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/ptrace.h>
  61#include <asm/sections.h>
  62#include <asm/siginfo.h>
  63#include <asm/tlbdebug.h>
  64#include <asm/traps.h>
  65#include <linux/uaccess.h>
  66#include <asm/watch.h>
  67#include <asm/mmu_context.h>
  68#include <asm/types.h>
  69#include <asm/stacktrace.h>
  70#include <asm/tlbex.h>
  71#include <asm/uasm.h>
  72
  73#include <asm/mach-loongson64/cpucfg-emul.h>
  74
  75#include "access-helper.h"
  76
  77extern void check_wait(void);
  78extern asmlinkage void rollback_handle_int(void);
  79extern asmlinkage void handle_int(void);
  80extern asmlinkage void handle_adel(void);
  81extern asmlinkage void handle_ades(void);
  82extern asmlinkage void handle_ibe(void);
  83extern asmlinkage void handle_dbe(void);
  84extern asmlinkage void handle_sys(void);
  85extern asmlinkage void handle_bp(void);
  86extern asmlinkage void handle_ri(void);
  87extern asmlinkage void handle_ri_rdhwr_tlbp(void);
  88extern asmlinkage void handle_ri_rdhwr(void);
  89extern asmlinkage void handle_cpu(void);
  90extern asmlinkage void handle_ov(void);
  91extern asmlinkage void handle_tr(void);
  92extern asmlinkage void handle_msa_fpe(void);
  93extern asmlinkage void handle_fpe(void);
  94extern asmlinkage void handle_ftlb(void);
  95extern asmlinkage void handle_gsexc(void);
  96extern asmlinkage void handle_msa(void);
  97extern asmlinkage void handle_mdmx(void);
  98extern asmlinkage void handle_watch(void);
  99extern asmlinkage void handle_mt(void);
 100extern asmlinkage void handle_dsp(void);
 101extern asmlinkage void handle_mcheck(void);
 102extern asmlinkage void handle_reserved(void);
 103extern void tlb_do_page_fault_0(void);
 104
 105void (*board_be_init)(void);
 106int (*board_be_handler)(struct pt_regs *regs, int is_fixup);
 107void (*board_nmi_handler_setup)(void);
 108void (*board_ejtag_handler_setup)(void);
 109void (*board_bind_eic_interrupt)(int irq, int regset);
 110void (*board_ebase_setup)(void);
 111void(*board_cache_error_setup)(void);
 112
 
 
 
 
 
 
 113static void show_raw_backtrace(unsigned long reg29, const char *loglvl,
 114			       bool user)
 115{
 116	unsigned long *sp = (unsigned long *)(reg29 & ~3);
 117	unsigned long addr;
 118
 119	printk("%sCall Trace:", loglvl);
 120#ifdef CONFIG_KALLSYMS
 121	printk("%s\n", loglvl);
 122#endif
 123	while (!kstack_end(sp)) {
 124		if (__get_addr(&addr, sp++, user)) {
 125			printk("%s (Bad stack address)", loglvl);
 126			break;
 127		}
 128		if (__kernel_text_address(addr))
 129			print_ip_sym(loglvl, addr);
 130	}
 131	printk("%s\n", loglvl);
 132}
 133
 134#ifdef CONFIG_KALLSYMS
 135int raw_show_trace;
 136static int __init set_raw_show_trace(char *str)
 137{
 138	raw_show_trace = 1;
 139	return 1;
 140}
 141__setup("raw_show_trace", set_raw_show_trace);
 142#endif
 143
 144static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
 145			   const char *loglvl, bool user)
 146{
 147	unsigned long sp = regs->regs[29];
 148	unsigned long ra = regs->regs[31];
 149	unsigned long pc = regs->cp0_epc;
 150
 151	if (!task)
 152		task = current;
 153
 154	if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
 155		show_raw_backtrace(sp, loglvl, user);
 156		return;
 157	}
 158	printk("%sCall Trace:\n", loglvl);
 159	do {
 160		print_ip_sym(loglvl, pc);
 161		pc = unwind_stack(task, &sp, pc, &ra);
 162	} while (pc);
 163	pr_cont("\n");
 164}
 165
 166/*
 167 * This routine abuses get_user()/put_user() to reference pointers
 168 * with at least a bit of error checking ...
 169 */
 170static void show_stacktrace(struct task_struct *task,
 171	const struct pt_regs *regs, const char *loglvl, bool user)
 172{
 173	const int field = 2 * sizeof(unsigned long);
 174	unsigned long stackdata;
 175	int i;
 176	unsigned long *sp = (unsigned long *)regs->regs[29];
 177
 178	printk("%sStack :", loglvl);
 179	i = 0;
 180	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
 181		if (i && ((i % (64 / field)) == 0)) {
 182			pr_cont("\n");
 183			printk("%s       ", loglvl);
 184		}
 185		if (i > 39) {
 186			pr_cont(" ...");
 187			break;
 188		}
 189
 190		if (__get_addr(&stackdata, sp++, user)) {
 191			pr_cont(" (Bad stack address)");
 192			break;
 193		}
 194
 195		pr_cont(" %0*lx", field, stackdata);
 196		i++;
 197	}
 198	pr_cont("\n");
 199	show_backtrace(task, regs, loglvl, user);
 200}
 201
 202void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
 203{
 204	struct pt_regs regs;
 205
 206	regs.cp0_status = KSU_KERNEL;
 207	if (sp) {
 208		regs.regs[29] = (unsigned long)sp;
 209		regs.regs[31] = 0;
 210		regs.cp0_epc = 0;
 211	} else {
 212		if (task && task != current) {
 213			regs.regs[29] = task->thread.reg29;
 214			regs.regs[31] = 0;
 215			regs.cp0_epc = task->thread.reg31;
 216		} else {
 217			prepare_frametrace(&regs);
 218		}
 219	}
 220	show_stacktrace(task, &regs, loglvl, false);
 221}
 222
 223static void show_code(void *pc, bool user)
 224{
 225	long i;
 226	unsigned short *pc16 = NULL;
 227
 228	printk("Code:");
 229
 230	if ((unsigned long)pc & 1)
 231		pc16 = (u16 *)((unsigned long)pc & ~1);
 232
 233	for(i = -3 ; i < 6 ; i++) {
 234		if (pc16) {
 235			u16 insn16;
 236
 237			if (__get_inst16(&insn16, pc16 + i, user))
 238				goto bad_address;
 239
 240			pr_cont("%c%04x%c", (i?' ':'<'), insn16, (i?' ':'>'));
 241		} else {
 242			u32 insn32;
 243
 244			if (__get_inst32(&insn32, (u32 *)pc + i, user))
 245				goto bad_address;
 246
 247			pr_cont("%c%08x%c", (i?' ':'<'), insn32, (i?' ':'>'));
 248		}
 249	}
 250	pr_cont("\n");
 251	return;
 252
 253bad_address:
 254	pr_cont(" (Bad address in epc)\n\n");
 255}
 256
 257static void __show_regs(const struct pt_regs *regs)
 258{
 259	const int field = 2 * sizeof(unsigned long);
 260	unsigned int cause = regs->cp0_cause;
 261	unsigned int exccode;
 262	int i;
 263
 264	show_regs_print_info(KERN_DEFAULT);
 265
 266	/*
 267	 * Saved main processor registers
 268	 */
 269	for (i = 0; i < 32; ) {
 270		if ((i % 4) == 0)
 271			printk("$%2d   :", i);
 272		if (i == 0)
 273			pr_cont(" %0*lx", field, 0UL);
 274		else if (i == 26 || i == 27)
 275			pr_cont(" %*s", field, "");
 276		else
 277			pr_cont(" %0*lx", field, regs->regs[i]);
 278
 279		i++;
 280		if ((i % 4) == 0)
 281			pr_cont("\n");
 282	}
 283
 284#ifdef CONFIG_CPU_HAS_SMARTMIPS
 285	printk("Acx    : %0*lx\n", field, regs->acx);
 286#endif
 287	if (MIPS_ISA_REV < 6) {
 288		printk("Hi    : %0*lx\n", field, regs->hi);
 289		printk("Lo    : %0*lx\n", field, regs->lo);
 290	}
 291
 292	/*
 293	 * Saved cp0 registers
 294	 */
 295	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
 296	       (void *) regs->cp0_epc);
 297	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
 298	       (void *) regs->regs[31]);
 299
 300	printk("Status: %08x	", (uint32_t) regs->cp0_status);
 301
 302	if (cpu_has_3kex) {
 303		if (regs->cp0_status & ST0_KUO)
 304			pr_cont("KUo ");
 305		if (regs->cp0_status & ST0_IEO)
 306			pr_cont("IEo ");
 307		if (regs->cp0_status & ST0_KUP)
 308			pr_cont("KUp ");
 309		if (regs->cp0_status & ST0_IEP)
 310			pr_cont("IEp ");
 311		if (regs->cp0_status & ST0_KUC)
 312			pr_cont("KUc ");
 313		if (regs->cp0_status & ST0_IEC)
 314			pr_cont("IEc ");
 315	} else if (cpu_has_4kex) {
 316		if (regs->cp0_status & ST0_KX)
 317			pr_cont("KX ");
 318		if (regs->cp0_status & ST0_SX)
 319			pr_cont("SX ");
 320		if (regs->cp0_status & ST0_UX)
 321			pr_cont("UX ");
 322		switch (regs->cp0_status & ST0_KSU) {
 323		case KSU_USER:
 324			pr_cont("USER ");
 325			break;
 326		case KSU_SUPERVISOR:
 327			pr_cont("SUPERVISOR ");
 328			break;
 329		case KSU_KERNEL:
 330			pr_cont("KERNEL ");
 331			break;
 332		default:
 333			pr_cont("BAD_MODE ");
 334			break;
 335		}
 336		if (regs->cp0_status & ST0_ERL)
 337			pr_cont("ERL ");
 338		if (regs->cp0_status & ST0_EXL)
 339			pr_cont("EXL ");
 340		if (regs->cp0_status & ST0_IE)
 341			pr_cont("IE ");
 342	}
 343	pr_cont("\n");
 344
 345	exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
 346	printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
 347
 348	if (1 <= exccode && exccode <= 5)
 349		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
 350
 351	printk("PrId  : %08x (%s)\n", read_c0_prid(),
 352	       cpu_name_string());
 353}
 354
 355/*
 356 * FIXME: really the generic show_regs should take a const pointer argument.
