>> 1 /* SPDX-License-Identifier: GPL-2.0-or-later
>> 2 * -*- mode: asm -*-
>> 3 *
>> 4 * linux/arch/m68k/kernel/entry.S
>> 5 *
>> 6 * Copyright (C) 1991, 1992 Linus Torvalds
>> 7 *
>> 8 * Linux/m68k support by Hamish Macdonald
>> 9 *
>> 10 * 68060 fixes by Jesper Skov
>> 11 *
>> 12 */
>> 13
1 /* 14 /*
2 * This file is subject to the terms and condi !! 15 * entry.S contains the system-call and fault low-level handling routines.
3 * License. See the file "COPYING" in the mai !! 16 * This also contains the timer-interrupt handler, as well as all interrupts
4 * for more details. !! 17 * and faults that can result in a task-switch.
5 * !! 18 *
6 * Copyright (C) 1994 - 2000, 2001, 2003 Ralf !! 19 * NOTE: This code handles signal-recognition, which happens every time
7 * Copyright (C) 1999, 2000 Silicon Graphics, !! 20 * after a timer-interrupt and after each system call.
8 * Copyright (C) 2001 MIPS Technologies, Inc. !! 21 *
9 */ 22 */
10 23
11 #include <asm/asm.h> !! 24 /*
12 #include <asm/asmmacro.h> !! 25 * 12/03/96 Jes: Currently we only support m68k single-cpu systems, so
13 #include <asm/compiler.h> !! 26 * all pointers that used to be 'current' are now entry
14 #include <asm/irqflags.h> !! 27 * number 0 in the 'current_set' list.
15 #include <asm/regdef.h> !! 28 *
16 #include <asm/mipsregs.h> !! 29 * 6/05/00 RZ: addedd writeback completion after return from sighandler
17 #include <asm/stackframe.h> !! 30 * for 68040
18 #include <asm/isadep.h> !! 31 */
19 #include <asm/thread_info.h> <<
20 32
21 #ifndef CONFIG_PREEMPTION !! 33 #include <linux/linkage.h>
22 #define resume_kernel restore_all !! 34 #include <asm/errno.h>
23 #else !! 35 #include <asm/setup.h>
24 #define __ret_from_irq ret_from_exception !! 36 #include <asm/traps.h>
>> 37 #include <asm/unistd.h>
>> 38 #include <asm/asm-offsets.h>
>> 39 #include <asm/entry.h>
>> 40
>> 41 .globl system_call, buserr, trap, resume
>> 42 .globl sys_call_table
>> 43 .globl __sys_fork, __sys_clone, __sys_vfork
>> 44 .globl bad_interrupt
>> 45 .globl auto_irqhandler_fixup
>> 46 .globl user_irqvec_fixup
>> 47
>> 48 .text
>> 49 ENTRY(__sys_fork)
>> 50 SAVE_SWITCH_STACK
>> 51 jbsr sys_fork
>> 52 lea %sp@(24),%sp
>> 53 rts
>> 54
>> 55 ENTRY(__sys_clone)
>> 56 SAVE_SWITCH_STACK
>> 57 pea %sp@(SWITCH_STACK_SIZE)
>> 58 jbsr m68k_clone
>> 59 lea %sp@(28),%sp
>> 60 rts
>> 61
>> 62 ENTRY(__sys_vfork)
>> 63 SAVE_SWITCH_STACK
>> 64 jbsr sys_vfork
>> 65 lea %sp@(24),%sp
>> 66 rts
>> 67
>> 68 ENTRY(__sys_clone3)
>> 69 SAVE_SWITCH_STACK
>> 70 pea %sp@(SWITCH_STACK_SIZE)
>> 71 jbsr m68k_clone3
>> 72 lea %sp@(28),%sp
>> 73 rts
>> 74
>> 75 ENTRY(sys_sigreturn)
>> 76 SAVE_SWITCH_STACK
>> 77 movel %sp,%a1 | switch_stack pointer
>> 78 lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
>> 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()
>> 84
>> 85 ENTRY(sys_rt_sigreturn)
>> 86 SAVE_SWITCH_STACK
>> 87 movel %sp,%a1 | switch_stack pointer
>> 88 lea %sp@(SWITCH_STACK_SIZE),%a0 | pt_regs pointer
>> 89 lea %sp@(-84),%sp | leave a gap
>> 90 movel %a1,%sp@-
>> 91 movel %a0,%sp@-
>> 92 | stack contents:
>> 93 | [original pt_regs address] [original switch_stack address]
>> 94 | [gap] [switch_stack] [pt_regs] [exception frame]
>> 95 jbsr do_rt_sigreturn
>> 96
>> 97 1:
>> 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.
