| /* -*- mode: asm -*- |
| * |
| * 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 |
| * |
| */ |
| |
| /* |
| * entry.S contains the system-call and fault low-level handling routines. |
| * This also contains the timer-interrupt handler, as well as all interrupts |
| * and faults that can result in a task-switch. |
| * |
| * NOTE: This code handles signal-recognition, which happens every time |
| * after a timer-interrupt and after each system call. |
| * |
| */ |
| |
| /* |
| * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so |
| * all pointers that used to be 'current' are now entry |
| * number 0 in the 'current_set' list. |
| * |
| * 6/05/00 RZ: addedd writeback completion after return from sighandler |
| * for 68040 |
| */ |
| |
| #include <linux/linkage.h> |
| #include <asm/entry.h> |
| #include <asm/errno.h> |
| #include <asm/setup.h> |
| #include <asm/segment.h> |
| #include <asm/traps.h> |
| #include <asm/unistd.h> |
| |
| #include <asm/asm-offsets.h> |
| |
| .globl system_call, buserr, trap, resume |
| .globl sys_call_table |
| .globl sys_fork, sys_clone, sys_vfork |
| .globl ret_from_interrupt, bad_interrupt |
| .globl auto_irqhandler_fixup |
| .globl user_irqvec_fixup, user_irqhandler_fixup |
| |
| .text |
| ENTRY(buserr) |
| SAVE_ALL_INT |
| GET_CURRENT(%d0) |
| movel %sp,%sp@- | stack frame pointer argument |
| bsrl buserr_c |
| addql #4,%sp |
| jra .Lret_from_exception |
| |
| ENTRY(trap) |
| SAVE_ALL_INT |
| GET_CURRENT(%d0) |
| movel %sp,%sp@- | stack frame pointer argument |
| bsrl trap_c |
| addql #4,%sp |
| jra .Lret_from_exception |
| |
| | After a fork we jump here directly from resume, |
| | so that %d1 contains the previous task |
| | schedule_tail now used regardless of CONFIG_SMP |
| ENTRY(ret_from_fork) |
| movel %d1,%sp@- |
| jsr schedule_tail |
| addql #4,%sp |
| jra .Lret_from_exception |
| |
| do_trace_entry: |
| movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace |
| subql #4,%sp |
| SAVE_SWITCH_STACK |
| jbsr syscall_trace |
| RESTORE_SWITCH_STACK |
| addql #4,%sp |
| movel %sp@(PT_OFF_ORIG_D0),%d0 |
| cmpl #NR_syscalls,%d0 |
| jcs syscall |
| badsys: |
| movel #-ENOSYS,%sp@(PT_OFF_D0) |
| jra ret_from_syscall |
| |
| do_trace_exit: |
| subql #4,%sp |
| SAVE_SWITCH_STACK |
| jbsr syscall_trace |
| RESTORE_SWITCH_STACK |
| addql #4,%sp |
| jra .Lret_from_exception |
| |
| ENTRY(ret_from_signal) |
| tstb %curptr@(TASK_INFO+TINFO_FLAGS+2) |
| jge 1f |
| jbsr syscall_trace |
| 1: RESTORE_SWITCH_STACK |
| addql #4,%sp |
| /* on 68040 complete pending writebacks if any */ |
| #ifdef CONFIG_M68040 |
| bfextu %sp@(PT_OFF_FORMATVEC){#0,#4},%d0 |
| subql #7,%d0 | bus error frame ? |
| jbne 1f |
| movel %sp,%sp@- |
| jbsr berr_040cleanup |
| addql #4,%sp |
| 1: |
| #endif |
| jra .Lret_from_exception |
| |
| ENTRY(system_call) |
| SAVE_ALL_SYS |
| |
| GET_CURRENT(%d1) |
| | save top of frame |
| movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0) |
| |
| | syscall trace? |
| tstb %curptr@(TASK_INFO+TINFO_FLAGS+2) |
| jmi do_trace_entry |
| cmpl #NR_syscalls,%d0 |
| jcc badsys |
| syscall: |
| jbsr @(sys_call_table,%d0:l:4)@(0) |
| movel %d0,%sp@(PT_OFF_D0) | save the return value |
| ret_from_syscall: |
| |oriw #0x0700,%sr |
| movew %curptr@(TASK_INFO+TINFO_FLAGS+2),%d0 |
| jne syscall_exit_work |
| 1: RESTORE_ALL |
| |
| syscall_exit_work: |
