1 /* !! 1 /* SPDX-License-Identifier: GPL-2.0-or-later
2 * linux/arch/nios2/kernel/entry.S !! 2 * -*- mode: asm -*-
3 * <<
4 * Copyright (C) 2013-2014 Altera Corporation <<
5 * Copyright (C) 2009, Wind River Systems Inc <<
6 * <<
7 * Implemented by fredrik.markstrom@gmail.com <<
8 * 3 *
9 * Copyright (C) 1999-2002, Greg Ungerer (ger !! 4 * linux/arch/m68k/kernel/entry.S
10 * Copyright (C) 1998 D. Jeff Dionne <jeff@li <<
11 * Kenneth Albanowski <kja <<
12 * Copyright (C) 2000 Lineo Inc. (www.lineo. <<
13 * Copyright (C) 2004 Microtronix Datacom Lt <<
14 * 5 *
15 * This file is subject to the terms and condi !! 6 * Copyright (C) 1991, 1992 Linus Torvalds
16 * License. See the file "COPYING" in the mai <<
17 * for more details. <<
18 * 7 *
19 * Linux/m68k support by Hamish Macdonald 8 * Linux/m68k support by Hamish Macdonald
20 * 9 *
21 * 68060 fixes by Jesper Skov 10 * 68060 fixes by Jesper Skov
22 * ColdFire support by Greg Ungerer (gerg@snap !! 11 *
23 * 5307 fixes by David W. Miller !! 12 */
24 * linux 2.4 support David McCullough <davidm@s !! 13
>> 14 /*
>> 15 * entry.S contains the system-call and fault low-level handling routines.
>> 16 * This also contains the timer-interrupt handler, as well as all interrupts
>> 17 * and faults that can result in a task-switch.
>> 18 *
>> 19 * NOTE: This code handles signal-recognition, which happens every time
>> 20 * after a timer-interrupt and after each system call.
>> 21 *
>> 22 */
>> 23
>> 24 /*
>> 25 * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so
>> 26 * all pointers that used to be 'current' are now entry
>> 27 * number 0 in the 'current_set' list.
>> 28 *
>> 29 * 6/05/00 RZ: addedd writeback completion after return from sighandler
>> 30 * for 68040
25 */ 31 */
26 32
27 #include <linux/sys.h> <<
28 #include <linux/linkage.h> 33 #include <linux/linkage.h>
29 #include <asm/asm-offsets.h> <<
30 #include <asm/asm-macros.h> <<
31 #include <asm/thread_info.h> <<
32 #include <asm/errno.h> 34 #include <asm/errno.h>
33 #include <asm/setup.h> 35 #include <asm/setup.h>
34 #include <asm/entry.h> !! 36 #include <asm/traps.h>
35 #include <asm/unistd.h> 37 #include <asm/unistd.h>
36 #include <asm/processor.h> !! 38 #include <asm/asm-offsets.h>
37 !! 39 #include <asm/entry.h>
38 .macro GET_THREAD_INFO reg <<
39 .if THREAD_SIZE & 0xffff0000 <<
40 andhi \reg, sp, %hi(~(THREAD_SIZE-1) <<
41 .else <<
42 addi \reg, r0, %lo(~(THREAD_SIZE-1) <<
43 and \reg, \reg, sp <<
44 .endif <<
45 .endm <<
46 <<
47 .macro kuser_cmpxchg_check <<
48 /* <<
49 * Make sure our user space atomic hel <<
50 * interrupted in a critical region. <<
51 * ea-4 = address of interrupted insn <<
52 * sp = saved regs. <<
53 * cmpxchg_ldw = first critical insn, <<
54 * If ea <= cmpxchg_stw and ea > cmpxc <<
55 * cmpxchg_ldw + 4. <<
56 */ <<
57 /* et = cmpxchg_stw + 4 */ <<
58 movui et, (KUSER_BASE + 4 + (cmpxchg <<
59 bgtu ea, et, 1f <<
60 <<
61 subi et, et, (cmpxchg_stw - cmpxchg <<
62 bltu ea, et, 1f <<
63 stw et, PT_EA(sp) /* fix up EA * <<
64 mov ea, et <<
65 1: <<
66 .endm <<
67 40
68 .section .rodata !! 41 .globl system_call, buserr, trap, resume
69 .align 4 !! 42 .globl sys_call_table
70 exception_table: !! 43 .globl __sys_fork, __sys_clone, __sys_vfork
71 .word unhandled_exception /* 0 - !! 44 .globl bad_interrupt
72 .word unhandled_exception /* 1 - !! 45 .globl auto_irqhandler_fixup
73 .word external_interrupt /* 2 - !! 46 .globl user_irqvec_fixup
74 .word handle_trap /* 3 - <<
75 <<
76 .word instruction_trap /* 4 - <<
77 .word handle_illegal /* 5 - <<
78 .word handle_unaligned /* 6 - <<
