FreeBSD/Linux Kernel Cross Reference
sys/x86/x86/msi.c
1 /*-
2 * Copyright (c) 2006 Yahoo!, Inc.
3 * All rights reserved.
4 * Written by: John Baldwin <jhb@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the author nor the names of any co-contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 /*
32 * Support for PCI Message Signalled Interrupts (MSI). MSI interrupts on
33 * x86 are basically APIC messages that the northbridge delivers directly
34 * to the local APICs as if they had come from an I/O APIC.
35 */
36
37 #include <sys/cdefs.h>
38 __FBSDID("$FreeBSD: releng/10.2/sys/x86/x86/msi.c 214631 2010-11-01 18:18:46Z jhb $");
39
40 #include <sys/param.h>
41 #include <sys/bus.h>
42 #include <sys/kernel.h>
43 #include <sys/lock.h>
44 #include <sys/malloc.h>
45 #include <sys/mutex.h>
46 #include <sys/sx.h>
47 #include <sys/systm.h>
48 #include <x86/apicreg.h>
49 #include <machine/cputypes.h>
50 #include <machine/md_var.h>
51 #include <machine/frame.h>
52 #include <machine/intr_machdep.h>
53 #include <machine/apicvar.h>
54 #include <machine/specialreg.h>
55 #include <dev/pci/pcivar.h>
56
57 /* Fields in address for Intel MSI messages. */
58 #define MSI_INTEL_ADDR_DEST 0x000ff000
59 #define MSI_INTEL_ADDR_RH 0x00000008
60 # define MSI_INTEL_ADDR_RH_ON 0x00000008
61 # define MSI_INTEL_ADDR_RH_OFF 0x00000000
62 #define MSI_INTEL_ADDR_DM 0x00000004
63 # define MSI_INTEL_ADDR_DM_PHYSICAL 0x00000000
64 # define MSI_INTEL_ADDR_DM_LOGICAL 0x00000004
65
66 /* Fields in data for Intel MSI messages. */
67 #define MSI_INTEL_DATA_TRGRMOD IOART_TRGRMOD /* Trigger mode. */
68 # define MSI_INTEL_DATA_TRGREDG IOART_TRGREDG
69 # define MSI_INTEL_DATA_TRGRLVL IOART_TRGRLVL
70 #define MSI_INTEL_DATA_LEVEL 0x00004000 /* Polarity. */
71 # define MSI_INTEL_DATA_DEASSERT 0x00000000
72 # define MSI_INTEL_DATA_ASSERT 0x00004000
73 #define MSI_INTEL_DATA_DELMOD IOART_DELMOD /* Delivery mode. */
74 # define MSI_INTEL_DATA_DELFIXED IOART_DELFIXED
75 # define MSI_INTEL_DATA_DELLOPRI IOART_DELLOPRI
76 # define MSI_INTEL_DATA_DELSMI IOART_DELSMI
77 # define MSI_INTEL_DATA_DELNMI IOART_DELNMI
78 # define MSI_INTEL_DATA_DELINIT IOART_DELINIT
79 # define MSI_INTEL_DATA_DELEXINT IOART_DELEXINT
80 #define MSI_INTEL_DATA_INTVEC IOART_INTVEC /* Interrupt vector. */
81
82 /*
83 * Build Intel MSI message and data values from a source. AMD64 systems
84 * seem to be compatible, so we use the same function for both.
85 */
86 #define INTEL_ADDR(msi) \
87 (MSI_INTEL_ADDR_BASE | (msi)->msi_cpu << 12 | \
88 MSI_INTEL_ADDR_RH_OFF | MSI_INTEL_ADDR_DM_PHYSICAL)
89 #define INTEL_DATA(msi) \
90 (MSI_INTEL_DATA_TRGREDG | MSI_INTEL_DATA_DELFIXED | (msi)->msi_vector)
91
92 static MALLOC_DEFINE(M_MSI, "msi", "PCI MSI");
93
94 /*
95 * MSI sources are bunched into groups. This is because MSI forces
96 * all of the messages to share the address and data registers and
97 * thus certain properties (such as the local APIC ID target on x86).
