xref: /freebsd/sys/x86/iommu/intel_idpgtbl.c (revision 38effe887ee979f91ad5abf42a2291558e7ff8d1)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2013 The FreeBSD Foundation
5  * All rights reserved.
6  *
7  * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
8  * under sponsorship from the FreeBSD Foundation.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/malloc.h>
38 #include <sys/bus.h>
39 #include <sys/interrupt.h>
40 #include <sys/kernel.h>
41 #include <sys/ktr.h>
42 #include <sys/lock.h>
43 #include <sys/memdesc.h>
44 #include <sys/mutex.h>
45 #include <sys/proc.h>
46 #include <sys/rwlock.h>
47 #include <sys/rman.h>
48 #include <sys/sf_buf.h>
49 #include <sys/sysctl.h>
50 #include <sys/taskqueue.h>
51 #include <sys/tree.h>
52 #include <sys/uio.h>
53 #include <sys/vmem.h>
54 #include <vm/vm.h>
55 #include <vm/vm_extern.h>
56 #include <vm/vm_kern.h>
57 #include <vm/vm_object.h>
58 #include <vm/vm_page.h>
59 #include <vm/vm_pager.h>
60 #include <vm/vm_map.h>
61 #include <machine/atomic.h>
62 #include <machine/bus.h>
63 #include <machine/cpu.h>
64 #include <machine/md_var.h>
65 #include <machine/specialreg.h>
66 #include <x86/include/busdma_impl.h>
67 #include <x86/iommu/intel_reg.h>
68 #include <x86/iommu/busdma_dmar.h>
69 #include <dev/pci/pcireg.h>
70 #include <x86/iommu/intel_dmar.h>
71 
72 static int domain_unmap_buf_locked(struct dmar_domain *domain,
73     dmar_gaddr_t base, dmar_gaddr_t size, int flags);
74 
75 /*
76  * The cache of the identity mapping page tables for the DMARs.  Using
77  * the cache saves significant amount of memory for page tables by
78  * reusing the page tables, since usually DMARs are identical and have
79  * the same capabilities.  Still, cache records the information needed
80  * to match DMAR capabilities and page table format, to correctly
81  * handle different DMARs.
82  */
83 
84 struct idpgtbl {
85 	dmar_gaddr_t maxaddr;	/* Page table covers the guest address
86 				   range [0..maxaddr) */
87 	int pglvl;		/* Total page table levels ignoring
88 				   superpages */
89 	int leaf;		/* The last materialized page table
90 				   level, it is non-zero if superpages
91 				   are supported */
92 	vm_object_t pgtbl_obj;	/* The page table pages */
93 	LIST_ENTRY(idpgtbl) link;
94 };
95 
96 static struct sx idpgtbl_lock;
97 SX_SYSINIT(idpgtbl, &idpgtbl_lock, "idpgtbl");
98 static LIST_HEAD(, idpgtbl) idpgtbls = LIST_HEAD_INITIALIZER(idpgtbls);
99 static MALLOC_DEFINE(M_DMAR_IDPGTBL, "dmar_idpgtbl",
100     "Intel DMAR Identity mappings cache elements");
101 
102 /*
103  * Build the next level of the page tables for the identity mapping.
104  * - lvl is the level to build;
105  * - idx is the index of the page table page in the pgtbl_obj, which is
106  *   being allocated filled now;
107  * - addr is the starting address in the bus address space which is
108  *   mapped by the page table page.