79 .word handle_unaligned /* 7 - <<
80 <<
81 .word handle_diverror /* 8 - <<
82 .word protection_exception_ba /* 9 - <<
83 .word protection_exception_instr /* 10 <<
84 .word protection_exception_ba /* 11 <<
85 <<
86 .word unhandled_exception /* 12 <<
87 .word protection_exception_pte /* 13 <<
88 .word protection_exception_pte /* 14 <<
89 .word protection_exception_pte /* 15 <<
90 <<
91 .word unhandled_exception /* 16 <<
92 <<
93 trap_table: <<
94 .word handle_system_call /* 0 <<
95 .word handle_trap_1 /* 1 <<
96 .word handle_trap_2 /* 2 <<
97 .word handle_trap_3 /* 3 <<
98 .word handle_trap_reserved /* 4 <<
99 .word handle_trap_reserved /* 5 <<
100 .word handle_trap_reserved /* 6 <<
101 .word handle_trap_reserved /* 7 <<
102 .word handle_trap_reserved /* 8 <<
103 .word handle_trap_reserved /* 9 <<
104 .word handle_trap_reserved /* 10 <<
105 .word handle_trap_reserved /* 11 <<
106 .word handle_trap_reserved /* 12 <<
107 .word handle_trap_reserved /* 13 <<
108 .word handle_trap_reserved /* 14 <<
109 .word handle_trap_reserved /* 15 <<
110 .word handle_trap_reserved /* 16 <<
111 .word handle_trap_reserved /* 17 <<
112 .word handle_trap_reserved /* 18 <<
113 .word handle_trap_reserved /* 19 <<
114 .word handle_trap_reserved /* 20 <<
115 .word handle_trap_reserved /* 21 <<
116 .word handle_trap_reserved /* 22 <<
117 .word handle_trap_reserved /* 23 <<
118 .word handle_trap_reserved /* 24 <<
119 .word handle_trap_reserved /* 25 <<
120 .word handle_trap_reserved /* 26 <<
121 .word handle_trap_reserved /* 27 <<
122 .word handle_trap_reserved /* 28 <<
123 .word handle_trap_reserved /* 29 <<
124 #ifdef CONFIG_KGDB <<
125 .word handle_kgdb_breakpoint /* 30 <<
126 #else <<
127 .word instruction_trap <<
128 #endif <<
129 .word handle_breakpoint /* 31 <<
130 47
131 .text 48 .text
132 .set noat !! 49 ENTRY(__sys_fork)
133 .set nobreak !! 50 SAVE_SWITCH_STACK
134 !! 51 jbsr sys_fork
135 ENTRY(inthandler) !! 52 lea %sp@(24),%sp
136 SAVE_ALL !! 53 rts
137 <<
138 kuser_cmpxchg_check <<
139 54
140 /* Clear EH bit before we get a new ex !! 55 ENTRY(__sys_clone)
141 * and after we have saved it to the e !! 56 SAVE_SWITCH_STACK
142 * whether it's trap, tlb-miss or inte !! 57 pea %sp@(SWITCH_STACK_SIZE)
143 * estatus is not updated the next exc !! 58 jbsr m68k_clone
144 */ !! 59 lea %sp@(28),%sp
145 rdctl r24, status !! 60 rts
146 movi r9, %lo(~STATUS_EH) <<
147 and r24, r24, r9 <<
148 wrctl status, r24 <<
149 <<
150 /* Read cause and vector and branch to <<
151 mov r4, sp <<
152 rdctl r5, exception <<
153 movia r9, exception_table <<
154 add r24, r9, r5 <<
155 ldw r24, 0(r24) <<
156 jmp r24 <<
157 <<
158 <<
159 /********************************************* <<
160 * Handle traps <<
161 ********************************************* <<
162 */ <<
163 ENTRY(handle_trap) <<
164 ldwio r24, -4(ea) /* instruction <<
165 srli r24, r24, 4 <<
166 andi r24, r24, 0x7c <<
167 movia r9,trap_table <<
168 add r24, r24, r9 <<
169 ldw r24, 0(r24) <<
170 jmp r24 <<
171 61
>> 62 ENTRY(__sys_vfork)
>> 63 SAVE_SWITCH_STACK
>> 64 jbsr sys_vfork
>> 65 lea %sp@(24),%sp
>> 66 rts
172 67
173 /********************************************* !! 68 ENTRY(__sys_clone3)
174 * Handle system calls <<
175 ********************************************* <<
176 */ <<
177 ENTRY(handle_system_call) <<
178 /* Enable interrupts */ <<
179 rdctl r10, status <<
180 ori r10, r10, STATUS_PIE <<
181 wrctl status, r10 <<
182 <<
183 /* Reload registers destroyed by commo <<
184 ldw r4, PT_R4(sp) <<
185 ldw r5, PT_R5(sp) <<
186 <<
187 local_restart: <<
