[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 <linux/config.h>

#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

#ifdef CONFIG_PREEMPT
	.macro	preempt_stop
	.endm
#else
	.macro	preempt_stop
	local_irq_disable
	.endm
#define resume_kernel	restore_all
#endif

	.text
	.align	5
FEXPORT(ret_from_exception)
	preempt_stop
FEXPORT(ret_from_irq)
	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_fork)
	jal	schedule_tail		# a0 = task_t *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

FEXPORT(restore_all)			# restore full frame
#ifdef CONFIG_MIPS_MT_SMTC
/* Detect and execute deferred IPI "interrupts" */
	move	a0,sp
	jal	deferred_smtc_ipi
/* 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 */
	.set	noat
	RESTORE_TEMP
	RESTORE_AT
	RESTORE_STATIC
FEXPORT(restore_partial)		# restore partial frame
	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

FEXPORT(syscall_exit_work_partial)
	SAVE_STATIC
syscall_exit_work:
	li	t0, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
	and	t0, a2			# a2 is preloaded with TI_FLAGS
	beqz	t0, work_pending	# trace bit set?
	local_irq_enable		# could let do_syscall_trace()
					# call schedule() instead
	move	a0, sp
	li	a1, 1
	jal	do_syscall_trace
	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	*/
	10	#include <linux/config.h>
	11
	12	#include <asm/asm.h>
	13	#include <asm/asmmacro.h>
	14	#include <asm/regdef.h>
	15	#include <asm/mipsregs.h>
	16	#include <asm/stackframe.h>
	17	#include <asm/isadep.h>
	18	#include <asm/thread_info.h>
	19	#include <asm/war.h>
41c594ab RB	20	#ifdef CONFIG_MIPS_MT_SMTC
	21	#include <asm/mipsmtregs.h>
	22	#endif
1da177e4 LT	23
1da177e4 LT	24	#ifdef CONFIG_PREEMPT
c2648527	25	.macro preempt_stop
1da177e4 LT	26	.endm
1da177e4 LT	27	#else
c2648527 TS	28	.macro preempt_stop
c2648527 TS	29	local_irq_disable
1da177e4 LT	30	.endm
	31	#define resume_kernel restore_all
	32	#endif
	33
	34	.text
	35	.align 5
	36	FEXPORT(ret_from_exception)
	37	preempt_stop
	38	FEXPORT(ret_from_irq)
	39	LONG_L t0, PT_STATUS(sp) # returning to kernel mode?
	40	andi t0, t0, KU_USER
	41	beqz t0, resume_kernel
	42
c2648527 TS	43	resume_userspace:
c2648527 TS	44	local_irq_disable # make sure we dont miss an
1da177e4 LT	45	# interrupt setting need_resched
	46	# between sampling and return
	47	LONG_L a2, TI_FLAGS($28) # current->work
c2648527 TS	48	andi t0, a2, _TIF_WORK_MASK # (ignoring syscall_trace)
c2648527 TS	49	bnez t0, work_pending
1da177e4 LT	50	j restore_all
	51
	52	#ifdef CONFIG_PREEMPT
c2648527	53	resume_kernel:
a18815ab	54	local_irq_disable
1da177e4 LT	55	lw t0, TI_PRE_COUNT($28)
	56	bnez t0, restore_all
	57	need_resched:
	58	LONG_L t0, TI_FLAGS($28)
	59	andi t1, t0, _TIF_NEED_RESCHED
	60	beqz t1, restore_all
	61	LONG_L t0, PT_STATUS(sp) # Interrupts off?
	62	andi t0, 1
	63	beqz t0, restore_all
a18815ab	64	jal preempt_schedule_irq
cdaed73a	65	b need_resched
1da177e4 LT	66	#endif
	67
	68	FEXPORT(ret_from_fork)