>> 103
>> 104 movel %d0,%sp | discard the leftover junk
>> 105 RESTORE_SWITCH_STACK
>> 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
>> 135
>> 136 ENTRY(ret_from_kernel_thread)
>> 137 | a3 contains the kernel thread payload, d7 - its argument
>> 138 movel %d1,%sp@-
>> 139 jsr schedule_tail
>> 140 movel %d7,(%sp)
>> 141 jsr %a3@
>> 142 addql #4,%sp
>> 143 jra ret_from_exception
>> 144
>> 145 #if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
>> 146
>> 147 #ifdef TRAP_DBG_INTERRUPT
>> 148
>> 149 .globl dbginterrupt
>> 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
25 #endif 157 #endif
26 158
27 .text !! 159 ENTRY(reschedule)
28 .align 5 !! 160 /* save top of frame */
29 #ifndef CONFIG_PREEMPTION !! 161 pea %sp@
30 FEXPORT(ret_from_exception) !! 162 jbsr set_esp0
31 local_irq_disable !! 163 addql #4,%sp
32 b __ret_from_irq !! 164 pea ret_from_exception
33 #endif !! 165 jmp schedule
34 FEXPORT(ret_from_irq) !! 166
35 LONG_S s0, TI_REGS($28) !! 167 ENTRY(ret_from_user_signal)
36 FEXPORT(__ret_from_irq) !! 168 moveq #__NR_sigreturn,%d0
37 /* !! 169 trap #0
38 * We can be coming here from a syscall done i !! 170
39 * e.g. a failed kernel_execve(). !! 171 ENTRY(ret_from_user_rt_signal)
40 */ !! 172 movel #__NR_rt_sigreturn,%d0
41 resume_userspace_check: !! 173 trap #0
42 LONG_L t0, PT_STATUS(sp) <<
43 andi t0, t0, KU_USER <<
44 beqz t0, resume_kernel <<
45 174
46 resume_userspace: <<
47 local_irq_disable # make <<
48 # inte <<
49 # betw <<
50 LONG_L a2, TI_FLAGS($28) # curr <<
51 andi t0, a2, _TIF_WORK_MASK # (ign <<
52 bnez t0, work_pending <<
53 j restore_all <<
54 <<
55 #ifdef CONFIG_PREEMPTION <<
56 resume_kernel: <<
57 local_irq_disable <<
58 lw t0, TI_PRE_COUNT($28) <<
59 bnez t0, restore_all <<
60 LONG_L t0, TI_FLAGS($28) <<
61 andi t1, t0, _TIF_NEED_RESCHED <<
62 beqz t1, restore_all <<
63 LONG_L t0, PT_STATUS(sp) <<
64 andi t0, 1 <<
65 beqz t0, restore_all <<
66 PTR_LA ra, restore_all <<
67 j preempt_schedule_irq <<
68 #endif <<
69 <<
70 FEXPORT(ret_from_kernel_thread) <<
71 jal schedule_tail # a0 = <<
72 move a0, s1 <<
73 jal s0 <<
74 j syscall_exit <<
75 <<
76 FEXPORT(ret_from_fork) <<
77 jal schedule_tail # a0 = <<
78 <<
79 FEXPORT(syscall_exit) <<
80 #ifdef CONFIG_DEBUG_RSEQ <<
81 move a0, sp <<
82 jal rseq_syscall <<
83 #endif <<
84 local_irq_disable # make <<
85 # sign <<
86 # samp <<
87 LONG_L a2, TI_FLAGS($28) # curr <<
88 li t0, _TIF_ALLWORK_MASK <<
89 and t0, a2, t0 <<
90 bnez t0, syscall_exit_work <<
91 <<
92 restore_all: # rest <<
93 .set noat <<
94 RESTORE_TEMP <<
95 RESTORE_AT <<
96 RESTORE_STATIC <<
97 restore_partial: # restore part <<
98 #ifdef CONFIG_TRACE_IRQFLAGS <<
99 SAVE_STATIC <<
100 SAVE_AT <<
101 SAVE_TEMP <<
102 LONG_L v0, PT_STATUS(sp) <<
103 #if defined(CONFIG_CPU_R3000) <<
104 and v0, ST0_IEP <<
105 #else 175 #else
106 and v0, ST0_IE !! 176
107 #endif !! 177 do_trace_entry:
108 beqz v0, 1f !! 178 movel #-ENOSYS,%sp@(PT_OFF_D0)| needed for strace
