2 * Copyright (C) 2000-2003 Axis Communications AB
4 * Authors: Bjorn Wesen (bjornw@axis.com)
5 * Tobias Anderberg (tobiasa@axis.com), CRISv32 port.
7 * Code for the system-call and fault low-level handling routines.
9 * NOTE: This code handles signal-recognition, which happens every time
10 * after a timer-interrupt and after each system call.
12 * Stack layout in 'ret_from_system_call':
13 * ptrace needs to have all regs on the stack.
14 * if the order here is changed, it needs to be
15 * updated in fork.c:copy_process, signal.c:do_signal,
16 * ptrace.c and ptrace.h
20 #include <linux/linkage.h>
21 #include <linux/sys.h>
22 #include <asm/unistd.h>
23 #include <asm/errno.h>
24 #include <asm/thread_info.h>
25 #include <asm/asm-offsets.h>
27 #include <hwregs/asm/reg_map_asm.h>
28 #include <hwregs/asm/intr_vect_defs_asm.h>
30 ;; Exported functions.
35 .globl multiple_interrupt
37 .globl spurious_interrupt
39 .globl gdb_handle_exception
42 ; Check if preemptive kernel scheduling should be done.
46 ; Load current task struct.
47 movs.w -8192, $r0 ; THREAD_SIZE = 8192
50 addoq +TI_preempt_count, $r0, $acr
51 move.d [$acr], $r10 ; Preemption disabled?
56 addoq +TI_flags, $r0, $acr
58 btstq TIF_NEED_RESCHED, $r10 ; Check if need_resched is set.
62 ; Do preemptive kernel scheduling.
63 jsr preempt_schedule_irq
66 ; Load new task struct.
67 movs.w -8192, $r0 ; THREAD_SIZE = 8192.
70 ; One more time with new task.
74 #define _resume_kernel _Rexit
77 ; Called at exit from fork. schedule_tail must be called to drop
78 ; spinlock if CONFIG_PREEMPT.
79 .type ret_from_fork,@function
85 .size ret_from_fork, . - ret_from_fork
87 .type ret_from_intr,@function
89 ;; Check for resched if preemptive kernel, or if we're going back to
90 ;; user-mode. This test matches the user_regs(regs) macro. Don't simply
91 ;; test CCS since that doesn't necessarily reflect what mode we'll
93 addoq +PT_ccs, $sp, $acr
95 btstq 16, $r0 ; User-mode flag.
97 .size ret_from_intr, . - ret_from_intr + 2 ; +2 includes the dslot.
99 ; Note that di below is in delay slot.
100 .type _resume_userspace,@function
102 di ; So need_resched and sigpending don't change.
104 movs.w -8192, $r0 ; THREAD_SIZE == 8192
107 addoq +TI_flags, $r0, $acr ; current->work
109 and.d _TIF_WORK_MASK, $r10 ; Work to be done on return?
114 .size _resume_userspace, . - _resume_userspace
116 ;; The system_call is called by a BREAK instruction, which looks pretty
117 ;; much like any other exception.
119 ;; System calls can't be made from interrupts but we still stack ERP
120 ;; to have a complete stack frame.
122 ;; In r9 we have the wanted syscall number. Arguments come in r10,r11,r12,
125 ;; This function looks on the _surface_ like spaghetti programming, but it's
126 ;; really designed so that the fast-path does not force cache-loading of
127 ;; non-used instructions. Only the non-common cases cause the outlined code
130 .type system_call,@function
132 ;; Stack-frame similar to the irq heads, which is reversed in
133 ;; ret_from_sys_call.
134 subq 12, $sp ; Skip EXS, EDA.
141 ei ; Allow IRQs while handling system call
149 subq 14*4, $sp ; Make room for R0-R13.
150 movem $r13, [$sp] ; Push R0-R13
152 move.d $r10, [$sp] ; Push orig_r10.
154 ; Set S-bit when kernel debugging to keep hardware breakpoints active.
155 #ifdef CONFIG_ETRAX_KGDB
162 addoq +PT_r10, $sp, $acr
165 ;; Check if this process is syscall-traced.
