Home | History | Annotate | Line # | Download | only in iq80310
      1 /*	$NetBSD: iq80310_intr.c,v 1.36 2020/11/21 15:30:07 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 #include <sys/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: iq80310_intr.c,v 1.36 2020/11/21 15:30:07 thorpej Exp $");
     40 
     41 #ifndef EVBARM_SPL_NOINLINE
     42 #define	EVBARM_SPL_NOINLINE
     43 #endif
     44 
     45 /*
     46  * Interrupt support for the Intel IQ80310.
     47  */
     48 
     49 #include <sys/param.h>
     50 #include <sys/systm.h>
     51 #include <sys/kmem.h>
     52 
     53 #include <sys/bus.h>
     54 #include <machine/intr.h>
     55 
     56 #include <arm/cpufunc.h>
     57 
     58 #include <arm/xscale/i80200reg.h>
     59 #include <arm/xscale/i80200var.h>
     60 
     61 #include <evbarm/iq80310/iq80310reg.h>
     62 #include <evbarm/iq80310/iq80310var.h>
     63 #include <evbarm/iq80310/obiovar.h>
     64 
     65 /* Interrupt handler queues. */
     66 struct intrq intrq[NIRQ];
     67 
     68 /* Interrupts to mask at each level. */
     69 int iq80310_imask[NIPL];
     70 
     71 /* Interrupts pending. */
     72 volatile int iq80310_ipending;
     73 
     74 /* Software copy of the IRQs we have enabled. */
     75 uint32_t intr_enabled;
     76 
     77 #ifdef __HAVE_FAST_SOFTINTS
     78 /*
     79  * Map a software interrupt queue index (at the top of the word, and
     80  * highest priority softintr is encountered first in an ffs()).
     81  */
     82 #define	SI_TO_IRQBIT(si)	(1U << (31 - (si)))
     83 
     84 /*
     85  * Map a software interrupt queue to an interrupt priority level.
     86  */
     87 static const int si_to_ipl[SI_NQUEUES] = {
     88 	IPL_SOFT,		/* SI_SOFT */
     89 	IPL_SOFTCLOCK,		/* SI_SOFTCLOCK */
     90 	IPL_SOFTNET,		/* SI_SOFTNET */
     91 	IPL_SOFTSERIAL,		/* SI_SOFTSERIAL */
     92 };
     93 #endif
     94 
     95 void	iq80310_intr_dispatch(struct trapframe *frame);
     96 
     97 static inline uint32_t
     98 iq80310_intstat_read(void)
     99 {
    100 	uint32_t intstat;
    101 
    102 	intstat = CPLD_READ(IQ80310_XINT3_STATUS) & 0x1f;
    103 #if defined(IRQ_READ_XINT0)
    104 	if (IRQ_READ_XINT0)
    105 		intstat |= (CPLD_READ(IQ80310_XINT0_STATUS) & 0x7) << 5;
    106 #endif
    107 
    108 	/* XXX Why do we have to mask off? */
    109 	return (intstat & intr_enabled);
    110 }
    111 
    112 static inline void
    113 iq80310_set_intrmask(void)
    114 {
    115 	uint32_t disabled;
    116 
    117 	intr_enabled |= IRQ_BITS_ALWAYS_ON;
    118 
    119 	/* The XINT_MASK register sets a bit to *disable*. */
    120 	disabled = (~intr_enabled) & IRQ_BITS;
    121 
    122 	CPLD_WRITE(IQ80310_XINT_MASK, disabled & 0x1f);
    123 }
    124 
    125 static inline void
    126 iq80310_enable_irq(int irq)
    127 {
    128 
    129 	intr_enabled |= (1U << irq);
    130 	iq80310_set_intrmask();
    131 }
    132 
    133 static inline void
    134 iq80310_disable_irq(int irq)
    135 {
    136 
    137 	intr_enabled &= ~(1U << irq);
    138 	iq80310_set_intrmask();
    139 }
    140 
    141 /*
    142  * NOTE: This routine must be called with interrupts disabled in the CPSR.
