xref: /src/sys/arch/arm/xscale/i80321_icu.c

/*	$NetBSD: i80321_icu.c,v 1.3 2002/07/30 04:45:41 thorpej Exp $	*/

/*
 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
 * All rights reserved.
 *
 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed for the NetBSD Project by
 *	Wasabi Systems, Inc.
 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
 *    or promote products derived from this software without specific prior
 *    written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Interrupt support for the Intel i80321 I/O Processor.
 */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>

#include <uvm/uvm_extern.h>

#include <machine/bus.h>
#include <machine/intr.h>

#include <arm/cpufunc.h>

#include <arm/xscale/i80321reg.h>
#include <arm/xscale/i80321var.h>

/* Interrupt handler queues. */
struct intrq intrq[NIRQ];

/* Interrupts to mask at each level. */
static int imask[NIPL];

/* Current interrupt priority level. */
__volatile int current_spl_level;

/* Interrupts pending. */
static __volatile int ipending;

/* Software copy of the IRQs we have enabled. */
__volatile uint32_t intr_enabled;

/* Mask if interrupts steered to FIQs. */
uint32_t intr_steer;

/*
 * Map a software interrupt queue index (to the unused bits in the
 * ICU registers -- XXX will need to revisit this if those bits are
 * ever used in future steppings).
 */
static const uint32_t si_to_irqbit[SI_NQUEUES] = {
	ICU_INT_bit26,		/* SI_SOFT */
	ICU_INT_bit22,		/* SI_SOFTCLOCK */
	ICU_INT_bit5,		/* SI_SOFTNET */
	ICU_INT_bit4,		/* SI_SOFTSERIAL */
};

#define	INT_SWMASK							\
	((1U << ICU_INT_bit26) | (1U << ICU_INT_bit22) |		\
	 (1U << ICU_INT_bit5)  | (1U << ICU_INT_bit4))

#define	SI_TO_IRQBIT(si)	(1U << si_to_irqbit[(si)])

/*
 * Map a software interrupt queue to an interrupt priority level.
 */
static const int si_to_ipl[SI_NQUEUES] = {
	IPL_SOFT,		/* SI_SOFT */
	IPL_SOFTCLOCK,		/* SI_SOFTCLOCK */
	IPL_SOFTNET,		/* SI_SOFTNET */
	IPL_SOFTSERIAL,		/* SI_SOFTSERIAL */
};

/*
 * Interrupt bit names.
 */
const char *i80321_irqnames[] = {
	"DMA0 EOT",
	"DMA0 EOC",
	"DMA1 EOT",
	"DMA1 EOC",
	"irq 4",
	"irq 5",
	"AAU EOT",
	"AAU EOC",
	"core PMU",
	"TMR0 (hardclock)",
	"TMR1",
	"I2C0",
	"I2C1",
	"MU",
	"BIST",
	"periph PMU",
	"XScale PMU",
	"BIU error",
	"ATU error",
	"MCU error",
	"DMA0 error",
	"DMA1 error",
	"irq 22",
	"AAU error",
	"MU error",
	"SSP",
	"irq 26",
	"irq 27",
	"irq 28",
	"irq 29",
	"irq 30",
	"irq 31",
};

void	i80321_intr_dispatch(struct clockframe *frame);

static __inline uint32_t
i80321_iintsrc_read(void)
{
	uint32_t iintsrc;

	__asm __volatile("mrc p6, 0, %0, c8, c0, 0"
		: "=r" (iintsrc));

	/*
	 * The IINTSRC register shows bits that are active even
	 * if they are masked in INTCTL, so we have to mask them
	 * off with the interrupts we consider enabled.
	 */
	return (iintsrc & intr_enabled);
}

static __inline void
i80321_set_intrmask(void)
{

	__asm __volatile("mcr p6, 0, %0, c0, c0, 0"
		:
		: "r" (intr_enabled & ICU_INT_HWMASK));
}

static __inline void
i80321_set_intrsteer(void)
{

	__asm __volatile("mcr p6, 0, %0, c4, c0, 0"
		:
		: "r" (intr_steer & ICU_INT_HWMASK));
}

static __inline void
i80321_enable_irq(int irq)
{

	intr_enabled |= (1U << irq);
	i80321_set_intrmask();
}

static __inline void
i80321_disable_irq(int irq)
{

	intr_enabled &= ~(1U << irq);
	i80321_set_intrmask();
}

/*
 * NOTE: This routine must be called with interrupts disabled in the CPSR.
 */
static void
i80321_intr_calculate_masks(void)
{
	struct intrq *iq;
	struct intrhand *ih;
	int irq, ipl;

