xref: /netbsd-src/sys/arch/x86/pci/pci_msi_machdep.c (revision 0a4cb760d31176d181b1c5355e72dcfa3e752248)
1 /*	$NetBSD: pci_msi_machdep.c,v 1.19 2023/11/21 23:22:23 gutteridge Exp $	*/
2 
3 /*
4  * Copyright (c) 2015 Internet Initiative Japan Inc.
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 NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * TODO
31  *
32  *     - PBA (Pending Bit Array) support
33  *     - HyperTransport mapping support
34  */
35 
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: pci_msi_machdep.c,v 1.19 2023/11/21 23:22:23 gutteridge Exp $");
38 
39 #include "opt_intrdebug.h"
40 #include "ioapic.h"
41 
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/time.h>
45 #include <sys/systm.h>
46 #include <sys/cpu.h>
47 #include <sys/errno.h>
48 #include <sys/device.h>
49 #include <sys/intr.h>
50 #include <sys/kmem.h>
51 
52 #include <dev/pci/pcivar.h>
53 
54 #include <machine/i82093var.h>
55 #include <machine/pic.h>
56 
57 #include <x86/pci/msipic.h>
58 #include <x86/pci/pci_msi_machdep.h>
59 
60 #ifdef INTRDEBUG
61 #define MSIDEBUG
62 #endif
63 
64 #ifdef MSIDEBUG
65 #define DPRINTF(msg) printf msg
66 #else
67 #define DPRINTF(msg)
68 #endif
69 
70 static pci_intr_handle_t
pci_msi_calculate_handle(struct pic * msi_pic,int vector)71 pci_msi_calculate_handle(struct pic *msi_pic, int vector)
72 {
73 	pci_intr_handle_t pih;
74 
75 	KASSERT(msipic_is_msi_pic(msi_pic));
76 
77 	pih = __SHIFTIN((uint64_t)msipic_get_devid(msi_pic), MSI_INT_DEV_MASK)
78 	    | __SHIFTIN((uint64_t)vector, MSI_INT_VEC_MASK)
79 	    | APIC_INT_VIA_MSI;
80 	if (msi_pic->pic_type == PIC_MSI)
81 		MSI_INT_MAKE_MSI(pih);
82 	else if (msi_pic->pic_type == PIC_MSIX)
83 		MSI_INT_MAKE_MSIX(pih);
84 	else
85 		panic("%s: Unexpected pic_type: %d\n", __func__,
86 		    msi_pic->pic_type);
87 
88 	return pih;
89 }
90 
91 #ifdef __HAVE_PCI_MSI_MSIX
92 static pci_intr_handle_t *
pci_msi_alloc_vectors(struct pic * msi_pic,uint * table_indexes,int * count)93 pci_msi_alloc_vectors(struct pic *msi_pic, uint *table_indexes, int *count)
94 {
95 	struct intrsource *isp;
96 	pci_intr_handle_t *vectors, pih;
97 	int i;
98 	const char *intrstr;
99 	char intrstr_buf[INTRIDBUF];
100 
101 	vectors = kmem_zalloc(sizeof(vectors[0]) * (*count), KM_SLEEP);
102 	mutex_enter(&cpu_lock);
103 	for (i = 0; i < *count; i++) {
104 		u_int table_index;
105 
106 		if (table_indexes == NULL)
107 			table_index = i;
108 		else
109 			table_index = table_indexes[i];
110 
111 		pih = pci_msi_calculate_handle(msi_pic, table_index);
112 
113 		intrstr = x86_pci_msi_string(NULL, pih, intrstr_buf,
114 		    sizeof(intrstr_buf));
115 		isp = intr_allocate_io_intrsource(intrstr);
116 		if (isp == NULL) {
117 			mutex_exit(&cpu_lock);
118 			DPRINTF(("can't allocate io_intersource\n"));
119 			kmem_free(vectors, sizeof(vectors[0]) * (*count));
120 			return NULL;
121 		}
122 
123 		vectors[i] = pih;
124 	}
125 	mutex_exit(&cpu_lock);
126 
127 	return vectors;
128 }
129 #endif /* __HAVE_PCI_MSI_MSIX */
130 
131 static void
pci_msi_free_vectors(struct pic * msi_pic,pci_intr_handle_t * pihs,int count)132 pci_msi_free_vectors(struct pic *msi_pic, pci_intr_handle_t *pihs, int count)
