--- /dev/null
+/*
+ * 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
git.openpandora.org / pandora-kernel.git / blobdiff