1 /* $Id: entry.S,v 1.35 2004/02/21 14:45:47 lethal 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/thread_info.h>
18 #include <asm/unistd.h>
20 #if !defined(CONFIG_NFSD) && !defined(CONFIG_NFSD_MODULE)
21 #define sys_nfsservctl sys_ni_syscall
24 #if !defined(CONFIG_MMU)
25 #define sys_madvise sys_ni_syscall
26 #define sys_readahead sys_ni_syscall
27 #define sys_mprotect sys_ni_syscall
28 #define sys_msync sys_ni_syscall
29 #define sys_mlock sys_ni_syscall
30 #define sys_munlock sys_ni_syscall
31 #define sys_mlockall sys_ni_syscall
32 #define sys_munlockall sys_ni_syscall
33 #define sys_mremap sys_ni_syscall
34 #define sys_mincore sys_ni_syscall
35 #define sys_remap_file_pages sys_ni_syscall
39 ! GNU as (as of 2.9.1) changes bf/s into bt/s and bra, when the address
40 ! to be jumped is too far, but it causes illegal slot exception.
43 * entry.S contains the system-call and fault low-level handling routines.
44 * This also contains the timer-interrupt handler, as well as all interrupts
45 * and faults that can result in a task-switch.
47 * NOTE: This code handles signal-recognition, which happens every time
48 * after a timer-interrupt and after each system call.
50 * NOTE: This code uses a convention that instructions in the delay slot
51 * of a transfer-control instruction are indented by an extra space, thus:
53 * jmp @k0 ! control-transfer instruction
54 * ldc k1, ssr ! delay slot
56 * Stack layout in 'ret_from_syscall':
57 * ptrace needs to have all regs on the stack.
58 * if the order here is changed, it needs to be
59 * updated in ptrace.c and ptrace.h
77 #if defined(CONFIG_CPU_SH3)
80 #if defined(CONFIG_CPU_SUBTYPE_SH7707) || defined(CONFIG_CPU_SUBTYPE_SH7709)
81 INTEVT = 0xa4000000 ! INTEVTE2(0xa4000000)
85 MMU_TEA = 0xfffffffc ! TLB Exception Address Register
86 #elif defined(CONFIG_CPU_SH4)
90 MMU_TEA = 0xff00000c ! TLB Exception Address Register
93 #if defined(CONFIG_KGDB_NMI)
94 NMI_VEC = 0x1c0 ! Must catch early for debounce
97 /* Offsets to the stack */
98 OFF_R0 = 0 /* Return value. New ABI also arg4 */
99 OFF_R1 = 4 /* New ABI: arg5 */
100 OFF_R2 = 8 /* New ABI: arg6 */
101 OFF_R3 = 12 /* New ABI: syscall_nr */
102 OFF_R4 = 16 /* New ABI: arg0 */
103 OFF_R5 = 20 /* New ABI: arg1 */
104 OFF_R6 = 24 /* New ABI: arg2 */
105 OFF_R7 = 28 /* New ABI: arg3 */
118 #define k_ex_code r2_bank /* r2_bank1 */
119 #define g_imask r6 /* r6_bank1 */
120 #define k_g_imask r6_bank /* r6_bank1 */
121 #define current r7 /* r7_bank1 */
124 * Kernel mode register usage:
127 * k2 scratch (Exception code)
128 * k3 scratch (Return address)
131 * k6 Global Interrupt Mask (0--15 << 4)
132 * k7 CURRENT_THREAD_INFO (pointer to current thread info)
136 ! TLB Miss / Initial Page write exception handling
138 ! TLB hits, but the access violate the protection.
139 ! It can be valid access, such as stack grow and/or C-O-W.
142 ! Find the pmd/pte entry and loadtlb
143 ! If it's not found, cause address error (SEGV)
145 ! Although this could be written in assembly language (and it'd be faster),
146 ! this first version depends *much* on C implementation.