	/* First, figure out which IPLs each IRQ has. */
	for (irq = 0; irq < NIRQ; irq++) {
		int levels = 0;
		iq = &intrq[irq];
		i80321_disable_irq(irq);
		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
		     ih = TAILQ_NEXT(ih, ih_list))
			levels |= (1U << ih->ih_ipl);
		iq->iq_levels = levels;
	}

	/* Next, figure out which IRQs are used by each IPL. */
	for (ipl = 0; ipl < NIPL; ipl++) {
		int irqs = 0;
		for (irq = 0; irq < NIRQ; irq++) {
			if (intrq[irq].iq_levels & (1U << ipl))
				irqs |= (1U << irq);
		}
		imask[ipl] = irqs;
	}

	imask[IPL_NONE] = 0;

	/*
	 * Initialize the soft interrupt masks to block themselves.
	 */
	imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
	imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
	imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
	imask[IPL_SOFTSERIAL] = SI_TO_IRQBIT(SI_SOFTSERIAL);

	/*
	 * splsoftclock() is the only interface that users of the
	 * generic software interrupt facility have to block their
	 * soft intrs, so splsoftclock() must also block IPL_SOFT.
	 */
	imask[IPL_SOFTCLOCK] |= imask[IPL_SOFT];

	/*
	 * splsoftnet() must also block splsoftclock(), since we don't
	 * want timer-driven network events to occur while we're
	 * processing incoming packets.
	 */
	imask[IPL_SOFTNET] |= imask[IPL_SOFTCLOCK];

	/*
	 * Enforce a heirarchy that gives "slow" device (or devices with
	 * limited input buffer space/"real-time" requirements) a better
	 * chance at not dropping data.
	 */
	imask[IPL_BIO] |= imask[IPL_SOFTNET];
	imask[IPL_NET] |= imask[IPL_BIO];
	imask[IPL_SOFTSERIAL] |= imask[IPL_NET];
	imask[IPL_TTY] |= imask[IPL_SOFTSERIAL];

	/*
	 * splvm() blocks all interrupts that use the kernel memory
	 * allocation facilities.
	 */
	imask[IPL_IMP] |= imask[IPL_TTY];

	/*
	 * Audio devices are not allowed to perform memory allocation
	 * in their interrupt routines, and they have fairly "real-time"
	 * requirements, so give them a high interrupt priority.
	 */
	imask[IPL_AUDIO] |= imask[IPL_IMP];

	/*
	 * splclock() must block anything that uses the scheduler.
	 */
	imask[IPL_CLOCK] |= imask[IPL_AUDIO];

	/*
	 * No separate statclock on the IQ80310.
	 */
	imask[IPL_STATCLOCK] |= imask[IPL_CLOCK];

	/*
	 * splhigh() must block "everything".
	 */
	imask[IPL_HIGH] |= imask[IPL_STATCLOCK];

	/*
	 * XXX We need serial drivers to run at the absolute highest priority
	 * in order to avoid overruns, so serial > high.
	 */
	imask[IPL_SERIAL] |= imask[IPL_HIGH];

	/*
	 * Now compute which IRQs must be blocked when servicing any
	 * given IRQ.
	 */
	for (irq = 0; irq < NIRQ; irq++) {
		int irqs = (1U << irq);
		iq = &intrq[irq];
		if (TAILQ_FIRST(&iq->iq_list) != NULL)
			i80321_enable_irq(irq);
		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
		     ih = TAILQ_NEXT(ih, ih_list))
			irqs |= imask[ih->ih_ipl];
		iq->iq_mask = irqs;
	}
}

static void
i80321_do_pending(void)
{
	static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
	int new, oldirqstate;

	if (__cpu_simple_lock_try(&processing) == 0)
		return;

	new = current_spl_level;

	oldirqstate = disable_interrupts(I32_bit);

#define	DO_SOFTINT(si)							\
	if ((ipending & ~new) & SI_TO_IRQBIT(si)) {			\
		ipending &= ~SI_TO_IRQBIT(si);				\
		current_spl_level |= imask[si_to_ipl[(si)]];		\
		restore_interrupts(oldirqstate);			\
		softintr_dispatch(si);					\
		oldirqstate = disable_interrupts(I32_bit);		\
		current_spl_level = new;				\
	}

	DO_SOFTINT(SI_SOFTSERIAL);
	DO_SOFTINT(SI_SOFTNET);
	DO_SOFTINT(SI_SOFTCLOCK);
	DO_SOFTINT(SI_SOFT);

	__cpu_simple_unlock(&processing);

	restore_interrupts(oldirqstate);
}

int
_splraise(int ipl)
{
	int old, oldirqstate;

	oldirqstate = disable_interrupts(I32_bit);
	old = current_spl_level;
	current_spl_level |= imask[ipl];

	restore_interrupts(oldirqstate);

	return (old);
}

__inline void
splx(int new)
{
	int oldirqstate, hwpend;

	current_spl_level = new;