 357 */
 358void show_regs(struct pt_regs *regs)
 359{
 360	__show_regs(regs);
 361	dump_stack();
 362}
 363
 364void show_registers(struct pt_regs *regs)
 365{
 366	const int field = 2 * sizeof(unsigned long);
 367
 368	__show_regs(regs);
 369	print_modules();
 370	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
 371	       current->comm, current->pid, current_thread_info(), current,
 372	      field, current_thread_info()->tp_value);
 373	if (cpu_has_userlocal) {
 374		unsigned long tls;
 375
 376		tls = read_c0_userlocal();
 377		if (tls != current_thread_info()->tp_value)
 378			printk("*HwTLS: %0*lx\n", field, tls);
 379	}
 380
 381	show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
 382	show_code((void *)regs->cp0_epc, user_mode(regs));
 383	printk("\n");
 384}
 385
 386static DEFINE_RAW_SPINLOCK(die_lock);
 387
 388void __noreturn die(const char *str, struct pt_regs *regs)
 389{
 390	static int die_counter;
 391	int sig = SIGSEGV;
 392
 393	oops_enter();
 394
 395	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
 396		       SIGSEGV) == NOTIFY_STOP)
 397		sig = 0;
 398
 399	console_verbose();
 400	raw_spin_lock_irq(&die_lock);
 401	bust_spinlocks(1);
 402
 403	printk("%s[#%d]:\n", str, ++die_counter);
 404	show_registers(regs);
 405	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 406	raw_spin_unlock_irq(&die_lock);
 407
 408	oops_exit();
 409
 410	if (in_interrupt())
 411		panic("Fatal exception in interrupt");
 412
 413	if (panic_on_oops)
 414		panic("Fatal exception");
 415
 416	if (regs && kexec_should_crash(current))
 417		crash_kexec(regs);
 418
 419	do_exit(sig);
 420}
 421
 422extern struct exception_table_entry __start___dbe_table[];
 423extern struct exception_table_entry __stop___dbe_table[];
 424
 425__asm__(
 426"	.section	__dbe_table, \"a\"\n"
 427"	.previous			\n");
 428
 429/* Given an address, look for it in the exception tables. */
 430static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
 431{
 432	const struct exception_table_entry *e;
 433
 434	e = search_extable(__start___dbe_table,
 435			   __stop___dbe_table - __start___dbe_table, addr);
 436	if (!e)
 437		e = search_module_dbetables(addr);
 438	return e;
 439}
 440
 441asmlinkage void do_be(struct pt_regs *regs)
 442{
 443	const int field = 2 * sizeof(unsigned long);
 444	const struct exception_table_entry *fixup = NULL;
 445	int data = regs->cp0_cause & 4;
 446	int action = MIPS_BE_FATAL;
 447	enum ctx_state prev_state;
 448
 449	prev_state = exception_enter();
 450	/* XXX For now.	 Fixme, this searches the wrong table ...  */
 451	if (data && !user_mode(regs))
 452		fixup = search_dbe_tables(exception_epc(regs));
 453
 454	if (fixup)
 455		action = MIPS_BE_FIXUP;
 456
 457	if (board_be_handler)
 458		action = board_be_handler(regs, fixup != NULL);
 459	else
 460		mips_cm_error_report();
 461
 462	switch (action) {
 463	case MIPS_BE_DISCARD:
 464		goto out;
 465	case MIPS_BE_FIXUP:
 466		if (fixup) {
 467			regs->cp0_epc = fixup->nextinsn;
 468			goto out;
 469		}
 470		break;
 471	default:
 472		break;
 473	}
 474
 475	/*
 476	 * Assume it would be too dangerous to continue ...
 477	 */
 478	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
 479	       data ? "Data" : "Instruction",
 480	       field, regs->cp0_epc, field, regs->regs[31]);
 481	if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
 482		       SIGBUS) == NOTIFY_STOP)
 483		goto out;
 484
 485	die_if_kernel("Oops", regs);
 486	force_sig(SIGBUS);
 487
 488out:
 489	exception_exit(prev_state);
 490}
 491
 492/*
 493 * ll/sc, rdhwr, sync emulation
 494 */
 495
 496#define OPCODE 0xfc000000
 497#define BASE   0x03e00000
 498#define RT     0x001f0000
 499#define OFFSET 0x0000ffff
 500#define LL     0xc0000000
 501#define SC     0xe0000000
 502#define SPEC0  0x00000000
 503#define SPEC3  0x7c000000
 504#define RD     0x0000f800
 505#define FUNC   0x0000003f
 506#define SYNC   0x0000000f
 507#define RDHWR  0x0000003b
 508
 509/*  microMIPS definitions   */
 510#define MM_POOL32A_FUNC 0xfc00ffff
 511#define MM_RDHWR        0x00006b3c
 512#define MM_RS           0x001f0000
 513#define MM_RT           0x03e00000
 514
 515/*
 516 * The ll_bit is cleared by r*_switch.S
 517 */
 518
 519unsigned int ll_bit;
 520struct task_struct *ll_task;
 521
 522static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
 523{
 524	unsigned long value, __user *vaddr;
 525	long offset;
 526
 527	/*
 528	 * analyse the ll instruction that just caused a ri exception
 529	 * and put the referenced address to addr.
 530	 */
 531
 532	/* sign extend offset */
 533	offset = opcode & OFFSET;
 534	offset <<= 16;
 535	offset >>= 16;
 536
 537	vaddr = (unsigned long __user *)
 538		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 539
 540	if ((unsigned long)vaddr & 3)
 541		return SIGBUS;
 542	if (get_user(value, vaddr))
 543		return SIGSEGV;
 544
 545	preempt_disable();
 546
 547	if (ll_task == NULL || ll_task == current) {
 548		ll_bit = 1;
 549	} else {
 550		ll_bit = 0;
 551	}
 552	ll_task = current;
 553
 554	preempt_enable();
 555
 556	regs->regs[(opcode & RT) >> 16] = value;
 557
 558	return 0;
 559}
 560
 561static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
 562{
 563	unsigned long __user *vaddr;
 564	unsigned long reg;
 565	long offset;
 566
 567	/*
 568	 * analyse the sc instruction that just caused a ri exception
 569	 * and put the referenced address to addr.
 570	 */
 571
 572	/* sign extend offset */
 573	offset = opcode & OFFSET;
 574	offset <<= 16;
 575	offset >>= 16;
 576
 577	vaddr = (unsigned long __user *)
 578		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 579	reg = (opcode & RT) >> 16;
 580
 581	if ((unsigned long)vaddr & 3)
 582		return SIGBUS;
 583
 584	preempt_disable();
 585
 586	if (ll_bit == 0 || ll_task != current) {
 587		regs->regs[reg] = 0;
 588		preempt_enable();
 589		return 0;
 590	}
 591
 592	preempt_enable();
 593
 594	if (put_user(regs->regs[reg], vaddr))
 595		return SIGSEGV;
 596
 597	regs->regs[reg] = 1;
 598
 599	return 0;
 600}
 601
 602/*
 603 * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
 604 * opcodes are supposed to result in coprocessor unusable exceptions if
 605 * executed on ll/sc-less processors.  That's the theory.  In practice a
 606 * few processors such as NEC's VR4100 throw reserved instruction exceptions
 607 * instead, so we're doing the emulation thing in both exception handlers.
 608 */
 609static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
 610{
 611	if ((opcode & OPCODE) == LL) {
 612		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 613				1, regs, 0);
 614		return simulate_ll(regs, opcode);
 615	}
 616	if ((opcode & OPCODE) == SC) {
 617		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 618				1, regs, 0);
 619		return simulate_sc(regs, opcode);
 620	}
 621
 622	return -1;			/* Must be something else ... */
 623}
 624
 625/*
 626 * Simulate trapping 'rdhwr' instructions to provide user accessible
 627 * registers not implemented in hardware.
