xref: /freebsd/sys/x86/iommu/intel_dmar.h (revision 86c9d9918f1db7cdd968b60f8902466887bcd9e9)
1 /*-
2  * Copyright (c) 2013-2015 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  * $FreeBSD$
30  */
31 
32 #ifndef __X86_IOMMU_INTEL_DMAR_H
33 #define	__X86_IOMMU_INTEL_DMAR_H
34 
35 /* Host or physical memory address, after translation. */
36 typedef uint64_t dmar_haddr_t;
37 /* Guest or bus address, before translation. */
38 typedef uint64_t dmar_gaddr_t;
39 
40 struct dmar_qi_genseq {
41 	u_int gen;
42 	uint32_t seq;
43 };
44 
45 struct dmar_map_entry {
46 	dmar_gaddr_t start;
47 	dmar_gaddr_t end;
48 	dmar_gaddr_t free_after;	/* Free space after the entry */
49 	dmar_gaddr_t free_down;		/* Max free space below the
50 					   current R/B tree node */
51 	u_int flags;
52 	TAILQ_ENTRY(dmar_map_entry) dmamap_link; /* Link for dmamap entries */
53 	RB_ENTRY(dmar_map_entry) rb_entry;	 /* Links for domain entries */
54 	TAILQ_ENTRY(dmar_map_entry) unroll_link; /* Link for unroll after
55 						    dmamap_load failure */
56 	struct dmar_domain *domain;
57 	struct dmar_qi_genseq gseq;
58 };
59 
60 RB_HEAD(dmar_gas_entries_tree, dmar_map_entry);
61 RB_PROTOTYPE(dmar_gas_entries_tree, dmar_map_entry, rb_entry,
62     dmar_gas_cmp_entries);
63 
64 #define	DMAR_MAP_ENTRY_PLACE	0x0001	/* Fake entry */
65 #define	DMAR_MAP_ENTRY_RMRR	0x0002	/* Permanent, not linked by
66 					   dmamap_link */
67 #define	DMAR_MAP_ENTRY_MAP	0x0004	/* Busdma created, linked by
68 					   dmamap_link */
69 #define	DMAR_MAP_ENTRY_UNMAPPED	0x0010	/* No backing pages */
70 #define	DMAR_MAP_ENTRY_QI_NF	0x0020	/* qi task, do not free entry */
71 #define	DMAR_MAP_ENTRY_READ	0x1000	/* Read permitted */
72 #define	DMAR_MAP_ENTRY_WRITE	0x2000	/* Write permitted */
73 #define	DMAR_MAP_ENTRY_SNOOP	0x4000	/* Snoop */
74 #define	DMAR_MAP_ENTRY_TM	0x8000	/* Transient */
75 
76 /*
77  * Locking annotations:
78  * (u) - Protected by dmar unit lock
79  * (d) - Protected by domain lock
80  * (c) - Immutable after initialization
81  */
82 
83 /*
84  * The domain abstraction.  Most non-constant members of the domain
85  * are locked by the owning dmar unit lock, not by the domain lock.
86  * Most important, dmar lock protects the contexts list.
87  *
88  * The domain lock protects the address map for the domain, and list
89  * of unload entries delayed.
90  *
91  * Page tables pages and pages content is protected by the vm object
92  * lock pgtbl_obj, which contains the page tables pages.