109  */
110 static void
111 domain_idmap_nextlvl(struct idpgtbl *tbl, int lvl, vm_pindex_t idx,
112     dmar_gaddr_t addr)
113 {
114 	vm_page_t m1;
115 	dmar_pte_t *pte;
116 	struct sf_buf *sf;
117 	dmar_gaddr_t f, pg_sz;
118 	vm_pindex_t base;
119 	int i;
120 
121 	VM_OBJECT_ASSERT_LOCKED(tbl->pgtbl_obj);
122 	if (addr >= tbl->maxaddr)
123 		return;
124 	(void)dmar_pgalloc(tbl->pgtbl_obj, idx, DMAR_PGF_OBJL | DMAR_PGF_WAITOK |
125 	    DMAR_PGF_ZERO);
126 	base = idx * DMAR_NPTEPG + 1; /* Index of the first child page of idx */
127 	pg_sz = pglvl_page_size(tbl->pglvl, lvl);
128 	if (lvl != tbl->leaf) {
129 		for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz)
130 			domain_idmap_nextlvl(tbl, lvl + 1, base + i, f);
131 	}
132 	VM_OBJECT_WUNLOCK(tbl->pgtbl_obj);
133 	pte = dmar_map_pgtbl(tbl->pgtbl_obj, idx, DMAR_PGF_WAITOK, &sf);
134 	if (lvl == tbl->leaf) {
135 		for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz) {
136 			if (f >= tbl->maxaddr)
137 				break;
138 			pte[i].pte = (DMAR_PTE_ADDR_MASK & f) |
139 			    DMAR_PTE_R | DMAR_PTE_W;
140 		}
141 	} else {
142 		for (i = 0, f = addr; i < DMAR_NPTEPG; i++, f += pg_sz) {
143 			if (f >= tbl->maxaddr)
144 				break;
145 			m1 = dmar_pgalloc(tbl->pgtbl_obj, base + i,
146 			    DMAR_PGF_NOALLOC);
147 			KASSERT(m1 != NULL, ("lost page table page"));
148 			pte[i].pte = (DMAR_PTE_ADDR_MASK &
149 			    VM_PAGE_TO_PHYS(m1)) | DMAR_PTE_R | DMAR_PTE_W;
150 		}
151 	}
152 	/* domain_get_idmap_pgtbl flushes CPU cache if needed. */
153 	dmar_unmap_pgtbl(sf);
154 	VM_OBJECT_WLOCK(tbl->pgtbl_obj);
155 }
156 
157 /*
158  * Find a ready and compatible identity-mapping page table in the
159  * cache. If not found, populate the identity-mapping page table for
160  * the context, up to the maxaddr. The maxaddr byte is allowed to be
161  * not mapped, which is aligned with the definition of Maxmem as the
162  * highest usable physical address + 1.  If superpages are used, the
163  * maxaddr is typically mapped.
164  */
165 vm_object_t
166 domain_get_idmap_pgtbl(struct dmar_domain *domain, dmar_gaddr_t maxaddr)
167 {
168 	struct dmar_unit *unit;
169 	struct idpgtbl *tbl;
170 	vm_object_t res;
171 	vm_page_t m;
172 	int leaf, i;
173 
174 	leaf = 0; /* silence gcc */
175 
176 	/*
177 	 * First, determine where to stop the paging structures.
178 	 */
179 	for (i = 0; i < domain->pglvl; i++) {
180 		if (i == domain->pglvl - 1 || domain_is_sp_lvl(domain, i)) {
181 			leaf = i;
182 			break;
183 		}
184 	}
185 
186 	/*
187 	 * Search the cache for a compatible page table.  Qualified
188 	 * page table must map up to maxaddr, its level must be
189 	 * supported by the DMAR and leaf should be equal to the
190 	 * calculated value.  The later restriction could be lifted
191 	 * but I believe it is currently impossible to have any
192 	 * deviations for existing hardware.
193 	 */
194 	sx_slock(&idpgtbl_lock);
195 	LIST_FOREACH(tbl, &idpgtbls, link) {
196 		if (tbl->maxaddr >= maxaddr &&
197 		    dmar_pglvl_supported(domain->dmar, tbl->pglvl) &&
198 		    tbl->leaf == leaf) {
199 			res = tbl->pgtbl_obj;
200 			vm_object_reference(res);
201 			sx_sunlock(&idpgtbl_lock);
202 			domain->pglvl = tbl->pglvl; /* XXXKIB ? */
203 			goto end;
204 		}
205 	}
206 
207 	/*
208 	 * Not found in cache, relock the cache into exclusive mode to
209 	 * be able to add element, and recheck cache again after the
210 	 * relock.
211 	 */
212 	sx_sunlock(&idpgtbl_lock);
213 	sx_xlock(&idpgtbl_lock);
214 	LIST_FOREACH(tbl, &idpgtbls, link) {
215 		if (tbl->maxaddr >= maxaddr &&
216 		    dmar_pglvl_supported(domain->dmar, tbl->pglvl) &&
217 		    tbl->leaf == leaf) {
218 			res = tbl->pgtbl_obj;
219 			vm_object_reference(res);
220 			sx_xunlock(&idpgtbl_lock);
221 			domain->pglvl = tbl->pglvl; /* XXXKIB ? */
222 			return (res);
223 		}
224 	}
225 
226 	/*
227 	 * Still not found, create new page table.
