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);
 106static int (*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
 113void mips_set_be_handler(int (*handler)(struct pt_regs *regs, int is_fixup))
 114{
 115	board_be_handler = handler;
 116}
 117EXPORT_SYMBOL_GPL(mips_set_be_handler);
 118
 119static void show_raw_backtrace(unsigned long reg29, const char *loglvl,
 120			       bool user)
 121{
 122	unsigned long *sp = (unsigned long *)(reg29 & ~3);
 123	unsigned long addr;
 124
 125	printk("%sCall Trace:", loglvl);
 126#ifdef CONFIG_KALLSYMS
 127	printk("%s\n", loglvl);
 128#endif
 129	while (!kstack_end(sp)) {
 130		if (__get_addr(&addr, sp++, user)) {
 
 
 131			printk("%s (Bad stack address)", loglvl);
 132			break;
 133		}
 134		if (__kernel_text_address(addr))
 135			print_ip_sym(loglvl, addr);
 136	}
 137	printk("%s\n", loglvl);
 138}
 139
 140#ifdef CONFIG_KALLSYMS
 141int raw_show_trace;
 142static int __init set_raw_show_trace(char *str)
 143{
 144	raw_show_trace = 1;
 145	return 1;
 146}
 147__setup("raw_show_trace", set_raw_show_trace);
 148#endif
 149
 150static void show_backtrace(struct task_struct *task, const struct pt_regs *regs,
 151			   const char *loglvl, bool user)
 152{
 153	unsigned long sp = regs->regs[29];
 154	unsigned long ra = regs->regs[31];
 155	unsigned long pc = regs->cp0_epc;
 156
 157	if (!task)
 158		task = current;
 159
 160	if (raw_show_trace || user_mode(regs) || !__kernel_text_address(pc)) {
 161		show_raw_backtrace(sp, loglvl, user);
 162		return;
 163	}
 164	printk("%sCall Trace:\n", loglvl);
 165	do {
 166		print_ip_sym(loglvl, pc);
 167		pc = unwind_stack(task, &sp, pc, &ra);
 168	} while (pc);
 169	pr_cont("\n");
 170}
 171
 172/*
 173 * This routine abuses get_user()/put_user() to reference pointers
 174 * with at least a bit of error checking ...
 175 */
 176static void show_stacktrace(struct task_struct *task,
 177	const struct pt_regs *regs, const char *loglvl, bool user)
 178{
 179	const int field = 2 * sizeof(unsigned long);
 180	unsigned long stackdata;
 181	int i;
 182	unsigned long *sp = (unsigned long *)regs->regs[29];
 183
 184	printk("%sStack :", loglvl);
 185	i = 0;
 186	while ((unsigned long) sp & (PAGE_SIZE - 1)) {
 187		if (i && ((i % (64 / field)) == 0)) {
 188			pr_cont("\n");
 189			printk("%s       ", loglvl);
 190		}
 191		if (i > 39) {
 192			pr_cont(" ...");
 193			break;
 194		}
 195
 196		if (__get_addr(&stackdata, sp++, user)) {
 197			pr_cont(" (Bad stack address)");
 198			break;
 199		}
 200
 201		pr_cont(" %0*lx", field, stackdata);
 202		i++;
 203	}
 204	pr_cont("\n");
 205	show_backtrace(task, regs, loglvl, user);
 206}
 207
 208void show_stack(struct task_struct *task, unsigned long *sp, const char *loglvl)
 209{
 210	struct pt_regs regs;
 
 211
 212	regs.cp0_status = KSU_KERNEL;
 213	if (sp) {
 214		regs.regs[29] = (unsigned long)sp;
 215		regs.regs[31] = 0;
 216		regs.cp0_epc = 0;
 217	} else {
 218		if (task && task != current) {
 219			regs.regs[29] = task->thread.reg29;
 220			regs.regs[31] = 0;
 221			regs.cp0_epc = task->thread.reg31;
 222		} else {
 223			prepare_frametrace(&regs);
 224		}
 225	}
 226	show_stacktrace(task, &regs, loglvl, false);
 
 
 
 
 
 
 227}
 228
 229static void show_code(void *pc, bool user)
 230{
 231	long i;
 232	unsigned short *pc16 = NULL;
 233
 234	printk("Code:");
 235
 236	if ((unsigned long)pc & 1)
 237		pc16 = (u16 *)((unsigned long)pc & ~1);
 238
 239	for(i = -3 ; i < 6 ; i++) {
 240		if (pc16) {
 241			u16 insn16;
 242
 243			if (__get_inst16(&insn16, pc16 + i, user))
 244				goto bad_address;
 245
 246			pr_cont("%c%04x%c", (i?' ':'<'), insn16, (i?' ':'>'));
 247		} else {
 248			u32 insn32;
 249
 250			if (__get_inst32(&insn32, (u32 *)pc + i, user))
 251				goto bad_address;
 252
 253			pr_cont("%c%08x%c", (i?' ':'<'), insn32, (i?' ':'>'));
 254		}
 
 255	}
 256	pr_cont("\n");
 257	return;
 258
 259bad_address:
 260	pr_cont(" (Bad address in epc)\n\n");
 261}
 262
 263static void __show_regs(const struct pt_regs *regs)
 264{
 265	const int field = 2 * sizeof(unsigned long);
 266	unsigned int cause = regs->cp0_cause;
 267	unsigned int exccode;
 268	int i;
 269
 270	show_regs_print_info(KERN_DEFAULT);
 271
 272	/*
 273	 * Saved main processor registers
 274	 */
 275	for (i = 0; i < 32; ) {
 276		if ((i % 4) == 0)
 277			printk("$%2d   :", i);
 278		if (i == 0)
 279			pr_cont(" %0*lx", field, 0UL);
 280		else if (i == 26 || i == 27)
 281			pr_cont(" %*s", field, "");
 282		else
 283			pr_cont(" %0*lx", field, regs->regs[i]);
 284
 285		i++;
 286		if ((i % 4) == 0)
 287			pr_cont("\n");
 288	}
 289
 290#ifdef CONFIG_CPU_HAS_SMARTMIPS
 291	printk("Acx    : %0*lx\n", field, regs->acx);
 292#endif
 293	if (MIPS_ISA_REV < 6) {
 294		printk("Hi    : %0*lx\n", field, regs->hi);
 295		printk("Lo    : %0*lx\n", field, regs->lo);
 296	}
 297
 298	/*
 299	 * Saved cp0 registers
 300	 */
 301	printk("epc   : %0*lx %pS\n", field, regs->cp0_epc,
 302	       (void *) regs->cp0_epc);
 303	printk("ra    : %0*lx %pS\n", field, regs->regs[31],
 304	       (void *) regs->regs[31]);
 305
 306	printk("Status: %08x	", (uint32_t) regs->cp0_status);
 307
 308	if (cpu_has_3kex) {
 309		if (regs->cp0_status & ST0_KUO)
 310			pr_cont("KUo ");
 311		if (regs->cp0_status & ST0_IEO)
 312			pr_cont("IEo ");
 313		if (regs->cp0_status & ST0_KUP)
 314			pr_cont("KUp ");
 315		if (regs->cp0_status & ST0_IEP)
 316			pr_cont("IEp ");
 317		if (regs->cp0_status & ST0_KUC)
 318			pr_cont("KUc ");
 319		if (regs->cp0_status & ST0_IEC)
 320			pr_cont("IEc ");
 321	} else if (cpu_has_4kex) {
 322		if (regs->cp0_status & ST0_KX)
 323			pr_cont("KX ");
 324		if (regs->cp0_status & ST0_SX)
 325			pr_cont("SX ");
 326		if (regs->cp0_status & ST0_UX)
 327			pr_cont("UX ");
 328		switch (regs->cp0_status & ST0_KSU) {
 329		case KSU_USER:
 330			pr_cont("USER ");
 331			break;
 332		case KSU_SUPERVISOR:
 333			pr_cont("SUPERVISOR ");
 334			break;
 335		case KSU_KERNEL:
 336			pr_cont("KERNEL ");
 337			break;
 338		default:
 339			pr_cont("BAD_MODE ");
 340			break;
 341		}
 342		if (regs->cp0_status & ST0_ERL)
 343			pr_cont("ERL ");
 344		if (regs->cp0_status & ST0_EXL)
 345			pr_cont("EXL ");
 346		if (regs->cp0_status & ST0_IE)
 347			pr_cont("IE ");
 348	}
 349	pr_cont("\n");
 350
 351	exccode = (cause & CAUSEF_EXCCODE) >> CAUSEB_EXCCODE;
 352	printk("Cause : %08x (ExcCode %02x)\n", cause, exccode);
 353
 354	if (1 <= exccode && exccode <= 5)
 355		printk("BadVA : %0*lx\n", field, regs->cp0_badvaddr);
 356
 357	printk("PrId  : %08x (%s)\n", read_c0_prid(),
 358	       cpu_name_string());
 359}
 360
 361/*
 362 * FIXME: really the generic show_regs should take a const pointer argument.
 363 */
 364void show_regs(struct pt_regs *regs)
 365{
 366	__show_regs(regs);
 367	dump_stack();
 368}
 369
 370void show_registers(struct pt_regs *regs)
 371{
 372	const int field = 2 * sizeof(unsigned long);
 
 373
 374	__show_regs(regs);
 375	print_modules();
 376	printk("Process %s (pid: %d, threadinfo=%p, task=%p, tls=%0*lx)\n",
 377	       current->comm, current->pid, current_thread_info(), current,
 378	      field, current_thread_info()->tp_value);
 379	if (cpu_has_userlocal) {
 380		unsigned long tls;
 381
 382		tls = read_c0_userlocal();
 383		if (tls != current_thread_info()->tp_value)
 384			printk("*HwTLS: %0*lx\n", field, tls);
 385	}
 386
 387	show_stacktrace(current, regs, KERN_DEFAULT, user_mode(regs));
 388	show_code((void *)regs->cp0_epc, user_mode(regs));
 
 
 
 389	printk("\n");
 
