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+/* $Id: entry.S,v 1.23 2004/10/19 13:07:37 starvik Exp $
+ *
+ * linux/arch/cris/entry.S
+ *
+ * Copyright (C) 2000, 2001, 2002 Axis Communications AB
+ *
+ * Authors: Bjorn Wesen (bjornw@axis.com)
+ *
+ * $Log: entry.S,v $
+ * Revision 1.23 2004/10/19 13:07:37 starvik
+ * Merge of Linux 2.6.9
+ *
+ * Revision 1.22 2004/06/21 10:29:55 starvik
+ * Merge of Linux 2.6.7
+ *
+ * Revision 1.21 2004/06/09 05:30:27 starvik
+ * Clean up multiple interrupt handling.
+ * Prevent interrupts from interrupting each other.
+ * Handle all active interrupts.
+ *
+ * Revision 1.20 2004/06/08 08:55:32 starvik
+ * Removed unused code
+ *
+ * Revision 1.19 2004/06/04 11:56:15 starvik
+ * Implemented page table lookup for refills in assembler for improved performance.
+ *
+ * Revision 1.18 2004/05/11 12:28:25 starvik
+ * Merge of Linux 2.6.6
+ *
+ * Revision 1.17 2003/09/11 07:29:49 starvik
+ * Merge of Linux 2.6.0-test5
+ *
+ * Revision 1.16 2003/07/04 08:27:41 starvik
+ * Merge of Linux 2.5.74
+ *
+ * Revision 1.15 2003/04/09 07:32:55 starvik
+ * resume should return task_struct, not thread_info
+ *
+ * Revision 1.14 2003/04/09 05:20:44 starvik
+ * Merge of Linux 2.5.67
+ *
+ * Revision 1.13 2002/12/11 15:42:02 starvik
+ * Extracted v10 (ETRAX 100LX) specific stuff from arch/cris/kernel/*.c
+ *
+ * Revision 1.12 2002/12/10 09:00:10 starvik
+ * Merge of Linux 2.5.51
+ *
+ * Revision 1.11 2002/12/05 07:53:10 starvik
+ * Corrected constants used with btstq
+ *
+ * Revision 1.10 2002/11/27 08:45:10 starvik
+ * pid is in task_struct, not thread_info
+ *
+ * Revision 1.9 2002/11/26 09:52:05 starvik
+ * Added preemptive kernel scheduling (if CONFIG_PREEMPT)
+ *
+ * Revision 1.8 2002/11/20 11:56:11 starvik
+ * Merge of Linux 2.5.48
+ *
+ * Revision 1.7 2002/11/18 13:02:42 starvik
+ * Added fourth parameter to do_notify_resume
+ * Minor cleanup
+ *
+ * Revision 1.6 2002/11/11 10:37:50 starvik
+ * Use new asm-offset defines
+ * Modified for new location of current->work etc
+ * Removed SYMBOL_NAME from syscalls
+ * Added some new syscalls
+ *
+ * Revision 1.5 2002/11/05 06:45:11 starvik
+ * Merge of Linux 2.5.45
+ *
+ * Revision 1.4 2002/02/05 15:41:31 bjornw
+ * Rewritten to conform better to current 2.5 code (similar to arch/i386)
+ *
+ * Revision 1.3 2002/01/21 15:22:20 bjornw
+ * NICE_DOGGY fix from 2.4 arch/cris
+ *
+ * Revision 1.37 2001/12/07 17:03:55 bjornw
+ * Call a c-hook called watchdog_bite_hook instead of show_registers directly
+ *
+ * Revision 1.36 2001/11/22 13:36:36 bjornw
+ * * In ret_from_intr, check regs->dccr for usermode reentrance instead of
+ * DCCR explicitely (because the latter might not reflect current reality)
+ * * In mmu_bus_fault, set $r9 _after_ calling the C-code instead of before
+ * since $r9 is call-clobbered and is potentially needed afterwards
+ *
+ * Revision 1.35 2001/10/30 17:10:15 bjornw
+ * Add some syscalls
+ *
+ * Revision 1.34 2001/10/01 14:45:03 bjornw
+ * Removed underscores and added register prefixes
+ *
+ * Revision 1.33 2001/08/21 13:48:01 jonashg
+ * Added fix by HP to avoid oops when doing a hard_reset_now.
+ *
+ * Revision 1.32 2001/08/14 04:32:02 hp
+ * In _resume, add comment why R9 is saved; don't sound like it's call-saved.
+ *
+ * Revision 1.31 2001/07/25 16:07:42 bjornw
+ * softirq_active/mask -> softirq_pending only
+ *
+ * Revision 1.30 2001/07/05 01:03:32 hp
+ * - include asm/errno.h to get ENOSYS.
+ * - Use ENOSYS, not local constant LENOSYS; tweak comments.
+ * - Explain why .include, not #include is used.
+ * - Make oops-register-dump if watchdog bits and it's not expected.
+ * - Don't jsr, use jump _hard_reset_now, and skip spurious nop.
+ * - Use correct section attribute for section .rodata.
+ * - Adjust sys_ni_syscall fill number.
+ *
+ * Revision 1.29 2001/06/25 14:07:00 hp
+ * Fix review comment.
+ * * head.S: Use IO_STATE, IO_FIELD and IO_MASK constructs instead of
+ * magic numbers. Add comment that -traditional must not be used.
+ * * entry.S (SYMBOL_NAME): Change redefinition to use ## concatenation.
+ * Correct and update comment.
+ * * Makefile (.S.o): Don't use -traditional. Add comment why the
+ * toplevel rule can't be used (now that there's a reason).
+ *
+ * Revision 1.28 2001/06/21 02:00:40 hp
+ * * entry.S: Include asm/unistd.h.