188 stw r2, PT_ORIG_R2(sp) <<
189 /* Check that the requested system cal <<
190 movui r1, __NR_syscalls <<
191 bgeu r2, r1, ret_invsyscall <<
192 slli r1, r2, 2 <<
193 movhi r11, %hiadj(sys_call_table) <<
194 add r1, r1, r11 <<
195 ldw r1, %lo(sys_call_table)(r1) <<
196 <<
197 /* Check if we are being traced */ <<
198 GET_THREAD_INFO r11 <<
199 ldw r11,TI_FLAGS(r11) <<
200 BTBNZ r11,r11,TIF_SYSCALL_TRACE,trac <<
201 <<
202 /* Execute the system call */ <<
203 callr r1 <<
204 <<
205 /* If the syscall returns a negative r <<
206 * Set r7 to 1 to indicate error, <<
207 * Negate r2 to get a positive error <<
208 * If the syscall returns zero or a po <<
209 * Set r7 to 0. <<
210 * The sigreturn system calls will ski <<
211 * adding to register ra. To avoid des <<
212 */ <<
213 translate_rc_and_ret: <<
214 movi r1, 0 <<
215 bge r2, zero, 3f <<
216 ldw r1, PT_ORIG_R2(sp) <<
217 addi r1, r1, 1 <<
218 beq r1, zero, 3f <<
219 sub r2, zero, r2 <<
220 movi r1, 1 <<
221 3: <<
222 stw r2, PT_R2(sp) <<
223 stw r1, PT_R7(sp) <<
224 end_translate_rc_and_ret: <<
225 <<
226 ret_from_exception: <<
227 ldw r1, PT_ESTATUS(sp) <<
228 /* if so, skip resched, signals */ <<
229 TSTBNZ r1, r1, ESTATUS_EU, Luser_retu <<
230 <<
231 restore_all: <<
232 rdctl r10, status <<
233 andi r10, r10, %lo(~STATUS_PIE) <<
234 wrctl status, r10 <<
235 RESTORE_ALL <<
236 eret <<
237 <<
238 /* If the syscall number was invalid r <<
239 ret_invsyscall: <<
240 movi r2, -ENOSYS <<
241 br translate_rc_and_ret <<
242 <<
243 /* This implements the same as above, <<
244 * do_syscall_trace_enter and do_sysca <<
245 * syscall in order for utilities like <<
246 */ <<
247 traced_system_call: <<
248 SAVE_SWITCH_STACK 69 SAVE_SWITCH_STACK
249 call do_syscall_trace_enter !! 70 pea %sp@(SWITCH_STACK_SIZE)
250 RESTORE_SWITCH_STACK !! 71 jbsr m68k_clone3
>> 72 lea %sp@(28),%sp
>> 73 rts
251 74
252 /* Create system call register argumen !! 75 ENTRY(sys_sigreturn)
253 arguments on stack are already in p <<
254 of pt_regs. */ <<
255 ldw r2, PT_R2(sp) <<
256 ldw r4, PT_R4(sp) <<
257 ldw r5, PT_R5(sp) <<
258 ldw r6, PT_R6(sp) <<
259 ldw r7, PT_R7(sp) <<
260 <<
261 /* Fetch the syscall function. */ <<
262 movui r1, __NR_syscalls <<
263 bgeu r2, r1, traced_invsyscall <<
264 slli r1, r2, 2 <<
265 movhi r11,%hiadj(sys_call_table) <<
266 add r1, r1, r11 <<
267 ldw r1, %lo(sys_call_table)(r1) <<
268 <<
269 callr r1 <<
270 <<
271 /* If the syscall returns a negative r <<
272 * Set r7 to 1 to indicate error, <<
273 * Negate r2 to get a positive error <<
274 * If the syscall returns zero or a po <<
275 * Set r7 to 0. <<
276 * The sigreturn system calls will ski <<
277 * adding to register ra. To avoid des <<
278 */ <<
279 translate_rc_and_ret2: <<
280 movi r1, 0 <<
281 bge r2, zero, 4f <<
282 ldw r1, PT_ORIG_R2(sp) <<
283 addi r1, r1, 1 <<
284 beq r1, zero, 4f <<
285 sub r2, zero, r2 <<
286 movi r1, 1 <<
287 4: <<
288 stw r2, PT_R2(sp) <<
289 stw r1, PT_R7(sp) <<
290 end_translate_rc_and_ret2: <<
291 SAVE_SWITCH_STACK 76 SAVE_SWITCH_STACK
292 call do_syscall_trace_exit !! 77 movel %sp,%a1 | switch_stack pointer
293 RESTORE_SWITCH_STACK !! 78 lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
294 br ret_from_exception !! 79 lea %sp@(-84),%sp | leave a gap
>> 80 movel %a1,%sp@-
>> 81 movel %a0,%sp@-
>> 82 jbsr do_sigreturn
>> 83 jra 1f | shared with rt_sigreturn()
295 84
296 /* If the syscall number was invalid r !! 85 ENTRY(sys_rt_sigreturn)
297 traced_invsyscall: <<
298 movi r2, -ENOSYS <<
299 br translate_rc_and_ret2 <<
300 <<
301 Luser_return: <<
302 GET_THREAD_INFO r11 <<
