FreeBSD/Linux Kernel Cross Reference
sys/i386/i386/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("$FreeBSD$");
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 <machine/apicreg.h>
49 #include <machine/md_var.h>
50 #include <machine/frame.h>
51 #include <machine/intr_machdep.h>
52 #include <machine/apicvar.h>
53 #include <dev/pci/pcivar.h>
54
55 /* Fields in address for Intel MSI messages. */
56 #define MSI_INTEL_ADDR_DEST 0x000ff000
57 #define MSI_INTEL_ADDR_RH 0x00000008
58 # define MSI_INTEL_ADDR_RH_ON 0x00000008
59 # define MSI_INTEL_ADDR_RH_OFF 0x00000000
60 #define MSI_INTEL_ADDR_DM 0x00000004
61 # define MSI_INTEL_ADDR_DM_PHYSICAL 0x00000000
62 # define MSI_INTEL_ADDR_DM_LOGICAL 0x00000004
63
64 /* Fields in data for Intel MSI messages. */
65 #define MSI_INTEL_DATA_TRGRMOD IOART_TRGRMOD /* Trigger mode. */
66 # define MSI_INTEL_DATA_TRGREDG IOART_TRGREDG
67 # define MSI_INTEL_DATA_TRGRLVL IOART_TRGRLVL
68 #define MSI_INTEL_DATA_LEVEL 0x00004000 /* Polarity. */
69 # define MSI_INTEL_DATA_DEASSERT 0x00000000
70 # define MSI_INTEL_DATA_ASSERT 0x00004000
71 #define MSI_INTEL_DATA_DELMOD IOART_DELMOD /* Delivery mode. */
72 # define MSI_INTEL_DATA_DELFIXED IOART_DELFIXED
73 # define MSI_INTEL_DATA_DELLOPRI IOART_DELLOPRI
74 # define MSI_INTEL_DATA_DELSMI IOART_DELSMI
75 # define MSI_INTEL_DATA_DELNMI IOART_DELNMI
76 # define MSI_INTEL_DATA_DELINIT IOART_DELINIT
77 # define MSI_INTEL_DATA_DELEXINT IOART_DELEXINT
78 #define MSI_INTEL_DATA_INTVEC IOART_INTVEC /* Interrupt vector. */
79
80 /*
81 * Build Intel MSI message and data values from a source. AMD64 systems
82 * seem to be compatible, so we use the same function for both.
83 */
84 #define INTEL_ADDR(msi) \
85 (MSI_INTEL_ADDR_BASE | (msi)->msi_cpu << 12 | \
86 MSI_INTEL_ADDR_RH_OFF | MSI_INTEL_ADDR_DM_PHYSICAL)
87 #define INTEL_DATA(msi) \
88 (MSI_INTEL_DATA_TRGREDG | MSI_INTEL_DATA_DELFIXED | (msi)->msi_vector)
89
90 static MALLOC_DEFINE(M_MSI, "msi", "PCI MSI");
91
92 /*
93 * MSI sources are bunched into groups. This is because MSI forces
94 * all of the messages to share the address and data registers and
95 * thus certain properties (such as the local APIC ID target on x86).
96 * Each group has a 'first' source that contains information global to
97 * the group. These fields are marked with (g) below.
98 *
99 * Note that local APIC ID is kind of special. Each message will be
100 * assigned an ID by the system; however, a group will use the ID from
101 * the first message.
102 *
103 * For MSI-X, each message is isolated.
