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i80321_icu.c revision 1.7
      1 /*	$NetBSD: i80321_icu.c,v 1.7 2003/06/16 20:00:58 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 #ifndef EVBARM_SPL_NOINLINE
     39 #define	EVBARM_SPL_NOINLINE
     40 #endif
     41 
     42 /*
     43  * Interrupt support for the Intel i80321 I/O Processor.
     44  */
     45 
     46 #include <sys/param.h>
     47 #include <sys/systm.h>
     48 #include <sys/malloc.h>
     49 
     50 #include <uvm/uvm_extern.h>
     51 
     52 #include <machine/bus.h>
     53 #include <machine/intr.h>
     54 
     55 #include <arm/cpufunc.h>
     56 
     57 #include <arm/xscale/i80321reg.h>
     58 #include <arm/xscale/i80321var.h>
     59 
     60 /* Interrupt handler queues. */
     61 struct intrq intrq[NIRQ];
     62 
     63 /* Interrupts to mask at each level. */
     64 int i80321_imask[NIPL];
     65 
     66 /* Current interrupt priority level. */
     67 __volatile int current_spl_level;
     68 
     69 /* Interrupts pending. */
     70 __volatile int i80321_ipending;
     71 
     72 /* Software copy of the IRQs we have enabled. */
     73 __volatile uint32_t intr_enabled;
     74 
     75 /* Mask if interrupts steered to FIQs. */
     76 uint32_t intr_steer;
     77 
     78 /*
     79  * Map a software interrupt queue index (to the unused bits in the
     80  * ICU registers -- XXX will need to revisit this if those bits are
     81  * ever used in future steppings).
     82  */
     83 static const uint32_t si_to_irqbit[SI_NQUEUES] = {
     84 	ICU_INT_bit26,		/* SI_SOFT */
     85 	ICU_INT_bit22,		/* SI_SOFTCLOCK */
     86 	ICU_INT_bit5,		/* SI_SOFTNET */
     87 	ICU_INT_bit4,		/* SI_SOFTSERIAL */
     88 };
     89 
     90 #define	SI_TO_IRQBIT(si)	(1U << si_to_irqbit[(si)])
     91 
     92 /*
     93  * Map a software interrupt queue to an interrupt priority level.
     94  */
     95 static const int si_to_ipl[SI_NQUEUES] = {
     96 	IPL_SOFT,		/* SI_SOFT */
     97 	IPL_SOFTCLOCK,		/* SI_SOFTCLOCK */
     98 	IPL_SOFTNET,		/* SI_SOFTNET */
     99 	IPL_SOFTSERIAL,		/* SI_SOFTSERIAL */
    100 };
    101 
    102 /*
    103  * Interrupt bit names.
    104  */
    105 const char *i80321_irqnames[] = {
    106 	"DMA0 EOT",
    107 	"DMA0 EOC",
    108 	"DMA1 EOT",
    109 	"DMA1 EOC",
    110 	"irq 4",
    111 	"irq 5",
    112 	"AAU EOT",
    113 	"AAU EOC",
    114 	"core PMU",
    115 	"TMR0 (hardclock)",
    116 	"TMR1",
    117 	"I2C0",
    118 	"I2C1",
    119 	"MU",
    120 	"BIST",
    121 	"periph PMU",
    122 	"XScale PMU",
    123 	"BIU error",
    124 	"ATU error",
    125 	"MCU error",
    126 	"DMA0 error",
    127 	"DMA1 error",
    128 	"irq 22",
    129 	"AAU error",
    130 	"MU error",
    131 	"SSP",
    132 	"irq 26",
    133 	"irq 27",
    134 	"irq 28",
    135 	"irq 29",
    136 	"irq 30",
    137 	"irq 31",
    138 };
    139 
    140 void	i80321_intr_dispatch(struct clockframe *frame);
    141 
    142 static __inline uint32_t
    143 i80321_iintsrc_read(void)
    144 {
    145 	uint32_t iintsrc;
    146 
    147 	__asm __volatile("mrc p6, 0, %0, c8, c0, 0"
    148 		: "=r" (iintsrc));
    149 
    150 	/*
    151 	 * The IINTSRC register shows bits that are active even
    152 	 * if they are masked in INTCTL, so we have to mask them
    153 	 * off with the interrupts we consider enabled.