	69	jal schedule_tail # a0 = task_t *prev
	70
	71	FEXPORT(syscall_exit)
	72	local_irq_disable # make sure need_resched and
	73	# signals dont change between
	74	# sampling and return
	75	LONG_L a2, TI_FLAGS($28) # current->work
	76	li t0, _TIF_ALLWORK_MASK
	77	and t0, a2, t0
	78	bnez t0, syscall_exit_work
	79
	80	FEXPORT(restore_all) # restore full frame
41c594ab RB	81	#ifdef CONFIG_MIPS_MT_SMTC
	82	/* Detect and execute deferred IPI "interrupts" */
	83	move a0,sp
	84	jal deferred_smtc_ipi
	85	/* Re-arm any temporarily masked interrupts not explicitly "acked" */
	86	mfc0 v0, CP0_TCSTATUS
	87	ori v1, v0, TCSTATUS_IXMT
	88	mtc0 v1, CP0_TCSTATUS
	89	andi v0, TCSTATUS_IXMT
	90	ehb
	91	mfc0 t0, CP0_TCCONTEXT
	92	DMT 9 # dmt t1
	93	jal mips_ihb
	94	mfc0 t2, CP0_STATUS
	95	andi t3, t0, 0xff00
	96	or t2, t2, t3
	97	mtc0 t2, CP0_STATUS
	98	ehb
	99	andi t1, t1, VPECONTROL_TE
	100	beqz t1, 1f
	101	EMT
	102	1:
	103	mfc0 v1, CP0_TCSTATUS
477654fc	104	/* We set IXMT above, XOR should clear it here */
41c594ab RB	105	xori v1, v1, TCSTATUS_IXMT
	106	or v1, v0, v1
	107	mtc0 v1, CP0_TCSTATUS
	108	ehb
	109	xor t0, t0, t3
	110	mtc0 t0, CP0_TCCONTEXT
	111	#endif /* CONFIG_MIPS_MT_SMTC */
1da177e4 LT	112	.set noat
	113	RESTORE_TEMP
	114	RESTORE_AT
	115	RESTORE_STATIC
	116	FEXPORT(restore_partial) # restore partial frame
	117	RESTORE_SOME
	118	RESTORE_SP_AND_RET
	119	.set at
	120
c2648527 TS	121	work_pending:
c2648527 TS	122	andi t0, a2, _TIF_NEED_RESCHED # a2 is preloaded with TI_FLAGS
1da177e4 LT	123	beqz t0, work_notifysig
	124	work_resched:
	125	jal schedule
	126
c2648527	127	local_irq_disable # make sure need_resched and
1da177e4 LT	128	# signals dont change between
	129	# sampling and return
	130	LONG_L a2, TI_FLAGS($28)
	131	andi t0, a2, _TIF_WORK_MASK # is there any work to be done
	132	# other than syscall tracing?
	133	beqz t0, restore_all
	134	andi t0, a2, _TIF_NEED_RESCHED
	135	bnez t0, work_resched
	136
	137	work_notifysig: # deal with pending signals and
	138	# notify-resume requests
	139	move a0, sp
	140	li a1, 0
	141	jal do_notify_resume # a2 already loaded
0bf0e3e2	142	j resume_userspace
1da177e4 LT	143
	144	FEXPORT(syscall_exit_work_partial)
	145	SAVE_STATIC
c2648527 TS	146	syscall_exit_work:
	147	li t0, _TIF_SYSCALL_TRACE \| _TIF_SYSCALL_AUDIT
	148	and t0, a2 # a2 is preloaded with TI_FLAGS
	149	beqz t0, work_pending # trace bit set?
1da177e4 LT	150	local_irq_enable # could let do_syscall_trace()
	151	# call schedule() instead
	152	move a0, sp
	153	li a1, 1
	154	jal do_syscall_trace
	155	b resume_userspace
bce1a286 RB	156
	157	#if defined(CONFIG_CPU_MIPSR2) \|\| defined(CONFIG_MIPS_MT)
	158
	159	/*
	160	* MIPS32R2 Instruction Hazard Barrier - must be called
	161	*
	162	* For C code use the inline version named instruction_hazard().
	163	*/
	164	LEAF(mips_ihb)
	165	.set mips32r2
	166	jr.hb ra
	167	nop
	168	END(mips_ihb)
	169
	170	#endif /* CONFIG_CPU_MIPSR2 or CONFIG_MIPS_MT */