Home | History | Annotate | Line # | Download | only in fdt
fdt_intr.c revision 1.13
      1 /* $NetBSD: fdt_intr.c,v 1.13 2018/07/02 12:17:05 jmcneill 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 1.13 2018/07/02 12:17:05 jmcneill 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 
     56 static u_int *	get_specifier_by_index(int, int, int *);
     57 static u_int *	get_specifier_from_map(int, const u_int *, int *);
     58 
     59 static int
     60 fdtbus_get_interrupt_parent(int phandle)
     61 {
     62 	u_int interrupt_parent;
     63 
     64 	while (phandle >= 0) {
     65 		if (of_getprop_uint32(phandle, "interrupt-parent",
     66 		    &interrupt_parent) == 0) {
     67 			break;
     68 		}
     69 		if (phandle == 0) {
     70 			return -1;
     71 		}
     72 		phandle = OF_parent(phandle);
     73 	}
     74 	if (phandle < 0) {
     75 		return -1;
     76 	}
     77 
     78 	const void *data = fdtbus_get_data();
     79 	const int off = fdt_node_offset_by_phandle(data, interrupt_parent);
     80 	if (off < 0) {
     81 		return -1;
     82 	}
     83 
     84 	return fdtbus_offset2phandle(off);
     85 }
     86 
     87 static struct fdtbus_interrupt_controller *
     88 fdtbus_get_interrupt_controller(int phandle)
     89 {
     90 	struct fdtbus_interrupt_controller * ic;
     91 	LIST_FOREACH(ic, &fdtbus_interrupt_controllers, ic_next) {
     92 		if (ic->ic_phandle == phandle)
     93 			return ic;
     94 	}
     95 	return NULL;
     96 }
     97 
     98 int
     99 fdtbus_register_interrupt_controller(device_t dev, int phandle,
    100     const struct fdtbus_interrupt_controller_func *funcs)
    101 {
    102 	struct fdtbus_interrupt_controller *ic;
    103 
    104 	ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
    105 	ic->ic_dev = dev;
    106 	ic->ic_phandle = phandle;
    107 	ic->ic_funcs = funcs;
    108 
    109 	LIST_INSERT_HEAD(&fdtbus_interrupt_controllers, ic, ic_next);
    110 
    111 	return 0;
    112 }
    113 
    114 void *
    115 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
    116     int (*func)(void *), void *arg)
    117 {
    118 	struct fdtbus_interrupt_controller *ic;
    119 	struct fdtbus_interrupt_cookie *c = NULL;
    120 	u_int *specifier;
    121 	int ihandle;
    122 	void *ih;
    123 
    124 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    125 	if (specifier == NULL)
    126 		return NULL;
    127 
    128 	ic = fdtbus_get_interrupt_controller(ihandle);
    129 	if (ic == NULL)
    130 		return NULL;
    131 
    132 	ih = ic->ic_funcs->establish(ic->ic_dev, specifier,
    133 	    ipl, flags, func, arg);
    134 	if (ih != NULL) {
    135 		c = kmem_alloc(sizeof(*c), KM_SLEEP);
    136 		c->c_ic = ic;
    137 		c->c_ih = ih;
    138 	}
    139 
    140 	return c;
    141 }
    142 
    143 void
    144 fdtbus_intr_disestablish(int phandle, void *cookie)
    145 {
    146 	struct fdtbus_interrupt_cookie *c = cookie;
    147 	struct fdtbus_interrupt_controller *ic = c->c_ic;
    148 	void *ih = c->c_ih;
    149 
    150 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
    151 }
    152 
    153 bool
    154 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
    155 {
    156 	struct fdtbus_interrupt_controller *ic;
    157 	u_int *specifier;
    158 	int ihandle;
    159 
    160 	specifier = get_specifier_by_index(phandle, index, &ihandle);
    161 
    162 	ic = fdtbus_get_interrupt_controller(ihandle);
    163 	if (ic == NULL)
    164 		return false;
    165 
    166 	return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
    167 }
    168 
    169 static int
    170 find_address_cells(int phandle)
    171 {
    172 	uint32_t cells;
    173 
    174 	if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
    175 		cells = 2;
    176 
    177 	return cells;
    178 }
    179 
    180 static int
    181 find_interrupt_cells(int phandle)
    182 {
    183 	uint32_t cells;
    184 
    185 	while (phandle > 0) {
    186 		if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
    187 			return cells;
