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Merge tag 'driver-core-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git...
[deliverable/linux.git] / arch / mips / kernel / traps.c
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, 01, 06 Ralf Baechle
7 * Copyright (C) 1995, 1996 Paul M. Antoine
8 * Copyright (C) 1998 Ulf Carlsson
9 * Copyright (C) 1999 Silicon Graphics, Inc.
10 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11 * Copyright (C) 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki
12 * Copyright (C) 2000, 2001, 2012 MIPS Technologies, Inc. All rights reserved.
13 * Copyright (C) 2014, Imagination Technologies Ltd.
14 */
15 #include <linux/bitops.h>
16 #include <linux/bug.h>
17 #include <linux/compiler.h>
18 #include <linux/context_tracking.h>
19 #include <linux/cpu_pm.h>
20 #include <linux/kexec.h>
21 #include <linux/init.h>
22 #include <linux/kernel.h>
23 #include <linux/module.h>
24 #include <linux/mm.h>
25 #include <linux/sched.h>
26 #include <linux/smp.h>
27 #include <linux/spinlock.h>
28 #include <linux/kallsyms.h>
29 #include <linux/bootmem.h>
30 #include <linux/interrupt.h>
31 #include <linux/ptrace.h>
32 #include <linux/kgdb.h>
33 #include <linux/kdebug.h>
34 #include <linux/kprobes.h>
35 #include <linux/notifier.h>
36 #include <linux/kdb.h>
37 #include <linux/irq.h>
38 #include <linux/perf_event.h>
39
40 #include <asm/addrspace.h>
41 #include <asm/bootinfo.h>
42 #include <asm/branch.h>
43 #include <asm/break.h>
44 #include <asm/cop2.h>
45 #include <asm/cpu.h>
46 #include <asm/cpu-type.h>
47 #include <asm/dsp.h>
48 #include <asm/fpu.h>
49 #include <asm/fpu_emulator.h>
50 #include <asm/idle.h>
51 #include <asm/mips-r2-to-r6-emul.h>
52 #include <asm/mipsregs.h>
53 #include <asm/mipsmtregs.h>
54 #include <asm/module.h>
55 #include <asm/msa.h>
56 #include <asm/pgtable.h>
57 #include <asm/ptrace.h>
58 #include <asm/sections.h>
59 #include <asm/siginfo.h>
60 #include <asm/tlbdebug.h>
61 #include <asm/traps.h>
62 #include <asm/uaccess.h>
63 #include <asm/watch.h>
64 #include <asm/mmu_context.h>
65 #include <asm/types.h>
66 #include <asm/stacktrace.h>
67 #include <asm/uasm.h>
68
69 extern void check_wait(void);
70 extern asmlinkage void rollback_handle_int(void);
71 extern asmlinkage void handle_int(void);
72 extern u32 handle_tlbl[];
73 extern u32 handle_tlbs[];
74 extern u32 handle_tlbm[];
75 extern asmlinkage void handle_adel(void);
76 extern asmlinkage void handle_ades(void);
77 extern asmlinkage void handle_ibe(void);
78 extern asmlinkage void handle_dbe(void);
79 extern asmlinkage void handle_sys(void);
80 extern asmlinkage void handle_bp(void);
81 extern asmlinkage void handle_ri(void);
82 extern asmlinkage void handle_ri_rdhwr_vivt(void);
83 extern asmlinkage void handle_ri_rdhwr(void);
84 extern asmlinkage void handle_cpu(void);
85 extern asmlinkage void handle_ov(void);
86 extern asmlinkage void handle_tr(void);
87 extern asmlinkage void handle_msa_fpe(void);
88 extern asmlinkage void handle_fpe(void);
89 extern asmlinkage void handle_ftlb(void);
90 extern asmlinkage void handle_msa(void);
91 extern asmlinkage void handle_mdmx(void);
92 extern asmlinkage void handle_watch(void);
93 extern asmlinkage void handle_mt(void);
94 extern asmlinkage void handle_dsp(void);
95 extern asmlinkage void handle_mcheck(void);
96 extern asmlinkage void handle_reserved(void);
97 extern void tlb_do_page_fault_0(void);
98
99 void (*board_be_init)(void);
100 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
101 void (*board_nmi_handler_setup)(void);
102 void (*board_ejtag_handler_setup)(void);
103 void (*board_bind_eic_interrupt)(int irq, int regset);
104 void (*board_ebase_setup)(void);
105 void(*board_cache_error_setup)(void);
106
107 static void show_raw_backtrace(unsigned long reg29)
108 {
109 unsigned long *sp = (unsigned long *)(reg29 & ~3);
110 unsigned long addr;
111
112 printk("Call Trace:");
113 #ifdef CONFIG_KALLSYMS
114 printk("\n");
115 #endif
116 while (!kstack_end(sp)) {
117 unsigned long __user *p =
118 (unsigned long __user *)(unsigned long)sp++;
119 if (__get_user(addr, p)) {
120 printk(" (Bad stack address)");
121 break;
122 }
123 if (__kernel_text_address(addr))
124 print_ip_sym(addr);
125 }
126 printk("\n");
127 }
128
129 #ifdef CONFIG_KALLSYMS
130 int raw_show_trace;
131 static int __init set_raw_show_trace(char *str)
132 {
133 raw_show_trace = 1;
134 return 1;
135 }
136 __setup("raw_show_trace", set_raw_show_trace);
137 #endif
138
139 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
140 {
141 unsigned long sp = regs->regs[29];
142 unsigned long ra = regs->regs[31];
143 unsigned long pc = regs->cp0_epc;
144
145 if (!task)
146 task = current;
147
148 if (raw_show_trace || !__kernel_text_address(pc)) {
149 show_raw_backtrace(sp);
150 return;
151 }
152 printk("Call Trace:\n");
153 do {
154 print_ip_sym(pc);
155 pc = unwind_stack(task, &sp, pc, &ra);
156 } while (pc);
157 printk("\n");
158 }
159
160 /*
161 * This routine abuses get_user()/put_user() to reference pointers
162 * with at least a bit of error checking ...
163 */
164 static void show_stacktrace(struct task_struct *task,
165 const struct pt_regs *regs)
166 {
167 const int field = 2 * sizeof(unsigned long);
168 long stackdata;
169 int i;
170 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
171
172 printk("Stack :");
173 i = 0;
174 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
175 if (i && ((i % (64 / field)) == 0))
176 printk("\n ");
177 if (i > 39) {
178 printk(" ...");
179 break;
180 }
181
182 if (__get_user(stackdata, sp++)) {
183 printk(" (Bad stack address)");
184 break;
185 }
186
187 printk(" %0*lx", field, stackdata);
188 i++;
189 }
190 printk("\n");
191 show_backtrace(task, regs);
192 }
193
194 void show_stack(struct task_struct *task, unsigned long *sp)
195 {
196 struct pt_regs regs;
197 mm_segment_t old_fs = get_fs();
198 if (sp) {
199 regs.regs[29] = (unsigned long)sp;
200 regs.regs[31] = 0;
201 regs.cp0_epc = 0;
202 } else {
203 if (task && task != current) {
204 regs.regs[29] = task->thread.reg29;
205 regs.regs[31] = 0;
206 regs.cp0_epc = task->thread.reg31;
207 #ifdef CONFIG_KGDB_KDB
208 } else if (atomic_read(&kgdb_active) != -1 &&
209 kdb_current_regs) {
210 memcpy(&regs, kdb_current_regs, sizeof(regs));
211 #endif /* CONFIG_KGDB_KDB */
212 } else {
213 prepare_frametrace(&regs);
214 }
215 }
216 /*
217 * show_stack() deals exclusively with kernel mode, so be sure to access
218 * the stack in the kernel (not user) address space.
