fdt_intr.c revision 1.29 1 /* $NetBSD: fdt_intr.c,v 1.29 2021/01/15 22:59:49 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 1.29 2021/01/15 22:59:49 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 return fdtbus_intr_establish_xname(phandle, index, ipl, flags,
185 func, arg, NULL);
186 }
187
188 void *
189 fdtbus_intr_establish_xname(int phandle, u_int index, int ipl, int flags,
190 int (*func)(void *), void *arg, const char *xname)
191 {
192 const u_int *specifier;
193 int ihandle;
194
195 specifier = get_specifier_by_index(phandle, index, &ihandle);
196 if (specifier == NULL)
197 return NULL;
198
199 return fdtbus_intr_establish_raw(ihandle, specifier, ipl,
200 flags, func, arg, xname);
201 }
202
203 void *
204 fdtbus_intr_establish_byname(int phandle, const char *name, int ipl,
205 int flags, int (*func)(void *), void *arg, const char *xname)
206 {
207 u_int index;
208 int err;
209
210 err = fdtbus_get_index(phandle, "interrupt-names", name, &index);
211 if (err != 0)
212 return NULL;
213
214 return fdtbus_intr_establish_xname(phandle, index, ipl, flags, func,
215 arg, xname);
216 }
217
218 void *
219 fdtbus_intr_establish_raw(int ihandle, const u_int *specifier, int ipl,
220 int flags, int (*func)(void *), void *arg, const char *xname)
221 {
222 struct fdtbus_interrupt_controller *ic;
223 struct fdtbus_interrupt_cookie *c;
224 void *ih;
225
226 ic = fdtbus_get_interrupt_controller(ihandle);
227 if (ic == NULL) {
228 printf("%s: ihandle %d is not a controller\n",__func__,ihandle);
229 return NULL;
230 }
231
232 c = kmem_zalloc(sizeof(*c), KM_SLEEP);
233 c->c_ic = ic;
234 mutex_enter(&fdtbus_interrupt_cookie_mutex);
235 LIST_INSERT_HEAD(&fdtbus_interrupt_cookies, c, c_next);
236 mutex_exit(&fdtbus_interrupt_cookie_mutex);
237
238 /*
239 * XXX This leaves a small window where the handler is registered
240 * (and thus could be called) before the cookie on the list has a
241 * valid lookup key (and thus can be found). This will cause a
242 * panic in fdt_intr_mask() if that is called from the handler before
243 * this situation is resolved. For now we just cross our fingers
244 * and hope that the device won't actually interrupt until we return.
245 */
246 ih = ic->ic_funcs->establish(ic->ic_dev, __UNCONST(specifier),
247 ipl, flags, func, arg, xname);
248 if (ih != NULL) {
249 atomic_store_release(&c->c_ih, ih);
250 } else {
251 mutex_enter(&fdtbus_interrupt_cookie_mutex);
252 LIST_REMOVE(c, c_next);
253 mutex_exit(&fdtbus_interrupt_cookie_mutex);
254 kmem_free(c, sizeof(*c));
255 }
256
257 return ih;
258 }
259
260 void
261 fdtbus_intr_disestablish(int phandle, void *cookie)
262 {
263 struct fdtbus_interrupt_cookie *c;
264
265 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
266 panic("%s: interrupt handle not valid", __func__);
267 }
268
269 const struct fdtbus_interrupt_controller *ic = c->c_ic;
270 ic->ic_funcs->disestablish(ic->ic_dev, cookie);
271
272 /*
273 * Wait for any dangling references other than ours to
274 * drain away.
275 */
276 mutex_enter(&fdtbus_interrupt_cookie_mutex);
277 while (c->c_refcnt != 1) {
278 KASSERT(c->c_refcnt > 0);
279 fdtbus_interrupt_cookies_wanted = true;
280 cv_wait(&fdtbus_interrupt_cookie_wait,
281 &fdtbus_interrupt_cookie_mutex);
282 }
283 LIST_REMOVE(c, c_next);
284 mutex_exit(&fdtbus_interrupt_cookie_mutex);
285
286 kmem_free(c, sizeof(*c));
287 }
288
289 void
290 fdtbus_intr_mask(int phandle, void *cookie)
291 {
292 struct fdtbus_interrupt_cookie *c;
293
294 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
295 panic("%s: interrupt handle not valid", __func__);
296 }
297
298 struct fdtbus_interrupt_controller * const ic = c->c_ic;
299
300 if (ic->ic_funcs->mask == NULL) {
301 panic("%s: no 'mask' method for %s", __func__,
302 device_xname(ic->ic_dev));
303 }
304
305 ic->ic_funcs->mask(ic->ic_dev, cookie);
306 fdtbus_put_interrupt_cookie(c);
307 }
308
309 void
310 fdtbus_intr_unmask(int phandle, void *cookie)
311 {
312 struct fdtbus_interrupt_cookie *c;
313
314 if ((c = fdtbus_get_interrupt_cookie(cookie)) == NULL) {
315 panic("%s: interrupt handle not valid", __func__);
316 }
317
318 struct fdtbus_interrupt_controller * const ic = c->c_ic;
319
320 if (ic->ic_funcs->unmask == NULL) {
321 panic("%s: no 'unmask' method for %s", __func__,
322 device_xname(ic->ic_dev));
323 }
324
325 ic->ic_funcs->unmask(ic->ic_dev, cookie);
326 fdtbus_put_interrupt_cookie(c);
327 }
328
329 bool
330 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
331 {
332 const u_int *specifier;
333 int ihandle;
334
335 specifier = get_specifier_by_index(phandle, index, &ihandle);
336 if (specifier == NULL)
337 return false;
