Home | History | Annotate | Line # | Download | only in fdt
fdt_intr.c revision 1.11.6.3
      1 /* $NetBSD: fdt_intr.c,v 1.11.6.3 2018/11/26 01:52:31 pgoyette Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2015-2018 Jared 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 1.11.6.3 2018/11/26 01:52:31 pgoyette Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 #include <sys/kmem.h>
     35 #include <sys/queue.h>
     36 
     37 #include <libfdt.h>
     38 #include <dev/fdt/fdtvar.h>
     39 
     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 	LIST_ENTRY(fdtbus_interrupt_controller) ic_next;
     46 };
     47 
     48 static LIST_HEAD(, fdtbus_interrupt_controller) fdtbus_interrupt_controllers =
     49     LIST_HEAD_INITIALIZER(fdtbus_interrupt_controllers);
     50 
     51 struct fdtbus_interrupt_cookie {
     52 	struct fdtbus_interrupt_controller *c_ic;
     53 	void *c_ih;
     54 
     55 	LIST_ENTRY(fdtbus_interrupt_cookie) c_next;
     56 };
     57 
     58 static LIST_HEAD(, fdtbus_interrupt_cookie) fdtbus_interrupt_cookies =
     59     LIST_HEAD_INITIALIZER(fdtbus_interrupt_cookies);
     60 
     61 static const u_int *	get_specifier_by_index(int, int, int *);
     62 static const u_int *	get_specifier_from_map(int, const u_int *, int *);
     63 
     64 /*
     65  * Find the interrupt controller for a given node. This function will either
     66  * return the phandle of the interrupt controller for this node, or the phandle
     67  * of a node containing an interrupt-map table that can be used to find the
     68  * real interrupt controller.
     69  */
     70 static int
     71 fdtbus_get_interrupt_parent(int phandle)
     72 {
     73 	int iparent = phandle;
     74 
     75 	do {
     76 		/*
     77 		 * If the node is an interrupt-controller, we are done. Note that
     78 		 * a node cannot be an interrupt-controller for itself, so we skip
     79 		 * the leaf node here.
     80 		 */
     81 		if (phandle != iparent && of_hasprop(iparent, "interrupt-controller"))
     82 			return iparent;
     83 
     84 		/*
     85 		 * If the node has an explicit interrupt-parent, follow the reference.
     86 		 */
     87 		if (of_hasprop(iparent, "interrupt-parent"))
     88 			return fdtbus_get_phandle(iparent, "interrupt-parent");
     89 
     90 		/*
     91 		 * If the node has an interrupt-map, use it. The caller is responsible
     92 		 * for parsing the interrupt-map and finding the real interrupt parent.
     93 		 */
     94 		if (phandle != iparent && of_hasprop(iparent, "interrupt-map"))
     95 			return iparent;
     96 
     97 		/*
     98 		 * Continue searching up the tree.
     99 		 */
    100 		iparent = OF_parent(iparent);
    101 	} while (iparent > 0);
    102 
    103 	return 0;
    104 }
    105 
    106 static struct fdtbus_interrupt_controller *
    107 fdtbus_get_interrupt_controller(int phandle)
    108 {
    109 	struct fdtbus_interrupt_controller * ic;
    110 	LIST_FOREACH(ic, &fdtbus_interrupt_controllers, ic_next) {
    111 		if (ic->ic_phandle == phandle)
    112 			return ic;
    113 	}
    114 	return NULL;
    115 }
    116 
    117 int
    118 fdtbus_register_interrupt_controller(device_t dev, int phandle,
    119     const struct fdtbus_interrupt_controller_func *funcs)
    120 {
    121 	struct fdtbus_interrupt_controller *ic;
    122 
    123 	ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
    124 	ic->ic_dev = dev;
    125 	ic->ic_phandle = phandle;
    126 	ic->ic_funcs = funcs;
    127 
    128 	LIST_INSERT_HEAD(&fdtbus_interrupt_controllers, ic, ic_next);
    129 
    130 	return 0;
    131 }
    132 
    133 void *
    134 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
    135     int (*func)(void *), void *arg)
    136 {
    137 	const u_int *specifier;
    138 	int ihandle;
    139 
    140 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    141 	if (specifier == NULL)
    142 		return NULL;
    143 
    144 	return fdtbus_intr_establish_raw(ihandle, specifier, ipl,
    145 	    flags, func, arg);
    146 }
    147 
    148 void *
    149 fdtbus_intr_establish_raw(int ihandle, const u_int *specifier, int ipl,
    150     int flags, int (*func)(void *), void *arg)
    151 {
    152 	struct fdtbus_interrupt_controller *ic;
    153 	struct fdtbus_interrupt_cookie *c;
    154 	void *ih;
    155 
    156 	ic = fdtbus_get_interrupt_controller(ihandle);
    157 	if (ic == NULL)
    158 		return NULL;
    159 
    160 	ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier),
    161 	    ipl, flags, func, arg);
    162 	if (ih != NULL) {
    163 		c = kmem_alloc(sizeof(*c), KM_SLEEP);
    164 		c->c_ic = ic;
    165 		c->c_ih = ih;
    166 		LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next);
    167 	}
    168 
    169 	return ih;
    170 }
    171 
    172 void
    173 fdtbus_intr_disestablish(int phandle, void *cookie)
    174 {
    175 	struct fdtbus_interrupt_controller *ic = NULL;
    176 	struct fdtbus_interrupt_cookie *c;
    177 
    178 	LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) {
    179 		if (c->c_ih == cookie) {
    180 			ic = c->c_ic;
    181 			LIST_REMOVE(c, c_next);
    182 			kmem_free(c, sizeof(*c));
    183 			break;
    184 		}
    185 	}