 628 */
 629static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
 630{
 631	struct thread_info *ti = task_thread_info(current);
 632
 633	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 634			1, regs, 0);
 635	switch (rd) {
 636	case MIPS_HWR_CPUNUM:		/* CPU number */
 637		regs->regs[rt] = smp_processor_id();
 638		return 0;
 639	case MIPS_HWR_SYNCISTEP:	/* SYNCI length */
 640		regs->regs[rt] = min(current_cpu_data.dcache.linesz,
 641				     current_cpu_data.icache.linesz);
 642		return 0;
 643	case MIPS_HWR_CC:		/* Read count register */
 644		regs->regs[rt] = read_c0_count();
 645		return 0;
 646	case MIPS_HWR_CCRES:		/* Count register resolution */
 647		switch (current_cpu_type()) {
 648		case CPU_20KC:
 649		case CPU_25KF:
 650			regs->regs[rt] = 1;
 651			break;
 652		default:
 653			regs->regs[rt] = 2;
 654		}
 655		return 0;
 656	case MIPS_HWR_ULR:		/* Read UserLocal register */
 657		regs->regs[rt] = ti->tp_value;
 658		return 0;
 659	default:
 660		return -1;
 661	}
 662}
 663
 664static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
 665{
 666	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
 667		int rd = (opcode & RD) >> 11;
 668		int rt = (opcode & RT) >> 16;
 669
 670		simulate_rdhwr(regs, rd, rt);
 671		return 0;
 672	}
 673
 674	/* Not ours.  */
 675	return -1;
 676}
 677
 678static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
 679{
 680	if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
 681		int rd = (opcode & MM_RS) >> 16;
 682		int rt = (opcode & MM_RT) >> 21;
 683		simulate_rdhwr(regs, rd, rt);
 684		return 0;
 685	}
 686
 687	/* Not ours.  */
 688	return -1;
 689}
 690
 691static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
 692{
 693	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
 694		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 695				1, regs, 0);
 696		return 0;
 697	}
 698
 699	return -1;			/* Must be something else ... */
 700}
 701
 702/*
 703 * Loongson-3 CSR instructions emulation
 704 */
 705
 706#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
 707
 708#define LWC2             0xc8000000
 709#define RS               BASE
 710#define CSR_OPCODE2      0x00000118
 711#define CSR_OPCODE2_MASK 0x000007ff
 712#define CSR_FUNC_MASK    RT
 713#define CSR_FUNC_CPUCFG  0x8
 714
 715static int simulate_loongson3_cpucfg(struct pt_regs *regs,
 716				     unsigned int opcode)
 717{
 718	int op = opcode & OPCODE;
 719	int op2 = opcode & CSR_OPCODE2_MASK;
 720	int csr_func = (opcode & CSR_FUNC_MASK) >> 16;
 721
 722	if (op == LWC2 && op2 == CSR_OPCODE2 && csr_func == CSR_FUNC_CPUCFG) {
 723		int rd = (opcode & RD) >> 11;
 724		int rs = (opcode & RS) >> 21;
 725		__u64 sel = regs->regs[rs];
 726
 727		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 728
 729		/* Do not emulate on unsupported core models. */
 730		preempt_disable();
 731		if (!loongson3_cpucfg_emulation_enabled(&current_cpu_data)) {
 732			preempt_enable();
 733			return -1;
 734		}
 735		regs->regs[rd] = loongson3_cpucfg_read_synthesized(
 736			&current_cpu_data, sel);
 737		preempt_enable();
 738		return 0;
 739	}
 740
 741	/* Not ours.  */
 742	return -1;
 743}
 744#endif /* CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION */
 745
 746asmlinkage void do_ov(struct pt_regs *regs)
 747{
 748	enum ctx_state prev_state;
 749
 750	prev_state = exception_enter();
 751	die_if_kernel("Integer overflow", regs);
 752
 753	force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->cp0_epc);
 754	exception_exit(prev_state);
 755}
 756
 757#ifdef CONFIG_MIPS_FP_SUPPORT
 758
 759/*
 760 * Send SIGFPE according to FCSR Cause bits, which must have already
 761 * been masked against Enable bits.  This is impotant as Inexact can
 762 * happen together with Overflow or Underflow, and `ptrace' can set
 763 * any bits.
 764 */
 765void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
 766		     struct task_struct *tsk)
 767{
 768	int si_code = FPE_FLTUNK;
 769
 770	if (fcr31 & FPU_CSR_INV_X)
 771		si_code = FPE_FLTINV;
 772	else if (fcr31 & FPU_CSR_DIV_X)
 773		si_code = FPE_FLTDIV;
 774	else if (fcr31 & FPU_CSR_OVF_X)
 775		si_code = FPE_FLTOVF;
 776	else if (fcr31 & FPU_CSR_UDF_X)
 777		si_code = FPE_FLTUND;
 778	else if (fcr31 & FPU_CSR_INE_X)
 779		si_code = FPE_FLTRES;
 780
 781	force_sig_fault_to_task(SIGFPE, si_code, fault_addr, tsk);
 782}
 783
 784int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
 785{
 786	int si_code;
 787
 788	switch (sig) {
 789	case 0:
 790		return 0;
 791
 792	case SIGFPE:
 793		force_fcr31_sig(fcr31, fault_addr, current);
 794		return 1;
 795
 796	case SIGBUS:
 797		force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
 798		return 1;
 799
 800	case SIGSEGV:
 801		mmap_read_lock(current->mm);
 802		if (vma_lookup(current->mm, (unsigned long)fault_addr))
 803			si_code = SEGV_ACCERR;
 804		else
 805			si_code = SEGV_MAPERR;
 806		mmap_read_unlock(current->mm);
 807		force_sig_fault(SIGSEGV, si_code, fault_addr);
 808		return 1;
 809
 810	default:
 811		force_sig(sig);
 812		return 1;
 813	}
 814}
 815
 816static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
 817		       unsigned long old_epc, unsigned long old_ra)
 818{
 819	union mips_instruction inst = { .word = opcode };
 820	void __user *fault_addr;
 821	unsigned long fcr31;
 822	int sig;
 823
 824	/* If it's obviously not an FP instruction, skip it */
 825	switch (inst.i_format.opcode) {
 826	case cop1_op:
 827	case cop1x_op:
 828	case lwc1_op:
 829	case ldc1_op:
 830	case swc1_op:
 831	case sdc1_op:
 832		break;
 833
 834	default:
 835		return -1;
 836	}
 837
 838	/*
 839	 * do_ri skipped over the instruction via compute_return_epc, undo
 840	 * that for the FPU emulator.
 841	 */
 842	regs->cp0_epc = old_epc;
 843	regs->regs[31] = old_ra;
 844
 845	/* Run the emulator */
 846	sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 847				       &fault_addr);
 848
 849	/*
 850	 * We can't allow the emulated instruction to leave any
 851	 * enabled Cause bits set in $fcr31.
 852	 */
 853	fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
 854	current->thread.fpu.fcr31 &= ~fcr31;
 855
 856	/* Restore the hardware register state */
 857	own_fpu(1);
 858
 859	/* Send a signal if required.  */
 860	process_fpemu_return(sig, fault_addr, fcr31);
 861
 862	return 0;
 863}
 864
 865/*
 866 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
 867 */
 868asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 869{
 870	enum ctx_state prev_state;
 871	void __user *fault_addr;
 872	int sig;
 873
 874	prev_state = exception_enter();
 875	if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
 876		       SIGFPE) == NOTIFY_STOP)
 877		goto out;
 878
 879	/* Clear FCSR.Cause before enabling interrupts */
 880	write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
 881	local_irq_enable();
 882
 883	die_if_kernel("FP exception in kernel code", regs);
 884
 885	if (fcr31 & FPU_CSR_UNI_X) {
 886		/*
 887		 * Unimplemented operation exception.  If we've got the full
 888		 * software emulator on-board, let's use it...
 889		 *
 890		 * Force FPU to dump state into task/thread context.  We're
 891		 * moving a lot of data here for what is probably a single
 892		 * instruction, but the alternative is to pre-decode the FP
 893		 * register operands before invoking the emulator, which seems
 894		 * a bit extreme for what should be an infrequent event.
 895		 */
 896
 897		/* Run the emulator */
 898		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 899					       &fault_addr);
 900
 901		/*
 902		 * We can't allow the emulated instruction to leave any
 903		 * enabled Cause bits set in $fcr31.
 904		 */
 905		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
 906		current->thread.fpu.fcr31 &= ~fcr31;
 907
 908		/* Restore the hardware register state */
 909		own_fpu(1);	/* Using the FPU again.	 */
 910	} else {
 911		sig = SIGFPE;
 912		fault_addr = (void __user *) regs->cp0_epc;
 913	}
 914
 915	/* Send a signal if required.  */
 916	process_fpemu_return(sig, fault_addr, fcr31);
 917
 918out:
 919	exception_exit(prev_state);
 920}
 921
 922/*
 923 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
 924 * emulated more than some threshold number of instructions, force migration to
 925 * a "CPU" that has FP support.
 926 */
 927static void mt_ase_fp_affinity(void)
 928{
 929#ifdef CONFIG_MIPS_MT_FPAFF
 930	if (mt_fpemul_threshold > 0 &&
 931	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
 932		/*
 933		 * If there's no FPU present, or if the application has already
 934		 * restricted the allowed set to exclude any CPUs with FPUs,
 935		 * we'll skip the procedure.
 936		 */
 937		if (cpumask_intersects(&current->cpus_mask, &mt_fpu_cpumask)) {
 938			cpumask_t tmask;
 939
 940			current->thread.user_cpus_allowed
 941				= current->cpus_mask;
 942			cpumask_and(&tmask, &current->cpus_mask,
 943				    &mt_fpu_cpumask);
 944			set_cpus_allowed_ptr(current, &tmask);
 945			set_thread_flag(TIF_FPUBOUND);
 946		}
 947	}
 948#endif /* CONFIG_MIPS_MT_FPAFF */
 949}
 950
 951#else /* !CONFIG_MIPS_FP_SUPPORT */
 952
 953static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
 954		       unsigned long old_epc, unsigned long old_ra)
 955{
 956	return -1;
 957}
 958
 959#endif /* !CONFIG_MIPS_FP_SUPPORT */
 960
 961void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
 962	const char *str)
 963{
 964	char b[40];
 965
 966#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
 967	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
 968			 SIGTRAP) == NOTIFY_STOP)
 969		return;
 970#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
 971
 972	if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
 973		       SIGTRAP) == NOTIFY_STOP)
 974		return;
 975
 976	/*
 977	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
 978	 * insns, even for trap and break codes that indicate arithmetic
 979	 * failures.  Weird ...
 980	 * But should we continue the brokenness???  --macro
 981	 */
 982	switch (code) {
 983	case BRK_OVERFLOW:
 984	case BRK_DIVZERO:
 985		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
 986		die_if_kernel(b, regs);
 987		force_sig_fault(SIGFPE,
 988				code == BRK_DIVZERO ? FPE_INTDIV : FPE_INTOVF,
 989				(void __user *) regs->cp0_epc);
 990		break;
 991	case BRK_BUG:
 992		die_if_kernel("Kernel bug detected", regs);
 993		force_sig(SIGTRAP);
 994		break;
 995	case BRK_MEMU:
 996		/*
 997		 * This breakpoint code is used by the FPU emulator to retake
 998		 * control of the CPU after executing the instruction from the
 999		 * delay slot of an emulated branch.
1000		 *
1001		 * Terminate if exception was recognized as a delay slot return
1002		 * otherwise handle as normal.