    143  */
    144 static void
    145 iq80310_intr_calculate_masks(void)
    146 {
    147 	struct intrq *iq;
    148 	struct intrhand *ih;
    149 	int irq, ipl;
    150 
    151 	/* First, figure out which IPLs each IRQ has. */
    152 	for (irq = 0; irq < NIRQ; irq++) {
    153 		int levels = 0;
    154 		iq = &intrq[irq];
    155 		iq80310_disable_irq(irq);
    156 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    157 		     ih = TAILQ_NEXT(ih, ih_list))
    158 			levels |= (1U << ih->ih_ipl);
    159 		iq->iq_levels = levels;
    160 	}
    161 
    162 	/* Next, figure out which IRQs are used by each IPL. */
    163 	for (ipl = 0; ipl < NIPL; ipl++) {
    164 		int irqs = 0;
    165 		for (irq = 0; irq < NIRQ; irq++) {
    166 			if (intrq[irq].iq_levels & (1U << ipl))
    167 				irqs |= (1U << irq);
    168 		}
    169 		iq80310_imask[ipl] = irqs;
    170 	}
    171 
    172 	iq80310_imask[IPL_NONE] = 0;
    173 	iq80310_imask[IPL_SOFTCLOCK] = 0;
    174 	iq80310_imask[IPL_SOFTNET] = 0;
    175 	iq80310_imask[IPL_SOFTSERIAL] = 0;
    176 
    177 	/*
    178 	 * splsoftnet() must also block splsoftclock(), since we don't
    179 	 * want timer-driven network events to occur while we're
    180 	 * processing incoming packets.
    181 	 */
    182 	iq80310_imask[IPL_SOFTNET] |= iq80310_imask[IPL_SOFTCLOCK];
    183 
    184 	/*
    185 	 * Enforce a hierarchy that gives "slow" device (or devices with
    186 	 * limited input buffer space/"real-time" requirements) a better
    187 	 * chance at not dropping data.
    188 	 */
    189 	iq80310_imask[IPL_BIO] |= iq80310_imask[IPL_SOFTNET];
    190 	iq80310_imask[IPL_NET] |= iq80310_imask[IPL_BIO];
    191 	iq80310_imask[IPL_SOFTSERIAL] |= iq80310_imask[IPL_NET];
    192 	iq80310_imask[IPL_TTY] |= iq80310_imask[IPL_SOFTSERIAL];
    193 
    194 	/*
    195 	 * splvm() blocks all interrupts that use the kernel memory
    196 	 * allocation facilities.
    197 	 */
    198 	iq80310_imask[IPL_VM] |= iq80310_imask[IPL_TTY];
    199 
    200 	/*
    201 	 * Audio devices are not allowed to perform memory allocation
    202 	 * in their interrupt routines, and they have fairly "real-time"
    203 	 * requirements, so give them a high interrupt priority.
    204 	 */
    205 	iq80310_imask[IPL_AUDIO] |= iq80310_imask[IPL_VM];
    206 
    207 	/*
    208 	 * splclock() must block anything that uses the scheduler.
    209 	 */
    210 	iq80310_imask[IPL_CLOCK] |= iq80310_imask[IPL_AUDIO];
    211 
    212 	/*
    213 	 * No separate statclock on the IQ80310.
    214 	 */
    215 #ifdef IPL_STATCLOCK
    216 	iq80310_imask[IPL_STATCLOCK] |= iq80310_imask[IPL_CLOCK];
    217 #endif
    218 
    219 	/*
    220 	 * splhigh() must block "everything".
    221 	 */
    222 #ifdef IPL_STATCLOCK
    223 	iq80310_imask[IPL_HIGH] |= iq80310_imask[IPL_STATCLOCK];
    224 #else
    225 	iq80310_imask[IPL_HIGH] |= iq80310_imask[IPL_CLOCK];
    226 #endif
    227 
    228 	/*
    229 	 * XXX We need serial drivers to run at the absolute highest priority
    230 	 * in order to avoid overruns, so serial > high.
    231 	 */
    232 	iq80310_imask[IPL_SERIAL] |= iq80310_imask[IPL_HIGH];
    233 
    234 	/*
    235 	 * Now compute which IRQs must be blocked when servicing any
    236 	 * given IRQ.