+ * (_sys_call_table): Use section .rodata, not .data.
+ * (_kernel_thread): Move from...
+ * * process.c: ... here.
+ * * entryoffsets.c (VAL): Break out from...
+ * (OF): Use VAL.
+ * (LCLONE_VM): New asmified value from CLONE_VM.
+ *
+ * Revision 1.27 2001/05/29 11:25:27 markusl
+ * In case of "spurious_interrupt", do hard_reset instead of hanging system in a loop...
+ *
+ * Revision 1.26 2001/05/15 15:46:03 bjornw
+ * Include config.h now that we use some CONFIG_ options
+ *
+ * Revision 1.25 2001/05/15 05:38:47 hp
+ * Tweaked code in _ret_from_sys_call
+ *
+ * Revision 1.24 2001/05/15 05:27:49 hp
+ * Save r9 in r1 over function call rather than on stack.
+ *
+ * Revision 1.23 2001/05/15 05:10:00 hp
+ * Generate entry.S structure offsets from C
+ *
+ * Revision 1.22 2001/04/17 13:58:39 orjanf
+ * * Renamed CONFIG_KGDB to CONFIG_ETRAX_KGDB.
+ *
+ * Revision 1.21 2001/04/17 11:33:29 orjanf
+ * Updated according to review:
+ * * Included asm/sv_addr_ag.h to get macro for internal register.
+ * * Corrected comment regarding system call argument passing.
+ * * Removed comment about instruction being in a delay slot.
+ * * Added comment about SYMBOL_NAME macro.
+ *
+ * Revision 1.20 2001/04/12 08:51:07 hp
+ * - Add entry for sys_fcntl64. In fact copy last piece from i386 including ...
+ * - .rept to fill table to safe state with sys_ni_syscall.
+ *
+ * Revision 1.19 2001/04/04 09:43:32 orjanf
+ * * Moved do_sigtrap from traps.c to entry.S.
+ * * LTASK_PID need not be global anymore.
+ *
+ * Revision 1.18 2001/03/26 09:25:02 markusl
+ * Updated after review, should now handle USB interrupts correctly.
+ *
+ * Revision 1.17 2001/03/21 16:12:55 bjornw
+ * * Always make room for the cpu status record in the frame, in order to
+ * use the same framelength and layout for both mmu busfaults and normal
+ * irqs. No need to check for the explicit CRIS_FRAME_FIXUP type anymore.
+ * * Fixed bug with using addq for popping the stack in the epilogue - it
+ * destroyed the flag register. Use instructions that don't affect the
+ * flag register instead.
+ * * Removed write to R_PORT_PA_DATA during spurious_interrupt
+ *
+ * Revision 1.16 2001/03/20 19:43:02 bjornw
+ * * Get rid of esp0 setting
+ * * Give a 7th argument to a systemcall - the stackframe
+ *
+ * Revision 1.15 2001/03/05 13:14:30 bjornw
+ * Spelling fix
+ *
+ * Revision 1.14 2001/02/23 08:36:36 perf
+ * New ABI; syscallnr=r9, arg5=mof, arg6=srp.
+ * Corrected tracesys call check.
+ *
+ * Revision 1.13 2001/02/15 08:40:55 perf
+ * H-P by way of perf;
+ * - (_system_call): Don't read system call function address into r1.
+ * - (RBFExit): There is no such thing as a null pop. Adjust sp by addq.
+ * - (_system_call): Don't use r10 and don't save and restore it.
+ * - (THREAD_ESP0): New constant.
+ * - (_system_call): Inline set_esp0.
+ *
+ * Revision 1.12 2001/01/31 17:56:25 orjanf
+ * Added definition of LTASK_PID and made it global.
+ *
+ * Revision 1.11 2001/01/10 21:13:29 bjornw
+ * SYMBOL_NAME is defined incorrectly for the compiler options we currently use
+ *
+ * Revision 1.10 2000/12/18 23:47:56 bjornw
+ * * Added syscall trace support (ptrace), completely untested of course
+ * * Removed redundant check for NULL entries in syscall_table
+ *
+ * Revision 1.9 2000/11/21 16:40:51 bjornw
+ * * New frame type used when an SBFS frame needs to be popped without
+ * actually restarting the instruction
+ * * Enable interrupts in signal_return (they did so in x86, I hope it's a good
+ * idea)
+ *
+ * Revision 1.8 2000/11/17 16:53:35 bjornw
+ * Added detection of frame-type in Rexit, so that mmu_bus_fault can
+ * use ret_from_intr in the return-path to check for signals (like SEGV)
+ * and other foul things that might have occurred during the fault.
+ *
+ * Revision 1.7 2000/10/06 15:04:28 bjornw
+ * Include mof in register savings
+ *
+ * Revision 1.6 2000/09/12 16:02:44 bjornw
+ * Linux-2.4.0-test7 derived updates
+ *
+ * Revision 1.5 2000/08/17 15:35:15 bjornw
+ * 2.4.0-test6 changed local_irq_count and friends API
+ *
+ * Revision 1.4 2000/08/02 13:59:30 bjornw
+ * Removed olduname and uname from the syscall list
+ *
+ * Revision 1.3 2000/07/31 13:32:58 bjornw
+ * * Export ret_from_intr
+ * * _resume updated (prev/last tjohejsan)
+ * * timer_interrupt obsolete
+ * * SIGSEGV detection in mmu_bus_fault temporarily disabled
+ *
+ *
+ */
+
+/*
+ * entry.S contains the system-call and fault low-level handling routines.
+ *
+ * NOTE: This code handles signal-recognition, which happens every time
+ * after a timer-interrupt and after each system call.
+ *
+ * Stack layout in 'ret_from_system_call':
+ * ptrace needs to have all regs on the stack.