    186 
    187 	if (ic == NULL)
    188 		panic("%s: interrupt handle not valid", __func__);
    189 
    190 	return ic->ic_funcs->disestablish(ic->ic_dev, cookie);
    191 }
    192 
    193 bool
    194 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    195 {
    196 	const u_int *specifier;
    197 	int ihandle;
    198 
    199 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    200 	if (specifier == NULL)
    201 		return false;
    202 
    203 	return fdtbus_intr_str_raw(ihandle, specifier, buf, buflen);
    204 }
    205 
    206 bool
    207 fdtbus_intr_str_raw(int ihandle, const u_int *specifier, char *buf, size_t buflen)
    208 {
    209 	struct fdtbus_interrupt_controller *ic;
    210 
    211 	ic = fdtbus_get_interrupt_controller(ihandle);
    212 	if (ic == NULL)
    213 		return false;
    214 
    215 	return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen);
    216 }
    217 
    218 static int
    219 find_address_cells(int phandle)
    220 {
    221 	uint32_t cells;
    222 
    223 	if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
    224 		cells = 2;
    225 
    226 	return cells;
    227 }
    228 
    229 static int
    230 find_interrupt_cells(int phandle)
    231 {
    232 	uint32_t cells;
    233 
    234 	while (phandle > 0) {
    235 		if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
    236 			return cells;
    237 		phandle = OF_parent(phandle);
    238 	}
    239 	return 0;
    240 }
    241 
    242 static const u_int *
    243 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
    244 {
    245 	const u_int *result = NULL;
    246 	int len, resid;
    247 
    248 	const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
    249 	if (data == NULL || len <= 0)
    250 		return NULL;
    251 	resid = len;
    252 
    253 	/* child unit address: #address-cells prop of child bus node */
    254 	const int cua_cells = find_address_cells(phandle);
    255 	/* child interrupt specifier: #interrupt-cells of the nexus node */
    256 	const int cis_cells = find_interrupt_cells(phandle);
    257 
    258 	/* Offset (in cells) from map entry to child unit address specifier */
    259 	const u_int cua_off = 0;
    260 	/* Offset (in cells) from map entry to child interrupt specifier */
    261 	const u_int cis_off = cua_off + cua_cells;
    262 	/* Offset (in cells) from map entry to interrupt parent phandle */
    263 	const u_int ip_off = cis_off + cis_cells;
    264 	/* Offset (in cells) from map entry to parent unit specifier */
    265 	const u_int pus_off = ip_off + 1;
    266 
    267 	const u_int *p = (const u_int *)data;
    268 	while (resid > 0) {
    269 		/* Interrupt parent phandle */
    270 		const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
    271 
    272 		/* parent unit specifier: #address-cells of the interrupt parent */
    273 		const u_int pus_cells = find_address_cells(iparent);
    274 		/* parent interrupt specifier: #interrupt-cells of the interrupt parent */
    275 		const u_int pis_cells = find_interrupt_cells(iparent);
    276 
    277 		/* Offset (in cells) from map entry to parent interrupt specifier */
    278 		const u_int pis_off = pus_off + pus_cells;
    279 
    280 #ifdef FDT_INTR_DEBUG
    281 		printf(" intr map (len %d):", pis_off + pis_cells);
    282 		for (int i = 0; i < pis_off + pis_cells; i++)
    283 			printf(" %08x", p[i]);
    284 		printf("\n");
    285 #endif
    286 
    287 		if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
    288 #ifdef FDT_INTR_DEBUG
    289 			const int slen = pus_cells + pis_cells;
    290 			printf(" intr map match iparent %08x slen %d:", iparent, slen);
    291 			for (int i = 0; i < slen; i++)
    292 				printf(" %08x", p[pus_off + i]);
    293 			printf("\n");
    294 #endif
    295 			result = &p[pus_off];
    296 			*piphandle = iparent;
    297 			goto done;
    298 		}
    299 		/* Determine the length of the entry and skip that many
    300 		 * 32 bit words
    301 		 */
    302 		const u_int reclen = pis_off + pis_cells;
    303 		resid -= reclen * sizeof(u_int);
    304 		p += reclen;
    305 	}
    306 
    307 done:
    308 	return result;
    309 }
    310 
    311 static const u_int *
    312 get_specifier_by_index(int phandle, int pindex, int *piphandle)
    313 {
    314 	const u_int *node_specifier;
    315 	int interrupt_parent, interrupt_cells, len;
    316 
    317 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    318 	if (interrupt_parent <= 0)
    319 		return NULL;
    320 
    321 	node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
    322 	if (node_specifier == NULL)
    323 		return NULL;
    324 
    325 	interrupt_cells = find_interrupt_cells(interrupt_parent);
    326 	if (interrupt_cells <= 0)
    327 		return NULL;
    328 
    329 	const u_int spec_length = len / 4;
    330 	const u_int nintr = spec_length / interrupt_cells;
    331 	if (pindex >= nintr)
    332 		return NULL;
    333 
    334 	node_specifier += (interrupt_cells * pindex);
    335 
    336 	if (of_hasprop(interrupt_parent, "interrupt-map"))
    337 		return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
    338 
    339 	*piphandle = interrupt_parent;
    340 
    341 	return node_specifier;
    342 }
    343