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fdt_intr.c revision 1.11.6.1
      1 /* $NetBSD: fdt_intr.c,v 1.11.6.1 2018/07/28 04:37:44 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 1.11.6.1 2018/07/28 04:37:44 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 (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 	struct fdtbus_interrupt_controller *ic;
    138 	struct fdtbus_interrupt_cookie *c = NULL;
    139 	const u_int *specifier;
    140 	int ihandle;
    141 	void *ih;
    142 
    143 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    144 	if (specifier == NULL)
    145 		return NULL;
    146 
    147 	ic = fdtbus_get_interrupt_controller(ihandle);
    148 	if (ic == NULL)
    149 		return NULL;
    150 
    151 	ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier),
    152 	    ipl, flags, func, arg);
    153 	if (ih != NULL) {
    154 		c = kmem_alloc(sizeof(*c), KM_SLEEP);
    155 		c->c_ic = ic;
    156 		c->c_ih = ih;
    157 		LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next);
    158 	}
    159 
    160 	return ih;
    161 }
    162 
    163 void
    164 fdtbus_intr_disestablish(int phandle, void *cookie)
    165 {
    166 	struct fdtbus_interrupt_controller *ic = NULL;
    167 	struct fdtbus_interrupt_cookie *c;
    168 
    169 	LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) {
    170 		if (c->c_ih == cookie) {
    171 			ic = c->c_ic;
    172 			LIST_REMOVE(c, c_next);
    173 			kmem_free(c, sizeof(*c));
    174 			break;
    175 		}
    176 	}
    177 
    178 	if (ic != NULL)
    179 		panic("%s: interrupt handle not valid", __func__);
    180 
    181 	return ic->ic_funcs->disestablish(ic->ic_dev, cookie);
    182 }
    183 
    184 bool
    185 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    186 {
    187 	struct fdtbus_interrupt_controller *ic;
    188 	const u_int *specifier;
    189 	int ihandle;
    190 
    191 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    192 
    193 	ic = fdtbus_get_interrupt_controller(ihandle);
    194 	if (ic == NULL)
    195 		return false;
    196 
    197 	return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen);
    198 }
    199 
    200 static int
    201 find_address_cells(int phandle)
    202 {
    203 	uint32_t cells;
    204 
    205 	if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
    206 		cells = 2;
    207 
    208 	return cells;
    209 }
    210 
    211 static int
    212 find_interrupt_cells(int phandle)
    213 {
    214 	uint32_t cells;
    215 
    216 	while (phandle > 0) {
    217 		if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
    218 			return cells;
    219 		phandle = OF_parent(phandle);
    220 	}
    221 	return 0;
    222 }
    223 
    224 static const u_int *
    225 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
    226 {
    227 	const u_int *result = NULL;
    228 	int len, resid;
    229 
    230 	const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
    231 	if (data == NULL || len <= 0)
    232 		return NULL;
    233 	resid = len;
    234 
    235 	/* child unit address: #address-cells prop of child bus node */
    236 	const int cua_cells = find_address_cells(phandle);
    237 	/* child interrupt specifier: #interrupt-cells of the nexus node */
    238 	const int cis_cells = find_interrupt_cells(phandle);
    239 
    240 	/* Offset (in cells) from map entry to child unit address specifier */
    241 	const u_int cua_off = 0;
    242 	/* Offset (in cells) from map entry to child interrupt specifier */
    243 	const u_int cis_off = cua_off + cua_cells;
    244 	/* Offset (in cells) from map entry to interrupt parent phandle */
    245 	const u_int ip_off = cis_off + cis_cells;
    246 	/* Offset (in cells) from map entry to parent unit specifier */
    247 	const u_int pus_off = ip_off + 1;
    248 
    249 	const u_int *p = (const u_int *)data;
    250 	while (resid > 0) {
    251 		/* Interrupt parent phandle */
    252 		const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
    253 
    254 		/* parent unit specifier: #address-cells of the interrupt parent */
    255 		const u_int pus_cells = find_address_cells(iparent);
    256 		/* parent interrupt specifier: #interrupt-cells of the interrupt parent */
    257 		const u_int pis_cells = find_interrupt_cells(iparent);
    258 
    259 		/* Offset (in cells) from map entry to parent interrupt specifier */
    260 		const u_int pis_off = pus_off + pus_cells;
    261 
    262 #ifdef FDT_INTR_DEBUG
    263 		printf(" intr map (len %d):", pis_off + pis_cells);
    264 		for (int i = 0; i < pis_off + pis_cells; i++)
    265 			printf(" %08x", p[i]);
    266 		printf("\n");
    267 #endif
    268 
    269 		if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
    270 #ifdef FDT_INTR_DEBUG
    271 			const int slen = pus_cells + pis_cells;
    272 			printf(" intr map match iparent %08x slen %d:", iparent, slen);
    273 			for (int i = 0; i < slen; i++)
    274 				printf(" %08x", p[pus_off + i]);
    275 			printf("\n");
    276 #endif
    277 			result = &p[pus_off];
    278 			*piphandle = iparent;
    279 			goto done;
    280 		}
    281 		/* Determine the length of the entry and skip that many
    282 		 * 32 bit words
    283 		 */
    284 		const u_int reclen = pis_off + pis_cells;
    285 		resid -= reclen * sizeof(u_int);
    286 		p += reclen;
    287 	}
    288 
    289 done:
    290 	return result;
    291 }
    292 
    293 static const u_int *
    294 get_specifier_by_index(int phandle, int pindex, int *piphandle)
    295 {
    296 	const u_int *node_specifier;
    297 	int interrupt_parent, interrupt_cells, len;
    298 
    299 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    300 	if (interrupt_parent <= 0)
    301 		return NULL;
    302 
    303 	node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
    304 	if (node_specifier == NULL)
    305 		return NULL;
    306 
    307 	interrupt_cells = find_interrupt_cells(interrupt_parent);
    308 	if (interrupt_cells <= 0)
    309 		return NULL;
    310 
    311 	const u_int spec_length = len / 4;
    312 	const u_int nintr = spec_length / interrupt_cells;
    313 	if (pindex >= nintr)
    314 		return NULL;
    315 
    316 	node_specifier += (interrupt_cells * pindex);
    317 
    318 	if (of_hasprop(interrupt_parent, "interrupt-map"))
    319 		return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
    320 
    321 	*piphandle = interrupt_parent;
    322 
    323 	return node_specifier;
    324 }
    325