1003		 */
1004		if (do_dsemulret(regs))
1005			return;
1006
1007		die_if_kernel("Math emu break/trap", regs);
1008		force_sig(SIGTRAP);
1009		break;
1010	default:
1011		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
1012		die_if_kernel(b, regs);
1013		if (si_code) {
1014			force_sig_fault(SIGTRAP, si_code, NULL);
1015		} else {
1016			force_sig(SIGTRAP);
1017		}
1018	}
1019}
1020
1021asmlinkage void do_bp(struct pt_regs *regs)
1022{
1023	unsigned long epc = msk_isa16_mode(exception_epc(regs));
1024	unsigned int opcode, bcode;
1025	enum ctx_state prev_state;
1026	bool user = user_mode(regs);
1027
1028	prev_state = exception_enter();
1029	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1030	if (get_isa16_mode(regs->cp0_epc)) {
1031		u16 instr[2];
1032
1033		if (__get_inst16(&instr[0], (u16 *)epc, user))
1034			goto out_sigsegv;
1035
1036		if (!cpu_has_mmips) {
1037			/* MIPS16e mode */
1038			bcode = (instr[0] >> 5) & 0x3f;
1039		} else if (mm_insn_16bit(instr[0])) {
1040			/* 16-bit microMIPS BREAK */
1041			bcode = instr[0] & 0xf;
1042		} else {
1043			/* 32-bit microMIPS BREAK */
1044			if (__get_inst16(&instr[1], (u16 *)(epc + 2), user))
1045				goto out_sigsegv;
1046			opcode = (instr[0] << 16) | instr[1];
1047			bcode = (opcode >> 6) & ((1 << 20) - 1);
1048		}
1049	} else {
1050		if (__get_inst32(&opcode, (u32 *)epc, user))
1051			goto out_sigsegv;
1052		bcode = (opcode >> 6) & ((1 << 20) - 1);
1053	}
1054
1055	/*
1056	 * There is the ancient bug in the MIPS assemblers that the break
1057	 * code starts left to bit 16 instead to bit 6 in the opcode.
1058	 * Gas is bug-compatible, but not always, grrr...
1059	 * We handle both cases with a simple heuristics.  --macro
1060	 */
1061	if (bcode >= (1 << 10))
1062		bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
1063
1064	/*
1065	 * notify the kprobe handlers, if instruction is likely to
1066	 * pertain to them.
1067	 */
1068	switch (bcode) {
1069	case BRK_UPROBE:
1070		if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
1071			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1072			goto out;
1073		else
1074			break;
1075	case BRK_UPROBE_XOL:
1076		if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1077			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1078			goto out;
1079		else
1080			break;
1081	case BRK_KPROBE_BP:
1082		if (notify_die(DIE_BREAK, "debug", regs, bcode,
1083			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1084			goto out;
1085		else
1086			break;
1087	case BRK_KPROBE_SSTEPBP:
1088		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1089			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1090			goto out;
1091		else
1092			break;
1093	default:
1094		break;
1095	}
1096
1097	do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1098
1099out:
1100	exception_exit(prev_state);
1101	return;
1102
1103out_sigsegv:
1104	force_sig(SIGSEGV);
1105	goto out;
1106}
1107
1108asmlinkage void do_tr(struct pt_regs *regs)
1109{
1110	u32 opcode, tcode = 0;
1111	enum ctx_state prev_state;
1112	u16 instr[2];
1113	bool user = user_mode(regs);
1114	unsigned long epc = msk_isa16_mode(exception_epc(regs));
1115
1116	prev_state = exception_enter();
1117	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1118	if (get_isa16_mode(regs->cp0_epc)) {
1119		if (__get_inst16(&instr[0], (u16 *)(epc + 0), user) ||
1120		    __get_inst16(&instr[1], (u16 *)(epc + 2), user))
1121			goto out_sigsegv;
1122		opcode = (instr[0] << 16) | instr[1];
1123		/* Immediate versions don't provide a code.  */
1124		if (!(opcode & OPCODE))
1125			tcode = (opcode >> 12) & ((1 << 4) - 1);
1126	} else {
1127		if (__get_inst32(&opcode, (u32 *)epc, user))
1128			goto out_sigsegv;
1129		/* Immediate versions don't provide a code.  */
1130		if (!(opcode & OPCODE))
1131			tcode = (opcode >> 6) & ((1 << 10) - 1);
1132	}
1133
1134	do_trap_or_bp(regs, tcode, 0, "Trap");
1135
1136out:
1137	exception_exit(prev_state);
1138	return;
1139
1140out_sigsegv:
1141	force_sig(SIGSEGV);
1142	goto out;
1143}
1144
1145asmlinkage void do_ri(struct pt_regs *regs)
1146{
1147	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1148	unsigned long old_epc = regs->cp0_epc;
1149	unsigned long old31 = regs->regs[31];
1150	enum ctx_state prev_state;
1151	unsigned int opcode = 0;
1152	int status = -1;
1153
1154	/*
1155	 * Avoid any kernel code. Just emulate the R2 instruction
1156	 * as quickly as possible.
1157	 */
1158	if (mipsr2_emulation && cpu_has_mips_r6 &&
1159	    likely(user_mode(regs)) &&
1160	    likely(get_user(opcode, epc) >= 0)) {
1161		unsigned long fcr31 = 0;
1162
1163		status = mipsr2_decoder(regs, opcode, &fcr31);
1164		switch (status) {
1165		case 0:
1166		case SIGEMT:
1167			return;
1168		case SIGILL:
1169			goto no_r2_instr;
1170		default:
1171			process_fpemu_return(status,
1172					     &current->thread.cp0_baduaddr,
1173					     fcr31);
1174			return;
1175		}
1176	}
1177
1178no_r2_instr:
1179
1180	prev_state = exception_enter();
1181	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1182
1183	if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1184		       SIGILL) == NOTIFY_STOP)
1185		goto out;
1186
1187	die_if_kernel("Reserved instruction in kernel code", regs);
1188
1189	if (unlikely(compute_return_epc(regs) < 0))
1190		goto out;
1191
1192	if (!get_isa16_mode(regs->cp0_epc)) {
1193		if (unlikely(get_user(opcode, epc) < 0))
1194			status = SIGSEGV;
1195
1196		if (!cpu_has_llsc && status < 0)
1197			status = simulate_llsc(regs, opcode);
1198
1199		if (status < 0)
1200			status = simulate_rdhwr_normal(regs, opcode);
1201
1202		if (status < 0)
1203			status = simulate_sync(regs, opcode);
1204
1205		if (status < 0)
1206			status = simulate_fp(regs, opcode, old_epc, old31);
1207
1208#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
1209		if (status < 0)
1210			status = simulate_loongson3_cpucfg(regs, opcode);
1211#endif
1212	} else if (cpu_has_mmips) {
1213		unsigned short mmop[2] = { 0 };
1214
1215		if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1216			status = SIGSEGV;
1217		if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1218			status = SIGSEGV;
1219		opcode = mmop[0];
1220		opcode = (opcode << 16) | mmop[1];
1221
1222		if (status < 0)
1223			status = simulate_rdhwr_mm(regs, opcode);
1224	}
1225
1226	if (status < 0)
1227		status = SIGILL;
1228
1229	if (unlikely(status > 0)) {
1230		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
1231		regs->regs[31] = old31;
1232		force_sig(status);
1233	}
1234
1235out:
1236	exception_exit(prev_state);
1237}
1238
1239/*
1240 * No lock; only written during early bootup by CPU 0.
1241 */
1242static RAW_NOTIFIER_HEAD(cu2_chain);
1243
1244int __ref register_cu2_notifier(struct notifier_block *nb)
1245{
1246	return raw_notifier_chain_register(&cu2_chain, nb);
1247}
1248
1249int cu2_notifier_call_chain(unsigned long val, void *v)
1250{
1251	return raw_notifier_call_chain(&cu2_chain, val, v);
1252}
1253
1254static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1255	void *data)
1256{
1257	struct pt_regs *regs = data;
1258
1259	die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1260			      "instruction", regs);
1261	force_sig(SIGILL);
1262
1263	return NOTIFY_OK;
1264}
1265
1266#ifdef CONFIG_MIPS_FP_SUPPORT
1267
1268static int enable_restore_fp_context(int msa)
1269{
1270	int err, was_fpu_owner, prior_msa;
1271	bool first_fp;
1272
1273	/* Initialize context if it hasn't been used already */
1274	first_fp = init_fp_ctx(current);
1275
1276	if (first_fp) {
1277		preempt_disable();
1278		err = own_fpu_inatomic(1);
1279		if (msa && !err) {
1280			enable_msa();
1281			/*
1282			 * with MSA enabled, userspace can see MSACSR
1283			 * and MSA regs, but the values in them are from
1284			 * other task before current task, restore them
1285			 * from saved fp/msa context
1286			 */
1287			write_msa_csr(current->thread.fpu.msacsr);
1288			/*
1289			 * own_fpu_inatomic(1) just restore low 64bit,
1290			 * fix the high 64bit
1291			 */
1292			init_msa_upper();
1293			set_thread_flag(TIF_USEDMSA);
1294			set_thread_flag(TIF_MSA_CTX_LIVE);
1295		}
1296		preempt_enable();
1297		return err;
1298	}
1299
1300	/*
1301	 * This task has formerly used the FP context.
1302	 *
1303	 * If this thread has no live MSA vector context then we can simply
1304	 * restore the scalar FP context. If it has live MSA vector context
1305	 * (that is, it has or may have used MSA since last performing a
1306	 * function call) then we'll need to restore the vector context. This
1307	 * applies even if we're currently only executing a scalar FP
1308	 * instruction. This is because if we were to later execute an MSA
1309	 * instruction then we'd either have to:
1310	 *
1311	 *  - Restore the vector context & clobber any registers modified by
1312	 *    scalar FP instructions between now & then.
1313	 *
1314	 * or
1315	 *
1316	 *  - Not restore the vector context & lose the most significant bits
1317	 *    of all vector registers.
