldr r5, [sp, #S_PSR] @ Get SVC cpsr
294 svc_exit r5 @ return from exception
295 UNWIND(.fnend )
296 ENDPROC(__und_svc)
298 .align 5
299 __pabt_svc:
300 svc_entry
301 mov r2, sp @ regs
302 pabt_helper
303 svc_exit r5 @ return from exception
304 UNWIND(.fnend )
305 ENDPROC(__pabt_svc)
307 .align 5
308 __fiq_svc:
309 svc_entry trace=0
310 mov r0, sp @ struct pt_regs *regs
311 bl handle_fiq_as_nmi
312 svc_exit_via_fiq
313 UNWIND(.fnend )
314 ENDPROC(__fiq_svc)
316 .align 5
317 .LCcralign:
318 .word cr_alignment
319 #ifdef MULTI_DABORT
320 .LCprocfns:
321 .word processor
322 #endif
323 .LCfp:
324 .word fp_enter
326 /*
327 * Abort mode handlers
328 */
330 @
331 @ Taking a FIQ in abort mode is similar to taking a FIQ in SVC mode
332 @ and reuses the same macros. However in abort mode we must also
333 @ save/restore lr_abt and spsr_abt to make nested aborts safe.
334 @
335 .align 5
336 __fiq_abt:
337 svc_entry trace=0
339 ARM( msr cpsr_c, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
340 THUMB( mov r0, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
341 THUMB( msr cpsr_c, r0 )
342 mov r1, lr @ Save lr_abt
343 mrs r2, spsr @ Save spsr_abt, abort is now safe
344 ARM( msr cpsr_c, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
345 THUMB( mov r0, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
346 THUMB( msr cpsr_c, r0 )
347 stmfd sp!, {r1 - r2}
349 add r0, sp, #8 @ struct pt_regs *regs
350 bl handle_fiq_as_nmi
352 ldmfd sp!, {r1 - r2}
353 ARM( msr cpsr_c, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
354 THUMB( mov r0, #ABT_MODE | PSR_I_BIT | PSR_F_BIT )
355 THUMB( msr cpsr_c, r0 )
356 mov lr, r1 @ Restore lr_abt, abort is unsafe
357 msr spsr_cxsf, r2 @ Restore spsr_abt
358 ARM( msr cpsr_c, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
359 THUMB( mov r0, #SVC_MODE | PSR_I_BIT | PSR_F_BIT )
360 THUMB( msr cpsr_c, r0 )
362 svc_exit_via_fiq
363 UNWIND(.fnend )
364 ENDPROC(__fiq_abt)
366 /*
367 * User mode handlers
368 *
369 * EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
370 */
372 #if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
373 #error "sizeof(struct pt_regs) must be a multiple of 8"
374 #endif
376 .macro usr_entry, trace=1, uaccess=1
377 UNWIND(.fnstart )
378 UNWIND(.cantunwind ) @ don't unwind the user space
379 sub sp, sp, #S_FRAME_SIZE
380 ARM( stmib sp, {r1 - r12} )
381 THUMB( stmia sp, {r0 - r12} )
383 ATRAP( mrc p15, 0, r7, c1, c0, 0)
384 ATRAP( ldr r8, .LCcralign)
386 ldmia r0, {r3 - r5}
387 add r0, sp, #S_PC @ here for interlock avoidance
388 mov r6, #-1 @ "" "" "" ""
390 str r3, [sp] @ save the "real" r0 copied
391 @ from the exception stack
393 ATRAP( ldr r8, [r8, #0])
395 @
396 @ We are now ready to fill in the remaining blanks on the stack:
397 @
398 @ r4 - lr_<exception>, already fixed up for correct return/restart
399 @ r5 - spsr_<exception>
400 @ r6 - orig_r0 (see pt_regs definition in ptrace.h)
401 @
402 @ Also, separately save sp_usr and lr_usr
403 @
404 stmia r0, {r4 - r6}
405 ARM( stmdb r0, {sp, lr}^ )
406 THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
408 .if \uaccess
409 uaccess_disable ip
410 .endif
412 @ Enable the alignment trap while in kernel mode
413 ATRAP( teq r8, r7)
414 ATRAP( mcrne p15, 0, r8, c1, c0, 0)
416 @
417 @ Clear FP to mark the first stack frame
418 @
419 zero_fp
421 .if \trace
422 #ifdef CONFIG_TRACE_IRQFLAGS
423 bl trace_hardirqs_off
424 #endif
425 ct_user_exit save = 0
426 .endif
427 .endm
429 .macro kuser_cmpxchg_check
430 #if !defined(CONFIG_CPU_32v6K) && defined(CONFIG_KUSER_HELPERS)
431 #ifndef CONFIG_MMU
432 #warning "NPTL on non MMU needs fixing"
433 #else
434 @ Make sure our user space atomic helper is restarted
435 @ if it was interrupted in a critical region. Here we
436 @ perform a quick test inline since it should be false
437 @ 99.9999% of the time. The rest is done out of line.