228 	 */
229 	tbl = malloc(sizeof(*tbl), M_DMAR_IDPGTBL, M_WAITOK);
230 	tbl->pglvl = domain->pglvl;
231 	tbl->leaf = leaf;
232 	tbl->maxaddr = maxaddr;
233 	tbl->pgtbl_obj = vm_pager_allocate(OBJT_PHYS, NULL,
234 	    IDX_TO_OFF(pglvl_max_pages(tbl->pglvl)), 0, 0, NULL);
235 	VM_OBJECT_WLOCK(tbl->pgtbl_obj);
236 	domain_idmap_nextlvl(tbl, 0, 0, 0);
237 	VM_OBJECT_WUNLOCK(tbl->pgtbl_obj);
238 	LIST_INSERT_HEAD(&idpgtbls, tbl, link);
239 	res = tbl->pgtbl_obj;
240 	vm_object_reference(res);
241 	sx_xunlock(&idpgtbl_lock);
242 
243 end:
244 	/*
245 	 * Table was found or created.
246 	 *
247 	 * If DMAR does not snoop paging structures accesses, flush
248 	 * CPU cache to memory.  Note that dmar_unmap_pgtbl() coherent
249 	 * argument was possibly invalid at the time of the identity
250 	 * page table creation, since DMAR which was passed at the
251 	 * time of creation could be coherent, while current DMAR is
252 	 * not.
253 	 *
254 	 * If DMAR cannot look into the chipset write buffer, flush it
255 	 * as well.
256 	 */
257 	unit = domain->dmar;
258 	if (!DMAR_IS_COHERENT(unit)) {
259 		VM_OBJECT_WLOCK(res);
260 		for (m = vm_page_lookup(res, 0); m != NULL;
261 		     m = vm_page_next(m))
262 			pmap_invalidate_cache_pages(&m, 1);
263 		VM_OBJECT_WUNLOCK(res);
264 	}
265 	if ((unit->hw_cap & DMAR_CAP_RWBF) != 0) {
266 		DMAR_LOCK(unit);
267 		dmar_flush_write_bufs(unit);
268 		DMAR_UNLOCK(unit);
269 	}
270 
271 	return (res);
272 }
273 
274 /*
275  * Return a reference to the identity mapping page table to the cache.
276  */
277 void
278 put_idmap_pgtbl(vm_object_t obj)
279 {
280 	struct idpgtbl *tbl, *tbl1;
281 	vm_object_t rmobj;
282 
283 	sx_slock(&idpgtbl_lock);
284 	KASSERT(obj->ref_count >= 2, ("lost cache reference"));
285 	vm_object_deallocate(obj);
286 
287 	/*
288 	 * Cache always owns one last reference on the page table object.
289 	 * If there is an additional reference, object must stay.
290 	 */
291 	if (obj->ref_count > 1) {
292 		sx_sunlock(&idpgtbl_lock);
293 		return;
294 	}
295 
296 	/*
297 	 * Cache reference is the last, remove cache element and free
298 	 * page table object, returning the page table pages to the
299 	 * system.
300 	 */
301 	sx_sunlock(&idpgtbl_lock);
302 	sx_xlock(&idpgtbl_lock);
303 	LIST_FOREACH_SAFE(tbl, &idpgtbls, link, tbl1) {
304 		rmobj = tbl->pgtbl_obj;
305 		if (rmobj->ref_count == 1) {
306 			LIST_REMOVE(tbl, link);
307 			atomic_subtract_int(&dmar_tbl_pagecnt,
308 			    rmobj->resident_page_count);
309 			vm_object_deallocate(rmobj);
310 			free(tbl, M_DMAR_IDPGTBL);
311 		}
312 	}
313 	sx_xunlock(&idpgtbl_lock);
314 }
315 
316 /*
317  * The core routines to map and unmap host pages at the given guest
318  * address.  Support superpages.
319  */
320 
321 /*
322  * Index of the pte for the guest address base in the page table at
323  * the level lvl.
324  */
325 static int
326 domain_pgtbl_pte_off(struct dmar_domain *domain, dmar_gaddr_t base, int lvl)
327 {
328 
329 	base >>= DMAR_PAGE_SHIFT + (domain->pglvl - lvl - 1) *
330 	    DMAR_NPTEPGSHIFT;
331 	return (base & DMAR_PTEMASK);
332 }
333 
334 /*
335  * Returns the page index of the page table page in the page table
336  * object, which maps the given address base at the page table level
337  * lvl.
