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iq80310_intr.c revision 1.9
      1 /*	$NetBSD: iq80310_intr.c,v 1.9 2002/02/09 03:52:31 thorpej Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
      5  * All rights reserved.
      6  *
      7  * Written by Jason R. Thorpe for Wasabi Systems, Inc.
      8  *
      9  * Redistribution and use in source and binary forms, with or without
     10  * modification, are permitted provided that the following conditions
     11  * are met:
     12  * 1. Redistributions of source code must retain the above copyright
     13  *    notice, this list of conditions and the following disclaimer.
     14  * 2. Redistributions in binary form must reproduce the above copyright
     15  *    notice, this list of conditions and the following disclaimer in the
     16  *    documentation and/or other materials provided with the distribution.
     17  * 3. All advertising materials mentioning features or use of this software
     18  *    must display the following acknowledgement:
     19  *	This product includes software developed for the NetBSD Project by
     20  *	Wasabi Systems, Inc.
     21  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
     22  *    or promote products derived from this software without specific prior
     23  *    written permission.
     24  *
     25  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
     26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     27  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     28  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
     29  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     35  * POSSIBILITY OF SUCH DAMAGE.
     36  */
     37 
     38 /*
     39  * Interrupt support for the Intel IQ80310.
     40  */
     41 
     42 #include <sys/param.h>
     43 #include <sys/systm.h>
     44 #include <sys/malloc.h>
     45 
     46 #include <uvm/uvm_extern.h>
     47 
     48 #include <machine/bus.h>
     49 #include <machine/intr.h>
     50 
     51 #include <arm/cpufunc.h>
     52 
     53 #include <arm/xscale/i80200reg.h>
     54 #include <arm/xscale/i80200var.h>
     55 
     56 #include <evbarm/iq80310/iq80310reg.h>
     57 #include <evbarm/iq80310/iq80310var.h>
     58 #include <evbarm/iq80310/obiovar.h>
     59 
     60 #if defined(IOP310_TEAMASA_NPWR)
     61 /*
     62  * We have 5 interrupt source bits -- all in XINT3.  All interrupts
     63  * can be masked in the CPLD.
     64  */
     65 #define	IRQ_BITS		0x1f
     66 #define	IRQ_BITS_ALWAYS_ON	0x00
     67 #else /* Default to stock IQ80310 */
     68 /*
     69  * We have 8 interrupt source bits -- 5 in the XINT3 register, and 3
     70  * in the XINT0 register (the upper 3).  Note that the XINT0 IRQs
     71  * (SPCI INTA, INTB, and INTC) are always enabled, since they can not
     72  * be masked out in the CPLD (it provides only status, not masking,
     73  * for those interrupts).
     74  */
     75 #define	IRQ_BITS		0xff
     76 #define	IRQ_BITS_ALWAYS_ON	0xe0
     77 #define	IRQ_READ_XINT0		1	/* XXX only if board rev >= F */
     78 #endif /* list of IQ80310-based designs */
     79 
     80 /* Interrupt handler queues. */
     81 struct intrq intrq[NIRQ];
     82 
     83 /* Interrupts to mask at each level. */
     84 static int imask[NIPL];
     85 
     86 /* Current interrupt priority level. */
     87 __volatile int current_spl_level;
     88 
     89 /* Interrupts pending. */
     90 static __volatile int ipending;
     91 
     92 /* Software copy of the IRQs we have enabled. */
     93 uint32_t intr_enabled;
     94 
     95 /*
     96  * Map a software interrupt queue index (at the top of the word, and
     97  * highest priority softintr is encountered first in an ffs()).
     98  */
     99 #define	SI_TO_IRQBIT(si)	(1U << (31 - (si)))
    100 
    101 /*
    102  * Map a software interrupt queue to an interrupt priority level.