438 cmp r4, #TASK_SIZE
439 blhs kuser_cmpxchg64_fixup
440 #endif
441 #endif
442 .endm
444 .align 5
445 __dabt_usr:
446 usr_entry uaccess=0
447 kuser_cmpxchg_check
448 mov r2, sp
449 dabt_helper
450 b ret_from_exception
451 UNWIND(.fnend )
452 ENDPROC(__dabt_usr)
454 .align 5
455 __irq_usr:
456 usr_entry
457 kuser_cmpxchg_check
458 irq_handler
459 get_thread_info tsk
460 mov why, #0
461 b ret_to_user_from_irq
462 UNWIND(.fnend )
463 ENDPROC(__irq_usr)
465 .ltorg
467 .align 5
468 __und_usr:
469 usr_entry uaccess=0
471 mov r2, r4
472 mov r3, r5
474 @ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the
475 @ faulting instruction depending on Thumb mode.
476 @ r3 = regs->ARM_cpsr
477 @
478 @ The emulation code returns using r9 if it has emulated the
479 @ instruction, or the more conventional lr if we are to treat
480 @ this as a real undefined instruction
481 @
482 badr r9, ret_from_exception
484 @ IRQs must be enabled before attempting to read the instruction from
485 @ user space since that could cause a page/translation fault if the
486 @ page table was modified by another CPU.
487 enable_irq
489 tst r3, #PSR_T_BIT @ Thumb mode?
490 bne __und_usr_thumb
491 sub r4, r2, #4 @ ARM instr at LR - 4
492 1: ldrt r0, [r4]
493 ARM_BE8(rev r0, r0) @ little endian instruction
495 uaccess_disable ip
497 @ r0 = 32-bit ARM instruction which caused the exception
498 @ r2 = PC value for the following instruction (:= regs->ARM_pc)
499 @ r4 = PC value for the faulting instruction
500 @ lr = 32-bit undefined instruction function
501 badr lr, __und_usr_fault_32
502 b call_fpe
504 __und_usr_thumb:
505 @ Thumb instruction
506 sub r4, r2, #2 @ First half of thumb instr at LR - 2
507 #if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
508 /*
509 * Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms
510 * can never be supported in a single kernel, this code is not applicable at
511 * all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be
512 * made about .arch directives.
513 */
514 #if __LINUX_ARM_ARCH__ < 7
515 /* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */
516 #define NEED_CPU_ARCHITECTURE
517 ldr r5, .LCcpu_architecture
518 ldr r5, [r5]
519 cmp r5, #CPU_ARCH_ARMv7
520 blo __und_usr_fault_16 @ 16bit undefined instruction
521 /*
522 * The following code won't get run unless the running CPU really is v7, so
523 * coding round the lack of ldrht on older arches is pointless. Temporarily
524 * override the assembler target arch with the minimum required instead:
525 */
526 .arch armv6t2
527 #endif
528 2: ldrht r5, [r4]
529 ARM_BE8(rev16 r5, r5) @ little endian instruction
530 cmp r5, #0xe800 @ 32bit instruction if xx != 0
531 blo __und_usr_fault_16_pan @ 16bit undefined instruction
532 3: ldrht r0, [r2]
533 ARM_BE8(rev16 r0, r0) @ little endian instruction
534 uaccess_disable ip
535 add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
536 str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
537 orr r0, r0, r5, lsl #16
538 badr lr, __und_usr_fault_32
539 @ r0 = the two 16-bit Thumb instructions which caused the exception
540 @ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc)
541 @ r4 = PC value for the first 16-bit Thumb instruction
542 @ lr = 32bit undefined instruction function
544 #if __LINUX_ARM_ARCH__ < 7
545 /* If the target arch was overridden, change it back: */
546 #ifdef CONFIG_CPU_32v6K
547 .arch armv6k
548 #else
549 .arch armv6
550 #endif
551 #endif /* __LINUX_ARM_ARCH__ < 7 */
552 #else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
553 b __und_usr_fault_16
554 #endif
555 UNWIND(.fnend)
556 ENDPROC(__und_usr)
558 /*
559 * The out of line fixup for the ldrt instructions above.
