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CommitLineData
1da177e4
LT
1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994 - 1999, 2000 by Ralf Baechle and others.
40ac5d47 7 * Copyright (C) 2005, 2006 by Ralf Baechle (ralf@linux-mips.org)
1da177e4
LT
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 * Copyright (C) 2004 Thiemo Seufer
34c2f668 10 * Copyright (C) 2013 Imagination Technologies Ltd.
1da177e4 11 */
1da177e4 12#include <linux/errno.h>
1da177e4 13#include <linux/sched.h>
b17b0153 14#include <linux/sched/debug.h>
29930025 15#include <linux/sched/task.h>
68db0cf1 16#include <linux/sched/task_stack.h>
7bcf7717 17#include <linux/tick.h>
1da177e4
LT
18#include <linux/kernel.h>
19#include <linux/mm.h>
20#include <linux/stddef.h>
21#include <linux/unistd.h>
cae39d13 22#include <linux/export.h>
1da177e4 23#include <linux/ptrace.h>
1da177e4
LT
24#include <linux/mman.h>
25#include <linux/personality.h>
26#include <linux/sys.h>
1da177e4
LT
27#include <linux/init.h>
28#include <linux/completion.h>
63077519 29#include <linux/kallsyms.h>
94109102 30#include <linux/random.h>
9791554b 31#include <linux/prctl.h>
1da177e4 32
94109102 33#include <asm/asm.h>
1da177e4
LT
34#include <asm/bootinfo.h>
35#include <asm/cpu.h>
432c6bac 36#include <asm/dsemul.h>
e50c0a8f 37#include <asm/dsp.h>
1da177e4 38#include <asm/fpu.h>
d42d8d10 39#include <asm/irq.h>
1db1af84 40#include <asm/msa.h>
1da177e4 41#include <asm/pgtable.h>
1da177e4
LT
42#include <asm/mipsregs.h>
43#include <asm/processor.h>
60be939c 44#include <asm/reg.h>
7c0f6ba6 45#include <linux/uaccess.h>
1da177e4
LT
46#include <asm/io.h>
47#include <asm/elf.h>
48#include <asm/isadep.h>
49#include <asm/inst.h>
1df0f0ff 50#include <asm/stacktrace.h>
856839b7 51#include <asm/irq_regs.h>
1da177e4 52
cdbedc61
TG
53#ifdef CONFIG_HOTPLUG_CPU
54void arch_cpu_idle_dead(void)
1da177e4 55{
a00eeede 56 play_dead();
cdbedc61
TG
57}
58#endif
1b2bc75c 59
1da177e4 60asmlinkage void ret_from_fork(void);
8f54bcac 61asmlinkage void ret_from_kernel_thread(void);
1da177e4
LT
62
63void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp)
64{
65 unsigned long status;
66
67 /* New thread loses kernel privileges. */
bbaf238b 68 status = regs->cp0_status & ~(ST0_CU0|ST0_CU1|ST0_FR|KU_MASK);
1da177e4
LT
69 status |= KU_USER;
70 regs->cp0_status = status;
76e5846d
JH
71 lose_fpu(0);
72 clear_thread_flag(TIF_MSA_CTX_LIVE);
1da177e4 73 clear_used_math();
432c6bac 74 atomic_set(&current->thread.bd_emu_frame, BD_EMUFRAME_NONE);
a3056b1c 75 init_dsp();
1da177e4
LT
76 regs->cp0_epc = pc;
77 regs->regs[29] = sp;
1da177e4
LT
78}
79
432c6bac
PB
80void exit_thread(struct task_struct *tsk)
81{
82 /*
83 * User threads may have allocated a delay slot emulation frame.
84 * If so, clean up that allocation.
85 */
86 if (!(current->flags & PF_KTHREAD))
87 dsemul_thread_cleanup(tsk);
88}
89
39148e94
JH
90int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
91{
92 /*
93 * Save any process state which is live in hardware registers to the
94 * parent context prior to duplication. This prevents the new child
95 * state becoming stale if the parent is preempted before copy_thread()
96 * gets a chance to save the parent's live hardware registers to the
97 * child context.
