xref: /netbsd-src/sys/arch/mips/cavium/octeon_intr.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: octeon_intr.c,v 1.24 2020/08/18 07:41:41 skrll Exp $	*/
2 /*
3  * Copyright 2001, 2002 Wasabi Systems, Inc.
4  * All rights reserved.
5  *
6  * Written by Jason R. Thorpe and Simon Burge for Wasabi Systems, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. All advertising materials mentioning features or use of this software
17  *    must display the following acknowledgement:
18  *      This product includes software developed for the NetBSD Project by
19  *      Wasabi Systems, Inc.
20  * 4. The name of Wasabi Systems, Inc. may not be used to endorse
21  *    or promote products derived from this software without specific prior
22  *    written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY WASABI SYSTEMS, INC. ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
27  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL WASABI SYSTEMS, INC
28  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
34  * POSSIBILITY OF SUCH DAMAGE.
35  */
36 
37 /*
38  * Platform-specific interrupt support for the MIPS Malta.
39  */
40 
41 #include "opt_multiprocessor.h"
42 
43 #include "cpunode.h"
44 #define __INTR_PRIVATE
45 
46 #include <sys/cdefs.h>
47 __KERNEL_RCSID(0, "$NetBSD: octeon_intr.c,v 1.24 2020/08/18 07:41:41 skrll Exp $");
48 
49 #include <sys/param.h>
50 #include <sys/cpu.h>
51 #include <sys/systm.h>
52 #include <sys/device.h>
53 #include <sys/intr.h>
54 #include <sys/kernel.h>
55 #include <sys/kmem.h>
56 #include <sys/atomic.h>
57 
58 #include <lib/libkern/libkern.h>
59 
60 #include <mips/locore.h>
61 
62 #include <mips/cavium/dev/octeon_ciureg.h>
63 #include <mips/cavium/octeonvar.h>
64 
65 /*
66  * XXX:
67  * Force all interrupts (except clock intrs and IPIs) to be routed
68  * through cpu0 until MP on MIPS is more stable.
69  */
70 #define	OCTEON_CPU0_INTERRUPTS
71 
72 
73 /*
74  * This is a mask of bits to clear in the SR when we go to a
75  * given hardware interrupt priority level.
76  */
77 static const struct ipl_sr_map octeon_ipl_sr_map = {
78     .sr_bits = {
79 	[IPL_NONE] =		0,
80 	[IPL_SOFTCLOCK] =	MIPS_SOFT_INT_MASK_0,
81 	[IPL_SOFTNET] =		MIPS_SOFT_INT_MASK,
82 	[IPL_VM] =		MIPS_SOFT_INT_MASK | MIPS_INT_MASK_0,
83 	[IPL_SCHED] =		MIPS_SOFT_INT_MASK | MIPS_INT_MASK_0
84 				    | MIPS_INT_MASK_1 | MIPS_INT_MASK_5,
85 	[IPL_DDB] =		MIPS_SOFT_INT_MASK | MIPS_INT_MASK_0
86 				    | MIPS_INT_MASK_1 | MIPS_INT_MASK_5,
87 	[IPL_HIGH] =		MIPS_INT_MASK,
88     },
89 };
90 
91 static const char * octeon_intrnames[NIRQS] = {
92 	"workq 0",
93 	"workq 1",
94 	"workq 2",
95 	"workq 3",
96 	"workq 4",
97 	"workq 5",
98 	"workq 6",
99 	"workq 7",
100 	"workq 8",
101 	"workq 9",
102 	"workq 10",
103 	"workq 11",
104 	"workq 12",
105 	"workq 13",
106 	"workq 14",
107 	"workq 15",
108 	"gpio 0",
109 	"gpio 1",
110 	"gpio 2",
111 	"gpio 3",
112 	"gpio 4",
113 	"gpio 5",
114 	"gpio 6",
115 	"gpio 7",
116 	"gpio 8",
117 	"gpio 9",
118 	"gpio 10",
119 	"gpio 11",
120 	"gpio 12",
121 	"gpio 13",
122 	"gpio 14",
123 	"gpio 15",
124 	"mbox 0-15",
125 	"mbox 16-31",
126 	"uart 0",
127 	"uart 1",
128 	"pci inta",
129 	"pci intb",
130 	"pci intc",
131 	"pci intd",
132 	"pci msi 0-15",
133 	"pci msi 16-31",
134 	"pci msi 32-47",
135 	"pci msi 48-63",
136 	"wdog summary",
137 	"twsi",
138 	"rml",
139 	"trace",
140 	"gmx drop",
141 	"reserved",
142 	"ipd drop",
143 	"reserved",
144 	"timer 0",
145 	"timer 1",
146 	"timer 2",
147 	"timer 3",
148 	"usb",
149 	"pcm/tdm",
150 	"mpi/spi",
151 	"reserved",
152 	"reserved",
153 	"reserved",
154 	"reserved",
155 	"reserved",
156 };
157 
158 struct octeon_intrhand {
159 	int (*ih_func)(void *);
160 	void *ih_arg;
161 	int ih_irq;
162 	int ih_ipl;
163 };
164 
165 #ifdef MULTIPROCESSOR
166 static int octeon_send_ipi(struct cpu_info *, int);
167 static int octeon_ipi_intr(void *);
168 
169 static struct octeon_intrhand ipi_intrhands[2] = {
170 	[0] = {
171 		.ih_func = octeon_ipi_intr,
172 		.ih_arg = (void *)(uintptr_t)__BITS(15,0),
173 		.ih_irq = CIU_INT_MBOX_15_0,
174 		.ih_ipl = IPL_HIGH,
175 	},
176 	[1] = {
177 		.ih_func = octeon_ipi_intr,
178 		.ih_arg = (void *)(uintptr_t)__BITS(31,16),
179 		.ih_irq = CIU_INT_MBOX_31_16,
180 		.ih_ipl = IPL_SCHED,
181 	},
182 };
183 
184 static int ipi_prio[NIPIS] = {
185 	[IPI_NOP] = IPL_HIGH,
186 	[IPI_AST] = IPL_HIGH,
187 	[IPI_SHOOTDOWN] = IPL_SCHED,
188 	[IPI_SYNCICACHE] = IPL_HIGH,
189 	[IPI_KPREEMPT] = IPL_HIGH,
190 	[IPI_SUSPEND] = IPL_HIGH,
191 	[IPI_HALT] = IPL_HIGH,
192 	[IPI_XCALL] = IPL_HIGH,
193 	[IPI_GENERIC] = IPL_HIGH,
194 	[IPI_WDOG] = IPL_HIGH,
195 };
196 
197 #endif
198 
199 static struct octeon_intrhand *octciu_intrs[NIRQS] = {
200 #ifdef MULTIPROCESSOR
201 	[CIU_INT_MBOX_15_0] = &ipi_intrhands[0],
202 	[CIU_INT_MBOX_31_16] = &ipi_intrhands[1],
203 #endif
204 };
205 
206 static kmutex_t octeon_intr_lock;
207 
208 #if defined(MULTIPROCESSOR)
209 #define	OCTEON_NCPU	MAXCPUS
210 #else
211 #define	OCTEON_NCPU	1
212 #endif
213 
214 struct cpu_softc octeon_cpu_softc[OCTEON_NCPU];
215 
216 static void
217 octeon_intr_setup(void)
218 {
219 	struct cpu_softc *cpu;
220 	int cpunum;
221 
222 #define X(a)	MIPS_PHYS_TO_XKPHYS(OCTEON_CCA_NONE, (a))
223 
224 	for (cpunum = 0; cpunum < OCTEON_NCPU; cpunum++) {
225 		cpu = &octeon_cpu_softc[cpunum];
226 
227 		cpu->cpu_ip2_sum0 = X(CIU_IP2_SUM0(cpunum));
228 		cpu->cpu_ip3_sum0 = X(CIU_IP3_SUM0(cpunum));
229 		cpu->cpu_ip4_sum0 = X(CIU_IP4_SUM0(cpunum));
230 
231 		cpu->cpu_int_sum1 = X(CIU_INT_SUM1);
232 
233 		cpu->cpu_ip2_en[0] = X(CIU_IP2_EN0(cpunum));
234 		cpu->cpu_ip3_en[0] = X(CIU_IP3_EN0(cpunum));
235 		cpu->cpu_ip4_en[0] = X(CIU_IP4_EN0(cpunum));
236 
237 		cpu->cpu_ip2_en[1] = X(CIU_IP2_EN1(cpunum));
238 		cpu->cpu_ip3_en[1] = X(CIU_IP3_EN1(cpunum));
239 		cpu->cpu_ip4_en[1] = X(CIU_IP4_EN1(cpunum));
240 
241 		cpu->cpu_wdog = X(CIU_WDOG(cpunum));
242 		cpu->cpu_pp_poke = X(CIU_PP_POKE(cpunum));
243 
244 #ifdef MULTIPROCESSOR
245 		cpu->cpu_mbox_set = X(CIU_MBOX_SET(cpunum));
246 		cpu->cpu_mbox_clr = X(CIU_MBOX_CLR(cpunum));
247 #endif
248 	}
249 
250 #undef X
251 
252 }
253 
254 void
255 octeon_intr_init(struct cpu_info *ci)
256 {
257 	const int cpunum = cpu_index(ci);
258 	struct cpu_softc *cpu = &octeon_cpu_softc[cpunum];
259 	const char * const xname = cpu_name(ci);
260 	int bank;
261 
262 	cpu->cpu_ci = ci;
263 	ci->ci_softc = cpu;
264 
265 	KASSERT(cpunum == ci->ci_cpuid);
266 
267 	if (ci->ci_cpuid == 0) {
268 		ipl_sr_map = octeon_ipl_sr_map;
269 		mutex_init(&octeon_intr_lock, MUTEX_DEFAULT, IPL_HIGH);
270 #ifdef MULTIPROCESSOR
271 		mips_locoresw.lsw_send_ipi = octeon_send_ipi;
272 #endif
273 
274 		octeon_intr_setup();
275 	}
276 
277 #ifdef MULTIPROCESSOR
278 	// Enable the IPIs
279 	cpu->cpu_ip4_enable[0] |= __BIT(CIU_INT_MBOX_15_0);
280 	cpu->cpu_ip3_enable[0] |= __BIT(CIU_INT_MBOX_31_16);
281 #endif
282 
283 	if (ci->ci_dev) {
284 		for (bank = 0; bank < NBANKS; bank++) {
285 			aprint_verbose_dev(ci->ci_dev,
286 			    "enabling intr masks %u "
287 			    " %#"PRIx64"/%#"PRIx64"/%#"PRIx64"\n",
288 			    bank,
289 			    cpu->cpu_ip2_enable[bank],
290 			    cpu->cpu_ip3_enable[bank],
291 			    cpu->cpu_ip4_enable[bank]);
292 		}
293 	}
294 
295 	for (bank = 0; bank < NBANKS; bank++) {
296 		mips3_sd(cpu->cpu_ip2_en[bank], cpu->cpu_ip2_enable[bank]);
297 		mips3_sd(cpu->cpu_ip3_en[bank], cpu->cpu_ip3_enable[bank]);
298 		mips3_sd(cpu->cpu_ip4_en[bank], cpu->cpu_ip4_enable[bank]);
299 	}
300 
301 #ifdef MULTIPROCESSOR
302 	mips3_sd(cpu->cpu_mbox_clr, __BITS(31,0));
303 #endif
304 
305 	for (int i = 0; i < NIRQS; i++) {
306 		if (octeon_intrnames[i] == NULL)
307 			octeon_intrnames[i] = kmem_asprintf("irq %d", i);
308 		evcnt_attach_dynamic(&cpu->cpu_intr_evs[i],
309 		    EVCNT_TYPE_INTR, NULL, xname, octeon_intrnames[i]);
310 	}
311 }
312 
313 void
314 octeon_cal_timer(int corefreq)
315 {
316 	/* Compute the number of cycles per second. */
317 	curcpu()->ci_cpu_freq = corefreq;
318 
319 	/* Compute the number of ticks for hz. */
320 	curcpu()->ci_cycles_per_hz = (curcpu()->ci_cpu_freq + hz / 2) / hz;
321 
322 	/* Compute the delay divisor and reciprical. */
323 	curcpu()->ci_divisor_delay =
324 	    ((curcpu()->ci_cpu_freq + 500000) / 1000000);
325 #if 0
326 	MIPS_SET_CI_RECIPRICAL(curcpu());
