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ofw_irqhandler.c revision 1.13
      1 /*	$NetBSD: ofw_irqhandler.c,v 1.13 2008/01/06 03:45:27 matt Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1994-1998 Mark Brinicombe.
      5  * Copyright (c) 1994 Brini.
      6  * All rights reserved.
      7  *
      8  * This code is derived from software written for Brini by Mark Brinicombe
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by Mark Brinicombe
     21  *	for the NetBSD Project.
     22  * 4. The name of the company nor the name of the author may be used to
     23  *    endorse or promote products derived from this software without specific
     24  *    prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     36  *
     37  *	from: irqhandler.c
     38  *
     39  * IRQ/FIQ initialisation, claim, release and handler routines
     40  *
     41  * Created      : 30/09/94
     42  */
     43 
     44 #include <sys/cdefs.h>
     45 __KERNEL_RCSID(0, "$NetBSD: ofw_irqhandler.c,v 1.13 2008/01/06 03:45:27 matt Exp $");
     46 
     47 #include <sys/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/syslog.h>
     50 #include <sys/malloc.h>
     51 
     52 #include <uvm/uvm_extern.h>
     53 
     54 #include <machine/intr.h>
     55 #include <machine/irqhandler.h>
     56 #include <machine/cpu.h>
     57 
     58 irqhandler_t *irqhandlers[NIRQS];
     59 
     60 u_int current_mask;
     61 u_int actual_mask;
     62 u_int disabled_mask;
     63 u_int irqmasks[IPL_LEVELS];
     64 extern u_int intrcnt[];
     65 
     66 extern char *_intrnames;
     67 
     68 /* Prototypes */
     69 
     70 int podule_irqhandler		__P((void));
     71 extern void set_spl_masks	__P((void));
     72 
     73 /*
     74  * void irq_init(void)
     75  *
     76  * Initialise the IRQ/FIQ sub system
     77  */
     78 
     79 void
     80 irq_init()
     81 {
     82 	int loop;
     83 
     84 	/* Clear all the IRQ handlers and the irq block masks */
     85 	for (loop = 0; loop < NIRQS; ++loop) {
     86 		irqhandlers[loop] = NULL;
     87 	}
     88 
     89 	/*
     90 	 * Setup the irqmasks for the different Interrupt Priority Levels
     91 	 * We will start with no bits set and these will be updated as handlers
     92 	 * are installed at different IPL's.
     93 	 */
     94 	for (loop = 0; loop < IPL_LEVELS; ++loop)
     95 		irqmasks[loop] = 0;
     96 
     97 	current_mask = 0x00000000;
     98 	disabled_mask = 0x00000000;
     99 	actual_mask = 0x00000000;
    100 
    101 	set_spl_masks();
    102 
    103 	/* Enable IRQ's and FIQ's */
    104 	enable_interrupts(I32_bit | F32_bit);
    105 }
    106 
    107 
    108 /*
    109  * int irq_claim(int irq, irqhandler_t *handler)
    110  *
    111  * Enable an IRQ and install a handler for it.
    112  */
    113 
    114 int
    115 irq_claim(irq, handler, group, name)
    116 	int irq;
    117 	irqhandler_t *handler;
    118 	const char *group;
    119 	const char *name;
    120 {
    121 	int level;
    122 
    123 #ifdef DIAGNOSTIC
    124 	/* Sanity check */
    125 	if (handler == NULL)
    126 		panic("NULL interrupt handler");
    127 	if (handler->ih_func == NULL)
    128 		panic("Interrupt handler does not have a function");
    129 #endif	/* DIAGNOSTIC */
    130 
    131 	/*
    132 	 * IRQ_INSTRUCT indicates that we should get the irq number
    133 	 * from the irq structure
    134 	 */
    135 	if (irq == IRQ_INSTRUCT)
    136 		irq = handler->ih_num;
    137 
    138 	/* Make sure the irq number is valid */
    139 	if (irq < 0 || irq >= NIRQS)
    140 		return(-1);
    141 
    142 	/* Make sure the level is valid */
    143 	if (handler->ih_level < 0 || handler->ih_level >= IPL_LEVELS)
    144     	        return(-1);
    145 
    146 	evcnt_attach_dynamic(&handler->ih_ev, EVCNT_TYPE_INTR, NULL,
    147 	    group, name);
    148 
    149 	/* Attach handler at top of chain */
    150 	handler->ih_next = irqhandlers[irq];
    151 	irqhandlers[irq] = handler;
    152 
    153 	/*
    154 	 * Reset the flags for this handler.