    237 	 */
    238 	for (irq = 0; irq < NIRQ; irq++) {
    239 		int irqs = (1U << irq);
    240 		iq = &intrq[irq];
    241 		if (TAILQ_FIRST(&iq->iq_list) != NULL)
    242 			iq80310_enable_irq(irq);
    243 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    244 		     ih = TAILQ_NEXT(ih, ih_list))
    245 			irqs |= iq80310_imask[ih->ih_ipl];
    246 		iq->iq_mask = irqs;
    247 	}
    248 }
    249 
    250 #ifdef __HAVE_FAST_SOFTINTS
    251 void
    252 iq80310_do_soft(void)
    253 {
    254 	static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
    255 	struct cpu_info * const ci = curcpu();
    256 	int new, oldirqstate;
    257 
    258 	if (__cpu_simple_lock_try(&processing) == 0)
    259 		return;
    260 
    261 	new = ci->ci_cpl;
    262 
    263 	oldirqstate = disable_interrupts(I32_bit);
    264 
    265 #define	DO_SOFTINT(si)							\
    266 	if ((iq80310_ipending & ~new) & SI_TO_IRQBIT(si)) {		\
    267 		iq80310_ipending &= ~SI_TO_IRQBIT(si);			\
    268 		ci->ci_cpl |= iq80310_imask[si_to_ipl[(si)]];	\
    269 		restore_interrupts(oldirqstate);			\
    270 		softintr_dispatch(si);					\
    271 		oldirqstate = disable_interrupts(I32_bit);		\
    272 		ci->ci_cpl = new;				\
    273 	}
    274 
    275 	DO_SOFTINT(SI_SOFTSERIAL);
    276 	DO_SOFTINT(SI_SOFTNET);
    277 	DO_SOFTINT(SI_SOFTCLOCK);
    278 	DO_SOFTINT(SI_SOFT);
    279 
    280 	__cpu_simple_unlock(&processing);
    281 
    282 	restore_interrupts(oldirqstate);
    283 }
    284 #endif	/* __HAVE_SOFT_FASTINTS */
    285 
    286 int
    287 _splraise(int ipl)
    288 {
    289 
    290 	return (iq80310_splraise(ipl));
    291 }
    292 
    293 inline void
    294 splx(int new)
    295 {
    296 
    297 	return (iq80310_splx(new));
    298 }
    299 
    300 int
    301 _spllower(int ipl)
    302 {
    303 
    304 	return (iq80310_spllower(ipl));
    305 }
    306 
    307 #ifdef __HAVE_FAST_SOFTINTS
    308 void
    309 _setsoftintr(int si)
    310 {
    311 	int oldirqstate;
    312 
    313 	oldirqstate = disable_interrupts(I32_bit);
    314 	iq80310_ipending |= SI_TO_IRQBIT(si);
    315 	restore_interrupts(oldirqstate);
    316 
    317 	/* Process unmasked pending soft interrupts. */
    318 	if ((iq80310_ipending & ~IRQ_BITS) & ~curcpl())
    319 		iq80310_do_soft();
    320 }
    321 #endif
    322 
    323 void
    324 iq80310_intr_init(void)
    325 {
    326 	struct intrq *iq;
    327 	int i;
    328 
    329 	/*
    330 	 * The Secondary PCI interrupts INTA, INTB, and INTC
    331 	 * area always enabled, since they cannot be masked
    332 	 * in the CPLD.
