xref: /freebsd/sys/x86/iommu/intel_utils.c (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
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/bus.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/malloc.h>
38 #include <sys/memdesc.h>
39 #include <sys/mutex.h>
40 #include <sys/proc.h>
41 #include <sys/queue.h>
42 #include <sys/rman.h>
43 #include <sys/rwlock.h>
44 #include <sys/sched.h>
45 #include <sys/sf_buf.h>
46 #include <sys/sysctl.h>
47 #include <sys/systm.h>
48 #include <sys/taskqueue.h>
49 #include <sys/time.h>
50 #include <sys/tree.h>
51 #include <sys/vmem.h>
52 #include <dev/pci/pcivar.h>
53 #include <vm/vm.h>
54 #include <vm/vm_extern.h>
55 #include <vm/vm_kern.h>
56 #include <vm/vm_object.h>
57 #include <vm/vm_page.h>
58 #include <vm/vm_map.h>
59 #include <vm/vm_pageout.h>
60 #include <machine/bus.h>
61 #include <machine/cpu.h>
62 #include <machine/intr_machdep.h>
63 #include <x86/include/apicvar.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 
69 u_int
70 dmar_nd2mask(u_int nd)
71 {
72 	static const u_int masks[] = {
73 		0x000f,	/* nd == 0 */
74 		0x002f,	/* nd == 1 */
75 		0x00ff,	/* nd == 2 */
76 		0x02ff,	/* nd == 3 */
77 		0x0fff,	/* nd == 4 */
78 		0x2fff,	/* nd == 5 */
79 		0xffff,	/* nd == 6 */
80 		0x0000,	/* nd == 7 reserved */
81 	};
82 
83 	KASSERT(nd <= 6, ("number of domains %d", nd));
84 	return (masks[nd]);
85 }
86 
87 static const struct sagaw_bits_tag {
88 	int agaw;
89 	int cap;
90 	int awlvl;
91 	int pglvl;
92 } sagaw_bits[] = {
93 	{.agaw = 30, .cap = DMAR_CAP_SAGAW_2LVL, .awlvl = DMAR_CTX2_AW_2LVL,
94 	    .pglvl = 2},
95 	{.agaw = 39, .cap = DMAR_CAP_SAGAW_3LVL, .awlvl = DMAR_CTX2_AW_3LVL,
96 	    .pglvl = 3},
97 	{.agaw = 48, .cap = DMAR_CAP_SAGAW_4LVL, .awlvl = DMAR_CTX2_AW_4LVL,
98 	    .pglvl = 4},
99 	{.agaw = 57, .cap = DMAR_CAP_SAGAW_5LVL, .awlvl = DMAR_CTX2_AW_5LVL,
100 	    .pglvl = 5},
101 	{.agaw = 64, .cap = DMAR_CAP_SAGAW_6LVL, .awlvl = DMAR_CTX2_AW_6LVL,
102 	    .pglvl = 6}
103 };
104 
105 bool
106 dmar_pglvl_supported(struct dmar_unit *unit, int pglvl)
107 {
108 	int i;
109 
110 	for (i = 0; i < nitems(sagaw_bits); i++) {
111 		if (sagaw_bits[i].pglvl != pglvl)
112 			continue;
113 		if ((DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap) != 0)
114 			return (true);
115 	}
116 	return (false);
117 }
118 
119 int
120 domain_set_agaw(struct dmar_domain *domain, int mgaw)
121 {
122 	int sagaw, i;
123 
124 	domain->mgaw = mgaw;
125 	sagaw = DMAR_CAP_SAGAW(domain->dmar->hw_cap);
126 	for (i = 0; i < nitems(sagaw_bits); i++) {
127 		if (sagaw_bits[i].agaw >= mgaw) {
128 			domain->agaw = sagaw_bits[i].agaw;
129 			domain->pglvl = sagaw_bits[i].pglvl;
130 			domain->awlvl = sagaw_bits[i].awlvl;
131 			return (0);
132 		}
133 	}
134 	device_printf(domain->dmar->dev,
135 	    "context request mgaw %d: no agaw found, sagaw %x\n",
136 	    mgaw, sagaw);
137 	return (EINVAL);
138 }
139 
140 /*
141  * Find a best fit mgaw for the given maxaddr:
142  *   - if allow_less is false, must find sagaw which maps all requested
143  *     addresses (used by identity mappings);
144  *   - if allow_less is true, and no supported sagaw can map all requested
145  *     address space, accept the biggest sagaw, whatever is it.
