ixp12x0_intr.c revision 1.6 1 /* $NetBSD: ixp12x0_intr.c,v 1.6 2003/02/22 11:13:10 igy Exp $ */
2
3 /*
4 * Copyright (c) 2002 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Ichiro FUKUHARA and Naoto Shimazaki.
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 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the NetBSD
21 * Foundation, Inc. and its contributors.
22 * 4. Neither the name of The NetBSD Foundation nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36 * POSSIBILITY OF SUCH DAMAGE.
37 */
38
39 /*
40 * Interrupt support for the Intel ixp12x0
41 */
42
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/malloc.h>
46 #include <sys/termios.h>
47
48 #include <uvm/uvm_extern.h>
49
50 #include <machine/bus.h>
51 #include <machine/intr.h>
52
53 #include <arm/cpufunc.h>
54
55 #include <arm/ixp12x0/ixp12x0reg.h>
56 #include <arm/ixp12x0/ixp12x0var.h>
57 #include <arm/ixp12x0/ixp12x0_comreg.h>
58 #include <arm/ixp12x0/ixp12x0_comvar.h>
59 #include <arm/ixp12x0/ixp12x0_pcireg.h>
60
61 extern u_int32_t ixpcom_cr; /* current cr from *_com.c */
62 extern u_int32_t ixpcom_imask; /* tell mask to *_com.c */
63
64 /* Interrupt handler queues. */
65 struct intrq intrq[NIRQ];
66
67 /* Interrupts to mask at each level. */
68 static u_int32_t imask[NIPL];
69 static u_int32_t pci_imask[NIPL];
70
71 /* Current interrupt priority level. */
72 __volatile int current_spl_level;
73
74 /* Software copy of the IRQs we have enabled. */
75 __volatile u_int32_t intr_enabled;
76 __volatile u_int32_t pci_intr_enabled;
77
78 /* Interrupts pending. */
79 static __volatile int ipending;
80
81 /*
82 * Map a software interrupt queue index (to the unused bits in the
83 * ICU registers -- XXX will need to revisit this if those bits are
84 * ever used in future steppings).
85 */
86 static const u_int32_t si_to_irqbit[SI_NQUEUES] = {
87 IXP12X0_INTR_bit30, /* SI_SOFT */
88 IXP12X0_INTR_bit29, /* SI_SOFTCLOCK */
89 IXP12X0_INTR_bit28, /* SI_SOFTNET */
90 IXP12X0_INTR_bit27, /* SI_SOFTSERIAL */
91 };
92
93 #define INT_SWMASK \
94 ((1U << IXP12X0_INTR_bit30) | (1U << IXP12X0_INTR_bit29) | \
95 (1U << IXP12X0_INTR_bit28) | (1U << IXP12X0_INTR_bit27))
96
97 #define SI_TO_IRQBIT(si) (1U << si_to_irqbit[(si)])
98
99 /*
100 * Map a software interrupt queue to an interrupt priority level.
101 */
102 static const int si_to_ipl[SI_NQUEUES] = {
103 IPL_SOFT, /* SI_SOFT */
104 IPL_SOFTCLOCK, /* SI_SOFTCLOCK */
105 IPL_SOFTNET, /* SI_SOFTNET */
106 IPL_SOFTSERIAL, /* SI_SOFTSERIAL */
107 };
108
109 void ixp12x0_intr_dispatch(struct irqframe *frame);
110
111 static __inline u_int32_t
112 ixp12x0_irq_read(void)
113 {
114 return IXPREG(IXP12X0_IRQ_VBASE) & IXP12X0_INTR_MASK;
115 }
116
117 static __inline u_int32_t
118 ixp12x0_pci_irq_read(void)
119 {
120 return IXPREG(IXPPCI_IRQ_STATUS);
121 }
122
123 static void
124 ixp12x0_enable_uart_irq(void)
125 {
126 ixpcom_imask = 0;
127 if (ixpcom_sc)
128 bus_space_write_4(ixpcom_sc->sc_iot, ixpcom_sc->sc_ioh,
129 IXPCOM_CR, ixpcom_cr & ~ixpcom_imask);
130 }
131
132 static void
133 ixp12x0_disable_uart_irq(void)
134 {
135 ixpcom_imask = CR_RIE | CR_XIE;
136 if (ixpcom_sc)
137 bus_space_write_4(ixpcom_sc->sc_iot, ixpcom_sc->sc_ioh,
138 IXPCOM_CR, ixpcom_cr & ~ixpcom_imask);
139 }
140
141 static void
142 ixp12x0_set_intrmask(u_int32_t irqs, u_int32_t pci_irqs)
143 {
144 if (irqs & (1U << IXP12X0_INTR_UART)) {
145 ixp12x0_disable_uart_irq();
146 } else {
147 ixp12x0_enable_uart_irq();
148 }
149 IXPREG(IXPPCI_IRQ_ENABLE_CLEAR) = pci_irqs;
150 IXPREG(IXPPCI_IRQ_ENABLE_SET) = pci_intr_enabled & ~pci_irqs;
151 }
152
153 static void
154 ixp12x0_enable_irq(int irq)
155 {
156 if (irq < SYS_NIRQ) {
157 intr_enabled |= (1U << irq);
158 switch (irq) {
159 case IXP12X0_INTR_UART:
160 ixp12x0_enable_uart_irq();
161 break;
162
163 case IXP12X0_INTR_PCI:
164 /* nothing to do */
165 break;
166 default:
167 panic("enable_irq:bad IRQ %d", irq);
168 }
169 } else {
170 pci_intr_enabled |= (1U << (irq - SYS_NIRQ));
171 IXPREG(IXPPCI_IRQ_ENABLE_SET) = (1U << (irq - SYS_NIRQ));
172 }
173 }
174
175 static __inline void
176 ixp12x0_disable_irq(int irq)
177 {
178 if (irq < SYS_NIRQ) {
179 intr_enabled ^= ~(1U << irq);
180 switch (irq) {
181 case IXP12X0_INTR_UART:
182 ixp12x0_disable_uart_irq();
183 break;
184
185 case IXP12X0_INTR_PCI:
186 /* nothing to do */
187 break;
188 default:
189 /* nothing to do */
190 }
191 } else {
192 pci_intr_enabled &= ~(1U << (irq - SYS_NIRQ));
193 IXPREG(IXPPCI_IRQ_ENABLE_CLEAR) = (1U << (irq - SYS_NIRQ));
194 }
195 }
196
197 /*
198 * NOTE: This routine must be called with interrupts disabled in the CPSR.
199 */
200 static void
201 ixp12x0_intr_calculate_masks(void)
202 {
203 struct intrq *iq;
204 struct intrhand *ih;
205 int irq, ipl;
206
207 /* First, figure out which IPLs each IRQ has. */
208 for (irq = 0; irq < NIRQ; irq++) {
209 int levels = 0;
210 iq = &intrq[irq];
211 ixp12x0_disable_irq(irq);
212 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
213 ih = TAILQ_NEXT(ih, ih_list))
214 levels |= (1U << ih->ih_ipl);
215 iq->iq_levels = levels;
216 }
217
218 /* Next, figure out which IRQs are used by each IPL. */
219 for (ipl = 0; ipl < NIPL; ipl++) {
220 int irqs = 0;
221 int pci_irqs = 0;
222 for (irq = 0; irq < SYS_NIRQ; irq++) {
223 if (intrq[irq].iq_levels & (1U << ipl))
224 irqs |= (1U << irq);
225 }
226 imask[ipl] = irqs;
227 for (irq = 0; irq < SYS_NIRQ; irq++) {
228 if (intrq[irq + SYS_NIRQ].iq_levels & (1U << ipl))
229 pci_irqs |= (1U << irq);
230 }
231 pci_imask[ipl] = pci_irqs;
232 }
233
234 imask[IPL_NONE] = 0;
235 pci_imask[IPL_NONE] = 0;
236
237 /*
238 * Initialize the soft interrupt masks to block themselves.
