m68knommu: platform code merge for 68000 core cpus

This patch merges all 68000 core cpus into one directory.
There is a lot of common code in the 68328, 68EZ328 and 68VZ328 directories.

This will also facilitate easy development of support for original stand
alone MC68000 CPU machines.

Signed-off-by: Luis Alves <ljalvs@gmail.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>

1 files changed, 261 insertions, 0 deletions

diff --git a/arch/m68k/platform/68000/entry.S b/arch/m68k/platform/68000/entry.S
new file mode 100644
index 000000000000..7f91c2fde509
--- /dev/null
+++ b/arch/m68k/platform/68000/entry.S
@@ -0,0 +1,261 @@
+/*
+ *  linux/arch/m68knommu/platform/68328/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
+ */
+
+#include <linux/linkage.h>
+#include <asm/thread_info.h>
+#include <asm/unistd.h>
+#include <asm/errno.h>
+#include <asm/setup.h>
+#include <asm/segment.h>
+#include <asm/traps.h>
+#include <asm/asm-offsets.h>
+#include <asm/entry.h>
+
+.text
+
+.globl system_call
+.globl resume
+.globl ret_from_exception
+.globl ret_from_signal
+.globl sys_call_table
+.globl ret_from_interrupt
+.globl bad_interrupt
+.globl inthandler1
+.globl inthandler2
+.globl inthandler3
+.globl inthandler4
+.globl inthandler5
+.globl inthandler6
+.globl inthandler7
+
+badsys:
+	movel	#-ENOSYS,%sp@(PT_OFF_D0)
+	jra	ret_from_exception
+
+do_trace:
+	movel	#-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/
+	subql	#4,%sp
+	SAVE_SWITCH_STACK
+	jbsr	syscall_trace_enter
+	RESTORE_SWITCH_STACK
+	addql	#4,%sp
+	movel	%sp@(PT_OFF_ORIG_D0),%d1
+	movel	#-ENOSYS,%d0
+	cmpl	#NR_syscalls,%d1
+	jcc	1f
+	lsl	#2,%d1
+	lea	sys_call_table, %a0
+	jbsr	%a0@(%d1)
+
+1:	movel	%d0,%sp@(PT_OFF_D0)	/* save the return value */
+	subql	#4,%sp			/* dummy return address */
+	SAVE_SWITCH_STACK
+	jbsr	syscall_trace_leave
+
+ret_from_signal:
+	RESTORE_SWITCH_STACK
+	addql	#4,%sp
+	jra	ret_from_exception
+
+ENTRY(system_call)
+	SAVE_ALL_SYS
+
+	/* save top of frame*/
+	pea	%sp@
+	jbsr	set_esp0
+	addql	#4,%sp
+
+	movel	%sp@(PT_OFF_ORIG_D0),%d0
+
+	movel	%sp,%d1			/* get thread_info pointer */
+	andl	#-THREAD_SIZE,%d1
+	movel	%d1,%a2
+	btst	#(TIF_SYSCALL_TRACE%8),%a2@(TINFO_FLAGS+(31-TIF_SYSCALL_TRACE)/8)
+	jne	do_trace
+	cmpl	#NR_syscalls,%d0
+	jcc	badsys
+	lsl	#2,%d0
+	lea	sys_call_table,%a0
+	movel	%a0@(%d0), %a0
+	jbsr	%a0@
+	movel	%d0,%sp@(PT_OFF_D0)	/* save the return value*/
+
+ret_from_exception:
+	btst	#5,%sp@(PT_OFF_SR)	/* check if returning to kernel*/
+	jeq	Luser_return		/* if so, skip resched, signals*/
+
+Lkernel_return:
+	RESTORE_ALL
+
+Luser_return:
+	/* only allow interrupts when we are really the last one on the*/
+	/* kernel stack, otherwise stack overflow can occur during*/
+	/* heavy interrupt load*/
+	andw	#ALLOWINT,%sr
+
+	movel	%sp,%d1			/* get thread_info pointer */
+	andl	#-THREAD_SIZE,%d1
+	movel	%d1,%a2
+1:
+	move	%a2@(TINFO_FLAGS),%d1	/* thread_info->flags */
+	jne	Lwork_to_do
+	RESTORE_ALL
+
+Lwork_to_do:
+	movel	%a2@(TINFO_FLAGS),%d1	/* thread_info->flags */
+	btst	#TIF_NEED_RESCHED,%d1
+	jne	reschedule
+
+Lsignal_return:
+	subql	#4,%sp			/* dummy return address*/
+	SAVE_SWITCH_STACK
+	pea	%sp@(SWITCH_STACK_SIZE)
+	bsrw	do_notify_resume
+	addql	#4,%sp
+	RESTORE_SWITCH_STACK
+	addql	#4,%sp
+	jra	1b
+
+/*
+ * This is the main interrupt handler, responsible for calling process_int()
+ */
+inthandler1:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#65,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler2:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#66,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler3:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#67,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler4:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#68,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler5:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#69,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler6:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#70,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler7:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	#71,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+inthandler:
+	SAVE_ALL_INT
+	movew	%sp@(PT_OFF_FORMATVEC), %d0
+	and	#0x3ff, %d0
+
+	movel	%sp,%sp@-
+	movel	%d0,%sp@- 		/*  put vector # on stack*/
+	jbsr	process_int		/*  process the IRQ*/
+3:     	addql	#8,%sp			/*  pop parameters off stack*/
+	bra	ret_from_interrupt
+
+ret_from_interrupt:
+	jeq	1f
+2:
+	RESTORE_ALL
+1:
+	moveb	%sp@(PT_OFF_SR), %d0
+	and	#7, %d0
+	jhi	2b
+
+	/* check if we need to do software interrupts */
+	jeq	ret_from_exception
+
+	pea	ret_from_exception
+	jra	do_softirq
+
+
+/*
+ * Handler for uninitialized and spurious interrupts.
+ */
+ENTRY(bad_interrupt)
+	addql	#1,irq_err_count
+	rte
+
+/*
+ * 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.
+ */
+ENTRY(resume)
+	movel	%a0,%d1				/* save prev thread in d1 */
+	movew	%sr,%a0@(TASK_THREAD+THREAD_SR)	/* save sr */
+	SAVE_SWITCH_STACK
+	movel	%sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */
+	movel	%usp,%a3			/* save usp */
+	movel	%a3,%a0@(TASK_THREAD+THREAD_USP)
+
+	movel	%a1@(TASK_THREAD+THREAD_USP),%a3 /* restore user stack */
+	movel	%a3,%usp
+	movel	%a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */
+	RESTORE_SWITCH_STACK
+	movew	%a1@(TASK_THREAD+THREAD_SR),%sr	/* restore thread status reg */
+	rts
+