146  */
147 int
148 dmar_maxaddr2mgaw(struct dmar_unit *unit, dmar_gaddr_t maxaddr, bool allow_less)
149 {
150 	int i;
151 
152 	for (i = 0; i < nitems(sagaw_bits); i++) {
153 		if ((1ULL << sagaw_bits[i].agaw) >= maxaddr &&
154 		    (DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap) != 0)
155 			break;
156 	}
157 	if (allow_less && i == nitems(sagaw_bits)) {
158 		do {
159 			i--;
160 		} while ((DMAR_CAP_SAGAW(unit->hw_cap) & sagaw_bits[i].cap)
161 		    == 0);
162 	}
163 	if (i < nitems(sagaw_bits))
164 		return (sagaw_bits[i].agaw);
165 	KASSERT(0, ("no mgaw for maxaddr %jx allow_less %d",
166 	    (uintmax_t) maxaddr, allow_less));
167 	return (-1);
168 }
169 
170 /*
171  * Calculate the total amount of page table pages needed to map the
172  * whole bus address space on the context with the selected agaw.
173  */
174 vm_pindex_t
175 pglvl_max_pages(int pglvl)
176 {
177 	vm_pindex_t res;
178 	int i;
179 
180 	for (res = 0, i = pglvl; i > 0; i--) {
181 		res *= DMAR_NPTEPG;
182 		res++;
183 	}
184 	return (res);
185 }
186 
187 /*
188  * Return true if the page table level lvl supports the superpage for
189  * the context ctx.
190  */
191 int
192 domain_is_sp_lvl(struct dmar_domain *domain, int lvl)
193 {
194 	int alvl, cap_sps;
195 	static const int sagaw_sp[] = {
196 		DMAR_CAP_SPS_2M,
197 		DMAR_CAP_SPS_1G,
198 		DMAR_CAP_SPS_512G,
199 		DMAR_CAP_SPS_1T
200 	};
201 
202 	alvl = domain->pglvl - lvl - 1;
203 	cap_sps = DMAR_CAP_SPS(domain->dmar->hw_cap);
204 	return (alvl < nitems(sagaw_sp) && (sagaw_sp[alvl] & cap_sps) != 0);
205 }
206 
207 dmar_gaddr_t
208 pglvl_page_size(int total_pglvl, int lvl)
209 {
210 	int rlvl;
211 	static const dmar_gaddr_t pg_sz[] = {
212 		(dmar_gaddr_t)DMAR_PAGE_SIZE,
213 		(dmar_gaddr_t)DMAR_PAGE_SIZE << DMAR_NPTEPGSHIFT,
214 		(dmar_gaddr_t)DMAR_PAGE_SIZE << (2 * DMAR_NPTEPGSHIFT),
215 		(dmar_gaddr_t)DMAR_PAGE_SIZE << (3 * DMAR_NPTEPGSHIFT),
216 		(dmar_gaddr_t)DMAR_PAGE_SIZE << (4 * DMAR_NPTEPGSHIFT),
217 		(dmar_gaddr_t)DMAR_PAGE_SIZE << (5 * DMAR_NPTEPGSHIFT)
218 	};
219 
220 	KASSERT(lvl >= 0 && lvl < total_pglvl,
221 	    ("total %d lvl %d", total_pglvl, lvl));
222 	rlvl = total_pglvl - lvl - 1;
223 	KASSERT(rlvl < nitems(pg_sz), ("sizeof pg_sz lvl %d", lvl));
224 	return (pg_sz[rlvl]);
225 }
226 
227 dmar_gaddr_t
228 domain_page_size(struct dmar_domain *domain, int lvl)
229 {
230 
231 	return (pglvl_page_size(domain->pglvl, lvl));
232 }
233 
234 int
235 calc_am(struct dmar_unit *unit, dmar_gaddr_t base, dmar_gaddr_t size,
236     dmar_gaddr_t *isizep)
237 {
238 	dmar_gaddr_t isize;
239 	int am;
240 
241 	for (am = DMAR_CAP_MAMV(unit->hw_cap);; am--) {
242 		isize = 1ULL << (am + DMAR_PAGE_SHIFT);
243 		if ((base & (isize - 1)) == 0 && size >= isize)
244 			break;
245 		if (am == 0)
246 			break;
247 	}
248 	*isizep = isize;
249 	return (am);
250 }
251 
252 dmar_haddr_t dmar_high;
253 int haw;
254 int dmar_tbl_pagecnt;
255 
256 vm_page_t
257 dmar_pgalloc(vm_object_t obj, vm_pindex_t idx, int flags)
258 {
259 	vm_page_t m;