+ * if the order here is changed, it needs to be
+ * updated in fork.c:copy_process, signal.c:do_signal,
+ * ptrace.c and ptrace.h
+ *
+ */
+
+#include <linux/config.h>
+#include <linux/linkage.h>
+#include <linux/sys.h>
+#include <asm/unistd.h>
+#include <asm/arch/sv_addr_ag.h>
+#include <asm/errno.h>
+#include <asm/thread_info.h>
+#include <asm/arch/offset.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+ ;; functions exported from this file
+
+ .globl system_call
+ .globl ret_from_intr
+ .globl ret_from_fork
+ .globl resume
+ .globl multiple_interrupt
+ .globl hwbreakpoint
+ .globl IRQ1_interrupt
+ .globl spurious_interrupt
+ .globl hw_bp_trigs
+ .globl mmu_bus_fault
+ .globl do_sigtrap
+ .globl gdb_handle_breakpoint
+ .globl sys_call_table
+
+ ;; below are various parts of system_call which are not in the fast-path
+
+#ifdef CONFIG_PREEMPT
+ ; Check if preemptive kernel scheduling should be done
+_resume_kernel:
+ ; Load current task struct
+ movs.w -8192, $r0 ; THREAD_SIZE = 8192
+ and.d $sp, $r0
+ move.d [$r0+TI_preempt_count], $r10 ; Preemption disabled?
+ bne _Rexit
+ nop
+_need_resched:
+ move.d [$r0+TI_flags], $r10
+ btstq TIF_NEED_RESCHED, $r10 ; Check if need_resched is set
+ bpl _Rexit
+ nop
+ ; Ok, lets's do some preemptive kernel scheduling
+ move.d PREEMPT_ACTIVE, $r10
+ move.d $r10, [$r0+TI_preempt_count] ; Mark as active
+ ei
+ jsr schedule
+ clear.d [$r0+TI_preempt_count] ; Mark as inactive
+ di
+ ; Load new task struct
+ movs.w -8192, $r0 ; THREAD_SIZE = 8192
+ and.d $sp, $r0
+ ; One more time (with new task)
+ ba _need_resched
+ nop
+#else
+#define _resume_kernel _Rexit
+#endif
+
+ ; Called at exit from fork. schedule_tail must be called to drop
+ ; spinlock if CONFIG_PREEMPT
+ret_from_fork:
+ jsr schedule_tail
+ ba ret_from_sys_call
+ nop
+
+ret_from_intr:
+ ;; check for resched if preemptive kernel or if we're going back to user-mode
+ ;; this test matches the user_regs(regs) macro
+ ;; we cannot simply test $dccr, because that does not necessarily
+ ;; reflect what mode we'll return into.
+
+ move.d [$sp + PT_dccr], $r0; regs->dccr
+ btstq 8, $r0 ; U-flag
+ bpl _resume_kernel
+ ; Note that di below is in delay slot
+
+_resume_userspace:
+ di ; so need_resched and sigpending don't change
+
+ movs.w -8192, $r0 ; THREAD_SIZE == 8192
+ and.d $sp, $r0
+
+ move.d [$r0+TI_flags], $r10 ; current->work
+ and.d _TIF_WORK_MASK, $r10 ; is there any work to be done on return
+ bne _work_pending
+ nop
+ ba _Rexit
+ nop
+
+ ;; The system_call is called by a BREAK instruction, which works like
+ ;; an interrupt call but it stores the return PC in BRP instead of IRP.
+ ;; Since we dont really want to have two epilogues (one for system calls
+ ;; and one for interrupts) we push the contents of BRP instead of IRP in the
+ ;; system call prologue, to make it look like an ordinary interrupt on the
+ ;; stackframe.
+ ;;
+ ;; Since we can't have system calls inside interrupts, it should not matter
+ ;; that we don't stack IRP.
+ ;;
+ ;; In r9 we have the wanted syscall number. Arguments come in r10,r11,r12,r13,mof,srp
+ ;;
+ ;; This function looks on the _surface_ like spaghetti programming, but it's
+ ;; really designed so that the fast-path does not force cache-loading of non-used
+ ;; instructions. Only the non-common cases cause the outlined code to run..
+
+system_call:
+ ;; stack-frame similar to the irq heads, which is reversed in ret_from_sys_call
+ move $brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+ push $srp
+ push $dccr
+ push $mof
+ subq 14*4, $sp ; make room for r0-r13
+ movem $r13, [$sp] ; push r0-r13
+ push $r10 ; push orig_r10
+ clear.d [$sp=$sp-4] ; frametype == 0, normal stackframe
+
+ movs.w -ENOSYS, $r0
+ move.d $r0, [$sp+PT_r10] ; put the default return value in r10 in the frame
+
+ ;; check if this process is syscall-traced
+
+ movs.w -8192, $r0 ; THREAD_SIZE == 8192
+ and.d $sp, $r0
+
+ move.d [$r0+TI_flags], $r0
+ btstq TIF_SYSCALL_TRACE, $r0
+ bmi _syscall_trace_entry
+ nop
+
+_syscall_traced:
+
+ ;; check for sanity in the requested syscall number
+
+ cmpu.w NR_syscalls, $r9
+ bcc ret_from_sys_call
+ lslq 2, $r9 ; multiply by 4, in the delay slot
+
+ ;; as a bonus 7th parameter, we give the location on the stack
+ ;; of the register structure itself. some syscalls need this.
+
+ push $sp
+
+ ;; the parameter carrying registers r10, r11, r12 and 13 are intact.
+ ;; the fifth and sixth parameters (if any) was in mof and srp
+ ;; respectively, and we need to put them on the stack.
