/* *  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/arch/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 r0work_pending:	tst	r1, #_TIF_NEED_RESCHED	bne	work_resched	tst	r1, #_TIF_NOTIFY_RESUME | _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_pendingno_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 r1 - 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 /*============================================================================= * 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	5ENTRY(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_OFF2:	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, #objectENTRY(sys_call_table)#include "calls.S"#undef ABI#undef OBSOLETE /*============================================================================ * Special system call wrappers */@ r0 = syscall number@ r8 = syscall table		.type	sys_syscall, #functionsys_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 #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, #objectENTRY(sys_oabi_call_table)#include "calls.S"#undef ABI#undef OBSOLETE #endif