Home | History | Annotate | Line # | Download | only in fdt
fdt_intr.c revision 1.3.2.3
      1 /* $NetBSD: fdt_intr.c,v 1.3.2.3 2016/03/19 11:30:09 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2015 Jared D. McNeill <jmcneill (at) invisible.ca>
      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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: fdt_intr.c,v 1.3.2.3 2016/03/19 11:30:09 skrll Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/kmem.h>
     35 
     36 #include <libfdt.h>
     37 #include <dev/fdt/fdtvar.h>
     38 
     39 struct fdtbus_interrupt_controller {
     40 	device_t ic_dev;
     41 	int ic_phandle;
     42 	const struct fdtbus_interrupt_controller_func *ic_funcs;
     43 
     44 	struct fdtbus_interrupt_controller *ic_next;
     45 };
     46 
     47 static struct fdtbus_interrupt_controller *fdtbus_ic = NULL;
     48 
     49 static bool has_interrupt_map(int phandle);
     50 static u_int *get_entry_from_map(int phandle, int pindex, u_int *spec);
     51 static u_int *get_specifier_by_index(int phandle, int pindex, u_int *spec);
     52 
     53 static int
     54 fdtbus_get_interrupt_parent(int phandle)
     55 {
     56 	u_int interrupt_parent;
     57 
     58 	while (phandle >= 0) {
     59 		if (of_getprop_uint32(phandle, "interrupt-parent",
     60 		    &interrupt_parent) == 0) {
     61 			break;
     62 		}
     63 		if (phandle == 0) {
     64 			return -1;
     65 		}
     66 		phandle = OF_parent(phandle);
     67 	}
     68 	if (phandle < 0) {
     69 		return -1;
     70 	}
     71 
     72 	const void *data = fdtbus_get_data();
     73 	const int off = fdt_node_offset_by_phandle(data, interrupt_parent);
     74 	if (off < 0) {
     75 		return -1;
     76 	}
     77 
     78 	return fdtbus_offset2phandle(off);
     79 }
     80 
     81 static struct fdtbus_interrupt_controller *
     82 fdtbus_get_interrupt_controller_ic(int phandle)
     83 {
     84 	struct fdtbus_interrupt_controller * ic;
     85 	for (ic = fdtbus_ic; ic; ic = ic->ic_next) {
     86 		if (ic->ic_phandle == phandle) {
     87 			return ic;
     88 		}
     89 	}
     90 	return NULL;
     91 }
     92 
     93 static struct fdtbus_interrupt_controller *
     94 fdtbus_get_interrupt_controller(int phandle)
     95 {
     96 	const int ic_phandle = fdtbus_get_interrupt_parent(phandle);
     97 	if (ic_phandle < 0) {
     98 		return NULL;
     99 	}
    100 
    101 	return fdtbus_get_interrupt_controller_ic(ic_phandle);
    102 }
    103 
    104 int
    105 fdtbus_register_interrupt_controller(device_t dev, int phandle,
    106     const struct fdtbus_interrupt_controller_func *funcs)
    107 {
    108 	struct fdtbus_interrupt_controller *ic;
    109 
    110 	ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
    111 	ic->ic_dev = dev;
    112 	ic->ic_phandle = phandle;
    113 	ic->ic_funcs = funcs;
    114 
    115 	ic->ic_next = fdtbus_ic;
    116 	fdtbus_ic = ic;
    117 
    118 	return 0;
    119 }
    120 
    121 void *
    122 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
    123     int (*func)(void *), void *arg)
    124 {
    125 	void * result = NULL;
    126 	u_int *specifier;
    127 	u_int spec_length;
    128 	int ihandle;
    129 	struct fdtbus_interrupt_controller *ic;
    130 
    131 	if (has_interrupt_map(phandle)) {
    132 		specifier = get_entry_from_map(phandle, index, &spec_length);
    133 		ihandle = be32toh(specifier[1]);
    134 		ihandle = fdtbus_get_phandle_from_native(ihandle);
    135 		specifier += 2;
    136 	} else {
    137 		specifier = get_specifier_by_index(phandle, index,
    138 						   &spec_length);
    139 		ihandle = phandle;
    140 	}
    141 	if (specifier == NULL) {
    142 		printf("%s: Unable to get specifier %d for phandle %d\n",
    143 		       __func__, index, phandle);
