xref: /netbsd-src/sys/dev/fdt/fdt_intr.c (revision b2a8932dbe9fdfd3d41d60d0a04b9a3ba294763d)
1 /* $NetBSD: fdt_intr.c,v 1.11 2017/06/11 12:56:36 jmcneill 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 1.11 2017/06/11 12:56:36 jmcneill 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 struct fdtbus_interrupt_cookie {
48 	struct fdtbus_interrupt_controller *c_ic;
49 	void *c_ih;
50 };
51 
52 static struct fdtbus_interrupt_controller *fdtbus_ic = NULL;
53 
54 static bool	has_interrupt_map(int);
55 static u_int *	get_specifier_by_index(int, int, int *);
56 static u_int *	get_specifier_from_map(int, int, int *);
57 
58 static int
59 fdtbus_get_interrupt_parent(int phandle)
60 {
61 	u_int interrupt_parent;
62 
63 	while (phandle >= 0) {
64 		if (of_getprop_uint32(phandle, "interrupt-parent",
65 		    &interrupt_parent) == 0) {
66 			break;
67 		}
68 		if (phandle == 0) {
69 			return -1;
70 		}
71 		phandle = OF_parent(phandle);
72 	}
73 	if (phandle < 0) {
74 		return -1;
75 	}
76 
77 	const void *data = fdtbus_get_data();
78 	const int off = fdt_node_offset_by_phandle(data, interrupt_parent);
79 	if (off < 0) {
80 		return -1;
81 	}
82 
83 	return fdtbus_offset2phandle(off);
84 }
85 
86 static struct fdtbus_interrupt_controller *
87 fdtbus_get_interrupt_controller(int phandle)
88 {
89 	struct fdtbus_interrupt_controller * ic;
90 	for (ic = fdtbus_ic; ic; ic = ic->ic_next) {
91 		if (ic->ic_phandle == phandle) {
92 			return ic;
93 		}
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 	ic->ic_next = fdtbus_ic;
110 	fdtbus_ic = ic;
111 
112 	return 0;
113 }
114 
115 void *
116 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
117     int (*func)(void *), void *arg)
118 {
119 	struct fdtbus_interrupt_controller *ic;
120 	struct fdtbus_interrupt_cookie *c = NULL;
121 	u_int *specifier;
122 	int ihandle;
123 	void *ih;
124 
125 	specifier = get_specifier_by_index(phandle, index, &ihandle);
126 	if (specifier == NULL)
127 		return NULL;
128 
129 	ic = fdtbus_get_interrupt_controller(ihandle);
130 	if (ic == NULL)
131 		return NULL;
132 
133 	ih = ic->ic_funcs->establish(ic->ic_dev, specifier,
134 	    ipl, flags, func, arg);
135 	if (ih != NULL) {
136 		c = kmem_alloc(sizeof(*c), KM_SLEEP);
137 		c->c_ic = ic;
138 		c->c_ih = ih;
139 	}
140 
141 	return c;
142 }
143 
144 void
145 fdtbus_intr_disestablish(int phandle, void *cookie)
146 {
147 	struct fdtbus_interrupt_cookie *c = cookie;
148 	struct fdtbus_interrupt_controller *ic = c->c_ic;
149 	void *ih = c->c_ih;
150 
151 	return ic->ic_funcs->disestablish(ic->ic_dev, ih);
152 }
153 
154 bool
155 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
156 {
157 	struct fdtbus_interrupt_controller *ic;
158 	u_int *specifier;
159 	int ihandle;
160 
161 	specifier = get_specifier_by_index(phandle, index, &ihandle);
162 
163 	ic = fdtbus_get_interrupt_controller(ihandle);
164 	if (ic == NULL)
165 		return false;
166 
167 	return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
168 }
169 
170 static int
171 find_interrupt_map(int phandle)
172 {
173 	while (phandle > 0) {
174 		if (of_hasprop(phandle, "interrupt-map"))
175 			return phandle;
176 		phandle = OF_parent(phandle);
177 	}
178 	return -1;
179 }
180 
181 static int
182 find_address_cells(int phandle)
183 {
184 	uint32_t cells;
185 
186 	if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
187 		cells = 2;
188 
189 	return cells;
190 }
191 
192 static int
193 find_interrupt_cells(int phandle)
194 {
195 	uint32_t cells;
196 
197 	while (phandle > 0) {
198 		if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
199 			return cells;
200 		phandle = OF_parent(phandle);
201 	}
202 	return 0;
203 }
204 
205 static bool
206 has_interrupt_map(int phandle)
207 {
208 	return find_interrupt_map(OF_parent(phandle)) != -1;
209 }
210 
211 static u_int *
212 get_specifier_from_map(int phandle, int pindex, int *piphandle)
213 {
214 	const u_int *node_specifier = NULL;
215 	u_int *result = NULL;
216 	int len, resid;
217 
218 	const u_int interrupt_cells = find_interrupt_cells(phandle);
219 	if (interrupt_cells < 1)
220 		return NULL;
221 
222 	node_specifier = fdt_getprop(fdtbus_get_data(), fdtbus_phandle2offset(phandle),
223 	    "interrupts", &len);
224 	if (node_specifier == NULL)
225 		return NULL;
226 
227 	const u_int spec_length = len / 4;
228 	const u_int nintr = spec_length / interrupt_cells;
229 	if (pindex >= nintr)
