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gro: Allow tunnel stacking in the case of FOU/GUE
[linux/fpc-iii.git] / arch / mips / kernel / traps.c
blob74403953e4079d94012cd841d388f6c6409d3d96
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/bootinfo.h>
41 #include <asm/branch.h>
42 #include <asm/break.h>
43 #include <asm/cop2.h>
44 #include <asm/cpu.h>
45 #include <asm/cpu-type.h>
46 #include <asm/dsp.h>
47 #include <asm/fpu.h>
48 #include <asm/fpu_emulator.h>
49 #include <asm/idle.h>
50 #include <asm/mips-r2-to-r6-emul.h>
51 #include <asm/mipsregs.h>
52 #include <asm/mipsmtregs.h>
53 #include <asm/module.h>
54 #include <asm/msa.h>
55 #include <asm/pgtable.h>
56 #include <asm/ptrace.h>
57 #include <asm/sections.h>
58 #include <asm/tlbdebug.h>
59 #include <asm/traps.h>
60 #include <asm/uaccess.h>
61 #include <asm/watch.h>
62 #include <asm/mmu_context.h>
63 #include <asm/types.h>
64 #include <asm/stacktrace.h>
65 #include <asm/uasm.h>
66
67 extern void check_wait(void);
68 extern asmlinkage void rollback_handle_int(void);
69 extern asmlinkage void handle_int(void);
70 extern u32 handle_tlbl[];
71 extern u32 handle_tlbs[];
72 extern u32 handle_tlbm[];
73 extern asmlinkage void handle_adel(void);
74 extern asmlinkage void handle_ades(void);
75 extern asmlinkage void handle_ibe(void);
76 extern asmlinkage void handle_dbe(void);
77 extern asmlinkage void handle_sys(void);
78 extern asmlinkage void handle_bp(void);
79 extern asmlinkage void handle_ri(void);
80 extern asmlinkage void handle_ri_rdhwr_vivt(void);
81 extern asmlinkage void handle_ri_rdhwr(void);
82 extern asmlinkage void handle_cpu(void);
83 extern asmlinkage void handle_ov(void);
84 extern asmlinkage void handle_tr(void);
85 extern asmlinkage void handle_msa_fpe(void);
86 extern asmlinkage void handle_fpe(void);
87 extern asmlinkage void handle_ftlb(void);
88 extern asmlinkage void handle_msa(void);
89 extern asmlinkage void handle_mdmx(void);
90 extern asmlinkage void handle_watch(void);
91 extern asmlinkage void handle_mt(void);
92 extern asmlinkage void handle_dsp(void);
93 extern asmlinkage void handle_mcheck(void);
94 extern asmlinkage void handle_reserved(void);
95 extern void tlb_do_page_fault_0(void);
96
97 void (*board_be_init)(void);
98 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
99 void (*board_nmi_handler_setup)(void);
100 void (*board_ejtag_handler_setup)(void);
101 void (*board_bind_eic_interrupt)(int irq, int regset);
102 void (*board_ebase_setup)(void);
103 void(*board_cache_error_setup)(void);
104
105 static void show_raw_backtrace(unsigned long reg29)
106 {
107 unsigned long *sp = (unsigned long *)(reg29 & ~3);
108 unsigned long addr;
109
110 printk("Call Trace:");
111 #ifdef CONFIG_KALLSYMS
112 printk("\n");
113 #endif
114 while (!kstack_end(sp)) {
115 unsigned long __user *p =
116 (unsigned long __user *)(unsigned long)sp++;
117 if (__get_user(addr, p)) {
118 printk(" (Bad stack address)");
119 break;
120 }
121 if (__kernel_text_address(addr))
122 print_ip_sym(addr);
123 }
124 printk("\n");
125 }
126
127 #ifdef CONFIG_KALLSYMS
128 int raw_show_trace;
129 static int __init set_raw_show_trace(char *str)
130 {
131 raw_show_trace = 1;
132 return 1;
133 }
134 __setup("raw_show_trace", set_raw_show_trace);
135 #endif
136
137 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
138 {
139 unsigned long sp = regs->regs[29];
140 unsigned long ra = regs->regs[31];
141 unsigned long pc = regs->cp0_epc;
142
143 if (!task)
144 task = current;
145
146 if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
147 show_raw_backtrace(sp);
148 return;
149 }
150 printk("Call Trace:\n");
151 do {
152 print_ip_sym(pc);
153 pc = unwind_stack(task, &sp, pc, &ra);
154 } while (pc);
155 printk("\n");
156 }
157
158 /*
159 * This routine abuses get_user()/put_user() to reference pointers
160 * with at least a bit of error checking ...
161 */
162 static void show_stacktrace(struct task_struct *task,
163 const struct pt_regs *regs)
164 {
165 const int field = 2 * sizeof(unsigned long);
166 long stackdata;
167 int i;
168 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
169
170 printk("Stack :");
171 i = 0;
172 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
173 if (i && ((i % (64 / field)) == 0))
174 printk("\n ");
175 if (i > 39) {
176 printk(" ...");
177 break;
178 }
179
180 if (__get_user(stackdata, sp++)) {
181 printk(" (Bad stack address)");
182 break;
183 }
184
185 printk(" %0*lx", field, stackdata);
186 i++;
187 }
188 printk("\n");
189 show_backtrace(task, regs);
190 }
191
192 void show_stack(struct task_struct *task, unsigned long *sp)
193 {
194 struct pt_regs regs;
195 mm_segment_t old_fs = get_fs();
196 if (sp) {
197 regs.regs[29] = (unsigned long)sp;
198 regs.regs[31] = 0;
199 regs.cp0_epc = 0;
200 } else {
201 if (task && task != current) {
202 regs.regs[29] = task->thread.reg29;
203 regs.regs[31] = 0;
204 regs.cp0_epc = task->thread.reg31;
205 #ifdef CONFIG_KGDB_KDB
206 } else if (atomic_read(&kgdb_active) != -1 &&
207 kdb_current_regs) {
208 memcpy(&regs, kdb_current_regs, sizeof(regs));
209 #endif /* CONFIG_KGDB_KDB */
210 } else {
211 prepare_frametrace(&regs);
212 }
213 }
214 /*
215 * show_stack() deals exclusively with kernel mode, so be sure to access
216 * the stack in the kernel (not user) address space.