    144 		goto done;
    145 	}
    146 	ic = fdtbus_get_interrupt_controller(ihandle);
    147 	if (ic == NULL) {
    148 		printf("%s: Unable to get interrupt controller for %d\n",
    149 		       __func__, ihandle);
    150 		goto done;
    151 	}
    152 	result = ic->ic_funcs->establish(ic->ic_dev, specifier,
    153 					       ipl, flags, func, arg);
    154 done:
    155 	if (has_interrupt_map(phandle))
    156 	    specifier -= 2;
    157 	if (specifier && spec_length > 0)
    158 		kmem_free(specifier, spec_length);
    159 	return result;
    160 }
    161 
    162 void
    163 fdtbus_intr_disestablish(int phandle, void *ih)
    164 {
    165 	struct fdtbus_interrupt_controller *ic;
    166 
    167 	ic = fdtbus_get_interrupt_controller(phandle);
    168 	KASSERT(ic != NULL);
    169 
    170 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
    171 }
    172 
    173 bool
    174 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    175 {
    176 	bool result = false;
    177 	struct fdtbus_interrupt_controller *ic;
    178 	int ihandle;
    179 	u_int *specifier;
    180 	u_int spec_length;
    181 	if (has_interrupt_map(phandle)) {
    182 		specifier = get_entry_from_map(phandle, index,
    183 			&spec_length);
    184 		ihandle = be32toh(specifier[1]);
    185 		ihandle = fdtbus_get_phandle_from_native(ihandle);
    186 		specifier += 2;
    187 	} else {
    188 		ihandle = phandle;
    189 		specifier = get_specifier_by_index(phandle, index,
    190 						   &spec_length);
    191 	}
    192 	if (specifier == NULL) {
    193 		printf("%s: Unable to get specifier %d for phandle %d\n",
    194 		       __func__, index, phandle);
    195 		goto done;
    196 	}
    197 	ic = fdtbus_get_interrupt_controller(ihandle);
    198 	if (ic == NULL) {
    199 		printf("%s: Unable to get interrupt controller for %d\n",
    200 		       __func__, ihandle);
    201 		goto done;
    202 	}
    203 	result = ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
    204 done:
    205 	if (has_interrupt_map(phandle))
    206 	    specifier -= 2;
    207 	if (specifier && spec_length > 0)
    208 		kmem_free(specifier, spec_length);
    209 	return result;
    210 }
    211 
    212 /*
    213  * Devices that have multiple interrupts, connected to two or more
    214  * interrupt sources use an interrupt map rather than a simple
    215  * interrupt parent to indicate which interrupt controller goes with
    216  * which map.  The interrupt map is contained in the node describing
    217  * the first level parent and contains one entry per interrupt:
    218  *   index -- the index of the entry in the map
    219  *   &parent -- pointer to the node containing the actual interrupt parent
    220  *              for the specific interrupt
    221  *  [specifier 0 - specifier N-1] The N (usually 2 or 3) 32 bit words
    222  *              that make up the specifier.
    223  *
    224  * returns true if the device phandle has an interrupt-parent that
    225  * contains an interrupt-map.
    226  */
    227 static bool
    228 has_interrupt_map(int phandle)
    229 {
    230 	int ic_phandle;
    231 	of_getprop_uint32(phandle, "interrupt-parent", &ic_phandle);
    232 	ic_phandle = fdtbus_get_phandle_from_native(ic_phandle);
    233 	if (ic_phandle <= 0)
    234 		return false;
    235 	int len = OF_getproplen(ic_phandle, "interrupt-map");
    236 	if (len > 0)
    237 		return true;
    238 	return false;
    239 }
    240 
    241 /*
    242  * Walk the specifier map and return a pointer to the map entry
    243  * associated with pindex.  Return null if there is no entry.
    244  *
    245  * Because the length of the specifier depends on the interrupt
    246  * controller, we need to repeatedly obtain interrupt-celss for
    247  * the controller for the current index.