1318	 *
1319	 * Neither of those options is acceptable. We cannot restore the least
1320	 * significant bits of the registers now & only restore the most
1321	 * significant bits later because the most significant bits of any
1322	 * vector registers whose aliased FP register is modified now will have
1323	 * been zeroed. We'd have no way to know that when restoring the vector
1324	 * context & thus may load an outdated value for the most significant
1325	 * bits of a vector register.
1326	 */
1327	if (!msa && !thread_msa_context_live())
1328		return own_fpu(1);
1329
1330	/*
1331	 * This task is using or has previously used MSA. Thus we require
1332	 * that Status.FR == 1.
1333	 */
1334	preempt_disable();
1335	was_fpu_owner = is_fpu_owner();
1336	err = own_fpu_inatomic(0);
1337	if (err)
1338		goto out;
1339
1340	enable_msa();
1341	write_msa_csr(current->thread.fpu.msacsr);
1342	set_thread_flag(TIF_USEDMSA);
1343
1344	/*
1345	 * If this is the first time that the task is using MSA and it has
1346	 * previously used scalar FP in this time slice then we already nave
1347	 * FP context which we shouldn't clobber. We do however need to clear
1348	 * the upper 64b of each vector register so that this task has no
1349	 * opportunity to see data left behind by another.
1350	 */
1351	prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1352	if (!prior_msa && was_fpu_owner) {
1353		init_msa_upper();
1354
1355		goto out;
1356	}
1357
1358	if (!prior_msa) {
1359		/*
1360		 * Restore the least significant 64b of each vector register
1361		 * from the existing scalar FP context.
1362		 */
1363		_restore_fp(current);
1364
1365		/*
1366		 * The task has not formerly used MSA, so clear the upper 64b
1367		 * of each vector register such that it cannot see data left
1368		 * behind by another task.
1369		 */
1370		init_msa_upper();
1371	} else {
1372		/* We need to restore the vector context. */
1373		restore_msa(current);
1374
1375		/* Restore the scalar FP control & status register */
1376		if (!was_fpu_owner)
1377			write_32bit_cp1_register(CP1_STATUS,
1378						 current->thread.fpu.fcr31);
1379	}
1380
1381out:
1382	preempt_enable();
1383
1384	return 0;
1385}
1386
1387#else /* !CONFIG_MIPS_FP_SUPPORT */
1388
1389static int enable_restore_fp_context(int msa)
1390{
1391	return SIGILL;
1392}
1393
1394#endif /* CONFIG_MIPS_FP_SUPPORT */
1395
1396asmlinkage void do_cpu(struct pt_regs *regs)
1397{
1398	enum ctx_state prev_state;
1399	unsigned int __user *epc;
1400	unsigned long old_epc, old31;
1401	unsigned int opcode;
1402	unsigned int cpid;
1403	int status;
1404
1405	prev_state = exception_enter();
1406	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1407
1408	if (cpid != 2)
1409		die_if_kernel("do_cpu invoked from kernel context!", regs);
1410
1411	switch (cpid) {
1412	case 0:
1413		epc = (unsigned int __user *)exception_epc(regs);
1414		old_epc = regs->cp0_epc;
1415		old31 = regs->regs[31];
1416		opcode = 0;
1417		status = -1;
1418
1419		if (unlikely(compute_return_epc(regs) < 0))
1420			break;
1421
1422		if (!get_isa16_mode(regs->cp0_epc)) {
1423			if (unlikely(get_user(opcode, epc) < 0))
1424				status = SIGSEGV;
1425
1426			if (!cpu_has_llsc && status < 0)
1427				status = simulate_llsc(regs, opcode);
1428		}
1429
1430		if (status < 0)
1431			status = SIGILL;
1432
1433		if (unlikely(status > 0)) {
1434			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
1435			regs->regs[31] = old31;
1436			force_sig(status);
1437		}
1438
1439		break;
1440
1441#ifdef CONFIG_MIPS_FP_SUPPORT
1442	case 3:
1443		/*
1444		 * The COP3 opcode space and consequently the CP0.Status.CU3
1445		 * bit and the CP0.Cause.CE=3 encoding have been removed as
1446		 * of the MIPS III ISA.  From the MIPS IV and MIPS32r2 ISAs
1447		 * up the space has been reused for COP1X instructions, that
1448		 * are enabled by the CP0.Status.CU1 bit and consequently
1449		 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1450		 * exceptions.  Some FPU-less processors that implement one
1451		 * of these ISAs however use this code erroneously for COP1X
1452		 * instructions.  Therefore we redirect this trap to the FP
1453		 * emulator too.
1454		 */
1455		if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1456			force_sig(SIGILL);
1457			break;
1458		}
1459		fallthrough;
1460	case 1: {
1461		void __user *fault_addr;
1462		unsigned long fcr31;
1463		int err, sig;
1464
1465		err = enable_restore_fp_context(0);
1466
1467		if (raw_cpu_has_fpu && !err)
1468			break;
1469
1470		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1471					       &fault_addr);
1472
1473		/*
1474		 * We can't allow the emulated instruction to leave
1475		 * any enabled Cause bits set in $fcr31.
1476		 */
1477		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
1478		current->thread.fpu.fcr31 &= ~fcr31;
1479
1480		/* Send a signal if required.  */
1481		if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1482			mt_ase_fp_affinity();
1483
1484		break;
1485	}
1486#else /* CONFIG_MIPS_FP_SUPPORT */
1487	case 1:
1488	case 3:
1489		force_sig(SIGILL);
1490		break;
1491#endif /* CONFIG_MIPS_FP_SUPPORT */
1492
1493	case 2:
1494		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1495		break;
1496	}
1497
1498	exception_exit(prev_state);
1499}
1500
1501asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1502{
1503	enum ctx_state prev_state;
1504
1505	prev_state = exception_enter();
1506	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1507	if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1508		       current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1509		goto out;
1510
1511	/* Clear MSACSR.Cause before enabling interrupts */
1512	write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1513	local_irq_enable();
1514
1515	die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1516	force_sig(SIGFPE);
1517out:
1518	exception_exit(prev_state);
1519}
1520
1521asmlinkage void do_msa(struct pt_regs *regs)
1522{
1523	enum ctx_state prev_state;
1524	int err;
1525
1526	prev_state = exception_enter();
1527
1528	if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1529		force_sig(SIGILL);
1530		goto out;
1531	}
1532
1533	die_if_kernel("do_msa invoked from kernel context!", regs);
1534
1535	err = enable_restore_fp_context(1);
1536	if (err)
1537		force_sig(SIGILL);
1538out:
1539	exception_exit(prev_state);
1540}
1541
1542asmlinkage void do_mdmx(struct pt_regs *regs)
1543{
1544	enum ctx_state prev_state;
1545
1546	prev_state = exception_enter();
1547	force_sig(SIGILL);
1548	exception_exit(prev_state);
1549}
1550
1551/*
1552 * Called with interrupts disabled.
1553 */
1554asmlinkage void do_watch(struct pt_regs *regs)
1555{
1556	enum ctx_state prev_state;
1557
1558	prev_state = exception_enter();
1559	/*
1560	 * Clear WP (bit 22) bit of cause register so we don't loop
1561	 * forever.
1562	 */
1563	clear_c0_cause(CAUSEF_WP);
1564
1565	/*
1566	 * If the current thread has the watch registers loaded, save
1567	 * their values and send SIGTRAP.  Otherwise another thread
1568	 * left the registers set, clear them and continue.
1569	 */
1570	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1571		mips_read_watch_registers();
1572		local_irq_enable();
1573		force_sig_fault(SIGTRAP, TRAP_HWBKPT, NULL);
1574	} else {
1575		mips_clear_watch_registers();
1576		local_irq_enable();
1577	}
1578	exception_exit(prev_state);
1579}
1580
1581asmlinkage void do_mcheck(struct pt_regs *regs)
1582{
1583	int multi_match = regs->cp0_status & ST0_TS;
1584	enum ctx_state prev_state;
1585
1586	prev_state = exception_enter();
1587	show_regs(regs);
1588
1589	if (multi_match) {
1590		dump_tlb_regs();
1591		pr_info("\n");
1592		dump_tlb_all();
1593	}
1594
1595	show_code((void *)regs->cp0_epc, user_mode(regs));
1596
1597	/*
1598	 * Some chips may have other causes of machine check (e.g. SB1
1599	 * graduation timer)
1600	 */
1601	panic("Caught Machine Check exception - %scaused by multiple "
1602	      "matching entries in the TLB.",
1603	      (multi_match) ? "" : "not ");
1604}
1605
1606asmlinkage void do_mt(struct pt_regs *regs)
1607{
1608	int subcode;
1609
1610	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1611			>> VPECONTROL_EXCPT_SHIFT;
1612	switch (subcode) {
1613	case 0:
1614		printk(KERN_DEBUG "Thread Underflow\n");
1615		break;
1616	case 1:
1617		printk(KERN_DEBUG "Thread Overflow\n");
1618		break;
1619	case 2:
1620		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1621		break;
1622	case 3:
1623		printk(KERN_DEBUG "Gating Storage Exception\n");
1624		break;
1625	case 4:
1626		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1627		break;
1628	case 5:
1629		printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1630		break;
1631	default:
1632		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1633			subcode);
1634		break;
1635	}
1636	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1637
1638	force_sig(SIGILL);
1639}
1640
1641
1642asmlinkage void do_dsp(struct pt_regs *regs)
1643{
1644	if (cpu_has_dsp)
1645		panic("Unexpected DSP exception");
1646
1647	force_sig(SIGILL);
1648}
1649
1650asmlinkage void do_reserved(struct pt_regs *regs)
1651{
1652	/*
1653	 * Game over - no way to handle this if it ever occurs.	 Most probably
1654	 * caused by a new unknown cpu type or after another deadly
1655	 * hard/software error.
1656	 */
1657	show_regs(regs);
1658	panic("Caught reserved exception %ld - should not happen.",
1659	      (regs->cp0_cause & 0x7f) >> 2);
1660}
1661
1662static int __initdata l1parity = 1;
1663static int __init nol1parity(char *s)
1664{
1665	l1parity = 0;
1666	return 1;
1667}
1668__setup("nol1par", nol1parity);
1669static int __initdata l2parity = 1;
1670static int __init nol2parity(char *s)
1671{
1672	l2parity = 0;
1673	return 1;
1674}
1675__setup("nol2par", nol2parity);
1676
1677/*
1678 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1679 * it different ways.
