xref: /netbsd-src/sys/dev/fdt/fdt_intr.c (revision 946379e7b37692fc43f68eb0d1c10daa0a7f3b6c)
1 /* $NetBSD: fdt_intr.c,v 1.7 2016/01/10 23:01:29 marty Exp $ */
2 
3 /*-
4  * Copyright (c) 2015 Jared D. McNeill <jmcneill@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 1.7 2016/01/10 23:01:29 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, u_int *spec);
51 static u_int *get_specifier_by_index(int phandle, int pindex, u_int *spec);
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 	void * result = NULL;
126 	u_int *specifier;
127 	u_int spec_length;
128 	int ihandle;
129 	struct fdtbus_interrupt_controller *ic;
130 
131 	if (has_interrupt_map(phandle)) {
132 		specifier = get_entry_from_map(phandle, index, &spec_length);
133 		ihandle = be32toh(specifier[1]);
134 		ihandle = fdtbus_get_phandle_from_native(ihandle);
135 		specifier += 2;
136 	} else {
137 		specifier = get_specifier_by_index(phandle, index,
138 						   &spec_length);
139 		ihandle = phandle;
140 	}
141 	if (specifier == NULL) {
142 		printf("%s: Unable to get specifier %d for phandle %d\n",
143 		       __func__, index, phandle);
144 		goto done;
145 	}
146 	ic = fdtbus_get_interrupt_controller(ihandle);
147 	if (ic == NULL) {
148 		printf("%s: Unable to get interrupt controller for %d\n",
149 		       __func__, ihandle);
150 		goto done;
151 	}
152 	result = ic->ic_funcs->establish(ic->ic_dev, specifier,
153 					       ipl, flags, func, arg);
154 done:
155 	if (has_interrupt_map(phandle))
156 	    specifier -= 2;
157 	if (specifier && spec_length > 0)
158 		kmem_free(specifier, spec_length);
159 	return result;
160 }
161 
162 void
163 fdtbus_intr_disestablish(int phandle, void *ih)
164 {
165 	struct fdtbus_interrupt_controller *ic;
166 
167 	ic = fdtbus_get_interrupt_controller(phandle);
168 	KASSERT(ic != NULL);
169 
170 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
171 }
172 
173 bool
174 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
175 {
176 	bool result = false;
177 	struct fdtbus_interrupt_controller *ic;
178 	int ihandle;
179 	u_int *specifier;
180 	u_int spec_length;
181 	if (has_interrupt_map(phandle)) {
182 		specifier = get_entry_from_map(phandle, index,
183 			&spec_length);
184 		ihandle = be32toh(specifier[1]);
185 		ihandle = fdtbus_get_phandle_from_native(ihandle);
186 		specifier += 2;
187 	} else {
188 		ihandle = phandle;
189 		specifier = get_specifier_by_index(phandle, index,
190 						   &spec_length);
191 	}
192 	if (specifier == NULL) {
193 		printf("%s: Unable to get specifier %d for phandle %d\n",
194 		       __func__, index, phandle);
195 		goto done;
196 	}
197 	ic = fdtbus_get_interrupt_controller(ihandle);
198 	if (ic == NULL) {
199 		printf("%s: Unable to get interrupt controller for %d\n",
200 		       __func__, ihandle);
201 		goto done;
202 	}
203 	result = ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
204 done:
205 	if (has_interrupt_map(phandle))
206 	    specifier -= 2;
207 	if (specifier && spec_length > 0)
208 		kmem_free(specifier, spec_length);
209 	return result;
210 }
211 
212 /*
213  * Devices that have multiple interrupts, connected to two or more
214  * interrupt sources use an interrupt map rather than a simple
215  * interrupt parent to indicate which interrupt controller goes with
216  * which map.  The interrupt map is contained in the node describing
217  * the first level parent and contains one entry per interrupt:
218  *   index -- the index of the entry in the map
219  *   &parent -- pointer to the node containing the actual interrupt parent
220  *              for the specific interrupt
221  *  [specifier 0 - specifier N-1] The N (usually 2 or 3) 32 bit words
222  *              that make up the specifier.
223  *
224  * returns true if the device phandle has an interrupt-parent that
225  * contains an interrupt-map.
226  */
227 static bool
228 has_interrupt_map(int phandle)
229 {
230 	int ic_phandle;
231 	of_getprop_uint32(phandle, "interrupt-parent", &ic_phandle);
232 	ic_phandle = fdtbus_get_phandle_from_native(ic_phandle);
233 	if (ic_phandle <= 0)
234 		return false;
235 	int len = OF_getproplen(ic_phandle, "interrupt-map");
236 	if (len > 0)
237 		return true;
238 	return false;
239 }
240 
241 /*
242  * Walk the specifier map and return a pointer to the map entry
243  * associated with pindex.  Return null if there is no entry.