303 ldw r10, TI_FLAGS(r11) <<
304 ANDI32 r11, r10, _TIF_WORK_MASK <<
305 beq r11, r0, restore_all <<
306 BTBZ r1, r10, TIF_NEED_RESCHED, Lsi <<
307 <<
308 /* Reschedule work */ <<
309 call schedule <<
310 br ret_from_exception <<
311 <<
312 Lsignal_return: <<
313 ANDI32 r1, r10, _TIF_SIGPENDING | _TI <<
314 beq r1, r0, restore_all <<
315 mov r4, sp /* pt_ <<
316 SAVE_SWITCH_STACK 86 SAVE_SWITCH_STACK
317 call do_notify_resume !! 87 movel %sp,%a1 | switch_stack pointer
318 beq r2, r0, no_work_pending !! 88 lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
319 RESTORE_SWITCH_STACK !! 89 lea %sp@(-84),%sp | leave a gap
320 /* prepare restart syscall here withou !! 90 movel %a1,%sp@-
321 ldw r2, PT_R2(sp) /* reload sysc !! 91 movel %a0,%sp@-
322 ldw r4, PT_R4(sp) /* reload sysc !! 92 | stack contents:
323 ldw r5, PT_R5(sp) !! 93 | [original pt_regs address] [original switch_stack address]
324 ldw r6, PT_R6(sp) !! 94 | [gap] [switch_stack] [pt_regs] [exception frame]
325 ldw r7, PT_R7(sp) !! 95 jbsr do_rt_sigreturn
326 ldw r8, PT_R8(sp) !! 96
327 ldw r9, PT_R9(sp) !! 97 1:
328 br local_restart /* restart sys !! 98 | stack contents now:
>> 99 | [original pt_regs address] [original switch_stack address]
>> 100 | [unused part of the gap] [moved switch_stack] [moved pt_regs]
>> 101 | [replacement exception frame]
>> 102 | return value of do_{rt_,}sigreturn() points to moved switch_stack.
329 103
330 no_work_pending: !! 104 movel %d0,%sp | discard the leftover junk
331 RESTORE_SWITCH_STACK 105 RESTORE_SWITCH_STACK
332 br ret_from_exception !! 106 | stack contents now is just [syscall return address] [pt_regs] [frame]
>> 107 | return pt_regs.d0
>> 108 movel %sp@(PT_OFF_D0+4),%d0
>> 109 rts
>> 110
>> 111 ENTRY(buserr)
>> 112 SAVE_ALL_INT
>> 113 GET_CURRENT(%d0)
>> 114 movel %sp,%sp@- | stack frame pointer argument
>> 115 jbsr buserr_c
>> 116 addql #4,%sp
>> 117 jra ret_from_exception
>> 118
>> 119 ENTRY(trap)
>> 120 SAVE_ALL_INT
>> 121 GET_CURRENT(%d0)
>> 122 movel %sp,%sp@- | stack frame pointer argument
>> 123 jbsr trap_c
>> 124 addql #4,%sp
>> 125 jra ret_from_exception
>> 126
>> 127 | After a fork we jump here directly from resume,
>> 128 | so that %d1 contains the previous task
>> 129 | schedule_tail now used regardless of CONFIG_SMP
>> 130 ENTRY(ret_from_fork)
>> 131 movel %d1,%sp@-
>> 132 jsr schedule_tail
>> 133 addql #4,%sp
>> 134 jra ret_from_exception
333 135
334 /********************************************* !! 136 ENTRY(ret_from_kernel_thread)
335 * Handle external interrupts. !! 137 | a3 contains the kernel thread payload, d7 - its argument
336 ********************************************* !! 138 movel %d1,%sp@-
337 */ !! 139 jsr schedule_tail
338 /* !! 140 movel %d7,(%sp)
339 * This is the generic interrupt handler (for !! 141 jsr %a3@
340 * sources). It figures out the vector number !! 142 addql #4,%sp
341 * interrupt service routine directly. !! 143 jra ret_from_exception
342 */ !! 144
343 external_interrupt: !! 145 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
344 rdctl r12, ipending !! 146
345 rdctl r9, ienable !! 147 #ifdef TRAP_DBG_INTERRUPT
346 and r12, r12, r9 !! 148
347 /* skip if no interrupt is pending */ !! 149 .globl dbginterrupt
348 beq r12, r0, ret_from_interrupt !! 150 ENTRY(dbginterrupt)
>> 151 SAVE_ALL_INT
>> 152 GET_CURRENT(%d0)
>> 153 movel %sp,%sp@- /* stack frame pointer argument */
>> 154 jsr dbginterrupt_c
>> 155 addql #4,%sp
>> 156 jra ret_from_exception
>> 157 #endif
349 158
350 /* !! 159 ENTRY(reschedule)
351 * Process an external hardware interr !! 160 /* save top of frame */