104 */
105 struct msi_intsrc {
106 struct intsrc msi_intsrc;
107 device_t msi_dev; /* Owning device. (g) */
108 struct msi_intsrc *msi_first; /* First source in group. */
109 u_int msi_irq; /* IRQ cookie. */
110 u_int msi_msix; /* MSI-X message. */
111 u_int msi_vector:8; /* IDT vector. */
112 u_int msi_cpu:8; /* Local APIC ID. (g) */
113 u_int msi_count:8; /* Messages in this group. (g) */
114 };
115
116 static void msi_create_source(void);
117 static void msi_enable_source(struct intsrc *isrc);
118 static void msi_disable_source(struct intsrc *isrc, int eoi);
119 static void msi_eoi_source(struct intsrc *isrc);
120 static void msi_enable_intr(struct intsrc *isrc);
121 static void msi_disable_intr(struct intsrc *isrc);
122 static int msi_vector(struct intsrc *isrc);
123 static int msi_source_pending(struct intsrc *isrc);
124 static int msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
125 enum intr_polarity pol);
126 static void msi_assign_cpu(struct intsrc *isrc, u_int apic_id);
127
128 struct pic msi_pic = { msi_enable_source, msi_disable_source, msi_eoi_source,
129 msi_enable_intr, msi_disable_intr, msi_vector,
130 msi_source_pending, NULL, NULL, msi_config_intr,
131 msi_assign_cpu };
132
133 static int msi_enabled;
134 static int msi_last_irq;
135 static struct mtx msi_lock;
136
137 static void
138 msi_enable_source(struct intsrc *isrc)
139 {
140 }
141
142 static void
143 msi_disable_source(struct intsrc *isrc, int eoi)
144 {
145
146 if (eoi == PIC_EOI)
147 lapic_eoi();
148 }
149
150 static void
151 msi_eoi_source(struct intsrc *isrc)
152 {
153
154 lapic_eoi();
155 }
156
157 static void
158 msi_enable_intr(struct intsrc *isrc)
159 {
160 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
161
162 apic_enable_vector(msi->msi_vector);
163 }
164
165 static void
166 msi_disable_intr(struct intsrc *isrc)
167 {
168 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
169
170 apic_disable_vector(msi->msi_vector);
171 }
172
173 static int
174 msi_vector(struct intsrc *isrc)
175 {
176 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
177
178 return (msi->msi_irq);
179 }
180
181 static int
182 msi_source_pending(struct intsrc *isrc)
183 {
184
185 return (0);
186 }
187
188 static int
189 msi_config_intr(struct intsrc *isrc, enum intr_trigger trig,
190 enum intr_polarity pol)
191 {
192
193 return (ENODEV);
194 }
195
196 static void
197 msi_assign_cpu(struct intsrc *isrc, u_int apic_id)
198 {
199 struct msi_intsrc *msi = (struct msi_intsrc *)isrc;
200
201 msi->msi_cpu = apic_id;
202 if (bootverbose)
203 printf("msi: Assigning %s IRQ %d to local APIC %u\n",
204 msi->msi_msix ? "MSI-X" : "MSI", msi->msi_irq,
205 msi->msi_cpu);
206 pci_remap_msi_irq(msi->msi_dev, msi->msi_irq);
207 }
208
209 void
210 msi_init(void)
211 {
212
213 /* Check if we have a supported CPU. */
214 if (!(strcmp(cpu_vendor, "GenuineIntel") == 0 ||
215 strcmp(cpu_vendor, "AuthenticAMD") == 0))
216 return;
217
218 msi_enabled = 1;
219 intr_register_pic(&msi_pic);
220 mtx_init(&msi_lock, "msi", NULL, MTX_DEF);
221 }
222
223 void
224 msi_create_source(void)
225 {
226 struct msi_intsrc *msi;
227 u_int irq;
228
229 mtx_lock(&msi_lock);
230 if (msi_last_irq >= NUM_MSI_INTS) {
231 mtx_unlock(&msi_lock);
232 return;
233 }
234 irq = msi_last_irq + FIRST_MSI_INT;
235 msi_last_irq++;
236 mtx_unlock(&msi_lock);
237
238 msi = malloc(sizeof(struct msi_intsrc), M_MSI, M_WAITOK | M_ZERO);
239 msi->msi_intsrc.is_pic = &msi_pic;
240 msi->msi_irq = irq;
241 intr_register_source(&msi->msi_intsrc);
242 nexus_add_irq(irq);
243 }
244
245 /*
246 * Try to allocate 'count' interrupt sources with contiguous IDT values. If
247 * we allocate any new sources, then their IRQ values will be at the end of
248 * the irqs[] array, with *newirq being the index of the first new IRQ value
249 * and *newcount being the number of new IRQ values added.