217 */
218 set_fs(KERNEL_DS);
219 show_stacktrace(task, &regs);
220 set_fs(old_fs);
221 }
222
223 static void show_code(unsigned int __user *pc)
224 {
225 long i;
226 unsigned short __user *pc16 = NULL;
227
228 printk("\nCode:");
229
230 if ((unsigned long)pc & 1)
231 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
232 for(i = -3 ; i < 6 ; i++) {
233 unsigned int insn;
234 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
235 printk(" (Bad address in epc)\n");
236 break;
237 }
238 printk("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
239 }
240 }
241
242 static void __show_regs(const struct pt_regs *regs)
243 {
244 const int field = 2 * sizeof(unsigned long);
245 unsigned int cause = regs->cp0_cause;
246 int i;
247
248 show_regs_print_info(KERN_DEFAULT);
249
250 /*
251 * Saved main processor registers
252 */
253 for (i = 0; i < 32; ) {
254 if ((i % 4) == 0)
255 printk("$%2d :", i);
256 if (i == 0)
257 printk(" %0*lx", field, 0UL);
258 else if (i == 26 || i == 27)
259 printk(" %*s", field, "");
260 else
261 printk(" %0*lx", field, regs->regs[i]);
262
263 i++;
264 if ((i % 4) == 0)
265 printk("\n");
266 }
267
268 #ifdef CONFIG_CPU_HAS_SMARTMIPS
269 printk("Acx : %0*lx\n", field, regs->acx);
270 #endif
271 printk("Hi : %0*lx\n", field, regs->hi);
272 printk("Lo : %0*lx\n", field, regs->lo);
273
274 /*
275 * Saved cp0 registers
276 */
277 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
278 (void *) regs->cp0_epc);
279 printk("ra : %0*lx %pS\n", field, regs->regs[31],
280 (void *) regs->regs[31]);
281
282 printk("Status: %08x ", (uint32_t) regs->cp0_status);
283
284 if (cpu_has_3kex) {
285 if (regs->cp0_status & ST0_KUO)
286 printk("KUo ");
287 if (regs->cp0_status & ST0_IEO)
288 printk("IEo ");
289 if (regs->cp0_status & ST0_KUP)
290 printk("KUp ");
291 if (regs->cp0_status & ST0_IEP)
292 printk("IEp ");
293 if (regs->cp0_status & ST0_KUC)
294 printk("KUc ");
295 if (regs->cp0_status & ST0_IEC)
296 printk("IEc ");
297 } else if (cpu_has_4kex) {
298 if (regs->cp0_status & ST0_KX)
299 printk("KX ");
300 if (regs->cp0_status & ST0_SX)
301 printk("SX ");
302 if (regs->cp0_status & ST0_UX)
303 printk("UX ");
304 switch (regs->cp0_status & ST0_KSU) {
305 case KSU_USER:
306 printk("USER ");
307 break;
308 case KSU_SUPERVISOR:
309 printk("SUPERVISOR ");
310 break;
311 case KSU_KERNEL:
312 printk("KERNEL ");
313 break;
314 default:
315 printk("BAD_MODE ");
316 break;
317 }
318 if (regs->cp0_status & ST0_ERL)
319 printk("ERL ");
320 if (regs->cp0_status & ST0_EXL)
321 printk("EXL ");
322 if (regs->cp0_status & ST0_IE)
323 printk("IE ");
324 }
325 printk("\n");
326
327 printk("Cause : %08x\n", cause);
328
329 cause = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
330 if (1 <= cause && cause <= 5)
331 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
332
333 printk("PrId : %08x (%s)\n", read_c0_prid(),
334 cpu_name_string());
335 }
336
337 /*
338 * FIXME: really the generic show_regs should take a const pointer argument.
339 */
340 void show_regs(struct pt_regs *regs)
341 {
342 __show_regs((struct pt_regs *)regs);
343 }
344
345 void show_registers(struct pt_regs *regs)
346 {
347 const int field = 2 * sizeof(unsigned long);
348 mm_segment_t old_fs = get_fs();
349
350 __show_regs(regs);
351 print_modules();
352 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
353 current->comm, current->pid, current_thread_info(), current,
354 field, current_thread_info()->tp_value);
355 if (cpu_has_userlocal) {
356 unsigned long tls;
357
358 tls = read_c0_userlocal();
359 if (tls != current_thread_info()->tp_value)
360 printk("*HwTLS: %0*lx\n", field, tls);
361 }
362
363 if (!user_mode(regs))
364 /* Necessary for getting the correct stack content */
365 set_fs(KERNEL_DS);
366 show_stacktrace(current, regs);
367 show_code((unsigned int __user *) regs->cp0_epc);
368 printk("\n");
369 set_fs(old_fs);
370 }
371
372 static int regs_to_trapnr(struct pt_regs *regs)
373 {
374 return (regs->cp0_cause >> 2) & 0x1f;
375 }
376
377 static DEFINE_RAW_SPINLOCK(die_lock);
378
379 void __noreturn die(const char *str, struct pt_regs *regs)
380 {
381 static int die_counter;
382 int sig = SIGSEGV;
383
384 oops_enter();
385
386 if (notify_die(DIE_OOPS, str, regs, 0, regs_to_trapnr(regs),
387 SIGSEGV) == NOTIFY_STOP)
388 sig = 0;
389
390 console_verbose();
391 raw_spin_lock_irq(&die_lock);
392 bust_spinlocks(1);
393
394 printk("%s[#%d]:\n", str, ++die_counter);
395 show_registers(regs);
396 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
397 raw_spin_unlock_irq(&die_lock);
398
399 oops_exit();
400
401 if (in_interrupt())
402 panic("Fatal exception in interrupt");
403
404 if (panic_on_oops) {
405 printk(KERN_EMERG "Fatal exception: panic in 5 seconds");
406 ssleep(5);
407 panic("Fatal exception");
408 }
409
410 if (regs && kexec_should_crash(current))
411 crash_kexec(regs);
412
413 do_exit(sig);
414 }
415
416 extern struct exception_table_entry __start___dbe_table[];
417 extern struct exception_table_entry __stop___dbe_table[];
418
419 __asm__(
420 " .section __dbe_table, \"a\"\n"
421 " .previous \n");
422
423 /* Given an address, look for it in the exception tables. */
424 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
425 {
426 const struct exception_table_entry *e;
427
428 e = search_extable(__start___dbe_table, __stop___dbe_table - 1, addr);
429 if (!e)
430 e = search_module_dbetables(addr);
431 return e;
432 }
433
434 asmlinkage void do_be(struct pt_regs *regs)
435 {
436 const int field = 2 * sizeof(unsigned long);
437 const struct exception_table_entry *fixup = NULL;
438 int data = regs->cp0_cause & 4;
439 int action = MIPS_BE_FATAL;
440 enum ctx_state prev_state;
441
442 prev_state = exception_enter();
443 /* XXX For now. Fixme, this searches the wrong table ... */
444 if (data && !user_mode(regs))
445 fixup = search_dbe_tables(exception_epc(regs));
446
447 if (fixup)
448 action = MIPS_BE_FIXUP;
449
450 if (board_be_handler)
451 action = board_be_handler(regs, fixup != NULL);
452
453 switch (action) {
454 case MIPS_BE_DISCARD:
455 goto out;
456 case MIPS_BE_FIXUP:
457 if (fixup) {
458 regs->cp0_epc = fixup->nextinsn;
459 goto out;
460 }
461 break;
462 default:
463 break;
464 }
465
466 /*
467 * Assume it would be too dangerous to continue ...
468 */
469 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
470 data ? "Data" : "Instruction",
471 field, regs->cp0_epc, field, regs->regs[31]);
472 if (notify_die(DIE_OOPS, "bus error", regs, 0, regs_to_trapnr(regs),
473 SIGBUS) == NOTIFY_STOP)
474 goto out;
475
476 die_if_kernel("Oops", regs);
477 force_sig(SIGBUS, current);
478
479 out:
480 exception_exit(prev_state);
481 }
482
483 /*
484 * ll/sc, rdhwr, sync emulation
485 */
486
487 #define OPCODE 0xfc000000
488 #define BASE 0x03e00000
489 #define RT 0x001f0000
490 #define OFFSET 0x0000ffff
491 #define LL 0xc0000000
492 #define SC 0xe0000000
493 #define SPEC0 0x00000000
494 #define SPEC3 0x7c000000
495 #define RD 0x0000f800
496 #define FUNC 0x0000003f
497 #define SYNC 0x0000000f
498 #define RDHWR 0x0000003b
499
500 /* microMIPS definitions */
501 #define MM_POOL32A_FUNC 0xfc00ffff
502 #define MM_RDHWR 0x00006b3c
503 #define MM_RS 0x001f0000
504 #define MM_RT 0x03e00000
505
506 /*
507 * The ll_bit is cleared by r*_switch.S
508 */
509
510 unsigned int ll_bit;
511 struct task_struct *ll_task;
512
513 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
514 {
515 unsigned long value, __user *vaddr;
516 long offset;
517
518 /*
519 * analyse the ll instruction that just caused a ri exception
520 * and put the referenced address to addr.
