ifpga_intr.c revision 1.5 1 /* $NetBSD: ifpga_intr.c,v 1.5 2006/11/24 21:20:05 wiz Exp $ */
2
3 /*
4 * Copyright (c) 2001, 2002 Wasabi Systems, Inc.
5 * All rights reserved.
6 *
7 * Written by Jason R. Thorpe for Wasabi Systems, Inc.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed for the NetBSD Project by
20 * Wasabi Systems, Inc.
21 * 4. The name of Wasabi Systems, Inc. may not be used to endorse
22 * or promote products derived from this software without specific prior
23 * written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
27 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
28 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL WASABI SYSTEMS, INC
29 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
30 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
31 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
32 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
33 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
35 * POSSIBILITY OF SUCH DAMAGE.
36 */
37
38 #ifndef EVBARM_SPL_NOINLINE
39 #define EVBARM_SPL_NOINLINE
40 #endif
41
42 /*
43 * Interrupt support for the Integrator FPGA.
44 */
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/malloc.h>
49
50 #include <uvm/uvm_extern.h>
51
52 #include <machine/bus.h>
53 #include <machine/intr.h>
54
55 #include <arm/cpufunc.h>
56
57 #include <evbarm/ifpga/ifpgareg.h>
58 #include <evbarm/ifpga/ifpgavar.h>
59
60 /* Interrupt handler queues. */
61 struct intrq intrq[NIRQ];
62
63 /* Interrupts to mask at each level. */
64 int ifpga_imask[NIPL];
65
66 /* Current interrupt priority level. */
67 volatile int current_spl_level;
68
69 /* Interrupts pending. */
70 volatile int ifpga_ipending;
71
72 /* Software copy of the IRQs we have enabled. */
73 volatile uint32_t intr_enabled;
74
75 /* Mask if interrupts steered to FIQs. */
76 uint32_t intr_steer;
77
78 /*
79 * Map a software interrupt queue index (to the unused bits in the
80 * ICU registers -- XXX will need to revisit this if those bits are
81 * ever used in future steppings).
82 */
83 static const uint32_t si_to_irqbit[SI_NQUEUES] = {
84 IFPGA_INTR_bit31, /* SI_SOFT */
85 IFPGA_INTR_bit30, /* SI_SOFTCLOCK */
86 IFPGA_INTR_bit29, /* SI_SOFTNET */
87 IFPGA_INTR_bit28, /* SI_SOFTSERIAL */
88 };
89
90 #define SI_TO_IRQBIT(si) (si_to_irqbit[(si)])
91
92 /*
93 * Map a software interrupt queue to an interrupt priority level.
94 */
95 static const int si_to_ipl[SI_NQUEUES] = {
96 IPL_SOFT, /* SI_SOFT */
97 IPL_SOFTCLOCK, /* SI_SOFTCLOCK */
98 IPL_SOFTNET, /* SI_SOFTNET */
99 IPL_SOFTSERIAL, /* SI_SOFTSERIAL */
100 };
101
102 /*
103 * Interrupt bit names.
