xref: /openbmc/linux/arch/arm/kernel/entry-armv.S (revision 4b0e07a5566a4e3f141e52c1f17e683e4a5bba91)
11da177e4SLinus Torvalds/*
21da177e4SLinus Torvalds *  linux/arch/arm/kernel/entry-armv.S
31da177e4SLinus Torvalds *
41da177e4SLinus Torvalds *  Copyright (C) 1996,1997,1998 Russell King.
51da177e4SLinus Torvalds *  ARM700 fix by Matthew Godbolt (linux-user@willothewisp.demon.co.uk)
61da177e4SLinus Torvalds *
71da177e4SLinus Torvalds * This program is free software; you can redistribute it and/or modify
81da177e4SLinus Torvalds * it under the terms of the GNU General Public License version 2 as
91da177e4SLinus Torvalds * published by the Free Software Foundation.
101da177e4SLinus Torvalds *
111da177e4SLinus Torvalds *  Low-level vector interface routines
121da177e4SLinus Torvalds *
131da177e4SLinus Torvalds *  Note:  there is a StrongARM bug in the STMIA rn, {regs}^ instruction that causes
141da177e4SLinus Torvalds *  it to save wrong values...  Be aware!
151da177e4SLinus Torvalds */
161da177e4SLinus Torvalds#include <linux/config.h>
171da177e4SLinus Torvalds
181da177e4SLinus Torvalds#include <asm/glue.h>
191da177e4SLinus Torvalds#include <asm/vfpmacros.h>
20bce495d8SRussell King#include <asm/hardware.h>		@ should be moved into entry-macro.S
21bce495d8SRussell King#include <asm/arch/irqs.h>		@ should be moved into entry-macro.S
22bce495d8SRussell King#include <asm/arch/entry-macro.S>
231da177e4SLinus Torvalds
241da177e4SLinus Torvalds#include "entry-header.S"
251da177e4SLinus Torvalds
261da177e4SLinus Torvalds/*
271da177e4SLinus Torvalds * Invalid mode handlers
281da177e4SLinus Torvalds */
291da177e4SLinus Torvalds	.macro	inv_entry, sym, reason
301da177e4SLinus Torvalds	sub	sp, sp, #S_FRAME_SIZE		@ Allocate frame size in one go
311da177e4SLinus Torvalds	stmia	sp, {r0 - lr}			@ Save XXX r0 - lr
321da177e4SLinus Torvalds	ldr	r4, .LC\sym
331da177e4SLinus Torvalds	mov	r1, #\reason
341da177e4SLinus Torvalds	.endm
351da177e4SLinus Torvalds
361da177e4SLinus Torvalds__pabt_invalid:
371da177e4SLinus Torvalds	inv_entry abt, BAD_PREFETCH
381da177e4SLinus Torvalds	b	1f
391da177e4SLinus Torvalds
401da177e4SLinus Torvalds__dabt_invalid:
411da177e4SLinus Torvalds	inv_entry abt, BAD_DATA
421da177e4SLinus Torvalds	b	1f
431da177e4SLinus Torvalds
441da177e4SLinus Torvalds__irq_invalid:
451da177e4SLinus Torvalds	inv_entry irq, BAD_IRQ
461da177e4SLinus Torvalds	b	1f
471da177e4SLinus Torvalds
481da177e4SLinus Torvalds__und_invalid:
491da177e4SLinus Torvalds	inv_entry und, BAD_UNDEFINSTR
501da177e4SLinus Torvalds
511da177e4SLinus Torvalds1:	zero_fp
521da177e4SLinus Torvalds	ldmia	r4, {r5 - r7}			@ Get XXX pc, cpsr, old_r0
531da177e4SLinus Torvalds	add	r4, sp, #S_PC
541da177e4SLinus Torvalds	stmia	r4, {r5 - r7}			@ Save XXX pc, cpsr, old_r0
551da177e4SLinus Torvalds	mov	r0, sp
561da177e4SLinus Torvalds	and	r2, r6, #31			@ int mode
571da177e4SLinus Torvalds	b	bad_mode
581da177e4SLinus Torvalds
591da177e4SLinus Torvalds/*
601da177e4SLinus Torvalds * SVC mode handlers
611da177e4SLinus Torvalds */
621da177e4SLinus Torvalds	.macro	svc_entry, sym
631da177e4SLinus Torvalds	sub	sp, sp, #S_FRAME_SIZE
641da177e4SLinus Torvalds	stmia	sp, {r0 - r12}			@ save r0 - r12
651da177e4SLinus Torvalds	ldr	r2, .LC\sym
661da177e4SLinus Torvalds	add	r0, sp, #S_FRAME_SIZE
671da177e4SLinus Torvalds	ldmia	r2, {r2 - r4}			@ get pc, cpsr
681da177e4SLinus Torvalds	add	r5, sp, #S_SP
691da177e4SLinus Torvalds	mov	r1, lr
701da177e4SLinus Torvalds
711da177e4SLinus Torvalds	@
721da177e4SLinus Torvalds	@ We are now ready to fill in the remaining blanks on the stack:
731da177e4SLinus Torvalds	@
741da177e4SLinus Torvalds	@  r0 - sp_svc
751da177e4SLinus Torvalds	@  r1 - lr_svc
761da177e4SLinus Torvalds	@  r2 - lr_<exception>, already fixed up for correct return/restart
771da177e4SLinus Torvalds	@  r3 - spsr_<exception>
781da177e4SLinus Torvalds	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)
791da177e4SLinus Torvalds	@
801da177e4SLinus Torvalds	stmia	r5, {r0 - r4}
811da177e4SLinus Torvalds	.endm
821da177e4SLinus Torvalds
831da177e4SLinus Torvalds	.align	5
841da177e4SLinus Torvalds__dabt_svc:
851da177e4SLinus Torvalds	svc_entry abt
861da177e4SLinus Torvalds
871da177e4SLinus Torvalds	@
881da177e4SLinus Torvalds	@ get ready to re-enable interrupts if appropriate
891da177e4SLinus Torvalds	@
901da177e4SLinus Torvalds	mrs	r9, cpsr
911da177e4SLinus Torvalds	tst	r3, #PSR_I_BIT
921da177e4SLinus Torvalds	biceq	r9, r9, #PSR_I_BIT
931da177e4SLinus Torvalds
941da177e4SLinus Torvalds	@
951da177e4SLinus Torvalds	@ Call the processor-specific abort handler:
961da177e4SLinus Torvalds	@
971da177e4SLinus Torvalds	@  r2 - aborted context pc
981da177e4SLinus Torvalds	@  r3 - aborted context cpsr
991da177e4SLinus Torvalds	@
1001da177e4SLinus Torvalds	@ The abort handler must return the aborted address in r0, and
1011da177e4SLinus Torvalds	@ the fault status register in r1.  r9 must be preserved.