338  */
339 static vm_pindex_t
340 domain_pgtbl_get_pindex(struct dmar_domain *domain, dmar_gaddr_t base, int lvl)
341 {
342 	vm_pindex_t idx, pidx;
343 	int i;
344 
345 	KASSERT(lvl >= 0 && lvl < domain->pglvl,
346 	    ("wrong lvl %p %d", domain, lvl));
347 
348 	for (pidx = idx = 0, i = 0; i < lvl; i++, pidx = idx) {
349 		idx = domain_pgtbl_pte_off(domain, base, i) +
350 		    pidx * DMAR_NPTEPG + 1;
351 	}
352 	return (idx);
353 }
354 
355 static dmar_pte_t *
356 domain_pgtbl_map_pte(struct dmar_domain *domain, dmar_gaddr_t base, int lvl,
357     int flags, vm_pindex_t *idxp, struct sf_buf **sf)
358 {
359 	vm_page_t m;
360 	struct sf_buf *sfp;
361 	dmar_pte_t *pte, *ptep;
362 	vm_pindex_t idx, idx1;
363 
364 	DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
365 	KASSERT((flags & DMAR_PGF_OBJL) != 0, ("lost PGF_OBJL"));
366 
367 	idx = domain_pgtbl_get_pindex(domain, base, lvl);
368 	if (*sf != NULL && idx == *idxp) {
369 		pte = (dmar_pte_t *)sf_buf_kva(*sf);
370 	} else {
371 		if (*sf != NULL)
372 			dmar_unmap_pgtbl(*sf);
373 		*idxp = idx;
374 retry:
375 		pte = dmar_map_pgtbl(domain->pgtbl_obj, idx, flags, sf);
376 		if (pte == NULL) {
377 			KASSERT(lvl > 0,
378 			    ("lost root page table page %p", domain));
379 			/*
380 			 * Page table page does not exist, allocate
381 			 * it and create a pte in the preceeding page level
382 			 * to reference the allocated page table page.
383 			 */
384 			m = dmar_pgalloc(domain->pgtbl_obj, idx, flags |
385 			    DMAR_PGF_ZERO);
386 			if (m == NULL)
387 				return (NULL);
388 
389 			/*
390 			 * Prevent potential free while pgtbl_obj is
391 			 * unlocked in the recursive call to
392 			 * domain_pgtbl_map_pte(), if other thread did
393 			 * pte write and clean while the lock is
394 			 * dropped.
395 			 */
396 			m->ref_count++;
397 
398 			sfp = NULL;
399 			ptep = domain_pgtbl_map_pte(domain, base, lvl - 1,
400 			    flags, &idx1, &sfp);
401 			if (ptep == NULL) {
402 				KASSERT(m->pindex != 0,
403 				    ("loosing root page %p", domain));
404 				m->ref_count--;
405 				dmar_pgfree(domain->pgtbl_obj, m->pindex,
406 				    flags);
407 				return (NULL);
408 			}
409 			dmar_pte_store(&ptep->pte, DMAR_PTE_R | DMAR_PTE_W |
410 			    VM_PAGE_TO_PHYS(m));
411 			dmar_flush_pte_to_ram(domain->dmar, ptep);
412 			sf_buf_page(sfp)->ref_count += 1;
413 			m->ref_count--;
414 			dmar_unmap_pgtbl(sfp);
415 			/* Only executed once. */
416 			goto retry;
417 		}
418 	}
419 	pte += domain_pgtbl_pte_off(domain, base, lvl);
420 	return (pte);
421 }
422 
423 static int
424 domain_map_buf_locked(struct dmar_domain *domain, dmar_gaddr_t base,
425     dmar_gaddr_t size, vm_page_t *ma, uint64_t pflags, int flags)
426 {
427 	dmar_pte_t *pte;
428 	struct sf_buf *sf;
429 	dmar_gaddr_t pg_sz, base1, size1;
430 	vm_pindex_t pi, c, idx, run_sz;
431 	int lvl;
432 	bool superpage;
433 
434 	DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
435 
436 	base1 = base;
437 	size1 = size;
438 	flags |= DMAR_PGF_OBJL;
439 	TD_PREP_PINNED_ASSERT;
440 
441 	for (sf = NULL, pi = 0; size > 0; base += pg_sz, size -= pg_sz,
442 	    pi += run_sz) {
443 		for (lvl = 0, c = 0, superpage = false;; lvl++) {
444 			pg_sz = domain_page_size(domain, lvl);
445 			run_sz = pg_sz >> DMAR_PAGE_SHIFT;
446 			if (lvl == domain->pglvl - 1)
447 				break;
448 			/*
449 			 * Check if the current base suitable for the
450 			 * superpage mapping.  First, verify the level.
