arch/arm/kernel/entry-common.S - android_kernel_htc_msm8960 - Gitiles

 /*
  *  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 <asm/unwind.h>

 #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:
  UNWIND(.fnstart	)
  UNWIND(.cantunwind	)
 	disable_irq				@ disable interrupts
 	ldr	r1, [tsk, #TI_FLAGS]
 	tst	r1, #_TIF_WORK_MASK
 	bne	fast_work_pending
 #if defined(CONFIG_IRQSOFF_TRACER)
 	asm_trace_hardirqs_on
 #endif

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

 	restore_user_regs fast = 1, offset = S_OFF
  UNWIND(.fnend		)

 /*
  * 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|_TIF_NOTIFY_RESUME
 	beq	no_work_pending
 	mov	r0, sp				@ 'regs'
 	mov	r2, why				@ 'syscall'
 	tst	r1, #_TIF_SIGPENDING		@ delivering a signal?
 	movne	why, #0				@ prevent further restarts
 	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
 ENTRY(ret_to_user_from_irq)
 	ldr	r1, [tsk, #TI_FLAGS]
 	tst	r1, #_TIF_WORK_MASK
 	bne	work_pending
 no_work_pending:
 #if defined(CONFIG_IRQSOFF_TRACER)
 	asm_trace_hardirqs_on
 #endif
 	/* perform architecture specific actions before user return */
 	arch_ret_to_user r1, lr

 	restore_user_regs fast = 0, offset = 0
 ENDPROC(ret_to_user_from_irq)
 ENDPROC(ret_to_user)

 /*
  * 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
 ENDPROC(ret_from_fork)

 	.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_FUNCTION_TRACER
 /*
  * When compiling with -pg, gcc inserts a call to the mcount routine at the
  * start of every function.  In mcount, apart from the function's address (in
  * lr), we need to get hold of the function's caller's address.
  *
  * Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
  *
  *	bl	mcount
  *
  * These versions have the limitation that in order for the mcount routine to
  * be able to determine the function's caller's address, an APCS-style frame
  * pointer (which is set up with something like the code below) is required.
  *
  *	mov     ip, sp
  *	push    {fp, ip, lr, pc}
  *	sub     fp, ip, #4
  *
  * With EABI, these frame pointers are not available unless -mapcs-frame is
  * specified, and if building as Thumb-2, not even then.
  *
  * Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
  * with call sites like:
  *
  *	push	{lr}
  *	bl	__gnu_mcount_nc
  *
  * With these compilers, frame pointers are not necessary.
  *
  * mcount can be thought of as a function called in the middle of a subroutine
  * call.  As such, it needs to be transparent for both the caller and the
  * callee: the original lr needs to be restored when leaving mcount, and no
  * registers should be clobbered.  (In the __gnu_mcount_nc implementation, we
  * clobber the ip register.  This is OK because the ARM calling convention
  * allows it to be clobbered in subroutines and doesn't use it to hold
  * parameters.)
  *
  * When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
  * for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
  * arch/arm/kernel/ftrace.c).
  */

 #ifndef CONFIG_OLD_MCOUNT
 #if (__GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
 #error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
 #endif
 #endif

 .macro __mcount suffix
 	mcount_enter
 	ldr	r0, =ftrace_trace_function
 	ldr	r2, [r0]
 	adr	r0, .Lftrace_stub
 	cmp	r0, r2
 	bne	1f

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	ldr     r1, =ftrace_graph_return
 	ldr     r2, [r1]
 	cmp     r0, r2
 	bne     ftrace_graph_caller\suffix

 	ldr     r1, =ftrace_graph_entry
 	ldr     r2, [r1]
 	ldr     r0, =ftrace_graph_entry_stub
 	cmp     r0, r2
 	bne     ftrace_graph_caller\suffix
 #endif

 	mcount_exit

 1: 	mcount_get_lr	r1			@ lr of instrumented func
 	mov	r0, lr				@ instrumented function
 	sub	r0, r0, #MCOUNT_INSN_SIZE
 	adr	lr, BSYM(2f)
 	mov	pc, r2
 2:	mcount_exit
 .endm