1021da177e4SLinus Torvalds	@
1031da177e4SLinus Torvalds#ifdef MULTI_ABORT
1041da177e4SLinus Torvalds	ldr	r4, .LCprocfns
1051da177e4SLinus Torvalds	mov	lr, pc
1061da177e4SLinus Torvalds	ldr	pc, [r4]
1071da177e4SLinus Torvalds#else
1081da177e4SLinus Torvalds	bl	CPU_ABORT_HANDLER
1091da177e4SLinus Torvalds#endif
1101da177e4SLinus Torvalds
1111da177e4SLinus Torvalds	@
1121da177e4SLinus Torvalds	@ set desired IRQ state, then call main handler
1131da177e4SLinus Torvalds	@
1141da177e4SLinus Torvalds	msr	cpsr_c, r9
1151da177e4SLinus Torvalds	mov	r2, sp
1161da177e4SLinus Torvalds	bl	do_DataAbort
1171da177e4SLinus Torvalds
1181da177e4SLinus Torvalds	@
1191da177e4SLinus Torvalds	@ IRQs off again before pulling preserved data off the stack
1201da177e4SLinus Torvalds	@
1211ec42c0cSRussell King	disable_irq
1221da177e4SLinus Torvalds
1231da177e4SLinus Torvalds	@
1241da177e4SLinus Torvalds	@ restore SPSR and restart the instruction
1251da177e4SLinus Torvalds	@
1261da177e4SLinus Torvalds	ldr	r0, [sp, #S_PSR]
1271da177e4SLinus Torvalds	msr	spsr_cxsf, r0
1281da177e4SLinus Torvalds	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
1291da177e4SLinus Torvalds
1301da177e4SLinus Torvalds	.align	5
1311da177e4SLinus Torvalds__irq_svc:
1321da177e4SLinus Torvalds	svc_entry irq
1331da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
1341da177e4SLinus Torvalds	get_thread_info r8
1351da177e4SLinus Torvalds	ldr	r9, [r8, #TI_PREEMPT]		@ get preempt count
1361da177e4SLinus Torvalds	add	r7, r9, #1			@ increment it
1371da177e4SLinus Torvalds	str	r7, [r8, #TI_PREEMPT]
1381da177e4SLinus Torvalds#endif
1391da177e4SLinus Torvalds1:	get_irqnr_and_base r0, r6, r5, lr
1401da177e4SLinus Torvalds	movne	r1, sp
1411da177e4SLinus Torvalds	@
1421da177e4SLinus Torvalds	@ routine called with r0 = irq number, r1 = struct pt_regs *
1431da177e4SLinus Torvalds	@
1441da177e4SLinus Torvalds	adrne	lr, 1b
1451da177e4SLinus Torvalds	bne	asm_do_IRQ
1461da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
1471da177e4SLinus Torvalds	ldr	r0, [r8, #TI_FLAGS]		@ get flags
1481da177e4SLinus Torvalds	tst	r0, #_TIF_NEED_RESCHED
1491da177e4SLinus Torvalds	blne	svc_preempt
1501da177e4SLinus Torvaldspreempt_return:
1511da177e4SLinus Torvalds	ldr	r0, [r8, #TI_PREEMPT]		@ read preempt value
1521da177e4SLinus Torvalds	teq	r0, r7
1531da177e4SLinus Torvalds	str	r9, [r8, #TI_PREEMPT]		@ restore preempt count
1541da177e4SLinus Torvalds	strne	r0, [r0, -r0]			@ bug()
1551da177e4SLinus Torvalds#endif
1561da177e4SLinus Torvalds	ldr	r0, [sp, #S_PSR]		@ irqs are already disabled
1571da177e4SLinus Torvalds	msr	spsr_cxsf, r0
1581da177e4SLinus Torvalds	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
1591da177e4SLinus Torvalds
1601da177e4SLinus Torvalds	.ltorg
1611da177e4SLinus Torvalds
1621da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
1631da177e4SLinus Torvaldssvc_preempt:
1641da177e4SLinus Torvalds	teq	r9, #0				@ was preempt count = 0
1651da177e4SLinus Torvalds	ldreq	r6, .LCirq_stat
1661da177e4SLinus Torvalds	movne	pc, lr				@ no
1671da177e4SLinus Torvalds	ldr	r0, [r6, #4]			@ local_irq_count
1681da177e4SLinus Torvalds	ldr	r1, [r6, #8]			@ local_bh_count
1691da177e4SLinus Torvalds	adds	r0, r0, r1
1701da177e4SLinus Torvalds	movne	pc, lr
1711da177e4SLinus Torvalds	mov	r7, #0				@ preempt_schedule_irq
1721da177e4SLinus Torvalds	str	r7, [r8, #TI_PREEMPT]		@ expects preempt_count == 0
1731da177e4SLinus Torvalds1:	bl	preempt_schedule_irq		@ irq en/disable is done inside
1741da177e4SLinus Torvalds	ldr	r0, [r8, #TI_FLAGS]		@ get new tasks TI_FLAGS
1751da177e4SLinus Torvalds	tst	r0, #_TIF_NEED_RESCHED
1761da177e4SLinus Torvalds	beq	preempt_return			@ go again
1771da177e4SLinus Torvalds	b	1b
1781da177e4SLinus Torvalds#endif
1791da177e4SLinus Torvalds
1801da177e4SLinus Torvalds	.align	5
1811da177e4SLinus Torvalds__und_svc:
1821da177e4SLinus Torvalds	svc_entry und
1831da177e4SLinus Torvalds
1841da177e4SLinus Torvalds	@
1851da177e4SLinus Torvalds	@ call emulation code, which returns using r9 if it has emulated
1861da177e4SLinus Torvalds	@ the instruction, or the more conventional lr if we are to treat
1871da177e4SLinus Torvalds	@ this as a real undefined instruction
1881da177e4SLinus Torvalds	@
1891da177e4SLinus Torvalds	@  r0 - instruction
1901da177e4SLinus Torvalds	@
1911da177e4SLinus Torvalds	ldr	r0, [r2, #-4]
1921da177e4SLinus Torvalds	adr	r9, 1f
1931da177e4SLinus Torvalds	bl	call_fpe
1941da177e4SLinus Torvalds
1951da177e4SLinus Torvalds	mov	r0, sp				@ struct pt_regs *regs
1961da177e4SLinus Torvalds	bl	do_undefinstr
1971da177e4SLinus Torvalds
1981da177e4SLinus Torvalds	@
1991da177e4SLinus Torvalds	@ IRQs off again before pulling preserved data off the stack
2001da177e4SLinus Torvalds	@
2011ec42c0cSRussell King1:	disable_irq
2021da177e4SLinus Torvalds
2031da177e4SLinus Torvalds	@
2041da177e4SLinus Torvalds	@ restore SPSR and restart the instruction
2051da177e4SLinus Torvalds	@
2061da177e4SLinus Torvalds	ldr	lr, [sp, #S_PSR]		@ Get SVC cpsr
2071da177e4SLinus Torvalds	msr	spsr_cxsf, lr
2081da177e4SLinus Torvalds	ldmia	sp, {r0 - pc}^			@ Restore SVC registers
2091da177e4SLinus Torvalds
2101da177e4SLinus Torvalds	.align	5
2111da177e4SLinus Torvalds__pabt_svc:
2121da177e4SLinus Torvalds	svc_entry abt
2131da177e4SLinus Torvalds
2141da177e4SLinus Torvalds	@
2151da177e4SLinus Torvalds	@ re-enable interrupts if appropriate
2161da177e4SLinus Torvalds	@
2171da177e4SLinus Torvalds	mrs	r9, cpsr
2181da177e4SLinus Torvalds	tst	r3, #PSR_I_BIT
2191da177e4SLinus Torvalds	biceq	r9, r9, #PSR_I_BIT
2201da177e4SLinus Torvalds	msr	cpsr_c, r9
2211da177e4SLinus Torvalds
2221da177e4SLinus Torvalds	@
2231da177e4SLinus Torvalds	@ set args, then call main handler
2241da177e4SLinus Torvalds	@
2251da177e4SLinus Torvalds	@  r0 - address of faulting instruction
2261da177e4SLinus Torvalds	@  r1 - pointer to registers on stack
2271da177e4SLinus Torvalds	@
2281da177e4SLinus Torvalds	mov	r0, r2				@ address (pc)
2291da177e4SLinus Torvalds	mov	r1, sp				@ regs