451 			 */
452 			if (!domain_is_sp_lvl(domain, lvl))
453 				continue;
454 			/*
455 			 * Next, look at the size of the mapping and
456 			 * alignment of both guest and host addresses.
457 			 */
458 			if (size < pg_sz || (base & (pg_sz - 1)) != 0 ||
459 			    (VM_PAGE_TO_PHYS(ma[pi]) & (pg_sz - 1)) != 0)
460 				continue;
461 			/* All passed, check host pages contiguouty. */
462 			if (c == 0) {
463 				for (c = 1; c < run_sz; c++) {
464 					if (VM_PAGE_TO_PHYS(ma[pi + c]) !=
465 					    VM_PAGE_TO_PHYS(ma[pi + c - 1]) +
466 					    PAGE_SIZE)
467 						break;
468 				}
469 			}
470 			if (c >= run_sz) {
471 				superpage = true;
472 				break;
473 			}
474 		}
475 		KASSERT(size >= pg_sz,
476 		    ("mapping loop overflow %p %jx %jx %jx", domain,
477 		    (uintmax_t)base, (uintmax_t)size, (uintmax_t)pg_sz));
478 		KASSERT(pg_sz > 0, ("pg_sz 0 lvl %d", lvl));
479 		pte = domain_pgtbl_map_pte(domain, base, lvl, flags, &idx, &sf);
480 		if (pte == NULL) {
481 			KASSERT((flags & DMAR_PGF_WAITOK) == 0,
482 			    ("failed waitable pte alloc %p", domain));
483 			if (sf != NULL)
484 				dmar_unmap_pgtbl(sf);
485 			domain_unmap_buf_locked(domain, base1, base - base1,
486 			    flags);
487 			TD_PINNED_ASSERT;
488 			return (ENOMEM);
489 		}
490 		dmar_pte_store(&pte->pte, VM_PAGE_TO_PHYS(ma[pi]) | pflags |
491 		    (superpage ? DMAR_PTE_SP : 0));
492 		dmar_flush_pte_to_ram(domain->dmar, pte);
493 		sf_buf_page(sf)->ref_count += 1;
494 	}
495 	if (sf != NULL)
496 		dmar_unmap_pgtbl(sf);
497 	TD_PINNED_ASSERT;
498 	return (0);
499 }
500 
501 int
502 domain_map_buf(struct dmar_domain *domain, dmar_gaddr_t base, dmar_gaddr_t size,
503     vm_page_t *ma, uint64_t pflags, int flags)
504 {
505 	struct dmar_unit *unit;
506 	int error;
507 
508 	unit = domain->dmar;
509 
510 	KASSERT((domain->flags & DMAR_DOMAIN_IDMAP) == 0,
511 	    ("modifying idmap pagetable domain %p", domain));
512 	KASSERT((base & DMAR_PAGE_MASK) == 0,
513 	    ("non-aligned base %p %jx %jx", domain, (uintmax_t)base,
514 	    (uintmax_t)size));
515 	KASSERT((size & DMAR_PAGE_MASK) == 0,
516 	    ("non-aligned size %p %jx %jx", domain, (uintmax_t)base,
517 	    (uintmax_t)size));
518 	KASSERT(size > 0, ("zero size %p %jx %jx", domain, (uintmax_t)base,
519 	    (uintmax_t)size));
520 	KASSERT(base < (1ULL << domain->agaw),
521 	    ("base too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
522 	    (uintmax_t)size, domain->agaw));
523 	KASSERT(base + size < (1ULL << domain->agaw),
524 	    ("end too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
525 	    (uintmax_t)size, domain->agaw));
526 	KASSERT(base + size > base,
527 	    ("size overflow %p %jx %jx", domain, (uintmax_t)base,