133 {
134 	pci_intr_handle_t pih;
135 	int i;
136 	const char *intrstr;
137 	char intrstr_buf[INTRIDBUF];
138 
139 	mutex_enter(&cpu_lock);
140 	for (i = 0; i < count; i++) {
141 		pih = pci_msi_calculate_handle(msi_pic, i);
142 		intrstr = x86_pci_msi_string(NULL, pih, intrstr_buf,
143 		    sizeof(intrstr_buf));
144 		intr_free_io_intrsource(intrstr);
145 	}
146 	mutex_exit(&cpu_lock);
147 
148 	kmem_free(pihs, sizeof(pihs[0]) * count);
149 }
150 
151 #ifdef __HAVE_PCI_MSI_MSIX
152 static int
pci_msi_alloc_common(pci_intr_handle_t ** ihps,int * count,const struct pci_attach_args * pa,bool exact)153 pci_msi_alloc_common(pci_intr_handle_t **ihps, int *count,
154     const struct pci_attach_args *pa, bool exact)
155 {
156 	struct pic *msi_pic;
157 	pci_intr_handle_t *vectors;
158 	int error, i;
159 
160 #if NIOAPIC > 0
161 	if (nioapics == 0) {
162 		DPRINTF(("no IOAPIC.\n"));
163 		return ENODEV;
164 	}
165 #endif
166 
167 	if ((pa->pa_flags & PCI_FLAGS_MSI_OKAY) == 0) {
168 		DPRINTF(("PCI host bridge does not support MSI.\n"));
169 		return ENODEV;
170 	}
171 
172 	msi_pic = msipic_construct_msi_pic(pa);
173 	if (msi_pic == NULL) {
174 		DPRINTF(("cannot allocate MSI pic.\n"));
175 		return EINVAL;
176 	}
177 
178 	vectors = NULL;
179 	while (*count > 0) {
180 		vectors = pci_msi_alloc_vectors(msi_pic, NULL, count);
181 		if (vectors != NULL)
182 			break;
183 
184 		if (exact) {
185 			DPRINTF(("cannot allocate MSI vectors.\n"));
186 			msipic_destruct_msi_pic(msi_pic);
187 			return ENOMEM;
188 		} else {
189 			(*count) >>= 1; /* must be power of 2. */
190 			continue;
191 		}
192 	}
193 	if (vectors == NULL) {
194 		DPRINTF(("cannot allocate MSI vectors.\n"));
195 		msipic_destruct_msi_pic(msi_pic);
196 		return ENOMEM;
197 	}
198 
199 	for (i = 0; i < *count; i++) {
200 		MSI_INT_MAKE_MSI(vectors[i]);
201 	}
202 
203 	error = msipic_set_msi_vectors(msi_pic, NULL, *count);
204 	if (error) {
205 		pci_msi_free_vectors(msi_pic, vectors, *count);
206 		msipic_destruct_msi_pic(msi_pic);
207 		return error;
208 	}
209 
210 	*ihps = vectors;
211 #ifdef XENPV
212 	if (xen_map_msi_pirq(msi_pic, *count)) {
213 		DPRINTF(("xen_map_msi_pirq() failed\n"));
214 		pci_msi_free_vectors(msi_pic, vectors, *count);
215 		msipic_destruct_msi_pic(msi_pic);
216 		return EINVAL;
217 	}
218 #endif
219 
220 	return 0;
221 }
222 #endif /* __HAVE_PCI_MSI_MSIX */
223 
224 static void *
pci_msi_common_establish(pci_chipset_tag_t pc,pci_intr_handle_t ih,int level,int (* func)(void *),void * arg,struct pic * pic,const char * xname)225 pci_msi_common_establish(pci_chipset_tag_t pc, pci_intr_handle_t ih,
226     int level, int (*func)(void *), void *arg, struct pic *pic,
227     const char *xname)
228 {
229 	int irq, pin;
230 	bool mpsafe;
231 
232 	KASSERT(INT_VIA_MSI(ih));
233 
234 	irq = -1;
235 	pin = MSI_INT_VEC(ih);
236 	mpsafe = ((ih & MPSAFE_MASK) != 0);
237 
238 	return intr_establish_xname(irq, pic, pin, IST_EDGE, level, func, arg,
239 	    mpsafe, xname);
240 }
241 
242 static void
pci_msi_common_disestablish(pci_chipset_tag_t pc,void * cookie)243 pci_msi_common_disestablish(pci_chipset_tag_t pc, void *cookie)
