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fdt_intr.c revision 1.23
      1 /* $NetBSD: fdt_intr.c,v 1.23 2019/11/16 21:53:38 mlelstv 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 1.23 2019/11/16 21:53:38 mlelstv 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 		printf("%s: handle not found %u@%x\n",__func__,index,phandle);
    143 		return NULL;
    144 	}
    145 
    146 	return fdtbus_intr_establish_raw(ihandle, specifier, ipl,
    147 	    flags, func, arg);
    148 }
    149 
    150 void *
    151 fdtbus_intr_establish_byname(int phandle, const char *name, int ipl,
    152     int flags, int (*func)(void *), void *arg)
    153 {
    154 	u_int index;
    155 	int err;
    156 
    157 	err = fdtbus_get_index(phandle, "interrupt-names", name, &index);
    158 	if (err != 0)
    159 		return NULL;
    160 
    161 	return fdtbus_intr_establish(phandle, index, ipl, flags, func, arg);
    162 }
    163 
    164 void *
    165 fdtbus_intr_establish_raw(int ihandle, const u_int *specifier, int ipl,
    166     int flags, int (*func)(void *), void *arg)
    167 {
    168 	struct fdtbus_interrupt_controller *ic;
    169 	struct fdtbus_interrupt_cookie *c;
    170 	void *ih;
    171 
    172 	ic = fdtbus_get_interrupt_controller(ihandle);
    173 	if (ic == NULL) {
    174 		printf("%s: ihandle %d is not a controller\n",__func__,ihandle);
    175 		return NULL;
    176 	}
    177 
    178 	ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier),
    179 	    ipl, flags, func, arg);
    180 	if (ih != NULL) {
    181 		c = kmem_alloc(sizeof(*c), KM_SLEEP);
    182 		c->c_ic = ic;
    183 		c->c_ih = ih;
    184 		LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next);
    185 	}
    186 
    187 	return ih;
    188 }
    189 
    190 void
    191 fdtbus_intr_disestablish(int phandle, void *cookie)
    192 {
    193 	struct fdtbus_interrupt_controller *ic = NULL;
    194 	struct fdtbus_interrupt_cookie *c;
    195 
    196 	LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) {
    197 		if (c->c_ih == cookie) {
    198 			ic = c->c_ic;
    199 			LIST_REMOVE(c, c_next);
    200 			kmem_free(c, sizeof(*c));
    201 			break;
    202 		}
    203 	}
    204 
    205 	if (ic == NULL)
    206 		panic("%s: interrupt handle not valid", __func__);
    207 
    208 	return ic->ic_funcs->disestablish(ic->ic_dev, cookie);
    209 }
    210 
    211 bool
    212 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    213 {
    214 	const u_int *specifier;
    215 	int ihandle;
    216 
    217 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    218 	if (specifier == NULL)
    219 		return false;
    220 
    221 	return fdtbus_intr_str_raw(ihandle, specifier, buf, buflen);
    222 }
    223 
    224 bool
    225 fdtbus_intr_str_raw(int ihandle, const u_int *specifier, char *buf, size_t buflen)
    226 {
    227 	struct fdtbus_interrupt_controller *ic;
    228 
    229 	ic = fdtbus_get_interrupt_controller(ihandle);
    230 	if (ic == NULL)
    231 		return false;
    232 
    233 	return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen);
    234 }
    235 
    236 static int
    237 find_address_cells(int phandle)
    238 {
    239 	uint32_t cells;
    240 
    241 	if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
    242 		cells = 2;
    243 
    244 	return cells;
    245 }
    246 
    247 static int
    248 find_interrupt_cells(int phandle)
    249 {
    250 	uint32_t cells;
    251 
    252 	while (phandle > 0) {
    253 		if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
    254 			return cells;
    255 		phandle = OF_parent(phandle);
    256 	}
    257 	return 0;
    258 }
    259 
    260 static const u_int *
    261 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
    262 {
    263 	const u_int *result = NULL;
    264 	int len, resid;
    265 
    266 	const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
    267 	if (data == NULL || len <= 0)
    268 		return NULL;
    269 	resid = len;
    270 