98 * Each group has a 'first' source that contains information global to
99 * the group. These fields are marked with (g) below.
100 *
101 * Note that local APIC ID is kind of special. Each message will be
102 * assigned an ID by the system; however, a group will use the ID from
103 * the first message.
104 *
105 * For MSI-X, each message is isolated.
106 */
107 struct msi_intsrc {
108 struct intsrc msi_intsrc;
109 device_t msi_dev; /* Owning device. (g) */
110 struct msi_intsrc *msi_first; /* First source in group. */
111 u_int msi_irq; /* IRQ cookie. */
112 u_int msi_msix; /* MSI-X message. */
113 u_int msi_vector:8; /* IDT vector. */
114 u_int msi_cpu:8; /* Local APIC ID. (g) */
115 u_int msi_count:8; /* Messages in this group. (g) */
116 u_int msi_maxcount:8; /* Alignment for this group. (g) */
117 int *msi_irqs; /* Group's IRQ list. (g) */
118 };
119
120 static void msi_create_source(void);
121 static void msi_enable_source(struct intsrc *isrc);
122 static void msi_disable_source(struct intsrc *isrc, int eoi);
123 static void msi_eoi_source(struct intsrc *isrc);
124 static void msi_enable_intr(struct intsrc *isrc);
125 static void msi_disable_intr(struct intsrc *isrc);
126 static int msi_vector(struct intsrc *isrc);
127 static int msi_source_pending(struct intsrc *isrc);
128 static int msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
129 enum intr_polarity pol);
130 static int msi_assign_cpu(struct intsrc *isrc, u_int apic_id);
131
132 struct pic msi_pic = { msi_enable_source, msi_disable_source, msi_eoi_source,
133 msi_enable_intr, msi_disable_intr, msi_vector,
134 msi_source_pending, NULL, NULL, msi_config_intr,
135 msi_assign_cpu };
136
137 static int msi_enabled;
138 static int msi_last_irq;
139 static struct mtx msi_lock;
140
141 static void
142 msi_enable_source(struct intsrc *isrc)
143 {
144 }
145
146 static void
147 msi_disable_source(struct intsrc *isrc, int eoi)
148 {
149
150 if (eoi == PIC_EOI)
151 lapic_eoi();
152 }
153
154 static void
155 msi_eoi_source(struct intsrc *isrc)
156 {
157
158 lapic_eoi();
159 }
160
161 static void
162 msi_enable_intr(struct intsrc *isrc)
163 {
164 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
165
166 apic_enable_vector(msi->msi_cpu, msi->msi_vector);
167 }
168
169 static void
170 msi_disable_intr(struct intsrc *isrc)
171 {
172 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
173
174 apic_disable_vector(msi->msi_cpu, msi->msi_vector);
175 }
176
177 static int
178 msi_vector(struct intsrc *isrc)
179 {
180 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
181
182 return (msi->msi_irq);
183 }
184
185 static int
186 msi_source_pending(struct intsrc *isrc)
187 {
188
189 return (0);
190 }
191
192 static int
193 msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
194 enum intr_polarity pol)
195 {
196
197 return (ENODEV);
198 }
199
200 static int
201 msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
202 {
203 struct msi_intsrc *sib, *msi = (struct msi_intsrc *)isrc;
204 int old_vector;
205 u_int old_id;
206 int i, vector;
207
208 /*
209 * Only allow CPUs to be assigned to the first message for an
210 * MSI group.