528 	    (uintmax_t)size));
529 	KASSERT((pflags & (DMAR_PTE_R | DMAR_PTE_W)) != 0,
530 	    ("neither read nor write %jx", (uintmax_t)pflags));
531 	KASSERT((pflags & ~(DMAR_PTE_R | DMAR_PTE_W | DMAR_PTE_SNP |
532 	    DMAR_PTE_TM)) == 0,
533 	    ("invalid pte flags %jx", (uintmax_t)pflags));
534 	KASSERT((pflags & DMAR_PTE_SNP) == 0 ||
535 	    (unit->hw_ecap & DMAR_ECAP_SC) != 0,
536 	    ("PTE_SNP for dmar without snoop control %p %jx",
537 	    domain, (uintmax_t)pflags));
538 	KASSERT((pflags & DMAR_PTE_TM) == 0 ||
539 	    (unit->hw_ecap & DMAR_ECAP_DI) != 0,
540 	    ("PTE_TM for dmar without DIOTLB %p %jx",
541 	    domain, (uintmax_t)pflags));
542 	KASSERT((flags & ~DMAR_PGF_WAITOK) == 0, ("invalid flags %x", flags));
543 
544 	DMAR_DOMAIN_PGLOCK(domain);
545 	error = domain_map_buf_locked(domain, base, size, ma, pflags, flags);
546 	DMAR_DOMAIN_PGUNLOCK(domain);
547 	if (error != 0)
548 		return (error);
549 
550 	if ((unit->hw_cap & DMAR_CAP_CM) != 0)
551 		domain_flush_iotlb_sync(domain, base, size);
552 	else if ((unit->hw_cap & DMAR_CAP_RWBF) != 0) {
553 		/* See 11.1 Write Buffer Flushing. */
554 		DMAR_LOCK(unit);
555 		dmar_flush_write_bufs(unit);
556 		DMAR_UNLOCK(unit);
557 	}
558 	return (0);
559 }
560 
561 static void domain_unmap_clear_pte(struct dmar_domain *domain,
562     dmar_gaddr_t base, int lvl, int flags, dmar_pte_t *pte,
563     struct sf_buf **sf, bool free_fs);
564 
565 static void
566 domain_free_pgtbl_pde(struct dmar_domain *domain, dmar_gaddr_t base,
567     int lvl, int flags)
568 {
569 	struct sf_buf *sf;
570 	dmar_pte_t *pde;
571 	vm_pindex_t idx;
572 
573 	sf = NULL;
574 	pde = domain_pgtbl_map_pte(domain, base, lvl, flags, &idx, &sf);
575 	domain_unmap_clear_pte(domain, base, lvl, flags, pde, &sf, true);
576 }
577 
578 static void
579 domain_unmap_clear_pte(struct dmar_domain *domain, dmar_gaddr_t base, int lvl,
580     int flags, dmar_pte_t *pte, struct sf_buf **sf, bool free_sf)
581 {
582 	vm_page_t m;
583 
584 	dmar_pte_clear(&pte->pte);
585 	dmar_flush_pte_to_ram(domain->dmar, pte);
586 	m = sf_buf_page(*sf);
587 	if (free_sf) {
588 		dmar_unmap_pgtbl(*sf);
589 		*sf = NULL;
590 	}
591 	m->ref_count--;
592 	if (m->ref_count != 0)
593 		return;
594 	KASSERT(lvl != 0,
595 	    ("lost reference (lvl) on root pg domain %p base %jx lvl %d",
596 	    domain, (uintmax_t)base, lvl));
597 	KASSERT(m->pindex != 0,
598 	    ("lost reference (idx) on root pg domain %p base %jx lvl %d",
599 	    domain, (uintmax_t)base, lvl));
600 	dmar_pgfree(domain->pgtbl_obj, m->pindex, flags);
601 	domain_free_pgtbl_pde(domain, base, lvl - 1, flags);
602 }
603 
604 /*
605  * Assumes that the unmap is never partial.
