[deliverable/linux.git] / arch / mips / kernel / entry.S

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/regdef.h>
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/isadep.h>
#include <asm/thread_info.h>
#include <asm/war.h>

#ifndef CONFIG_PREEMPT
#define resume_kernel	restore_all
#else
#define __ret_from_irq	ret_from_exception
#endif

	.text
	.align	5
#ifndef CONFIG_PREEMPT
FEXPORT(ret_from_exception)
	local_irq_disable			# preempt stop
	b	__ret_from_irq
#endif
FEXPORT(ret_from_irq)
	LONG_S	s0, TI_REGS($28)
FEXPORT(__ret_from_irq)
/*
 * We can be coming here from a syscall done in the kernel space,
 * e.g. a failed kernel_execve().
 */
resume_userspace_check:
	LONG_L	t0, PT_STATUS(sp)		# returning to kernel mode?
	andi	t0, t0, KU_USER
	beqz	t0, resume_kernel

resume_userspace:
	local_irq_disable		# make sure we dont miss an
					# interrupt setting need_resched
					# between sampling and return
	LONG_L	a2, TI_FLAGS($28)	# current->work
	andi	t0, a2, _TIF_WORK_MASK	# (ignoring syscall_trace)
	bnez	t0, work_pending
	j	restore_all

#ifdef CONFIG_PREEMPT
resume_kernel:
	local_irq_disable
	lw	t0, TI_PRE_COUNT($28)
	bnez	t0, restore_all
need_resched:
	LONG_L	t0, TI_FLAGS($28)
	andi	t1, t0, _TIF_NEED_RESCHED
	beqz	t1, restore_all
	LONG_L	t0, PT_STATUS(sp)		# Interrupts off?
	andi	t0, 1
	beqz	t0, restore_all
	jal	preempt_schedule_irq
	b	need_resched
#endif

FEXPORT(ret_from_kernel_thread)
	jal	schedule_tail		# a0 = struct task_struct *prev
	move	a0, s1
	jal	s0
	j	syscall_exit

FEXPORT(ret_from_fork)
	jal	schedule_tail		# a0 = struct task_struct *prev

FEXPORT(syscall_exit)
	local_irq_disable		# make sure need_resched and
					# signals dont change between
					# sampling and return
	LONG_L	a2, TI_FLAGS($28)	# current->work
	li	t0, _TIF_ALLWORK_MASK
	and	t0, a2, t0
	bnez	t0, syscall_exit_work

restore_all:				# restore full frame
	.set	noat
	RESTORE_TEMP
	RESTORE_AT
	RESTORE_STATIC
restore_partial:		# restore partial frame
#ifdef CONFIG_TRACE_IRQFLAGS
	SAVE_STATIC
	SAVE_AT
	SAVE_TEMP
	LONG_L	v0, PT_STATUS(sp)
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
	and	v0, ST0_IEP
#else
	and	v0, ST0_IE
#endif
	beqz	v0, 1f
	jal	trace_hardirqs_on
	b	2f
1:	jal	trace_hardirqs_off
2:
	RESTORE_TEMP
	RESTORE_AT
	RESTORE_STATIC
#endif
	RESTORE_SOME
	RESTORE_SP_AND_RET
	.set	at

work_pending:
	andi	t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
	beqz	t0, work_notifysig
work_resched:
	jal	schedule

	local_irq_disable		# make sure need_resched and
					# signals dont change between
					# sampling and return
	LONG_L	a2, TI_FLAGS($28)
	andi	t0, a2, _TIF_WORK_MASK	# is there any work to be done
					# other than syscall tracing?
	beqz	t0, restore_all
	andi	t0, a2, _TIF_NEED_RESCHED
	bnez	t0, work_resched

work_notifysig:				# deal with pending signals and
					# notify-resume requests
	move	a0, sp
	li	a1, 0
	jal	do_notify_resume	# a2 already loaded
	j	resume_userspace_check