166 movs.w -8192, $r0 ; THREAD_SIZE == 8192
169 addoq +TI_flags, $r0, $acr
171 btstq TIF_SYSCALL_TRACE, $r0
172 bmi _syscall_trace_entry
176 ;; Check for sanity in the requested syscall number.
177 cmpu.w NR_syscalls, $r9
178 bhs ret_from_sys_call
179 lslq 2, $r9 ; Multiply by 4, in the delay slot.
181 ;; The location on the stack for the register structure is passed as a
182 ;; seventh argument. Some system calls need this.
187 ;; The registers carrying parameters (R10-R13) are intact. The optional
188 ;; fifth and sixth parameters is in MOF and SRP respectivly. Put them
189 ;; back on the stack.
195 ;; Actually to the system call.
196 addo.d +sys_call_table, $r9, $acr
201 addq 3*4, $sp ; Pop the mof, srp and regs parameters.
202 addoq +PT_r10, $sp, $acr
203 move.d $r10, [$acr] ; Save the return value.
205 moveq 1, $r9 ; "Parameter" to ret_from_sys_call to
206 ; show it was a sys call.
208 ;; Fall through into ret_from_sys_call to return.
211 ;; R9 is a parameter:
215 ;; Get the current task-struct pointer.
216 movs.w -8192, $r0 ; THREAD_SIZE == 8192
219 di ; Make sure need_resched and sigpending don't change.
221 addoq +TI_flags, $r0, $acr
223 and.d _TIF_ALLWORK_MASK, $r1
224 bne _syscall_exit_work
226 .size system_call, . - system_call
228 .type _Rexit,@function
230 ;; This epilogue MUST match the prologues in multiple_interrupt, irq.h
232 addq 4, $sp ; Skip orig_r10.
233 movem [$sp+], $r13 ; Registers R0-R13.
242 addq 8, $sp ; Skip EXS, EDA.
244 rfe ; Restore condition code stack in delay-slot.
245 .size _Rexit, . - _Rexit
247 ;; We get here after doing a syscall if extra work might need to be done
248 ;; perform syscall exit tracing if needed.
250 .type _syscall_exit_work,@function
252 ;; R0 contains current at this point and irq's are disabled.
254 addoq +TI_flags, $r0, $acr
256 btstq TIF_SYSCALL_TRACE, $r1
260 move.d $r9, $r1 ; Preserve R9.
266 .size _syscall_exit_work, . - _syscall_exit_work
268 .type _work_pending,@function
270 addoq +TI_flags, $r0, $acr
272 btstq TIF_NEED_RESCHED, $r10 ; Need resched?
273 bpl _work_notifysig ; No, must be signal/notify.
275 .size _work_pending, . - _work_pending
277 .type _work_resched,@function
279 move.d $r9, $r1 ; Preserve R9.
285 addoq +TI_flags, $r0, $acr
287 and.d _TIF_WORK_MASK, $r1 ; Ignore sycall trace counter.
290 btstq TIF_NEED_RESCHED, $r1
291 bmi _work_resched ; current->work.need_resched.
293 .size _work_resched, . - _work_resched
295 .type _work_notifysig,@function
297 ;; Deal with pending signals and notify-resume requests.
299 addoq +TI_flags, $r0, $acr
300 move.d [$acr], $r12 ; The thread_info_flags parameter.
301 move.d $sp, $r11 ; The regs param.
303 move.d $r9, $r10 ; do_notify_resume syscall/irq param.
307 .size _work_notifysig, . - _work_notifysig
309 ;; We get here as a sidetrack when we've entered a syscall with the
310 ;; trace-bit set. We need to call do_syscall_trace and then continue
313 _syscall_trace_entry:
314 ;; PT_r10 in the frame contains -ENOSYS as required, at this point.
319 ;; Now re-enter the syscall code to do the syscall itself. We need to
320 ;; restore R9 here to contain the wanted syscall, and the other
321 ;; parameter-bearing registers.
322 addoq +PT_r9, $sp, $acr
324 addoq +PT_orig_r10, $sp, $acr
325 move.d [$acr], $r10 ; PT_r10 is already -ENOSYS.
