1 /* $Id: entry.S,v 1.37 2004/06/11 13:02:46 doyu Exp $
3 * linux/arch/sh/entry.S
5 * Copyright (C) 1999, 2000, 2002 Niibe Yutaka
6 * Copyright (C) 2003 Paul Mundt
8 * This file is subject to the terms and conditions of the GNU General Public
9 * License. See the file "COPYING" in the main directory of this archive
14 #include <linux/sys.h>
15 #include <linux/linkage.h>
16 #include <linux/config.h>
17 #include <asm/asm-offsets.h>
18 #include <asm/thread_info.h>
19 #include <asm/cpu/mmu_context.h>
20 #include <asm/unistd.h>
22 #if !defined(CONFIG_NFSD) && !defined(CONFIG_NFSD_MODULE)
23 #define sys_nfsservctl sys_ni_syscall
26 #if !defined(CONFIG_MMU)
27 #define sys_madvise sys_ni_syscall
28 #define sys_readahead sys_ni_syscall
29 #define sys_mprotect sys_ni_syscall
30 #define sys_msync sys_ni_syscall
31 #define sys_mlock sys_ni_syscall
32 #define sys_munlock sys_ni_syscall
33 #define sys_mlockall sys_ni_syscall
34 #define sys_munlockall sys_ni_syscall
35 #define sys_mremap sys_ni_syscall
36 #define sys_mincore sys_ni_syscall
37 #define sys_remap_file_pages sys_ni_syscall
41 ! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address
42 ! to be jumped is too far, but it causes illegal slot exception.
45 * entry.S contains the system-call and fault low-level handling routines.
46 * This also contains the timer-interrupt handler, as well as all interrupts
47 * and faults that can result in a task-switch.
49 * NOTE: This code handles signal-recognition, which happens every time
50 * after a timer-interrupt and after each system call.
52 * NOTE: This code uses a convention that instructions in the delay slot
53 * of a transfer-control instruction are indented by an extra space, thus:
55 * jmp @k0 ! control-transfer instruction
56 * ldc k1, ssr ! delay slot
58 * Stack layout in 'ret_from_syscall':
59 * ptrace needs to have all regs on the stack.
60 * if the order here is changed, it needs to be
61 * updated in ptrace.c and ptrace.h
79 #if defined(CONFIG_KGDB_NMI)
80 NMI_VEC = 0x1c0 ! Must catch early for debounce
83 /* Offsets to the stack */
84 OFF_R0 = 0 /* Return value. New ABI also arg4 */
85 OFF_R1 = 4 /* New ABI: arg5 */
86 OFF_R2 = 8 /* New ABI: arg6 */
87 OFF_R3 = 12 /* New ABI: syscall_nr */
88 OFF_R4 = 16 /* New ABI: arg0 */
89 OFF_R5 = 20 /* New ABI: arg1 */
90 OFF_R6 = 24 /* New ABI: arg2 */
91 OFF_R7 = 28 /* New ABI: arg3 */
104 #define k_ex_code r2_bank /* r2_bank1 */
105 #define g_imask r6 /* r6_bank1 */
106 #define k_g_imask r6_bank /* r6_bank1 */
107 #define current r7 /* r7_bank1 */
110 * Kernel mode register usage:
113 * k2 scratch (Exception code)
114 * k3 scratch (Return address)
117 * k6 Global Interrupt Mask (0--15 << 4)
118 * k7 CURRENT_THREAD_INFO (pointer to current thread info)
122 ! TLB Miss / Initial Page write exception handling
124 ! TLB hits, but the access violate the protection.
125 ! It can be valid access, such as stack grow and/or C-O-W.
128 ! Find the pmd/pte entry and loadtlb
129 ! If it's not found, cause address error (SEGV)
131 ! Although this could be written in assembly language (and it'd be faster),
132 ! this first version depends *much* on C implementation.
141 mov.l __INV_IMASK, r11; \
144 stc k_g_imask, r11; \
148 #if defined(CONFIG_PREEMPT)
149 # define preempt_stop() CLI()
151 # define preempt_stop()
152 # define resume_kernel restore_all
155 #if defined(CONFIG_MMU)
162 ENTRY(tlb_miss_store)
167 ENTRY(initial_page_write)
172 ENTRY(tlb_protection_violation_load)
177 ENTRY(tlb_protection_violation_store)
205 2: .long __do_page_fault
206 3: .long do_page_fault
209 ENTRY(address_error_load)
211 mov #0,r5 ! writeaccess = 0
214 ENTRY(address_error_store)
216 mov #1,r5 ! writeaccess = 1
221 mov.l @r0, r6 ! address
228 2: .long do_address_error
229 #endif /* CONFIG_MMU */
231 #if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
232 ! Handle kernel debug if either kgdb (SW) or gdb-stub (FW) is present.