    188 		phandle = OF_parent(phandle);
    189 	}
    190 	return 0;
    191 }
    192 
    193 static u_int *
    194 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
    195 {
    196 	u_int *result = NULL;
    197 	int len, resid;
    198 
    199 	const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
    200 	if (data == NULL || len <= 0)
    201 		return NULL;
    202 	resid = len;
    203 
    204 	/* child unit address: #address-cells prop of child bus node */
    205 	const int cua_cells = find_address_cells(phandle);
    206 	/* child interrupt specifier: #interrupt-cells of the nexus node */
    207 	const int cis_cells = find_interrupt_cells(phandle);
    208 
    209 	/* Offset (in cells) from map entry to child unit address specifier */
    210 	const u_int cua_off = 0;
    211 	/* Offset (in cells) from map entry to child interrupt specifier */
    212 	const u_int cis_off = cua_off + cua_cells;
    213 	/* Offset (in cells) from map entry to interrupt parent phandle */
    214 	const u_int ip_off = cis_off + cis_cells;
    215 	/* Offset (in cells) from map entry to parent unit specifier */
    216 	const u_int pus_off = ip_off + 1;
    217 
    218 	const u_int *p = (const u_int *)data;
    219 	while (resid > 0) {
    220 		/* Interrupt parent phandle */
    221 		const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
    222 
    223 		/* parent unit specifier: #address-cells of the interrupt parent */
    224 		const u_int pus_cells = find_address_cells(iparent);
    225 		/* parent interrupt specifier: #interrupt-cells of the interrupt parent */
    226 		const u_int pis_cells = find_interrupt_cells(iparent);
    227 
    228 		/* Offset (in cells) from map entry to parent interrupt specifier */
    229 		const u_int pis_off = pus_off + pus_cells;
    230 
    231 #ifdef FDT_INTR_DEBUG
    232 		printf(" intr map (len %d):", pis_off + pis_cells);
    233 		for (int i = 0; i < pis_off + pis_cells; i++)
    234 			printf(" %08x", p[i]);
    235 		printf("\n");
    236 #endif
    237 
    238 		if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
    239 			const int slen = pus_cells + pis_cells;
    240 #ifdef FDT_INTR_DEBUG
    241 			printf(" intr map match iparent %08x slen %d:", iparent, slen);
    242 			for (int i = 0; i < slen; i++)
    243 				printf(" %08x", p[pus_off + i]);
    244 			printf("\n");
    245 #endif
    246 			result = kmem_alloc(slen, KM_SLEEP);
    247 			memcpy(result, &p[pus_off], slen * 4);
    248 			*piphandle = iparent;
    249 			goto done;
    250 		}
    251 		/* Determine the length of the entry and skip that many
    252 		 * 32 bit words
    253 		 */
    254 		const u_int reclen = pis_off + pis_cells;
    255 		resid -= reclen * sizeof(u_int);
    256 		p += reclen;
    257 	}
    258 
    259 done:
    260 	return result;
    261 }
    262 
    263 static u_int *
    264 get_specifier_by_index(int phandle, int pindex, int *piphandle)
    265 {
    266 	const u_int *node_specifier;
    267 	u_int *specifier;
    268 	int interrupt_parent, interrupt_cells, len;
    269 
    270 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
    271 	if (interrupt_parent <= 0)
    272 		return NULL;
    273 
    274 	node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
    275 	if (node_specifier == NULL)
    276 		return NULL;
    277 
    278 	interrupt_cells = find_interrupt_cells(interrupt_parent);
    279 	if (interrupt_cells <= 0)
    280 		return NULL;
    281 
    282 	const u_int spec_length = len / 4;
    283 	const u_int nintr = spec_length / interrupt_cells;
    284 	if (pindex >= nintr)
    285 		return NULL;
    286 
    287 	node_specifier += (interrupt_cells * pindex);
    288 
    289 	if (of_hasprop(interrupt_parent, "interrupt-map"))
    290 		return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
    291 
    292 	specifier = kmem_alloc(interrupt_cells * sizeof(u_int), KM_SLEEP);
    293 	memcpy(specifier, node_specifier, interrupt_cells * 4);
    294 
    295 	*piphandle = interrupt_parent;
    296 
    297 	return specifier;
    298 }
    299