fdt_intr.c revision 1.27 1 /* $NetBSD: fdt_intr.c,v 1.27 2021/01/15 00:38:23 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 1.27 2021/01/15 00:38:23 jmcneill Exp $");
31
32 #include <sys/param.h>
33 #include <sys/atomic.h>
34 #include <sys/bus.h>
35 #include <sys/kmem.h>
36 #include <sys/queue.h>
37 #include <sys/mutex.h>
38 #include <sys/condvar.h>
39
40 #include <libfdt.h>
41 #include <dev/fdt/fdtvar.h>
42 #include <dev/fdt/fdt_private.h>
43
44 struct fdtbus_interrupt_controller {
45 device_t ic_dev;
46 int ic_phandle;
47 const struct fdtbus_interrupt_controller_func *ic_funcs;
48
49 LIST_ENTRY(fdtbus_interrupt_controller) ic_next;
50 };
51
52 static LIST_HEAD(, fdtbus_interrupt_controller) fdtbus_interrupt_controllers =
53 LIST_HEAD_INITIALIZER(fdtbus_interrupt_controllers);
54
55 struct fdtbus_interrupt_cookie {
56 struct fdtbus_interrupt_controller *c_ic;
57 void *c_ih;
58
59 LIST_ENTRY(fdtbus_interrupt_cookie) c_next;
60 uint32_t c_refcnt;
61 };
62
63 static LIST_HEAD(, fdtbus_interrupt_cookie) fdtbus_interrupt_cookies =
64 LIST_HEAD_INITIALIZER(fdtbus_interrupt_cookies);
65 static kmutex_t fdtbus_interrupt_cookie_mutex;
66 static kcondvar_t fdtbus_interrupt_cookie_wait;
67 static bool fdtbus_interrupt_cookies_wanted;
68
69 static const u_int * get_specifier_by_index(int, int, int *);
70 static const u_int * get_specifier_from_map(int, const u_int *, int *);
71
72 void
73 fdtbus_intr_init(void)
74 {
75
76 mutex_init(&fdtbus_interrupt_cookie_mutex, MUTEX_DEFAULT, IPL_HIGH);
77 cv_init(&fdtbus_interrupt_cookie_wait, "fdtintr");
78 }
79
80 /*
81 * Find the interrupt controller for a given node. This function will either
82 * return the phandle of the interrupt controller for this node, or the phandle
83 * of a node containing an interrupt-map table that can be used to find the
84 * real interrupt controller.
85 */
86 static int
87 fdtbus_get_interrupt_parent(int phandle)
88 {
89 int iparent = phandle;
90
91 do {
92 /*
93 * If the node is an interrupt-controller, we are done. Note that
94 * a node cannot be an interrupt-controller for itself, so we skip
95 * the leaf node here.
96 */
97 if (phandle != iparent && of_hasprop(iparent, "interrupt-controller"))
98 return iparent;
99
100 /*
101 * If the node has an explicit interrupt-parent, follow the reference.
102 */
103 if (of_hasprop(iparent, "interrupt-parent"))
104 return fdtbus_get_phandle(iparent, "interrupt-parent");
105
106 /*
107 * If the node has an interrupt-map, use it. The caller is responsible
108 * for parsing the interrupt-map and finding the real interrupt parent.
109 */
110 if (phandle != iparent && of_hasprop(iparent, "interrupt-map"))
111 return iparent;
112
113 /*
114 * Continue searching up the tree.