219 */
220 set_fs(KERNEL_DS);
221 show_stacktrace(task, &regs);
222 set_fs(old_fs);
223 }
224
225 static void show_code(unsigned int __user *pc)
226 {
227 long i;
228 unsigned short __user *pc16 = NULL;
229
230 printk("\nCode:");
231
232 if ((unsigned long)pc & 1)
233 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
234 for(i = -3 ; i < 6 ; i++) {
235 unsigned int insn;
236 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
237 printk(" (Bad address in epc)\n");
238 break;
239 }
240 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
241 }
242 }
243
244 static void __show_regs(const struct pt_regs *regs)
245 {
246 const int field = 2 * sizeof(unsigned long);
247 unsigned int cause = regs->cp0_cause;
248 unsigned int exccode;
249 int i;
250
251 show_regs_print_info(KERN_DEFAULT);
252
253 /*
254 * Saved main processor registers
255 */
256 for (i = 0; i < 32; ) {
257 if ((i % 4) == 0)
258 printk("$%2d :", i);
259 if (i == 0)
260 printk(" %0*lx", field, 0UL);
261 else if (i == 26 || i == 27)
262 printk(" %*s", field, "");
263 else
264 printk(" %0*lx", field, regs->regs[i]);
265
266 i++;
267 if ((i % 4) == 0)
268 printk("\n");
269 }
270
271 #ifdef CONFIG_CPU_HAS_SMARTMIPS
272 printk("Acx : %0*lx\n", field, regs->acx);
273 #endif
274 printk("Hi : %0*lx\n", field, regs->hi);
275 printk("Lo : %0*lx\n", field, regs->lo);
276
277 /*
278 * Saved cp0 registers
279 */
280 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
281 (void *) regs->cp0_epc);
282 printk("ra : %0*lx %pS\n", field, regs->regs[31],
283 (void *) regs->regs[31]);
284
285 printk("Status: %08x ", (uint32_t) regs->cp0_status);
286
287 if (cpu_has_3kex) {
288 if (regs->cp0_status & ST0_KUO)
289 printk("KUo ");
290 if (regs->cp0_status & ST0_IEO)
291 printk("IEo ");
292 if (regs->cp0_status & ST0_KUP)
293 printk("KUp ");
294 if (regs->cp0_status & ST0_IEP)
295 printk("IEp ");
296 if (regs->cp0_status & ST0_KUC)
297 printk("KUc ");
298 if (regs->cp0_status & ST0_IEC)
299 printk("IEc ");
300 } else if (cpu_has_4kex) {
301 if (regs->cp0_status & ST0_KX)
302 printk("KX ");
303 if (regs->cp0_status & ST0_SX)
304 printk("SX ");
305 if (regs->cp0_status & ST0_UX)
306 printk("UX ");
307 switch (regs->cp0_status & ST0_KSU) {
308 case KSU_USER:
309 printk("USER ");
310 break;
311 case KSU_SUPERVISOR:
312 printk("SUPERVISOR ");
313 break;
314 case KSU_KERNEL:
315 printk("KERNEL ");
316 break;
317 default:
318 printk("BAD_MODE ");
319 break;
320 }
321 if (regs->cp0_status & ST0_ERL)
322 printk("ERL ");
323 if (regs->cp0_status & ST0_EXL)
324 printk("EXL ");
325 if (regs->cp0_status & ST0_IE)
326 printk("IE ");
327 }
328 printk("\n");
329
330 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
331 printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
332
333 if (1 <= exccode && exccode <= 5)
334 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
335
336 printk("PrId : %08x (%s)\n", read_c0_prid(),
337 cpu_name_string());
338 }
339
340 /*
341 * FIXME: really the generic show_regs should take a const pointer argument.
342 */
343 void show_regs(struct pt_regs *regs)
344 {
345 __show_regs((struct pt_regs *)regs);
346 }
347
348 void show_registers(struct pt_regs *regs)
349 {
350 const int field = 2 * sizeof(unsigned long);
351 mm_segment_t old_fs = get_fs();
352
353 __show_regs(regs);
354 print_modules();
355 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
356 current->comm, current->pid, current_thread_info(), current,
357 field, current_thread_info()->tp_value);
358 if (cpu_has_userlocal) {
359 unsigned long tls;
360
361 tls = read_c0_userlocal();
362 if (tls != current_thread_info()->tp_value)
363 printk("*HwTLS: %0*lx\n", field, tls);
364 }
365
366 if (!user_mode(regs))
367 /* Necessary for getting the correct stack content */
368 set_fs(KERNEL_DS);
369 show_stacktrace(current, regs);
370 show_code((unsigned int __user *) regs->cp0_epc);
371 printk("\n");
372 set_fs(old_fs);
373 }
374
375 static DEFINE_RAW_SPINLOCK(die_lock);
376
377 void __noreturn die(const char *str, struct pt_regs *regs)
378 {
379 static int die_counter;
380 int sig = SIGSEGV;
381
382 oops_enter();
383
384 if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
385 SIGSEGV) == NOTIFY_STOP)
386 sig = 0;
387
388 console_verbose();
389 raw_spin_lock_irq(&die_lock);
390 bust_spinlocks(1);
391
392 printk("%s[#%d]:\n", str, ++die_counter);
393 show_registers(regs);
394 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
395 raw_spin_unlock_irq(&die_lock);
396
397 oops_exit();
398
399 if (in_interrupt())
400 panic("Fatal exception in interrupt");
401
402 if (panic_on_oops) {
403 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
404 ssleep(5);
405 panic("Fatal exception");
406 }
407
408 if (regs && kexec_should_crash(current))
409 crash_kexec(regs);
410
411 do_exit(sig);
412 }
413
414 extern struct exception_table_entry __start___dbe_table[];
415 extern struct exception_table_entry __stop___dbe_table[];
416
417 __asm__(
418 " .section __dbe_table, \"a\"\n"
419 " .previous \n");
420
421 /* Given an address, look for it in the exception tables. */
422 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
423 {
424 const struct exception_table_entry *e;
425
426 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
427 if (!e)
428 e = search_module_dbetables(addr);
429 return e;
430 }
431
432 asmlinkage void do_be(struct pt_regs *regs)
433 {
434 const int field = 2 * sizeof(unsigned long);
435 const struct exception_table_entry *fixup = NULL;
436 int data = regs->cp0_cause & 4;
437 int action = MIPS_BE_FATAL;
438 enum ctx_state prev_state;
439
440 prev_state = exception_enter();
441 /* XXX For now. Fixme, this searches the wrong table ... */
442 if (data && !user_mode(regs))
443 fixup = search_dbe_tables(exception_epc(regs));
444
445 if (fixup)
446 action = MIPS_BE_FIXUP;
447
448 if (board_be_handler)
449 action = board_be_handler(regs, fixup != NULL);
450
451 switch (action) {
452 case MIPS_BE_DISCARD:
453 goto out;
454 case MIPS_BE_FIXUP:
455 if (fixup) {
456 regs->cp0_epc = fixup->nextinsn;
457 goto out;
458 }
459 break;
460 default:
461 break;
462 }
463
464 /*
465 * Assume it would be too dangerous to continue ...
466 */
467 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
468 data ? "Data" : "Instruction",
469 field, regs->cp0_epc, field, regs->regs[31]);
470 if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
471 SIGBUS) == NOTIFY_STOP)
472 goto out;
473
474 die_if_kernel("Oops", regs);
475 force_sig(SIGBUS, current);
476
477 out:
478 exception_exit(prev_state);
479 }
480
481 /*
482 * ll/sc, rdhwr, sync emulation
483 */
484
485 #define OPCODE 0xfc000000
486 #define BASE 0x03e00000
487 #define RT 0x001f0000
488 #define OFFSET 0x0000ffff
489 #define LL 0xc0000000
490 #define SC 0xe0000000
491 #define SPEC0 0x00000000
492 #define SPEC3 0x7c000000
493 #define RD 0x0000f800
494 #define FUNC 0x0000003f
495 #define SYNC 0x0000000f
496 #define RDHWR 0x0000003b
497
498 /* microMIPS definitions */
499 #define MM_POOL32A_FUNC 0xfc00ffff
500 #define MM_RDHWR 0x00006b3c
501 #define MM_RS 0x001f0000
502 #define MM_RT 0x03e00000
503
504 /*
505 * The ll_bit is cleared by r*_switch.S
506 */
507
508 unsigned int ll_bit;
509 struct task_struct *ll_task;
510
511 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
512 {
513 unsigned long value, __user *vaddr;
514 long offset;
515
516 /*
517 * analyse the ll instruction that just caused a ri exception
518 * and put the referenced address to addr.
519 */
520
521 /* sign extend offset */
522 offset = opcode & OFFSET;
523 offset <<= 16;
524 offset >>= 16;
525
526 vaddr = (unsigned long __user *)
527 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
528
529 if ((unsigned long)vaddr & 3)
530 return SIGBUS;
531 if (get_user(value, vaddr))
532 return SIGSEGV;
533
534 preempt_disable();
535
536 if (ll_task == NULL || ll_task == current) {
537 ll_bit = 1;
538 } else {
539 ll_bit = 0;
540 }
541 ll_task = current;
542
543 preempt_enable();
544
545 regs->regs[(opcode & RT) >> 16] = value;
546
547 return 0;
548 }
549
550 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
551 {
552 unsigned long __user *vaddr;
553 unsigned long reg;
554 long offset;
555
556 /*
557 * analyse the sc instruction that just caused a ri exception
558 * and put the referenced address to addr.
559 */
560
561 /* sign extend offset */
562 offset = opcode & OFFSET;
563 offset <<= 16;
564 offset >>= 16;
565
566 vaddr = (unsigned long __user *)
567 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
568 reg = (opcode & RT) >> 16;
569
570 if ((unsigned long)vaddr & 3)
571 return SIGBUS;
572
573 preempt_disable();
574
575 if (ll_bit == 0 || ll_task != current) {
576 regs->regs[reg] = 0;
577 preempt_enable();
578 return 0;
579 }
580
581 preempt_enable();
582
583 if (put_user(regs->regs[reg], vaddr))
584 return SIGSEGV;
585
586 regs->regs[reg] = 1;
587
588 return 0;
589 }
590
591 /*
592 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
593 * opcodes are supposed to result in coprocessor unusable exceptions if
594 * executed on ll/sc-less processors. That's the theory. In practice a
595 * few processors such as NEC's VR4100 throw reserved instruction exceptions
596 * instead, so we're doing the emulation thing in both exception handlers.
597 */
598 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
599 {
600 if ((opcode & OPCODE) == LL) {
601 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
602 1, regs, 0);
603 return simulate_ll(regs, opcode);
604 }
605 if ((opcode & OPCODE) == SC) {
606 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
607 1, regs, 0);
608 return simulate_sc(regs, opcode);
609 }
610
611 return -1; /* Must be something else ... */
612 }
613
614 /*
615 * Simulate trapping 'rdhwr' instructions to provide user accessible
616 * registers not implemented in hardware.
617 */
618 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
619 {
620 struct thread_info *ti = task_thread_info(current);
621
622 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
623 1, regs, 0);
624 switch (rd) {
625 case 0: /* CPU number */
626 regs->regs[rt] = smp_processor_id();
627 return 0;
628 case 1: /* SYNCI length */
629 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
630 current_cpu_data.icache.linesz);
631 return 0;
632 case 2: /* Read count register */
633 regs->regs[rt] = read_c0_count();
634 return 0;
635 case 3: /* Count register resolution */
636 switch (current_cpu_type()) {
637 case CPU_20KC:
638 case CPU_25KF:
639 regs->regs[rt] = 1;
640 break;
641 default:
642 regs->regs[rt] = 2;
643 }
644 return 0;
645 case 29:
646 regs->regs[rt] = ti->tp_value;
647 return 0;
648 default:
649 return -1;
650 }
651 }
652
653 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
654 {
655 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
656 int rd = (opcode & RD) >> 11;
657 int rt = (opcode & RT) >> 16;
658
659 simulate_rdhwr(regs, rd, rt);
660 return 0;
661 }
662
663 /* Not ours. */
664 return -1;
665 }
666
667 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
668 {
669 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
670 int rd = (opcode & MM_RS) >> 16;
671 int rt = (opcode & MM_RT) >> 21;
672 simulate_rdhwr(regs, rd, rt);
673 return 0;
674 }
675
676 /* Not ours. */
677 return -1;
678 }
679
680 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
681 {
682 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
683 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
684 1, regs, 0);
685 return 0;
686 }
687
688 return -1; /* Must be something else ... */
689 }
690
691 asmlinkage void do_ov(struct pt_regs *regs)
692 {
693 enum ctx_state prev_state;
694 siginfo_t info = {
695 .si_signo = SIGFPE,
696 .si_code = FPE_INTOVF,
697 .si_addr = (void __user *)regs->cp0_epc,
698 };
699
700 prev_state = exception_enter();
701 die_if_kernel("Integer overflow", regs);
702
703 force_sig_info(SIGFPE, &info, current);
704 exception_exit(prev_state);
705 }
706
707 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
708 {
709 struct siginfo si = { 0 };
710
711 switch (sig) {
712 case 0:
713 return 0;
714
715 case SIGFPE:
716 si.si_addr = fault_addr;
717 si.si_signo = sig;
718 /*
719 * Inexact can happen together with Overflow or Underflow.
720 * Respect the mask to deliver the correct exception.
721 */
722 fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
723 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
724 if (fcr31 & FPU_CSR_INV_X)
725 si.si_code = FPE_FLTINV;
726 else if (fcr31 & FPU_CSR_DIV_X)
727 si.si_code = FPE_FLTDIV;
728 else if (fcr31 & FPU_CSR_OVF_X)
729 si.si_code = FPE_FLTOVF;
730 else if (fcr31 & FPU_CSR_UDF_X)
731 si.si_code = FPE_FLTUND;
732 else if (fcr31 & FPU_CSR_INE_X)
733 si.si_code = FPE_FLTRES;
734 else
735 si.si_code = __SI_FAULT;
736 force_sig_info(sig, &si, current);
737 return 1;
738
739 case SIGBUS:
740 si.si_addr = fault_addr;
741 si.si_signo = sig;
742 si.si_code = BUS_ADRERR;
743 force_sig_info(sig, &si, current);
744 return 1;
745
746 case SIGSEGV:
747 si.si_addr = fault_addr;
748 si.si_signo = sig;
749 down_read(&current->mm->mmap_sem);
750 if (find_vma(current->mm, (unsigned long)fault_addr))
751 si.si_code = SEGV_ACCERR;
752 else
753 si.si_code = SEGV_MAPERR;
754 up_read(&current->mm->mmap_sem);
755 force_sig_info(sig, &si, current);
756 return 1;
757
758 default:
759 force_sig(sig, current);
760 return 1;
761 }
762 }
763
764 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
765 unsigned long old_epc, unsigned long old_ra)
766 {
767 union mips_instruction inst = { .word = opcode };
768 void __user *fault_addr;
769 unsigned long fcr31;
770 int sig;
771
772 /* If it's obviously not an FP instruction, skip it */
773 switch (inst.i_format.opcode) {
774 case cop1_op:
775 case cop1x_op:
776 case lwc1_op:
777 case ldc1_op:
778 case swc1_op:
779 case sdc1_op:
780 break;
781
782 default:
783 return -1;
784 }
785
786 /*
787 * do_ri skipped over the instruction via compute_return_epc, undo
788 * that for the FPU emulator.
789 */
790 regs->cp0_epc = old_epc;
791 regs->regs[31] = old_ra;
792
793 /* Save the FP context to struct thread_struct */
794 lose_fpu(1);
795
796 /* Run the emulator */
797 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
798 &fault_addr);
799 fcr31 = current->thread.fpu.fcr31;
800
801 /*
802 * We can't allow the emulated instruction to leave any of
803 * the cause bits set in $fcr31.
804 */
805 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
806
807 /* Restore the hardware register state */
808 own_fpu(1);
809
810 /* Send a signal if required. */
811 process_fpemu_return(sig, fault_addr, fcr31);
812
813 return 0;
814 }
815
816 /*
817 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
818 */
819 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
820 {
821 enum ctx_state prev_state;
822 void __user *fault_addr;
823 int sig;
824
825 prev_state = exception_enter();
826 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
827 SIGFPE) == NOTIFY_STOP)
828 goto out;
829
830 /* Clear FCSR.Cause before enabling interrupts */
831 write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X);
832 local_irq_enable();
833
834 die_if_kernel("FP exception in kernel code", regs);
835
836 if (fcr31 & FPU_CSR_UNI_X) {
837 /*
838 * Unimplemented operation exception. If we've got the full
839 * software emulator on-board, let's use it...
840 *
841 * Force FPU to dump state into task/thread context. We're
842 * moving a lot of data here for what is probably a single
843 * instruction, but the alternative is to pre-decode the FP
844 * register operands before invoking the emulator, which seems
845 * a bit extreme for what should be an infrequent event.
846 */
847 /* Ensure 'resume' not overwrite saved fp context again. */
848 lose_fpu(1);
849
850 /* Run the emulator */
851 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
852 &fault_addr);
853 fcr31 = current->thread.fpu.fcr31;
854
855 /*
856 * We can't allow the emulated instruction to leave any of
857 * the cause bits set in $fcr31.
858 */
859 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
860
861 /* Restore the hardware register state */
862 own_fpu(1); /* Using the FPU again. */
863 } else {
864 sig = SIGFPE;
865 fault_addr = (void __user *) regs->cp0_epc;
866 }
867
868 /* Send a signal if required. */
869 process_fpemu_return(sig, fault_addr, fcr31);
870
871 out:
872 exception_exit(prev_state);
873 }
874
875 void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
876 const char *str)
877 {
878 siginfo_t info = { 0 };
879 char b[40];
880
881 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
882 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
883 SIGTRAP) == NOTIFY_STOP)
884 return;
885 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
886
887 if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
888 SIGTRAP) == NOTIFY_STOP)
889 return;
890
891 /*
892 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
893 * insns, even for trap and break codes that indicate arithmetic
894 * failures. Weird ...
895 * But should we continue the brokenness??? --macro
896 */
897 switch (code) {
898 case BRK_OVERFLOW:
899 case BRK_DIVZERO:
900 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
901 die_if_kernel(b, regs);
902 if (code == BRK_DIVZERO)
903 info.si_code = FPE_INTDIV;
904 else
905 info.si_code = FPE_INTOVF;
906 info.si_signo = SIGFPE;
907 info.si_addr = (void __user *) regs->cp0_epc;
908 force_sig_info(SIGFPE, &info, current);
909 break;
910 case BRK_BUG:
911 die_if_kernel("Kernel bug detected", regs);
912 force_sig(SIGTRAP, current);
913 break;
914 case BRK_MEMU:
915 /*
916 * This breakpoint code is used by the FPU emulator to retake
917 * control of the CPU after executing the instruction from the
918 * delay slot of an emulated branch.
919 *
920 * Terminate if exception was recognized as a delay slot return
921 * otherwise handle as normal.
922 */
923 if (do_dsemulret(regs))
924 return;
925
926 die_if_kernel("Math emu break/trap", regs);
927 force_sig(SIGTRAP, current);
928 break;
929 default:
930 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
931 die_if_kernel(b, regs);
932 if (si_code) {
933 info.si_signo = SIGTRAP;
934 info.si_code = si_code;
935 force_sig_info(SIGTRAP, &info, current);
936 } else {
937 force_sig(SIGTRAP, current);
938 }
939 }
940 }
941
942 asmlinkage void do_bp(struct pt_regs *regs)
943 {
944 unsigned long epc = msk_isa16_mode(exception_epc(regs));
945 unsigned int opcode, bcode;
946 enum ctx_state prev_state;
947 mm_segment_t seg;
948
949 seg = get_fs();
950 if (!user_mode(regs))
951 set_fs(KERNEL_DS);
952
953 prev_state = exception_enter();
954 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
955 if (get_isa16_mode(regs->cp0_epc)) {
956 u16 instr[2];
957
958 if (__get_user(instr[0], (u16 __user *)epc))
959 goto out_sigsegv;
960
961 if (!cpu_has_mmips) {
962 /* MIPS16e mode */
963 bcode = (instr[0] >> 5) & 0x3f;
964 } else if (mm_insn_16bit(instr[0])) {
965 /* 16-bit microMIPS BREAK */
966 bcode = instr[0] & 0xf;
967 } else {
968 /* 32-bit microMIPS BREAK */
969 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
970 goto out_sigsegv;
971 opcode = (instr[0] << 16) | instr[1];
972 bcode = (opcode >> 6) & ((1 << 20) - 1);
973 }
974 } else {
975 if (__get_user(opcode, (unsigned int __user *)epc))
976 goto out_sigsegv;
977 bcode = (opcode >> 6) & ((1 << 20) - 1);
978 }
979
980 /*
981 * There is the ancient bug in the MIPS assemblers that the break
982 * code starts left to bit 16 instead to bit 6 in the opcode.
983 * Gas is bug-compatible, but not always, grrr...
984 * We handle both cases with a simple heuristics. --macro
985 */
986 if (bcode >= (1 << 10))
987 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
988
989 /*
990 * notify the kprobe handlers, if instruction is likely to
991 * pertain to them.
992 */
993 switch (bcode) {
994 case BRK_UPROBE:
995 if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
996 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
997 goto out;
998 else
999 break;
1000 case BRK_UPROBE_XOL:
1001 if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1002 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1003 goto out;
1004 else
1005 break;
1006 case BRK_KPROBE_BP:
1007 if (notify_die(DIE_BREAK, "debug", regs, bcode,
1008 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1009 goto out;
1010 else
1011 break;
1012 case BRK_KPROBE_SSTEPBP:
1013 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1014 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1015 goto out;
1016 else
1017 break;
1018 default:
1019 break;
1020 }
1021
1022 do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1023
1024 out:
1025 set_fs(seg);
1026 exception_exit(prev_state);
1027 return;
1028
1029 out_sigsegv:
1030 force_sig(SIGSEGV, current);
1031 goto out;
1032 }
1033
1034 asmlinkage void do_tr(struct pt_regs *regs)
1035 {
1036 u32 opcode, tcode = 0;
1037 enum ctx_state prev_state;
1038 u16 instr[2];
1039 mm_segment_t seg;
1040 unsigned long epc = msk_isa16_mode(exception_epc(regs));
1041
1042 seg = get_fs();
1043 if (!user_mode(regs))
1044 set_fs(get_ds());
1045
1046 prev_state = exception_enter();
1047 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1048 if (get_isa16_mode(regs->cp0_epc)) {
1049 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1050 __get_user(instr[1], (u16 __user *)(epc + 2)))
1051 goto out_sigsegv;
1052 opcode = (instr[0] << 16) | instr[1];
1053 /* Immediate versions don't provide a code. */
1054 if (!(opcode & OPCODE))
1055 tcode = (opcode >> 12) & ((1 << 4) - 1);
1056 } else {
1057 if (__get_user(opcode, (u32 __user *)epc))
1058 goto out_sigsegv;
1059 /* Immediate versions don't provide a code. */
1060 if (!(opcode & OPCODE))
1061 tcode = (opcode >> 6) & ((1 << 10) - 1);
1062 }
1063
1064 do_trap_or_bp(regs, tcode, 0, "Trap");
1065
1066 out:
1067 set_fs(seg);
1068 exception_exit(prev_state);
1069 return;
1070
1071 out_sigsegv:
1072 force_sig(SIGSEGV, current);
1073 goto out;
1074 }
1075
1076 asmlinkage void do_ri(struct pt_regs *regs)
1077 {
1078 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1079 unsigned long old_epc = regs->cp0_epc;
1080 unsigned long old31 = regs->regs[31];
1081 enum ctx_state prev_state;
1082 unsigned int opcode = 0;
1083 int status = -1;
1084
1085 /*
1086 * Avoid any kernel code. Just emulate the R2 instruction
1087 * as quickly as possible.
1088 */
1089 if (mipsr2_emulation && cpu_has_mips_r6 &&
1090 likely(user_mode(regs)) &&
1091 likely(get_user(opcode, epc) >= 0)) {
1092 unsigned long fcr31 = 0;
1093
1094 status = mipsr2_decoder(regs, opcode, &fcr31);
1095 switch (status) {
1096 case 0:
1097 case SIGEMT:
1098 task_thread_info(current)->r2_emul_return = 1;
1099 return;
1100 case SIGILL:
1101 goto no_r2_instr;
1102 default:
1103 process_fpemu_return(status,
1104 &current->thread.cp0_baduaddr,
1105 fcr31);
1106 task_thread_info(current)->r2_emul_return = 1;
1107 return;
1108 }
1109 }
1110
1111 no_r2_instr:
1112
1113 prev_state = exception_enter();
1114 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1115
1116 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1117 SIGILL) == NOTIFY_STOP)
1118 goto out;
1119
1120 die_if_kernel("Reserved instruction in kernel code", regs);
1121
1122 if (unlikely(compute_return_epc(regs) < 0))
1123 goto out;
1124
1125 if (!get_isa16_mode(regs->cp0_epc)) {
1126 if (unlikely(get_user(opcode, epc) < 0))
1127 status = SIGSEGV;
1128
1129 if (!cpu_has_llsc && status < 0)
1130 status = simulate_llsc(regs, opcode);
1131
1132 if (status < 0)
1133 status = simulate_rdhwr_normal(regs, opcode);
1134
1135 if (status < 0)
1136 status = simulate_sync(regs, opcode);
1137
1138 if (status < 0)
1139 status = simulate_fp(regs, opcode, old_epc, old31);
1140 } else if (cpu_has_mmips) {
1141 unsigned short mmop[2] = { 0 };
1142
1143 if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1144 status = SIGSEGV;
1145 if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1146 status = SIGSEGV;
1147 opcode = mmop[0];
1148 opcode = (opcode << 16) | mmop[1];
1149
1150 if (status < 0)
1151 status = simulate_rdhwr_mm(regs, opcode);
1152 }
1153
1154 if (status < 0)
1155 status = SIGILL;
1156
1157 if (unlikely(status > 0)) {
1158 regs->cp0_epc = old_epc; /* Undo skip-over. */
1159 regs->regs[31] = old31;
1160 force_sig(status, current);
1161 }
1162
1163 out:
1164 exception_exit(prev_state);
1165 }
1166
1167 /*
1168 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1169 * emulated more than some threshold number of instructions, force migration to
1170 * a "CPU" that has FP support.
1171 */
1172 static void mt_ase_fp_affinity(void)
1173 {
1174 #ifdef CONFIG_MIPS_MT_FPAFF
1175 if (mt_fpemul_threshold > 0 &&
1176 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1177 /*
1178 * If there's no FPU present, or if the application has already
1179 * restricted the allowed set to exclude any CPUs with FPUs,
1180 * we'll skip the procedure.
1181 */
1182 if (cpumask_intersects(&current->cpus_allowed, &mt_fpu_cpumask)) {
1183 cpumask_t tmask;
1184
1185 current->thread.user_cpus_allowed
1186 = current->cpus_allowed;
1187 cpumask_and(&tmask, &current->cpus_allowed,
1188 &mt_fpu_cpumask);
1189 set_cpus_allowed_ptr(current, &tmask);
1190 set_thread_flag(TIF_FPUBOUND);
1191 }
1192 }
1193 #endif /* CONFIG_MIPS_MT_FPAFF */
1194 }
1195
1196 /*
1197 * No lock; only written during early bootup by CPU 0.
1198 */
1199 static RAW_NOTIFIER_HEAD(cu2_chain);
1200
1201 int __ref register_cu2_notifier(struct notifier_block *nb)
1202 {
1203 return raw_notifier_chain_register(&cu2_chain, nb);
1204 }
1205
1206 int cu2_notifier_call_chain(unsigned long val, void *v)
1207 {
1208 return raw_notifier_call_chain(&cu2_chain, val, v);
1209 }
1210
1211 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1212 void *data)
1213 {
1214 struct pt_regs *regs = data;
1215
1216 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1217 "instruction", regs);
1218 force_sig(SIGILL, current);
1219
1220 return NOTIFY_OK;
1221 }
1222
1223 static int wait_on_fp_mode_switch(atomic_t *p)
1224 {
1225 /*
1226 * The FP mode for this task is currently being switched. That may
1227 * involve modifications to the format of this tasks FP context which
1228 * make it unsafe to proceed with execution for the moment. Instead,
1229 * schedule some other task.
1230 */
1231 schedule();
1232 return 0;
1233 }
1234
1235 static int enable_restore_fp_context(int msa)
1236 {
1237 int err, was_fpu_owner, prior_msa;
1238
1239 /*
1240 * If an FP mode switch is currently underway, wait for it to
1241 * complete before proceeding.
1242 */
1243 wait_on_atomic_t(&current->mm->context.fp_mode_switching,
1244 wait_on_fp_mode_switch, TASK_KILLABLE);
1245
1246 if (!used_math()) {
1247 /* First time FP context user. */
1248 preempt_disable();
1249 err = init_fpu();
1250 if (msa && !err) {
1251 enable_msa();
1252 _init_msa_upper();
1253 set_thread_flag(TIF_USEDMSA);
1254 set_thread_flag(TIF_MSA_CTX_LIVE);
1255 }
1256 preempt_enable();
1257 if (!err)
1258 set_used_math();
1259 return err;
1260 }
1261
1262 /*
1263 * This task has formerly used the FP context.
1264 *
1265 * If this thread has no live MSA vector context then we can simply
1266 * restore the scalar FP context. If it has live MSA vector context
1267 * (that is, it has or may have used MSA since last performing a
1268 * function call) then we'll need to restore the vector context. This
1269 * applies even if we're currently only executing a scalar FP
1270 * instruction. This is because if we were to later execute an MSA
1271 * instruction then we'd either have to:
1272 *
1273 * - Restore the vector context & clobber any registers modified by
1274 * scalar FP instructions between now & then.
1275 *
1276 * or
1277 *
1278 * - Not restore the vector context & lose the most significant bits
1279 * of all vector registers.
1280 *
1281 * Neither of those options is acceptable. We cannot restore the least
1282 * significant bits of the registers now & only restore the most
1283 * significant bits later because the most significant bits of any
1284 * vector registers whose aliased FP register is modified now will have
1285 * been zeroed. We'd have no way to know that when restoring the vector
1286 * context & thus may load an outdated value for the most significant
1287 * bits of a vector register.
1288 */
1289 if (!msa && !thread_msa_context_live())
1290 return own_fpu(1);
1291
1292 /*
1293 * This task is using or has previously used MSA. Thus we require
1294 * that Status.FR == 1.
1295 */
1296 preempt_disable();
1297 was_fpu_owner = is_fpu_owner();
1298 err = own_fpu_inatomic(0);
1299 if (err)
1300 goto out;
1301
1302 enable_msa();
1303 write_msa_csr(current->thread.fpu.msacsr);
1304 set_thread_flag(TIF_USEDMSA);
1305
1306 /*
1307 * If this is the first time that the task is using MSA and it has
1308 * previously used scalar FP in this time slice then we already nave
1309 * FP context which we shouldn't clobber. We do however need to clear
1310 * the upper 64b of each vector register so that this task has no
1311 * opportunity to see data left behind by another.
1312 */
1313 prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1314 if (!prior_msa && was_fpu_owner) {
1315 _init_msa_upper();
1316
1317 goto out;
1318 }
1319
1320 if (!prior_msa) {
1321 /*
1322 * Restore the least significant 64b of each vector register
1323 * from the existing scalar FP context.
1324 */
1325 _restore_fp(current);
1326
1327 /*
1328 * The task has not formerly used MSA, so clear the upper 64b
1329 * of each vector register such that it cannot see data left
1330 * behind by another task.
1331 */
1332 _init_msa_upper();
1333 } else {
1334 /* We need to restore the vector context. */
1335 restore_msa(current);
1336
1337 /* Restore the scalar FP control & status register */
1338 if (!was_fpu_owner)
1339 write_32bit_cp1_register(CP1_STATUS,
1340 current->thread.fpu.fcr31);
1341 }
1342
1343 out:
1344 preempt_enable();
1345
1346 return 0;
1347 }
1348
1349 asmlinkage void do_cpu(struct pt_regs *regs)
1350 {
1351 enum ctx_state prev_state;
1352 unsigned int __user *epc;
1353 unsigned long old_epc, old31;
1354 void __user *fault_addr;
1355 unsigned int opcode;
1356 unsigned long fcr31;
1357 unsigned int cpid;
1358 int status, err;
1359 unsigned long __maybe_unused flags;
1360 int sig;
1361
1362 prev_state = exception_enter();
1363 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1364
1365 if (cpid != 2)
1366 die_if_kernel("do_cpu invoked from kernel context!", regs);
1367
1368 switch (cpid) {
1369 case 0:
1370 epc = (unsigned int __user *)exception_epc(regs);
1371 old_epc = regs->cp0_epc;
1372 old31 = regs->regs[31];
1373 opcode = 0;
1374 status = -1;
1375
1376 if (unlikely(compute_return_epc(regs) < 0))
1377 break;
1378
1379 if (!get_isa16_mode(regs->cp0_epc)) {
1380 if (unlikely(get_user(opcode, epc) < 0))
1381 status = SIGSEGV;
1382
1383 if (!cpu_has_llsc && status < 0)
1384 status = simulate_llsc(regs, opcode);
1385 }
1386
1387 if (status < 0)
1388 status = SIGILL;
1389
1390 if (unlikely(status > 0)) {
1391 regs->cp0_epc = old_epc; /* Undo skip-over. */
1392 regs->regs[31] = old31;
1393 force_sig(status, current);
1394 }
1395
1396 break;
1397
1398 case 3:
1399 /*
1400 * The COP3 opcode space and consequently the CP0.Status.CU3
1401 * bit and the CP0.Cause.CE=3 encoding have been removed as
1402 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1403 * up the space has been reused for COP1X instructions, that
1404 * are enabled by the CP0.Status.CU1 bit and consequently
1405 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1406 * exceptions. Some FPU-less processors that implement one
1407 * of these ISAs however use this code erroneously for COP1X
1408 * instructions. Therefore we redirect this trap to the FP
1409 * emulator too.
1410 */
1411 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1412 force_sig(SIGILL, current);
1413 break;
1414 }
1415 /* Fall through. */
1416
1417 case 1:
1418 err = enable_restore_fp_context(0);
1419
1420 if (raw_cpu_has_fpu && !err)
1421 break;
1422
1423 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1424 &fault_addr);
1425 fcr31 = current->thread.fpu.fcr31;
1426
1427 /*
1428 * We can't allow the emulated instruction to leave
1429 * any of the cause bits set in $fcr31.
1430 */
1431 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
1432
1433 /* Send a signal if required. */
1434 if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1435 mt_ase_fp_affinity();
1436
1437 break;
1438
1439 case 2:
1440 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1441 break;
1442 }
1443
1444 exception_exit(prev_state);
1445 }
1446
1447 asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1448 {
1449 enum ctx_state prev_state;
1450
1451 prev_state = exception_enter();
1452 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1453 if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1454 current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1455 goto out;
1456
1457 /* Clear MSACSR.Cause before enabling interrupts */
1458 write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1459 local_irq_enable();
1460
1461 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1462 force_sig(SIGFPE, current);
1463 out:
1464 exception_exit(prev_state);
1465 }
1466
1467 asmlinkage void do_msa(struct pt_regs *regs)
1468 {
1469 enum ctx_state prev_state;
1470 int err;
1471
1472 prev_state = exception_enter();
1473
1474 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1475 force_sig(SIGILL, current);
1476 goto out;
1477 }
1478
1479 die_if_kernel("do_msa invoked from kernel context!", regs);
1480
1481 err = enable_restore_fp_context(1);
1482 if (err)
1483 force_sig(SIGILL, current);
1484 out:
1485 exception_exit(prev_state);
1486 }
1487
1488 asmlinkage void do_mdmx(struct pt_regs *regs)
1489 {
1490 enum ctx_state prev_state;
1491
1492 prev_state = exception_enter();
1493 force_sig(SIGILL, current);
1494 exception_exit(prev_state);
1495 }
1496
1497 /*
1498 * Called with interrupts disabled.
1499 */
1500 asmlinkage void do_watch(struct pt_regs *regs)
1501 {
1502 siginfo_t info = { .si_signo = SIGTRAP, .si_code = TRAP_HWBKPT };
1503 enum ctx_state prev_state;
1504 u32 cause;
1505
1506 prev_state = exception_enter();
1507 /*
1508 * Clear WP (bit 22) bit of cause register so we don't loop
1509 * forever.
1510 */
1511 cause = read_c0_cause();
1512 cause &= ~(1 << 22);
1513 write_c0_cause(cause);
1514
1515 /*
1516 * If the current thread has the watch registers loaded, save
1517 * their values and send SIGTRAP. Otherwise another thread
1518 * left the registers set, clear them and continue.
