arch/m68knommu/platform/coldfire/entry.S - maze/linux - Git at Google

 /*
  *  linux/arch/m68knommu/platform/5307/entry.S
  *
  *  Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
  *  Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>,
  *                      Kenneth Albanowski <kjahds@kjahds.com>,
  *  Copyright (C) 2000  Lineo Inc. (www.lineo.com)
  *  Copyright (C) 2004-2006  Macq Electronique SA. (www.macqel.com)
  *
  * Based on:
  *
  *  linux/arch/m68k/kernel/entry.S
  *
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file README.legal in the main directory of this archive
  * for more details.
  *
  * Linux/m68k support by Hamish Macdonald
  *
  * 68060 fixes by Jesper Skov
  * ColdFire support by Greg Ungerer (gerg@snapgear.com)
  * 5307 fixes by David W. Miller
  * linux 2.4 support David McCullough <davidm@snapgear.com>
  * Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
  */

 #include <linux/sys.h>
 #include <linux/linkage.h>
 #include <asm/unistd.h>
 #include <asm/thread_info.h>
 #include <asm/errno.h>
 #include <asm/setup.h>
 #include <asm/segment.h>
 #include <asm/asm-offsets.h>
 #include <asm/entry.h>

 .bss

 sw_ksp:
 .long	0

 sw_usp:
 .long	0

 .text

 .globl system_call
 .globl resume
 .globl ret_from_exception
 .globl ret_from_signal
 .globl sys_call_table
 .globl ret_from_interrupt
 .globl inthandler
 .globl fasthandler

 enosys:
 	mov.l	#sys_ni_syscall,%d3
 	bra	1f

 ENTRY(system_call)
 	SAVE_ALL
 	move	#0x2000,%sr		/* enable intrs again */

 	cmpl	#NR_syscalls,%d0
 	jcc	enosys
 	lea	sys_call_table,%a0
 	lsll	#2,%d0			/* movel %a0@(%d0:l:4),%d3 */
 	movel	%a0@(%d0),%d3
 	jeq	enosys

 1:
 	movel	%sp,%d2			/* get thread_info pointer */
 	andl	#-THREAD_SIZE,%d2	/* at start of kernel stack */
 	movel	%d2,%a0
 	movel	%a0@,%a1		/* save top of frame */
 	movel	%sp,%a1@(TASK_THREAD+THREAD_ESP0)
 	btst	#(TIF_SYSCALL_TRACE%8),%a0@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
 	bnes	1f

 	movel	%d3,%a0
 	jbsr	%a0@
 	movel	%d0,%sp@(PT_OFF_D0)	/* save the return value */
 	jra	ret_from_exception
 1:
 	movel	#-ENOSYS,%d2		/* strace needs -ENOSYS in PT_OFF_D0 */
 	movel	%d2,PT_OFF_D0(%sp)	/* on syscall entry */
 	subql	#4,%sp
 	SAVE_SWITCH_STACK
 	jbsr	syscall_trace
 	RESTORE_SWITCH_STACK
 	addql	#4,%sp
 	movel	%d3,%a0
 	jbsr	%a0@
 	movel	%d0,%sp@(PT_OFF_D0)		/* save the return value */
 	subql	#4,%sp			/* dummy return address */
 	SAVE_SWITCH_STACK
 	jbsr	syscall_trace

 ret_from_signal:
 	RESTORE_SWITCH_STACK
 	addql	#4,%sp

 ret_from_exception:
 	move	#0x2700,%sr		/* disable intrs */
 	btst	#5,%sp@(PT_OFF_SR)	/* check if returning to kernel */
 	jeq	Luser_return		/* if so, skip resched, signals */

 #ifdef CONFIG_PREEMPT
 	movel	%sp,%d1			/* get thread_info pointer */
 	andl	#-THREAD_SIZE,%d1	/* at base of kernel stack */
 	movel	%d1,%a0
 	movel	%a0@(TI_FLAGS),%d1	/* get thread_info->flags */
 	andl	#_TIF_NEED_RESCHED,%d1
 	jeq	Lkernel_return

 	movel	%a0@(TI_PREEMPTCOUNT),%d1
 	cmpl	#0,%d1
 	jne	Lkernel_return

 	pea	Lkernel_return
 	jmp	preempt_schedule_irq	/* preempt the kernel */
 #endif

 Lkernel_return:
 	moveml	%sp@,%d1-%d5/%a0-%a2
 	lea	%sp@(32),%sp		/* space for 8 regs */
 	movel	%sp@+,%d0
 	addql	#4,%sp			/* orig d0 */
 	addl	%sp@+,%sp		/* stk adj */
 	rte