211 */
212 if (msi->msi_first != msi)
213 return (EINVAL);
214
215 /* Store information to free existing irq. */
216 old_vector = msi->msi_vector;
217 old_id = msi->msi_cpu;
218 if (old_id == apic_id)
219 return (0);
220
221 /* Allocate IDT vectors on this cpu. */
222 if (msi->msi_count > 1) {
223 KASSERT(msi->msi_msix == 0, ("MSI-X message group"));
224 vector = apic_alloc_vectors(apic_id, msi->msi_irqs,
225 msi->msi_count, msi->msi_maxcount);
226 } else
227 vector = apic_alloc_vector(apic_id, msi->msi_irq);
228 if (vector == 0)
229 return (ENOSPC);
230
231 msi->msi_cpu = apic_id;
232 msi->msi_vector = vector;
233 if (msi->msi_intsrc.is_handlers > 0)
234 apic_enable_vector(msi->msi_cpu, msi->msi_vector);
235 if (bootverbose)
236 printf("msi: Assigning %s IRQ %d to local APIC %u vector %u\n",
237 msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
238 msi->msi_cpu, msi->msi_vector);
239 for (i = 1; i < msi->msi_count; i++) {
240 sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
241 sib->msi_cpu = apic_id;
242 sib->msi_vector = vector + i;
243 if (sib->msi_intsrc.is_handlers > 0)
244 apic_enable_vector(sib->msi_cpu, sib->msi_vector);
245 if (bootverbose)
246 printf(
247 "msi: Assigning MSI IRQ %d to local APIC %u vector %u\n",
248 sib->msi_irq, sib->msi_cpu, sib->msi_vector);
249 }
250 BUS_REMAP_INTR(device_get_parent(msi->msi_dev), msi->msi_dev,
251 msi->msi_irq);
252
253 /*
254 * Free the old vector after the new one is established. This is done
255 * to prevent races where we could miss an interrupt.
256 */
257 if (msi->msi_intsrc.is_handlers > 0)
258 apic_disable_vector(old_id, old_vector);
259 apic_free_vector(old_id, old_vector, msi->msi_irq);
260 for (i = 1; i < msi->msi_count; i++) {
261 sib = (struct msi_intsrc *)intr_lookup_source(msi->msi_irqs[i]);
262 if (sib->msi_intsrc.is_handlers > 0)
263 apic_disable_vector(old_id, old_vector + i);
264 apic_free_vector(old_id, old_vector + i, msi->msi_irqs[i]);
265 }
266 return (0);
267 }
268
269 void
270 msi_init(void)
271 {
272
273 /* Check if we have a supported CPU. */
274 switch (cpu_vendor_id) {
275 case CPU_VENDOR_INTEL:
276 case CPU_VENDOR_AMD:
277 break;
278 case CPU_VENDOR_CENTAUR:
279 if (CPUID_TO_FAMILY(cpu_id) == 0x6 &&
280 CPUID_TO_MODEL(cpu_id) >= 0xf)
281 break;
282 /* FALLTHROUGH */
283 default:
284 return;
285 }
286
287 msi_enabled = 1;
288 intr_register_pic(&msi_pic);
289 mtx_init(&msi_lock, "msi", NULL, MTX_DEF);
290 }
291
292 static void
293 msi_create_source(void)
294 {
295 struct msi_intsrc *msi;
296 u_int irq;
297
298 mtx_lock(&msi_lock);
299 if (msi_last_irq >= NUM_MSI_INTS) {
300 mtx_unlock(&msi_lock);
301 return;
302 }
303 irq = msi_last_irq + FIRST_MSI_INT;
304 msi_last_irq++;
305 mtx_unlock(&msi_lock);
306
307 msi = malloc(sizeof(struct msi_intsrc), M_MSI, M_WAITOK | M_ZERO);
308 msi->msi_intsrc.is_pic = &msi_pic;
309 msi->msi_irq = irq;
310 intr_register_source(&msi->msi_intsrc);
311 nexus_add_irq(irq);
312 }
313
314 /*
315 * Try to allocate 'count' interrupt sources with contiguous IDT values.