98 */
99 preempt_disable();
100
101 if (is_msa_enabled())
102 save_msa(current);
103 else if (is_fpu_owner())
104 _save_fp(current);
105
106 save_dsp(current);
107
108 preempt_enable();
109
110 *dst = *src;
111 return 0;
112}
113
e2c5aaa5
AD
114/*
115 * Copy architecture-specific thread state
116 */
f9c4e3a6
JC
117int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
118 unsigned long kthread_arg, struct task_struct *p, unsigned long tls)
1da177e4 119{
75bb07e7 120 struct thread_info *ti = task_thread_info(p);
afa86fc4 121 struct pt_regs *childregs, *regs = current_pt_regs();
484889fc 122 unsigned long childksp;
1da177e4 123
75bb07e7 124 childksp = (unsigned long)task_stack_page(p) + THREAD_SIZE - 32;
1da177e4 125
1da177e4
LT
126 /* set up new TSS. */
127 childregs = (struct pt_regs *) childksp - 1;
484889fc
DD
128 /* Put the stack after the struct pt_regs. */
129 childksp = (unsigned long) childregs;
8f54bcac
AV
130 p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1);
131 if (unlikely(p->flags & PF_KTHREAD)) {
e2c5aaa5 132 /* kernel thread */
8f54bcac
AV
133 unsigned long status = p->thread.cp0_status;
134 memset(childregs, 0, sizeof(struct pt_regs));
135 ti->addr_limit = KERNEL_DS;
136 p->thread.reg16 = usp; /* fn */
e2c5aaa5 137 p->thread.reg17 = kthread_arg;
8f54bcac
AV
138 p->thread.reg29 = childksp;
139 p->thread.reg31 = (unsigned long) ret_from_kernel_thread;
140#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
141 status = (status & ~(ST0_KUP | ST0_IEP | ST0_IEC)) |
142 ((status & (ST0_KUC | ST0_IEC)) << 2);
143#else
144 status |= ST0_EXL;
145#endif
146 childregs->cp0_status = status;
147 return 0;
148 }
e2c5aaa5
AD
149
150 /* user thread */
1da177e4 151 *childregs = *regs;
70342287
RB
152 childregs->regs[7] = 0; /* Clear error flag */
153 childregs->regs[2] = 0; /* Child gets zero as return value */
64b3122d
AV
154 if (usp)
155 childregs->regs[29] = usp;
8f54bcac 156 ti->addr_limit = USER_DS;
1da177e4 157
1da177e4
LT
158 p->thread.reg29 = (unsigned long) childregs;
159 p->thread.reg31 = (unsigned long) ret_from_fork;
160
161 /*
162 * New tasks lose permission to use the fpu. This accelerates context
163 * switching for most programs since they don't use the fpu.
164 */
1da177e4 165 childregs->cp0_status &= ~(ST0_CU2|ST0_CU1);
1da177e4 166
1da177e4 167 clear_tsk_thread_flag(p, TIF_USEDFPU);
7daef8f2
PB
168 clear_tsk_thread_flag(p, TIF_USEDMSA);
169 clear_tsk_thread_flag(p, TIF_MSA_CTX_LIVE);
1da177e4 170
f088fc84 171#ifdef CONFIG_MIPS_MT_FPAFF
6657fe0a 172 clear_tsk_thread_flag(p, TIF_FPUBOUND);
f088fc84
RB
173#endif /* CONFIG_MIPS_MT_FPAFF */
174
432c6bac
PB
175 atomic_set(&p->thread.bd_emu_frame, BD_EMUFRAME_NONE);
176
3c37026d 177 if (clone_flags & CLONE_SETTLS)
f9c4e3a6 178 ti->tp_value = tls;
3c37026d 179
1da177e4
LT
180 return 0;
181}
182
36ecafc5
GF
183#ifdef CONFIG_CC_STACKPROTECTOR
184#include <linux/stackprotector.h>
185unsigned long __stack_chk_guard __read_mostly;
186EXPORT_SYMBOL(__stack_chk_guard);
187#endif
188
b5943182
FBH
189struct mips_frame_info {
190 void *func;
191 unsigned long func_size;
192 int frame_size;
193 int pc_offset;
194};
dc953df1 195
5000653e
TW
196#define J_TARGET(pc,target) \
197 (((unsigned long)(pc) & 0xf0000000) | ((target) << 2))
198
bb9bc468 199static inline int is_ra_save_ins(union mips_instruction *ip, int *poff)
c0efbb6d 200{
34c2f668 201#ifdef CONFIG_CPU_MICROMIPS
34c2f668
LY
202 /*
203 * swsp ra,offset
204 * swm16 reglist,offset(sp)
205 * swm32 reglist,offset(sp)
206 * sw32 ra,offset(sp)
207 * jradiussp - NOT SUPPORTED
208 *
209 * microMIPS is way more fun...