244  *
245  * Because the length of the specifier depends on the interrupt
246  * controller, we need to repeatedly obtain interrupt-celss for
247  * the controller for the current index.
248  *
249  */
250 static u_int *
251 get_entry_from_map(int phandle, int pindex, u_int *spec_length)
252 {
253 	int intr_cells;
254 	int intr_parent;
255 	u_int *result = NULL;
256 
257 	of_getprop_uint32(phandle, "#interrupt-cells", &intr_cells);
258 	of_getprop_uint32(phandle, "interrupt-parent", &intr_parent);
259 
260 	intr_parent = fdtbus_get_phandle_from_native(intr_parent);
261 	int len = OF_getproplen(intr_parent, "interrupt-map");
262 	if (len <= 0) {
263 		printf("%s: no interrupt-map.\n", __func__);
264 		return NULL;
265 	}
266 	uint resid = len;
267 	char *data = kmem_alloc(len, KM_SLEEP);
268 	len = OF_getprop(intr_parent, "interrupt-map", data, len);
269 	if (len <= 0) {
270 		printf("%s:  can't get property interrupt-map.\n", __func__);
271 		goto done;
272 	}
273 	u_int *p = (u_int *)data;
274 
275 	while (resid > 0) {
276 		u_int index = be32toh(p[0]);
277 		const u_int parent = fdtbus_get_phandle_from_native(be32toh(p[intr_cells]));
278 		u_int pintr_cells;
279 		of_getprop_uint32(parent, "#interrupt-cells", &pintr_cells);
280 		if (index == pindex) {
281 			result = kmem_alloc((pintr_cells + 2) * sizeof(u_int),
282 					    KM_SLEEP);
283 			*spec_length = (pintr_cells + 2) * sizeof (u_int);
284 			for (int i = 0; i < pintr_cells + 2; i++)
285 				result[i] =  p[i];
286 			goto done;
287 
288 		}
289 		/* Determine the length of the entry and skip that many
290 		 * 32 bit words
291 		 */
292 		const u_int reclen = (intr_cells + pintr_cells + 1);
293 		resid -= reclen * sizeof(u_int);
294 		p += reclen;
295 	}
296 done:
297 	kmem_free(data, len);
298 	return result;
299 }
300 
301 
302 /*
303  * Devices that don't connect to more than one interrupt source use
304  * an array of specifiers.  Find the specifier that matches pindex
305  * and return a pointer to it.
306  *
307  */
308 static u_int *get_specifier_by_index(int phandle, int pindex,
309 				     u_int *spec_length)
310 {
311 	u_int *specifiers;
312 	u_int *specifier;
313 	int interrupt_parent, interrupt_cells, len;
314 
315 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
316 	if (interrupt_parent <= 0) {
317 		printf("%s: interrupt_parent sanity check failed\n", __func__);
318 		printf("%s: interrupt_parent = %d\n", __func__,
319 		       interrupt_parent);
320 		return NULL;
321 	}
322 
323 	len = OF_getprop(interrupt_parent, "#interrupt-cells",
324 			 &interrupt_cells,  sizeof(interrupt_cells));
325 	interrupt_cells = be32toh(interrupt_cells);
326 	if (len != sizeof(interrupt_cells) || interrupt_cells <= 0) {
327 		printf("%s: interrupt_cells sanity check failed\n", __func__);
328 		return NULL;
329 	}
330 
331 	len = OF_getproplen(phandle, "interrupts");
332 	if (len <= 0) {
333 		printf("%s: Couldn't get property interrupts\n", __func__);
334 		return NULL;
335 	}
336 
337 	const u_int clen = interrupt_cells * sizeof(u_int);
338 	const u_int nintr = len / interrupt_cells;
339 
340 	if (pindex >= nintr)
341 		return NULL;
342 
343 	specifiers = kmem_alloc(len, KM_SLEEP);
344 
345 	if (OF_getprop(phandle, "interrupts", specifiers, len) != len) {
346 		kmem_free(specifiers, len);
347 		return NULL;
348 	}
349 	specifier = kmem_alloc(interrupt_cells * sizeof(u_int), KM_SLEEP);
350 	*spec_length = interrupt_cells * sizeof(u_int);
351 	for (int i = 0; i < interrupt_cells; i++)
352 		specifier[i] = specifiers[pindex * clen + i];
353 	kmem_free(specifiers, len);
354 	return specifier;
355 }
356