521 */
522
523 /* sign extend offset */
524 offset = opcode & OFFSET;
525 offset <<= 16;
526 offset >>= 16;
527
528 vaddr = (unsigned long __user *)
529 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
530
531 if ((unsigned long)vaddr & 3)
532 return SIGBUS;
533 if (get_user(value, vaddr))
534 return SIGSEGV;
535
536 preempt_disable();
537
538 if (ll_task == NULL || ll_task == current) {
539 ll_bit = 1;
540 } else {
541 ll_bit = 0;
542 }
543 ll_task = current;
544
545 preempt_enable();
546
547 regs->regs[(opcode & RT) >> 16] = value;
548
549 return 0;
550 }
551
552 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
553 {
554 unsigned long __user *vaddr;
555 unsigned long reg;
556 long offset;
557
558 /*
559 * analyse the sc instruction that just caused a ri exception
560 * and put the referenced address to addr.
561 */
562
563 /* sign extend offset */
564 offset = opcode & OFFSET;
565 offset <<= 16;
566 offset >>= 16;
567
568 vaddr = (unsigned long __user *)
569 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
570 reg = (opcode & RT) >> 16;
571
572 if ((unsigned long)vaddr & 3)
573 return SIGBUS;
574
575 preempt_disable();
576
577 if (ll_bit == 0 || ll_task != current) {
578 regs->regs[reg] = 0;
579 preempt_enable();
580 return 0;
581 }
582
583 preempt_enable();
584
585 if (put_user(regs->regs[reg], vaddr))
586 return SIGSEGV;
587
588 regs->regs[reg] = 1;
589
590 return 0;
591 }
592
593 /*
594 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
595 * opcodes are supposed to result in coprocessor unusable exceptions if
596 * executed on ll/sc-less processors. That's the theory. In practice a
597 * few processors such as NEC's VR4100 throw reserved instruction exceptions
598 * instead, so we're doing the emulation thing in both exception handlers.
599 */
600 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
601 {
602 if ((opcode & OPCODE) == LL) {
603 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
604 1, regs, 0);
605 return simulate_ll(regs, opcode);
606 }
607 if ((opcode & OPCODE) == SC) {
608 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
609 1, regs, 0);
610 return simulate_sc(regs, opcode);
611 }
612
613 return -1; /* Must be something else ... */
614 }
615
616 /*
617 * Simulate trapping 'rdhwr' instructions to provide user accessible
618 * registers not implemented in hardware.
619 */
620 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
621 {
622 struct thread_info *ti = task_thread_info(current);
623
624 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
625 1, regs, 0);
626 switch (rd) {
627 case 0: /* CPU number */
628 regs->regs[rt] = smp_processor_id();
629 return 0;
630 case 1: /* SYNCI length */
631 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
632 current_cpu_data.icache.linesz);
633 return 0;
634 case 2: /* Read count register */
635 regs->regs[rt] = read_c0_count();
636 return 0;
637 case 3: /* Count register resolution */
638 switch (current_cpu_type()) {
639 case CPU_20KC:
640 case CPU_25KF:
641 regs->regs[rt] = 1;
642 break;
643 default:
644 regs->regs[rt] = 2;
645 }
646 return 0;
647 case 29:
648 regs->regs[rt] = ti->tp_value;
649 return 0;
650 default:
651 return -1;
652 }
653 }
654
655 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
656 {
657 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
658 int rd = (opcode & RD) >> 11;
659 int rt = (opcode & RT) >> 16;
660
661 simulate_rdhwr(regs, rd, rt);
662 return 0;
663 }
664
665 /* Not ours. */
666 return -1;
667 }
668
669 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned short opcode)
670 {
671 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
672 int rd = (opcode & MM_RS) >> 16;
673 int rt = (opcode & MM_RT) >> 21;
674 simulate_rdhwr(regs, rd, rt);
675 return 0;
676 }
677
678 /* Not ours. */
679 return -1;
680 }
681
682 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
683 {
684 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
685 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
686 1, regs, 0);
687 return 0;
688 }
689
690 return -1; /* Must be something else ... */
691 }
692
693 asmlinkage void do_ov(struct pt_regs *regs)
694 {
695 enum ctx_state prev_state;
696 siginfo_t info = {
697 .si_signo = SIGFPE,
698 .si_code = FPE_INTOVF,
699 .si_addr = (void __user *)regs->cp0_epc,
700 };
701
702 prev_state = exception_enter();
703 die_if_kernel("Integer overflow", regs);
704
705 force_sig_info(SIGFPE, &info, current);
706 exception_exit(prev_state);
707 }
708
709 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
710 {
711 struct siginfo si = { 0 };
712
713 switch (sig) {
714 case 0:
715 return 0;
716
717 case SIGFPE:
718 si.si_addr = fault_addr;
719 si.si_signo = sig;
720 /*
721 * Inexact can happen together with Overflow or Underflow.
722 * Respect the mask to deliver the correct exception.
723 */
724 fcr31 &= (fcr31 & FPU_CSR_ALL_E) <<
725 (ffs(FPU_CSR_ALL_X) - ffs(FPU_CSR_ALL_E));
726 if (fcr31 & FPU_CSR_INV_X)
727 si.si_code = FPE_FLTINV;
728 else if (fcr31 & FPU_CSR_DIV_X)
729 si.si_code = FPE_FLTDIV;
730 else if (fcr31 & FPU_CSR_OVF_X)
731 si.si_code = FPE_FLTOVF;
732 else if (fcr31 & FPU_CSR_UDF_X)
733 si.si_code = FPE_FLTUND;
734 else if (fcr31 & FPU_CSR_INE_X)
735 si.si_code = FPE_FLTRES;
736 else
737 si.si_code = __SI_FAULT;
738 force_sig_info(sig, &si, current);
739 return 1;
740
741 case SIGBUS:
742 si.si_addr = fault_addr;
743 si.si_signo = sig;
744 si.si_code = BUS_ADRERR;
745 force_sig_info(sig, &si, current);
746 return 1;
747
748 case SIGSEGV:
749 si.si_addr = fault_addr;
750 si.si_signo = sig;
751 down_read(&current->mm->mmap_sem);
752 if (find_vma(current->mm, (unsigned long)fault_addr))
753 si.si_code = SEGV_ACCERR;
754 else
755 si.si_code = SEGV_MAPERR;
756 up_read(&current->mm->mmap_sem);
757 force_sig_info(sig, &si, current);
758 return 1;
759
760 default:
761 force_sig(sig, current);
762 return 1;
763 }
764 }
765
766 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
767 unsigned long old_epc, unsigned long old_ra)
768 {
769 union mips_instruction inst = { .word = opcode };
770 void __user *fault_addr;
771 unsigned long fcr31;
772 int sig;
773
774 /* If it's obviously not an FP instruction, skip it */
775 switch (inst.i_format.opcode) {
776 case cop1_op:
777 case cop1x_op:
778 case lwc1_op:
779 case ldc1_op:
780 case swc1_op:
781 case sdc1_op:
782 break;
783
784 default:
785 return -1;
786 }
787
788 /*
789 * do_ri skipped over the instruction via compute_return_epc, undo
790 * that for the FPU emulator.
791 */
792 regs->cp0_epc = old_epc;
793 regs->regs[31] = old_ra;
794
795 /* Save the FP context to struct thread_struct */
796 lose_fpu(1);
797
798 /* Run the emulator */
799 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
800 &fault_addr);
801 fcr31 = current->thread.fpu.fcr31;
802
803 /*
804 * We can't allow the emulated instruction to leave any of
805 * the cause bits set in $fcr31.
806 */
807 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
808
809 /* Restore the hardware register state */
810 own_fpu(1);
811
812 /* Send a signal if required. */
813 process_fpemu_return(sig, fault_addr, fcr31);
814
815 return 0;
816 }
817
818 /*
819 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
820 */
821 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
822 {
823 enum ctx_state prev_state;
824 void __user *fault_addr;
825 int sig;
826
827 prev_state = exception_enter();
828 if (notify_die(DIE_FP, "FP exception", regs, 0, regs_to_trapnr(regs),
829 SIGFPE) == NOTIFY_STOP)
830 goto out;
831
832 /* Clear FCSR.Cause before enabling interrupts */
833 write_32bit_cp1_register(CP1_STATUS, fcr31 & ~FPU_CSR_ALL_X);
834 local_irq_enable();
835
836 die_if_kernel("FP exception in kernel code", regs);
837
838 if (fcr31 & FPU_CSR_UNI_X) {
839 /*
840 * Unimplemented operation exception. If we've got the full
841 * software emulator on-board, let's use it...
842 *
843 * Force FPU to dump state into task/thread context. We're
844 * moving a lot of data here for what is probably a single
845 * instruction, but the alternative is to pre-decode the FP
846 * register operands before invoking the emulator, which seems
847 * a bit extreme for what should be an infrequent event.
848 */
849 /* Ensure 'resume' not overwrite saved fp context again. */
850 lose_fpu(1);
851
852 /* Run the emulator */
853 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
854 &fault_addr);
855 fcr31 = current->thread.fpu.fcr31;
856
857 /*
858 * We can't allow the emulated instruction to leave any of
859 * the cause bits set in $fcr31.
860 */
861 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
862
863 /* Restore the hardware register state */
864 own_fpu(1); /* Using the FPU again. */
865 } else {
866 sig = SIGFPE;
867 fault_addr = (void __user *) regs->cp0_epc;
868 }
869
870 /* Send a signal if required. */
871 process_fpemu_return(sig, fault_addr, fcr31);
872
873 out:
874 exception_exit(prev_state);
875 }
876
877 void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
878 const char *str)
879 {
880 siginfo_t info = { 0 };
881 char b[40];
882
883 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
884 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
885 return;
886 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
887
888 if (notify_die(DIE_TRAP, str, regs, code, regs_to_trapnr(regs),
889 SIGTRAP) == NOTIFY_STOP)
890 return;
891
892 /*
893 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
894 * insns, even for trap and break codes that indicate arithmetic
895 * failures. Weird ...
896 * But should we continue the brokenness??? --macro
897 */
898 switch (code) {
899 case BRK_OVERFLOW:
900 case BRK_DIVZERO:
901 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
902 die_if_kernel(b, regs);
903 if (code == BRK_DIVZERO)
904 info.si_code = FPE_INTDIV;
905 else
906 info.si_code = FPE_INTOVF;
907 info.si_signo = SIGFPE;
908 info.si_addr = (void __user *) regs->cp0_epc;
909 force_sig_info(SIGFPE, &info, current);
910 break;
911 case BRK_BUG:
912 die_if_kernel("Kernel bug detected", regs);
913 force_sig(SIGTRAP, current);
914 break;
915 case BRK_MEMU:
916 /*
917 * This breakpoint code is used by the FPU emulator to retake
918 * control of the CPU after executing the instruction from the
919 * delay slot of an emulated branch.
920 *
921 * Terminate if exception was recognized as a delay slot return
922 * otherwise handle as normal.
923 */
924 if (do_dsemulret(regs))
925 return;
926
927 die_if_kernel("Math emu break/trap", regs);
928 force_sig(SIGTRAP, current);
929 break;
930 default:
931 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
932 die_if_kernel(b, regs);
933 force_sig(SIGTRAP, current);
934 }
935 }
936
937 asmlinkage void do_bp(struct pt_regs *regs)
938 {
939 unsigned long epc = msk_isa16_mode(exception_epc(regs));
940 unsigned int opcode, bcode;
941 enum ctx_state prev_state;
942 mm_segment_t seg;
943
944 seg = get_fs();
945 if (!user_mode(regs))
946 set_fs(KERNEL_DS);
947
948 prev_state = exception_enter();
949 if (get_isa16_mode(regs->cp0_epc)) {
950 u16 instr[2];
951
952 if (__get_user(instr[0], (u16 __user *)epc))
953 goto out_sigsegv;
954
955 if (!cpu_has_mmips) {
956 /* MIPS16e mode */
957 bcode = (instr[0] >> 5) & 0x3f;
958 } else if (mm_insn_16bit(instr[0])) {
959 /* 16-bit microMIPS BREAK */
960 bcode = instr[0] & 0xf;
961 } else {
962 /* 32-bit microMIPS BREAK */
963 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
964 goto out_sigsegv;
965 opcode = (instr[0] << 16) | instr[1];
966 bcode = (opcode >> 6) & ((1 << 20) - 1);
967 }
968 } else {
969 if (__get_user(opcode, (unsigned int __user *)epc))
970 goto out_sigsegv;
971 bcode = (opcode >> 6) & ((1 << 20) - 1);
972 }
973
974 /*
975 * There is the ancient bug in the MIPS assemblers that the break
976 * code starts left to bit 16 instead to bit 6 in the opcode.
977 * Gas is bug-compatible, but not always, grrr...
978 * We handle both cases with a simple heuristics. --macro
979 */
980 if (bcode >= (1 << 10))
981 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
982
983 /*
984 * notify the kprobe handlers, if instruction is likely to
985 * pertain to them.
986 */
987 switch (bcode) {
988 case BRK_KPROBE_BP:
989 if (notify_die(DIE_BREAK, "debug", regs, bcode,
990 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
991 goto out;
992 else
993 break;
994 case BRK_KPROBE_SSTEPBP:
995 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
996 regs_to_trapnr(regs), SIGTRAP) == NOTIFY_STOP)
997 goto out;
998 else
999 break;
1000 default:
1001 break;
1002 }
1003
1004 do_trap_or_bp(regs, bcode, "Break");
1005
1006 out:
1007 set_fs(seg);
1008 exception_exit(prev_state);
1009 return;
1010
1011 out_sigsegv:
1012 force_sig(SIGSEGV, current);
1013 goto out;
1014 }
1015
1016 asmlinkage void do_tr(struct pt_regs *regs)
1017 {
1018 u32 opcode, tcode = 0;
1019 enum ctx_state prev_state;
1020 u16 instr[2];
1021 mm_segment_t seg;
1022 unsigned long epc = msk_isa16_mode(exception_epc(regs));
1023
1024 seg = get_fs();
1025 if (!user_mode(regs))
1026 set_fs(get_ds());
1027
1028 prev_state = exception_enter();
1029 if (get_isa16_mode(regs->cp0_epc)) {
1030 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1031 __get_user(instr[1], (u16 __user *)(epc + 2)))
1032 goto out_sigsegv;
1033 opcode = (instr[0] << 16) | instr[1];
1034 /* Immediate versions don't provide a code. */
1035 if (!(opcode & OPCODE))
1036 tcode = (opcode >> 12) & ((1 << 4) - 1);
1037 } else {
1038 if (__get_user(opcode, (u32 __user *)epc))
1039 goto out_sigsegv;
1040 /* Immediate versions don't provide a code. */
1041 if (!(opcode & OPCODE))
1042 tcode = (opcode >> 6) & ((1 << 10) - 1);
1043 }
1044
1045 do_trap_or_bp(regs, tcode, "Trap");
1046
1047 out:
1048 set_fs(seg);
1049 exception_exit(prev_state);
1050 return;
1051
1052 out_sigsegv:
1053 force_sig(SIGSEGV, current);
1054 goto out;
1055 }
1056
1057 asmlinkage void do_ri(struct pt_regs *regs)
1058 {
1059 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1060 unsigned long old_epc = regs->cp0_epc;
1061 unsigned long old31 = regs->regs[31];
1062 enum ctx_state prev_state;
1063 unsigned int opcode = 0;
1064 int status = -1;
1065
1066 /*
1067 * Avoid any kernel code. Just emulate the R2 instruction
1068 * as quickly as possible.