239 */
240 imask[IPL_SOFT] = SI_TO_IRQBIT(SI_SOFT);
241 imask[IPL_SOFTCLOCK] = SI_TO_IRQBIT(SI_SOFTCLOCK);
242 imask[IPL_SOFTNET] = SI_TO_IRQBIT(SI_SOFTNET);
243 imask[IPL_SOFTSERIAL] = SI_TO_IRQBIT(SI_SOFTSERIAL);
244
245 /*
246 * splsoftclock() is the only interface that users of the
247 * generic software interrupt facility have to block their
248 * soft intrs, so splsoftclock() must also block IPL_SOFT.
249 */
250 imask[IPL_SOFTCLOCK] |= imask[IPL_SOFT];
251 pci_imask[IPL_SOFTCLOCK] |= pci_imask[IPL_SOFT];
252
253 /*
254 * splsoftnet() must also block splsoftclock(), since we don't
255 * want timer-driven network events to occur while we're
256 * processing incoming packets.
257 */
258 imask[IPL_SOFTNET] |= imask[IPL_SOFTCLOCK];
259 pci_imask[IPL_SOFTNET] |= pci_imask[IPL_SOFTCLOCK];
260
261 /*
262 * Enforce a heirarchy that gives "slow" device (or devices with
263 * limited input buffer space/"real-time" requirements) a better
264 * chance at not dropping data.
265 */
266 imask[IPL_BIO] |= imask[IPL_SOFTNET];
267 pci_imask[IPL_BIO] |= pci_imask[IPL_SOFTNET];
268 imask[IPL_NET] |= imask[IPL_BIO];
269 pci_imask[IPL_NET] |= pci_imask[IPL_BIO];
270 imask[IPL_SOFTSERIAL] |= imask[IPL_NET];
271 pci_imask[IPL_SOFTSERIAL] |= pci_imask[IPL_NET];
272 imask[IPL_TTY] |= imask[IPL_SOFTSERIAL];
273 pci_imask[IPL_TTY] |= pci_imask[IPL_SOFTSERIAL];
274
275 /*
276 * splvm() blocks all interrupts that use the kernel memory
277 * allocation facilities.
278 */
279 imask[IPL_IMP] |= imask[IPL_TTY];
280 pci_imask[IPL_IMP] |= pci_imask[IPL_TTY];
281
282 /*
283 * Audio devices are not allowed to perform memory allocation
284 * in their interrupt routines, and they have fairly "real-time"
285 * requirements, so give them a high interrupt priority.
286 */
287 imask[IPL_AUDIO] |= imask[IPL_IMP];
288 pci_imask[IPL_AUDIO] |= pci_imask[IPL_IMP];
289
290 /*
291 * splclock() must block anything that uses the scheduler.
292 */
293 imask[IPL_CLOCK] |= imask[IPL_AUDIO];
294 pci_imask[IPL_CLOCK] |= pci_imask[IPL_AUDIO];
295
296 /*
297 * No separate statclock on the IXP12x0.
298 */
299 imask[IPL_STATCLOCK] |= imask[IPL_CLOCK];
300 pci_imask[IPL_STATCLOCK] |= pci_imask[IPL_CLOCK];
301
302 /*
303 * splhigh() must block "everything".
304 */
305 imask[IPL_HIGH] |= imask[IPL_STATCLOCK];
306 pci_imask[IPL_HIGH] |= pci_imask[IPL_STATCLOCK];
307
308 /*
309 * XXX We need serial drivers to run at the absolute highest priority
310 * in order to avoid overruns, so serial > high.
311 */
312 imask[IPL_SERIAL] |= imask[IPL_HIGH];
313 pci_imask[IPL_SERIAL] |= pci_imask[IPL_HIGH];
314
315 /*
316 * Now compute which IRQs must be blocked when servicing any
317 * given IRQ.
