xref: /freebsd/sys/arm64/iommu/iommu.c (revision 19fae0f66023a97a9b464b3beeeabb2081f575b3) 
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2020 Ruslan Bukin <br@bsdpad.com>
5  *
6  * This software was developed by SRI International and the University of
7  * Cambridge Computer Laboratory (Department of Computer Science and
8  * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
9  * DARPA SSITH research programme.
10  *
11  * Portions of this work was supported by Innovate UK project 105694,
12  * "Digital Security by Design (DSbD) Technology Platform Prototype".
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "opt_platform.h"
37 
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD$");
40 
41 #include <sys/param.h>
42 #include <sys/bus.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/memdesc.h>
46 #include <sys/tree.h>
47 #include <sys/taskqueue.h>
48 #include <sys/lock.h>
49 #include <sys/mutex.h>
50 #include <sys/sx.h>
51 #include <sys/sysctl.h>
52 #include <vm/vm.h>
53 
54 #include <dev/pci/pcireg.h>
55 #include <dev/pci/pcivar.h>
56 #include <machine/bus.h>
57 #include <dev/iommu/busdma_iommu.h>
58 #include <machine/vmparam.h>
59 
60 #ifdef FDT
61 #include <dev/fdt/fdt_common.h>
62 #include <dev/ofw/ofw_bus.h>
63 #include <dev/ofw/ofw_bus_subr.h>
64 #endif
65 
66 #include "iommu.h"
67 #include "iommu_if.h"
68 
69 static MALLOC_DEFINE(M_IOMMU, "IOMMU", "IOMMU framework");
70 
71 #define	IOMMU_LIST_LOCK()		sx_xlock(&iommu_sx)
72 #define	IOMMU_LIST_UNLOCK()		sx_xunlock(&iommu_sx)
73 #define	IOMMU_LIST_ASSERT_LOCKED()	sx_assert(&iommu_sx, SA_XLOCKED)
74 
75 #define dprintf(fmt, ...)
76 
77 static struct sx iommu_sx;
78 
79 struct iommu_entry {
80 	struct iommu_unit *iommu;
81 	LIST_ENTRY(iommu_entry) next;
82 };
83 static LIST_HEAD(, iommu_entry) iommu_list = LIST_HEAD_INITIALIZER(iommu_list);
84 
85 static int
86 iommu_domain_unmap_buf(struct iommu_domain *iodom, iommu_gaddr_t base,
87     iommu_gaddr_t size, int flags)
88 {
89 	struct iommu_unit *iommu;
90 	int error;
91 
92 	iommu = iodom->iommu;
93 
94 	error = IOMMU_UNMAP(iommu->dev, iodom, base, size);
95 
96 	return (error);
97 }
98 
99 static int
100 iommu_domain_map_buf(struct iommu_domain *iodom, iommu_gaddr_t base,
101     iommu_gaddr_t size, vm_page_t *ma, uint64_t eflags, int flags)
102 {
103 	struct iommu_unit *iommu;
104 	vm_prot_t prot;
105 	vm_offset_t va;
106 	int error;
107 
108 	dprintf("%s: base %lx, size %lx\n", __func__, base, size);
109 
110 	prot = 0;
111 	if (eflags & IOMMU_MAP_ENTRY_READ)
112 		prot |= VM_PROT_READ;
113 	if (eflags & IOMMU_MAP_ENTRY_WRITE)
114 		prot |= VM_PROT_WRITE;
115 
116 	va = base;
117 
118 	iommu = iodom->iommu;
119 
120 	error = IOMMU_MAP(iommu->dev, iodom, va, ma, size, prot);
121 
122 	return (error);
123 }
124 
125 static const struct iommu_domain_map_ops domain_map_ops = {
126 	.map = iommu_domain_map_buf,
127 	.unmap = iommu_domain_unmap_buf,
128 };
129 
130 static struct iommu_domain *
131 iommu_domain_alloc(struct iommu_unit *iommu)
132 {
133 	struct iommu_domain *iodom;
134 
135 	iodom = IOMMU_DOMAIN_ALLOC(iommu->dev, iommu);
136 	if (iodom == NULL)
137 		return (NULL);
138 
139 	KASSERT(iodom->end != 0, ("domain end is not set"));
140 
141 	iommu_domain_init(iommu, iodom, &domain_map_ops);
142 	iodom->iommu = iommu;
143 	iommu_gas_init_domain(iodom);
144 
145 	return (iodom);
146 }
147 
148 static int
149 iommu_domain_free(struct iommu_domain *iodom)
150 {
151 	struct iommu_unit *iommu;
152 
153 	iommu = iodom->iommu;
154 
155 	IOMMU_LOCK(iommu);
156 
157 	if ((iodom->flags & IOMMU_DOMAIN_GAS_INITED) != 0) {
158 		IOMMU_DOMAIN_LOCK(iodom);
159 		iommu_gas_fini_domain(iodom);