210 */
a3552dac 211 if (mm_insn_16bit(ip->halfword[1])) {
bb9bc468
PB
212 switch (ip->mm16_r5_format.opcode) {
213 case mm_swsp16_op:
214 if (ip->mm16_r5_format.rt != 31)
215 return 0;
216
217 *poff = ip->mm16_r5_format.simmediate;
218 *poff = (*poff << 2) / sizeof(ulong);
219 return 1;
220
221 case mm_pool16c_op:
222 switch (ip->mm16_m_format.func) {
223 case mm_swm16_op:
224 *poff = ip->mm16_m_format.imm;
225 *poff += 1 + ip->mm16_m_format.rlist;
226 *poff = (*poff << 2) / sizeof(ulong);
227 return 1;
228
229 default:
230 return 0;
231 }
232
233 default:
234 return 0;
235 }
34c2f668 236 }
bb9bc468
PB
237
238 switch (ip->i_format.opcode) {
239 case mm_sw32_op:
240 if (ip->i_format.rs != 29)
241 return 0;
242 if (ip->i_format.rt != 31)
243 return 0;
244
245 *poff = ip->i_format.simmediate / sizeof(ulong);
246 return 1;
247
248 case mm_pool32b_op:
249 switch (ip->mm_m_format.func) {
250 case mm_swm32_func:
251 if (ip->mm_m_format.rd < 0x10)
252 return 0;
253 if (ip->mm_m_format.base != 29)
254 return 0;
255
256 *poff = ip->mm_m_format.simmediate;
257 *poff += (ip->mm_m_format.rd & 0xf) * sizeof(u32);
258 *poff /= sizeof(ulong);
259 return 1;
260 default:
261 return 0;
262 }
263
264 default:
265 return 0;
34c2f668
LY
266 }
267#else
c0efbb6d 268 /* sw / sd $ra, offset($sp) */
bb9bc468
PB
269 if ((ip->i_format.opcode == sw_op || ip->i_format.opcode == sd_op) &&
270 ip->i_format.rs == 29 && ip->i_format.rt == 31) {
271 *poff = ip->i_format.simmediate / sizeof(ulong);
272 return 1;
273 }
274
275 return 0;
34c2f668 276#endif
c0efbb6d
FBH
277}
278
e7438c4b 279static inline int is_jump_ins(union mips_instruction *ip)
c0efbb6d 280{
34c2f668
LY
281#ifdef CONFIG_CPU_MICROMIPS
282 /*
283 * jr16,jrc,jalr16,jalr16
284 * jal
285 * jalr/jr,jalr.hb/jr.hb,jalrs,jalrs.hb
286 * jraddiusp - NOT SUPPORTED
287 *
288 * microMIPS is kind of more fun...