155 mov.l __INV_IMASK, r11; \
158 stc k_g_imask, r11; \
162 #if defined(CONFIG_PREEMPT)
163 # define preempt_stop() CLI()
165 # define preempt_stop()
166 # define resume_kernel restore_all
169 #if defined(CONFIG_MMU)
176 ENTRY(tlb_miss_store)
181 ENTRY(initial_page_write)
186 ENTRY(tlb_protection_violation_load)
191 ENTRY(tlb_protection_violation_store)
219 2: .long __do_page_fault
220 3: .long do_page_fault
223 ENTRY(address_error_load)
225 mov #0,r5 ! writeaccess = 0
228 ENTRY(address_error_store)
230 mov #1,r5 ! writeaccess = 1
235 mov.l @r0, r6 ! address
242 2: .long do_address_error
243 #endif /* CONFIG_MMU */
245 #if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
246 ! Handle kernel debug if either kgdb (SW) or gdb-stub (FW) is present.
247 ! If both are configured, handle the debug traps (breakpoints) in SW,
248 ! but still allow BIOS traps to FW.
252 #if defined(CONFIG_SH_STANDARD_BIOS) && defined(CONFIG_SH_KGDB)
253 /* Force BIOS call to FW (debug_trap put TRA in r8) */
258 #endif /* CONFIG_SH_STANDARD_BIOS && CONFIG_SH_KGDB */
261 #if defined(CONFIG_SH_KGDB)
262 /* Jump to kgdb, pass stacked regs as arg */
268 3: .long kgdb_handle_exception
269 #endif /* CONFIG_SH_KGDB */
271 #if defined(CONFIG_SH_STANDARD_BIOS)
272 /* Unwind the stack and jmp to the debug entry */
283 mov.l 1f, r9 ! BL =1, RB=1, IMASK=0x0F
285 ldc r8, sr ! here, change the register bank
308 2: .long gdb_vbr_vector
309 #endif /* CONFIG_SH_STANDARD_BIOS */
311 #endif /* CONFIG_SH_STANDARD_BIOS || CONFIG_SH_KGDB */
316 #if defined(CONFIG_SH_STANDARD_BIOS) || defined(CONFIG_SH_KGDB)
318 mov.l @(r0,r15), r0 ! get status register
320 shll r0 ! kernel space?
323 mov.l @r15, r0 ! Restore R0 value
329 ENTRY(exception_error)
338 1: .long break_point_trap_software
339 2: .long do_exception_error
347 mov.l @(r0,r15), r0 ! get status register
349 shll r0 ! kernel space?
350 bt/s resume_kernel ! Yes, it's from kernel, go back soon
353 #ifdef CONFIG_PREEMPT
357 mov.l @(TI_PRE_COUNT,r8), r0 ! current_thread_info->preempt_count
361 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
362 tst #_TIF_NEED_RESCHED, r0 ! need_resched set?
366 mov.l @(r0,r15), r0 ! get status register
367 and #0xf0, r0 ! interrupts off (exception path)?
372 mov.l r0, @(TI_PRE_COUNT,r8)
379 mov.l r0, @(TI_PRE_COUNT,r8)
389 1: .long PREEMPT_ACTIVE
393 ENTRY(resume_userspace)
394 ! r8: current_thread_info
396 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
397 tst #_TIF_WORK_MASK, r0
399 tst #_TIF_NEED_RESCHED, r0
403 ! r0: current_thread_info->flags
404 ! r8: current_thread_info
405 ! t: result of "tst #_TIF_NEED_RESCHED, r0"
407 tst #_TIF_SIGPENDING, r0
417 #ifndef CONFIG_PREEMPT
419 mov.l @(OFF_SP,r15), r0 ! get user space stack pointer
426 ! SP >= 0xc0000000 : gUSA mark
427 mov.l @(r0,r15), r2 ! get user space PC (program counter)
428 mov.l @(OFF_R0,r15), r3 ! end point
429 cmp/hs r3, r2 ! r2 >= r3?
431 add r3, r1 ! rewind point #2
432 mov.l r1, @(r0,r15) ! reset PC to rewind point #2
441 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
442 tst #_TIF_WORK_MASK, r0
445 tst #_TIF_NEED_RESCHED, r0
453 ! r0: current_thread_info->flags
454 ! r8: current_thread_info
455 tst #_TIF_SYSCALL_TRACE, r0
457 tst #_TIF_NEED_RESCHED, r0
459 ! XXX setup arguments...
460 mov.l 4f, r0 ! do_syscall_trace
469 ! XXX setup arguments...
