/* * Copyright (C) 2000-2003 Axis Communications AB * * Authors: Bjorn Wesen (bjornw@axis.com) * Tobias Anderberg (tobiasa@axis.com), 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 #include #include #include #include #include #include #include ;; 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. #ifdef CONFIG_PREEMPT _resume_kernel: di ; 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 nop _need_resched: addoq +TI_flags, $r0, $acr move.d [$acr], $r10 btstq TIF_NEED_RESCHED, $r10 ; Check if need_resched is set. bpl _Rexit nop ; Do preemptive kernel scheduling. jsr preempt_schedule_irq nop ; 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 nop 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. 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. _resume_userspace: 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 nop ba _Rexit nop ;; 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.. system_call: ;; 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. #ifdef CONFIG_ETRAX_KGDB move $ccs, $r0 or.d (1<<9), $r0 move $r0, $ccs #endif 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 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 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 nop 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. ret_from_sys_call: ;; 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 nop _Rexit: ;; 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. _syscall_exit_work: ;; R0 contains current at this point and irq's are disabled. addoq +TI_flags, $r0, $acr move.d [$acr], $r1 btstq TIF_SYSCALL_TRACE, $r1 bpl _work_pending nop ei move.d $r9, $r1 ; Preserve R9. jsr do_syscall_trace nop move.d $r1, $r9 ba _resume_userspace nop _work_pending: addoq +TI_flags, $r0, $acr move.d [$acr], $r10 btstq TIF_NEED_RESCHED, $r10 ; Need resched? bpl _work_notifysig ; No, must be signal/notify. nop _work_resched: move.d $r9, $r1 ; Preserve R9. jsr schedule nop move.d $r1, $r9 di addoq +TI_flags, $r0, $acr move.d [$acr], $r1 and.d _TIF_WORK_MASK, $r1 ; Ignore sycall 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. addoq +TI_flags, $r0, $acr move.d [$acr], $r12 ; The thread_info_flags parameter. move.d $sp, $r11 ; The regs param. jsr do_notify_resume move.d $r9, $r10 ; do_notify_resume syscall/irq param. 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 nop ;; 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 nop ;; 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. resume: 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. di 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. nop nmi_interrupt: ;; 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 nop 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 nop 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 rfn .comm cause_of_death, 4 ;; Don't declare this anywhere. spurious_interrupt: di jump hard_reset_now nop ;; 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. multiple_interrupt: ;; 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. #ifdef CONFIG_ETRAX_KGDB move $ccs, $r0 or.d (1<<9), $r0 move $r0, $ccs #endif jsr crisv32_do_multiple move.d $sp, $r10 jump ret_from_intr nop do_sigtrap: ;; 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 nop jump ret_from_intr ; Use the return routine for interrupts. nop gdb_handle_exception: subq 4, $sp move.d $r0, [$sp] #ifdef CONFIG_ETRAX_KGDB 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+], $r0 ; Restore R0 in delay slot. #endif _ugdb_handle_exception: ba do_sigtrap ; SIGTRAP the offending process. move.d [$sp+], $r0 ; Restore R0 in delay slot. .global kernel_execve kernel_execve: move.d __NR_execve, $r9 break 13 ret nop .data .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 sys_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 .long sys_ni_syscall /* 285 */ /* available */ .long sys_add_key .long sys_request_key .long sys_keyctl .long sys_ioprio_set .long sys_ioprio_get /* 290 */ .long sys_inotify_init .long sys_inotify_add_watch .long sys_inotify_rm_watch .long sys_migrate_pages .long sys_openat /* 295 */ .long sys_mkdirat .long sys_mknodat .long sys_fchownat .long sys_futimesat .long sys_fstatat64 /* 300 */ .long sys_unlinkat .long sys_renameat .long sys_linkat .long sys_symlinkat .long sys_readlinkat /* 305 */ .long sys_fchmodat .long sys_faccessat .long sys_pselect6 .long sys_ppoll .long sys_unshare /* 310 */ .long sys_set_robust_list .long sys_get_robust_list .long sys_splice .long sys_sync_file_range .long sys_tee /* 315 */ .long sys_vmsplice .long sys_move_pages .long sys_getcpu .long sys_epoll_pwait .long sys_utimensat /* 320 */ .long sys_signalfd .long sys_timerfd_create .long sys_eventfd .long sys_fallocate .long sys_timerfd_settime /* 325 */ .long sys_timerfd_gettime /* * 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