326 addoq +PT_r11, $sp, $acr
328 addoq +PT_r12, $sp, $acr
330 addoq +PT_r13, $sp, $acr
332 addoq +PT_mof, $sp, $acr
334 addoq +PT_srp, $sp, $acr
340 ;; Resume performs the actual task-switching, by switching stack
341 ;; pointers. Input arguments are:
345 ;; R12 = thread offset in task struct.
347 ;; Returns old current in R10.
349 .type resume,@function
352 move $srp, [$sp] ; Keep old/new PC on the stack.
353 add.d $r12, $r10 ; R10 = current tasks tss.
354 addoq +THREAD_ccs, $r10, $acr
355 move $ccs, [$acr] ; Save IRQ enable state.
358 addoq +THREAD_usp, $r10, $acr
359 move $usp, [$acr] ; Save user-mode stackpointer.
361 ;; See copy_thread for the reason why register R9 is saved.
363 movem $r9, [$sp] ; Save non-scratch registers and R9.
365 addoq +THREAD_ksp, $r10, $acr
366 move.d $sp, [$acr] ; Save kernel SP for old task.
368 move.d $sp, $r10 ; Return last running task in R10.
369 and.d -8192, $r10 ; Get thread_info from stackpointer.
370 addoq +TI_task, $r10, $acr
371 move.d [$acr], $r10 ; Get task.
372 add.d $r12, $r11 ; Find the new tasks tss.
373 addoq +THREAD_ksp, $r11, $acr
374 move.d [$acr], $sp ; Switch to new stackframe.
375 movem [$sp+], $r9 ; Restore non-scratch registers and R9.
377 addoq +THREAD_usp, $r11, $acr
378 move [$acr], $usp ; Restore user-mode stackpointer.
380 addoq +THREAD_ccs, $r11, $acr
381 move [$acr], $ccs ; Restore IRQ enable status.
383 jump $acr ; Restore PC.
385 .size resume, . - resume
389 ;; If we receive a watchdog interrupt while it is not expected, then set
390 ;; up a canonical frame and dump register contents before dying.
392 ;; This prologue MUST match the one in irq.h and the struct in ptregs.h!
393 subq 12, $sp ; Skip EXS, EDA.
407 subq 14*4, $sp ; Make room for R0-R13.
408 movem $r13, [$sp] ; Push R0-R13.
410 move.d $r10, [$sp] ; Push orig_r10.
411 move.d REG_ADDR(intr_vect, regi_irq, r_nmi), $r0
413 btstq REG_BIT(intr_vect, r_nmi, watchdog), $r0
416 jsr handle_watchdog_bite ; In time.c.
417 move.d $sp, $r10 ; Pointer to registers
418 1: btstq REG_BIT(intr_vect, r_nmi, ext), $r0
422 move.d $sp, $r10 ; Pointer to registers
423 1: addq 4, $sp ; Skip orig_r10
433 addq 8, $sp ; Skip EXS, EDA.
437 .comm cause_of_death, 4 ;; Don't declare this anywhere.
444 ;; This handles the case when multiple interrupts arrive at the same
445 ;; time. Jump to the first set interrupt bit in a priotiry fashion. The
446 ;; hardware will call the unserved interrupts after the handler
448 .type multiple_interrupt, @function
450 ;; This prologue MUST match the one in irq.h and the struct in ptregs.h!
451 subq 12, $sp ; Skip EXS, EDA.
465 subq 14*4, $sp ; Make room for R0-R13.
466 movem $r13, [$sp] ; Push R0-R13.
468 move.d $r10, [$sp] ; Push orig_r10.
470 ; Set S-bit when kernel debugging to keep hardware breakpoints active.
471 #ifdef CONFIG_ETRAX_KGDB
477 jsr crisv32_do_multiple
481 .size multiple_interrupt, . - multiple_interrupt
484 ;; Sigtraps the process that executed the BREAK instruction. Creates a
485 ;; frame that Rexit expects.
504 di ; Need to disable irq's at this point.
505 subq 14*4, $sp ; Make room for r0-r13.
506 movem $r13, [$sp] ; Push the r0-r13 registers.
508 move.d $r10, [$sp] ; Push orig_r10.
510 movs.w -8192, $r9 ; THREAD_SIZE == 8192
513 ;; thread_info as first parameter
515 moveq 5, $r11 ; SIGTRAP as second argument.