233 ! If both are configured, handle the debug traps (breakpoints) in SW,
234 ! but still allow BIOS traps to FW.
238 #if defined(CONFIG_SH_STANDARD_BIOS) && defined(CONFIG_SH_KGDB)
239 /* Force BIOS call to FW (debug_trap put TRA in r8) */
244 #endif /* CONFIG_SH_STANDARD_BIOS && CONFIG_SH_KGDB */
247 #if defined(CONFIG_SH_KGDB)
248 /* Jump to kgdb, pass stacked regs as arg */
254 3: .long kgdb_handle_exception
255 #endif /* CONFIG_SH_KGDB */
257 #if defined(CONFIG_SH_STANDARD_BIOS)
258 /* Unwind the stack and jmp to the debug entry */
269 mov.l 1f, r9 ! BL =1, RB=1, IMASK=0x0F
271 ldc r8, sr ! here, change the register bank
294 2: .long gdb_vbr_vector
295 #endif /* CONFIG_SH_STANDARD_BIOS */
297 #endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */
302 #if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
304 mov.l @(r0,r15), r0 ! get status register
306 shll r0 ! kernel space?
309 mov.l @r15, r0 ! Restore R0 value
315 ENTRY(exception_error)
324 1: .long break_point_trap_software
325 2: .long do_exception_error
333 mov.l @(r0,r15), r0 ! get status register
335 shll r0 ! kernel space?
336 bt/s resume_kernel ! Yes, it's from kernel, go back soon
339 #ifdef CONFIG_PREEMPT
343 mov.l @(TI_PRE_COUNT,r8), r0 ! current_thread_info->preempt_count
347 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
348 tst #_TIF_NEED_RESCHED, r0 ! need_resched set?
352 mov.l @(r0,r15), r0 ! get status register
353 and #0xf0, r0 ! interrupts off (exception path)?
358 mov.l r0, @(TI_PRE_COUNT,r8)
365 mov.l r0, @(TI_PRE_COUNT,r8)
375 1: .long PREEMPT_ACTIVE
379 ENTRY(resume_userspace)
380 ! r8: current_thread_info
382 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
383 tst #_TIF_WORK_MASK, r0
385 tst #_TIF_NEED_RESCHED, r0
389 ! r0: current_thread_info->flags
390 ! r8: current_thread_info
391 ! t: result of "tst #_TIF_NEED_RESCHED, r0"
393 tst #_TIF_SIGPENDING, r0
403 #ifndef CONFIG_PREEMPT
405 mov.l @(OFF_SP,r15), r0 ! get user space stack pointer
412 ! SP >= 0xc0000000 : gUSA mark
413 mov.l @(r0,r15), r2 ! get user space PC (program counter)
414 mov.l @(OFF_R0,r15), r3 ! end point
415 cmp/hs r3, r2 ! r2 >= r3?
417 add r3, r1 ! rewind point #2
418 mov.l r1, @(r0,r15) ! reset PC to rewind point #2
427 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
428 tst #_TIF_WORK_MASK, r0
431 tst #_TIF_NEED_RESCHED, r0
439 ! r0: current_thread_info->flags
440 ! r8: current_thread_info
441 tst #_TIF_SYSCALL_TRACE, r0
443 tst #_TIF_NEED_RESCHED, r0
445 ! XXX setup arguments...
446 mov.l 4f, r0 ! do_syscall_trace
455 ! XXX setup arguments...
456 mov.l 4f, r11 ! Call do_syscall_trace which notifies
457 jsr @r11 ! superior (will chomp R[0-7])
459 ! Reload R0-R4 from kernel stack, where the
460 ! parent may have modified them using
461 ! ptrace(POKEUSR). (Note that R0-R2 are
462 ! used by the system call handler directly
463 ! from the kernel stack anyway, so don't need
464 ! to be reloaded here.) This allows the parent
465 ! to rewrite system calls and args on the fly.