 390}
 391
 392static DEFINE_RAW_SPINLOCK(die_lock);
 393
 394void __noreturn die(const char *str, struct pt_regs *regs)
 395{
 396	static int die_counter;
 397	int sig = SIGSEGV;
 398
 399	oops_enter();
 400
 401	if (notify_die(DIE_OOPS, str, regs, 0, current->thread.trap_nr,
 402		       SIGSEGV) == NOTIFY_STOP)
 403		sig = 0;
 404
 405	console_verbose();
 406	raw_spin_lock_irq(&die_lock);
 407	bust_spinlocks(1);
 408
 409	printk("%s[#%d]:\n", str, ++die_counter);
 410	show_registers(regs);
 411	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 412	raw_spin_unlock_irq(&die_lock);
 413
 414	oops_exit();
 415
 416	if (in_interrupt())
 417		panic("Fatal exception in interrupt");
 418
 419	if (panic_on_oops)
 420		panic("Fatal exception");
 421
 422	if (regs && kexec_should_crash(current))
 423		crash_kexec(regs);
 424
 425	make_task_dead(sig);
 426}
 427
 428extern struct exception_table_entry __start___dbe_table[];
 429extern struct exception_table_entry __stop___dbe_table[];
 430
 431__asm__(
 432"	.section	__dbe_table, \"a\"\n"
 433"	.previous			\n");
 434
 435/* Given an address, look for it in the exception tables. */
 436static const struct exception_table_entry *search_dbe_tables(unsigned long addr)
 437{
 438	const struct exception_table_entry *e;
 439
 440	e = search_extable(__start___dbe_table,
 441			   __stop___dbe_table - __start___dbe_table, addr);
 442	if (!e)
 443		e = search_module_dbetables(addr);
 444	return e;
 445}
 446
 447asmlinkage void do_be(struct pt_regs *regs)
 448{
 449	const int field = 2 * sizeof(unsigned long);
 450	const struct exception_table_entry *fixup = NULL;
 451	int data = regs->cp0_cause & 4;
 452	int action = MIPS_BE_FATAL;
 453	enum ctx_state prev_state;
 454
 455	prev_state = exception_enter();
 456	/* XXX For now.	 Fixme, this searches the wrong table ...  */
 457	if (data && !user_mode(regs))
 458		fixup = search_dbe_tables(exception_epc(regs));
 459
 460	if (fixup)
 461		action = MIPS_BE_FIXUP;
 462
 463	if (board_be_handler)
 464		action = board_be_handler(regs, fixup != NULL);
 465	else
 466		mips_cm_error_report();
 467
 468	switch (action) {
 469	case MIPS_BE_DISCARD:
 470		goto out;
 471	case MIPS_BE_FIXUP:
 472		if (fixup) {
 473			regs->cp0_epc = fixup->nextinsn;
 474			goto out;
 475		}
 476		break;
 477	default:
 478		break;
 479	}
 480
 481	/*
 482	 * Assume it would be too dangerous to continue ...
 483	 */
 484	printk(KERN_ALERT "%s bus error, epc == %0*lx, ra == %0*lx\n",
 485	       data ? "Data" : "Instruction",
 486	       field, regs->cp0_epc, field, regs->regs[31]);
 487	if (notify_die(DIE_OOPS, "bus error", regs, 0, current->thread.trap_nr,
 488		       SIGBUS) == NOTIFY_STOP)
 489		goto out;
 490
 491	die_if_kernel("Oops", regs);
 492	force_sig(SIGBUS);
 493
 494out:
 495	exception_exit(prev_state);
 496}
 497
 498/*
 499 * ll/sc, rdhwr, sync emulation
 500 */
 501
 502#define OPCODE 0xfc000000
 503#define BASE   0x03e00000
 504#define RT     0x001f0000
 505#define OFFSET 0x0000ffff
 506#define LL     0xc0000000
 507#define SC     0xe0000000
 508#define SPEC0  0x00000000
 509#define SPEC3  0x7c000000
 510#define RD     0x0000f800
 511#define FUNC   0x0000003f
 512#define SYNC   0x0000000f
 513#define RDHWR  0x0000003b
 514
 515/*  microMIPS definitions   */
 516#define MM_POOL32A_FUNC 0xfc00ffff
 517#define MM_RDHWR        0x00006b3c
 518#define MM_RS           0x001f0000
 519#define MM_RT           0x03e00000
 520
 521/*
 522 * The ll_bit is cleared by r*_switch.S
 523 */
 524
 525unsigned int ll_bit;
 526struct task_struct *ll_task;
 527
 528static inline int simulate_ll(struct pt_regs *regs, unsigned int opcode)
 529{
 530	unsigned long value, __user *vaddr;
 531	long offset;
 532
 533	/*
 534	 * analyse the ll instruction that just caused a ri exception
 535	 * and put the referenced address to addr.
 536	 */
 537
 538	/* sign extend offset */
 539	offset = opcode & OFFSET;
 540	offset <<= 16;
 541	offset >>= 16;
 542
 543	vaddr = (unsigned long __user *)
 544		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 545
 546	if ((unsigned long)vaddr & 3)
 547		return SIGBUS;
 548	if (get_user(value, vaddr))
 549		return SIGSEGV;
 550
 551	preempt_disable();
 552
 553	if (ll_task == NULL || ll_task == current) {
 554		ll_bit = 1;
 555	} else {
 556		ll_bit = 0;
 557	}
 558	ll_task = current;
 559
 560	preempt_enable();
 561
 562	regs->regs[(opcode & RT) >> 16] = value;
 563
 564	return 0;
 565}
 566
 567static inline int simulate_sc(struct pt_regs *regs, unsigned int opcode)
 568{
 569	unsigned long __user *vaddr;
 570	unsigned long reg;
 571	long offset;
 572
 573	/*
 574	 * analyse the sc instruction that just caused a ri exception
 575	 * and put the referenced address to addr.
 576	 */
 577
 578	/* sign extend offset */
 579	offset = opcode & OFFSET;
 580	offset <<= 16;
 581	offset >>= 16;
 582
 583	vaddr = (unsigned long __user *)
 584		((unsigned long)(regs->regs[(opcode & BASE) >> 21]) + offset);
 585	reg = (opcode & RT) >> 16;
 586
 587	if ((unsigned long)vaddr & 3)
 588		return SIGBUS;
 589
 590	preempt_disable();
 591
 592	if (ll_bit == 0 || ll_task != current) {
 593		regs->regs[reg] = 0;
 594		preempt_enable();
 595		return 0;
 596	}
 597
 598	preempt_enable();
 599
 600	if (put_user(regs->regs[reg], vaddr))
 601		return SIGSEGV;
 602
 603	regs->regs[reg] = 1;
 604
 605	return 0;
 606}
 607
 608/*
 609 * ll uses the opcode of lwc0 and sc uses the opcode of swc0.  That is both
 610 * opcodes are supposed to result in coprocessor unusable exceptions if
 611 * executed on ll/sc-less processors.  That's the theory.  In practice a
 612 * few processors such as NEC's VR4100 throw reserved instruction exceptions
 613 * instead, so we're doing the emulation thing in both exception handlers.
 614 */
 615static int simulate_llsc(struct pt_regs *regs, unsigned int opcode)
 616{
 617	if ((opcode & OPCODE) == LL) {
 618		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 619				1, regs, 0);
 620		return simulate_ll(regs, opcode);
 621	}
 622	if ((opcode & OPCODE) == SC) {
 623		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 624				1, regs, 0);
 625		return simulate_sc(regs, opcode);
 626	}
 627
 628	return -1;			/* Must be something else ... */
 629}
 630
 631/*
 632 * Simulate trapping 'rdhwr' instructions to provide user accessible
 633 * registers not implemented in hardware.
 634 */
 635static int simulate_rdhwr(struct pt_regs *regs, int rd, int rt)
 636{
 637	struct thread_info *ti = task_thread_info(current);
 638
 639	perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 640			1, regs, 0);
 641	switch (rd) {
 642	case MIPS_HWR_CPUNUM:		/* CPU number */
 643		regs->regs[rt] = smp_processor_id();
 644		return 0;
 645	case MIPS_HWR_SYNCISTEP:	/* SYNCI length */
 646		regs->regs[rt] = min(current_cpu_data.dcache.linesz,
 647				     current_cpu_data.icache.linesz);
 648		return 0;
 649	case MIPS_HWR_CC:		/* Read count register */
 650		regs->regs[rt] = read_c0_count();
 651		return 0;
 652	case MIPS_HWR_CCRES:		/* Count register resolution */
 653		switch (current_cpu_type()) {
 654		case CPU_20KC:
 655		case CPU_25KF:
 656			regs->regs[rt] = 1;
 657			break;
 658		default:
 659			regs->regs[rt] = 2;
 660		}
 661		return 0;
 662	case MIPS_HWR_ULR:		/* Read UserLocal register */
 663		regs->regs[rt] = ti->tp_value;
 664		return 0;
 665	default:
 666		return -1;
 667	}
 668}
 669
 670static int simulate_rdhwr_normal(struct pt_regs *regs, unsigned int opcode)
 671{
 672	if ((opcode & OPCODE) == SPEC3 && (opcode & FUNC) == RDHWR) {
 673		int rd = (opcode & RD) >> 11;
 674		int rt = (opcode & RT) >> 16;
 675
 676		simulate_rdhwr(regs, rd, rt);
 677		return 0;
 678	}
 679
 680	/* Not ours.  */
 681	return -1;
 682}
 683
 684static int simulate_rdhwr_mm(struct pt_regs *regs, unsigned int opcode)
 685{
 686	if ((opcode & MM_POOL32A_FUNC) == MM_RDHWR) {
 687		int rd = (opcode & MM_RS) >> 16;
 688		int rt = (opcode & MM_RT) >> 21;
 689		simulate_rdhwr(regs, rd, rt);
 690		return 0;
 691	}
 692
 693	/* Not ours.  */
 694	return -1;
 695}
 696
 697static int simulate_sync(struct pt_regs *regs, unsigned int opcode)
 698{
 699	if ((opcode & OPCODE) == SPEC0 && (opcode & FUNC) == SYNC) {
 700		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS,
 701				1, regs, 0);
 702		return 0;
 703	}
 704
 705	return -1;			/* Must be something else ... */
 706}
 707
 708/*
 709 * Loongson-3 CSR instructions emulation
 710 */
 711
 712#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
 713
 714#define LWC2             0xc8000000
 715#define RS               BASE
 716#define CSR_OPCODE2      0x00000118
 717#define CSR_OPCODE2_MASK 0x000007ff
 718#define CSR_FUNC_MASK    RT
 719#define CSR_FUNC_CPUCFG  0x8
 720
 721static int simulate_loongson3_cpucfg(struct pt_regs *regs,
 722				     unsigned int opcode)
 723{
 724	int op = opcode & OPCODE;
 725	int op2 = opcode & CSR_OPCODE2_MASK;
 726	int csr_func = (opcode & CSR_FUNC_MASK) >> 16;
 727
 728	if (op == LWC2 && op2 == CSR_OPCODE2 && csr_func == CSR_FUNC_CPUCFG) {
 729		int rd = (opcode & RD) >> 11;
 730		int rs = (opcode & RS) >> 21;
 731		__u64 sel = regs->regs[rs];
 732
 733		perf_sw_event(PERF_COUNT_SW_EMULATION_FAULTS, 1, regs, 0);
 734
 735		/* Do not emulate on unsupported core models. */
 736		preempt_disable();
 737		if (!loongson3_cpucfg_emulation_enabled(&current_cpu_data)) {
 738			preempt_enable();
 739			return -1;
 740		}
 741		regs->regs[rd] = loongson3_cpucfg_read_synthesized(
 742			&current_cpu_data, sel);
 743		preempt_enable();
 744		return 0;
 745	}
 746
 747	/* Not ours.  */
 748	return -1;
 749}
 750#endif /* CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION */
 751
 752asmlinkage void do_ov(struct pt_regs *regs)
 753{
 754	enum ctx_state prev_state;
 755
 756	prev_state = exception_enter();
 757	die_if_kernel("Integer overflow", regs);
 758
 759	force_sig_fault(SIGFPE, FPE_INTOVF, (void __user *)regs->cp0_epc);
 760	exception_exit(prev_state);
 761}
 762
 763#ifdef CONFIG_MIPS_FP_SUPPORT
 764
 765/*
 766 * Send SIGFPE according to FCSR Cause bits, which must have already
 767 * been masked against Enable bits.  This is impotant as Inexact can
 768 * happen together with Overflow or Underflow, and `ptrace' can set
 769 * any bits.
 770 */
 771void force_fcr31_sig(unsigned long fcr31, void __user *fault_addr,
 772		     struct task_struct *tsk)
 773{
 774	int si_code = FPE_FLTUNK;
 775
 776	if (fcr31 & FPU_CSR_INV_X)
 777		si_code = FPE_FLTINV;
 778	else if (fcr31 & FPU_CSR_DIV_X)
 779		si_code = FPE_FLTDIV;
 780	else if (fcr31 & FPU_CSR_OVF_X)
 781		si_code = FPE_FLTOVF;
 782	else if (fcr31 & FPU_CSR_UDF_X)
 783		si_code = FPE_FLTUND;
 784	else if (fcr31 & FPU_CSR_INE_X)
 785		si_code = FPE_FLTRES;
 786
 787	force_sig_fault_to_task(SIGFPE, si_code, fault_addr, tsk);
 788}
 789
 790int process_fpemu_return(int sig, void __user *fault_addr, unsigned long fcr31)
 791{
 792	int si_code;
 