316 */
317 int
318 msi_alloc(device_t dev, int count, int maxcount, int *irqs)
319 {
320 struct msi_intsrc *msi, *fsrc;
321 u_int cpu;
322 int cnt, i, *mirqs, vector;
323
324 if (!msi_enabled)
325 return (ENXIO);
326
327 if (count > 1)
328 mirqs = malloc(count * sizeof(*mirqs), M_MSI, M_WAITOK);
329 else
330 mirqs = NULL;
331 again:
332 mtx_lock(&msi_lock);
333
334 /* Try to find 'count' free IRQs. */
335 cnt = 0;
336 for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
337 msi = (struct msi_intsrc *)intr_lookup_source(i);
338
339 /* End of allocated sources, so break. */
340 if (msi == NULL)
341 break;
342
343 /* If this is a free one, save its IRQ in the array. */
344 if (msi->msi_dev == NULL) {
345 irqs[cnt] = i;
346 cnt++;
347 if (cnt == count)
348 break;
349 }
350 }
351
352 /* Do we need to create some new sources? */
353 if (cnt < count) {
354 /* If we would exceed the max, give up. */
355 if (i + (count - cnt) > FIRST_MSI_INT + NUM_MSI_INTS) {
356 mtx_unlock(&msi_lock);
357 free(mirqs, M_MSI);
358 return (ENXIO);
359 }
360 mtx_unlock(&msi_lock);
361
362 /* We need count - cnt more sources. */
363 while (cnt < count) {
364 msi_create_source();
365 cnt++;
366 }
367 goto again;
368 }
369
370 /* Ok, we now have the IRQs allocated. */
371 KASSERT(cnt == count, ("count mismatch"));
372
373 /* Allocate 'count' IDT vectors. */
374 cpu = intr_next_cpu();
375 vector = apic_alloc_vectors(cpu, irqs, count, maxcount);
376 if (vector == 0) {
377 mtx_unlock(&msi_lock);
378 free(mirqs, M_MSI);
379 return (ENOSPC);
380 }
381
382 /* Assign IDT vectors and make these messages owned by 'dev'. */
383 fsrc = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
384 for (i = 0; i < count; i++) {
385 msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
386 msi->msi_cpu = cpu;
387 msi->msi_dev = dev;
388 msi->msi_vector = vector + i;
389 if (bootverbose)
390 printf(
391 "msi: routing MSI IRQ %d to local APIC %u vector %u\n",
392 msi->msi_irq, msi->msi_cpu, msi->msi_vector);
393 msi->msi_first = fsrc;
394 KASSERT(msi->msi_intsrc.is_handlers == 0,
395 ("dead MSI has handlers"));
396 }
397 fsrc->msi_count = count;
398 fsrc->msi_maxcount = maxcount;
399 if (count > 1)
400 bcopy(irqs, mirqs, count * sizeof(*mirqs));
401 fsrc->msi_irqs = mirqs;
402 mtx_unlock(&msi_lock);
403
404 return (0);
405 }
406
407 int
408 msi_release(int *irqs, int count)
409 {
410 struct msi_intsrc *msi, *first;
411 int i;
412
413 mtx_lock(&msi_lock);
414 first = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
415 if (first == NULL) {
416 mtx_unlock(&msi_lock);
417 return (ENOENT);
418 }
419
420 /* Make sure this isn't an MSI-X message. */
421 if (first->msi_msix) {
422 mtx_unlock(&msi_lock);
423 return (EINVAL);
424 }
425
426 /* Make sure this message is allocated to a group. */
427 if (first->msi_first == NULL) {
428 mtx_unlock(&msi_lock);
429 return (ENXIO);
430 }
431
432 /*
433 * Make sure this is the start of a group and that we are releasing
434 * the entire group.
435 */
436 if (first->msi_first != first || first->msi_count != count) {
437 mtx_unlock(&msi_lock);
438 return (EINVAL);
439 }
440 KASSERT(first->msi_dev != NULL, ("unowned group"));
441
442 /* Clear all the extra messages in the group. */
443 for (i = 1; i < count; i++) {
444 msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
445 KASSERT(msi->msi_first == first, ("message not in group"));
446 KASSERT(msi->msi_dev == first->msi_dev, ("owner mismatch"));
447 msi->msi_first = NULL;
448 msi->msi_dev = NULL;
449 apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
450 msi->msi_vector = 0;
451 }
452
453 /* Clear out the first message. */
454 first->msi_first = NULL;
455 first->msi_dev = NULL;
456 apic_free_vector(first->msi_cpu, first->msi_vector, first->msi_irq);
457 first->msi_vector = 0;
458 first->msi_count = 0;
459 first->msi_maxcount = 0;
460 free(first->msi_irqs, M_MSI);
461 first->msi_irqs = NULL;
462
463 mtx_unlock(&msi_lock);
464 return (0);
465 }
466
467 int
468 msi_map(int irq, uint64_t *addr, uint32_t *data)
469 {
470 struct msi_intsrc *msi;
471
472 mtx_lock(&msi_lock);
473 msi = (struct msi_intsrc *)intr_lookup_source(irq);
474 if (msi == NULL) {
475 mtx_unlock(&msi_lock);
476 return (ENOENT);
477 }
478
479 /* Make sure this message is allocated to a device. */
480 if (msi->msi_dev == NULL) {
481 mtx_unlock(&msi_lock);
482 return (ENXIO);
483 }
484
485 /*
486 * If this message isn't an MSI-X message, make sure it's part
487 * of a group, and switch to the first message in the
488 * group.