1519 */
1520 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1521 mips_read_watch_registers();
1522 local_irq_enable();
1523 force_sig_info(SIGTRAP, &info, current);
1524 } else {
1525 mips_clear_watch_registers();
1526 local_irq_enable();
1527 }
1528 exception_exit(prev_state);
1529 }
1530
1531 asmlinkage void do_mcheck(struct pt_regs *regs)
1532 {
1533 int multi_match = regs->cp0_status & ST0_TS;
1534 enum ctx_state prev_state;
1535 mm_segment_t old_fs = get_fs();
1536
1537 prev_state = exception_enter();
1538 show_regs(regs);
1539
1540 if (multi_match) {
1541 dump_tlb_regs();
1542 pr_info("\n");
1543 dump_tlb_all();
1544 }
1545
1546 if (!user_mode(regs))
1547 set_fs(KERNEL_DS);
1548
1549 show_code((unsigned int __user *) regs->cp0_epc);
1550
1551 set_fs(old_fs);
1552
1553 /*
1554 * Some chips may have other causes of machine check (e.g. SB1
1555 * graduation timer)
1556 */
1557 panic("Caught Machine Check exception - %scaused by multiple "
1558 "matching entries in the TLB.",
1559 (multi_match) ? "" : "not ");
1560 }
1561
1562 asmlinkage void do_mt(struct pt_regs *regs)
1563 {
1564 int subcode;
1565
1566 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1567 >> VPECONTROL_EXCPT_SHIFT;
1568 switch (subcode) {
1569 case 0:
1570 printk(KERN_DEBUG "Thread Underflow\n");
1571 break;
1572 case 1:
1573 printk(KERN_DEBUG "Thread Overflow\n");
1574 break;
1575 case 2:
1576 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1577 break;
1578 case 3:
1579 printk(KERN_DEBUG "Gating Storage Exception\n");
1580 break;
1581 case 4:
1582 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1583 break;
1584 case 5:
1585 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1586 break;
1587 default:
1588 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1589 subcode);
1590 break;
1591 }
1592 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1593
1594 force_sig(SIGILL, current);
1595 }
1596
1597
1598 asmlinkage void do_dsp(struct pt_regs *regs)
1599 {
1600 if (cpu_has_dsp)
1601 panic("Unexpected DSP exception");
1602
1603 force_sig(SIGILL, current);
1604 }
1605
1606 asmlinkage void do_reserved(struct pt_regs *regs)
1607 {
1608 /*
1609 * Game over - no way to handle this if it ever occurs. Most probably
1610 * caused by a new unknown cpu type or after another deadly
1611 * hard/software error.
1612 */
1613 show_regs(regs);
1614 panic("Caught reserved exception %ld - should not happen.",
1615 (regs->cp0_cause & 0x7f) >> 2);
1616 }
1617
1618 static int __initdata l1parity = 1;
1619 static int __init nol1parity(char *s)
1620 {
1621 l1parity = 0;
1622 return 1;
1623 }
1624 __setup("nol1par", nol1parity);
1625 static int __initdata l2parity = 1;
1626 static int __init nol2parity(char *s)
1627 {
1628 l2parity = 0;
1629 return 1;
1630 }
1631 __setup("nol2par", nol2parity);
1632
1633 /*
1634 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1635 * it different ways.
1636 */
1637 static inline void parity_protection_init(void)
1638 {
1639 switch (current_cpu_type()) {
1640 case CPU_24K:
1641 case CPU_34K:
1642 case CPU_74K:
1643 case CPU_1004K:
1644 case CPU_1074K:
1645 case CPU_INTERAPTIV:
1646 case CPU_PROAPTIV:
1647 case CPU_P5600:
1648 case CPU_QEMU_GENERIC:
1649 case CPU_I6400:
1650 {
1651 #define ERRCTL_PE 0x80000000
1652 #define ERRCTL_L2P 0x00800000
1653 unsigned long errctl;
1654 unsigned int l1parity_present, l2parity_present;
1655
1656 errctl = read_c0_ecc();
1657 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1658
1659 /* probe L1 parity support */
1660 write_c0_ecc(errctl | ERRCTL_PE);
1661 back_to_back_c0_hazard();
1662 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1663
1664 /* probe L2 parity support */
1665 write_c0_ecc(errctl|ERRCTL_L2P);
1666 back_to_back_c0_hazard();
1667 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1668
1669 if (l1parity_present && l2parity_present) {
1670 if (l1parity)
1671 errctl |= ERRCTL_PE;
1672 if (l1parity ^ l2parity)
1673 errctl |= ERRCTL_L2P;
1674 } else if (l1parity_present) {
1675 if (l1parity)
1676 errctl |= ERRCTL_PE;
1677 } else if (l2parity_present) {
1678 if (l2parity)
1679 errctl |= ERRCTL_L2P;
1680 } else {
1681 /* No parity available */
1682 }
1683
1684 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1685
1686 write_c0_ecc(errctl);
1687 back_to_back_c0_hazard();
1688 errctl = read_c0_ecc();
1689 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1690
1691 if (l1parity_present)
1692 printk(KERN_INFO "Cache parity protection %sabled\n",
1693 (errctl & ERRCTL_PE) ? "en" : "dis");
1694
1695 if (l2parity_present) {
1696 if (l1parity_present && l1parity)
1697 errctl ^= ERRCTL_L2P;
1698 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1699 (errctl & ERRCTL_L2P) ? "en" : "dis");
1700 }
1701 }
1702 break;
1703
1704 case CPU_5KC:
1705 case CPU_5KE:
1706 case CPU_LOONGSON1:
1707 write_c0_ecc(0x80000000);
1708 back_to_back_c0_hazard();
1709 /* Set the PE bit (bit 31) in the c0_errctl register. */
1710 printk(KERN_INFO "Cache parity protection %sabled\n",
1711 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1712 break;
1713 case CPU_20KC:
1714 case CPU_25KF:
1715 /* Clear the DE bit (bit 16) in the c0_status register. */
1716 printk(KERN_INFO "Enable cache parity protection for "
1717 "MIPS 20KC/25KF CPUs.\n");
1718 clear_c0_status(ST0_DE);
1719 break;
1720 default:
1721 break;
1722 }
1723 }
1724
1725 asmlinkage void cache_parity_error(void)
1726 {
1727 const int field = 2 * sizeof(unsigned long);
1728 unsigned int reg_val;
1729
1730 /* For the moment, report the problem and hang. */
1731 printk("Cache error exception:\n");
1732 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1733 reg_val = read_c0_cacheerr();
1734 printk("c0_cacheerr == %08x\n", reg_val);
1735
1736 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1737 reg_val & (1<<30) ? "secondary" : "primary",
1738 reg_val & (1<<31) ? "data" : "insn");
1739 if ((cpu_has_mips_r2_r6) &&
1740 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1741 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1742 reg_val & (1<<29) ? "ED " : "",
1743 reg_val & (1<<28) ? "ET " : "",
1744 reg_val & (1<<27) ? "ES " : "",
1745 reg_val & (1<<26) ? "EE " : "",
1746 reg_val & (1<<25) ? "EB " : "",
1747 reg_val & (1<<24) ? "EI " : "",
1748 reg_val & (1<<23) ? "E1 " : "",
1749 reg_val & (1<<22) ? "E0 " : "");
1750 } else {
1751 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1752 reg_val & (1<<29) ? "ED " : "",
1753 reg_val & (1<<28) ? "ET " : "",
1754 reg_val & (1<<26) ? "EE " : "",
1755 reg_val & (1<<25) ? "EB " : "",
1756 reg_val & (1<<24) ? "EI " : "",
1757 reg_val & (1<<23) ? "E1 " : "",
1758 reg_val & (1<<22) ? "E0 " : "");
1759 }
1760 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1761
1762 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1763 if (reg_val & (1<<22))
1764 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1765
1766 if (reg_val & (1<<23))
1767 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1768 #endif
1769
1770 panic("Can't handle the cache error!");
1771 }
1772
1773 asmlinkage void do_ftlb(void)
1774 {
1775 const int field = 2 * sizeof(unsigned long);
1776 unsigned int reg_val;
1777
1778 /* For the moment, report the problem and hang. */
1779 if ((cpu_has_mips_r2_r6) &&
1780 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1781 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1782 read_c0_ecc());
1783 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1784 reg_val = read_c0_cacheerr();
1785 pr_err("c0_cacheerr == %08x\n", reg_val);
1786
1787 if ((reg_val & 0xc0000000) == 0xc0000000) {
1788 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1789 } else {
1790 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1791 reg_val & (1<<30) ? "secondary" : "primary",
1792 reg_val & (1<<31) ? "data" : "insn");
1793 }
1794 } else {
1795 pr_err("FTLB error exception\n");
1796 }
1797 /* Just print the cacheerr bits for now */
1798 cache_parity_error();
1799 }
1800
1801 /*
1802 * SDBBP EJTAG debug exception handler.
1803 * We skip the instruction and return to the next instruction.
1804 */
1805 void ejtag_exception_handler(struct pt_regs *regs)
1806 {
1807 const int field = 2 * sizeof(unsigned long);
1808 unsigned long depc, old_epc, old_ra;
1809 unsigned int debug;
1810
1811 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1812 depc = read_c0_depc();
1813 debug = read_c0_debug();
1814 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1815 if (debug & 0x80000000) {
1816 /*
1817 * In branch delay slot.
1818 * We cheat a little bit here and use EPC to calculate the
1819 * debug return address (DEPC). EPC is restored after the
1820 * calculation.
