/* * linux/arch/m68knommu/platform/5307/entry.S * * Copyright (C) 1999-2007, Greg Ungerer (gerg@snapgear.com) * Copyright (C) 1998 D. Jeff Dionne , * Kenneth Albanowski , * 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 * Bug, speed and maintainability fixes by Philippe De Muyter */ #include #include #include #include #include #include #include #include #include .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: move #0x2700,%sr /* disable intrs */ btst #5,%sp@(PT_SR) /* check if returning to kernel */ jeq Luser_return /* if so, skip resched, signals */ #ifdef CONFIG_PREEMPT 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_NEED_RESCHED,%d1 jeq Lkernel_return movel %a0@(TI_PREEMPTCOUNT),%d1 cmpl #0,%d1 jne Lkernel_return pea Lkernel_return jmp preempt_schedule_irq /* preempt the kernel */ #endif 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 */ move #0x2000,%sr /* enable intrs again */ 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) moveb %sp@(PT_SR),%d0 andl #0x7,%d0 jeq 1f RESTORE_ALL 1: /* 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