289 */
67c75057
PB
290 if (mm_insn_16bit(ip->halfword[1])) {
291 if ((ip->mm16_r5_format.opcode == mm_pool16c_op &&
292 (ip->mm16_r5_format.rt & mm_jr16_op) == mm_jr16_op))
293 return 1;
294 return 0;
295 }
296
096a0de4
PB
297 if (ip->j_format.opcode == mm_j32_op)
298 return 1;
67c75057 299 if (ip->j_format.opcode == mm_jal32_op)
34c2f668
LY
300 return 1;
301 if (ip->r_format.opcode != mm_pool32a_op ||
302 ip->r_format.func != mm_pool32axf_op)
303 return 0;
635c9907 304 return ((ip->u_format.uimmediate >> 6) & mm_jalr_op) == mm_jalr_op;
34c2f668 305#else
e7438c4b
TW
306 if (ip->j_format.opcode == j_op)
307 return 1;
c0efbb6d
FBH
308 if (ip->j_format.opcode == jal_op)
309 return 1;
310 if (ip->r_format.opcode != spec_op)
311 return 0;
312 return ip->r_format.func == jalr_op || ip->r_format.func == jr_op;
34c2f668 313#endif
c0efbb6d
FBH
314}
315
316static inline int is_sp_move_ins(union mips_instruction *ip)
317{
34c2f668
LY
318#ifdef CONFIG_CPU_MICROMIPS
319 /*
320 * addiusp -imm
321 * addius5 sp,-imm
322 * addiu32 sp,sp,-imm
323 * jradiussp - NOT SUPPORTED
324 *
325 * microMIPS is not more fun...
326 */
a3552dac
PB
327 if (mm_insn_16bit(ip->halfword[1])) {
328 return (ip->mm16_r3_format.opcode == mm_pool16d_op &&
329 ip->mm16_r3_format.simmediate && mm_addiusp_func) ||
330 (ip->mm16_r5_format.opcode == mm_pool16d_op &&
331 ip->mm16_r5_format.rt == 29);
34c2f668 332 }
a3552dac 333
635c9907
RB
334 return ip->mm_i_format.opcode == mm_addiu32_op &&
335 ip->mm_i_format.rt == 29 && ip->mm_i_format.rs == 29;
34c2f668 336#else
c0efbb6d
FBH
337 /* addiu/daddiu sp,sp,-imm */
338 if (ip->i_format.rs != 29 || ip->i_format.rt != 29)
339 return 0;
340 if (ip->i_format.opcode == addiu_op || ip->i_format.opcode == daddiu_op)
341 return 1;
34c2f668 342#endif
c0efbb6d
FBH
343 return 0;
344}
345
f66686f7 346static int get_frame_info(struct mips_frame_info *info)
1da177e4 347{
a3552dac 348 bool is_mmips = IS_ENABLED(CONFIG_CPU_MICROMIPS);
b6c7a324
PB
349 union mips_instruction insn, *ip, *ip_end;
350 const unsigned int max_insns = 128;
351 unsigned int i;
c0efbb6d 352
1da177e4 353 info->pc_offset = -1;
63077519 354 info->frame_size = 0;
1da177e4 355
ccaf7caf 356 ip = (void *)msk_isa16_mode((ulong)info->func);
29b376ff
FBH
357 if (!ip)
358 goto err;
359
b6c7a324 360 ip_end = (void *)ip + info->func_size;
29b376ff 361
b6c7a324 362 for (i = 0; i < max_insns && ip < ip_end; i++, ip++) {
a3552dac
PB
363 if (is_mmips && mm_insn_16bit(ip->halfword[0])) {
364 insn.halfword[0] = 0;
365 insn.halfword[1] = ip->halfword[0];
366 } else if (is_mmips) {
367 insn.halfword[0] = ip->halfword[1];
368 insn.halfword[1] = ip->halfword[0];