 .macro __ftrace_caller suffix
 	mcount_enter

 	mcount_get_lr	r1			@ lr of instrumented func
 	mov	r0, lr				@ instrumented function
 	sub	r0, r0, #MCOUNT_INSN_SIZE

 	.globl ftrace_call\suffix
 ftrace_call\suffix:
 	bl	ftrace_stub

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	.globl ftrace_graph_call\suffix
 ftrace_graph_call\suffix:
 	mov	r0, r0
 #endif

 	mcount_exit
 .endm

 .macro __ftrace_graph_caller
 	sub	r0, fp, #4		@ &lr of instrumented routine (&parent)
 #ifdef CONFIG_DYNAMIC_FTRACE
 	@ called from __ftrace_caller, saved in mcount_enter
 	ldr	r1, [sp, #16]		@ instrumented routine (func)
 #else
 	@ called from __mcount, untouched in lr
 	mov	r1, lr			@ instrumented routine (func)
 #endif
 	sub	r1, r1, #MCOUNT_INSN_SIZE
 	mov	r2, fp			@ frame pointer
 	bl	prepare_ftrace_return
 	mcount_exit
 .endm

 #ifdef CONFIG_OLD_MCOUNT
 /*
  * mcount
  */

 .macro mcount_enter
 	stmdb	sp!, {r0-r3, lr}
 .endm

 .macro mcount_get_lr reg
 	ldr	\reg, [fp, #-4]
 .endm

 .macro mcount_exit
 	ldr	lr, [fp, #-4]
 	ldmia	sp!, {r0-r3, pc}
 .endm

 ENTRY(mcount)
 #ifdef CONFIG_DYNAMIC_FTRACE
 	stmdb	sp!, {lr}
 	ldr	lr, [fp, #-4]
 	ldmia	sp!, {pc}
 #else
 	__mcount _old
 #endif
 ENDPROC(mcount)

 #ifdef CONFIG_DYNAMIC_FTRACE
 ENTRY(ftrace_caller_old)
 	__ftrace_caller _old
 ENDPROC(ftrace_caller_old)
 #endif

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(ftrace_graph_caller_old)
 	__ftrace_graph_caller
 ENDPROC(ftrace_graph_caller_old)
 #endif

 .purgem mcount_enter
 .purgem mcount_get_lr
 .purgem mcount_exit
 #endif

 /*
  * __gnu_mcount_nc
  */

 .macro mcount_enter
 	stmdb	sp!, {r0-r3, lr}
 .endm

 .macro mcount_get_lr reg
 	ldr	\reg, [sp, #20]
 .endm

 .macro mcount_exit
 	ldmia	sp!, {r0-r3, ip, lr}
 	mov	pc, ip
 .endm

 ENTRY(__gnu_mcount_nc)
 #ifdef CONFIG_DYNAMIC_FTRACE
 	mov	ip, lr
 	ldmia	sp!, {lr}
 	mov	pc, ip
 #else
 	__mcount
 #endif
 ENDPROC(__gnu_mcount_nc)

 #ifdef CONFIG_DYNAMIC_FTRACE
 ENTRY(ftrace_caller)
 	__ftrace_caller
 ENDPROC(ftrace_caller)
 #endif

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 ENTRY(ftrace_graph_caller)
 	__ftrace_graph_caller
 ENDPROC(ftrace_graph_caller)
 #endif

 .purgem mcount_enter
 .purgem mcount_get_lr
 .purgem mcount_exit

 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
 	.globl return_to_handler
 return_to_handler:
 	stmdb	sp!, {r0-r3}
 	mov	r0, fp			@ frame pointer
 	bl	ftrace_return_to_handler
 	mov	lr, r0			@ r0 has real ret addr
 	ldmia	sp!, {r0-r3}
 	mov	pc, lr
 #endif