1069 */
1070 if (mipsr2_emulation && cpu_has_mips_r6 &&
1071 likely(user_mode(regs)) &&
1072 likely(get_user(opcode, epc) >= 0)) {
1073 unsigned long fcr31 = 0;
1074
1075 status = mipsr2_decoder(regs, opcode, &fcr31);
1076 switch (status) {
1077 case 0:
1078 case SIGEMT:
1079 task_thread_info(current)->r2_emul_return = 1;
1080 return;
1081 case SIGILL:
1082 goto no_r2_instr;
1083 default:
1084 process_fpemu_return(status,
1085 &current->thread.cp0_baduaddr,
1086 fcr31);
1087 task_thread_info(current)->r2_emul_return = 1;
1088 return;
1089 }
1090 }
1091
1092 no_r2_instr:
1093
1094 prev_state = exception_enter();
1095
1096 if (notify_die(DIE_RI, "RI Fault", regs, 0, regs_to_trapnr(regs),
1097 SIGILL) == NOTIFY_STOP)
1098 goto out;
1099
1100 die_if_kernel("Reserved instruction in kernel code", regs);
1101
1102 if (unlikely(compute_return_epc(regs) < 0))
1103 goto out;
1104
1105 if (get_isa16_mode(regs->cp0_epc)) {
1106 unsigned short mmop[2] = { 0 };
1107
1108 if (unlikely(get_user(mmop[0], epc) < 0))
1109 status = SIGSEGV;
1110 if (unlikely(get_user(mmop[1], epc) < 0))
1111 status = SIGSEGV;
1112 opcode = (mmop[0] << 16) | mmop[1];
1113
1114 if (status < 0)
1115 status = simulate_rdhwr_mm(regs, opcode);
1116 } else {
1117 if (unlikely(get_user(opcode, epc) < 0))
1118 status = SIGSEGV;
1119
1120 if (!cpu_has_llsc && status < 0)
1121 status = simulate_llsc(regs, opcode);
1122
1123 if (status < 0)
1124 status = simulate_rdhwr_normal(regs, opcode);
1125
1126 if (status < 0)
1127 status = simulate_sync(regs, opcode);
1128
1129 if (status < 0)
1130 status = simulate_fp(regs, opcode, old_epc, old31);
1131 }
1132
1133 if (status < 0)
1134 status = SIGILL;
1135
1136 if (unlikely(status > 0)) {
1137 regs->cp0_epc = old_epc; /* Undo skip-over. */
1138 regs->regs[31] = old31;
1139 force_sig(status, current);
1140 }
1141
1142 out:
1143 exception_exit(prev_state);
1144 }
1145
1146 /*
1147 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
1148 * emulated more than some threshold number of instructions, force migration to
1149 * a "CPU" that has FP support.
1150 */
1151 static void mt_ase_fp_affinity(void)
1152 {
1153 #ifdef CONFIG_MIPS_MT_FPAFF
1154 if (mt_fpemul_threshold > 0 &&
1155 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
1156 /*
1157 * If there's no FPU present, or if the application has already
1158 * restricted the allowed set to exclude any CPUs with FPUs,
1159 * we'll skip the procedure.
1160 */
1161 if (cpumask_intersects(&current->cpus_allowed, &mt_fpu_cpumask)) {
1162 cpumask_t tmask;
1163
1164 current->thread.user_cpus_allowed
1165 = current->cpus_allowed;
1166 cpumask_and(&tmask, &current->cpus_allowed,
1167 &mt_fpu_cpumask);
1168 set_cpus_allowed_ptr(current, &tmask);
1169 set_thread_flag(TIF_FPUBOUND);
1170 }
1171 }
1172 #endif /* CONFIG_MIPS_MT_FPAFF */
1173 }
1174
1175 /*
1176 * No lock; only written during early bootup by CPU 0.
1177 */
1178 static RAW_NOTIFIER_HEAD(cu2_chain);
1179
1180 int __ref register_cu2_notifier(struct notifier_block *nb)
1181 {
1182 return raw_notifier_chain_register(&cu2_chain, nb);
1183 }
1184
1185 int cu2_notifier_call_chain(unsigned long val, void *v)
1186 {
1187 return raw_notifier_call_chain(&cu2_chain, val, v);
1188 }
1189
1190 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1191 void *data)
1192 {
1193 struct pt_regs *regs = data;
1194
1195 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1196 "instruction", regs);
1197 force_sig(SIGILL, current);
1198
1199 return NOTIFY_OK;
1200 }
1201
1202 static int wait_on_fp_mode_switch(atomic_t *p)
1203 {
1204 /*
1205 * The FP mode for this task is currently being switched. That may
1206 * involve modifications to the format of this tasks FP context which
1207 * make it unsafe to proceed with execution for the moment. Instead,
1208 * schedule some other task.
1209 */
1210 schedule();
1211 return 0;
1212 }
1213
1214 static int enable_restore_fp_context(int msa)
1215 {
1216 int err, was_fpu_owner, prior_msa;
1217
1218 /*
1219 * If an FP mode switch is currently underway, wait for it to
1220 * complete before proceeding.
1221 */
1222 wait_on_atomic_t(&current->mm->context.fp_mode_switching,
1223 wait_on_fp_mode_switch, TASK_KILLABLE);
1224
1225 if (!used_math()) {
1226 /* First time FP context user. */
1227 preempt_disable();
1228 err = init_fpu();
1229 if (msa && !err) {
1230 enable_msa();
1231 init_msa_upper();
1232 set_thread_flag(TIF_USEDMSA);
1233 set_thread_flag(TIF_MSA_CTX_LIVE);
1234 }
1235 preempt_enable();
1236 if (!err)
1237 set_used_math();
1238 return err;
1239 }
1240
1241 /*
1242 * This task has formerly used the FP context.
1243 *
1244 * If this thread has no live MSA vector context then we can simply
1245 * restore the scalar FP context. If it has live MSA vector context
1246 * (that is, it has or may have used MSA since last performing a
1247 * function call) then we'll need to restore the vector context. This
1248 * applies even if we're currently only executing a scalar FP
1249 * instruction. This is because if we were to later execute an MSA
1250 * instruction then we'd either have to:
1251 *
1252 * - Restore the vector context & clobber any registers modified by
1253 * scalar FP instructions between now & then.
1254 *
1255 * or
1256 *
1257 * - Not restore the vector context & lose the most significant bits
1258 * of all vector registers.
1259 *
1260 * Neither of those options is acceptable. We cannot restore the least
1261 * significant bits of the registers now & only restore the most
1262 * significant bits later because the most significant bits of any
1263 * vector registers whose aliased FP register is modified now will have
1264 * been zeroed. We'd have no way to know that when restoring the vector
1265 * context & thus may load an outdated value for the most significant
1266 * bits of a vector register.
1267 */
1268 if (!msa && !thread_msa_context_live())
1269 return own_fpu(1);
1270
1271 /*
1272 * This task is using or has previously used MSA. Thus we require
1273 * that Status.FR == 1.
1274 */
1275 preempt_disable();
1276 was_fpu_owner = is_fpu_owner();
1277 err = own_fpu_inatomic(0);
1278 if (err)
1279 goto out;
1280
1281 enable_msa();
1282 write_msa_csr(current->thread.fpu.msacsr);
1283 set_thread_flag(TIF_USEDMSA);
1284
1285 /*
1286 * If this is the first time that the task is using MSA and it has
1287 * previously used scalar FP in this time slice then we already nave
1288 * FP context which we shouldn't clobber. We do however need to clear
1289 * the upper 64b of each vector register so that this task has no
1290 * opportunity to see data left behind by another.
1291 */
1292 prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1293 if (!prior_msa && was_fpu_owner) {
1294 init_msa_upper();
1295
1296 goto out;
1297 }
1298
1299 if (!prior_msa) {
1300 /*
1301 * Restore the least significant 64b of each vector register
1302 * from the existing scalar FP context.
1303 */
1304 _restore_fp(current);
1305
1306 /*
1307 * The task has not formerly used MSA, so clear the upper 64b
1308 * of each vector register such that it cannot see data left
1309 * behind by another task.
1310 */
1311 init_msa_upper();
1312 } else {
1313 /* We need to restore the vector context. */
1314 restore_msa(current);
1315
1316 /* Restore the scalar FP control & status register */
1317 if (!was_fpu_owner)
1318 write_32bit_cp1_register(CP1_STATUS,
1319 current->thread.fpu.fcr31);
1320 }
1321
1322 out:
1323 preempt_enable();
1324
1325 return 0;
1326 }
1327
1328 asmlinkage void do_cpu(struct pt_regs *regs)
1329 {
1330 enum ctx_state prev_state;
1331 unsigned int __user *epc;
1332 unsigned long old_epc, old31;
1333 void __user *fault_addr;
1334 unsigned int opcode;
1335 unsigned long fcr31;
1336 unsigned int cpid;
1337 int status, err;
1338 unsigned long __maybe_unused flags;
1339 int sig;
1340
1341 prev_state = exception_enter();
1342 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1343
1344 if (cpid != 2)
1345 die_if_kernel("do_cpu invoked from kernel context!", regs);
1346
1347 switch (cpid) {
1348 case 0:
1349 epc = (unsigned int __user *)exception_epc(regs);
1350 old_epc = regs->cp0_epc;
1351 old31 = regs->regs[31];
1352 opcode = 0;
1353 status = -1;
1354
1355 if (unlikely(compute_return_epc(regs) < 0))
1356 break;
1357
1358 if (get_isa16_mode(regs->cp0_epc)) {
1359 unsigned short mmop[2] = { 0 };
1360
1361 if (unlikely(get_user(mmop[0], epc) < 0))
1362 status = SIGSEGV;
1363 if (unlikely(get_user(mmop[1], epc) < 0))
1364 status = SIGSEGV;
1365 opcode = (mmop[0] << 16) | mmop[1];
1366
1367 if (status < 0)
1368 status = simulate_rdhwr_mm(regs, opcode);
1369 } else {
1370 if (unlikely(get_user(opcode, epc) < 0))
1371 status = SIGSEGV;
1372
1373 if (!cpu_has_llsc && status < 0)
1374 status = simulate_llsc(regs, opcode);
1375
1376 if (status < 0)
1377 status = simulate_rdhwr_normal(regs, opcode);
1378 }
1379
1380 if (status < 0)
1381 status = SIGILL;
1382
1383 if (unlikely(status > 0)) {
1384 regs->cp0_epc = old_epc; /* Undo skip-over. */
1385 regs->regs[31] = old31;
1386 force_sig(status, current);
1387 }
1388
1389 break;
1390
1391 case 3:
1392 /*
1393 * The COP3 opcode space and consequently the CP0.Status.CU3
1394 * bit and the CP0.Cause.CE=3 encoding have been removed as
1395 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1396 * up the space has been reused for COP1X instructions, that
1397 * are enabled by the CP0.Status.CU1 bit and consequently
1398 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1399 * exceptions. Some FPU-less processors that implement one
1400 * of these ISAs however use this code erroneously for COP1X
1401 * instructions. Therefore we redirect this trap to the FP
1402 * emulator too.
1403 */
1404 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1405 force_sig(SIGILL, current);
1406 break;
1407 }
1408 /* Fall through. */
1409
1410 case 1:
1411 err = enable_restore_fp_context(0);
1412
1413 if (raw_cpu_has_fpu && !err)
1414 break;
1415
1416 sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1417 &fault_addr);
1418 fcr31 = current->thread.fpu.fcr31;
1419
1420 /*
1421 * We can't allow the emulated instruction to leave
1422 * any of the cause bits set in $fcr31.
1423 */
1424 current->thread.fpu.fcr31 &= ~FPU_CSR_ALL_X;
1425
1426 /* Send a signal if required. */
1427 if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1428 mt_ase_fp_affinity();
1429
1430 break;
1431
1432 case 2:
1433 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1434 break;
1435 }
1436
1437 exception_exit(prev_state);
1438 }
1439
1440 asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1441 {
1442 enum ctx_state prev_state;
1443
1444 prev_state = exception_enter();
1445 if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1446 regs_to_trapnr(regs), SIGFPE) == NOTIFY_STOP)
1447 goto out;
1448
1449 /* Clear MSACSR.Cause before enabling interrupts */
1450 write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1451 local_irq_enable();
1452
1453 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1454 force_sig(SIGFPE, current);
1455 out:
1456 exception_exit(prev_state);
1457 }
1458
1459 asmlinkage void do_msa(struct pt_regs *regs)
1460 {
1461 enum ctx_state prev_state;
1462 int err;
1463
1464 prev_state = exception_enter();
1465
1466 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1467 force_sig(SIGILL, current);
1468 goto out;
1469 }
1470
1471 die_if_kernel("do_msa invoked from kernel context!", regs);
1472
1473 err = enable_restore_fp_context(1);
1474 if (err)
1475 force_sig(SIGILL, current);
1476 out:
1477 exception_exit(prev_state);
1478 }
1479
1480 asmlinkage void do_mdmx(struct pt_regs *regs)
1481 {
1482 enum ctx_state prev_state;
1483
1484 prev_state = exception_enter();
1485 force_sig(SIGILL, current);
1486 exception_exit(prev_state);
1487 }
1488
1489 /*
1490 * Called with interrupts disabled.
1491 */
1492 asmlinkage void do_watch(struct pt_regs *regs)
1493 {
1494 enum ctx_state prev_state;
1495 u32 cause;
1496
1497 prev_state = exception_enter();
1498 /*
1499 * Clear WP (bit 22) bit of cause register so we don't loop
1500 * forever.
1501 */
1502 cause = read_c0_cause();
1503 cause &= ~(1 << 22);
1504 write_c0_cause(cause);
1505
1506 /*
1507 * If the current thread has the watch registers loaded, save
1508 * their values and send SIGTRAP. Otherwise another thread
1509 * left the registers set, clear them and continue.
1510 */
1511 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1512 mips_read_watch_registers();
1513 local_irq_enable();
1514 force_sig(SIGTRAP, current);
1515 } else {
1516 mips_clear_watch_registers();
1517 local_irq_enable();
1518 }
1519 exception_exit(prev_state);
1520 }
1521
1522 asmlinkage void do_mcheck(struct pt_regs *regs)
1523 {
1524 const int field = 2 * sizeof(unsigned long);
1525 int multi_match = regs->cp0_status & ST0_TS;
1526 enum ctx_state prev_state;
1527 mm_segment_t old_fs = get_fs();
1528
1529 prev_state = exception_enter();
1530 show_regs(regs);
1531
1532 if (multi_match) {
1533 pr_err("Index : %0x\n", read_c0_index());
1534 pr_err("Pagemask: %0x\n", read_c0_pagemask());
1535 pr_err("EntryHi : %0*lx\n", field, read_c0_entryhi());
1536 pr_err("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
1537 pr_err("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
1538 pr_err("Wired : %0x\n", read_c0_wired());
1539 pr_err("Pagegrain: %0x\n", read_c0_pagegrain());
1540 if (cpu_has_htw) {
1541 pr_err("PWField : %0*lx\n", field, read_c0_pwfield());
1542 pr_err("PWSize : %0*lx\n", field, read_c0_pwsize());
1543 pr_err("PWCtl : %0x\n", read_c0_pwctl());
1544 }
1545 pr_err("\n");
1546 dump_tlb_all();
1547 }
1548
1549 if (!user_mode(regs))
1550 set_fs(KERNEL_DS);
1551
1552 show_code((unsigned int __user *) regs->cp0_epc);
1553
1554 set_fs(old_fs);
1555
1556 /*
1557 * Some chips may have other causes of machine check (e.g. SB1
1558 * graduation timer)
1559 */
1560 panic("Caught Machine Check exception - %scaused by multiple "
1561 "matching entries in the TLB.",
1562 (multi_match) ? "" : "not ");
1563 }
1564
1565 asmlinkage void do_mt(struct pt_regs *regs)
1566 {
1567 int subcode;
1568
1569 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1570 >> VPECONTROL_EXCPT_SHIFT;
1571 switch (subcode) {
1572 case 0:
1573 printk(KERN_DEBUG "Thread Underflow\n");
1574 break;
1575 case 1:
1576 printk(KERN_DEBUG "Thread Overflow\n");
1577 break;
1578 case 2:
1579 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1580 break;
1581 case 3:
1582 printk(KERN_DEBUG "Gating Storage Exception\n");
1583 break;
1584 case 4:
1585 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1586 break;
1587 case 5:
1588 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1589 break;
1590 default:
1591 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1592 subcode);
1593 break;
1594 }
1595 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1596
1597 force_sig(SIGILL, current);
1598 }
1599
1600
1601 asmlinkage void do_dsp(struct pt_regs *regs)
1602 {
1603 if (cpu_has_dsp)
1604 panic("Unexpected DSP exception");
1605
1606 force_sig(SIGILL, current);
1607 }
1608
1609 asmlinkage void do_reserved(struct pt_regs *regs)
1610 {
1611 /*
1612 * Game over - no way to handle this if it ever occurs. Most probably
1613 * caused by a new unknown cpu type or after another deadly
1614 * hard/software error.