    271 	/* child unit address: #address-cells prop of child bus node */
    272 	const int cua_cells = find_address_cells(phandle);
    273 	/* child interrupt specifier: #interrupt-cells of the nexus node */
    274 	const int cis_cells = find_interrupt_cells(phandle);
    275 
    276 	/* Offset (in cells) from map entry to child unit address specifier */
    277 	const u_int cua_off = 0;
    278 	/* Offset (in cells) from map entry to child interrupt specifier */
    279 	const u_int cis_off = cua_off + cua_cells;
    280 	/* Offset (in cells) from map entry to interrupt parent phandle */
    281 	const u_int ip_off = cis_off + cis_cells;
    282 	/* Offset (in cells) from map entry to parent unit specifier */
    283 	const u_int pus_off = ip_off + 1;
    284 
    285 	const u_int *p = (const u_int *)data;
    286 	while (resid > 0) {
    287 		/* Interrupt parent phandle */
    288 		const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
    289 
    290 		/* parent unit specifier: #address-cells of the interrupt parent */
    291 		const u_int pus_cells = find_address_cells(iparent);
    292 		/* parent interrupt specifier: #interrupt-cells of the interrupt parent */
    293 		const u_int pis_cells = find_interrupt_cells(iparent);
    294 
    295 		/* Offset (in cells) from map entry to parent interrupt specifier */
    296 		const u_int pis_off = pus_off + pus_cells;
    297 
    298 #ifdef FDT_INTR_DEBUG
    299 		printf(" intr map (len %d):", pis_off + pis_cells);
    300 		for (int i = 0; i < pis_off + pis_cells; i++)
    301 			printf(" %08x", p[i]);
    302 		printf("\n");
    303 #endif
    304 
    305 		if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
    306 #ifdef FDT_INTR_DEBUG
    307 			const int slen = pus_cells + pis_cells;
    308 			printf(" intr map match iparent %08x slen %d:", iparent, slen);
    309 			for (int i = 0; i < slen; i++)
    310 				printf(" %08x", p[pus_off + i]);
    311 			printf("\n");
    312 #endif
    313 			result = &p[pus_off];
    314 			*piphandle = iparent;
    315 			goto done;
    316 		}
    317 		/* Determine the length of the entry and skip that many
    318 		 * 32 bit words
    319 		 */
    320 		const u_int reclen = pis_off + pis_cells;
    321 		resid -= reclen * sizeof(u_int);
    322 		p += reclen;
    323 	}
    324 
    325 done:
    326 	return result;
    327 }
    328 
    329 
    330 static const u_int *
    331 get_specifier_from_extended(int phandle, int pindex, int *piphandle)
    332 {
    333 	const u_int *result = NULL;
    334 	struct fdt_phandle_data data;
    335 
    336 	if (fdtbus_get_phandle_with_data(phandle, "interrupts-extended",
    337 		"#interrupt-cells", pindex, &data) == 0) {
    338 		*piphandle = data.phandle;
    339 		result = data.values;
    340 	}
    341 
    342 	return result;
    343 }
    344 
    345 static const u_int *
    346 get_specifier_by_index(int phandle, int pindex, int *piphandle)
    347 {
    348 	const u_int *node_specifier;
    349 	int interrupt_parent, interrupt_cells, len;
    350 
    351 	if (of_hasprop(phandle, "interrupts-extended"))
    352 		return get_specifier_from_extended(phandle, pindex, piphandle);
    353 
    354 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    355 	if (interrupt_parent <= 0)
    356 		return NULL;
    357 
    358 	node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
    359 	if (node_specifier == NULL)
    360 		return NULL;
    361 
    362 	interrupt_cells = find_interrupt_cells(interrupt_parent);
    363 	if (interrupt_cells <= 0)
    364 		return NULL;
    365 
    366 	const u_int spec_length = len / 4;
    367 	const u_int nintr = spec_length / interrupt_cells;
    368 	if (pindex >= nintr)
    369 		return NULL;
    370 
    371 	node_specifier += (interrupt_cells * pindex);
    372 
    373 	if (of_hasprop(interrupt_parent, "interrupt-map"))
    374 		return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
    375 
    376 	*piphandle = interrupt_parent;
    377 
    378 	return node_specifier;
    379 }
    380