2301da177e4SLinus Torvalds	bl	do_PrefetchAbort		@ call abort handler
2311da177e4SLinus Torvalds
2321da177e4SLinus Torvalds	@
2331da177e4SLinus Torvalds	@ IRQs off again before pulling preserved data off the stack
2341da177e4SLinus Torvalds	@
2351ec42c0cSRussell King	disable_irq
2361da177e4SLinus Torvalds
2371da177e4SLinus Torvalds	@
2381da177e4SLinus Torvalds	@ restore SPSR and restart the instruction
2391da177e4SLinus Torvalds	@
2401da177e4SLinus Torvalds	ldr	r0, [sp, #S_PSR]
2411da177e4SLinus Torvalds	msr	spsr_cxsf, r0
2421da177e4SLinus Torvalds	ldmia	sp, {r0 - pc}^			@ load r0 - pc, cpsr
2431da177e4SLinus Torvalds
2441da177e4SLinus Torvalds	.align	5
2451da177e4SLinus Torvalds.LCirq:
2461da177e4SLinus Torvalds	.word	__temp_irq
2471da177e4SLinus Torvalds.LCund:
2481da177e4SLinus Torvalds	.word	__temp_und
2491da177e4SLinus Torvalds.LCabt:
2501da177e4SLinus Torvalds	.word	__temp_abt
2511da177e4SLinus Torvalds#ifdef MULTI_ABORT
2521da177e4SLinus Torvalds.LCprocfns:
2531da177e4SLinus Torvalds	.word	processor
2541da177e4SLinus Torvalds#endif
2551da177e4SLinus Torvalds.LCfp:
2561da177e4SLinus Torvalds	.word	fp_enter
2571da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
2581da177e4SLinus Torvalds.LCirq_stat:
2591da177e4SLinus Torvalds	.word	irq_stat
2601da177e4SLinus Torvalds#endif
2611da177e4SLinus Torvalds
2621da177e4SLinus Torvalds/*
2631da177e4SLinus Torvalds * User mode handlers
2641da177e4SLinus Torvalds */
2651da177e4SLinus Torvalds	.macro	usr_entry, sym
2661da177e4SLinus Torvalds	sub	sp, sp, #S_FRAME_SIZE		@ Allocate frame size in one go
2671da177e4SLinus Torvalds	stmia	sp, {r0 - r12}			@ save r0 - r12
2681da177e4SLinus Torvalds	ldr	r7, .LC\sym
2691da177e4SLinus Torvalds	add	r5, sp, #S_PC
2701da177e4SLinus Torvalds	ldmia	r7, {r2 - r4}			@ Get USR pc, cpsr
2711da177e4SLinus Torvalds
2722d2669b6SNicolas Pitre#if __LINUX_ARM_ARCH__ < 6
2732d2669b6SNicolas Pitre	@ make sure our user space atomic helper is aborted
2742d2669b6SNicolas Pitre	cmp	r2, #VIRT_OFFSET
2752d2669b6SNicolas Pitre	bichs	r3, r3, #PSR_Z_BIT
2762d2669b6SNicolas Pitre#endif
2772d2669b6SNicolas Pitre
2781da177e4SLinus Torvalds	@
2791da177e4SLinus Torvalds	@ We are now ready to fill in the remaining blanks on the stack:
2801da177e4SLinus Torvalds	@
2811da177e4SLinus Torvalds	@  r2 - lr_<exception>, already fixed up for correct return/restart
2821da177e4SLinus Torvalds	@  r3 - spsr_<exception>
2831da177e4SLinus Torvalds	@  r4 - orig_r0 (see pt_regs definition in ptrace.h)
2841da177e4SLinus Torvalds	@
2851da177e4SLinus Torvalds	@ Also, separately save sp_usr and lr_usr
2861da177e4SLinus Torvalds	@
2871da177e4SLinus Torvalds	stmia	r5, {r2 - r4}
2881da177e4SLinus Torvalds	stmdb	r5, {sp, lr}^
2891da177e4SLinus Torvalds
2901da177e4SLinus Torvalds	@
2911da177e4SLinus Torvalds	@ Enable the alignment trap while in kernel mode
2921da177e4SLinus Torvalds	@
2931da177e4SLinus Torvalds	alignment_trap r7, r0, __temp_\sym
2941da177e4SLinus Torvalds
2951da177e4SLinus Torvalds	@
2961da177e4SLinus Torvalds	@ Clear FP to mark the first stack frame
2971da177e4SLinus Torvalds	@
2981da177e4SLinus Torvalds	zero_fp
2991da177e4SLinus Torvalds	.endm
3001da177e4SLinus Torvalds
3011da177e4SLinus Torvalds	.align	5
3021da177e4SLinus Torvalds__dabt_usr:
3031da177e4SLinus Torvalds	usr_entry abt
3041da177e4SLinus Torvalds
3051da177e4SLinus Torvalds	@
3061da177e4SLinus Torvalds	@ Call the processor-specific abort handler:
3071da177e4SLinus Torvalds	@
3081da177e4SLinus Torvalds	@  r2 - aborted context pc
3091da177e4SLinus Torvalds	@  r3 - aborted context cpsr
3101da177e4SLinus Torvalds	@
3111da177e4SLinus Torvalds	@ The abort handler must return the aborted address in r0, and
3121da177e4SLinus Torvalds	@ the fault status register in r1.
3131da177e4SLinus Torvalds	@
3141da177e4SLinus Torvalds#ifdef MULTI_ABORT
3151da177e4SLinus Torvalds	ldr	r4, .LCprocfns
3161da177e4SLinus Torvalds	mov	lr, pc
3171da177e4SLinus Torvalds	ldr	pc, [r4]
3181da177e4SLinus Torvalds#else
3191da177e4SLinus Torvalds	bl	CPU_ABORT_HANDLER
3201da177e4SLinus Torvalds#endif
3211da177e4SLinus Torvalds
3221da177e4SLinus Torvalds	@
3231da177e4SLinus Torvalds	@ IRQs on, then call the main handler
3241da177e4SLinus Torvalds	@
3251ec42c0cSRussell King	enable_irq
3261da177e4SLinus Torvalds	mov	r2, sp
3271da177e4SLinus Torvalds	adr	lr, ret_from_exception
3281da177e4SLinus Torvalds	b	do_DataAbort
3291da177e4SLinus Torvalds
3301da177e4SLinus Torvalds	.align	5
3311da177e4SLinus Torvalds__irq_usr:
3321da177e4SLinus Torvalds	usr_entry irq
3331da177e4SLinus Torvalds
3341da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
3351da177e4SLinus Torvalds	get_thread_info r8
3361da177e4SLinus Torvalds	ldr	r9, [r8, #TI_PREEMPT]		@ get preempt count
3371da177e4SLinus Torvalds	add	r7, r9, #1			@ increment it
3381da177e4SLinus Torvalds	str	r7, [r8, #TI_PREEMPT]
3391da177e4SLinus Torvalds#endif
3401da177e4SLinus Torvalds1:	get_irqnr_and_base r0, r6, r5, lr
3411da177e4SLinus Torvalds	movne	r1, sp
3421da177e4SLinus Torvalds	adrne	lr, 1b
3431da177e4SLinus Torvalds	@
3441da177e4SLinus Torvalds	@ routine called with r0 = irq number, r1 = struct pt_regs *
3451da177e4SLinus Torvalds	@
3461da177e4SLinus Torvalds	bne	asm_do_IRQ
3471da177e4SLinus Torvalds#ifdef CONFIG_PREEMPT
3481da177e4SLinus Torvalds	ldr	r0, [r8, #TI_PREEMPT]
3491da177e4SLinus Torvalds	teq	r0, r7
3501da177e4SLinus Torvalds	str	r9, [r8, #TI_PREEMPT]
3511da177e4SLinus Torvalds	strne	r0, [r0, -r0]
3521da177e4SLinus Torvalds	mov	tsk, r8
3531da177e4SLinus Torvalds#else
3541da177e4SLinus Torvalds	get_thread_info tsk
3551da177e4SLinus Torvalds#endif
3561da177e4SLinus Torvalds	mov	why, #0
3571da177e4SLinus Torvalds	b	ret_to_user
3581da177e4SLinus Torvalds
3591da177e4SLinus Torvalds	.ltorg
3601da177e4SLinus Torvalds
3611da177e4SLinus Torvalds	.align	5
3621da177e4SLinus Torvalds__und_usr:
3631da177e4SLinus Torvalds	usr_entry und
3641da177e4SLinus Torvalds
3651da177e4SLinus Torvalds	tst	r3, #PSR_T_BIT			@ Thumb mode?