93  */
94 struct dmar_domain {
95 	int domain;			/* (c) DID, written in context entry */
96 	int mgaw;			/* (c) Real max address width */
97 	int agaw;			/* (c) Adjusted guest address width */
98 	int pglvl;			/* (c) The pagelevel */
99 	int awlvl;			/* (c) The pagelevel as the bitmask,
100 					   to set in context entry */
101 	dmar_gaddr_t end;		/* (c) Highest address + 1 in
102 					   the guest AS */
103 	u_int ctx_cnt;			/* (u) Number of contexts owned */
104 	u_int refs;			/* (u) Refs, including ctx */
105 	struct dmar_unit *dmar;		/* (c) */
106 	struct mtx lock;		/* (c) */
107 	LIST_ENTRY(dmar_domain) link;	/* (u) Member in the dmar list */
108 	LIST_HEAD(, dmar_ctx) contexts;	/* (u) */
109 	vm_object_t pgtbl_obj;		/* (c) Page table pages */
110 	u_int flags;			/* (u) */
111 	u_int entries_cnt;		/* (d) */
112 	struct dmar_gas_entries_tree rb_root; /* (d) */
113 	struct dmar_map_entries_tailq unload_entries; /* (d) Entries to
114 							 unload */
115 	struct dmar_map_entry *first_place, *last_place; /* (d) */
116 	struct task unload_task;	/* (c) */
117 	u_int batch_no;
118 };
119 
120 struct dmar_ctx {
121 	struct bus_dma_tag_dmar ctx_tag; /* (c) Root tag */
122 	uint16_t rid;			/* (c) pci RID */
123 	uint64_t last_fault_rec[2];	/* Last fault reported */
124 	struct dmar_domain *domain;	/* (c) */
125 	LIST_ENTRY(dmar_ctx) link;	/* (u) Member in the domain list */
126 	u_int refs;			/* (u) References from tags */
127 	u_int flags;			/* (u) */
128 	u_long loads;			/* atomic updates, for stat only */
129 	u_long unloads;			/* same */
130 };
131 
132 #define	DMAR_DOMAIN_GAS_INITED		0x0001
133 #define	DMAR_DOMAIN_PGTBL_INITED	0x0002
134 #define	DMAR_DOMAIN_IDMAP		0x0010	/* Domain uses identity
135 						   page table */
136 #define	DMAR_DOMAIN_RMRR		0x0020	/* Domain contains RMRR entry,
137 						   cannot be turned off */
138 
139 /* struct dmar_ctx flags */
140 #define	DMAR_CTX_FAULTED	0x0001	/* Fault was reported,
141 					   last_fault_rec is valid */
142 #define	DMAR_CTX_DISABLED	0x0002	/* Device is disabled, the
143 					   ephemeral reference is kept
144 					   to prevent context destruction */
145 
146 #define	DMAR_DOMAIN_PGLOCK(dom)		VM_OBJECT_WLOCK((dom)->pgtbl_obj)
147 #define	DMAR_DOMAIN_PGTRYLOCK(dom)	VM_OBJECT_TRYWLOCK((dom)->pgtbl_obj)
148 #define	DMAR_DOMAIN_PGUNLOCK(dom)	VM_OBJECT_WUNLOCK((dom)->pgtbl_obj)
149 #define	DMAR_DOMAIN_ASSERT_PGLOCKED(dom) \
150 	VM_OBJECT_ASSERT_WLOCKED((dom)->pgtbl_obj)
151 
152 #define	DMAR_DOMAIN_LOCK(dom)	mtx_lock(&(dom)->lock)
153 #define	DMAR_DOMAIN_UNLOCK(dom)	mtx_unlock(&(dom)->lock)
154 #define	DMAR_DOMAIN_ASSERT_LOCKED(dom) mtx_assert(&(dom)->lock, MA_OWNED)
155 
156 struct dmar_msi_data {
157 	int irq;
158 	int irq_rid;
159 	struct resource *irq_res;
160 	void *intr_handle;
161 	int (*handler)(void *);
162 	int msi_data_reg;
163 	int msi_addr_reg;
164 	int msi_uaddr_reg;
165 	void (*enable_intr)(struct dmar_unit *);
166 	void (*disable_intr)(struct dmar_unit *);
167 	const char *name;
168 };
169 
170 #define	DMAR_INTR_FAULT		0
171 #define	DMAR_INTR_QI		1
172 #define	DMAR_INTR_TOTAL		2
173 
174 struct dmar_unit {