260 	int zeroed, aflags;
261 
262 	zeroed = (flags & DMAR_PGF_ZERO) != 0 ? VM_ALLOC_ZERO : 0;
263 	aflags = zeroed | VM_ALLOC_NOBUSY | VM_ALLOC_SYSTEM | VM_ALLOC_NODUMP |
264 	    ((flags & DMAR_PGF_WAITOK) != 0 ? VM_ALLOC_WAITFAIL :
265 	    VM_ALLOC_NOWAIT);
266 	for (;;) {
267 		if ((flags & DMAR_PGF_OBJL) == 0)
268 			VM_OBJECT_WLOCK(obj);
269 		m = vm_page_lookup(obj, idx);
270 		if ((flags & DMAR_PGF_NOALLOC) != 0 || m != NULL) {
271 			if ((flags & DMAR_PGF_OBJL) == 0)
272 				VM_OBJECT_WUNLOCK(obj);
273 			break;
274 		}
275 		m = vm_page_alloc_contig(obj, idx, aflags, 1, 0,
276 		    dmar_high, PAGE_SIZE, 0, VM_MEMATTR_DEFAULT);
277 		if ((flags & DMAR_PGF_OBJL) == 0)
278 			VM_OBJECT_WUNLOCK(obj);
279 		if (m != NULL) {
280 			if (zeroed && (m->flags & PG_ZERO) == 0)
281 				pmap_zero_page(m);
282 			atomic_add_int(&dmar_tbl_pagecnt, 1);
283 			break;
284 		}
285 		if ((flags & DMAR_PGF_WAITOK) == 0)
286 			break;
287 	}
288 	return (m);
289 }
290 
291 void
292 dmar_pgfree(vm_object_t obj, vm_pindex_t idx, int flags)
293 {
294 	vm_page_t m;
295 
296 	if ((flags & DMAR_PGF_OBJL) == 0)
297 		VM_OBJECT_WLOCK(obj);
298 	m = vm_page_lookup(obj, idx);
299 	if (m != NULL) {
300 		vm_page_free(m);
301 		atomic_subtract_int(&dmar_tbl_pagecnt, 1);
302 	}
303 	if ((flags & DMAR_PGF_OBJL) == 0)
304 		VM_OBJECT_WUNLOCK(obj);
305 }
306 
307 void *
308 dmar_map_pgtbl(vm_object_t obj, vm_pindex_t idx, int flags,
309     struct sf_buf **sf)
310 {
311 	vm_page_t m;
312 	bool allocated;
313 
314 	if ((flags & DMAR_PGF_OBJL) == 0)
315 		VM_OBJECT_WLOCK(obj);
316 	m = vm_page_lookup(obj, idx);
317 	if (m == NULL && (flags & DMAR_PGF_ALLOC) != 0) {
318 		m = dmar_pgalloc(obj, idx, flags | DMAR_PGF_OBJL);
319 		allocated = true;
320 	} else
321 		allocated = false;
322 	if (m == NULL) {
323 		if ((flags & DMAR_PGF_OBJL) == 0)
324 			VM_OBJECT_WUNLOCK(obj);
325 		return (NULL);
326 	}
327 	/* Sleepable allocations cannot fail. */
328 	if ((flags & DMAR_PGF_WAITOK) != 0)
329 		VM_OBJECT_WUNLOCK(obj);
330 	sched_pin();
331 	*sf = sf_buf_alloc(m, SFB_CPUPRIVATE | ((flags & DMAR_PGF_WAITOK)
332 	    == 0 ? SFB_NOWAIT : 0));
333 	if (*sf == NULL) {
334 		sched_unpin();
335 		if (allocated) {
336 			VM_OBJECT_ASSERT_WLOCKED(obj);
337 			dmar_pgfree(obj, m->pindex, flags | DMAR_PGF_OBJL);
338 		}
339 		if ((flags & DMAR_PGF_OBJL) == 0)
340 			VM_OBJECT_WUNLOCK(obj);
341 		return (NULL);
342 	}
343 	if ((flags & (DMAR_PGF_WAITOK | DMAR_PGF_OBJL)) ==
344 	    (DMAR_PGF_WAITOK | DMAR_PGF_OBJL))
345 		VM_OBJECT_WLOCK(obj);
346 	else if ((flags & (DMAR_PGF_WAITOK | DMAR_PGF_OBJL)) == 0)
347 		VM_OBJECT_WUNLOCK(obj);
348 	return ((void *)sf_buf_kva(*sf));
349 }
350 
351 void
352 dmar_unmap_pgtbl(struct sf_buf *sf)
353 {
354 
355 	sf_buf_free(sf);
356 	sched_unpin();
357 }
358 
359 static void
360 dmar_flush_transl_to_ram(struct dmar_unit *unit, void *dst, size_t sz)
361 {
362 
363 	if (DMAR_IS_COHERENT(unit))
364 		return;
365 	/*
366 	 * If DMAR does not snoop paging structures accesses, flush
367 	 * CPU cache to memory.