 Luser_return:
 	movel	%sp,%d1			/* get thread_info pointer */
 	andl	#-THREAD_SIZE,%d1	/* at base of kernel stack */
 	movel	%d1,%a0
 	movel	%a0@(TI_FLAGS),%d1	/* get thread_info->flags */
 	andl	#_TIF_WORK_MASK,%d1
 	jne	Lwork_to_do		/* still work to do */

 Lreturn:
 	move	#0x2700,%sr		/* disable intrs */
 	movel	sw_usp,%a0		/* get usp */
 	movel	%sp@(PT_OFF_PC),%a0@-	/* copy exception program counter */
 	movel	%sp@(PT_OFF_FORMATVEC),%a0@- /* copy exception format/vector/sr */
 	moveml	%sp@,%d1-%d5/%a0-%a2
 	lea	%sp@(32),%sp		/* space for 8 regs */
 	movel	%sp@+,%d0
 	addql	#4,%sp			/* orig d0 */
 	addl	%sp@+,%sp		/* stk adj */
 	addql	#8,%sp			/* remove exception */
 	movel	%sp,sw_ksp		/* save ksp */
 	subql	#8,sw_usp		/* set exception */
 	movel	sw_usp,%sp		/* restore usp */
 	rte

 Lwork_to_do:
 	movel	%a0@(TI_FLAGS),%d1	/* get thread_info->flags */
 	move	#0x2000,%sr		/* enable intrs again */
 	btst	#TIF_NEED_RESCHED,%d1
 	jne	reschedule

 	/* GERG: do we need something here for TRACEing?? */

 Lsignal_return:
 	subql	#4,%sp			/* dummy return address */
 	SAVE_SWITCH_STACK
 	pea	%sp@(SWITCH_STACK_SIZE)
 	clrl	%sp@-
 	jsr	do_signal
 	addql	#8,%sp
 	RESTORE_SWITCH_STACK
 	addql	#4,%sp
 	jmp	Lreturn

 /*
  * This is the generic interrupt handler (for all hardware interrupt
  * sources). Calls upto high level code to do all the work.
  */
 ENTRY(inthandler)
 	SAVE_ALL
 	moveq	#-1,%d0
 	movel	%d0,%sp@(PT_OFF_ORIG_D0)

 	movew	%sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
 	andl	#0x03fc,%d0		/* mask out vector only */

 	movel	%sp,%sp@-		/* push regs arg */
 	lsrl	#2,%d0			/* calculate real vector # */
 	movel	%d0,%sp@-		/* push vector number */
 	jbsr	do_IRQ			/* call high level irq handler */
 	lea	%sp@(8),%sp		/* pop args off stack */

 	bra	ret_from_interrupt	/* this was fallthrough */

 /*
  * This is the fast interrupt handler (for certain hardware interrupt
  * sources). Unlike the normal interrupt handler it just uses the
  * current stack (doesn't care if it is user or kernel). It also
  * doesn't bother doing the bottom half handlers.
  */
 ENTRY(fasthandler)
 	SAVE_LOCAL

 	movew	%sp@(PT_OFF_FORMATVEC),%d0
 	andl	#0x03fc,%d0		/* mask out vector only */

 	movel	%sp,%sp@-		/* push regs arg */
 	lsrl	#2,%d0			/* calculate real vector # */
 	movel	%d0,%sp@-		/* push vector number */
 	jbsr	do_IRQ			/* call high level irq handler */
 	lea	%sp@(8),%sp		/* pop args off stack */

 	RESTORE_LOCAL

 ENTRY(ret_from_interrupt)
 	/* the fasthandler is confusing me, haven't seen any user */
 	jmp	ret_from_exception

 /*
  * Beware - when entering resume, prev (the current task) is
  * in a0, next (the new task) is in a1,so don't change these
  * registers until their contents are no longer needed.
  * This is always called in supervisor mode, so don't bother to save
  * and restore sr; user's process sr is actually in the stack.
  */
 ENTRY(resume)
 	movel	%a0, %d1			/* get prev thread in d1 */

 	movel	sw_usp,%d0			/* save usp */
 	movel	%d0,%a0@(TASK_THREAD+THREAD_USP)