104 */
105 const char *ifpga_irqnames[] = {
106 "soft", /* 0 */
107 "uart 0", /* 1 */
108 "uart 1", /* 2 */
109 "kbd", /* 3 */
110 "mouse", /* 4 */
111 "tmr 0", /* 5 */
112 "tmr 1 hard", /* 6 */
113 "tmr 2 stat", /* 7 */
114 "rtc", /* 8 */
115 "exp 0", /* 9 */
116 "exp 1", /* 10 */
117 "exp 2", /* 11 */
118 "exp 3", /* 12 */
119 "pci 0", /* 13 */
120 "pci 1", /* 14 */
121 "pci 2", /* 15 */
122 "pci 3", /* 16 */
123 "V3 br", /* 17 */
124 "deg", /* 18 */
125 "enum", /* 19 */
126 "pci lb", /* 20 */
127 "autoPC", /* 21 */
128 "irq 22", /* 22 */
129 "irq 23", /* 23 */
130 "irq 24", /* 24 */
131 "irq 25", /* 25 */
132 "irq 26", /* 26 */
133 "irq 27", /* 27 */
134 "irq 28", /* 28 */
135 "irq 29", /* 29 */
136 "irq 30", /* 30 */
137 "irq 31", /* 31 */
138 };
139
140 void ifpga_intr_dispatch(struct clockframe *frame);
141
142 extern struct ifpga_softc *ifpga_sc;
143
144 static inline uint32_t
145 ifpga_iintsrc_read(void)
146 {
147 return bus_space_read_4(ifpga_sc->sc_iot, ifpga_sc->sc_irq_ioh,
148 IFPGA_INTR_STATUS);
149 }
150
151 static inline void
152 ifpga_enable_irq(int irq)
153 {
154
155 intr_enabled |= (1U << irq);
156 ifpga_set_intrmask();
157 }
158
159 static inline void
160 ifpga_disable_irq(int irq)
161 {
162
163 intr_enabled &= ~(1U << irq);
164 ifpga_set_intrmask();
165 }
166
167 /*
168 * NOTE: This routine must be called with interrupts disabled in the CPSR.
169 */
170 static void
171 ifpga_intr_calculate_masks(void)
172 {
173 struct intrq *iq;
174 struct intrhand *ih;
175 int irq, ipl;
176
177 /* First, figure out which IPLs each IRQ has. */
178 for (irq = 0; irq < NIRQ; irq++) {
179 int levels = 0;
180 iq = &intrq[irq];
181 ifpga_disable_irq(irq);
182 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
183 ih = TAILQ_NEXT(ih, ih_list))
184 levels |= (1U << ih->ih_ipl);
185 iq->iq_levels = levels;
186 }
187
188 /* Next, figure out which IRQs are used by each IPL. */
189 for (ipl = 0; ipl < NIPL; ipl++) {
190 int irqs = 0;
191 for (irq = 0; irq < NIRQ; irq++) {
192 if (intrq[irq].iq_levels & (1U << ipl))
193 irqs |= (1U << irq);
194 }
195 ifpga_imask[ipl] = irqs;
196 }
197
198 ifpga_imask[IPL_NONE] = 0;
199
200 /*
201 * Initialize the soft interrupt masks to block themselves.
202 */
203 ifpga_imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
204 ifpga_imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
205 ifpga_imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
206 ifpga_imask[IPL_SOFTSERIAL] = SI_TO_IRQBIT(SI_SOFTSERIAL);
207
208 /*
209 * splsoftclock() is the only interface that users of the
210 * generic software interrupt facility have to block their
211 * soft intrs, so splsoftclock() must also block IPL_SOFT.
212 */
213 ifpga_imask[IPL_SOFTCLOCK] |= ifpga_imask[IPL_SOFT];
214
215 /*
216 * splsoftnet() must also block splsoftclock(), since we don't
217 * want timer-driven network events to occur while we're
218 * processing incoming packets.
219 */
220 ifpga_imask[IPL_SOFTNET] |= ifpga_imask[IPL_SOFTCLOCK];
221
222 /*
223 * Enforce a hierarchy that gives "slow" device (or devices with
224 * limited input buffer space/"real-time" requirements) a better
225 * chance at not dropping data.
226 */
227 ifpga_imask[IPL_BIO] |= ifpga_imask[IPL_SOFTNET];
228 ifpga_imask[IPL_NET] |= ifpga_imask[IPL_BIO];
229 ifpga_imask[IPL_SOFTSERIAL] |= ifpga_imask[IPL_NET];
230 ifpga_imask[IPL_TTY] |= ifpga_imask[IPL_SOFTSERIAL];
231
232 /*
233 * splvm() blocks all interrupts that use the kernel memory
234 * allocation facilities.