338
339 return fdtbus_intr_str_raw(ihandle, specifier, buf, buflen);
340 }
341
342 bool
343 fdtbus_intr_str_raw(int ihandle, const u_int *specifier, char *buf, size_t buflen)
344 {
345 struct fdtbus_interrupt_controller *ic;
346
347 ic = fdtbus_get_interrupt_controller(ihandle);
348 if (ic == NULL)
349 return false;
350
351 return ic->ic_funcs->intrstr(ic->ic_dev, __UNCONST(specifier), buf, buflen);
352 }
353
354 static int
355 find_address_cells(int phandle)
356 {
357 uint32_t cells;
358
359 if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
360 cells = 2;
361
362 return cells;
363 }
364
365 static int
366 find_interrupt_cells(int phandle)
367 {
368 uint32_t cells;
369
370 while (phandle > 0) {
371 if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
372 return cells;
373 phandle = OF_parent(phandle);
374 }
375 return 0;
376 }
377
378 static const u_int *
379 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
380 {
381 const u_int *result = NULL;
382 int len, resid;
383
384 const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
385 if (data == NULL || len <= 0)
386 return NULL;
387 resid = len;
388
389 /* child unit address: #address-cells prop of child bus node */
390 const int cua_cells = find_address_cells(phandle);
391 /* child interrupt specifier: #interrupt-cells of the nexus node */
392 const int cis_cells = find_interrupt_cells(phandle);
393
394 /* Offset (in cells) from map entry to child unit address specifier */
395 const u_int cua_off = 0;
396 /* Offset (in cells) from map entry to child interrupt specifier */
397 const u_int cis_off = cua_off + cua_cells;
398 /* Offset (in cells) from map entry to interrupt parent phandle */
399 const u_int ip_off = cis_off + cis_cells;
400 /* Offset (in cells) from map entry to parent unit specifier */
401 const u_int pus_off = ip_off + 1;
402
403 const u_int *p = (const u_int *)data;
404 while (resid > 0) {
405 /* Interrupt parent phandle */
406 const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
407
408 /* parent unit specifier: #address-cells of the interrupt parent */
409 const u_int pus_cells = find_address_cells(iparent);
410 /* parent interrupt specifier: #interrupt-cells of the interrupt parent */
411 const u_int pis_cells = find_interrupt_cells(iparent);
412
413 /* Offset (in cells) from map entry to parent interrupt specifier */
414 const u_int pis_off = pus_off + pus_cells;
415
416 #ifdef FDT_INTR_DEBUG
417 printf(" intr map (len %d):", pis_off + pis_cells);
418 for (int i = 0; i < pis_off + pis_cells; i++)
419 printf(" %08x", p[i]);
420 printf("\n");
421 #endif
422
423 if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
424 #ifdef FDT_INTR_DEBUG
425 const int slen = pus_cells + pis_cells;
426 printf(" intr map match iparent %08x slen %d:", iparent, slen);
427 for (int i = 0; i < slen; i++)
428 printf(" %08x", p[pus_off + i]);
429 printf("\n");
430 #endif
431 result = &p[pus_off];
432 *piphandle = iparent;
433 goto done;
434 }
435 /* Determine the length of the entry and skip that many
436 * 32 bit words
437 */
438 const u_int reclen = pis_off + pis_cells;
439 resid -= reclen * sizeof(u_int);
440 p += reclen;
441 }
442
443 done:
444 return result;
445 }
446
447
448 static const u_int *
449 get_specifier_from_extended(int phandle, int pindex, int *piphandle)
450 {
451 const u_int *result = NULL;
452 struct fdt_phandle_data data;
453
454 if (fdtbus_get_phandle_with_data(phandle, "interrupts-extended",
455 "#interrupt-cells", pindex, &data) == 0) {
456 *piphandle = data.phandle;
457 result = data.values;
458 }
459
460 return result;
461 }
462
463 static const u_int *
464 get_specifier_by_index(int phandle, int pindex, int *piphandle)
465 {
466 const u_int *node_specifier;
467 int interrupt_parent, interrupt_cells, len;
468
469 if (of_hasprop(phandle, "interrupts-extended"))
470 return get_specifier_from_extended(phandle, pindex, piphandle);
471
472 interrupt_parent = fdtbus_get_interrupt_parent(phandle);
473 if (interrupt_parent <= 0)
474 return NULL;
475
476 node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
477 if (node_specifier == NULL)
478 return NULL;
479
480 interrupt_cells = find_interrupt_cells(interrupt_parent);
481 if (interrupt_cells <= 0)
482 return NULL;
483
484 const u_int spec_length = len / 4;
485 const u_int nintr = spec_length / interrupt_cells;
486 if (pindex >= nintr)
487 return NULL;
488
489 node_specifier += (interrupt_cells * pindex);
490
491 if (of_hasprop(interrupt_parent, "interrupt-map"))
492 return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
493
494 *piphandle = interrupt_parent;
495
496 return node_specifier;
497 }
498