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fdt_intr.c revision 1.6
      1 /* $NetBSD: fdt_intr.c,v 1.6 2016/01/07 04:26:44 marty 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 1.6 2016/01/07 04:26:44 marty 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 #define MAX_SPEC_LENGTH 6
     40 struct fdtbus_interrupt_controller {
     41 	device_t ic_dev;
     42 	int ic_phandle;
     43 	const struct fdtbus_interrupt_controller_func *ic_funcs;
     44 
     45 	struct fdtbus_interrupt_controller *ic_next;
     46 };
     47 
     48 static struct fdtbus_interrupt_controller *fdtbus_ic = NULL;
     49 
     50 static bool has_interrupt_map(int phandle);
     51 static u_int *get_entry_from_map(int phandle, int pindex, u_int *spec);
     52 static u_int *get_specifier_by_index(int phandle, int pindex, u_int *spec);
     53 
     54 static int
     55 fdtbus_get_interrupt_parent(int phandle)
     56 {
     57 	u_int interrupt_parent;
     58 
     59 	while (phandle >= 0) {
     60 		if (of_getprop_uint32(phandle, "interrupt-parent",
     61 		    &interrupt_parent) == 0) {
     62 			break;
     63 		}
     64 		if (phandle == 0) {
     65 			return -1;
     66 		}
     67 		phandle = OF_parent(phandle);
     68 	}
     69 	if (phandle < 0) {
     70 		return -1;
     71 	}
     72 
     73 	const void *data = fdtbus_get_data();
     74 	const int off = fdt_node_offset_by_phandle(data, interrupt_parent);
     75 	if (off < 0) {
     76 		return -1;
     77 	}
     78 
     79 	return fdtbus_offset2phandle(off);
     80 }
     81 
     82 static struct fdtbus_interrupt_controller *
     83 fdtbus_get_interrupt_controller_ic(int phandle)
     84 {
     85 	struct fdtbus_interrupt_controller * ic;
     86 	for (ic = fdtbus_ic; ic; ic = ic->ic_next) {
     87 		if (ic->ic_phandle == phandle) {
     88 			return ic;
     89 		}
     90 	}
     91 	return NULL;
     92 }
     93 
     94 static struct fdtbus_interrupt_controller *
     95 fdtbus_get_interrupt_controller(int phandle)
     96 {
     97 	const int ic_phandle = fdtbus_get_interrupt_parent(phandle);
     98 	if (ic_phandle < 0) {
     99 		return NULL;
    100 	}
    101 
    102 	return fdtbus_get_interrupt_controller_ic(ic_phandle);
    103 }
    104 
    105 int
    106 fdtbus_register_interrupt_controller(device_t dev, int phandle,
    107     const struct fdtbus_interrupt_controller_func *funcs)
    108 {
    109 	struct fdtbus_interrupt_controller *ic;
    110 
    111 	ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
    112 	ic->ic_dev = dev;
    113 	ic->ic_phandle = phandle;
    114 	ic->ic_funcs = funcs;
    115 
    116 	ic->ic_next = fdtbus_ic;
    117 	fdtbus_ic = ic;
    118 
    119 	return 0;
    120 }
    121 
    122 void *
    123 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
    124     int (*func)(void *), void *arg)
    125 {
    126 	u_int *specifier;
    127 	u_int maxspec[MAX_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, maxspec);
    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, maxspec);
    138 		ihandle = phandle;
    139 	}
    140 	if (specifier == NULL) {
    141 		printf("%s: Unable to get specifier %d for phandle %d\n",
    142 		       __func__, index, phandle);
    143 		return NULL;
    144 	}
    145 	ic = fdtbus_get_interrupt_controller(ihandle);
    146 	if (ic == NULL) {
    147 		printf("%s: Unable to get interrupt controller for %d\n",
    148 		       __func__, ihandle);
    149 		return NULL;
    150 	}
    151 	return ic->ic_funcs->establish(ic->ic_dev, specifier,
    152 					       ipl, flags, func, arg);
    153 }
    154 
    155 void
    156 fdtbus_intr_disestablish(int phandle, void *ih)
    157 {
    158 	struct fdtbus_interrupt_controller *ic;
    159 
    160 	ic = fdtbus_get_interrupt_controller(phandle);
    161 	KASSERT(ic != NULL);
    162 
    163 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
    164 }
    165 
    166 bool
    167 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    168 {
    169 	struct fdtbus_interrupt_controller *ic;
    170 	int ihandle;
    171 	u_int *specifier;
    172 	u_int maxspec[MAX_SPEC_LENGTH];
    173 	if (has_interrupt_map(phandle)) {
    174 		specifier = get_entry_from_map(phandle, index, maxspec);
    175 		ihandle = be32toh(specifier[1]);
    176 		ihandle = fdtbus_get_phandle_from_native(ihandle);
    177 		specifier += 2;
    178 	} else {
    179 		ihandle = phandle;
    180 		specifier = get_specifier_by_index(phandle, index, maxspec);
    181 	}
    182 	if (specifier == NULL) {
    183 		printf("%s: Unable to get specifier %d for phandle %d\n",
    184 		       __func__, index, phandle);
    185 		return false;
    186 	}
    187 	ic = fdtbus_get_interrupt_controller(ihandle);
    188 	if (ic == NULL) {
    189 		printf("%s: Unable to get interrupt controller for %d\n",
    190 		       __func__, ihandle);
    191 		return false;
    192 	}
    193 	return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
    194 }
    195 
    196 /*
    197  * Devices that have multiple interrupts, connected to two or more
    198  * interrupt sources use an interrupt map rather than a simple
    199  * interrupt parent to indicate which interrupt controller goes with
    200  * which map.  The interrupt map is contained in the node describing
    201  * the first level parent and contains one entry per interrupt:
    202  *   index -- the index of the entry in the map
    203  *   &parent -- pointer to the node containing the actual interrupt parent
    204  *              for the specific interrupt
    205  *  [specifier 0 - specifier N-1] The N (usually 2 or 3) 32 bit words
    206  *              that make up the specifier.
