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/extable.h>
25 #include <linux/mm.h>
26 #include <linux/sched/mm.h>
27 #include <linux/sched/debug.h>
28 #include <linux/smp.h>
29 #include <linux/spinlock.h>
30 #include <linux/kallsyms.h>
31 #include <linux/memblock.h>
32 #include <linux/interrupt.h>
33 #include <linux/ptrace.h>
34 #include <linux/kgdb.h>
35 #include <linux/kdebug.h>
36 #include <linux/kprobes.h>
37 #include <linux/notifier.h>
38 #include <linux/kdb.h>
39 #include <linux/irq.h>
40 #include <linux/perf_event.h>
41
42 #include <asm/addrspace.h>
43 #include <asm/bootinfo.h>
44 #include <asm/branch.h>
45 #include <asm/break.h>
46 #include <asm/cop2.h>
47 #include <asm/cpu.h>
48 #include <asm/cpu-type.h>
49 #include <asm/dsp.h>
50 #include <asm/fpu.h>
51 #include <asm/fpu_emulator.h>
52 #include <asm/idle.h>
53 #include <asm/isa-rev.h>
54 #include <asm/mips-cps.h>
55 #include <asm/mips-r2-to-r6-emul.h>
56 #include <asm/mipsregs.h>
57 #include <asm/mipsmtregs.h>
58 #include <asm/module.h>
59 #include <asm/msa.h>
60 #include <asm/pgtable.h>
61 #include <asm/ptrace.h>
62 #include <asm/sections.h>
63 #include <asm/siginfo.h>
64 #include <asm/tlbdebug.h>
65 #include <asm/traps.h>
66 #include <linux/uaccess.h>
67 #include <asm/watch.h>
68 #include <asm/mmu_context.h>
69 #include <asm/types.h>
70 #include <asm/stacktrace.h>
71 #include <asm/tlbex.h>
72 #include <asm/uasm.h>
73
74 extern void check_wait(void);
75 extern asmlinkage void rollback_handle_int(void);
76 extern asmlinkage void handle_int(void);
77 extern asmlinkage void handle_adel(void);
78 extern asmlinkage void handle_ades(void);
79 extern asmlinkage void handle_ibe(void);
80 extern asmlinkage void handle_dbe(void);
81 extern asmlinkage void handle_sys(void);
82 extern asmlinkage void handle_bp(void);
83 extern asmlinkage void handle_ri(void);
84 extern asmlinkage void handle_ri_rdhwr_tlbp(void);
85 extern asmlinkage void handle_ri_rdhwr(void);
86 extern asmlinkage void handle_cpu(void);
87 extern asmlinkage void handle_ov(void);
88 extern asmlinkage void handle_tr(void);
89 extern asmlinkage void handle_msa_fpe(void);
90 extern asmlinkage void handle_fpe(void);
91 extern asmlinkage void handle_ftlb(void);
92 extern asmlinkage void handle_msa(void);
93 extern asmlinkage void handle_mdmx(void);
94 extern asmlinkage void handle_watch(void);
95 extern asmlinkage void handle_mt(void);
96 extern asmlinkage void handle_dsp(void);
97 extern asmlinkage void handle_mcheck(void);
98 extern asmlinkage void handle_reserved(void);
99 extern void tlb_do_page_fault_0(void);
100
101 void (*board_be_init)(void);
102 int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
103 void (*board_nmi_handler_setup)(void);
104 void (*board_ejtag_handler_setup)(void);
105 void (*board_bind_eic_interrupt)(int irq, int regset);
106 void (*board_ebase_setup)(void);
107 void(*board_cache_error_setup)(void);
108
show_raw_backtrace(unsigned long reg29)109 static void show_raw_backtrace(unsigned long reg29)
110 {
111 unsigned long *sp = (unsigned long *)(reg29 & ~3);
112 unsigned long addr;
113
114 printk("Call Trace:");
115 #ifdef CONFIG_KALLSYMS
116 printk("\n");
117 #endif
118 while (!kstack_end(sp)) {
119 unsigned long __user *p =
120 (unsigned long __user *)(unsigned long)sp++;
121 if (__get_user(addr, p)) {
122 printk(" (Bad stack address)");
123 break;
124 }
125 if (__kernel_text_address(addr))
126 print_ip_sym(addr);
127 }
128 printk("\n");
129 }
130
131 #ifdef CONFIG_KALLSYMS
132 int raw_show_trace;
set_raw_show_trace(char * str)133 static int __init set_raw_show_trace(char *str)
134 {
135 raw_show_trace = 1;
136 return 1;
137 }
138 __setup("raw_show_trace", set_raw_show_trace);
139 #endif
140
show_backtrace(struct task_struct * task,const struct pt_regs * regs)141 static void show_backtrace(struct task_struct *task, const struct pt_regs *regs)
142 {
143 unsigned long sp = regs->regs[29];
144 unsigned long ra = regs->regs[31];
145 unsigned long pc = regs->cp0_epc;
146
147 if (!task)
148 task = current;
149
150 if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
151 show_raw_backtrace(sp);
152 return;
153 }
154 printk("Call Trace:\n");
155 do {
156 print_ip_sym(pc);
157 pc = unwind_stack(task, &sp, pc, &ra);
158 } while (pc);
159 pr_cont("\n");
160 }
161
162 /*
163 * This routine abuses get_user()/put_user() to reference pointers
164 * with at least a bit of error checking ...
165 */
show_stacktrace(struct task_struct * task,const struct pt_regs * regs)166 static void show_stacktrace(struct task_struct *task,
167 const struct pt_regs *regs)
168 {
169 const int field = 2 * sizeof(unsigned long);
170 long stackdata;
171 int i;
172 unsigned long __user *sp = (unsigned long __user *)regs->regs[29];
173
174 printk("Stack :");
175 i = 0;
176 while ((unsigned long) sp & (PAGE_SIZE - 1)) {
177 if (i && ((i % (64 / field)) == 0)) {
178 pr_cont("\n");
179 printk(" ");
180 }
181 if (i > 39) {
182 pr_cont(" ...");
183 break;
184 }
185
186 if (__get_user(stackdata, sp++)) {
187 pr_cont(" (Bad stack address)");
188 break;
189 }
190
191 pr_cont(" %0*lx", field, stackdata);
192 i++;
193 }
194 pr_cont("\n");
195 show_backtrace(task, regs);
196 }
197
show_stack(struct task_struct * task,unsigned long * sp)198 void show_stack(struct task_struct *task, unsigned long *sp)
199 {
200 struct pt_regs regs;
201 mm_segment_t old_fs = get_fs();
202
203 regs.cp0_status = KSU_KERNEL;
204 if (sp) {
205 regs.regs[29] = (unsigned long)sp;
206 regs.regs[31] = 0;
207 regs.cp0_epc = 0;
208 } else {
209 if (task && task != current) {
210 regs.regs[29] = task->thread.reg29;
211 regs.regs[31] = 0;
212 regs.cp0_epc = task->thread.reg31;
213 #ifdef CONFIG_KGDB_KDB
214 } else if (atomic_read(&kgdb_active) != -1 &&
215 kdb_current_regs) {
216 memcpy(®s, kdb_current_regs, sizeof(regs));
217 #endif /* CONFIG_KGDB_KDB */
218 } else {
219 prepare_frametrace(®s);
220 }
221 }
222 /*
223 * show_stack() deals exclusively with kernel mode, so be sure to access
224 * the stack in the kernel (not user) address space.
225 */
226 set_fs(KERNEL_DS);
227 show_stacktrace(task, ®s);
228 set_fs(old_fs);
229 }
230
show_code(unsigned int __user * pc)231 static void show_code(unsigned int __user *pc)
232 {
233 long i;
234 unsigned short __user *pc16 = NULL;
235
236 printk("Code:");
237
238 if ((unsigned long)pc & 1)
239 pc16 = (unsigned short __user *)((unsigned long)pc & ~1);
240 for(i = -3 ; i < 6 ; i++) {
241 unsigned int insn;
242 if (pc16 ? __get_user(insn, pc16 + i) : __get_user(insn, pc + i)) {
243 pr_cont(" (Bad address in epc)\n");
244 break;
245 }
246 pr_cont("%c%0*x%c", (i?' ':'<'), pc16 ? 4 : 8, insn, (i?' ':'>'));
247 }
248 pr_cont("\n");
249 }
250
__show_regs(const struct pt_regs * regs)251 static void __show_regs(const struct pt_regs *regs)
252 {
253 const int field = 2 * sizeof(unsigned long);
254 unsigned int cause = regs->cp0_cause;
255 unsigned int exccode;
256 int i;
257
258 show_regs_print_info(KERN_DEFAULT);
259
260 /*
261 * Saved main processor registers
262 */
263 for (i = 0; i < 32; ) {
264 if ((i % 4) == 0)
265 printk("$%2d :", i);
266 if (i == 0)
267 pr_cont(" %0*lx", field, 0UL);
268 else if (i == 26 || i == 27)
269 pr_cont(" %*s", field, "");
270 else
271 pr_cont(" %0*lx", field, regs->regs[i]);
272
273 i++;
274 if ((i % 4) == 0)
275 pr_cont("\n");
276 }
277
278 #ifdef CONFIG_CPU_HAS_SMARTMIPS
279 printk("Acx : %0*lx\n", field, regs->acx);
280 #endif
281 if (MIPS_ISA_REV < 6) {
282 printk("Hi : %0*lx\n", field, regs->hi);
283 printk("Lo : %0*lx\n", field, regs->lo);
284 }
285
286 /*
287 * Saved cp0 registers
288 */
289 printk("epc : %0*lx %pS\n", field, regs->cp0_epc,
290 (void *) regs->cp0_epc);
291 printk("ra : %0*lx %pS\n", field, regs->regs[31],
292 (void *) regs->regs[31]);
293
294 printk("Status: %08x ", (uint32_t) regs->cp0_status);
295
296 if (cpu_has_3kex) {
297 if (regs->cp0_status & ST0_KUO)
298 pr_cont("KUo ");
299 if (regs->cp0_status & ST0_IEO)
300 pr_cont("IEo ");
301 if (regs->cp0_status & ST0_KUP)
302 pr_cont("KUp ");
303 if (regs->cp0_status & ST0_IEP)
304 pr_cont("IEp ");
305 if (regs->cp0_status & ST0_KUC)
306 pr_cont("KUc ");
307 if (regs->cp0_status & ST0_IEC)
308 pr_cont("IEc ");
309 } else if (cpu_has_4kex) {
310 if (regs->cp0_status & ST0_KX)
311 pr_cont("KX ");
312 if (regs->cp0_status & ST0_SX)
313 pr_cont("SX ");
314 if (regs->cp0_status & ST0_UX)
315 pr_cont("UX ");
316 switch (regs->cp0_status & ST0_KSU) {
317 case KSU_USER:
318 pr_cont("USER ");
319 break;
320 case KSU_SUPERVISOR:
321 pr_cont("SUPERVISOR ");
322 break;
323 case KSU_KERNEL:
324 pr_cont("KERNEL ");
325 break;
326 default:
327 pr_cont("BAD_MODE ");
328 break;
329 }
330 if (regs->cp0_status & ST0_ERL)
331 pr_cont("ERL ");
332 if (regs->cp0_status & ST0_EXL)
333 pr_cont("EXL ");
334 if (regs->cp0_status & ST0_IE)
335 pr_cont("IE ");
336 }
337 pr_cont("\n");
338
339 exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
340 printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
341
342 if (1 <= exccode && exccode <= 5)
343 printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
344
345 printk("PrId : %08x (%s)\n", read_c0_prid(),
346 cpu_name_string());
347 }
348
349 /*
350 * FIXME: really the generic show_regs should take a const pointer argument.