352 */ !! 161 pea %sp@
>> 162 jbsr set_esp0
>> 163 addql #4,%sp
>> 164 pea ret_from_exception
>> 165 jmp schedule
>> 166
>> 167 ENTRY(ret_from_user_signal)
>> 168 moveq #__NR_sigreturn,%d0
>> 169 trap #0
>> 170
>> 171 ENTRY(ret_from_user_rt_signal)
>> 172 movel #__NR_rt_sigreturn,%d0
>> 173 trap #0
353 174
354 addi ea, ea, -4 /* re-issue th !! 175 #else
355 stw ea, PT_EA(sp) <<
356 2: movi r4, %lo(-1) /* Start from <<
357 highes <<
358 /* This is the <<
359 1: andi r10, r12, 1 /* Isolate bit <<
360 srli r12, r12, 1 /* shift count <<
361 multip <<
362 addi r4, r4, 1 <<
363 beq r10, r0, 1b <<
364 mov r5, sp /* Setup pt_re <<
365 call do_IRQ <<
366 rdctl r12, ipending /* check again <<
367 rdctl r9, ienable /* Isolate pos <<
368 and r12, r12, r9 <<
369 bne r12, r0, 2b <<
370 /* br ret_from_interrupt */ /* fall <<
371 <<
372 ENTRY(ret_from_interrupt) <<
373 ldw r1, PT_ESTATUS(sp) /* che <<
374 TSTBNZ r1, r1, ESTATUS_EU, Luser_retu <<
375 <<
376 #ifdef CONFIG_PREEMPTION <<
377 GET_THREAD_INFO r1 <<
378 ldw r4, TI_PREEMPT_COUNT(r1) <<
379 bne r4, r0, restore_all <<
380 ldw r4, TI_FLAGS(r1) <<
381 BTBZ r10, r4, TIF_NEED_RESCHED, res <<
382 ldw r4, PT_ESTATUS(sp) /* ? I <<
383 andi r10, r4, ESTATUS_EPIE <<
384 beq r10, r0, restore_all <<
385 call preempt_schedule_irq <<
386 #endif <<
387 br restore_all <<
388 176
389 /********************************************* !! 177 do_trace_entry:
390 * A few syscall wrappers !! 178 movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
391 ********************************************* !! 179 subql #4,%sp
392 */ <<
393 /* <<
394 * int clone(unsigned long clone_flags, unsign <<
395 * int __user * parent_tidptr, in <<
396 * int tls_val) <<
397 */ <<
398 ENTRY(sys_clone) <<
399 SAVE_SWITCH_STACK 180 SAVE_SWITCH_STACK
400 subi sp, sp, 4 /* make space for tl !! 181 jbsr syscall_trace_enter
401 stw r8, 0(sp) /* pass tls pointer <<
402 call nios2_clone <<
403 addi sp, sp, 4 <<
404 RESTORE_SWITCH_STACK 182 RESTORE_SWITCH_STACK
405 ret !! 183 addql #4,%sp
>> 184 addql #1,%d0 | optimization for cmpil #-1,%d0
>> 185 jeq ret_from_syscall
>> 186 movel %sp@(PT_OFF_ORIG_D0),%d0
>> 187 cmpl #NR_syscalls,%d0
>> 188 jcs syscall
>> 189 jra ret_from_syscall
>> 190 badsys:
>> 191 movel #-ENOSYS,%sp@(PT_OFF_D0)
>> 192 jra ret_from_syscall
406 193
407 ENTRY(sys_rt_sigreturn) !! 194 do_trace_exit:
>> 195 subql #4,%sp
408 SAVE_SWITCH_STACK 196 SAVE_SWITCH_STACK
409 mov r4, sp !! 197 jbsr syscall_trace_leave
410 call do_rt_sigreturn <<
411 RESTORE_SWITCH_STACK 198 RESTORE_SWITCH_STACK
412 addi ra, ra, (end_translate_rc_and_ !! 199 addql #4,%sp
413 ret !! 200 jra .Lret_from_exception
414 201
415 /********************************************* !! 202 ENTRY(system_call)
416 * A few other wrappers and stubs !! 203 SAVE_ALL_SYS
417 ********************************************* !! 204
418 */ !! 205 GET_CURRENT(%d1)
419 protection_exception_pte: !! 206 movel %d1,%a1
420 rdctl r6, pteaddr <<
421 slli r6, r6, 10 <<
422 call do_page_fault <<
423 br ret_from_exception <<
424 <<
425 protection_exception_ba: <<
426 rdctl r6, badaddr <<
427 call do_page_fault <<
428 br ret_from_exception <<
429 <<
430 protection_exception_instr: <<
431 call handle_supervisor_instr <<
432 br ret_from_exception <<
433 <<
434 handle_breakpoint: <<
435 call breakpoint_c <<
436 br ret_from_exception <<
437 207
438 #ifdef CONFIG_NIOS2_ALIGNMENT_TRAP !! 208 | save top of frame
439 handle_unaligned: !! 209 movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
>> 210
>> 211 | syscall trace?