318 */
319 for (irq = 0; irq < NIRQ; irq++) {
320 int irqs;
321 int pci_irqs;
322
323 if (irq < SYS_NIRQ) {
324 irqs = (1U << irq);
325 pci_irqs = 0;
326 } else {
327 irqs = 0;
328 pci_irqs = (1U << (irq - SYS_NIRQ));
329 }
330 iq = &intrq[irq];
331 if (TAILQ_FIRST(&iq->iq_list) != NULL)
332 ixp12x0_enable_irq(irq);
333 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
334 ih = TAILQ_NEXT(ih, ih_list)) {
335 irqs |= imask[ih->ih_ipl];
336 pci_irqs |= pci_imask[ih->ih_ipl];
337 }
338 iq->iq_mask = irqs;
339 iq->iq_pci_mask = pci_irqs;
340 }
341 }
342
343 static void
344 ixp12x0_do_pending(void)
345 {
346 static __cpu_simple_lock_t processing = __SIMPLELOCK_UNLOCKED;
347 int new;
348 u_int oldirqstate;
349
350 if (__cpu_simple_lock_try(&processing) == 0)
351 return;
352
353 new = current_spl_level;
354
355 oldirqstate = disable_interrupts(I32_bit);
356
357 #define DO_SOFTINT(si) \
358 if ((ipending & ~imask[new]) & SI_TO_IRQBIT(si)) { \
359 ipending &= ~SI_TO_IRQBIT(si); \
360 current_spl_level = si_to_ipl[(si)]; \
361 restore_interrupts(oldirqstate); \
362 softintr_dispatch(si); \
363 oldirqstate = disable_interrupts(I32_bit); \
364 current_spl_level = new; \
365 }
366
367 DO_SOFTINT(SI_SOFTSERIAL);
368 DO_SOFTINT(SI_SOFTNET);
369 DO_SOFTINT(SI_SOFTCLOCK);
370 DO_SOFTINT(SI_SOFT);
371
372 __cpu_simple_unlock(&processing);
373
374 restore_interrupts(oldirqstate);
375 }
376
377 __inline void
378 splx(int new)
379 {
380 int old;
381 u_int oldirqstate;
382
383 if (current_spl_level == new)
384 return;
385 oldirqstate = disable_interrupts(I32_bit);
386 old = current_spl_level;
387 current_spl_level = new;
388 ixp12x0_set_intrmask(imask[new], pci_imask[new]);
389 restore_interrupts(oldirqstate);
390
391 /* If there are software interrupts to process, do it. */
392 if ((ipending & INT_SWMASK) & ~imask[new])
393 ixp12x0_do_pending();
394 }
395
396 int
397 _splraise(int ipl)
398 {
399 int old = current_spl_level;
400
401 if (old >= ipl)
402 return (old);
403 splx(ipl);
404 return (old);
405 }
406
407 int
408 _spllower(int ipl)
409 {
410 int old = current_spl_level;
411
412 if (old <= ipl)
413 return (old);
414 splx(ipl);
415 return (old);
416 }
417
418 void
419 _setsoftintr(int si)
420 {
421 u_int oldirqstate;
422
423 oldirqstate = disable_interrupts(I32_bit);
424 ipending |= SI_TO_IRQBIT(si);
425 restore_interrupts(oldirqstate);
426
427 /* Process unmasked pending soft interrupts. */
428 if ((ipending & INT_SWMASK) & ~imask[current_spl_level])
429 ixp12x0_do_pending();
430 }
431
432 /*
433 * ixp12x0_intr_init:
434 *
435 * Initialize the rest of the interrupt subsystem, making it
436 * ready to handle interrupts from devices.