FEXPORT(syscall_exit_partial)
	local_irq_disable		# make sure need_resched doesn't
					# change between and return
	LONG_L	a2, TI_FLAGS($28)	# current->work
	li	t0, _TIF_ALLWORK_MASK
	and	t0, a2
	beqz	t0, restore_partial
	SAVE_STATIC
syscall_exit_work:
	LONG_L	t0, PT_STATUS(sp)		# returning to kernel mode?
	andi	t0, t0, KU_USER
	beqz	t0, resume_kernel
	li	t0, _TIF_WORK_SYSCALL_EXIT
	and	t0, a2			# a2 is preloaded with TI_FLAGS
	beqz	t0, work_pending	# trace bit set?
	local_irq_enable		# could let syscall_trace_leave()
					# call schedule() instead
	move	a0, sp
	jal	syscall_trace_leave
	b	resume_userspace

#if defined(CONFIG_CPU_MIPSR2) || defined(CONFIG_MIPS_MT)

/*
 * MIPS32R2 Instruction Hazard Barrier - must be called
 *
 * For C code use the inline version named instruction_hazard().
 */
LEAF(mips_ihb)
	.set	mips32r2
	jr.hb	ra
	nop
	END(mips_ihb)

#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1994 - 2000, 2001, 2003 Ralf Baechle
	7	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	8	* Copyright (C) 2001 MIPS Technologies, Inc.
	9	*/
1da177e4 LT	10
	11	#include <asm/asm.h>
	12	#include <asm/asmmacro.h>
	13	#include <asm/regdef.h>
	14	#include <asm/mipsregs.h>
	15	#include <asm/stackframe.h>
	16	#include <asm/isadep.h>
	17	#include <asm/thread_info.h>
	18	#include <asm/war.h>
	19
f431baa5	20	#ifndef CONFIG_PREEMPT
1da177e4	21	#define resume_kernel restore_all
7da8a581 FBH	22	#else
7da8a581 FBH	23	#define __ret_from_irq ret_from_exception
1da177e4 LT	24	#endif
	25
	26	.text
	27	.align 5
7da8a581	28	#ifndef CONFIG_PREEMPT
1da177e4	29	FEXPORT(ret_from_exception)
7da8a581 FBH	30	local_irq_disable # preempt stop
7da8a581 FBH	31	b __ret_from_irq
f431baa5	32	#endif
7da8a581 FBH	33	FEXPORT(ret_from_irq)
	34	LONG_S s0, TI_REGS($28)
	35	FEXPORT(__ret_from_irq)
c90e6fbb DA	36	/*
	37	* We can be coming here from a syscall done in the kernel space,
	38	* e.g. a failed kernel_execve().
	39	*/
	40	resume_userspace_check:
1da177e4 LT	41	LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
	42	andi t0, t0, KU_USER
	43	beqz t0, resume_kernel
	44
c2648527 TS	45	resume_userspace:
c2648527 TS	46	local_irq_disable # make sure we dont miss an
1da177e4 LT	47	# interrupt setting need_resched
	48	# between sampling and return
	49	LONG_L a2, TI_FLAGS($28) # current->work
c2648527 TS	50	andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
c2648527 TS	51	bnez t0, work_pending
1da177e4 LT	52	j restore_all
	53
	54	#ifdef CONFIG_PREEMPT
c2648527	55	resume_kernel:
a18815ab	56	local_irq_disable
1da177e4 LT	57	lw t0, TI_PRE_COUNT($28)
	58	bnez t0, restore_all
	59	need_resched:
	60	LONG_L t0, TI_FLAGS($28)
	61	andi t1, t0, _TIF_NEED_RESCHED
	62	beqz t1, restore_all
	63	LONG_L t0, PT_STATUS(sp) # Interrupts off?
	64	andi t0, 1
	65	beqz t0, restore_all
a18815ab	66	jal preempt_schedule_irq
cdaed73a	67	b need_resched
1da177e4 LT	68	#endif
1da177e4 LT	69
8f54bcac AV	70	FEXPORT(ret_from_kernel_thread)
	71	jal schedule_tail # a0 = struct task_struct *prev
	72	move a0, s1
	73	jal s0