    333 	 */
    334 	intr_enabled |= IRQ_BITS_ALWAYS_ON;
    335 
    336 	for (i = 0; i < NIRQ; i++) {
    337 		iq = &intrq[i];
    338 		TAILQ_INIT(&iq->iq_list);
    339 
    340 		snprintf(iq->iq_name, sizeof(iq->iq_name), "irq %d", i);
    341 	}
    342 
    343 	iq80310_intr_calculate_masks();
    344 
    345 	/* Enable external interrupts on the i80200. */
    346 	i80200_extirq_dispatch = iq80310_intr_dispatch;
    347 	i80200_intr_enable(INTCTL_IM | INTCTL_PM);
    348 
    349 	/* Enable IRQs (don't yet use FIQs). */
    350 	enable_interrupts(I32_bit);
    351 }
    352 
    353 void
    354 iq80310_intr_evcnt_attach(void)
    355 {
    356 	struct intrq *iq;
    357 	int i;
    358 
    359 	for (i = 0; i < NIRQ; i++) {
    360 		iq = &intrq[i];
    361 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
    362 		    NULL, "iq80310", iq->iq_name);
    363 	}
    364 }
    365 
    366 void *
    367 iq80310_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
    368 {
    369 	struct intrq *iq;
    370 	struct intrhand *ih;
    371 	u_int oldirqstate;
    372 
    373 	if (irq < 0 || irq > NIRQ)
    374 		panic("iq80310_intr_establish: IRQ %d out of range", irq);
    375 
    376 	ih = kmem_alloc(sizeof(*ih), KM_SLEEP);
    377 	ih->ih_func = func;
    378 	ih->ih_arg = arg;
    379 	ih->ih_ipl = ipl;
    380 	ih->ih_irq = irq;
    381 
    382 	iq = &intrq[irq];
    383 
    384 	/* All IQ80310 interrupts are level-triggered. */
    385 	iq->iq_ist = IST_LEVEL;
    386 
    387 	oldirqstate = disable_interrupts(I32_bit);
    388 
    389 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
    390 
    391 	iq80310_intr_calculate_masks();
    392 
    393 	restore_interrupts(oldirqstate);
    394 
    395 	return (ih);
    396 }
    397 
    398 void
    399 iq80310_intr_disestablish(void *cookie)
    400 {
    401 	struct intrhand *ih = cookie;
    402 	struct intrq *iq = &intrq[ih->ih_irq];
    403 	int oldirqstate;
    404 
    405 	oldirqstate = disable_interrupts(I32_bit);
    406 
    407 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
    408 
    409 	iq80310_intr_calculate_masks();
    410 
    411 	restore_interrupts(oldirqstate);
    412 }
    413 
    414 void
    415 iq80310_intr_dispatch(struct trapframe *frame)
    416 {
    417 	struct intrq *iq;
    418 	struct intrhand *ih;
    419 	int oldirqstate, pcpl, irq, ibit, hwpend, rv;
    420 	struct cpu_info * const ci = curcpu();
    421 #if 0
    422 	int stray;
    423 
    424 	stray = 1;
    425 #endif
    426 
    427 	/* First, disable external IRQs. */
    428 	i80200_intr_disable(INTCTL_IM | INTCTL_PM);
    429 
    430 	pcpl = ci->ci_cpl;
    431 
    432 	for (hwpend = iq80310_intstat_read(); hwpend != 0;) {
    433 		irq = ffs(hwpend) - 1;
    434 		ibit = (1U << irq);
    435 
    436 #if 0
    437 		stray = 0;
    438 #endif
    439 
    440 		hwpend &= ~ibit;
    441 
    442 		if (pcpl & ibit) {
    443 			/*
    444 			 * IRQ is masked; mark it as pending and check
    445 			 * the next one.  Note: external IRQs are already
    446 			 * disabled.
    447 			 */
    448 			iq80310_ipending |= ibit;
    449 			continue;
    450 		}
    451 
    452 		iq80310_ipending &= ~ibit;
    453 		rv = 0;
    454 
    455 		iq = &intrq[irq];
    456 		iq->iq_ev.ev_count++;
    457 		ci->ci_data.cpu_nintr++;
    458 		ci->ci_cpl |= iq->iq_mask;
    459 		oldirqstate = enable_interrupts(I32_bit);
    460 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    461 		     ih = TAILQ_NEXT(ih, ih_list)) {
    462 			rv |= (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    463 		}
    464 		restore_interrupts(oldirqstate);
    465 
    466 		ci->ci_cpl = pcpl;
    467 
    468 #if 0 /* XXX */
    469 		if (rv == 0)
    470 			printf("Stray interrupt: IRQ %d\n", irq);
    471 #endif
    472 	}
    473 
    474 #if 0 /* XXX */
    475 	if (stray)
    476 		printf("Stray external interrupt\n");
    477 #endif
    478 
    479 #ifdef __HAVE_FAST_SOFTINTS
    480 	/* Check for pendings soft intrs. */
    481 	if ((iq80310_ipending & ~IRQ_BITS) & ~ci->ci_cpl) {
    482 		oldirqstate = enable_interrupts(I32_bit);
    483 		iq80310_do_soft();
    484 		restore_interrupts(oldirqstate);
    485 	}
    486 #endif
    487 
    488 	/*
    489 	 * If no hardware interrupts are masked, re-enable external
    490 	 * interrupts.
    491 	 */
    492 	if ((iq80310_ipending & IRQ_BITS) == 0)
    493 		i80200_intr_enable(INTCTL_IM | INTCTL_PM);
    494 }
    495