466 mov.l @(OFF_R4,r15), r4 ! arg0
467 mov.l @(OFF_R5,r15), r5
468 mov.l @(OFF_R6,r15), r6
469 mov.l @(OFF_R7,r15), r7 ! arg3
470 mov.l @(OFF_R3,r15), r3 ! syscall_nr
471 ! Arrange for do_syscall_trace to be called
472 ! again as the system call returns.
473 mov.l 2f, r10 ! Number of syscalls
478 mov.l r0, @(OFF_R0,r15) ! Return value
484 * Arguments #0 to #3: R4--R7
485 * Arguments #4 to #6: R0, R1, R2
486 * TRA: (number of arguments + 0x10) x 4
488 * This code also handles delegating other traps to the BIOS/gdb stub
494 * 0x0-0xf old syscall ABI
495 * 0x10-0x1f new syscall ABI
496 * 0x20-0xff delegated through debug_trap to BIOS/gdb stub.
498 * Note: When we're first called, the TRA value must be shifted
499 * right 2 bits in order to get the value that was used as the "trapa"
512 1: .long schedule_tail
516 mov.l @r9, r8 ! Read from TRA (Trap Address) Register
518 ! Is the trap argument >= 0x20? (TRA will be >= 0x80)
525 mov.l r8, @r9 ! set TRA value to tra
527 ! Call the system call handler through the table.
528 ! First check for bad syscall number
530 mov.l 2f, r8 ! Number of syscalls
532 bf/s good_system_call
534 syscall_badsys: ! Bad syscall number
537 mov.l r0, @(OFF_R0,r15) ! Return value
543 good_system_call: ! Good syscall number
544 mov.l @(TI_FLAGS,r8), r8
545 mov #_TIF_SYSCALL_TRACE, r10
547 bf syscall_trace_entry
551 mov.l 3f, r8 ! Load the address of sys_call_table
554 jsr @r8 ! jump to specific syscall handler
556 mov.l r0, @(OFF_R0,r15) ! save the return value
562 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
563 tst #_TIF_ALLWORK_MASK, r0
577 or r9, r8 ! BL =1, RB=1
578 ldc r8, sr ! here, change the register bank
587 mov.l @r15+, k4 ! original stack pointer
590 mov.l @r15+, k3 ! original SR
594 add #4, r15 ! Skip syscall number
597 mov.l @r15+, k0 ! DSP mode marker
599 cmp/eq k0, k1 ! Do we have a DSP stack frame?
602 stc sr, k0 ! Enable CPU DSP mode
603 or k1, k0 ! (within kernel it may be disabled)
605 mov r2, k0 ! Backup r2
607 ! Restore DSP registers from stack
626 mov k0, r2 ! Restore r2
630 ! Calculate new SR value
631 mov k3, k2 ! original SR value
633 and k1, k2 ! Mask orignal SR value
635 mov k3, k0 ! Calculate IMASK-bits
643 6: or k0, k2 ! Set the IMASK-bits
646 #if defined(CONFIG_KGDB_NMI)
652 mov.l @r15+, k2 ! restore EXPEVT
660 3: .long sys_call_table
661 4: .long do_syscall_trace
662 5: .long 0x00001000 ! DSP
666 .long 0xffffff0f ! ~(IMASK)
668 ! Exception Vector Base
670 ! Should be aligned page boundary.
684 2: .long ret_from_exception
698 #if defined(CONFIG_KGDB_NMI)
699 ! Debounce (filter nested NMI)
713 #endif /* defined(CONFIG_KGDB_NMI) */
720 3: .long ret_from_irq
721 4: .long ret_from_exception
727 ! Using k0, k1 for scratch registers (r0_bank1, r1_bank),
728 ! save all registers onto stack.
730 stc ssr, k0 ! Is it from kernel space?
731 shll k0 ! Check MD bit (bit30) by shifting it into...
732 shll k0 ! ...the T bit
733 bt/s 1f ! It's a kernel to kernel transition.
734 mov r15, k0 ! save original stack to k0
735 /* User space to kernel */
737 shll8 k1 ! k1 := 8192 (== THREAD_SIZE)
739 mov k1, r15 ! change to kernel stack
745 mov.l r2, @-r15 ! Save r2, we need another reg
748 tst r2, k4 ! Check if in DSP mode
749 mov.l @r15+, r2 ! Restore r2 now
751 mov #0, k4 ! Set marker for no stack frame
753 mov r2, k4 ! Backup r2 (in k4) for later
755 ! Save DSP registers on stack
766 ! GAS is broken, does not generate correct "movs.l Ds,@-As" instr.