369 } else {
370 insn.word = ip->word;
371 }
c0efbb6d 372
a3552dac 373 if (is_jump_ins(&insn))
63077519 374 break;
a3552dac 375
0cceb4aa 376 if (!info->frame_size) {
a3552dac 377 if (is_sp_move_ins(&insn))
34c2f668
LY
378 {
379#ifdef CONFIG_CPU_MICROMIPS
380 if (mm_insn_16bit(ip->halfword[0]))
381 {
382 unsigned short tmp;
383
384 if (ip->halfword[0] & mm_addiusp_func)
385 {
386 tmp = (((ip->halfword[0] >> 1) & 0x1ff) << 2);
387 info->frame_size = -(signed short)(tmp | ((tmp & 0x100) ? 0xfe00 : 0));
388 } else {
389 tmp = (ip->halfword[0] >> 1);
390 info->frame_size = -(signed short)(tmp & 0xf);
391 }
392 ip = (void *) &ip->halfword[1];
393 ip--;
394 } else
395#endif
0cceb4aa 396 info->frame_size = - ip->i_format.simmediate;
34c2f668 397 }
0cceb4aa 398 continue;
63077519 399 }
bb9bc468
PB
400 if (info->pc_offset == -1 &&
401 is_ra_save_ins(&insn, &info->pc_offset))
0cceb4aa 402 break;
1da177e4 403 }
f66686f7
AN
404 if (info->frame_size && info->pc_offset >= 0) /* nested */
405 return 0;
406 if (info->pc_offset < 0) /* leaf */
407 return 1;
a90c59e6 408 /* prologue seems bogus... */
29b376ff 409err:
f66686f7 410 return -1;
1da177e4
LT
411}
412
b5943182
FBH
413static struct mips_frame_info schedule_mfi __read_mostly;
414
5000653e
TW
415#ifdef CONFIG_KALLSYMS
416static unsigned long get___schedule_addr(void)
417{
418 return kallsyms_lookup_name("__schedule");
419}
420#else
421static unsigned long get___schedule_addr(void)
422{
423 union mips_instruction *ip = (void *)schedule;
424 int max_insns = 8;
425 int i;
426
427 for (i = 0; i < max_insns; i++, ip++) {
428 if (ip->j_format.opcode == j_op)
429 return J_TARGET(ip, ip->j_format.target);
430 }
431 return 0;
432}
433#endif
434
1da177e4
LT
435static int __init frame_info_init(void)
436{
b5943182 437 unsigned long size = 0;
63077519 438#ifdef CONFIG_KALLSYMS
b5943182 439 unsigned long ofs;
5000653e
TW
440#endif
441 unsigned long addr;
b5943182 442
5000653e
TW
443 addr = get___schedule_addr();
444 if (!addr)
445 addr = (unsigned long)schedule;
446
447#ifdef CONFIG_KALLSYMS
448 kallsyms_lookup_size_offset(addr, &size, &ofs);
63077519 449#endif
5000653e 450 schedule_mfi.func = (void *)addr;
b5943182
FBH
451 schedule_mfi.func_size = size;
452
453 get_frame_info(&schedule_mfi);
6057a798
FBH
454
455 /*
456 * Without schedule() frame info, result given by
457 * thread_saved_pc() and get_wchan() are not reliable.
458 */
b5943182 459 if (schedule_mfi.pc_offset < 0)
6057a798 460 printk("Can't analyze schedule() prologue at %p\n", schedule);
63077519 461
1da177e4
LT
462 return 0;
463}
464
465arch_initcall(frame_info_init);
466
467/*
468 * Return saved PC of a blocked thread.