1615 */
1616 show_regs(regs);
1617 panic("Caught reserved exception %ld - should not happen.",
1618 (regs->cp0_cause & 0x7f) >> 2);
1619 }
1620
1621 static int __initdata l1parity = 1;
1622 static int __init nol1parity(char *s)
1623 {
1624 l1parity = 0;
1625 return 1;
1626 }
1627 __setup("nol1par", nol1parity);
1628 static int __initdata l2parity = 1;
1629 static int __init nol2parity(char *s)
1630 {
1631 l2parity = 0;
1632 return 1;
1633 }
1634 __setup("nol2par", nol2parity);
1635
1636 /*
1637 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1638 * it different ways.
1639 */
1640 static inline void parity_protection_init(void)
1641 {
1642 switch (current_cpu_type()) {
1643 case CPU_24K:
1644 case CPU_34K:
1645 case CPU_74K:
1646 case CPU_1004K:
1647 case CPU_1074K:
1648 case CPU_INTERAPTIV:
1649 case CPU_PROAPTIV:
1650 case CPU_P5600:
1651 case CPU_QEMU_GENERIC:
1652 {
1653 #define ERRCTL_PE 0x80000000
1654 #define ERRCTL_L2P 0x00800000
1655 unsigned long errctl;
1656 unsigned int l1parity_present, l2parity_present;
1657
1658 errctl = read_c0_ecc();
1659 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1660
1661 /* probe L1 parity support */
1662 write_c0_ecc(errctl | ERRCTL_PE);
1663 back_to_back_c0_hazard();
1664 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1665
1666 /* probe L2 parity support */
1667 write_c0_ecc(errctl|ERRCTL_L2P);
1668 back_to_back_c0_hazard();
1669 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1670
1671 if (l1parity_present && l2parity_present) {
1672 if (l1parity)
1673 errctl |= ERRCTL_PE;
1674 if (l1parity ^ l2parity)
1675 errctl |= ERRCTL_L2P;
1676 } else if (l1parity_present) {
1677 if (l1parity)
1678 errctl |= ERRCTL_PE;
1679 } else if (l2parity_present) {
1680 if (l2parity)
1681 errctl |= ERRCTL_L2P;
1682 } else {
1683 /* No parity available */
1684 }
1685
1686 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1687
1688 write_c0_ecc(errctl);
1689 back_to_back_c0_hazard();
1690 errctl = read_c0_ecc();
1691 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1692
1693 if (l1parity_present)
1694 printk(KERN_INFO "Cache parity protection %sabled\n",
1695 (errctl & ERRCTL_PE) ? "en" : "dis");
1696
1697 if (l2parity_present) {
1698 if (l1parity_present && l1parity)
1699 errctl ^= ERRCTL_L2P;
1700 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1701 (errctl & ERRCTL_L2P) ? "en" : "dis");
1702 }
1703 }
1704 break;
1705
1706 case CPU_5KC:
1707 case CPU_5KE:
1708 case CPU_LOONGSON1:
1709 write_c0_ecc(0x80000000);
1710 back_to_back_c0_hazard();
1711 /* Set the PE bit (bit 31) in the c0_errctl register. */
1712 printk(KERN_INFO "Cache parity protection %sabled\n",
1713 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1714 break;
1715 case CPU_20KC:
1716 case CPU_25KF:
1717 /* Clear the DE bit (bit 16) in the c0_status register. */
1718 printk(KERN_INFO "Enable cache parity protection for "
1719 "MIPS 20KC/25KF CPUs.\n");
1720 clear_c0_status(ST0_DE);
1721 break;
1722 default:
1723 break;
1724 }
1725 }
1726
1727 asmlinkage void cache_parity_error(void)
1728 {
1729 const int field = 2 * sizeof(unsigned long);
1730 unsigned int reg_val;
1731
1732 /* For the moment, report the problem and hang. */
1733 printk("Cache error exception:\n");
1734 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1735 reg_val = read_c0_cacheerr();
1736 printk("c0_cacheerr == %08x\n", reg_val);
1737
1738 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1739 reg_val & (1<<30) ? "secondary" : "primary",
1740 reg_val & (1<<31) ? "data" : "insn");
1741 if ((cpu_has_mips_r2_r6) &&
1742 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1743 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1744 reg_val & (1<<29) ? "ED " : "",
1745 reg_val & (1<<28) ? "ET " : "",
1746 reg_val & (1<<27) ? "ES " : "",
1747 reg_val & (1<<26) ? "EE " : "",
1748 reg_val & (1<<25) ? "EB " : "",
1749 reg_val & (1<<24) ? "EI " : "",
1750 reg_val & (1<<23) ? "E1 " : "",
1751 reg_val & (1<<22) ? "E0 " : "");
1752 } else {
1753 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1754 reg_val & (1<<29) ? "ED " : "",
1755 reg_val & (1<<28) ? "ET " : "",
1756 reg_val & (1<<26) ? "EE " : "",
1757 reg_val & (1<<25) ? "EB " : "",
1758 reg_val & (1<<24) ? "EI " : "",
1759 reg_val & (1<<23) ? "E1 " : "",
1760 reg_val & (1<<22) ? "E0 " : "");
1761 }
1762 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1763
1764 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1765 if (reg_val & (1<<22))
1766 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1767
1768 if (reg_val & (1<<23))
1769 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1770 #endif
1771
1772 panic("Can't handle the cache error!");
1773 }
1774
1775 asmlinkage void do_ftlb(void)
1776 {
1777 const int field = 2 * sizeof(unsigned long);
1778 unsigned int reg_val;
1779
1780 /* For the moment, report the problem and hang. */
1781 if ((cpu_has_mips_r2_r6) &&
1782 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1783 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1784 read_c0_ecc());
1785 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1786 reg_val = read_c0_cacheerr();
1787 pr_err("c0_cacheerr == %08x\n", reg_val);
1788
1789 if ((reg_val & 0xc0000000) == 0xc0000000) {
1790 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1791 } else {
1792 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1793 reg_val & (1<<30) ? "secondary" : "primary",
1794 reg_val & (1<<31) ? "data" : "insn");
1795 }
1796 } else {
1797 pr_err("FTLB error exception\n");
1798 }
1799 /* Just print the cacheerr bits for now */
1800 cache_parity_error();
1801 }
1802
1803 /*
1804 * SDBBP EJTAG debug exception handler.
1805 * We skip the instruction and return to the next instruction.
1806 */
1807 void ejtag_exception_handler(struct pt_regs *regs)
1808 {
1809 const int field = 2 * sizeof(unsigned long);
1810 unsigned long depc, old_epc, old_ra;
1811 unsigned int debug;
1812
1813 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1814 depc = read_c0_depc();
1815 debug = read_c0_debug();
1816 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1817 if (debug & 0x80000000) {
1818 /*
1819 * In branch delay slot.