560 */
561 .pushsection .text.fixup, "ax"
562 .align 2
563 4: str r4, [sp, #S_PC] @ retry current instruction
564 ret r9
565 .popsection
566 .pushsection __ex_table,"a"
567 .long 1b, 4b
568 #if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
569 .long 2b, 4b
570 .long 3b, 4b
571 #endif
572 .popsection
574 /*
575 * Check whether the instruction is a co-processor instruction.
576 * If yes, we need to call the relevant co-processor handler.
577 *
578 * Note that we don't do a full check here for the co-processor
579 * instructions; all instructions with bit 27 set are well
580 * defined. The only instructions that should fault are the
581 * co-processor instructions. However, we have to watch out
582 * for the ARM6/ARM7 SWI bug.
583 *
584 * NEON is a special case that has to be handled here. Not all
585 * NEON instructions are co-processor instructions, so we have
586 * to make a special case of checking for them. Plus, there's
587 * five groups of them, so we have a table of mask/opcode pairs
588 * to check against, and if any match then we branch off into the
589 * NEON handler code.
590 *
591 * Emulators may wish to make use of the following registers:
592 * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
593 * r2 = PC value to resume execution after successful emulation
594 * r9 = normal "successful" return address
595 * r10 = this threads thread_info structure
596 * lr = unrecognised instruction return address
597 * IRQs enabled, FIQs enabled.
598 */
599 @
600 @ Fall-through from Thumb-2 __und_usr
601 @
602 #ifdef CONFIG_NEON
603 get_thread_info r10 @ get current thread
604 adr r6, .LCneon_thumb_opcodes
605 b 2f
606 #endif
607 call_fpe:
608 get_thread_info r10 @ get current thread
609 #ifdef CONFIG_NEON
610 adr r6, .LCneon_arm_opcodes
611 2: ldr r5, [r6], #4 @ mask value
612 ldr r7, [r6], #4 @ opcode bits matching in mask
613 cmp r5, #0 @ end mask?
614 beq 1f
615 and r8, r0, r5
616 cmp r8, r7 @ NEON instruction?