    103  */
    104 static const int si_to_ipl[SI_NQUEUES] = {
    105 	IPL_SOFT,		/* SI_SOFT */
    106 	IPL_SOFTCLOCK,		/* SI_SOFTCLOCK */
    107 	IPL_SOFTNET,		/* SI_SOFTNET */
    108 	IPL_SOFTSERIAL,		/* SI_SOFTSERIAL */
    109 };
    110 
    111 void	iq80310_intr_dispatch(struct clockframe *frame);
    112 
    113 static __inline uint32_t
    114 iq80310_intstat_read(void)
    115 {
    116 	uint32_t intstat;
    117 
    118 	intstat = CPLD_READ(IQ80310_XINT3_STATUS) & 0x1f;
    119 #if defined(IRQ_READ_XINT0)
    120 	if (IRQ_READ_XINT0)
    121 		intstat |= (CPLD_READ(IQ80310_XINT0_STATUS) & 0x7) << 5;
    122 #endif
    123 
    124 	/* XXX Why do we have to mask off? */
    125 	return (intstat & intr_enabled);
    126 }
    127 
    128 static __inline void
    129 iq80310_set_intrmask(void)
    130 {
    131 	uint32_t disabled;
    132 
    133 	intr_enabled |= IRQ_BITS_ALWAYS_ON;
    134 
    135 	/* The XINT_MASK register sets a bit to *disable*. */
    136 	disabled = (~intr_enabled) & IRQ_BITS;
    137 
    138 	CPLD_WRITE(IQ80310_XINT_MASK, disabled & 0x1f);
    139 }
    140 
    141 static __inline void
    142 iq80310_enable_irq(int irq)
    143 {
    144 
    145 	intr_enabled |= (1U << irq);
    146 	iq80310_set_intrmask();
    147 }
    148 
    149 static __inline void
    150 iq80310_disable_irq(int irq)
    151 {
    152 
    153 	intr_enabled &= ~(1U << irq);
    154 	iq80310_set_intrmask();
    155 }
    156 
    157 /*
    158  * NOTE: This routine must be called with interrupts disabled in the CPSR.
    159  */
    160 static void
    161 iq80310_intr_calculate_masks(void)
    162 {
    163 	struct intrq *iq;
    164 	struct intrhand *ih;
    165 	int irq, ipl;
    166 
    167 	/* First, figure out which IPLs each IRQ has. */
    168 	for (irq = 0; irq < NIRQ; irq++) {
    169 		int levels = 0;
    170 		iq = &intrq[irq];
    171 		iq80310_disable_irq(irq);
    172 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    173 		     ih = TAILQ_NEXT(ih, ih_list))
    174 			levels |= (1U << ih->ih_ipl);
    175 		iq->iq_levels = levels;
    176 	}
    177 
    178 	/* Next, figure out which IRQs are used by each IPL. */
    179 	for (ipl = 0; ipl < NIPL; ipl++) {
    180 		int irqs = 0;
    181 		for (irq = 0; irq < NIRQ; irq++) {
    182 			if (intrq[irq].iq_levels & (1U << ipl))
    183 				irqs |= (1U << irq);
    184 		}
    185 		imask[ipl] = irqs;
    186 	}
    187 
    188 	imask[IPL_NONE] = 0;
    189 
    190 	/*
    191 	 * Initialize the soft interrupt masks to block themselves.
    192 	 */
    193 	imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
    194 	imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
    195 	imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
    196 	imask[IPL_SOFTSERIAL] = SI_TO_IRQBIT(SI_SOFTSERIAL);
    197 
    198 	/*
    199 	 * splsoftclock() is the only interface that users of the
    200 	 * generic software interrupt facility have to block their
    201 	 * soft intrs, so splsoftclock() must also block IPL_SOFT.
    202 	 */
    203 	imask[IPL_SOFTCLOCK] |= imask[IPL_SOFT];
    204 
    205 	/*
    206 	 * splsoftnet() must also block splsoftclock(), since we don't
    207 	 * want timer-driven network events to occur while we're
    208 	 * processing incoming packets.
    209 	 */
    210 	imask[IPL_SOFTNET] |= imask[IPL_SOFTCLOCK];
    211 
    212 	/*
    213 	 * Enforce a heirarchy that gives "slow" device (or devices with
    214 	 * limited input buffer space/"real-time" requirements) a better
    215 	 * chance at not dropping data.
    216 	 */
    217 	imask[IPL_BIO] |= imask[IPL_SOFTNET];
    218 	imask[IPL_NET] |= imask[IPL_BIO];
    219 	imask[IPL_SOFTSERIAL] |= imask[IPL_NET];
    220 	imask[IPL_TTY] |= imask[IPL_SOFTSERIAL];
    221 
    222 	/*
    223 	 * splvm() blocks all interrupts that use the kernel memory
    224 	 * allocation facilities.
    225 	 */
    226 	imask[IPL_IMP] |= imask[IPL_TTY];
    227 
    228 	/*
    229 	 * Audio devices are not allowed to perform memory allocation
    230 	 * in their interrupt routines, and they have fairly "real-time"
    231 	 * requirements, so give them a high interrupt priority.
    232 	 */
    233 	imask[IPL_AUDIO] |= imask[IPL_IMP];
    234 
    235 	/*
    236 	 * splclock() must block anything that uses the scheduler.
    237 	 */
    238 	imask[IPL_CLOCK] |= imask[IPL_AUDIO];
    239 
    240 	/*
    241 	 * No separate statclock on the IQ80310.