518 jump ret_from_intr ; Use the return routine for interrupts.
521 gdb_handle_exception:
524 #ifdef CONFIG_ETRAX_KGDB
525 move $ccs, $r0 ; U-flag not affected by previous insns.
526 btstq 16, $r0 ; Test the U-flag.
527 bmi _ugdb_handle_exception ; Go to user mode debugging.
528 nop ; Empty delay-slot (cannot pop R0 here).
529 ba kgdb_handle_exception ; Go to kernel debugging.
530 move.d [$sp+], $r0 ; Restore R0 in delay slot.
533 _ugdb_handle_exception:
534 ba do_sigtrap ; SIGTRAP the offending process.
535 move.d [$sp+], $r0 ; Restore R0 in delay slot.
537 .global kernel_execve
538 .type kernel_execve,@function
540 move.d __NR_execve, $r9
544 .size kernel_execve, . - kernel_execve
550 .long sys_restart_syscall ; 0 - old "setup()" system call, used
556 .long sys_open /* 5 */
561 .long sys_unlink /* 10 */
566 .long sys_chmod /* 15 */
568 .long sys_ni_syscall /* old break syscall holder */
571 .long sys_getpid /* 20 */
576 .long sys_stime /* 25 */
581 .long sys_utime /* 30 */
582 .long sys_ni_syscall /* old stty syscall holder */
583 .long sys_ni_syscall /* old gtty syscall holder */
586 .long sys_ni_syscall /* 35 old ftime syscall holder */
591 .long sys_rmdir /* 40 */
595 .long sys_ni_syscall /* old prof syscall holder */
596 .long sys_brk /* 45 */
601 .long sys_getegid16 /* 50 */
603 .long sys_umount /* recycled never used phys( */
604 .long sys_ni_syscall /* old lock syscall holder */
606 .long sys_fcntl /* 55 */
607 .long sys_ni_syscall /* old mpx syscall holder */
609 .long sys_ni_syscall /* old ulimit syscall holder */
610 .long sys_ni_syscall /* old sys_olduname holder */
611 .long sys_umask /* 60 */
616 .long sys_getpgrp /* 65 */
621 .long sys_setreuid16 /* 70 */
625 .long sys_sethostname
626 .long sys_setrlimit /* 75 */
627 .long sys_old_getrlimit
629 .long sys_gettimeofday
630 .long sys_settimeofday
631 .long sys_getgroups16 /* 80 */
632 .long sys_setgroups16
633 .long sys_select /* was old_select in Linux/E100 */
636 .long sys_readlink /* 85 */
640 .long sys_old_readdir
641 .long sys_old_mmap /* 90 */
646 .long sys_fchown16 /* 95 */
647 .long sys_getpriority
648 .long sys_setpriority
649 .long sys_ni_syscall /* old profil syscall holder */
651 .long sys_fstatfs /* 100 */
652 .long sys_ni_syscall /* sys_ioperm in i386 */
656 .long sys_getitimer /* 105 */
660 .long sys_ni_syscall /* old sys_uname holder */
661 .long sys_ni_syscall /* sys_iopl in i386 */
663 .long sys_ni_syscall /* old "idle" system call */
664 .long sys_ni_syscall /* vm86old in i386 */
666 .long sys_swapoff /* 115 */
671 .long sys_clone /* 120 */
672 .long sys_setdomainname
674 .long sys_ni_syscall /* sys_modify_ldt */
676 .long sys_mprotect /* 125 */
677 .long sys_sigprocmask
678 .long sys_ni_syscall /* old "create_module" */
679 .long sys_init_module
680 .long sys_delete_module
681 .long sys_ni_syscall /* 130: old "get_kernel_syms" */
686 .long sys_sysfs /* 135 */
687 .long sys_personality
688 .long sys_ni_syscall /* for afs_syscall */
691 .long sys_llseek /* 140 */
696 .long sys_readv /* 145 */
701 .long sys_mlock /* 150 */
705 .long sys_sched_setparam
706 .long sys_sched_getparam /* 155 */
707 .long sys_sched_setscheduler
708 .long sys_sched_getscheduler
709 .long sys_sched_yield
710 .long sys_sched_get_priority_max
