1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 *  Copyright (C) 1995-1996  Gary Thomas (gdt@linuxppc.org)
   4 *  Copyright 2007-2010 Freescale Semiconductor, Inc.
   5 *
 
 
 
 
 
   6 *  Modified by Cort Dougan (cort@cs.nmt.edu)
   7 *  and Paul Mackerras (paulus@samba.org)
   8 */
   9
  10/*
  11 * This file handles the architecture-dependent parts of hardware exceptions
  12 */
  13
  14#include <linux/errno.h>
  15#include <linux/sched.h>
  16#include <linux/sched/debug.h>
  17#include <linux/kernel.h>
  18#include <linux/mm.h>
  19#include <linux/pkeys.h>
  20#include <linux/stddef.h>
  21#include <linux/unistd.h>
  22#include <linux/ptrace.h>
  23#include <linux/user.h>
  24#include <linux/interrupt.h>
  25#include <linux/init.h>
  26#include <linux/extable.h>
  27#include <linux/module.h>	/* print_modules */
  28#include <linux/prctl.h>
  29#include <linux/delay.h>
  30#include <linux/kprobes.h>
  31#include <linux/kexec.h>
  32#include <linux/backlight.h>
  33#include <linux/bug.h>
  34#include <linux/kdebug.h>
 
  35#include <linux/ratelimit.h>
  36#include <linux/context_tracking.h>
  37#include <linux/smp.h>
  38#include <linux/console.h>
  39#include <linux/kmsg_dump.h>
  40
  41#include <asm/emulated_ops.h>
 
  42#include <linux/uaccess.h>
  43#include <asm/debugfs.h>
  44#include <asm/interrupt.h>
  45#include <asm/io.h>
  46#include <asm/machdep.h>
  47#include <asm/rtas.h>
  48#include <asm/pmc.h>
  49#include <asm/reg.h>
  50#ifdef CONFIG_PMAC_BACKLIGHT
  51#include <asm/backlight.h>
  52#endif
  53#ifdef CONFIG_PPC64
  54#include <asm/firmware.h>
  55#include <asm/processor.h>
 
  56#endif
  57#include <asm/kexec.h>
  58#include <asm/ppc-opcode.h>
  59#include <asm/rio.h>
  60#include <asm/fadump.h>
  61#include <asm/switch_to.h>
  62#include <asm/tm.h>
  63#include <asm/debug.h>
  64#include <asm/asm-prototypes.h>
  65#include <asm/hmi.h>
  66#include <sysdev/fsl_pci.h>
  67#include <asm/kprobes.h>
  68#include <asm/stacktrace.h>
  69#include <asm/nmi.h>
  70#include <asm/disassemble.h>
  71
  72#if defined(CONFIG_DEBUGGER) || defined(CONFIG_KEXEC_CORE)
  73int (*__debugger)(struct pt_regs *regs) __read_mostly;
  74int (*__debugger_ipi)(struct pt_regs *regs) __read_mostly;
  75int (*__debugger_bpt)(struct pt_regs *regs) __read_mostly;
  76int (*__debugger_sstep)(struct pt_regs *regs) __read_mostly;
  77int (*__debugger_iabr_match)(struct pt_regs *regs) __read_mostly;
  78int (*__debugger_break_match)(struct pt_regs *regs) __read_mostly;
  79int (*__debugger_fault_handler)(struct pt_regs *regs) __read_mostly;
  80
  81EXPORT_SYMBOL(__debugger);
  82EXPORT_SYMBOL(__debugger_ipi);
  83EXPORT_SYMBOL(__debugger_bpt);
  84EXPORT_SYMBOL(__debugger_sstep);
  85EXPORT_SYMBOL(__debugger_iabr_match);
  86EXPORT_SYMBOL(__debugger_break_match);
  87EXPORT_SYMBOL(__debugger_fault_handler);
  88#endif
  89
  90/* Transactional Memory trap debug */
  91#ifdef TM_DEBUG_SW
  92#define TM_DEBUG(x...) printk(KERN_INFO x)
  93#else
  94#define TM_DEBUG(x...) do { } while(0)
  95#endif
  96
  97static const char *signame(int signr)
  98{
  99	switch (signr) {
 100	case SIGBUS:	return "bus error";
 101	case SIGFPE:	return "floating point exception";
 102	case SIGILL:	return "illegal instruction";
 103	case SIGSEGV:	return "segfault";
 104	case SIGTRAP:	return "unhandled trap";
 105	}
 106
 107	return "unknown signal";
 108}
 109
 110/*
 111 * Trap & Exception support
 112 */
 113
 114#ifdef CONFIG_PMAC_BACKLIGHT
 115static void pmac_backlight_unblank(void)
 116{
 117	mutex_lock(&pmac_backlight_mutex);
 118	if (pmac_backlight) {
 119		struct backlight_properties *props;
 120
 121		props = &pmac_backlight->props;
 122		props->brightness = props->max_brightness;
 123		props->power = FB_BLANK_UNBLANK;
 124		backlight_update_status(pmac_backlight);
 125	}
 126	mutex_unlock(&pmac_backlight_mutex);
 127}
 128#else
 129static inline void pmac_backlight_unblank(void) { }
 130#endif
 131
 132/*
 133 * If oops/die is expected to crash the machine, return true here.
 134 *
 135 * This should not be expected to be 100% accurate, there may be
 136 * notifiers registered or other unexpected conditions that may bring
 137 * down the kernel. Or if the current process in the kernel is holding
 138 * locks or has other critical state, the kernel may become effectively
 139 * unusable anyway.
 140 */
 141bool die_will_crash(void)
 142{
 143	if (should_fadump_crash())
 144		return true;
 145	if (kexec_should_crash(current))
 146		return true;
 147	if (in_interrupt() || panic_on_oops ||
 148			!current->pid || is_global_init(current))
 149		return true;
 150
 151	return false;
 152}
 153
 154static arch_spinlock_t die_lock = __ARCH_SPIN_LOCK_UNLOCKED;
 155static int die_owner = -1;
 156static unsigned int die_nest_count;
 157static int die_counter;
 158
 159extern void panic_flush_kmsg_start(void)
 160{
 161	/*
 162	 * These are mostly taken from kernel/panic.c, but tries to do
 163	 * relatively minimal work. Don't use delay functions (TB may
 164	 * be broken), don't crash dump (need to set a firmware log),
 165	 * don't run notifiers. We do want to get some information to
 166	 * Linux console.
 167	 */
 168	console_verbose();
 169	bust_spinlocks(1);
 170}
 171
 172extern void panic_flush_kmsg_end(void)
 173{
 174	printk_safe_flush_on_panic();
 175	kmsg_dump(KMSG_DUMP_PANIC);
 176	bust_spinlocks(0);
 177	debug_locks_off();
 178	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
 179}
 180
 181static unsigned long oops_begin(struct pt_regs *regs)
 182{
 183	int cpu;
 184	unsigned long flags;
 185
 186	oops_enter();
 187
 188	/* racy, but better than risking deadlock. */
 189	raw_local_irq_save(flags);
 190	cpu = smp_processor_id();
 191	if (!arch_spin_trylock(&die_lock)) {
 192		if (cpu == die_owner)
 193			/* nested oops. should stop eventually */;
 194		else
 195			arch_spin_lock(&die_lock);
 196	}
 197	die_nest_count++;
 198	die_owner = cpu;
 199	console_verbose();
 200	bust_spinlocks(1);
 201	if (machine_is(powermac))
 202		pmac_backlight_unblank();
 203	return flags;
 204}
 205NOKPROBE_SYMBOL(oops_begin);
 206
 207static void oops_end(unsigned long flags, struct pt_regs *regs,
 208			       int signr)
 209{
 210	bust_spinlocks(0);
 211	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 212	die_nest_count--;
 213	oops_exit();
 214	printk("\n");
 215	if (!die_nest_count) {
 216		/* Nest count reaches zero, release the lock. */
 217		die_owner = -1;
 218		arch_spin_unlock(&die_lock);
 219	}
 220	raw_local_irq_restore(flags);
 221
 222	/*
 223	 * system_reset_excption handles debugger, crash dump, panic, for 0x100
 224	 */
 225	if (TRAP(regs) == INTERRUPT_SYSTEM_RESET)
 226		return;
 227
 228	crash_fadump(regs, "die oops");
 229
 230	if (kexec_should_crash(current))
 
 
 
 
 231		crash_kexec(regs);
 232
 
 
 
 
 
 
 
 
 233	if (!signr)
 234		return;
 235
 236	/*
 237	 * While our oops output is serialised by a spinlock, output
 238	 * from panic() called below can race and corrupt it. If we
 239	 * know we are going to panic, delay for 1 second so we have a
 240	 * chance to get clean backtraces from all CPUs that are oopsing.
 241	 */
 242	if (in_interrupt() || panic_on_oops || !current->pid ||
 243	    is_global_init(current)) {
 244		mdelay(MSEC_PER_SEC);
 245	}
 246
 
 
 247	if (panic_on_oops)
 248		panic("Fatal exception");
 249	do_exit(signr);
 250}
 251NOKPROBE_SYMBOL(oops_end);
 252
 253static char *get_mmu_str(void)
 254{
 255	if (early_radix_enabled())
 256		return " MMU=Radix";
 257	if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
 258		return " MMU=Hash";
 259	return "";
 260}
 261
 262static int __die(const char *str, struct pt_regs *regs, long err)
 263{
 264	printk("Oops: %s, sig: %ld [#%d]\n", str, err, ++die_counter);
 265
 266	printk("%s PAGE_SIZE=%luK%s%s%s%s%s%s %s\n",
 267	       IS_ENABLED(CONFIG_CPU_LITTLE_ENDIAN) ? "LE" : "BE",
 268	       PAGE_SIZE / 1024, get_mmu_str(),
 269	       IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "",
 270	       IS_ENABLED(CONFIG_SMP) ? " SMP" : "",
 271	       IS_ENABLED(CONFIG_SMP) ? (" NR_CPUS=" __stringify(NR_CPUS)) : "",
 272	       debug_pagealloc_enabled() ? " DEBUG_PAGEALLOC" : "",
 273	       IS_ENABLED(CONFIG_NUMA) ? " NUMA" : "",
 274	       ppc_md.name ? ppc_md.name : "");
 
 
 275
 276	if (notify_die(DIE_OOPS, str, regs, err, 255, SIGSEGV) == NOTIFY_STOP)
 277		return 1;
 278
 279	print_modules();
 280	show_regs(regs);
 281
 282	return 0;
 283}
 284NOKPROBE_SYMBOL(__die);
 285
 286void die(const char *str, struct pt_regs *regs, long err)
 287{
 288	unsigned long flags;
 289
 290	/*
 291	 * system_reset_excption handles debugger, crash dump, panic, for 0x100
 292	 */
 293	if (TRAP(regs) != INTERRUPT_SYSTEM_RESET) {
 294		if (debugger(regs))
 295			return;
 296	}
 297
 298	flags = oops_begin(regs);
 299	if (__die(str, regs, err))
 300		err = 0;
 301	oops_end(flags, regs, err);
 302}
 303NOKPROBE_SYMBOL(die);
 304
 305void user_single_step_report(struct pt_regs *regs)
 
 306{
 307	force_sig_fault(SIGTRAP, TRAP_TRACE, (void __user *)regs->nip);
 
 
 
 308}
 309
 310static void show_signal_msg(int signr, struct pt_regs *regs, int code,
 311			    unsigned long addr)
 312{
 313	static DEFINE_RATELIMIT_STATE(rs, DEFAULT_RATELIMIT_INTERVAL,
 314				      DEFAULT_RATELIMIT_BURST);
 315
 316	if (!show_unhandled_signals)
 317		return;
 318
 319	if (!unhandled_signal(current, signr))
 320		return;
 321
 322	if (!__ratelimit(&rs))
 323		return;
 324
 325	pr_info("%s[%d]: %s (%d) at %lx nip %lx lr %lx code %x",
 326		current->comm, current->pid, signame(signr), signr,
 327		addr, regs->nip, regs->link, code);
 328
 329	print_vma_addr(KERN_CONT " in ", regs->nip);
 330
 331	pr_cont("\n");
 332
 333	show_user_instructions(regs);
 334}
 335
 336static bool exception_common(int signr, struct pt_regs *regs, int code,
 337			      unsigned long addr)
 338{
 339	if (!user_mode(regs)) {
 340		die("Exception in kernel mode", regs, signr);
 341		return false;
 342	}
 343
 344	/*
 345	 * Must not enable interrupts even for user-mode exception, because
 346	 * this can be called from machine check, which may be a NMI or IRQ
 347	 * which don't like interrupts being enabled. Could check for
 348	 * in_hardirq || in_nmi perhaps, but there doesn't seem to be a good
 349	 * reason why _exception() should enable irqs for an exception handler,
 350	 * the handlers themselves do that directly.
 351	 */
 352
 353	show_signal_msg(signr, regs, code, addr);
 
 354
 355	current->thread.trap_nr = code;
 356
 357	return true;
 
 
 
 358}
 359
 360void _exception_pkey(struct pt_regs *regs, unsigned long addr, int key)
 361{
 362	if (!exception_common(SIGSEGV, regs, SEGV_PKUERR, addr))
 363		return;
 
 
 
 364
 365	force_sig_pkuerr((void __user *) addr, key);
 366}
 367
 368void _exception(int signr, struct pt_regs *regs, int code, unsigned long addr)
 369{
 370	if (!exception_common(signr, regs, code, addr))
 371		return;
 372
 373	force_sig_fault(signr, code, (void __user *)addr);
 374}
 375
 
 376/*
 377 * The interrupt architecture has a quirk in that the HV interrupts excluding
 378 * the NMIs (0x100 and 0x200) do not clear MSR[RI] at entry. The first thing
 379 * that an interrupt handler must do is save off a GPR into a scratch register,
 380 * and all interrupts on POWERNV (HV=1) use the HSPRG1 register as scratch.
 381 * Therefore an NMI can clobber an HV interrupt's live HSPRG1 without noticing
 382 * that it is non-reentrant, which leads to random data corruption.
 383 *
 384 * The solution is for NMI interrupts in HV mode to check if they originated
 385 * from these critical HV interrupt regions. If so, then mark them not
 386 * recoverable.
 387 *
 388 * An alternative would be for HV NMIs to use SPRG for scratch to avoid the
 389 * HSPRG1 clobber, however this would cause guest SPRG to be clobbered. Linux
 390 * guests should always have MSR[RI]=0 when its scratch SPRG is in use, so
 391 * that would work. However any other guest OS that may have the SPRG live
 392 * and MSR[RI]=1 could encounter silent corruption.
 393 *
 394 * Builds that do not support KVM could take this second option to increase
 395 * the recoverability of NMIs.
 396 */
 397void hv_nmi_check_nonrecoverable(struct pt_regs *regs)
 398{
 399#ifdef CONFIG_PPC_POWERNV
 400	unsigned long kbase = (unsigned long)_stext;
 401	unsigned long nip = regs->nip;
 402
 403	if (!(regs->msr & MSR_RI))
 404		return;
 405	if (!(regs->msr & MSR_HV))
 406		return;
 407	if (regs->msr & MSR_PR)
 408		return;
 409
 410	/*
 411	 * Now test if the interrupt has hit a range that may be using
 412	 * HSPRG1 without having RI=0 (i.e., an HSRR interrupt). The
 413	 * problem ranges all run un-relocated. Test real and virt modes
 414	 * at the same time by dropping the high bit of the nip (virt mode
 415	 * entry points still have the +0x4000 offset).
 416	 */
 417	nip &= ~0xc000000000000000ULL;
 418	if ((nip >= 0x500 && nip < 0x600) || (nip >= 0x4500 && nip < 0x4600))
 419		goto nonrecoverable;
 420	if ((nip >= 0x980 && nip < 0xa00) || (nip >= 0x4980 && nip < 0x4a00))
 421		goto nonrecoverable;
 422	if ((nip >= 0xe00 && nip < 0xec0) || (nip >= 0x4e00 && nip < 0x4ec0))
 423		goto nonrecoverable;
 424	if ((nip >= 0xf80 && nip < 0xfa0) || (nip >= 0x4f80 && nip < 0x4fa0))
 425		goto nonrecoverable;
 426
 427	/* Trampoline code runs un-relocated so subtract kbase. */
 428	if (nip >= (unsigned long)(start_real_trampolines - kbase) &&
 429			nip < (unsigned long)(end_real_trampolines - kbase))
 430		goto nonrecoverable;
 431	if (nip >= (unsigned long)(start_virt_trampolines - kbase) &&
 432			nip < (unsigned long)(end_virt_trampolines - kbase))
 433		goto nonrecoverable;
 434	return;
 435
 436nonrecoverable:
 437	regs_set_return_msr(regs, regs->msr & ~MSR_RI);
 438#endif
 439}
 440DEFINE_INTERRUPT_HANDLER_NMI(system_reset_exception)
 441{
 442	unsigned long hsrr0, hsrr1;
 443	bool saved_hsrrs = false;
 444
 445	/*
 446	 * System reset can interrupt code where HSRRs are live and MSR[RI]=1.
 447	 * The system reset interrupt itself may clobber HSRRs (e.g., to call
 448	 * OPAL), so save them here and restore them before returning.
 449	 *
 450	 * Machine checks don't need to save HSRRs, as the real mode handler
 451	 * is careful to avoid them, and the regular handler is not delivered
 452	 * as an NMI.
 453	 */
 454	if (cpu_has_feature(CPU_FTR_HVMODE)) {
 455		hsrr0 = mfspr(SPRN_HSRR0);
 456		hsrr1 = mfspr(SPRN_HSRR1);
 457		saved_hsrrs = true;
 458	}
 459
 460	hv_nmi_check_nonrecoverable(regs);
 461
 462	__this_cpu_inc(irq_stat.sreset_irqs);
 463
 464	/* See if any machine dependent calls */
 465	if (ppc_md.system_reset_exception) {
 466		if (ppc_md.system_reset_exception(regs))
 467			goto out;
 468	}
 469
 470	if (debugger(regs))
 471		goto out;
 472
 473	kmsg_dump(KMSG_DUMP_OOPS);
 474	/*
 475	 * A system reset is a request to dump, so we always send
 476	 * it through the crashdump code (if fadump or kdump are
 477	 * registered).
 478	 */
 479	crash_fadump(regs, "System Reset");
 480
 481	crash_kexec(regs);
 482
 483	/*
 484	 * We aren't the primary crash CPU. We need to send it
 485	 * to a holding pattern to avoid it ending up in the panic
 486	 * code.
 487	 */
 488	crash_kexec_secondary(regs);
 489
 490	/*
 491	 * No debugger or crash dump registered, print logs then
 492	 * panic.
 493	 */
 494	die("System Reset", regs, SIGABRT);
 495
 496	mdelay(2*MSEC_PER_SEC); /* Wait a little while for others to print */
 497	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
 498	nmi_panic(regs, "System Reset");
 499
 500out:
 501#ifdef CONFIG_PPC_BOOK3S_64
 502	BUG_ON(get_paca()->in_nmi == 0);
 503	if (get_paca()->in_nmi > 1)
 504		die("Unrecoverable nested System Reset", regs, SIGABRT);
 505#endif
 506	/* Must die if the interrupt is not recoverable */
 507	if (!(regs->msr & MSR_RI)) {
 508		/* For the reason explained in die_mce, nmi_exit before die */
 509		nmi_exit();
 510		die("Unrecoverable System Reset", regs, SIGABRT);
 511	}
 512
 513	if (saved_hsrrs) {
 514		mtspr(SPRN_HSRR0, hsrr0);
 515		mtspr(SPRN_HSRR1, hsrr1);
 516	}
 517
 518	/* What should we do here? We could issue a shutdown or hard reset. */
 519
 520	return 0;
 521}
 522
 
 
 523/*
 524 * I/O accesses can cause machine checks on powermacs.
 525 * Check if the NIP corresponds to the address of a sync
 526 * instruction for which there is an entry in the exception
 527 * table.
 
 
 
 528 *  -- paulus.
 529 */
 530static inline int check_io_access(struct pt_regs *regs)
 531{
 532#ifdef CONFIG_PPC32
 533	unsigned long msr = regs->msr;
 534	const struct exception_table_entry *entry;
 535	unsigned int *nip = (unsigned int *)regs->nip;
 536
 537	if (((msr & 0xffff0000) == 0 || (msr & (0x80000 | 0x40000)))
 538	    && (entry = search_exception_tables(regs->nip)) != NULL) {
 539		/*
 540		 * Check that it's a sync instruction, or somewhere
 541		 * in the twi; isync; nop sequence that inb/inw/inl uses.
 542		 * As the address is in the exception table
 543		 * we should be able to read the instr there.
 544		 * For the debug message, we look at the preceding
 545		 * load or store.
 546		 */
 547		if (*nip == PPC_RAW_NOP())
 548			nip -= 2;
 549		else if (*nip == PPC_RAW_ISYNC())
 550			--nip;
 551		if (*nip == PPC_RAW_SYNC() || get_op(*nip) == OP_TRAP) {
 552			unsigned int rb;
 553
 554			--nip;
 555			rb = (*nip >> 11) & 0x1f;
 556			printk(KERN_DEBUG "%s bad port %lx at %p\n",
 557			       (*nip & 0x100)? "OUT to": "IN from",
 558			       regs->gpr[rb] - _IO_BASE, nip);
 559			regs_set_return_msr(regs, regs->msr | MSR_RI);
 560			regs_set_return_ip(regs, extable_fixup(entry));
 561			return 1;
 562		}
 563	}
 564#endif /* CONFIG_PPC32 */
 565	return 0;
 566}
 567
 568#ifdef CONFIG_PPC_ADV_DEBUG_REGS
 569/* On 4xx, the reason for the machine check or program exception
 570   is in the ESR. */
 571#define get_reason(regs)	((regs)->dsisr)
 
 
 
 
 
 572#define REASON_FP		ESR_FP
 573#define REASON_ILLEGAL		(ESR_PIL | ESR_PUO)
 574#define REASON_PRIVILEGED	ESR_PPR
 575#define REASON_TRAP		ESR_PTR
 576#define REASON_PREFIXED		0
 577#define REASON_BOUNDARY		0
 578
 579/* single-step stuff */
 580#define single_stepping(regs)	(current->thread.debug.dbcr0 & DBCR0_IC)
 581#define clear_single_step(regs)	(current->thread.debug.dbcr0 &= ~DBCR0_IC)
 582#define clear_br_trace(regs)	do {} while(0)
 583#else
 584/* On non-4xx, the reason for the machine check or program
 585   exception is in the MSR. */
 586#define get_reason(regs)	((regs)->msr)
 587#define REASON_TM		SRR1_PROGTM
 588#define REASON_FP		SRR1_PROGFPE
 589#define REASON_ILLEGAL		SRR1_PROGILL
 590#define REASON_PRIVILEGED	SRR1_PROGPRIV
 591#define REASON_TRAP		SRR1_PROGTRAP
 592#define REASON_PREFIXED		SRR1_PREFIXED
 593#define REASON_BOUNDARY		SRR1_BOUNDARY
 594
 595#define single_stepping(regs)	((regs)->msr & MSR_SE)
 596#define clear_single_step(regs)	(regs_set_return_msr((regs), (regs)->msr & ~MSR_SE))
 597#define clear_br_trace(regs)	(regs_set_return_msr((regs), (regs)->msr & ~MSR_BE))
 598#endif
 599
 600#define inst_length(reason)	(((reason) & REASON_PREFIXED) ? 8 : 4)
 
 
 
 
 
 
 
 
 
 
 601
 602#if defined(CONFIG_E500)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 603int machine_check_e500mc(struct pt_regs *regs)
 604{
 605	unsigned long mcsr = mfspr(SPRN_MCSR);
 606	unsigned long pvr = mfspr(SPRN_PVR);
 607	unsigned long reason = mcsr;
 608	int recoverable = 1;
 609
 610	if (reason & MCSR_LD) {
 611		recoverable = fsl_rio_mcheck_exception(regs);
 612		if (recoverable == 1)
 613			goto silent_out;
 614	}
 615
 616	printk("Machine check in kernel mode.\n");
 617	printk("Caused by (from MCSR=%lx): ", reason);
 618
 619	if (reason & MCSR_MCP)
 620		pr_cont("Machine Check Signal\n");
 621
 622	if (reason & MCSR_ICPERR) {
 623		pr_cont("Instruction Cache Parity Error\n");
 624
 625		/*
 626		 * This is recoverable by invalidating the i-cache.
 627		 */
 628		mtspr(SPRN_L1CSR1, mfspr(SPRN_L1CSR1) | L1CSR1_ICFI);
 629		while (mfspr(SPRN_L1CSR1) & L1CSR1_ICFI)
 630			;
 631
 632		/*
 633		 * This will generally be accompanied by an instruction
 634		 * fetch error report -- only treat MCSR_IF as fatal
 635		 * if it wasn't due to an L1 parity error.
 636		 */
 637		reason &= ~MCSR_IF;
 638	}
 639
 640	if (reason & MCSR_DCPERR_MC) {
 641		pr_cont("Data Cache Parity Error\n");
 642
 643		/*
 644		 * In write shadow mode we auto-recover from the error, but it
 645		 * may still get logged and cause a machine check.  We should
 646		 * only treat the non-write shadow case as non-recoverable.
 647		 */
 648		/* On e6500 core, L1 DCWS (Data cache write shadow mode) bit
 649		 * is not implemented but L1 data cache always runs in write
 650		 * shadow mode. Hence on data cache parity errors HW will
 651		 * automatically invalidate the L1 Data Cache.
 652		 */
 653		if (PVR_VER(pvr) != PVR_VER_E6500) {
 654			if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
 655				recoverable = 0;
 656		}
 657	}
 658
 659	if (reason & MCSR_L2MMU_MHIT) {
 660		pr_cont("Hit on multiple TLB entries\n");
 661		recoverable = 0;
 662	}
 663
 664	if (reason & MCSR_NMI)
 665		pr_cont("Non-maskable interrupt\n");
 666
 667	if (reason & MCSR_IF) {
 668		pr_cont("Instruction Fetch Error Report\n");
 669		recoverable = 0;
 670	}
 671
 672	if (reason & MCSR_LD) {
 673		pr_cont("Load Error Report\n");
 674		recoverable = 0;
 675	}
 676
 677	if (reason & MCSR_ST) {
 678		pr_cont("Store Error Report\n");
 679		recoverable = 0;
 680	}
 681
 682	if (reason & MCSR_LDG) {
 683		pr_cont("Guarded Load Error Report\n");
 684		recoverable = 0;
 685	}
 686
 687	if (reason & MCSR_TLBSYNC)
 688		pr_cont("Simultaneous tlbsync operations\n");
 689
 690	if (reason & MCSR_BSL2_ERR) {
 691		pr_cont("Level 2 Cache Error\n");
 692		recoverable = 0;
 693	}
 694
 695	if (reason & MCSR_MAV) {
 696		u64 addr;
 697
 698		addr = mfspr(SPRN_MCAR);
 699		addr |= (u64)mfspr(SPRN_MCARU) << 32;
 700
 701		pr_cont("Machine Check %s Address: %#llx\n",
 702		       reason & MCSR_MEA ? "Effective" : "Physical", addr);
 703	}
 704
 705silent_out:
 706	mtspr(SPRN_MCSR, mcsr);
 707	return mfspr(SPRN_MCSR) == 0 && recoverable;
 708}
 709
 710int machine_check_e500(struct pt_regs *regs)
 711{
 712	unsigned long reason = mfspr(SPRN_MCSR);
 713
 714	if (reason & MCSR_BUS_RBERR) {
 715		if (fsl_rio_mcheck_exception(regs))
 716			return 1;
 717		if (fsl_pci_mcheck_exception(regs))
 718			return 1;
 719	}
 720
 721	printk("Machine check in kernel mode.\n");
 722	printk("Caused by (from MCSR=%lx): ", reason);
 723
 724	if (reason & MCSR_MCP)
 725		pr_cont("Machine Check Signal\n");
 726	if (reason & MCSR_ICPERR)
 727		pr_cont("Instruction Cache Parity Error\n");
 728	if (reason & MCSR_DCP_PERR)
 729		pr_cont("Data Cache Push Parity Error\n");
 730	if (reason & MCSR_DCPERR)
 731		pr_cont("Data Cache Parity Error\n");
 732	if (reason & MCSR_BUS_IAERR)
 733		pr_cont("Bus - Instruction Address Error\n");
 734	if (reason & MCSR_BUS_RAERR)
 735		pr_cont("Bus - Read Address Error\n");
 736	if (reason & MCSR_BUS_WAERR)
 737		pr_cont("Bus - Write Address Error\n");
 738	if (reason & MCSR_BUS_IBERR)
 739		pr_cont("Bus - Instruction Data Error\n");
 740	if (reason & MCSR_BUS_RBERR)
 741		pr_cont("Bus - Read Data Bus Error\n");
 742	if (reason & MCSR_BUS_WBERR)
 743		pr_cont("Bus - Write Data Bus Error\n");
 744	if (reason & MCSR_BUS_IPERR)
 745		pr_cont("Bus - Instruction Parity Error\n");
 746	if (reason & MCSR_BUS_RPERR)
 747		pr_cont("Bus - Read Parity Error\n");
 748
 749	return 0;
 750}
 751
 752int machine_check_generic(struct pt_regs *regs)
 753{
 754	return 0;
 755}
 756#elif defined(CONFIG_PPC32)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 757int machine_check_generic(struct pt_regs *regs)
 758{
 759	unsigned long reason = regs->msr;
 760
 761	printk("Machine check in kernel mode.\n");
 762	printk("Caused by (from SRR1=%lx): ", reason);
 763	switch (reason & 0x601F0000) {
 764	case 0x80000:
 765		pr_cont("Machine check signal\n");
 766		break;
 
 767	case 0x40000:
 768	case 0x140000:	/* 7450 MSS error and TEA */
 769		pr_cont("Transfer error ack signal\n");
 770		break;
 771	case 0x20000:
 772		pr_cont("Data parity error signal\n");
 773		break;
 774	case 0x10000:
 775		pr_cont("Address parity error signal\n");
 776		break;
 777	case 0x20000000:
 778		pr_cont("L1 Data Cache error\n");
 779		break;
 780	case 0x40000000:
 781		pr_cont("L1 Instruction Cache error\n");
 782		break;
 783	case 0x00100000:
 784		pr_cont("L2 data cache parity error\n");
 785		break;
 786	default:
 787		pr_cont("Unknown values in msr\n");
 788	}
 789	return 0;
 790}
 791#endif /* everything else */
 792
 793void die_mce(const char *str, struct pt_regs *regs, long err)
 794{
 795	/*
 796	 * The machine check wants to kill the interrupted context, but
 797	 * do_exit() checks for in_interrupt() and panics in that case, so
 798	 * exit the irq/nmi before calling die.
 799	 */
 800	if (in_nmi())
 801		nmi_exit();
 802	else
 803		irq_exit();
 804	die(str, regs, err);
 805}
 806
 807/*
 808 * BOOK3S_64 does not usually call this handler as a non-maskable interrupt
 809 * (it uses its own early real-mode handler to handle the MCE proper
 810 * and then raises irq_work to call this handler when interrupts are
 811 * enabled). The only time when this is not true is if the early handler
 812 * is unrecoverable, then it does call this directly to try to get a
 813 * message out.
 814 */
 815static void __machine_check_exception(struct pt_regs *regs)
 816{
 
 817	int recover = 0;
 818
 819	__this_cpu_inc(irq_stat.mce_exceptions);
 820
 821	add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
 822
 823	/* See if any machine dependent calls. In theory, we would want
 824	 * to call the CPU first, and call the ppc_md. one if the CPU
 825	 * one returns a positive number. However there is existing code
 826	 * that assumes the board gets a first chance, so let's keep it
 827	 * that way for now and fix things later. --BenH.
 828	 */
 829	if (ppc_md.machine_check_exception)
 830		recover = ppc_md.machine_check_exception(regs);
 831	else if (cur_cpu_spec->machine_check)
 832		recover = cur_cpu_spec->machine_check(regs);
 833
 834	if (recover > 0)
 835		goto bail;
 836
 837	if (debugger_fault_handler(regs))
 838		goto bail;
 839
 840	if (check_io_access(regs))
 841		goto bail;
 842
 843	die_mce("Machine check", regs, SIGBUS);
 844
 845bail:
 846	/* Must die if the interrupt is not recoverable */
 847	if (!(regs->msr & MSR_RI))
 848		die_mce("Unrecoverable Machine check", regs, SIGBUS);
 849}
 850
 851#ifdef CONFIG_PPC_BOOK3S_64
 852DEFINE_INTERRUPT_HANDLER_ASYNC(machine_check_exception_async)
 853{
 854	__machine_check_exception(regs);
 855}
 856#endif
 857DEFINE_INTERRUPT_HANDLER_NMI(machine_check_exception)
 858{
 859	__machine_check_exception(regs);
 860
 861	return 0;
 
 862}
 863
 864DEFINE_INTERRUPT_HANDLER(SMIException) /* async? */
 865{
 866	die("System Management Interrupt", regs, SIGABRT);
 867}
 868
 869#ifdef CONFIG_VSX
 870static void p9_hmi_special_emu(struct pt_regs *regs)
 871{
 872	unsigned int ra, rb, t, i, sel, instr, rc;
 873	const void __user *addr;
 874	u8 vbuf[16] __aligned(16), *vdst;
 875	unsigned long ea, msr, msr_mask;
 876	bool swap;
 877
 878	if (__get_user(instr, (unsigned int __user *)regs->nip))
 879		return;
 880
 881	/*
 882	 * lxvb16x	opcode: 0x7c0006d8
 883	 * lxvd2x	opcode: 0x7c000698
 884	 * lxvh8x	opcode: 0x7c000658
 885	 * lxvw4x	opcode: 0x7c000618
 886	 */
 887	if ((instr & 0xfc00073e) != 0x7c000618) {
 888		pr_devel("HMI vec emu: not vector CI %i:%s[%d] nip=%016lx"
 889			 " instr=%08x\n",
 890			 smp_processor_id(), current->comm, current->pid,
 891			 regs->nip, instr);
 892		return;
 893	}
 894
 895	/* Grab vector registers into the task struct */
 896	msr = regs->msr; /* Grab msr before we flush the bits */
 897	flush_vsx_to_thread(current);
 898	enable_kernel_altivec();
 899
 900	/*
 901	 * Is userspace running with a different endian (this is rare but
 902	 * not impossible)
 903	 */
 904	swap = (msr & MSR_LE) != (MSR_KERNEL & MSR_LE);
 905
 906	/* Decode the instruction */
 907	ra = (instr >> 16) & 0x1f;
 908	rb = (instr >> 11) & 0x1f;
 909	t = (instr >> 21) & 0x1f;
 910	if (instr & 1)
 911		vdst = (u8 *)&current->thread.vr_state.vr[t];
 912	else
 913		vdst = (u8 *)&current->thread.fp_state.fpr[t][0];
 914
 915	/* Grab the vector address */
 916	ea = regs->gpr[rb] + (ra ? regs->gpr[ra] : 0);
 917	if (is_32bit_task())
 918		ea &= 0xfffffffful;
 919	addr = (__force const void __user *)ea;
 920
 921	/* Check it */
 922	if (!access_ok(addr, 16)) {
 923		pr_devel("HMI vec emu: bad access %i:%s[%d] nip=%016lx"
 924			 " instr=%08x addr=%016lx\n",
 925			 smp_processor_id(), current->comm, current->pid,
 926			 regs->nip, instr, (unsigned long)addr);
 927		return;
 928	}
 929
 930	/* Read the vector */
 931	rc = 0;
 932	if ((unsigned long)addr & 0xfUL)
 933		/* unaligned case */
 934		rc = __copy_from_user_inatomic(vbuf, addr, 16);
 935	else
 936		__get_user_atomic_128_aligned(vbuf, addr, rc);
 937	if (rc) {
 938		pr_devel("HMI vec emu: page fault %i:%s[%d] nip=%016lx"
 939			 " instr=%08x addr=%016lx\n",
 940			 smp_processor_id(), current->comm, current->pid,
 941			 regs->nip, instr, (unsigned long)addr);
 942		return;
 943	}
 944
 945	pr_devel("HMI vec emu: emulated vector CI %i:%s[%d] nip=%016lx"
 946		 " instr=%08x addr=%016lx\n",
 947		 smp_processor_id(), current->comm, current->pid, regs->nip,
 948		 instr, (unsigned long) addr);
 949
 950	/* Grab instruction "selector" */
 951	sel = (instr >> 6) & 3;
 952
 953	/*
 954	 * Check to make sure the facility is actually enabled. This
 955	 * could happen if we get a false positive hit.
 956	 *
 957	 * lxvd2x/lxvw4x always check MSR VSX sel = 0,2
 958	 * lxvh8x/lxvb16x check MSR VSX or VEC depending on VSR used sel = 1,3
 959	 */
 960	msr_mask = MSR_VSX;
 961	if ((sel & 1) && (instr & 1)) /* lxvh8x & lxvb16x + VSR >= 32 */
 962		msr_mask = MSR_VEC;
 963	if (!(msr & msr_mask)) {
 964		pr_devel("HMI vec emu: MSR fac clear %i:%s[%d] nip=%016lx"
 965			 " instr=%08x msr:%016lx\n",
 966			 smp_processor_id(), current->comm, current->pid,
 967			 regs->nip, instr, msr);
 968		return;
 969	}
 970
 971	/* Do logging here before we modify sel based on endian */
 972	switch (sel) {
 973	case 0:	/* lxvw4x */
 974		PPC_WARN_EMULATED(lxvw4x, regs);
 975		break;
 976	case 1: /* lxvh8x */
 977		PPC_WARN_EMULATED(lxvh8x, regs);
 978		break;
 979	case 2: /* lxvd2x */
 980		PPC_WARN_EMULATED(lxvd2x, regs);
 981		break;
 982	case 3: /* lxvb16x */
 983		PPC_WARN_EMULATED(lxvb16x, regs);
 984		break;
 985	}
 986
 987#ifdef __LITTLE_ENDIAN__
 988	/*
 989	 * An LE kernel stores the vector in the task struct as an LE
 990	 * byte array (effectively swapping both the components and
 991	 * the content of the components). Those instructions expect
 992	 * the components to remain in ascending address order, so we
 993	 * swap them back.
 994	 *
 995	 * If we are running a BE user space, the expectation is that
 996	 * of a simple memcpy, so forcing the emulation to look like
 997	 * a lxvb16x should do the trick.
 998	 */
 999	if (swap)
1000		sel = 3;
1001
1002	switch (sel) {
1003	case 0:	/* lxvw4x */
1004		for (i = 0; i < 4; i++)
1005			((u32 *)vdst)[i] = ((u32 *)vbuf)[3-i];
1006		break;
1007	case 1: /* lxvh8x */
1008		for (i = 0; i < 8; i++)
1009			((u16 *)vdst)[i] = ((u16 *)vbuf)[7-i];
1010		break;
1011	case 2: /* lxvd2x */
1012		for (i = 0; i < 2; i++)
1013			((u64 *)vdst)[i] = ((u64 *)vbuf)[1-i];
1014		break;
1015	case 3: /* lxvb16x */
1016		for (i = 0; i < 16; i++)
1017			vdst[i] = vbuf[15-i];
1018		break;
1019	}
1020#else /* __LITTLE_ENDIAN__ */
1021	/* On a big endian kernel, a BE userspace only needs a memcpy */
1022	if (!swap)
1023		sel = 3;
1024
1025	/* Otherwise, we need to swap the content of the components */
1026	switch (sel) {
1027	case 0:	/* lxvw4x */
1028		for (i = 0; i < 4; i++)
1029			((u32 *)vdst)[i] = cpu_to_le32(((u32 *)vbuf)[i]);
1030		break;
1031	case 1: /* lxvh8x */
1032		for (i = 0; i < 8; i++)
1033			((u16 *)vdst)[i] = cpu_to_le16(((u16 *)vbuf)[i]);
1034		break;
1035	case 2: /* lxvd2x */
1036		for (i = 0; i < 2; i++)
1037			((u64 *)vdst)[i] = cpu_to_le64(((u64 *)vbuf)[i]);
1038		break;
1039	case 3: /* lxvb16x */
1040		memcpy(vdst, vbuf, 16);
1041		break;
1042	}
1043#endif /* !__LITTLE_ENDIAN__ */
1044
1045	/* Go to next instruction */
1046	regs_add_return_ip(regs, 4);
1047}
1048#endif /* CONFIG_VSX */
1049
1050DEFINE_INTERRUPT_HANDLER_ASYNC(handle_hmi_exception)
1051{
1052	struct pt_regs *old_regs;
1053
1054	old_regs = set_irq_regs(regs);
1055
1056#ifdef CONFIG_VSX
1057	/* Real mode flagged P9 special emu is needed */
1058	if (local_paca->hmi_p9_special_emu) {
1059		local_paca->hmi_p9_special_emu = 0;
1060
1061		/*
1062		 * We don't want to take page faults while doing the
1063		 * emulation, we just replay the instruction if necessary.
1064		 */
1065		pagefault_disable();
1066		p9_hmi_special_emu(regs);
1067		pagefault_enable();
1068	}
1069#endif /* CONFIG_VSX */
1070
1071	if (ppc_md.handle_hmi_exception)
1072		ppc_md.handle_hmi_exception(regs);
1073
 
1074	set_irq_regs(old_regs);
1075}
1076
1077DEFINE_INTERRUPT_HANDLER(unknown_exception)
1078{
1079	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1080	       regs->nip, regs->msr, regs->trap);
1081
1082	_exception(SIGTRAP, regs, TRAP_UNK, 0);
1083}
1084
1085DEFINE_INTERRUPT_HANDLER_ASYNC(unknown_async_exception)
1086{
1087	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1088	       regs->nip, regs->msr, regs->trap);
1089
1090	_exception(SIGTRAP, regs, TRAP_UNK, 0);
1091}
1092
1093DEFINE_INTERRUPT_HANDLER_NMI(unknown_nmi_exception)
1094{
1095	printk("Bad trap at PC: %lx, SR: %lx, vector=%lx\n",
1096	       regs->nip, regs->msr, regs->trap);
1097
1098	_exception(SIGTRAP, regs, TRAP_UNK, 0);
1099
1100	return 0;
1101}
1102
1103DEFINE_INTERRUPT_HANDLER(instruction_breakpoint_exception)
1104{
 
 
1105	if (notify_die(DIE_IABR_MATCH, "iabr_match", regs, 5,
1106					5, SIGTRAP) == NOTIFY_STOP)
1107		return;
1108	if (debugger_iabr_match(regs))
1109		return;
1110	_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
 
 
 
1111}
1112
1113DEFINE_INTERRUPT_HANDLER(RunModeException)
1114{
1115	_exception(SIGTRAP, regs, TRAP_UNK, 0);
1116}
1117
1118static void __single_step_exception(struct pt_regs *regs)
1119{
 
 
1120	clear_single_step(regs);
1121	clear_br_trace(regs);
1122
1123	if (kprobe_post_handler(regs))
1124		return;
1125
1126	if (notify_die(DIE_SSTEP, "single_step", regs, 5,
1127					5, SIGTRAP) == NOTIFY_STOP)
1128		return;
1129	if (debugger_sstep(regs))
1130		return;
1131
1132	_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
1133}
1134
1135DEFINE_INTERRUPT_HANDLER(single_step_exception)
1136{
1137	__single_step_exception(regs);
1138}
 
1139
1140/*
1141 * After we have successfully emulated an instruction, we have to
1142 * check if the instruction was being single-stepped, and if so,
1143 * pretend we got a single-step exception.  This was pointed out
1144 * by Kumar Gala.  -- paulus
1145 */
1146static void emulate_single_step(struct pt_regs *regs)
1147{
1148	if (single_stepping(regs))
1149		__single_step_exception(regs);
1150}
1151
1152static inline int __parse_fpscr(unsigned long fpscr)
1153{
1154	int ret = FPE_FLTUNK;
1155
1156	/* Invalid operation */
1157	if ((fpscr & FPSCR_VE) && (fpscr & FPSCR_VX))
1158		ret = FPE_FLTINV;
1159
1160	/* Overflow */
1161	else if ((fpscr & FPSCR_OE) && (fpscr & FPSCR_OX))
1162		ret = FPE_FLTOVF;
1163
1164	/* Underflow */
1165	else if ((fpscr & FPSCR_UE) && (fpscr & FPSCR_UX))
1166		ret = FPE_FLTUND;
1167
1168	/* Divide by zero */
1169	else if ((fpscr & FPSCR_ZE) && (fpscr & FPSCR_ZX))
1170		ret = FPE_FLTDIV;
1171
1172	/* Inexact result */
1173	else if ((fpscr & FPSCR_XE) && (fpscr & FPSCR_XX))
1174		ret = FPE_FLTRES;
1175
1176	return ret;
1177}
1178
1179static void parse_fpe(struct pt_regs *regs)
1180{
1181	int code = 0;
1182
1183	flush_fp_to_thread(current);
1184
1185#ifdef CONFIG_PPC_FPU_REGS
1186	code = __parse_fpscr(current->thread.fp_state.fpscr);
1187#endif
1188
1189	_exception(SIGFPE, regs, code, regs->nip);
1190}
1191
1192/*
1193 * Illegal instruction emulation support.  Originally written to
1194 * provide the PVR to user applications using the mfspr rd, PVR.
1195 * Return non-zero if we can't emulate, or -EFAULT if the associated
1196 * memory access caused an access fault.  Return zero on success.
1197 *
1198 * There are a couple of ways to do this, either "decode" the instruction
1199 * or directly match lots of bits.  In this case, matching lots of
1200 * bits is faster and easier.
1201 *
1202 */
1203static int emulate_string_inst(struct pt_regs *regs, u32 instword)
1204{
1205	u8 rT = (instword >> 21) & 0x1f;
1206	u8 rA = (instword >> 16) & 0x1f;
1207	u8 NB_RB = (instword >> 11) & 0x1f;
1208	u32 num_bytes;
1209	unsigned long EA;
1210	int pos = 0;
1211
1212	/* Early out if we are an invalid form of lswx */
1213	if ((instword & PPC_INST_STRING_MASK) == PPC_INST_LSWX)
1214		if ((rT == rA) || (rT == NB_RB))
1215			return -EINVAL;
1216
1217	EA = (rA == 0) ? 0 : regs->gpr[rA];
1218
1219	switch (instword & PPC_INST_STRING_MASK) {
1220		case PPC_INST_LSWX:
1221		case PPC_INST_STSWX:
1222			EA += NB_RB;
1223			num_bytes = regs->xer & 0x7f;
1224			break;
1225		case PPC_INST_LSWI:
1226		case PPC_INST_STSWI:
1227			num_bytes = (NB_RB == 0) ? 32 : NB_RB;
1228			break;
1229		default:
1230			return -EINVAL;
1231	}
1232
1233	while (num_bytes != 0)
1234	{
1235		u8 val;
1236		u32 shift = 8 * (3 - (pos & 0x3));
1237
1238		/* if process is 32-bit, clear upper 32 bits of EA */
1239		if ((regs->msr & MSR_64BIT) == 0)
1240			EA &= 0xFFFFFFFF;
1241
1242		switch ((instword & PPC_INST_STRING_MASK)) {
1243			case PPC_INST_LSWX:
1244			case PPC_INST_LSWI:
1245				if (get_user(val, (u8 __user *)EA))
1246					return -EFAULT;
1247				/* first time updating this reg,
1248				 * zero it out */
1249				if (pos == 0)
1250					regs->gpr[rT] = 0;
1251				regs->gpr[rT] |= val << shift;
1252				break;
1253			case PPC_INST_STSWI:
1254			case PPC_INST_STSWX:
1255				val = regs->gpr[rT] >> shift;
1256				if (put_user(val, (u8 __user *)EA))
1257					return -EFAULT;
1258				break;
1259		}
1260		/* move EA to next address */
1261		EA += 1;
1262		num_bytes--;
1263
1264		/* manage our position within the register */
1265		if (++pos == 4) {
1266			pos = 0;
1267			if (++rT == 32)
1268				rT = 0;
1269		}
1270	}
1271
1272	return 0;
1273}
1274
1275static int emulate_popcntb_inst(struct pt_regs *regs, u32 instword)
1276{
1277	u32 ra,rs;
1278	unsigned long tmp;
1279
1280	ra = (instword >> 16) & 0x1f;
1281	rs = (instword >> 21) & 0x1f;
1282
1283	tmp = regs->gpr[rs];
1284	tmp = tmp - ((tmp >> 1) & 0x5555555555555555ULL);
1285	tmp = (tmp & 0x3333333333333333ULL) + ((tmp >> 2) & 0x3333333333333333ULL);
1286	tmp = (tmp + (tmp >> 4)) & 0x0f0f0f0f0f0f0f0fULL;
1287	regs->gpr[ra] = tmp;
1288
1289	return 0;
1290}
1291
1292static int emulate_isel(struct pt_regs *regs, u32 instword)
1293{
1294	u8 rT = (instword >> 21) & 0x1f;
1295	u8 rA = (instword >> 16) & 0x1f;
1296	u8 rB = (instword >> 11) & 0x1f;
1297	u8 BC = (instword >> 6) & 0x1f;
1298	u8 bit;
1299	unsigned long tmp;
1300
1301	tmp = (rA == 0) ? 0 : regs->gpr[rA];
1302	bit = (regs->ccr >> (31 - BC)) & 0x1;
1303
1304	regs->gpr[rT] = bit ? tmp : regs->gpr[rB];
1305
1306	return 0;
1307}
1308
1309#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1310static inline bool tm_abort_check(struct pt_regs *regs, int cause)
1311{
1312        /* If we're emulating a load/store in an active transaction, we cannot
1313         * emulate it as the kernel operates in transaction suspended context.
1314         * We need to abort the transaction.  This creates a persistent TM
1315         * abort so tell the user what caused it with a new code.
1316	 */
1317	if (MSR_TM_TRANSACTIONAL(regs->msr)) {
1318		tm_enable();
1319		tm_abort(cause);
1320		return true;
1321	}
1322	return false;
1323}
1324#else
1325static inline bool tm_abort_check(struct pt_regs *regs, int reason)
1326{
1327	return false;
1328}
1329#endif
1330
1331static int emulate_instruction(struct pt_regs *regs)
1332{
1333	u32 instword;
1334	u32 rd;
1335
1336	if (!user_mode(regs))
1337		return -EINVAL;
 
1338
1339	if (get_user(instword, (u32 __user *)(regs->nip)))
1340		return -EFAULT;
1341
1342	/* Emulate the mfspr rD, PVR. */
1343	if ((instword & PPC_INST_MFSPR_PVR_MASK) == PPC_INST_MFSPR_PVR) {
1344		PPC_WARN_EMULATED(mfpvr, regs);
1345		rd = (instword >> 21) & 0x1f;
1346		regs->gpr[rd] = mfspr(SPRN_PVR);
1347		return 0;
1348	}
1349
1350	/* Emulating the dcba insn is just a no-op.  */
1351	if ((instword & PPC_INST_DCBA_MASK) == PPC_INST_DCBA) {
1352		PPC_WARN_EMULATED(dcba, regs);
1353		return 0;
1354	}
1355
1356	/* Emulate the mcrxr insn.  */
1357	if ((instword & PPC_INST_MCRXR_MASK) == PPC_INST_MCRXR) {
1358		int shift = (instword >> 21) & 0x1c;
1359		unsigned long msk = 0xf0000000UL >> shift;
1360
1361		PPC_WARN_EMULATED(mcrxr, regs);
1362		regs->ccr = (regs->ccr & ~msk) | ((regs->xer >> shift) & msk);
1363		regs->xer &= ~0xf0000000UL;
1364		return 0;
1365	}
1366
1367	/* Emulate load/store string insn. */
1368	if ((instword & PPC_INST_STRING_GEN_MASK) == PPC_INST_STRING) {
1369		if (tm_abort_check(regs,
1370				   TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT))
1371			return -EINVAL;
1372		PPC_WARN_EMULATED(string, regs);
1373		return emulate_string_inst(regs, instword);
1374	}
1375
1376	/* Emulate the popcntb (Population Count Bytes) instruction. */
1377	if ((instword & PPC_INST_POPCNTB_MASK) == PPC_INST_POPCNTB) {
1378		PPC_WARN_EMULATED(popcntb, regs);
1379		return emulate_popcntb_inst(regs, instword);
1380	}
1381
1382	/* Emulate isel (Integer Select) instruction */
1383	if ((instword & PPC_INST_ISEL_MASK) == PPC_INST_ISEL) {
1384		PPC_WARN_EMULATED(isel, regs);
1385		return emulate_isel(regs, instword);
1386	}
1387
1388	/* Emulate sync instruction variants */
1389	if ((instword & PPC_INST_SYNC_MASK) == PPC_INST_SYNC) {
1390		PPC_WARN_EMULATED(sync, regs);
1391		asm volatile("sync");
1392		return 0;
1393	}
1394
1395#ifdef CONFIG_PPC64
1396	/* Emulate the mfspr rD, DSCR. */
1397	if ((((instword & PPC_INST_MFSPR_DSCR_USER_MASK) ==
1398		PPC_INST_MFSPR_DSCR_USER) ||
1399	     ((instword & PPC_INST_MFSPR_DSCR_MASK) ==
1400		PPC_INST_MFSPR_DSCR)) &&
1401			cpu_has_feature(CPU_FTR_DSCR)) {
1402		PPC_WARN_EMULATED(mfdscr, regs);
1403		rd = (instword >> 21) & 0x1f;
1404		regs->gpr[rd] = mfspr(SPRN_DSCR);
1405		return 0;
1406	}
1407	/* Emulate the mtspr DSCR, rD. */
1408	if ((((instword & PPC_INST_MTSPR_DSCR_USER_MASK) ==
1409		PPC_INST_MTSPR_DSCR_USER) ||
1410	     ((instword & PPC_INST_MTSPR_DSCR_MASK) ==
1411		PPC_INST_MTSPR_DSCR)) &&
1412			cpu_has_feature(CPU_FTR_DSCR)) {
1413		PPC_WARN_EMULATED(mtdscr, regs);
1414		rd = (instword >> 21) & 0x1f;
1415		current->thread.dscr = regs->gpr[rd];
1416		current->thread.dscr_inherit = 1;
1417		mtspr(SPRN_DSCR, current->thread.dscr);
1418		return 0;
1419	}
1420#endif
1421
1422	return -EINVAL;
1423}
1424
1425int is_valid_bugaddr(unsigned long addr)
1426{
1427	return is_kernel_addr(addr);
1428}
1429
1430#ifdef CONFIG_MATH_EMULATION
1431static int emulate_math(struct pt_regs *regs)
1432{
1433	int ret;
 
1434
1435	ret = do_mathemu(regs);
1436	if (ret >= 0)
1437		PPC_WARN_EMULATED(math, regs);
1438
1439	switch (ret) {
1440	case 0:
1441		emulate_single_step(regs);
1442		return 0;
1443	case 1: {
1444			int code = 0;
1445			code = __parse_fpscr(current->thread.fp_state.fpscr);
1446			_exception(SIGFPE, regs, code, regs->nip);
1447			return 0;
1448		}
1449	case -EFAULT:
1450		_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1451		return 0;
1452	}
1453
1454	return -1;
1455}
1456#else
1457static inline int emulate_math(struct pt_regs *regs) { return -1; }
1458#endif
1459
1460static void do_program_check(struct pt_regs *regs)
1461{
 
1462	unsigned int reason = get_reason(regs);
1463
1464	/* We can now get here via a FP Unavailable exception if the core
1465	 * has no FPU, in that case the reason flags will be 0 */
1466
1467	if (reason & REASON_FP) {
1468		/* IEEE FP exception */
1469		parse_fpe(regs);
1470		return;
1471	}
1472	if (reason & REASON_TRAP) {
1473		unsigned long bugaddr;
1474		/* Debugger is first in line to stop recursive faults in
1475		 * rcu_lock, notify_die, or atomic_notifier_call_chain */
1476		if (debugger_bpt(regs))
1477			return;
1478
1479		if (kprobe_handler(regs))
1480			return;
1481
1482		/* trap exception */
1483		if (notify_die(DIE_BPT, "breakpoint", regs, 5, 5, SIGTRAP)
1484				== NOTIFY_STOP)
1485			return;
1486
1487		bugaddr = regs->nip;
1488		/*
1489		 * Fixup bugaddr for BUG_ON() in real mode
1490		 */
1491		if (!is_kernel_addr(bugaddr) && !(regs->msr & MSR_IR))
1492			bugaddr += PAGE_OFFSET;
1493
1494		if (!(regs->msr & MSR_PR) &&  /* not user-mode */
1495		    report_bug(bugaddr, regs) == BUG_TRAP_TYPE_WARN) {
1496			regs_add_return_ip(regs, 4);
1497			return;
1498		}
1499		_exception(SIGTRAP, regs, TRAP_BRKPT, regs->nip);
1500		return;
1501	}
1502#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1503	if (reason & REASON_TM) {
1504		/* This is a TM "Bad Thing Exception" program check.
1505		 * This occurs when:
1506		 * -  An rfid/hrfid/mtmsrd attempts to cause an illegal
1507		 *    transition in TM states.
1508		 * -  A trechkpt is attempted when transactional.
1509		 * -  A treclaim is attempted when non transactional.
1510		 * -  A tend is illegally attempted.
1511		 * -  writing a TM SPR when transactional.
1512		 *
1513		 * If usermode caused this, it's done something illegal and
 
 
 
 
 
1514		 * gets a SIGILL slap on the wrist.  We call it an illegal
1515		 * operand to distinguish from the instruction just being bad
1516		 * (e.g. executing a 'tend' on a CPU without TM!); it's an
1517		 * illegal /placement/ of a valid instruction.
1518		 */
1519		if (user_mode(regs)) {
1520			_exception(SIGILL, regs, ILL_ILLOPN, regs->nip);
1521			return;
1522		} else {
1523			printk(KERN_EMERG "Unexpected TM Bad Thing exception "
1524			       "at %lx (msr 0x%lx) tm_scratch=%llx\n",
1525			       regs->nip, regs->msr, get_paca()->tm_scratch);
1526			die("Unrecoverable exception", regs, SIGABRT);
1527		}
1528	}
1529#endif
1530
1531	/*
1532	 * If we took the program check in the kernel skip down to sending a
1533	 * SIGILL. The subsequent cases all relate to emulating instructions
1534	 * which we should only do for userspace. We also do not want to enable
1535	 * interrupts for kernel faults because that might lead to further
1536	 * faults, and loose the context of the original exception.
1537	 */
1538	if (!user_mode(regs))
1539		goto sigill;
1540
1541	interrupt_cond_local_irq_enable(regs);
 
 
1542
1543	/* (reason & REASON_ILLEGAL) would be the obvious thing here,
1544	 * but there seems to be a hardware bug on the 405GP (RevD)
1545	 * that means ESR is sometimes set incorrectly - either to
1546	 * ESR_DST (!?) or 0.  In the process of chasing this with the
1547	 * hardware people - not sure if it can happen on any illegal
1548	 * instruction or only on FP instructions, whether there is a
1549	 * pattern to occurrences etc. -dgibson 31/Mar/2003
1550	 */
1551	if (!emulate_math(regs))
1552		return;
1553
1554	/* Try to emulate it if we should. */
1555	if (reason & (REASON_ILLEGAL | REASON_PRIVILEGED)) {
1556		switch (emulate_instruction(regs)) {
1557		case 0:
1558			regs_add_return_ip(regs, 4);
1559			emulate_single_step(regs);
1560			return;
1561		case -EFAULT:
1562			_exception(SIGSEGV, regs, SEGV_MAPERR, regs->nip);
1563			return;
1564		}
1565	}
1566
1567sigill:
1568	if (reason & REASON_PRIVILEGED)
1569		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
1570	else
1571		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1572
 
 
1573}
1574
1575DEFINE_INTERRUPT_HANDLER(program_check_exception)
1576{
1577	do_program_check(regs);
1578}
1579
1580/*
1581 * This occurs when running in hypervisor mode on POWER6 or later
1582 * and an illegal instruction is encountered.
1583 */
1584DEFINE_INTERRUPT_HANDLER(emulation_assist_interrupt)
1585{
1586	regs_set_return_msr(regs, regs->msr | REASON_ILLEGAL);
1587	do_program_check(regs);
1588}
 
1589
1590DEFINE_INTERRUPT_HANDLER(alignment_exception)
1591{
 
1592	int sig, code, fixed = 0;
1593	unsigned long  reason;
1594
1595	interrupt_cond_local_irq_enable(regs);
1596
1597	reason = get_reason(regs);
1598	if (reason & REASON_BOUNDARY) {
1599		sig = SIGBUS;
1600		code = BUS_ADRALN;
1601		goto bad;
1602	}
1603
1604	if (tm_abort_check(regs, TM_CAUSE_ALIGNMENT | TM_CAUSE_PERSISTENT))
1605		return;
1606
1607	/* we don't implement logging of alignment exceptions */
1608	if (!(current->thread.align_ctl & PR_UNALIGN_SIGBUS))
1609		fixed = fix_alignment(regs);
1610
1611	if (fixed == 1) {
1612		/* skip over emulated instruction */
1613		regs_add_return_ip(regs, inst_length(reason));
1614		emulate_single_step(regs);
1615		return;
1616	}
1617
1618	/* Operand address was bad */
1619	if (fixed == -EFAULT) {
1620		sig = SIGSEGV;
1621		code = SEGV_ACCERR;
1622	} else {
1623		sig = SIGBUS;
1624		code = BUS_ADRALN;
1625	}
1626bad:
1627	if (user_mode(regs))
1628		_exception(sig, regs, code, regs->dar);
1629	else
1630		bad_page_fault(regs, sig);
 
 
 
1631}
1632
1633DEFINE_INTERRUPT_HANDLER(stack_overflow_exception)
1634{
1635	die("Kernel stack overflow", regs, SIGSEGV);
 
 
 
 
 
 
 
1636}
1637
1638DEFINE_INTERRUPT_HANDLER(kernel_fp_unavailable_exception)
1639{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1640	printk(KERN_EMERG "Unrecoverable FP Unavailable Exception "
1641			  "%lx at %lx\n", regs->trap, regs->nip);
1642	die("Unrecoverable FP Unavailable Exception", regs, SIGABRT);
 
 
1643}
1644
1645DEFINE_INTERRUPT_HANDLER(altivec_unavailable_exception)
1646{
 
 
1647	if (user_mode(regs)) {
1648		/* A user program has executed an altivec instruction,
1649		   but this kernel doesn't support altivec. */
1650		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1651		return;
1652	}
1653
1654	printk(KERN_EMERG "Unrecoverable VMX/Altivec Unavailable Exception "
1655			"%lx at %lx\n", regs->trap, regs->nip);
1656	die("Unrecoverable VMX/Altivec Unavailable Exception", regs, SIGABRT);
 
 
 
1657}
1658
1659DEFINE_INTERRUPT_HANDLER(vsx_unavailable_exception)
1660{
1661	if (user_mode(regs)) {
1662		/* A user program has executed an vsx instruction,
1663		   but this kernel doesn't support vsx. */
1664		_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
1665		return;
1666	}
1667
1668	printk(KERN_EMERG "Unrecoverable VSX Unavailable Exception "
1669			"%lx at %lx\n", regs->trap, regs->nip);
1670	die("Unrecoverable VSX Unavailable Exception", regs, SIGABRT);
1671}
1672
1673#ifdef CONFIG_PPC64
1674static void tm_unavailable(struct pt_regs *regs)
1675{
1676#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1677	if (user_mode(regs)) {
1678		current->thread.load_tm++;
1679		regs_set_return_msr(regs, regs->msr | MSR_TM);
1680		tm_enable();
1681		tm_restore_sprs(&current->thread);
1682		return;
1683	}
1684#endif
1685	pr_emerg("Unrecoverable TM Unavailable Exception "
1686			"%lx at %lx\n", regs->trap, regs->nip);
1687	die("Unrecoverable TM Unavailable Exception", regs, SIGABRT);
1688}
1689
1690DEFINE_INTERRUPT_HANDLER(facility_unavailable_exception)
1691{
1692	static char *facility_strings[] = {
1693		[FSCR_FP_LG] = "FPU",
1694		[FSCR_VECVSX_LG] = "VMX/VSX",
1695		[FSCR_DSCR_LG] = "DSCR",
1696		[FSCR_PM_LG] = "PMU SPRs",
1697		[FSCR_BHRB_LG] = "BHRB",
1698		[FSCR_TM_LG] = "TM",
1699		[FSCR_EBB_LG] = "EBB",
1700		[FSCR_TAR_LG] = "TAR",
1701		[FSCR_MSGP_LG] = "MSGP",
1702		[FSCR_SCV_LG] = "SCV",
1703		[FSCR_PREFIX_LG] = "PREFIX",
1704	};
1705	char *facility = "unknown";
1706	u64 value;
1707	u32 instword, rd;
1708	u8 status;
1709	bool hv;
1710
1711	hv = (TRAP(regs) == INTERRUPT_H_FAC_UNAVAIL);
1712	if (hv)
1713		value = mfspr(SPRN_HFSCR);
1714	else
1715		value = mfspr(SPRN_FSCR);
1716
1717	status = value >> 56;
1718	if ((hv || status >= 2) &&
1719	    (status < ARRAY_SIZE(facility_strings)) &&
1720	    facility_strings[status])
1721		facility = facility_strings[status];
1722
1723	/* We should not have taken this interrupt in kernel */
1724	if (!user_mode(regs)) {
1725		pr_emerg("Facility '%s' unavailable (%d) exception in kernel mode at %lx\n",
1726			 facility, status, regs->nip);
1727		die("Unexpected facility unavailable exception", regs, SIGABRT);
1728	}
1729
1730	interrupt_cond_local_irq_enable(regs);
1731
1732	if (status == FSCR_DSCR_LG) {
1733		/*
1734		 * User is accessing the DSCR register using the problem
1735		 * state only SPR number (0x03) either through a mfspr or
1736		 * a mtspr instruction. If it is a write attempt through
1737		 * a mtspr, then we set the inherit bit. This also allows
1738		 * the user to write or read the register directly in the
1739		 * future by setting via the FSCR DSCR bit. But in case it
1740		 * is a read DSCR attempt through a mfspr instruction, we
1741		 * just emulate the instruction instead. This code path will
1742		 * always emulate all the mfspr instructions till the user
1743		 * has attempted at least one mtspr instruction. This way it
1744		 * preserves the same behaviour when the user is accessing
1745		 * the DSCR through privilege level only SPR number (0x11)
1746		 * which is emulated through illegal instruction exception.
1747		 * We always leave HFSCR DSCR set.
1748		 */
1749		if (get_user(instword, (u32 __user *)(regs->nip))) {
1750			pr_err("Failed to fetch the user instruction\n");
1751			return;
1752		}
1753
1754		/* Write into DSCR (mtspr 0x03, RS) */
1755		if ((instword & PPC_INST_MTSPR_DSCR_USER_MASK)
1756				== PPC_INST_MTSPR_DSCR_USER) {
1757			rd = (instword >> 21) & 0x1f;
1758			current->thread.dscr = regs->gpr[rd];
1759			current->thread.dscr_inherit = 1;
1760			current->thread.fscr |= FSCR_DSCR;
1761			mtspr(SPRN_FSCR, current->thread.fscr);
1762		}
1763
1764		/* Read from DSCR (mfspr RT, 0x03) */
1765		if ((instword & PPC_INST_MFSPR_DSCR_USER_MASK)
1766				== PPC_INST_MFSPR_DSCR_USER) {
1767			if (emulate_instruction(regs)) {
1768				pr_err("DSCR based mfspr emulation failed\n");
1769				return;
1770			}
1771			regs_add_return_ip(regs, 4);
1772			emulate_single_step(regs);
1773		}
1774		return;
1775	}
1776
1777	if (status == FSCR_TM_LG) {
1778		/*
1779		 * If we're here then the hardware is TM aware because it
1780		 * generated an exception with FSRM_TM set.
1781		 *
1782		 * If cpu_has_feature(CPU_FTR_TM) is false, then either firmware
1783		 * told us not to do TM, or the kernel is not built with TM
1784		 * support.
1785		 *
1786		 * If both of those things are true, then userspace can spam the
1787		 * console by triggering the printk() below just by continually
1788		 * doing tbegin (or any TM instruction). So in that case just
1789		 * send the process a SIGILL immediately.
1790		 */
1791		if (!cpu_has_feature(CPU_FTR_TM))
1792			goto out;
1793
1794		tm_unavailable(regs);
1795		return;
1796	}
1797
 
 
 
 
 
 
 
 
 
1798	pr_err_ratelimited("%sFacility '%s' unavailable (%d), exception at 0x%lx, MSR=%lx\n",
1799		hv ? "Hypervisor " : "", facility, status, regs->nip, regs->msr);
1800
1801out:
1802	_exception(SIGILL, regs, ILL_ILLOPC, regs->nip);
 
 
 
 
 
1803}
1804#endif
1805
1806#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
1807
1808DEFINE_INTERRUPT_HANDLER(fp_unavailable_tm)
1809{
1810	/* Note:  This does not handle any kind of FP laziness. */
1811
1812	TM_DEBUG("FP Unavailable trap whilst transactional at 0x%lx, MSR=%lx\n",
1813		 regs->nip, regs->msr);
1814
1815        /* We can only have got here if the task started using FP after
1816         * beginning the transaction.  So, the transactional regs are just a
1817         * copy of the checkpointed ones.  But, we still need to recheckpoint
1818         * as we're enabling FP for the process; it will return, abort the
1819         * transaction, and probably retry but now with FP enabled.  So the
1820         * checkpointed FP registers need to be loaded.
1821	 */
1822	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1823
1824	/*
1825	 * Reclaim initially saved out bogus (lazy) FPRs to ckfp_state, and
1826	 * then it was overwrite by the thr->fp_state by tm_reclaim_thread().
1827	 *
1828	 * At this point, ck{fp,vr}_state contains the exact values we want to
1829	 * recheckpoint.
1830	 */
1831
1832	/* Enable FP for the task: */
1833	current->thread.load_fp = 1;
1834
1835	/*
1836	 * Recheckpoint all the checkpointed ckpt, ck{fp, vr}_state registers.
 
 
 
1837	 */
1838	tm_recheckpoint(&current->thread);
 
 
 
 
 
 
 
 
1839}
1840
1841DEFINE_INTERRUPT_HANDLER(altivec_unavailable_tm)
1842{
1843	/* See the comments in fp_unavailable_tm().  This function operates
1844	 * the same way.
1845	 */
1846
1847	TM_DEBUG("Vector Unavailable trap whilst transactional at 0x%lx,"
1848		 "MSR=%lx\n",
1849		 regs->nip, regs->msr);
1850	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1851	current->thread.load_vec = 1;
1852	tm_recheckpoint(&current->thread);
1853	current->thread.used_vr = 1;
 
 
 
 
 
 
1854}
1855
1856DEFINE_INTERRUPT_HANDLER(vsx_unavailable_tm)
1857{
 
 
1858	/* See the comments in fp_unavailable_tm().  This works similarly,
1859	 * though we're loading both FP and VEC registers in here.
1860	 *
1861	 * If FP isn't in use, load FP regs.  If VEC isn't in use, load VEC
1862	 * regs.  Either way, set MSR_VSX.
1863	 */
1864
1865	TM_DEBUG("VSX Unavailable trap whilst transactional at 0x%lx,"
1866		 "MSR=%lx\n",
1867		 regs->nip, regs->msr);
1868
1869	current->thread.used_vsr = 1;
1870
 
 
 
 
 
 
1871	/* This reclaims FP and/or VR regs if they're already enabled */
1872	tm_reclaim_current(TM_CAUSE_FAC_UNAV);
1873
1874	current->thread.load_vec = 1;
1875	current->thread.load_fp = 1;
 
 
 
 
 
 
 
1876
1877	tm_recheckpoint(&current->thread);
 
 
 
1878}
1879#endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
1880
1881#ifdef CONFIG_PPC64
1882DECLARE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi);
1883DEFINE_INTERRUPT_HANDLER_NMI(performance_monitor_exception_nmi)
1884{
1885	__this_cpu_inc(irq_stat.pmu_irqs);
1886
1887	perf_irq(regs);
1888
1889	return 0;
1890}
1891#endif
1892
1893DECLARE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async);
1894DEFINE_INTERRUPT_HANDLER_ASYNC(performance_monitor_exception_async)
1895{
1896	__this_cpu_inc(irq_stat.pmu_irqs);
1897
1898	perf_irq(regs);
1899}
 
 
 
1900
1901DEFINE_INTERRUPT_HANDLER_RAW(performance_monitor_exception)
1902{
1903	/*
1904	 * On 64-bit, if perf interrupts hit in a local_irq_disable
1905	 * (soft-masked) region, we consider them as NMIs. This is required to
1906	 * prevent hash faults on user addresses when reading callchains (and
1907	 * looks better from an irq tracing perspective).
1908	 */
1909	if (IS_ENABLED(CONFIG_PPC64) && unlikely(arch_irq_disabled_regs(regs)))
1910		performance_monitor_exception_nmi(regs);
1911	else
1912		performance_monitor_exception_async(regs);
1913
1914	return 0;
1915}
 
1916
1917#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1918static void handle_debug(struct pt_regs *regs, unsigned long debug_status)
1919{
1920	int changed = 0;
1921	/*
1922	 * Determine the cause of the debug event, clear the
1923	 * event flags and send a trap to the handler. Torez
1924	 */
1925	if (debug_status & (DBSR_DAC1R | DBSR_DAC1W)) {
1926		dbcr_dac(current) &= ~(DBCR_DAC1R | DBCR_DAC1W);
1927#ifdef CONFIG_PPC_ADV_DEBUG_DAC_RANGE
1928		current->thread.debug.dbcr2 &= ~DBCR2_DAC12MODE;
1929#endif
1930		do_send_trap(regs, mfspr(SPRN_DAC1), debug_status,
1931			     5);
1932		changed |= 0x01;
1933	}  else if (debug_status & (DBSR_DAC2R | DBSR_DAC2W)) {
1934		dbcr_dac(current) &= ~(DBCR_DAC2R | DBCR_DAC2W);
1935		do_send_trap(regs, mfspr(SPRN_DAC2), debug_status,
1936			     6);
1937		changed |= 0x01;
1938	}  else if (debug_status & DBSR_IAC1) {
1939		current->thread.debug.dbcr0 &= ~DBCR0_IAC1;
1940		dbcr_iac_range(current) &= ~DBCR_IAC12MODE;
1941		do_send_trap(regs, mfspr(SPRN_IAC1), debug_status,
1942			     1);
1943		changed |= 0x01;
1944	}  else if (debug_status & DBSR_IAC2) {
1945		current->thread.debug.dbcr0 &= ~DBCR0_IAC2;
1946		do_send_trap(regs, mfspr(SPRN_IAC2), debug_status,
1947			     2);
1948		changed |= 0x01;
1949	}  else if (debug_status & DBSR_IAC3) {
1950		current->thread.debug.dbcr0 &= ~DBCR0_IAC3;
1951		dbcr_iac_range(current) &= ~DBCR_IAC34MODE;
1952		do_send_trap(regs, mfspr(SPRN_IAC3), debug_status,
1953			     3);
1954		changed |= 0x01;
1955	}  else if (debug_status & DBSR_IAC4) {
1956		current->thread.debug.dbcr0 &= ~DBCR0_IAC4;
1957		do_send_trap(regs, mfspr(SPRN_IAC4), debug_status,
1958			     4);
1959		changed |= 0x01;
1960	}
1961	/*
1962	 * At the point this routine was called, the MSR(DE) was turned off.
1963	 * Check all other debug flags and see if that bit needs to be turned
1964	 * back on or not.
1965	 */
1966	if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
1967			       current->thread.debug.dbcr1))
1968		regs_set_return_msr(regs, regs->msr | MSR_DE);
1969	else
1970		/* Make sure the IDM flag is off */
1971		current->thread.debug.dbcr0 &= ~DBCR0_IDM;
1972
1973	if (changed & 0x01)
1974		mtspr(SPRN_DBCR0, current->thread.debug.dbcr0);
1975}
1976
1977DEFINE_INTERRUPT_HANDLER(DebugException)
1978{
1979	unsigned long debug_status = regs->dsisr;
1980
1981	current->thread.debug.dbsr = debug_status;
1982
1983	/* Hack alert: On BookE, Branch Taken stops on the branch itself, while
1984	 * on server, it stops on the target of the branch. In order to simulate
1985	 * the server behaviour, we thus restart right away with a single step
1986	 * instead of stopping here when hitting a BT
1987	 */
1988	if (debug_status & DBSR_BT) {
1989		regs_set_return_msr(regs, regs->msr & ~MSR_DE);
1990
1991		/* Disable BT */
1992		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_BT);
1993		/* Clear the BT event */
1994		mtspr(SPRN_DBSR, DBSR_BT);
1995
1996		/* Do the single step trick only when coming from userspace */
1997		if (user_mode(regs)) {
1998			current->thread.debug.dbcr0 &= ~DBCR0_BT;
1999			current->thread.debug.dbcr0 |= DBCR0_IDM | DBCR0_IC;
2000			regs_set_return_msr(regs, regs->msr | MSR_DE);
2001			return;
2002		}
2003
2004		if (kprobe_post_handler(regs))
2005			return;
2006
2007		if (notify_die(DIE_SSTEP, "block_step", regs, 5,
2008			       5, SIGTRAP) == NOTIFY_STOP) {
2009			return;
2010		}
2011		if (debugger_sstep(regs))
2012			return;
2013	} else if (debug_status & DBSR_IC) { 	/* Instruction complete */
2014		regs_set_return_msr(regs, regs->msr & ~MSR_DE);
2015
2016		/* Disable instruction completion */
2017		mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
2018		/* Clear the instruction completion event */
2019		mtspr(SPRN_DBSR, DBSR_IC);
2020
2021		if (kprobe_post_handler(regs))
2022			return;
2023
2024		if (notify_die(DIE_SSTEP, "single_step", regs, 5,
2025			       5, SIGTRAP) == NOTIFY_STOP) {
2026			return;
2027		}
2028
2029		if (debugger_sstep(regs))
2030			return;
2031
2032		if (user_mode(regs)) {
2033			current->thread.debug.dbcr0 &= ~DBCR0_IC;
2034			if (DBCR_ACTIVE_EVENTS(current->thread.debug.dbcr0,
2035					       current->thread.debug.dbcr1))
2036				regs_set_return_msr(regs, regs->msr | MSR_DE);
2037			else
2038				/* Make sure the IDM bit is off */
2039				current->thread.debug.dbcr0 &= ~DBCR0_IDM;
2040		}
2041
2042		_exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
2043	} else
2044		handle_debug(regs, debug_status);
2045}
 
2046#endif /* CONFIG_PPC_ADV_DEBUG_REGS */
2047
 
 
 
 
 
 
 
 
2048#ifdef CONFIG_ALTIVEC
2049DEFINE_INTERRUPT_HANDLER(altivec_assist_exception)
2050{
2051	int err;
2052
2053	if (!user_mode(regs)) {
2054		printk(KERN_EMERG "VMX/Altivec assist exception in kernel mode"
2055		       " at %lx\n", regs->nip);
2056		die("Kernel VMX/Altivec assist exception", regs, SIGILL);
2057	}
2058
2059	flush_altivec_to_thread(current);
2060
2061	PPC_WARN_EMULATED(altivec, regs);
2062	err = emulate_altivec(regs);
2063	if (err == 0) {
2064		regs_add_return_ip(regs, 4); /* skip emulated instruction */
2065		emulate_single_step(regs);
2066		return;
2067	}
2068
2069	if (err == -EFAULT) {
2070		/* got an error reading the instruction */
2071		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2072	} else {
2073		/* didn't recognize the instruction */
2074		/* XXX quick hack for now: set the non-Java bit in the VSCR */
2075		printk_ratelimited(KERN_ERR "Unrecognized altivec instruction "
2076				   "in %s at %lx\n", current->comm, regs->nip);
2077		current->thread.vr_state.vscr.u[3] |= 0x10000;
2078	}
2079}
2080#endif /* CONFIG_ALTIVEC */
2081
2082#ifdef CONFIG_FSL_BOOKE
2083DEFINE_INTERRUPT_HANDLER(CacheLockingException)
 
2084{
2085	unsigned long error_code = regs->dsisr;
2086
2087	/* We treat cache locking instructions from the user
2088	 * as priv ops, in the future we could try to do
2089	 * something smarter
2090	 */
2091	if (error_code & (ESR_DLK|ESR_ILK))
2092		_exception(SIGILL, regs, ILL_PRVOPC, regs->nip);
2093	return;
2094}
2095#endif /* CONFIG_FSL_BOOKE */
2096
2097#ifdef CONFIG_SPE
2098DEFINE_INTERRUPT_HANDLER(SPEFloatingPointException)
2099{
2100	extern int do_spe_mathemu(struct pt_regs *regs);
2101	unsigned long spefscr;
2102	int fpexc_mode;
2103	int code = FPE_FLTUNK;
2104	int err;
2105
2106	interrupt_cond_local_irq_enable(regs);
2107
2108	flush_spe_to_thread(current);
2109
2110	spefscr = current->thread.spefscr;
2111	fpexc_mode = current->thread.fpexc_mode;
2112
2113	if ((spefscr & SPEFSCR_FOVF) && (fpexc_mode & PR_FP_EXC_OVF)) {
2114		code = FPE_FLTOVF;
2115	}
2116	else if ((spefscr & SPEFSCR_FUNF) && (fpexc_mode & PR_FP_EXC_UND)) {
2117		code = FPE_FLTUND;
2118	}
2119	else if ((spefscr & SPEFSCR_FDBZ) && (fpexc_mode & PR_FP_EXC_DIV))
2120		code = FPE_FLTDIV;
2121	else if ((spefscr & SPEFSCR_FINV) && (fpexc_mode & PR_FP_EXC_INV)) {
2122		code = FPE_FLTINV;
2123	}
2124	else if ((spefscr & (SPEFSCR_FG | SPEFSCR_FX)) && (fpexc_mode & PR_FP_EXC_RES))
2125		code = FPE_FLTRES;
2126
2127	err = do_spe_mathemu(regs);
2128	if (err == 0) {
2129		regs_add_return_ip(regs, 4); /* skip emulated instruction */
2130		emulate_single_step(regs);
2131		return;
2132	}
2133
2134	if (err == -EFAULT) {
2135		/* got an error reading the instruction */
2136		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2137	} else if (err == -EINVAL) {
2138		/* didn't recognize the instruction */
2139		printk(KERN_ERR "unrecognized spe instruction "
2140		       "in %s at %lx\n", current->comm, regs->nip);
2141	} else {
2142		_exception(SIGFPE, regs, code, regs->nip);
2143	}
2144
2145	return;
2146}
2147
2148DEFINE_INTERRUPT_HANDLER(SPEFloatingPointRoundException)
2149{
2150	extern int speround_handler(struct pt_regs *regs);
2151	int err;
2152
2153	interrupt_cond_local_irq_enable(regs);
2154
2155	preempt_disable();
2156	if (regs->msr & MSR_SPE)
2157		giveup_spe(current);
2158	preempt_enable();
2159
2160	regs_add_return_ip(regs, -4);
2161	err = speround_handler(regs);
2162	if (err == 0) {
2163		regs_add_return_ip(regs, 4); /* skip emulated instruction */
2164		emulate_single_step(regs);
2165		return;
2166	}
2167
2168	if (err == -EFAULT) {
2169		/* got an error reading the instruction */
2170		_exception(SIGSEGV, regs, SEGV_ACCERR, regs->nip);
2171	} else if (err == -EINVAL) {
2172		/* didn't recognize the instruction */
2173		printk(KERN_ERR "unrecognized spe instruction "
2174		       "in %s at %lx\n", current->comm, regs->nip);
2175	} else {
2176		_exception(SIGFPE, regs, FPE_FLTUNK, regs->nip);
2177		return;
2178	}
2179}
2180#endif
2181
2182/*
2183 * We enter here if we get an unrecoverable exception, that is, one
2184 * that happened at a point where the RI (recoverable interrupt) bit
2185 * in the MSR is 0.  This indicates that SRR0/1 are live, and that
2186 * we therefore lost state by taking this exception.
2187 */
2188void __noreturn unrecoverable_exception(struct pt_regs *regs)
2189{
2190	pr_emerg("Unrecoverable exception %lx at %lx (msr=%lx)\n",
2191		 regs->trap, regs->nip, regs->msr);
2192	die("Unrecoverable exception", regs, SIGABRT);
2193	/* die() should not return */
2194	for (;;)
2195		;
2196}
2197
2198#if defined(CONFIG_BOOKE_WDT) || defined(CONFIG_40x)
2199/*
2200 * Default handler for a Watchdog exception,
2201 * spins until a reboot occurs
2202 */
2203void __attribute__ ((weak)) WatchdogHandler(struct pt_regs *regs)
2204{
2205	/* Generic WatchdogHandler, implement your own */
2206	mtspr(SPRN_TCR, mfspr(SPRN_TCR)&(~TCR_WIE));
2207	return;
2208}
2209
2210DEFINE_INTERRUPT_HANDLER_NMI(WatchdogException)
2211{
2212	printk (KERN_EMERG "PowerPC Book-E Watchdog Exception\n");
2213	WatchdogHandler(regs);
2214	return 0;
2215}
2216#endif
2217
2218/*
2219 * We enter here if we discover during exception entry that we are
2220 * running in supervisor mode with a userspace value in the stack pointer.
2221 */
2222DEFINE_INTERRUPT_HANDLER(kernel_bad_stack)
2223{
2224	printk(KERN_EMERG "Bad kernel stack pointer %lx at %lx\n",
2225	       regs->gpr[1], regs->nip);
2226	die("Bad kernel stack pointer", regs, SIGABRT);
2227}
2228
2229void __init trap_init(void)
2230{
2231}
2232
2233
2234#ifdef CONFIG_PPC_EMULATED_STATS
2235
2236#define WARN_EMULATED_SETUP(type)	.type = { .name = #type }
2237
2238struct ppc_emulated ppc_emulated = {
2239#ifdef CONFIG_ALTIVEC
2240	WARN_EMULATED_SETUP(altivec),
2241#endif
2242	WARN_EMULATED_SETUP(dcba),
2243	WARN_EMULATED_SETUP(dcbz),
2244	WARN_EMULATED_SETUP(fp_pair),
2245	WARN_EMULATED_SETUP(isel),
2246	WARN_EMULATED_SETUP(mcrxr),
2247	WARN_EMULATED_SETUP(mfpvr),
2248	WARN_EMULATED_SETUP(multiple),
2249	WARN_EMULATED_SETUP(popcntb),
2250	WARN_EMULATED_SETUP(spe),
2251	WARN_EMULATED_SETUP(string),
2252	WARN_EMULATED_SETUP(sync),
2253	WARN_EMULATED_SETUP(unaligned),
2254#ifdef CONFIG_MATH_EMULATION
2255	WARN_EMULATED_SETUP(math),
2256#endif
2257#ifdef CONFIG_VSX
2258	WARN_EMULATED_SETUP(vsx),
2259#endif
2260#ifdef CONFIG_PPC64
2261	WARN_EMULATED_SETUP(mfdscr),
2262	WARN_EMULATED_SETUP(mtdscr),
2263	WARN_EMULATED_SETUP(lq_stq),
2264	WARN_EMULATED_SETUP(lxvw4x),
2265	WARN_EMULATED_SETUP(lxvh8x),
2266	WARN_EMULATED_SETUP(lxvd2x),
2267	WARN_EMULATED_SETUP(lxvb16x),
2268#endif
2269};
2270
2271u32 ppc_warn_emulated;
2272
2273void ppc_warn_emulated_print(const char *type)
2274{
2275	pr_warn_ratelimited("%s used emulated %s instruction\n", current->comm,
2276			    type);
2277}
2278
2279static int __init ppc_warn_emulated_init(void)
2280{
2281	struct dentry *dir;
2282	unsigned int i;
2283	struct ppc_emulated_entry *entries = (void *)&ppc_emulated;
2284
 
 
 
2285	dir = debugfs_create_dir("emulated_instructions",
2286				 powerpc_debugfs_root);
 
 
2287
2288	debugfs_create_u32("do_warn", 0644, dir, &ppc_warn_emulated);
2289
2290	for (i = 0; i < sizeof(ppc_emulated)/sizeof(*entries); i++)
2291		debugfs_create_u32(entries[i].name, 0644, dir,
2292				   (u32 *)&entries[i].val.counter);
 
 
 
 
 
 
2293
2294	return 0;
 
 
 
 
2295}
2296
2297device_initcall(ppc_warn_emulated_init);
2298
2299#endif /* CONFIG_PPC_EMULATED_STATS */