    242 	 */
    243 	imask[IPL_STATCLOCK] |= imask[IPL_CLOCK];
    244 
    245 	/*
    246 	 * splhigh() must block "everything".
    247 	 */
    248 	imask[IPL_HIGH] |= imask[IPL_STATCLOCK];
    249 
    250 	/*
    251 	 * XXX We need serial drivers to run at the absolute highest priority
    252 	 * in order to avoid overruns, so serial > high.
    253 	 */
    254 	imask[IPL_SERIAL] |= imask[IPL_HIGH];
    255 
    256 	/*
    257 	 * Now compute which IRQs must be blocked when servicing any
    258 	 * given IRQ.
    259 	 */
    260 	for (irq = 0; irq < NIRQ; irq++) {
    261 		int irqs = (1U << irq);
    262 		iq = &intrq[irq];
    263 		if (TAILQ_FIRST(&iq->iq_list) != NULL)
    264 			iq80310_enable_irq(irq);
    265 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    266 		     ih = TAILQ_NEXT(ih, ih_list))
    267 			irqs |= imask[ih->ih_ipl];
    268 		iq->iq_mask = irqs;
    269 	}
    270 }
    271 
    272 static void
    273 iq80310_do_pending(void)
    274 {
    275 	static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
    276 	int new, oldirqstate;
    277 
    278 	if (__cpu_simple_lock_try(&processing) == 0)
    279 		return;
    280 
    281 	new = current_spl_level;
    282 
    283 	oldirqstate = disable_interrupts(I32_bit);
    284 
    285 #define	DO_SOFTINT(si)							\
    286 	if ((ipending & ~new) & SI_TO_IRQBIT(si)) {			\
    287 		ipending &= ~SI_TO_IRQBIT(si);				\
    288 		current_spl_level |= imask[si_to_ipl[(si)]];		\
    289 		restore_interrupts(oldirqstate);			\
    290 		softintr_dispatch(si);					\
    291 		oldirqstate = disable_interrupts(I32_bit);		\
    292 		current_spl_level = new;				\
    293 	}
    294 
    295 	DO_SOFTINT(SI_SOFTSERIAL);
    296 	DO_SOFTINT(SI_SOFTNET);
    297 	DO_SOFTINT(SI_SOFTCLOCK);
    298 	DO_SOFTINT(SI_SOFT);
    299 
    300 	__cpu_simple_unlock(&processing);
    301 
    302 	restore_interrupts(oldirqstate);
    303 }
    304 
    305 int
    306 _splraise(int ipl)
    307 {
    308 	int old, oldirqstate;
    309 
    310 	oldirqstate = disable_interrupts(I32_bit);
    311 	old = current_spl_level;
    312 	current_spl_level |= imask[ipl];
    313 
    314 	restore_interrupts(oldirqstate);
    315 
    316 	return (old);
    317 }
    318 
    319 __inline void
    320 splx(int new)
    321 {
    322 	int old;
    323 
    324 	old = current_spl_level;
    325 	current_spl_level = new;
    326 
    327 	/*
    328 	 * If there are pending hardware interrupts (i.e. the
    329 	 * external interrupt is disabled in the ICU), and all
    330 	 * hardware interrupts are being unblocked, then re-enable
    331 	 * the external hardware interrupt.
    332 	 *
    333 	 * XXX We have to wait for ALL hardware interrupts to
    334 	 * XXX be unblocked, because we currently lose if we
    335 	 * XXX get nested interrupts, and I don't know why yet.
    336 	 */
    337 	if ((new & IRQ_BITS) == 0 && (ipending & IRQ_BITS))
    338 		i80200_intr_enable(INTCTL_IM);
    339 
    340 	/* If there are software interrupts to process, do it. */
    341 	if ((ipending & ~IRQ_BITS) & ~new)
    342 		iq80310_do_pending();
    343 }
    344 
    345 int
    346 _spllower(int ipl)
    347 {
    348 	int old = current_spl_level;
    349 
    350 	splx(imask[ipl]);
    351 	return (old);
    352 }
    353 
    354 void
    355 _setsoftintr(int si)
    356 {
    357 	int oldirqstate;
    358 
    359 	oldirqstate = disable_interrupts(I32_bit);
    360 	ipending |= SI_TO_IRQBIT(si);
    361 	restore_interrupts(oldirqstate);
    362 
    363 	/* Process unmasked pending soft interrupts. */
    364 	if ((ipending & ~IRQ_BITS) & ~current_spl_level)
    365 		iq80310_do_pending();
    366 }
    367 
    368 void
    369 iq80310_intr_init(void)
    370 {
    371 	struct intrq *iq;
    372 	int i;
    373 
    374 	/*
    375 	 * The Secondary PCI interrupts INTA, INTB, and INTC
    376 	 * area always enabled, since they cannot be masked
    377 	 * in the CPLD.
