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Diffstat (limited to 'arch/m68knommu/platform/coldfire')
| -rw-r--r-- | arch/m68knommu/platform/coldfire/entry.S | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/arch/m68knommu/platform/coldfire/entry.S b/arch/m68knommu/platform/coldfire/entry.S new file mode 100644 index 00000000000..b333731b875 --- /dev/null +++ b/arch/m68knommu/platform/coldfire/entry.S @@ -0,0 +1,235 @@ +/* + * 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_D0) /* save the return value */ + jra ret_from_exception +1: + movel #-ENOSYS,%d2 /* strace needs -ENOSYS in PT_D0 */ + movel %d2,PT_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_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: + btst #5,%sp@(PT_SR) /* check if returning to kernel */ + jeq Luser_return /* if so, skip resched, signals */ + +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_PC),%a0@- /* copy exception program counter */ + movel %sp@(PT_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 */ + 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_ORIG_D0) + + movew %sp@(PT_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_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) + jeq 2f +1: + RESTORE_ALL +2: + moveb %sp@(PT_SR),%d0 + andl #0x7,%d0 + jhi 1b + + /* check if we need to do software interrupts */ + movel irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0 + jeq ret_from_exception + + pea ret_from_exception + jmp do_softirq + +/* + * 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 |