606  */
607 static int
608 domain_unmap_buf_locked(struct dmar_domain *domain, dmar_gaddr_t base,
609     dmar_gaddr_t size, int flags)
610 {
611 	dmar_pte_t *pte;
612 	struct sf_buf *sf;
613 	vm_pindex_t idx;
614 	dmar_gaddr_t pg_sz;
615 	int lvl;
616 
617 	DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
618 	if (size == 0)
619 		return (0);
620 
621 	KASSERT((domain->flags & DMAR_DOMAIN_IDMAP) == 0,
622 	    ("modifying idmap pagetable domain %p", domain));
623 	KASSERT((base & DMAR_PAGE_MASK) == 0,
624 	    ("non-aligned base %p %jx %jx", domain, (uintmax_t)base,
625 	    (uintmax_t)size));
626 	KASSERT((size & DMAR_PAGE_MASK) == 0,
627 	    ("non-aligned size %p %jx %jx", domain, (uintmax_t)base,
628 	    (uintmax_t)size));
629 	KASSERT(base < (1ULL << domain->agaw),
630 	    ("base too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
631 	    (uintmax_t)size, domain->agaw));
632 	KASSERT(base + size < (1ULL << domain->agaw),
633 	    ("end too high %p %jx %jx agaw %d", domain, (uintmax_t)base,
634 	    (uintmax_t)size, domain->agaw));
635 	KASSERT(base + size > base,
636 	    ("size overflow %p %jx %jx", domain, (uintmax_t)base,
637 	    (uintmax_t)size));
638 	KASSERT((flags & ~DMAR_PGF_WAITOK) == 0, ("invalid flags %x", flags));
639 
640 	pg_sz = 0; /* silence gcc */
641 	flags |= DMAR_PGF_OBJL;
642 	TD_PREP_PINNED_ASSERT;
643 
644 	for (sf = NULL; size > 0; base += pg_sz, size -= pg_sz) {
645 		for (lvl = 0; lvl < domain->pglvl; lvl++) {
646 			if (lvl != domain->pglvl - 1 &&
647 			    !domain_is_sp_lvl(domain, lvl))
648 				continue;
649 			pg_sz = domain_page_size(domain, lvl);
650 			if (pg_sz > size)
651 				continue;
652 			pte = domain_pgtbl_map_pte(domain, base, lvl, flags,
653 			    &idx, &sf);
654 			KASSERT(pte != NULL,
655 			    ("sleeping or page missed %p %jx %d 0x%x",
656 			    domain, (uintmax_t)base, lvl, flags));
657 			if ((pte->pte & DMAR_PTE_SP) != 0 ||
658 			    lvl == domain->pglvl - 1) {
659 				domain_unmap_clear_pte(domain, base, lvl,
660 				    flags, pte, &sf, false);
661 				break;
662 			}
663 		}
664 		KASSERT(size >= pg_sz,
665 		    ("unmapping loop overflow %p %jx %jx %jx", domain,
666 		    (uintmax_t)base, (uintmax_t)size, (uintmax_t)pg_sz));
667 	}
668 	if (sf != NULL)
669 		dmar_unmap_pgtbl(sf);
670 	/*
671 	 * See 11.1 Write Buffer Flushing for an explanation why RWBF
672 	 * can be ignored there.
673 	 */
674 
675 	TD_PINNED_ASSERT;
676 	return (0);
677 }
678 
679 int
680 domain_unmap_buf(struct dmar_domain *domain, dmar_gaddr_t base,
681     dmar_gaddr_t size, int flags)
682 {
683 	int error;
684 
685 	DMAR_DOMAIN_PGLOCK(domain);
686 	error = domain_unmap_buf_locked(domain, base, size, flags);
687 	DMAR_DOMAIN_PGUNLOCK(domain);
688 	return (error);
689 }
690 
691 int
692 domain_alloc_pgtbl(struct dmar_domain *domain)
693 {
694 	vm_page_t m;
695 
696 	KASSERT(domain->pgtbl_obj == NULL,
697 	    ("already initialized %p", domain));
698 
699 	domain->pgtbl_obj = vm_pager_allocate(OBJT_PHYS, NULL,
700 	    IDX_TO_OFF(pglvl_max_pages(domain->pglvl)), 0, 0, NULL);
701 	DMAR_DOMAIN_PGLOCK(domain);
702 	m = dmar_pgalloc(domain->pgtbl_obj, 0, DMAR_PGF_WAITOK |