    378 	 */
    379 	intr_enabled |= IRQ_BITS_ALWAYS_ON;
    380 
    381 	for (i = 0; i < NIRQ; i++) {
    382 		iq = &intrq[i];
    383 		TAILQ_INIT(&iq->iq_list);
    384 
    385 		sprintf(iq->iq_name, "irq %d", i);
    386 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
    387 		    NULL, "iq80310", iq->iq_name);
    388 	}
    389 
    390 	iq80310_intr_calculate_masks();
    391 
    392 	/* Enable external interrupts on the i80200. */
    393 	i80200_extirq_dispatch = iq80310_intr_dispatch;
    394 	i80200_intr_enable(INTCTL_IM);
    395 
    396 	/* Enable IRQs (don't yet use FIQs). */
    397 	enable_interrupts(I32_bit);
    398 }
    399 
    400 void *
    401 iq80310_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
    402 {
    403 	struct intrq *iq;
    404 	struct intrhand *ih;
    405 	u_int oldirqstate;
    406 
    407 	if (irq < 0 || irq > NIRQ)
    408 		panic("iq80310_intr_establish: IRQ %d out of range", irq);
    409 
    410 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
    411 	if (ih == NULL)
    412 		return (NULL);
    413 
    414 	ih->ih_func = func;
    415 	ih->ih_arg = arg;
    416 	ih->ih_ipl = ipl;
    417 	ih->ih_irq = irq;
    418 
    419 	iq = &intrq[irq];
    420 
    421 	/* All IQ80310 interrupts are level-triggered. */
    422 	iq->iq_ist = IST_LEVEL;
    423 
    424 	oldirqstate = disable_interrupts(I32_bit);
    425 
    426 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
    427 
    428 	iq80310_intr_calculate_masks();
    429 
    430 	restore_interrupts(oldirqstate);
    431 
    432 	return (ih);
    433 }
    434 
    435 void
    436 iq80310_intr_disestablish(void *cookie)
    437 {
    438 	struct intrhand *ih = cookie;
    439 	struct intrq *iq = &intrq[ih->ih_irq];
    440 	int oldirqstate;
    441 
    442 	oldirqstate = disable_interrupts(I32_bit);
    443 
    444 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
    445 
    446 	iq80310_intr_calculate_masks();
    447 
    448 	restore_interrupts(oldirqstate);
    449 }
    450 
    451 void
    452 iq80310_intr_dispatch(struct clockframe *frame)
    453 {
    454 	struct intrq *iq;
    455 	struct intrhand *ih;
    456 	int oldirqstate, pcpl, irq, ibit, hwpend;
    457 
    458 	/* First, disable external IRQs. */
    459 	i80200_intr_disable(INTCTL_IM);
    460 
    461 	pcpl = current_spl_level;
    462 
    463 	for (hwpend = iq80310_intstat_read(); hwpend != 0;) {
    464 		irq = ffs(hwpend) - 1;
    465 		ibit = (1U << irq);
    466 
    467 		hwpend &= ~ibit;
    468 
    469 		if (pcpl & ibit) {
    470 			/*
    471 			 * IRQ is masked; mark it as pending and check
    472 			 * the next one.  Note: external IRQs are already
    473 			 * disabled.
    474 			 */
    475 			ipending |= ibit;
    476 			continue;
    477 		}
    478 
    479 		ipending &= ~ibit;
    480 
    481 		iq = &intrq[irq];
    482 		iq->iq_ev.ev_count++;
    483 		uvmexp.intrs++;
    484 		current_spl_level |= iq->iq_mask;
    485 		oldirqstate = enable_interrupts(I32_bit);
    486 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    487 		     ih = TAILQ_NEXT(ih, ih_list)) {
    488 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    489 		}
    490 		restore_interrupts(oldirqstate);
    491 
    492 		current_spl_level = pcpl;
    493 	}
    494 
    495 	/* Check for pendings soft intrs. */
    496 	if ((ipending & ~IRQ_BITS) & ~current_spl_level) {
    497 		oldirqstate = enable_interrupts(I32_bit);
    498 		iq80310_do_pending();
    499 		restore_interrupts(oldirqstate);
    500 	}
    501 
    502 	/*
    503 	 * If no hardware interrupts are masked, re-enable external
    504 	 * interrupts.
    505 	 */
    506 	if ((ipending & IRQ_BITS) == 0)
    507 		i80200_intr_enable(INTCTL_IM);
    508 }
    509