489 */
490 if (!msi->msi_msix) {
491 if (msi->msi_first == NULL) {
492 mtx_unlock(&msi_lock);
493 return (ENXIO);
494 }
495 msi = msi->msi_first;
496 }
497
498 *addr = INTEL_ADDR(msi);
499 *data = INTEL_DATA(msi);
500 mtx_unlock(&msi_lock);
501 return (0);
502 }
503
504 int
505 msix_alloc(device_t dev, int *irq)
506 {
507 struct msi_intsrc *msi;
508 u_int cpu;
509 int i, vector;
510
511 if (!msi_enabled)
512 return (ENXIO);
513
514 again:
515 mtx_lock(&msi_lock);
516
517 /* Find a free IRQ. */
518 for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
519 msi = (struct msi_intsrc *)intr_lookup_source(i);
520
521 /* End of allocated sources, so break. */
522 if (msi == NULL)
523 break;
524
525 /* Stop at the first free source. */
526 if (msi->msi_dev == NULL)
527 break;
528 }
529
530 /* Do we need to create a new source? */
531 if (msi == NULL) {
532 /* If we would exceed the max, give up. */
533 if (i + 1 > FIRST_MSI_INT + NUM_MSI_INTS) {
534 mtx_unlock(&msi_lock);
535 return (ENXIO);
536 }
537 mtx_unlock(&msi_lock);
538
539 /* Create a new source. */
540 msi_create_source();
541 goto again;
542 }
543
544 /* Allocate an IDT vector. */
545 cpu = intr_next_cpu();
546 vector = apic_alloc_vector(cpu, i);
547 if (vector == 0) {
548 mtx_unlock(&msi_lock);
549 return (ENOSPC);
550 }
551 if (bootverbose)
552 printf("msi: routing MSI-X IRQ %d to local APIC %u vector %u\n",
553 msi->msi_irq, cpu, vector);
554
555 /* Setup source. */
556 msi->msi_cpu = cpu;
557 msi->msi_dev = dev;
558 msi->msi_first = msi;
559 msi->msi_vector = vector;
560 msi->msi_msix = 1;
561 msi->msi_count = 1;
562 msi->msi_maxcount = 1;
563 msi->msi_irqs = NULL;
564
565 KASSERT(msi->msi_intsrc.is_handlers == 0, ("dead MSI-X has handlers"));
566 mtx_unlock(&msi_lock);
567
568 *irq = i;
569 return (0);
570 }
571
572 int
573 msix_release(int irq)
574 {
575 struct msi_intsrc *msi;
576
577 mtx_lock(&msi_lock);
578 msi = (struct msi_intsrc *)intr_lookup_source(irq);
579 if (msi == NULL) {
580 mtx_unlock(&msi_lock);
581 return (ENOENT);
582 }
583
584 /* Make sure this is an MSI-X message. */
585 if (!msi->msi_msix) {
586 mtx_unlock(&msi_lock);
587 return (EINVAL);
588 }
589
590 KASSERT(msi->msi_dev != NULL, ("unowned message"));
591
592 /* Clear out the message. */
593 msi->msi_first = NULL;
594 msi->msi_dev = NULL;
595 apic_free_vector(msi->msi_cpu, msi->msi_vector, msi->msi_irq);
596 msi->msi_vector = 0;
597 msi->msi_msix = 0;
598 msi->msi_count = 0;
599 msi->msi_maxcount = 0;
600
601 mtx_unlock(&msi_lock);
602 return (0);
603 }
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