1680 */
1681static inline __init void parity_protection_init(void)
1682{
1683#define ERRCTL_PE	0x80000000
1684#define ERRCTL_L2P	0x00800000
1685
1686	if (mips_cm_revision() >= CM_REV_CM3) {
1687		ulong gcr_ectl, cp0_ectl;
1688
1689		/*
1690		 * With CM3 systems we need to ensure that the L1 & L2
1691		 * parity enables are set to the same value, since this
1692		 * is presumed by the hardware engineers.
1693		 *
1694		 * If the user disabled either of L1 or L2 ECC checking,
1695		 * disable both.
1696		 */
1697		l1parity &= l2parity;
1698		l2parity &= l1parity;
1699
1700		/* Probe L1 ECC support */
1701		cp0_ectl = read_c0_ecc();
1702		write_c0_ecc(cp0_ectl | ERRCTL_PE);
1703		back_to_back_c0_hazard();
1704		cp0_ectl = read_c0_ecc();
1705
1706		/* Probe L2 ECC support */
1707		gcr_ectl = read_gcr_err_control();
1708
1709		if (!(gcr_ectl & CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT) ||
1710		    !(cp0_ectl & ERRCTL_PE)) {
1711			/*
1712			 * One of L1 or L2 ECC checking isn't supported,
1713			 * so we cannot enable either.
1714			 */
1715			l1parity = l2parity = 0;
1716		}
1717
1718		/* Configure L1 ECC checking */
1719		if (l1parity)
1720			cp0_ectl |= ERRCTL_PE;
1721		else
1722			cp0_ectl &= ~ERRCTL_PE;
1723		write_c0_ecc(cp0_ectl);
1724		back_to_back_c0_hazard();
1725		WARN_ON(!!(read_c0_ecc() & ERRCTL_PE) != l1parity);
1726
1727		/* Configure L2 ECC checking */
1728		if (l2parity)
1729			gcr_ectl |= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1730		else
1731			gcr_ectl &= ~CM_GCR_ERR_CONTROL_L2_ECC_EN;
1732		write_gcr_err_control(gcr_ectl);
1733		gcr_ectl = read_gcr_err_control();
1734		gcr_ectl &= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1735		WARN_ON(!!gcr_ectl != l2parity);
1736
1737		pr_info("Cache parity protection %sabled\n",
1738			l1parity ? "en" : "dis");
1739		return;
1740	}
1741
1742	switch (current_cpu_type()) {
1743	case CPU_24K:
1744	case CPU_34K:
1745	case CPU_74K:
1746	case CPU_1004K:
1747	case CPU_1074K:
1748	case CPU_INTERAPTIV:
1749	case CPU_PROAPTIV:
1750	case CPU_P5600:
1751	case CPU_QEMU_GENERIC:
1752	case CPU_P6600:
1753		{
1754			unsigned long errctl;
1755			unsigned int l1parity_present, l2parity_present;
1756
1757			errctl = read_c0_ecc();
1758			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1759
1760			/* probe L1 parity support */
1761			write_c0_ecc(errctl | ERRCTL_PE);
1762			back_to_back_c0_hazard();
1763			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1764
1765			/* probe L2 parity support */
1766			write_c0_ecc(errctl|ERRCTL_L2P);
1767			back_to_back_c0_hazard();
1768			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1769
1770			if (l1parity_present && l2parity_present) {
1771				if (l1parity)
1772					errctl |= ERRCTL_PE;
1773				if (l1parity ^ l2parity)
1774					errctl |= ERRCTL_L2P;
1775			} else if (l1parity_present) {
1776				if (l1parity)
1777					errctl |= ERRCTL_PE;
1778			} else if (l2parity_present) {
1779				if (l2parity)
1780					errctl |= ERRCTL_L2P;
1781			} else {
1782				/* No parity available */
1783			}
1784
1785			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1786
1787			write_c0_ecc(errctl);
1788			back_to_back_c0_hazard();
1789			errctl = read_c0_ecc();
1790			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1791
1792			if (l1parity_present)
1793				printk(KERN_INFO "Cache parity protection %sabled\n",
1794				       (errctl & ERRCTL_PE) ? "en" : "dis");
1795
1796			if (l2parity_present) {
1797				if (l1parity_present && l1parity)
1798					errctl ^= ERRCTL_L2P;
1799				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1800				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1801			}
1802		}
1803		break;
1804
1805	case CPU_5KC:
1806	case CPU_5KE:
1807	case CPU_LOONGSON32:
1808		write_c0_ecc(0x80000000);
1809		back_to_back_c0_hazard();
1810		/* Set the PE bit (bit 31) in the c0_errctl register. */
1811		printk(KERN_INFO "Cache parity protection %sabled\n",
1812		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1813		break;
1814	case CPU_20KC:
1815	case CPU_25KF:
1816		/* Clear the DE bit (bit 16) in the c0_status register. */
1817		printk(KERN_INFO "Enable cache parity protection for "
1818		       "MIPS 20KC/25KF CPUs.\n");
1819		clear_c0_status(ST0_DE);
1820		break;
1821	default:
1822		break;
1823	}
1824}
1825
1826asmlinkage void cache_parity_error(void)
1827{
1828	const int field = 2 * sizeof(unsigned long);
1829	unsigned int reg_val;
1830
1831	/* For the moment, report the problem and hang. */
1832	printk("Cache error exception:\n");
1833	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1834	reg_val = read_c0_cacheerr();
1835	printk("c0_cacheerr == %08x\n", reg_val);
1836
1837	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1838	       reg_val & (1<<30) ? "secondary" : "primary",
1839	       reg_val & (1<<31) ? "data" : "insn");
1840	if ((cpu_has_mips_r2_r6) &&
1841	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1842		pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1843			reg_val & (1<<29) ? "ED " : "",
1844			reg_val & (1<<28) ? "ET " : "",
1845			reg_val & (1<<27) ? "ES " : "",
1846			reg_val & (1<<26) ? "EE " : "",
1847			reg_val & (1<<25) ? "EB " : "",
1848			reg_val & (1<<24) ? "EI " : "",
1849			reg_val & (1<<23) ? "E1 " : "",
1850			reg_val & (1<<22) ? "E0 " : "");
1851	} else {
1852		pr_err("Error bits: %s%s%s%s%s%s%s\n",
1853			reg_val & (1<<29) ? "ED " : "",
1854			reg_val & (1<<28) ? "ET " : "",
1855			reg_val & (1<<26) ? "EE " : "",
1856			reg_val & (1<<25) ? "EB " : "",
1857			reg_val & (1<<24) ? "EI " : "",
1858			reg_val & (1<<23) ? "E1 " : "",
1859			reg_val & (1<<22) ? "E0 " : "");
1860	}
1861	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1862
1863#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1864	if (reg_val & (1<<22))
1865		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1866
1867	if (reg_val & (1<<23))
1868		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1869#endif
1870
1871	panic("Can't handle the cache error!");
1872}
1873
1874asmlinkage void do_ftlb(void)
1875{
1876	const int field = 2 * sizeof(unsigned long);
1877	unsigned int reg_val;
1878
1879	/* For the moment, report the problem and hang. */
1880	if ((cpu_has_mips_r2_r6) &&
1881	    (((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
1882	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
1883		pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1884		       read_c0_ecc());
1885		pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1886		reg_val = read_c0_cacheerr();
1887		pr_err("c0_cacheerr == %08x\n", reg_val);
1888
1889		if ((reg_val & 0xc0000000) == 0xc0000000) {
1890			pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1891		} else {
1892			pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1893			       reg_val & (1<<30) ? "secondary" : "primary",
1894			       reg_val & (1<<31) ? "data" : "insn");
1895		}
1896	} else {
1897		pr_err("FTLB error exception\n");
1898	}
1899	/* Just print the cacheerr bits for now */
1900	cache_parity_error();
1901}
1902
1903asmlinkage void do_gsexc(struct pt_regs *regs, u32 diag1)
1904{
1905	u32 exccode = (diag1 & LOONGSON_DIAG1_EXCCODE) >>
1906			LOONGSON_DIAG1_EXCCODE_SHIFT;
1907	enum ctx_state prev_state;
1908
1909	prev_state = exception_enter();
1910
1911	switch (exccode) {
1912	case 0x08:
1913		/* Undocumented exception, will trigger on certain
1914		 * also-undocumented instructions accessible from userspace.
1915		 * Processor state is not otherwise corrupted, but currently
1916		 * we don't know how to proceed. Maybe there is some
1917		 * undocumented control flag to enable the instructions?
1918		 */
1919		force_sig(SIGILL);
1920		break;
1921
1922	default:
1923		/* None of the other exceptions, documented or not, have
1924		 * further details given; none are encountered in the wild
1925		 * either. Panic in case some of them turn out to be fatal.
1926		 */
1927		show_regs(regs);
1928		panic("Unhandled Loongson exception - GSCause = %08x", diag1);
1929	}
1930
1931	exception_exit(prev_state);
1932}
1933
1934/*
1935 * SDBBP EJTAG debug exception handler.
1936 * We skip the instruction and return to the next instruction.
1937 */
1938void ejtag_exception_handler(struct pt_regs *regs)
1939{
1940	const int field = 2 * sizeof(unsigned long);
1941	unsigned long depc, old_epc, old_ra;
1942	unsigned int debug;
1943
1944	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1945	depc = read_c0_depc();
1946	debug = read_c0_debug();
1947	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1948	if (debug & 0x80000000) {
1949		/*
1950		 * In branch delay slot.
1951		 * We cheat a little bit here and use EPC to calculate the
1952		 * debug return address (DEPC). EPC is restored after the
1953		 * calculation.
