intc_fdt.c revision 1.8 1 /* $NetBSD: intc_fdt.c,v 1.8 2025/02/09 10:08:37 skrll Exp $ */
2
3 /*-
4 * Copyright (c) 2023 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Nick Hudson
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include "opt_multiprocessor.h"
33
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: intc_fdt.c,v 1.8 2025/02/09 10:08:37 skrll Exp $");
36
37 #include <sys/param.h>
38
39 #include <sys/bus.h>
40 #include <sys/cpu.h>
41 #include <sys/device.h>
42 #include <sys/evcnt.h>
43 #include <sys/kmem.h>
44 #include <sys/intr.h>
45
46 #include <dev/fdt/fdtvar.h>
47
48 #include <machine/frame.h>
49 #include <machine/machdep.h>
50 #include <machine/sysreg.h>
51
52 static const struct device_compatible_entry compat_data[] = {
53 { .compat = "riscv,cpu-intc" },
54 DEVICE_COMPAT_EOL
55 };
56
57
58 struct intc_irqhandler;
59 struct intc_irq;
60
61 typedef int (*intcih_t)(void *);
62
63 struct intc_irqhandler {
64 struct intc_irq *ih_irq;
65 intcih_t ih_fn;
66 void *ih_arg;
67 TAILQ_ENTRY(intc_irqhandler)
68 ih_next;
69 };
70
71 struct intc_irq {
72 struct intc_fdt_softc *intr_sc;
73 void *intr_ih;
74 void *intr_arg;
75 int intr_refcnt;
76 int intr_ipl;
77 int intr_source;
78 int intr_istflags;
79 struct evcnt *pcpu_evs;
80 TAILQ_HEAD(, intc_irqhandler)
81 intr_handlers;
82 };
83
84
85 struct intc_fdt_softc {
86 device_t sc_dev;
87 bus_space_tag_t sc_bst;
88 bus_space_handle_t sc_bsh;
89
90 struct intc_irq *sc_irq[IRQ_NSOURCES];
91
92 struct evcnt sc_evs[IRQ_NSOURCES];
93
94 struct cpu_info *sc_ci;
95 cpuid_t sc_hartid;
96 };
97
98 static const char * const intc_sources[IRQ_NSOURCES] = {
99 /* Software interrupts */
100 "(reserved)",
101 "Supervisor software",
102 "Virtual Supervisor software",
103 "Machine software",
104
105 /* Timer interrupts */
106 "(reserved)",
107 "Supervisor timer",
108 "Virtual Supervisor timer",
109 "Machine timer",
110
111 /* External interrupts */
112 "(reserved)",
113 "Supervisor external",
114 "Virtual Supervisor external",
115 "Machine external",
116
117 "(reserved)",
118 "Supervisor guest external.",
119 "(reserved)",
120 "(reserved)"
121 };
122
123 #ifndef MULTIPROCESSOR
124 struct intc_fdt_softc *intc_sc;
125 #endif
126
127
128 static inline struct intc_fdt_softc *
129 intc_getsc(struct cpu_info *ci)
130 {
131 #ifdef MULTIPROCESSOR
132 return ci->ci_intcsoftc;
133 #else
134 return intc_sc;
135 #endif
136 }
137
138 static void *
139 intc_intr_establish(struct intc_fdt_softc *sc, u_int source, u_int ipl,
140 u_int istflags, int (*func)(void *), void *arg, const char *xname)
141 {
142 if (source > IRQ_NSOURCES)
143 return NULL;
144
145 const device_t dev = sc->sc_dev;
146 struct intc_irq *irq = sc->sc_irq[source];
147 if (irq == NULL) {
148 irq = kmem_alloc(sizeof(*irq), KM_SLEEP);
149 irq->intr_sc = sc;
150 irq->intr_refcnt = 0;
151 irq->intr_arg = arg;
152 irq->intr_ipl = ipl;
153 irq->intr_istflags = istflags;
154 irq->intr_source = source;
155 TAILQ_INIT(&irq->intr_handlers);
156 sc->sc_irq[source] = irq;
157
158 evcnt_attach_dynamic(&sc->sc_evs[source], EVCNT_TYPE_INTR, NULL,
159 device_xname(sc->sc_dev), intc_sources[source]);
160 } else {
161 if (irq->intr_arg == NULL || arg == NULL) {
162 device_printf(dev,
163 "cannot share irq with NULL-arg handler\n");
164 return NULL;
165 }
166 if (irq->intr_ipl != ipl) {
167 device_printf(dev,
168 "cannot share irq with different ipl\n");
169 return NULL;
170 }
171 if (irq->intr_istflags != istflags) {
172 device_printf(dev,
173 "cannot share irq between mpsafe/non-mpsafe\n");
174 return NULL;
175 }
176 }
177
178 struct intc_irqhandler *irqh = kmem_alloc(sizeof(*irqh), KM_SLEEP);
179 irqh->ih_irq = irq;
180 irqh->ih_fn = func;
181 irqh->ih_arg = arg;
182
183 irq->intr_refcnt++;
184 TAILQ_INSERT_TAIL(&irq->intr_handlers, irqh, ih_next);
185
186 /*
187 * XXX interrupt_distribute(9) assumes that any interrupt
188 * handle can be used as an input to the MD interrupt_distribute
189 * implementation, so we are forced to return the handle
190 * we got back from intr_establish(). Upshot is that the
191 * input to bcm2835_icu_fdt_disestablish() is ambiguous for
192 * shared IRQs, rendering them un-disestablishable.