3661da177e4SLinus Torvalds	bne	fpundefinstr			@ ignore FP
3671da177e4SLinus Torvalds	sub	r4, r2, #4
3681da177e4SLinus Torvalds
3691da177e4SLinus Torvalds	@
3701da177e4SLinus Torvalds	@ fall through to the emulation code, which returns using r9 if
3711da177e4SLinus Torvalds	@ it has emulated the instruction, or the more conventional lr
3721da177e4SLinus Torvalds	@ if we are to treat this as a real undefined instruction
3731da177e4SLinus Torvalds	@
3741da177e4SLinus Torvalds	@  r0 - instruction
3751da177e4SLinus Torvalds	@
3761da177e4SLinus Torvalds1:	ldrt	r0, [r4]
3771da177e4SLinus Torvalds	adr	r9, ret_from_exception
3781da177e4SLinus Torvalds	adr	lr, fpundefinstr
3791da177e4SLinus Torvalds	@
3801da177e4SLinus Torvalds	@ fallthrough to call_fpe
3811da177e4SLinus Torvalds	@
3821da177e4SLinus Torvalds
3831da177e4SLinus Torvalds/*
3841da177e4SLinus Torvalds * The out of line fixup for the ldrt above.
3851da177e4SLinus Torvalds */
3861da177e4SLinus Torvalds	.section .fixup, "ax"
3871da177e4SLinus Torvalds2:	mov	pc, r9
3881da177e4SLinus Torvalds	.previous
3891da177e4SLinus Torvalds	.section __ex_table,"a"
3901da177e4SLinus Torvalds	.long	1b, 2b
3911da177e4SLinus Torvalds	.previous
3921da177e4SLinus Torvalds
3931da177e4SLinus Torvalds/*
3941da177e4SLinus Torvalds * Check whether the instruction is a co-processor instruction.
3951da177e4SLinus Torvalds * If yes, we need to call the relevant co-processor handler.
3961da177e4SLinus Torvalds *
3971da177e4SLinus Torvalds * Note that we don't do a full check here for the co-processor
3981da177e4SLinus Torvalds * instructions; all instructions with bit 27 set are well
3991da177e4SLinus Torvalds * defined.  The only instructions that should fault are the
4001da177e4SLinus Torvalds * co-processor instructions.  However, we have to watch out
4011da177e4SLinus Torvalds * for the ARM6/ARM7 SWI bug.
4021da177e4SLinus Torvalds *
4031da177e4SLinus Torvalds * Emulators may wish to make use of the following registers:
4041da177e4SLinus Torvalds *  r0  = instruction opcode.
4051da177e4SLinus Torvalds *  r2  = PC+4
4061da177e4SLinus Torvalds *  r10 = this threads thread_info structure.
4071da177e4SLinus Torvalds */
4081da177e4SLinus Torvaldscall_fpe:
4091da177e4SLinus Torvalds	tst	r0, #0x08000000			@ only CDP/CPRT/LDC/STC have bit 27
4101da177e4SLinus Torvalds#if defined(CONFIG_CPU_ARM610) || defined(CONFIG_CPU_ARM710)
4111da177e4SLinus Torvalds	and	r8, r0, #0x0f000000		@ mask out op-code bits
4121da177e4SLinus Torvalds	teqne	r8, #0x0f000000			@ SWI (ARM6/7 bug)?
4131da177e4SLinus Torvalds#endif
4141da177e4SLinus Torvalds	moveq	pc, lr
4151da177e4SLinus Torvalds	get_thread_info r10			@ get current thread
4161da177e4SLinus Torvalds	and	r8, r0, #0x00000f00		@ mask out CP number
4171da177e4SLinus Torvalds	mov	r7, #1
4181da177e4SLinus Torvalds	add	r6, r10, #TI_USED_CP
4191da177e4SLinus Torvalds	strb	r7, [r6, r8, lsr #8]		@ set appropriate used_cp[]
4201da177e4SLinus Torvalds#ifdef CONFIG_IWMMXT
4211da177e4SLinus Torvalds	@ Test if we need to give access to iWMMXt coprocessors
4221da177e4SLinus Torvalds	ldr	r5, [r10, #TI_FLAGS]
4231da177e4SLinus Torvalds	rsbs	r7, r8, #(1 << 8)		@ CP 0 or 1 only
4241da177e4SLinus Torvalds	movcss	r7, r5, lsr #(TIF_USING_IWMMXT + 1)
4251da177e4SLinus Torvalds	bcs	iwmmxt_task_enable
4261da177e4SLinus Torvalds#endif
4271ec42c0cSRussell King	enable_irq
4281da177e4SLinus Torvalds	add	pc, pc, r8, lsr #6
4291da177e4SLinus Torvalds	mov	r0, r0
4301da177e4SLinus Torvalds
4311da177e4SLinus Torvalds	mov	pc, lr				@ CP#0
4321da177e4SLinus Torvalds	b	do_fpe				@ CP#1 (FPE)
4331da177e4SLinus Torvalds	b	do_fpe				@ CP#2 (FPE)
4341da177e4SLinus Torvalds	mov	pc, lr				@ CP#3
4351da177e4SLinus Torvalds	mov	pc, lr				@ CP#4
4361da177e4SLinus Torvalds	mov	pc, lr				@ CP#5
4371da177e4SLinus Torvalds	mov	pc, lr				@ CP#6
4381da177e4SLinus Torvalds	mov	pc, lr				@ CP#7
4391da177e4SLinus Torvalds	mov	pc, lr				@ CP#8
4401da177e4SLinus Torvalds	mov	pc, lr				@ CP#9
4411da177e4SLinus Torvalds#ifdef CONFIG_VFP
4421da177e4SLinus Torvalds	b	do_vfp				@ CP#10 (VFP)
4431da177e4SLinus Torvalds	b	do_vfp				@ CP#11 (VFP)
4441da177e4SLinus Torvalds#else
4451da177e4SLinus Torvalds	mov	pc, lr				@ CP#10 (VFP)
4461da177e4SLinus Torvalds	mov	pc, lr				@ CP#11 (VFP)
4471da177e4SLinus Torvalds#endif
4481da177e4SLinus Torvalds	mov	pc, lr				@ CP#12
4491da177e4SLinus Torvalds	mov	pc, lr				@ CP#13
4501da177e4SLinus Torvalds	mov	pc, lr				@ CP#14 (Debug)
4511da177e4SLinus Torvalds	mov	pc, lr				@ CP#15 (Control)
4521da177e4SLinus Torvalds
4531da177e4SLinus Torvaldsdo_fpe:
4541da177e4SLinus Torvalds	ldr	r4, .LCfp
4551da177e4SLinus Torvalds	add	r10, r10, #TI_FPSTATE		@ r10 = workspace
4561da177e4SLinus Torvalds	ldr	pc, [r4]			@ Call FP module USR entry point
4571da177e4SLinus Torvalds
4581da177e4SLinus Torvalds/*
4591da177e4SLinus Torvalds * The FP module is called with these registers set:
4601da177e4SLinus Torvalds *  r0  = instruction
4611da177e4SLinus Torvalds *  r2  = PC+4
4621da177e4SLinus Torvalds *  r9  = normal "successful" return address
4631da177e4SLinus Torvalds *  r10 = FP workspace
4641da177e4SLinus Torvalds *  lr  = unrecognised FP instruction return address
4651da177e4SLinus Torvalds */
4661da177e4SLinus Torvalds
4671da177e4SLinus Torvalds	.data
4681da177e4SLinus TorvaldsENTRY(fp_enter)
4691da177e4SLinus Torvalds	.word	fpundefinstr
4701da177e4SLinus Torvalds	.text
4711da177e4SLinus Torvalds
4721da177e4SLinus Torvaldsfpundefinstr:
4731da177e4SLinus Torvalds	mov	r0, sp
4741da177e4SLinus Torvalds	adr	lr, ret_from_exception
4751da177e4SLinus Torvalds	b	do_undefinstr
4761da177e4SLinus Torvalds
4771da177e4SLinus Torvalds	.align	5
4781da177e4SLinus Torvalds__pabt_usr:
4791da177e4SLinus Torvalds	usr_entry abt
4801da177e4SLinus Torvalds
4811ec42c0cSRussell King	enable_irq				@ Enable interrupts
4821da177e4SLinus Torvalds	mov	r0, r2				@ address (pc)
4831da177e4SLinus Torvalds	mov	r1, sp				@ regs
4841da177e4SLinus Torvalds	bl	do_PrefetchAbort		@ call abort handler
4851da177e4SLinus Torvalds	/* fall through */
4861da177e4SLinus Torvalds/*
4871da177e4SLinus Torvalds * This is the return code to user mode for abort handlers
4881da177e4SLinus Torvalds */
4891da177e4SLinus TorvaldsENTRY(ret_from_exception)
4901da177e4SLinus Torvalds	get_thread_info tsk
4911da177e4SLinus Torvalds	mov	why, #0
4921da177e4SLinus Torvalds	b	ret_to_user
4931da177e4SLinus Torvalds
4941da177e4SLinus Torvalds/*
4951da177e4SLinus Torvalds * Register switch for ARMv3 and ARMv4 processors
4961da177e4SLinus Torvalds * r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
4971da177e4SLinus Torvalds * previous and next are guaranteed not to be the same.