 ENTRY(ftrace_stub)
 .Lftrace_stub:
 	mov	pc, lr
 ENDPROC(ftrace_stub)

 #endif /* CONFIG_FUNCTION_TRACER */

 /*=============================================================================
  * 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
  ARM(	add	r8, sp, #S_PC		)
  ARM(	stmdb	r8, {sp, lr}^		)	@ Calling sp, lr
  THUMB(	mov	r8, sp			)
  THUMB(	store_user_sp_lr r8, r10, S_SP	)	@ 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
 #ifdef CONFIG_CPU_ENDIAN_BE8
 	rev	r10, r10			@ little endian instruction
 #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

 #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

 	ldr	r10, [tsk, #TI_FLAGS]		@ check for syscall tracing
 	stmdb	sp!, {r4, r5}			@ push fifth and sixth args

 #ifdef CONFIG_SECCOMP
 	tst	r10, #_TIF_SECCOMP
 	beq	1f
 	mov	r0, scno
 	bl	__secure_computing
 	add	r0, sp, #S_R0 + S_OFF		@ pointer to regs
 	ldmia	r0, {r0 - r3}			@ have to reload r0 - r3
 1:
 #endif

 	tst	r10, #_TIF_SYSCALL_TRACE		@ are we tracing syscalls?
 	bne	__sys_trace

 	cmp	scno, #NR_syscalls		@ check upper syscall limit
 	adr	lr, BSYM(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
 ENDPROC(vector_swi)

 	/*
 	 * 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, BSYM(__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
 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
 ENDPROC(sys_syscall)

 sys_fork_wrapper:
 		add	r0, sp, #S_OFF
 		b	sys_fork
 ENDPROC(sys_fork_wrapper)

 sys_vfork_wrapper:
 		add	r0, sp, #S_OFF
 		b	sys_vfork
 ENDPROC(sys_vfork_wrapper)

 sys_execve_wrapper:
 		add	r3, sp, #S_OFF
 		b	sys_execve
 ENDPROC(sys_execve_wrapper)

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

 sys_sigreturn_wrapper:
 		add	r0, sp, #S_OFF
 		mov	why, #0		@ prevent syscall restart handling
 		b	sys_sigreturn
 ENDPROC(sys_sigreturn_wrapper)

 sys_rt_sigreturn_wrapper:
 		add	r0, sp, #S_OFF
 		mov	why, #0		@ prevent syscall restart handling
 		b	sys_rt_sigreturn
 ENDPROC(sys_rt_sigreturn_wrapper)

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

 sys_statfs64_wrapper:
 		teq	r1, #88
 		moveq	r1, #84
 		b	sys_statfs64
 ENDPROC(sys_statfs64_wrapper)

 sys_fstatfs64_wrapper:
 		teq	r1, #88
 		moveq	r1, #84
 		b	sys_fstatfs64
 ENDPROC(sys_fstatfs64_wrapper)

 /*
  * 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	sys_mmap_pgoff
 		mov	r0, #-EINVAL
 		mov	pc, lr
 #else
 		str	r5, [sp, #4]
 		b	sys_mmap_pgoff
 #endif
 ENDPROC(sys_mmap2)

 #ifdef CONFIG_OABI_COMPAT

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

 sys_oabi_pread64:
 		stmia	sp, {r3, r4}
 		b	sys_pread64
 ENDPROC(sys_oabi_pread64)

 sys_oabi_pwrite64:
 		stmia	sp, {r3, r4}
 		b	sys_pwrite64
 ENDPROC(sys_oabi_pwrite64)

 sys_oabi_truncate64:
 		mov	r3, r2
 		mov	r2, r1
 		b	sys_truncate64
 ENDPROC(sys_oabi_truncate64)

 sys_oabi_ftruncate64:
 		mov	r3, r2
 		mov	r2, r1
 		b	sys_ftruncate64
 ENDPROC(sys_oabi_ftruncate64)

 sys_oabi_readahead:
 		str	r3, [sp]
 		mov	r3, r2
 		mov	r2, r1
 		b	sys_readahead
 ENDPROC(sys_oabi_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
	/*
	* 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 <asm/unwind.h>

