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