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Diffstat (limited to 'arch/m68k/include/asm/entry.h')
| -rw-r--r-- | arch/m68k/include/asm/entry.h | 261 |
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 0000000000..9b52b060c7 --- /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 */ |