	#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:
	UNWIND(.fnstart )
	UNWIND(.cantunwind )
	disable_irq @ disable interrupts
	ldr r1, [tsk, #TI_FLAGS]
	tst r1, #_TIF_WORK_MASK
	bne fast_work_pending
	#if defined(CONFIG_IRQSOFF_TRACER)
	asm_trace_hardirqs_on
	#endif

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

	restore_user_regs fast = 1, offset = S_OFF
	UNWIND(.fnend )

	/*
	* 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\|_TIF_NOTIFY_RESUME
	beq no_work_pending
	mov r0, sp @ 'regs'
	mov r2, why @ 'syscall'
	tst r1, #_TIF_SIGPENDING @ delivering a signal?
	movne why, #0 @ prevent further restarts
	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
	ENTRY(ret_to_user_from_irq)
	ldr r1, [tsk, #TI_FLAGS]
	tst r1, #_TIF_WORK_MASK
	bne work_pending
	no_work_pending:
	#if defined(CONFIG_IRQSOFF_TRACER)
	asm_trace_hardirqs_on
	#endif
	/* perform architecture specific actions before user return */
	arch_ret_to_user r1, lr

	restore_user_regs fast = 0, offset = 0
	ENDPROC(ret_to_user_from_irq)
	ENDPROC(ret_to_user)

	/*
	* 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
	ENDPROC(ret_from_fork)

	.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_FUNCTION_TRACER
	/*
	* When compiling with -pg, gcc inserts a call to the mcount routine at the
	* start of every function. In mcount, apart from the function's address (in
	* lr), we need to get hold of the function's caller's address.
	*
	* Older GCCs (pre-4.4) inserted a call to a routine called mcount like this:
	*
	* bl mcount
	*
	* These versions have the limitation that in order for the mcount routine to
	* be able to determine the function's caller's address, an APCS-style frame
	* pointer (which is set up with something like the code below) is required.
	*
	* mov ip, sp
	* push {fp, ip, lr, pc}
	* sub fp, ip, #4
	*
	* With EABI, these frame pointers are not available unless -mapcs-frame is
	* specified, and if building as Thumb-2, not even then.
	*
	* Newer GCCs (4.4+) solve this problem by introducing a new version of mcount,
	* with call sites like:
	*
	* push {lr}
	* bl __gnu_mcount_nc
	*
	* With these compilers, frame pointers are not necessary.
	*
	* mcount can be thought of as a function called in the middle of a subroutine
	* call. As such, it needs to be transparent for both the caller and the
	* callee: the original lr needs to be restored when leaving mcount, and no
	* registers should be clobbered. (In the __gnu_mcount_nc implementation, we
	* clobber the ip register. This is OK because the ARM calling convention
	* allows it to be clobbered in subroutines and doesn't use it to hold
	* parameters.)
	*
	* When using dynamic ftrace, we patch out the mcount call by a "mov r0, r0"
	* for the mcount case, and a "pop {lr}" for the __gnu_mcount_nc case (see
	* arch/arm/kernel/ftrace.c).
	*/

	#ifndef CONFIG_OLD_MCOUNT
	#if (__GNUC__ < 4 \|\| (__GNUC__ == 4 && __GNUC_MINOR__ < 4))
	#error Ftrace requires CONFIG_FRAME_POINTER=y with GCC older than 4.4.0.
	#endif
	#endif

	.macro __mcount suffix
	mcount_enter
	ldr r0, =ftrace_trace_function
	ldr r2, [r0]
	adr r0, .Lftrace_stub
	cmp r0, r2
	bne 1f