351 */
show_regs(struct pt_regs * regs)352 void show_regs(struct pt_regs *regs)
353 {
354 __show_regs(regs);
355 dump_stack();
356 }
357
show_registers(struct pt_regs * regs)358 void show_registers(struct pt_regs *regs)
359 {
360 const int field = 2 * sizeof(unsigned long);
361 mm_segment_t old_fs = get_fs();
362
363 __show_regs(regs);
364 print_modules();
365 printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
366 current->comm, current->pid, current_thread_info(), current,
367 field, current_thread_info()->tp_value);
368 if (cpu_has_userlocal) {
369 unsigned long tls;
370
371 tls = read_c0_userlocal();
372 if (tls != current_thread_info()->tp_value)
373 printk("*HwTLS: %0*lx\n", field, tls);
374 }
375
376 if (!user_mode(regs))
377 /* Necessary for getting the correct stack content */
378 set_fs(KERNEL_DS);
379 show_stacktrace(current, regs);
380 show_code((unsigned int __user *) regs->cp0_epc);
381 printk("\n");
382 set_fs(old_fs);
383 }
384
385 static DEFINE_RAW_SPINLOCK(die_lock);
386
die(const char * str,struct pt_regs * regs)387 void __noreturn die(const char *str, struct pt_regs *regs)
388 {
389 static int die_counter;
390 int sig = SIGSEGV;
391
392 oops_enter();
393
394 if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
395 SIGSEGV) == NOTIFY_STOP)
396 sig = 0;
397
398 console_verbose();
399 raw_spin_lock_irq(&die_lock);
400 bust_spinlocks(1);
401
402 printk("%s[#%d]:\n", str, ++die_counter);
403 show_registers(regs);
404 add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
405 raw_spin_unlock_irq(&die_lock);
406
407 oops_exit();
408
409 if (in_interrupt())
410 panic("Fatal exception in interrupt");
411
412 if (panic_on_oops)
413 panic("Fatal exception");
414
415 if (regs && kexec_should_crash(current))
416 crash_kexec(regs);
417
418 make_task_dead(sig);
419 }
420
421 extern struct exception_table_entry __start___dbe_table[];
422 extern struct exception_table_entry __stop___dbe_table[];
423
424 __asm__(
425 " .section __dbe_table, \"a\"\n"
426 " .previous \n");
427
428 /* Given an address, look for it in the exception tables. */
search_dbe_tables(unsigned long addr)429 static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
430 {
431 const struct exception_table_entry *e;
432
433 e = search_extable(__start___dbe_table,
434 __stop___dbe_table - __start___dbe_table, addr);
435 if (!e)
436 e = search_module_dbetables(addr);
437 return e;
438 }
439
do_be(struct pt_regs * regs)440 asmlinkage void do_be(struct pt_regs *regs)
441 {
442 const int field = 2 * sizeof(unsigned long);
443 const struct exception_table_entry *fixup = NULL;
444 int data = regs->cp0_cause & 4;
445 int action = MIPS_BE_FATAL;
446 enum ctx_state prev_state;
447
448 prev_state = exception_enter();
449 /* XXX For now. Fixme, this searches the wrong table ... */
450 if (data && !user_mode(regs))
451 fixup = search_dbe_tables(exception_epc(regs));
452
453 if (fixup)
454 action = MIPS_BE_FIXUP;
455
456 if (board_be_handler)
457 action = board_be_handler(regs, fixup != NULL);
458 else
459 mips_cm_error_report();
460
461 switch (action) {
462 case MIPS_BE_DISCARD:
463 goto out;
464 case MIPS_BE_FIXUP:
465 if (fixup) {
466 regs->cp0_epc = fixup->nextinsn;
467 goto out;
468 }
469 break;
470 default:
471 break;
472 }
473
474 /*
475 * Assume it would be too dangerous to continue ...
476 */
477 printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
478 data ? "Data" : "Instruction",
479 field, regs->cp0_epc, field, regs->regs[31]);
480 if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
481 SIGBUS) == NOTIFY_STOP)
482 goto out;
483
484 die_if_kernel("Oops", regs);
485 force_sig(SIGBUS);
486
487 out:
488 exception_exit(prev_state);
489 }
490
491 /*
492 * ll/sc, rdhwr, sync emulation
493 */
494
495 #define OPCODE 0xfc000000
496 #define BASE 0x03e00000
497 #define RT 0x001f0000
498 #define OFFSET 0x0000ffff
499 #define LL 0xc0000000
500 #define SC 0xe0000000
501 #define SPEC0 0x00000000
502 #define SPEC3 0x7c000000
503 #define RD 0x0000f800
504 #define FUNC 0x0000003f
505 #define SYNC 0x0000000f
506 #define RDHWR 0x0000003b
507
508 /* microMIPS definitions */
509 #define MM_POOL32A_FUNC 0xfc00ffff
510 #define MM_RDHWR 0x00006b3c
511 #define MM_RS 0x001f0000
512 #define MM_RT 0x03e00000
513
514 /*
515 * The ll_bit is cleared by r*_switch.S
516 */
517
518 unsigned int ll_bit;
519 struct task_struct *ll_task;
520
simulate_ll(struct pt_regs * regs,unsigned int opcode)521 static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
522 {
523 unsigned long value, __user *vaddr;
524 long offset;
525
526 /*
527 * analyse the ll instruction that just caused a ri exception
528 * and put the referenced address to addr.
529 */
530
531 /* sign extend offset */
532 offset = opcode & OFFSET;
533 offset <<= 16;
534 offset >>= 16;
535
536 vaddr = (unsigned long __user *)
537 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
538
539 if ((unsigned long)vaddr & 3)
540 return SIGBUS;
541 if (get_user(value, vaddr))
542 return SIGSEGV;
543
544 preempt_disable();
545
546 if (ll_task == NULL || ll_task == current) {
547 ll_bit = 1;
548 } else {
549 ll_bit = 0;
550 }
551 ll_task = current;
552
553 preempt_enable();
554
555 regs->regs[(opcode & RT) >> 16] = value;
556
557 return 0;
558 }
559
simulate_sc(struct pt_regs * regs,unsigned int opcode)560 static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
561 {
562 unsigned long __user *vaddr;
563 unsigned long reg;
564 long offset;
565
566 /*
567 * analyse the sc instruction that just caused a ri exception
568 * and put the referenced address to addr.
569 */
570
571 /* sign extend offset */
572 offset = opcode & OFFSET;
573 offset <<= 16;
574 offset >>= 16;
575
576 vaddr = (unsigned long __user *)
577 ((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
578 reg = (opcode & RT) >> 16;
579
580 if ((unsigned long)vaddr & 3)
581 return SIGBUS;
582
583 preempt_disable();
584
585 if (ll_bit == 0 || ll_task != current) {
586 regs->regs[reg] = 0;
587 preempt_enable();
588 return 0;
589 }
590
591 preempt_enable();
592
593 if (put_user(regs->regs[reg], vaddr))
594 return SIGSEGV;
595
596 regs->regs[reg] = 1;
597
598 return 0;
599 }
600
601 /*
602 * ll uses the opcode of lwc0 and sc uses the opcode of swc0. That is both
603 * opcodes are supposed to result in coprocessor unusable exceptions if
604 * executed on ll/sc-less processors. That's the theory. In practice a
605 * few processors such as NEC's VR4100 throw reserved instruction exceptions
606 * instead, so we're doing the emulation thing in both exception handlers.
607 */
simulate_llsc(struct pt_regs * regs,unsigned int opcode)608 static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
609 {
610 if ((opcode & OPCODE) == LL) {
611 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
612 1, regs, 0);
613 return simulate_ll(regs, opcode);
614 }
615 if ((opcode & OPCODE) == SC) {
616 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
617 1, regs, 0);
618 return simulate_sc(regs, opcode);
619 }
620
621 return -1; /* Must be something else ... */
622 }
623
624 /*
625 * Simulate trapping 'rdhwr' instructions to provide user accessible
626 * registers not implemented in hardware.