    207  *
    208  * returns true if the device phandle has an interrupt-parent that
    209  * contains an interrupt-map.
    210  */
    211 static bool
    212 has_interrupt_map(int phandle)
    213 {
    214 	int ic_phandle;
    215 	of_getprop_uint32(phandle, "interrupt-parent", &ic_phandle);
    216 	ic_phandle = fdtbus_get_phandle_from_native(ic_phandle);
    217 	if (ic_phandle <= 0)
    218 		return false;
    219 	int len = OF_getproplen(ic_phandle, "interrupt-map");
    220 	if (len > 0)
    221 		return true;
    222 	return false;
    223 }
    224 
    225 /*
    226  * Walk the specifier map and return a pointer to the map entry
    227  * associated with pindex.  Return null if there is no entry.
    228  *
    229  * Because the length of the specifier depends on the interrupt
    230  * controller, we need to repeatedly obtain interrupt-celss for
    231  * the controller for the current index.
    232  *
    233  */
    234 static u_int *
    235 get_entry_from_map(int phandle, int pindex, u_int *specifier)
    236 {
    237 	int intr_cells;
    238 	int intr_parent;
    239 	u_int *result = NULL;
    240 
    241 	of_getprop_uint32(phandle, "#interrupt-cells", &intr_cells);
    242 	of_getprop_uint32(phandle, "interrupt-parent", &intr_parent);
    243 
    244 	intr_parent = fdtbus_get_phandle_from_native(intr_parent);
    245 	int len = OF_getproplen(intr_parent, "interrupt-map");
    246 	if (len <= 0) {
    247 		printf("%s: no interrupt-map.\n", __func__);
    248 		return NULL;
    249 	}
    250 	uint resid = len;
    251 	char *data = kmem_alloc(len, KM_SLEEP);
    252 	len = OF_getprop(intr_parent, "interrupt-map", data, len);
    253 	if (len <= 0) {
    254 		printf("%s:  can't get property interrupt-map.\n", __func__);
    255 		goto done;
    256 	}
    257 	u_int *p = (u_int *)data;
    258 
    259 	while (resid > 0) {
    260 		u_int index = be32toh(p[0]);
    261 		const u_int parent = fdtbus_get_phandle_from_native(be32toh(p[intr_cells]));
    262 		u_int pintr_cells;
    263 		of_getprop_uint32(parent, "#interrupt-cells", &pintr_cells);
    264 		if (index == pindex) {
    265 			for (int i = 0; i < pintr_cells; i++)
    266 				specifier[i] =  p[i];
    267 			result = specifier;
    268 			goto done;
    269 
    270 		}
    271 		/* Determine the length of the entry and skip that many
    272 		 * 32 bit words
    273 		 */
    274 		const u_int reclen = (intr_cells + pintr_cells + 1);
    275 		resid -= reclen * sizeof(u_int);
    276 		p += reclen;
    277 	}
    278 done:
    279 	kmem_free(data, len);
    280 	return result;
    281 }
    282 
    283 
    284 /*
    285  * Devices that don't connect to more than one interrupt source use
    286  * an array of specifiers.  Find the specifier that matches pindex
    287  * and return a pointer to it.
    288  *
    289  */
    290 static u_int *get_specifier_by_index(int phandle, int pindex, u_int *specifier)
    291 {
    292 	u_int *specifiers;
    293 	int interrupt_parent, interrupt_cells, len;
    294 
    295 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    296 	if (interrupt_parent <= 0) {
    297 		printf("%s: interrupt_parent sanity check failed\n", __func__);
    298 		printf("%s: interrupt_parent = %d\n", __func__,
    299 		       interrupt_parent);
    300 		return NULL;
    301 	}
    302 
    303 	len = OF_getprop(interrupt_parent, "#interrupt-cells",
    304 			 &interrupt_cells,  sizeof(interrupt_cells));
    305 	interrupt_cells = be32toh(interrupt_cells);
    306 	if (len != sizeof(interrupt_cells) || interrupt_cells <= 0) {
    307 		printf("%s: interrupt_cells sanity check failed\n", __func__);
    308 		return NULL;
    309 	}
    310 
    311 	len = OF_getproplen(phandle, "interrupts");
    312 	if (len <= 0) {
    313 		printf("%s: Couldn't get property interrupts\n", __func__);
    314 		return NULL;
    315 	}
    316 
    317 	const u_int clen = interrupt_cells * sizeof(u_int);
    318 	const u_int nintr = len / interrupt_cells;
    319 
    320 	if (pindex >= nintr)
    321 		return NULL;
    322 
    323 	specifiers = kmem_alloc(len, KM_SLEEP);
    324 
    325 	if (OF_getprop(phandle, "interrupts", specifiers, len) != len) {
    326 		kmem_free(specifiers, len);
    327 		return NULL;
    328 	}
    329 	for (int i = 0; i < interrupt_cells; i++)
    330 		specifier[i] = specifiers[pindex * clen + i];
    331 	kmem_free(specifiers, len);
    332 	return specifier;
    333 }
    334