327 #endif
328 
329 	mips3_cp0_count_write(0);
330 	mips3_cp0_compare_write(0);
331 }
332 
333 void *
334 octeon_intr_establish(int irq, int ipl, int (*func)(void *), void *arg)
335 {
336 	struct octeon_intrhand *ih;
337 	struct cpu_softc *cpu;
338 #ifndef OCTEON_CPU0_INTERRUPTS
339 	int cpunum;
340 #endif
341 
342 	if (irq >= NIRQS)
343 		panic("octeon_intr_establish: bogus IRQ %d", irq);
344 	if (ipl < IPL_VM)
345 		panic("octeon_intr_establish: bogus IPL %d", ipl);
346 
347 	ih = kmem_zalloc(sizeof(*ih), KM_NOSLEEP);
348 	if (ih == NULL)
349 		return (NULL);
350 
351 	ih->ih_func = func;
352 	ih->ih_arg = arg;
353 	ih->ih_irq = irq;
354 	ih->ih_ipl = ipl;
355 
356 	mutex_enter(&octeon_intr_lock);
357 
358 	/*
359 	 * First, make it known.
360 	 */
361 	KASSERTMSG(octciu_intrs[irq] == NULL, "irq %d in use! (%p)",
362 	    irq, octciu_intrs[irq]);
363 
364 	octciu_intrs[irq] = ih;
365 	membar_producer();
366 
367 	/*
368 	 * Now enable it.
369 	 */
370 	const int bank = irq / 64;
371 	const uint64_t irq_mask = __BIT(irq % 64);
372 
373 	switch (ipl) {
374 	case IPL_VM:
375 		cpu = &octeon_cpu_softc[0];
376 		cpu->cpu_ip2_enable[bank] |= irq_mask;
377 		mips3_sd(cpu->cpu_ip2_en[bank], cpu->cpu_ip2_enable[bank]);
378 		break;
379 
380 	case IPL_SCHED:
381 #ifdef OCTEON_CPU0_INTERRUPTS
382 		cpu = &octeon_cpu_softc[0];
383 		cpu->cpu_ip3_enable[bank] |= irq_mask;
384 		mips3_sd(cpu->cpu_ip3_en[bank], cpu->cpu_ip3_enable[bank]);
385 #else	/* OCTEON_CPU0_INTERRUPTS */
386 		for (cpunum = 0; cpunum < OCTEON_NCPU; cpunum++) {
387 			cpu = &octeon_cpu_softc[cpunum];
388 			if (cpu->cpu_ci == NULL)
389 				break;
390 			cpu->cpu_ip3_enable[bank] |= irq_mask;
391 			mips3_sd(cpu->cpu_ip3_en[bank], cpu->cpu_ip3_enable[bank]);
392 		}
393 #endif	/* OCTEON_CPU0_INTERRUPTS */
394 		break;
395 
396 	case IPL_DDB:
397 	case IPL_HIGH:
398 #ifdef OCTEON_CPU0_INTERRUPTS
399 		cpu = &octeon_cpu_softc[0];
400 		cpu->cpu_ip4_enable[bank] |= irq_mask;
401 		mips3_sd(cpu->cpu_ip4_en[bank], cpu->cpu_ip4_enable[bank]);
402 #else	/* OCTEON_CPU0_INTERRUPTS */
403 		for (cpunum = 0; cpunum < OCTEON_NCPU; cpunum++) {
404 			cpu = &octeon_cpu_softc[cpunum];
405 			if (cpu->cpu_ci == NULL)
406 				break;
407 			cpu->cpu_ip4_enable[bank] |= irq_mask;
408 			mips3_sd(cpu->cpu_ip4_en[bank], cpu->cpu_ip4_enable[bank]);
409 		}
410 #endif	/* OCTEON_CPU0_INTERRUPTS */
411 		break;
412 	}
413 
414 	mutex_exit(&octeon_intr_lock);
415 
416 	return ih;
417 }
418 
419 void
420 octeon_intr_disestablish(void *cookie)
421 {
422 	struct octeon_intrhand * const ih = cookie;
423 	struct cpu_softc *cpu;
424 	const int irq = ih->ih_irq & (NIRQS-1);
425 	const int ipl = ih->ih_ipl;
426 	int cpunum;
427 
428 	mutex_enter(&octeon_intr_lock);
429 
430 	/*
431 	 * First disable it.