470 mov.l 4f, r11 ! Call do_syscall_trace which notifies
471 jsr @r11 ! superior (will chomp R[0-7])
473 ! Reload R0-R4 from kernel stack, where the
474 ! parent may have modified them using
475 ! ptrace(POKEUSR). (Note that R0-R2 are
476 ! used by the system call handler directly
477 ! from the kernel stack anyway, so don't need
478 ! to be reloaded here.) This allows the parent
479 ! to rewrite system calls and args on the fly.
480 mov.l @(OFF_R4,r15), r4 ! arg0
481 mov.l @(OFF_R5,r15), r5
482 mov.l @(OFF_R6,r15), r6
483 mov.l @(OFF_R7,r15), r7 ! arg3
484 mov.l @(OFF_R3,r15), r3 ! syscall_nr
485 ! Arrange for do_syscall_trace to be called
486 ! again as the system call returns.
487 mov.l 2f, r10 ! Number of syscalls
492 mov.l r0, @(OFF_R0,r15) ! Return value
498 * Arguments #0 to #3: R4--R7
499 * Arguments #4 to #6: R0, R1, R2
500 * TRA: (number of arguments + 0x10) x 4
502 * This code also handles delegating other traps to the BIOS/gdb stub
508 * 0x0-0xf old syscall ABI
509 * 0x10-0x1f new syscall ABI
510 * 0x20-0xff delegated through debug_trap to BIOS/gdb stub.
512 * Note: When we're first called, the TRA value must be shifted
513 * right 2 bits in order to get the value that was used as the "trapa"
526 1: .long schedule_tail
530 mov.l @r9, r8 ! Read from TRA (Trap Address) Register
532 ! Is the trap argument >= 0x20? (TRA will be >= 0x80)
539 mov.l r8, @r9 ! set TRA value to tra
541 ! Call the system call handler through the table.
542 ! First check for bad syscall number
544 mov.l 2f, r8 ! Number of syscalls
546 bf/s good_system_call
548 syscall_badsys: ! Bad syscall number
551 mov.l r0, @(OFF_R0,r15) ! Return value
557 good_system_call: ! Good syscall number
558 mov.l @(TI_FLAGS,r8), r8
559 mov #_TIF_SYSCALL_TRACE, r10
561 bf syscall_trace_entry
565 mov.l 3f, r8 ! Load the address of sys_call_table
568 jsr @r8 ! jump to specific syscall handler
570 mov.l r0, @(OFF_R0,r15) ! save the return value
576 mov.l @(TI_FLAGS,r8), r0 ! current_thread_info->flags
577 tst #_TIF_ALLWORK_MASK, r0
591 or r9, r8 ! BL =1, RB=1
592 ldc r8, sr ! here, change the register bank
601 mov.l @r15+, k4 ! original stack pointer
604 mov.l @r15+, k3 ! original SR
608 add #4, r15 ! Skip syscall number
611 mov.l @r15+, k0 ! DSP mode marker
613 cmp/eq k0, k1 ! Do we have a DSP stack frame?
616 stc sr, k0 ! Enable CPU DSP mode
617 or k1, k0 ! (within kernel it may be disabled)
619 mov r2, k0 ! Backup r2
621 ! Restore DSP registers from stack
640 mov k0, r2 ! Restore r2
644 ! Calculate new SR value
645 mov k3, k2 ! original SR value
647 and k1, k2 ! Mask orignal SR value
649 mov k3, k0 ! Calculate IMASK-bits
657 6: or k0, k2 ! Set the IMASK-bits
660 #if defined(CONFIG_KGDB_NMI)
666 mov.l @r15+, k2 ! restore EXPEVT
674 3: .long sys_call_table
675 4: .long do_syscall_trace
676 5: .long 0x00001000 ! DSP
680 .long 0xffffff0f ! ~(IMASK)
682 ! Exception Vector Base
684 ! Should be aligned page boundary.
698 2: .long ret_from_exception
712 #if defined(CONFIG_KGDB_NMI)
713 ! Debounce (filter nested NMI)
727 #endif /* defined(CONFIG_KGDB_NMI) */
734 3: .long ret_from_irq
735 4: .long ret_from_exception
741 ! Using k0, k1 for scratch registers (r0_bank1, r1_bank),
742 ! save all registers onto stack.
744 stc ssr, k0 ! Is it from kernel space?
745 shll k0 ! Check MD bit (bit30) by shifting it into...
