fdt_intr.c revision 1.15 1 /* $NetBSD: fdt_intr.c,v 1.15 2018/07/02 17:50:02 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 1.15 2018/07/02 17:50:02 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 /*
60 * Find the interrupt controller for a given node. This function will either
61 * return the phandle of the interrupt controller for this node, or the phandle
62 * of a node containing an interrupt-map table that can be used to find the
63 * real interrupt controller.
64 */
65 static int
66 fdtbus_get_interrupt_parent(int phandle)
67 {
68 int iparent = phandle;
69
70 do {
71 /*
72 * If the node is an interrupt-controller, we are done. Note that
73 * a node cannot be an interrupt-controller for itself, so we skip
74 * the leaf node here.
75 */
76 if (phandle != iparent && of_hasprop(iparent, "interrupt-controller"))
77 return iparent;
78
79 /*
80 * If the node has an explicit interrupt-parent, follow the reference.
81 */
82 if (of_hasprop(iparent, "interrupt-parent"))
83 return fdtbus_get_phandle(iparent, "interrupt-parent");
84
85 /*
86 * If the node has an interrupt-map, use it. The caller is responsible
87 * for parsing the interrupt-map and finding the real interrupt parent.
88 */
89 if (of_hasprop(iparent, "interrupt-map"))
90 return iparent;
91
92 /*
93 * Continue searching up the tree.
94 */
95 iparent = OF_parent(iparent);
96 } while (iparent > 0);
97
98 return 0;
99 }
100
101 static struct fdtbus_interrupt_controller *
102 fdtbus_get_interrupt_controller(int phandle)
103 {
104 struct fdtbus_interrupt_controller * ic;
105 LIST_FOREACH(ic, &fdtbus_interrupt_controllers, ic_next) {
106 if (ic->ic_phandle == phandle)
107 return ic;
108 }
109 return NULL;
110 }
111
112 int
113 fdtbus_register_interrupt_controller(device_t dev, int phandle,
114 const struct fdtbus_interrupt_controller_func *funcs)
115 {
116 struct fdtbus_interrupt_controller *ic;
117
118 ic = kmem_alloc(sizeof(*ic), KM_SLEEP);
119 ic->ic_dev = dev;
120 ic->ic_phandle = phandle;
121 ic->ic_funcs = funcs;
122
123 LIST_INSERT_HEAD(&fdtbus_interrupt_controllers, ic, ic_next);
124
125 return 0;
126 }
127
128 void *
129 fdtbus_intr_establish(int phandle, u_int index, int ipl, int flags,
130 int (*func)(void *), void *arg)
131 {
132 struct fdtbus_interrupt_controller *ic;
133 struct fdtbus_interrupt_cookie *c = NULL;
134 u_int *specifier;
135 int ihandle;
136 void *ih;
137
138 specifier = get_specifier_by_index(phandle, index, &ihandle);
139 if (specifier == NULL)
140 return NULL;
141
142 ic = fdtbus_get_interrupt_controller(ihandle);
143 if (ic == NULL)
144 return NULL;
145
146 ih = ic->ic_funcs->establish(ic->ic_dev, specifier,
147 ipl, flags, func, arg);
148 if (ih != NULL) {
149 c = kmem_alloc(sizeof(*c), KM_SLEEP);
150 c->c_ic = ic;
151 c->c_ih = ih;
152 }
153
154 return c;
155 }
156
157 void
158 fdtbus_intr_disestablish(int phandle, void *cookie)
159 {
160 struct fdtbus_interrupt_cookie *c = cookie;
161 struct fdtbus_interrupt_controller *ic = c->c_ic;
162 void *ih = c->c_ih;
163
164 return ic->ic_funcs->disestablish(ic->ic_dev, ih);
165 }
166
167 bool
168 fdtbus_intr_str(int phandle, u_int index, char *buf, size_t buflen)
169 {
170 struct fdtbus_interrupt_controller *ic;
171 u_int *specifier;
172 int ihandle;
173
174 specifier = get_specifier_by_index(phandle, index, &ihandle);
175
176 ic = fdtbus_get_interrupt_controller(ihandle);
177 if (ic == NULL)
178 return false;
179
180 return ic->ic_funcs->intrstr(ic->ic_dev, specifier, buf, buflen);
181 }
182
183 static int
184 find_address_cells(int phandle)
185 {
186 uint32_t cells;
187
188 if (of_getprop_uint32(phandle, "#address-cells", &cells) != 0)
189 cells = 2;
190
191 return cells;
192 }
193
194 static int
195 find_interrupt_cells(int phandle)