109 jal trace_hardirqs_on !! 179 subql #4,%sp
110 b 2f !! 180 SAVE_SWITCH_STACK
111 1: jal trace_hardirqs_off !! 181 jbsr syscall_trace_enter
112 2: !! 182 RESTORE_SWITCH_STACK
113 RESTORE_TEMP !! 183 addql #4,%sp
114 RESTORE_AT !! 184 addql #1,%d0 | optimization for cmpil #-1,%d0
115 RESTORE_STATIC !! 185 jeq ret_from_syscall
116 #endif !! 186 movel %sp@(PT_OFF_ORIG_D0),%d0
117 RESTORE_SOME !! 187 cmpl #NR_syscalls,%d0
118 RESTORE_SP_AND_RET !! 188 jcs syscall
119 .set at !! 189 jra ret_from_syscall
120 !! 190 badsys:
121 work_pending: !! 191 movel #-ENOSYS,%sp@(PT_OFF_D0)
122 andi t0, a2, _TIF_NEED_RESCHED # a2 !! 192 jra ret_from_syscall
123 beqz t0, work_notifysig !! 193
124 work_resched: !! 194 do_trace_exit:
125 TRACE_IRQS_OFF !! 195 subql #4,%sp
126 jal schedule !! 196 SAVE_SWITCH_STACK
127 !! 197 jbsr syscall_trace_leave
128 local_irq_disable # make !! 198 RESTORE_SWITCH_STACK
129 # sign !! 199 addql #4,%sp
130 # samp !! 200 jra .Lret_from_exception
131 LONG_L a2, TI_FLAGS($28) !! 201
132 andi t0, a2, _TIF_WORK_MASK # is t !! 202 ENTRY(system_call)
133 # othe !! 203 SAVE_ALL_SYS
134 beqz t0, restore_all !! 204
135 andi t0, a2, _TIF_NEED_RESCHED !! 205 GET_CURRENT(%d1)
136 bnez t0, work_resched !! 206 movel %d1,%a1
137 !! 207
138 work_notifysig: # deal !! 208 | save top of frame
139 # noti !! 209 movel %sp,%curptr@(TASK_THREAD+THREAD_ESP0)
140 move a0, sp !! 210
141 li a1, 0 !! 211 | syscall trace?
142 jal do_notify_resume # a2 a !! 212 tstb %a1@(TINFO_FLAGS+2)
143 j resume_userspace_check !! 213 jmi do_trace_entry
144 !! 214 | seccomp filter active?
145 FEXPORT(syscall_exit_partial) !! 215 btst #5,%a1@(TINFO_FLAGS+2)
146 #ifdef CONFIG_DEBUG_RSEQ !! 216 bnes do_trace_entry
147 move a0, sp !! 217 cmpl #NR_syscalls,%d0
148 jal rseq_syscall !! 218 jcc badsys
149 #endif !! 219 syscall:
150 local_irq_disable # make !! 220 jbsr @(sys_call_table,%d0:l:4)@(0)
151 # chan !! 221 movel %d0,%sp@(PT_OFF_D0) | save the return value
152 LONG_L a2, TI_FLAGS($28) # curr !! 222 ret_from_syscall:
153 li t0, _TIF_ALLWORK_MASK !! 223 |oriw #0x0700,%sr
154 and t0, a2 !! 224 movel %curptr@(TASK_STACK),%a1
155 beqz t0, restore_partial !! 225 movew %a1@(TINFO_FLAGS+2),%d0
156 SAVE_STATIC !! 226 jne syscall_exit_work
>> 227 1: RESTORE_ALL
>> 228
157 syscall_exit_work: 229 syscall_exit_work:
158 LONG_L t0, PT_STATUS(sp) !! 230 btst #5,%sp@(PT_OFF_SR) | check if returning to kernel
159 andi t0, t0, KU_USER !! 231 bnes 1b | if so, skip resched, signals
160 beqz t0, resume_kernel !! 232 lslw #1,%d0
161 li t0, _TIF_WORK_SYSCALL_EXIT !! 233 jcs do_trace_exit
162 and t0, a2 # a2 i !! 234 jmi do_delayed_trace
163 beqz t0, work_pending # trac !! 235 lslw #8,%d0
164 local_irq_enable # coul !! 236 jne do_signal_return
165 # call !! 237 pea resume_userspace
166 TRACE_IRQS_ON !! 238 jra schedule
167 move a0, sp !! 239
168 jal syscall_trace_leave !! 240
169 b resume_userspace !! 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