469 */
470unsigned long thread_saved_pc(struct task_struct *tsk)
471{
472 struct thread_struct *t = &tsk->thread;
473
474 /* New born processes are a special case */
475 if (t->reg31 == (unsigned long) ret_from_fork)
476 return t->reg31;
b5943182 477 if (schedule_mfi.pc_offset < 0)
1da177e4 478 return 0;
b5943182 479 return ((unsigned long *)t->reg29)[schedule_mfi.pc_offset];
1da177e4
LT
480}
481
1da177e4 482
f66686f7 483#ifdef CONFIG_KALLSYMS
94ea09c6
DK
484/* generic stack unwinding function */
485unsigned long notrace unwind_stack_by_address(unsigned long stack_page,
486 unsigned long *sp,
487 unsigned long pc,
488 unsigned long *ra)
f66686f7 489{
db8466c5 490 unsigned long low, high, irq_stack_high;
f66686f7 491 struct mips_frame_info info;
f66686f7 492 unsigned long size, ofs;
db8466c5 493 struct pt_regs *regs;
4d157d5e 494 int leaf;
f66686f7 495
f66686f7
AN
496 if (!stack_page)
497 return 0;
498
1924600c 499 /*
db8466c5
MR
500 * IRQ stacks start at IRQ_STACK_START
501 * task stacks at THREAD_SIZE - 32
1924600c 502 */
db8466c5
MR
503 low = stack_page;
504 if (!preemptible() && on_irq_stack(raw_smp_processor_id(), *sp)) {
505 high = stack_page + IRQ_STACK_START;
506 irq_stack_high = high;
507 } else {
508 high = stack_page + THREAD_SIZE - 32;
509 irq_stack_high = 0;
510 }
511
512 /*
513 * If we reached the top of the interrupt stack, start unwinding
514 * the interrupted task stack.
515 */
516 if (unlikely(*sp == irq_stack_high)) {
517 unsigned long task_sp = *(unsigned long *)*sp;
518
519 /*
520 * Check that the pointer saved in the IRQ stack head points to
521 * something within the stack of the current task
522 */
523 if (!object_is_on_stack((void *)task_sp))
524 return 0;
525
526 /*
527 * Follow pointer to tasks kernel stack frame where interrupted
528 * state was saved.
529 */
530 regs = (struct pt_regs *)task_sp;
531 pc = regs->cp0_epc;
532 if (!user_mode(regs) && __kernel_text_address(pc)) {
533 *sp = regs->regs[29];
534 *ra = regs->regs[31];
535 return pc;
1924600c
AN
536 }
537 return 0;
538 }
55b74283 539 if (!kallsyms_lookup_size_offset(pc, &size, &ofs))
f66686f7 540 return 0;
1fd69098 541 /*
25985edc 542 * Return ra if an exception occurred at the first instruction
1fd69098 543 */
1924600c
AN
544 if (unlikely(ofs == 0)) {
545 pc = *ra;
546 *ra = 0;
547 return pc;
548 }
f66686f7
AN
549
550 info.func = (void *)(pc - ofs);
551 info.func_size = ofs; /* analyze from start to ofs */
4d157d5e
FBH
552 leaf = get_frame_info(&info);
553 if (leaf < 0)
f66686f7 554 return 0;
4d157d5e 555
db8466c5 556 if (*sp < low || *sp + info.frame_size > high)
f66686f7
AN
557 return 0;
558
4d157d5e
FBH
559 if (leaf)
560 /*
561 * For some extreme cases, get_frame_info() can
562 * consider wrongly a nested function as a leaf
563 * one. In that cases avoid to return always the
564 * same value.
565 */
1924600c 566 pc = pc != *ra ? *ra : 0;
4d157d5e
FBH
567 else
568 pc = ((unsigned long *)(*sp))[info.pc_offset];
569
570 *sp += info.frame_size;
1924600c 571 *ra = 0;
4d157d5e 572 return __kernel_text_address(pc) ? pc : 0;
f66686f7 573}
94ea09c6
DK
574EXPORT_SYMBOL(unwind_stack_by_address);
575
576/* used by show_backtrace() */
577unsigned long unwind_stack(struct task_struct *task, unsigned long *sp,
578 unsigned long pc, unsigned long *ra)
579{
d42d8d10
MR
580 unsigned long stack_page = 0;
581 int cpu;
582
583 for_each_possible_cpu(cpu) {
584 if (on_irq_stack(cpu, *sp)) {
585 stack_page = (unsigned long)irq_stack[cpu];
586 break;
587 }
588 }
589
590 if (!stack_page)
591 stack_page = (unsigned long)task_stack_page(task);
592
94ea09c6
DK
593 return unwind_stack_by_address(stack_page, sp, pc, ra);
594}
f66686f7 595#endif
b5943182
FBH
596
597/*
598 * get_wchan - a maintenance nightmare^W^Wpain in the ass ...
