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      1 /*	$NetBSD: sysasic.c,v 1.14 2008/04/28 20:23:16 martin Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2001, 2002 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     26  * POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: sysasic.c,v 1.14 2008/04/28 20:23:16 martin Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/systm.h>
     34 #include <sys/device.h>
     35 #include <sys/syslog.h>
     36 
     37 #include <sh3/exception.h>
     38 
     39 #include <machine/intr.h>
     40 #include <machine/sysasicvar.h>
     41 
     42 #define SYSASIC_INTR_ST		0xa05f6900
     43 #define SYSASIC_INTR_EN(level)	(0xa05f6910 + ((level) << 4))
     44 
     45 #define SYSASIC_IRQ_LEVEL_13	0
     46 #define SYSASIC_IRQ_LEVEL_11	1
     47 #define SYSASIC_IRQ_LEVEL_9	2
     48 #define SYSASIC_IRQ_LEVEL_MAX	2
     49 #define SYSASIC_IRQ_INDEX_TO_IRQ(i)	(13 - 2 * (i))
     50 
     51 /* per-irq */
     52 struct sysasic_intrhand {
     53 	/* for quick check on interrupt */
     54 #define SYSASIC_EVENT_NMAP	((SYSASIC_EVENT_MAX + 1 + (32 - 1)) / 32)
     55 #define SYSASIC_EVENT_INTR_MAP(ev)	((ev) >> 5)
     56 #define SYSASIC_EVENT_INTR_BIT(ev)	((unsigned) 1 << ((ev) & 31))
     57 	unsigned	syh_events[SYSASIC_EVENT_NMAP];	/* enabled */
     58 	unsigned	syh_hndmap[SYSASIC_EVENT_NMAP];	/* handler installed */
     59 
     60 	void	*syh_intc;
     61 	int	syh_idx;
     62 } sysasic_intrhand[SYSASIC_IRQ_LEVEL_MAX + 1];
     63 
     64 /* per-event */
     65 struct	syh_eventhand {
     66 	int	(*hnd_fn)(void *);	/* sub handler */
     67 	void	*hnd_arg;
     68 	struct sysasic_intrhand *hnd_syh;
     69 } sysasic_eventhand[SYSASIC_EVENT_MAX + 1];
     70 
     71 int sysasic_intr(void *);
     72 
     73 const char * __pure
     74 sysasic_intr_string(int irl)
     75 {
     76 
     77 	switch (irl) {
     78 	default:
     79 #ifdef DEBUG
     80 		panic("sysasic_intr_string: unknown IRL%d", irl);
     81 #endif
     82 	case SYSASIC_IRL9:
     83 		return "SH4 IRL 9";
     84 	case SYSASIC_IRL11:
     85 		return "SH4 IRL 11";
     86 	case SYSASIC_IRL13:
     87 		return "SH4 IRL 13";
     88 	}
     89 	/* NOTREACHED */
     90 }
     91 
     92 /*
     93  * Set up an interrupt handler to start being called.
     94  */
     95 void *
     96 sysasic_intr_establish(int event, int ipl, int irl, int (*ih_fun)(void *),
     97     void *ih_arg)
     98 {
     99 	struct sysasic_intrhand *syh;
    100 	struct syh_eventhand *hnd;
    101 	int idx;
    102 	static const int idx2evt[3] = {
    103 		SH_INTEVT_IRL13, SH_INTEVT_IRL11, SH_INTEVT_IRL9
    104 	};
    105 #ifdef DEBUG
    106 	int i;
    107 #endif
    108 
    109 	KDASSERT(event >= 0 && event <= SYSASIC_EVENT_MAX);
    110 	KDASSERT(ih_fun);
    111 
    112 	/*
    113 	 * Dreamcast use SH4 INTC as IRL mode.  If IRQ is specified,
    114 	 * its priority level is fixed.
    115 	 *
    116 	 * We use IPL to specify the IRQ for clearness, that is, we use
    117 	 * a splxxx() and IPL_XXX pair in a device driver.
    118 	 */
    119 	switch (irl) {
    120 	default:
    121 #ifdef DEBUG
    122 		panic("sysasic_intr_establish: unknown IRL %d", irl);
    123 #endif
    124 	case SYSASIC_IRL9:
    125 		idx = SYSASIC_IRQ_LEVEL_9;
    126 		break;
    127 	case SYSASIC_IRL11:
    128 		idx = SYSASIC_IRQ_LEVEL_11;
    129 		break;
    130 	case SYSASIC_IRL13:
    131 		idx = SYSASIC_IRQ_LEVEL_13;
    132 		break;
    133 	}
    134 
    135 	syh = &sysasic_intrhand[idx];
    136 
    137 	if (syh->syh_intc == NULL) {
    138 		syh->syh_idx	= idx;
    139 		syh->syh_intc	= intc_intr_establish(idx2evt[idx], IST_LEVEL,
    140 		    irl, sysasic_intr, syh);
    141 	}
    142 
    143 #ifdef DEBUG
    144 	/* check if the event handler is already installed */
    145 	for (i = 0; i <= SYSASIC_IRQ_LEVEL_MAX; i++)
    146 		if ((sysasic_intrhand[i].syh_hndmap[SYSASIC_EVENT_INTR_MAP(event)] &
    147 		    SYSASIC_EVENT_INTR_BIT(event)) != 0)
    148 			panic("sysasic_intr_establish: event %d already installed irq %d",
    149 			    event, SYSASIC_IRQ_INDEX_TO_IRQ(i));
    150 #endif
    151 
    152 	/* mark this event is established */
    153 	syh->syh_hndmap[SYSASIC_EVENT_INTR_MAP(event)] |=
    154 	    SYSASIC_EVENT_INTR_BIT(event);
    155 
    156 	hnd = &sysasic_eventhand[event];
    157 	hnd->hnd_fn = ih_fun;
    158 	hnd->hnd_arg = ih_arg;
    159 	hnd->hnd_syh = syh;
    160 	sysasic_intr_enable(hnd, 1);
    161 
    162 	return (void *)hnd;
    163 }
    164 
    165 /*
    166  * Deregister an interrupt handler.
    167  */
    168 void
    169 sysasic_intr_disestablish(void *arg)
    170 {
    171 	struct syh_eventhand *hnd = arg;
    172 	struct sysasic_intrhand *syh;
    173 	int event;
    174 	int i;
    175 
    176 	event = hnd - sysasic_eventhand;
    177 	KDASSERT(event >= 0 && event <= SYSASIC_EVENT_MAX);
    178 	syh = hnd->hnd_syh;
    179 
    180 #ifdef DIAGNOSTIC
    181 	if ((syh->syh_hndmap[SYSASIC_EVENT_INTR_MAP(event)] &
    182 	    SYSASIC_EVENT_INTR_BIT(event)) == 0)
    183 		panic("sysasic_intr_disestablish: event %d not installed for irq %d",
    184 		    event, SYSASIC_IRQ_INDEX_TO_IRQ(syh->syh_idx));
    185 #endif
    186 
    187 	sysasic_intr_enable(hnd, 0);
    188 	hnd->hnd_fn = 0;
    189 	hnd->hnd_arg = 0;
    190 	hnd->hnd_syh = 0;
    191 
    192 	syh->syh_hndmap[SYSASIC_EVENT_INTR_MAP(event)] &=
    193 	    ~SYSASIC_EVENT_INTR_BIT(event);
    194 
    195 	/* deinstall intrc if no event exists */
    196 	for (i = 0; i < SYSASIC_EVENT_NMAP; i++)
    197 		if (syh->syh_hndmap[i])
    198 			return;
    199 	intc_intr_disestablish(syh->syh_intc);
    200 	syh->syh_intc = 0;
    201 }
    202 
    203 void
    204 sysasic_intr_enable(void *arg, int on)
    205 {
    206 	struct syh_eventhand *hnd = arg;
    207 	struct sysasic_intrhand *syh;
    208 	int event;
    209 	volatile uint32_t *masks, *stats;
    210 	int evmap;
    211 	unsigned evbit;
    212 
    213 	event = hnd - sysasic_eventhand;
    214 	KDASSERT(event >= 0 && event <= SYSASIC_EVENT_MAX);
    215 	syh = hnd->hnd_syh;
    216 
    217 #ifdef DIAGNOSTIC
    218 	if ((syh->syh_hndmap[SYSASIC_EVENT_INTR_MAP(event)] &
    219 	    SYSASIC_EVENT_INTR_BIT(event)) == 0)
    220 		panic("sysasic_intr_enable: event %d not installed for irq %d",
    221 		    event, SYSASIC_IRQ_INDEX_TO_IRQ(syh->syh_idx));
    222 #endif
    223 
    224 	masks = (volatile uint32_t *) SYSASIC_INTR_EN(syh->syh_idx);
    225 	stats = (volatile uint32_t *) SYSASIC_INTR_ST;
    226 	evmap = SYSASIC_EVENT_INTR_MAP(event);
    227 	evbit = SYSASIC_EVENT_INTR_BIT(event);
    228 
    229 	if (on) {
    230 		/* clear pending event if any */
    231 		stats[evmap] = evbit;
    232 
    233 		/* set event map */
    234 		syh->syh_events[evmap] |= evbit;
    235 
    236 		/* enable interrupt */
    237 		masks[evmap] = syh->syh_events[evmap];
    238 	} else {
    239 		/* disable interrupt */
    240 		masks[evmap] = syh->syh_events[evmap] & ~evbit;
    241 
    242 		/* clear pending event if any */
    243 		stats[evmap] = evbit;
    244 
    245 		/* clear event map */
    246 		syh->syh_events[evmap] &= ~evbit;
    247 	}
    248 }
    249 
    250 int
    251 sysasic_intr(void *arg)
    252 {
    253 	struct sysasic_intrhand *syh = arg;
    254 	unsigned ev;
    255 	int n, pos;
    256 	uint32_t *evwatched;
    257 	volatile uint32_t *evmap;
    258 	struct syh_eventhand *evh;
    259 #ifdef DEBUG
    260 	int handled = 0;
    261 	static int reportcnt = 10;
    262 #endif
    263 
    264 	/* bitmap of watched events */
    265 	evwatched = syh->syh_events;
    266 
    267 	/* status / clear */
    268 	evmap = (volatile uint32_t *) SYSASIC_INTR_ST;
    269 
    270 	for (n = 0; n < (SYSASIC_EVENT_NMAP << 5); n |= 31, n++, evmap++) {
    271 		if ((ev = *evwatched++) && (ev &= *evmap)) {
    272 
    273 			/* clear interrupts */
    274 			*evmap = ev;
    275 
    276 			n--;	/* to point at current bit after  n += pos */
    277 
    278 			/* call handlers */
    279 			do {
    280 				pos = ffs(ev);
    281 				n += pos;
    282 #ifdef __OPTIMIZE__
    283 				/* optimized, assuming 1 <= pos <= 32 */
    284 				__asm("shld	%2,%0"
    285 				    : "=r" (ev) : "0" (ev), "r" (-pos));
    286 #else
    287 				/* ``shift count >= bit width'' is undefined */
    288 				if (pos >= 32)
    289 					ev = 0;
    290 				else
    291 					ev >>= pos;
    292 #endif
    293 
    294 				evh = &sysasic_eventhand[n];
    295 #ifdef DEBUG
    296 				KDASSERT(evh->hnd_fn);
    297 				if ((*evh->hnd_fn)(evh->hnd_arg))
    298 					handled = 1;
    299 #else
    300 				(*evh->hnd_fn)(evh->hnd_arg);
    301 #endif
    302 			} while (ev);
    303 		}
    304 	}
    305 
    306 #ifdef DEBUG
    307 	if (!handled && reportcnt > 0) {
    308 		reportcnt--;
    309 		log(LOG_ERR, "sysasic_intr: stray irq%d interrupt%s\n",
    310 		    SYSASIC_IRQ_INDEX_TO_IRQ(syh->syh_idx),
    311 		    reportcnt == 0 ? "; stopped logging" : "");
    312 	}
    313 #endif
    314 
    315 	return 0;
    316 }
    317