235 */
236 ifpga_imask[IPL_VM] |= ifpga_imask[IPL_TTY];
237
238 /*
239 * Audio devices are not allowed to perform memory allocation
240 * in their interrupt routines, and they have fairly "real-time"
241 * requirements, so give them a high interrupt priority.
242 */
243 ifpga_imask[IPL_AUDIO] |= ifpga_imask[IPL_VM];
244
245 /*
246 * splclock() must block anything that uses the scheduler.
247 */
248 ifpga_imask[IPL_CLOCK] |= ifpga_imask[IPL_AUDIO];
249
250 /*
251 * splstatclock() must also block the clock.
252 */
253 ifpga_imask[IPL_STATCLOCK] |= ifpga_imask[IPL_CLOCK];
254
255 /*
256 * splhigh() must block "everything".
257 */
258 ifpga_imask[IPL_HIGH] |= ifpga_imask[IPL_STATCLOCK];
259
260 /*
261 * XXX We need serial drivers to run at the absolute highest priority
262 * in order to avoid overruns, so serial > high.
263 */
264 ifpga_imask[IPL_SERIAL] |= ifpga_imask[IPL_HIGH];
265
266 /*
267 * Now compute which IRQs must be blocked when servicing any
268 * given IRQ.
269 */
270 for (irq = 0; irq < NIRQ; irq++) {
271 int irqs = (1U << irq);
272 iq = &intrq[irq];
273 if (TAILQ_FIRST(&iq->iq_list) != NULL)
274 ifpga_enable_irq(irq);
275 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
276 ih = TAILQ_NEXT(ih, ih_list))
277 irqs |= ifpga_imask[ih->ih_ipl];
278 iq->iq_mask = irqs;
279 }
280 }
281
282 void
283 ifpga_do_pending(void)
284 {
285 static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
286 int new, oldirqstate;
287
288 if (__cpu_simple_lock_try(&processing) == 0)
289 return;
290
291 new = current_spl_level;
292
293 oldirqstate = disable_interrupts(I32_bit);
294
295 #define DO_SOFTINT(si) \
296 if ((ifpga_ipending & ~new) & SI_TO_IRQBIT(si)) { \
297 ifpga_ipending &= ~SI_TO_IRQBIT(si); \
298 current_spl_level |= ifpga_imask[si_to_ipl[(si)]]; \
299 restore_interrupts(oldirqstate); \
300 softintr_dispatch(si); \
301 oldirqstate = disable_interrupts(I32_bit); \
302 current_spl_level = new; \
303 }
304
305 DO_SOFTINT(SI_SOFTSERIAL);
306 DO_SOFTINT(SI_SOFTNET);
307 DO_SOFTINT(SI_SOFTCLOCK);
308 DO_SOFTINT(SI_SOFT);
309
310 __cpu_simple_unlock(&processing);
311
312 restore_interrupts(oldirqstate);
313 }
314
315 void
316 splx(int new)
317 {
318
319 ifpga_splx(new);
320 }
321
322 int
323 _spllower(int ipl)
324 {
325
326 return (ifpga_spllower(ipl));
327 }
328
329 int
330 _splraise(int ipl)
331 {
332
333 return (ifpga_splraise(ipl));
334 }
335
336 void
337 _setsoftintr(int si)
338 {
339 int oldirqstate;
340
341 oldirqstate = disable_interrupts(I32_bit);
342 ifpga_ipending |= SI_TO_IRQBIT(si);
343 restore_interrupts(oldirqstate);
344
345 /* Process unmasked pending soft interrupts. */
346 if ((ifpga_ipending & INT_SWMASK) & ~current_spl_level)
347 ifpga_do_pending();
348 }
349
350 /*
351 * ifpga_intr_init:
352 *
353 * Initialize the rest of the interrupt subsystem, making it
354 * ready to handle interrupts from devices.