4981da177e4SLinus Torvalds */
4991da177e4SLinus TorvaldsENTRY(__switch_to)
5001da177e4SLinus Torvalds	add	ip, r1, #TI_CPU_SAVE
5011da177e4SLinus Torvalds	ldr	r3, [r2, #TI_TP_VALUE]
5021da177e4SLinus Torvalds	stmia	ip!, {r4 - sl, fp, sp, lr}	@ Store most regs on stack
5031da177e4SLinus Torvalds	ldr	r6, [r2, #TI_CPU_DOMAIN]!
5041da177e4SLinus Torvalds#if defined(CONFIG_CPU_XSCALE) && !defined(CONFIG_IWMMXT)
5051da177e4SLinus Torvalds	mra	r4, r5, acc0
5061da177e4SLinus Torvalds	stmia   ip, {r4, r5}
5071da177e4SLinus Torvalds#endif
508*4b0e07a5SNicolas Pitre#if defined(CONFIG_HAS_TLS_REG)
5092d2669b6SNicolas Pitre	mcr	p15, 0, r3, c13, c0, 3		@ set TLS register
510*4b0e07a5SNicolas Pitre#elif !defined(CONFIG_TLS_REG_EMUL)
5111da177e4SLinus Torvalds	mov	r4, #0xffff0fff
5122d2669b6SNicolas Pitre	str	r3, [r4, #-15]			@ TLS val at 0xffff0ff0
5132d2669b6SNicolas Pitre#endif
5141da177e4SLinus Torvalds	mcr	p15, 0, r6, c3, c0, 0		@ Set domain register
5151da177e4SLinus Torvalds#ifdef CONFIG_VFP
5161da177e4SLinus Torvalds	@ Always disable VFP so we can lazily save/restore the old
5171da177e4SLinus Torvalds	@ state. This occurs in the context of the previous thread.
5181da177e4SLinus Torvalds	VFPFMRX	r4, FPEXC
5191da177e4SLinus Torvalds	bic	r4, r4, #FPEXC_ENABLE
5201da177e4SLinus Torvalds	VFPFMXR	FPEXC, r4
5211da177e4SLinus Torvalds#endif
5221da177e4SLinus Torvalds#if defined(CONFIG_IWMMXT)
5231da177e4SLinus Torvalds	bl	iwmmxt_task_switch
5241da177e4SLinus Torvalds#elif defined(CONFIG_CPU_XSCALE)
5251da177e4SLinus Torvalds	add	r4, r2, #40			@ cpu_context_save->extra
5261da177e4SLinus Torvalds	ldmib	r4, {r4, r5}
5271da177e4SLinus Torvalds	mar	acc0, r4, r5
5281da177e4SLinus Torvalds#endif
5291da177e4SLinus Torvalds	ldmib	r2, {r4 - sl, fp, sp, pc}	@ Load all regs saved previously
5301da177e4SLinus Torvalds
5311da177e4SLinus Torvalds	__INIT
5322d2669b6SNicolas Pitre
5332d2669b6SNicolas Pitre/*
5342d2669b6SNicolas Pitre * User helpers.
5352d2669b6SNicolas Pitre *
5362d2669b6SNicolas Pitre * These are segment of kernel provided user code reachable from user space
5372d2669b6SNicolas Pitre * at a fixed address in kernel memory.  This is used to provide user space
5382d2669b6SNicolas Pitre * with some operations which require kernel help because of unimplemented
5392d2669b6SNicolas Pitre * native feature and/or instructions in many ARM CPUs. The idea is for
5402d2669b6SNicolas Pitre * this code to be executed directly in user mode for best efficiency but
5412d2669b6SNicolas Pitre * which is too intimate with the kernel counter part to be left to user
5422d2669b6SNicolas Pitre * libraries.  In fact this code might even differ from one CPU to another
5432d2669b6SNicolas Pitre * depending on the available  instruction set and restrictions like on
5442d2669b6SNicolas Pitre * SMP systems.  In other words, the kernel reserves the right to change
5452d2669b6SNicolas Pitre * this code as needed without warning. Only the entry points and their
5462d2669b6SNicolas Pitre * results are guaranteed to be stable.
5472d2669b6SNicolas Pitre *
5482d2669b6SNicolas Pitre * Each segment is 32-byte aligned and will be moved to the top of the high
5492d2669b6SNicolas Pitre * vector page.  New segments (if ever needed) must be added in front of
5502d2669b6SNicolas Pitre * existing ones.  This mechanism should be used only for things that are
5512d2669b6SNicolas Pitre * really small and justified, and not be abused freely.
5522d2669b6SNicolas Pitre *
5532d2669b6SNicolas Pitre * User space is expected to implement those things inline when optimizing
5542d2669b6SNicolas Pitre * for a processor that has the necessary native support, but only if such
5552d2669b6SNicolas Pitre * resulting binaries are already to be incompatible with earlier ARM
5562d2669b6SNicolas Pitre * processors due to the use of unsupported instructions other than what
5572d2669b6SNicolas Pitre * is provided here.  In other words don't make binaries unable to run on
5582d2669b6SNicolas Pitre * earlier processors just for the sake of not using these kernel helpers
5592d2669b6SNicolas Pitre * if your compiled code is not going to use the new instructions for other
5602d2669b6SNicolas Pitre * purpose.
5612d2669b6SNicolas Pitre */
5622d2669b6SNicolas Pitre
5632d2669b6SNicolas Pitre	.align	5
5642d2669b6SNicolas Pitre	.globl	__kuser_helper_start
5652d2669b6SNicolas Pitre__kuser_helper_start:
5662d2669b6SNicolas Pitre
5672d2669b6SNicolas Pitre/*
5682d2669b6SNicolas Pitre * Reference prototype:
5692d2669b6SNicolas Pitre *
5702d2669b6SNicolas Pitre *	int __kernel_cmpxchg(int oldval, int newval, int *ptr)
5712d2669b6SNicolas Pitre *
5722d2669b6SNicolas Pitre * Input:
5732d2669b6SNicolas Pitre *
5742d2669b6SNicolas Pitre *	r0 = oldval
5752d2669b6SNicolas Pitre *	r1 = newval
5762d2669b6SNicolas Pitre *	r2 = ptr
5772d2669b6SNicolas Pitre *	lr = return address
5782d2669b6SNicolas Pitre *
5792d2669b6SNicolas Pitre * Output:
5802d2669b6SNicolas Pitre *
5812d2669b6SNicolas Pitre *	r0 = returned value (zero or non-zero)
5822d2669b6SNicolas Pitre *	C flag = set if r0 == 0, clear if r0 != 0
5832d2669b6SNicolas Pitre *
5842d2669b6SNicolas Pitre * Clobbered:
5852d2669b6SNicolas Pitre *
5862d2669b6SNicolas Pitre *	r3, ip, flags
5872d2669b6SNicolas Pitre *
5882d2669b6SNicolas Pitre * Definition and user space usage example:
5892d2669b6SNicolas Pitre *
5902d2669b6SNicolas Pitre *	typedef int (__kernel_cmpxchg_t)(int oldval, int newval, int *ptr);
5912d2669b6SNicolas Pitre *	#define __kernel_cmpxchg (*(__kernel_cmpxchg_t *)0xffff0fc0)
5922d2669b6SNicolas Pitre *
5932d2669b6SNicolas Pitre * Atomically store newval in *ptr if *ptr is equal to oldval for user space.