617 bne 2b
618 mov r7, #1
619 strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used
620 strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used
621 b do_vfp @ let VFP handler handle this
622 1:
623 #endif
624 tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
625 tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2
626 reteq lr
627 and r8, r0, #0x00000f00 @ mask out CP number
628 THUMB( lsr r8, r8, #8 )
629 mov r7, #1
630 add r6, r10, #TI_USED_CP
631 ARM( strb r7, [r6, r8, lsr #8] ) @ set appropriate used_cp[]
632 THUMB( strb r7, [r6, r8] ) @ set appropriate used_cp[]
633 #ifdef CONFIG_IWMMXT
634 @ Test if we need to give access to iWMMXt coprocessors
635 ldr r5, [r10, #TI_FLAGS]
636 rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
637 movcss r7, r5, lsr #(TIF_USING_IWMMXT + 1)
638 bcs iwmmxt_task_enable
639 #endif
640 ARM( add pc, pc, r8, lsr #6 )
641 THUMB( lsl r8, r8, #2 )
642 THUMB( add pc, r8 )
643 nop
645 ret.w lr @ CP#0
646 W(b) do_fpe @ CP#1 (FPE)
647 W(b) do_fpe @ CP#2 (FPE)
648 ret.w lr @ CP#3
649 #ifdef CONFIG_CRUNCH
650 b crunch_task_enable @ CP#4 (MaverickCrunch)
651 b crunch_task_enable @ CP#5 (MaverickCrunch)
652 b crunch_task_enable @ CP#6 (MaverickCrunch)
653 #else
654 ret.w lr @ CP#4
655 ret.w lr @ CP#5
656 ret.w lr @ CP#6
657 #endif
658 ret.w lr @ CP#7
659 ret.w lr @ CP#8
660 ret.w lr @ CP#9
661 #ifdef CONFIG_VFP
662 W(b) do_vfp @ CP#10 (VFP)
663 W(b) do_vfp @ CP#11 (VFP)
664 #else
665 ret.w lr @ CP#10 (VFP)
666 ret.w lr @ CP#11 (VFP)
667 #endif
668 ret.w lr @ CP#12
669 ret.w lr @ CP#13
670 ret.w lr @ CP#14 (Debug)
671 ret.w lr @ CP#15 (Control)
673 #ifdef NEED_CPU_ARCHITECTURE
674 .align 2
675 .LCcpu_architecture:
676 .word __cpu_architecture
677 #endif
679 #ifdef CONFIG_NEON
680 .align 6
682 .LCneon_arm_opcodes:
683 .word 0xfe000000 @ mask
684 .word 0xf2000000 @ opcode
686 .word 0xff100000 @ mask
687 .word 0xf4000000 @ opcode
689 .word 0x00000000 @ mask
690 .word 0x00000000 @ opcode
692 .LCneon_thumb_opcodes:
693 .word 0xef000000 @ mask
694 .word 0xef000000 @ opcode
696 .word 0xff100000 @ mask
697 .word 0xf9000000 @ opcode
699 .word 0x00000000 @ mask
700 .word 0x00000000 @ opcode
701 #endif
703 do_fpe:
704 ldr r4, .LCfp
705 add r10, r10, #TI_FPSTATE @ r10 = workspace
706 ldr pc, [r4] @ Call FP module USR entry point
708 /*
709 * The FP module is called with these registers set:
710 * r0 = instruction
711 * r2 = PC+4
712 * r9 = normal "successful" return address
713 * r10 = FP workspace
714 * lr = unrecognised FP instruction return address
715 */
717 .pushsection .data
718 ENTRY(fp_enter)
719 .word no_fp
720 .popsection
722 ENTRY(no_fp)
723 ret lr
724 ENDPROC(no_fp)
726 __und_usr_fault_32:
727 mov r1, #4
728 b 1f
729 __und_usr_fault_16_pan:
730 uaccess_disable ip
731 __und_usr_fault_16:
732 mov r1, #2
733 1: mov r0, sp
734 badr lr, ret_from_exception
735 b __und_fault
736 ENDPROC(__und_usr_fault_32)
737 ENDPROC(__und_usr_fault_16)
739 .align 5
740 __pabt_usr:
741 usr_entry
742 mov r2, sp @ regs
743 pabt_helper
744 UNWIND(.fnend )
745 /* fall through */
746 /*
747 * This is the return code to user mode for abort handlers
748 */
749 ENTRY(ret_from_exception)
750 UNWIND(.fnstart )
751 UNWIND(.cantunwind )
752 get_thread_info tsk
753 mov why, #0
754 b ret_to_user
755 UNWIND(.fnend )
756 ENDPROC(__pabt_usr)
757 ENDPROC(ret_from_exception)
759 .align 5
760 __fiq_usr:
761 usr_entry trace=0
762 kuser_cmpxchg_check
763 mov r0, sp @ struct pt_regs *regs
764 bl handle_fiq_as_nmi
765 get_thread_info tsk
766 restore_user_regs fast = 0, offset = 0
767 UNWIND(.fnend )
768 ENDPROC(__fiq_usr)
770 /*
771 * Register switch for ARMv3 and ARMv4 processors
772 * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
773 * previous and next are guaranteed not to be the same.