>> 212 tstb %a1@(TINFO_FLAGS+2)
>> 213 jmi do_trace_entry
>> 214 | seccomp filter active?
>> 215 btst #5,%a1@(TINFO_FLAGS+2)
>> 216 bnes do_trace_entry
>> 217 cmpl #NR_syscalls,%d0
>> 218 jcc badsys
>> 219 syscall:
>> 220 jbsr @(sys_call_table,%d0:l:4)@(0)
>> 221 movel %d0,%sp@(PT_OFF_D0) | save the return value
>> 222 ret_from_syscall:
>> 223 |oriw #0x0700,%sr
>> 224 movel %curptr@(TASK_STACK),%a1
>> 225 movew %a1@(TINFO_FLAGS+2),%d0
>> 226 jne syscall_exit_work
>> 227 1: RESTORE_ALL
>> 228
>> 229 syscall_exit_work:
>> 230 btst #5,%sp@(PT_OFF_SR) | check if returning to kernel
>> 231 bnes 1b | if so, skip resched, signals
>> 232 lslw #1,%d0
>> 233 jcs do_trace_exit
>> 234 jmi do_delayed_trace
>> 235 lslw #8,%d0
>> 236 jne do_signal_return
>> 237 pea resume_userspace
>> 238 jra schedule
>> 239
>> 240
>> 241 ENTRY(ret_from_exception)
>> 242 .Lret_from_exception:
>> 243 btst #5,%sp@(PT_OFF_SR) | check if returning to kernel
>> 244 bnes 1f | if so, skip resched, signals
>> 245 | only allow interrupts when we are really the last one on the
>> 246 | kernel stack, otherwise stack overflow can occur during
>> 247 | heavy interrupt load
>> 248 andw #ALLOWINT,%sr
>> 249
>> 250 resume_userspace:
>> 251 movel %curptr@(TASK_STACK),%a1
>> 252 moveb %a1@(TINFO_FLAGS+3),%d0
>> 253 jne exit_work
>> 254 1: RESTORE_ALL
>> 255
>> 256 exit_work:
>> 257 | save top of frame
>> 258 movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
>> 259 lslb #1,%d0
>> 260 jne do_signal_return
>> 261 pea resume_userspace
>> 262 jra schedule
>> 263
>> 264
>> 265 do_signal_return:
>> 266 |andw #ALLOWINT,%sr
>> 267 subql #4,%sp | dummy return address
440 SAVE_SWITCH_STACK 268 SAVE_SWITCH_STACK
441 call handle_unaligned_c !! 269 pea %sp@(SWITCH_STACK_SIZE)
>> 270 bsrl do_notify_resume
>> 271 addql #4,%sp
442 RESTORE_SWITCH_STACK 272 RESTORE_SWITCH_STACK
443 br ret_from_exception !! 273 addql #4,%sp
444 #else !! 274 jbra resume_userspace
445 handle_unaligned: <<
446 call handle_unaligned_c <<
447 br ret_from_exception <<
448 #endif <<
449 275
450 handle_illegal: !! 276 do_delayed_trace:
451 call handle_illegal_c !! 277 bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR
452 br ret_from_exception !! 278 pea 1 | send SIGTRAP
453 !! 279 movel %curptr,%sp@-
454 handle_diverror: !! 280 pea LSIGTRAP
455 call handle_diverror_c !! 281 jbsr send_sig
456 br ret_from_exception !! 282 addql #8,%sp
457 !! 283 addql #4,%sp
458 #ifdef CONFIG_KGDB !! 284 jbra resume_userspace
459 handle_kgdb_breakpoint: !! 285
460 call kgdb_breakpoint_c !! 286
461 br ret_from_exception !! 287 /* This is the main interrupt handler for autovector interrupts */
462 #endif !! 288
>> 289 ENTRY(auto_inthandler)
>> 290 SAVE_ALL_INT
>> 291 GET_CURRENT(%d0)
>> 292 | put exception # in d0
>> 293 bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0
>> 294 subw #VEC_SPUR,%d0
>> 295
>> 296 movel %sp,%sp@-
>> 297 movel %d0,%sp@- | put vector # on stack
>> 298 auto_irqhandler_fixup = . + 2
>> 299 jsr do_IRQ | process the IRQ
>> 300 addql #8,%sp | pop parameters off stack
>> 301 jra ret_from_exception
>> 302
>> 303 /* Handler for user defined interrupt vectors */
>> 304
>> 305 ENTRY(user_inthandler)