+
+ push $srp
+ push $mof
+
+ jsr [$r9+sys_call_table] ; actually do the system call
+ addq 3*4, $sp ; pop the mof, srp and regs parameters
+ move.d $r10, [$sp+PT_r10] ; save the return value
+
+ moveq 1, $r9 ; "parameter" to ret_from_sys_call to show it was a sys call
+
+ ;; fall through into ret_from_sys_call to return
+
+ret_from_sys_call:
+ ;; r9 is a parameter - if >=1 we came from a syscall, if 0, from an irq
+
+ ;; get the current task-struct pointer (see top for defs)
+
+ movs.w -8192, $r0 ; THREAD_SIZE == 8192
+ and.d $sp, $r0
+
+ di ; make sure need_resched and sigpending don't change
+ move.d [$r0+TI_flags],$r1
+ and.d _TIF_ALLWORK_MASK, $r1
+ bne _syscall_exit_work
+ nop
+
+_Rexit:
+ ;; this epilogue MUST match the prologues in multiple_interrupt, irq.h and ptregs.h
+ pop $r10 ; frametype
+ bne _RBFexit ; was not CRIS_FRAME_NORMAL, handle otherwise
+ addq 4, $sp ; skip orig_r10, in delayslot
+ movem [$sp+], $r13 ; registers r0-r13
+ pop $mof ; multiply overflow register
+ pop $dccr ; condition codes
+ pop $srp ; subroutine return pointer
+ ;; now we have a 4-word SBFS frame which we do not want to restore
+ ;; using RBF since it was not stacked with SBFS. instead we would like to
+ ;; just get the PC value to restart it with, and skip the rest of
+ ;; the frame.
+ ;; Also notice that it's important to use instructions here that
+ ;; keep the interrupts disabled (since we've already popped DCCR)
+ move [$sp=$sp+16], $p8; pop the SBFS frame from the sp
+ jmpu [$sp-16] ; return through the irp field in the sbfs frame
+
+_RBFexit:
+ movem [$sp+], $r13 ; registers r0-r13, in delay slot
+ pop $mof ; multiply overflow register
+ pop $dccr ; condition codes
+ pop $srp ; subroutine return pointer
+ rbf [$sp+] ; return by popping the CPU status
+
+ ;; We get here after doing a syscall if extra work might need to be done
+ ;; perform syscall exit tracing if needed
+
+_syscall_exit_work:
+ ;; $r0 contains current at this point and irq's are disabled
+
+ move.d [$r0+TI_flags], $r1
+ btstq TIF_SYSCALL_TRACE, $r1
+ bpl _work_pending
+ nop
+
+ ei
+
+ move.d $r9, $r1 ; preserve r9
+ jsr do_syscall_trace
+ move.d $r1, $r9
+
+ ba _resume_userspace
+ nop
+
+_work_pending:
+ move.d [$r0+TI_flags], $r1
+ btstq TIF_NEED_RESCHED, $r1
+ bpl _work_notifysig ; was neither trace nor sched, must be signal/notify
+ nop
+
+_work_resched:
+ move.d $r9, $r1 ; preserve r9
+ jsr schedule
+ move.d $r1, $r9
+ di
+
+ move.d [$r0+TI_flags], $r1
+ and.d _TIF_WORK_MASK, $r1; ignore the syscall trace counter
+ beq _Rexit
+ nop
+ btstq TIF_NEED_RESCHED, $r1
+ bmi _work_resched ; current->work.need_resched
+ nop
+
+_work_notifysig:
+ ;; deal with pending signals and notify-resume requests
+
+ move.d $r9, $r10 ; do_notify_resume syscall/irq param
+ moveq 0, $r11 ; oldset param - 0 in this case
+ move.d $sp, $r12 ; the regs param
+ move.d $r1, $r13 ; the thread_info_flags parameter
+ jsr do_notify_resume
+
+ ba _Rexit
+ nop
+
+ ;; We get here as a sidetrack when we've entered a syscall with the
+ ;; trace-bit set. We need to call do_syscall_trace and then continue
+ ;; with the call.
+
+_syscall_trace_entry:
+ ;; PT_r10 in the frame contains -ENOSYS as required, at this point
+
+ jsr do_syscall_trace
+
+ ;; now re-enter the syscall code to do the syscall itself
+ ;; we need to restore $r9 here to contain the wanted syscall, and
+ ;; the other parameter-bearing registers
+
+ move.d [$sp+PT_r9], $r9
+ move.d [$sp+PT_orig_r10], $r10 ; PT_r10 is already filled with -ENOSYS.
+ move.d [$sp+PT_r11], $r11
+ move.d [$sp+PT_r12], $r12
+ move.d [$sp+PT_r13], $r13
+ move [$sp+PT_mof], $mof
+ move [$sp+PT_srp], $srp
+
+ ba _syscall_traced
+ nop
+
+ ;; resume performs the actual task-switching, by switching stack pointers
+ ;; input arguments: r10 = prev, r11 = next, r12 = thread offset in task struct
+ ;; returns old current in r10
+ ;;
+ ;; TODO: see the i386 version. The switch_to which calls resume in our version
+ ;; could really be an inline asm of this.
+
+resume:
+ push $srp ; we keep the old/new PC on the stack
+ add.d $r12, $r10 ; r10 = current tasks tss
+ move $dccr, [$r10+THREAD_dccr]; save irq enable state
+ di
+
+ move $usp, [$r10+ THREAD_usp] ; save user-mode stackpointer
+
+ ;; See copy_thread for the reason why register R9 is saved.
+ subq 10*4, $sp
+ movem $r9, [$sp] ; save non-scratch registers and R9.