5942d2669b6SNicolas Pitre * Return zero if *ptr was changed or non-zero if no exchange happened.
5952d2669b6SNicolas Pitre * The C flag is also set if *ptr was changed to allow for assembly
5962d2669b6SNicolas Pitre * optimization in the calling code.
5972d2669b6SNicolas Pitre *
5982d2669b6SNicolas Pitre * For example, a user space atomic_add implementation could look like this:
5992d2669b6SNicolas Pitre *
6002d2669b6SNicolas Pitre * #define atomic_add(ptr, val) \
6012d2669b6SNicolas Pitre *	({ register unsigned int *__ptr asm("r2") = (ptr); \
6022d2669b6SNicolas Pitre *	   register unsigned int __result asm("r1"); \
6032d2669b6SNicolas Pitre *	   asm volatile ( \
6042d2669b6SNicolas Pitre *	       "1: @ atomic_add\n\t" \
6052d2669b6SNicolas Pitre *	       "ldr	r0, [r2]\n\t" \
6062d2669b6SNicolas Pitre *	       "mov	r3, #0xffff0fff\n\t" \
6072d2669b6SNicolas Pitre *	       "add	lr, pc, #4\n\t" \
6082d2669b6SNicolas Pitre *	       "add	r1, r0, %2\n\t" \
6092d2669b6SNicolas Pitre *	       "add	pc, r3, #(0xffff0fc0 - 0xffff0fff)\n\t" \
6102d2669b6SNicolas Pitre *	       "bcc	1b" \
6112d2669b6SNicolas Pitre *	       : "=&r" (__result) \
6122d2669b6SNicolas Pitre *	       : "r" (__ptr), "rIL" (val) \
6132d2669b6SNicolas Pitre *	       : "r0","r3","ip","lr","cc","memory" ); \
6142d2669b6SNicolas Pitre *	   __result; })
6152d2669b6SNicolas Pitre */
6162d2669b6SNicolas Pitre
6172d2669b6SNicolas Pitre__kuser_cmpxchg:				@ 0xffff0fc0
6182d2669b6SNicolas Pitre
6192d2669b6SNicolas Pitre#if __LINUX_ARM_ARCH__ < 6
6202d2669b6SNicolas Pitre
6212d2669b6SNicolas Pitre#ifdef CONFIG_SMP  /* sanity check */
6222d2669b6SNicolas Pitre#error "CONFIG_SMP on a machine supporting pre-ARMv6 processors?"
6232d2669b6SNicolas Pitre#endif
6242d2669b6SNicolas Pitre
6252d2669b6SNicolas Pitre	/*
6262d2669b6SNicolas Pitre	 * Theory of operation:
6272d2669b6SNicolas Pitre	 *
6282d2669b6SNicolas Pitre	 * We set the Z flag before loading oldval. If ever an exception
6292d2669b6SNicolas Pitre	 * occurs we can not be sure the loaded value will still be the same
6302d2669b6SNicolas Pitre	 * when the exception returns, therefore the user exception handler
6312d2669b6SNicolas Pitre	 * will clear the Z flag whenever the interrupted user code was
6322d2669b6SNicolas Pitre	 * actually from the kernel address space (see the usr_entry macro).
6332d2669b6SNicolas Pitre	 *
6342d2669b6SNicolas Pitre	 * The post-increment on the str is used to prevent a race with an
6352d2669b6SNicolas Pitre	 * exception happening just after the str instruction which would
6362d2669b6SNicolas Pitre	 * clear the Z flag although the exchange was done.
6372d2669b6SNicolas Pitre	 */
6382d2669b6SNicolas Pitre	teq	ip, ip			@ set Z flag
6392d2669b6SNicolas Pitre	ldr	ip, [r2]		@ load current val
6402d2669b6SNicolas Pitre	add	r3, r2, #1		@ prepare store ptr
6412d2669b6SNicolas Pitre	teqeq	ip, r0			@ compare with oldval if still allowed
6422d2669b6SNicolas Pitre	streq	r1, [r3, #-1]!		@ store newval if still allowed
6432d2669b6SNicolas Pitre	subs	r0, r2, r3		@ if r2 == r3 the str occured
6442d2669b6SNicolas Pitre	mov	pc, lr
6452d2669b6SNicolas Pitre
6462d2669b6SNicolas Pitre#else
6472d2669b6SNicolas Pitre
6482d2669b6SNicolas Pitre	ldrex	r3, [r2]
6492d2669b6SNicolas Pitre	subs	r3, r3, r0
6502d2669b6SNicolas Pitre	strexeq	r3, r1, [r2]
6512d2669b6SNicolas Pitre	rsbs	r0, r3, #0
6522d2669b6SNicolas Pitre	mov	pc, lr
6532d2669b6SNicolas Pitre
6542d2669b6SNicolas Pitre#endif
6552d2669b6SNicolas Pitre
6562d2669b6SNicolas Pitre	.align	5
6572d2669b6SNicolas Pitre
6582d2669b6SNicolas Pitre/*
6592d2669b6SNicolas Pitre * Reference prototype:
6602d2669b6SNicolas Pitre *
6612d2669b6SNicolas Pitre *	int __kernel_get_tls(void)
6622d2669b6SNicolas Pitre *
6632d2669b6SNicolas Pitre * Input:
6642d2669b6SNicolas Pitre *
6652d2669b6SNicolas Pitre *	lr = return address
6662d2669b6SNicolas Pitre *
6672d2669b6SNicolas Pitre * Output:
6682d2669b6SNicolas Pitre *
6692d2669b6SNicolas Pitre *	r0 = TLS value
6702d2669b6SNicolas Pitre *
6712d2669b6SNicolas Pitre * Clobbered:
6722d2669b6SNicolas Pitre *
6732d2669b6SNicolas Pitre *	the Z flag might be lost
6742d2669b6SNicolas Pitre *
6752d2669b6SNicolas Pitre * Definition and user space usage example:
6762d2669b6SNicolas Pitre *
6772d2669b6SNicolas Pitre *	typedef int (__kernel_get_tls_t)(void);
6782d2669b6SNicolas Pitre *	#define __kernel_get_tls (*(__kernel_get_tls_t *)0xffff0fe0)
6792d2669b6SNicolas Pitre *
6802d2669b6SNicolas Pitre * Get the TLS value as previously set via the __ARM_NR_set_tls syscall.
6812d2669b6SNicolas Pitre *
6822d2669b6SNicolas Pitre * This could be used as follows:
6832d2669b6SNicolas Pitre *
6842d2669b6SNicolas Pitre * #define __kernel_get_tls() \
6852d2669b6SNicolas Pitre *	({ register unsigned int __val asm("r0"); \
6862d2669b6SNicolas Pitre *         asm( "mov r0, #0xffff0fff; mov lr, pc; sub pc, r0, #31" \
6872d2669b6SNicolas Pitre *	        : "=r" (__val) : : "lr","cc" ); \
6882d2669b6SNicolas Pitre *	   __val; })
6892d2669b6SNicolas Pitre */
6902d2669b6SNicolas Pitre
6912d2669b6SNicolas Pitre__kuser_get_tls:				@ 0xffff0fe0
6922d2669b6SNicolas Pitre
693*4b0e07a5SNicolas Pitre#if !defined(CONFIG_HAS_TLS_REG) && !defined(CONFIG_TLS_REG_EMUL)
6942d2669b6SNicolas Pitre
6952d2669b6SNicolas Pitre	ldr	r0, [pc, #(16 - 8)]		@ TLS stored at 0xffff0ff0
6962d2669b6SNicolas Pitre	mov	pc, lr
6972d2669b6SNicolas Pitre
6982d2669b6SNicolas Pitre#else
6992d2669b6SNicolas Pitre
7002d2669b6SNicolas Pitre	mrc	p15, 0, r0, c13, c0, 3		@ read TLS register
7012d2669b6SNicolas Pitre	mov	pc, lr
7022d2669b6SNicolas Pitre
7032d2669b6SNicolas Pitre#endif
7042d2669b6SNicolas Pitre
7052d2669b6SNicolas Pitre	.rep	5
7062d2669b6SNicolas Pitre	.word	0			@ pad up to __kuser_helper_version
7072d2669b6SNicolas Pitre	.endr
7082d2669b6SNicolas Pitre
7092d2669b6SNicolas Pitre/*
7102d2669b6SNicolas Pitre * Reference declaration:
7112d2669b6SNicolas Pitre *
7122d2669b6SNicolas Pitre *	extern unsigned int __kernel_helper_version;
7132d2669b6SNicolas Pitre *
7142d2669b6SNicolas Pitre * Definition and user space usage example:
7152d2669b6SNicolas Pitre *
7162d2669b6SNicolas Pitre *	#define __kernel_helper_version (*(unsigned int *)0xffff0ffc)
7172d2669b6SNicolas Pitre *
7182d2669b6SNicolas Pitre * User space may read this to determine the curent number of helpers
7192d2669b6SNicolas Pitre * available.