432 	 */
433 	const int bank = irq / 64;
434 	const uint64_t irq_mask = ~__BIT(irq % 64);
435 
436 	switch (ipl) {
437 	case IPL_VM:
438 		cpu = &octeon_cpu_softc[0];
439 		cpu->cpu_ip2_enable[bank] &= ~irq_mask;
440 		mips3_sd(cpu->cpu_ip2_en[bank], cpu->cpu_ip2_enable[bank]);
441 		break;
442 
443 	case IPL_SCHED:
444 		for (cpunum = 0; cpunum < OCTEON_NCPU; cpunum++) {
445 			cpu = &octeon_cpu_softc[cpunum];
446 			if (cpu->cpu_ci == NULL)
447 				break;
448 			cpu->cpu_ip3_enable[bank] &= ~irq_mask;
449 			mips3_sd(cpu->cpu_ip3_en[bank], cpu->cpu_ip3_enable[bank]);
450 		}
451 		break;
452 
453 	case IPL_DDB:
454 	case IPL_HIGH:
455 		for (cpunum = 0; cpunum < OCTEON_NCPU; cpunum++) {
456 			cpu = &octeon_cpu_softc[cpunum];
457 			if (cpu->cpu_ci == NULL)
458 				break;
459 			cpu->cpu_ip4_enable[bank] &= ~irq_mask;
460 			mips3_sd(cpu->cpu_ip4_en[bank], cpu->cpu_ip4_enable[bank]);
461 		}
462 		break;
463 	}
464 
465 	/*
466 	 * Now remove it since we shouldn't get interrupts for it.
467 	 */
468 	octciu_intrs[irq] = NULL;
469 
470 	mutex_exit(&octeon_intr_lock);
471 
472 	kmem_free(ih, sizeof(*ih));
473 }
474 
475 void
476 octeon_iointr(int ipl, vaddr_t pc, uint32_t ipending)
477 {
478 	struct cpu_info * const ci = curcpu();
479 	struct cpu_softc * const cpu = ci->ci_softc;
480 	int bank;
481 
482 	KDASSERT(mips_cp0_status_read() & MIPS_SR_INT_IE);
483 	KASSERT((ipending & ~MIPS_INT_MASK) == 0);
484 	KASSERT(ipending & MIPS_HARD_INT_MASK);
485 	uint64_t hwpend[2] = { 0, 0 };
486 
487 	const uint64_t sum1 = mips3_ld(cpu->cpu_int_sum1);
488 
489 	if (ipending & MIPS_INT_MASK_2) {
490 		hwpend[0] = mips3_ld(cpu->cpu_ip4_sum0)
491 		    & cpu->cpu_ip4_enable[0];
492 		hwpend[1] = sum1 & cpu->cpu_ip4_enable[1];
493 	} else if (ipending & MIPS_INT_MASK_1) {
494 		hwpend[0] = mips3_ld(cpu->cpu_ip3_sum0)
495 		    & cpu->cpu_ip3_enable[0];
496 		hwpend[1] = sum1 & cpu->cpu_ip3_enable[1];
497 	} else if (ipending & MIPS_INT_MASK_0) {
498 		hwpend[0] = mips3_ld(cpu->cpu_ip2_sum0)
499 		    & cpu->cpu_ip2_enable[0];
500 		hwpend[1] = sum1 & cpu->cpu_ip2_enable[1];
501 	} else {
502 		panic("octeon_iointr: unexpected ipending %#x", ipending);
503 	}
504 	for (bank = 0; bank <= 1; bank++) {
505 		while (hwpend[bank] != 0) {
506 			const int bit = ffs64(hwpend[bank]) - 1;
507 			const int irq = (bank * 64) + bit;
508 			hwpend[bank] &= ~__BIT(bit);
509 
510 			struct octeon_intrhand * const ih = octciu_intrs[irq];
511 			cpu->cpu_intr_evs[irq].ev_count++;
512 			if (__predict_true(ih != NULL)) {