627 */
simulate_rdhwr(struct pt_regs * regs,int rd,int rt)628 static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
629 {
630 struct thread_info *ti = task_thread_info(current);
631
632 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
633 1, regs, 0);
634 switch (rd) {
635 case MIPS_HWR_CPUNUM: /* CPU number */
636 regs->regs[rt] = smp_processor_id();
637 return 0;
638 case MIPS_HWR_SYNCISTEP: /* SYNCI length */
639 regs->regs[rt] = min(current_cpu_data.dcache.linesz,
640 current_cpu_data.icache.linesz);
641 return 0;
642 case MIPS_HWR_CC: /* Read count register */
643 regs->regs[rt] = read_c0_count();
644 return 0;
645 case MIPS_HWR_CCRES: /* Count register resolution */
646 switch (current_cpu_type()) {
647 case CPU_20KC:
648 case CPU_25KF:
649 regs->regs[rt] = 1;
650 break;
651 default:
652 regs->regs[rt] = 2;
653 }
654 return 0;
655 case MIPS_HWR_ULR: /* Read UserLocal register */
656 regs->regs[rt] = ti->tp_value;
657 return 0;
658 default:
659 return -1;
660 }
661 }
662
simulate_rdhwr_normal(struct pt_regs * regs,unsigned int opcode)663 static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
664 {
665 if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
666 int rd = (opcode & RD) >> 11;
667 int rt = (opcode & RT) >> 16;
668
669 simulate_rdhwr(regs, rd, rt);
670 return 0;
671 }
672
673 /* Not ours. */
674 return -1;
675 }
676
simulate_rdhwr_mm(struct pt_regs * regs,unsigned int opcode)677 static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
678 {
679 if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
680 int rd = (opcode & MM_RS) >> 16;
681 int rt = (opcode & MM_RT) >> 21;
682 simulate_rdhwr(regs, rd, rt);
683 return 0;
684 }
685
686 /* Not ours. */
687 return -1;
688 }
689
simulate_sync(struct pt_regs * regs,unsigned int opcode)690 static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
691 {
692 if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
693 perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
694 1, regs, 0);
695 return 0;
696 }
697
698 return -1; /* Must be something else ... */
699 }
700
do_ov(struct pt_regs * regs)701 asmlinkage void do_ov(struct pt_regs *regs)
702 {
703 enum ctx_state prev_state;
704
705 prev_state = exception_enter();
706 die_if_kernel("Integer overflow", regs);
707
708 force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->cp0_epc);
709 exception_exit(prev_state);
710 }
711
712 #ifdef CONFIG_MIPS_FP_SUPPORT
713
714 /*
715 * Send SIGFPE according to FCSR Cause bits, which must have already
716 * been masked against Enable bits. This is impotant as Inexact can
717 * happen together with Overflow or Underflow, and `ptrace' can set
718 * any bits.
719 */
force_fcr31_sig(unsigned long fcr31,void __user * fault_addr,struct task_struct * tsk)720 void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
721 struct task_struct *tsk)
722 {
723 int si_code = FPE_FLTUNK;
724
725 if (fcr31 & FPU_CSR_INV_X)
726 si_code = FPE_FLTINV;
727 else if (fcr31 & FPU_CSR_DIV_X)
728 si_code = FPE_FLTDIV;
729 else if (fcr31 & FPU_CSR_OVF_X)
730 si_code = FPE_FLTOVF;
731 else if (fcr31 & FPU_CSR_UDF_X)
732 si_code = FPE_FLTUND;
733 else if (fcr31 & FPU_CSR_INE_X)
734 si_code = FPE_FLTRES;
735
736 force_sig_fault_to_task(SIGFPE, si_code, fault_addr, tsk);
737 }
738
process_fpemu_return(int sig,void __user * fault_addr,unsigned long fcr31)739 int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
740 {
741 int si_code;
742 struct vm_area_struct *vma;
743
744 switch (sig) {
745 case 0:
746 return 0;
747
748 case SIGFPE:
749 force_fcr31_sig(fcr31, fault_addr, current);
750 return 1;
751
752 case SIGBUS:
753 force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
754 return 1;
755
756 case SIGSEGV:
757 down_read(¤t->mm->mmap_sem);
758 vma = find_vma(current->mm, (unsigned long)fault_addr);
759 if (vma && (vma->vm_start <= (unsigned long)fault_addr))
760 si_code = SEGV_ACCERR;
761 else
762 si_code = SEGV_MAPERR;
763 up_read(¤t->mm->mmap_sem);
764 force_sig_fault(SIGSEGV, si_code, fault_addr);
765 return 1;
766
767 default:
768 force_sig(sig);
769 return 1;
770 }
771 }
772
simulate_fp(struct pt_regs * regs,unsigned int opcode,unsigned long old_epc,unsigned long old_ra)773 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
774 unsigned long old_epc, unsigned long old_ra)
775 {
776 union mips_instruction inst = { .word = opcode };
777 void __user *fault_addr;
778 unsigned long fcr31;
779 int sig;
780
781 /* If it's obviously not an FP instruction, skip it */
782 switch (inst.i_format.opcode) {
783 case cop1_op:
784 case cop1x_op:
785 case lwc1_op:
786 case ldc1_op:
787 case swc1_op:
788 case sdc1_op:
789 break;
790
791 default:
792 return -1;
793 }
794
795 /*
796 * do_ri skipped over the instruction via compute_return_epc, undo
797 * that for the FPU emulator.
798 */
799 regs->cp0_epc = old_epc;
800 regs->regs[31] = old_ra;
801
802 /* Run the emulator */
803 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
804 &fault_addr);
805
806 /*
807 * We can't allow the emulated instruction to leave any
808 * enabled Cause bits set in $fcr31.
809 */
810 fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
811 current->thread.fpu.fcr31 &= ~fcr31;
812
813 /* Restore the hardware register state */
814 own_fpu(1);
815
816 /* Send a signal if required. */
817 process_fpemu_return(sig, fault_addr, fcr31);
818
819 return 0;
820 }
821
822 /*
823 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
824 */
do_fpe(struct pt_regs * regs,unsigned long fcr31)825 asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
826 {
827 enum ctx_state prev_state;
828 void __user *fault_addr;
829 int sig;
830
831 prev_state = exception_enter();
832 if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
833 SIGFPE) == NOTIFY_STOP)
834 goto out;
835
836 /* Clear FCSR.Cause before enabling interrupts */
837 write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
838 local_irq_enable();
839
840 die_if_kernel("FP exception in kernel code", regs);
841
842 if (fcr31 & FPU_CSR_UNI_X) {
843 /*
844 * Unimplemented operation exception. If we've got the full
845 * software emulator on-board, let's use it...
846 *
847 * Force FPU to dump state into task/thread context. We're
848 * moving a lot of data here for what is probably a single
849 * instruction, but the alternative is to pre-decode the FP
850 * register operands before invoking the emulator, which seems
851 * a bit extreme for what should be an infrequent event.
852 */
853
854 /* Run the emulator */
855 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 1,
856 &fault_addr);
857
858 /*
859 * We can't allow the emulated instruction to leave any
860 * enabled Cause bits set in $fcr31.
861 */
862 fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
863 current->thread.fpu.fcr31 &= ~fcr31;
864
865 /* Restore the hardware register state */
866 own_fpu(1); /* Using the FPU again. */
867 } else {
868 sig = SIGFPE;
869 fault_addr = (void __user *) regs->cp0_epc;
870 }
871
872 /* Send a signal if required. */
873 process_fpemu_return(sig, fault_addr, fcr31);
874
875 out:
876 exception_exit(prev_state);
877 }
878
879 /*
880 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
881 * emulated more than some threshold number of instructions, force migration to
882 * a "CPU" that has FP support.
883 */
mt_ase_fp_affinity(void)884 static void mt_ase_fp_affinity(void)
885 {
886 #ifdef CONFIG_MIPS_MT_FPAFF
887 if (mt_fpemul_threshold > 0 &&
888 ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
889 /*
890 * If there's no FPU present, or if the application has already
891 * restricted the allowed set to exclude any CPUs with FPUs,
892 * we'll skip the procedure.
893 */
894 if (cpumask_intersects(¤t->cpus_mask, &mt_fpu_cpumask)) {
895 cpumask_t tmask;
896
897 current->thread.user_cpus_allowed
898 = current->cpus_mask;
899 cpumask_and(&tmask, ¤t->cpus_mask,
900 &mt_fpu_cpumask);
901 set_cpus_allowed_ptr(current, &tmask);
902 set_thread_flag(TIF_FPUBOUND);
903 }
904 }
905 #endif /* CONFIG_MIPS_MT_FPAFF */
906 }
907
908 #else /* !CONFIG_MIPS_FP_SUPPORT */
909
simulate_fp(struct pt_regs * regs,unsigned int opcode,unsigned long old_epc,unsigned long old_ra)910 static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
911 unsigned long old_epc, unsigned long old_ra)
912 {
913 return -1;
914 }
915
916 #endif /* !CONFIG_MIPS_FP_SUPPORT */
917
do_trap_or_bp(struct pt_regs * regs,unsigned int code,int si_code,const char * str)918 void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
919 const char *str)
920 {
921 char b[40];
922
923 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
924 if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
925 SIGTRAP) == NOTIFY_STOP)
926 return;
927 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
928
929 if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
930 SIGTRAP) == NOTIFY_STOP)
931 return;
932
933 /*
934 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
935 * insns, even for trap and break codes that indicate arithmetic
936 * failures. Weird ...
