xref: /freebsd/sys/arm64/iommu/iommu.c (revision 2e3f49888ec8851bafb22011533217487764fdb0) 
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/param.h>
39 #include <sys/bus.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/memdesc.h>
43 #include <sys/tree.h>
44 #include <sys/taskqueue.h>
45 #include <sys/lock.h>
46 #include <sys/mutex.h>
47 #include <sys/sx.h>
48 #include <sys/sysctl.h>
49 #include <vm/vm.h>
50 
51 #include <dev/pci/pcireg.h>
52 #include <dev/pci/pcivar.h>
53 #include <machine/bus.h>
54 #include <dev/iommu/busdma_iommu.h>
55 #include <machine/vmparam.h>
56 
57 #ifdef FDT
58 #include <dev/fdt/fdt_common.h>
59 #include <dev/ofw/ofw_bus.h>
60 #include <dev/ofw/ofw_bus_subr.h>
61 #endif
62 
63 #include "iommu.h"
64 #include "iommu_if.h"
65 
66 static MALLOC_DEFINE(M_IOMMU, "IOMMU", "IOMMU framework");
67 
68 #define	IOMMU_LIST_LOCK()		sx_xlock(&iommu_sx)
69 #define	IOMMU_LIST_UNLOCK()		sx_xunlock(&iommu_sx)
70 #define	IOMMU_LIST_ASSERT_LOCKED()	sx_assert(&iommu_sx, SA_XLOCKED)
71 
72 #define dprintf(fmt, ...)
73 
74 static struct sx iommu_sx;
75 
76 struct iommu_entry {
77 	struct iommu_unit *iommu;
78 	LIST_ENTRY(iommu_entry) next;
79 };
80 static LIST_HEAD(, iommu_entry) iommu_list = LIST_HEAD_INITIALIZER(iommu_list);
81 
82 static int
83 iommu_domain_unmap_buf(struct iommu_domain *iodom, iommu_gaddr_t base,
84     iommu_gaddr_t size, int flags)
85 {
86 	struct iommu_unit *iommu;
87 	int error;
88 
89 	iommu = iodom->iommu;
90 
91 	error = IOMMU_UNMAP(iommu->dev, iodom, base, size);
92 
93 	return (error);
94 }
95 
96 static int
97 iommu_domain_map_buf(struct iommu_domain *iodom, iommu_gaddr_t base,
98     iommu_gaddr_t size, vm_page_t *ma, uint64_t eflags, int flags)
99 {
100 	struct iommu_unit *iommu;
101 	vm_prot_t prot;
102 	vm_offset_t va;
103 	int error;
104 
105 	dprintf("%s: base %lx, size %lx\n", __func__, base, size);
106 
107 	prot = 0;
108 	if (eflags & IOMMU_MAP_ENTRY_READ)
109 		prot |= VM_PROT_READ;
110 	if (eflags & IOMMU_MAP_ENTRY_WRITE)
111 		prot |= VM_PROT_WRITE;
112 
113 	va = base;
114 
115 	iommu = iodom->iommu;
116 
117 	error = IOMMU_MAP(iommu->dev, iodom, va, ma, size, prot);
118 
119 	return (error);
120 }
121 
122 static const struct iommu_domain_map_ops domain_map_ops = {
123 	.map = iommu_domain_map_buf,
124 	.unmap = iommu_domain_unmap_buf,
125 };
126 
127 static struct iommu_domain *
128 iommu_domain_alloc(struct iommu_unit *iommu)
129 {
130 	struct iommu_domain *iodom;
131 
132 	iodom = IOMMU_DOMAIN_ALLOC(iommu->dev, iommu);
133 	if (iodom == NULL)
134 		return (NULL);
135 
136 	KASSERT(iodom->end != 0, ("domain end is not set"));
137 
138 	iommu_domain_init(iommu, iodom, &domain_map_ops);
139 	iodom->iommu = iommu;
140 	iommu_gas_init_domain(iodom);
141 
142 	return (iodom);
143 }
144 
145 static int
146 iommu_domain_free(struct iommu_domain *iodom)
147 {
148 	struct iommu_unit *iommu;
149 
150 	iommu = iodom->iommu;
151 
152 	IOMMU_LOCK(iommu);
153 
154 	if ((iodom->flags & IOMMU_DOMAIN_GAS_INITED) != 0) {
155 		IOMMU_DOMAIN_LOCK(iodom);
156 		iommu_gas_fini_domain(iodom);
157 		IOMMU_DOMAIN_UNLOCK(iodom);
158 	}
159 
160 	iommu_domain_fini(iodom);
161 
162 	IOMMU_DOMAIN_FREE(iommu->dev, iodom);
163 	IOMMU_UNLOCK(iommu);
164 
165 	return (0);
166 }
167 
168 static void
169 iommu_tag_init(struct iommu_domain *iodom, struct bus_dma_tag_iommu *t)
170 {