7202d2669b6SNicolas Pitre */
7212d2669b6SNicolas Pitre
7222d2669b6SNicolas Pitre__kuser_helper_version:				@ 0xffff0ffc
7232d2669b6SNicolas Pitre	.word	((__kuser_helper_end - __kuser_helper_start) >> 5)
7242d2669b6SNicolas Pitre
7252d2669b6SNicolas Pitre	.globl	__kuser_helper_end
7262d2669b6SNicolas Pitre__kuser_helper_end:
7272d2669b6SNicolas Pitre
7282d2669b6SNicolas Pitre
7291da177e4SLinus Torvalds/*
7301da177e4SLinus Torvalds * Vector stubs.
7311da177e4SLinus Torvalds *
7327933523dSRussell King * This code is copied to 0xffff0200 so we can use branches in the
7337933523dSRussell King * vectors, rather than ldr's.  Note that this code must not
7347933523dSRussell King * exceed 0x300 bytes.
7351da177e4SLinus Torvalds *
7361da177e4SLinus Torvalds * Common stub entry macro:
7371da177e4SLinus Torvalds *   Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
7381da177e4SLinus Torvalds */
7391da177e4SLinus Torvalds	.macro	vector_stub, name, sym, correction=0
7401da177e4SLinus Torvalds	.align	5
7411da177e4SLinus Torvalds
7421da177e4SLinus Torvaldsvector_\name:
7431da177e4SLinus Torvalds	ldr	r13, .LCs\sym
7441da177e4SLinus Torvalds	.if \correction
7451da177e4SLinus Torvalds	sub	lr, lr, #\correction
7461da177e4SLinus Torvalds	.endif
7471da177e4SLinus Torvalds	str	lr, [r13]			@ save lr_IRQ
7481da177e4SLinus Torvalds	mrs	lr, spsr
7491da177e4SLinus Torvalds	str	lr, [r13, #4]			@ save spsr_IRQ
7501da177e4SLinus Torvalds	@
7511da177e4SLinus Torvalds	@ now branch to the relevant MODE handling routine
7521da177e4SLinus Torvalds	@
7531da177e4SLinus Torvalds	mrs	r13, cpsr
7541da177e4SLinus Torvalds	bic	r13, r13, #MODE_MASK
755acaca3c9SRussell King	orr	r13, r13, #SVC_MODE
7561da177e4SLinus Torvalds	msr	spsr_cxsf, r13			@ switch to SVC_32 mode
7571da177e4SLinus Torvalds
7581da177e4SLinus Torvalds	and	lr, lr, #15
7591da177e4SLinus Torvalds	ldr	lr, [pc, lr, lsl #2]
7601da177e4SLinus Torvalds	movs	pc, lr				@ Changes mode and branches
7611da177e4SLinus Torvalds	.endm
7621da177e4SLinus Torvalds
7637933523dSRussell King	.globl	__stubs_start
7641da177e4SLinus Torvalds__stubs_start:
7651da177e4SLinus Torvalds/*
7661da177e4SLinus Torvalds * Interrupt dispatcher
7671da177e4SLinus Torvalds */
7681da177e4SLinus Torvalds	vector_stub	irq, irq, 4
7691da177e4SLinus Torvalds
7701da177e4SLinus Torvalds	.long	__irq_usr			@  0  (USR_26 / USR_32)
7711da177e4SLinus Torvalds	.long	__irq_invalid			@  1  (FIQ_26 / FIQ_32)
7721da177e4SLinus Torvalds	.long	__irq_invalid			@  2  (IRQ_26 / IRQ_32)
7731da177e4SLinus Torvalds	.long	__irq_svc			@  3  (SVC_26 / SVC_32)
7741da177e4SLinus Torvalds	.long	__irq_invalid			@  4
7751da177e4SLinus Torvalds	.long	__irq_invalid			@  5
7761da177e4SLinus Torvalds	.long	__irq_invalid			@  6
7771da177e4SLinus Torvalds	.long	__irq_invalid			@  7
7781da177e4SLinus Torvalds	.long	__irq_invalid			@  8
7791da177e4SLinus Torvalds	.long	__irq_invalid			@  9
7801da177e4SLinus Torvalds	.long	__irq_invalid			@  a
7811da177e4SLinus Torvalds	.long	__irq_invalid			@  b
7821da177e4SLinus Torvalds	.long	__irq_invalid			@  c
7831da177e4SLinus Torvalds	.long	__irq_invalid			@  d
7841da177e4SLinus Torvalds	.long	__irq_invalid			@  e
7851da177e4SLinus Torvalds	.long	__irq_invalid			@  f
7861da177e4SLinus Torvalds
7871da177e4SLinus Torvalds/*
7881da177e4SLinus Torvalds * Data abort dispatcher
7891da177e4SLinus Torvalds * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
7901da177e4SLinus Torvalds */
7911da177e4SLinus Torvalds	vector_stub	dabt, abt, 8
7921da177e4SLinus Torvalds
7931da177e4SLinus Torvalds	.long	__dabt_usr			@  0  (USR_26 / USR_32)
7941da177e4SLinus Torvalds	.long	__dabt_invalid			@  1  (FIQ_26 / FIQ_32)
7951da177e4SLinus Torvalds	.long	__dabt_invalid			@  2  (IRQ_26 / IRQ_32)
7961da177e4SLinus Torvalds	.long	__dabt_svc			@  3  (SVC_26 / SVC_32)
7971da177e4SLinus Torvalds	.long	__dabt_invalid			@  4
7981da177e4SLinus Torvalds	.long	__dabt_invalid			@  5
7991da177e4SLinus Torvalds	.long	__dabt_invalid			@  6
8001da177e4SLinus Torvalds	.long	__dabt_invalid			@  7
8011da177e4SLinus Torvalds	.long	__dabt_invalid			@  8
8021da177e4SLinus Torvalds	.long	__dabt_invalid			@  9
8031da177e4SLinus Torvalds	.long	__dabt_invalid			@  a
8041da177e4SLinus Torvalds	.long	__dabt_invalid			@  b
8051da177e4SLinus Torvalds	.long	__dabt_invalid			@  c
8061da177e4SLinus Torvalds	.long	__dabt_invalid			@  d
8071da177e4SLinus Torvalds	.long	__dabt_invalid			@  e
8081da177e4SLinus Torvalds	.long	__dabt_invalid			@  f
8091da177e4SLinus Torvalds
8101da177e4SLinus Torvalds/*
8111da177e4SLinus Torvalds * Prefetch abort dispatcher
8121da177e4SLinus Torvalds * Enter in ABT mode, spsr = USR CPSR, lr = USR PC
8131da177e4SLinus Torvalds */
8141da177e4SLinus Torvalds	vector_stub	pabt, abt, 4
8151da177e4SLinus Torvalds
8161da177e4SLinus Torvalds	.long	__pabt_usr			@  0 (USR_26 / USR_32)
8171da177e4SLinus Torvalds	.long	__pabt_invalid			@  1 (FIQ_26 / FIQ_32)
8181da177e4SLinus Torvalds	.long	__pabt_invalid			@  2 (IRQ_26 / IRQ_32)
8191da177e4SLinus Torvalds	.long	__pabt_svc			@  3 (SVC_26 / SVC_32)
8201da177e4SLinus Torvalds	.long	__pabt_invalid			@  4
8211da177e4SLinus Torvalds	.long	__pabt_invalid			@  5
8221da177e4SLinus Torvalds	.long	__pabt_invalid			@  6
8231da177e4SLinus Torvalds	.long	__pabt_invalid			@  7
8241da177e4SLinus Torvalds	.long	__pabt_invalid			@  8
8251da177e4SLinus Torvalds	.long	__pabt_invalid			@  9
8261da177e4SLinus Torvalds	.long	__pabt_invalid			@  a
8271da177e4SLinus Torvalds	.long	__pabt_invalid			@  b
8281da177e4SLinus Torvalds	.long	__pabt_invalid			@  c
8291da177e4SLinus Torvalds	.long	__pabt_invalid			@  d