937 * But should we continue the brokenness??? --macro
938 */
939 switch (code) {
940 case BRK_OVERFLOW:
941 case BRK_DIVZERO:
942 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
943 die_if_kernel(b, regs);
944 force_sig_fault(SIGFPE,
945 code == BRK_DIVZERO ? FPE_INTDIV : FPE_INTOVF,
946 (void __user *) regs->cp0_epc);
947 break;
948 case BRK_BUG:
949 die_if_kernel("Kernel bug detected", regs);
950 force_sig(SIGTRAP);
951 break;
952 case BRK_MEMU:
953 /*
954 * This breakpoint code is used by the FPU emulator to retake
955 * control of the CPU after executing the instruction from the
956 * delay slot of an emulated branch.
957 *
958 * Terminate if exception was recognized as a delay slot return
959 * otherwise handle as normal.
960 */
961 if (do_dsemulret(regs))
962 return;
963
964 die_if_kernel("Math emu break/trap", regs);
965 force_sig(SIGTRAP);
966 break;
967 default:
968 scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
969 die_if_kernel(b, regs);
970 if (si_code) {
971 force_sig_fault(SIGTRAP, si_code, NULL);
972 } else {
973 force_sig(SIGTRAP);
974 }
975 }
976 }
977
do_bp(struct pt_regs * regs)978 asmlinkage void do_bp(struct pt_regs *regs)
979 {
980 unsigned long epc = msk_isa16_mode(exception_epc(regs));
981 unsigned int opcode, bcode;
982 enum ctx_state prev_state;
983 mm_segment_t seg;
984
985 seg = get_fs();
986 if (!user_mode(regs))
987 set_fs(KERNEL_DS);
988
989 prev_state = exception_enter();
990 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
991 if (get_isa16_mode(regs->cp0_epc)) {
992 u16 instr[2];
993
994 if (__get_user(instr[0], (u16 __user *)epc))
995 goto out_sigsegv;
996
997 if (!cpu_has_mmips) {
998 /* MIPS16e mode */
999 bcode = (instr[0] >> 5) & 0x3f;
1000 } else if (mm_insn_16bit(instr[0])) {
1001 /* 16-bit microMIPS BREAK */
1002 bcode = instr[0] & 0xf;
1003 } else {
1004 /* 32-bit microMIPS BREAK */
1005 if (__get_user(instr[1], (u16 __user *)(epc + 2)))
1006 goto out_sigsegv;
1007 opcode = (instr[0] << 16) | instr[1];
1008 bcode = (opcode >> 6) & ((1 << 20) - 1);
1009 }
1010 } else {
1011 if (__get_user(opcode, (unsigned int __user *)epc))
1012 goto out_sigsegv;
1013 bcode = (opcode >> 6) & ((1 << 20) - 1);
1014 }
1015
1016 /*
1017 * There is the ancient bug in the MIPS assemblers that the break
1018 * code starts left to bit 16 instead to bit 6 in the opcode.
1019 * Gas is bug-compatible, but not always, grrr...
1020 * We handle both cases with a simple heuristics. --macro
1021 */
1022 if (bcode >= (1 << 10))
1023 bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
1024
1025 /*
1026 * notify the kprobe handlers, if instruction is likely to
1027 * pertain to them.
1028 */
1029 switch (bcode) {
1030 case BRK_UPROBE:
1031 if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
1032 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1033 goto out;
1034 else
1035 break;
1036 case BRK_UPROBE_XOL:
1037 if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1038 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1039 goto out;
1040 else
1041 break;
1042 case BRK_KPROBE_BP:
1043 if (notify_die(DIE_BREAK, "debug", regs, bcode,
1044 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1045 goto out;
1046 else
1047 break;
1048 case BRK_KPROBE_SSTEPBP:
1049 if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1050 current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1051 goto out;
1052 else
1053 break;
1054 default:
1055 break;
1056 }
1057
1058 do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1059
1060 out:
1061 set_fs(seg);
1062 exception_exit(prev_state);
1063 return;
1064
1065 out_sigsegv:
1066 force_sig(SIGSEGV);
1067 goto out;
1068 }
1069
do_tr(struct pt_regs * regs)1070 asmlinkage void do_tr(struct pt_regs *regs)
1071 {
1072 u32 opcode, tcode = 0;
1073 enum ctx_state prev_state;
1074 u16 instr[2];
1075 mm_segment_t seg;
1076 unsigned long epc = msk_isa16_mode(exception_epc(regs));
1077
1078 seg = get_fs();
1079 if (!user_mode(regs))
1080 set_fs(KERNEL_DS);
1081
1082 prev_state = exception_enter();
1083 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1084 if (get_isa16_mode(regs->cp0_epc)) {
1085 if (__get_user(instr[0], (u16 __user *)(epc + 0)) ||
1086 __get_user(instr[1], (u16 __user *)(epc + 2)))
1087 goto out_sigsegv;
1088 opcode = (instr[0] << 16) | instr[1];
1089 /* Immediate versions don't provide a code. */
1090 if (!(opcode & OPCODE))
1091 tcode = (opcode >> 12) & ((1 << 4) - 1);
1092 } else {
1093 if (__get_user(opcode, (u32 __user *)epc))
1094 goto out_sigsegv;
1095 /* Immediate versions don't provide a code. */
1096 if (!(opcode & OPCODE))
1097 tcode = (opcode >> 6) & ((1 << 10) - 1);
1098 }
1099
1100 do_trap_or_bp(regs, tcode, 0, "Trap");
1101
1102 out:
1103 set_fs(seg);
1104 exception_exit(prev_state);
1105 return;
1106
1107 out_sigsegv:
1108 force_sig(SIGSEGV);
1109 goto out;
1110 }
1111
do_ri(struct pt_regs * regs)1112 asmlinkage void do_ri(struct pt_regs *regs)
1113 {
1114 unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1115 unsigned long old_epc = regs->cp0_epc;
1116 unsigned long old31 = regs->regs[31];
1117 enum ctx_state prev_state;
1118 unsigned int opcode = 0;
1119 int status = -1;
1120
1121 /*
1122 * Avoid any kernel code. Just emulate the R2 instruction
1123 * as quickly as possible.
1124 */
1125 if (mipsr2_emulation && cpu_has_mips_r6 &&
1126 likely(user_mode(regs)) &&
1127 likely(get_user(opcode, epc) >= 0)) {
1128 unsigned long fcr31 = 0;
1129
1130 status = mipsr2_decoder(regs, opcode, &fcr31);
1131 switch (status) {
1132 case 0:
1133 case SIGEMT:
1134 return;
1135 case SIGILL:
1136 goto no_r2_instr;
1137 default:
1138 process_fpemu_return(status,
1139 ¤t->thread.cp0_baduaddr,
1140 fcr31);
1141 return;
1142 }
1143 }
1144
1145 no_r2_instr:
1146
1147 prev_state = exception_enter();
1148 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1149
1150 if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1151 SIGILL) == NOTIFY_STOP)
1152 goto out;
1153
1154 die_if_kernel("Reserved instruction in kernel code", regs);
1155
1156 if (unlikely(compute_return_epc(regs) < 0))
1157 goto out;
1158
1159 if (!get_isa16_mode(regs->cp0_epc)) {
1160 if (unlikely(get_user(opcode, epc) < 0))
1161 status = SIGSEGV;
1162
1163 if (!cpu_has_llsc && status < 0)
1164 status = simulate_llsc(regs, opcode);
1165
1166 if (status < 0)
1167 status = simulate_rdhwr_normal(regs, opcode);
1168
1169 if (status < 0)
1170 status = simulate_sync(regs, opcode);
1171
1172 if (status < 0)
1173 status = simulate_fp(regs, opcode, old_epc, old31);
1174 } else if (cpu_has_mmips) {
1175 unsigned short mmop[2] = { 0 };
1176
1177 if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1178 status = SIGSEGV;
1179 if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1180 status = SIGSEGV;
1181 opcode = mmop[0];
1182 opcode = (opcode << 16) | mmop[1];
1183
1184 if (status < 0)
1185 status = simulate_rdhwr_mm(regs, opcode);
1186 }
1187
1188 if (status < 0)
1189 status = SIGILL;
1190
1191 if (unlikely(status > 0)) {
1192 regs->cp0_epc = old_epc; /* Undo skip-over. */
1193 regs->regs[31] = old31;
1194 force_sig(status);
1195 }
1196
1197 out:
1198 exception_exit(prev_state);
1199 }
1200
1201 /*
1202 * No lock; only written during early bootup by CPU 0.
