[mirror_ubuntu-focal-kernel.git] / arch / arm / kernel / entry-common.S

/*
 *  linux/arch/arm/kernel/entry-common.S
 *
 *  Copyright (C) 2000 Russell King
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <asm/unistd.h>
#include <asm/ftrace.h>
#include <mach/entry-macro.S>

#include "entry-header.S"


	.align	5
/*
 * This is the fast syscall return path.  We do as little as
 * possible here, and this includes saving r0 back into the SVC
 * stack.
 */
ret_fast_syscall:
	disable_irq				@ disable interrupts
	ldr	r1, [tsk, #TI_FLAGS]
	tst	r1, #_TIF_WORK_MASK
	bne	fast_work_pending

	/* perform architecture specific actions before user return */
	arch_ret_to_user r1, lr

	@ fast_restore_user_regs
	ldr	r1, [sp, #S_OFF + S_PSR]	@ get calling cpsr
	ldr	lr, [sp, #S_OFF + S_PC]!	@ get pc
	msr	spsr_cxsf, r1			@ save in spsr_svc
	ldmdb	sp, {r1 - lr}^			@ get calling r1 - lr
	mov	r0, r0
	add	sp, sp, #S_FRAME_SIZE - S_PC
	movs	pc, lr				@ return & move spsr_svc into cpsr

/*
 * Ok, we need to do extra processing, enter the slow path.
 */
fast_work_pending:
	str	r0, [sp, #S_R0+S_OFF]!		@ returned r0
work_pending:
	tst	r1, #_TIF_NEED_RESCHED
	bne	work_resched
	tst	r1, #_TIF_SIGPENDING
	beq	no_work_pending
	mov	r0, sp				@ 'regs'
	mov	r2, why				@ 'syscall'
	bl	do_notify_resume
	b	ret_slow_syscall		@ Check work again

work_resched:
	bl	schedule
/*
 * "slow" syscall return path.  "why" tells us if this was a real syscall.
 */
ENTRY(ret_to_user)
ret_slow_syscall:
	disable_irq				@ disable interrupts
	ldr	r1, [tsk, #TI_FLAGS]
	tst	r1, #_TIF_WORK_MASK
	bne	work_pending
no_work_pending:
	/* perform architecture specific actions before user return */
	arch_ret_to_user r1, lr

	@ slow_restore_user_regs
	ldr	r1, [sp, #S_PSR]		@ get calling cpsr
	ldr	lr, [sp, #S_PC]!		@ get pc
	msr	spsr_cxsf, r1			@ save in spsr_svc
	ldmdb	sp, {r0 - lr}^			@ get calling r0 - lr
	mov	r0, r0
	add	sp, sp, #S_FRAME_SIZE - S_PC
	movs	pc, lr				@ return & move spsr_svc into cpsr

/*
 * This is how we return from a fork.
 */
ENTRY(ret_from_fork)
	bl	schedule_tail
	get_thread_info tsk
	ldr	r1, [tsk, #TI_FLAGS]		@ check for syscall tracing
	mov	why, #1
	tst	r1, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
	beq	ret_slow_syscall
	mov	r1, sp
	mov	r0, #1				@ trace exit [IP = 1]
	bl	syscall_trace
	b	ret_slow_syscall
	

	.equ NR_syscalls,0
#define CALL(x) .equ NR_syscalls,NR_syscalls+1
#include "calls.S"
#undef CALL
#define CALL(x) .long x

#ifdef CONFIG_FTRACE
#ifdef CONFIG_DYNAMIC_FTRACE
ENTRY(mcount)
	stmdb sp!, {r0-r3, lr}
	mov r0, lr
	sub r0, r0, #MCOUNT_INSN_SIZE

	.globl mcount_call
mcount_call:
	bl ftrace_stub
	ldmia sp!, {r0-r3, pc}

ENTRY(ftrace_caller)
	stmdb sp!, {r0-r3, lr}
	ldr r1, [fp, #-4]
	mov r0, lr
	sub r0, r0, #MCOUNT_INSN_SIZE