746 shll k0 ! ...the T bit
747 bt/s 1f ! It's a kernel to kernel transition.
748 mov r15, k0 ! save original stack to k0
749 /* User space to kernel */
751 shll8 k1 ! k1 := 8192 (== THREAD_SIZE)
753 mov k1, r15 ! change to kernel stack
759 mov.l r2, @-r15 ! Save r2, we need another reg
762 tst r2, k4 ! Check if in DSP mode
763 mov.l @r15+, r2 ! Restore r2 now
765 mov #0, k4 ! Set marker for no stack frame
767 mov r2, k4 ! Backup r2 (in k4) for later
769 ! Save DSP registers on stack
780 ! GAS is broken, does not generate correct "movs.l Ds,@-As" instr.
782 ! FIXME: Make sure that this is still the case with newer toolchains,
783 ! as we're not at all interested in supporting ancient toolchains at
784 ! this point. -- PFM.
787 .word 0xf653 ! movs.l a1, @-r2
788 .word 0xf6f3 ! movs.l a0g, @-r2
789 .word 0xf6d3 ! movs.l a1g, @-r2
790 .word 0xf6c3 ! movs.l m0, @-r2
791 .word 0xf6e3 ! movs.l m1, @-r2
794 mov k4, r2 ! Restore r2
795 mov.l 1f, k4 ! Force DSP stack frame
797 mov.l k4, @-r15 ! Push DSP mode marker onto stack
799 ! Save the user registers on the stack.
800 mov.l k2, @-r15 ! EXPEVT
801 mov.l k4, @-r15 ! set TRA (default: -1)
810 lds k3, pr ! Set the return address to pr
812 mov.l k0, @-r15 ! save orignal stack
821 stc sr, r8 ! Back to normal register bank, and
822 or k1, r8 ! Block all interrupts
825 ldc r8, sr ! ...changed here.
835 ! Then, dispatch to the handler, according to the exception code.
846 1: .long 0x00001000 ! DSP=1
847 2: .long 0x000080f0 ! FD=1, IMASK=15
848 3: .long 0xcfffffff ! RB=0, BL=0
849 4: .long exception_handling_table
852 ENTRY(exception_none)
857 ENTRY(sys_call_table)
858 .long sys_ni_syscall /* 0 - old "setup()" system call*/
863 .long sys_open /* 5 */
868 .long sys_unlink /* 10 */
873 .long sys_chmod /* 15 */
875 .long sys_ni_syscall /* old break syscall holder */
878 .long sys_getpid /* 20 */
883 .long sys_stime /* 25 */
888 .long sys_utime /* 30 */
889 .long sys_ni_syscall /* old stty syscall holder */
890 .long sys_ni_syscall /* old gtty syscall holder */
893 .long sys_ni_syscall /* 35 */ /* old ftime syscall holder */
898 .long sys_rmdir /* 40 */
902 .long sys_ni_syscall /* old prof syscall holder */
903 .long sys_brk /* 45 */
908 .long sys_getegid16 /* 50 */
910 .long sys_umount /* recycled never used phys() */
911 .long sys_ni_syscall /* old lock syscall holder */
913 .long sys_fcntl /* 55 */
914 .long sys_ni_syscall /* old mpx syscall holder */
916 .long sys_ni_syscall /* old ulimit syscall holder */
917 .long sys_ni_syscall /* sys_olduname */
918 .long sys_umask /* 60 */
923 .long sys_getpgrp /* 65 */
928 .long sys_setreuid16 /* 70 */
932 .long sys_sethostname
933 .long sys_setrlimit /* 75 */
934 .long sys_old_getrlimit
936 .long sys_gettimeofday
937 .long sys_settimeofday
938 .long sys_getgroups16 /* 80 */
939 .long sys_setgroups16
940 .long sys_ni_syscall /* sys_oldselect */
943 .long sys_readlink /* 85 */
948 .long old_mmap /* 90 */
953 .long sys_fchown16 /* 95 */
954 .long sys_getpriority
955 .long sys_setpriority
956 .long sys_ni_syscall /* old profil syscall holder */
958 .long sys_fstatfs /* 100 */
959 .long sys_ni_syscall /* ioperm */
963 .long sys_getitimer /* 105 */
968 .long sys_ni_syscall /* 110 */ /* iopl */