1203 */
1204 static RAW_NOTIFIER_HEAD(cu2_chain);
1205
register_cu2_notifier(struct notifier_block * nb)1206 int __ref register_cu2_notifier(struct notifier_block *nb)
1207 {
1208 return raw_notifier_chain_register(&cu2_chain, nb);
1209 }
1210
cu2_notifier_call_chain(unsigned long val,void * v)1211 int cu2_notifier_call_chain(unsigned long val, void *v)
1212 {
1213 return raw_notifier_call_chain(&cu2_chain, val, v);
1214 }
1215
default_cu2_call(struct notifier_block * nfb,unsigned long action,void * data)1216 static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1217 void *data)
1218 {
1219 struct pt_regs *regs = data;
1220
1221 die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1222 "instruction", regs);
1223 force_sig(SIGILL);
1224
1225 return NOTIFY_OK;
1226 }
1227
1228 #ifdef CONFIG_MIPS_FP_SUPPORT
1229
enable_restore_fp_context(int msa)1230 static int enable_restore_fp_context(int msa)
1231 {
1232 int err, was_fpu_owner, prior_msa;
1233 bool first_fp;
1234
1235 /* Initialize context if it hasn't been used already */
1236 first_fp = init_fp_ctx(current);
1237
1238 if (first_fp) {
1239 preempt_disable();
1240 err = own_fpu_inatomic(1);
1241 if (msa && !err) {
1242 enable_msa();
1243 /*
1244 * with MSA enabled, userspace can see MSACSR
1245 * and MSA regs, but the values in them are from
1246 * other task before current task, restore them
1247 * from saved fp/msa context
1248 */
1249 write_msa_csr(current->thread.fpu.msacsr);
1250 /*
1251 * own_fpu_inatomic(1) just restore low 64bit,
1252 * fix the high 64bit
1253 */
1254 init_msa_upper();
1255 set_thread_flag(TIF_USEDMSA);
1256 set_thread_flag(TIF_MSA_CTX_LIVE);
1257 }
1258 preempt_enable();
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 #else /* !CONFIG_MIPS_FP_SUPPORT */
1350
enable_restore_fp_context(int msa)1351 static int enable_restore_fp_context(int msa)
1352 {
1353 return SIGILL;
1354 }
1355
1356 #endif /* CONFIG_MIPS_FP_SUPPORT */
1357
do_cpu(struct pt_regs * regs)1358 asmlinkage void do_cpu(struct pt_regs *regs)
1359 {
1360 enum ctx_state prev_state;
1361 unsigned int __user *epc;
1362 unsigned long old_epc, old31;
1363 unsigned int opcode;
1364 unsigned int cpid;
1365 int status;
1366
1367 prev_state = exception_enter();
1368 cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1369
1370 if (cpid != 2)
1371 die_if_kernel("do_cpu invoked from kernel context!", regs);
1372
1373 switch (cpid) {
1374 case 0:
1375 epc = (unsigned int __user *)exception_epc(regs);
1376 old_epc = regs->cp0_epc;
1377 old31 = regs->regs[31];
1378 opcode = 0;
1379 status = -1;
1380
1381 if (unlikely(compute_return_epc(regs) < 0))
1382 break;
1383
1384 if (!get_isa16_mode(regs->cp0_epc)) {
1385 if (unlikely(get_user(opcode, epc) < 0))
1386 status = SIGSEGV;
1387
1388 if (!cpu_has_llsc && status < 0)
1389 status = simulate_llsc(regs, opcode);
1390 }
1391
1392 if (status < 0)
1393 status = SIGILL;
1394
1395 if (unlikely(status > 0)) {
1396 regs->cp0_epc = old_epc; /* Undo skip-over. */
1397 regs->regs[31] = old31;
1398 force_sig(status);
1399 }
1400
1401 break;
1402
1403 #ifdef CONFIG_MIPS_FP_SUPPORT
1404 case 3:
1405 /*
1406 * The COP3 opcode space and consequently the CP0.Status.CU3
1407 * bit and the CP0.Cause.CE=3 encoding have been removed as
1408 * of the MIPS III ISA. From the MIPS IV and MIPS32r2 ISAs
1409 * up the space has been reused for COP1X instructions, that
1410 * are enabled by the CP0.Status.CU1 bit and consequently
1411 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1412 * exceptions. Some FPU-less processors that implement one
1413 * of these ISAs however use this code erroneously for COP1X
1414 * instructions. Therefore we redirect this trap to the FP
1415 * emulator too.
1416 */
1417 if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1418 force_sig(SIGILL);
1419 break;
1420 }
1421 /* Fall through. */
1422
1423 case 1: {
1424 void __user *fault_addr;
1425 unsigned long fcr31;
1426 int err, sig;
1427
1428 err = enable_restore_fp_context(0);
1429
1430 if (raw_cpu_has_fpu && !err)
1431 break;
1432
1433 sig = fpu_emulator_cop1Handler(regs, ¤t->thread.fpu, 0,
1434 &fault_addr);
1435
1436 /*
1437 * We can't allow the emulated instruction to leave
1438 * any enabled Cause bits set in $fcr31.
1439 */
1440 fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
1441 current->thread.fpu.fcr31 &= ~fcr31;
1442
1443 /* Send a signal if required. */
1444 if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1445 mt_ase_fp_affinity();
1446
1447 break;
1448 }
1449 #else /* CONFIG_MIPS_FP_SUPPORT */
1450 case 1:
1451 case 3:
1452 force_sig(SIGILL);
1453 break;
1454 #endif /* CONFIG_MIPS_FP_SUPPORT */
1455
1456 case 2:
1457 raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1458 break;
1459 }
1460
1461 exception_exit(prev_state);
1462 }
1463
do_msa_fpe(struct pt_regs * regs,unsigned int msacsr)1464 asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1465 {
1466 enum ctx_state prev_state;
1467
1468 prev_state = exception_enter();
1469 current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1470 if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1471 current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1472 goto out;
1473
1474 /* Clear MSACSR.Cause before enabling interrupts */
1475 write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1476 local_irq_enable();
1477
1478 die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1479 force_sig(SIGFPE);
1480 out:
1481 exception_exit(prev_state);
1482 }
1483
do_msa(struct pt_regs * regs)1484 asmlinkage void do_msa(struct pt_regs *regs)
1485 {
1486 enum ctx_state prev_state;
1487 int err;
1488
1489 prev_state = exception_enter();
1490
1491 if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1492 force_sig(SIGILL);
1493 goto out;
1494 }
1495
1496 die_if_kernel("do_msa invoked from kernel context!", regs);
1497
1498 err = enable_restore_fp_context(1);
1499 if (err)
1500 force_sig(SIGILL);
1501 out:
1502 exception_exit(prev_state);
1503 }
1504
do_mdmx(struct pt_regs * regs)1505 asmlinkage void do_mdmx(struct pt_regs *regs)
1506 {
1507 enum ctx_state prev_state;
1508
1509 prev_state = exception_enter();
1510 force_sig(SIGILL);
1511 exception_exit(prev_state);
1512 }
1513
1514 /*
1515 * Called with interrupts disabled.
1516 */
do_watch(struct pt_regs * regs)1517 asmlinkage void do_watch(struct pt_regs *regs)
1518 {
1519 enum ctx_state prev_state;
1520
1521 prev_state = exception_enter();
1522 /*
1523 * Clear WP (bit 22) bit of cause register so we don't loop
1524 * forever.
1525 */
1526 clear_c0_cause(CAUSEF_WP);
1527
1528 /*
1529 * If the current thread has the watch registers loaded, save
1530 * their values and send SIGTRAP. Otherwise another thread
1531 * left the registers set, clear them and continue.
1532 */
1533 if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1534 mips_read_watch_registers();
1535 local_irq_enable();
1536 force_sig_fault(SIGTRAP, TRAP_HWBKPT, NULL);
1537 } else {
1538 mips_clear_watch_registers();
1539 local_irq_enable();
1540 }
1541 exception_exit(prev_state);
1542 }
1543
do_mcheck(struct pt_regs * regs)1544 asmlinkage void do_mcheck(struct pt_regs *regs)
1545 {
1546 int multi_match = regs->cp0_status & ST0_TS;
1547 enum ctx_state prev_state;
1548 mm_segment_t old_fs = get_fs();
1549
1550 prev_state = exception_enter();
1551 show_regs(regs);
1552
1553 if (multi_match) {
1554 dump_tlb_regs();
1555 pr_info("\n");
1556 dump_tlb_all();
1557 }
1558
1559 if (!user_mode(regs))
1560 set_fs(KERNEL_DS);
1561
1562 show_code((unsigned int __user *) regs->cp0_epc);
1563
1564 set_fs(old_fs);
1565
1566 /*
1567 * Some chips may have other causes of machine check (e.g. SB1
1568 * graduation timer)
1569 */
1570 panic("Caught Machine Check exception - %scaused by multiple "
1571 "matching entries in the TLB.",
1572 (multi_match) ? "" : "not ");
1573 }
1574
do_mt(struct pt_regs * regs)1575 asmlinkage void do_mt(struct pt_regs *regs)
1576 {
1577 int subcode;
1578
1579 subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1580 >> VPECONTROL_EXCPT_SHIFT;
1581 switch (subcode) {
1582 case 0:
1583 printk(KERN_DEBUG "Thread Underflow\n");
1584 break;
1585 case 1:
1586 printk(KERN_DEBUG "Thread Overflow\n");
1587 break;
1588 case 2:
1589 printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1590 break;
1591 case 3:
1592 printk(KERN_DEBUG "Gating Storage Exception\n");
1593 break;
1594 case 4:
1595 printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1596 break;
1597 case 5:
1598 printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1599 break;
1600 default:
1601 printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1602 subcode);
1603 break;
1604 }
1605 die_if_kernel("MIPS MT Thread exception in kernel", regs);
1606
1607 force_sig(SIGILL);
1608 }
1609
1610
do_dsp(struct pt_regs * regs)1611 asmlinkage void do_dsp(struct pt_regs *regs)
1612 {
1613 if (cpu_has_dsp)
1614 panic("Unexpected DSP exception");
1615
1616 force_sig(SIGILL);
1617 }
1618
do_reserved(struct pt_regs * regs)1619 asmlinkage void do_reserved(struct pt_regs *regs)
1620 {
1621 /*
1622 * Game over - no way to handle this if it ever occurs. Most probably
1623 * caused by a new unknown cpu type or after another deadly
1624 * hard/software error.
1625 */
1626 show_regs(regs);
1627 panic("Caught reserved exception %ld - should not happen.",
1628 (regs->cp0_cause & 0x7f) >> 2);
1629 }
1630
1631 static int __initdata l1parity = 1;
nol1parity(char * s)1632 static int __init nol1parity(char *s)
1633 {
1634 l1parity = 0;
1635 return 1;
1636 }
1637 __setup("nol1par", nol1parity);
1638 static int __initdata l2parity = 1;
nol2parity(char * s)1639 static int __init nol2parity(char *s)
1640 {
1641 l2parity = 0;
1642 return 1;
1643 }
1644 __setup("nol2par", nol2parity);
1645
1646 /*
1647 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1648 * it different ways.
1649 */
parity_protection_init(void)1650 static inline void parity_protection_init(void)
1651 {
1652 #define ERRCTL_PE 0x80000000
1653 #define ERRCTL_L2P 0x00800000
1654
1655 if (mips_cm_revision() >= CM_REV_CM3) {
1656 ulong gcr_ectl, cp0_ectl;
1657
1658 /*
1659 * With CM3 systems we need to ensure that the L1 & L2
1660 * parity enables are set to the same value, since this
1661 * is presumed by the hardware engineers.