160 		IOMMU_DOMAIN_UNLOCK(iodom);
161 	}
162 
163 	iommu_domain_fini(iodom);
164 
165 	IOMMU_DOMAIN_FREE(iommu->dev, iodom);
166 	IOMMU_UNLOCK(iommu);
167 
168 	return (0);
169 }
170 
171 static void
172 iommu_tag_init(struct iommu_domain *iodom, struct bus_dma_tag_iommu *t)
173 {
174 	bus_addr_t maxaddr;
175 
176 	maxaddr = MIN(iodom->end, BUS_SPACE_MAXADDR);
177 
178 	t->common.ref_count = 0;
179 	t->common.impl = &bus_dma_iommu_impl;
180 	t->common.alignment = 1;
181 	t->common.boundary = 0;
182 	t->common.lowaddr = maxaddr;
183 	t->common.highaddr = maxaddr;
184 	t->common.maxsize = maxaddr;
185 	t->common.nsegments = BUS_SPACE_UNRESTRICTED;
186 	t->common.maxsegsz = maxaddr;
187 }
188 
189 static struct iommu_ctx *
190 iommu_ctx_alloc(device_t requester, struct iommu_domain *iodom, bool disabled)
191 {
192 	struct iommu_unit *iommu;
193 	struct iommu_ctx *ioctx;
194 
195 	iommu = iodom->iommu;
196 
197 	ioctx = IOMMU_CTX_ALLOC(iommu->dev, iodom, requester, disabled);
198 	if (ioctx == NULL)
199 		return (NULL);
200 
201 	ioctx->domain = iodom;
202 
203 	return (ioctx);
204 }
205 
206 static int
207 iommu_ctx_init(device_t requester, struct iommu_ctx *ioctx)
208 {
209 	struct bus_dma_tag_iommu *tag;
210 	struct iommu_domain *iodom;
211 	struct iommu_unit *iommu;
212 	int error;
213 
214 	iodom = ioctx->domain;
215 	iommu = iodom->iommu;
216 
217 	error = IOMMU_CTX_INIT(iommu->dev, ioctx);
218 	if (error)
219 		return (error);
220 
221 	tag = ioctx->tag = malloc(sizeof(struct bus_dma_tag_iommu),
222 	    M_IOMMU, M_WAITOK | M_ZERO);
223 	tag->owner = requester;
224 	tag->ctx = ioctx;
225 	tag->ctx->domain = iodom;
226 
227 	iommu_tag_init(iodom, tag);
228 
229 	return (error);
230 }
231 
232 static struct iommu_unit *
233 iommu_lookup(device_t dev)
234 {
235 	struct iommu_entry *entry;
236 	struct iommu_unit *iommu;
237 
238 	IOMMU_LIST_LOCK();
239 	LIST_FOREACH(entry, &iommu_list, next) {
240 		iommu = entry->iommu;
241 		if (iommu->dev == dev) {
242 			IOMMU_LIST_UNLOCK();
243 			return (iommu);
244 		}
245 	}
246 	IOMMU_LIST_UNLOCK();
247 
248 	return (NULL);
249 }
250 
251 #ifdef FDT
252 struct iommu_ctx *
253 iommu_get_ctx_ofw(device_t dev, int channel)
254 {
255 	struct iommu_domain *iodom;
256 	struct iommu_unit *iommu;
257 	struct iommu_ctx *ioctx;
258 	phandle_t node, parent;
259 	device_t iommu_dev;
260 	pcell_t *cells;
261 	int niommus;
262 	int ncells;
263 	int error;
264 
265 	node = ofw_bus_get_node(dev);
266 	if (node <= 0) {
267 		device_printf(dev,
268 		    "%s called on not ofw based device.\n", __func__);
269 		return (NULL);
270 	}
271 
272 	error = ofw_bus_parse_xref_list_get_length(node,
273 	    "iommus", "#iommu-cells", &niommus);
274 	if (error) {
275 		device_printf(dev, "%s can't get iommu list.\n", __func__);
276 		return (NULL);
277 	}
278 
279 	if (niommus == 0) {
280 		device_printf(dev, "%s iommu list is empty.\n", __func__);
281 		return (NULL);
282 	}
283 
284 	error = ofw_bus_parse_xref_list_alloc(node, "iommus", "#iommu-cells",
285 	    channel, &parent, &ncells, &cells);
286 	if (error != 0) {
287 		device_printf(dev, "%s can't get iommu device xref.\n",
288 		    __func__);
289 		return (NULL);
290 	}
291 
292 	iommu_dev = OF_device_from_xref(parent);
293 	if (iommu_dev == NULL) {
294 		device_printf(dev, "%s can't get iommu device.\n", __func__);
295 		return (NULL);
296 	}
297 
298 	iommu = iommu_lookup(iommu_dev);
299 	if (iommu == NULL) {
300 		device_printf(dev, "%s can't lookup iommu.\n", __func__);
301 		return (NULL);
302 	}
303 
304 	/*
305 	 * In our current configuration we have a domain per each ctx,
306 	 * so allocate a domain first.