 	SAVE_SWITCH_STACK
 	movel	%sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
 	movel	%a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
 	RESTORE_SWITCH_STACK

 	movel	%a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
 	movel	%a0, sw_usp
 	rts
	/*
	* linux/arch/m68knommu/platform/5307/entry.S
	*
	* Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com)
	* Copyright (C) 1998 D. Jeff Dionne <jeff@lineo.ca>,
	* Kenneth Albanowski <kjahds@kjahds.com>,
	* Copyright (C) 2000 Lineo Inc. (www.lineo.com)
	* Copyright (C) 2004-2006 Macq Electronique SA. (www.macqel.com)
	*
	* Based on:
	*
	* linux/arch/m68k/kernel/entry.S
	*
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file README.legal in the main directory of this archive
	* for more details.
	*
	* Linux/m68k support by Hamish Macdonald
	*
	* 68060 fixes by Jesper Skov
	* ColdFire support by Greg Ungerer (gerg@snapgear.com)
	* 5307 fixes by David W. Miller
	* linux 2.4 support David McCullough <davidm@snapgear.com>
	* Bug, speed and maintainability fixes by Philippe De Muyter <phdm@macqel.be>
	*/

	#include <linux/sys.h>
	#include <linux/linkage.h>
	#include <asm/unistd.h>
	#include <asm/thread_info.h>
	#include <asm/errno.h>
	#include <asm/setup.h>
	#include <asm/segment.h>
	#include <asm/asm-offsets.h>
	#include <asm/entry.h>

	.bss

	sw_ksp:
	.long 0

	sw_usp:
	.long 0

	.text

	.globl system_call
	.globl resume
	.globl ret_from_exception
	.globl ret_from_signal
	.globl sys_call_table
	.globl ret_from_interrupt
	.globl inthandler
	.globl fasthandler

	enosys:
	mov.l #sys_ni_syscall,%d3
	bra 1f

	ENTRY(system_call)
	SAVE_ALL
	move #0x2000,%sr /* enable intrs again */

	cmpl #NR_syscalls,%d0
	jcc enosys
	lea sys_call_table,%a0
	lsll #2,%d0 /* movel %a0@(%d0:l:4),%d3 */
	movel %a0@(%d0),%d3
	jeq enosys

	1:
	movel %sp,%d2 /* get thread_info pointer */
	andl #-THREAD_SIZE,%d2 /* at start of kernel stack */
	movel %d2,%a0
	movel %a0@,%a1 /* save top of frame */
	movel %sp,%a1@(TASK_THREAD+THREAD_ESP0)
	btst #(TIF_SYSCALL_TRACE%8),%a0@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
	bnes 1f

	movel %d3,%a0
	jbsr %a0@
	movel %d0,%sp@(PT_OFF_D0) /* save the return value */
	jra ret_from_exception
	1:
	movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_OFF_D0 */
	movel %d2,PT_OFF_D0(%sp) /* on syscall entry */
	subql #4,%sp
	SAVE_SWITCH_STACK
	jbsr syscall_trace
	RESTORE_SWITCH_STACK
	addql #4,%sp
	movel %d3,%a0
	jbsr %a0@
	movel %d0,%sp@(PT_OFF_D0) /* save the return value */
	subql #4,%sp /* dummy return address */
	SAVE_SWITCH_STACK
	jbsr syscall_trace

	ret_from_signal:
	RESTORE_SWITCH_STACK
	addql #4,%sp

	ret_from_exception:
	move #0x2700,%sr /* disable intrs */
	btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel */
	jeq Luser_return /* if so, skip resched, signals */

	#ifdef CONFIG_PREEMPT
	movel %sp,%d1 /* get thread_info pointer */
	andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
	movel %d1,%a0
	movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
	andl #_TIF_NEED_RESCHED,%d1
	jeq Lkernel_return

	movel %a0@(TI_PREEMPTCOUNT),%d1
	cmpl #0,%d1
	jne Lkernel_return

	pea Lkernel_return
	jmp preempt_schedule_irq /* preempt the kernel */
	#endif

	Lkernel_return:
	moveml %sp@,%d1-%d5/%a0-%a2
	lea %sp@(32),%sp /* space for 8 regs */
	movel %sp@+,%d0
	addql #4,%sp /* orig d0 */
	addl %sp@+,%sp /* stk adj */
	rte