244 {
245 
246 	intr_disestablish(cookie);
247 }
248 
249 #ifdef __HAVE_PCI_MSI_MSIX
250 static int
pci_msix_alloc_common(pci_intr_handle_t ** ihps,u_int * table_indexes,int * count,const struct pci_attach_args * pa,bool exact)251 pci_msix_alloc_common(pci_intr_handle_t **ihps, u_int *table_indexes,
252     int *count, const struct pci_attach_args *pa, bool exact)
253 {
254 	struct pic *msix_pic;
255 	pci_intr_handle_t *vectors;
256 	int error, i;
257 
258 #if NIOAPIC > 0
259 	if (nioapics == 0) {
260 		DPRINTF(("no IOAPIC.\n"));
261 		return ENODEV;
262 	}
263 #endif
264 
265 	if ((pa->pa_flags & PCI_FLAGS_MSIX_OKAY) == 0) {
266 		DPRINTF(("PCI host bridge does not support MSI-X.\n"));
267 		return ENODEV;
268 	}
269 
270 	msix_pic = msipic_construct_msix_pic(pa);
271 	if (msix_pic == NULL)
272 		return EINVAL;
273 
274 	vectors = NULL;
275 	while (*count > 0) {
276 		vectors = pci_msi_alloc_vectors(msix_pic, table_indexes, count);
277 		if (vectors != NULL)
278 			break;
279 
280 		if (exact) {
281 			DPRINTF(("cannot allocate MSI-X vectors.\n"));
282 			msipic_destruct_msix_pic(msix_pic);
283 			return ENOMEM;
284 		} else {
285 			(*count)--;
286 			continue;
287 		}
288 	}
289 	if (vectors == NULL) {
290 		DPRINTF(("cannot allocate MSI-X vectors.\n"));
291 		msipic_destruct_msix_pic(msix_pic);
292 		return ENOMEM;
293 	}
294 
295 	for (i = 0; i < *count; i++) {
296 		MSI_INT_MAKE_MSIX(vectors[i]);
297 	}
298 
299 	error = msipic_set_msi_vectors(msix_pic, vectors, *count);
300 	if (error) {
301 		pci_msi_free_vectors(msix_pic, vectors, *count);
302 		msipic_destruct_msix_pic(msix_pic);
303 		return error;
304 	}
305 
306 	*ihps = vectors;
307 
308 #ifdef XENPV
309 	if (xen_map_msix_pirq(msix_pic, *count)) {
310 		DPRINTF(("xen_map_msi_pirq() failed\n"));
311 		pci_msi_free_vectors(msix_pic, vectors, *count);
312 		msipic_destruct_msix_pic(msix_pic);
313 		return EINVAL;
314 	}
315 #endif
316 	return 0;
317 }
318 
319 static int
x86_pci_msi_alloc(pci_intr_handle_t ** ihps,int * count,const struct pci_attach_args * pa)320 x86_pci_msi_alloc(pci_intr_handle_t **ihps, int *count,
321     const struct pci_attach_args *pa)
322 {
323 
324 	return pci_msi_alloc_common(ihps, count, pa, false);
325 }
326 
327 static int
x86_pci_msi_alloc_exact(pci_intr_handle_t ** ihps,int count,const struct pci_attach_args * pa)328 x86_pci_msi_alloc_exact(pci_intr_handle_t **ihps, int count,
329     const struct pci_attach_args *pa)
330 {
331 
332 	return pci_msi_alloc_common(ihps, &count, pa, true);
333 }
334 #endif /* __HAVE_PCI_MSI_MSIX */
335 
336 static void
x86_pci_msi_release_internal(pci_intr_handle_t * pihs,int count)337 x86_pci_msi_release_internal(pci_intr_handle_t *pihs, int count)
338 {
339 	struct pic *pic;
340 
341 	pic = msipic_find_msi_pic(MSI_INT_DEV(pihs[0]));
342 	if (pic == NULL)
343 		return;
344 
345 #ifdef XENPV
346 	xen_pci_msi_release(pic, count);
347 #endif
348 	pci_msi_free_vectors(pic, pihs, count);
349 	msipic_destruct_msi_pic(pic);
350 }
351 
352 #ifdef __HAVE_PCI_MSI_MSIX
353 static int
x86_pci_msix_alloc(pci_intr_handle_t ** ihps,int * count,const struct pci_attach_args * pa)354 x86_pci_msix_alloc(pci_intr_handle_t **ihps, int *count,