	.globl ftrace_call
ftrace_call:
	bl ftrace_stub
	ldmia sp!, {r0-r3, pc}

#else

ENTRY(mcount)
	stmdb sp!, {r0-r3, lr}
	ldr r0, =ftrace_trace_function
	ldr r2, [r0]
	adr r0, ftrace_stub
	cmp r0, r2
	bne trace
	ldmia sp!, {r0-r3, pc}

trace:
	ldr r1, [fp, #-4]
	mov r0, lr
	sub r0, r0, #MCOUNT_INSN_SIZE
	mov lr, pc
	mov pc, r2
	ldmia sp!, {r0-r3, pc}

#endif /* CONFIG_DYNAMIC_FTRACE */

	.globl ftrace_stub
ftrace_stub:
	mov pc, lr

#endif /* CONFIG_FTRACE */

/*=============================================================================
 * SWI handler
 *-----------------------------------------------------------------------------
 */

	/* If we're optimising for StrongARM the resulting code won't 
	   run on an ARM7 and we can save a couple of instructions.  
								--pb */
#ifdef CONFIG_CPU_ARM710
#define A710(code...) code
.Larm710bug:
	ldmia	sp, {r0 - lr}^			@ Get calling r0 - lr
	mov	r0, r0
	add	sp, sp, #S_FRAME_SIZE
	subs	pc, lr, #4
#else
#define A710(code...)
#endif

	.align	5
ENTRY(vector_swi)
	sub	sp, sp, #S_FRAME_SIZE
	stmia	sp, {r0 - r12}			@ Calling r0 - r12
	add	r8, sp, #S_PC
	stmdb	r8, {sp, lr}^			@ Calling sp, lr
	mrs	r8, spsr			@ called from non-FIQ mode, so ok.
	str	lr, [sp, #S_PC]			@ Save calling PC
	str	r8, [sp, #S_PSR]		@ Save CPSR
	str	r0, [sp, #S_OLD_R0]		@ Save OLD_R0
	zero_fp

	/*
	 * Get the system call number.
	 */

#if defined(CONFIG_OABI_COMPAT)

	/*
	 * If we have CONFIG_OABI_COMPAT then we need to look at the swi
	 * value to determine if it is an EABI or an old ABI call.
	 */
#ifdef CONFIG_ARM_THUMB
	tst	r8, #PSR_T_BIT
	movne	r10, #0				@ no thumb OABI emulation
	ldreq	r10, [lr, #-4]			@ get SWI instruction
#else
	ldr	r10, [lr, #-4]			@ get SWI instruction
  A710(	and	ip, r10, #0x0f000000		@ check for SWI		)
  A710(	teq	ip, #0x0f000000						)
  A710(	bne	.Larm710bug						)
#endif

#elif defined(CONFIG_AEABI)

	/*
	 * Pure EABI user space always put syscall number into scno (r7).
	 */
  A710(	ldr	ip, [lr, #-4]			@ get SWI instruction	)
  A710(	and	ip, ip, #0x0f000000		@ check for SWI		)
  A710(	teq	ip, #0x0f000000						)
  A710(	bne	.Larm710bug						)

#elif defined(CONFIG_ARM_THUMB)

	/* Legacy ABI only, possibly thumb mode. */
	tst	r8, #PSR_T_BIT			@ this is SPSR from save_user_regs
	addne	scno, r7, #__NR_SYSCALL_BASE	@ put OS number in
	ldreq	scno, [lr, #-4]

#else

	/* Legacy ABI only. */
	ldr	scno, [lr, #-4]			@ get SWI instruction
  A710(	and	ip, scno, #0x0f000000		@ check for SWI		)
  A710(	teq	ip, #0x0f000000						)
  A710(	bne	.Larm710bug						)

#endif

#ifdef CONFIG_ALIGNMENT_TRAP
	ldr	ip, __cr_alignment
	ldr	ip, [ip]
	mcr	p15, 0, ip, c1, c0		@ update control register
#endif
	enable_irq

	get_thread_info tsk
	adr	tbl, sys_call_table		@ load syscall table pointer
	ldr	ip, [tsk, #TI_FLAGS]		@ check for syscall tracing