250 */
251 int
252 msi_alloc(device_t dev, int count, int maxcount, int *irqs)
253 {
254 struct msi_intsrc *msi, *fsrc;
255 int cnt, i, vector;
256
257 if (!msi_enabled)
258 return (ENXIO);
259
260 again:
261 mtx_lock(&msi_lock);
262
263 /* Try to find 'count' free IRQs. */
264 cnt = 0;
265 for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
266 msi = (struct msi_intsrc *)intr_lookup_source(i);
267
268 /* End of allocated sources, so break. */
269 if (msi == NULL)
270 break;
271
272 /* If this is a free one, save its IRQ in the array. */
273 if (msi->msi_dev == NULL) {
274 irqs[cnt] = i;
275 cnt++;
276 if (cnt == count)
277 break;
278 }
279 }
280
281 /* Do we need to create some new sources? */
282 if (cnt < count) {
283 /* If we would exceed the max, give up. */
284 if (i + (count - cnt) > FIRST_MSI_INT + NUM_MSI_INTS) {
285 mtx_unlock(&msi_lock);
286 return (ENXIO);
287 }
288 mtx_unlock(&msi_lock);
289
290 /* We need count - cnt more sources. */
291 while (cnt < count) {
292 msi_create_source();
293 cnt++;
294 }
295 goto again;
296 }
297
298 /* Ok, we now have the IRQs allocated. */
299 KASSERT(cnt == count, ("count mismatch"));
300
301 /* Allocate 'count' IDT vectors. */
302 vector = apic_alloc_vectors(irqs, count, maxcount);
303 if (vector == 0) {
304 mtx_unlock(&msi_lock);
305 return (ENOSPC);
306 }
307
308 /* Assign IDT vectors and make these messages owned by 'dev'. */
309 fsrc = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
310 for (i = 0; i < count; i++) {
311 msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
312 msi->msi_dev = dev;
313 msi->msi_vector = vector + i;
314 if (bootverbose)
315 printf("msi: routing MSI IRQ %d to vector %u\n",
316 msi->msi_irq, msi->msi_vector);
317 msi->msi_first = fsrc;
318 KASSERT(msi->msi_intsrc.is_handlers == 0,
319 ("dead MSI has handlers"));
320 }
321 fsrc->msi_count = count;
322 mtx_unlock(&msi_lock);
323
324 return (0);
325 }
326
327 int
328 msi_release(int *irqs, int count)
329 {
330 struct msi_intsrc *msi, *first;
331 int i;
332
333 mtx_lock(&msi_lock);
334 first = (struct msi_intsrc *)intr_lookup_source(irqs[0]);
335 if (first == NULL) {
336 mtx_unlock(&msi_lock);
337 return (ENOENT);
338 }
339
340 /* Make sure this isn't an MSI-X message. */
341 if (first->msi_msix) {
342 mtx_unlock(&msi_lock);
343 return (EINVAL);
344 }
345
346 /* Make sure this message is allocated to a group. */
347 if (first->msi_first == NULL) {
348 mtx_unlock(&msi_lock);
349 return (ENXIO);
350 }
351
352 /*
353 * Make sure this is the start of a group and that we are releasing
354 * the entire group.