    248  *
    249  */
    250 static u_int *
    251 get_entry_from_map(int phandle, int pindex, u_int *spec_length)
    252 {
    253 	int intr_cells;
    254 	int intr_parent;
    255 	u_int *result = NULL;
    256 
    257 	of_getprop_uint32(phandle, "#interrupt-cells", &intr_cells);
    258 	of_getprop_uint32(phandle, "interrupt-parent", &intr_parent);
    259 
    260 	intr_parent = fdtbus_get_phandle_from_native(intr_parent);
    261 	int len = OF_getproplen(intr_parent, "interrupt-map");
    262 	if (len <= 0) {
    263 		printf("%s: no interrupt-map.\n", __func__);
    264 		return NULL;
    265 	}
    266 	uint resid = len;
    267 	char *data = kmem_alloc(len, KM_SLEEP);
    268 	len = OF_getprop(intr_parent, "interrupt-map", data, len);
    269 	if (len <= 0) {
    270 		printf("%s:  can't get property interrupt-map.\n", __func__);
    271 		goto done;
    272 	}
    273 	u_int *p = (u_int *)data;
    274 
    275 	while (resid > 0) {
    276 		u_int index = be32toh(p[0]);
    277 		const u_int parent = fdtbus_get_phandle_from_native(be32toh(p[intr_cells]));
    278 		u_int pintr_cells;
    279 		of_getprop_uint32(parent, "#interrupt-cells", &pintr_cells);
    280 		if (index == pindex) {
    281 			result = kmem_alloc((pintr_cells + 2) * sizeof(u_int),
    282 					    KM_SLEEP);
    283 			*spec_length = (pintr_cells + 2) * sizeof (u_int);
    284 			for (int i = 0; i < pintr_cells + 2; i++)
    285 				result[i] =  p[i];
    286 			goto done;
    287 
    288 		}
    289 		/* Determine the length of the entry and skip that many
    290 		 * 32 bit words
    291 		 */
    292 		const u_int reclen = (intr_cells + pintr_cells + 1);
    293 		resid -= reclen * sizeof(u_int);
    294 		p += reclen;
    295 	}
    296 done:
    297 	kmem_free(data, len);
    298 	return result;
    299 }
    300 
    301 
    302 /*
    303  * Devices that don't connect to more than one interrupt source use
    304  * an array of specifiers.  Find the specifier that matches pindex
    305  * and return a pointer to it.
    306  *
    307  */
    308 static u_int *get_specifier_by_index(int phandle, int pindex,
    309 				     u_int *spec_length)
    310 {
    311 	u_int *specifiers;
    312 	u_int *specifier;
    313 	int interrupt_parent, interrupt_cells, len;
    314 
    315 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    316 	if (interrupt_parent <= 0) {
    317 		printf("%s: interrupt_parent sanity check failed\n", __func__);
    318 		printf("%s: interrupt_parent = %d\n", __func__,
    319 		       interrupt_parent);
    320 		return NULL;
    321 	}
    322 
    323 	len = OF_getprop(interrupt_parent, "#interrupt-cells",
    324 			 &interrupt_cells,  sizeof(interrupt_cells));
    325 	interrupt_cells = be32toh(interrupt_cells);
    326 	if (len != sizeof(interrupt_cells) || interrupt_cells <= 0) {
    327 		printf("%s: interrupt_cells sanity check failed\n", __func__);
    328 		return NULL;
    329 	}
    330 
    331 	len = OF_getproplen(phandle, "interrupts");
    332 	if (len <= 0) {
    333 		printf("%s: Couldn't get property interrupts\n", __func__);
    334 		return NULL;
    335 	}
    336 
    337 	const u_int clen = interrupt_cells * sizeof(u_int);
    338 	const u_int nintr = len / interrupt_cells;
    339 
    340 	if (pindex >= nintr)
    341 		return NULL;
    342 
    343 	specifiers = kmem_alloc(len, KM_SLEEP);
    344 
    345 	if (OF_getprop(phandle, "interrupts", specifiers, len) != len) {
    346 		kmem_free(specifiers, len);
    347 		return NULL;
    348 	}
    349 	specifier = kmem_alloc(interrupt_cells * sizeof(u_int), KM_SLEEP);
    350 	*spec_length = interrupt_cells * sizeof(u_int);
    351 	for (int i = 0; i < interrupt_cells; i++)
    352 		specifier[i] = specifiers[pindex * clen + i];
    353 	kmem_free(specifiers, len);
    354 	return specifier;
    355 }
    356