#if defined(CONFIG_OABI_COMPAT)
	/*
	 * If the swi argument is zero, this is an EABI call and we do nothing.
	 *
	 * If this is an old ABI call, get the syscall number into scno and
	 * get the old ABI syscall table address.
	 */
	bics	r10, r10, #0xff000000
	eorne	scno, r10, #__NR_OABI_SYSCALL_BASE
	ldrne	tbl, =sys_oabi_call_table
#elif !defined(CONFIG_AEABI)
	bic	scno, scno, #0xff000000		@ mask off SWI op-code
	eor	scno, scno, #__NR_SYSCALL_BASE	@ check OS number
#endif

	stmdb	sp!, {r4, r5}			@ push fifth and sixth args
	tst	ip, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
	bne	__sys_trace

	cmp	scno, #NR_syscalls		@ check upper syscall limit
	adr	lr, ret_fast_syscall		@ return address
	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine

	add	r1, sp, #S_OFF
2:	mov	why, #0				@ no longer a real syscall
	cmp	scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
	eor	r0, scno, #__NR_SYSCALL_BASE	@ put OS number back
	bcs	arm_syscall	
	b	sys_ni_syscall			@ not private func

	/*
	 * This is the really slow path.  We're going to be doing
	 * context switches, and waiting for our parent to respond.
	 */
__sys_trace:
	mov	r2, scno
	add	r1, sp, #S_OFF
	mov	r0, #0				@ trace entry [IP = 0]
	bl	syscall_trace

	adr	lr, __sys_trace_return		@ return address
	mov	scno, r0			@ syscall number (possibly new)
	add	r1, sp, #S_R0 + S_OFF		@ pointer to regs
	cmp	scno, #NR_syscalls		@ check upper syscall limit
	ldmccia	r1, {r0 - r3}			@ have to reload r0 - r3
	ldrcc	pc, [tbl, scno, lsl #2]		@ call sys_* routine
	b	2b

__sys_trace_return:
	str	r0, [sp, #S_R0 + S_OFF]!	@ save returned r0
	mov	r2, scno
	mov	r1, sp
	mov	r0, #1				@ trace exit [IP = 1]
	bl	syscall_trace
	b	ret_slow_syscall

	.align	5
#ifdef CONFIG_ALIGNMENT_TRAP
	.type	__cr_alignment, #object
__cr_alignment:
	.word	cr_alignment
#endif
	.ltorg

/*
 * This is the syscall table declaration for native ABI syscalls.
 * With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
 */
#define ABI(native, compat) native
#ifdef CONFIG_AEABI
#define OBSOLETE(syscall) sys_ni_syscall
#else
#define OBSOLETE(syscall) syscall
#endif

	.type	sys_call_table, #object
ENTRY(sys_call_table)
#include "calls.S"
#undef ABI
#undef OBSOLETE

/*============================================================================
 * Special system call wrappers
 */
@ r0 = syscall number
@ r8 = syscall table
		.type	sys_syscall, #function
sys_syscall:
		bic	scno, r0, #__NR_OABI_SYSCALL_BASE
		cmp	scno, #__NR_syscall - __NR_SYSCALL_BASE
		cmpne	scno, #NR_syscalls	@ check range
		stmloia	sp, {r5, r6}		@ shuffle args
		movlo	r0, r1
		movlo	r1, r2
		movlo	r2, r3
		movlo	r3, r4
		ldrlo	pc, [tbl, scno, lsl #2]
		b	sys_ni_syscall