368 	 */
369 	pmap_invalidate_cache_range((uintptr_t)dst, (uintptr_t)dst + sz,
370 	    TRUE);
371 }
372 
373 void
374 dmar_flush_pte_to_ram(struct dmar_unit *unit, dmar_pte_t *dst)
375 {
376 
377 	dmar_flush_transl_to_ram(unit, dst, sizeof(*dst));
378 }
379 
380 void
381 dmar_flush_ctx_to_ram(struct dmar_unit *unit, dmar_ctx_entry_t *dst)
382 {
383 
384 	dmar_flush_transl_to_ram(unit, dst, sizeof(*dst));
385 }
386 
387 void
388 dmar_flush_root_to_ram(struct dmar_unit *unit, dmar_root_entry_t *dst)
389 {
390 
391 	dmar_flush_transl_to_ram(unit, dst, sizeof(*dst));
392 }
393 
394 /*
395  * Load the root entry pointer into the hardware, busily waiting for
396  * the completion.
397  */
398 int
399 dmar_load_root_entry_ptr(struct dmar_unit *unit)
400 {
401 	vm_page_t root_entry;
402 	int error;
403 
404 	/*
405 	 * Access to the GCMD register must be serialized while the
406 	 * command is submitted.
407 	 */
408 	DMAR_ASSERT_LOCKED(unit);
409 
410 	VM_OBJECT_RLOCK(unit->ctx_obj);
411 	root_entry = vm_page_lookup(unit->ctx_obj, 0);
412 	VM_OBJECT_RUNLOCK(unit->ctx_obj);
413 	dmar_write8(unit, DMAR_RTADDR_REG, VM_PAGE_TO_PHYS(root_entry));
414 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd | DMAR_GCMD_SRTP);
415 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_RTPS)
416 	    != 0));
417 	return (error);
418 }
419 
420 /*
421  * Globally invalidate the context entries cache, busily waiting for
422  * the completion.
423  */
424 int
425 dmar_inv_ctx_glob(struct dmar_unit *unit)
426 {
427 	int error;
428 
429 	/*
430 	 * Access to the CCMD register must be serialized while the
431 	 * command is submitted.
432 	 */
433 	DMAR_ASSERT_LOCKED(unit);
434 	KASSERT(!unit->qi_enabled, ("QI enabled"));
435 
436 	/*
437 	 * The DMAR_CCMD_ICC bit in the upper dword should be written
438 	 * after the low dword write is completed.  Amd64
439 	 * dmar_write8() does not have this issue, i386 dmar_write8()
440 	 * writes the upper dword last.
441 	 */
442 	dmar_write8(unit, DMAR_CCMD_REG, DMAR_CCMD_ICC | DMAR_CCMD_CIRG_GLOB);
443 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_CCMD_REG + 4) & DMAR_CCMD_ICC32)
444 	    == 0));
445 	return (error);
446 }
447 
448 /*
449  * Globally invalidate the IOTLB, busily waiting for the completion.