230 		return NULL;
231 
232 	node_specifier += (interrupt_cells * pindex);
233 
234 	const int nexus_phandle = find_interrupt_map(OF_parent(phandle));
235 
236 	const u_int *data = fdt_getprop(fdtbus_get_data(), fdtbus_phandle2offset(nexus_phandle),
237 	    "interrupt-map", &len);
238 	if (data == NULL || len <= 0) {
239 		printf("%s: can't get property interrupt-map.\n", __func__);
240 		return NULL;
241 	}
242 	resid = len;
243 
244 	/* child unit address: #address-cells prop of child bus node */
245 	const int cua_cells = find_address_cells(nexus_phandle);
246 	/* child interrupt specifier: #interrupt-cells of the nexus node */
247 	const int cis_cells = find_interrupt_cells(nexus_phandle);
248 
249 	/* Offset (in cells) from map entry to child unit address specifier */
250 	const u_int cua_off = 0;
251 	/* Offset (in cells) from map entry to child interrupt specifier */
252 	const u_int cis_off = cua_off + cua_cells;
253 	/* Offset (in cells) from map entry to interrupt parent phandle */
254 	const u_int ip_off = cis_off + cis_cells;
255 	/* Offset (in cells) from map entry to parent unit specifier */
256 	const u_int pus_off = ip_off + 1;
257 
258 #ifdef FDT_INTR_DEBUG
259 	printf("%s: phandle=%s nexus_phandle=%s\n", __func__,
260 	    fdt_get_name(fdtbus_get_data(), fdtbus_phandle2offset(phandle), NULL),
261 	    fdt_get_name(fdtbus_get_data(), fdtbus_phandle2offset(nexus_phandle), NULL));
262 	printf("cua_cells: %d, cis_cells: %d, ip_off = %d\n", cua_cells, cis_cells, ip_off);
263 	printf("searching for interrupt in map (data %p, len %d):", data, len);
264 	for (int i = 0; i < interrupt_cells; i++)
265 		printf(" %08x", node_specifier[i]);
266 	printf("\n");
267 #endif
268 
269 	const u_int *p = (const u_int *)data;
270 	while (resid > 0) {
271 		/* Interrupt parent phandle */
272 		const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
273 
274 		/* parent unit specifier: #address-cells of the interrupt parent */
275 		const u_int pus_cells = find_address_cells(iparent);
276 		/* parent interrupt specifier: #interrupt-cells of the interrupt parent */
277 		const u_int pis_cells = find_interrupt_cells(iparent);
278 
279 		/* Offset (in cells) from map entry to parent interrupt specifier */
280 		const u_int pis_off = pus_off + pus_cells;
281 
282 #ifdef FDT_INTR_DEBUG
283 		printf(" intr map (len %d):", pis_off + pis_cells);
284 		for (int i = 0; i < pis_off + pis_cells; i++)
285 			printf(" %08x", p[i]);
286 		printf("\n");
287 #endif
288 
289 		if (cis_cells == interrupt_cells && memcmp(&p[cis_off], node_specifier, interrupt_cells * 4) == 0) {
290 			const int slen = pus_cells + pis_cells;
291 #ifdef FDT_INTR_DEBUG
292 			printf(" intr map match iparent %08x slen %d:", iparent, slen);
293 			for (int i = 0; i < slen; i++)
294 				printf(" %08x", p[pus_off + i]);
295 			printf("\n");
296 #endif
297 			result = kmem_alloc(slen, KM_SLEEP);
298 			memcpy(result, &p[pus_off], slen * 4);
299 			*piphandle = iparent;
300 			goto done;
301 		}
302 		/* Determine the length of the entry and skip that many
303 		 * 32 bit words
304 		 */
305 		const u_int reclen = pis_off + pis_cells;
306 		resid -= reclen * sizeof(u_int);
307 		p += reclen;
308 	}
309 
310 done:
311 	return result;
312 }
313 
314 static u_int *
315 get_specifier_by_index(int phandle, int pindex, int *piphandle)
316 {
317 	const u_int *node_specifier;
318 	u_int *specifier;
319 	int interrupt_parent, interrupt_cells, len;
320 
321 	if (has_interrupt_map(phandle))
322 		return get_specifier_from_map(phandle, pindex, piphandle);
323 
324 	interrupt_parent = fdtbus_get_interrupt_parent(phandle);
325 	if (interrupt_parent <= 0)
326 		return NULL;
327 
328 	interrupt_cells = find_interrupt_cells(interrupt_parent);
329 	if (interrupt_cells <= 0)
330 		return NULL;
331 
332 	node_specifier = fdt_getprop(fdtbus_get_data(), fdtbus_phandle2offset(phandle),
333 	    "interrupts", &len);
334 	if (node_specifier == NULL)
335 		return NULL;
336 
337 	const u_int spec_length = len / 4;
338 	const u_int nintr = spec_length / interrupt_cells;
339 	if (pindex >= nintr)
340 		return NULL;
341 
342 	node_specifier += (interrupt_cells * pindex);
343 
344 	specifier = kmem_alloc(interrupt_cells * sizeof(u_int), KM_SLEEP);
345 	memcpy(specifier, node_specifier, interrupt_cells * 4);
346 
347 	*piphandle = interrupt_parent;
348 
349 	return specifier;
350 }
351