sys_fork_wrapper:
		add	r0, sp, #S_OFF
		b	sys_fork

sys_vfork_wrapper:
		add	r0, sp, #S_OFF
		b	sys_vfork

sys_execve_wrapper:
		add	r3, sp, #S_OFF
		b	sys_execve

sys_clone_wrapper:
		add	ip, sp, #S_OFF
		str	ip, [sp, #4]
		b	sys_clone

sys_sigsuspend_wrapper:
		add	r3, sp, #S_OFF
		b	sys_sigsuspend

sys_rt_sigsuspend_wrapper:
		add	r2, sp, #S_OFF
		b	sys_rt_sigsuspend

sys_sigreturn_wrapper:
		add	r0, sp, #S_OFF
		b	sys_sigreturn

sys_rt_sigreturn_wrapper:
		add	r0, sp, #S_OFF
		b	sys_rt_sigreturn

sys_sigaltstack_wrapper:
		ldr	r2, [sp, #S_OFF + S_SP]
		b	do_sigaltstack

sys_statfs64_wrapper:
		teq	r1, #88
		moveq	r1, #84
		b	sys_statfs64

sys_fstatfs64_wrapper:
		teq	r1, #88
		moveq	r1, #84
		b	sys_fstatfs64

/*
 * Note: off_4k (r5) is always units of 4K.  If we can't do the requested
 * offset, we return EINVAL.
 */
sys_mmap2:
#if PAGE_SHIFT > 12
		tst	r5, #PGOFF_MASK
		moveq	r5, r5, lsr #PAGE_SHIFT - 12
		streq	r5, [sp, #4]
		beq	do_mmap2
		mov	r0, #-EINVAL
		mov	pc, lr
#else
		str	r5, [sp, #4]
		b	do_mmap2
#endif

ENTRY(pabort_ifar)
		mrc	p15, 0, r0, cr6, cr0, 2
ENTRY(pabort_noifar)
		mov	pc, lr

#ifdef CONFIG_OABI_COMPAT

/*
 * These are syscalls with argument register differences
 */

sys_oabi_pread64:
		stmia	sp, {r3, r4}
		b	sys_pread64

sys_oabi_pwrite64:
		stmia	sp, {r3, r4}
		b	sys_pwrite64

sys_oabi_truncate64:
		mov	r3, r2
		mov	r2, r1
		b	sys_truncate64

sys_oabi_ftruncate64:
		mov	r3, r2
		mov	r2, r1
		b	sys_ftruncate64

sys_oabi_readahead:
		str	r3, [sp]
		mov	r3, r2
		mov	r2, r1
		b	sys_readahead

/*
 * Let's declare a second syscall table for old ABI binaries
 * using the compatibility syscall entries.
 */
#define ABI(native, compat) compat
#define OBSOLETE(syscall) syscall

	.type	sys_oabi_call_table, #object
ENTRY(sys_oabi_call_table)
#include "calls.S"
#undef ABI
#undef OBSOLETE