774 */
775 ENTRY(__switch_to)
776 UNWIND(.fnstart )
777 UNWIND(.cantunwind )
778 add ip, r1, #TI_CPU_SAVE
779 ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
780 THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
781 THUMB( str sp, [ip], #4 )
782 THUMB( str lr, [ip], #4 )
783 ldr r4, [r2, #TI_TP_VALUE]
784 ldr r5, [r2, #TI_TP_VALUE + 4]
785 #ifdef CONFIG_CPU_USE_DOMAINS
786 mrc p15, 0, r6, c3, c0, 0 @ Get domain register
787 str r6, [r1, #TI_CPU_DOMAIN] @ Save old domain register
788 ldr r6, [r2, #TI_CPU_DOMAIN]
789 #endif
790 switch_tls r1, r4, r5, r3, r7
791 #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
792 ldr r7, [r2, #TI_TASK]
793 ldr r8, =__stack_chk_guard
794 ldr r7, [r7, #TSK_STACK_CANARY]
795 #endif
796 #ifdef CONFIG_CPU_USE_DOMAINS
797 mcr p15, 0, r6, c3, c0, 0 @ Set domain register
798 #endif
799 mov r5, r0
800 add r4, r2, #TI_CPU_SAVE
801 ldr r0, =thread_notify_head
802 mov r1, #THREAD_NOTIFY_SWITCH
803 bl atomic_notifier_call_chain
804 #if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
805 str r7, [r8]
806 #endif
807 THUMB( mov ip, r4 )
808 mov r0, r5
809 ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
810 THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
811 THUMB( ldr sp, [ip], #4 )
812 THUMB( ldr pc, [ip] )
813 UNWIND(.fnend )
814 ENDPROC(__switch_to)
816 __INIT
818 /*
819 * User helpers.
820 *
821 * Each segment is 32-byte aligned and will be moved to the top of the high
822 * vector page. New segments (if ever needed) must be added in front of
823 * existing ones. This mechanism should be used only for things that are
824 * really small and justified, and not be abused freely.
825 *
826 * See Documentation/arm/kernel_user_helpers.txt for formal definitions.
827 */
828 THUMB( .arm )
830 .macro usr_ret, reg
831 #ifdef CONFIG_ARM_THUMB
832 bx \reg
833 #else
834 ret \reg
835 #endif
836 .endm
838 .macro kuser_pad, sym, size
839 .if (. - \sym) & 3
840 .rept 4 - (. - \sym) & 3
841 .byte 0
842 .endr
843 .endif
844 .rept (\size - (. - \sym)) / 4
845 .word 0xe7fddef1
846 .endr
847 .endm
849 #ifdef CONFIG_KUSER_HELPERS
850 .align 5
851 .globl __kuser_helper_start
852 __kuser_helper_start:
854 /*
855 * Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular
856 * kuser "slots", therefore 0xffff0f80 is not used as a valid entry point.
857 */
859 __kuser_cmpxchg64: @ 0xffff0f60
861 #if defined(CONFIG_CPU_32v6K)
863 stmfd sp!, {r4, r5, r6, r7}
864 ldrd r4, r5, [r0] @ load old val
865 ldrd r6, r7, [r1] @ load new val
866 smp_dmb arm
867 1: ldrexd r0, r1, [r2] @ load current val
868 eors r3, r0, r4 @ compare with oldval (1)
869 eoreqs r3, r1, r5 @ compare with oldval (2)
870 strexdeq r3, r6, r7, [r2] @ store newval if eq
871 teqeq r3, #1 @ success?
872 beq 1b @ if no then retry
873 smp_dmb arm
874 rsbs r0, r3, #0 @ set returned val and C flag
875 ldmfd sp!, {r4, r5, r6, r7}
876 usr_ret lr
878 #elif !defined(CONFIG_SMP)
880 #ifdef CONFIG_MMU
882 /*
883 * The only thing that can break atomicity in this cmpxchg64
884 * implementation is either an IRQ or a data abort exception
885 * causing another process/thread to be scheduled in the middle of
886 * the critical sequence. The same strategy as for cmpxchg is used.