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	ldr r1, =ftrace_graph_return
	ldr r2, [r1]
	cmp r0, r2
	bne ftrace_graph_caller\suffix

	ldr r1, =ftrace_graph_entry
	ldr r2, [r1]
	ldr r0, =ftrace_graph_entry_stub
	cmp r0, r2
	bne ftrace_graph_caller\suffix
	#endif

	mcount_exit

	1: mcount_get_lr r1 @ lr of instrumented func
	mov r0, lr @ instrumented function
	sub r0, r0, #MCOUNT_INSN_SIZE
	adr lr, BSYM(2f)
	mov pc, r2
	2: mcount_exit
	.endm

	.macro __ftrace_caller suffix
	mcount_enter

	mcount_get_lr r1 @ lr of instrumented func
	mov r0, lr @ instrumented function
	sub r0, r0, #MCOUNT_INSN_SIZE

	.globl ftrace_call\suffix
	ftrace_call\suffix:
	bl ftrace_stub

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	.globl ftrace_graph_call\suffix
	ftrace_graph_call\suffix:
	mov r0, r0
	#endif

	mcount_exit
	.endm

	.macro __ftrace_graph_caller
	sub r0, fp, #4 @ &lr of instrumented routine (&parent)
	#ifdef CONFIG_DYNAMIC_FTRACE
	@ called from __ftrace_caller, saved in mcount_enter
	ldr r1, [sp, #16] @ instrumented routine (func)
	#else
	@ called from __mcount, untouched in lr
	mov r1, lr @ instrumented routine (func)
	#endif
	sub r1, r1, #MCOUNT_INSN_SIZE
	mov r2, fp @ frame pointer
	bl prepare_ftrace_return
	mcount_exit
	.endm

	#ifdef CONFIG_OLD_MCOUNT
	/*
	* mcount
	*/

	.macro mcount_enter
	stmdb sp!, {r0-r3, lr}
	.endm

	.macro mcount_get_lr reg
	ldr \reg, [fp, #-4]
	.endm

	.macro mcount_exit
	ldr lr, [fp, #-4]
	ldmia sp!, {r0-r3, pc}
	.endm

	ENTRY(mcount)
	#ifdef CONFIG_DYNAMIC_FTRACE
	stmdb sp!, {lr}
	ldr lr, [fp, #-4]
	ldmia sp!, {pc}
	#else
	__mcount _old
	#endif
	ENDPROC(mcount)

	#ifdef CONFIG_DYNAMIC_FTRACE
	ENTRY(ftrace_caller_old)
	__ftrace_caller _old
	ENDPROC(ftrace_caller_old)
	#endif

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	ENTRY(ftrace_graph_caller_old)
	__ftrace_graph_caller
	ENDPROC(ftrace_graph_caller_old)
	#endif

	.purgem mcount_enter
	.purgem mcount_get_lr
	.purgem mcount_exit
	#endif

	/*
	* __gnu_mcount_nc
	*/

	.macro mcount_enter
	stmdb sp!, {r0-r3, lr}
	.endm

	.macro mcount_get_lr reg
	ldr \reg, [sp, #20]
	.endm

	.macro mcount_exit
	ldmia sp!, {r0-r3, ip, lr}
	mov pc, ip
	.endm

	ENTRY(__gnu_mcount_nc)
	#ifdef CONFIG_DYNAMIC_FTRACE
	mov ip, lr
	ldmia sp!, {lr}
	mov pc, ip
	#else
	__mcount
	#endif
	ENDPROC(__gnu_mcount_nc)

	#ifdef CONFIG_DYNAMIC_FTRACE
	ENTRY(ftrace_caller)
	__ftrace_caller
	ENDPROC(ftrace_caller)
	#endif

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	ENTRY(ftrace_graph_caller)
	__ftrace_graph_caller
	ENDPROC(ftrace_graph_caller)
	#endif