#endif
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/arm/kernel/entry-common.S
	3	*
	4	* Copyright (C) 2000 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
1da177e4	10
1da177e4	11	#include <asm/unistd.h>
395a59d0	12	#include <asm/ftrace.h>
a09e64fb	13	#include <mach/entry-macro.S>
1da177e4 LT	14
	15	#include "entry-header.S"
	16
1da177e4 LT	17
	18	.align 5
	19	/*
	20	* This is the fast syscall return path. We do as little as
	21	* possible here, and this includes saving r0 back into the SVC
	22	* stack.
	23	*/
	24	ret_fast_syscall:
1ec42c0c	25	disable_irq @ disable interrupts
1da177e4 LT	26	ldr r1, [tsk, #TI_FLAGS]
	27	tst r1, #_TIF_WORK_MASK
	28	bne fast_work_pending
f4dc9a4c	29
f80dff9d DW	30	/* perform architecture specific actions before user return */
	31	arch_ret_to_user r1, lr
	32
f4dc9a4c RK	33	@ fast_restore_user_regs
	34	ldr r1, [sp, #S_OFF + S_PSR] @ get calling cpsr
	35	ldr lr, [sp, #S_OFF + S_PC]! @ get pc
	36	msr spsr_cxsf, r1 @ save in spsr_svc
	37	ldmdb sp, {r1 - lr}^ @ get calling r1 - lr
	38	mov r0, r0
	39	add sp, sp, #S_FRAME_SIZE - S_PC
	40	movs pc, lr @ return & move spsr_svc into cpsr
1da177e4 LT	41
	42	/*
	43	* Ok, we need to do extra processing, enter the slow path.
	44	*/
	45	fast_work_pending:
	46	str r0, [sp, #S_R0+S_OFF]! @ returned r0
	47	work_pending:
	48	tst r1, #_TIF_NEED_RESCHED
	49	bne work_resched
a583f1b5	50	tst r1, #_TIF_SIGPENDING
1da177e4 LT	51	beq no_work_pending
	52	mov r0, sp @ 'regs'
	53	mov r2, why @ 'syscall'
	54	bl do_notify_resume
a6c61e9d	55	b ret_slow_syscall @ Check work again
1da177e4 LT	56
	57	work_resched:
	58	bl schedule
	59	/*
	60	* "slow" syscall return path. "why" tells us if this was a real syscall.
	61	*/
	62	ENTRY(ret_to_user)
	63	ret_slow_syscall:
1ec42c0c	64	disable_irq @ disable interrupts
1da177e4 LT	65	ldr r1, [tsk, #TI_FLAGS]
	66	tst r1, #_TIF_WORK_MASK
	67	bne work_pending
	68	no_work_pending:
f80dff9d DW	69	/* perform architecture specific actions before user return */
	70	arch_ret_to_user r1, lr
	71
f4dc9a4c RK	72	@ slow_restore_user_regs
	73	ldr r1, [sp, #S_PSR] @ get calling cpsr
	74	ldr lr, [sp, #S_PC]! @ get pc
	75	msr spsr_cxsf, r1 @ save in spsr_svc
7b544c99	76	ldmdb sp, {r0 - lr}^ @ get calling r0 - lr
f4dc9a4c RK	77	mov r0, r0
	78	add sp, sp, #S_FRAME_SIZE - S_PC
	79	movs pc, lr @ return & move spsr_svc into cpsr
1da177e4 LT	80
	81	/*
	82	* This is how we return from a fork.
	83	*/
	84	ENTRY(ret_from_fork)
	85	bl schedule_tail
	86	get_thread_info tsk
	87	ldr r1, [tsk, #TI_FLAGS] @ check for syscall tracing
	88	mov why, #1
	89	tst r1, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
	90	beq ret_slow_syscall
	91	mov r1, sp
	92	mov r0, #1 @ trace exit [IP = 1]
	93	bl syscall_trace
	94	b ret_slow_syscall
	95
	96
fa1b4f91 AV	97	.equ NR_syscalls,0
fa1b4f91 AV	98	#define CALL(x) .equ NR_syscalls,NR_syscalls+1
1da177e4	99	#include "calls.S"
fa1b4f91 AV	100	#undef CALL
fa1b4f91 AV	101	#define CALL(x) .long x
1da177e4	102
014c257c AS	103	#ifdef CONFIG_FTRACE
	104	#ifdef CONFIG_DYNAMIC_FTRACE
	105	ENTRY(mcount)
	106	stmdb sp!, {r0-r3, lr}
	107	mov r0, lr
395a59d0	108	sub r0, r0, #MCOUNT_INSN_SIZE
014c257c AS	109
	110	.globl mcount_call
