traps.c

	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_r6)
		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_r6) {
		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);

	if (!addr)
		panic(panic_null_cerr);

	memcpy((void *)(uncached_ebase + offset), addr, size);
}

static int __initdata rdhwr_noopt;
static int __init set_rdhwr_noopt(char *str)
{
	rdhwr_noopt = 1;
	return 1;
}

__setup("rdhwr_noopt", set_rdhwr_noopt);

void __init trap_init(void)
{
	extern char except_vec3_generic;
	extern char except_vec4;
	extern char except_vec3_r4000;
	unsigned long i;

	check_wait();

#if defined(CONFIG_KGDB)
	if (kgdb_early_setup)
		return; /* Already done */
#endif

	if (cpu_has_veic || cpu_has_vint) {
		unsigned long size = 0x200 + VECTORSPACING*64;
		ebase = (unsigned long)
			__alloc_bootmem(size, 1 << fls(size), 0);
	} else {
#ifdef CONFIG_KVM_GUEST
#define KVM_GUEST_KSEG0     0x40000000
        ebase = KVM_GUEST_KSEG0;
#else
        ebase = CKSEG0;
#endif
		if (cpu_has_mips_r2_r6)
			ebase += (read_c0_ebase() & 0x3ffff000);
	}

	if (cpu_has_mmips) {
		unsigned int config3 = read_c0_config3();

		if (IS_ENABLED(CONFIG_CPU_MICROMIPS))
			write_c0_config3(config3 | MIPS_CONF3_ISA_OE);
		else
			write_c0_config3(config3 & ~MIPS_CONF3_ISA_OE);
	}

	if (board_ebase_setup)
		board_ebase_setup();
	per_cpu_trap_init(true);

	/*
	 * Copy the generic exception handlers to their final destination.
	 * This will be overriden later as suitable for a particular
	 * configuration.
	 */
	set_handler(0x180, &except_vec3_generic, 0x80);

	/*
	 * Setup default vectors
	 */
	for (i = 0; i <= 31; i++)
		set_except_vector(i, handle_reserved);

	/*
	 * Copy the EJTAG debug exception vector handler code to it's final
	 * destination.
	 */
	if (cpu_has_ejtag && board_ejtag_handler_setup)
		board_ejtag_handler_setup();

	/*
	 * Only some CPUs have the watch exceptions.
	 */
	if (cpu_has_watch)
		set_except_vector(23, handle_watch);

	/*
	 * Initialise interrupt handlers
	 */
	if (cpu_has_veic || cpu_has_vint) {
		int nvec = cpu_has_veic ? 64 : 8;
		for (i = 0; i < nvec; i++)
			set_vi_handler(i, NULL);
	}
	else if (cpu_has_divec)
		set_handler(0x200, &except_vec4, 0x8);

	/*
	 * Some CPUs can enable/disable for cache parity detection, but does
	 * it different ways.
	 */
	parity_protection_init();

	/*
	 * The Data Bus Errors / Instruction Bus Errors are signaled
	 * by external hardware.  Therefore these two exceptions
	 * may have board specific handlers.
	 */
	if (board_be_init)
		board_be_init();

	set_except_vector(0, using_rollback_handler() ? rollback_handle_int
						      : handle_int);
	set_except_vector(1, handle_tlbm);
	set_except_vector(2, handle_tlbl);
	set_except_vector(3, handle_tlbs);

	set_except_vector(4, handle_adel);
	set_except_vector(5, handle_ades);

	set_except_vector(6, handle_ibe);
	set_except_vector(7, handle_dbe);

	set_except_vector(8, handle_sys);
	set_except_vector(9, handle_bp);
	set_except_vector(10, rdhwr_noopt ? handle_ri :
			  (cpu_has_vtag_icache ?
			   handle_ri_rdhwr_vivt : handle_ri_rdhwr));
	set_except_vector(11, handle_cpu);
	set_except_vector(12, handle_ov);
	set_except_vector(13, handle_tr);
	set_except_vector(14, handle_msa_fpe);

	if (current_cpu_type() == CPU_R6000 ||
	    current_cpu_type() == CPU_R6000A) {
		/*
		 * The R6000 is the only R-series CPU that features a machine
		 * check exception (similar to the R4000 cache error) and
		 * unaligned ldc1/sdc1 exception.  The handlers have not been
		 * written yet.	 Well, anyway there is no R6000 machine on the
		 * current list of targets for Linux/MIPS.
		 * (Duh, crap, there is someone with a triple R6k machine)
		 */
		//set_except_vector(14, handle_mc);
		//set_except_vector(15, handle_ndc);
	}


	if (board_nmi_handler_setup)
		board_nmi_handler_setup();

	if (cpu_has_fpu && !cpu_has_nofpuex)
		set_except_vector(15, handle_fpe);

	set_except_vector(16, handle_ftlb);

	if (cpu_has_rixiex) {
		set_except_vector(19, tlb_do_page_fault_0);
		set_except_vector(20, tlb_do_page_fault_0);
	}

	set_except_vector(21, handle_msa);
	set_except_vector(22, handle_mdmx);

	if (cpu_has_mcheck)
		set_except_vector(24, handle_mcheck);

	if (cpu_has_mipsmt)
		set_except_vector(25, handle_mt);

	set_except_vector(26, handle_dsp);

	if (board_cache_error_setup)
		board_cache_error_setup();

	if (cpu_has_vce)
		/* Special exception: R4[04]00 uses also the divec space. */
		set_handler(0x180, &except_vec3_r4000, 0x100);
	else if (cpu_has_4kex)
		set_handler(0x180, &except_vec3_generic, 0x80);
	else
		set_handler(0x080, &except_vec3_generic, 0x80);

	local_flush_icache_range(ebase, ebase + 0x400);

	sort_extable(__start___dbe_table, __stop___dbe_table);

	cu2_notifier(default_cu2_call, 0x80000000);	/* Run last  */
}

static int trap_pm_notifier(struct notifier_block *self, unsigned long cmd,
			    void *v)
{
	switch (cmd) {
	case CPU_PM_ENTER_FAILED:
	case CPU_PM_EXIT:
		configure_status();
		configure_hwrena();
		configure_exception_vector();

		/* Restore register with CPU number for TLB handlers */
		TLBMISS_HANDLER_RESTORE();

		break;
	}

	return NOTIFY_OK;
}

static struct notifier_block trap_pm_notifier_block = {
	.notifier_call = trap_pm_notifier,
};

static int __init trap_pm_init(void)
{
	return cpu_pm_register_notifier(&trap_pm_notifier_block);
}
arch_initcall(trap_pm_init);