711 .long sys_sched_get_priority_min /* 160 */
712 .long sys_sched_rr_get_interval
715 .long sys_setresuid16
716 .long sys_getresuid16 /* 165 */
717 .long sys_ni_syscall /* sys_vm86 */
718 .long sys_ni_syscall /* Old sys_query_module */
721 .long sys_setresgid16 /* 170 */
722 .long sys_getresgid16
724 .long sys_rt_sigreturn
725 .long sys_rt_sigaction
726 .long sys_rt_sigprocmask /* 175 */
727 .long sys_rt_sigpending
728 .long sys_rt_sigtimedwait
729 .long sys_rt_sigqueueinfo
730 .long sys_rt_sigsuspend
731 .long sys_pread64 /* 180 */
736 .long sys_capset /* 185 */
737 .long sys_sigaltstack
739 .long sys_ni_syscall /* streams1 */
740 .long sys_ni_syscall /* streams2 */
741 .long sys_vfork /* 190 */
745 .long sys_ftruncate64
746 .long sys_stat64 /* 195 */
751 .long sys_getgid /* 200 */
756 .long sys_getgroups /* 205 */
761 .long sys_setresgid /* 210 */
766 .long sys_setfsuid /* 215 */
771 .long sys_getdents64 /* 220 */
773 .long sys_ni_syscall /* reserved for TUX */
776 .long sys_readahead /* 225 */
781 .long sys_lgetxattr /* 230 */
786 .long sys_removexattr /* 235 */
787 .long sys_lremovexattr
788 .long sys_fremovexattr
791 .long sys_futex /* 240 */
792 .long sys_sched_setaffinity
793 .long sys_sched_getaffinity
794 .long sys_ni_syscall /* sys_set_thread_area */
795 .long sys_ni_syscall /* sys_get_thread_area */
796 .long sys_io_setup /* 245 */
798 .long sys_io_getevents
801 .long sys_fadvise64 /* 250 */
804 .long sys_lookup_dcookie
805 .long sys_epoll_create
806 .long sys_epoll_ctl /* 255 */
808 .long sys_remap_file_pages
809 .long sys_set_tid_address
810 .long sys_timer_create
811 .long sys_timer_settime /* 260 */
812 .long sys_timer_gettime
813 .long sys_timer_getoverrun
814 .long sys_timer_delete
815 .long sys_clock_settime
816 .long sys_clock_gettime /* 265 */
817 .long sys_clock_getres
818 .long sys_clock_nanosleep
821 .long sys_tgkill /* 270 */
823 .long sys_fadvise64_64
824 .long sys_ni_syscall /* sys_vserver */
825 .long sys_ni_syscall /* sys_mbind */
826 .long sys_ni_syscall /* 275 sys_get_mempolicy */
827 .long sys_ni_syscall /* sys_set_mempolicy */
830 .long sys_mq_timedsend
831 .long sys_mq_timedreceive /* 280 */
833 .long sys_mq_getsetattr
834 .long sys_ni_syscall /* reserved for kexec */
836 .long sys_ni_syscall /* 285 */ /* available */
838 .long sys_request_key
841 .long sys_ioprio_get /* 290 */
842 .long sys_inotify_init
843 .long sys_inotify_add_watch
844 .long sys_inotify_rm_watch
845 .long sys_migrate_pages
846 .long sys_openat /* 295 */
851 .long sys_fstatat64 /* 300 */
856 .long sys_readlinkat /* 305 */
861 .long sys_unshare /* 310 */
862 .long sys_set_robust_list
863 .long sys_get_robust_list
865 .long sys_sync_file_range
866 .long sys_tee /* 315 */
870 .long sys_epoll_pwait
871 .long sys_utimensat /* 320 */
873 .long sys_timerfd_create
876 .long sys_timerfd_settime /* 325 */
877 .long sys_timerfd_gettime
880 .long sys_epoll_create1
881 .long sys_dup3 /* 330 */
883 .long sys_inotify_init1
888 * NOTE!! This doesn't have to be exact - we just have
889 * to make sure we have _enough_ of the "sys_ni_syscall"
890 * entries. Don't panic if you notice that this hasn't
891 * been shrunk every time we add a new system call.
894 .rept NR_syscalls - (.-sys_call_table) / 4