170 249
171 #if defined(CONFIG_CPU_MIPSR2) || defined(CONF !! 250 resume_userspace:
172 defined(CONFIG_CPU_MIPSR6) || defined(CONF !! 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
>> 268 SAVE_SWITCH_STACK
>> 269 pea %sp@(SWITCH_STACK_SIZE)
>> 270 bsrl do_notify_resume
>> 271 addql #4,%sp
>> 272 RESTORE_SWITCH_STACK
>> 273 addql #4,%sp
>> 274 jbra resume_userspace
>> 275
>> 276 do_delayed_trace:
>> 277 bclr #7,%sp@(PT_OFF_SR) | clear trace bit in SR
>> 278 pea 1 | send SIGTRAP
>> 279 movel %curptr,%sp@-
>> 280 pea LSIGTRAP
>> 281 jbsr send_sig
>> 282 addql #8,%sp
>> 283 addql #4,%sp
>> 284 jbra resume_userspace
>> 285
>> 286
>> 287 /* This is the main interrupt handler for autovector interrupts */
>> 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
>> 329
>> 330 resume:
>> 331 /*
>> 332 * Beware - when entering resume, prev (the current task) is
>> 333 * in a0, next (the new task) is in a1,so don't change these
>> 334 * registers until their contents are no longer needed.
>> 335 */
>> 336
>> 337 /* save sr */
>> 338 movew %sr,%a0@(TASK_THREAD+THREAD_SR)
>> 339
>> 340 /* save fs (sfc,%dfc) (may be pointing to kernel memory) */
>> 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)
>> 348
>> 349 /* save non-scratch registers on stack */
>> 350 SAVE_SWITCH_STACK
>> 351
>> 352 /* save current kernel stack pointer */
>> 353 movel %sp,%a0@(TASK_THREAD+THREAD_KSP)
>> 354
>> 355 /* save floating point context */
>> 356 #ifndef CONFIG_M68KFPU_EMU_ONLY
>> 357 #ifdef CONFIG_M68KFPU_EMU
>> 358 tstl m68k_fputype
>> 359 jeq 3f
>> 360 #endif
>> 361 fsave %a0@(TASK_THREAD+THREAD_FPSTATE)
173 362
174 /* !! 363 #if defined(CONFIG_M68060)
175 * MIPS32R2 Instruction Hazard Barrier - must !! 364 #if !defined(CPU_M68060_ONLY)
176 * !! 365 btst #3,m68k_cputype+3
177 * For C code use the inline version named ins !! 366 beqs 1f
178 */ !! 367 #endif
179 LEAF(mips_ihb) !! 368 /* The 060 FPU keeps status in bits 15-8 of the first longword */
180 .set MIPS_ISA_LEVEL_RAW !! 369 tstb %a0@(TASK_THREAD+THREAD_FPSTATE+2)
181 jr.hb ra !! 370 jeq 3f
182 nop !! 371 #if !defined(CPU_M68060_ONLY)
183 END(mips_ihb) !! 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 */
>> 416
>> 417 /* restore the kernel stack pointer */
>> 418 movel %a1@(TASK_THREAD+THREAD_KSP),%sp
>> 419
>> 420 /* restore non-scratch registers */
>> 421 RESTORE_SWITCH_STACK
>> 422
>> 423 /* restore user stack pointer */
>> 424 movel %a1@(TASK_THREAD+THREAD_USP),%a0
>> 425 movel %a0,%usp
>> 426
>> 427 /* restore fs (sfc,%dfc) */
>> 428 movew %a1@(TASK_THREAD+THREAD_FC),%a0
>> 429 movec %a0,%sfc
>> 430 movec %a0,%dfc
>> 431
>> 432 /* restore status register */
>> 433 movew %a1@(TASK_THREAD+THREAD_SR),%d0
>> 434 oriw #0x0700,%d0
>> 435 movew %d0,%sr
>> 436
>> 437 rts
184 438
185 #endif /* CONFIG_CPU_MIPSR2 - CONFIG_CPU_MIPSR !! 439 #endif /* CONFIG_MMU && !CONFIG_COLDFIRE */
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