blob: f9d27807b914b2c27d53a7b4298962cbf3664a25 [file] [log] [blame]
* Copyright (C) 2000-2003 Axis Communications AB
* Authors: Bjorn Wesen (
* Tobias Anderberg (, CRISv32 port.
* Code for 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/linkage.h>
#include <linux/sys.h>
#include <asm/unistd.h>
#include <asm/errno.h>
#include <asm/thread_info.h>
#include <asm/asm-offsets.h>
#include <asm/arch/hwregs/asm/reg_map_asm.h>
#include <asm/arch/hwregs/asm/intr_vect_defs_asm.h>
;; Exported functions.
.globl system_call
.globl ret_from_intr
.globl ret_from_fork
.globl resume
.globl multiple_interrupt
.globl nmi_interrupt
.globl spurious_interrupt
.globl do_sigtrap
.globl gdb_handle_exception
.globl sys_call_table
; Check if preemptive kernel scheduling should be done.
; Load current task struct.
movs.w -8192, $r0 ; THREAD_SIZE = 8192
and.d $sp, $r0
addoq +TI_preempt_count, $r0, $acr
move.d [$acr], $r10 ; Preemption disabled?
bne _Rexit
addoq +TI_flags, $r0, $acr
move.d [$acr], $r10
btstq TIF_NEED_RESCHED, $r10 ; Check if need_resched is set.
bpl _Rexit
; Do preemptive kernel scheduling.
jsr preempt_schedule_irq
; Load new task struct.
movs.w -8192, $r0 ; THREAD_SIZE = 8192.
and.d $sp, $r0
; One more time with new task.
ba _need_resched
#define _resume_kernel _Rexit
; Called at exit from fork. schedule_tail must be called to drop
; spinlock if CONFIG_PREEMPT.
jsr schedule_tail
ba ret_from_sys_call
;; Check for resched if preemptive kernel, or if we're going back to
;; user-mode. This test matches the user_regs(regs) macro. Don't simply
;; test CCS since that doesn't necessarily reflect what mode we'll
;; return into.
addoq +PT_ccs, $sp, $acr
move.d [$acr], $r0
btstq 16, $r0 ; User-mode flag.
bpl _resume_kernel
; Note that di below is in delay slot.
di ; So need_resched and sigpending don't change.
movs.w -8192, $r0 ; THREAD_SIZE == 8192
and.d $sp, $r0
addoq +TI_flags, $r0, $acr ; current->work
move.d [$acr], $r10
and.d _TIF_WORK_MASK, $r10 ; Work to be done on return?
bne _work_pending
ba _Rexit
;; The system_call is called by a BREAK instruction, which looks pretty
;; much like any other exception.
;; System calls can't be made from interrupts but we still stack ERP
;; to have a complete stack frame.
;; 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..
;; Stack-frame similar to the irq heads, which is reversed in
;; ret_from_sys_call.
subq 12, $sp ; Skip EXS, EDA.
move $erp, [$sp]
subq 4, $sp
move $srp, [$sp]
subq 4, $sp
move $ccs, [$sp]
subq 4, $sp
ei ; Allow IRQs while handling system call
move $spc, [$sp]
subq 4, $sp
move $mof, [$sp]
subq 4, $sp
move $srs, [$sp]
subq 4, $sp
move.d $acr, [$sp]
subq 14*4, $sp ; Make room for R0-R13.
movem $r13, [$sp] ; Push R0-R13
subq 4, $sp
move.d $r10, [$sp] ; Push orig_r10.
; Set S-bit when kernel debugging to keep hardware breakpoints active.
move $ccs, $r0
or.d (1<<9), $r0
move $r0, $ccs
movs.w -ENOSYS, $r0
addoq +PT_r10, $sp, $acr
move.d $r0, [$acr]
;; Check if this process is syscall-traced.
movs.w -8192, $r0 ; THREAD_SIZE == 8192
and.d $sp, $r0
addoq +TI_flags, $r0, $acr
move.d [$acr], $r0
bmi _syscall_trace_entry
;; Check for sanity in the requested syscall number.
cmpu.w NR_syscalls, $r9
bhs ret_from_sys_call
lslq 2, $r9 ; Multiply by 4, in the delay slot.