437 */
438 void
439 ixp12x0_intr_init(void)
440 {
441 struct intrq *iq;
442 int i;
443
444 intr_enabled = 0;
445 pci_intr_enabled = 0;
446
447 for (i = 0; i < NIRQ; i++) {
448 iq = &intrq[i];
449 TAILQ_INIT(&iq->iq_list);
450
451 sprintf(iq->iq_name, "ipl %d", i);
452 evcnt_attach_dynamic(&iq->iq_ev, EVCNT_TYPE_INTR,
453 NULL, "ixpintr", iq->iq_name);
454 }
455 current_intr_depth = 0;
456 current_spl_level = 0;
457
458 ixp12x0_intr_calculate_masks();
459
460 /* Enable IRQs (don't yet use FIQs). */
461 enable_interrupts(I32_bit);
462 }
463
464 void *
465 ixp12x0_intr_establish(int irq, int ipl, int (*ih_func)(void *), void *arg)
466 {
467 struct intrq* iq;
468 struct intrhand* ih;
469 u_int oldirqstate;
470 #ifdef DEBUG
471 printf("ixp12x0_intr_establish(irq=%d, ipl=%d, ih_func=%08x, arg=%08x)\n",
472 irq, ipl, (u_int32_t) ih_func, (u_int32_t) arg);
473 #endif
474 if (irq < 0 || irq > NIRQ)
475 panic("ixp12x0_intr_establish: IRQ %d out of range", ipl);
476 if (ipl < 0 || ipl > NIPL)
477 panic("ixp12x0_intr_establish: IPL %d out of range", ipl);
478
479 ih = malloc(sizeof(*ih), M_DEVBUF, M_NOWAIT);
480 if (ih == NULL)
481 return (NULL);
482
483 ih->ih_func = ih_func;
484 ih->ih_arg = arg;
485 ih->ih_irq = irq;
486 ih->ih_ipl = ipl;
487
488 iq = &intrq[irq];
489 iq->iq_ist = IST_LEVEL;
490
491 oldirqstate = disable_interrupts(I32_bit);
492 TAILQ_INSERT_TAIL(&iq->iq_list, ih, ih_list);
493 ixp12x0_intr_calculate_masks();
494 restore_interrupts(oldirqstate);
495
496 return (ih);
497 }
498
499 void
500 ixp12x0_intr_disestablish(void *cookie)
501 {
502 struct intrhand* ih = cookie;
503 struct intrq* iq = &intrq[ih->ih_ipl];
504 u_int oldirqstate;
505
506 oldirqstate = disable_interrupts(I32_bit);
507 TAILQ_REMOVE(&iq->iq_list, ih, ih_list);
508 ixp12x0_intr_calculate_masks();
509 restore_interrupts(oldirqstate);
510 }
511
512 void
513 ixp12x0_intr_dispatch(struct clockframe *frame)
514 {
515 struct intrq* iq;
516 struct intrhand* ih;
517 u_int oldirqstate;
518 int pcpl;
519 u_int32_t hwpend;
520 u_int32_t pci_hwpend;
521 int irq;
522 u_int32_t ibit;
523
524 pcpl = current_spl_level;
525
526 hwpend = ixp12x0_irq_read();
527 pci_hwpend = ixp12x0_pci_irq_read();
528
529 while (hwpend) {
530 irq = ffs(hwpend) - 1;
531 ibit = (1U << irq);
532
533 iq = &intrq[irq];
534 iq->iq_ev.ev_count++;
535 uvmexp.intrs++;
536 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
537 ih = TAILQ_NEXT(ih, ih_list)) {
538 int ipl;
539 current_spl_level = ipl = ih->ih_ipl;
540 ixp12x0_set_intrmask(imask[ipl] | hwpend,
541 pci_imask[ipl] | pci_hwpend);
542 oldirqstate = enable_interrupts(I32_bit);
543 (void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
544 restore_interrupts(oldirqstate);
545 hwpend &= ~ibit;
546 }
547 }
548 while (pci_hwpend) {
549 irq = ffs(pci_hwpend) - 1;
550 ibit = (1U << irq);
551
552 iq = &intrq[irq + SYS_NIRQ];
553 iq->iq_ev.ev_count++;
554 uvmexp.intrs++;
555 for (ih = TAILQ_FIRST(&iq->iq_list); ih != NULL;
556 ih = TAILQ_NEXT(ih, ih_list)) {
557 int ipl;
558
559 current_spl_level = ipl = ih->ih_ipl;
560 ixp12x0_set_intrmask(imask[ipl] | hwpend,
561 pci_imask[ipl] | pci_hwpend);
562 oldirqstate = enable_interrupts(I32_bit);
563 (void) (*ih->ih_func)(ih->ih_arg ? ih->ih_arg : frame);
564 restore_interrupts(oldirqstate);
565 pci_hwpend &= ~ibit;
566 }
567 }
568
569 splx(pcpl);
570
571 /* Check for pendings soft intrs. */
572 if ((ipending & INT_SWMASK) & ~imask[pcpl]) {
573 oldirqstate = enable_interrupts(I32_bit);
574 ixp12x0_do_pending();
575 restore_interrupts(oldirqstate);
576 }
577 }
578