| btst #5,%sp@(PT_OFF_SR) | check if returning to kernel |
| bnes 1b | if so, skip resched, signals |
| lslw #1,%d0 |
| jcs do_trace_exit |
| jmi do_delayed_trace |
| lslw #8,%d0 |
| jmi do_signal_return |
| pea resume_userspace |
| jra schedule |
| |
| |
| ENTRY(ret_from_exception) |
| .Lret_from_exception: |
| btst #5,%sp@(PT_OFF_SR) | check if returning to kernel |
| bnes 1f | if so, skip resched, signals |
| | 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 |
| |
| resume_userspace: |
| moveb %curptr@(TASK_INFO+TINFO_FLAGS+3),%d0 |
| jne exit_work |
| 1: RESTORE_ALL |
| |
| exit_work: |
| | save top of frame |
| movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0) |
| lslb #1,%d0 |
| jmi do_signal_return |
| pea resume_userspace |
| jra schedule |
| |
| |
| do_signal_return: |
| |andw #ALLOWINT,%sr |
| subql #4,%sp | dummy return address |
| SAVE_SWITCH_STACK |
| pea %sp@(SWITCH_STACK_SIZE) |
| bsrl do_signal |
| addql #4,%sp |
| RESTORE_SWITCH_STACK |
| addql #4,%sp |
| jbra resume_userspace |
| |
| do_delayed_trace: |
| bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR |
| pea 1 | send SIGTRAP |
| movel %curptr,%sp@- |
| pea LSIGTRAP |
| jbsr send_sig |
| addql #8,%sp |
| addql #4,%sp |
| jbra resume_userspace |
| |
| |
| /* This is the main interrupt handler for autovector interrupts */ |
| |
| ENTRY(auto_inthandler) |
| SAVE_ALL_INT |
| GET_CURRENT(%d0) |
| addqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| | put exception # in d0 |
| bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0 |
| subw #VEC_SPUR,%d0 |
| |
| movel %sp,%sp@- |
| movel %d0,%sp@- | put vector # on stack |
| auto_irqhandler_fixup = . + 2 |
| jsr __m68k_handle_int | process the IRQ |
| addql #8,%sp | pop parameters off stack |
| |
| ret_from_interrupt: |
| subqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| jeq ret_from_last_interrupt |
| 2: RESTORE_ALL |
| |
| ALIGN |
| ret_from_last_interrupt: |
| moveq #(~ALLOWINT>>8)&0xff,%d0 |
| andb %sp@(PT_OFF_SR),%d0 |
| jne 2b |
| |
| /* check if we need to do software interrupts */ |
| tstl irq_stat+CPUSTAT_SOFTIRQ_PENDING |
| jeq .Lret_from_exception |
| pea ret_from_exception |
| jra do_softirq |
| |
| /* Handler for user defined interrupt vectors */ |
| |
| ENTRY(user_inthandler) |
| SAVE_ALL_INT |
| GET_CURRENT(%d0) |
| addqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| | put exception # in d0 |
| bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0 |
| user_irqvec_fixup = . + 2 |
| subw #VEC_USER,%d0 |
| |
| movel %sp,%sp@- |
| movel %d0,%sp@- | put vector # on stack |
| user_irqhandler_fixup = . + 2 |
| jsr __m68k_handle_int | process the IRQ |
| addql #8,%sp | pop parameters off stack |
| |
| subqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| jeq ret_from_last_interrupt |
| RESTORE_ALL |
| |
| /* Handler for uninitialized and spurious interrupts */ |
| |
| ENTRY(bad_inthandler) |
| SAVE_ALL_INT |
| GET_CURRENT(%d0) |
| addqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| |
| movel %sp,%sp@- |
| jsr handle_badint |
| addql #4,%sp |
| |
| subqb #1,%curptr@(TASK_INFO+TINFO_PREEMPT+1) |
| jeq ret_from_last_interrupt |
| RESTORE_ALL |
| |
| |
| ENTRY(sys_fork) |
| SAVE_SWITCH_STACK |
| pea %sp@(SWITCH_STACK_SIZE) |
| jbsr m68k_fork |
| addql #4,%sp |
| RESTORE_SWITCH_STACK |
| rts |
| |
| ENTRY(sys_clone) |