;; The location on the stack for the register structure is passed as a
;; seventh argument. Some system calls need this.
move.d $sp, $r0
subq 4, $sp
move.d $r0, [$sp]
;; The registers carrying parameters (R10-R13) are intact. The optional
;; fifth and sixth parameters is in MOF and SRP respectivly. Put them
;; back on the stack.
subq 4, $sp
move $srp, [$sp]
subq 4, $sp
move $mof, [$sp]
;; Actually to the system call.
addo.d +sys_call_table, $r9, $acr
move.d [$acr], $acr
jsr $acr
addq 3*4, $sp ; Pop the mof, srp and regs parameters.
addoq +PT_r10, $sp, $acr
move.d $r10, [$acr] ; 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.
;; R9 is a parameter:
;; >= 1 from syscall
;; 0 from irq
;; Get the current task-struct pointer.
movs.w -8192, $r0 ; THREAD_SIZE == 8192
and.d $sp, $r0
di ; Make sure need_resched and sigpending don't change.
addoq +TI_flags, $r0, $acr
move.d [$acr], $r1
and.d _TIF_ALLWORK_MASK, $r1
bne _syscall_exit_work
;; This epilogue MUST match the prologues in multiple_interrupt, irq.h
;; and ptregs.h.
addq 4, $sp ; Skip orig_r10.
movem [$sp+], $r13 ; Registers R0-R13.
move.d [$sp+], $acr
move [$sp], $srs
addq 4, $sp
move [$sp+], $mof
move [$sp+], $spc
move [$sp+], $ccs
move [$sp+], $srp
move [$sp+], $erp
addq 8, $sp ; Skip EXS, EDA.
jump $erp
rfe ; Restore condition code stack in delay-slot.
;; We get here after doing a syscall if extra work might need to be done
;; perform syscall exit tracing if needed.
;; R0 contains current at this point and irq's are disabled.
addoq +TI_flags, $r0, $acr
move.d [$acr], $r1
bpl _work_pending
move.d $r9, $r1 ; Preserve R9.
jsr do_syscall_trace
move.d $r1, $r9
ba _resume_userspace
addoq +TI_flags, $r0, $acr
move.d [$acr], $r10
btstq TIF_NEED_RESCHED, $r10 ; Need resched?
bpl _work_notifysig ; No, must be signal/notify.
move.d $r9, $r1 ; Preserve R9.
jsr schedule
move.d $r1, $r9
addoq +TI_flags, $r0, $acr
move.d [$acr], $r1
and.d _TIF_WORK_MASK, $r1 ; Ignore sycall trace counter.
beq _Rexit
bmi _work_resched ; current->work.need_resched.
;; Deal with pending signals and notify-resume requests.
addoq +TI_flags, $r0, $acr
move.d [$acr], $r13 ; The thread_info_flags parameter.
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.
jsr do_notify_resume
ba _Rexit
;; 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.
;; 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.
addoq +PT_r9, $sp, $acr
move.d [$acr], $r9
addoq +PT_orig_r10, $sp, $acr
move.d [$acr], $r10 ; PT_r10 is already -ENOSYS.
addoq +PT_r11, $sp, $acr
move.d [$acr], $r11
addoq +PT_r12, $sp, $acr
move.d [$acr], $r12
addoq +PT_r13, $sp, $acr
move.d [$acr], $r13
addoq +PT_mof, $sp, $acr
move [$acr], $mof
addoq +PT_srp, $sp, $acr
move [$acr], $srp
ba _syscall_traced
;; Resume performs the actual task-switching, by switching stack
;; pointers. Input arguments are:
;; R10 = prev
;; R11 = next
;; R12 = thread offset in task struct.
;; Returns old current in R10.
subq 4, $sp
move $srp, [$sp] ; Keep old/new PC on the stack.
add.d $r12, $r10 ; R10 = current tasks tss.
addoq +THREAD_ccs, $r10, $acr
move $ccs, [$acr] ; Save IRQ enable state.
addoq +THREAD_usp, $r10, $acr
move $usp, [$acr] ; 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.
addoq +THREAD_ksp, $r10, $acr
move.d $sp, [$acr] ; Save kernel SP for old task.
move.d $sp, $r10 ; Return last running task in R10.
and.d -8192, $r10 ; Get thread_info from stackpointer.
addoq +TI_task, $r10, $acr
move.d [$acr], $r10 ; Get task.
add.d $r12, $r11 ; Find the new tasks tss.
addoq +THREAD_ksp, $r11, $acr
move.d [$acr], $sp ; Switch to new stackframe.
movem [$sp+], $r9 ; Restore non-scratch registers and R9.
addoq +THREAD_usp, $r11, $acr
move [$acr], $usp ; Restore user-mode stackpointer.
addoq +THREAD_ccs, $r11, $acr
move [$acr], $ccs ; Restore IRQ enable status.
move.d [$sp+], $acr
jump $acr ; Restore PC.