355     const struct pci_attach_args *pa)
356 {
357 
358 	return pci_msix_alloc_common(ihps, NULL, count, pa, false);
359 }
360 
361 static int
x86_pci_msix_alloc_exact(pci_intr_handle_t ** ihps,int count,const struct pci_attach_args * pa)362 x86_pci_msix_alloc_exact(pci_intr_handle_t **ihps, int count,
363     const struct pci_attach_args *pa)
364 {
365 
366 	return pci_msix_alloc_common(ihps, NULL, &count, pa, true);
367 }
368 
369 static int
x86_pci_msix_alloc_map(pci_intr_handle_t ** ihps,u_int * table_indexes,int count,const struct pci_attach_args * pa)370 x86_pci_msix_alloc_map(pci_intr_handle_t **ihps, u_int *table_indexes,
371     int count, const struct pci_attach_args *pa)
372 {
373 
374 	return pci_msix_alloc_common(ihps, table_indexes, &count, pa, true);
375 }
376 #endif /* __HAVE_PCI_MSI_MSIX */
377 
378 static void
x86_pci_msix_release_internal(pci_intr_handle_t * pihs,int count)379 x86_pci_msix_release_internal(pci_intr_handle_t *pihs, int count)
380 {
381 	struct pic *pic;
382 
383 	pic = msipic_find_msi_pic(MSI_INT_DEV(pihs[0]));
384 	if (pic == NULL)
385 		return;
386 
387 #ifdef XENPV
388 	xen_pci_msi_release(pic, count);
389 #endif
390 	pci_msi_free_vectors(pic, pihs, count);
391 	msipic_destruct_msix_pic(pic);
392 }
393 
394 /*****************************************************************************/
395 /*
396  * extern for MD code.
397  */
398 
399 /*
400  * Return intrid for an MSI/MSI-X device.
401  * "buf" must be allocated by caller.
402  */
403 const char *
x86_pci_msi_string(pci_chipset_tag_t pc,pci_intr_handle_t ih,char * buf,size_t len)404 x86_pci_msi_string(pci_chipset_tag_t pc, pci_intr_handle_t ih, char *buf,
405     size_t len)
406 {
407 	int dev, vec;
408 
409 	KASSERT(INT_VIA_MSI(ih));
410 
411 	dev = MSI_INT_DEV(ih);
412 	vec = MSI_INT_VEC(ih);
413 	if (MSI_INT_IS_MSIX(ih))
414 		snprintf(buf, len, "msix%d vec %d", dev, vec);
415 	else
416 		snprintf(buf, len, "msi%d vec %d", dev, vec);
417 
418 	return buf;
419 }
420 
421 /*
422  * Release MSI handles.
423  */
424 void
x86_pci_msi_release(pci_chipset_tag_t pc,pci_intr_handle_t * pihs,int count)425 x86_pci_msi_release(pci_chipset_tag_t pc, pci_intr_handle_t *pihs, int count)
426 {
427 
428 	if (count < 1)
429 		return;
430 
431 	return x86_pci_msi_release_internal(pihs, count);
432 }
433 
434 /*
435  * Establish an MSI handle.
436  * If multiple MSI handles are required to be established, a device driver
437  * must call this function for each handle.
438  */
439 void *
x86_pci_msi_establish(pci_chipset_tag_t pc,pci_intr_handle_t ih,int level,int (* func)(void *),void * arg,const char * xname)440 x86_pci_msi_establish(pci_chipset_tag_t pc, pci_intr_handle_t ih,
441     int level, int (*func)(void *), void *arg, const char *xname)
442 {
443 	struct pic *pic;
444 
445 	pic = msipic_find_msi_pic(MSI_INT_DEV(ih));
446 	if (pic == NULL) {
447 		DPRINTF(("pci_intr_handler has no msi_pic\n"));
448 		return NULL;
449 	}
450 
451 	return pci_msi_common_establish(pc, ih, level, func, arg, pic, xname);
452 }
453 
454 /*
455  * Disestablish an MSI handle.