355 */
356 if (first->msi_first != first || first->msi_count != count) {
357 mtx_unlock(&msi_lock);
358 return (EINVAL);
359 }
360 KASSERT(first->msi_dev != NULL, ("unowned group"));
361
362 /* Clear all the extra messages in the group. */
363 for (i = 1; i < count; i++) {
364 msi = (struct msi_intsrc *)intr_lookup_source(irqs[i]);
365 KASSERT(msi->msi_first == first, ("message not in group"));
366 KASSERT(msi->msi_dev == first->msi_dev, ("owner mismatch"));
367 msi->msi_first = NULL;
368 msi->msi_dev = NULL;
369 apic_free_vector(msi->msi_vector, msi->msi_irq);
370 msi->msi_vector = 0;
371 }
372
373 /* Clear out the first message. */
374 first->msi_first = NULL;
375 first->msi_dev = NULL;
376 apic_free_vector(first->msi_vector, first->msi_irq);
377 first->msi_vector = 0;
378 first->msi_count = 0;
379
380 mtx_unlock(&msi_lock);
381 return (0);
382 }
383
384 int
385 msi_map(int irq, uint64_t *addr, uint32_t *data)
386 {
387 struct msi_intsrc *msi;
388
389 mtx_lock(&msi_lock);
390 msi = (struct msi_intsrc *)intr_lookup_source(irq);
391 if (msi == NULL) {
392 mtx_unlock(&msi_lock);
393 return (ENOENT);
394 }
395
396 /* Make sure this message is allocated to a device. */
397 if (msi->msi_dev == NULL) {
398 mtx_unlock(&msi_lock);
399 return (ENXIO);
400 }
401
402 /*
403 * If this message isn't an MSI-X message, make sure it's part
404 * of a group, and switch to the first message in the
405 * group.
406 */
407 if (!msi->msi_msix) {
408 if (msi->msi_first == NULL) {
409 mtx_unlock(&msi_lock);
410 return (ENXIO);
411 }
412 msi = msi->msi_first;
413 }
414
415 *addr = INTEL_ADDR(msi);
416 *data = INTEL_DATA(msi);
417 mtx_unlock(&msi_lock);
418 return (0);
419 }
420
421 int
422 msix_alloc(device_t dev, int *irq)
423 {
424 struct msi_intsrc *msi;
425 int i, vector;
426
427 if (!msi_enabled)
428 return (ENXIO);
429
430 again:
431 mtx_lock(&msi_lock);
432
433 /* Find a free IRQ. */
434 for (i = FIRST_MSI_INT; i < FIRST_MSI_INT + NUM_MSI_INTS; i++) {
435 msi = (struct msi_intsrc *)intr_lookup_source(i);
436
437 /* End of allocated sources, so break. */
438 if (msi == NULL)
439 break;
440
441 /* Stop at the first free source. */
442 if (msi->msi_dev == NULL)
443 break;
444 }
445
446 /* Do we need to create a new source? */
447 if (msi == NULL) {
448 /* If we would exceed the max, give up. */
449 if (i + 1 > FIRST_MSI_INT + NUM_MSI_INTS) {
450 mtx_unlock(&msi_lock);
451 return (ENXIO);
452 }
453 mtx_unlock(&msi_lock);
454
455 /* Create a new source. */
456 msi_create_source();
457 goto again;
458 }
459
460 /* Allocate an IDT vector. */
461 vector = apic_alloc_vector(i);
462 if (bootverbose)
463 printf("msi: routing MSI-X IRQ %d to vector %u\n", msi->msi_irq,
464 vector);
465
466 /* Setup source. */
467 msi->msi_dev = dev;
468 msi->msi_vector = vector;
469 msi->msi_msix = 1;
470
471 KASSERT(msi->msi_intsrc.is_handlers == 0, ("dead MSI-X has handlers"));
472 mtx_unlock(&msi_lock);
473
474 *irq = i;
475 return (0);
476 }
477
478 int
479 msix_release(int irq)
480 {
481 struct msi_intsrc *msi;
482
483 mtx_lock(&msi_lock);
484 msi = (struct msi_intsrc *)intr_lookup_source(irq);
485 if (msi == NULL) {
486 mtx_unlock(&msi_lock);
487 return (ENOENT);
488 }
489
490 /* Make sure this is an MSI-X message. */
491 if (!msi->msi_msix) {
492 mtx_unlock(&msi_lock);
493 return (EINVAL);
494 }
495
496 KASSERT(msi->msi_dev != NULL, ("unowned message"));
497
498 /* Clear out the message. */
499 msi->msi_dev = NULL;
500 apic_free_vector(msi->msi_vector, msi->msi_irq);
501 msi->msi_vector = 0;
502 msi->msi_msix = 0;
503
504 mtx_unlock(&msi_lock);
505 return (0);
506 }
Cache object: c2000df611280e1af737b7f7e6d569d5
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