>> 306 SAVE_ALL_INT
>> 307 GET_CURRENT(%d0)
>> 308 | put exception # in d0
>> 309 bfextu %sp@(PT_OFF_FORMATVEC){#4,#10},%d0
>> 310 user_irqvec_fixup = . + 2
>> 311 subw #VEC_USER,%d0
>> 312
>> 313 movel %sp,%sp@-
>> 314 movel %d0,%sp@- | put vector # on stack
>> 315 jsr do_IRQ | process the IRQ
>> 316 addql #8,%sp | pop parameters off stack
>> 317 jra ret_from_exception
>> 318
>> 319 /* Handler for uninitialized and spurious interrupts */
>> 320
>> 321 ENTRY(bad_inthandler)
>> 322 SAVE_ALL_INT
>> 323 GET_CURRENT(%d0)
>> 324
>> 325 movel %sp,%sp@-
>> 326 jsr handle_badint
>> 327 addql #4,%sp
>> 328 jra ret_from_exception
463 329
464 handle_trap_1: !! 330 resume:
465 call handle_trap_1_c !! 331 /*
466 br ret_from_exception !! 332 * Beware - when entering resume, prev (the current task) is
467 !! 333 * in a0, next (the new task) is in a1,so don't change these
468 handle_trap_2: !! 334 * registers until their contents are no longer needed.
469 call handle_trap_2_c !! 335 */
470 br ret_from_exception <<
471 <<
472 handle_trap_3: <<
473 handle_trap_reserved: <<
474 call handle_trap_3_c <<
475 br ret_from_exception <<
476 <<
477 /* <<
478 * Beware - when entering resume, prev (the cu <<
479 * in r4, next (the new task) is in r5, don't <<
480 * registers. <<
481 */ <<
482 ENTRY(resume) <<
483 336
484 rdctl r7, status !! 337 /* save sr */
485 stw r7, TASK_THREAD + THREAD_KPSR( !! 338 movew %sr,%a0@(TASK_THREAD+THREAD_SR)
486 339
487 andi r7, r7, %lo(~STATUS_PIE) !! 340 /* save fs (sfc,%dfc) (may be pointing to kernel memory) */
488 wrctl status, r7 !! 341 movec %sfc,%d0
>> 342 movew %d0,%a0@(TASK_THREAD+THREAD_FC)
>> 343
>> 344 /* save usp */
>> 345 /* it is better to use a movel here instead of a movew 8*) */
>> 346 movec %usp,%d0
>> 347 movel %d0,%a0@(TASK_THREAD+THREAD_USP)
489 348
>> 349 /* save non-scratch registers on stack */
490 SAVE_SWITCH_STACK 350 SAVE_SWITCH_STACK
491 stw sp, TASK_THREAD + THREAD_KSP(r <<
492 ldw sp, TASK_THREAD + THREAD_KSP(r <<
493 movia r24, _current_thread <<
494 GET_THREAD_INFO r1 <<
495 stw r1, 0(r24) <<
496 RESTORE_SWITCH_STACK <<
497 <<
498 ldw r7, TASK_THREAD + THREAD_KPSR( <<
499 wrctl status, r7 <<
500 ret <<
501 351
502 ENTRY(ret_from_fork) !! 352 /* save current kernel stack pointer */
503 call schedule_tail !! 353 movel %sp,%a0@(TASK_THREAD+THREAD_KSP)
504 br ret_from_exception <<
505 354
506 ENTRY(ret_from_kernel_thread) !! 355 /* save floating point context */
507 call schedule_tail !! 356 #ifndef CONFIG_M68KFPU_EMU_ONLY
508 mov r4,r17 /* arg */ !! 357 #ifdef CONFIG_M68KFPU_EMU
509 callr r16 /* function */ !! 358 tstl m68k_fputype
510 br ret_from_exception !! 359 jeq 3f
>> 360 #endif
>> 361 fsave %a0@(TASK_THREAD+THREAD_FPSTATE)
511 362
512 /* !! 363 #if defined(CONFIG_M68060)
513 * Kernel user helpers. !! 364 #if !defined(CPU_M68060_ONLY)
514 * !! 365 btst #3,m68k_cputype+3
515 * Each segment is 64-byte aligned and will be !! 366 beqs 1f
516 * New segments (if ever needed) must be added !! 367 #endif
517 * This mechanism should be used only for thin !! 368 /* The 060 FPU keeps status in bits 15-8 of the first longword */
518 * justified, and not be abused freely. !! 369 tstb %a0@(TASK_THREAD+THREAD_FPSTATE+2)