456  * If multiple MSI handles are required to be disestablished, a device driver
457  * must call this function for each handle.
458  */
459 void
x86_pci_msi_disestablish(pci_chipset_tag_t pc,void * cookie)460 x86_pci_msi_disestablish(pci_chipset_tag_t pc, void *cookie)
461 {
462 
463 	pci_msi_common_disestablish(pc, cookie);
464 }
465 
466 /*
467  * Release MSI-X handles.
468  */
469 void
x86_pci_msix_release(pci_chipset_tag_t pc,pci_intr_handle_t * pihs,int count)470 x86_pci_msix_release(pci_chipset_tag_t pc, pci_intr_handle_t *pihs, int count)
471 {
472 
473 	if (count < 1)
474 		return;
475 
476 	return x86_pci_msix_release_internal(pihs, count);
477 }
478 
479 /*
480  * Establish an MSI-X handle.
481  * If multiple MSI-X handles are required to be established, a device driver
482  * must call this function for each handle.
483  */
484 void *
x86_pci_msix_establish(pci_chipset_tag_t pc,pci_intr_handle_t ih,int level,int (* func)(void *),void * arg,const char * xname)485 x86_pci_msix_establish(pci_chipset_tag_t pc, pci_intr_handle_t ih,
486     int level, int (*func)(void *), void *arg, const char *xname)
487 {
488 	struct pic *pic;
489 
490 	pic = msipic_find_msi_pic(MSI_INT_DEV(ih));
491 	if (pic == NULL) {
492 		DPRINTF(("pci_intr_handler has no msi_pic\n"));
493 		return NULL;
494 	}
495 
496 	return pci_msi_common_establish(pc, ih, level, func, arg, pic, xname);
497 }
498 
499 /*
500  * Disestablish an MSI-X handle.
501  * If multiple MSI-X handles are required to be disestablished, a device driver
502  * must call this function for each handle.
503  */
504 void
x86_pci_msix_disestablish(pci_chipset_tag_t pc,void * cookie)505 x86_pci_msix_disestablish(pci_chipset_tag_t pc, void *cookie)
506 {
507 
508 	pci_msi_common_disestablish(pc, cookie);
509 }
510 
511 #ifdef __HAVE_PCI_MSI_MSIX
512 /*****************************************************************************/
513 /*
514  * extern for MI code.
515  */
516 
517 /*
518  * This function is used by device drivers like pci_intr_map().
519  *
520  * "ihps" is the array of vector numbers which MSI used instead of IRQ number.
521  * "count" must be power of 2.
522  * "count" can decrease if struct intrsource cannot be allocated.
523  * if count == 0, return non-zero value.
524  */
525 int
pci_msi_alloc(const struct pci_attach_args * pa,pci_intr_handle_t ** ihps,int * count)526 pci_msi_alloc(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
527     int *count)
528 {
529 	int hw_max;
530 
531 	/* MSI vector count must be power of 2. */
532 	KASSERT(*count > 0);
533 	KASSERT(((*count - 1) & *count) == 0);
534 
535 	hw_max = pci_msi_count(pa->pa_pc, pa->pa_tag);
536 	if (hw_max == 0)
537 		return ENODEV;
538 
539 	if (*count > hw_max) {
540 		DPRINTF(("cut off MSI count to %d\n", hw_max));
541 		*count = hw_max; /* cut off hw_max */
542 	}
543 
544 	return x86_pci_msi_alloc(ihps, count, pa);
545 }
546 
547 /*
548  * This function is used by device drivers like pci_intr_map().
549  *
550  * "ihps" is the array  of vector numbers which MSI used instead of IRQ number.
551  * "count" must be power of 2.
552  * "count" can not decrease.
553  * If "count" struct intrsources cannot be allocated, return non-zero value.
554  */
555 int
pci_msi_alloc_exact(const struct pci_attach_args * pa,pci_intr_handle_t ** ihps,int count)556 pci_msi_alloc_exact(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
557     int count)
558 {
559 	int hw_max;
560 
561 	/* MSI vector count must be power of 2. */
562 	KASSERT(count > 0);
563 	KASSERT(((count - 1) & count) == 0);
564 
565 	hw_max = pci_msi_count(pa->pa_pc, pa->pa_tag);
566 	if (hw_max == 0)
567 		return ENODEV;
568 
569 	if (count > hw_max) {
570 		DPRINTF(("over hardware max MSI count %d\n", hw_max));
571 		return EINVAL;
572 	}
573 
574 	return x86_pci_msi_alloc_exact(ihps, count, pa);
575 }
576 
577 /*
578  * This function is used by device drivers like pci_intr_map().