307 	 */
308 	iodom = iommu_domain_alloc(iommu);
309 	if (iodom == NULL) {
310 		device_printf(dev, "%s can't allocate domain.\n", __func__);
311 		return (NULL);
312 	}
313 
314 	ioctx = iommu_ctx_alloc(dev, iodom, false);
315 	if (ioctx == NULL) {
316 		iommu_domain_free(iodom);
317 		return (NULL);
318 	}
319 
320 	ioctx->domain = iodom;
321 
322 	error = IOMMU_OFW_MD_DATA(iommu->dev, ioctx, cells, ncells);
323 	if (error) {
324 		device_printf(dev, "%s can't set MD data\n", __func__);
325 		return (NULL);
326 	}
327 
328 	error = iommu_ctx_init(dev, ioctx);
329 	if (error) {
330 		IOMMU_CTX_FREE(iommu->dev, ioctx);
331 		iommu_domain_free(iodom);
332 		return (NULL);
333 	}
334 
335 	return (ioctx);
336 }
337 #endif
338 
339 struct iommu_ctx *
340 iommu_get_ctx(struct iommu_unit *iommu, device_t requester,
341     uint16_t rid, bool disabled, bool rmrr)
342 {
343 	struct iommu_domain *iodom;
344 	struct iommu_ctx *ioctx;
345 	int error;
346 
347 	IOMMU_LOCK(iommu);
348 	ioctx = IOMMU_CTX_LOOKUP(iommu->dev, requester);
349 	if (ioctx) {
350 		IOMMU_UNLOCK(iommu);
351 		return (ioctx);
352 	}
353 	IOMMU_UNLOCK(iommu);
354 
355 	/*
356 	 * In our current configuration we have a domain per each ctx.
357 	 * So allocate a domain first.