1821 */
1822 old_epc = regs->cp0_epc;
1823 old_ra = regs->regs[31];
1824 regs->cp0_epc = depc;
1825 compute_return_epc(regs);
1826 depc = regs->cp0_epc;
1827 regs->cp0_epc = old_epc;
1828 regs->regs[31] = old_ra;
1829 } else
1830 depc += 4;
1831 write_c0_depc(depc);
1832
1833 #if 0
1834 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1835 write_c0_debug(debug | 0x100);
1836 #endif
1837 }
1838
1839 /*
1840 * NMI exception handler.
1841 * No lock; only written during early bootup by CPU 0.
1842 */
1843 static RAW_NOTIFIER_HEAD(nmi_chain);
1844
1845 int register_nmi_notifier(struct notifier_block *nb)
1846 {
1847 return raw_notifier_chain_register(&nmi_chain, nb);
1848 }
1849
1850 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1851 {
1852 char str[100];
1853
1854 nmi_enter();
1855 raw_notifier_call_chain(&nmi_chain, 0, regs);
1856 bust_spinlocks(1);
1857 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1858 smp_processor_id(), regs->cp0_epc);
1859 regs->cp0_epc = read_c0_errorepc();
1860 die(str, regs);
1861 nmi_exit();
1862 }
1863
1864 #define VECTORSPACING 0x100 /* for EI/VI mode */
1865
1866 unsigned long ebase;
1867 unsigned long exception_handlers[32];
1868 unsigned long vi_handlers[64];
1869
1870 void __init *set_except_vector(int n, void *addr)
1871 {
1872 unsigned long handler = (unsigned long) addr;
1873 unsigned long old_handler;
1874
1875 #ifdef CONFIG_CPU_MICROMIPS
1876 /*
1877 * Only the TLB handlers are cache aligned with an even
1878 * address. All other handlers are on an odd address and
1879 * require no modification. Otherwise, MIPS32 mode will
1880 * be entered when handling any TLB exceptions. That
1881 * would be bad...since we must stay in microMIPS mode.
1882 */
1883 if (!(handler & 0x1))
1884 handler |= 1;
1885 #endif
1886 old_handler = xchg(&exception_handlers[n], handler);
1887
1888 if (n == 0 && cpu_has_divec) {
1889 #ifdef CONFIG_CPU_MICROMIPS
1890 unsigned long jump_mask = ~((1 << 27) - 1);
1891 #else
1892 unsigned long jump_mask = ~((1 << 28) - 1);
1893 #endif
1894 u32 *buf = (u32 *)(ebase + 0x200);
1895 unsigned int k0 = 26;
1896 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1897 uasm_i_j(&buf, handler & ~jump_mask);
1898 uasm_i_nop(&buf);
1899 } else {
1900 UASM_i_LA(&buf, k0, handler);
1901 uasm_i_jr(&buf, k0);
1902 uasm_i_nop(&buf);
1903 }
1904 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1905 }
1906 return (void *)old_handler;
1907 }
1908
1909 static void do_default_vi(void)
1910 {
1911 show_regs(get_irq_regs());
1912 panic("Caught unexpected vectored interrupt.");
1913 }
1914
1915 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1916 {
1917 unsigned long handler;
1918 unsigned long old_handler = vi_handlers[n];
1919 int srssets = current_cpu_data.srsets;
1920 u16 *h;
1921 unsigned char *b;
1922
1923 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1924
1925 if (addr == NULL) {
1926 handler = (unsigned long) do_default_vi;
1927 srs = 0;
1928 } else
1929 handler = (unsigned long) addr;
1930 vi_handlers[n] = handler;
1931
1932 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
1933
1934 if (srs >= srssets)
1935 panic("Shadow register set %d not supported", srs);
1936
1937 if (cpu_has_veic) {
1938 if (board_bind_eic_interrupt)
1939 board_bind_eic_interrupt(n, srs);
1940 } else if (cpu_has_vint) {
1941 /* SRSMap is only defined if shadow sets are implemented */
1942 if (srssets > 1)
1943 change_c0_srsmap(0xf << n*4, srs << n*4);
1944 }
1945
1946 if (srs == 0) {
1947 /*
1948 * If no shadow set is selected then use the default handler
1949 * that does normal register saving and standard interrupt exit
1950 */
1951 extern char except_vec_vi, except_vec_vi_lui;
1952 extern char except_vec_vi_ori, except_vec_vi_end;
1953 extern char rollback_except_vec_vi;
1954 char *vec_start = using_rollback_handler() ?
1955 &rollback_except_vec_vi : &except_vec_vi;
1956 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
1957 const int lui_offset = &except_vec_vi_lui - vec_start + 2;
1958 const int ori_offset = &except_vec_vi_ori - vec_start + 2;
1959 #else
1960 const int lui_offset = &except_vec_vi_lui - vec_start;
1961 const int ori_offset = &except_vec_vi_ori - vec_start;
1962 #endif
1963 const int handler_len = &except_vec_vi_end - vec_start;
1964
1965 if (handler_len > VECTORSPACING) {
1966 /*
1967 * Sigh... panicing won't help as the console
1968 * is probably not configured :(
1969 */
1970 panic("VECTORSPACING too small");
1971 }
1972
1973 set_handler(((unsigned long)b - ebase), vec_start,
1974 #ifdef CONFIG_CPU_MICROMIPS
1975 (handler_len - 1));
1976 #else
1977 handler_len);
1978 #endif
1979 h = (u16 *)(b + lui_offset);
1980 *h = (handler >> 16) & 0xffff;
1981 h = (u16 *)(b + ori_offset);
1982 *h = (handler & 0xffff);
1983 local_flush_icache_range((unsigned long)b,
1984 (unsigned long)(b+handler_len));
1985 }
1986 else {
1987 /*
1988 * In other cases jump directly to the interrupt handler. It
1989 * is the handler's responsibility to save registers if required
1990 * (eg hi/lo) and return from the exception using "eret".
1991 */
1992 u32 insn;
1993
1994 h = (u16 *)b;
1995 /* j handler */
1996 #ifdef CONFIG_CPU_MICROMIPS
1997 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
1998 #else
1999 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2000 #endif
2001 h[0] = (insn >> 16) & 0xffff;
2002 h[1] = insn & 0xffff;
2003 h[2] = 0;
2004 h[3] = 0;
2005 local_flush_icache_range((unsigned long)b,
2006 (unsigned long)(b+8));
2007 }
2008
2009 return (void *)old_handler;
2010 }
2011
2012 void *set_vi_handler(int n, vi_handler_t addr)
2013 {
2014 return set_vi_srs_handler(n, addr, 0);
2015 }
2016
2017 extern void tlb_init(void);
2018
2019 /*
2020 * Timer interrupt
2021 */
2022 int cp0_compare_irq;
2023 EXPORT_SYMBOL_GPL(cp0_compare_irq);
2024 int cp0_compare_irq_shift;
2025
2026 /*
2027 * Performance counter IRQ or -1 if shared with timer
2028 */
2029 int cp0_perfcount_irq;
2030 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2031
2032 /*
2033 * Fast debug channel IRQ or -1 if not present
2034 */
2035 int cp0_fdc_irq;
2036 EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2037
2038 static int noulri;
2039
2040 static int __init ulri_disable(char *s)
2041 {
2042 pr_info("Disabling ulri\n");
2043 noulri = 1;
2044
2045 return 1;
2046 }
2047 __setup("noulri", ulri_disable);
2048
2049 /* configure STATUS register */
2050 static void configure_status(void)
2051 {
2052 /*
2053 * Disable coprocessors and select 32-bit or 64-bit addressing
2054 * and the 16/32 or 32/32 FPR register model. Reset the BEV
2055 * flag that some firmware may have left set and the TS bit (for
2056 * IP27). Set XX for ISA IV code to work.