970 .long sys_ni_syscall /* idle */
971 .long sys_ni_syscall /* vm86old */
973 .long sys_swapoff /* 115 */
978 .long sys_clone /* 120 */
979 .long sys_setdomainname
981 .long sys_ni_syscall /* sys_modify_ldt */
983 .long sys_mprotect /* 125 */
984 .long sys_sigprocmask
985 .long sys_ni_syscall /* old "create_module" */
986 .long sys_init_module
987 .long sys_delete_module
988 .long sys_ni_syscall /* 130: old "get_kernel_syms" */
993 .long sys_sysfs /* 135 */
994 .long sys_personality
995 .long sys_ni_syscall /* for afs_syscall */
998 .long sys_llseek /* 140 */
1003 .long sys_readv /* 145 */
1008 .long sys_mlock /* 150 */
1011 .long sys_munlockall
1012 .long sys_sched_setparam
1013 .long sys_sched_getparam /* 155 */
1014 .long sys_sched_setscheduler
1015 .long sys_sched_getscheduler
1016 .long sys_sched_yield
1017 .long sys_sched_get_priority_max
1018 .long sys_sched_get_priority_min /* 160 */
1019 .long sys_sched_rr_get_interval
1022 .long sys_setresuid16
1023 .long sys_getresuid16 /* 165 */
1024 .long sys_ni_syscall /* vm86 */
1025 .long sys_ni_syscall /* old "query_module" */
1027 .long sys_nfsservctl
1028 .long sys_setresgid16 /* 170 */
1029 .long sys_getresgid16
1031 .long sys_rt_sigreturn
1032 .long sys_rt_sigaction
1033 .long sys_rt_sigprocmask /* 175 */
1034 .long sys_rt_sigpending
1035 .long sys_rt_sigtimedwait
1036 .long sys_rt_sigqueueinfo
1037 .long sys_rt_sigsuspend
1038 .long sys_pread_wrapper /* 180 */
1039 .long sys_pwrite_wrapper
1043 .long sys_capset /* 185 */
1044 .long sys_sigaltstack
1046 .long sys_ni_syscall /* streams1 */
1047 .long sys_ni_syscall /* streams2 */
1048 .long sys_vfork /* 190 */
1051 .long sys_truncate64
1052 .long sys_ftruncate64
1053 .long sys_stat64 /* 195 */
1058 .long sys_getgid /* 200 */
1063 .long sys_getgroups /* 205 */
1068 .long sys_setresgid /* 210 */
1073 .long sys_setfsuid /* 215 */
1075 .long sys_pivot_root
1078 .long sys_getdents64 /* 220 */
1080 .long sys_ni_syscall /* reserved for TUX */
1081 .long sys_ni_syscall /* Reserved for Security */
1083 .long sys_readahead /* 225 */
1088 .long sys_lgetxattr /* 230 */
1091 .long sys_llistxattr
1092 .long sys_flistxattr
1093 .long sys_removexattr /* 235 */
1094 .long sys_lremovexattr
1095 .long sys_fremovexattr
1097 .long sys_sendfile64
1098 .long sys_futex /* 240 */
1099 .long sys_sched_setaffinity
1100 .long sys_sched_getaffinity
1101 .long sys_ni_syscall
1102 .long sys_ni_syscall
1103 .long sys_io_setup /* 245 */
1104 .long sys_io_destroy
1105 .long sys_io_getevents
1108 .long sys_fadvise64 /* 250 */
1109 .long sys_ni_syscall
1110 .long sys_exit_group
1111 .long sys_lookup_dcookie
1112 .long sys_epoll_create
1113 .long sys_epoll_ctl /* 255 */
1114 .long sys_epoll_wait
1115 .long sys_remap_file_pages
1116 .long sys_set_tid_address
1117 .long sys_timer_create
1118 .long sys_timer_settime /* 260 */
1119 .long sys_timer_gettime
1120 .long sys_timer_getoverrun
1121 .long sys_timer_delete
1122 .long sys_clock_settime
1123 .long sys_clock_gettime /* 265 */
1124 .long sys_clock_getres
1125 .long sys_clock_nanosleep
1128 .long sys_tgkill /* 270 */
1130 .long sys_fadvise64_64_wrapper
1131 .long sys_ni_syscall /* Reserved for vserver */
1132 .long sys_ni_syscall
1134 /* End of entry.S */