450  */
451 int
452 dmar_inv_iotlb_glob(struct dmar_unit *unit)
453 {
454 	int error, reg;
455 
456 	DMAR_ASSERT_LOCKED(unit);
457 	KASSERT(!unit->qi_enabled, ("QI enabled"));
458 
459 	reg = 16 * DMAR_ECAP_IRO(unit->hw_ecap);
460 	/* See a comment about DMAR_CCMD_ICC in dmar_inv_ctx_glob. */
461 	dmar_write8(unit, reg + DMAR_IOTLB_REG_OFF, DMAR_IOTLB_IVT |
462 	    DMAR_IOTLB_IIRG_GLB | DMAR_IOTLB_DR | DMAR_IOTLB_DW);
463 	DMAR_WAIT_UNTIL(((dmar_read4(unit, reg + DMAR_IOTLB_REG_OFF + 4) &
464 	    DMAR_IOTLB_IVT32) == 0));
465 	return (error);
466 }
467 
468 /*
469  * Flush the chipset write buffers.  See 11.1 "Write Buffer Flushing"
470  * in the architecture specification.
471  */
472 int
473 dmar_flush_write_bufs(struct dmar_unit *unit)
474 {
475 	int error;
476 
477 	DMAR_ASSERT_LOCKED(unit);
478 
479 	/*
480 	 * DMAR_GCMD_WBF is only valid when CAP_RWBF is reported.
481 	 */
482 	KASSERT((unit->hw_cap & DMAR_CAP_RWBF) != 0,
483 	    ("dmar%d: no RWBF", unit->unit));
484 
485 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd | DMAR_GCMD_WBF);
486 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_WBFS)
487 	    != 0));
488 	return (error);
489 }
490 
491 int
492 dmar_enable_translation(struct dmar_unit *unit)
493 {
494 	int error;
495 
496 	DMAR_ASSERT_LOCKED(unit);
497 	unit->hw_gcmd |= DMAR_GCMD_TE;
498 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd);
499 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_TES)
500 	    != 0));
501 	return (error);
502 }
503 
504 int
505 dmar_disable_translation(struct dmar_unit *unit)
506 {
507 	int error;
508 
509 	DMAR_ASSERT_LOCKED(unit);
510 	unit->hw_gcmd &= ~DMAR_GCMD_TE;
511 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd);
512 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_TES)
513 	    == 0));
514 	return (error);
515 }
516 
517 int
518 dmar_load_irt_ptr(struct dmar_unit *unit)
519 {
520 	uint64_t irta, s;
521 	int error;
522 
523 	DMAR_ASSERT_LOCKED(unit);
524 	irta = unit->irt_phys;
525 	if (DMAR_X2APIC(unit))
526 		irta |= DMAR_IRTA_EIME;
527 	s = fls(unit->irte_cnt) - 2;
528 	KASSERT(unit->irte_cnt >= 2 && s <= DMAR_IRTA_S_MASK &&
529 	    powerof2(unit->irte_cnt),
530 	    ("IRTA_REG_S overflow %x", unit->irte_cnt));
531 	irta |= s;
532 	dmar_write8(unit, DMAR_IRTA_REG, irta);
533 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd | DMAR_GCMD_SIRTP);
534 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_IRTPS)
535 	    != 0));
536 	return (error);
537 }
538 
539 int
540 dmar_enable_ir(struct dmar_unit *unit)
541 {
542 	int error;
543 
544 	DMAR_ASSERT_LOCKED(unit);
545 	unit->hw_gcmd |= DMAR_GCMD_IRE;
546 	unit->hw_gcmd &= ~DMAR_GCMD_CFI;
547 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd);
548 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_IRES)
549 	    != 0));
550 	return (error);
551 }
552 
553 int
554 dmar_disable_ir(struct dmar_unit *unit)
555 {
556 	int error;
557 
558 	DMAR_ASSERT_LOCKED(unit);
559 	unit->hw_gcmd &= ~DMAR_GCMD_IRE;
560 	dmar_write4(unit, DMAR_GCMD_REG, unit->hw_gcmd);
561 	DMAR_WAIT_UNTIL(((dmar_read4(unit, DMAR_GSTS_REG) & DMAR_GSTS_IRES)
562 	    == 0));
563 	return (error);
564 }
565 
566 #define BARRIER_F				\