171 	bus_addr_t maxaddr;
172 
173 	maxaddr = MIN(iodom->end, BUS_SPACE_MAXADDR);
174 
175 	t->common.ref_count = 0;
176 	t->common.impl = &bus_dma_iommu_impl;
177 	t->common.alignment = 1;
178 	t->common.boundary = 0;
179 	t->common.lowaddr = maxaddr;
180 	t->common.highaddr = maxaddr;
181 	t->common.maxsize = maxaddr;
182 	t->common.nsegments = BUS_SPACE_UNRESTRICTED;
183 	t->common.maxsegsz = maxaddr;
184 }
185 
186 static struct iommu_ctx *
187 iommu_ctx_alloc(device_t requester, struct iommu_domain *iodom, bool disabled)
188 {
189 	struct iommu_unit *iommu;
190 	struct iommu_ctx *ioctx;
191 
192 	iommu = iodom->iommu;
193 
194 	ioctx = IOMMU_CTX_ALLOC(iommu->dev, iodom, requester, disabled);
195 	if (ioctx == NULL)
196 		return (NULL);
197 
198 	ioctx->domain = iodom;
199 
200 	return (ioctx);
201 }
202 
203 static int
204 iommu_ctx_init(device_t requester, struct iommu_ctx *ioctx)
205 {
206 	struct bus_dma_tag_iommu *tag;
207 	struct iommu_domain *iodom;
208 	struct iommu_unit *iommu;
209 	int error;
210 
211 	iodom = ioctx->domain;
212 	iommu = iodom->iommu;
213 
214 	error = IOMMU_CTX_INIT(iommu->dev, ioctx);
215 	if (error)
216 		return (error);
217 
218 	tag = ioctx->tag = malloc(sizeof(struct bus_dma_tag_iommu),
219 	    M_IOMMU, M_WAITOK | M_ZERO);
220 	tag->owner = requester;
221 	tag->ctx = ioctx;
222 	tag->ctx->domain = iodom;
223 
224 	iommu_tag_init(iodom, tag);
225 
226 	return (error);
227 }
228 
229 static struct iommu_unit *
230 iommu_lookup(device_t dev)
231 {
232 	struct iommu_entry *entry;
233 	struct iommu_unit *iommu;
234 
235 	IOMMU_LIST_LOCK();
236 	LIST_FOREACH(entry, &iommu_list, next) {
237 		iommu = entry->iommu;
238 		if (iommu->dev == dev) {
239 			IOMMU_LIST_UNLOCK();
240 			return (iommu);
241 		}
242 	}
243 	IOMMU_LIST_UNLOCK();
244 
245 	return (NULL);
246 }
247 
248 #ifdef FDT
249 struct iommu_ctx *
250 iommu_get_ctx_ofw(device_t dev, int channel)
251 {
252 	struct iommu_domain *iodom;
253 	struct iommu_unit *iommu;
254 	struct iommu_ctx *ioctx;
255 	phandle_t node, parent;
256 	device_t iommu_dev;
257 	pcell_t *cells;
258 	int niommus;
259 	int ncells;
260 	int error;
261 
262 	node = ofw_bus_get_node(dev);
263 	if (node <= 0) {
264 		device_printf(dev,
265 		    "%s called on not ofw based device.\n", __func__);
266 		return (NULL);
267 	}
268 
269 	error = ofw_bus_parse_xref_list_get_length(node,
270 	    "iommus", "#iommu-cells", &niommus);
271 	if (error) {
272 		device_printf(dev, "%s can't get iommu list.\n", __func__);
273 		return (NULL);
274 	}
275 
276 	if (niommus == 0) {
277 		device_printf(dev, "%s iommu list is empty.\n", __func__);
278 		return (NULL);
279 	}
280 
281 	error = ofw_bus_parse_xref_list_alloc(node, "iommus", "#iommu-cells",
282 	    channel, &parent, &ncells, &cells);
283 	if (error != 0) {
284 		device_printf(dev, "%s can't get iommu device xref.\n",
285 		    __func__);
286 		return (NULL);
287 	}
288 
289 	iommu_dev = OF_device_from_xref(parent);
290 	if (iommu_dev == NULL) {
291 		device_printf(dev, "%s can't get iommu device.\n", __func__);
292 		return (NULL);
293 	}
294 
295 	iommu = iommu_lookup(iommu_dev);
296 	if (iommu == NULL) {
297 		device_printf(dev, "%s can't lookup iommu.\n", __func__);
298 		return (NULL);
299 	}
300 
301 	/*
302 	 * In our current configuration we have a domain per each ctx,
303 	 * so allocate a domain first.