1662 *
1663 * If the user disabled either of L1 or L2 ECC checking,
1664 * disable both.
1665 */
1666 l1parity &= l2parity;
1667 l2parity &= l1parity;
1668
1669 /* Probe L1 ECC support */
1670 cp0_ectl = read_c0_ecc();
1671 write_c0_ecc(cp0_ectl | ERRCTL_PE);
1672 back_to_back_c0_hazard();
1673 cp0_ectl = read_c0_ecc();
1674
1675 /* Probe L2 ECC support */
1676 gcr_ectl = read_gcr_err_control();
1677
1678 if (!(gcr_ectl & CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT) ||
1679 !(cp0_ectl & ERRCTL_PE)) {
1680 /*
1681 * One of L1 or L2 ECC checking isn't supported,
1682 * so we cannot enable either.
1683 */
1684 l1parity = l2parity = 0;
1685 }
1686
1687 /* Configure L1 ECC checking */
1688 if (l1parity)
1689 cp0_ectl |= ERRCTL_PE;
1690 else
1691 cp0_ectl &= ~ERRCTL_PE;
1692 write_c0_ecc(cp0_ectl);
1693 back_to_back_c0_hazard();
1694 WARN_ON(!!(read_c0_ecc() & ERRCTL_PE) != l1parity);
1695
1696 /* Configure L2 ECC checking */
1697 if (l2parity)
1698 gcr_ectl |= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1699 else
1700 gcr_ectl &= ~CM_GCR_ERR_CONTROL_L2_ECC_EN;
1701 write_gcr_err_control(gcr_ectl);
1702 gcr_ectl = read_gcr_err_control();
1703 gcr_ectl &= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1704 WARN_ON(!!gcr_ectl != l2parity);
1705
1706 pr_info("Cache parity protection %sabled\n",
1707 l1parity ? "en" : "dis");
1708 return;
1709 }
1710
1711 switch (current_cpu_type()) {
1712 case CPU_24K:
1713 case CPU_34K:
1714 case CPU_74K:
1715 case CPU_1004K:
1716 case CPU_1074K:
1717 case CPU_INTERAPTIV:
1718 case CPU_PROAPTIV:
1719 case CPU_P5600:
1720 case CPU_QEMU_GENERIC:
1721 case CPU_P6600:
1722 {
1723 unsigned long errctl;
1724 unsigned int l1parity_present, l2parity_present;
1725
1726 errctl = read_c0_ecc();
1727 errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1728
1729 /* probe L1 parity support */
1730 write_c0_ecc(errctl | ERRCTL_PE);
1731 back_to_back_c0_hazard();
1732 l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1733
1734 /* probe L2 parity support */
1735 write_c0_ecc(errctl|ERRCTL_L2P);
1736 back_to_back_c0_hazard();
1737 l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1738
1739 if (l1parity_present && l2parity_present) {
1740 if (l1parity)
1741 errctl |= ERRCTL_PE;
1742 if (l1parity ^ l2parity)
1743 errctl |= ERRCTL_L2P;
1744 } else if (l1parity_present) {
1745 if (l1parity)
1746 errctl |= ERRCTL_PE;
1747 } else if (l2parity_present) {
1748 if (l2parity)
1749 errctl |= ERRCTL_L2P;
1750 } else {
1751 /* No parity available */
1752 }
1753
1754 printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1755
1756 write_c0_ecc(errctl);
1757 back_to_back_c0_hazard();
1758 errctl = read_c0_ecc();
1759 printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1760
1761 if (l1parity_present)
1762 printk(KERN_INFO "Cache parity protection %sabled\n",
1763 (errctl & ERRCTL_PE) ? "en" : "dis");
1764
1765 if (l2parity_present) {
1766 if (l1parity_present && l1parity)
1767 errctl ^= ERRCTL_L2P;
1768 printk(KERN_INFO "L2 cache parity protection %sabled\n",
1769 (errctl & ERRCTL_L2P) ? "en" : "dis");
1770 }
1771 }
1772 break;
1773
1774 case CPU_5KC:
1775 case CPU_5KE:
1776 case CPU_LOONGSON1:
1777 write_c0_ecc(0x80000000);
1778 back_to_back_c0_hazard();
1779 /* Set the PE bit (bit 31) in the c0_errctl register. */
1780 printk(KERN_INFO "Cache parity protection %sabled\n",
1781 (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1782 break;
1783 case CPU_20KC:
1784 case CPU_25KF:
1785 /* Clear the DE bit (bit 16) in the c0_status register. */
1786 printk(KERN_INFO "Enable cache parity protection for "
1787 "MIPS 20KC/25KF CPUs.\n");
1788 clear_c0_status(ST0_DE);
1789 break;
1790 default:
1791 break;
1792 }
1793 }
1794
cache_parity_error(void)1795 asmlinkage void cache_parity_error(void)
1796 {
1797 const int field = 2 * sizeof(unsigned long);
1798 unsigned int reg_val;
1799
1800 /* For the moment, report the problem and hang. */
1801 printk("Cache error exception:\n");
1802 printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1803 reg_val = read_c0_cacheerr();
1804 printk("c0_cacheerr == %08x\n", reg_val);
1805
1806 printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1807 reg_val & (1<<30) ? "secondary" : "primary",
1808 reg_val & (1<<31) ? "data" : "insn");
1809 if ((cpu_has_mips_r2_r6) &&
1810 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1811 pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1812 reg_val & (1<<29) ? "ED " : "",
1813 reg_val & (1<<28) ? "ET " : "",
1814 reg_val & (1<<27) ? "ES " : "",
1815 reg_val & (1<<26) ? "EE " : "",
1816 reg_val & (1<<25) ? "EB " : "",
1817 reg_val & (1<<24) ? "EI " : "",
1818 reg_val & (1<<23) ? "E1 " : "",
1819 reg_val & (1<<22) ? "E0 " : "");
1820 } else {
1821 pr_err("Error bits: %s%s%s%s%s%s%s\n",
1822 reg_val & (1<<29) ? "ED " : "",
1823 reg_val & (1<<28) ? "ET " : "",
1824 reg_val & (1<<26) ? "EE " : "",
1825 reg_val & (1<<25) ? "EB " : "",
1826 reg_val & (1<<24) ? "EI " : "",
1827 reg_val & (1<<23) ? "E1 " : "",
1828 reg_val & (1<<22) ? "E0 " : "");
1829 }
1830 printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1831
1832 #if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1833 if (reg_val & (1<<22))
1834 printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1835
1836 if (reg_val & (1<<23))
1837 printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1838 #endif
1839
1840 panic("Can't handle the cache error!");
1841 }
1842
do_ftlb(void)1843 asmlinkage void do_ftlb(void)
1844 {
1845 const int field = 2 * sizeof(unsigned long);
1846 unsigned int reg_val;
1847
1848 /* For the moment, report the problem and hang. */
1849 if ((cpu_has_mips_r2_r6) &&
1850 (((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
1851 ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
1852 pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1853 read_c0_ecc());
1854 pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1855 reg_val = read_c0_cacheerr();
1856 pr_err("c0_cacheerr == %08x\n", reg_val);
1857
1858 if ((reg_val & 0xc0000000) == 0xc0000000) {
1859 pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1860 } else {
1861 pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1862 reg_val & (1<<30) ? "secondary" : "primary",
1863 reg_val & (1<<31) ? "data" : "insn");
1864 }
1865 } else {
1866 pr_err("FTLB error exception\n");
1867 }
1868 /* Just print the cacheerr bits for now */
1869 cache_parity_error();
1870 }
1871
1872 /*
1873 * SDBBP EJTAG debug exception handler.
1874 * We skip the instruction and return to the next instruction.
1875 */
ejtag_exception_handler(struct pt_regs * regs)1876 void ejtag_exception_handler(struct pt_regs *regs)
1877 {
1878 const int field = 2 * sizeof(unsigned long);
1879 unsigned long depc, old_epc, old_ra;
1880 unsigned int debug;
1881
1882 printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1883 depc = read_c0_depc();
1884 debug = read_c0_debug();
1885 printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1886 if (debug & 0x80000000) {
1887 /*
1888 * In branch delay slot.
1889 * We cheat a little bit here and use EPC to calculate the
1890 * debug return address (DEPC). EPC is restored after the
1891 * calculation.
1892 */
1893 old_epc = regs->cp0_epc;
1894 old_ra = regs->regs[31];
1895 regs->cp0_epc = depc;
1896 compute_return_epc(regs);
1897 depc = regs->cp0_epc;
1898 regs->cp0_epc = old_epc;
1899 regs->regs[31] = old_ra;
1900 } else
1901 depc += 4;
1902 write_c0_depc(depc);
1903
1904 #if 0
1905 printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1906 write_c0_debug(debug | 0x100);
1907 #endif
1908 }
1909
1910 /*
1911 * NMI exception handler.
1912 * No lock; only written during early bootup by CPU 0.