768 ! FIXME: Make sure that this is still the case with newer toolchains,
769 ! as we're not at all interested in supporting ancient toolchains at
770 ! this point. -- PFM.
773 .word 0xf653 ! movs.l a1, @-r2
774 .word 0xf6f3 ! movs.l a0g, @-r2
775 .word 0xf6d3 ! movs.l a1g, @-r2
776 .word 0xf6c3 ! movs.l m0, @-r2
777 .word 0xf6e3 ! movs.l m1, @-r2
780 mov k4, r2 ! Restore r2
781 mov.l 1f, k4 ! Force DSP stack frame
783 mov.l k4, @-r15 ! Push DSP mode marker onto stack
785 ! Save the user registers on the stack.
786 mov.l k2, @-r15 ! EXPEVT
787 mov.l k4, @-r15 ! set TRA (default: -1)
796 lds k3, pr ! Set the return address to pr
798 mov.l k0, @-r15 ! save orignal stack
807 stc sr, r8 ! Back to normal register bank, and
808 or k1, r8 ! Block all interrupts
811 ldc r8, sr ! ...changed here.
821 ! Then, dispatch to the handler, according to the exception code.
832 1: .long 0x00001000 ! DSP=1
833 2: .long 0x000080f0 ! FD=1, IMASK=15
834 3: .long 0xcfffffff ! RB=0, BL=0
835 4: .long exception_handling_table
838 ENTRY(exception_none)
843 ENTRY(sys_call_table)
844 .long sys_ni_syscall /* 0 - old "setup()" system call*/
849 .long sys_open /* 5 */
854 .long sys_unlink /* 10 */
859 .long sys_chmod /* 15 */
861 .long sys_ni_syscall /* old break syscall holder */
864 .long sys_getpid /* 20 */
869 .long sys_stime /* 25 */
874 .long sys_utime /* 30 */
875 .long sys_ni_syscall /* old stty syscall holder */
876 .long sys_ni_syscall /* old gtty syscall holder */
879 .long sys_ni_syscall /* 35 */ /* old ftime syscall holder */
884 .long sys_rmdir /* 40 */
888 .long sys_ni_syscall /* old prof syscall holder */
889 .long sys_brk /* 45 */
894 .long sys_getegid16 /* 50 */
896 .long sys_umount /* recycled never used phys() */
897 .long sys_ni_syscall /* old lock syscall holder */
899 .long sys_fcntl /* 55 */
900 .long sys_ni_syscall /* old mpx syscall holder */
902 .long sys_ni_syscall /* old ulimit syscall holder */
903 .long sys_ni_syscall /* sys_olduname */
904 .long sys_umask /* 60 */
909 .long sys_getpgrp /* 65 */
914 .long sys_setreuid16 /* 70 */
918 .long sys_sethostname
919 .long sys_setrlimit /* 75 */
920 .long sys_old_getrlimit
922 .long sys_gettimeofday
923 .long sys_settimeofday
924 .long sys_getgroups16 /* 80 */
925 .long sys_setgroups16
926 .long sys_ni_syscall /* sys_oldselect */
929 .long sys_readlink /* 85 */
934 .long old_mmap /* 90 */
939 .long sys_fchown16 /* 95 */
940 .long sys_getpriority
941 .long sys_setpriority
942 .long sys_ni_syscall /* old profil syscall holder */
944 .long sys_fstatfs /* 100 */
945 .long sys_ni_syscall /* ioperm */
949 .long sys_getitimer /* 105 */
954 .long sys_ni_syscall /* 110 */ /* iopl */
956 .long sys_ni_syscall /* idle */
957 .long sys_ni_syscall /* vm86old */
959 .long sys_swapoff /* 115 */
964 .long sys_clone /* 120 */
965 .long sys_setdomainname
967 .long sys_ni_syscall /* sys_modify_ldt */
969 .long sys_mprotect /* 125 */
970 .long sys_sigprocmask
971 .long sys_ni_syscall /* old "create_module" */
972 .long sys_init_module
973 .long sys_delete_module
974 .long sys_ni_syscall /* 130: old "get_kernel_syms" */
979 .long sys_sysfs /* 135 */
980 .long sys_personality