	111	mcount_call:
	112	bl ftrace_stub
	113	ldmia sp!, {r0-r3, pc}
	114
	115	ENTRY(ftrace_caller)
	116	stmdb sp!, {r0-r3, lr}
	117	ldr r1, [fp, #-4]
	118	mov r0, lr
395a59d0	119	sub r0, r0, #MCOUNT_INSN_SIZE
014c257c AS	120
	121	.globl ftrace_call
	122	ftrace_call:
	123	bl ftrace_stub
	124	ldmia sp!, {r0-r3, pc}
	125
	126	#else
	127
	128	ENTRY(mcount)
	129	stmdb sp!, {r0-r3, lr}
	130	ldr r0, =ftrace_trace_function
	131	ldr r2, [r0]
	132	adr r0, ftrace_stub
	133	cmp r0, r2
	134	bne trace
	135	ldmia sp!, {r0-r3, pc}
	136
	137	trace:
	138	ldr r1, [fp, #-4]
	139	mov r0, lr
395a59d0	140	sub r0, r0, #MCOUNT_INSN_SIZE
014c257c AS	141	mov lr, pc
	142	mov pc, r2
	143	ldmia sp!, {r0-r3, pc}
	144
	145	#endif /* CONFIG_DYNAMIC_FTRACE */
	146
	147	.globl ftrace_stub
	148	ftrace_stub:
	149	mov pc, lr
	150
	151	#endif /* CONFIG_FTRACE */
	152
1da177e4 LT	153	/*=============================================================================
	154	* SWI handler
	155	*-----------------------------------------------------------------------------
	156	*/
	157
	158	/* If we're optimising for StrongARM the resulting code won't
	159	run on an ARM7 and we can save a couple of instructions.
	160	--pb */
	161	#ifdef CONFIG_CPU_ARM710
3f2829a3 NP	162	#define A710(code...) code
3f2829a3 NP	163	.Larm710bug:
1da177e4 LT	164	ldmia sp, {r0 - lr}^ @ Get calling r0 - lr
1da177e4 LT	165	mov r0, r0
1da177e4	166	add sp, sp, #S_FRAME_SIZE
60ac133a	167	subs pc, lr, #4
1da177e4	168	#else
3f2829a3	169	#define A710(code...)
1da177e4 LT	170	#endif
	171
	172	.align 5
	173	ENTRY(vector_swi)
f4dc9a4c RK	174	sub sp, sp, #S_FRAME_SIZE
	175	stmia sp, {r0 - r12} @ Calling r0 - r12
	176	add r8, sp, #S_PC
	177	stmdb r8, {sp, lr}^ @ Calling sp, lr
	178	mrs r8, spsr @ called from non-FIQ mode, so ok.
	179	str lr, [sp, #S_PC] @ Save calling PC
	180	str r8, [sp, #S_PSR] @ Save CPSR
	181	str r0, [sp, #S_OLD_R0] @ Save OLD_R0
1da177e4	182	zero_fp
e0f9f4a6 RK	183
	184	/*
	185	* Get the system call number.
	186	*/
3f2829a3	187
dd35afc2	188	#if defined(CONFIG_OABI_COMPAT)
3f2829a3	189
dd35afc2 NP	190	/*
	191	* If we have CONFIG_OABI_COMPAT then we need to look at the swi
	192	* value to determine if it is an EABI or an old ABI call.
	193	*/
	194	#ifdef CONFIG_ARM_THUMB
	195	tst r8, #PSR_T_BIT
	196	movne r10, #0 @ no thumb OABI emulation
	197	ldreq r10, [lr, #-4] @ get SWI instruction
	198	#else
	199	ldr r10, [lr, #-4] @ get SWI instruction
	200	A710( and ip, r10, #0x0f000000 @ check for SWI )
	201	A710( teq ip, #0x0f000000 )
	202	A710( bne .Larm710bug )
	203	#endif
	204
	205	#elif defined(CONFIG_AEABI)
	206
	207	/*
	208	* Pure EABI user space always put syscall number into scno (r7).
	209	*/
3f2829a3 NP	210	A710( ldr ip, [lr, #-4] @ get SWI instruction )
	211	A710( and ip, ip, #0x0f000000 @ check for SWI )
	212	A710( teq ip, #0x0f000000 )
	213	A710( bne .Larm710bug )
dd35afc2	214
3f2829a3	215	#elif defined(CONFIG_ARM_THUMB)
dd35afc2 NP	216
dd35afc2 NP	217	/* Legacy ABI only, possibly thumb mode. */
e0f9f4a6 RK	218	tst r8, #PSR_T_BIT @ this is SPSR from save_user_regs
	219	addne scno, r7, #__NR_SYSCALL_BASE @ put OS number in
	220	ldreq scno, [lr, #-4]
dd35afc2	221
e0f9f4a6	222	#else
dd35afc2 NP	223