703 	    DMAR_PGF_ZERO | DMAR_PGF_OBJL);
704 	/* No implicit free of the top level page table page. */
705 	m->ref_count = 1;
706 	DMAR_DOMAIN_PGUNLOCK(domain);
707 	DMAR_LOCK(domain->dmar);
708 	domain->flags |= DMAR_DOMAIN_PGTBL_INITED;
709 	DMAR_UNLOCK(domain->dmar);
710 	return (0);
711 }
712 
713 void
714 domain_free_pgtbl(struct dmar_domain *domain)
715 {
716 	vm_object_t obj;
717 	vm_page_t m;
718 
719 	obj = domain->pgtbl_obj;
720 	if (obj == NULL) {
721 		KASSERT((domain->dmar->hw_ecap & DMAR_ECAP_PT) != 0 &&
722 		    (domain->flags & DMAR_DOMAIN_IDMAP) != 0,
723 		    ("lost pagetable object domain %p", domain));
724 		return;
725 	}
726 	DMAR_DOMAIN_ASSERT_PGLOCKED(domain);
727 	domain->pgtbl_obj = NULL;
728 
729 	if ((domain->flags & DMAR_DOMAIN_IDMAP) != 0) {
730 		put_idmap_pgtbl(obj);
731 		domain->flags &= ~DMAR_DOMAIN_IDMAP;
732 		return;
733 	}
734 
735 	/* Obliterate ref_counts */
736 	VM_OBJECT_ASSERT_WLOCKED(obj);
737 	for (m = vm_page_lookup(obj, 0); m != NULL; m = vm_page_next(m))
738 		m->ref_count = 0;
739 	VM_OBJECT_WUNLOCK(obj);
740 	vm_object_deallocate(obj);
741 }
742 
743 static inline uint64_t
744 domain_wait_iotlb_flush(struct dmar_unit *unit, uint64_t wt, int iro)
745 {
746 	uint64_t iotlbr;
747 
748 	dmar_write8(unit, iro + DMAR_IOTLB_REG_OFF, DMAR_IOTLB_IVT |
749 	    DMAR_IOTLB_DR | DMAR_IOTLB_DW | wt);
750 	for (;;) {
751 		iotlbr = dmar_read8(unit, iro + DMAR_IOTLB_REG_OFF);
752 		if ((iotlbr & DMAR_IOTLB_IVT) == 0)
753 			break;
754 		cpu_spinwait();
755 	}
756 	return (iotlbr);
757 }
758 
759 void
760 domain_flush_iotlb_sync(struct dmar_domain *domain, dmar_gaddr_t base,
761     dmar_gaddr_t size)
762 {
763 	struct dmar_unit *unit;
764 	dmar_gaddr_t isize;
765 	uint64_t iotlbr;
766 	int am, iro;
767 
768 	unit = domain->dmar;
769 	KASSERT(!unit->qi_enabled, ("dmar%d: sync iotlb flush call",
770 	    unit->unit));
771 	iro = DMAR_ECAP_IRO(unit->hw_ecap) * 16;
772 	DMAR_LOCK(unit);
773 	if ((unit->hw_cap & DMAR_CAP_PSI) == 0 || size > 2 * 1024 * 1024) {
774 		iotlbr = domain_wait_iotlb_flush(unit, DMAR_IOTLB_IIRG_DOM |
775 		    DMAR_IOTLB_DID(domain->domain), iro);
776 		KASSERT((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
777 		    DMAR_IOTLB_IAIG_INVLD,
778 		    ("dmar%d: invalidation failed %jx", unit->unit,
779 		    (uintmax_t)iotlbr));
780 	} else {
781 		for (; size > 0; base += isize, size -= isize) {
782 			am = calc_am(unit, base, size, &isize);
783 			dmar_write8(unit, iro, base | am);
784 			iotlbr = domain_wait_iotlb_flush(unit,
785 			    DMAR_IOTLB_IIRG_PAGE |
786 			    DMAR_IOTLB_DID(domain->domain), iro);
787 			KASSERT((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
788 			    DMAR_IOTLB_IAIG_INVLD,
789 			    ("dmar%d: PSI invalidation failed "
790 			    "iotlbr 0x%jx base 0x%jx size 0x%jx am %d",
791 			    unit->unit, (uintmax_t)iotlbr,
792 			    (uintmax_t)base, (uintmax_t)size, am));
793 			/*
794 			 * Any non-page granularity covers whole guest
795 			 * address space for the domain.
796 			 */
797 			if ((iotlbr & DMAR_IOTLB_IAIG_MASK) !=
798 			    DMAR_IOTLB_IAIG_PAGE)
799 				break;
800 		}
801 	}
802 	DMAR_UNLOCK(unit);
803 }
804