+
+ move.d $sp, [$r10+THREAD_ksp] ; save the kernel stack pointer for the old task
+ move.d $sp, $r10 ; return last running task in r10
+ and.d -8192, $r10 ; get thread_info from stackpointer
+ move.d [$r10+TI_task], $r10 ; get task
+ add.d $r12, $r11 ; find the new tasks tss
+ move.d [$r11+THREAD_ksp], $sp ; switch into the new stackframe by restoring kernel sp
+
+ movem [$sp+], $r9 ; restore non-scratch registers and R9.
+
+ move [$r11+THREAD_usp], $usp ; restore user-mode stackpointer
+
+ move [$r11+THREAD_dccr], $dccr ; restore irq enable status
+ jump [$sp+] ; restore PC
+
+ ;; This is the MMU bus fault handler.
+ ;; It needs to stack the CPU status and overall is different
+ ;; from the other interrupt handlers.
+
+mmu_bus_fault:
+ ;; For refills we try to do a quick page table lookup. If it is
+ ;; a real fault we let the mm subsystem handle it.
+
+ ;; the first longword in the sbfs frame was the interrupted PC
+ ;; which fits nicely with the "IRP" slot in pt_regs normally used to
+ ;; contain the return address. used by Oops to print kernel errors.
+ sbfs [$sp=$sp-16] ; push the internal CPU status
+ push $dccr
+ di
+ subq 2*4, $sp
+ movem $r1, [$sp]
+ move.d [R_MMU_CAUSE], $r1
+ ;; ETRAX 100LX TR89 bugfix: if the second half of an unaligned
+ ;; write causes a MMU-fault, it will not be restarted correctly.
+ ;; This could happen if a write crosses a page-boundary and the
+ ;; second page is not yet COW'ed or even loaded. The workaround
+ ;; is to clear the unaligned bit in the CPU status record, so
+ ;; that the CPU will rerun both the first and second halves of
+ ;; the instruction. This will not have any sideeffects unless
+ ;; the first half goes to any device or memory that can't be
+ ;; written twice, and which is mapped through the MMU.
+ ;;
+ ;; We only need to do this for writes.
+ btstq 8, $r1 ; Write access?
+ bpl 1f
+ nop
+ move.d [$sp+16], $r0 ; Clear unaligned bit in csrinstr
+ and.d ~(1<<5), $r0
+ move.d $r0, [$sp+16]
+1: btstq 12, $r1 ; Refill?
+ bpl 2f
+ lsrq PMD_SHIFT, $r1 ; Get PMD index into PGD (bit 24-31)
+ move.d [current_pgd], $r0 ; PGD for the current process
+ move.d [$r0+$r1.d], $r0 ; Get PMD
+ beq 2f
+ nop
+ and.w PAGE_MASK, $r0 ; Remove PMD flags
+ move.d [R_MMU_CAUSE], $r1
+ lsrq PAGE_SHIFT, $r1
+ and.d 0x7ff, $r1 ; Get PTE index into PMD (bit 13-24)
+ move.d [$r0+$r1.d], $r1 ; Get PTE
+ beq 2f
+ nop
+ ;; Store in TLB
+ move.d $r1, [R_TLB_LO]
+ ;; Return
+ movem [$sp+], $r1
+ pop $dccr
+ rbf [$sp+] ; return by popping the CPU status
+
+2: ; PMD or PTE missing, let the mm subsystem fix it up.
+ movem [$sp+], $r1
+ pop $dccr
+
+ ; Ok, not that easy, pass it on to the mm subsystem
+ ; The MMU status record is now on the stack
+ push $srp ; make a stackframe similar to pt_regs
+ push $dccr
+ push $mof
+ di
+ subq 14*4, $sp
+ movem $r13, [$sp]
+ push $r10 ; dummy orig_r10
+ moveq 1, $r10
+ push $r10 ; frametype == 1, BUSFAULT frame type
+
+ move.d $sp, $r10 ; pt_regs argument to handle_mmu_bus_fault
+
+ jsr handle_mmu_bus_fault ; in arch/cris/arch-v10/mm/fault.c
+
+ ;; now we need to return through the normal path, we cannot just
+ ;; do the RBFexit since we might have killed off the running
+ ;; process due to a SEGV, scheduled due to a page blocking or
+ ;; whatever.
+
+ moveq 0, $r9 ; busfault is equivalent to an irq
+
+ ba ret_from_intr
+ nop
+
+ ;; special handlers for breakpoint and NMI
+hwbreakpoint:
+ push $dccr
+ di
+ push $r10
+ push $r11
+ move.d [hw_bp_trig_ptr],$r10
+ move $brp,$r11
+ move.d $r11,[$r10+]
+ move.d $r10,[hw_bp_trig_ptr]
+1: pop $r11
+ pop $r10
+ pop $dccr
+ retb
+ nop
+
+IRQ1_interrupt:
+
+#if defined(CONFIG_ETRAX_WATCHDOG) && !defined(CONFIG_SVINTO_SIM)
+;; If we receive a watchdog interrupt while it is not expected, then set
+;; up a canonical frame and dump register contents before dying.
+
+ ;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
+ move $brp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+ push $srp
+ push $dccr
+ push $mof
+ di
+ subq 14*4, $sp
+ movem $r13, [$sp]
+ push $r10 ; push orig_r10
+ clear.d [$sp=$sp-4] ; frametype == 0, normal frame
+
+;; We don't check that we actually were bit by the watchdog as opposed to
+;; an external NMI, since there is currently no handler for external NMI.
+
+;; Check if we're waiting for reset to happen, as signalled by
+;; hard_reset_now setting cause_of_death to a magic value. If so, just
+;; get stuck until reset happens.
+ .comm cause_of_death, 4 ;; Don't declare this anywhere.
+ move.d [cause_of_death], $r10
+ cmp.d 0xbedead, $r10
+_killed_by_death:
+ beq _killed_by_death
+ nop
+
+;; We'll see this in ksymoops dumps.