| SAVE_SWITCH_STACK |
| pea %sp@(SWITCH_STACK_SIZE) |
| jbsr m68k_clone |
| addql #4,%sp |
| RESTORE_SWITCH_STACK |
| rts |
| |
| ENTRY(sys_vfork) |
| SAVE_SWITCH_STACK |
| pea %sp@(SWITCH_STACK_SIZE) |
| jbsr m68k_vfork |
| addql #4,%sp |
| RESTORE_SWITCH_STACK |
| rts |
| |
| ENTRY(sys_sigreturn) |
| SAVE_SWITCH_STACK |
| jbsr do_sigreturn |
| RESTORE_SWITCH_STACK |
| rts |
| |
| ENTRY(sys_rt_sigreturn) |
| SAVE_SWITCH_STACK |
| jbsr do_rt_sigreturn |
| RESTORE_SWITCH_STACK |
| rts |
| |
| resume: |
| /* |
| * 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. |
| */ |
| |
| /* save sr */ |
| movew %sr,%a0@(TASK_THREAD+THREAD_SR) |
| |
| /* save fs (sfc,%dfc) (may be pointing to kernel memory) */ |
| movec %sfc,%d0 |
| movew %d0,%a0@(TASK_THREAD+THREAD_FS) |
| |
| /* save usp */ |
| /* it is better to use a movel here instead of a movew 8*) */ |
| movec %usp,%d0 |
| movel %d0,%a0@(TASK_THREAD+THREAD_USP) |
| |
| /* save non-scratch registers on stack */ |
| SAVE_SWITCH_STACK |
| |
| /* save current kernel stack pointer */ |
| movel %sp,%a0@(TASK_THREAD+THREAD_KSP) |
| |
| /* save floating point context */ |
| #ifndef CONFIG_M68KFPU_EMU_ONLY |
| #ifdef CONFIG_M68KFPU_EMU |
| tstl m68k_fputype |
| jeq 3f |
| #endif |
| fsave %a0@(TASK_THREAD+THREAD_FPSTATE) |
| |
| #if defined(CONFIG_M68060) |
| #if !defined(CPU_M68060_ONLY) |
| btst #3,m68k_cputype+3 |
| beqs 1f |
| #endif |
| /* The 060 FPU keeps status in bits 15-8 of the first longword */ |
| tstb %a0@(TASK_THREAD+THREAD_FPSTATE+2) |
| jeq 3f |
| #if !defined(CPU_M68060_ONLY) |
| jra 2f |
| #endif |
| #endif /* CONFIG_M68060 */ |
| #if !defined(CPU_M68060_ONLY) |
| 1: tstb %a0@(TASK_THREAD+THREAD_FPSTATE) |
| jeq 3f |
| #endif |
| 2: fmovemx %fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG) |
| fmoveml %fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL) |
| 3: |
| #endif /* CONFIG_M68KFPU_EMU_ONLY */ |
| /* Return previous task in %d1 */ |
| movel %curptr,%d1 |
| |
| /* switch to new task (a1 contains new task) */ |
| movel %a1,%curptr |
| |
| /* restore floating point context */ |
| #ifndef CONFIG_M68KFPU_EMU_ONLY |
| #ifdef CONFIG_M68KFPU_EMU |
| tstl m68k_fputype |
| jeq 4f |
| #endif |
| #if defined(CONFIG_M68060) |
| #if !defined(CPU_M68060_ONLY) |
| btst #3,m68k_cputype+3 |
| beqs 1f |
| #endif |
| /* The 060 FPU keeps status in bits 15-8 of the first longword */ |
| tstb %a1@(TASK_THREAD+THREAD_FPSTATE+2) |
| jeq 3f |
| #if !defined(CPU_M68060_ONLY) |
| jra 2f |
| #endif |
| #endif /* CONFIG_M68060 */ |
| #if !defined(CPU_M68060_ONLY) |
| 1: tstb %a1@(TASK_THREAD+THREAD_FPSTATE) |
| jeq 3f |
| #endif |
| 2: fmovemx %a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7 |
| fmoveml %a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar |
| 3: frestore %a1@(TASK_THREAD+THREAD_FPSTATE) |
| 4: |
| #endif /* CONFIG_M68KFPU_EMU_ONLY */ |
| |
| /* restore the kernel stack pointer */ |
| movel %a1@(TASK_THREAD+THREAD_KSP),%sp |
| |
| /* restore non-scratch registers */ |
| RESTORE_SWITCH_STACK |
| |
| /* restore user stack pointer */ |
| movel %a1@(TASK_THREAD+THREAD_USP),%a0 |
| movel %a0,%usp |
| |
| /* restore fs (sfc,%dfc) */ |
| movew %a1@(TASK_THREAD+THREAD_FS),%a0 |
| movec %a0,%sfc |
| movec %a0,%dfc |
| |
| /* restore status register */ |
| movew %a1@(TASK_THREAD+THREAD_SR),%sr |
| |
| rts |
| |