981 .long sys_ni_syscall /* for afs_syscall */
984 .long sys_llseek /* 140 */
989 .long sys_readv /* 145 */
994 .long sys_mlock /* 150 */
998 .long sys_sched_setparam
999 .long sys_sched_getparam /* 155 */
1000 .long sys_sched_setscheduler
1001 .long sys_sched_getscheduler
1002 .long sys_sched_yield
1003 .long sys_sched_get_priority_max
1004 .long sys_sched_get_priority_min /* 160 */
1005 .long sys_sched_rr_get_interval
1008 .long sys_setresuid16
1009 .long sys_getresuid16 /* 165 */
1010 .long sys_ni_syscall /* vm86 */
1011 .long sys_ni_syscall /* old "query_module" */
1013 .long sys_nfsservctl
1014 .long sys_setresgid16 /* 170 */
1015 .long sys_getresgid16
1017 .long sys_rt_sigreturn
1018 .long sys_rt_sigaction
1019 .long sys_rt_sigprocmask /* 175 */
1020 .long sys_rt_sigpending
1021 .long sys_rt_sigtimedwait
1022 .long sys_rt_sigqueueinfo
1023 .long sys_rt_sigsuspend
1024 .long sys_pread_wrapper /* 180 */
1025 .long sys_pwrite_wrapper
1029 .long sys_capset /* 185 */
1030 .long sys_sigaltstack
1032 .long sys_ni_syscall /* streams1 */
1033 .long sys_ni_syscall /* streams2 */
1034 .long sys_vfork /* 190 */
1037 .long sys_truncate64
1038 .long sys_ftruncate64
1039 .long sys_stat64 /* 195 */
1044 .long sys_getgid /* 200 */
1049 .long sys_getgroups /* 205 */
1054 .long sys_setresgid /* 210 */
1059 .long sys_setfsuid /* 215 */
1061 .long sys_pivot_root
1064 .long sys_getdents64 /* 220 */
1066 .long sys_ni_syscall /* reserved for TUX */
1067 .long sys_ni_syscall /* Reserved for Security */
1069 .long sys_readahead /* 225 */
1074 .long sys_lgetxattr /* 230 */
1077 .long sys_llistxattr
1078 .long sys_flistxattr
1079 .long sys_removexattr /* 235 */
1080 .long sys_lremovexattr
1081 .long sys_fremovexattr
1083 .long sys_sendfile64
1084 .long sys_futex /* 240 */
1085 .long sys_sched_setaffinity
1086 .long sys_sched_getaffinity
1087 .long sys_ni_syscall
1088 .long sys_ni_syscall
1089 .long sys_io_setup /* 245 */
1090 .long sys_io_destroy
1091 .long sys_io_getevents
1094 .long sys_fadvise64 /* 250 */
1095 .long sys_ni_syscall
1096 .long sys_exit_group
1097 .long sys_lookup_dcookie
1098 .long sys_epoll_create
1099 .long sys_epoll_ctl /* 255 */
1100 .long sys_epoll_wait
1101 .long sys_remap_file_pages
1102 .long sys_set_tid_address
1103 .long sys_timer_create
1104 .long sys_timer_settime /* 260 */
1105 .long sys_timer_gettime
1106 .long sys_timer_getoverrun
1107 .long sys_timer_delete
1108 .long sys_clock_settime
1109 .long sys_clock_gettime /* 265 */
1110 .long sys_clock_getres
1111 .long sys_clock_nanosleep
1114 .long sys_tgkill /* 270 */
1116 .long sys_fadvise64_64_wrapper
1117 .long sys_ni_syscall /* Reserved for vserver */
1118 .long sys_ni_syscall /* Reserved for mbind */
1119 .long sys_ni_syscall /* 275 - get_mempolicy */
1120 .long sys_ni_syscall /* set_mempolicy */
1123 .long sys_mq_timedsend
1124 .long sys_mq_timedreceive /* 280 */
1126 .long sys_mq_getsetattr
1127 .long sys_ni_syscall /* Reserved for kexec */
1129 .long sys_add_key /* 285 */
1130 .long sys_request_key
1132 .long sys_ioprio_set
1133 .long sys_ioprio_get
1134 .long sys_inotify_init /* 290 */
1135 .long sys_inotify_add_watch
1136 .long sys_inotify_rm_watch
1138 /* End of entry.S */