175 	device_t dev;
176 	int unit;
177 	uint16_t segment;
178 	uint64_t base;
179 
180 	/* Resources */
181 	int reg_rid;
182 	struct resource *regs;
183 
184 	struct dmar_msi_data intrs[DMAR_INTR_TOTAL];
185 
186 	/* Hardware registers cache */
187 	uint32_t hw_ver;
188 	uint64_t hw_cap;
189 	uint64_t hw_ecap;
190 	uint32_t hw_gcmd;
191 
192 	/* Data for being a dmar */
193 	struct mtx lock;
194 	LIST_HEAD(, dmar_domain) domains;
195 	struct unrhdr *domids;
196 	vm_object_t ctx_obj;
197 	u_int barrier_flags;
198 
199 	/* Fault handler data */
200 	struct mtx fault_lock;
201 	uint64_t *fault_log;
202 	int fault_log_head;
203 	int fault_log_tail;
204 	int fault_log_size;
205 	struct task fault_task;
206 	struct taskqueue *fault_taskqueue;
207 
208 	/* QI */
209 	int qi_enabled;
210 	vm_offset_t inv_queue;
211 	vm_size_t inv_queue_size;
212 	uint32_t inv_queue_avail;
213 	uint32_t inv_queue_tail;
214 	volatile uint32_t inv_waitd_seq_hw; /* hw writes there on wait
215 					       descr completion */
216 	uint64_t inv_waitd_seq_hw_phys;
217 	uint32_t inv_waitd_seq; /* next sequence number to use for wait descr */
218 	u_int inv_waitd_gen;	/* seq number generation AKA seq overflows */
219 	u_int inv_seq_waiters;	/* count of waiters for seq */
220 	u_int inv_queue_full;	/* informational counter */
221 
222 	/* IR */
223 	int ir_enabled;
224 	vm_paddr_t irt_phys;
225 	dmar_irte_t *irt;
226 	u_int irte_cnt;
227 	vmem_t *irtids;
228 
229 	/* Delayed freeing of map entries queue processing */
230 	struct dmar_map_entries_tailq tlb_flush_entries;
231 	struct task qi_task;
232 	struct taskqueue *qi_taskqueue;
233 
234 	/* Busdma delayed map load */
235 	struct task dmamap_load_task;
236 	TAILQ_HEAD(, bus_dmamap_dmar) delayed_maps;
237 	struct taskqueue *delayed_taskqueue;
238 
239 	int dma_enabled;
240 };
241 
242 #define	DMAR_LOCK(dmar)		mtx_lock(&(dmar)->lock)
243 #define	DMAR_UNLOCK(dmar)	mtx_unlock(&(dmar)->lock)
244 #define	DMAR_ASSERT_LOCKED(dmar) mtx_assert(&(dmar)->lock, MA_OWNED)
245 
246 #define	DMAR_FAULT_LOCK(dmar)	mtx_lock_spin(&(dmar)->fault_lock)
247 #define	DMAR_FAULT_UNLOCK(dmar)	mtx_unlock_spin(&(dmar)->fault_lock)
248 #define	DMAR_FAULT_ASSERT_LOCKED(dmar) mtx_assert(&(dmar)->fault_lock, MA_OWNED)
249 
250 #define	DMAR_IS_COHERENT(dmar)	(((dmar)->hw_ecap & DMAR_ECAP_C) != 0)
251 #define	DMAR_HAS_QI(dmar)	(((dmar)->hw_ecap & DMAR_ECAP_QI) != 0)
252 #define	DMAR_X2APIC(dmar) \
253 	(x2apic_mode && ((dmar)->hw_ecap & DMAR_ECAP_EIM) != 0)
254 
255 /* Barrier ids */
256 #define	DMAR_BARRIER_RMRR	0
257 #define	DMAR_BARRIER_USEQ	1
258 
259 struct dmar_unit *dmar_find(device_t dev);
260 struct dmar_unit *dmar_find_hpet(device_t dev, uint16_t *rid);
261 struct dmar_unit *dmar_find_ioapic(u_int apic_id, uint16_t *rid);
262 
263 u_int dmar_nd2mask(u_int nd);
264 bool dmar_pglvl_supported(struct dmar_unit *unit, int pglvl);
265 int domain_set_agaw(struct dmar_domain *domain, int mgaw);
266 int dmar_maxaddr2mgaw(struct dmar_unit *unit, dmar_gaddr_t maxaddr,
267     bool allow_less);
268 vm_pindex_t pglvl_max_pages(int pglvl);
269 int domain_is_sp_lvl(struct dmar_domain *domain, int lvl);