115 */
116 iparent = OF_parent(iparent);
117 } while (iparent > 0);
118
119 return 0;
120 }
121
122 static struct fdtbus_interrupt_controller *
123 fdtbus_get_interrupt_controller(int phandle)
124 {
125 struct fdtbus_interrupt_controller * ic;
126 LIST_FOREACH(ic, &fdtbus_interrupt_controllers, ic_next) {
127 if (ic->ic_phandle == phandle)
128 return ic;
129 }
130 return NULL;
131 }
132
133 int
134 fdtbus_register_interrupt_controller(device_t dev, int phandle,
135 const struct fdtbus_interrupt_controller_func *funcs)
136 {
137 struct fdtbus_interrupt_controller *ic;
138
139 ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
140 ic->ic_dev = dev;
141 ic->ic_phandle = phandle;
142 ic->ic_funcs = funcs;
143
144 LIST_INSERT_HEAD(&fdtbus_interrupt_controllers, ic, ic_next);
145
146 return 0;
147 }
148
149 static struct fdtbus_interrupt_cookie *
150 fdtbus_get_interrupt_cookie(void *cookie)
151 {
152 struct fdtbus_interrupt_cookie *c;
153
154 mutex_enter(&fdtbus_interrupt_cookie_mutex);
155 LIST_FOREACH(c, &fdtbus_interrupt_cookies, c_next) {
156 if (c->c_ih == cookie) {
157 c->c_refcnt++;
158 KASSERT(c->c_refcnt > 0);
159 break;
160 }
161 }
162 mutex_exit(&fdtbus_interrupt_cookie_mutex);
163 return c;
164 }
165
166 static void
167 fdtbus_put_interrupt_cookie(struct fdtbus_interrupt_cookie *c)
168 {
169
170 mutex_enter(&fdtbus_interrupt_cookie_mutex);
171 KASSERT(c->c_refcnt > 0);
172 c->c_refcnt--;
173 if (fdtbus_interrupt_cookies_wanted) {
174 fdtbus_interrupt_cookies_wanted = false;
175 cv_signal(&fdtbus_interrupt_cookie_wait);
176 }
177 mutex_exit(&fdtbus_interrupt_cookie_mutex);
178 }
179
180 void *
181 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
182 int (*func)(void *), void *arg)
183 {
184 const u_int *specifier;
185 int ihandle;
186
187 specifier = get_specifier_by_index(phandle, index, &ihandle);
188 if (specifier == NULL)
189 return NULL;
190
191 return fdtbus_intr_establish_raw(ihandle, specifier, ipl,
192 flags, func, arg);
193 }
194
195 void *
196 fdtbus_intr_establish_byname(int phandle, const char *name, int ipl,
197 int flags, int (*func)(void *), void *arg)
198 {
199 u_int index;
200 int err;
201
202 err = fdtbus_get_index(phandle, "interrupt-names", name, &index);
203 if (err != 0)
204 return NULL;
205
206 return fdtbus_intr_establish(phandle, index, ipl, flags, func, arg);
207 }
208
209 void *
210 fdtbus_intr_establish_raw(int ihandle, const u_int *specifier, int ipl,
211 int flags, int (*func)(void *), void *arg)
212 {
213 struct fdtbus_interrupt_controller *ic;
214 struct fdtbus_interrupt_cookie *c;
215 void *ih;
216
217 ic = fdtbus_get_interrupt_controller(ihandle);
218 if (ic == NULL) {
219 printf("%s: ihandle %d is not a controller\n",__func__,ihandle);
220 return NULL;
221 }
222
223 c = kmem_zalloc(sizeof(*c), KM_SLEEP);
224 c->c_ic = ic;
225 mutex_enter(&fdtbus_interrupt_cookie_mutex);
226 LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next);
227 mutex_exit(&fdtbus_interrupt_cookie_mutex);
228
229 /*
230 * XXX This leaves a small window where the handler is registered
231 * (and thus could be called) before the cookie on the list has a
232 * valid lookup key (and thus can be found). This will cause a
233 * panic in fdt_intr_mask() if that is called from the handler before
234 * this situation is resolved. For now we just cross our fingers
235 * and hope that the device won't actually interrupt until we return.