2057 */
2058 unsigned int status_set = ST0_CU0;
2059 #ifdef CONFIG_64BIT
2060 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2061 #endif
2062 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2063 status_set |= ST0_XX;
2064 if (cpu_has_dsp)
2065 status_set |= ST0_MX;
2066
2067 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2068 status_set);
2069 }
2070
2071 /* configure HWRENA register */
2072 static void configure_hwrena(void)
2073 {
2074 unsigned int hwrena = cpu_hwrena_impl_bits;
2075
2076 if (cpu_has_mips_r2_r6)
2077 hwrena |= 0x0000000f;
2078
2079 if (!noulri && cpu_has_userlocal)
2080 hwrena |= (1 << 29);
2081
2082 if (hwrena)
2083 write_c0_hwrena(hwrena);
2084 }
2085
2086 static void configure_exception_vector(void)
2087 {
2088 if (cpu_has_veic || cpu_has_vint) {
2089 unsigned long sr = set_c0_status(ST0_BEV);
2090 write_c0_ebase(ebase);
2091 write_c0_status(sr);
2092 /* Setting vector spacing enables EI/VI mode */
2093 change_c0_intctl(0x3e0, VECTORSPACING);
2094 }
2095 if (cpu_has_divec) {
2096 if (cpu_has_mipsmt) {
2097 unsigned int vpflags = dvpe();
2098 set_c0_cause(CAUSEF_IV);
2099 evpe(vpflags);
2100 } else
2101 set_c0_cause(CAUSEF_IV);
2102 }
2103 }
2104
2105 void per_cpu_trap_init(bool is_boot_cpu)
2106 {
2107 unsigned int cpu = smp_processor_id();
2108
2109 configure_status();
2110 configure_hwrena();
2111
2112 configure_exception_vector();
2113
2114 /*
2115 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2116 *
2117 * o read IntCtl.IPTI to determine the timer interrupt
2118 * o read IntCtl.IPPCI to determine the performance counter interrupt
2119 * o read IntCtl.IPFDC to determine the fast debug channel interrupt
2120 */
2121 if (cpu_has_mips_r2_r6) {
2122 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2123 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2124 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2125 cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2126 if (!cp0_fdc_irq)
2127 cp0_fdc_irq = -1;
2128
2129 } else {
2130 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2131 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2132 cp0_perfcount_irq = -1;
2133 cp0_fdc_irq = -1;
2134 }
2135
2136 if (!cpu_data[cpu].asid_cache)
2137 cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;
2138
2139 atomic_inc(&init_mm.mm_count);
2140 current->active_mm = &init_mm;
2141 BUG_ON(current->mm);
2142 enter_lazy_tlb(&init_mm, current);
2143
2144 /* Boot CPU's cache setup in setup_arch(). */
2145 if (!is_boot_cpu)
2146 cpu_cache_init();
2147 tlb_init();
2148 TLBMISS_HANDLER_SETUP();
2149 }
2150
2151 /* Install CPU exception handler */
2152 void set_handler(unsigned long offset, void *addr, unsigned long size)
2153 {
2154 #ifdef CONFIG_CPU_MICROMIPS
2155 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2156 #else
2157 memcpy((void *)(ebase + offset), addr, size);
2158 #endif
2159 local_flush_icache_range(ebase + offset, ebase + offset + size);
2160 }
2161
2162 static char panic_null_cerr[] =
2163 "Trying to set NULL cache error exception handler";
2164
2165 /*
2166 * Install uncached CPU exception handler.
2167 * This is suitable only for the cache error exception which is the only
2168 * exception handler that is being run uncached.
2169 */
2170 void set_uncached_handler(unsigned long offset, void *addr,
2171 unsigned long size)
2172 {
2173 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2174
2175 if (!addr)
2176 panic(panic_null_cerr);
2177
2178 memcpy((void *)(uncached_ebase + offset), addr, size);
2179 }
2180
2181 static int __initdata rdhwr_noopt;
2182 static int __init set_rdhwr_noopt(char *str)
2183 {
2184 rdhwr_noopt = 1;
2185 return 1;
2186 }
2187
2188 __setup("rdhwr_noopt", set_rdhwr_noopt);
2189
2190 void __init trap_init(void)
2191 {
2192 extern char except_vec3_generic;
2193 extern char except_vec4;
2194 extern char except_vec3_r4000;
2195 unsigned long i;
2196
2197 check_wait();
2198
2199 if (cpu_has_veic || cpu_has_vint) {
2200 unsigned long size = 0x200 + VECTORSPACING*64;
2201 ebase = (unsigned long)
2202 __alloc_bootmem(size, 1 << fls(size), 0);
2203 } else {
2204 ebase = CAC_BASE;
2205
2206 if (cpu_has_mips_r2_r6)
2207 ebase += (read_c0_ebase() & 0x3ffff000);
2208 }
2209
2210 if (cpu_has_mmips) {
2211 unsigned int config3 = read_c0_config3();
2212
2213 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2214 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2215 else
2216 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2217 }
2218
2219 if (board_ebase_setup)
2220 board_ebase_setup();
2221 per_cpu_trap_init(true);
2222
2223 /*
2224 * Copy the generic exception handlers to their final destination.
2225 * This will be overridden later as suitable for a particular
2226 * configuration.
2227 */
2228 set_handler(0x180, &except_vec3_generic, 0x80);
2229
2230 /*
2231 * Setup default vectors
2232 */
2233 for (i = 0; i <= 31; i++)
2234 set_except_vector(i, handle_reserved);
2235
2236 /*
2237 * Copy the EJTAG debug exception vector handler code to it's final
2238 * destination.
2239 */
2240 if (cpu_has_ejtag && board_ejtag_handler_setup)
2241 board_ejtag_handler_setup();
2242
2243 /*
2244 * Only some CPUs have the watch exceptions.
2245 */
2246 if (cpu_has_watch)
2247 set_except_vector(EXCCODE_WATCH, handle_watch);
2248
2249 /*
2250 * Initialise interrupt handlers
2251 */
2252 if (cpu_has_veic || cpu_has_vint) {
2253 int nvec = cpu_has_veic ? 64 : 8;
2254 for (i = 0; i < nvec; i++)
2255 set_vi_handler(i, NULL);
2256 }
2257 else if (cpu_has_divec)
2258 set_handler(0x200, &except_vec4, 0x8);
2259
2260 /*
2261 * Some CPUs can enable/disable for cache parity detection, but does
2262 * it different ways.
2263 */
2264 parity_protection_init();
2265
2266 /*
2267 * The Data Bus Errors / Instruction Bus Errors are signaled
2268 * by external hardware. Therefore these two exceptions
2269 * may have board specific handlers.
2270 */
2271 if (board_be_init)
2272 board_be_init();
2273
2274 set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2275 rollback_handle_int : handle_int);
2276 set_except_vector(EXCCODE_MOD, handle_tlbm);
2277 set_except_vector(EXCCODE_TLBL, handle_tlbl);
2278 set_except_vector(EXCCODE_TLBS, handle_tlbs);
2279
2280 set_except_vector(EXCCODE_ADEL, handle_adel);
2281 set_except_vector(EXCCODE_ADES, handle_ades);
2282
2283 set_except_vector(EXCCODE_IBE, handle_ibe);
2284 set_except_vector(EXCCODE_DBE, handle_dbe);
2285
2286 set_except_vector(EXCCODE_SYS, handle_sys);
2287 set_except_vector(EXCCODE_BP, handle_bp);
2288 set_except_vector(EXCCODE_RI, rdhwr_noopt ? handle_ri :
2289 (cpu_has_vtag_icache ?
2290 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2291 set_except_vector(EXCCODE_CPU, handle_cpu);
2292 set_except_vector(EXCCODE_OV, handle_ov);
2293 set_except_vector(EXCCODE_TR, handle_tr);
2294 set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2295
2296 if (current_cpu_type() == CPU_R6000 ||
2297 current_cpu_type() == CPU_R6000A) {
2298 /*
2299 * The R6000 is the only R-series CPU that features a machine
2300 * check exception (similar to the R4000 cache error) and
2301 * unaligned ldc1/sdc1 exception. The handlers have not been
2302 * written yet. Well, anyway there is no R6000 machine on the
2303 * current list of targets for Linux/MIPS.
2304 * (Duh, crap, there is someone with a triple R6k machine)
2305 */
2306 //set_except_vector(14, handle_mc);
2307 //set_except_vector(15, handle_ndc);
2308 }
2309
2310
2311 if (board_nmi_handler_setup)
2312 board_nmi_handler_setup();
2313
2314 if (cpu_has_fpu && !cpu_has_nofpuex)
2315 set_except_vector(EXCCODE_FPE, handle_fpe);
2316
2317 set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2318
2319 if (cpu_has_rixiex) {
2320 set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2321 set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2322 }
2323
2324 set_except_vector(EXCCODE_MSADIS, handle_msa);
2325 set_except_vector(EXCCODE_MDMX, handle_mdmx);
2326
2327 if (cpu_has_mcheck)
2328 set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2329
2330 if (cpu_has_mipsmt)
2331 set_except_vector(EXCCODE_THREAD, handle_mt);
2332
2333 set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2334
2335 if (board_cache_error_setup)
2336 board_cache_error_setup();
2337
2338 if (cpu_has_vce)
2339 /* Special exception: R4[04]00 uses also the divec space. */
2340 set_handler(0x180, &except_vec3_r4000, 0x100);
2341 else if (cpu_has_4kex)
2342 set_handler(0x180, &except_vec3_generic, 0x80);
2343 else
2344 set_handler(0x080, &except_vec3_generic, 0x80);
2345
2346 local_flush_icache_range(ebase, ebase + 0x400);
2347
2348 sort_extable(__start___dbe_table, __stop___dbe_table);
2349
2350 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2351 }
2352
2353 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2354 void *v)
2355 {
2356 switch (cmd) {
2357 case CPU_PM_ENTER_FAILED:
2358 case CPU_PM_EXIT:
2359 configure_status();
2360 configure_hwrena();
2361 configure_exception_vector();
2362
2363 /* Restore register with CPU number for TLB handlers */
2364 TLBMISS_HANDLER_RESTORE();
2365
2366 break;
2367 }
2368
2369 return NOTIFY_OK;
2370 }
2371
2372 static struct notifier_block trap_pm_notifier_block = {
2373 .notifier_call = trap_pm_notifier,
2374 };
2375
2376 static int __init trap_pm_init(void)
2377 {
2378 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2379 }
2380 arch_initcall(trap_pm_init);
Linux kernel - Deliverables
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