Initial import

1 files changed, 260 insertions, 0 deletions

diff --git a/arch/m68k/include/asm/entry.h b/arch/m68k/include/asm/entry.h
new file mode 100644
index 000000000..d7de0f1a8
--- /dev/null
+++ b/arch/m68k/include/asm/entry.h
@@ -0,0 +1,260 @@
+#ifndef __M68K_ENTRY_H
+#define __M68K_ENTRY_H
+
+#include <asm/setup.h>
+#include <asm/page.h>
+#ifdef __ASSEMBLY__
+#include <asm/thread_info.h>
+#endif
+
+/*
+ * Stack layout in 'ret_from_exception':
+ *
+ *	This allows access to the syscall arguments in registers d1-d5
+ *
+ *	 0(sp) - d1
+ *	 4(sp) - d2
+ *	 8(sp) - d3
+ *	 C(sp) - d4
+ *	10(sp) - d5
+ *	14(sp) - a0
+ *	18(sp) - a1
+ *	1C(sp) - a2
+ *	20(sp) - d0
+ *	24(sp) - orig_d0
+ *	28(sp) - stack adjustment
+ *	2C(sp) - [ sr              ] [ format & vector ]
+ *	2E(sp) - [ pc-hiword       ] [ sr              ]
+ *	30(sp) - [ pc-loword       ] [ pc-hiword       ]
+ *	32(sp) - [ format & vector ] [ pc-loword       ]
+ *		  ^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^
+ *			M68K		  COLDFIRE
+ */
+
+/* the following macro is used when enabling interrupts */
+#if defined(MACH_ATARI_ONLY)
+	/* block out HSYNC = ipl 2 on the atari */
+#define ALLOWINT	(~0x500)
+#else
+	/* portable version */
+#define ALLOWINT	(~0x700)
+#endif /* machine compilation types */
+
+#ifdef __ASSEMBLY__
+/*
+ * This defines the normal kernel pt-regs layout.
+ *
+ * regs a3-a6 and d6-d7 are preserved by C code
+ * the kernel doesn't mess with usp unless it needs to
+ */
+#define SWITCH_STACK_SIZE	(6*4+4)	/* includes return address */
+
+#ifdef CONFIG_COLDFIRE
+#ifdef CONFIG_COLDFIRE_SW_A7
+/*
+ * This is made a little more tricky on older ColdFires. There is no
+ * separate supervisor and user stack pointers. Need to artificially
+ * construct a usp in software... When doing this we need to disable
+ * interrupts, otherwise bad things will happen.
+ */
+.globl sw_usp
+.globl sw_ksp
+
+.macro SAVE_ALL_SYS
+	move	#0x2700,%sr		/* disable intrs */
+	btst	#5,%sp@(2)		/* from user? */
+	bnes	6f			/* no, skip */
+	movel	%sp,sw_usp		/* save user sp */
+	addql	#8,sw_usp		/* remove exception */
+	movel	sw_ksp,%sp		/* kernel sp */
+	subql	#8,%sp			/* room for exception */
+	clrl	%sp@-			/* stkadj */
+	movel	%d0,%sp@-		/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	lea	%sp@(-32),%sp		/* space for 8 regs */
+	moveml	%d1-%d5/%a0-%a2,%sp@
+	movel	sw_usp,%a0		/* get usp */
+	movel	%a0@-,%sp@(PT_OFF_PC)	/* copy exception program counter */
+	movel	%a0@-,%sp@(PT_OFF_FORMATVEC)/*copy exception format/vector/sr */
+	bra	7f
+	6:
+	clrl	%sp@-			/* stkadj */
+	movel	%d0,%sp@-		/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	lea	%sp@(-32),%sp		/* space for 8 regs */
+	moveml	%d1-%d5/%a0-%a2,%sp@
+	7:
+.endm
+
+.macro SAVE_ALL_INT
+	SAVE_ALL_SYS
+	moveq	#-1,%d0			/* not system call entry */
+	movel	%d0,%sp@(PT_OFF_ORIG_D0)
+.endm
+
+.macro RESTORE_USER
+	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		/* stkadj */
+	addql	#8,%sp			/* remove exception */
+	movel	%sp,sw_ksp		/* save ksp */
+	subql	#8,sw_usp		/* set exception */
+	movel	sw_usp,%sp		/* restore usp */
+	rte
+.endm
+
+.macro RDUSP
+	movel	sw_usp,%a3
+.endm
+
+.macro WRUSP
+	movel	%a3,sw_usp
+.endm
+
+#else /* !CONFIG_COLDFIRE_SW_A7 */
+/*
+ * Modern ColdFire parts have separate supervisor and user stack
+ * pointers. Simple load and restore macros for this case.