236 */
237 ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier),
238 ipl, flags, func, arg, NULL);
239 if (ih != NULL) {
240 atomic_store_release(&c->c_ih, ih);
241 } else {
242 mutex_enter(&fdtbus_interrupt_cookie_mutex);
243 LIST_REMOVE(c, c_next);
244 mutex_exit(&fdtbus_interrupt_cookie_mutex);
245 kmem_free(c, sizeof(*c));
246 }
247
248 return ih;
249 }
250
251 void
252 fdtbus_intr_disestablish(int phandle, void *cookie)
253 {
254 struct fdtbus_interrupt_cookie *c;
255
256 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
257 panic("%s: interrupt handle not valid", __func__);
258 }
259
260 const struct fdtbus_interrupt_controller *ic = c->c_ic;
261 ic->ic_funcs->disestablish(ic->ic_dev, cookie);
262
263 /*
264 * Wait for any dangling references other than ours to
265 * drain away.
266 */
267 mutex_enter(&fdtbus_interrupt_cookie_mutex);
268 while (c->c_refcnt != 1) {
269 KASSERT(c->c_refcnt > 0);
270 fdtbus_interrupt_cookies_wanted = true;
271 cv_wait(&fdtbus_interrupt_cookie_wait,
272 &fdtbus_interrupt_cookie_mutex);
273 }
274 LIST_REMOVE(c, c_next);
275 mutex_exit(&fdtbus_interrupt_cookie_mutex);
276
277 kmem_free(c, sizeof(*c));
278 }
279
280 void
281 fdtbus_intr_mask(int phandle, void *cookie)
282 {
283 struct fdtbus_interrupt_cookie *c;
284
285 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
286 panic("%s: interrupt handle not valid", __func__);
287 }
288
289 struct fdtbus_interrupt_controller * const ic = c->c_ic;
290
291 if (ic->ic_funcs->mask == NULL) {
292 panic("%s: no 'mask' method for %s", __func__,
293 device_xname(ic->ic_dev));
294 }
295
296 ic->ic_funcs->mask(ic->ic_dev, cookie);
297 fdtbus_put_interrupt_cookie(c);
298 }
299
300 void
301 fdtbus_intr_unmask(int phandle, void *cookie)
302 {
303 struct fdtbus_interrupt_cookie *c;
304
305 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
306 panic("%s: interrupt handle not valid", __func__);
307 }
308
309 struct fdtbus_interrupt_controller * const ic = c->c_ic;
310
311 if (ic->ic_funcs->unmask == NULL) {
312 panic("%s: no 'unmask' method for %s", __func__,
313 device_xname(ic->ic_dev));
314 }
315
316 ic->ic_funcs->unmask(ic->ic_dev, cookie);
317 fdtbus_put_interrupt_cookie(c);
318 }
319
320 bool
321 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
322 {
323 const u_int *specifier;
324 int ihandle;
325
326 specifier = get_specifier_by_index(phandle, index, &ihandle);
327 if (specifier == NULL)
328 return false;
329
330 return fdtbus_intr_str_raw(ihandle, specifier, buf, buflen);
331 }
332
333 bool
334 fdtbus_intr_str_raw(int ihandle, const u_int *specifier, char *buf, size_t buflen)
335 {
336 struct fdtbus_interrupt_controller *ic;
337
338 ic = fdtbus_get_interrupt_controller(ihandle);
339 if (ic == NULL)
340 return false;
341
342 return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen);
343 }
344
345 static int
346 find_address_cells(int phandle)
347 {
348 uint32_t cells;
349
350 if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
351 cells = 2;
352
353 return cells;
354 }
355
356 static int
357 find_interrupt_cells(int phandle)
358 {
359 uint32_t cells;
360
361 while (phandle > 0) {
362 if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
363 return cells;
364 phandle = OF_parent(phandle);
365 }
366 return 0;
367 }
368
369 static const u_int *
370 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
371 {
372 const u_int *result = NULL;
373 int len, resid;
374
375 const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
376 if (data == NULL || len <= 0)