270 dmar_gaddr_t pglvl_page_size(int total_pglvl, int lvl);
271 dmar_gaddr_t domain_page_size(struct dmar_domain *domain, int lvl);
272 int calc_am(struct dmar_unit *unit, dmar_gaddr_t base, dmar_gaddr_t size,
273     dmar_gaddr_t *isizep);
274 struct vm_page *dmar_pgalloc(vm_object_t obj, vm_pindex_t idx, int flags);
275 void dmar_pgfree(vm_object_t obj, vm_pindex_t idx, int flags);
276 void *dmar_map_pgtbl(vm_object_t obj, vm_pindex_t idx, int flags,
277     struct sf_buf **sf);
278 void dmar_unmap_pgtbl(struct sf_buf *sf);
279 int dmar_load_root_entry_ptr(struct dmar_unit *unit);
280 int dmar_inv_ctx_glob(struct dmar_unit *unit);
281 int dmar_inv_iotlb_glob(struct dmar_unit *unit);
282 int dmar_flush_write_bufs(struct dmar_unit *unit);
283 void dmar_flush_pte_to_ram(struct dmar_unit *unit, dmar_pte_t *dst);
284 void dmar_flush_ctx_to_ram(struct dmar_unit *unit, dmar_ctx_entry_t *dst);
285 void dmar_flush_root_to_ram(struct dmar_unit *unit, dmar_root_entry_t *dst);
286 int dmar_enable_translation(struct dmar_unit *unit);
287 int dmar_disable_translation(struct dmar_unit *unit);
288 int dmar_load_irt_ptr(struct dmar_unit *unit);
289 int dmar_enable_ir(struct dmar_unit *unit);
290 int dmar_disable_ir(struct dmar_unit *unit);
291 bool dmar_barrier_enter(struct dmar_unit *dmar, u_int barrier_id);
292 void dmar_barrier_exit(struct dmar_unit *dmar, u_int barrier_id);
293 
294 int dmar_fault_intr(void *arg);
295 void dmar_enable_fault_intr(struct dmar_unit *unit);
296 void dmar_disable_fault_intr(struct dmar_unit *unit);
297 int dmar_init_fault_log(struct dmar_unit *unit);
298 void dmar_fini_fault_log(struct dmar_unit *unit);
299 
300 int dmar_qi_intr(void *arg);
301 void dmar_enable_qi_intr(struct dmar_unit *unit);
302 void dmar_disable_qi_intr(struct dmar_unit *unit);
303 int dmar_init_qi(struct dmar_unit *unit);
304 void dmar_fini_qi(struct dmar_unit *unit);
305 void dmar_qi_invalidate_locked(struct dmar_domain *domain, dmar_gaddr_t start,
306     dmar_gaddr_t size, struct dmar_qi_genseq *pseq);
307 void dmar_qi_invalidate_ctx_glob_locked(struct dmar_unit *unit);
308 void dmar_qi_invalidate_iotlb_glob_locked(struct dmar_unit *unit);
309 void dmar_qi_invalidate_iec_glob(struct dmar_unit *unit);
310 void dmar_qi_invalidate_iec(struct dmar_unit *unit, u_int start, u_int cnt);
311 
312 vm_object_t domain_get_idmap_pgtbl(struct dmar_domain *domain,
313     dmar_gaddr_t maxaddr);
314 void put_idmap_pgtbl(vm_object_t obj);
315 int domain_map_buf(struct dmar_domain *domain, dmar_gaddr_t base,
316     dmar_gaddr_t size, vm_page_t *ma, uint64_t pflags, int flags);
317 int domain_unmap_buf(struct dmar_domain *domain, dmar_gaddr_t base,
318     dmar_gaddr_t size, int flags);
319 void domain_flush_iotlb_sync(struct dmar_domain *domain, dmar_gaddr_t base,
320     dmar_gaddr_t size);
321 int domain_alloc_pgtbl(struct dmar_domain *domain);
322 void domain_free_pgtbl(struct dmar_domain *domain);
323 
324 struct dmar_ctx *dmar_instantiate_ctx(struct dmar_unit *dmar, device_t dev,
325     bool rmrr);
326 struct dmar_ctx *dmar_get_ctx_for_dev(struct dmar_unit *dmar, device_t dev,