	/*
	 * If there are pending HW interrupts which are being
	 * unmasked, then enable them in the INTCTL register.
	 * This will cause them to come flooding in.
	 */
	hwpend = (ipending & ICU_INT_HWMASK) & ~new;
	if (hwpend != 0) {
		oldirqstate = disable_interrupts(I32_bit);
		intr_enabled |= hwpend;
		i80321_set_intrmask();
		restore_interrupts(oldirqstate);
	}

	/* If there are software interrupts to process, do it. */
	if ((ipending & INT_SWMASK) & ~new)
		i80321_do_pending();
}

int
_spllower(int ipl)
{
	int old = current_spl_level;

	splx(imask[ipl]);
	return (old);
}

void
_setsoftintr(int si)
{
	int oldirqstate;

	oldirqstate = disable_interrupts(I32_bit);
	ipending |= SI_TO_IRQBIT(si);
	restore_interrupts(oldirqstate);

	/* Process unmasked pending soft interrupts. */
	if ((ipending & INT_SWMASK) & ~current_spl_level)
		i80321_do_pending();
}

/*
 * i80321_icu_init:
 *
 *	Initialize the i80321 ICU.  Called early in bootstrap
 *	to make sure the ICU is in a pristine state.
 */
void
i80321_icu_init(void)
{

	intr_enabled = 0;	/* All interrupts disabled */
	i80321_set_intrmask();

	intr_steer = 0;		/* All interrupts steered to IRQ */
	i80321_set_intrsteer();
}

/*
 * i80321_intr_init:
 *
 *	Initialize the rest of the interrupt subsystem, making it
 *	ready to handle interrupts from devices.
 */
void
i80321_intr_init(void)
{
	struct intrq *iq;
	int i;

	intr_enabled = 0;

	for (i = 0; i < NIRQ; i++) {
		iq = &intrq[i];
		TAILQ_INIT(&iq->iq_list);

		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
		    NULL, "iop321", i80321_irqnames[i]);
	}

	i80321_intr_calculate_masks();

	/* Enable IRQs (don't yet use FIQs). */
	enable_interrupts(I32_bit);
}

void *
i80321_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
{
	struct intrq *iq;
	struct intrhand *ih;
	u_int oldirqstate;

	if (irq < 0 || irq > NIRQ)
		panic("i80321_intr_establish: IRQ %d out of range", irq);

	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
	if (ih == NULL)
		return (NULL);

	ih->ih_func = func;
	ih->ih_arg = arg;
	ih->ih_ipl = ipl;
	ih->ih_irq = irq;

	iq = &intrq[irq];

	/* All IOP321 interrupts are level-triggered. */
	iq->iq_ist = IST_LEVEL;

	oldirqstate = disable_interrupts(I32_bit);

	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);

	i80321_intr_calculate_masks();

	restore_interrupts(oldirqstate);

	return (ih);
}

void
i80321_intr_disestablish(void *cookie)
{
	struct intrhand *ih = cookie;
	struct intrq *iq = &intrq[ih->ih_irq];
	int oldirqstate;

	oldirqstate = disable_interrupts(I32_bit);

	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);

	i80321_intr_calculate_masks();

	restore_interrupts(oldirqstate);
}

void
i80321_intr_dispatch(struct clockframe *frame)
{
	struct intrq *iq;
	struct intrhand *ih;
	int oldirqstate, pcpl, irq, ibit, hwpend;

	pcpl = current_spl_level;

	hwpend = i80321_iintsrc_read();

	/*
	 * Disable all the interrupts that are pending.  We will
	 * reenable them once they are processed and not masked.
	 */
	intr_enabled &= ~hwpend;
	i80321_set_intrmask();

	while (hwpend != 0) {
		irq = ffs(hwpend) - 1;
		ibit = (1U << irq);

		hwpend &= ~ibit;

		if (pcpl & ibit) {
			/*
			 * IRQ is masked; mark it as pending and check
			 * the next one.  Note: the IRQ is already disabled.
			 */
			ipending |= ibit;
			continue;
		}

		ipending &= ~ibit;

		iq = &intrq[irq];
		iq->iq_ev.ev_count++;
		uvmexp.intrs++;
		current_spl_level |= iq->iq_mask;
		oldirqstate = enable_interrupts(I32_bit);
		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
		     ih = TAILQ_NEXT(ih, ih_list)) {
			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
		}
		restore_interrupts(oldirqstate);

		current_spl_level = pcpl;

		/* Re-enable this interrupt now that's it's cleared. */
		intr_enabled |= ibit;
		i80321_set_intrmask();
	}

	/* Check for pendings soft intrs. */
	if ((ipending & INT_SWMASK) & ~current_spl_level) {
		oldirqstate = enable_interrupts(I32_bit);
		i80321_do_pending();
		restore_interrupts(oldirqstate);
	}
}