1954		 */
1955		old_epc = regs->cp0_epc;
1956		old_ra = regs->regs[31];
1957		regs->cp0_epc = depc;
1958		compute_return_epc(regs);
1959		depc = regs->cp0_epc;
1960		regs->cp0_epc = old_epc;
1961		regs->regs[31] = old_ra;
1962	} else
1963		depc += 4;
1964	write_c0_depc(depc);
1965
1966#if 0
1967	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1968	write_c0_debug(debug | 0x100);
1969#endif
1970}
1971
1972/*
1973 * NMI exception handler.
1974 * No lock; only written during early bootup by CPU 0.
1975 */
1976static RAW_NOTIFIER_HEAD(nmi_chain);
1977
1978int register_nmi_notifier(struct notifier_block *nb)
1979{
1980	return raw_notifier_chain_register(&nmi_chain, nb);
1981}
1982
1983void __noreturn nmi_exception_handler(struct pt_regs *regs)
1984{
1985	char str[100];
1986
1987	nmi_enter();
1988	raw_notifier_call_chain(&nmi_chain, 0, regs);
1989	bust_spinlocks(1);
1990	snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1991		 smp_processor_id(), regs->cp0_epc);
1992	regs->cp0_epc = read_c0_errorepc();
1993	die(str, regs);
1994	nmi_exit();
1995}
1996
1997unsigned long ebase;
1998EXPORT_SYMBOL_GPL(ebase);
1999unsigned long exception_handlers[32];
2000unsigned long vi_handlers[64];
2001
2002void reserve_exception_space(phys_addr_t addr, unsigned long size)
2003{
2004	memblock_reserve(addr, size);
2005}
2006
2007void __init *set_except_vector(int n, void *addr)
2008{
2009	unsigned long handler = (unsigned long) addr;
2010	unsigned long old_handler;
2011
2012#ifdef CONFIG_CPU_MICROMIPS
2013	/*
2014	 * Only the TLB handlers are cache aligned with an even
2015	 * address. All other handlers are on an odd address and
2016	 * require no modification. Otherwise, MIPS32 mode will
2017	 * be entered when handling any TLB exceptions. That
2018	 * would be bad...since we must stay in microMIPS mode.
2019	 */
2020	if (!(handler & 0x1))
2021		handler |= 1;
2022#endif
2023	old_handler = xchg(&exception_handlers[n], handler);
2024
2025	if (n == 0 && cpu_has_divec) {
2026#ifdef CONFIG_CPU_MICROMIPS
2027		unsigned long jump_mask = ~((1 << 27) - 1);
2028#else
2029		unsigned long jump_mask = ~((1 << 28) - 1);
2030#endif
2031		u32 *buf = (u32 *)(ebase + 0x200);
2032		unsigned int k0 = 26;
2033		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
2034			uasm_i_j(&buf, handler & ~jump_mask);
2035			uasm_i_nop(&buf);
2036		} else {
2037			UASM_i_LA(&buf, k0, handler);
2038			uasm_i_jr(&buf, k0);
2039			uasm_i_nop(&buf);
2040		}
2041		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
2042	}
2043	return (void *)old_handler;
2044}
2045
2046static void do_default_vi(void)
2047{
2048	show_regs(get_irq_regs());
2049	panic("Caught unexpected vectored interrupt.");
2050}
2051
2052static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
2053{
2054	unsigned long handler;
2055	unsigned long old_handler = vi_handlers[n];
2056	int srssets = current_cpu_data.srsets;
2057	u16 *h;
2058	unsigned char *b;
2059
2060	BUG_ON(!cpu_has_veic && !cpu_has_vint);
2061
2062	if (addr == NULL) {
2063		handler = (unsigned long) do_default_vi;
2064		srs = 0;
2065	} else
2066		handler = (unsigned long) addr;
2067	vi_handlers[n] = handler;
2068
2069	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
2070
2071	if (srs >= srssets)
2072		panic("Shadow register set %d not supported", srs);
2073
2074	if (cpu_has_veic) {
2075		if (board_bind_eic_interrupt)
2076			board_bind_eic_interrupt(n, srs);
2077	} else if (cpu_has_vint) {
2078		/* SRSMap is only defined if shadow sets are implemented */
2079		if (srssets > 1)
2080			change_c0_srsmap(0xf << n*4, srs << n*4);
2081	}
2082
2083	if (srs == 0) {
2084		/*
2085		 * If no shadow set is selected then use the default handler
2086		 * that does normal register saving and standard interrupt exit
2087		 */
2088		extern char except_vec_vi, except_vec_vi_lui;
2089		extern char except_vec_vi_ori, except_vec_vi_end;
2090		extern char rollback_except_vec_vi;
2091		char *vec_start = using_rollback_handler() ?
2092			&rollback_except_vec_vi : &except_vec_vi;
2093#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
2094		const int lui_offset = &except_vec_vi_lui - vec_start + 2;
2095		const int ori_offset = &except_vec_vi_ori - vec_start + 2;
2096#else
2097		const int lui_offset = &except_vec_vi_lui - vec_start;
2098		const int ori_offset = &except_vec_vi_ori - vec_start;
2099#endif
2100		const int handler_len = &except_vec_vi_end - vec_start;
2101
2102		if (handler_len > VECTORSPACING) {
2103			/*
2104			 * Sigh... panicing won't help as the console
2105			 * is probably not configured :(
2106			 */
2107			panic("VECTORSPACING too small");
2108		}
2109
2110		set_handler(((unsigned long)b - ebase), vec_start,
2111#ifdef CONFIG_CPU_MICROMIPS
2112				(handler_len - 1));
2113#else
2114				handler_len);
2115#endif
2116		h = (u16 *)(b + lui_offset);
2117		*h = (handler >> 16) & 0xffff;
2118		h = (u16 *)(b + ori_offset);
2119		*h = (handler & 0xffff);
2120		local_flush_icache_range((unsigned long)b,
2121					 (unsigned long)(b+handler_len));
2122	}
2123	else {
2124		/*
2125		 * In other cases jump directly to the interrupt handler. It
2126		 * is the handler's responsibility to save registers if required
2127		 * (eg hi/lo) and return from the exception using "eret".
2128		 */
2129		u32 insn;
2130
2131		h = (u16 *)b;
2132		/* j handler */
2133#ifdef CONFIG_CPU_MICROMIPS
2134		insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
2135#else
2136		insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2137#endif
2138		h[0] = (insn >> 16) & 0xffff;
2139		h[1] = insn & 0xffff;
2140		h[2] = 0;
2141		h[3] = 0;
2142		local_flush_icache_range((unsigned long)b,
2143					 (unsigned long)(b+8));
2144	}
2145
2146	return (void *)old_handler;
2147}
2148
2149void *set_vi_handler(int n, vi_handler_t addr)
2150{
2151	return set_vi_srs_handler(n, addr, 0);
2152}
2153
2154extern void tlb_init(void);
2155
2156/*
2157 * Timer interrupt
2158 */
2159int cp0_compare_irq;
2160EXPORT_SYMBOL_GPL(cp0_compare_irq);
2161int cp0_compare_irq_shift;
2162
2163/*
2164 * Performance counter IRQ or -1 if shared with timer
2165 */
2166int cp0_perfcount_irq;
2167EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2168
2169/*
2170 * Fast debug channel IRQ or -1 if not present
2171 */
2172int cp0_fdc_irq;
2173EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2174
2175static int noulri;
2176
2177static int __init ulri_disable(char *s)
2178{
2179	pr_info("Disabling ulri\n");
2180	noulri = 1;
2181
2182	return 1;
2183}
2184__setup("noulri", ulri_disable);
2185
2186/* configure STATUS register */
2187static void configure_status(void)
2188{
2189	/*
2190	 * Disable coprocessors and select 32-bit or 64-bit addressing
2191	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
2192	 * flag that some firmware may have left set and the TS bit (for
2193	 * IP27).  Set XX for ISA IV code to work.
2194	 */
2195	unsigned int status_set = ST0_KERNEL_CUMASK;
2196#ifdef CONFIG_64BIT
2197	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2198#endif
2199	if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2200		status_set |= ST0_XX;
2201	if (cpu_has_dsp)
2202		status_set |= ST0_MX;
2203
2204	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2205			 status_set);
2206	back_to_back_c0_hazard();
2207}
2208
2209unsigned int hwrena;
2210EXPORT_SYMBOL_GPL(hwrena);
2211
2212/* configure HWRENA register */
2213static void configure_hwrena(void)
2214{
2215	hwrena = cpu_hwrena_impl_bits;
2216
2217	if (cpu_has_mips_r2_r6)
2218		hwrena |= MIPS_HWRENA_CPUNUM |
2219			  MIPS_HWRENA_SYNCISTEP |
2220			  MIPS_HWRENA_CC |
2221			  MIPS_HWRENA_CCRES;
2222
2223	if (!noulri && cpu_has_userlocal)
2224		hwrena |= MIPS_HWRENA_ULR;
2225
2226	if (hwrena)
2227		write_c0_hwrena(hwrena);
2228}
2229
2230static void configure_exception_vector(void)
2231{
2232	if (cpu_has_mips_r2_r6) {
2233		unsigned long sr = set_c0_status(ST0_BEV);
2234		/* If available, use WG to set top bits of EBASE */
2235		if (cpu_has_ebase_wg) {
2236#ifdef CONFIG_64BIT
2237			write_c0_ebase_64(ebase | MIPS_EBASE_WG);
2238#else
2239			write_c0_ebase(ebase | MIPS_EBASE_WG);
2240#endif
2241		}
2242		write_c0_ebase(ebase);
2243		write_c0_status(sr);
2244	}
2245	if (cpu_has_veic || cpu_has_vint) {
2246		/* Setting vector spacing enables EI/VI mode  */
2247		change_c0_intctl(0x3e0, VECTORSPACING);
2248	}
2249	if (cpu_has_divec) {
2250		if (cpu_has_mipsmt) {
2251			unsigned int vpflags = dvpe();
2252			set_c0_cause(CAUSEF_IV);
2253			evpe(vpflags);
2254		} else
2255			set_c0_cause(CAUSEF_IV);
2256	}
2257}
2258
2259void per_cpu_trap_init(bool is_boot_cpu)
2260{
2261	unsigned int cpu = smp_processor_id();
2262
2263	configure_status();
2264	configure_hwrena();
2265
2266	configure_exception_vector();
2267
2268	/*
2269	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2270	 *
2271	 *  o read IntCtl.IPTI to determine the timer interrupt
2272	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
2273	 *  o read IntCtl.IPFDC to determine the fast debug channel interrupt
2274	 */
2275	if (cpu_has_mips_r2_r6) {
2276		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2277		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2278		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2279		cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2280		if (!cp0_fdc_irq)
2281			cp0_fdc_irq = -1;
2282
2283	} else {
2284		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2285		cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2286		cp0_perfcount_irq = -1;
2287		cp0_fdc_irq = -1;
2288	}
2289
2290	if (cpu_has_mmid)
2291		cpu_data[cpu].asid_cache = 0;
2292	else if (!cpu_data[cpu].asid_cache)
2293		cpu_data[cpu].asid_cache = asid_first_version(cpu);
2294
2295	mmgrab(&init_mm);
2296	current->active_mm = &init_mm;
2297	BUG_ON(current->mm);
2298	enter_lazy_tlb(&init_mm, current);
2299
2300	/* Boot CPU's cache setup in setup_arch(). */
2301	if (!is_boot_cpu)
2302		cpu_cache_init();
2303	tlb_init();
2304	TLBMISS_HANDLER_SETUP();
2305}
2306
2307/* Install CPU exception handler */
2308void set_handler(unsigned long offset, void *addr, unsigned long size)
2309{
2310#ifdef CONFIG_CPU_MICROMIPS
2311	memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2312#else
2313	memcpy((void *)(ebase + offset), addr, size);
2314#endif
2315	local_flush_icache_range(ebase + offset, ebase + offset + size);
2316}
2317
2318static const char panic_null_cerr[] =
2319	"Trying to set NULL cache error exception handler\n";
2320
2321/*
2322 * Install uncached CPU exception handler.
