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fdt_intr.c revision 1.4
      1 /* $NetBSD: fdt_intr.c,v 1.4 2016/01/05 21:53:48 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 1.4 2016/01/05 21:53:48 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 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);
     51 static u_int *get_specifier_by_index(int phandle, int pindex);
     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 	u_int *specifier;
    126 	int ihandle;
    127 	struct fdtbus_interrupt_controller *ic;
    128 
    129 	if (has_interrupt_map(phandle)) {
    130 		specifier = get_entry_from_map(phandle, index);
    131 		ihandle = be32toh(specifier[1]);
    132 		ihandle = fdtbus_get_phandle_from_native(ihandle);
    133 		specifier += 2;
    134 	} else {
    135 		specifier = get_specifier_by_index(phandle, index);
    136 		ihandle = phandle;
    137 	}
    138 	ic = fdtbus_get_interrupt_controller(ihandle);
    139 	if (ic == NULL)
    140 		return NULL;
    141 	return ic->ic_funcs->establish(ic->ic_dev, specifier,
    142 					       ipl, flags, func, arg);
    143 }
    144 
    145 void
    146 fdtbus_intr_disestablish(int phandle, void *ih)
    147 {
    148 	struct fdtbus_interrupt_controller *ic;
    149 
    150 	ic = fdtbus_get_interrupt_controller(phandle);
    151 	KASSERT(ic != NULL);
    152 
    153 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
    154 }
    155 
    156 bool
    157 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    158 {
    159 	struct fdtbus_interrupt_controller *ic;
    160 	int ihandle;
    161 	u_int *specifier;
    162 
    163 	if (has_interrupt_map(phandle)) {
    164 		specifier = get_entry_from_map(phandle, index);
    165 		ihandle = be32toh(specifier[1]);
    166 		ihandle = fdtbus_get_phandle_from_native(ihandle);
    167 	} else {
    168 		ihandle = phandle;
    169 		specifier = get_specifier_by_index(phandle, index);
    170 	}
    171 	ic = fdtbus_get_interrupt_controller(ihandle);
    172 	if (ic == NULL)
    173 		return false;
    174 	return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
    175 }
    176 
    177 /*
    178  * Devices that have multiple interrupts, connected to two or more
    179  * interrupt sources use an interrupt map rather than a simple
    180  * interrupt parent to indicate which interrupt controller goes with
    181  * which map.  The interrupt map is contained in the node describing
    182  * the first level parent and contains one entry per interrupt:
    183  *   index -- the index of the entry in the map
    184  *   &parent -- pointer to the node containing the actual interrupt parent
    185  *              for the specific interrupt
    186  *  [specifier 0 - specifier N-1] The N (usually 2 or 3) 32 bit words
    187  *              that make up the specifier.
    188  *
    189  * returns true if the device phandle has an interrupt-parent that
    190  * contains an interrupt-map.
    191  */
    192 static bool
    193 has_interrupt_map(int phandle)
    194 {
    195 	int ic_phandle;
    196 	of_getprop_uint32(phandle, "interrupt-parent", &ic_phandle);
    197 	if (ic_phandle <= 0)
    198 		return false;
    199 	ic_phandle = fdtbus_get_phandle_from_native(ic_phandle);
    200 	if (ic_phandle <= 0)
    201 		return false;
    202 	int len = OF_getproplen(ic_phandle, "interrupt-map");
    203 	if (len > 0)
    204 		return true;
    205 	return false;
    206 }
    207 
    208 /*
    209  * Walk the specifier map and return a pointer to the map entry
    210  * associated with pindex.  Return null if there is no entry.
    211  *
    212  * Because the length of the specifier depends on the interrupt
    213  * controller, we need to repeatedly obtain interrupt-celss for
    214  * the controller for the current index.