513 #ifdef MULTIPROCESSOR
514 				if (ipl == IPL_VM) {
515 					KERNEL_LOCK(1, NULL);
516 #endif
517 					(*ih->ih_func)(ih->ih_arg);
518 #ifdef MULTIPROCESSOR
519 					KERNEL_UNLOCK_ONE(NULL);
520 				} else {
521 					(*ih->ih_func)(ih->ih_arg);
522 				}
523 #endif
524 				KDASSERT(mips_cp0_status_read() & MIPS_SR_INT_IE);
525 			}
526 		}
527 	}
528 	KDASSERT(mips_cp0_status_read() & MIPS_SR_INT_IE);
529 }
530 
531 #ifdef MULTIPROCESSOR
532 __CTASSERT(NIPIS < 16);
533 
534 int
535 octeon_ipi_intr(void *arg)
536 {
537 	struct cpu_info * const ci = curcpu();
538 	struct cpu_softc * const cpu = ci->ci_softc;
539 	const uint32_t mbox_mask = (uintptr_t) arg;
540 	uint32_t ipi_mask = mbox_mask;
541 
542 	KASSERTMSG((mbox_mask & __BITS(31,16)) == 0 || ci->ci_cpl >= IPL_SCHED,
543 	    "mbox_mask %#"PRIx32" cpl %d", mbox_mask, ci->ci_cpl);
544 
545 	ipi_mask &= mips3_ld(cpu->cpu_mbox_set);
546 	if (ipi_mask == 0)
547 		return 0;
548 
549 	mips3_sd(cpu->cpu_mbox_clr, ipi_mask);
550 
551 	KASSERT(__SHIFTOUT(ipi_mask, mbox_mask) < __BIT(NIPIS));
552 
553 #if NWDOG > 0
554 	// Handle WDOG requests ourselves.
555 	if (ipi_mask & __BIT(IPI_WDOG)) {
556 		softint_schedule(cpu->cpu_wdog_sih);
557 		atomic_and_64(&ci->ci_request_ipis, ~__BIT(IPI_WDOG));
558 		ipi_mask &= ~__BIT(IPI_WDOG);
559 		ci->ci_evcnt_per_ipi[IPI_WDOG].ev_count++;
560 		if (__predict_true(ipi_mask == 0))
561 			return 1;
562 	}
563 #endif
564 
565 	/* if the request is clear, it was previously processed */
566 	if ((ci->ci_request_ipis & ipi_mask) == 0)
567 		return 0;
568 
569 	atomic_or_64(&ci->ci_active_ipis, ipi_mask);
570 	atomic_and_64(&ci->ci_request_ipis, ~ipi_mask);
571 
572 	ipi_process(ci, __SHIFTOUT(ipi_mask, mbox_mask));
573 
574 	atomic_and_64(&ci->ci_active_ipis, ~ipi_mask);
575 
576 	return 1;
577 }
578 
579 int
580 octeon_send_ipi(struct cpu_info *ci, int req)
581 {
582 	KASSERT(req < NIPIS);
583 	if (ci == NULL) {
584 		CPU_INFO_ITERATOR cii;
585 		for (CPU_INFO_FOREACH(cii, ci)) {
586 			if (ci != curcpu()) {
587 				octeon_send_ipi(ci, req);
588 			}
589 		}
590 		return 0;
591 	}
592 	KASSERT(cold || ci->ci_softc != NULL);
593 	if (ci->ci_softc == NULL)
594 		return -1;
595 
596 	struct cpu_softc * const cpu = ci->ci_softc;
597 	const u_int ipi_shift = ipi_prio[req] == IPL_SCHED ? 16 : 0;
598 	const uint32_t ipi_mask = __BIT(req + ipi_shift);
599 
600 	atomic_or_64(&ci->ci_request_ipis, ipi_mask);
601 
602 	mips3_sd(cpu->cpu_mbox_set, ipi_mask);
603 
604 	return 0;
605 }
606 #endif	/* MULTIPROCESSOR */
607