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isa_irqhandler.c revision 1.26
      1 /*	$NetBSD: isa_irqhandler.c,v 1.25 2010/12/20 00:25:43 matt Exp $	*/
      2 
      3 /*
      4  * Copyright 1997
      5  * Digital Equipment Corporation. All rights reserved.
      6  *
      7  * This software is furnished under license and may be used and
      8  * copied only in accordance with the following terms and conditions.
      9  * Subject to these conditions, you may download, copy, install,
     10  * use, modify and distribute this software in source and/or binary
     11  * form. No title or ownership is transferred hereby.
     12  *
     13  * 1) Any source code used, modified or distributed must reproduce
     14  *    and retain this copyright notice and list of conditions as
     15  *    they appear in the source file.
     16  *
     17  * 2) No right is granted to use any trade name, trademark, or logo of
     18  *    Digital Equipment Corporation. Neither the "Digital Equipment
     19  *    Corporation" name nor any trademark or logo of Digital Equipment
     20  *    Corporation may be used to endorse or promote products derived
     21  *    from this software without the prior written permission of
     22  *    Digital Equipment Corporation.
     23  *
     24  * 3) This software is provided "AS-IS" and any express or implied
     25  *    warranties, including but not limited to, any implied warranties
     26  *    of merchantability, fitness for a particular purpose, or
     27  *    non-infringement are disclaimed. In no event shall DIGITAL be
     28  *    liable for any damages whatsoever, and in particular, DIGITAL
     29  *    shall not be liable for special, indirect, consequential, or
     30  *    incidental damages or damages for lost profits, loss of
     31  *    revenue or loss of use, whether such damages arise in contract,
     32  *    negligence, tort, under statute, in equity, at law or otherwise,
     33  *    even if advised of the possibility of such damage.
     34  */
     35 
     36 /*
     37  * Copyright (c) 1994-1998 Mark Brinicombe.
     38  * Copyright (c) 1994 Brini.
     39  * All rights reserved.
     40  *
     41  * This code is derived from software written for Brini by Mark Brinicombe
     42  *
     43  * Redistribution and use in source and binary forms, with or without
     44  * modification, are permitted provided that the following conditions
     45  * are met:
     46  * 1. Redistributions of source code must retain the above copyright
     47  *    notice, this list of conditions and the following disclaimer.
     48  * 2. Redistributions in binary form must reproduce the above copyright
     49  *    notice, this list of conditions and the following disclaimer in the
     50  *    documentation and/or other materials provided with the distribution.
     51  * 3. All advertising materials mentioning features or use of this software
     52  *    must display the following acknowledgement:
     53  *	This product includes software developed by Mark Brinicombe
     54  *	for the NetBSD Project.
     55  * 4. The name of the company nor the name of the author may be used to
     56  *    endorse or promote products derived from this software without specific
     57  *    prior written permission.
     58  *
     59  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     60  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     61  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     62  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     63  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     64  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     65  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     66  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     67  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     68  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     69  *
     70  * IRQ/FIQ initialisation, claim, release and handler routines
     71  *
     72  *	from: irqhandler.c
     73  *
     74  * Created      : 30/09/94
     75  */
     76 
     77 #include <sys/cdefs.h>
     78 __KERNEL_RCSID(0, "$NetBSD: isa_irqhandler.c,v 1.25 2010/12/20 00:25:43 matt Exp $");
     79 
     80 #include <sys/param.h>
     81 #include <sys/systm.h>
     82 #include <sys/syslog.h>
     83 #include <sys/malloc.h>
     84 #include <sys/intr.h>
     85 
     86 #include <arm/locore.h>
     87 
     88 #include <machine/irqhandler.h>
     89 
     90 irqhandler_t *irqhandlers[NIRQS];
     91 
     92 u_int current_mask;
     93 u_int actual_mask;
     94 u_int disabled_mask;
     95 u_int irqmasks[NIPL];
     96 
     97 /* Prototypes */
     98 
     99 extern void set_spl_masks(void);
    100 void irq_calculatemasks(void);
    101 void stray_irqhandler(u_int);
    102 
    103 #define WriteWord(a, b) *((volatile unsigned int *)(a)) = (b)
    104 
    105 /*
    106  * void irq_init(void)
    107  *
    108  * Initialise the IRQ/FIQ sub system
    109  */
    110 
    111 void
    112 irq_init(void)
    113 {
    114 	int loop;
    115 
    116 	/* Clear all the IRQ handlers and the irq block masks */
    117 	for (loop = 0; loop < NIRQS; ++loop) {
    118 		irqhandlers[loop] = NULL;
    119 	}
    120 
    121 	/*
    122 	 * Setup the irqmasks for the different Interrupt Priority Levels
    123 	 * We will start with no bits set and these will be updated as handlers
    124 	 * are installed at different IPL's.