567 	u_int f_done, f_inproc, f_wakeup;	\
568 						\
569 	f_done = 1 << (barrier_id * 3);		\
570 	f_inproc = 1 << (barrier_id * 3 + 1);	\
571 	f_wakeup = 1 << (barrier_id * 3 + 2)
572 
573 bool
574 dmar_barrier_enter(struct dmar_unit *dmar, u_int barrier_id)
575 {
576 	BARRIER_F;
577 
578 	DMAR_LOCK(dmar);
579 	if ((dmar->barrier_flags & f_done) != 0) {
580 		DMAR_UNLOCK(dmar);
581 		return (false);
582 	}
583 
584 	if ((dmar->barrier_flags & f_inproc) != 0) {
585 		while ((dmar->barrier_flags & f_inproc) != 0) {
586 			dmar->barrier_flags |= f_wakeup;
587 			msleep(&dmar->barrier_flags, &dmar->lock, 0,
588 			    "dmarb", 0);
589 		}
590 		KASSERT((dmar->barrier_flags & f_done) != 0,
591 		    ("dmar%d barrier %d missing done", dmar->unit, barrier_id));
592 		DMAR_UNLOCK(dmar);
593 		return (false);
594 	}
595 
596 	dmar->barrier_flags |= f_inproc;
597 	DMAR_UNLOCK(dmar);
598 	return (true);
599 }
600 
601 void
602 dmar_barrier_exit(struct dmar_unit *dmar, u_int barrier_id)
603 {
604 	BARRIER_F;
605 
606 	DMAR_ASSERT_LOCKED(dmar);
607 	KASSERT((dmar->barrier_flags & (f_done | f_inproc)) == f_inproc,
608 	    ("dmar%d barrier %d missed entry", dmar->unit, barrier_id));
609 	dmar->barrier_flags |= f_done;
610 	if ((dmar->barrier_flags & f_wakeup) != 0)
611 		wakeup(&dmar->barrier_flags);
612 	dmar->barrier_flags &= ~(f_inproc | f_wakeup);
613 	DMAR_UNLOCK(dmar);
614 }
615 
616 int dmar_match_verbose;
617 int dmar_batch_coalesce = 100;
618 struct timespec dmar_hw_timeout = {
619 	.tv_sec = 0,
620 	.tv_nsec = 1000000
621 };
622 
623 static const uint64_t d = 1000000000;
624 
625 void
626 dmar_update_timeout(uint64_t newval)
627 {
628 
629 	/* XXXKIB not atomic */
630 	dmar_hw_timeout.tv_sec = newval / d;
631 	dmar_hw_timeout.tv_nsec = newval % d;
632 }
633 
634 uint64_t
635 dmar_get_timeout(void)
636 {
637 
638 	return ((uint64_t)dmar_hw_timeout.tv_sec * d +
639 	    dmar_hw_timeout.tv_nsec);
640 }
641 
642 static int
643 dmar_timeout_sysctl(SYSCTL_HANDLER_ARGS)
644 {
645 	uint64_t val;
646 	int error;
647 
648 	val = dmar_get_timeout();
649 	error = sysctl_handle_long(oidp, &val, 0, req);
650 	if (error != 0 || req->newptr == NULL)
651 		return (error);
652 	dmar_update_timeout(val);
653 	return (error);
654 }
655 
656 static SYSCTL_NODE(_hw, OID_AUTO, dmar, CTLFLAG_RD, NULL, "");
657 SYSCTL_INT(_hw_dmar, OID_AUTO, tbl_pagecnt, CTLFLAG_RD,
658     &dmar_tbl_pagecnt, 0,
659     "Count of pages used for DMAR pagetables");
660 SYSCTL_INT(_hw_dmar, OID_AUTO, match_verbose, CTLFLAG_RWTUN,
661     &dmar_match_verbose, 0,
662     "Verbose matching of the PCI devices to DMAR paths");
663 SYSCTL_INT(_hw_dmar, OID_AUTO, batch_coalesce, CTLFLAG_RWTUN,
664     &dmar_batch_coalesce, 0,
665     "Number of qi batches between interrupt");
666 SYSCTL_PROC(_hw_dmar, OID_AUTO, timeout,
667     CTLTYPE_U64 | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
668     dmar_timeout_sysctl, "QU",
669     "Timeout for command wait, in nanoseconds");
670 #ifdef INVARIANTS
671 int dmar_check_free;
672 SYSCTL_INT(_hw_dmar, OID_AUTO, check_free, CTLFLAG_RWTUN,
673     &dmar_check_free, 0,
674     "Check the GPA RBtree for free_down and free_after validity");
675 #endif
676 
677