dd35afc2 NP	224	/* Legacy ABI only. */
e0f9f4a6	225	ldr scno, [lr, #-4] @ get SWI instruction
3f2829a3 NP	226	A710( and ip, scno, #0x0f000000 @ check for SWI )
	227	A710( teq ip, #0x0f000000 )
	228	A710( bne .Larm710bug )
dd35afc2	229
e0f9f4a6	230	#endif
1da177e4 LT	231
	232	#ifdef CONFIG_ALIGNMENT_TRAP
	233	ldr ip, __cr_alignment
	234	ldr ip, [ip]
	235	mcr p15, 0, ip, c1, c0 @ update control register
	236	#endif
1ec42c0c	237	enable_irq
1da177e4	238
1da177e4	239	get_thread_info tsk
dd35afc2	240	adr tbl, sys_call_table @ load syscall table pointer
1da177e4	241	ldr ip, [tsk, #TI_FLAGS] @ check for syscall tracing
dd35afc2 NP	242
	243	#if defined(CONFIG_OABI_COMPAT)
	244	/*
	245	* If the swi argument is zero, this is an EABI call and we do nothing.
	246	*
	247	* If this is an old ABI call, get the syscall number into scno and
	248	* get the old ABI syscall table address.
	249	*/
	250	bics r10, r10, #0xff000000
	251	eorne scno, r10, #__NR_OABI_SYSCALL_BASE
	252	ldrne tbl, =sys_oabi_call_table
	253	#elif !defined(CONFIG_AEABI)
1da177e4	254	bic scno, scno, #0xff000000 @ mask off SWI op-code
e0f9f4a6	255	eor scno, scno, #__NR_SYSCALL_BASE @ check OS number
3f2829a3	256	#endif
dd35afc2	257
3f2829a3	258	stmdb sp!, {r4, r5} @ push fifth and sixth args
1da177e4 LT	259	tst ip, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
	260	bne __sys_trace
	261
1da177e4	262	cmp scno, #NR_syscalls @ check upper syscall limit
3f2829a3	263	adr lr, ret_fast_syscall @ return address
1da177e4 LT	264	ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
	265
	266	add r1, sp, #S_OFF
	267	2: mov why, #0 @ no longer a real syscall
e0f9f4a6 RK	268	cmp scno, #(__ARM_NR_BASE - __NR_SYSCALL_BASE)
e0f9f4a6 RK	269	eor r0, scno, #__NR_SYSCALL_BASE @ put OS number back
1da177e4 LT	270	bcs arm_syscall
	271	b sys_ni_syscall @ not private func
	272
	273	/*
	274	* This is the really slow path. We're going to be doing
	275	* context switches, and waiting for our parent to respond.
	276	*/
	277	__sys_trace:
3f471126	278	mov r2, scno
1da177e4 LT	279	add r1, sp, #S_OFF
	280	mov r0, #0 @ trace entry [IP = 0]
	281	bl syscall_trace
	282
	283	adr lr, __sys_trace_return @ return address
3f471126	284	mov scno, r0 @ syscall number (possibly new)
1da177e4 LT	285	add r1, sp, #S_R0 + S_OFF @ pointer to regs
	286	cmp scno, #NR_syscalls @ check upper syscall limit
	287	ldmccia r1, {r0 - r3} @ have to reload r0 - r3
	288	ldrcc pc, [tbl, scno, lsl #2] @ call sys_* routine
	289	b 2b
	290
	291	__sys_trace_return:
	292	str r0, [sp, #S_R0 + S_OFF]! @ save returned r0
3f471126	293	mov r2, scno
1da177e4 LT	294	mov r1, sp
	295	mov r0, #1 @ trace exit [IP = 1]
	296	bl syscall_trace
	297	b ret_slow_syscall
	298
	299	.align 5
	300	#ifdef CONFIG_ALIGNMENT_TRAP
	301	.type __cr_alignment, #object
	302	__cr_alignment:
	303	.word cr_alignment
dd35afc2 NP	304	#endif
	305	.ltorg
	306
	307	/*
	308	* This is the syscall table declaration for native ABI syscalls.
	309	* With EABI a couple syscalls are obsolete and defined as sys_ni_syscall.
	310	*/
	311	#define ABI(native, compat) native
	312	#ifdef CONFIG_AEABI
	313	#define OBSOLETE(syscall) sys_ni_syscall
	314	#else
	315	#define OBSOLETE(syscall) syscall