2323 * This is suitable only for the cache error exception which is the only
2324 * exception handler that is being run uncached.
2325 */
2326void set_uncached_handler(unsigned long offset, void *addr,
2327	unsigned long size)
2328{
2329	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2330
2331	if (!addr)
2332		panic(panic_null_cerr);
2333
2334	memcpy((void *)(uncached_ebase + offset), addr, size);
2335}
2336
2337static int __initdata rdhwr_noopt;
2338static int __init set_rdhwr_noopt(char *str)
2339{
2340	rdhwr_noopt = 1;
2341	return 1;
2342}
2343
2344__setup("rdhwr_noopt", set_rdhwr_noopt);
2345
2346void __init trap_init(void)
2347{
2348	extern char except_vec3_generic;
2349	extern char except_vec4;
2350	extern char except_vec3_r4000;
2351	unsigned long i, vec_size;
2352	phys_addr_t ebase_pa;
2353
2354	check_wait();
2355
2356	if (!cpu_has_mips_r2_r6) {
2357		ebase = CAC_BASE;
2358		vec_size = 0x400;
2359	} else {
2360		if (cpu_has_veic || cpu_has_vint)
2361			vec_size = 0x200 + VECTORSPACING*64;
2362		else
2363			vec_size = PAGE_SIZE;
2364
2365		ebase_pa = memblock_phys_alloc(vec_size, 1 << fls(vec_size));
2366		if (!ebase_pa)
2367			panic("%s: Failed to allocate %lu bytes align=0x%x\n",
2368			      __func__, vec_size, 1 << fls(vec_size));
2369
2370		/*
2371		 * Try to ensure ebase resides in KSeg0 if possible.
2372		 *
2373		 * It shouldn't generally be in XKPhys on MIPS64 to avoid
2374		 * hitting a poorly defined exception base for Cache Errors.
2375		 * The allocation is likely to be in the low 512MB of physical,
2376		 * in which case we should be able to convert to KSeg0.
2377		 *
2378		 * EVA is special though as it allows segments to be rearranged
2379		 * and to become uncached during cache error handling.
2380		 */
2381		if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
2382			ebase = CKSEG0ADDR(ebase_pa);
2383		else
2384			ebase = (unsigned long)phys_to_virt(ebase_pa);
2385	}
2386
2387	if (cpu_has_mmips) {
2388		unsigned int config3 = read_c0_config3();
2389
2390		if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2391			write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2392		else
2393			write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2394	}
2395
2396	if (board_ebase_setup)
2397		board_ebase_setup();
2398	per_cpu_trap_init(true);
2399	memblock_set_bottom_up(false);
2400
2401	/*
2402	 * Copy the generic exception handlers to their final destination.
2403	 * This will be overridden later as suitable for a particular
2404	 * configuration.
2405	 */
2406	set_handler(0x180, &except_vec3_generic, 0x80);
2407
2408	/*
2409	 * Setup default vectors
2410	 */
2411	for (i = 0; i <= 31; i++)
2412		set_except_vector(i, handle_reserved);
2413
2414	/*
2415	 * Copy the EJTAG debug exception vector handler code to it's final
2416	 * destination.
2417	 */
2418	if (cpu_has_ejtag && board_ejtag_handler_setup)
2419		board_ejtag_handler_setup();
2420
2421	/*
2422	 * Only some CPUs have the watch exceptions.
2423	 */
2424	if (cpu_has_watch)
2425		set_except_vector(EXCCODE_WATCH, handle_watch);
2426
2427	/*
2428	 * Initialise interrupt handlers
2429	 */
2430	if (cpu_has_veic || cpu_has_vint) {
2431		int nvec = cpu_has_veic ? 64 : 8;
2432		for (i = 0; i < nvec; i++)
2433			set_vi_handler(i, NULL);
2434	}
2435	else if (cpu_has_divec)
2436		set_handler(0x200, &except_vec4, 0x8);
2437
2438	/*
2439	 * Some CPUs can enable/disable for cache parity detection, but does
2440	 * it different ways.
2441	 */
2442	parity_protection_init();
2443
2444	/*
2445	 * The Data Bus Errors / Instruction Bus Errors are signaled
2446	 * by external hardware.  Therefore these two exceptions
2447	 * may have board specific handlers.
2448	 */
2449	if (board_be_init)
2450		board_be_init();
2451
2452	set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2453					rollback_handle_int : handle_int);
2454	set_except_vector(EXCCODE_MOD, handle_tlbm);
2455	set_except_vector(EXCCODE_TLBL, handle_tlbl);
2456	set_except_vector(EXCCODE_TLBS, handle_tlbs);
2457
2458	set_except_vector(EXCCODE_ADEL, handle_adel);
2459	set_except_vector(EXCCODE_ADES, handle_ades);
2460
2461	set_except_vector(EXCCODE_IBE, handle_ibe);
2462	set_except_vector(EXCCODE_DBE, handle_dbe);
2463
2464	set_except_vector(EXCCODE_SYS, handle_sys);
2465	set_except_vector(EXCCODE_BP, handle_bp);
2466
2467	if (rdhwr_noopt)
2468		set_except_vector(EXCCODE_RI, handle_ri);
2469	else {
2470		if (cpu_has_vtag_icache)
2471			set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2472		else if (current_cpu_type() == CPU_LOONGSON64)
2473			set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2474		else
2475			set_except_vector(EXCCODE_RI, handle_ri_rdhwr);
2476	}
2477
2478	set_except_vector(EXCCODE_CPU, handle_cpu);
2479	set_except_vector(EXCCODE_OV, handle_ov);
2480	set_except_vector(EXCCODE_TR, handle_tr);
2481	set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2482
2483	if (board_nmi_handler_setup)
2484		board_nmi_handler_setup();
2485
2486	if (cpu_has_fpu && !cpu_has_nofpuex)
2487		set_except_vector(EXCCODE_FPE, handle_fpe);
2488
2489	if (cpu_has_ftlbparex)
2490		set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2491
2492	if (cpu_has_gsexcex)
2493		set_except_vector(LOONGSON_EXCCODE_GSEXC, handle_gsexc);
2494
2495	if (cpu_has_rixiex) {
2496		set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2497		set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2498	}
2499
2500	set_except_vector(EXCCODE_MSADIS, handle_msa);
2501	set_except_vector(EXCCODE_MDMX, handle_mdmx);
2502
2503	if (cpu_has_mcheck)
2504		set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2505
2506	if (cpu_has_mipsmt)
2507		set_except_vector(EXCCODE_THREAD, handle_mt);
2508
2509	set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2510
2511	if (board_cache_error_setup)
2512		board_cache_error_setup();
2513
2514	if (cpu_has_vce)
2515		/* Special exception: R4[04]00 uses also the divec space. */
2516		set_handler(0x180, &except_vec3_r4000, 0x100);
2517	else if (cpu_has_4kex)
2518		set_handler(0x180, &except_vec3_generic, 0x80);
2519	else
2520		set_handler(0x080, &except_vec3_generic, 0x80);
2521
2522	local_flush_icache_range(ebase, ebase + vec_size);
2523
2524	sort_extable(__start___dbe_table, __stop___dbe_table);
2525
2526	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
2527}
2528
2529static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2530			    void *v)
2531{
2532	switch (cmd) {
2533	case CPU_PM_ENTER_FAILED:
2534	case CPU_PM_EXIT:
2535		configure_status();
2536		configure_hwrena();
2537		configure_exception_vector();
2538
2539		/* Restore register with CPU number for TLB handlers */
2540		TLBMISS_HANDLER_RESTORE();
2541
2542		break;
2543	}
2544
2545	return NOTIFY_OK;
2546}
2547
2548static struct notifier_block trap_pm_notifier_block = {
2549	.notifier_call = trap_pm_notifier,
2550};
2551
2552static int __init trap_pm_init(void)
2553{
2554	return cpu_pm_register_notifier(&trap_pm_notifier_block);
2555}
2556arch_initcall(trap_pm_init);