    155 	 * As the handler is now in the chain mark it as active.
    156 	 */
    157 	handler->ih_flags = 0 | IRQ_FLAG_ACTIVE;
    158 
    159 	/*
    160 	 * Record the interrupt number for accounting.
    161 	 * Done here as the accounting number may not be the same as the
    162 	 * IRQ number though for the moment they are
    163 	 */
    164 	handler->ih_num = irq;
    165 
    166 	/*
    167 	 * Update the irq masks.
    168 	 * Find the lowest interrupt priority on the irq chain.
    169 	 * Interrupt is allowable at priorities lower than this.
    170 	 * If ih_level is out of range then don't bother to update
    171 	 * the masks.
    172 	 */
    173 	if (handler->ih_level >= 0 && handler->ih_level < IPL_LEVELS) {
    174 		irqhandler_t *ptr;
    175 
    176 		/*
    177 		 * Find the lowest interrupt priority on the irq chain.
    178 		 * Interrupt is allowable at priorities lower than this.
    179 		 */
    180 		ptr = irqhandlers[irq];
    181 		if (ptr) {
    182 			level = ptr->ih_level - 1;
    183 			while (ptr) {
    184 				if (ptr->ih_level - 1 < level)
    185 					level = ptr->ih_level - 1;
    186 				ptr = ptr->ih_next;
    187 			}
    188 			while (level >= 0) {
    189 				irqmasks[level] |= (1 << irq);
    190 				--level;
    191 			}
    192 		}
    193 
    194 #include "sl.h"
    195 #include "ppp.h"
    196 #if NSL > 0 || NPPP > 0
    197 		/* In the presence of SLIP or PPP, splimp > spltty. */
    198 		irqmasks[IPL_NET] &= irqmasks[IPL_TTY];
    199 #endif
    200 	}
    201 
    202 	enable_irq(irq);
    203 	set_spl_masks();
    204 
    205 	return(0);
    206 }
    207 
    208 
    209 /*
    210  * int irq_release(int irq, irqhandler_t *handler)
    211  *
    212  * Disable an IRQ and remove a handler for it.
    213  */
    214 
    215 int
    216 irq_release(irq, handler)
    217 	int irq;
    218 	irqhandler_t *handler;
    219 {
    220 	int level;
    221 	irqhandler_t *irqhand;
    222 	irqhandler_t **prehand;
    223 
    224 	/*
    225 	 * IRQ_INSTRUCT indicates that we should get the irq number
    226 	 * from the irq structure
    227 	 */
    228 	if (irq == IRQ_INSTRUCT)
    229 		irq = handler->ih_num;
    230 
    231 	/* Make sure the irq number is valid */
    232 	if (irq < 0 || irq >= NIRQS)
    233 		return(-1);
    234 
    235 	/* Locate the handler */
    236 	irqhand = irqhandlers[irq];
    237 	prehand = &irqhandlers[irq];
    238 
    239 	while (irqhand && handler != irqhand) {
    240 		prehand = &irqhand;
    241 		irqhand = irqhand->ih_next;
    242 	}
    243 
    244 	/* Remove the handler if located */
    245 	if (irqhand)
    246 		*prehand = irqhand->ih_next;
    247 	else
    248 		return(-1);
    249 
    250 	/* Now the handler has been removed from the chain mark is as inactive */
    251 	irqhand->ih_flags &= ~IRQ_FLAG_ACTIVE;
    252 
    253 	/* Make sure the head of the handler list is active */
    254 	if (irqhandlers[irq])
    255 		irqhandlers[irq]->ih_flags |= IRQ_FLAG_ACTIVE;
    256 
    257 	/*
    258 	 * Update the irq masks.