519 * !! 370 jeq 3f
520 */ !! 371 #if !defined(CPU_M68060_ONLY)
>> 372 jra 2f
>> 373 #endif
>> 374 #endif /* CONFIG_M68060 */
>> 375 #if !defined(CPU_M68060_ONLY)
>> 376 1: tstb %a0@(TASK_THREAD+THREAD_FPSTATE)
>> 377 jeq 3f
>> 378 #endif
>> 379 2: fmovemx %fp0-%fp7,%a0@(TASK_THREAD+THREAD_FPREG)
>> 380 fmoveml %fpcr/%fpsr/%fpiar,%a0@(TASK_THREAD+THREAD_FPCNTL)
>> 381 3:
>> 382 #endif /* CONFIG_M68KFPU_EMU_ONLY */
>> 383 /* Return previous task in %d1 */
>> 384 movel %curptr,%d1
>> 385
>> 386 /* switch to new task (a1 contains new task) */
>> 387 movel %a1,%curptr
>> 388
>> 389 /* restore floating point context */
>> 390 #ifndef CONFIG_M68KFPU_EMU_ONLY
>> 391 #ifdef CONFIG_M68KFPU_EMU
>> 392 tstl m68k_fputype
>> 393 jeq 4f
>> 394 #endif
>> 395 #if defined(CONFIG_M68060)
>> 396 #if !defined(CPU_M68060_ONLY)
>> 397 btst #3,m68k_cputype+3
>> 398 beqs 1f
>> 399 #endif
>> 400 /* The 060 FPU keeps status in bits 15-8 of the first longword */
>> 401 tstb %a1@(TASK_THREAD+THREAD_FPSTATE+2)
>> 402 jeq 3f
>> 403 #if !defined(CPU_M68060_ONLY)
>> 404 jra 2f
>> 405 #endif
>> 406 #endif /* CONFIG_M68060 */
>> 407 #if !defined(CPU_M68060_ONLY)
>> 408 1: tstb %a1@(TASK_THREAD+THREAD_FPSTATE)
>> 409 jeq 3f
>> 410 #endif
>> 411 2: fmovemx %a1@(TASK_THREAD+THREAD_FPREG),%fp0-%fp7
>> 412 fmoveml %a1@(TASK_THREAD+THREAD_FPCNTL),%fpcr/%fpsr/%fpiar
>> 413 3: frestore %a1@(TASK_THREAD+THREAD_FPSTATE)
>> 414 4:
>> 415 #endif /* CONFIG_M68KFPU_EMU_ONLY */
521 416
522 /* Filling pads with undefined instructions. !! 417 /* restore the kernel stack pointer */
523 .macro kuser_pad sym size !! 418 movel %a1@(TASK_THREAD+THREAD_KSP),%sp
524 .if ((. - \sym) & 3) <<
525 .rept (4 - (. - \sym) & 3) <<
526 .byte 0 <<
527 .endr <<
528 .endif <<
529 .rept ((\size - (. - \sym)) / 4) <<
530 .word 0xdeadbeef <<
531 .endr <<
532 .endm <<
533 <<
534 .align 6 <<
535 .globl __kuser_helper_start <<
536 __kuser_helper_start: <<
537 419
538 __kuser_helper_version: !! 420 /* restore non-scratch registers */
539 .word ((__kuser_helper_end - __kuser !! 421 RESTORE_SWITCH_STACK
540 422
541 __kuser_cmpxchg: !! 423 /* restore user stack pointer */
542 /* !! 424 movel %a1@(TASK_THREAD+THREAD_USP),%a0
543 * r4 pointer to exchange variable !! 425 movel %a0,%usp
544 * r5 old value !! 426
545 * r6 new value !! 427 /* restore fs (sfc,%dfc) */
546 */ !! 428 movew %a1@(TASK_THREAD+THREAD_FC),%a0
547 cmpxchg_ldw: !! 429 movec %a0,%sfc
548 ldw r2, 0(r4) !! 430 movec %a0,%dfc
549 sub r2, r2, r5 !! 431
550 bne r2, zero, cmpxchg_ret !! 432 /* restore status register */
551 !! 433 movew %a1@(TASK_THREAD+THREAD_SR),%d0
552 /* We had a match, store the new value !! 434 oriw #0x0700,%d0
553 cmpxchg_stw: !! 435 movew %d0,%sr
554 stw r6, 0(r4) <<
555 cmpxchg_ret: <<
556 ret <<
557 <<
558 kuser_pad __kuser_cmpxchg, 64 <<
559 <<
560 .globl __kuser_sigtramp <<
561 __kuser_sigtramp: <<
562 movi r2, __NR_rt_sigreturn <<
563 trap <<
564 436
565 kuser_pad __kuser_sigtramp, 64 !! 437 rts
566 438
567 .globl __kuser_helper_end !! 439 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
568 __kuser_helper_end: <<
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.