1913 */
1914 static RAW_NOTIFIER_HEAD(nmi_chain);
1915
register_nmi_notifier(struct notifier_block * nb)1916 int register_nmi_notifier(struct notifier_block *nb)
1917 {
1918 return raw_notifier_chain_register(&nmi_chain, nb);
1919 }
1920
nmi_exception_handler(struct pt_regs * regs)1921 void __noreturn nmi_exception_handler(struct pt_regs *regs)
1922 {
1923 char str[100];
1924
1925 nmi_enter();
1926 raw_notifier_call_chain(&nmi_chain, 0, regs);
1927 bust_spinlocks(1);
1928 snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1929 smp_processor_id(), regs->cp0_epc);
1930 regs->cp0_epc = read_c0_errorepc();
1931 die(str, regs);
1932 nmi_exit();
1933 }
1934
1935 #define VECTORSPACING 0x100 /* for EI/VI mode */
1936
1937 unsigned long ebase;
1938 EXPORT_SYMBOL_GPL(ebase);
1939 unsigned long exception_handlers[32];
1940 unsigned long vi_handlers[64];
1941
set_except_vector(int n,void * addr)1942 void __init *set_except_vector(int n, void *addr)
1943 {
1944 unsigned long handler = (unsigned long) addr;
1945 unsigned long old_handler;
1946
1947 #ifdef CONFIG_CPU_MICROMIPS
1948 /*
1949 * Only the TLB handlers are cache aligned with an even
1950 * address. All other handlers are on an odd address and
1951 * require no modification. Otherwise, MIPS32 mode will
1952 * be entered when handling any TLB exceptions. That
1953 * would be bad...since we must stay in microMIPS mode.
1954 */
1955 if (!(handler & 0x1))
1956 handler |= 1;
1957 #endif
1958 old_handler = xchg(&exception_handlers[n], handler);
1959
1960 if (n == 0 && cpu_has_divec) {
1961 #ifdef CONFIG_CPU_MICROMIPS
1962 unsigned long jump_mask = ~((1 << 27) - 1);
1963 #else
1964 unsigned long jump_mask = ~((1 << 28) - 1);
1965 #endif
1966 u32 *buf = (u32 *)(ebase + 0x200);
1967 unsigned int k0 = 26;
1968 if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
1969 uasm_i_j(&buf, handler & ~jump_mask);
1970 uasm_i_nop(&buf);
1971 } else {
1972 UASM_i_LA(&buf, k0, handler);
1973 uasm_i_jr(&buf, k0);
1974 uasm_i_nop(&buf);
1975 }
1976 local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
1977 }
1978 return (void *)old_handler;
1979 }
1980
do_default_vi(void)1981 static void do_default_vi(void)
1982 {
1983 show_regs(get_irq_regs());
1984 panic("Caught unexpected vectored interrupt.");
1985 }
1986
set_vi_srs_handler(int n,vi_handler_t addr,int srs)1987 static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
1988 {
1989 unsigned long handler;
1990 unsigned long old_handler = vi_handlers[n];
1991 int srssets = current_cpu_data.srsets;
1992 u16 *h;
1993 unsigned char *b;
1994
1995 BUG_ON(!cpu_has_veic && !cpu_has_vint);
1996
1997 if (addr == NULL) {
1998 handler = (unsigned long) do_default_vi;
1999 srs = 0;
2000 } else
2001 handler = (unsigned long) addr;
2002 vi_handlers[n] = handler;
2003
2004 b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
2005
2006 if (srs >= srssets)
2007 panic("Shadow register set %d not supported", srs);
2008
2009 if (cpu_has_veic) {
2010 if (board_bind_eic_interrupt)
2011 board_bind_eic_interrupt(n, srs);
2012 } else if (cpu_has_vint) {
2013 /* SRSMap is only defined if shadow sets are implemented */
2014 if (srssets > 1)
2015 change_c0_srsmap(0xf << n*4, srs << n*4);
2016 }
2017
2018 if (srs == 0) {
2019 /*
2020 * If no shadow set is selected then use the default handler
2021 * that does normal register saving and standard interrupt exit
2022 */
2023 extern const u8 except_vec_vi[], except_vec_vi_lui[];
2024 extern const u8 except_vec_vi_ori[], except_vec_vi_end[];
2025 extern const u8 rollback_except_vec_vi[];
2026 const u8 *vec_start = using_rollback_handler() ?
2027 rollback_except_vec_vi : except_vec_vi;
2028 #if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
2029 const int lui_offset = except_vec_vi_lui - vec_start + 2;
2030 const int ori_offset = except_vec_vi_ori - vec_start + 2;
2031 #else
2032 const int lui_offset = except_vec_vi_lui - vec_start;
2033 const int ori_offset = except_vec_vi_ori - vec_start;
2034 #endif
2035 const int handler_len = except_vec_vi_end - vec_start;
2036
2037 if (handler_len > VECTORSPACING) {
2038 /*
2039 * Sigh... panicing won't help as the console
2040 * is probably not configured :(
2041 */
2042 panic("VECTORSPACING too small");
2043 }
2044
2045 set_handler(((unsigned long)b - ebase), vec_start,
2046 #ifdef CONFIG_CPU_MICROMIPS
2047 (handler_len - 1));
2048 #else
2049 handler_len);
2050 #endif
2051 h = (u16 *)(b + lui_offset);
2052 *h = (handler >> 16) & 0xffff;
2053 h = (u16 *)(b + ori_offset);
2054 *h = (handler & 0xffff);
2055 local_flush_icache_range((unsigned long)b,
2056 (unsigned long)(b+handler_len));
2057 }
2058 else {
2059 /*
2060 * In other cases jump directly to the interrupt handler. It
2061 * is the handler's responsibility to save registers if required
2062 * (eg hi/lo) and return from the exception using "eret".
2063 */
2064 u32 insn;
2065
2066 h = (u16 *)b;
2067 /* j handler */
2068 #ifdef CONFIG_CPU_MICROMIPS
2069 insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
2070 #else
2071 insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2072 #endif
2073 h[0] = (insn >> 16) & 0xffff;
2074 h[1] = insn & 0xffff;
2075 h[2] = 0;
2076 h[3] = 0;
2077 local_flush_icache_range((unsigned long)b,
2078 (unsigned long)(b+8));
2079 }
2080
2081 return (void *)old_handler;
2082 }
2083
set_vi_handler(int n,vi_handler_t addr)2084 void *set_vi_handler(int n, vi_handler_t addr)
2085 {
2086 return set_vi_srs_handler(n, addr, 0);
2087 }
2088
2089 extern void tlb_init(void);
2090
2091 /*
2092 * Timer interrupt
2093 */
2094 int cp0_compare_irq;
2095 EXPORT_SYMBOL_GPL(cp0_compare_irq);
2096 int cp0_compare_irq_shift;
2097
2098 /*
2099 * Performance counter IRQ or -1 if shared with timer
2100 */
2101 int cp0_perfcount_irq;
2102 EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2103
2104 /*
2105 * Fast debug channel IRQ or -1 if not present
2106 */
2107 int cp0_fdc_irq;
2108 EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2109
2110 static int noulri;
2111
ulri_disable(char * s)2112 static int __init ulri_disable(char *s)
2113 {
2114 pr_info("Disabling ulri\n");
2115 noulri = 1;
2116
2117 return 1;
2118 }
2119 __setup("noulri", ulri_disable);
2120
2121 /* configure STATUS register */
configure_status(void)2122 static void configure_status(void)
2123 {
2124 /*
2125 * Disable coprocessors and select 32-bit or 64-bit addressing
2126 * and the 16/32 or 32/32 FPR register model. Reset the BEV
2127 * flag that some firmware may have left set and the TS bit (for
2128 * IP27). Set XX for ISA IV code to work.
2129 */
2130 unsigned int status_set = ST0_CU0;
2131 #ifdef CONFIG_64BIT
2132 status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2133 #endif
2134 if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2135 status_set |= ST0_XX;
2136 if (cpu_has_dsp)
2137 status_set |= ST0_MX;
2138
2139 change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2140 status_set);
2141 back_to_back_c0_hazard();
2142 }
2143
2144 unsigned int hwrena;
2145 EXPORT_SYMBOL_GPL(hwrena);
2146
2147 /* configure HWRENA register */
configure_hwrena(void)2148 static void configure_hwrena(void)
2149 {
2150 hwrena = cpu_hwrena_impl_bits;
2151
2152 if (cpu_has_mips_r2_r6)
2153 hwrena |= MIPS_HWRENA_CPUNUM |
2154 MIPS_HWRENA_SYNCISTEP |
2155 MIPS_HWRENA_CC |
2156 MIPS_HWRENA_CCRES;
2157
2158 if (!noulri && cpu_has_userlocal)
2159 hwrena |= MIPS_HWRENA_ULR;
2160
2161 if (hwrena)
2162 write_c0_hwrena(hwrena);
2163 }
2164
configure_exception_vector(void)2165 static void configure_exception_vector(void)
2166 {
2167 if (cpu_has_mips_r2_r6) {
2168 unsigned long sr = set_c0_status(ST0_BEV);
2169 /* If available, use WG to set top bits of EBASE */
2170 if (cpu_has_ebase_wg) {
2171 #ifdef CONFIG_64BIT
2172 write_c0_ebase_64(ebase | MIPS_EBASE_WG);
2173 #else
2174 write_c0_ebase(ebase | MIPS_EBASE_WG);
2175 #endif
2176 }
2177 write_c0_ebase(ebase);
2178 write_c0_status(sr);
2179 }
2180 if (cpu_has_veic || cpu_has_vint) {
2181 /* Setting vector spacing enables EI/VI mode */
2182 change_c0_intctl(0x3e0, VECTORSPACING);
2183 }
2184 if (cpu_has_divec) {
2185 if (cpu_has_mipsmt) {
2186 unsigned int vpflags = dvpe();
2187 set_c0_cause(CAUSEF_IV);
2188 evpe(vpflags);
2189 } else
2190 set_c0_cause(CAUSEF_IV);
2191 }
2192 }
2193
per_cpu_trap_init(bool is_boot_cpu)2194 void per_cpu_trap_init(bool is_boot_cpu)
2195 {
2196 unsigned int cpu = smp_processor_id();
2197
2198 configure_status();
2199 configure_hwrena();
2200
2201 configure_exception_vector();
2202
2203 /*
2204 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2205 *
2206 * o read IntCtl.IPTI to determine the timer interrupt
2207 * o read IntCtl.IPPCI to determine the performance counter interrupt
2208 * o read IntCtl.IPFDC to determine the fast debug channel interrupt
2209 */
2210 if (cpu_has_mips_r2_r6) {
2211 cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2212 cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2213 cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2214 cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2215 if (!cp0_fdc_irq)
2216 cp0_fdc_irq = -1;
2217
2218 } else {
2219 cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2220 cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2221 cp0_perfcount_irq = -1;
2222 cp0_fdc_irq = -1;
2223 }
2224
2225 if (cpu_has_mmid)
2226 cpu_data[cpu].asid_cache = 0;
2227 else if (!cpu_data[cpu].asid_cache)
2228 cpu_data[cpu].asid_cache = asid_first_version(cpu);
2229
2230 mmgrab(&init_mm);
2231 current->active_mm = &init_mm;
2232 BUG_ON(current->mm);
2233 enter_lazy_tlb(&init_mm, current);
2234
2235 /* Boot CPU's cache setup in setup_arch(). */
2236 if (!is_boot_cpu)
2237 cpu_cache_init();
2238 tlb_init();
2239 TLBMISS_HANDLER_SETUP();
2240 }
2241
2242 /* Install CPU exception handler */
set_handler(unsigned long offset,const void * addr,unsigned long size)2243 void set_handler(unsigned long offset, const void *addr, unsigned long size)
2244 {
2245 #ifdef CONFIG_CPU_MICROMIPS
2246 memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2247 #else
2248 memcpy((void *)(ebase + offset), addr, size);
2249 #endif
2250 local_flush_icache_range(ebase + offset, ebase + offset + size);
2251 }
2252
2253 static const char panic_null_cerr[] =
2254 "Trying to set NULL cache error exception handler\n";
2255
2256 /*
2257 * Install uncached CPU exception handler.