327     uint16_t rid, bool id_mapped, bool rmrr_init);
328 int dmar_move_ctx_to_domain(struct dmar_domain *domain, struct dmar_ctx *ctx);
329 void dmar_free_ctx_locked(struct dmar_unit *dmar, struct dmar_ctx *ctx);
330 void dmar_free_ctx(struct dmar_ctx *ctx);
331 struct dmar_ctx *dmar_find_ctx_locked(struct dmar_unit *dmar, uint16_t rid);
332 void dmar_domain_unload_entry(struct dmar_map_entry *entry, bool free);
333 void dmar_domain_unload(struct dmar_domain *domain,
334     struct dmar_map_entries_tailq *entries, bool cansleep);
335 void dmar_domain_free_entry(struct dmar_map_entry *entry, bool free);
336 
337 int dmar_init_busdma(struct dmar_unit *unit);
338 void dmar_fini_busdma(struct dmar_unit *unit);
339 device_t dmar_get_requester(device_t dev, uint16_t *rid);
340 
341 void dmar_gas_init_domain(struct dmar_domain *domain);
342 void dmar_gas_fini_domain(struct dmar_domain *domain);
343 struct dmar_map_entry *dmar_gas_alloc_entry(struct dmar_domain *domain,
344     u_int flags);
345 void dmar_gas_free_entry(struct dmar_domain *domain,
346     struct dmar_map_entry *entry);
347 void dmar_gas_free_space(struct dmar_domain *domain,
348     struct dmar_map_entry *entry);
349 int dmar_gas_map(struct dmar_domain *domain,
350     const struct bus_dma_tag_common *common, dmar_gaddr_t size, int offset,
351     u_int eflags, u_int flags, vm_page_t *ma, struct dmar_map_entry **res);
352 void dmar_gas_free_region(struct dmar_domain *domain,
353     struct dmar_map_entry *entry);
354 int dmar_gas_map_region(struct dmar_domain *domain,
355     struct dmar_map_entry *entry, u_int eflags, u_int flags, vm_page_t *ma);
356 int dmar_gas_reserve_region(struct dmar_domain *domain, dmar_gaddr_t start,
357     dmar_gaddr_t end);
358 
359 void dmar_dev_parse_rmrr(struct dmar_domain *domain, device_t dev,
360     struct dmar_map_entries_tailq *rmrr_entries);
361 int dmar_instantiate_rmrr_ctxs(struct dmar_unit *dmar);
362 
363 void dmar_quirks_post_ident(struct dmar_unit *dmar);
364 void dmar_quirks_pre_use(struct dmar_unit *dmar);
365 
366 int dmar_init_irt(struct dmar_unit *unit);
367 void dmar_fini_irt(struct dmar_unit *unit);
368 
369 #define	DMAR_GM_CANWAIT	0x0001
370 #define	DMAR_GM_CANSPLIT 0x0002
371 
372 #define	DMAR_PGF_WAITOK	0x0001
373 #define	DMAR_PGF_ZERO	0x0002
374 #define	DMAR_PGF_ALLOC	0x0004
375 #define	DMAR_PGF_NOALLOC 0x0008
376 #define	DMAR_PGF_OBJL	0x0010
377 
378 extern dmar_haddr_t dmar_high;
379 extern int haw;
380 extern int dmar_tbl_pagecnt;
381 extern int dmar_match_verbose;
382 extern int dmar_batch_coalesce;
383 extern int dmar_check_free;
384 
385 static inline uint32_t
386 dmar_read4(const struct dmar_unit *unit, int reg)
387 {
388 
389 	return (bus_read_4(unit->regs, reg));
390 }
391 
392 static inline uint64_t
393 dmar_read8(const struct dmar_unit *unit, int reg)
394 {
395 #ifdef __i386__
396 	uint32_t high, low;
397 
398 	low = bus_read_4(unit->regs, reg);
399 	high = bus_read_4(unit->regs, reg + 4);
400 	return (low | ((uint64_t)high << 32));
401 #else
402 	return (bus_read_8(unit->regs, reg));
403 #endif
404 }
405 
406 static inline void