887 */
888 stmfd sp!, {r4, r5, r6, lr}
889 ldmia r0, {r4, r5} @ load old val
890 ldmia r1, {r6, lr} @ load new val
891 1: ldmia r2, {r0, r1} @ load current val
892 eors r3, r0, r4 @ compare with oldval (1)
893 eoreqs r3, r1, r5 @ compare with oldval (2)
894 2: stmeqia r2, {r6, lr} @ store newval if eq
895 rsbs r0, r3, #0 @ set return val and C flag
896 ldmfd sp!, {r4, r5, r6, pc}
898 .text
899 kuser_cmpxchg64_fixup:
900 @ Called from kuser_cmpxchg_fixup.
901 @ r4 = address of interrupted insn (must be preserved).
902 @ sp = saved regs. r7 and r8 are clobbered.
903 @ 1b = first critical insn, 2b = last critical insn.
904 @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
905 mov r7, #0xffff0fff
906 sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
907 subs r8, r4, r7
908 rsbcss r8, r8, #(2b - 1b)
909 strcs r7, [sp, #S_PC]
910 #if __LINUX_ARM_ARCH__ < 6
911 bcc kuser_cmpxchg32_fixup
912 #endif
913 ret lr
914 .previous
916 #else
917 #warning "NPTL on non MMU needs fixing"
918 mov r0, #-1
919 adds r0, r0, #0
920 usr_ret lr
921 #endif
923 #else
924 #error "incoherent kernel configuration"
925 #endif
927 kuser_pad __kuser_cmpxchg64, 64
929 __kuser_memory_barrier: @ 0xffff0fa0
930 smp_dmb arm
931 usr_ret lr
933 kuser_pad __kuser_memory_barrier, 32
935 __kuser_cmpxchg: @ 0xffff0fc0
937 #if __LINUX_ARM_ARCH__ < 6
939 #ifdef CONFIG_MMU
941 /*
942 * The only thing that can break atomicity in this cmpxchg
943 * implementation is either an IRQ or a data abort exception
944 * causing another process/thread to be scheduled in the middle
945 * of the critical sequence. To prevent this, code is added to
946 * the IRQ and data abort exception handlers to set the pc back
947 * to the beginning of the critical section if it is found to be
948 * within that critical section (see kuser_cmpxchg_fixup).
949 */
950 1: ldr r3, [r2] @ load current val
951 subs r3, r3, r0 @ compare with oldval
952 2: streq r1, [r2] @ store newval if eq
953 rsbs r0, r3, #0 @ set return val and C flag
954 usr_ret lr
956 .text
957 kuser_cmpxchg32_fixup:
958 @ Called from kuser_cmpxchg_check macro.
959 @ r4 = address of interrupted insn (must be preserved).
960 @ sp = saved regs. r7 and r8 are clobbered.
961 @ 1b = first critical insn, 2b = last critical insn.
962 @ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
963 mov r7, #0xffff0fff
964 sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
965 subs r8, r4, r7
966 rsbcss r8, r8, #(2b - 1b)
967 strcs r7, [sp, #S_PC]
968 ret lr
969 .previous
971 #else
972 #warning "NPTL on non MMU needs fixing"
973 mov r0, #-1
974 adds r0, r0, #0
975 usr_ret lr
976 #endif
978 #else
980 smp_dmb arm
981 1: ldrex r3, [r2]
982 subs r3, r3, r0
983 strexeq r3, r1, [r2]
984 teqeq r3, #1
985 beq 1b
986 rsbs r0, r3, #0
987 /* beware -- each __kuser slot must be 8 instructions max */
988 ALT_SMP(b __kuser_memory_barrier)
989 ALT_UP(usr_ret lr)
991 #endif
993 kuser_pad __kuser_cmpxchg, 32
995 __kuser_get_tls: @ 0xffff0fe0
996 ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
997 usr_ret lr
998 mrc p15, 0, r0, c13, c0, 3 @ 0xffff0fe8 hardware TLS code
999 kuser_pad __kuser_get_tls, 16
1000 .rep 3
1001 .word 0 @ 0xffff0ff0 software TLS value, then
1002 .endr @ pad up to __kuser_helper_version
1004 __kuser_helper_version: @ 0xffff0ffc
1005 .word ((__kuser_helper_end - __kuser_helper_start) >> 5)
1007 .globl __kuser_helper_end
1008 __kuser_helper_end:
1010 #endif
1012 THUMB( .thumb )
1014 /*
1015 * Vector stubs.