    125 	 */
    126 	for (loop = 0; loop < NIPL; ++loop)
    127 		irqmasks[loop] = 0;
    128 
    129 	current_mask = 0x00000000;
    130 	disabled_mask = 0x00000000;
    131 	actual_mask = 0x00000000;
    132 
    133 	set_spl_masks();
    134 
    135 	/* Enable IRQ's and FIQ's */
    136 	enable_interrupts(I32_bit | F32_bit);
    137 }
    138 
    139 
    140 /*
    141  * int irq_claim(int irq, irqhandler_t *handler)
    142  *
    143  * Enable an IRQ and install a handler for it.
    144  */
    145 
    146 int
    147 irq_claim(int irq, irqhandler_t *handler, const char *group, const char *name)
    148 {
    149 
    150 #ifdef DIAGNOSTIC
    151 	/* Sanity check */
    152 	if (handler == NULL)
    153 		panic("NULL interrupt handler");
    154 	if (handler->ih_func == NULL)
    155 		panic("Interrupt handler does not have a function");
    156 #endif	/* DIAGNOSTIC */
    157 
    158 	/*
    159 	 * IRQ_INSTRUCT indicates that we should get the irq number
    160 	 * from the irq structure
    161 	 */
    162 	if (irq == IRQ_INSTRUCT)
    163 		irq = handler->ih_num;
    164 
    165 	/* Make sure the irq number is valid */
    166 	if (irq < 0 || irq >= NIRQS)
    167 		return(-1);
    168 
    169 	/* Make sure the level is valid */
    170 	if (handler->ih_level < 0 || handler->ih_level >= NIPL)
    171     	        return(-1);
    172 
    173 	/* Attach evcnt */
    174 	evcnt_attach_dynamic(&handler->ih_ev, EVCNT_TYPE_INTR, NULL,
    175 	    group, name);
    176 
    177 	/* Attach handler at top of chain */
    178 	handler->ih_next = irqhandlers[irq];
    179 	irqhandlers[irq] = handler;
    180 
    181 	/*
    182 	 * Reset the flags for this handler.
    183 	 * As the handler is now in the chain mark it as active.
    184 	 */
    185 	handler->ih_flags = 0 | IRQ_FLAG_ACTIVE;
    186 
    187 	/*
    188 	 * Record the interrupt number for accounting.
    189 	 * Done here as the accounting number may not be the same as the
    190 	 * IRQ number though for the moment they are
    191 	 */
    192 	handler->ih_num = irq;
    193 
    194 	irq_calculatemasks();
    195 
    196 	enable_irq(irq);
    197 	set_spl_masks();
    198 	return(0);
    199 }
    200 
    201 
    202 /*
    203  * int irq_release(int irq, irqhandler_t *handler)
    204  *
    205  * Disable an IRQ and remove a handler for it.
    206  */
    207 
    208 int
    209 irq_release(int irq, irqhandler_t *handler)
    210 {
    211 	irqhandler_t *irqhand;
    212 	irqhandler_t **prehand;
    213 
    214 	/*
    215 	 * IRQ_INSTRUCT indicates that we should get the irq number
    216 	 * from the irq structure
    217 	 */
    218 	if (irq == IRQ_INSTRUCT)
    219 		irq = handler->ih_num;
    220 
    221 	/* Make sure the irq number is valid */
    222 	if (irq < 0 || irq >= NIRQS)
    223 		return(-1);
    224 
    225 	/* Locate the handler */
    226 	prehand = &irqhandlers[irq];
    227 	irqhand = *prehand;
    228 
    229 	while (irqhand && handler != irqhand) {
    230 		prehand = &irqhand->ih_next;
    231 		irqhand = *prehand;
    232 	}
    233 
    234 	/* Remove the handler if located */
    235 	if (irqhand)
    236 		*prehand = irqhand->ih_next;
    237 	else
    238 		return(-1);
    239 
    240 	/* The handler has been removed from the chain so mark it as inactive */
    241 	irqhand->ih_flags &= ~IRQ_FLAG_ACTIVE;
    242 
    243 	/* Make sure the head of the handler list is active */
    244 	if (irqhandlers[irq])
    245 		irqhandlers[irq]->ih_flags |= IRQ_FLAG_ACTIVE;
    246 
    247 	evcnt_detach(&irqhand->ih_ev);
    248 
    249 	irq_calculatemasks();
    250 
    251 	/*
    252 	 * Disable the appropriate mask bit if there are no handlers left for
    253 	 * this IRQ.
    254 	 */
    255 	if (irqhandlers[irq] == NULL)
    256 		disable_irq(irq);
    257 
    258 	set_spl_masks();
    259 
    260 	return(0);
    261 }
    262 
    263 /* adapted from .../i386/isa/isa_machdep.c */
    264 /*
    265  * Recalculate the interrupt masks from scratch.