8301da177e4SLinus Torvalds	.long	__pabt_invalid			@  e
8311da177e4SLinus Torvalds	.long	__pabt_invalid			@  f
8321da177e4SLinus Torvalds
8331da177e4SLinus Torvalds/*
8341da177e4SLinus Torvalds * Undef instr entry dispatcher
8351da177e4SLinus Torvalds * Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
8361da177e4SLinus Torvalds */
8371da177e4SLinus Torvalds	vector_stub	und, und
8381da177e4SLinus Torvalds
8391da177e4SLinus Torvalds	.long	__und_usr			@  0 (USR_26 / USR_32)
8401da177e4SLinus Torvalds	.long	__und_invalid			@  1 (FIQ_26 / FIQ_32)
8411da177e4SLinus Torvalds	.long	__und_invalid			@  2 (IRQ_26 / IRQ_32)
8421da177e4SLinus Torvalds	.long	__und_svc			@  3 (SVC_26 / SVC_32)
8431da177e4SLinus Torvalds	.long	__und_invalid			@  4
8441da177e4SLinus Torvalds	.long	__und_invalid			@  5
8451da177e4SLinus Torvalds	.long	__und_invalid			@  6
8461da177e4SLinus Torvalds	.long	__und_invalid			@  7
8471da177e4SLinus Torvalds	.long	__und_invalid			@  8
8481da177e4SLinus Torvalds	.long	__und_invalid			@  9
8491da177e4SLinus Torvalds	.long	__und_invalid			@  a
8501da177e4SLinus Torvalds	.long	__und_invalid			@  b
8511da177e4SLinus Torvalds	.long	__und_invalid			@  c
8521da177e4SLinus Torvalds	.long	__und_invalid			@  d
8531da177e4SLinus Torvalds	.long	__und_invalid			@  e
8541da177e4SLinus Torvalds	.long	__und_invalid			@  f
8551da177e4SLinus Torvalds
8561da177e4SLinus Torvalds	.align	5
8571da177e4SLinus Torvalds
8581da177e4SLinus Torvalds/*=============================================================================
8591da177e4SLinus Torvalds * Undefined FIQs
8601da177e4SLinus Torvalds *-----------------------------------------------------------------------------
8611da177e4SLinus Torvalds * Enter in FIQ mode, spsr = ANY CPSR, lr = ANY PC
8621da177e4SLinus Torvalds * MUST PRESERVE SVC SPSR, but need to switch to SVC mode to show our msg.
8631da177e4SLinus Torvalds * Basically to switch modes, we *HAVE* to clobber one register...  brain
8641da177e4SLinus Torvalds * damage alert!  I don't think that we can execute any code in here in any
8651da177e4SLinus Torvalds * other mode than FIQ...  Ok you can switch to another mode, but you can't
8661da177e4SLinus Torvalds * get out of that mode without clobbering one register.
8671da177e4SLinus Torvalds */
8681da177e4SLinus Torvaldsvector_fiq:
8691da177e4SLinus Torvalds	disable_fiq
8701da177e4SLinus Torvalds	subs	pc, lr, #4
8711da177e4SLinus Torvalds
8721da177e4SLinus Torvalds/*=============================================================================
8731da177e4SLinus Torvalds * Address exception handler
8741da177e4SLinus Torvalds *-----------------------------------------------------------------------------
8751da177e4SLinus Torvalds * These aren't too critical.
8761da177e4SLinus Torvalds * (they're not supposed to happen, and won't happen in 32-bit data mode).
8771da177e4SLinus Torvalds */
8781da177e4SLinus Torvalds
8791da177e4SLinus Torvaldsvector_addrexcptn:
8801da177e4SLinus Torvalds	b	vector_addrexcptn
8811da177e4SLinus Torvalds
8821da177e4SLinus Torvalds/*
8831da177e4SLinus Torvalds * We group all the following data together to optimise
8841da177e4SLinus Torvalds * for CPUs with separate I & D caches.
8851da177e4SLinus Torvalds */
8861da177e4SLinus Torvalds	.align	5
8871da177e4SLinus Torvalds
8881da177e4SLinus Torvalds.LCvswi:
8891da177e4SLinus Torvalds	.word	vector_swi
8901da177e4SLinus Torvalds
8911da177e4SLinus Torvalds.LCsirq:
8921da177e4SLinus Torvalds	.word	__temp_irq
8931da177e4SLinus Torvalds.LCsund:
8941da177e4SLinus Torvalds	.word	__temp_und
8951da177e4SLinus Torvalds.LCsabt:
8961da177e4SLinus Torvalds	.word	__temp_abt
8971da177e4SLinus Torvalds
8987933523dSRussell King	.globl	__stubs_end
8991da177e4SLinus Torvalds__stubs_end:
9001da177e4SLinus Torvalds
9017933523dSRussell King	.equ	stubs_offset, __vectors_start + 0x200 - __stubs_start
9021da177e4SLinus Torvalds
9037933523dSRussell King	.globl	__vectors_start
9047933523dSRussell King__vectors_start:
9051da177e4SLinus Torvalds	swi	SYS_ERROR0
9067933523dSRussell King	b	vector_und + stubs_offset
9077933523dSRussell King	ldr	pc, .LCvswi + stubs_offset
9087933523dSRussell King	b	vector_pabt + stubs_offset
9097933523dSRussell King	b	vector_dabt + stubs_offset
9107933523dSRussell King	b	vector_addrexcptn + stubs_offset
9117933523dSRussell King	b	vector_irq + stubs_offset
9127933523dSRussell King	b	vector_fiq + stubs_offset
9131da177e4SLinus Torvalds
9147933523dSRussell King	.globl	__vectors_end
9157933523dSRussell King__vectors_end:
9161da177e4SLinus Torvalds
9171da177e4SLinus Torvalds	.data
9181da177e4SLinus Torvalds
9191da177e4SLinus Torvalds/*
9201da177e4SLinus Torvalds * Do not reorder these, and do not insert extra data between...
9211da177e4SLinus Torvalds */
9221da177e4SLinus Torvalds
9231da177e4SLinus Torvalds__temp_irq:
9241da177e4SLinus Torvalds	.word	0				@ saved lr_irq
9251da177e4SLinus Torvalds	.word	0				@ saved spsr_irq
9261da177e4SLinus Torvalds	.word	-1				@ old_r0
9271da177e4SLinus Torvalds__temp_und:
9281da177e4SLinus Torvalds	.word	0				@ Saved lr_und
9291da177e4SLinus Torvalds	.word	0				@ Saved spsr_und
9301da177e4SLinus Torvalds	.word	-1				@ old_r0
9311da177e4SLinus Torvalds__temp_abt:
9321da177e4SLinus Torvalds	.word	0				@ Saved lr_abt
9331da177e4SLinus Torvalds	.word	0				@ Saved spsr_abt
9341da177e4SLinus Torvalds	.word	-1				@ old_r0
9351da177e4SLinus Torvalds
9361da177e4SLinus Torvalds	.globl	cr_alignment
9371da177e4SLinus Torvalds	.globl	cr_no_alignment
9381da177e4SLinus Torvaldscr_alignment:
9391da177e4SLinus Torvalds	.space	4
9401da177e4SLinus Torvaldscr_no_alignment:
9411da177e4SLinus Torvalds	.space	4
942