 793
 794	switch (sig) {
 795	case 0:
 796		return 0;
 797
 798	case SIGFPE:
 799		force_fcr31_sig(fcr31, fault_addr, current);
 800		return 1;
 801
 802	case SIGBUS:
 803		force_sig_fault(SIGBUS, BUS_ADRERR, fault_addr);
 804		return 1;
 805
 806	case SIGSEGV:
 807		mmap_read_lock(current->mm);
 808		if (vma_lookup(current->mm, (unsigned long)fault_addr))
 
 809			si_code = SEGV_ACCERR;
 810		else
 811			si_code = SEGV_MAPERR;
 812		mmap_read_unlock(current->mm);
 813		force_sig_fault(SIGSEGV, si_code, fault_addr);
 814		return 1;
 815
 816	default:
 817		force_sig(sig);
 818		return 1;
 819	}
 820}
 821
 822static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
 823		       unsigned long old_epc, unsigned long old_ra)
 824{
 825	union mips_instruction inst = { .word = opcode };
 826	void __user *fault_addr;
 827	unsigned long fcr31;
 828	int sig;
 829
 830	/* If it's obviously not an FP instruction, skip it */
 831	switch (inst.i_format.opcode) {
 832	case cop1_op:
 833	case cop1x_op:
 834	case lwc1_op:
 835	case ldc1_op:
 836	case swc1_op:
 837	case sdc1_op:
 838		break;
 839
 840	default:
 841		return -1;
 842	}
 843
 844	/*
 845	 * do_ri skipped over the instruction via compute_return_epc, undo
 846	 * that for the FPU emulator.
 847	 */
 848	regs->cp0_epc = old_epc;
 849	regs->regs[31] = old_ra;
 850
 851	/* Run the emulator */
 852	sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 853				       &fault_addr);
 854
 855	/*
 856	 * We can't allow the emulated instruction to leave any
 857	 * enabled Cause bits set in $fcr31.
 858	 */
 859	fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
 860	current->thread.fpu.fcr31 &= ~fcr31;
 861
 862	/* Restore the hardware register state */
 863	own_fpu(1);
 864
 865	/* Send a signal if required.  */
 866	process_fpemu_return(sig, fault_addr, fcr31);
 867
 868	return 0;
 869}
 870
 871/*
 872 * XXX Delayed fp exceptions when doing a lazy ctx switch XXX
 873 */
 874asmlinkage void do_fpe(struct pt_regs *regs, unsigned long fcr31)
 875{
 876	enum ctx_state prev_state;
 877	void __user *fault_addr;
 878	int sig;
 879
 880	prev_state = exception_enter();
 881	if (notify_die(DIE_FP, "FP exception", regs, 0, current->thread.trap_nr,
 882		       SIGFPE) == NOTIFY_STOP)
 883		goto out;
 884
 885	/* Clear FCSR.Cause before enabling interrupts */
 886	write_32bit_cp1_register(CP1_STATUS, fcr31 & ~mask_fcr31_x(fcr31));
 887	local_irq_enable();
 888
 889	die_if_kernel("FP exception in kernel code", regs);
 890
 891	if (fcr31 & FPU_CSR_UNI_X) {
 892		/*
 893		 * Unimplemented operation exception.  If we've got the full
 894		 * software emulator on-board, let's use it...
 895		 *
 896		 * Force FPU to dump state into task/thread context.  We're
 897		 * moving a lot of data here for what is probably a single
 898		 * instruction, but the alternative is to pre-decode the FP
 899		 * register operands before invoking the emulator, which seems
 900		 * a bit extreme for what should be an infrequent event.
 901		 */
 902
 903		/* Run the emulator */
 904		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 1,
 905					       &fault_addr);
 906
 907		/*
 908		 * We can't allow the emulated instruction to leave any
 909		 * enabled Cause bits set in $fcr31.
 910		 */
 911		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
 912		current->thread.fpu.fcr31 &= ~fcr31;
 913
 914		/* Restore the hardware register state */
 915		own_fpu(1);	/* Using the FPU again.	 */
 916	} else {
 917		sig = SIGFPE;
 918		fault_addr = (void __user *) regs->cp0_epc;
 919	}
 920
 921	/* Send a signal if required.  */
 922	process_fpemu_return(sig, fault_addr, fcr31);
 923
 924out:
 925	exception_exit(prev_state);
 926}
 927
 928/*
 929 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
 930 * emulated more than some threshold number of instructions, force migration to
 931 * a "CPU" that has FP support.
 932 */
 933static void mt_ase_fp_affinity(void)
 934{
 935#ifdef CONFIG_MIPS_MT_FPAFF
 936	if (mt_fpemul_threshold > 0 &&
 937	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
 938		/*
 939		 * If there's no FPU present, or if the application has already
 940		 * restricted the allowed set to exclude any CPUs with FPUs,
 941		 * we'll skip the procedure.
 942		 */
 943		if (cpumask_intersects(&current->cpus_mask, &mt_fpu_cpumask)) {
 944			cpumask_t tmask;
 945
 946			current->thread.user_cpus_allowed
 947				= current->cpus_mask;
 948			cpumask_and(&tmask, &current->cpus_mask,
 949				    &mt_fpu_cpumask);
 950			set_cpus_allowed_ptr(current, &tmask);
 951			set_thread_flag(TIF_FPUBOUND);
 952		}
 953	}
 954#endif /* CONFIG_MIPS_MT_FPAFF */
 955}
 956
 957#else /* !CONFIG_MIPS_FP_SUPPORT */
 958
 959static int simulate_fp(struct pt_regs *regs, unsigned int opcode,
 960		       unsigned long old_epc, unsigned long old_ra)
 961{
 962	return -1;
 963}
 964
 965#endif /* !CONFIG_MIPS_FP_SUPPORT */
 966
 967void do_trap_or_bp(struct pt_regs *regs, unsigned int code, int si_code,
 968	const char *str)
 969{
 970	char b[40];
 971
 972#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
 973	if (kgdb_ll_trap(DIE_TRAP, str, regs, code, current->thread.trap_nr,
 974			 SIGTRAP) == NOTIFY_STOP)
 975		return;
 976#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
 977
 978	if (notify_die(DIE_TRAP, str, regs, code, current->thread.trap_nr,
 979		       SIGTRAP) == NOTIFY_STOP)
 980		return;
 981
 982	/*
 983	 * A short test says that IRIX 5.3 sends SIGTRAP for all trap
 984	 * insns, even for trap and break codes that indicate arithmetic
 985	 * failures.  Weird ...
 986	 * But should we continue the brokenness???  --macro
 987	 */
 988	switch (code) {
 989	case BRK_OVERFLOW:
 990	case BRK_DIVZERO:
 991		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
 992		die_if_kernel(b, regs);
 993		force_sig_fault(SIGFPE,
 994				code == BRK_DIVZERO ? FPE_INTDIV : FPE_INTOVF,
 995				(void __user *) regs->cp0_epc);
 996		break;
 997	case BRK_BUG:
 998		die_if_kernel("Kernel bug detected", regs);
 999		force_sig(SIGTRAP);
1000		break;
1001	case BRK_MEMU:
1002		/*
1003		 * This breakpoint code is used by the FPU emulator to retake
1004		 * control of the CPU after executing the instruction from the
1005		 * delay slot of an emulated branch.
1006		 *
1007		 * Terminate if exception was recognized as a delay slot return
1008		 * otherwise handle as normal.
1009		 */
1010		if (do_dsemulret(regs))
1011			return;
1012
1013		die_if_kernel("Math emu break/trap", regs);
1014		force_sig(SIGTRAP);
1015		break;
1016	default:
1017		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
1018		die_if_kernel(b, regs);
1019		if (si_code) {
1020			force_sig_fault(SIGTRAP, si_code, NULL);
1021		} else {
1022			force_sig(SIGTRAP);
1023		}
1024	}
1025}
1026
1027asmlinkage void do_bp(struct pt_regs *regs)
1028{
1029	unsigned long epc = msk_isa16_mode(exception_epc(regs));
1030	unsigned int opcode, bcode;
1031	enum ctx_state prev_state;
1032	bool user = user_mode(regs);
 
 
 