304 	 */
305 	iodom = iommu_domain_alloc(iommu);
306 	if (iodom == NULL) {
307 		device_printf(dev, "%s can't allocate domain.\n", __func__);
308 		return (NULL);
309 	}
310 
311 	ioctx = iommu_ctx_alloc(dev, iodom, false);
312 	if (ioctx == NULL) {
313 		iommu_domain_free(iodom);
314 		return (NULL);
315 	}
316 
317 	ioctx->domain = iodom;
318 
319 	error = IOMMU_OFW_MD_DATA(iommu->dev, ioctx, cells, ncells);
320 	if (error) {
321 		device_printf(dev, "%s can't set MD data\n", __func__);
322 		return (NULL);
323 	}
324 
325 	error = iommu_ctx_init(dev, ioctx);
326 	if (error) {
327 		IOMMU_CTX_FREE(iommu->dev, ioctx);
328 		iommu_domain_free(iodom);
329 		return (NULL);
330 	}
331 
332 	return (ioctx);
333 }
334 #endif
335 
336 struct iommu_ctx *
337 iommu_get_ctx(struct iommu_unit *iommu, device_t requester,
338     uint16_t rid, bool disabled, bool rmrr)
339 {
340 	struct iommu_domain *iodom;
341 	struct iommu_ctx *ioctx;
342 	int error;
343 
344 	IOMMU_LOCK(iommu);
345 	ioctx = IOMMU_CTX_LOOKUP(iommu->dev, requester);
346 	if (ioctx) {
347 		IOMMU_UNLOCK(iommu);
348 		return (ioctx);
349 	}
350 	IOMMU_UNLOCK(iommu);
351 
352 	/*
353 	 * In our current configuration we have a domain per each ctx.
354 	 * So allocate a domain first.
355 	 */
356 	iodom = iommu_domain_alloc(iommu);
357 	if (iodom == NULL)
358 		return (NULL);
359 
360 	ioctx = iommu_ctx_alloc(requester, iodom, disabled);
361 	if (ioctx == NULL) {
362 		iommu_domain_free(iodom);
363 		return (NULL);
364 	}
365 
366 	error = iommu_ctx_init(requester, ioctx);
367 	if (error) {
368 		IOMMU_CTX_FREE(iommu->dev, ioctx);
369 		iommu_domain_free(iodom);
370 		return (NULL);
371 	}
372 
373 	return (ioctx);
374 }
375 
376 void
377 iommu_free_ctx_locked(struct iommu_unit *iommu, struct iommu_ctx *ioctx)
378 {
379 	struct bus_dma_tag_iommu *tag;
380 
381 	IOMMU_ASSERT_LOCKED(iommu);
382 
383 	tag = ioctx->tag;
384 
385 	IOMMU_CTX_FREE(iommu->dev, ioctx);
386 
387 	free(tag, M_IOMMU);
388 }
389 
390 void
391 iommu_free_ctx(struct iommu_ctx *ioctx)
392 {
393 	struct iommu_unit *iommu;
394 	struct iommu_domain *iodom;
395 	int error;
396 
397 	iodom = ioctx->domain;
398 	iommu = iodom->iommu;
399 
400 	IOMMU_LOCK(iommu);
401 	iommu_free_ctx_locked(iommu, ioctx);
402 	IOMMU_UNLOCK(iommu);
403 
404 	/* Since we have a domain per each ctx, remove the domain too. */
405 	error = iommu_domain_free(iodom);
406 	if (error)
407 		device_printf(iommu->dev, "Could not free a domain\n");
408 }
409 
410 static void
411 iommu_domain_free_entry(struct iommu_map_entry *entry, bool free)
412 {
413 	iommu_gas_free_space(entry);