;; 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!
subq 12, $sp ; Skip EXS, EDA.
move $nrp, [$sp]
subq 4, $sp
move $srp, [$sp]
subq 4, $sp
move $ccs, [$sp]
subq 4, $sp
move $spc, [$sp]
subq 4, $sp
move $mof, [$sp]
subq 4, $sp
move $srs, [$sp]
subq 4, $sp
move.d $acr, [$sp]
subq 14*4, $sp ; Make room for R0-R13.
movem $r13, [$sp] ; Push R0-R13.
subq 4, $sp
move.d $r10, [$sp] ; Push orig_r10.
move.d REG_ADDR(intr_vect, regi_irq, r_nmi), $r0
move.d [$r0], $r0
btstq REG_BIT(intr_vect, r_nmi, watchdog), $r0
bpl 1f
jsr handle_watchdog_bite ; In time.c.
move.d $sp, $r10 ; Pointer to registers
1: btstq REG_BIT(intr_vect, r_nmi, ext), $r0
bpl 1f
jsr handle_nmi
move.d $sp, $r10 ; Pointer to registers
1: addq 4, $sp ; Skip orig_r10
movem [$sp+], $r13
move.d [$sp+], $acr
move [$sp], $srs
addq 4, $sp
move [$sp+], $mof
move [$sp+], $spc
move [$sp+], $ccs
move [$sp+], $srp
move [$sp+], $nrp
addq 8, $sp ; Skip EXS, EDA.
jump $nrp
.comm cause_of_death, 4 ;; Don't declare this anywhere.
jump hard_reset_now
;; This handles the case when multiple interrupts arrive at the same
;; time. Jump to the first set interrupt bit in a priotiry fashion. The
;; hardware will call the unserved interrupts after the handler
;; finishes.
;; This prologue MUST match the one in irq.h and the struct in ptregs.h!
subq 12, $sp ; Skip EXS, EDA.
move $erp, [$sp]
subq 4, $sp
move $srp, [$sp]
subq 4, $sp
move $ccs, [$sp]
subq 4, $sp
move $spc, [$sp]
subq 4, $sp
move $mof, [$sp]
subq 4, $sp
move $srs, [$sp]
subq 4, $sp
move.d $acr, [$sp]
subq 14*4, $sp ; Make room for R0-R13.
movem $r13, [$sp] ; Push R0-R13.
subq 4, $sp
move.d $r10, [$sp] ; Push orig_r10.
; Set S-bit when kernel debugging to keep hardware breakpoints active.
move $ccs, $r0
or.d (1<<9), $r0
move $r0, $ccs
jsr crisv32_do_multiple
move.d $sp, $r10
jump ret_from_intr
;; Sigtraps the process that executed the BREAK instruction. Creates a
;; frame that Rexit expects.
subq 4, $sp
move $eda, [$sp]
subq 4, $sp
move $exs, [$sp]
subq 4, $sp
move $erp, [$sp]
subq 4, $sp
move $srp, [$sp]
subq 4, $sp
move $ccs, [$sp]
subq 4, $sp
move $spc, [$sp]
subq 4, $sp
move $mof, [$sp]
subq 4, $sp
move $srs, [$sp]
subq 4, $sp
move.d $acr, [$sp]
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.
subq 4, $sp
move.d $r10, [$sp] ; Push orig_r10.
movs.w -8192, $r9 ; THREAD_SIZE == 8192
and.d $sp, $r9
;; thread_info as first parameter
move.d $r9, $r10
moveq 5, $r11 ; SIGTRAP as second argument.
jsr ugdb_trap_user
jump ret_from_intr ; Use the return routine for interrupts.
subq 4, $sp
move.d $r0, [$sp]
move $ccs, $r0 ; U-flag not affected by previous insns.
btstq 16, $r0 ; Test the U-flag.
bmi _ugdb_handle_exception ; Go to user mode debugging.
nop ; Empty delay-slot (cannot pop R0 here).
ba kgdb_handle_exception ; Go to kernel debugging.
move.d [$sp+], $r0 ; Restore R0 in delay slot.
ba do_sigtrap ; SIGTRAP the offending process.
move.d [$sp+], $r0 ; Restore R0 in delay slot.
.section .rodata,"a"
.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