599 */
600unsigned long get_wchan(struct task_struct *task)
601{
602 unsigned long pc = 0;
603#ifdef CONFIG_KALLSYMS
604 unsigned long sp;
1924600c 605 unsigned long ra = 0;
b5943182
FBH
606#endif
607
608 if (!task || task == current || task->state == TASK_RUNNING)
609 goto out;
610 if (!task_stack_page(task))
611 goto out;
612
613 pc = thread_saved_pc(task);
614
615#ifdef CONFIG_KALLSYMS
616 sp = task->thread.reg29 + schedule_mfi.frame_size;
617
618 while (in_sched_functions(pc))
1924600c 619 pc = unwind_stack(task, &sp, pc, &ra);
b5943182
FBH
620#endif
621
622out:
623 return pc;
624}
94109102
FBH
625
626/*
627 * Don't forget that the stack pointer must be aligned on a 8 bytes
628 * boundary for 32-bits ABI and 16 bytes for 64-bits ABI.
629 */
630unsigned long arch_align_stack(unsigned long sp)
631{
632 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
633 sp -= get_random_int() & ~PAGE_MASK;
634
635 return sp & ALMASK;
636}
856839b7
ES
637
638static void arch_dump_stack(void *info)
639{
640 struct pt_regs *regs;
641
642 regs = get_irq_regs();
643
644 if (regs)
645 show_regs(regs);
646
647 dump_stack();
648}
649
9a01c3ed 650void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
856839b7 651{
9a01c3ed
CM
652 long this_cpu = get_cpu();
653
654 if (cpumask_test_cpu(this_cpu, mask) && !exclude_self)
655 dump_stack();
656
657 smp_call_function_many(mask, arch_dump_stack, NULL, 1);
658
659 put_cpu();
856839b7 660}
9791554b
PB
661
662int mips_get_process_fp_mode(struct task_struct *task)
663{
664 int value = 0;
665
666 if (!test_tsk_thread_flag(task, TIF_32BIT_FPREGS))
667 value |= PR_FP_MODE_FR;
668 if (test_tsk_thread_flag(task, TIF_HYBRID_FPREGS))
669 value |= PR_FP_MODE_FRE;
670
671 return value;
672}
673
6b832257
PB
674static void prepare_for_fp_mode_switch(void *info)
675{
676 struct mm_struct *mm = info;
677
678 if (current->mm == mm)
679 lose_fpu(1);
680}
681
9791554b
PB
682int mips_set_process_fp_mode(struct task_struct *task, unsigned int value)
683{
684 const unsigned int known_bits = PR_FP_MODE_FR | PR_FP_MODE_FRE;
9791554b 685 struct task_struct *t;
6b832257 686 int max_users;
9791554b
PB
687
688 /* Check the value is valid */
689 if (value & ~known_bits)
690 return -EOPNOTSUPP;
691
692 /* Avoid inadvertently triggering emulation */
b244614a
MN
693 if ((value & PR_FP_MODE_FR) && raw_cpu_has_fpu &&
694 !(raw_current_cpu_data.fpu_id & MIPS_FPIR_F64))
9791554b 695 return -EOPNOTSUPP;
b244614a 696 if ((value & PR_FP_MODE_FRE) && raw_cpu_has_fpu && !cpu_has_fre)
9791554b
PB
697 return -EOPNOTSUPP;
698
13e45f09 699 /* FR = 0 not supported in MIPS R6 */
b244614a 700 if (!(value & PR_FP_MODE_FR) && raw_cpu_has_fpu && cpu_has_mips_r6)
13e45f09
MC
701 return -EOPNOTSUPP;
702
bd239f1e
PB
703 /* Proceed with the mode switch */
704 preempt_disable();
705
9791554b
PB
706 /* Save FP & vector context, then disable FPU & MSA */
707 if (task->signal == current->signal)
708 lose_fpu(1);
709
710 /* Prevent any threads from obtaining live FP context */
711 atomic_set(&task->mm->context.fp_mode_switching, 1);
712 smp_mb__after_atomic();
713
714 /*
6b832257
PB
715 * If there are multiple online CPUs then force any which are running
716 * threads in this process to lose their FPU context, which they can't
717 * regain until fp_mode_switching is cleared later.