414 
415 	if (free)
416 		iommu_gas_free_entry(entry);
417 	else
418 		entry->flags = 0;
419 }
420 
421 void
422 iommu_domain_unload(struct iommu_domain *iodom,
423     struct iommu_map_entries_tailq *entries, bool cansleep)
424 {
425 	struct iommu_map_entry *entry, *entry1;
426 	int error __diagused;
427 
428 	TAILQ_FOREACH_SAFE(entry, entries, dmamap_link, entry1) {
429 		KASSERT((entry->flags & IOMMU_MAP_ENTRY_MAP) != 0,
430 		    ("not mapped entry %p %p", iodom, entry));
431 		error = iodom->ops->unmap(iodom, entry->start, entry->end -
432 		    entry->start, cansleep ? IOMMU_PGF_WAITOK : 0);
433 		KASSERT(error == 0, ("unmap %p error %d", iodom, error));
434 		TAILQ_REMOVE(entries, entry, dmamap_link);
435 		iommu_domain_free_entry(entry, true);
436         }
437 
438 	if (TAILQ_EMPTY(entries))
439 		return;
440 
441 	panic("entries map is not empty");
442 }
443 
444 int
445 iommu_register(struct iommu_unit *iommu)
446 {
447 	struct iommu_entry *entry;
448 
449 	mtx_init(&iommu->lock, "IOMMU", NULL, MTX_DEF);
450 
451 	entry = malloc(sizeof(struct iommu_entry), M_IOMMU, M_WAITOK | M_ZERO);
452 	entry->iommu = iommu;
453 
454 	IOMMU_LIST_LOCK();
455 	LIST_INSERT_HEAD(&iommu_list, entry, next);
456 	IOMMU_LIST_UNLOCK();
457 
458 	iommu_init_busdma(iommu);
459 
460 	return (0);
461 }
462 
463 int
464 iommu_unregister(struct iommu_unit *iommu)
465 {
466 	struct iommu_entry *entry, *tmp;
467 
468 	IOMMU_LIST_LOCK();
469 	LIST_FOREACH_SAFE(entry, &iommu_list, next, tmp) {
470 		if (entry->iommu == iommu) {
471 			LIST_REMOVE(entry, next);
472 			free(entry, M_IOMMU);
473 		}
474 	}
475 	IOMMU_LIST_UNLOCK();
476 
477 	iommu_fini_busdma(iommu);
478 
479 	mtx_destroy(&iommu->lock);
480 
481 	return (0);
482 }
483 
484 struct iommu_unit *
485 iommu_find(device_t dev, bool verbose)
486 {
487 	struct iommu_entry *entry;
488 	struct iommu_unit *iommu;
489 	int error;
490 
491 	IOMMU_LIST_LOCK();
492 	LIST_FOREACH(entry, &iommu_list, next) {
493 		iommu = entry->iommu;
494 		error = IOMMU_FIND(iommu->dev, dev);
495 		if (error == 0) {
496 			IOMMU_LIST_UNLOCK();
497 			return (entry->iommu);
498 		}
499 	}
500 	IOMMU_LIST_UNLOCK();
501 
502 	return (NULL);
503 }
504 
505 void
506 iommu_domain_unload_entry(struct iommu_map_entry *entry, bool free,
507     bool cansleep __unused)
508 {
509 
510 	dprintf("%s\n", __func__);
511 
512 	iommu_domain_free_entry(entry, free);
513 }
514 
515 static void
516 iommu_init(void)
517 {
518 
519 	sx_init(&iommu_sx, "IOMMU list");
520 }
521 
522 SYSINIT(iommu, SI_SUB_DRIVERS, SI_ORDER_FIRST, iommu_init, NULL);
523