    266  * We could code special registry and deregistry versions of this function that
    267  * would be faster, but the code would be nastier, and we don't expect this to
    268  * happen very much anyway.
    269  */
    270 void
    271 irq_calculatemasks(void)
    272 {
    273 	int          irq, level;
    274 	irqhandler_t *ptr;
    275 	int          irqlevel[NIRQS];
    276 
    277 	/* First, figure out which levels each IRQ uses. */
    278 	for (irq = 0; irq < NIRQS; irq++) {
    279 		int levels = 0;
    280 		for (ptr = irqhandlers[irq]; ptr; ptr = ptr->ih_next)
    281 			levels |= 1 << ptr->ih_level;
    282 		irqlevel[irq] = levels;
    283 	}
    284 
    285 	/* Then figure out which IRQs use each level. */
    286 	for (level = 0; level < NIPL; level++) {
    287 		int irqs = 0;
    288 		for (irq = 0; irq < NIRQS; irq++)
    289 			if (irqlevel[irq] & (1 << level))
    290 				irqs |= 1 << irq;
    291 		irqmasks[level] = ~irqs;
    292 	}
    293 
    294 	/*
    295 	 * Enforce a hierarchy that gives slow devices a better chance at not
    296 	 * dropping data.
    297 	 */
    298 	KASSERT(irqmasks[IPL_NONE] == ~0);
    299 	irqmasks[IPL_SOFTCLOCK] &= irqmasks[IPL_NONE];
    300 	irqmasks[IPL_SOFTBIO] &= irqmasks[IPL_SOFTCLOCK];
    301 	irqmasks[IPL_SOFTNET] &= irqmasks[IPL_SOFTBIO];
    302 	irqmasks[IPL_SOFTSERIAL] &= irqmasks[IPL_SOFTNET];
    303 	irqmasks[IPL_VM] &= irqmasks[IPL_SOFTSERIAL];
    304 	irqmasks[IPL_CLOCK] &= irqmasks[IPL_VM];
    305 	irqmasks[IPL_HIGH] &= irqmasks[IPL_CLOCK];
    306 }
    307 
    308 
    309 void *
    310 intr_claim(int irq, int level, int (*ih_func)(void *), void *ih_arg, const char *group, const char *name)
    311 {
    312 	irqhandler_t *ih;
    313 
    314 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT | M_ZERO);
    315 	if (!ih)
    316 		panic("intr_claim(): Cannot malloc handler memory");
    317 
    318 	ih->ih_level = level;
    319 	ih->ih_func = ih_func;
    320 	ih->ih_arg = ih_arg;
    321 	ih->ih_flags = 0;
    322 
    323 	if (irq_claim(irq, ih, group, name) != 0)
    324 		return(NULL);
    325 
    326 	return(ih);
    327 }
    328 
    329 int
    330 intr_release(void *arg)
    331 {
    332 	irqhandler_t *ih = (irqhandler_t *)arg;
    333 
    334 	if (irq_release(ih->ih_num, ih) == 0) {
    335 		free(ih, M_DEVBUF);
    336 		return(0);
    337 	}
    338 	return(1);
    339 }
    340 
    341 
    342 /*
    343  * void disable_irq(int irq)
    344  *
    345  * Disables a specific irq. The irq is removed from the master irq mask
    346  */
    347 
    348 void
    349 disable_irq(int irq)
    350 {
    351 	u_int oldirqstate;
    352 
    353 	oldirqstate = disable_interrupts(I32_bit);
    354 	current_mask &= ~(1 << irq);
    355 	irq_setmasks();
    356 	restore_interrupts(oldirqstate);
    357 }
    358 
    359 
    360 /*
    361  * void enable_irq(int irq)
    362  *
    363  * Enables a specific irq. The irq is added to the master irq mask
    364  * This routine should be used with caution. A handler should already
    365  * be installed.
    366  */
    367 
    368 void
    369 enable_irq(int irq)
    370 {
    371 	u_int oldirqstate;
    372 
    373 	oldirqstate = disable_interrupts(I32_bit);
    374 	current_mask |= (1 << irq);
    375 	irq_setmasks();
    376 	restore_interrupts(oldirqstate);
    377 }
    378 
    379 
    380 /*
    381  * void stray_irqhandler(u_int mask)
    382  *
    383  * Handler for stray interrupts. This gets called if a handler cannot be
    384  * found for an interrupt.
    385  */
    386 
    387 void
    388 stray_irqhandler(u_int mask)
    389 {
    390 	static u_int stray_irqs = 0;
    391 
    392 	if (++stray_irqs <= 8)
    393 		log(LOG_ERR, "Stray interrupt %08x%s\n", mask,
    394 		    stray_irqs >= 8 ? ": stopped logging" : "");
    395 }
    396