358 	 */
359 	iodom = iommu_domain_alloc(iommu);
360 	if (iodom == NULL)
361 		return (NULL);
362 
363 	ioctx = iommu_ctx_alloc(requester, iodom, disabled);
364 	if (ioctx == NULL) {
365 		iommu_domain_free(iodom);
366 		return (NULL);
367 	}
368 
369 	error = iommu_ctx_init(requester, ioctx);
370 	if (error) {
371 		IOMMU_CTX_FREE(iommu->dev, ioctx);
372 		iommu_domain_free(iodom);
373 		return (NULL);
374 	}
375 
376 	return (ioctx);
377 }
378 
379 void
380 iommu_free_ctx_locked(struct iommu_unit *iommu, struct iommu_ctx *ioctx)
381 {
382 	struct bus_dma_tag_iommu *tag;
383 
384 	IOMMU_ASSERT_LOCKED(iommu);
385 
386 	tag = ioctx->tag;
387 
388 	IOMMU_CTX_FREE(iommu->dev, ioctx);
389 
390 	free(tag, M_IOMMU);
391 }
392 
393 void
394 iommu_free_ctx(struct iommu_ctx *ioctx)
395 {
396 	struct iommu_unit *iommu;
397 	struct iommu_domain *iodom;
398 	int error;
399 
400 	iodom = ioctx->domain;
401 	iommu = iodom->iommu;
402 
403 	IOMMU_LOCK(iommu);
404 	iommu_free_ctx_locked(iommu, ioctx);
405 	IOMMU_UNLOCK(iommu);
406 
407 	/* Since we have a domain per each ctx, remove the domain too. */
408 	error = iommu_domain_free(iodom);
409 	if (error)
410 		device_printf(iommu->dev, "Could not free a domain\n");
411 }
412 
413 static void
414 iommu_domain_free_entry(struct iommu_map_entry *entry, bool free)
415 {
416 	iommu_gas_free_space(entry);
417 
418 	if (free)
419 		iommu_gas_free_entry(entry);
420 	else
421 		entry->flags = 0;
422 }
423 
424 void
425 iommu_domain_unload(struct iommu_domain *iodom,
426     struct iommu_map_entries_tailq *entries, bool cansleep)
427 {
428 	struct iommu_map_entry *entry, *entry1;
429 	int error __diagused;
430 
431 	TAILQ_FOREACH_SAFE(entry, entries, dmamap_link, entry1) {
432 		KASSERT((entry->flags & IOMMU_MAP_ENTRY_MAP) != 0,
433 		    ("not mapped entry %p %p", iodom, entry));
434 		error = iodom->ops->unmap(iodom, entry->start, entry->end -
435 		    entry->start, cansleep ? IOMMU_PGF_WAITOK : 0);
436 		KASSERT(error == 0, ("unmap %p error %d", iodom, error));
437 		TAILQ_REMOVE(entries, entry, dmamap_link);
438 		iommu_domain_free_entry(entry, true);
439         }
440 
441 	if (TAILQ_EMPTY(entries))
442 		return;
443 
444 	panic("entries map is not empty");
445 }
446 
447 int
448 iommu_register(struct iommu_unit *iommu)
449 {
450 	struct iommu_entry *entry;
451 
452 	mtx_init(&iommu->lock, "IOMMU", NULL, MTX_DEF);
453 
454 	entry = malloc(sizeof(struct iommu_entry), M_IOMMU, M_WAITOK | M_ZERO);
455 	entry->iommu = iommu;
456 
457 	IOMMU_LIST_LOCK();
458 	LIST_INSERT_HEAD(&iommu_list, entry, next);
459 	IOMMU_LIST_UNLOCK();
460 
461 	iommu_init_busdma(iommu);
462 
463 	return (0);
464 }
465 
466 int
467 iommu_unregister(struct iommu_unit *iommu)
468 {
469 	struct iommu_entry *entry, *tmp;
470 
471 	IOMMU_LIST_LOCK();
472 	LIST_FOREACH_SAFE(entry, &iommu_list, next, tmp) {
473 		if (entry->iommu == iommu) {
474 			LIST_REMOVE(entry, next);
475 			free(entry, M_IOMMU);
476 		}
477 	}
478 	IOMMU_LIST_UNLOCK();
479 
480 	iommu_fini_busdma(iommu);
481 
482 	mtx_destroy(&iommu->lock);
483 
484 	return (0);
485 }
486 
487 struct iommu_unit *
488 iommu_find(device_t dev, bool verbose)
489 {
490 	struct iommu_entry *entry;
491 	struct iommu_unit *iommu;
492 	int error;
493 
494 	IOMMU_LIST_LOCK();
495 	LIST_FOREACH(entry, &iommu_list, next) {
496 		iommu = entry->iommu;
497 		error = IOMMU_FIND(iommu->dev, dev);
498 		if (error == 0) {
499 			IOMMU_LIST_UNLOCK();
500 			return (entry->iommu);
501 		}
502 	}
503 	IOMMU_LIST_UNLOCK();
504 
505 	return (NULL);
506 }
507 
508 void
509 iommu_domain_unload_entry(struct iommu_map_entry *entry, bool free,
510     bool cansleep __unused)
511 {
512 
513 	dprintf("%s\n", __func__);
514 
515 	iommu_domain_free_entry(entry, free);
516 }
517 
518 static void
519 iommu_init(void)
520 {
521 
522 	sx_init(&iommu_sx, "IOMMU list");
523 }
524 
525 SYSINIT(iommu, SI_SUB_DRIVERS, SI_ORDER_FIRST, iommu_init, NULL);
526