355 */
356 void
357 ifpga_intr_init(void)
358 {
359 struct intrq *iq;
360 int i;
361
362 intr_enabled = 0;
363
364 for (i = 0; i < NIRQ; i++) {
365 iq = &intrq[i];
366 TAILQ_INIT(&iq->iq_list);
367
368 evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
369 NULL, "ifpga", ifpga_irqnames[i]);
370 }
371 }
372
373 void
374 ifpga_intr_postinit(void)
375 {
376 ifpga_intr_calculate_masks();
377
378 /* Enable IRQs (don't yet use FIQs). */
379 enable_interrupts(I32_bit);
380 }
381
382 void *
383 ifpga_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
384 {
385 struct intrq *iq;
386 struct intrhand *ih;
387 u_int oldirqstate;
388
389 if (irq < 0 || irq > NIRQ)
390 panic("ifpga_intr_establish: IRQ %d out of range", irq);
391
392 ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
393 if (ih == NULL)
394 return (NULL);
395
396 ih->ih_func = func;
397 ih->ih_arg = arg;
398 ih->ih_ipl = ipl;
399 ih->ih_irq = irq;
400
401 iq = &intrq[irq];
402
403 /* All IOP321 interrupts are level-triggered. */
404 iq->iq_ist = IST_LEVEL;
405
406 oldirqstate = disable_interrupts(I32_bit);
407
408 TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
409
410 ifpga_intr_calculate_masks();
411
412 restore_interrupts(oldirqstate);
413
414 return (ih);
415 }
416
417 void
418 ifpga_intr_disestablish(void *cookie)
419 {
420 struct intrhand *ih = cookie;
421 struct intrq *iq = &intrq[ih->ih_irq];
422 int oldirqstate;
423
424 oldirqstate = disable_interrupts(I32_bit);
425
426 TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
427
428 ifpga_intr_calculate_masks();
429
430 restore_interrupts(oldirqstate);
431 }
432
433 void
434 ifpga_intr_dispatch(struct clockframe *frame)
435 {
436 struct intrq *iq;
437 struct intrhand *ih;
438 int oldirqstate, pcpl, irq, ibit, hwpend;
439
440 pcpl = current_spl_level;
441
442 hwpend = ifpga_iintsrc_read();
443
444 /*
445 * Disable all the interrupts that are pending. We will
446 * reenable them once they are processed and not masked.
447 */
448 intr_enabled &= ~hwpend;
449 ifpga_set_intrmask();
450
451 /* Wait for these interrupts to be suppressed. */
452 while ((ifpga_iintsrc_read() & hwpend) != 0)
453 ;
454
455 while (hwpend != 0) {
456 irq = ffs(hwpend) - 1;
457 ibit = (1U << irq);
458
459 hwpend &= ~ibit;
460
461 if (pcpl & ibit) {
462 /*
463 * IRQ is masked; mark it as pending and check
464 * the next one. Note: the IRQ is already disabled.
465 */
466 ifpga_ipending |= ibit;
467 continue;
468 }
469
470 ifpga_ipending &= ~ibit;
471
472 iq = &intrq[irq];
473 iq->iq_ev.ev_count++;
474 uvmexp.intrs++;
475 current_spl_level |= iq->iq_mask;
476 oldirqstate = enable_interrupts(I32_bit);
477 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
478 ih = TAILQ_NEXT(ih, ih_list)) {
479 (void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
480 }
481 restore_interrupts(oldirqstate);
482 current_spl_level = pcpl;
483
484 hwpend |= (ifpga_ipending & IFPGA_INTR_HWMASK) & ~pcpl;
485
486 /* Re-enable this interrupt now that's it's cleared. */
487 intr_enabled |= ibit;
488 ifpga_set_intrmask();
489 }
490
491 /* Check for pendings soft intrs. */
492 if ((ifpga_ipending & INT_SWMASK) & ~current_spl_level) {
493 oldirqstate = enable_interrupts(I32_bit);
494 ifpga_do_pending();
495 restore_interrupts(oldirqstate);
496 }
497 }
498