1820 * We cheat a little bit here and use EPC to calculate the
1821 * debug return address (DEPC). EPC is restored after the
1822 * calculation.
1823 */
1824 old_epc = regs->cp0_epc;
1825 old_ra = regs->regs[31];
1826 regs->cp0_epc = depc;
1827 compute_return_epc(regs);
1828 depc = regs->cp0_epc;
1829 regs->cp0_epc = old_epc;
1830 regs->regs[31] = old_ra;
1831 } else
1832 depc += 4;
1833 write_c0_depc(depc);
1834
1835 #if 0
1836 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1837 write_c0_debug(debug | 0x100);
1838 #endif
1839 }
1840
1841 /*
1842 * NMI exception handler.
1843 * No lock; only written during early bootup by CPU 0.
1844 */
1845 static RAW_NOTIFIER_HEAD(nmi_chain);
1846
1847 int register_nmi_notifier(struct notifier_block *nb)
1848 {
1849 return raw_notifier_chain_register(&nmi_chain, nb);
1850 }
1851
1852 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1853 {
1854 char str[100];
1855
1856 raw_notifier_call_chain(&nmi_chain, 0, regs);
1857 bust_spinlocks(1);
1858 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1859 smp_processor_id(), regs->cp0_epc);
1860 regs->cp0_epc = read_c0_errorepc();
1861 die(str, regs);
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 defined(CONFIG_KGDB)
2200 if (kgdb_early_setup)
2201 return; /* Already done */
2202 #endif
2203
2204 if (cpu_has_veic || cpu_has_vint) {
2205 unsigned long size = 0x200 + VECTORSPACING*64;
2206 ebase = (unsigned long)
2207 __alloc_bootmem(size, 1 << fls(size), 0);
2208 } else {
2209 #ifdef CONFIG_KVM_GUEST
2210 #define KVM_GUEST_KSEG0 0x40000000
2211 ebase = KVM_GUEST_KSEG0;
2212 #else
2213 ebase = CKSEG0;
2214 #endif
2215 if (cpu_has_mips_r2_r6)
2216 ebase += (read_c0_ebase() & 0x3ffff000);
2217 }
2218
2219 if (cpu_has_mmips) {
2220 unsigned int config3 = read_c0_config3();
2221
2222 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2223 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2224 else
2225 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2226 }
2227
2228 if (board_ebase_setup)
2229 board_ebase_setup();
2230 per_cpu_trap_init(true);
2231
2232 /*
2233 * Copy the generic exception handlers to their final destination.
2234 * This will be overriden later as suitable for a particular
2235 * configuration.
2236 */
2237 set_handler(0x180, &except_vec3_generic, 0x80);
2238
2239 /*
2240 * Setup default vectors
2241 */
2242 for (i = 0; i <= 31; i++)
2243 set_except_vector(i, handle_reserved);
2244
2245 /*
2246 * Copy the EJTAG debug exception vector handler code to it's final
2247 * destination.
2248 */
2249 if (cpu_has_ejtag && board_ejtag_handler_setup)
2250 board_ejtag_handler_setup();
2251
2252 /*
2253 * Only some CPUs have the watch exceptions.
2254 */
2255 if (cpu_has_watch)
2256 set_except_vector(23, handle_watch);
2257
2258 /*
2259 * Initialise interrupt handlers
2260 */
2261 if (cpu_has_veic || cpu_has_vint) {
2262 int nvec = cpu_has_veic ? 64 : 8;
2263 for (i = 0; i < nvec; i++)
2264 set_vi_handler(i, NULL);
2265 }
2266 else if (cpu_has_divec)
2267 set_handler(0x200, &except_vec4, 0x8);
2268
2269 /*
2270 * Some CPUs can enable/disable for cache parity detection, but does
2271 * it different ways.
2272 */
2273 parity_protection_init();
2274
2275 /*
2276 * The Data Bus Errors / Instruction Bus Errors are signaled
2277 * by external hardware. Therefore these two exceptions
2278 * may have board specific handlers.
2279 */
2280 if (board_be_init)
2281 board_be_init();
2282
2283 set_except_vector(0, using_rollback_handler() ? rollback_handle_int
2284 : handle_int);
2285 set_except_vector(1, handle_tlbm);
2286 set_except_vector(2, handle_tlbl);
2287 set_except_vector(3, handle_tlbs);
2288
2289 set_except_vector(4, handle_adel);
2290 set_except_vector(5, handle_ades);
2291
2292 set_except_vector(6, handle_ibe);
2293 set_except_vector(7, handle_dbe);
2294
2295 set_except_vector(8, handle_sys);
2296 set_except_vector(9, handle_bp);
2297 set_except_vector(10, rdhwr_noopt ? handle_ri :
2298 (cpu_has_vtag_icache ?
2299 handle_ri_rdhwr_vivt : handle_ri_rdhwr));
2300 set_except_vector(11, handle_cpu);
2301 set_except_vector(12, handle_ov);
2302 set_except_vector(13, handle_tr);
2303 set_except_vector(14, handle_msa_fpe);
2304
2305 if (current_cpu_type() == CPU_R6000 ||
2306 current_cpu_type() == CPU_R6000A) {
2307 /*
2308 * The R6000 is the only R-series CPU that features a machine
2309 * check exception (similar to the R4000 cache error) and
2310 * unaligned ldc1/sdc1 exception. The handlers have not been
2311 * written yet. Well, anyway there is no R6000 machine on the
2312 * current list of targets for Linux/MIPS.
2313 * (Duh, crap, there is someone with a triple R6k machine)
2314 */
2315 //set_except_vector(14, handle_mc);
2316 //set_except_vector(15, handle_ndc);
2317 }
2318
2319
2320 if (board_nmi_handler_setup)
2321 board_nmi_handler_setup();
2322
2323 if (cpu_has_fpu && !cpu_has_nofpuex)
2324 set_except_vector(15, handle_fpe);
2325
2326 set_except_vector(16, handle_ftlb);
2327
2328 if (cpu_has_rixiex) {
2329 set_except_vector(19, tlb_do_page_fault_0);
2330 set_except_vector(20, tlb_do_page_fault_0);
2331 }
2332
2333 set_except_vector(21, handle_msa);
2334 set_except_vector(22, handle_mdmx);
2335
2336 if (cpu_has_mcheck)
2337 set_except_vector(24, handle_mcheck);
2338
2339 if (cpu_has_mipsmt)
2340 set_except_vector(25, handle_mt);
2341
2342 set_except_vector(26, handle_dsp);
2343
2344 if (board_cache_error_setup)
2345 board_cache_error_setup();
2346
2347 if (cpu_has_vce)
2348 /* Special exception: R4[04]00 uses also the divec space. */
2349 set_handler(0x180, &except_vec3_r4000, 0x100);
2350 else if (cpu_has_4kex)
2351 set_handler(0x180, &except_vec3_generic, 0x80);
2352 else
2353 set_handler(0x080, &except_vec3_generic, 0x80);
2354
2355 local_flush_icache_range(ebase, ebase + 0x400);
2356
2357 sort_extable(__start___dbe_table, __stop___dbe_table);
2358
2359 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2360 }
2361
2362 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2363 void *v)
2364 {
2365 switch (cmd) {
2366 case CPU_PM_ENTER_FAILED:
2367 case CPU_PM_EXIT:
2368 configure_status();
2369 configure_hwrena();
2370 configure_exception_vector();
2371
2372 /* Restore register with CPU number for TLB handlers */
2373 TLBMISS_HANDLER_RESTORE();
2374
2375 break;
2376 }
2377
2378 return NOTIFY_OK;
2379 }
2380
2381 static struct notifier_block trap_pm_notifier_block = {
2382 .notifier_call = trap_pm_notifier,
2383 };
2384
2385 static int __init trap_pm_init(void)
2386 {
2387 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2388 }
2389 arch_initcall(trap_pm_init);
Linux with added FPC-III support