407 dmar_write4(const struct dmar_unit *unit, int reg, uint32_t val)
408 {
409 
410 	KASSERT(reg != DMAR_GCMD_REG || (val & DMAR_GCMD_TE) ==
411 	    (unit->hw_gcmd & DMAR_GCMD_TE),
412 	    ("dmar%d clearing TE 0x%08x 0x%08x", unit->unit,
413 	    unit->hw_gcmd, val));
414 	bus_write_4(unit->regs, reg, val);
415 }
416 
417 static inline void
418 dmar_write8(const struct dmar_unit *unit, int reg, uint64_t val)
419 {
420 
421 	KASSERT(reg != DMAR_GCMD_REG, ("8byte GCMD write"));
422 #ifdef __i386__
423 	uint32_t high, low;
424 
425 	low = val;
426 	high = val >> 32;
427 	bus_write_4(unit->regs, reg, low);
428 	bus_write_4(unit->regs, reg + 4, high);
429 #else
430 	bus_write_8(unit->regs, reg, val);
431 #endif
432 }
433 
434 /*
435  * dmar_pte_store and dmar_pte_clear ensure that on i386, 32bit writes
436  * are issued in the correct order.  For store, the lower word,
437  * containing the P or R and W bits, is set only after the high word
438  * is written.  For clear, the P bit is cleared first, then the high
439  * word is cleared.
440  *
441  * dmar_pte_update updates the pte.  For amd64, the update is atomic.
442  * For i386, it first disables the entry by clearing the word
443  * containing the P bit, and then defer to dmar_pte_store.  The locked
444  * cmpxchg8b is probably available on any machine having DMAR support,
445  * but interrupt translation table may be mapped uncached.
446  */
447 static inline void
448 dmar_pte_store1(volatile uint64_t *dst, uint64_t val)
449 {
450 #ifdef __i386__
451 	volatile uint32_t *p;
452 	uint32_t hi, lo;
453 
454 	hi = val >> 32;
455 	lo = val;
456 	p = (volatile uint32_t *)dst;
457 	*(p + 1) = hi;
458 	*p = lo;
459 #else
460 	*dst = val;
461 #endif
462 }
463 
464 static inline void
465 dmar_pte_store(volatile uint64_t *dst, uint64_t val)
466 {
467 
468 	KASSERT(*dst == 0, ("used pte %p oldval %jx newval %jx",
469 	    dst, (uintmax_t)*dst, (uintmax_t)val));
470 	dmar_pte_store1(dst, val);
471 }
472 
473 static inline void
474 dmar_pte_update(volatile uint64_t *dst, uint64_t val)
475 {
476 
477 #ifdef __i386__
478 	volatile uint32_t *p;
479 
480 	p = (volatile uint32_t *)dst;
481 	*p = 0;
482 #endif
483 	dmar_pte_store1(dst, val);
484 }
485 
486 static inline void
487 dmar_pte_clear(volatile uint64_t *dst)
488 {
489 #ifdef __i386__
490 	volatile uint32_t *p;
491 
492 	p = (volatile uint32_t *)dst;
493 	*p = 0;
494 	*(p + 1) = 0;
495 #else
496 	*dst = 0;
497 #endif
498 }
499 
500 static inline bool
501 dmar_test_boundary(dmar_gaddr_t start, dmar_gaddr_t size,
502     dmar_gaddr_t boundary)
503 {
504 
505 	if (boundary == 0)
506 		return (true);
507 	return (start + size <= ((start + boundary) & ~(boundary - 1)));
508 }
509 
510 #ifdef INVARIANTS
511 #define	TD_PREP_PINNED_ASSERT						\
512 	int old_td_pinned;						\
513 	old_td_pinned = curthread->td_pinned
514 #define	TD_PINNED_ASSERT						\
515 	KASSERT(curthread->td_pinned == old_td_pinned,			\
516 	    ("pin count leak: %d %d %s:%d", curthread->td_pinned,	\
517 	    old_td_pinned, __FILE__, __LINE__))
518 #else
519 #define	TD_PREP_PINNED_ASSERT
520 #define	TD_PINNED_ASSERT
521 #endif
522 
523 #endif
524