1da177e4 LT	316	#endif
	317
	318	.type sys_call_table, #object
	319	ENTRY(sys_call_table)
	320	#include "calls.S"
dd35afc2 NP	321	#undef ABI
dd35afc2 NP	322	#undef OBSOLETE
1da177e4 LT	323
	324	/*============================================================================
	325	* Special system call wrappers
	326	*/
	327	@ r0 = syscall number
567bd980	328	@ r8 = syscall table
1da177e4 LT	329	.type sys_syscall, #function
1da177e4 LT	330	sys_syscall:
5247593c	331	bic scno, r0, #__NR_OABI_SYSCALL_BASE
1da177e4 LT	332	cmp scno, #__NR_syscall - __NR_SYSCALL_BASE
	333	cmpne scno, #NR_syscalls @ check range
	334	stmloia sp, {r5, r6} @ shuffle args
	335	movlo r0, r1
	336	movlo r1, r2
	337	movlo r2, r3
	338	movlo r3, r4
	339	ldrlo pc, [tbl, scno, lsl #2]
	340	b sys_ni_syscall
	341
	342	sys_fork_wrapper:
	343	add r0, sp, #S_OFF
	344	b sys_fork
	345
	346	sys_vfork_wrapper:
	347	add r0, sp, #S_OFF
	348	b sys_vfork
	349
	350	sys_execve_wrapper:
	351	add r3, sp, #S_OFF
	352	b sys_execve
	353
	354	sys_clone_wrapper:
	355	add ip, sp, #S_OFF
	356	str ip, [sp, #4]
	357	b sys_clone
	358
	359	sys_sigsuspend_wrapper:
	360	add r3, sp, #S_OFF
	361	b sys_sigsuspend
	362
	363	sys_rt_sigsuspend_wrapper:
	364	add r2, sp, #S_OFF
	365	b sys_rt_sigsuspend
	366
	367	sys_sigreturn_wrapper:
	368	add r0, sp, #S_OFF
	369	b sys_sigreturn
	370
	371	sys_rt_sigreturn_wrapper:
	372	add r0, sp, #S_OFF
	373	b sys_rt_sigreturn
	374
	375	sys_sigaltstack_wrapper:
	376	ldr r2, [sp, #S_OFF + S_SP]
	377	b do_sigaltstack
	378
713c4815 NP	379	sys_statfs64_wrapper:
	380	teq r1, #88
	381	moveq r1, #84
	382	b sys_statfs64
	383
	384	sys_fstatfs64_wrapper:
	385	teq r1, #88
	386	moveq r1, #84
	387	b sys_fstatfs64
	388
1da177e4 LT	389	/*
	390	* Note: off_4k (r5) is always units of 4K. If we can't do the requested
	391	* offset, we return EINVAL.
	392	*/
	393	sys_mmap2:
	394	#if PAGE_SHIFT > 12
	395	tst r5, #PGOFF_MASK
	396	moveq r5, r5, lsr #PAGE_SHIFT - 12
	397	streq r5, [sp, #4]
	398	beq do_mmap2
	399	mov r0, #-EINVAL
7999d8d7	400	mov pc, lr
1da177e4 LT	401	#else
	402	str r5, [sp, #4]
	403	b do_mmap2
	404	#endif
687ad019	405
48d7927b PB	406	ENTRY(pabort_ifar)
	407	mrc p15, 0, r0, cr6, cr0, 2
	408	ENTRY(pabort_noifar)
	409	mov pc, lr
	410
687ad019	411	#ifdef CONFIG_OABI_COMPAT
dd35afc2	412
687ad019 NP	413	/*
	414	* These are syscalls with argument register differences
	415	*/
	416
	417	sys_oabi_pread64:
	418	stmia sp, {r3, r4}
	419	b sys_pread64
	420
	421	sys_oabi_pwrite64:
	422	stmia sp, {r3, r4}
	423	b sys_pwrite64
	424
	425	sys_oabi_truncate64:
	426	mov r3, r2
	427	mov r2, r1
	428	b sys_truncate64
	429
	430	sys_oabi_ftruncate64:
	431	mov r3, r2
	432	mov r2, r1
	433	b sys_ftruncate64
	434
	435	sys_oabi_readahead:
	436	str r3, [sp]
	437	mov r3, r2
	438	mov r2, r1
	439	b sys_readahead
	440
dd35afc2 NP	441	/*
	442	* Let's declare a second syscall table for old ABI binaries
	443	* using the compatibility syscall entries.
	444	*/
	445	#define ABI(native, compat) compat
	446	#define OBSOLETE(syscall) syscall
	447
	448	.type sys_oabi_call_table, #object
	449	ENTRY(sys_oabi_call_table)
	450	#include "calls.S"
	451	#undef ABI
	452	#undef OBSOLETE
	453
687ad019 NP	454	#endif
687ad019 NP	455