196 {
197 uint32_t cells;
198
199 while (phandle > 0) {
200 if (of_getprop_uint32(phandle, "#interrupt-cells", &cells) == 0)
201 return cells;
202 phandle = OF_parent(phandle);
203 }
204 return 0;
205 }
206
207 static u_int *
208 get_specifier_from_map(int phandle, const u_int *interrupt_spec, int *piphandle)
209 {
210 u_int *result = NULL;
211 int len, resid;
212
213 const u_int *data = fdtbus_get_prop(phandle, "interrupt-map", &len);
214 if (data == NULL || len <= 0)
215 return NULL;
216 resid = len;
217
218 /* child unit address: #address-cells prop of child bus node */
219 const int cua_cells = find_address_cells(phandle);
220 /* child interrupt specifier: #interrupt-cells of the nexus node */
221 const int cis_cells = find_interrupt_cells(phandle);
222
223 /* Offset (in cells) from map entry to child unit address specifier */
224 const u_int cua_off = 0;
225 /* Offset (in cells) from map entry to child interrupt specifier */
226 const u_int cis_off = cua_off + cua_cells;
227 /* Offset (in cells) from map entry to interrupt parent phandle */
228 const u_int ip_off = cis_off + cis_cells;
229 /* Offset (in cells) from map entry to parent unit specifier */
230 const u_int pus_off = ip_off + 1;
231
232 const u_int *p = (const u_int *)data;
233 while (resid > 0) {
234 /* Interrupt parent phandle */
235 const u_int iparent = fdtbus_get_phandle_from_native(be32toh(p[ip_off]));
236
237 /* parent unit specifier: #address-cells of the interrupt parent */
238 const u_int pus_cells = find_address_cells(iparent);
239 /* parent interrupt specifier: #interrupt-cells of the interrupt parent */
240 const u_int pis_cells = find_interrupt_cells(iparent);
241
242 /* Offset (in cells) from map entry to parent interrupt specifier */
243 const u_int pis_off = pus_off + pus_cells;
244
245 #ifdef FDT_INTR_DEBUG
246 printf(" intr map (len %d):", pis_off + pis_cells);
247 for (int i = 0; i < pis_off + pis_cells; i++)
248 printf(" %08x", p[i]);
249 printf("\n");
250 #endif
251
252 if (memcmp(&p[cis_off], interrupt_spec, cis_cells * 4) == 0) {
253 const int slen = pus_cells + pis_cells;
254 #ifdef FDT_INTR_DEBUG
255 printf(" intr map match iparent %08x slen %d:", iparent, slen);
256 for (int i = 0; i < slen; i++)
257 printf(" %08x", p[pus_off + i]);
258 printf("\n");
259 #endif
260 result = kmem_alloc(slen, KM_SLEEP);
261 memcpy(result, &p[pus_off], slen * 4);
262 *piphandle = iparent;
263 goto done;
264 }
265 /* Determine the length of the entry and skip that many
266 * 32 bit words
267 */
268 const u_int reclen = pis_off + pis_cells;
269 resid -= reclen * sizeof(u_int);
270 p += reclen;
271 }
272
273 done:
274 return result;
275 }
276
277 static u_int *
278 get_specifier_by_index(int phandle, int pindex, int *piphandle)
279 {
280 const u_int *node_specifier;
281 u_int *specifier;
282 int interrupt_parent, interrupt_cells, len;
283
284 interrupt_parent = fdtbus_get_interrupt_parent(phandle);
285 if (interrupt_parent <= 0)
286 return NULL;
287
288 node_specifier = fdtbus_get_prop(phandle, "interrupts", &len);
289 if (node_specifier == NULL)
290 return NULL;
291
292 interrupt_cells = find_interrupt_cells(interrupt_parent);
293 if (interrupt_cells <= 0)
294 return NULL;
295
296 const u_int spec_length = len / 4;
297 const u_int nintr = spec_length / interrupt_cells;
298 if (pindex >= nintr)
299 return NULL;
300
301 node_specifier += (interrupt_cells * pindex);
302
303 if (of_hasprop(interrupt_parent, "interrupt-map"))
304 return get_specifier_from_map(interrupt_parent, node_specifier, piphandle);
305
306 specifier = kmem_alloc(interrupt_cells * sizeof(u_int), KM_SLEEP);
307 memcpy(specifier, node_specifier, interrupt_cells * 4);
308
309 *piphandle = interrupt_parent;
310
311 return specifier;
312 }
313