 
1033
1034	prev_state = exception_enter();
1035	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1036	if (get_isa16_mode(regs->cp0_epc)) {
1037		u16 instr[2];
1038
1039		if (__get_inst16(&instr[0], (u16 *)epc, user))
1040			goto out_sigsegv;
1041
1042		if (!cpu_has_mmips) {
1043			/* MIPS16e mode */
1044			bcode = (instr[0] >> 5) & 0x3f;
1045		} else if (mm_insn_16bit(instr[0])) {
1046			/* 16-bit microMIPS BREAK */
1047			bcode = instr[0] & 0xf;
1048		} else {
1049			/* 32-bit microMIPS BREAK */
1050			if (__get_inst16(&instr[1], (u16 *)(epc + 2), user))
1051				goto out_sigsegv;
1052			opcode = (instr[0] << 16) | instr[1];
1053			bcode = (opcode >> 6) & ((1 << 20) - 1);
1054		}
1055	} else {
1056		if (__get_inst32(&opcode, (u32 *)epc, user))
1057			goto out_sigsegv;
1058		bcode = (opcode >> 6) & ((1 << 20) - 1);
1059	}
1060
1061	/*
1062	 * There is the ancient bug in the MIPS assemblers that the break
1063	 * code starts left to bit 16 instead to bit 6 in the opcode.
1064	 * Gas is bug-compatible, but not always, grrr...
1065	 * We handle both cases with a simple heuristics.  --macro
1066	 */
1067	if (bcode >= (1 << 10))
1068		bcode = ((bcode & ((1 << 10) - 1)) << 10) | (bcode >> 10);
1069
1070	/*
1071	 * notify the kprobe handlers, if instruction is likely to
1072	 * pertain to them.
1073	 */
1074	switch (bcode) {
1075	case BRK_UPROBE:
1076		if (notify_die(DIE_UPROBE, "uprobe", regs, bcode,
1077			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1078			goto out;
1079		else
1080			break;
1081	case BRK_UPROBE_XOL:
1082		if (notify_die(DIE_UPROBE_XOL, "uprobe_xol", regs, bcode,
1083			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1084			goto out;
1085		else
1086			break;
1087	case BRK_KPROBE_BP:
1088		if (notify_die(DIE_BREAK, "debug", regs, bcode,
1089			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1090			goto out;
1091		else
1092			break;
1093	case BRK_KPROBE_SSTEPBP:
1094		if (notify_die(DIE_SSTEPBP, "single_step", regs, bcode,
1095			       current->thread.trap_nr, SIGTRAP) == NOTIFY_STOP)
1096			goto out;
1097		else
1098			break;
1099	default:
1100		break;
1101	}
1102
1103	do_trap_or_bp(regs, bcode, TRAP_BRKPT, "Break");
1104
1105out:
 
1106	exception_exit(prev_state);
1107	return;
1108
1109out_sigsegv:
1110	force_sig(SIGSEGV);
1111	goto out;
1112}
1113
1114asmlinkage void do_tr(struct pt_regs *regs)
1115{
1116	u32 opcode, tcode = 0;
1117	enum ctx_state prev_state;
1118	u16 instr[2];
1119	bool user = user_mode(regs);
1120	unsigned long epc = msk_isa16_mode(exception_epc(regs));
1121
 
 
 
 
1122	prev_state = exception_enter();
1123	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1124	if (get_isa16_mode(regs->cp0_epc)) {
1125		if (__get_inst16(&instr[0], (u16 *)(epc + 0), user) ||
1126		    __get_inst16(&instr[1], (u16 *)(epc + 2), user))
1127			goto out_sigsegv;
1128		opcode = (instr[0] << 16) | instr[1];
1129		/* Immediate versions don't provide a code.  */
1130		if (!(opcode & OPCODE))
1131			tcode = (opcode >> 12) & ((1 << 4) - 1);
1132	} else {
1133		if (__get_inst32(&opcode, (u32 *)epc, user))
1134			goto out_sigsegv;
1135		/* Immediate versions don't provide a code.  */
1136		if (!(opcode & OPCODE))
1137			tcode = (opcode >> 6) & ((1 << 10) - 1);
1138	}
1139
1140	do_trap_or_bp(regs, tcode, 0, "Trap");
1141
1142out:
 