    215  *
    216  * this version leaks memory and needs a revisit
    217  */
    218 static u_int *
    219 get_entry_from_map(int phandle, int pindex)
    220 {
    221 	int intr_cells;
    222 	int intr_parent;
    223 
    224 	of_getprop_uint32(phandle, "#interrupt-cells", &intr_cells);
    225 	of_getprop_uint32(phandle, "interrupt-parent", &intr_parent);
    226 
    227 	intr_parent = fdtbus_get_phandle_from_native(intr_parent);
    228 	int len = OF_getproplen(intr_parent, "interrupt-map");
    229 	if (len <= 0) {
    230 		printf(" no interrupt-map.\n");
    231 		return NULL;
    232 	}
    233 	uint resid = len;
    234 	char *data = kmem_alloc(len, KM_SLEEP);
    235 	len = OF_getprop(intr_parent, "interrupt-map", data, len);
    236 	if (len <= 0) {
    237 		printf(" can't get property interrupt-map.\n");
    238 		return NULL;
    239 	}
    240 	u_int *p = (u_int *)data;
    241 
    242 	while (resid > 0) {
    243 		u_int index = be32toh(p[0]);
    244 		if (index == pindex) {
    245 			return &p[0];
    246 
    247 		}
    248 		/* Determine the length of the entry and skip that many
    249 		 * 32 bit words
    250 		 */
    251 		const u_int parent = fdtbus_get_phandle_from_native(be32toh(p[intr_cells]));
    252 		u_int pintr_cells;
    253 		of_getprop_uint32(parent, "#interrupt-cells", &pintr_cells);
    254 		const u_int reclen = (intr_cells + pintr_cells + 1);
    255 		resid -= reclen * sizeof(u_int);
    256 		p += reclen;
    257 	}
    258 	return NULL;
    259 }
    260 
    261 
    262 /*
    263  * Devices that don't connect to more than one interrupt source use
    264  * an array of specifiers.  Find the specifier that matches pindex
    265  * and return a pointer to it.
    266  *
    267  * This version leaks memory and needs a revisit.
    268  */
    269 static u_int *get_specifier_by_index(int phandle, int pindex)
    270 {
    271 	u_int *specifiers;
    272 	int interrupt_parent, interrupt_cells, len;
    273 
    274 	printf("%s: phandle = %d pindex = %d\n", __func__, phandle, pindex);
    275 
    276 	len = OF_getprop(phandle, "interrupt-parent", &interrupt_parent,
    277 	    sizeof(interrupt_parent));
    278 	interrupt_parent = be32toh(interrupt_parent);
    279 	interrupt_parent = fdtbus_get_phandle_from_native(interrupt_parent);
    280 	printf("%s: len = %d interrupt_parent = %d\n", __func__, len,
    281 	       interrupt_parent);
    282 	if (len != sizeof(interrupt_parent) || interrupt_parent <= 0) {
    283 		printf("%s: interrupt_parent sanity check failed\n", __func__);
    284 		return NULL;
    285 	}
    286 
    287 	len = OF_getprop(interrupt_parent, "#interrupt-cells",
    288 			 &interrupt_cells,  sizeof(interrupt_cells));
    289 	interrupt_cells = be32toh(interrupt_cells);
    290 	printf("%s: len = %d interrupt_cells = %d\n", __func__, len,
    291 	       interrupt_cells);
    292 	if (len != sizeof(interrupt_cells) || interrupt_cells <= 0) {
    293 		printf("%s: interrupt_celyls sanity check failed\n", __func__);
    294 		return NULL;
    295 	}
    296 
    297 	len = OF_getproplen(phandle, "interrupts");
    298 	if (len <= 0) {
    299 		printf("%s: Couldn't get property interrupts\n", __func__);
    300 		return NULL;
    301 	}
    302 
    303 	const u_int clen = interrupt_cells * sizeof(u_int);
    304 	const u_int nintr = len / interrupt_cells;
    305 
    306 	if (pindex >= nintr)
    307 		return NULL;
    308 
    309 	specifiers = kmem_alloc(len, KM_SLEEP);
    310 
    311 	if (OF_getprop(phandle, "interrupts", specifiers, len) != len) {
    312 		kmem_free(specifiers, len);
    313 		return NULL;
    314 	}
    315 	return &specifiers[pindex * clen];
    316 }
    317