    154 	 */
    155 	return (iintsrc & intr_enabled);
    156 }
    157 
    158 static __inline void
    159 i80321_set_intrsteer(void)
    160 {
    161 
    162 	__asm __volatile("mcr p6, 0, %0, c4, c0, 0"
    163 		:
    164 		: "r" (intr_steer & ICU_INT_HWMASK));
    165 }
    166 
    167 static __inline void
    168 i80321_enable_irq(int irq)
    169 {
    170 
    171 	intr_enabled |= (1U << irq);
    172 	i80321_set_intrmask();
    173 }
    174 
    175 static __inline void
    176 i80321_disable_irq(int irq)
    177 {
    178 
    179 	intr_enabled &= ~(1U << irq);
    180 	i80321_set_intrmask();
    181 }
    182 
    183 /*
    184  * NOTE: This routine must be called with interrupts disabled in the CPSR.
    185  */
    186 static void
    187 i80321_intr_calculate_masks(void)
    188 {
    189 	struct intrq *iq;
    190 	struct intrhand *ih;
    191 	int irq, ipl;
    192 
    193 	/* First, figure out which IPLs each IRQ has. */
    194 	for (irq = 0; irq < NIRQ; irq++) {
    195 		int levels = 0;
    196 		iq = &intrq[irq];
    197 		i80321_disable_irq(irq);
    198 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    199 		     ih = TAILQ_NEXT(ih, ih_list))
    200 			levels |= (1U << ih->ih_ipl);
    201 		iq->iq_levels = levels;
    202 	}
    203 
    204 	/* Next, figure out which IRQs are used by each IPL. */
    205 	for (ipl = 0; ipl < NIPL; ipl++) {
    206 		int irqs = 0;
    207 		for (irq = 0; irq < NIRQ; irq++) {
    208 			if (intrq[irq].iq_levels & (1U << ipl))
    209 				irqs |= (1U << irq);
    210 		}
    211 		i80321_imask[ipl] = irqs;
    212 	}
    213 
    214 	i80321_imask[IPL_NONE] = 0;
    215 
    216 	/*
    217 	 * Initialize the soft interrupt masks to block themselves.
    218 	 */
    219 	i80321_imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
    220 	i80321_imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
    221 	i80321_imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
    222 	i80321_imask[IPL_SOFTSERIAL] = SI_TO_IRQBIT(SI_SOFTSERIAL);
    223 
    224 	/*
    225 	 * splsoftclock() is the only interface that users of the
    226 	 * generic software interrupt facility have to block their
    227 	 * soft intrs, so splsoftclock() must also block IPL_SOFT.
    228 	 */
    229 	i80321_imask[IPL_SOFTCLOCK] |= i80321_imask[IPL_SOFT];
    230 
    231 	/*
    232 	 * splsoftnet() must also block splsoftclock(), since we don't
    233 	 * want timer-driven network events to occur while we're
    234 	 * processing incoming packets.
    235 	 */
    236 	i80321_imask[IPL_SOFTNET] |= i80321_imask[IPL_SOFTCLOCK];
    237 
    238 	/*
    239 	 * Enforce a heirarchy that gives "slow" device (or devices with
    240 	 * limited input buffer space/"real-time" requirements) a better
    241 	 * chance at not dropping data.
    242 	 */
    243 	i80321_imask[IPL_BIO] |= i80321_imask[IPL_SOFTNET];
    244 	i80321_imask[IPL_NET] |= i80321_imask[IPL_BIO];
    245 	i80321_imask[IPL_SOFTSERIAL] |= i80321_imask[IPL_NET];
    246 	i80321_imask[IPL_TTY] |= i80321_imask[IPL_SOFTSERIAL];
    247 
    248 	/*
    249 	 * splvm() blocks all interrupts that use the kernel memory
    250 	 * allocation facilities.
    251 	 */
    252 	i80321_imask[IPL_VM] |= i80321_imask[IPL_TTY];
    253 
    254 	/*
    255 	 * Audio devices are not allowed to perform memory allocation
    256 	 * in their interrupt routines, and they have fairly "real-time"
    257 	 * requirements, so give them a high interrupt priority.
    258 	 */
    259 	i80321_imask[IPL_AUDIO] |= i80321_imask[IPL_VM];
    260 
    261 	/*
    262 	 * splclock() must block anything that uses the scheduler.
    263 	 */
    264 	i80321_imask[IPL_CLOCK] |= i80321_imask[IPL_AUDIO];
    265 
    266 	/*
    267 	 * No separate statclock on the IQ80310.
    268 	 */
    269 	i80321_imask[IPL_STATCLOCK] |= i80321_imask[IPL_CLOCK];
    270 
    271 	/*
    272 	 * splhigh() must block "everything".
    273 	 */
    274 	i80321_imask[IPL_HIGH] |= i80321_imask[IPL_STATCLOCK];
    275 
    276 	/*
    277 	 * XXX We need serial drivers to run at the absolute highest priority
    278 	 * in order to avoid overruns, so serial > high.
    279 	 */
    280 	i80321_imask[IPL_SERIAL] |= i80321_imask[IPL_HIGH];
    281 
    282 	/*
    283 	 * Now compute which IRQs must be blocked when servicing any
    284 	 * given IRQ.
    285 	 */
    286 	for (irq = 0; irq < NIRQ; irq++) {
    287 		int irqs = (1U << irq);
    288 		iq = &intrq[irq];
    289 		if (TAILQ_FIRST(&iq->iq_list) != NULL)
    290 			i80321_enable_irq(irq);
    291 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    292 		     ih = TAILQ_NEXT(ih, ih_list))
    293 			irqs |= i80321_imask[ih->ih_ipl];
    294 		iq->iq_mask = irqs;
    295 	}
    296 }
    297 
    298 __inline void
    299 i80321_do_pending(void)
    300 {
    301 	static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
    302 	int new, oldirqstate;
    303 
    304 	if (__cpu_simple_lock_try(&processing) == 0)
    305 		return;
    306 
    307 	new = current_spl_level;
    308 
    309 	oldirqstate = disable_interrupts(I32_bit);
    310 
    311 #define	DO_SOFTINT(si)							\
    312 	if ((i80321_ipending & ~new) & SI_TO_IRQBIT(si)) {		\
    313 		i80321_ipending &= ~SI_TO_IRQBIT(si);			\
    314 		current_spl_level |= i80321_imask[si_to_ipl[(si)]];	\
    315 		restore_interrupts(oldirqstate);			\
    316 		softintr_dispatch(si);					\
    317 		oldirqstate = disable_interrupts(I32_bit);		\
    318 		current_spl_level = new;				\
    319 	}
    320 
    321 	DO_SOFTINT(SI_SOFTSERIAL);
    322 	DO_SOFTINT(SI_SOFTNET);
    323 	DO_SOFTINT(SI_SOFTCLOCK);
    324 	DO_SOFTINT(SI_SOFT);
    325 
    326 	__cpu_simple_unlock(&processing);
    327 
    328 	restore_interrupts(oldirqstate);
    329 }
    330 
    331 void
    332 splx(int new)
    333 {
    334 
    335 	i80321_splx(new);
    336 }
    337 
    338 int
    339 _spllower(int ipl)
    340 {
    341 
    342 	return (i80321_spllower(ipl));
    343 }
    344 
    345 int
    346 _splraise(int ipl)
    347 {
    348 
    349 	return (i80321_splraise(ipl));
    350 }
    351 
    352 void
    353 _setsoftintr(int si)
    354 {
    355 	int oldirqstate;
    356 
    357 	oldirqstate = disable_interrupts(I32_bit);
    358 	i80321_ipending |= SI_TO_IRQBIT(si);
    359 	restore_interrupts(oldirqstate);
    360 
    361 	/* Process unmasked pending soft interrupts. */
    362 	if ((i80321_ipending & INT_SWMASK) & ~current_spl_level)
    363 		i80321_do_pending();
    364 }
    365 
    366 /*
    367  * i80321_icu_init:
    368  *
    369  *	Initialize the i80321 ICU.  Called early in bootstrap
    370  *	to make sure the ICU is in a pristine state.
    371  */
    372 void
    373 i80321_icu_init(void)
    374 {
    375 
    376 	intr_enabled = 0;	/* All interrupts disabled */
    377 	i80321_set_intrmask();
    378 
    379 	intr_steer = 0;		/* All interrupts steered to IRQ */
    380 	i80321_set_intrsteer();
    381 }
    382 
    383 /*
    384  * i80321_intr_init:
    385  *
    386  *	Initialize the rest of the interrupt subsystem, making it
    387  *	ready to handle interrupts from devices.
    388  */
    389 void
    390 i80321_intr_init(void)
    391 {
    392 	struct intrq *iq;
    393 	int i;
    394 
    395 	intr_enabled = 0;
    396 
    397 	for (i = 0; i < NIRQ; i++) {
    398 		iq = &intrq[i];
    399 		TAILQ_INIT(&iq->iq_list);
    400 
    401 		evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
    402 		    NULL, "iop321", i80321_irqnames[i]);
    403 	}
    404 
    405 	i80321_intr_calculate_masks();
    406 
    407 	/* Enable IRQs (don't yet use FIQs). */
    408 	enable_interrupts(I32_bit);
    409 }
    410 
    411 void *
    412 i80321_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
    413 {
    414 	struct intrq *iq;
    415 	struct intrhand *ih;
    416 	u_int oldirqstate;
    417 
    418 	if (irq < 0 || irq > NIRQ)
    419 		panic("i80321_intr_establish: IRQ %d out of range", irq);
    420 
    421 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
    422 	if (ih == NULL)
    423 		return (NULL);
    424 
    425 	ih->ih_func = func;
    426 	ih->ih_arg = arg;
    427 	ih->ih_ipl = ipl;
    428 	ih->ih_irq = irq;
    429 
    430 	iq = &intrq[irq];
    431 
    432 	/* All IOP321 interrupts are level-triggered. */
    433 	iq->iq_ist = IST_LEVEL;
    434 
    435 	oldirqstate = disable_interrupts(I32_bit);
    436 
    437 	TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
    438 
    439 	i80321_intr_calculate_masks();
    440 
    441 	restore_interrupts(oldirqstate);
    442 
    443 	return (ih);
    444 }
    445 
    446 void
    447 i80321_intr_disestablish(void *cookie)
    448 {
    449 	struct intrhand *ih = cookie;
    450 	struct intrq *iq = &intrq[ih->ih_irq];
    451 	int oldirqstate;
    452 
    453 	oldirqstate = disable_interrupts(I32_bit);
    454 
    455 	TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
    456 
    457 	i80321_intr_calculate_masks();
    458 
    459 	restore_interrupts(oldirqstate);
    460 }
    461 
    462 void
    463 i80321_intr_dispatch(struct clockframe *frame)
    464 {
    465 	struct intrq *iq;
    466 	struct intrhand *ih;
    467 	int oldirqstate, pcpl, irq, ibit, hwpend;
    468 
    469 	pcpl = current_spl_level;
    470 
    471 	hwpend = i80321_iintsrc_read();
    472 
    473 	/*
    474 	 * Disable all the interrupts that are pending.  We will
    475 	 * reenable them once they are processed and not masked.
    476 	 */
    477 	intr_enabled &= ~hwpend;
    478 	i80321_set_intrmask();
    479 
    480 	while (hwpend != 0) {
    481 		irq = ffs(hwpend) - 1;
    482 		ibit = (1U << irq);
    483 
    484 		hwpend &= ~ibit;
    485 
    486 		if (pcpl & ibit) {
    487 			/*
    488 			 * IRQ is masked; mark it as pending and check
    489 			 * the next one.  Note: the IRQ is already disabled.
    490 			 */
    491 			i80321_ipending |= ibit;
    492 			continue;
    493 		}
    494 
    495 		i80321_ipending &= ~ibit;
    496 
    497 		iq = &intrq[irq];
    498 		iq->iq_ev.ev_count++;
    499 		uvmexp.intrs++;
    500 		current_spl_level |= iq->iq_mask;
    501 		oldirqstate = enable_interrupts(I32_bit);
    502 		for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
    503 		     ih = TAILQ_NEXT(ih, ih_list)) {
    504 			(void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
    505 		}
    506 		restore_interrupts(oldirqstate);
    507 
    508 		current_spl_level = pcpl;
    509 
    510 		/* Re-enable this interrupt now that's it's cleared. */
    511 		intr_enabled |= ibit;
    512 		i80321_set_intrmask();
    513 	}
    514 
    515 	/* Check for pendings soft intrs. */
    516 	if ((i80321_ipending & INT_SWMASK) & ~current_spl_level) {
    517 		oldirqstate = enable_interrupts(I32_bit);
    518 		i80321_do_pending();
    519 		restore_interrupts(oldirqstate);
    520 	}
    521 }
    522