1143	exception_exit(prev_state);
1144	return;
1145
1146out_sigsegv:
1147	force_sig(SIGSEGV);
1148	goto out;
1149}
1150
1151asmlinkage void do_ri(struct pt_regs *regs)
1152{
1153	unsigned int __user *epc = (unsigned int __user *)exception_epc(regs);
1154	unsigned long old_epc = regs->cp0_epc;
1155	unsigned long old31 = regs->regs[31];
1156	enum ctx_state prev_state;
1157	unsigned int opcode = 0;
1158	int status = -1;
1159
1160	/*
1161	 * Avoid any kernel code. Just emulate the R2 instruction
1162	 * as quickly as possible.
1163	 */
1164	if (mipsr2_emulation && cpu_has_mips_r6 &&
1165	    likely(user_mode(regs)) &&
1166	    likely(get_user(opcode, epc) >= 0)) {
1167		unsigned long fcr31 = 0;
1168
1169		status = mipsr2_decoder(regs, opcode, &fcr31);
1170		switch (status) {
1171		case 0:
1172		case SIGEMT:
1173			return;
1174		case SIGILL:
1175			goto no_r2_instr;
1176		default:
1177			process_fpemu_return(status,
1178					     &current->thread.cp0_baduaddr,
1179					     fcr31);
1180			return;
1181		}
1182	}
1183
1184no_r2_instr:
1185
1186	prev_state = exception_enter();
1187	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1188
1189	if (notify_die(DIE_RI, "RI Fault", regs, 0, current->thread.trap_nr,
1190		       SIGILL) == NOTIFY_STOP)
1191		goto out;
1192
1193	die_if_kernel("Reserved instruction in kernel code", regs);
1194
1195	if (unlikely(compute_return_epc(regs) < 0))
1196		goto out;
1197
1198	if (!get_isa16_mode(regs->cp0_epc)) {
1199		if (unlikely(get_user(opcode, epc) < 0))
1200			status = SIGSEGV;
1201
1202		if (!cpu_has_llsc && status < 0)
1203			status = simulate_llsc(regs, opcode);
1204
1205		if (status < 0)
1206			status = simulate_rdhwr_normal(regs, opcode);
1207
1208		if (status < 0)
1209			status = simulate_sync(regs, opcode);
1210
1211		if (status < 0)
1212			status = simulate_fp(regs, opcode, old_epc, old31);
1213
1214#ifdef CONFIG_CPU_LOONGSON3_CPUCFG_EMULATION
1215		if (status < 0)
1216			status = simulate_loongson3_cpucfg(regs, opcode);
1217#endif
1218	} else if (cpu_has_mmips) {
1219		unsigned short mmop[2] = { 0 };
1220
1221		if (unlikely(get_user(mmop[0], (u16 __user *)epc + 0) < 0))
1222			status = SIGSEGV;
1223		if (unlikely(get_user(mmop[1], (u16 __user *)epc + 1) < 0))
1224			status = SIGSEGV;
1225		opcode = mmop[0];
1226		opcode = (opcode << 16) | mmop[1];
1227
1228		if (status < 0)
1229			status = simulate_rdhwr_mm(regs, opcode);
1230	}
1231
1232	if (status < 0)
1233		status = SIGILL;
1234
1235	if (unlikely(status > 0)) {
1236		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
1237		regs->regs[31] = old31;
1238		force_sig(status);
1239	}
1240
1241out:
1242	exception_exit(prev_state);
1243}
1244
1245/*
1246 * No lock; only written during early bootup by CPU 0.
1247 */
1248static RAW_NOTIFIER_HEAD(cu2_chain);
1249
1250int __ref register_cu2_notifier(struct notifier_block *nb)
1251{
1252	return raw_notifier_chain_register(&cu2_chain, nb);
1253}
1254
1255int cu2_notifier_call_chain(unsigned long val, void *v)
1256{
1257	return raw_notifier_call_chain(&cu2_chain, val, v);
1258}
1259
1260static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
1261	void *data)
1262{
1263	struct pt_regs *regs = data;
1264
1265	die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
1266			      "instruction", regs);
1267	force_sig(SIGILL);
1268
1269	return NOTIFY_OK;
1270}
1271
1272#ifdef CONFIG_MIPS_FP_SUPPORT
1273
1274static int enable_restore_fp_context(int msa)
1275{
1276	int err, was_fpu_owner, prior_msa;
1277	bool first_fp;
1278
1279	/* Initialize context if it hasn't been used already */
1280	first_fp = init_fp_ctx(current);
1281
1282	if (first_fp) {
1283		preempt_disable();
1284		err = own_fpu_inatomic(1);
1285		if (msa && !err) {
1286			enable_msa();
1287			/*
1288			 * with MSA enabled, userspace can see MSACSR
1289			 * and MSA regs, but the values in them are from
1290			 * other task before current task, restore them
1291			 * from saved fp/msa context
1292			 */
1293			write_msa_csr(current->thread.fpu.msacsr);
1294			/*
1295			 * own_fpu_inatomic(1) just restore low 64bit,
1296			 * fix the high 64bit
1297			 */
1298			init_msa_upper();
1299			set_thread_flag(TIF_USEDMSA);
1300			set_thread_flag(TIF_MSA_CTX_LIVE);
1301		}
1302		preempt_enable();
1303		return err;
1304	}
1305
1306	/*
1307	 * This task has formerly used the FP context.
1308	 *
1309	 * If this thread has no live MSA vector context then we can simply
1310	 * restore the scalar FP context. If it has live MSA vector context
1311	 * (that is, it has or may have used MSA since last performing a
1312	 * function call) then we'll need to restore the vector context. This
1313	 * applies even if we're currently only executing a scalar FP
1314	 * instruction. This is because if we were to later execute an MSA
1315	 * instruction then we'd either have to:
1316	 *
1317	 *  - Restore the vector context & clobber any registers modified by
1318	 *    scalar FP instructions between now & then.
1319	 *
1320	 * or
1321	 *
1322	 *  - Not restore the vector context & lose the most significant bits
1323	 *    of all vector registers.
1324	 *
1325	 * Neither of those options is acceptable. We cannot restore the least
1326	 * significant bits of the registers now & only restore the most
1327	 * significant bits later because the most significant bits of any
1328	 * vector registers whose aliased FP register is modified now will have
1329	 * been zeroed. We'd have no way to know that when restoring the vector
1330	 * context & thus may load an outdated value for the most significant
1331	 * bits of a vector register.
1332	 */
1333	if (!msa && !thread_msa_context_live())
1334		return own_fpu(1);
1335
1336	/*
1337	 * This task is using or has previously used MSA. Thus we require
1338	 * that Status.FR == 1.
1339	 */
1340	preempt_disable();
1341	was_fpu_owner = is_fpu_owner();
1342	err = own_fpu_inatomic(0);
1343	if (err)
1344		goto out;
1345
1346	enable_msa();
1347	write_msa_csr(current->thread.fpu.msacsr);
1348	set_thread_flag(TIF_USEDMSA);
1349
1350	/*
1351	 * If this is the first time that the task is using MSA and it has
1352	 * previously used scalar FP in this time slice then we already nave
1353	 * FP context which we shouldn't clobber. We do however need to clear
1354	 * the upper 64b of each vector register so that this task has no
1355	 * opportunity to see data left behind by another.
1356	 */
1357	prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
1358	if (!prior_msa && was_fpu_owner) {
1359		init_msa_upper();
1360
1361		goto out;
1362	}
1363
1364	if (!prior_msa) {
1365		/*
1366		 * Restore the least significant 64b of each vector register
1367		 * from the existing scalar FP context.
1368		 */
1369		_restore_fp(current);
1370
1371		/*
1372		 * The task has not formerly used MSA, so clear the upper 64b
1373		 * of each vector register such that it cannot see data left
1374		 * behind by another task.
1375		 */
1376		init_msa_upper();
1377	} else {
1378		/* We need to restore the vector context. */
1379		restore_msa(current);
1380
1381		/* Restore the scalar FP control & status register */
1382		if (!was_fpu_owner)
1383			write_32bit_cp1_register(CP1_STATUS,
1384						 current->thread.fpu.fcr31);
1385	}
1386
1387out:
1388	preempt_enable();
1389
1390	return 0;
1391}
1392
1393#else /* !CONFIG_MIPS_FP_SUPPORT */
1394
1395static int enable_restore_fp_context(int msa)
1396{
1397	return SIGILL;
1398}
1399
1400#endif /* CONFIG_MIPS_FP_SUPPORT */
1401
1402asmlinkage void do_cpu(struct pt_regs *regs)
1403{
1404	enum ctx_state prev_state;
1405	unsigned int __user *epc;
1406	unsigned long old_epc, old31;
1407	unsigned int opcode;
1408	unsigned int cpid;
1409	int status;
1410
1411	prev_state = exception_enter();
1412	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
1413
1414	if (cpid != 2)
1415		die_if_kernel("do_cpu invoked from kernel context!", regs);
1416
1417	switch (cpid) {
1418	case 0:
1419		epc = (unsigned int __user *)exception_epc(regs);
1420		old_epc = regs->cp0_epc;
1421		old31 = regs->regs[31];
1422		opcode = 0;
1423		status = -1;
1424
1425		if (unlikely(compute_return_epc(regs) < 0))
1426			break;
1427
1428		if (!get_isa16_mode(regs->cp0_epc)) {
1429			if (unlikely(get_user(opcode, epc) < 0))
1430				status = SIGSEGV;
1431
1432			if (!cpu_has_llsc && status < 0)
1433				status = simulate_llsc(regs, opcode);
1434		}
1435
1436		if (status < 0)
1437			status = SIGILL;
1438
1439		if (unlikely(status > 0)) {
1440			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
1441			regs->regs[31] = old31;
1442			force_sig(status);
1443		}
1444
1445		break;
1446
1447#ifdef CONFIG_MIPS_FP_SUPPORT
1448	case 3:
1449		/*
1450		 * The COP3 opcode space and consequently the CP0.Status.CU3
1451		 * bit and the CP0.Cause.CE=3 encoding have been removed as
1452		 * of the MIPS III ISA.  From the MIPS IV and MIPS32r2 ISAs
1453		 * up the space has been reused for COP1X instructions, that
1454		 * are enabled by the CP0.Status.CU1 bit and consequently
1455		 * use the CP0.Cause.CE=1 encoding for Coprocessor Unusable
1456		 * exceptions.  Some FPU-less processors that implement one
1457		 * of these ISAs however use this code erroneously for COP1X
1458		 * instructions.  Therefore we redirect this trap to the FP
1459		 * emulator too.
1460		 */
1461		if (raw_cpu_has_fpu || !cpu_has_mips_4_5_64_r2_r6) {
1462			force_sig(SIGILL);
1463			break;
1464		}
1465		fallthrough;
1466	case 1: {
1467		void __user *fault_addr;
1468		unsigned long fcr31;
1469		int err, sig;
1470
1471		err = enable_restore_fp_context(0);
1472
1473		if (raw_cpu_has_fpu && !err)
1474			break;
1475
1476		sig = fpu_emulator_cop1Handler(regs, &current->thread.fpu, 0,
1477					       &fault_addr);
1478
1479		/*
1480		 * We can't allow the emulated instruction to leave
1481		 * any enabled Cause bits set in $fcr31.
1482		 */
1483		fcr31 = mask_fcr31_x(current->thread.fpu.fcr31);
1484		current->thread.fpu.fcr31 &= ~fcr31;
1485
1486		/* Send a signal if required.  */
1487		if (!process_fpemu_return(sig, fault_addr, fcr31) && !err)
1488			mt_ase_fp_affinity();
1489
1490		break;
1491	}
1492#else /* CONFIG_MIPS_FP_SUPPORT */
1493	case 1:
1494	case 3:
1495		force_sig(SIGILL);
1496		break;
1497#endif /* CONFIG_MIPS_FP_SUPPORT */
1498
1499	case 2:
1500		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
1501		break;
1502	}
1503
1504	exception_exit(prev_state);
1505}
1506
1507asmlinkage void do_msa_fpe(struct pt_regs *regs, unsigned int msacsr)
1508{
1509	enum ctx_state prev_state;
1510
1511	prev_state = exception_enter();
1512	current->thread.trap_nr = (regs->cp0_cause >> 2) & 0x1f;
1513	if (notify_die(DIE_MSAFP, "MSA FP exception", regs, 0,
1514		       current->thread.trap_nr, SIGFPE) == NOTIFY_STOP)
1515		goto out;
1516
1517	/* Clear MSACSR.Cause before enabling interrupts */
1518	write_msa_csr(msacsr & ~MSA_CSR_CAUSEF);
1519	local_irq_enable();
1520
1521	die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
1522	force_sig(SIGFPE);
1523out:
1524	exception_exit(prev_state);
1525}
1526
1527asmlinkage void do_msa(struct pt_regs *regs)
1528{
1529	enum ctx_state prev_state;
1530	int err;
1531
1532	prev_state = exception_enter();
1533
1534	if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
1535		force_sig(SIGILL);
1536		goto out;
1537	}
1538
1539	die_if_kernel("do_msa invoked from kernel context!", regs);
1540
1541	err = enable_restore_fp_context(1);
1542	if (err)
1543		force_sig(SIGILL);
1544out:
1545	exception_exit(prev_state);
1546}
1547
1548asmlinkage void do_mdmx(struct pt_regs *regs)
1549{
1550	enum ctx_state prev_state;
1551
1552	prev_state = exception_enter();
1553	force_sig(SIGILL);
1554	exception_exit(prev_state);
1555}
1556
1557/*
1558 * Called with interrupts disabled.
1559 */
1560asmlinkage void do_watch(struct pt_regs *regs)
1561{
1562	enum ctx_state prev_state;
1563
1564	prev_state = exception_enter();
1565	/*
1566	 * Clear WP (bit 22) bit of cause register so we don't loop
1567	 * forever.
1568	 */
1569	clear_c0_cause(CAUSEF_WP);
1570
1571	/*
1572	 * If the current thread has the watch registers loaded, save
1573	 * their values and send SIGTRAP.  Otherwise another thread
1574	 * left the registers set, clear them and continue.
1575	 */
1576	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
1577		mips_read_watch_registers();
1578		local_irq_enable();
1579		force_sig_fault(SIGTRAP, TRAP_HWBKPT, NULL);
1580	} else {
1581		mips_clear_watch_registers();
1582		local_irq_enable();
1583	}
1584	exception_exit(prev_state);
1585}
1586
1587asmlinkage void do_mcheck(struct pt_regs *regs)
1588{
1589	int multi_match = regs->cp0_status & ST0_TS;
1590	enum ctx_state prev_state;
 
1591
1592	prev_state = exception_enter();
1593	show_regs(regs);
1594
1595	if (multi_match) {
1596		dump_tlb_regs();
1597		pr_info("\n");
1598		dump_tlb_all();
1599	}
1600
1601	show_code((void *)regs->cp0_epc, user_mode(regs));
 
 
 
 
 
1602
1603	/*
1604	 * Some chips may have other causes of machine check (e.g. SB1
1605	 * graduation timer)
1606	 */
1607	panic("Caught Machine Check exception - %scaused by multiple "
1608	      "matching entries in the TLB.",
1609	      (multi_match) ? "" : "not ");
1610}
1611
1612asmlinkage void do_mt(struct pt_regs *regs)
1613{
1614	int subcode;
1615
1616	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
1617			>> VPECONTROL_EXCPT_SHIFT;
1618	switch (subcode) {
1619	case 0:
1620		printk(KERN_DEBUG "Thread Underflow\n");
1621		break;
1622	case 1:
1623		printk(KERN_DEBUG "Thread Overflow\n");
1624		break;
1625	case 2:
1626		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
1627		break;
1628	case 3:
1629		printk(KERN_DEBUG "Gating Storage Exception\n");
1630		break;
1631	case 4:
1632		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
1633		break;
1634	case 5:
1635		printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
1636		break;
1637	default:
1638		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
1639			subcode);
1640		break;
1641	}
1642	die_if_kernel("MIPS MT Thread exception in kernel", regs);
1643
1644	force_sig(SIGILL);
1645}
1646
1647
1648asmlinkage void do_dsp(struct pt_regs *regs)
1649{
1650	if (cpu_has_dsp)
1651		panic("Unexpected DSP exception");
1652
1653	force_sig(SIGILL);
1654}
1655
1656asmlinkage void do_reserved(struct pt_regs *regs)
1657{
1658	/*
1659	 * Game over - no way to handle this if it ever occurs.	 Most probably
1660	 * caused by a new unknown cpu type or after another deadly
1661	 * hard/software error.
1662	 */
1663	show_regs(regs);
1664	panic("Caught reserved exception %ld - should not happen.",
1665	      (regs->cp0_cause & 0x7f) >> 2);
1666}
1667
1668static int __initdata l1parity = 1;
1669static int __init nol1parity(char *s)
1670{
1671	l1parity = 0;
1672	return 1;
1673}
1674__setup("nol1par", nol1parity);
1675static int __initdata l2parity = 1;
1676static int __init nol2parity(char *s)
1677{
1678	l2parity = 0;
1679	return 1;
1680}
1681__setup("nol2par", nol2parity);
1682
1683/*
1684 * Some MIPS CPUs can enable/disable for cache parity detection, but do
1685 * it different ways.
1686 */
1687static inline __init void parity_protection_init(void)
1688{
1689#define ERRCTL_PE	0x80000000
1690#define ERRCTL_L2P	0x00800000
1691
1692	if (mips_cm_revision() >= CM_REV_CM3) {
1693		ulong gcr_ectl, cp0_ectl;
1694
1695		/*
1696		 * With CM3 systems we need to ensure that the L1 & L2
1697		 * parity enables are set to the same value, since this
1698		 * is presumed by the hardware engineers.
1699		 *
1700		 * If the user disabled either of L1 or L2 ECC checking,
1701		 * disable both.
1702		 */
1703		l1parity &= l2parity;
1704		l2parity &= l1parity;
1705
1706		/* Probe L1 ECC support */
1707		cp0_ectl = read_c0_ecc();
1708		write_c0_ecc(cp0_ectl | ERRCTL_PE);
1709		back_to_back_c0_hazard();
1710		cp0_ectl = read_c0_ecc();
1711
1712		/* Probe L2 ECC support */
1713		gcr_ectl = read_gcr_err_control();
1714
1715		if (!(gcr_ectl & CM_GCR_ERR_CONTROL_L2_ECC_SUPPORT) ||
1716		    !(cp0_ectl & ERRCTL_PE)) {
1717			/*
1718			 * One of L1 or L2 ECC checking isn't supported,
1719			 * so we cannot enable either.
1720			 */
1721			l1parity = l2parity = 0;
1722		}
1723
1724		/* Configure L1 ECC checking */
1725		if (l1parity)
1726			cp0_ectl |= ERRCTL_PE;
1727		else
1728			cp0_ectl &= ~ERRCTL_PE;
1729		write_c0_ecc(cp0_ectl);
1730		back_to_back_c0_hazard();
1731		WARN_ON(!!(read_c0_ecc() & ERRCTL_PE) != l1parity);
1732
1733		/* Configure L2 ECC checking */
1734		if (l2parity)
1735			gcr_ectl |= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1736		else
1737			gcr_ectl &= ~CM_GCR_ERR_CONTROL_L2_ECC_EN;
1738		write_gcr_err_control(gcr_ectl);
1739		gcr_ectl = read_gcr_err_control();
1740		gcr_ectl &= CM_GCR_ERR_CONTROL_L2_ECC_EN;
1741		WARN_ON(!!gcr_ectl != l2parity);
1742
1743		pr_info("Cache parity protection %sabled\n",
1744			l1parity ? "en" : "dis");
1745		return;
1746	}
1747
1748	switch (current_cpu_type()) {
1749	case CPU_24K:
1750	case CPU_34K:
1751	case CPU_74K:
1752	case CPU_1004K:
1753	case CPU_1074K:
1754	case CPU_INTERAPTIV:
1755	case CPU_PROAPTIV:
1756	case CPU_P5600:
1757	case CPU_QEMU_GENERIC:
1758	case CPU_P6600:
1759		{
1760			unsigned long errctl;
1761			unsigned int l1parity_present, l2parity_present;
1762
1763			errctl = read_c0_ecc();
1764			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);
1765
1766			/* probe L1 parity support */
1767			write_c0_ecc(errctl | ERRCTL_PE);
1768			back_to_back_c0_hazard();
1769			l1parity_present = (read_c0_ecc() & ERRCTL_PE);
1770
1771			/* probe L2 parity support */
1772			write_c0_ecc(errctl|ERRCTL_L2P);
1773			back_to_back_c0_hazard();
1774			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);
1775
1776			if (l1parity_present && l2parity_present) {
1777				if (l1parity)
1778					errctl |= ERRCTL_PE;
1779				if (l1parity ^ l2parity)
1780					errctl |= ERRCTL_L2P;
1781			} else if (l1parity_present) {
1782				if (l1parity)
1783					errctl |= ERRCTL_PE;
1784			} else if (l2parity_present) {
1785				if (l2parity)
1786					errctl |= ERRCTL_L2P;
1787			} else {
1788				/* No parity available */
1789			}
1790
1791			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);
1792
1793			write_c0_ecc(errctl);
1794			back_to_back_c0_hazard();
1795			errctl = read_c0_ecc();
1796			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);
1797
1798			if (l1parity_present)
1799				printk(KERN_INFO "Cache parity protection %sabled\n",
1800				       (errctl & ERRCTL_PE) ? "en" : "dis");
1801
1802			if (l2parity_present) {
1803				if (l1parity_present && l1parity)
1804					errctl ^= ERRCTL_L2P;
1805				printk(KERN_INFO "L2 cache parity protection %sabled\n",
1806				       (errctl & ERRCTL_L2P) ? "en" : "dis");
1807			}
1808		}
1809		break;
1810
1811	case CPU_5KC:
1812	case CPU_5KE:
1813	case CPU_LOONGSON32:
1814		write_c0_ecc(0x80000000);
1815		back_to_back_c0_hazard();
1816		/* Set the PE bit (bit 31) in the c0_errctl register. */
1817		printk(KERN_INFO "Cache parity protection %sabled\n",
1818		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
1819		break;
1820	case CPU_20KC:
1821	case CPU_25KF:
1822		/* Clear the DE bit (bit 16) in the c0_status register. */
1823		printk(KERN_INFO "Enable cache parity protection for "
1824		       "MIPS 20KC/25KF CPUs.\n");
1825		clear_c0_status(ST0_DE);
1826		break;
1827	default:
1828		break;
1829	}
1830}
1831
1832asmlinkage void cache_parity_error(void)
1833{
1834	const int field = 2 * sizeof(unsigned long);
1835	unsigned int reg_val;
1836
1837	/* For the moment, report the problem and hang. */
1838	printk("Cache error exception:\n");
1839	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1840	reg_val = read_c0_cacheerr();
1841	printk("c0_cacheerr == %08x\n", reg_val);
1842
1843	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1844	       reg_val & (1<<30) ? "secondary" : "primary",
1845	       reg_val & (1<<31) ? "data" : "insn");
1846	if ((cpu_has_mips_r2_r6) &&
1847	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
1848		pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
1849			reg_val & (1<<29) ? "ED " : "",
1850			reg_val & (1<<28) ? "ET " : "",
1851			reg_val & (1<<27) ? "ES " : "",
1852			reg_val & (1<<26) ? "EE " : "",
1853			reg_val & (1<<25) ? "EB " : "",
1854			reg_val & (1<<24) ? "EI " : "",
1855			reg_val & (1<<23) ? "E1 " : "",
1856			reg_val & (1<<22) ? "E0 " : "");
1857	} else {
1858		pr_err("Error bits: %s%s%s%s%s%s%s\n",
1859			reg_val & (1<<29) ? "ED " : "",
1860			reg_val & (1<<28) ? "ET " : "",
1861			reg_val & (1<<26) ? "EE " : "",
1862			reg_val & (1<<25) ? "EB " : "",
1863			reg_val & (1<<24) ? "EI " : "",
1864			reg_val & (1<<23) ? "E1 " : "",
1865			reg_val & (1<<22) ? "E0 " : "");
1866	}
1867	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));
1868
1869#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
1870	if (reg_val & (1<<22))
1871		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());
1872
1873	if (reg_val & (1<<23))
1874		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
1875#endif
1876
1877	panic("Can't handle the cache error!");
1878}
1879
1880asmlinkage void do_ftlb(void)
1881{
1882	const int field = 2 * sizeof(unsigned long);
1883	unsigned int reg_val;
1884
1885	/* For the moment, report the problem and hang. */
1886	if ((cpu_has_mips_r2_r6) &&
1887	    (((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS) ||
1888	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_LOONGSON))) {
1889		pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
1890		       read_c0_ecc());
1891		pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
1892		reg_val = read_c0_cacheerr();
1893		pr_err("c0_cacheerr == %08x\n", reg_val);
1894
1895		if ((reg_val & 0xc0000000) == 0xc0000000) {
1896			pr_err("Decoded c0_cacheerr: FTLB parity error\n");
1897		} else {
1898			pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
1899			       reg_val & (1<<30) ? "secondary" : "primary",
1900			       reg_val & (1<<31) ? "data" : "insn");
1901		}
1902	} else {
1903		pr_err("FTLB error exception\n");
1904	}
1905	/* Just print the cacheerr bits for now */
1906	cache_parity_error();
1907}
1908
1909asmlinkage void do_gsexc(struct pt_regs *regs, u32 diag1)
1910{
1911	u32 exccode = (diag1 & LOONGSON_DIAG1_EXCCODE) >>
1912			LOONGSON_DIAG1_EXCCODE_SHIFT;
1913	enum ctx_state prev_state;
1914
1915	prev_state = exception_enter();
1916
1917	switch (exccode) {
1918	case 0x08:
1919		/* Undocumented exception, will trigger on certain
1920		 * also-undocumented instructions accessible from userspace.
1921		 * Processor state is not otherwise corrupted, but currently
1922		 * we don't know how to proceed. Maybe there is some
1923		 * undocumented control flag to enable the instructions?
1924		 */
1925		force_sig(SIGILL);
1926		break;
1927
1928	default:
1929		/* None of the other exceptions, documented or not, have
1930		 * further details given; none are encountered in the wild
1931		 * either. Panic in case some of them turn out to be fatal.
1932		 */
1933		show_regs(regs);
1934		panic("Unhandled Loongson exception - GSCause = %08x", diag1);
1935	}
1936
1937	exception_exit(prev_state);
1938}
1939
1940/*
1941 * SDBBP EJTAG debug exception handler.
1942 * We skip the instruction and return to the next instruction.
1943 */
1944void ejtag_exception_handler(struct pt_regs *regs)
1945{
1946	const int field = 2 * sizeof(unsigned long);
1947	unsigned long depc, old_epc, old_ra;
1948	unsigned int debug;
1949
1950	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
1951	depc = read_c0_depc();
1952	debug = read_c0_debug();
1953	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
1954	if (debug & 0x80000000) {
1955		/*
1956		 * In branch delay slot.
1957		 * We cheat a little bit here and use EPC to calculate the
1958		 * debug return address (DEPC). EPC is restored after the
1959		 * calculation.
1960		 */
1961		old_epc = regs->cp0_epc;
1962		old_ra = regs->regs[31];
1963		regs->cp0_epc = depc;
1964		compute_return_epc(regs);
1965		depc = regs->cp0_epc;
1966		regs->cp0_epc = old_epc;
1967		regs->regs[31] = old_ra;
1968	} else
1969		depc += 4;
1970	write_c0_depc(depc);
1971
1972#if 0
1973	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
1974	write_c0_debug(debug | 0x100);
1975#endif
1976}
1977
1978/*
1979 * NMI exception handler.
1980 * No lock; only written during early bootup by CPU 0.
1981 */
1982static RAW_NOTIFIER_HEAD(nmi_chain);
1983
1984int register_nmi_notifier(struct notifier_block *nb)
1985{
1986	return raw_notifier_chain_register(&nmi_chain, nb);
1987}
1988
1989void __noreturn nmi_exception_handler(struct pt_regs *regs)
1990{
1991	char str[100];
1992
1993	nmi_enter();
1994	raw_notifier_call_chain(&nmi_chain, 0, regs);
1995	bust_spinlocks(1);
1996	snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
1997		 smp_processor_id(), regs->cp0_epc);
1998	regs->cp0_epc = read_c0_errorepc();
1999	die(str, regs);
2000	nmi_exit();
2001}
2002
 
 
2003unsigned long ebase;
2004EXPORT_SYMBOL_GPL(ebase);
2005unsigned long exception_handlers[32];
2006unsigned long vi_handlers[64];
2007
2008void reserve_exception_space(phys_addr_t addr, unsigned long size)
2009{
2010	memblock_reserve(addr, size);
2011}
2012
2013void __init *set_except_vector(int n, void *addr)
2014{
2015	unsigned long handler = (unsigned long) addr;
2016	unsigned long old_handler;
2017
2018#ifdef CONFIG_CPU_MICROMIPS
2019	/*
2020	 * Only the TLB handlers are cache aligned with an even
2021	 * address. All other handlers are on an odd address and
2022	 * require no modification. Otherwise, MIPS32 mode will
2023	 * be entered when handling any TLB exceptions. That
2024	 * would be bad...since we must stay in microMIPS mode.
2025	 */
2026	if (!(handler & 0x1))
2027		handler |= 1;
2028#endif
2029	old_handler = xchg(&exception_handlers[n], handler);
2030
2031	if (n == 0 && cpu_has_divec) {
2032#ifdef CONFIG_CPU_MICROMIPS
2033		unsigned long jump_mask = ~((1 << 27) - 1);
2034#else
2035		unsigned long jump_mask = ~((1 << 28) - 1);
2036#endif
2037		u32 *buf = (u32 *)(ebase + 0x200);
2038		unsigned int k0 = 26;
2039		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
2040			uasm_i_j(&buf, handler & ~jump_mask);
2041			uasm_i_nop(&buf);
2042		} else {
2043			UASM_i_LA(&buf, k0, handler);
2044			uasm_i_jr(&buf, k0);
2045			uasm_i_nop(&buf);
2046		}
2047		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
2048	}
2049	return (void *)old_handler;
2050}
2051
2052static void do_default_vi(void)
2053{
2054	show_regs(get_irq_regs());
2055	panic("Caught unexpected vectored interrupt.");
2056}
2057
2058static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
2059{
2060	unsigned long handler;
2061	unsigned long old_handler = vi_handlers[n];
2062	int srssets = current_cpu_data.srsets;
2063	u16 *h;
2064	unsigned char *b;
2065
2066	BUG_ON(!cpu_has_veic && !cpu_has_vint);
2067
2068	if (addr == NULL) {
2069		handler = (unsigned long) do_default_vi;
2070		srs = 0;
2071	} else
2072		handler = (unsigned long) addr;
2073	vi_handlers[n] = handler;
2074
2075	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);
2076
2077	if (srs >= srssets)
2078		panic("Shadow register set %d not supported", srs);
2079
2080	if (cpu_has_veic) {
2081		if (board_bind_eic_interrupt)
2082			board_bind_eic_interrupt(n, srs);
2083	} else if (cpu_has_vint) {
2084		/* SRSMap is only defined if shadow sets are implemented */
2085		if (srssets > 1)
2086			change_c0_srsmap(0xf << n*4, srs << n*4);
2087	}
2088
2089	if (srs == 0) {
2090		/*
2091		 * If no shadow set is selected then use the default handler
2092		 * that does normal register saving and standard interrupt exit
2093		 */
2094		extern const u8 except_vec_vi[], except_vec_vi_lui[];
2095		extern const u8 except_vec_vi_ori[], except_vec_vi_end[];
2096		extern const u8 rollback_except_vec_vi[];
2097		const u8 *vec_start = using_rollback_handler() ?
2098				      rollback_except_vec_vi : except_vec_vi;
2099#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
2100		const int lui_offset = except_vec_vi_lui - vec_start + 2;
2101		const int ori_offset = except_vec_vi_ori - vec_start + 2;
2102#else
2103		const int lui_offset = except_vec_vi_lui - vec_start;
2104		const int ori_offset = except_vec_vi_ori - vec_start;
2105#endif
2106		const int handler_len = except_vec_vi_end - vec_start;
2107
2108		if (handler_len > VECTORSPACING) {
2109			/*
2110			 * Sigh... panicing won't help as the console
2111			 * is probably not configured :(
2112			 */
2113			panic("VECTORSPACING too small");
2114		}
2115
2116		set_handler(((unsigned long)b - ebase), vec_start,
2117#ifdef CONFIG_CPU_MICROMIPS
2118				(handler_len - 1));
2119#else
2120				handler_len);
2121#endif
2122		h = (u16 *)(b + lui_offset);
2123		*h = (handler >> 16) & 0xffff;
2124		h = (u16 *)(b + ori_offset);
2125		*h = (handler & 0xffff);
2126		local_flush_icache_range((unsigned long)b,
2127					 (unsigned long)(b+handler_len));
2128	}
2129	else {
2130		/*
2131		 * In other cases jump directly to the interrupt handler. It
2132		 * is the handler's responsibility to save registers if required
2133		 * (eg hi/lo) and return from the exception using "eret".
2134		 */
2135		u32 insn;
2136
2137		h = (u16 *)b;
2138		/* j handler */
2139#ifdef CONFIG_CPU_MICROMIPS
2140		insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
2141#else
2142		insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
2143#endif
2144		h[0] = (insn >> 16) & 0xffff;
2145		h[1] = insn & 0xffff;
2146		h[2] = 0;
2147		h[3] = 0;
2148		local_flush_icache_range((unsigned long)b,
2149					 (unsigned long)(b+8));
2150	}
2151
2152	return (void *)old_handler;
2153}
2154
2155void *set_vi_handler(int n, vi_handler_t addr)
2156{
2157	return set_vi_srs_handler(n, addr, 0);
2158}
2159
2160extern void tlb_init(void);
2161
2162/*
2163 * Timer interrupt
2164 */
2165int cp0_compare_irq;
2166EXPORT_SYMBOL_GPL(cp0_compare_irq);
2167int cp0_compare_irq_shift;
2168
2169/*
2170 * Performance counter IRQ or -1 if shared with timer
2171 */
2172int cp0_perfcount_irq;
2173EXPORT_SYMBOL_GPL(cp0_perfcount_irq);
2174
2175/*
2176 * Fast debug channel IRQ or -1 if not present
2177 */
2178int cp0_fdc_irq;
2179EXPORT_SYMBOL_GPL(cp0_fdc_irq);
2180
2181static int noulri;
2182
2183static int __init ulri_disable(char *s)
2184{
2185	pr_info("Disabling ulri\n");
2186	noulri = 1;
2187
2188	return 1;
2189}
2190__setup("noulri", ulri_disable);
2191
2192/* configure STATUS register */
2193static void configure_status(void)
2194{
2195	/*
2196	 * Disable coprocessors and select 32-bit or 64-bit addressing
2197	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
2198	 * flag that some firmware may have left set and the TS bit (for
2199	 * IP27).  Set XX for ISA IV code to work.
2200	 */
2201	unsigned int status_set = ST0_KERNEL_CUMASK;
2202#ifdef CONFIG_64BIT
2203	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
2204#endif
2205	if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
2206		status_set |= ST0_XX;
2207	if (cpu_has_dsp)
2208		status_set |= ST0_MX;
2209
2210	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
2211			 status_set);
2212	back_to_back_c0_hazard();
2213}
2214
2215unsigned int hwrena;
2216EXPORT_SYMBOL_GPL(hwrena);
2217
2218/* configure HWRENA register */
2219static void configure_hwrena(void)
2220{
2221	hwrena = cpu_hwrena_impl_bits;
2222
2223	if (cpu_has_mips_r2_r6)
2224		hwrena |= MIPS_HWRENA_CPUNUM |
2225			  MIPS_HWRENA_SYNCISTEP |
2226			  MIPS_HWRENA_CC |
2227			  MIPS_HWRENA_CCRES;
2228
2229	if (!noulri && cpu_has_userlocal)
2230		hwrena |= MIPS_HWRENA_ULR;
2231
2232	if (hwrena)
2233		write_c0_hwrena(hwrena);
2234}
2235
2236static void configure_exception_vector(void)
2237{
2238	if (cpu_has_mips_r2_r6) {
2239		unsigned long sr = set_c0_status(ST0_BEV);
2240		/* If available, use WG to set top bits of EBASE */
2241		if (cpu_has_ebase_wg) {
2242#ifdef CONFIG_64BIT
2243			write_c0_ebase_64(ebase | MIPS_EBASE_WG);
2244#else
2245			write_c0_ebase(ebase | MIPS_EBASE_WG);
2246#endif
2247		}
2248		write_c0_ebase(ebase);
2249		write_c0_status(sr);
2250	}
2251	if (cpu_has_veic || cpu_has_vint) {
2252		/* Setting vector spacing enables EI/VI mode  */
2253		change_c0_intctl(0x3e0, VECTORSPACING);
2254	}
2255	if (cpu_has_divec) {
2256		if (cpu_has_mipsmt) {
2257			unsigned int vpflags = dvpe();
2258			set_c0_cause(CAUSEF_IV);
2259			evpe(vpflags);
2260		} else
2261			set_c0_cause(CAUSEF_IV);
2262	}
2263}
2264
2265void per_cpu_trap_init(bool is_boot_cpu)
2266{
2267	unsigned int cpu = smp_processor_id();
2268
2269	configure_status();
2270	configure_hwrena();
2271
2272	configure_exception_vector();
2273
2274	/*
2275	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
2276	 *
2277	 *  o read IntCtl.IPTI to determine the timer interrupt
2278	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
2279	 *  o read IntCtl.IPFDC to determine the fast debug channel interrupt
2280	 */
2281	if (cpu_has_mips_r2_r6) {
2282		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
2283		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
2284		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
2285		cp0_fdc_irq = (read_c0_intctl() >> INTCTLB_IPFDC) & 7;
2286		if (!cp0_fdc_irq)
2287			cp0_fdc_irq = -1;
2288
2289	} else {
2290		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
2291		cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
2292		cp0_perfcount_irq = -1;
2293		cp0_fdc_irq = -1;
2294	}
2295
2296	if (cpu_has_mmid)
2297		cpu_data[cpu].asid_cache = 0;
2298	else if (!cpu_data[cpu].asid_cache)
2299		cpu_data[cpu].asid_cache = asid_first_version(cpu);
2300
2301	mmgrab(&init_mm);
2302	current->active_mm = &init_mm;
2303	BUG_ON(current->mm);
2304	enter_lazy_tlb(&init_mm, current);
2305
2306	/* Boot CPU's cache setup in setup_arch(). */
2307	if (!is_boot_cpu)
2308		cpu_cache_init();
2309	tlb_init();
2310	TLBMISS_HANDLER_SETUP();
2311}
2312
2313/* Install CPU exception handler */
2314void set_handler(unsigned long offset, const void *addr, unsigned long size)
2315{
2316#ifdef CONFIG_CPU_MICROMIPS
2317	memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
2318#else
2319	memcpy((void *)(ebase + offset), addr, size);
2320#endif
2321	local_flush_icache_range(ebase + offset, ebase + offset + size);
2322}
2323
2324static const char panic_null_cerr[] =
2325	"Trying to set NULL cache error exception handler\n";
2326
2327/*
2328 * Install uncached CPU exception handler.
2329 * This is suitable only for the cache error exception which is the only
2330 * exception handler that is being run uncached.
2331 */
2332void set_uncached_handler(unsigned long offset, void *addr,
2333	unsigned long size)
2334{
2335	unsigned long uncached_ebase = CKSEG1ADDR(ebase);
2336
2337	if (!addr)
2338		panic(panic_null_cerr);
2339
2340	memcpy((void *)(uncached_ebase + offset), addr, size);
2341}
2342
2343static int __initdata rdhwr_noopt;
2344static int __init set_rdhwr_noopt(char *str)
2345{
2346	rdhwr_noopt = 1;
2347	return 1;
2348}
2349
2350__setup("rdhwr_noopt", set_rdhwr_noopt);
2351
2352void __init trap_init(void)
2353{
2354	extern char except_vec3_generic;
2355	extern char except_vec4;
2356	extern char except_vec3_r4000;
2357	unsigned long i, vec_size;
2358	phys_addr_t ebase_pa;
2359
2360	check_wait();
2361
2362	if (!cpu_has_mips_r2_r6) {
2363		ebase = CAC_BASE;
 
2364		vec_size = 0x400;
 
 
2365	} else {
2366		if (cpu_has_veic || cpu_has_vint)
2367			vec_size = 0x200 + VECTORSPACING*64;
2368		else
2369			vec_size = PAGE_SIZE;
2370
2371		ebase_pa = memblock_phys_alloc(vec_size, 1 << fls(vec_size));
2372		if (!ebase_pa)
2373			panic("%s: Failed to allocate %lu bytes align=0x%x\n",
2374			      __func__, vec_size, 1 << fls(vec_size));
2375
2376		/*
2377		 * Try to ensure ebase resides in KSeg0 if possible.
2378		 *
2379		 * It shouldn't generally be in XKPhys on MIPS64 to avoid
2380		 * hitting a poorly defined exception base for Cache Errors.
2381		 * The allocation is likely to be in the low 512MB of physical,
2382		 * in which case we should be able to convert to KSeg0.
2383		 *
2384		 * EVA is special though as it allows segments to be rearranged
2385		 * and to become uncached during cache error handling.
2386		 */
2387		if (!IS_ENABLED(CONFIG_EVA) && !WARN_ON(ebase_pa >= 0x20000000))
2388			ebase = CKSEG0ADDR(ebase_pa);
2389		else
2390			ebase = (unsigned long)phys_to_virt(ebase_pa);
2391	}
2392
2393	if (cpu_has_mmips) {
2394		unsigned int config3 = read_c0_config3();
2395
2396		if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
2397			write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
2398		else
2399			write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
2400	}
2401
2402	if (board_ebase_setup)
2403		board_ebase_setup();
2404	per_cpu_trap_init(true);
2405	memblock_set_bottom_up(false);
2406
2407	/*
2408	 * Copy the generic exception handlers to their final destination.
2409	 * This will be overridden later as suitable for a particular
2410	 * configuration.
2411	 */
2412	set_handler(0x180, &except_vec3_generic, 0x80);
2413
2414	/*
2415	 * Setup default vectors
2416	 */
2417	for (i = 0; i <= 31; i++)
2418		set_except_vector(i, handle_reserved);
2419
2420	/*
2421	 * Copy the EJTAG debug exception vector handler code to it's final
2422	 * destination.
2423	 */
2424	if (cpu_has_ejtag && board_ejtag_handler_setup)
2425		board_ejtag_handler_setup();
2426
2427	/*
2428	 * Only some CPUs have the watch exceptions.
2429	 */
2430	if (cpu_has_watch)
2431		set_except_vector(EXCCODE_WATCH, handle_watch);
2432
2433	/*
2434	 * Initialise interrupt handlers
2435	 */
2436	if (cpu_has_veic || cpu_has_vint) {
2437		int nvec = cpu_has_veic ? 64 : 8;
2438		for (i = 0; i < nvec; i++)
2439			set_vi_handler(i, NULL);
2440	}
2441	else if (cpu_has_divec)
2442		set_handler(0x200, &except_vec4, 0x8);
2443
2444	/*
2445	 * Some CPUs can enable/disable for cache parity detection, but does
2446	 * it different ways.
2447	 */
2448	parity_protection_init();
2449
2450	/*
2451	 * The Data Bus Errors / Instruction Bus Errors are signaled
2452	 * by external hardware.  Therefore these two exceptions
2453	 * may have board specific handlers.
2454	 */
2455	if (board_be_init)
2456		board_be_init();
2457
2458	set_except_vector(EXCCODE_INT, using_rollback_handler() ?
2459					rollback_handle_int : handle_int);
2460	set_except_vector(EXCCODE_MOD, handle_tlbm);
2461	set_except_vector(EXCCODE_TLBL, handle_tlbl);
2462	set_except_vector(EXCCODE_TLBS, handle_tlbs);
2463
2464	set_except_vector(EXCCODE_ADEL, handle_adel);
2465	set_except_vector(EXCCODE_ADES, handle_ades);
2466
2467	set_except_vector(EXCCODE_IBE, handle_ibe);
2468	set_except_vector(EXCCODE_DBE, handle_dbe);
2469
2470	set_except_vector(EXCCODE_SYS, handle_sys);
2471	set_except_vector(EXCCODE_BP, handle_bp);
2472
2473	if (rdhwr_noopt)
2474		set_except_vector(EXCCODE_RI, handle_ri);
2475	else {
2476		if (cpu_has_vtag_icache)
2477			set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2478		else if (current_cpu_type() == CPU_LOONGSON64)
2479			set_except_vector(EXCCODE_RI, handle_ri_rdhwr_tlbp);
2480		else
2481			set_except_vector(EXCCODE_RI, handle_ri_rdhwr);
2482	}
2483
2484	set_except_vector(EXCCODE_CPU, handle_cpu);
2485	set_except_vector(EXCCODE_OV, handle_ov);
2486	set_except_vector(EXCCODE_TR, handle_tr);
2487	set_except_vector(EXCCODE_MSAFPE, handle_msa_fpe);
2488
2489	if (board_nmi_handler_setup)
2490		board_nmi_handler_setup();
2491
2492	if (cpu_has_fpu && !cpu_has_nofpuex)
2493		set_except_vector(EXCCODE_FPE, handle_fpe);
2494
2495	if (cpu_has_ftlbparex)
2496		set_except_vector(MIPS_EXCCODE_TLBPAR, handle_ftlb);
2497
2498	if (cpu_has_gsexcex)
2499		set_except_vector(LOONGSON_EXCCODE_GSEXC, handle_gsexc);
2500
2501	if (cpu_has_rixiex) {
2502		set_except_vector(EXCCODE_TLBRI, tlb_do_page_fault_0);
2503		set_except_vector(EXCCODE_TLBXI, tlb_do_page_fault_0);
2504	}
2505
2506	set_except_vector(EXCCODE_MSADIS, handle_msa);
2507	set_except_vector(EXCCODE_MDMX, handle_mdmx);
2508
2509	if (cpu_has_mcheck)
2510		set_except_vector(EXCCODE_MCHECK, handle_mcheck);
2511
2512	if (cpu_has_mipsmt)
2513		set_except_vector(EXCCODE_THREAD, handle_mt);
2514
2515	set_except_vector(EXCCODE_DSPDIS, handle_dsp);
2516
2517	if (board_cache_error_setup)
2518		board_cache_error_setup();
2519
2520	if (cpu_has_vce)
2521		/* Special exception: R4[04]00 uses also the divec space. */
2522		set_handler(0x180, &except_vec3_r4000, 0x100);
2523	else if (cpu_has_4kex)
2524		set_handler(0x180, &except_vec3_generic, 0x80);
2525	else
2526		set_handler(0x080, &except_vec3_generic, 0x80);
2527
2528	local_flush_icache_range(ebase, ebase + vec_size);
2529
2530	sort_extable(__start___dbe_table, __stop___dbe_table);
2531
2532	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
2533}
2534
2535static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
2536			    void *v)
2537{
2538	switch (cmd) {
2539	case CPU_PM_ENTER_FAILED:
2540	case CPU_PM_EXIT:
2541		configure_status();
2542		configure_hwrena();
2543		configure_exception_vector();
2544
2545		/* Restore register with CPU number for TLB handlers */
2546		TLBMISS_HANDLER_RESTORE();
2547
2548		break;
2549	}
2550
2551	return NOTIFY_OK;
2552}
2553
2554static struct notifier_block trap_pm_notifier_block = {
2555	.notifier_call = trap_pm_notifier,
2556};
2557
2558static int __init trap_pm_init(void)
2559{
2560	return cpu_pm_register_notifier(&trap_pm_notifier_block);
2561}
2562arch_initcall(trap_pm_init);