	.purgem mcount_enter
	.purgem mcount_get_lr
	.purgem mcount_exit

	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	.globl return_to_handler
	return_to_handler:
	stmdb sp!, {r0-r3}
	mov r0, fp @ frame pointer
	bl ftrace_return_to_handler
	mov lr, r0 @ r0 has real ret addr
	ldmia sp!, {r0-r3}
	mov pc, lr
	#endif

	ENTRY(ftrace_stub)
	.Lftrace_stub:
	mov pc, lr
	ENDPROC(ftrace_stub)

	#endif /* CONFIG_FUNCTION_TRACER */

	/*=============================================================================
	* 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
	ARM( add r8, sp, #S_PC )
	ARM( stmdb r8, {sp, lr}^ ) @ Calling sp, lr
	THUMB( mov r8, sp )
	THUMB( store_user_sp_lr r8, r10, S_SP ) @ 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
	#ifdef CONFIG_CPU_ENDIAN_BE8
	rev r10, r10 @ little endian instruction
	#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

	#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

	ldr r10, [tsk, #TI_FLAGS] @ check for syscall tracing
	stmdb sp!, {r4, r5} @ push fifth and sixth args

	#ifdef CONFIG_SECCOMP
	tst r10, #_TIF_SECCOMP
	beq 1f
	mov r0, scno
	bl __secure_computing
	add r0, sp, #S_R0 + S_OFF @ pointer to regs
	ldmia r0, {r0 - r3} @ have to reload r0 - r3
	1:
	#endif

	tst r10, #_TIF_SYSCALL_TRACE @ are we tracing syscalls?
	bne __sys_trace

	cmp scno, #NR_syscalls @ check upper syscall limit
	adr lr, BSYM(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
	ENDPROC(vector_swi)

	/*
	* 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, BSYM(__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
	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
	ENDPROC(sys_syscall)

	sys_fork_wrapper:
	add r0, sp, #S_OFF
	b sys_fork
	ENDPROC(sys_fork_wrapper)

	sys_vfork_wrapper:
	add r0, sp, #S_OFF
	b sys_vfork
	ENDPROC(sys_vfork_wrapper)

	sys_execve_wrapper:
	add r3, sp, #S_OFF
	b sys_execve
	ENDPROC(sys_execve_wrapper)

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

	sys_sigreturn_wrapper:
	add r0, sp, #S_OFF
	mov why, #0 @ prevent syscall restart handling
	b sys_sigreturn
	ENDPROC(sys_sigreturn_wrapper)

	sys_rt_sigreturn_wrapper:
	add r0, sp, #S_OFF
	mov why, #0 @ prevent syscall restart handling
	b sys_rt_sigreturn
	ENDPROC(sys_rt_sigreturn_wrapper)

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

	sys_statfs64_wrapper:
	teq r1, #88
	moveq r1, #84
	b sys_statfs64
	ENDPROC(sys_statfs64_wrapper)

	sys_fstatfs64_wrapper:
	teq r1, #88
	moveq r1, #84
	b sys_fstatfs64
	ENDPROC(sys_fstatfs64_wrapper)

	/*
	* 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 sys_mmap_pgoff
	mov r0, #-EINVAL
	mov pc, lr
	#else
	str r5, [sp, #4]
	b sys_mmap_pgoff
	#endif
	ENDPROC(sys_mmap2)

	#ifdef CONFIG_OABI_COMPAT

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

	sys_oabi_pread64:
	stmia sp, {r3, r4}
	b sys_pread64
	ENDPROC(sys_oabi_pread64)

	sys_oabi_pwrite64:
	stmia sp, {r3, r4}
	b sys_pwrite64
	ENDPROC(sys_oabi_pwrite64)

	sys_oabi_truncate64:
	mov r3, r2
	mov r2, r1
	b sys_truncate64
	ENDPROC(sys_oabi_truncate64)

	sys_oabi_ftruncate64:
	mov r3, r2
	mov r2, r1
	b sys_ftruncate64
	ENDPROC(sys_oabi_ftruncate64)

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