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