+ */
+.macro SAVE_ALL_SYS
+	move	#0x2700,%sr		/* disable intrs */
+	clrl	%sp@-			/* stkadj */
+	movel	%d0,%sp@-		/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	lea	%sp@(-32),%sp		/* space for 8 regs */
+	moveml	%d1-%d5/%a0-%a2,%sp@
+.endm
+
+.macro SAVE_ALL_INT
+	move	#0x2700,%sr		/* disable intrs */
+	clrl	%sp@-			/* stkadj */
+	pea	-1:w			/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	lea	%sp@(-32),%sp		/* space for 8 regs */
+	moveml	%d1-%d5/%a0-%a2,%sp@
+.endm
+
+.macro RESTORE_USER
+	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		/* stkadj */
+	rte
+.endm
+
+.macro RDUSP
+	/*move	%usp,%a3*/
+	.word	0x4e6b
+.endm
+
+.macro WRUSP
+	/*move	%a3,%usp*/
+	.word	0x4e63
+.endm
+
+#endif /* !CONFIG_COLDFIRE_SW_A7 */
+
+.macro SAVE_SWITCH_STACK
+	lea	%sp@(-24),%sp		/* 6 regs */
+	moveml	%a3-%a6/%d6-%d7,%sp@
+.endm
+
+.macro RESTORE_SWITCH_STACK
+	moveml	%sp@,%a3-%a6/%d6-%d7
+	lea	%sp@(24),%sp		/* 6 regs */
+.endm
+
+#else /* !CONFIG_COLDFIRE */
+
+/*
+ * All other types of m68k parts (68000, 680x0, CPU32) have the same
+ * entry and exit code.
+ */
+
+/*
+ * a -1 in the orig_d0 field signifies
+ * that the stack frame is NOT for syscall
+ */
+.macro SAVE_ALL_INT
+	clrl	%sp@-			/* stk_adj */
+	pea	-1:w			/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	moveml	%d1-%d5/%a0-%a2,%sp@-
+.endm
+
+.macro SAVE_ALL_SYS
+	clrl	%sp@-			/* stk_adj */
+	movel	%d0,%sp@-		/* orig d0 */
+	movel	%d0,%sp@-		/* d0 */
+	moveml	%d1-%d5/%a0-%a2,%sp@-
+.endm
+
+.macro RESTORE_ALL
+	moveml	%sp@+,%a0-%a2/%d1-%d5
+	movel	%sp@+,%d0
+	addql	#4,%sp			/* orig d0 */
+	addl	%sp@+,%sp		/* stk adj */
+	rte
+.endm
+
+
+.macro SAVE_SWITCH_STACK
+	moveml	%a3-%a6/%d6-%d7,%sp@-
+.endm
+
+.macro RESTORE_SWITCH_STACK
+	moveml	%sp@+,%a3-%a6/%d6-%d7
+.endm
+
+#endif /* !CONFIG_COLDFIRE */
+
+/*
+ * Register %a2 is reserved and set to current task on MMU enabled systems.
+ * Non-MMU systems do not reserve %a2 in this way, and this definition is
+ * not used for them.
+ */
+#ifdef CONFIG_MMU
+
+#define curptr a2
+
+#define GET_CURRENT(tmp) get_current tmp
+.macro get_current reg=%d0
+	movel	%sp,\reg
+	andl	#-THREAD_SIZE,\reg
+	movel	\reg,%curptr
+	movel	%curptr@,%curptr
+.endm
+
+#else
+
+#define GET_CURRENT(tmp)
+
+#endif /* CONFIG_MMU */
+
+#else /* C source */
+
+#define STR(X) STR1(X)
+#define STR1(X) #X
+
+#define SAVE_ALL_INT				\
+	"clrl	%%sp@-;"    /* stk_adj */	\
+	"pea	-1:w;"	    /* orig d0 = -1 */	\
+	"movel	%%d0,%%sp@-;" /* d0 */		\
+	"moveml	%%d1-%%d5/%%a0-%%a2,%%sp@-"
+
+#define GET_CURRENT(tmp) \
+	"movel	%%sp,"#tmp"\n\t" \
+	"andw	#-"STR(THREAD_SIZE)","#tmp"\n\t" \
+	"movel	"#tmp",%%a2\n\t" \
+	"movel	%%a2@,%%a2"
+
+#endif
+
+#endif /* __M68K_ENTRY_H */