+Watchdog_bite:
+
+#ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
+ ;; We just restart the watchdog here to be sure we dont get
+ ;; hit while printing the watchdogmsg below
+ ;; This restart is compatible with the rest of the C-code, so
+ ;; the C-code can keep restarting the watchdog after this point.
+ ;; The non-NICE_DOGGY code below though, disables the possibility
+ ;; to restart since it changes the watchdog key, to avoid any
+ ;; buggy loops etc. keeping the watchdog alive after this.
+ jsr reset_watchdog
+#else
+
+;; We need to extend the 3.3ms after the NMI at watchdog bite, so we have
+;; time for an oops-dump over a 115k2 serial wire. Another 100ms should do.
+
+;; Change the watchdog key to an arbitrary 3-bit value and restart the
+;; watchdog.
+#define WD_INIT 2
+ moveq IO_FIELD (R_WATCHDOG, key, WD_INIT), $r10
+ move.d R_WATCHDOG, $r11
+
+ move.d $r10, [$r11]
+ moveq IO_FIELD (R_WATCHDOG, key, \
+ IO_EXTRACT (R_WATCHDOG, key, \
+ IO_MASK (R_WATCHDOG, key)) \
+ ^ WD_INIT) \
+ | IO_STATE (R_WATCHDOG, enable, start), $r10
+ move.d $r10, [$r11]
+
+#endif
+
+;; Note that we don't do "setf m" here (or after two necessary NOPs),
+;; since *not* doing that saves us from re-entrancy checks. We don't want
+;; to get here again due to possible subsequent NMIs; we want the watchdog
+;; to reset us.
+
+ move.d _watchdogmsg,$r10
+ jsr printk
+
+ move.d $sp, $r10
+ jsr watchdog_bite_hook
+
+;; This nop is here so we see the "Watchdog_bite" label in ksymoops dumps
+;; rather than "spurious_interrupt".
+ nop
+;; At this point we drop down into spurious_interrupt, which will do a
+;; hard reset.
+
+ .section .rodata,"a"
+_watchdogmsg:
+ .ascii "Oops: bitten by watchdog\n\0"
+ .previous
+
+#endif /* CONFIG_ETRAX_WATCHDOG and not CONFIG_SVINTO_SIM */
+
+spurious_interrupt:
+ di
+ jump hard_reset_now
+
+ ;; this handles the case when multiple interrupts arrive at the same time
+ ;; we jump to the first set interrupt bit in a priority fashion
+ ;; the hardware will call the unserved interrupts after the handler finishes
+
+multiple_interrupt:
+ ;; this prologue MUST match the one in irq.h and the struct in ptregs.h!!!
+ move $irp,[$sp=$sp-16]; instruction pointer and room for a fake SBFS frame
+ push $srp
+ push $dccr
+ push $mof
+ di
+ subq 14*4, $sp
+ movem $r13, [$sp]
+ push $r10 ; push orig_r10
+ clear.d [$sp=$sp-4] ; frametype == 0, normal frame
+
+ moveq 2, $r2 ; first bit we care about is the timer0 irq
+ move.d [R_VECT_MASK_RD], $r0; read the irq bits that triggered the multiple irq
+ move.d $r0, [R_VECT_MASK_CLR] ; Block all active IRQs
+1:
+ btst $r2, $r0 ; check for the irq given by bit r2
+ bpl 2f
+ move.d $r2, $r10 ; First argument to do_IRQ
+ move.d $sp, $r11 ; second argument to do_IRQ
+ jsr do_IRQ
+2:
+ addq 1, $r2 ; next vector bit
+ cmp.b 32, $r2
+ bne 1b ; process all irq's up to and including number 31
+ moveq 0, $r9 ; make ret_from_intr realise we came from an ir
+
+ move.d $r0, [R_VECT_MASK_SET] ; Unblock all the IRQs
+ jump ret_from_intr
+
+do_sigtrap:
+ ;;
+ ;; SIGTRAP the process that executed the break instruction.
+ ;; Make a frame that Rexit in entry.S expects.
+ ;;
+ move $brp, [$sp=$sp-16] ; Push BRP while faking a cpu status record.
+ push $srp ; Push subroutine return pointer.
+ push $dccr ; Push condition codes.
+ push $mof ; Push multiply overflow reg.
+ di ; Need to disable irq's at this point.
+ subq 14*4, $sp ; Make room for r0-r13.
+ movem $r13, [$sp] ; Push the r0-r13 registers.
+ push $r10 ; Push orig_r10.
+ clear.d [$sp=$sp-4] ; Frametype - this is a normal stackframe.
+
+ movs.w -8192,$r9 ; THREAD_SIZE == 8192
+ and.d $sp, $r9
+ move.d [$r9+TI_task], $r10
+ move.d [$r10+TASK_pid], $r10 ; current->pid as arg1.
+ moveq 5, $r11 ; SIGTRAP as arg2.
+ jsr sys_kill
+ jump ret_from_intr ; Use the return routine for interrupts.
+
+gdb_handle_breakpoint:
+ push $dccr
+ push $r0
+#ifdef CONFIG_ETRAX_KGDB
+ move $dccr, $r0 ; U-flag not affected by previous insns.
+ btstq 8, $r0 ; Test the U-flag.
+ bmi _ugdb_handle_breakpoint ; Go to user mode debugging.
+ nop ; Empty delay slot (cannot pop r0 here).
+ pop $r0 ; Restore r0.
+ ba kgdb_handle_breakpoint ; Go to kernel debugging.
+ pop $dccr ; Restore dccr in delay slot.
+#endif
+
+_ugdb_handle_breakpoint:
+ move $brp, $r0 ; Use r0 temporarily for calculation.