    259 	 * If ih_level is out of range then don't bother to update
    260 	 * the masks.
    261 	 */
    262 	if (handler->ih_level >= 0 && handler->ih_level < IPL_LEVELS) {
    263 		irqhandler_t *ptr;
    264 
    265 		/* Clean the bit from all the masks */
    266 		for (level = 0; level < IPL_LEVELS; ++level)
    267 			irqmasks[level] &= ~(1 << irq);
    268 
    269 		/*
    270 		 * Find the lowest interrupt priority on the irq chain.
    271 		 * Interrupt is allowable at priorities lower than this.
    272 		 */
    273 		ptr = irqhandlers[irq];
    274 		if (ptr) {
    275 			level = ptr->ih_level - 1;
    276 			while (ptr) {
    277 				if (ptr->ih_level - 1 < level)
    278 					level = ptr->ih_level - 1;
    279 				ptr = ptr->ih_next;
    280 			}
    281 			while (level >= 0) {
    282 				irqmasks[level] |= (1 << irq);
    283 				--level;
    284 			}
    285 		}
    286 	}
    287 
    288 	/*
    289 	 * Disable the appropriate mask bit if there are no handlers left for
    290 	 * this IRQ.
    291 	 */
    292 	if (irqhandlers[irq] == NULL)
    293 		disable_irq(irq);
    294 
    295 	set_spl_masks();
    296 
    297 	return(0);
    298 }
    299 
    300 
    301 void *
    302 intr_claim(irq, level, ih_func, ih_arg, group, name)
    303 	int irq;
    304 	int level;
    305 	int (*ih_func) __P((void *));
    306 	void *ih_arg;
    307 	const char *group;
    308 	const char *name;
    309 {
    310 	irqhandler_t *ih;
    311 
    312 	ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT|M_ZERO);
    313 	if (!ih)
    314 		panic("intr_claim(): Cannot malloc handler memory");
    315 
    316 	ih->ih_level = level;
    317 	ih->ih_func = ih_func;
    318 	ih->ih_arg = ih_arg;
    319 	ih->ih_flags = 0;
    320 
    321 	if (irq_claim(irq, ih, group, name) != 0)
    322 		return(NULL);
    323 	return(ih);
    324 }
    325 
    326 
    327 int
    328 intr_release(arg)
    329 	void *arg;
    330 {
    331 	irqhandler_t *ih = (irqhandler_t *)arg;
    332 
    333 	if (irq_release(ih->ih_num, ih) == 0) {
    334 		free(ih, M_DEVBUF);
    335 		return(0);
    336 	}
    337 	return(1);
    338 }
    339 
    340 
    341 /*
    342  * void disable_irq(int irq)
    343  *
    344  * Disables a specific irq. The irq is removed from the master irq mask
    345  */
    346 
    347 void
    348 disable_irq(irq)
    349 	int irq;
    350 {
    351 	register 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(irq)
    370 	int irq;
    371 {
    372 	register u_int oldirqstate;
    373 
    374 	oldirqstate = disable_interrupts(I32_bit);
    375 	current_mask |= (1 << irq);
    376 	irq_setmasks();
    377 	restore_interrupts(oldirqstate);
    378 }
    379 
    380 
    381 /*
    382  * void stray_irqhandler(u_int mask)
    383  *
    384  * Handler for stray interrupts. This gets called if a handler cannot be
    385  * found for an interrupt.
    386  */
    387 
    388 void	stray_irqhandler(u_int);	/* called from assembly */
    389 
    390 void
    391 stray_irqhandler(mask)
    392 	u_int mask;
    393 {
    394 	static u_int stray_irqs = 0;
    395 
    396 	if (++stray_irqs <= 8)
    397 		log(LOG_ERR, "Stray interrupt %08x%s\n", mask,
    398 		    stray_irqs >= 8 ? ": stopped logging" : "");
    399 }
    400