summaryrefslogtreecommitdiffstats
path: root/arch/m68k/include/asm/entry.h
diff options
context:
space:
mode:
Diffstat (limited to 'arch/m68k/include/asm/entry.h')
-rw-r--r--arch/m68k/include/asm/entry.h261
1 files changed, 261 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..9b52b060c
--- /dev/null
+++ b/arch/m68k/include/asm/entry.h
@@ -0,0 +1,261 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#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 */