377 return NULL;
378 resid = len;
379
380 /* child unit address: #address-cells prop of child bus node */
381 const int cua_cells = find_address_cells(phandle);
382 /* child interrupt specifier: #interrupt-cells of the nexus node */
383 const int cis_cells = find_interrupt_cells(phandle);
384
385 /* Offset (in cells) from map entry to child unit address specifier */
386 const u_int cua_off = 0;
387 /* Offset (in cells) from map entry to child interrupt specifier */
388 const u_int cis_off = cua_off + cua_cells;
389 /* Offset (in cells) from map entry to interrupt parent phandle */
390 const u_int ip_off = cis_off + cis_cells;
391 /* Offset (in cells) from map entry to parent unit specifier */
392 const u_int pus_off = ip_off + 1;
393
394 const u_int *p = (const u_int *)data;
395 while (resid > 0) {
396 /* Interrupt parent phandle */
397 const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
398
399 /* parent unit specifier: #address-cells of the interrupt parent */
400 const u_int pus_cells = find_address_cells(iparent);
401 /* parent interrupt specifier: #interrupt-cells of the interrupt parent */
402 const u_int pis_cells = find_interrupt_cells(iparent);
403
404 /* Offset (in cells) from map entry to parent interrupt specifier */
405 const u_int pis_off = pus_off + pus_cells;
406
407 #ifdef FDT_INTR_DEBUG
408 printf(" intr map (len %d):", pis_off + pis_cells);
409 for (int i = 0; i < pis_off + pis_cells; i++)
410 printf(" %08x", p[i]);
411 printf("\n");
412 #endif
413
414 if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
415 #ifdef FDT_INTR_DEBUG
416 const int slen = pus_cells + pis_cells;
417 printf(" intr map match iparent %08x slen %d:", iparent, slen);
418 for (int i = 0; i < slen; i++)
419 printf(" %08x", p[pus_off + i]);
420 printf("\n");
421 #endif
422 result = &p[pus_off];
423 *piphandle = iparent;
424 goto done;
425 }
426 /* Determine the length of the entry and skip that many
427 * 32 bit words
428 */
429 const u_int reclen = pis_off + pis_cells;
430 resid -= reclen * sizeof(u_int);
431 p += reclen;
432 }
433
434 done:
435 return result;
436 }
437
438
439 static const u_int *
440 get_specifier_from_extended(int phandle, int pindex, int *piphandle)
441 {
442 const u_int *result = NULL;
443 struct fdt_phandle_data data;
444
445 if (fdtbus_get_phandle_with_data(phandle, "interrupts-extended",
446 "#interrupt-cells", pindex, &data) == 0) {
447 *piphandle = data.phandle;
448 result = data.values;
449 }
450
451 return result;
452 }
453
454 static const u_int *
455 get_specifier_by_index(int phandle, int pindex, int *piphandle)
456 {
457 const u_int *node_specifier;
458 int interrupt_parent, interrupt_cells, len;
459
460 if (of_hasprop(phandle, "interrupts-extended"))
461 return get_specifier_from_extended(phandle, pindex, piphandle);
462
463 interrupt_parent = fdtbus_get_interrupt_parent(phandle);
464 if (interrupt_parent <= 0)
465 return NULL;
466
467 node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
468 if (node_specifier == NULL)
469 return NULL;
470
471 interrupt_cells = find_interrupt_cells(interrupt_parent);
472 if (interrupt_cells <= 0)
473 return NULL;
474
475 const u_int spec_length = len / 4;
476 const u_int nintr = spec_length / interrupt_cells;
477 if (pindex >= nintr)
478 return NULL;
479
480 node_specifier += (interrupt_cells * pindex);
481
482 if (of_hasprop(interrupt_parent, "interrupt-map"))
483 return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
484
485 *piphandle = interrupt_parent;
486
487 return node_specifier;
488 }
489