1016 *
1017 * This code is copied to 0xffff1000 so we can use branches in the
1018 * vectors, rather than ldr's. Note that this code must not exceed
1019 * a page size.
1020 *
1021 * Common stub entry macro:
1022 * Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
1023 *
1024 * SP points to a minimal amount of processor-private memory, the address
1025 * of which is copied into r0 for the mode specific abort handler.
1026 */
1027 .macro vector_stub, name, mode, correction=0
1028 .align 5
1030 vector_\name:
1031 .if \correction
1032 sub lr, lr, #\correction
1033 .endif
1035 @
1036 @ Save r0, lr_<exception> (parent PC) and spsr_<exception>
1037 @ (parent CPSR)
1038 @
1039 stmia sp, {r0, lr} @ save r0, lr
1040 mrs lr, spsr
1041 str lr, [sp, #8] @ save spsr
1043 @
1044 @ Prepare for SVC32 mode. IRQs remain disabled.
1045 @
1046 mrs r0, cpsr
1047 eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
1048 msr spsr_cxsf, r0
1050 @
1051 @ the branch table must immediately follow this code
1052 @
1053 and lr, lr, #0x0f
1054 THUMB( adr r0, 1f )
1055 THUMB( ldr lr, [r0, lr, lsl #2] )
1056 mov r0, sp
1057 ARM( ldr lr, [pc, lr, lsl #2] )
1058 movs pc, lr @ branch to handler in SVC mode
1059 ENDPROC(vector_\name)
1061 .align 2
1062 @ handler addresses follow this label
1063 1:
1064 .endm
1066 .section .stubs, "ax", %progbits
1067 @ This must be the first word
1068 .word vector_swi
1070 vector_rst:
1071 ARM( swi SYS_ERROR0 )
1072 THUMB( svc #0 )
1073 THUMB( nop )
1074 b vector_und
1076 /*
1077 * Interrupt dispatcher
1078 */
1079 vector_stub irq, IRQ_MODE, 4
1081 .long __irq_usr @ 0 (USR_26 / USR_32)
1082 .long __irq_invalid @ 1 (FIQ_26 / FIQ_32)
1083 .long __irq_invalid @ 2 (IRQ_26 / IRQ_32)
1084 .long __irq_svc @ 3 (SVC_26 / SVC_32)
1085 .long __irq_invalid @ 4
1086 .long __irq_invalid @ 5
1087 .long __irq_invalid @ 6
1088 .long __irq_invalid @ 7
1089 .long __irq_invalid @ 8
1090 .long __irq_invalid @ 9
1091 .long __irq_invalid @ a
1092 .long __irq_invalid @ b
1093 .long __irq_invalid @ c
1094 .long __irq_invalid @ d
1095 .long __irq_invalid @ e
1096 .long __irq_invalid @ f
1098 /*
1099 * Data abort dispatcher
1100 * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
1101 */
1102 vector_stub dabt, ABT_MODE, 8
1104 .long __dabt_usr @ 0 (USR_26 / USR_32)
1105 .long __dabt_invalid @ 1 (FIQ_26 / FIQ_32)
1106 .long __dabt_invalid @ 2 (IRQ_26 / IRQ_32)
1107 .long __dabt_svc @ 3 (SVC_26 / SVC_32)
1108 .long __dabt_invalid @ 4
1109 .long __dabt_invalid @ 5
1110 .long __dabt_invalid @ 6
1111 .long __dabt_invalid @ 7
1112 .long __dabt_invalid @ 8
1113 .long __dabt_invalid @ 9
1114 .long __dabt_invalid @ a
1115 .long __dabt_invalid @ b
1116 .long __dabt_invalid @ c
1117 .long __dabt_invalid @ d
1118 .long __dabt_invalid @ e
1119 .long __dabt_invalid @ f
1121 /*
1122 * Prefetch abort dispatcher
1123 * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
1124 */