9791554b
PB
718 */
719 if (num_online_cpus() > 1) {
6b832257
PB
720 /* No need to send an IPI for the local CPU */
721 max_users = (task->mm == current->mm) ? 1 : 0;
9791554b 722
6b832257
PB
723 if (atomic_read(&current->mm->mm_users) > max_users)
724 smp_call_function(prepare_for_fp_mode_switch,
725 (void *)current->mm, 1);
9791554b
PB
726 }
727
728 /*
729 * There are now no threads of the process with live FP context, so it
730 * is safe to proceed with the FP mode switch.
731 */
732 for_each_thread(task, t) {
733 /* Update desired FP register width */
734 if (value & PR_FP_MODE_FR) {
735 clear_tsk_thread_flag(t, TIF_32BIT_FPREGS);
736 } else {
737 set_tsk_thread_flag(t, TIF_32BIT_FPREGS);
738 clear_tsk_thread_flag(t, TIF_MSA_CTX_LIVE);
739 }
740
741 /* Update desired FP single layout */
742 if (value & PR_FP_MODE_FRE)
743 set_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
744 else
745 clear_tsk_thread_flag(t, TIF_HYBRID_FPREGS);
746 }
747
748 /* Allow threads to use FP again */
749 atomic_set(&task->mm->context.fp_mode_switching, 0);
bd239f1e 750 preempt_enable();
9791554b
PB
751
752 return 0;
753}
08c941bf
MN
754
755#if defined(CONFIG_32BIT) || defined(CONFIG_MIPS32_O32)
756void mips_dump_regs32(u32 *uregs, const struct pt_regs *regs)
757{
758 unsigned int i;
759
760 for (i = MIPS32_EF_R1; i <= MIPS32_EF_R31; i++) {
761 /* k0/k1 are copied as zero. */
762 if (i == MIPS32_EF_R26 || i == MIPS32_EF_R27)
763 uregs[i] = 0;
764 else
765 uregs[i] = regs->regs[i - MIPS32_EF_R0];
766 }
767
768 uregs[MIPS32_EF_LO] = regs->lo;
769 uregs[MIPS32_EF_HI] = regs->hi;
770 uregs[MIPS32_EF_CP0_EPC] = regs->cp0_epc;
771 uregs[MIPS32_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
772 uregs[MIPS32_EF_CP0_STATUS] = regs->cp0_status;
773 uregs[MIPS32_EF_CP0_CAUSE] = regs->cp0_cause;
774}
775#endif /* CONFIG_32BIT || CONFIG_MIPS32_O32 */
776
777#ifdef CONFIG_64BIT
778void mips_dump_regs64(u64 *uregs, const struct pt_regs *regs)
779{
780 unsigned int i;
781
782 for (i = MIPS64_EF_R1; i <= MIPS64_EF_R31; i++) {
783 /* k0/k1 are copied as zero. */
784 if (i == MIPS64_EF_R26 || i == MIPS64_EF_R27)
785 uregs[i] = 0;
786 else
787 uregs[i] = regs->regs[i - MIPS64_EF_R0];
788 }
789
790 uregs[MIPS64_EF_LO] = regs->lo;
791 uregs[MIPS64_EF_HI] = regs->hi;
792 uregs[MIPS64_EF_CP0_EPC] = regs->cp0_epc;
793 uregs[MIPS64_EF_CP0_BADVADDR] = regs->cp0_badvaddr;
794 uregs[MIPS64_EF_CP0_STATUS] = regs->cp0_status;
795 uregs[MIPS64_EF_CP0_CAUSE] = regs->cp0_cause;
796}
797#endif /* CONFIG_64BIT */