[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>
#ifdef CONFIG_MIPS_MT_SMTC
#include <asm/mipsmtregs.h>
#endif

#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
#ifdef CONFIG_MIPS_MT_SMTC
#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
/* Re-arm any temporarily masked interrupts not explicitly "acked" */
	mfc0	v0, CP0_TCSTATUS
	ori	v1, v0, TCSTATUS_IXMT
	mtc0	v1, CP0_TCSTATUS
	andi	v0, TCSTATUS_IXMT
	_ehb
	mfc0	t0, CP0_TCCONTEXT
	DMT	9				# dmt t1
	jal	mips_ihb
	mfc0	t2, CP0_STATUS
	andi	t3, t0, 0xff00
	or	t2, t2, t3
	mtc0	t2, CP0_STATUS
	_ehb
	andi	t1, t1, VPECONTROL_TE
	beqz	t1, 1f
	EMT
1:
	mfc0	v1, CP0_TCSTATUS
	/* We set IXMT above, XOR should clear it here */
	xori	v1, v1, TCSTATUS_IXMT
	or	v1, v0, v1
	mtc0	v1, CP0_TCSTATUS
	_ehb
	xor	t0, t0, t3
	mtc0	t0, CP0_TCCONTEXT
#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
/* Detect and execute deferred IPI "interrupts" */
	LONG_L	s0, TI_REGS($28)
	LONG_S	sp, TI_REGS($28)
	jal	deferred_smtc_ipi
	LONG_S	s0, TI_REGS($28)
#endif /* CONFIG_MIPS_MT_SMTC */
	.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>
41c594ab RB	19	#ifdef CONFIG_MIPS_MT_SMTC
	20	#include <asm/mipsmtregs.h>
	21	#endif
1da177e4	22
f431baa5	23	#ifndef CONFIG_PREEMPT
1da177e4	24	#define resume_kernel restore_all
7da8a581 FBH	25	#else
7da8a581 FBH	26	#define __ret_from_irq ret_from_exception
1da177e4 LT	27	#endif
	28
	29	.text
	30	.align 5
7da8a581	31	#ifndef CONFIG_PREEMPT
1da177e4	32	FEXPORT(ret_from_exception)
7da8a581 FBH	33	local_irq_disable # preempt stop
7da8a581 FBH	34	b __ret_from_irq
f431baa5	35	#endif
7da8a581 FBH	36	FEXPORT(ret_from_irq)
	37	LONG_S s0, TI_REGS($28)
	38	FEXPORT(__ret_from_irq)
c90e6fbb DA	39	/*
	40	* We can be coming here from a syscall done in the kernel space,
	41	* e.g. a failed kernel_execve().
	42	*/
	43	resume_userspace_check:
1da177e4 LT	44	LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
	45	andi t0, t0, KU_USER
	46	beqz t0, resume_kernel
	47
c2648527 TS	48	resume_userspace:
c2648527 TS	49	local_irq_disable # make sure we dont miss an
1da177e4 LT	50	# interrupt setting need_resched
	51	# between sampling and return
	52	LONG_L a2, TI_FLAGS($28) # current->work
c2648527 TS	53	andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
c2648527 TS	54	bnez t0, work_pending
1da177e4 LT	55	j restore_all
	56
	57	#ifdef CONFIG_PREEMPT
c2648527	58	resume_kernel:
a18815ab	59	local_irq_disable
1da177e4 LT	60	lw t0, TI_PRE_COUNT($28)
	61	bnez t0, restore_all
	62	need_resched:
	63	LONG_L t0, TI_FLAGS($28)
	64	andi t1, t0, _TIF_NEED_RESCHED
	65	beqz t1, restore_all
	66	LONG_L t0, PT_STATUS(sp) # Interrupts off?
	67	andi t0, 1
	68	beqz t0, restore_all
a18815ab	69	jal preempt_schedule_irq
cdaed73a	70	b need_resched
1da177e4 LT	71	#endif
1da177e4 LT	72
8f54bcac AV	73	FEXPORT(ret_from_kernel_thread)
	74	jal schedule_tail # a0 = struct task_struct *prev
	75	move a0, s1
	76	jal s0
9b0e5d42	77	j syscall_exit
8f54bcac	78
1da177e4	79	FEXPORT(ret_from_fork)
36c8b586	80	jal schedule_tail # a0 = struct task_struct *prev
1da177e4 LT	81
	82	FEXPORT(syscall_exit)
	83	local_irq_disable # make sure need_resched and
	84	# signals dont change between
	85	# sampling and return
	86	LONG_L a2, TI_FLAGS($28) # current->work
	87	li t0, _TIF_ALLWORK_MASK
	88	and t0, a2, t0
	89	bnez t0, syscall_exit_work
	90
02f884ed	91	restore_all: # restore full frame
41c594ab	92	#ifdef CONFIG_MIPS_MT_SMTC
0db34215	93	#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
41c594ab RB	94	/* Re-arm any temporarily masked interrupts not explicitly "acked" */
	95	mfc0 v0, CP0_TCSTATUS
	96	ori v1, v0, TCSTATUS_IXMT
	97	mtc0 v1, CP0_TCSTATUS
	98	andi v0, TCSTATUS_IXMT
4277ff5e	99	_ehb
41c594ab RB	100	mfc0 t0, CP0_TCCONTEXT
	101	DMT 9 # dmt t1
	102	jal mips_ihb
	103	mfc0 t2, CP0_STATUS
	104	andi t3, t0, 0xff00
	105	or t2, t2, t3
	106	mtc0 t2, CP0_STATUS
4277ff5e	107	_ehb
41c594ab RB	108	andi t1, t1, VPECONTROL_TE
	109	beqz t1, 1f
	110	EMT
	111	1:
	112	mfc0 v1, CP0_TCSTATUS
477654fc	113	/* We set IXMT above, XOR should clear it here */
41c594ab RB	114	xori v1, v1, TCSTATUS_IXMT
	115	or v1, v0, v1
	116	mtc0 v1, CP0_TCSTATUS
4277ff5e	117	_ehb
41c594ab RB	118	xor t0, t0, t3
41c594ab RB	119	mtc0 t0, CP0_TCCONTEXT
0db34215	120	#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
d2bb01b0 KK	121	/* Detect and execute deferred IPI "interrupts" */
	122	LONG_L s0, TI_REGS($28)
	123	LONG_S sp, TI_REGS($28)
	124	jal deferred_smtc_ipi
	125	LONG_S s0, TI_REGS($28)
41c594ab	126	#endif /* CONFIG_MIPS_MT_SMTC */
1da177e4 LT	127	.set noat
	128	RESTORE_TEMP
	129	RESTORE_AT
	130	RESTORE_STATIC
02f884ed	131	restore_partial: # restore partial frame
192ef366 RB	132	#ifdef CONFIG_TRACE_IRQFLAGS
	133	SAVE_STATIC
	134	SAVE_AT
	135	SAVE_TEMP
	136	LONG_L v0, PT_STATUS(sp)
cbde5ebc CD	137	#if defined(CONFIG_CPU_R3000) \|\| defined(CONFIG_CPU_TX39XX)
	138	and v0, ST0_IEP
	139	#else
	140	and v0, ST0_IE
	141	#endif
192ef366 RB	142	beqz v0, 1f
	143	jal trace_hardirqs_on
	144	b 2f
	145	1: jal trace_hardirqs_off
	146	2:
	147	RESTORE_TEMP
	148	RESTORE_AT
	149	RESTORE_STATIC
	150	#endif
1da177e4 LT	151	RESTORE_SOME
	152	RESTORE_SP_AND_RET
	153	.set at
	154
c2648527 TS	155	work_pending:
c2648527 TS	156	andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
1da177e4 LT	157	beqz t0, work_notifysig
	158	work_resched:
	159	jal schedule
	160
c2648527	161	local_irq_disable # make sure need_resched and
1da177e4 LT	162	# signals dont change between
	163	# sampling and return
	164	LONG_L a2, TI_FLAGS($28)
	165	andi t0, a2, _TIF_WORK_MASK # is there any work to be done
	166	# other than syscall tracing?
	167	beqz t0, restore_all
	168	andi t0, a2, _TIF_NEED_RESCHED
	169	bnez t0, work_resched
	170
	171	work_notifysig: # deal with pending signals and
	172	# notify-resume requests
	173	move a0, sp
	174	li a1, 0
	175	jal do_notify_resume # a2 already loaded
c90e6fbb	176	j resume_userspace_check
1da177e4	177
02f884ed AV	178	FEXPORT(syscall_exit_partial)
	179	local_irq_disable # make sure need_resched doesn't
	180	# change between and return
	181	LONG_L a2, TI_FLAGS($28) # current->work
	182	li t0, _TIF_ALLWORK_MASK
	183	and t0, a2
	184	beqz t0, restore_partial
1da177e4	185	SAVE_STATIC
c2648527	186	syscall_exit_work:
f76f3308 AV	187	LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
	188	andi t0, t0, KU_USER
	189	beqz t0, resume_kernel
c19c20ac	190	li t0, _TIF_WORK_SYSCALL_EXIT
c2648527 TS	191	and t0, a2 # a2 is preloaded with TI_FLAGS
c2648527 TS	192	beqz t0, work_pending # trace bit set?
8b659a39	193	local_irq_enable # could let syscall_trace_leave()
1da177e4 LT	194	# call schedule() instead
1da177e4 LT	195	move a0, sp
8b659a39	196	jal syscall_trace_leave
1da177e4	197	b resume_userspace
bce1a286 RB	198
	199	#if defined(CONFIG_CPU_MIPSR2) \|\| defined(CONFIG_MIPS_MT)
	200
	201	/*
	202	* MIPS32R2 Instruction Hazard Barrier - must be called
	203	*
	204	* For C code use the inline version named instruction_hazard().
	205	*/
	206	LEAF(mips_ihb)
	207	.set mips32r2
	208	jr.hb ra
	209	nop
	210	END(mips_ihb)
	211
	212	#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */