traps.c

		if (unlikely(get_user(mmop[1], epc) < 0))
			status = SIGSEGV;
		opcode = (mmop[0] << 16) | mmop[1];

		if (status < 0)
			status = simulate_rdhwr_mm(regs, opcode);
	} else {
		if (unlikely(get_user(opcode, epc) < 0))
			status = SIGSEGV;

		if (!cpu_has_llsc && status < 0)
			status = simulate_llsc(regs, opcode);

		if (status < 0)
			status = simulate_rdhwr_normal(regs, opcode);

		if (status < 0)
			status = simulate_sync(regs, opcode);
	}

	if (status < 0)
		status = SIGILL;

	if (unlikely(status > 0)) {
		regs->cp0_epc = old_epc;		/* Undo skip-over.  */
		regs->regs[31] = old31;
		force_sig(status, current);
	}

out:
	exception_exit(prev_state);
}

/*
 * MIPS MT processors may have fewer FPU contexts than CPU threads. If we've
 * emulated more than some threshold number of instructions, force migration to
 * a "CPU" that has FP support.
 */
static void mt_ase_fp_affinity(void)
{
#ifdef CONFIG_MIPS_MT_FPAFF
	if (mt_fpemul_threshold > 0 &&
	     ((current->thread.emulated_fp++ > mt_fpemul_threshold))) {
		/*
		 * If there's no FPU present, or if the application has already
		 * restricted the allowed set to exclude any CPUs with FPUs,
		 * we'll skip the procedure.
		 */
		if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) {
			cpumask_t tmask;

			current->thread.user_cpus_allowed
				= current->cpus_allowed;
			cpus_and(tmask, current->cpus_allowed,
				mt_fpu_cpumask);
			set_cpus_allowed_ptr(current, &tmask);
			set_thread_flag(TIF_FPUBOUND);
		}
	}
#endif /* CONFIG_MIPS_MT_FPAFF */
}

/*
 * No lock; only written during early bootup by CPU 0.
 */
static RAW_NOTIFIER_HEAD(cu2_chain);

int __ref register_cu2_notifier(struct notifier_block *nb)
{
	return raw_notifier_chain_register(&cu2_chain, nb);
}

int cu2_notifier_call_chain(unsigned long val, void *v)
{
	return raw_notifier_call_chain(&cu2_chain, val, v);
}

static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
	void *data)
{
	struct pt_regs *regs = data;

	die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
			      "instruction", regs);
	force_sig(SIGILL, current);

	return NOTIFY_OK;
}

static int enable_restore_fp_context(int msa)
{
	int err, was_fpu_owner, prior_msa;

	if (!used_math()) {
		/* First time FP context user. */
		preempt_disable();
		err = init_fpu();
		if (msa && !err) {
			enable_msa();
			_init_msa_upper();
			set_thread_flag(TIF_USEDMSA);
			set_thread_flag(TIF_MSA_CTX_LIVE);
		}
		preempt_enable();
		if (!err)
			set_used_math();
		return err;
	}

	/*
	 * This task has formerly used the FP context.
	 *
	 * If this thread has no live MSA vector context then we can simply
	 * restore the scalar FP context. If it has live MSA vector context
	 * (that is, it has or may have used MSA since last performing a
	 * function call) then we'll need to restore the vector context. This
	 * applies even if we're currently only executing a scalar FP
	 * instruction. This is because if we were to later execute an MSA
	 * instruction then we'd either have to:
	 *
	 *  - Restore the vector context & clobber any registers modified by
	 *    scalar FP instructions between now & then.
	 *
	 * or
	 *
	 *  - Not restore the vector context & lose the most significant bits
	 *    of all vector registers.
	 *
	 * Neither of those options is acceptable. We cannot restore the least
	 * significant bits of the registers now & only restore the most
	 * significant bits later because the most significant bits of any
	 * vector registers whose aliased FP register is modified now will have
	 * been zeroed. We'd have no way to know that when restoring the vector
	 * context & thus may load an outdated value for the most significant
	 * bits of a vector register.
	 */
	if (!msa && !thread_msa_context_live())
		return own_fpu(1);

	/*
	 * This task is using or has previously used MSA. Thus we require
	 * that Status.FR == 1.
	 */
	preempt_disable();
	was_fpu_owner = is_fpu_owner();
	err = own_fpu_inatomic(0);
	if (err)
		goto out;

	enable_msa();
	write_msa_csr(current->thread.fpu.msacsr);
	set_thread_flag(TIF_USEDMSA);

	/*
	 * If this is the first time that the task is using MSA and it has
	 * previously used scalar FP in this time slice then we already nave
	 * FP context which we shouldn't clobber. We do however need to clear
	 * the upper 64b of each vector register so that this task has no
	 * opportunity to see data left behind by another.
	 */
	prior_msa = test_and_set_thread_flag(TIF_MSA_CTX_LIVE);
	if (!prior_msa && was_fpu_owner) {
		_init_msa_upper();

		goto out;
	}

	if (!prior_msa) {
		/*
		 * Restore the least significant 64b of each vector register
		 * from the existing scalar FP context.
		 */
		_restore_fp(current);

		/*
		 * The task has not formerly used MSA, so clear the upper 64b
		 * of each vector register such that it cannot see data left
		 * behind by another task.
		 */
		_init_msa_upper();
	} else {
		/* We need to restore the vector context. */
		restore_msa(current);

		/* Restore the scalar FP control & status register */
		if (!was_fpu_owner)
			asm volatile("ctc1 %0, $31" : : "r"(current->thread.fpu.fcr31));
	}

out:
	preempt_enable();

	return 0;
}

asmlinkage void do_cpu(struct pt_regs *regs)
{
	enum ctx_state prev_state;
	unsigned int __user *epc;
	unsigned long old_epc, old31;
	unsigned int opcode;
	unsigned int cpid;
	int status, err;
	unsigned long __maybe_unused flags;

	prev_state = exception_enter();
	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;

	if (cpid != 2)
		die_if_kernel("do_cpu invoked from kernel context!", regs);

	switch (cpid) {
	case 0:
		epc = (unsigned int __user *)exception_epc(regs);
		old_epc = regs->cp0_epc;
		old31 = regs->regs[31];
		opcode = 0;
		status = -1;

		if (unlikely(compute_return_epc(regs) < 0))
			goto out;

		if (get_isa16_mode(regs->cp0_epc)) {
			unsigned short mmop[2] = { 0 };

			if (unlikely(get_user(mmop[0], epc) < 0))
				status = SIGSEGV;
			if (unlikely(get_user(mmop[1], epc) < 0))
				status = SIGSEGV;
			opcode = (mmop[0] << 16) | mmop[1];

			if (status < 0)
				status = simulate_rdhwr_mm(regs, opcode);
		} else {
			if (unlikely(get_user(opcode, epc) < 0))
				status = SIGSEGV;

			if (!cpu_has_llsc && status < 0)
				status = simulate_llsc(regs, opcode);

			if (status < 0)
				status = simulate_rdhwr_normal(regs, opcode);
		}

		if (status < 0)
			status = SIGILL;

		if (unlikely(status > 0)) {
			regs->cp0_epc = old_epc;	/* Undo skip-over.  */
			regs->regs[31] = old31;
			force_sig(status, current);
		}

		goto out;

	case 3:
		/*
		 * Old (MIPS I and MIPS II) processors will set this code
		 * for COP1X opcode instructions that replaced the original
		 * COP3 space.	We don't limit COP1 space instructions in
		 * the emulator according to the CPU ISA, so we want to
		 * treat COP1X instructions consistently regardless of which
		 * code the CPU chose.	Therefore we redirect this trap to
		 * the FP emulator too.
		 *
		 * Then some newer FPU-less processors use this code
		 * erroneously too, so they are covered by this choice
		 * as well.
		 */
		if (raw_cpu_has_fpu)
			break;
		/* Fall through.  */

	case 1:
		err = enable_restore_fp_context(0);

		if (!raw_cpu_has_fpu || err) {
			int sig;
			void __user *fault_addr = NULL;
			sig = fpu_emulator_cop1Handler(regs,
						       &current->thread.fpu,
						       0, &fault_addr);
			if (!process_fpemu_return(sig, fault_addr) && !err)
				mt_ase_fp_affinity();
		}

		goto out;

	case 2:
		raw_notifier_call_chain(&cu2_chain, CU2_EXCEPTION, regs);
		goto out;
	}

	force_sig(SIGILL, current);

out:
	exception_exit(prev_state);
}

asmlinkage void do_msa_fpe(struct pt_regs *regs)
{
	enum ctx_state prev_state;

	prev_state = exception_enter();
	die_if_kernel("do_msa_fpe invoked from kernel context!", regs);
	force_sig(SIGFPE, current);
	exception_exit(prev_state);
}

asmlinkage void do_msa(struct pt_regs *regs)
{
	enum ctx_state prev_state;
	int err;

	prev_state = exception_enter();

	if (!cpu_has_msa || test_thread_flag(TIF_32BIT_FPREGS)) {
		force_sig(SIGILL, current);
		goto out;
	}

	die_if_kernel("do_msa invoked from kernel context!", regs);

	err = enable_restore_fp_context(1);
	if (err)
		force_sig(SIGILL, current);
out:
	exception_exit(prev_state);
}

asmlinkage void do_mdmx(struct pt_regs *regs)
{
	enum ctx_state prev_state;

	prev_state = exception_enter();
	force_sig(SIGILL, current);
	exception_exit(prev_state);
}

/*
 * Called with interrupts disabled.
 */
asmlinkage void do_watch(struct pt_regs *regs)
{
	enum ctx_state prev_state;
	u32 cause;

	prev_state = exception_enter();
	/*
	 * Clear WP (bit 22) bit of cause register so we don't loop
	 * forever.
	 */
	cause = read_c0_cause();
	cause &= ~(1 << 22);
	write_c0_cause(cause);

	/*
	 * If the current thread has the watch registers loaded, save
	 * their values and send SIGTRAP.  Otherwise another thread
	 * left the registers set, clear them and continue.
	 */
	if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) {
		mips_read_watch_registers();
		local_irq_enable();
		force_sig(SIGTRAP, current);
	} else {
		mips_clear_watch_registers();
		local_irq_enable();
	}
	exception_exit(prev_state);
}

asmlinkage void do_mcheck(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	int multi_match = regs->cp0_status & ST0_TS;
	enum ctx_state prev_state;

	prev_state = exception_enter();
	show_regs(regs);

	if (multi_match) {
		printk("Index	: %0x\n", read_c0_index());
		printk("Pagemask: %0x\n", read_c0_pagemask());
		printk("EntryHi : %0*lx\n", field, read_c0_entryhi());
		printk("EntryLo0: %0*lx\n", field, read_c0_entrylo0());
		printk("EntryLo1: %0*lx\n", field, read_c0_entrylo1());
		printk("\n");
		dump_tlb_all();
	}

	show_code((unsigned int __user *) regs->cp0_epc);

	/*
	 * Some chips may have other causes of machine check (e.g. SB1
	 * graduation timer)
	 */
	panic("Caught Machine Check exception - %scaused by multiple "
	      "matching entries in the TLB.",
	      (multi_match) ? "" : "not ");
}

asmlinkage void do_mt(struct pt_regs *regs)
{
	int subcode;

	subcode = (read_vpe_c0_vpecontrol() & VPECONTROL_EXCPT)
			>> VPECONTROL_EXCPT_SHIFT;
	switch (subcode) {
	case 0:
		printk(KERN_DEBUG "Thread Underflow\n");
		break;
	case 1:
		printk(KERN_DEBUG "Thread Overflow\n");
		break;
	case 2:
		printk(KERN_DEBUG "Invalid YIELD Qualifier\n");
		break;
	case 3:
		printk(KERN_DEBUG "Gating Storage Exception\n");
		break;
	case 4:
		printk(KERN_DEBUG "YIELD Scheduler Exception\n");
		break;
	case 5:
		printk(KERN_DEBUG "Gating Storage Scheduler Exception\n");
		break;
	default:
		printk(KERN_DEBUG "*** UNKNOWN THREAD EXCEPTION %d ***\n",
			subcode);
		break;
	}
	die_if_kernel("MIPS MT Thread exception in kernel", regs);

	force_sig(SIGILL, current);
}


asmlinkage void do_dsp(struct pt_regs *regs)
{
	if (cpu_has_dsp)
		panic("Unexpected DSP exception");

	force_sig(SIGILL, current);
}

asmlinkage void do_reserved(struct pt_regs *regs)
{
	/*
	 * Game over - no way to handle this if it ever occurs.	 Most probably
	 * caused by a new unknown cpu type or after another deadly
	 * hard/software error.
	 */
	show_regs(regs);
	panic("Caught reserved exception %ld - should not happen.",
	      (regs->cp0_cause & 0x7f) >> 2);
}

static int __initdata l1parity = 1;
static int __init nol1parity(char *s)
{
	l1parity = 0;
	return 1;
}
__setup("nol1par", nol1parity);
static int __initdata l2parity = 1;
static int __init nol2parity(char *s)
{
	l2parity = 0;
	return 1;
}
__setup("nol2par", nol2parity);

/*
 * Some MIPS CPUs can enable/disable for cache parity detection, but do
 * it different ways.
 */
static inline void parity_protection_init(void)
{
	switch (current_cpu_type()) {
	case CPU_24K:
	case CPU_34K:
	case CPU_74K:
	case CPU_1004K:
	case CPU_1074K:
	case CPU_INTERAPTIV:
	case CPU_PROAPTIV:
	case CPU_P5600:
		{
#define ERRCTL_PE	0x80000000
#define ERRCTL_L2P	0x00800000
			unsigned long errctl;
			unsigned int l1parity_present, l2parity_present;

			errctl = read_c0_ecc();
			errctl &= ~(ERRCTL_PE|ERRCTL_L2P);

			/* probe L1 parity support */
			write_c0_ecc(errctl | ERRCTL_PE);
			back_to_back_c0_hazard();
			l1parity_present = (read_c0_ecc() & ERRCTL_PE);

			/* probe L2 parity support */
			write_c0_ecc(errctl|ERRCTL_L2P);
			back_to_back_c0_hazard();
			l2parity_present = (read_c0_ecc() & ERRCTL_L2P);

			if (l1parity_present && l2parity_present) {
				if (l1parity)
					errctl |= ERRCTL_PE;
				if (l1parity ^ l2parity)
					errctl |= ERRCTL_L2P;
			} else if (l1parity_present) {
				if (l1parity)
					errctl |= ERRCTL_PE;
			} else if (l2parity_present) {
				if (l2parity)
					errctl |= ERRCTL_L2P;
			} else {
				/* No parity available */
			}

			printk(KERN_INFO "Writing ErrCtl register=%08lx\n", errctl);

			write_c0_ecc(errctl);
			back_to_back_c0_hazard();
			errctl = read_c0_ecc();
			printk(KERN_INFO "Readback ErrCtl register=%08lx\n", errctl);

			if (l1parity_present)
				printk(KERN_INFO "Cache parity protection %sabled\n",
				       (errctl & ERRCTL_PE) ? "en" : "dis");

			if (l2parity_present) {
				if (l1parity_present && l1parity)
					errctl ^= ERRCTL_L2P;
				printk(KERN_INFO "L2 cache parity protection %sabled\n",
				       (errctl & ERRCTL_L2P) ? "en" : "dis");
			}
		}
		break;

	case CPU_5KC:
	case CPU_5KE:
	case CPU_LOONGSON1:
		write_c0_ecc(0x80000000);
		back_to_back_c0_hazard();
		/* Set the PE bit (bit 31) in the c0_errctl register. */
		printk(KERN_INFO "Cache parity protection %sabled\n",
		       (read_c0_ecc() & 0x80000000) ? "en" : "dis");
		break;
	case CPU_20KC:
	case CPU_25KF:
		/* Clear the DE bit (bit 16) in the c0_status register. */
		printk(KERN_INFO "Enable cache parity protection for "
		       "MIPS 20KC/25KF CPUs.\n");
		clear_c0_status(ST0_DE);
		break;
	default:
		break;
	}
}

asmlinkage void cache_parity_error(void)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned int reg_val;

	/* For the moment, report the problem and hang. */
	printk("Cache error exception:\n");
	printk("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
	reg_val = read_c0_cacheerr();
	printk("c0_cacheerr == %08x\n", reg_val);

	printk("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
	       reg_val & (1<<30) ? "secondary" : "primary",
	       reg_val & (1<<31) ? "data" : "insn");
	if (cpu_has_mips_r2 &&
	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
		pr_err("Error bits: %s%s%s%s%s%s%s%s\n",
			reg_val & (1<<29) ? "ED " : "",
			reg_val & (1<<28) ? "ET " : "",
			reg_val & (1<<27) ? "ES " : "",
			reg_val & (1<<26) ? "EE " : "",
			reg_val & (1<<25) ? "EB " : "",
			reg_val & (1<<24) ? "EI " : "",
			reg_val & (1<<23) ? "E1 " : "",
			reg_val & (1<<22) ? "E0 " : "");
	} else {
		pr_err("Error bits: %s%s%s%s%s%s%s\n",
			reg_val & (1<<29) ? "ED " : "",
			reg_val & (1<<28) ? "ET " : "",
			reg_val & (1<<26) ? "EE " : "",
			reg_val & (1<<25) ? "EB " : "",
			reg_val & (1<<24) ? "EI " : "",
			reg_val & (1<<23) ? "E1 " : "",
			reg_val & (1<<22) ? "E0 " : "");
	}
	printk("IDX: 0x%08x\n", reg_val & ((1<<22)-1));

#if defined(CONFIG_CPU_MIPS32) || defined(CONFIG_CPU_MIPS64)
	if (reg_val & (1<<22))
		printk("DErrAddr0: 0x%0*lx\n", field, read_c0_derraddr0());

	if (reg_val & (1<<23))
		printk("DErrAddr1: 0x%0*lx\n", field, read_c0_derraddr1());
#endif

	panic("Can't handle the cache error!");
}

asmlinkage void do_ftlb(void)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned int reg_val;

	/* For the moment, report the problem and hang. */
	if (cpu_has_mips_r2 &&
	    ((current_cpu_data.processor_id & 0xff0000) == PRID_COMP_MIPS)) {
		pr_err("FTLB error exception, cp0_ecc=0x%08x:\n",
		       read_c0_ecc());
		pr_err("cp0_errorepc == %0*lx\n", field, read_c0_errorepc());
		reg_val = read_c0_cacheerr();
		pr_err("c0_cacheerr == %08x\n", reg_val);

		if ((reg_val & 0xc0000000) == 0xc0000000) {
			pr_err("Decoded c0_cacheerr: FTLB parity error\n");
		} else {
			pr_err("Decoded c0_cacheerr: %s cache fault in %s reference.\n",
			       reg_val & (1<<30) ? "secondary" : "primary",
			       reg_val & (1<<31) ? "data" : "insn");
		}
	} else {
		pr_err("FTLB error exception\n");
	}
	/* Just print the cacheerr bits for now */
	cache_parity_error();
}

/*
 * SDBBP EJTAG debug exception handler.
 * We skip the instruction and return to the next instruction.
 */
void ejtag_exception_handler(struct pt_regs *regs)
{
	const int field = 2 * sizeof(unsigned long);
	unsigned long depc, old_epc, old_ra;
	unsigned int debug;

	printk(KERN_DEBUG "SDBBP EJTAG debug exception - not handled yet, just ignored!\n");
	depc = read_c0_depc();
	debug = read_c0_debug();
	printk(KERN_DEBUG "c0_depc = %0*lx, DEBUG = %08x\n", field, depc, debug);
	if (debug & 0x80000000) {
		/*
		 * In branch delay slot.
		 * We cheat a little bit here and use EPC to calculate the
		 * debug return address (DEPC). EPC is restored after the
		 * calculation.
		 */
		old_epc = regs->cp0_epc;
		old_ra = regs->regs[31];
		regs->cp0_epc = depc;
		compute_return_epc(regs);
		depc = regs->cp0_epc;
		regs->cp0_epc = old_epc;
		regs->regs[31] = old_ra;
	} else
		depc += 4;
	write_c0_depc(depc);

#if 0
	printk(KERN_DEBUG "\n\n----- Enable EJTAG single stepping ----\n\n");
	write_c0_debug(debug | 0x100);
#endif
}

/*
 * NMI exception handler.
 * No lock; only written during early bootup by CPU 0.
 */
static RAW_NOTIFIER_HEAD(nmi_chain);

int register_nmi_notifier(struct notifier_block *nb)
{
	return raw_notifier_chain_register(&nmi_chain, nb);
}

void __noreturn nmi_exception_handler(struct pt_regs *regs)
{
	char str[100];

	raw_notifier_call_chain(&nmi_chain, 0, regs);
	bust_spinlocks(1);
	snprintf(str, 100, "CPU%d NMI taken, CP0_EPC=%lx\n",
		 smp_processor_id(), regs->cp0_epc);
	regs->cp0_epc = read_c0_errorepc();
	die(str, regs);
}

#define VECTORSPACING 0x100	/* for EI/VI mode */

unsigned long ebase;
unsigned long exception_handlers[32];
unsigned long vi_handlers[64];

void __init *set_except_vector(int n, void *addr)
{
	unsigned long handler = (unsigned long) addr;
	unsigned long old_handler;

#ifdef CONFIG_CPU_MICROMIPS
	/*
	 * Only the TLB handlers are cache aligned with an even
	 * address. All other handlers are on an odd address and
	 * require no modification. Otherwise, MIPS32 mode will
	 * be entered when handling any TLB exceptions. That
	 * would be bad...since we must stay in microMIPS mode.
	 */
	if (!(handler & 0x1))
		handler |= 1;
#endif
	old_handler = xchg(&exception_handlers[n], handler);

	if (n == 0 && cpu_has_divec) {
#ifdef CONFIG_CPU_MICROMIPS
		unsigned long jump_mask = ~((1 << 27) - 1);
#else
		unsigned long jump_mask = ~((1 << 28) - 1);
#endif
		u32 *buf = (u32 *)(ebase + 0x200);
		unsigned int k0 = 26;
		if ((handler & jump_mask) == ((ebase + 0x200) & jump_mask)) {
			uasm_i_j(&buf, handler & ~jump_mask);
			uasm_i_nop(&buf);
		} else {
			UASM_i_LA(&buf, k0, handler);
			uasm_i_jr(&buf, k0);
			uasm_i_nop(&buf);
		}
		local_flush_icache_range(ebase + 0x200, (unsigned long)buf);
	}
	return (void *)old_handler;
}

static void do_default_vi(void)
{
	show_regs(get_irq_regs());
	panic("Caught unexpected vectored interrupt.");
}

static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs)
{
	unsigned long handler;
	unsigned long old_handler = vi_handlers[n];
	int srssets = current_cpu_data.srsets;
	u16 *h;
	unsigned char *b;

	BUG_ON(!cpu_has_veic && !cpu_has_vint);

	if (addr == NULL) {
		handler = (unsigned long) do_default_vi;
		srs = 0;
	} else
		handler = (unsigned long) addr;
	vi_handlers[n] = handler;

	b = (unsigned char *)(ebase + 0x200 + n*VECTORSPACING);

	if (srs >= srssets)
		panic("Shadow register set %d not supported", srs);

	if (cpu_has_veic) {
		if (board_bind_eic_interrupt)
			board_bind_eic_interrupt(n, srs);
	} else if (cpu_has_vint) {
		/* SRSMap is only defined if shadow sets are implemented */
		if (srssets > 1)
			change_c0_srsmap(0xf << n*4, srs << n*4);
	}

	if (srs == 0) {
		/*
		 * If no shadow set is selected then use the default handler
		 * that does normal register saving and standard interrupt exit
		 */
		extern char except_vec_vi, except_vec_vi_lui;
		extern char except_vec_vi_ori, except_vec_vi_end;
		extern char rollback_except_vec_vi;
		char *vec_start = using_rollback_handler() ?
			&rollback_except_vec_vi : &except_vec_vi;
#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_BIG_ENDIAN)
		const int lui_offset = &except_vec_vi_lui - vec_start + 2;
		const int ori_offset = &except_vec_vi_ori - vec_start + 2;
#else
		const int lui_offset = &except_vec_vi_lui - vec_start;
		const int ori_offset = &except_vec_vi_ori - vec_start;
#endif
		const int handler_len = &except_vec_vi_end - vec_start;

		if (handler_len > VECTORSPACING) {
			/*
			 * Sigh... panicing won't help as the console
			 * is probably not configured :(
			 */
			panic("VECTORSPACING too small");
		}

		set_handler(((unsigned long)b - ebase), vec_start,
#ifdef CONFIG_CPU_MICROMIPS
				(handler_len - 1));
#else
				handler_len);
#endif
		h = (u16 *)(b + lui_offset);
		*h = (handler >> 16) & 0xffff;
		h = (u16 *)(b + ori_offset);
		*h = (handler & 0xffff);
		local_flush_icache_range((unsigned long)b,
					 (unsigned long)(b+handler_len));
	}
	else {
		/*
		 * In other cases jump directly to the interrupt handler. It
		 * is the handler's responsibility to save registers if required
		 * (eg hi/lo) and return from the exception using "eret".
		 */
		u32 insn;

		h = (u16 *)b;
		/* j handler */
#ifdef CONFIG_CPU_MICROMIPS
		insn = 0xd4000000 | (((u32)handler & 0x07ffffff) >> 1);
#else
		insn = 0x08000000 | (((u32)handler & 0x0fffffff) >> 2);
#endif
		h[0] = (insn >> 16) & 0xffff;
		h[1] = insn & 0xffff;
		h[2] = 0;
		h[3] = 0;
		local_flush_icache_range((unsigned long)b,
					 (unsigned long)(b+8));
	}

	return (void *)old_handler;
}

void *set_vi_handler(int n, vi_handler_t addr)
{
	return set_vi_srs_handler(n, addr, 0);
}

extern void tlb_init(void);

/*
 * Timer interrupt
 */
int cp0_compare_irq;
EXPORT_SYMBOL_GPL(cp0_compare_irq);
int cp0_compare_irq_shift;

/*
 * Performance counter IRQ or -1 if shared with timer
 */
int cp0_perfcount_irq;
EXPORT_SYMBOL_GPL(cp0_perfcount_irq);

static int noulri;

static int __init ulri_disable(char *s)
{
	pr_info("Disabling ulri\n");
	noulri = 1;

	return 1;
}
__setup("noulri", ulri_disable);

/* configure STATUS register */
static void configure_status(void)
{
	/*
	 * Disable coprocessors and select 32-bit or 64-bit addressing
	 * and the 16/32 or 32/32 FPR register model.  Reset the BEV
	 * flag that some firmware may have left set and the TS bit (for
	 * IP27).  Set XX for ISA IV code to work.
	 */
	unsigned int status_set = ST0_CU0;
#ifdef CONFIG_64BIT
	status_set |= ST0_FR|ST0_KX|ST0_SX|ST0_UX;
#endif
	if (current_cpu_data.isa_level & MIPS_CPU_ISA_IV)
		status_set |= ST0_XX;
	if (cpu_has_dsp)
		status_set |= ST0_MX;

	change_c0_status(ST0_CU|ST0_MX|ST0_RE|ST0_FR|ST0_BEV|ST0_TS|ST0_KX|ST0_SX|ST0_UX,
			 status_set);
}

/* configure HWRENA register */
static void configure_hwrena(void)
{
	unsigned int hwrena = cpu_hwrena_impl_bits;

	if (cpu_has_mips_r2)
		hwrena |= 0x0000000f;

	if (!noulri && cpu_has_userlocal)
		hwrena |= (1 << 29);

	if (hwrena)
		write_c0_hwrena(hwrena);
}

static void configure_exception_vector(void)
{
	if (cpu_has_veic || cpu_has_vint) {
		unsigned long sr = set_c0_status(ST0_BEV);
		write_c0_ebase(ebase);
		write_c0_status(sr);
		/* Setting vector spacing enables EI/VI mode  */
		change_c0_intctl(0x3e0, VECTORSPACING);
	}
	if (cpu_has_divec) {
		if (cpu_has_mipsmt) {
			unsigned int vpflags = dvpe();
			set_c0_cause(CAUSEF_IV);
			evpe(vpflags);
		} else
			set_c0_cause(CAUSEF_IV);
	}
}

void per_cpu_trap_init(bool is_boot_cpu)
{
	unsigned int cpu = smp_processor_id();

	configure_status();
	configure_hwrena();

	configure_exception_vector();

	/*
	 * Before R2 both interrupt numbers were fixed to 7, so on R2 only:
	 *
	 *  o read IntCtl.IPTI to determine the timer interrupt
	 *  o read IntCtl.IPPCI to determine the performance counter interrupt
	 */
	if (cpu_has_mips_r2) {
		cp0_compare_irq_shift = CAUSEB_TI - CAUSEB_IP;
		cp0_compare_irq = (read_c0_intctl() >> INTCTLB_IPTI) & 7;
		cp0_perfcount_irq = (read_c0_intctl() >> INTCTLB_IPPCI) & 7;
		if (cp0_perfcount_irq == cp0_compare_irq)
			cp0_perfcount_irq = -1;
	} else {
		cp0_compare_irq = CP0_LEGACY_COMPARE_IRQ;
		cp0_compare_irq_shift = CP0_LEGACY_PERFCNT_IRQ;
		cp0_perfcount_irq = -1;
	}

	if (!cpu_data[cpu].asid_cache)
		cpu_data[cpu].asid_cache = ASID_FIRST_VERSION;

	atomic_inc(&init_mm.mm_count);
	current->active_mm = &init_mm;
	BUG_ON(current->mm);
	enter_lazy_tlb(&init_mm, current);

		/* Boot CPU's cache setup in setup_arch(). */
		if (!is_boot_cpu)
			cpu_cache_init();
		tlb_init();
	TLBMISS_HANDLER_SETUP();
}

/* Install CPU exception handler */
void set_handler(unsigned long offset, void *addr, unsigned long size)
{
#ifdef CONFIG_CPU_MICROMIPS
	memcpy((void *)(ebase + offset), ((unsigned char *)addr - 1), size);
#else
	memcpy((void *)(ebase + offset), addr, size);
#endif
	local_flush_icache_range(ebase + offset, ebase + offset + size);
}

static char panic_null_cerr[] =
	"Trying to set NULL cache error exception handler";

/*
 * Install uncached CPU exception handler.
 * This is suitable only for the cache error exception which is the only
 * exception handler that is being run uncached.
 */
void set_uncached_handler(unsigned long offset, void *addr,
	unsigned long size)
{
	unsigned long uncached_ebase = CKSEG1ADDR(ebase);