+ subq 2, $r0 ; Set to address of previous instruction.
+ move $r0, $brp
+ pop $r0 ; Restore r0.
+ ba do_sigtrap ; SIGTRAP the offending process.
+ pop $dccr ; Restore dccr in delay slot.
+
+ .data
+
+hw_bp_trigs:
+ .space 64*4
+hw_bp_trig_ptr:
+ .dword hw_bp_trigs
+
+ .section .rodata,"a"
+sys_call_table:
+ .long sys_restart_syscall /* 0 - old "setup()" system call, used for restarting */
+ .long sys_exit
+ .long sys_fork
+ .long sys_read
+ .long sys_write
+ .long sys_open /* 5 */
+ .long sys_close
+ .long sys_waitpid
+ .long sys_creat
+ .long sys_link
+ .long sys_unlink /* 10 */
+ .long sys_execve
+ .long sys_chdir
+ .long sys_time
+ .long sys_mknod
+ .long sys_chmod /* 15 */
+ .long sys_lchown16
+ .long sys_ni_syscall /* old break syscall holder */
+ .long sys_stat
+ .long sys_lseek
+ .long sys_getpid /* 20 */
+ .long sys_mount
+ .long sys_oldumount
+ .long sys_setuid16
+ .long sys_getuid16
+ .long sys_stime /* 25 */
+ .long sys_ptrace
+ .long sys_alarm
+ .long sys_fstat
+ .long sys_pause
+ .long sys_utime /* 30 */
+ .long sys_ni_syscall /* old stty syscall holder */
+ .long sys_ni_syscall /* old gtty syscall holder */
+ .long sys_access
+ .long sys_nice
+ .long sys_ni_syscall /* 35 old ftime syscall holder */
+ .long sys_sync
+ .long sys_kill
+ .long sys_rename
+ .long sys_mkdir
+ .long sys_rmdir /* 40 */
+ .long sys_dup
+ .long sys_pipe
+ .long sys_times
+ .long sys_ni_syscall /* old prof syscall holder */
+ .long sys_brk /* 45 */
+ .long sys_setgid16
+ .long sys_getgid16
+ .long sys_signal
+ .long sys_geteuid16
+ .long sys_getegid16 /* 50 */
+ .long sys_acct
+ .long sys_umount /* recycled never used phys( */
+ .long sys_ni_syscall /* old lock syscall holder */
+ .long sys_ioctl
+ .long sys_fcntl /* 55 */
+ .long sys_ni_syscall /* old mpx syscall holder */
+ .long sys_setpgid
+ .long sys_ni_syscall /* old ulimit syscall holder */
+ .long sys_ni_syscall /* old sys_olduname holder */
+ .long sys_umask /* 60 */
+ .long sys_chroot
+ .long sys_ustat
+ .long sys_dup2
+ .long sys_getppid
+ .long sys_getpgrp /* 65 */
+ .long sys_setsid
+ .long sys_sigaction
+ .long sys_sgetmask
+ .long sys_ssetmask
+ .long sys_setreuid16 /* 70 */
+ .long sys_setregid16
+ .long sys_sigsuspend
+ .long sys_sigpending
+ .long sys_sethostname
+ .long sys_setrlimit /* 75 */
+ .long sys_old_getrlimit
+ .long sys_getrusage
+ .long sys_gettimeofday
+ .long sys_settimeofday
+ .long sys_getgroups16 /* 80 */
+ .long sys_setgroups16
+ .long sys_select /* was old_select in Linux/E100 */
+ .long sys_symlink
+ .long sys_lstat
+ .long sys_readlink /* 85 */
+ .long sys_uselib
+ .long sys_swapon
+ .long sys_reboot
+ .long old_readdir
+ .long old_mmap /* 90 */
+ .long sys_munmap
+ .long sys_truncate
+ .long sys_ftruncate
+ .long sys_fchmod
+ .long sys_fchown16 /* 95 */
+ .long sys_getpriority
+ .long sys_setpriority
+ .long sys_ni_syscall /* old profil syscall holder */
+ .long sys_statfs
+ .long sys_fstatfs /* 100 */
+ .long sys_ni_syscall /* sys_ioperm in i386 */
+ .long sys_socketcall
+ .long sys_syslog
+ .long sys_setitimer
+ .long sys_getitimer /* 105 */
+ .long sys_newstat
+ .long sys_newlstat
+ .long sys_newfstat
+ .long sys_ni_syscall /* old sys_uname holder */
+ .long sys_ni_syscall /* sys_iopl in i386 */
+ .long sys_vhangup
+ .long sys_ni_syscall /* old "idle" system call */
+ .long sys_ni_syscall /* vm86old in i386 */
+ .long sys_wait4
+ .long sys_swapoff /* 115 */
+ .long sys_sysinfo
+ .long sys_ipc
+ .long sys_fsync
+ .long sys_sigreturn
+ .long sys_clone /* 120 */
+ .long sys_setdomainname
+ .long sys_newuname
+ .long sys_ni_syscall /* sys_modify_ldt */
+ .long sys_adjtimex
+ .long sys_mprotect /* 125 */
+ .long sys_sigprocmask
+ .long sys_ni_syscall /* old "create_module" */
+ .long sys_init_module
+ .long sys_delete_module
+ .long sys_ni_syscall /* 130: old "get_kernel_syms" */
+ .long sys_quotactl
+ .long sys_getpgid
+ .long sys_fchdir
+ .long sys_bdflush
+ .long sys_sysfs /* 135 */
+ .long sys_personality
+ .long sys_ni_syscall /* for afs_syscall */
+ .long sys_setfsuid16
+ .long sys_setfsgid16
+ .long sys_llseek /* 140 */
+ .long sys_getdents
