Home | History | Annotate | Line # | Download | only in ep93xx
ep93xx_intr.c revision 1.1
      1 /* $NetBSD: ep93xx_intr.c,v 1.1 2004/12/22 19:07:14 joff Exp $ */
      2 
      3 /*
      4  * Copyright (c) 2002 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jesse Off
      9  *
     10  * This code is derived from software contributed to The NetBSD Foundation
     11  * by Ichiro FUKUHARA and Naoto Shimazaki.
     12  *
     13  * Redistribution and use in source and binary forms, with or without
     14  * modification, are permitted provided that the following conditions
     15  * are met:
     16  * 1. Redistributions of source code must retain the above copyright
     17  *    notice, this list of conditions and the following disclaimer.
     18  * 2. Redistributions in binary form must reproduce the above copyright
     19  *    notice, this list of conditions and the following disclaimer in the
     20  *    documentation and/or other materials provided with the distribution.
     21  * 3. All advertising materials mentioning features or use of this software
     22  *    must display the following acknowledgement:
     23  *        This product includes software developed by the NetBSD
     24  *        Foundation, Inc. and its contributors.
     25  * 4. Neither the name of The NetBSD Foundation nor the names of its
     26  *    contributors may be used to endorse or promote products derived
     27  *    from this software without specific prior written permission.
     28  *
     29  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     30  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     31  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     32  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     33  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     34  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     35  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     36  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     37  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     38  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     39  * POSSIBILITY OF SUCH DAMAGE.
     40  */
     41 
     42 #include <sys/cdefs.h>
     43 __KERNEL_RCSID(0, "$NetBSD: ep93xx_intr.c,v 1.1 2004/12/22 19:07:14 joff Exp $");
     44 
     45 /*
     46  * Interrupt support for the Cirrus Logic EP93XX
     47  */
     48 
     49 #include <sys/param.h>
     50 #include <sys/systm.h>
     51 #include <sys/malloc.h>
     52 #include <sys/termios.h>
     53 
     54 #include <uvm/uvm_extern.h>
     55 
     56 #include <machine/bus.h>
     57 #include <machine/intr.h>
     58 
     59 #include <arm/cpufunc.h>
     60 
     61 #include <arm/ep93xx/ep93xxreg.h>
     62 #include <arm/ep93xx/ep93xxvar.h>
     63 
     64 /* Interrupt handler queues. */
     65 struct intrq intrq[NIRQ];
     66 
     67 /* Interrupts to mask at each level. */
     68 static u_int32_t vic1_imask[NIPL];
     69 static u_int32_t vic2_imask[NIPL];
     70 
     71 /* Current interrupt priority level. */
     72 __volatile int current_spl_level;
     73 __volatile int hardware_spl_level;
     74 
     75 /* Software copy of the IRQs we have enabled. */
     76 __volatile u_int32_t vic1_intr_enabled;
     77 __volatile u_int32_t vic2_intr_enabled;
     78 
     79 /* Interrupts pending. */
     80 static __volatile int ipending;
     81 
     82 /*
     83  * Map a software interrupt queue index (to the unused bits in the
     84  * VIC1 register -- XXX will need to revisit this if those bits are
     85  * ever used in future steppings).
     86  */
     87 static const u_int32_t si_to_irqbit[SI_NQUEUES] = {
     88 	EP93XX_INTR_bit30,		/* SI_SOFT */
     89 	EP93XX_INTR_bit29,		/* SI_SOFTCLOCK */
     90 	EP93XX_INTR_bit28,		/* SI_SOFTNET */
     91 	EP93XX_INTR_bit27,		/* SI_SOFTSERIAL */
     92 };
     93 
     94 #define	INT_SWMASK							\
     95 	((1U << EP93XX_INTR_bit30) | (1U << EP93XX_INTR_bit29) |	\
     96 	 (1U << EP93XX_INTR_bit28) | (1U << EP93XX_INTR_bit27))
     97 
     98 #define	SI_TO_IRQBIT(si)	(1U << si_to_irqbit[(si)])
     99 
    100 /*
    101  * Map a software interrupt queue to an interrupt priority level.
    102  */
    103 static const int si_to_ipl[SI_NQUEUES] = {
    104 	IPL_SOFT,		/* SI_SOFT */
    105 	IPL_SOFTCLOCK,		/* SI_SOFTCLOCK */
    106 	IPL_SOFTNET,		/* SI_SOFTNET */
    107 	IPL_SOFTSERIAL,		/* SI_SOFTSERIAL */
    108 };
    109 
    110 void	ep93xx_intr_dispatch(struct irqframe *frame);
    111 
    112 #define VIC1REG(reg)	*((volatile u_int32_t*) (EP93XX_AHB_VBASE + \
    113 	EP93XX_AHB_VIC1 + (reg)))
    114 #define VIC2REG(reg)	*((volatile u_int32_t*) (EP93XX_AHB_VBASE + \
    115 	EP93XX_AHB_VIC2 + (reg)))
    116 
    117 static void
    118 ep93xx_set_intrmask(u_int32_t vic1_irqs, u_int32_t vic2_irqs)
    119 {
    120 	VIC1REG(EP93XX_VIC_IntEnClear) = vic1_irqs;
    121 	VIC1REG(EP93XX_VIC_IntEnable) = vic1_intr_enabled & ~vic1_irqs;
    122 	VIC2REG(EP93XX_VIC_IntEnClear) = vic2_irqs;
    123 	VIC2REG(EP93XX_VIC_IntEnable) = vic2_intr_enabled & ~vic2_irqs;
    124 }
    125 
    126 static void
    127 ep93xx_enable_irq(int irq)
    128 {
    129 	if (irq < VIC_NIRQ) {
    130 		vic1_intr_enabled |= (1U << irq);
    131 		VIC1REG(EP93XX_VIC_IntEnable) = (1U << irq);
    132 	} else {
    133 		vic2_intr_enabled |= (1U << (irq - VIC_NIRQ));
    134 		VIC2REG(EP93XX_VIC_IntEnable) = (1U << (irq - VIC_NIRQ));
    135 	}
    136 }
    137 
    138 static __inline void
    139 ep93xx_disable_irq(int irq)
    140 {
    141 	if (irq < VIC_NIRQ) {
    142 		vic1_intr_enabled &= ~(1U << irq);
    143 		VIC1REG(EP93XX_VIC_IntEnClear) = (1U << irq);
    144 	} else {
    145 		vic2_intr_enabled &= ~(1U << (irq - VIC_NIRQ));
    146 		VIC2REG(EP93XX_VIC_IntEnClear) = (1U << (irq - VIC_NIRQ));
    147 	}
    148 }
    149 
    150 /*
    151  * NOTE: This routine must be called with interrupts disabled in the CPSR.
    152  */
    153 static void
    154 ep93xx_intr_calculate_masks(void)
    155 {
    156 	struct intrq *iq;
    157 	struct intrhand *ih;
    158 	int irq, ipl;
    159 
    160 	/* First, figure out which IPLs each IRQ has. */
    161 	for (irq = 0; irq < NIRQ; irq++) {
    162 		int levels = 0;
    163 		iq = &intrq[irq];
    164 		ep93xx_disable_irq(irq);
    165 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    166 		     ih = TAILQ_NEXT(ih, ih_list))
    167 			levels |= (1U << ih->ih_ipl);
    168 		iq->iq_levels = levels;
    169 	}
    170 
    171 	/* Next, figure out which IRQs are used by each IPL. */
    172 	for (ipl = 0; ipl < NIPL; ipl++) {
    173 		int vic1_irqs = 0;
    174 		int vic2_irqs = 0;
    175 		for (irq = 0; irq < VIC_NIRQ; irq++) {
    176 			if (intrq[irq].iq_levels & (1U << ipl))
    177 				vic1_irqs |= (1U << irq);
    178 		}
    179 		vic1_imask[ipl] = vic1_irqs;
    180 		for (irq = 0; irq < VIC_NIRQ; irq++) {
    181 			if (intrq[irq + VIC_NIRQ].iq_levels & (1U << ipl))
    182 				vic2_irqs |= (1U << irq);
    183 		}
    184 		vic2_imask[ipl] = vic2_irqs;
    185 	}
    186 
    187 	vic1_imask[IPL_NONE] = 0;
    188 	vic2_imask[IPL_NONE] = 0;
    189 
    190 	/*
    191 	 * Initialize the soft interrupt masks to block themselves.
    192 	 */
    193 	vic1_imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
    194 	vic1_imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
    195 	vic1_imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
    196 	vic1_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 	vic1_imask[IPL_SOFTCLOCK] |= vic1_imask[IPL_SOFT];
    204 	vic2_imask[IPL_SOFTCLOCK] |= vic2_imask[IPL_SOFT];
    205 
    206 	/*
    207 	 * splsoftnet() must also block splsoftclock(), since we don't
    208 	 * want timer-driven network events to occur while we're
    209 	 * processing incoming packets.
    210 	 */
    211 	vic1_imask[IPL_SOFTNET] |= vic1_imask[IPL_SOFTCLOCK];
    212 	vic2_imask[IPL_SOFTNET] |= vic2_imask[IPL_SOFTCLOCK];
    213 
    214 	/*
    215 	 * Enforce a heirarchy that gives "slow" device (or devices with
    216 	 * limited input buffer space/"real-time" requirements) a better
    217 	 * chance at not dropping data.
    218 	 */
    219 	vic1_imask[IPL_BIO] |= vic1_imask[IPL_SOFTNET];
    220 	vic2_imask[IPL_BIO] |= vic2_imask[IPL_SOFTNET];
    221 	vic1_imask[IPL_NET] |= vic1_imask[IPL_BIO];
    222 	vic2_imask[IPL_NET] |= vic2_imask[IPL_BIO];
    223 	vic1_imask[IPL_SOFTSERIAL] |= vic1_imask[IPL_NET];
    224 	vic2_imask[IPL_SOFTSERIAL] |= vic2_imask[IPL_NET];
    225 	vic1_imask[IPL_TTY] |= vic1_imask[IPL_SOFTSERIAL];
    226 	vic2_imask[IPL_TTY] |= vic2_imask[IPL_SOFTSERIAL];
    227 
    228 	/*
    229 	 * splvm() blocks all interrupts that use the kernel memory
    230 	 * allocation facilities.
    231 	 */
    232 	vic1_imask[IPL_VM] |= vic1_imask[IPL_TTY];
    233 	vic2_imask[IPL_VM] |= vic2_imask[IPL_TTY];
    234 
    235 	/*
    236 	 * Audio devices are not allowed to perform memory allocation
    237 	 * in their interrupt routines, and they have fairly "real-time"
    238 	 * requirements, so give them a high interrupt priority.
    239 	 */
    240 	vic1_imask[IPL_AUDIO] |= vic1_imask[IPL_VM];
    241 	vic2_imask[IPL_AUDIO] |= vic2_imask[IPL_VM];
    242 
    243 	/*
    244 	 * splclock() must block anything that uses the scheduler.
    245 	 */
    246 	vic1_imask[IPL_CLOCK] |= vic1_imask[IPL_AUDIO];
    247 	vic2_imask[IPL_CLOCK] |= vic2_imask[IPL_AUDIO];
    248 
    249 	/*
    250 	 * No separate statclock on the EP93xx.
    251 	 */
    252 	vic1_imask[IPL_STATCLOCK] |= vic1_imask[IPL_CLOCK];
    253 	vic2_imask[IPL_STATCLOCK] |= vic2_imask[IPL_CLOCK];
    254 
    255 	/*
    256 	 * serial uarts have small buffers that need low-latency servicing
    257 	 */
    258 	vic1_imask[IPL_SERIAL] |= vic1_imask[IPL_STATCLOCK];
    259 	vic2_imask[IPL_SERIAL] |= vic2_imask[IPL_STATCLOCK];
    260 
    261 	/*
    262 	 * splhigh() must block "everything".
    263 	 */
    264 	vic1_imask[IPL_HIGH] |= vic1_imask[IPL_SERIAL];
    265 	vic2_imask[IPL_HIGH] |= vic2_imask[IPL_SERIAL];
    266 
    267 	/*
    268 	 * Now compute which IRQs must be blocked when servicing any
    269 	 * given IRQ.
    270 	 */
    271 	for (irq = 0; irq < NIRQ; irq++) {
    272 		int	vic1_irqs;
    273 		int	vic2_irqs;
    274 
    275 		if (irq < VIC_NIRQ) {
    276 			vic1_irqs = (1U << irq);
    277 			vic2_irqs = 0;
    278 		} else {
    279 			vic1_irqs = 0;
    280 			vic2_irqs = (1U << (irq - VIC_NIRQ));
    281 		}
    282 		iq = &intrq[irq];
    283 		if (TAILQ_FIRST(&iq->iq_list) != NULL)
    284 			ep93xx_enable_irq(irq);
    285 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    286 		     ih = TAILQ_NEXT(ih, ih_list)) {
    287 			vic1_irqs |= vic1_imask[ih->ih_ipl];
    288 			vic2_irqs |= vic2_imask[ih->ih_ipl];
    289 		}
    290 		iq->iq_vic1_mask = vic1_irqs;
    291 		iq->iq_vic2_mask = vic2_irqs;
    292 	}
    293 }
    294 
    295 static void
    296 ep93xx_do_pending(void)
    297 {
    298 	static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
    299 	int	new;
    300 	u_int	oldirqstate;
    301 
    302 	if (__cpu_simple_lock_try(&processing) == 0)
    303 		return;
    304 
    305 	new = current_spl_level;
    306 
    307 	oldirqstate = disable_interrupts(I32_bit);
    308 
    309 #define	DO_SOFTINT(si)							\
    310 	if ((ipending & ~vic1_imask[new]) & SI_TO_IRQBIT(si)) {		\
    311 		ipending &= ~SI_TO_IRQBIT(si);				\
    312 		current_spl_level = si_to_ipl[(si)];			\
    313 		restore_interrupts(oldirqstate);			\
    314 		softintr_dispatch(si);					\
    315 		oldirqstate = disable_interrupts(I32_bit);		\
    316 		current_spl_level = new;				\
    317 	}
    318 
    319 	DO_SOFTINT(SI_SOFTSERIAL);
    320 	DO_SOFTINT(SI_SOFTNET);
    321 	DO_SOFTINT(SI_SOFTCLOCK);
    322 	DO_SOFTINT(SI_SOFT);
    323 
    324 	__cpu_simple_unlock(&processing);
    325 
    326 	restore_interrupts(oldirqstate);
    327 }
    328 
    329 __inline void
    330 splx(int new)
    331 {
    332 	int	old;
    333 	u_int	oldirqstate;
    334 
    335 	oldirqstate = disable_interrupts(I32_bit);
    336 	old = current_spl_level;
    337 	current_spl_level = new;
    338 	if (new != hardware_spl_level) {
    339 		hardware_spl_level = new;
    340 		ep93xx_set_intrmask(vic1_imask[new], vic2_imask[new]);
    341 	}
    342 	restore_interrupts(oldirqstate);
    343 
    344 	/* If there are software interrupts to process, do it. */
    345 	if ((ipending & INT_SWMASK) & ~vic1_imask[new])
    346 		ep93xx_do_pending();
    347 }
    348 
    349 int
    350 _splraise(int ipl)
    351 {
    352 	int	old;
    353 	u_int	oldirqstate;
    354 
    355 	oldirqstate = disable_interrupts(I32_bit);
    356 	old = current_spl_level;
    357 	current_spl_level = ipl;
    358 	restore_interrupts(oldirqstate);
    359 	return (old);
    360 }
    361 
    362 int
    363 _spllower(int ipl)
    364 {
    365 	int	old = current_spl_level;
    366 
    367 	if (old <= ipl)
    368 		return (old);
    369 	splx(ipl);
    370 	return (old);
    371 }
    372 
    373 void
    374 _setsoftintr(int si)
    375 {
    376 	u_int	oldirqstate;
    377 
    378 	oldirqstate = disable_interrupts(I32_bit);
    379 	ipending |= SI_TO_IRQBIT(si);
    380 	restore_interrupts(oldirqstate);
    381 
    382 	/* Process unmasked pending soft interrupts. */
    383 	if ((ipending & INT_SWMASK) & ~vic1_imask[current_spl_level])
    384 		ep93xx_do_pending();
    385 }
    386 
    387 /*
    388  * ep93xx_intr_init:
    389  *
    390  *	Initialize the rest of the interrupt subsystem, making it
    391  *	ready to handle interrupts from devices.
    392  */
    393 void
    394 ep93xx_intr_init(void)
    395 {
    396 	struct intrq *iq;
    397 	int i;
    398 
    399 	vic1_intr_enabled = 0;
    400 	vic2_intr_enabled = 0;
    401 
    402 	for (i = 0; i < NIRQ; i++) {
    403 		iq = &intrq[i];
    404 		TAILQ_INIT(&iq->iq_list);
    405 
    406 		sprintf(iq->iq_name, "irq %d", i);
    407 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
    408 				     NULL, (i < VIC_NIRQ ? "vic1" : "vic2"),
    409 		                     iq->iq_name);
    410 	}
    411 	current_intr_depth = 0;
    412 	current_spl_level = 0;
    413 	hardware_spl_level = 0;
    414 
    415 	/* All interrupts should use IRQ not FIQ */
    416 	VIC1REG(EP93XX_VIC_IntSelect) = 0;
    417 	VIC2REG(EP93XX_VIC_IntSelect) = 0;
    418 
    419 	ep93xx_intr_calculate_masks();
    420 
    421 	/* Enable IRQs (don't yet use FIQs). */
    422 	enable_interrupts(I32_bit);
    423 }
    424 
    425 void *
    426 ep93xx_intr_establish(int irq, int ipl, int (*ih_func)(void *), void *arg)
    427 {
    428 	struct intrq*		iq;
    429 	struct intrhand*	ih;
    430 	u_int			oldirqstate;
    431 
    432 	if (irq < 0 || irq > NIRQ)
    433 		panic("ep93xx_intr_establish: IRQ %d out of range", irq);
    434 	if (ipl < 0 || ipl > NIPL)
    435 		panic("ep93xx_intr_establish: IPL %d out of range", ipl);
    436 
    437 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
    438 	if (ih == NULL)
    439 		return (NULL);
    440 
    441 	ih->ih_func = ih_func;
    442 	ih->ih_arg = arg;
    443 	ih->ih_irq = irq;
    444 	ih->ih_ipl = ipl;
    445 
    446 	iq = &intrq[irq];
    447 
    448 	oldirqstate = disable_interrupts(I32_bit);
    449 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
    450 	ep93xx_intr_calculate_masks();
    451 	restore_interrupts(oldirqstate);
    452 
    453 	return (ih);
    454 }
    455 
    456 void
    457 ep93xx_intr_disestablish(void *cookie)
    458 {
    459 	struct intrhand*	ih = cookie;
    460 	struct intrq*		iq = &intrq[ih->ih_irq];
    461 	u_int			oldirqstate;
    462 
    463 	oldirqstate = disable_interrupts(I32_bit);
    464 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
    465 	ep93xx_intr_calculate_masks();
    466 	restore_interrupts(oldirqstate);
    467 }
    468 
    469 void
    470 ep93xx_intr_dispatch(struct clockframe *frame)
    471 {
    472 	struct intrq*		iq;
    473 	struct intrhand*	ih;
    474 	u_int			oldirqstate;
    475 	int			pcpl;
    476 	u_int32_t		vic1_hwpend;
    477 	u_int32_t		vic2_hwpend;
    478 	int			irq;
    479 	u_int32_t		ibit;
    480 
    481 	pcpl = current_spl_level;
    482 
    483 	vic1_hwpend = VIC1REG(EP93XX_VIC_IRQStatus);
    484 	vic2_hwpend = VIC2REG(EP93XX_VIC_IRQStatus);
    485 
    486 	hardware_spl_level = pcpl;
    487 	ep93xx_set_intrmask(vic1_imask[pcpl] | vic1_hwpend,
    488 			     vic2_imask[pcpl] | vic2_hwpend);
    489 
    490 	vic1_hwpend &= ~vic1_imask[pcpl];
    491 	vic2_hwpend &= ~vic2_imask[pcpl];
    492 
    493 	while (vic1_hwpend) {
    494 		irq = ffs(vic1_hwpend) - 1;
    495 		ibit = (1U << irq);
    496 
    497 		iq = &intrq[irq];
    498 		iq->iq_ev.ev_count++;
    499 		uvmexp.intrs++;
    500 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    501 		     ih = TAILQ_NEXT(ih, ih_list)) {
    502 			int	ipl;
    503 
    504 			current_spl_level = ipl = ih->ih_ipl;
    505 			oldirqstate = enable_interrupts(I32_bit);
    506 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    507 			restore_interrupts(oldirqstate);
    508 			vic1_hwpend &= ~ibit;
    509 		}
    510 	}
    511 	while (vic2_hwpend) {
    512 		irq = ffs(vic2_hwpend) - 1;
    513 		ibit = (1U << irq);
    514 
    515 		iq = &intrq[irq + VIC_NIRQ];
    516 		iq->iq_ev.ev_count++;
    517 		uvmexp.intrs++;
    518 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    519 		     ih = TAILQ_NEXT(ih, ih_list)) {
    520 			int	ipl;
    521 
    522 			current_spl_level = ipl = ih->ih_ipl;
    523 			oldirqstate = enable_interrupts(I32_bit);
    524 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    525 			restore_interrupts(oldirqstate);
    526 			vic2_hwpend &= ~ibit;
    527 		}
    528 	}
    529 
    530 	current_spl_level = pcpl;
    531 	hardware_spl_level = pcpl;
    532 	ep93xx_set_intrmask(vic1_imask[pcpl], vic2_imask[pcpl]);
    533 
    534 	/* Check for pendings soft intrs. */
    535 	if ((ipending & INT_SWMASK) & ~vic1_imask[pcpl]) {
    536 		oldirqstate = enable_interrupts(I32_bit);
    537 		ep93xx_do_pending();
    538 		restore_interrupts(oldirqstate);
    539 	}
    540 }
    541