	Luser_return:
	movel %sp,%d1 /* get thread_info pointer */
	andl #-THREAD_SIZE,%d1 /* at base of kernel stack */
	movel %d1,%a0
	movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
	andl #_TIF_WORK_MASK,%d1
	jne Lwork_to_do /* still work to do */

	Lreturn:
	move #0x2700,%sr /* disable intrs */
	movel sw_usp,%a0 /* get usp */
	movel %sp@(PT_OFF_PC),%a0@- /* copy exception program counter */
	movel %sp@(PT_OFF_FORMATVEC),%a0@- /* copy exception format/vector/sr */
	moveml %sp@,%d1-%d5/%a0-%a2
	lea %sp@(32),%sp /* space for 8 regs */
	movel %sp@+,%d0
	addql #4,%sp /* orig d0 */
	addl %sp@+,%sp /* stk adj */
	addql #8,%sp /* remove exception */
	movel %sp,sw_ksp /* save ksp */
	subql #8,sw_usp /* set exception */
	movel sw_usp,%sp /* restore usp */
	rte

	Lwork_to_do:
	movel %a0@(TI_FLAGS),%d1 /* get thread_info->flags */
	move #0x2000,%sr /* enable intrs again */
	btst #TIF_NEED_RESCHED,%d1
	jne reschedule

	/* GERG: do we need something here for TRACEing?? */

	Lsignal_return:
	subql #4,%sp /* dummy return address */
	SAVE_SWITCH_STACK
	pea %sp@(SWITCH_STACK_SIZE)
	clrl %sp@-
	jsr do_signal
	addql #8,%sp
	RESTORE_SWITCH_STACK
	addql #4,%sp
	jmp Lreturn

	/*
	* This is the generic interrupt handler (for all hardware interrupt
	* sources). Calls upto high level code to do all the work.
	*/
	ENTRY(inthandler)
	SAVE_ALL
	moveq #-1,%d0
	movel %d0,%sp@(PT_OFF_ORIG_D0)

	movew %sp@(PT_OFF_FORMATVEC),%d0 /* put exception # in d0 */
	andl #0x03fc,%d0 /* mask out vector only */

	movel %sp,%sp@- /* push regs arg */
	lsrl #2,%d0 /* calculate real vector # */
	movel %d0,%sp@- /* push vector number */
	jbsr do_IRQ /* call high level irq handler */
	lea %sp@(8),%sp /* pop args off stack */

	bra ret_from_interrupt /* this was fallthrough */

	/*
	* This is the fast interrupt handler (for certain hardware interrupt
	* sources). Unlike the normal interrupt handler it just uses the
	* current stack (doesn't care if it is user or kernel). It also
	* doesn't bother doing the bottom half handlers.
	*/
	ENTRY(fasthandler)
	SAVE_LOCAL

	movew %sp@(PT_OFF_FORMATVEC),%d0
	andl #0x03fc,%d0 /* mask out vector only */

	movel %sp,%sp@- /* push regs arg */
	lsrl #2,%d0 /* calculate real vector # */
	movel %d0,%sp@- /* push vector number */
	jbsr do_IRQ /* call high level irq handler */
	lea %sp@(8),%sp /* pop args off stack */

	RESTORE_LOCAL

	ENTRY(ret_from_interrupt)
	/* the fasthandler is confusing me, haven't seen any user */
	jmp ret_from_exception

	/*
	* Beware - when entering resume, prev (the current task) is
	* in a0, next (the new task) is in a1,so don't change these
	* registers until their contents are no longer needed.
	* This is always called in supervisor mode, so don't bother to save
	* and restore sr; user's process sr is actually in the stack.
	*/
	ENTRY(resume)
	movel %a0, %d1 /* get prev thread in d1 */

	movel sw_usp,%d0 /* save usp */
	movel %d0,%a0@(TASK_THREAD+THREAD_USP)

	SAVE_SWITCH_STACK
	movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack pointer */
	movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
	RESTORE_SWITCH_STACK

	movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore thread user stack */
	movel %a0, sw_usp
	rts