579  *
580  * "ihps" is the array of vector numbers which MSI-X used instead of IRQ number.
581  * "count" can decrease if enough struct intrsources cannot be allocated.
582  * if count == 0, return non-zero value.
583  */
584 int
pci_msix_alloc(const struct pci_attach_args * pa,pci_intr_handle_t ** ihps,int * count)585 pci_msix_alloc(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
586     int *count)
587 {
588 	int hw_max;
589 
590 	KASSERT(*count > 0);
591 
592 	hw_max = pci_msix_count(pa->pa_pc, pa->pa_tag);
593 	if (hw_max == 0)
594 		return ENODEV;
595 
596 	if (*count > hw_max) {
597 		DPRINTF(("cut off MSI-X count to %d\n", hw_max));
598 		*count = hw_max; /* cut off hw_max */
599 	}
600 
601 	return x86_pci_msix_alloc(ihps, count, pa);
602 }
603 
604 /*
605  * This function is used by device drivers like pci_intr_map().
606  *
607  * "ihps" is the array of vector numbers which MSI-X used instead of IRQ number.
608  * "count" can not decrease.
609  * If "count" struct intrsource cannot be allocated, return non-zero value.
610  */
611 int
pci_msix_alloc_exact(const struct pci_attach_args * pa,pci_intr_handle_t ** ihps,int count)612 pci_msix_alloc_exact(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
613     int count)
614 {
615 	int hw_max;
616 
617 	KASSERT(count > 0);
618 
619 	hw_max = pci_msix_count(pa->pa_pc, pa->pa_tag);
620 	if (hw_max == 0)
621 		return ENODEV;
622 
623 	if (count > hw_max) {
624 		DPRINTF(("over hardware max MSI-X count %d\n", hw_max));
625 		return EINVAL;
626 	}
627 
628 	return x86_pci_msix_alloc_exact(ihps, count, pa);
629 }
630 
631 /*
632  * This function is used by device drivers like pci_intr_map().
633  * Furthermore, this function can map each handle to an MSI-X table index.
634  *
635  * "ihps" is the array of vector numbers which MSI-X used instead of IRQ number.
636  * "count" can not decrease.
637  * "map" size must be equal to "count".
638  * If "count" struct intrsource cannot be allocated, return non-zero value.
639  * e.g.
640  *     If "map" = { 1, 4, 0 },
641  *     1st handle is bound to MSI-X index 1
642  *     2nd handle is bound to MSI-X index 4
643  *     3rd handle is bound to MSI-X index 0
644  */
645 int
pci_msix_alloc_map(const struct pci_attach_args * pa,pci_intr_handle_t ** ihps,u_int * table_indexes,int count)646 pci_msix_alloc_map(const struct pci_attach_args *pa, pci_intr_handle_t **ihps,
647     u_int *table_indexes, int count)
648 {
649 	int hw_max, i, j;
650 
651 	KASSERT(count > 0);
652 
653 	hw_max = pci_msix_count(pa->pa_pc, pa->pa_tag);
654 	if (hw_max == 0)
655 		return ENODEV;
656 
657 	if (count > hw_max) {
658 		DPRINTF(("over hardware max MSI-X count %d\n", hw_max));
659 		return EINVAL;
660 	}
661 
662 	/* check not to duplicate table_index */
663 	for (i = 0; i < count; i++) {
664 		u_int basing = table_indexes[i];
665 
666 		KASSERT(table_indexes[i] < PCI_MSIX_MAX_VECTORS);
667 		if (basing >= hw_max) {
668 			DPRINTF(("table index is over hardware max MSI-X index %d\n",
669 				hw_max - 1));
670 			return EINVAL;
671 		}
672 
673 		for (j = i + 1; j < count; j++) {
674 			if (basing == table_indexes[j]) {
675 				DPRINTF(("MSI-X table index duplicated\n"));
676 				return EINVAL;
677 			}
678 		}
679 	}
680 
681 	return x86_pci_msix_alloc_map(ihps, table_indexes, count, pa);
682 }
683 #endif /* __HAVE_PCI_MSI_MSIX */
684