+ .long sys_select
+ .long sys_flock
+ .long sys_msync
+ .long sys_readv /* 145 */
+ .long sys_writev
+ .long sys_getsid
+ .long sys_fdatasync
+ .long sys_sysctl
+ .long sys_mlock /* 150 */
+ .long sys_munlock
+ .long sys_mlockall
+ .long sys_munlockall
+ .long sys_sched_setparam
+ .long sys_sched_getparam /* 155 */
+ .long sys_sched_setscheduler
+ .long sys_sched_getscheduler
+ .long sys_sched_yield
+ .long sys_sched_get_priority_max
+ .long sys_sched_get_priority_min /* 160 */
+ .long sys_sched_rr_get_interval
+ .long sys_nanosleep
+ .long sys_mremap
+ .long sys_setresuid16
+ .long sys_getresuid16 /* 165 */
+ .long sys_ni_syscall /* sys_vm86 */
+ .long sys_ni_syscall /* Old sys_query_module */
+ .long sys_poll
+ .long sys_nfsservctl
+ .long sys_setresgid16 /* 170 */
+ .long sys_getresgid16
+ .long sys_prctl
+ .long sys_rt_sigreturn
+ .long sys_rt_sigaction
+ .long sys_rt_sigprocmask /* 175 */
+ .long sys_rt_sigpending
+ .long sys_rt_sigtimedwait
+ .long sys_rt_sigqueueinfo
+ .long sys_rt_sigsuspend
+ .long sys_pread64 /* 180 */
+ .long sys_pwrite64
+ .long sys_chown16
+ .long sys_getcwd
+ .long sys_capget
+ .long sys_capset /* 185 */
+ .long sys_sigaltstack
+ .long sys_sendfile
+ .long sys_ni_syscall /* streams1 */
+ .long sys_ni_syscall /* streams2 */
+ .long sys_vfork /* 190 */
+ .long sys_getrlimit
+ .long sys_mmap2
+ .long sys_truncate64
+ .long sys_ftruncate64
+ .long sys_stat64 /* 195 */
+ .long sys_lstat64
+ .long sys_fstat64
+ .long sys_lchown
+ .long sys_getuid
+ .long sys_getgid /* 200 */
+ .long sys_geteuid
+ .long sys_getegid
+ .long sys_setreuid
+ .long sys_setregid
+ .long sys_getgroups /* 205 */
+ .long sys_setgroups
+ .long sys_fchown
+ .long sys_setresuid
+ .long sys_getresuid
+ .long sys_setresgid /* 210 */
+ .long sys_getresgid
+ .long sys_chown
+ .long sys_setuid
+ .long sys_setgid
+ .long sys_setfsuid /* 215 */
+ .long sys_setfsgid
+ .long sys_pivot_root
+ .long sys_mincore
+ .long sys_madvise
+ .long sys_getdents64 /* 220 */
+ .long sys_fcntl64
+ .long sys_ni_syscall /* reserved for TUX */
+ .long sys_ni_syscall
+ .long sys_gettid
+ .long sys_readahead /* 225 */
+ .long sys_setxattr
+ .long sys_lsetxattr
+ .long sys_fsetxattr
+ .long sys_getxattr
+ .long sys_lgetxattr /* 230 */
+ .long sys_fgetxattr
+ .long sys_listxattr
+ .long sys_llistxattr
+ .long sys_flistxattr
+ .long sys_removexattr /* 235 */
+ .long sys_lremovexattr
+ .long sys_fremovexattr
+ .long sys_tkill
+ .long sys_sendfile64
+ .long sys_futex /* 240 */
+ .long sys_sched_setaffinity
+ .long sys_sched_getaffinity
+ .long sys_ni_syscall /* sys_set_thread_area */
+ .long sys_ni_syscall /* sys_get_thread_area */
+ .long sys_io_setup /* 245 */
+ .long sys_io_destroy
+ .long sys_io_getevents
+ .long sys_io_submit
+ .long sys_io_cancel
+ .long sys_fadvise64 /* 250 */
+ .long sys_ni_syscall
+ .long sys_exit_group
+ .long sys_lookup_dcookie
+ .long sys_epoll_create
+ .long sys_epoll_ctl /* 255 */
+ .long sys_epoll_wait
+ .long sys_remap_file_pages
+ .long sys_set_tid_address
+ .long sys_timer_create
+ .long sys_timer_settime /* 260 */
+ .long sys_timer_gettime
+ .long sys_timer_getoverrun
+ .long sys_timer_delete
+ .long sys_clock_settime
+ .long sys_clock_gettime /* 265 */
+ .long sys_clock_getres
+ .long sys_clock_nanosleep
+ .long sys_statfs64
+ .long sys_fstatfs64
+ .long sys_tgkill /* 270 */
+ .long sys_utimes
+ .long sys_fadvise64_64
+ .long sys_ni_syscall /* sys_vserver */
+ .long sys_ni_syscall /* sys_mbind */
+ .long sys_ni_syscall /* 275 sys_get_mempolicy */
+ .long sys_ni_syscall /* sys_set_mempolicy */
+ .long sys_mq_open
+ .long sys_mq_unlink
+ .long sys_mq_timedsend
+ .long sys_mq_timedreceive /* 280 */
+ .long sys_mq_notify
+ .long sys_mq_getsetattr
+ .long sys_ni_syscall /* reserved for kexec */
+ .long sys_waitid
+
+ /*
+ * NOTE!! This doesn't have to be exact - we just have
+ * to make sure we have _enough_ of the "sys_ni_syscall"
+ * entries. Don't panic if you notice that this hasn't
+ * been shrunk every time we add a new system call.
+ */
+
+ .rept NR_syscalls-(.-sys_call_table)/4
+ .long sys_ni_syscall
+ .endr
+