193 */
194
195 return irqh;
196 }
197
198
199 static void *
200 intc_fdt_establish(device_t dev, u_int *specifier, int ipl, int flags,
201 int (*func)(void *), void *arg, const char *xname)
202 {
203 struct intc_fdt_softc * const sc = device_private(dev);
204
205 /*
206 * 1st (and only) cell is the interrupt source, e.g.
207 * 1 IRQ_SUPERVISOR_SOFTWARE
208 * 5 IRQ_SUPERVISOR_TIMER
209 * 9 IRQ_SUPERVISOR_EXTERNAL
210 */
211
212 const u_int source = be32toh(specifier[0]);
213 const u_int mpsafe = (flags & FDT_INTR_MPSAFE) ? IST_MPSAFE : 0;
214
215 return intc_intr_establish(sc, source, ipl, mpsafe, func, arg, xname);
216 }
217
218 static void
219 intc_fdt_disestablish(device_t dev, void *ih)
220 {
221 #if 0
222 struct intc_fdt_softc * const sc = device_private(dev);
223 #endif
224 }
225
226 static bool
227 intc_fdt_intrstr(device_t dev, u_int *specifier, char *buf, size_t buflen)
228 {
229 if (!specifier)
230 return false;
231
232 struct intc_fdt_softc * const sc = device_private(dev);
233 if (sc->sc_ci == NULL)
234 return false;
235
236 const u_int source = be32toh(specifier[0]);
237 snprintf(buf, buflen, "cpu%u/%s #%u", cpu_index(sc->sc_ci),
238 intc_sources[source], source);
239
240 return true;
241 }
242
243
244 struct fdtbus_interrupt_controller_func intc_fdt_funcs = {
245 .establish = intc_fdt_establish,
246 .disestablish = intc_fdt_disestablish,
247 .intrstr = intc_fdt_intrstr
248 };
249
250
251 static void
252 intc_intr_handler(struct trapframe *tf, register_t epc, register_t status,
253 register_t cause)
254 {
255 const int ppl = splhigh();
256 struct cpu_info * const ci = curcpu();
257 unsigned long pending;
258 int ipl;
259
260 KASSERT(CAUSE_INTERRUPT_P(cause));
261
262 struct intc_fdt_softc * const sc = intc_getsc(ci);
263
264 ci->ci_intr_depth++;
265 ci->ci_data.cpu_nintr++;
266
267 while (ppl < (ipl = splintr(&pending))) {
268 if (pending == 0)
269 continue;
270
271 splx(ipl);
272
273 int source = ffs(pending) - 1;
274 struct intc_irq *irq = sc->sc_irq[source];
275 sc->sc_evs[source].ev_count++;
276
277 KASSERTMSG(irq != NULL, "source %d\n", source);
278
279 if (irq) {
280 struct intc_irqhandler *iih;
281
282 bool mpsafe =
283 source != IRQ_SUPERVISOR_EXTERNAL ||
284 (irq->intr_istflags & IST_MPSAFE) != 0;
285 struct clockframe cf = {
286 .cf_epc = epc,
287 .cf_status = status,
288 .cf_intr_depth = ci->ci_intr_depth
289 };
290
291 if (!mpsafe) {
292 KERNEL_LOCK(1, NULL);
293 }
294
295 TAILQ_FOREACH(iih, &irq->intr_handlers, ih_next) {
296 int handled =
297 iih->ih_fn(iih->ih_arg ? iih->ih_arg : &cf);
298 if (handled)
299 break;
300 }
301
302 if (!mpsafe) {
303 KERNEL_UNLOCK_ONE(NULL);
304 }
305 }
306 splhigh();
307 }
308 ci->ci_intr_depth--;
309 splx(ppl);
310 }
311
312
313
314 static int
315 intc_match(device_t parent, cfdata_t cf, void *aux)
316 {
317 struct fdt_attach_args * const faa = aux;
318 return of_compatible_match(faa->faa_phandle, compat_data);
319 }
320
321 static void
322 intc_attach(device_t parent, device_t self, void *aux)
323 {
324 const struct fdt_attach_args * const faa = aux;
325 const int phandle = faa->faa_phandle;
326
327 int error = fdtbus_register_interrupt_controller(self, phandle,
328 &intc_fdt_funcs);
329 if (error) {
330 aprint_error(": couldn't register with fdtbus: %d\n", error);
331 return;
332 }
333
334 struct cpu_info * const ci = device_private(parent);
335 if (ci == NULL) {
336 aprint_naive(": disabled\n");
337 aprint_normal(": disabled\n");
338 return;
339 }
340 aprint_naive("\n");
341 aprint_normal(": local interrupt controller\n");
342
343 struct intc_fdt_softc * const sc = device_private(self);
344
345 riscv_intr_set_handler(intc_intr_handler);
346
347 sc->sc_dev = self;
348 sc->sc_ci = ci;
349 sc->sc_hartid = ci->ci_cpuid;
350
351 intc_intr_establish(sc, IRQ_SUPERVISOR_TIMER, IPL_SCHED, IST_MPSAFE,
352 riscv_timer_intr, NULL, "clock");
353 #ifdef MULTIPROCESSOR
354 ci->ci_intcsoftc = sc;
355 intc_intr_establish(sc, IRQ_SUPERVISOR_SOFTWARE, IPL_HIGH, IST_MPSAFE,
356 riscv_ipi_intr, NULL, "ipi");
357 #else
358 intc_sc = sc;
359 #endif
360 }
361
362 CFATTACH_DECL_NEW(intc_fdt, sizeof(struct intc_fdt_softc),
363 intc_match, intc_attach, NULL, NULL);
364