1125 vector_stub pabt, ABT_MODE, 4
1127 .long __pabt_usr @ 0 (USR_26 / USR_32)
1128 .long __pabt_invalid @ 1 (FIQ_26 / FIQ_32)
1129 .long __pabt_invalid @ 2 (IRQ_26 / IRQ_32)
1130 .long __pabt_svc @ 3 (SVC_26 / SVC_32)
1131 .long __pabt_invalid @ 4
1132 .long __pabt_invalid @ 5
1133 .long __pabt_invalid @ 6
1134 .long __pabt_invalid @ 7
1135 .long __pabt_invalid @ 8
1136 .long __pabt_invalid @ 9
1137 .long __pabt_invalid @ a
1138 .long __pabt_invalid @ b
1139 .long __pabt_invalid @ c
1140 .long __pabt_invalid @ d
1141 .long __pabt_invalid @ e
1142 .long __pabt_invalid @ f
1144 /*
1145 * Undef instr entry dispatcher
1146 * Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
1147 */
1148 vector_stub und, UND_MODE
1150 .long __und_usr @ 0 (USR_26 / USR_32)
1151 .long __und_invalid @ 1 (FIQ_26 / FIQ_32)
1152 .long __und_invalid @ 2 (IRQ_26 / IRQ_32)
1153 .long __und_svc @ 3 (SVC_26 / SVC_32)
1154 .long __und_invalid @ 4
1155 .long __und_invalid @ 5
1156 .long __und_invalid @ 6
1157 .long __und_invalid @ 7
1158 .long __und_invalid @ 8
1159 .long __und_invalid @ 9
1160 .long __und_invalid @ a
1161 .long __und_invalid @ b
1162 .long __und_invalid @ c
1163 .long __und_invalid @ d
1164 .long __und_invalid @ e
1165 .long __und_invalid @ f
1167 .align 5
1169 /*=============================================================================
1170 * Address exception handler
1171 *-----------------------------------------------------------------------------
1172 * These aren't too critical.
1173 * (they're not supposed to happen, and won't happen in 32-bit data mode).
1174 */
1176 vector_addrexcptn:
1177 b vector_addrexcptn
1179 /*=============================================================================
1180 * FIQ "NMI" handler
1181 *-----------------------------------------------------------------------------
1182 * Handle a FIQ using the SVC stack allowing FIQ act like NMI on x86
1183 * systems.
1184 */
1185 vector_stub fiq, FIQ_MODE, 4
1187 .long __fiq_usr @ 0 (USR_26 / USR_32)
1188 .long __fiq_svc @ 1 (FIQ_26 / FIQ_32)
1189 .long __fiq_svc @ 2 (IRQ_26 / IRQ_32)
1190 .long __fiq_svc @ 3 (SVC_26 / SVC_32)
1191 .long __fiq_svc @ 4
1192 .long __fiq_svc @ 5
1193 .long __fiq_svc @ 6
1194 .long __fiq_abt @ 7
1195 .long __fiq_svc @ 8
1196 .long __fiq_svc @ 9
1197 .long __fiq_svc @ a
1198 .long __fiq_svc @ b
1199 .long __fiq_svc @ c
1200 .long __fiq_svc @ d
1201 .long __fiq_svc @ e
1202 .long __fiq_svc @ f
1204 .globl vector_fiq
1206 .section .vectors, "ax", %progbits
1207 .L__vectors_start:
1208 W(b) vector_rst
1209 W(b) vector_und
1210 W(ldr) pc, .L__vectors_start + 0x1000
1211 W(b) vector_pabt
1212 W(b) vector_dabt
1213 W(b) vector_addrexcptn
1214 W(b) vector_irq
1215 W(b) vector_fiq
1217 .data
1219 .globl cr_alignment
1220 cr_alignment:
1221 .space 4
1223 #ifdef CONFIG_MULTI_IRQ_HANDLER
1224 .globl handle_arch_irq
1225 handle_arch_irq:
1226 .space 4
1227 #endif