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Diffstat (limited to 'arch/m68k/platform/68360/entry.S')
| -rw-r--r-- | arch/m68k/platform/68360/entry.S | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/arch/m68k/platform/68360/entry.S b/arch/m68k/platform/68360/entry.S new file mode 100644 index 000000000000..46c1b18c9dcb --- /dev/null +++ b/arch/m68k/platform/68360/entry.S @@ -0,0 +1,184 @@ +/* + * linux/arch/m68knommu/platform/68360/entry.S + * + * Copyright (C) 1991, 1992 Linus Torvalds + * Copyright (C) 2001 SED Systems, a Division of Calian Ltd. + * + * 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 + * M68360 Port by SED Systems, and Lineo. + */ + +#include <linux/sys.h> +#include <linux/linkage.h> +#include <asm/thread_info.h> +#include <asm/unistd.h> +#include <asm/errno.h> +#include <asm/setup.h> +#include <asm/segment.h> +#include <asm/traps.h> +#include <asm/asm-offsets.h> +#include <asm/entry.h> + +.text + +.globl system_call +.globl resume +.globl ret_from_exception +.globl ret_from_signal +.globl sys_call_table +.globl ret_from_interrupt +.globl bad_interrupt +.globl inthandler + +badsys: + movel #-ENOSYS,%sp@(PT_OFF_D0) + jra ret_from_exception + +do_trace: + movel #-ENOSYS,%sp@(PT_OFF_D0) /* needed for strace*/ + subql #4,%sp + SAVE_SWITCH_STACK + jbsr syscall_trace_enter + RESTORE_SWITCH_STACK + addql #4,%sp + movel %sp@(PT_OFF_ORIG_D0),%d1 + movel #-ENOSYS,%d0 + cmpl #NR_syscalls,%d1 + jcc 1f + lsl #2,%d1 + lea sys_call_table, %a0 + jbsr %a0@(%d1) + +1: movel %d0,%sp@(PT_OFF_D0) /* save the return value */ + subql #4,%sp /* dummy return address */ + SAVE_SWITCH_STACK + jbsr syscall_trace_leave + +ret_from_signal: + RESTORE_SWITCH_STACK + addql #4,%sp + jra ret_from_exception + +ENTRY(system_call) + SAVE_ALL + + /* save top of frame*/ + pea %sp@ + jbsr set_esp0 + addql #4,%sp + + movel %sp@(PT_OFF_ORIG_D0),%d0 + + movel %sp,%d1 /* get thread_info pointer */ + andl #-THREAD_SIZE,%d1 + movel %d1,%a2 + btst #(TIF_SYSCALL_TRACE%8),%a2@(TI_FLAGS+(31-TIF_SYSCALL_TRACE)/8) + jne do_trace + cmpl #NR_syscalls,%d0 + jcc badsys + lsl #2,%d0 + lea sys_call_table,%a0 + movel %a0@(%d0), %a0 + jbsr %a0@ + movel %d0,%sp@(PT_OFF_D0) /* save the return value*/ + +ret_from_exception: + btst #5,%sp@(PT_OFF_SR) /* check if returning to kernel*/ + jeq Luser_return /* if so, skip resched, signals*/ + +Lkernel_return: + RESTORE_ALL + +Luser_return: + /* only allow interrupts when we are really the last one on the*/ + /* kernel stack, otherwise stack overflow can occur during*/ + /* heavy interrupt load*/ + andw #ALLOWINT,%sr + + movel %sp,%d1 /* get thread_info pointer */ + andl #-THREAD_SIZE,%d1 + movel %d1,%a2 +1: + move %a2@(TI_FLAGS),%d1 /* thread_info->flags */ + jne Lwork_to_do + RESTORE_ALL + +Lwork_to_do: + movel %a2@(TI_FLAGS),%d1 /* thread_info->flags */ + btst #TIF_NEED_RESCHED,%d1 + jne reschedule + +Lsignal_return: + subql #4,%sp /* dummy return address*/ + SAVE_SWITCH_STACK + pea %sp@(SWITCH_STACK_SIZE) + bsrw do_signal + addql #4,%sp + RESTORE_SWITCH_STACK + addql #4,%sp + jra 1b + +/* + * This is the main interrupt handler, responsible for calling do_IRQ() + */ +inthandler: + SAVE_ALL + movew %sp@(PT_OFF_FORMATVEC), %d0 + and.l #0x3ff, %d0 + lsr.l #0x02, %d0 + + movel %sp,%sp@- + movel %d0,%sp@- /* put vector # on stack*/ + jbsr do_IRQ /* process the IRQ*/ +3: addql #8,%sp /* pop parameters off stack*/ + bra ret_from_interrupt + +ret_from_interrupt: + jeq 1f +2: + RESTORE_ALL +1: + moveb %sp@(PT_OFF_SR), %d0 + and #7, %d0 + jhi 2b + /* check if we need to do software interrupts */ + + movel irq_stat+CPUSTAT_SOFTIRQ_PENDING,%d0 + jeq ret_from_exception + + pea ret_from_exception + jra do_softirq + + +/* + * Handler for uninitialized and spurious interrupts. + */ +bad_interrupt: + addql #1,num_spurious + rte + +/* + * 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. + */ +ENTRY(resume) + movel %a0,%d1 /* save prev thread in d1 */ + movew %sr,%a0@(TASK_THREAD+THREAD_SR) /* save sr */ + movel %usp,%a2 /* save usp */ + movel %a2,%a0@(TASK_THREAD+THREAD_USP) + + SAVE_SWITCH_STACK + movel %sp,%a0@(TASK_THREAD+THREAD_KSP) /* save kernel stack */ + movel %a1@(TASK_THREAD+THREAD_KSP),%sp /* restore new thread stack */ + RESTORE_SWITCH_STACK + + movel %a1@(TASK_THREAD+THREAD_USP),%a0 /* restore user stack */ + movel %a0,%usp + movew %a1@(TASK_THREAD+THREAD_SR),%sr /* restore thread status reg */ + rts + |