9b0e5d42	74	j syscall_exit
8f54bcac	75
1da177e4	76	FEXPORT(ret_from_fork)
36c8b586	77	jal schedule_tail # a0 = struct task_struct *prev
1da177e4 LT	78
	79	FEXPORT(syscall_exit)
	80	local_irq_disable # make sure need_resched and
	81	# signals dont change between
	82	# sampling and return
	83	LONG_L a2, TI_FLAGS($28) # current->work
	84	li t0, _TIF_ALLWORK_MASK
	85	and t0, a2, t0
	86	bnez t0, syscall_exit_work
	87
02f884ed	88	restore_all: # restore full frame
1da177e4 LT	89	.set noat
	90	RESTORE_TEMP
	91	RESTORE_AT
	92	RESTORE_STATIC
02f884ed	93	restore_partial: # restore partial frame
192ef366 RB	94	#ifdef CONFIG_TRACE_IRQFLAGS
	95	SAVE_STATIC
	96	SAVE_AT
	97	SAVE_TEMP
	98	LONG_L v0, PT_STATUS(sp)
cbde5ebc CD	99	#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)
	100	and v0, ST0_IEP
	101	#else
	102	and v0, ST0_IE
	103	#endif
192ef366 RB	104	beqz v0, 1f
	105	jal trace_hardirqs_on
	106	b 2f
	107	1: jal trace_hardirqs_off
	108	2:
	109	RESTORE_TEMP
	110	RESTORE_AT
	111	RESTORE_STATIC
	112	#endif
1da177e4 LT	113	RESTORE_SOME
	114	RESTORE_SP_AND_RET
	115	.set at
	116
c2648527 TS	117	work_pending:
c2648527 TS	118	andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
1da177e4 LT	119	beqz t0, work_notifysig
	120	work_resched:
	121	jal schedule
	122
c2648527	123	local_irq_disable # make sure need_resched and
1da177e4 LT	124	# signals dont change between
	125	# sampling and return
	126	LONG_L a2, TI_FLAGS($28)
	127	andi t0, a2, _TIF_WORK_MASK # is there any work to be done
	128	# other than syscall tracing?
	129	beqz t0, restore_all
	130	andi t0, a2, _TIF_NEED_RESCHED
	131	bnez t0, work_resched
	132
	133	work_notifysig: # deal with pending signals and
	134	# notify-resume requests
	135	move a0, sp
	136	li a1, 0
	137	jal do_notify_resume # a2 already loaded
c90e6fbb	138	j resume_userspace_check
1da177e4	139
02f884ed AV	140	FEXPORT(syscall_exit_partial)
	141	local_irq_disable # make sure need_resched doesn't
	142	# change between and return
	143	LONG_L a2, TI_FLAGS($28) # current->work
	144	li t0, _TIF_ALLWORK_MASK
	145	and t0, a2
	146	beqz t0, restore_partial
1da177e4	147	SAVE_STATIC
c2648527	148	syscall_exit_work:
f76f3308 AV	149	LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
	150	andi t0, t0, KU_USER
	151	beqz t0, resume_kernel
c19c20ac	152	li t0, _TIF_WORK_SYSCALL_EXIT
c2648527 TS	153	and t0, a2 # a2 is preloaded with TI_FLAGS
c2648527 TS	154	beqz t0, work_pending # trace bit set?
8b659a39	155	local_irq_enable # could let syscall_trace_leave()
1da177e4 LT	156	# call schedule() instead
1da177e4 LT	157	move a0, sp
8b659a39	158	jal syscall_trace_leave
1da177e4	159	b resume_userspace
bce1a286 RB	160
	161	#if defined(CONFIG_CPU_MIPSR2) \|\| defined(CONFIG_MIPS_MT)
	162
	163	/*
	164	* MIPS32R2 Instruction Hazard Barrier - must be called
	165	*
	166	* For C code use the inline version named instruction_hazard().
	167	*/
	168	LEAF(mips_ihb)
	169	.set mips32r2
	170	jr.hb ra
	171	nop
	172	END(mips_ihb)
	173
	174	#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */