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shared_intr.c revision 1.16
      1 /* $NetBSD: shared_intr.c,v 1.16 2001/07/27 00:25:19 thorpej Exp $ */
      2 
      3 /*
      4  * Copyright (c) 1996 Carnegie-Mellon University.
      5  * All rights reserved.
      6  *
      7  * Authors: Chris G. Demetriou
      8  *
      9  * Permission to use, copy, modify and distribute this software and
     10  * its documentation is hereby granted, provided that both the copyright
     11  * notice and this permission notice appear in all copies of the
     12  * software, derivative works or modified versions, and any portions
     13  * thereof, and that both notices appear in supporting documentation.
     14  *
     15  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     16  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     17  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     18  *
     19  * Carnegie Mellon requests users of this software to return to
     20  *
     21  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     22  *  School of Computer Science
     23  *  Carnegie Mellon University
     24  *  Pittsburgh PA 15213-3890
     25  *
     26  * any improvements or extensions that they make and grant Carnegie the
     27  * rights to redistribute these changes.
     28  */
     29 
     30 /*
     31  * Common shared-interrupt-line functionality.
     32  */
     33 
     34 #include <sys/cdefs.h>			/* RCS ID & Copyright macro defns */
     35 
     36 __KERNEL_RCSID(0, "$NetBSD: shared_intr.c,v 1.16 2001/07/27 00:25:19 thorpej Exp $");
     37 
     38 #include <sys/param.h>
     39 #include <sys/kernel.h>
     40 #include <sys/systm.h>
     41 #include <sys/malloc.h>
     42 #include <sys/syslog.h>
     43 #include <sys/queue.h>
     44 
     45 #include <machine/intr.h>
     46 
     47 static const char *intr_typename __P((int));
     48 
     49 static const char *
     50 intr_typename(int type)
     51 {
     52 
     53 	switch (type) {
     54 	case IST_UNUSABLE:
     55 		return ("disabled");
     56 	case IST_NONE:
     57 		return ("none");
     58 	case IST_PULSE:
     59 		return ("pulsed");
     60 	case IST_EDGE:
     61 		return ("edge-triggered");
     62 	case IST_LEVEL:
     63 		return ("level-triggered");
     64 	}
     65 	panic("intr_typename: unknown type %d", type);
     66 }
     67 
     68 struct alpha_shared_intr *
     69 alpha_shared_intr_alloc(unsigned int n, unsigned int namesize)
     70 {
     71 	struct alpha_shared_intr *intr;
     72 	unsigned int i;
     73 
     74 	intr = malloc(n * sizeof (struct alpha_shared_intr), M_DEVBUF,
     75 	    cold ? M_NOWAIT : M_WAITOK);
     76 	if (intr == NULL)
     77 		panic("alpha_shared_intr_alloc: couldn't malloc intr");
     78 
     79 	for (i = 0; i < n; i++) {
     80 		TAILQ_INIT(&intr[i].intr_q);
     81 		intr[i].intr_sharetype = IST_NONE;
     82 		intr[i].intr_dfltsharetype = IST_NONE;
     83 		intr[i].intr_nstrays = 0;
     84 		intr[i].intr_maxstrays = 5;
     85 		intr[i].intr_private = NULL;
     86 		if (namesize != 0) {
     87 			intr[i].intr_string = malloc(namesize, M_DEVBUF,
     88 			    cold ? M_NOWAIT : M_WAITOK);
     89 			if (intr[i].intr_string == NULL)
     90 				panic("alpha_shared_intr_alloc: couldn't "
     91 				    "malloc intr string");
     92 		} else
     93 			intr[i].intr_string = NULL;
     94 	}
     95 
     96 	return (intr);
     97 }
     98 
     99 int
    100 alpha_shared_intr_dispatch(struct alpha_shared_intr *intr, unsigned int num)
    101 {
    102 	struct alpha_shared_intrhand *ih;
    103 	int rv, handled;
    104 
    105 	atomic_add_ulong(&intr[num].intr_evcnt.ev_count, 1);
    106 
    107 	ih = intr[num].intr_q.tqh_first;
    108 	handled = 0;
    109 	while (ih != NULL) {
    110 
    111 		/*
    112 		 * The handler returns one of three values:
    113 		 *   0:	This interrupt wasn't for me.
    114 		 *   1: This interrupt was for me.
    115 		 *  -1: This interrupt might have been for me, but I can't say
    116 		 *      for sure.
    117 		 */
    118 		rv = (*ih->ih_fn)(ih->ih_arg);
    119 
    120 		handled = handled || (rv != 0);
    121 		ih = ih->ih_q.tqe_next;
    122 	}
    123 
    124 	return (handled);
    125 }
    126 
    127 void *
    128 alpha_shared_intr_establish(struct alpha_shared_intr *intr, unsigned int num,
    129     int type, int level, int (*fn)(void *), void *arg, const char *basename)
    130 {
    131 	struct alpha_shared_intrhand *ih;
    132 
    133 	if (intr[num].intr_sharetype == IST_UNUSABLE) {
    134 		printf("alpha_shared_intr_establish: %s %d: unusable\n",
    135 		    basename, num);
    136 		return NULL;
    137 	}
    138 
    139 	/* no point in sleeping unless someone can free memory. */
    140 	ih = malloc(sizeof *ih, M_DEVBUF, cold ? M_NOWAIT : M_WAITOK);
    141 	if (ih == NULL)
    142 		panic("alpha_shared_intr_establish: can't malloc intrhand");
    143 
    144 #ifdef DIAGNOSTIC
    145 	if (type == IST_NONE)
    146 		panic("alpha_shared_intr_establish: bogus type");
    147 #endif
    148 
    149 	switch (intr[num].intr_sharetype) {
    150 	case IST_EDGE:
    151 	case IST_LEVEL:
    152 		if (type == intr[num].intr_sharetype)
    153 			break;
    154 	case IST_PULSE:
    155 		if (type != IST_NONE) {
    156 			if (intr[num].intr_q.tqh_first == NULL) {
    157 				printf("alpha_shared_intr_establish: %s %d: warning: using %s on %s\n",
    158 				    basename, num, intr_typename(type),
    159 				    intr_typename(intr[num].intr_sharetype));
    160 				type = intr[num].intr_sharetype;
    161 			} else {
    162 				panic("alpha_shared_intr_establish: %s %d: can't share %s with %s",
    163 				    basename, num, intr_typename(type),
    164 				    intr_typename(intr[num].intr_sharetype));
    165 			}
    166 		}
    167 		break;
    168 
    169 	case IST_NONE:
    170 		/* not currently used; safe */
    171 		break;
    172 	}
    173 
    174 	ih->ih_intrhead = intr;
    175 	ih->ih_fn = fn;
    176 	ih->ih_arg = arg;
    177 	ih->ih_level = level;
    178 	ih->ih_num = num;
    179 
    180 	intr[num].intr_sharetype = type;
    181 	TAILQ_INSERT_TAIL(&intr[num].intr_q, ih, ih_q);
    182 
    183 	return (ih);
    184 }
    185 
    186 void
    187 alpha_shared_intr_disestablish(struct alpha_shared_intr *intr, void *cookie,
    188     const char *basename)
    189 {
    190 	struct alpha_shared_intrhand *ih = cookie;
    191 	unsigned int num = ih->ih_num;
    192 
    193 	/*
    194 	 * Just remove it from the list and free the entry.  We let
    195 	 * the caller deal with resetting the share type, if appropriate.
    196 	 */
    197 	TAILQ_REMOVE(&intr[num].intr_q, ih, ih_q);
    198 }
    199 
    200 int
    201 alpha_shared_intr_get_sharetype(struct alpha_shared_intr *intr,
    202     unsigned int num)
    203 {
    204 
    205 	return (intr[num].intr_sharetype);
    206 }
    207 
    208 int
    209 alpha_shared_intr_isactive(struct alpha_shared_intr *intr, unsigned int num)
    210 {
    211 
    212 	return (intr[num].intr_q.tqh_first != NULL);
    213 }
    214 
    215 int
    216 alpha_shared_intr_firstactive(struct alpha_shared_intr *intr, unsigned int num)
    217 {
    218 
    219 	return (intr[num].intr_q.tqh_first != NULL &&
    220 		intr[num].intr_q.tqh_first->ih_q.tqe_next == NULL);
    221 }
    222 
    223 void
    224 alpha_shared_intr_set_dfltsharetype(struct alpha_shared_intr *intr,
    225     unsigned int num, int newdfltsharetype)
    226 {
    227 
    228 #ifdef DIAGNOSTIC
    229 	if (alpha_shared_intr_isactive(intr, num))
    230 		panic("alpha_shared_intr_set_dfltsharetype on active intr");
    231 #endif
    232 
    233 	intr[num].intr_dfltsharetype = newdfltsharetype;
    234 	intr[num].intr_sharetype = intr[num].intr_dfltsharetype;
    235 }
    236 
    237 void
    238 alpha_shared_intr_set_maxstrays(struct alpha_shared_intr *intr,
    239     unsigned int num, int newmaxstrays)
    240 {
    241 	int s = splhigh();
    242 	intr[num].intr_maxstrays = newmaxstrays;
    243 	intr[num].intr_nstrays = 0;
    244 	splx(s);
    245 }
    246 
    247 void
    248 alpha_shared_intr_stray(struct alpha_shared_intr *intr, unsigned int num,
    249     const char *basename)
    250 {
    251 
    252 	intr[num].intr_nstrays++;
    253 
    254 	if (intr[num].intr_maxstrays == 0)
    255 		return;
    256 
    257 	if (intr[num].intr_nstrays <= intr[num].intr_maxstrays)
    258 		log(LOG_ERR, "stray %s %d%s\n", basename, num,
    259 		    intr[num].intr_nstrays >= intr[num].intr_maxstrays ?
    260 		      "; stopped logging" : "");
    261 }
    262 
    263 void
    264 alpha_shared_intr_set_private(struct alpha_shared_intr *intr,
    265     unsigned int num, void *v)
    266 {
    267 
    268 	intr[num].intr_private = v;
    269 }
    270 
    271 void *
    272 alpha_shared_intr_get_private(struct alpha_shared_intr *intr,
    273     unsigned int num)
    274 {
    275 
    276 	return (intr[num].intr_private);
    277 }
    278 
    279 struct evcnt *
    280 alpha_shared_intr_evcnt(struct alpha_shared_intr *intr,
    281     unsigned int num)
    282 {
    283 
    284 	return (&intr[num].intr_evcnt);
    285 }
    286 
    287 char *
    288 alpha_shared_intr_string(struct alpha_shared_intr *intr,
    289     unsigned int num)
    290 {
    291 
    292 	return (intr[num].intr_string);
    293 }
    294