2258 * This is suitable only for the cache error exception which is the only
2259 * exception handler that is being run uncached.
2260 */
set_uncached_handler(unsigned long offset,void * addr,unsigned long size)2261 void set_uncached_handler(unsigned long offset, void *addr,
2262 unsigned long size)
2263 {
2264 unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2265
2266 if (!addr)
2267 panic(panic_null_cerr);
2268
2269 memcpy((void *)(uncached_ebase + offset), addr, size);
2270 }
2271
2272 static int __initdata rdhwr_noopt;
set_rdhwr_noopt(char * str)2273 static int __init set_rdhwr_noopt(char *str)
2274 {
2275 rdhwr_noopt = 1;
2276 return 1;
2277 }
2278
2279 __setup("rdhwr_noopt", set_rdhwr_noopt);
2280
trap_init(void)2281 void __init trap_init(void)
2282 {
2283 extern char except_vec3_generic;
2284 extern char except_vec4;
2285 extern char except_vec3_r4000;
2286 unsigned long i, vec_size;
2287 phys_addr_t ebase_pa;
2288
2289 check_wait();
2290
2291 if (!cpu_has_mips_r2_r6) {
2292 ebase = CAC_BASE;
2293 ebase_pa = virt_to_phys((void *)ebase);
2294 vec_size = 0x400;
2295
2296 memblock_reserve(ebase_pa, vec_size);
2297 } else {
2298 if (cpu_has_veic || cpu_has_vint)
2299 vec_size = 0x200 + VECTORSPACING*64;
2300 else
2301 vec_size = PAGE_SIZE;
2302
2303 ebase_pa = memblock_phys_alloc(vec_size, 1 << fls(vec_size));
2304 if (!ebase_pa)
2305 panic("%s: Failed to allocate %lu bytes align=0x%x\n",
2306 __func__, vec_size, 1 << fls(vec_size));
2307
2308 /*
2309 * Try to ensure ebase resides in KSeg0 if possible.
2310 *
2311 * It shouldn't generally be in XKPhys on MIPS64 to avoid
2312 * hitting a poorly defined exception base for Cache Errors.
2313 * The allocation is likely to be in the low 512MB of physical,
2314 * in which case we should be able to convert to KSeg0.
2315 *
2316 * EVA is special though as it allows segments to be rearranged
2317 * and to become uncached during cache error handling.
2318 */
2319 if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
2320 ebase = CKSEG0ADDR(ebase_pa);
2321 else
2322 ebase = (unsigned long)phys_to_virt(ebase_pa);
2323 }
2324
2325 if (cpu_has_mmips) {
2326 unsigned int config3 = read_c0_config3();
2327
2328 if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2329 write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2330 else
2331 write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2332 }
2333
2334 if (board_ebase_setup)
2335 board_ebase_setup();
2336 per_cpu_trap_init(true);
2337 memblock_set_bottom_up(false);
2338
2339 /*
2340 * Copy the generic exception handlers to their final destination.
2341 * This will be overridden later as suitable for a particular
2342 * configuration.
2343 */
2344 set_handler(0x180, &except_vec3_generic, 0x80);
2345
2346 /*
2347 * Setup default vectors
2348 */
2349 for (i = 0; i <= 31; i++)
2350 set_except_vector(i, handle_reserved);
2351
2352 /*
2353 * Copy the EJTAG debug exception vector handler code to it's final
2354 * destination.
2355 */
2356 if (cpu_has_ejtag && board_ejtag_handler_setup)
2357 board_ejtag_handler_setup();
2358
2359 /*
2360 * Only some CPUs have the watch exceptions.
2361 */
2362 if (cpu_has_watch)
2363 set_except_vector(EXCCODE_WATCH, handle_watch);
2364
2365 /*
2366 * Initialise interrupt handlers
2367 */
2368 if (cpu_has_veic || cpu_has_vint) {
2369 int nvec = cpu_has_veic ? 64 : 8;
2370 for (i = 0; i < nvec; i++)
2371 set_vi_handler(i, NULL);
2372 }
2373 else if (cpu_has_divec)
2374 set_handler(0x200, &except_vec4, 0x8);
2375
2376 /*
2377 * Some CPUs can enable/disable for cache parity detection, but does
2378 * it different ways.
2379 */
2380 parity_protection_init();
2381
2382 /*
2383 * The Data Bus Errors / Instruction Bus Errors are signaled
2384 * by external hardware. Therefore these two exceptions
2385 * may have board specific handlers.
2386 */
2387 if (board_be_init)
2388 board_be_init();
2389
2390 set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2391 rollback_handle_int : handle_int);
2392 set_except_vector(EXCCODE_MOD, handle_tlbm);
2393 set_except_vector(EXCCODE_TLBL, handle_tlbl);
2394 set_except_vector(EXCCODE_TLBS, handle_tlbs);
2395
2396 set_except_vector(EXCCODE_ADEL, handle_adel);
2397 set_except_vector(EXCCODE_ADES, handle_ades);
2398
2399 set_except_vector(EXCCODE_IBE, handle_ibe);
2400 set_except_vector(EXCCODE_DBE, handle_dbe);
2401
2402 set_except_vector(EXCCODE_SYS, handle_sys);
2403 set_except_vector(EXCCODE_BP, handle_bp);
2404
2405 if (rdhwr_noopt)
2406 set_except_vector(EXCCODE_RI, handle_ri);
2407 else {
2408 if (cpu_has_vtag_icache)
2409 set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2410 else if (current_cpu_type() == CPU_LOONGSON3)
2411 set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2412 else
2413 set_except_vector(EXCCODE_RI, handle_ri_rdhwr);
2414 }
2415
2416 set_except_vector(EXCCODE_CPU, handle_cpu);
2417 set_except_vector(EXCCODE_OV, handle_ov);
2418 set_except_vector(EXCCODE_TR, handle_tr);
2419 set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2420
2421 if (board_nmi_handler_setup)
2422 board_nmi_handler_setup();
2423
2424 if (cpu_has_fpu && !cpu_has_nofpuex)
2425 set_except_vector(EXCCODE_FPE, handle_fpe);
2426
2427 set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2428
2429 if (cpu_has_rixiex) {
2430 set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2431 set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2432 }
2433
2434 set_except_vector(EXCCODE_MSADIS, handle_msa);
2435 set_except_vector(EXCCODE_MDMX, handle_mdmx);
2436
2437 if (cpu_has_mcheck)
2438 set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2439
2440 if (cpu_has_mipsmt)
2441 set_except_vector(EXCCODE_THREAD, handle_mt);
2442
2443 set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2444
2445 if (board_cache_error_setup)
2446 board_cache_error_setup();
2447
2448 if (cpu_has_vce)
2449 /* Special exception: R4[04]00 uses also the divec space. */
2450 set_handler(0x180, &except_vec3_r4000, 0x100);
2451 else if (cpu_has_4kex)
2452 set_handler(0x180, &except_vec3_generic, 0x80);
2453 else
2454 set_handler(0x080, &except_vec3_generic, 0x80);
2455
2456 local_flush_icache_range(ebase, ebase + vec_size);
2457
2458 sort_extable(__start___dbe_table, __stop___dbe_table);
2459
2460 cu2_notifier(default_cu2_call, 0x80000000); /* Run last */
2461 }
2462
trap_pm_notifier(struct notifier_block * self,unsigned long cmd,void * v)2463 static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2464 void *v)
2465 {
2466 switch (cmd) {
2467 case CPU_PM_ENTER_FAILED:
2468 case CPU_PM_EXIT:
2469 configure_status();
2470 configure_hwrena();
2471 configure_exception_vector();
2472
2473 /* Restore register with CPU number for TLB handlers */
2474 TLBMISS_HANDLER_RESTORE();
2475
2476 break;
2477 }
2478
2479 return NOTIFY_OK;
2480 }
2481
2482 static struct notifier_block trap_pm_notifier_block = {
2483 .notifier_call = trap_pm_notifier,
2484 };
2485
trap_pm_init(void)2486 static int __init trap_pm_init(void)
2487 {
2488 return cpu_pm_register_notifier(&trap_pm_notifier_block);
2489 }
2490 arch_initcall(trap_pm_init);
2491