xref: /titanic_51/usr/src/uts/common/vm/hat.h (revision 4944b02ebdb42bbb8031cd6158822d445f03f9de)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #ifndef	_VM_HAT_H
41 #define	_VM_HAT_H
42 
43 #pragma ident	"%Z%%M%	%I%	%E% SMI"
44 
45 #include <sys/types.h>
46 #include <sys/t_lock.h>
47 #include <vm/faultcode.h>
48 #include <sys/kstat.h>
49 #include <sys/siginfo.h>
50 
51 #ifdef	__cplusplus
52 extern "C" {
53 #endif
54 
55 /*
56  * VM - Hardware Address Translation management.
57  *
58  * This file describes the machine independent interfaces to
59  * the hardware address translation management routines.  Other
60  * machine specific interfaces and structures are defined
61  * in <vm/hat_xxx.h>.  The hat layer manages the address
62  * translation hardware as a cache driven by calls from the
63  * higher levels of the VM system.
64  */
65 
66 struct hat;
67 struct kpme;
68 struct memseg;
69 
70 #include <vm/page.h>
71 
72 /*
73  * a callback used with hat_unload_callback()
74  * start and end mark are set to a range of unloaded addresses
75  * and the function is invoked with a pointer to this data structure
76  */
77 typedef struct hat_callback {
78 	caddr_t	hcb_start_addr;
79 	caddr_t hcb_end_addr;
80 	void	(*hcb_function)(struct hat_callback *);
81 	void	*hcb_data;
82 } hat_callback_t;
83 
84 #ifdef	_KERNEL
85 
86 /*
87  * One time hat initialization
88  */
89 void	hat_init(void);
90 
91 /*
92  * Notify hat of a system dump
93  */
94 void	hat_dump(void);
95 
96 /*
97  * Operations on an address space:
98  *
99  * struct hat *hat_alloc(as)
100  *	allocated a hat structure for as.
101  *
102  * void hat_free_start(hat)
103  *	informs hat layer process has finished executing but as has not
104  *	been cleaned up yet.
105  *
106  * void hat_free_end(hat)
107  *	informs hat layer as is being destroyed.  hat layer cannot use as
108  *	pointer after this call.
109  *
110  * void hat_swapin(hat)
111  *	allocate any hat resources required for process being swapped in.
112  *
113  * void hat_swapout(hat)
114  *	deallocate hat resources for process being swapped out.
115  *
116  * size_t hat_get_mapped_size(hat)
117  *	returns number of bytes that have valid mappings in hat.
118  *
119  * void hat_stats_enable(hat)
120  * void hat_stats_disable(hat)
121  *	enables/disables collection of stats for hat.
122  *
123  * int hat_dup(parenthat, childhat, addr, len, flags)
124  *	Duplicate address translations of the parent to the child.  Supports
125  *	the entire address range or a range depending on flag,
126  *	zero returned on success, non-zero on error
127  *
128  * void hat_thread_exit(thread)
129  *	Notifies the HAT that a thread is exiting, called after it has been
130  *	reassigned to the kernel AS.
131  */
132 
133 struct hat *hat_alloc(struct as *);
134 void	hat_free_start(struct hat *);
135 void	hat_free_end(struct hat *);
136 int	hat_dup(struct hat *, struct hat *, caddr_t, size_t, uint_t);
137 void	hat_swapin(struct hat *);
138 void	hat_swapout(struct hat *);
139 size_t	hat_get_mapped_size(struct hat *);
140 int	hat_stats_enable(struct hat *);
141 void	hat_stats_disable(struct hat *);
142 void	hat_thread_exit(kthread_t *);
143 
144 /*
145  * Operations on a named address within a segment:
146  *
147  * void hat_memload(hat, addr, pp, attr, flags)
148  *	load/lock the given page struct
149  *
150  * void hat_memload_array(hat, addr, len, ppa, attr, flags)
151  *	load/lock the given array of page structs
152  *
153  * void hat_devload(hat, addr, len, pf, attr, flags)
154  *	load/lock the given page frame number
155  *
156  * void hat_unlock(hat, addr, len)
157  *	unlock a given range of addresses
158  *
159  * void hat_unload(hat, addr, len, flags)
160  * void hat_unload_callback(hat, addr, len, flags, callback)
161  *	unload a given range of addresses (has optional callback)
162  *
163  * void hat_sync(hat, addr, len, flags)
164  *	synchronize mapping with software data structures
165  *
166  * void	hat_map(hat, addr, len, flags)
167  *
168  * void hat_setattr(hat, addr, len, attr)
169  * void hat_clrattr(hat, addr, len, attr)
170  * void hat_chgattr(hat, addr, len, attr)
171  *	modify attributes for a range of addresses. skips any invalid mappings
172  *
173  * uint_t hat_getattr(hat, addr, *attr)
174  *	returns attr for <hat,addr> in *attr.  returns 0 if there was a
175  *	mapping and *attr is valid, nonzero if there was no mapping and
176  *	*attr is not valid.
177  *
178  * size_t hat_getpagesize(hat, addr)
179  *	returns pagesize in bytes for <hat, addr>. returns -1 if there is
180  *	no mapping. This is an advisory call.
181  *
182  * pfn_t hat_getpfnum(hat, addr)
183  *	returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
184  *
185  * pfn_t hat_getkpfnum(addr)
186  *	returns pfn for non-memory mapped addr in kernel address space
187  *	or PFN_INVALID if mapping is invalid or is kernel memory.
188  *
189  * int hat_probe(hat, addr)
190  *	return 0 if no valid mapping is present.  Faster version
191  *	of hat_getattr in certain architectures.
192  *
193  * int hat_share(dhat, daddr, shat, saddr, len, szc)
194  *
195  * void hat_unshare(hat, addr, len, szc)
196  *
197  * void hat_chgprot(hat, addr, len, vprot)
198  *	This is a deprecated call.  New segment drivers should store
199  *	all attributes and use hat_*attr calls.
200  *	Change the protections in the virtual address range
201  *	given to the specified virtual protection.  If vprot is ~PROT_WRITE,
202  *	then remove write permission, leaving the other permissions
203  *	unchanged.  If vprot is ~PROT_USER, remove user permissions.
204  */
205 
206 void	hat_memload(struct hat *, caddr_t, struct page *, uint_t, uint_t);
207 void	hat_memload_array(struct hat *, caddr_t, size_t, struct page **,
208 		uint_t, uint_t);
209 
210 void	hat_devload(struct hat *, caddr_t, size_t, pfn_t, uint_t, int);
211 void	hat_unlock(struct hat *, caddr_t, size_t);
212 void	hat_unload(struct hat *, caddr_t, size_t, uint_t);
213 void	hat_unload_callback(struct hat *, caddr_t, size_t, uint_t,
214 		hat_callback_t *);
215 void	hat_sync(struct hat *, caddr_t, size_t, uint_t);
216 void	hat_map(struct hat *, caddr_t, size_t, uint_t);
217 void	hat_setattr(struct hat *, caddr_t, size_t, uint_t);
218 void	hat_clrattr(struct hat *, caddr_t, size_t, uint_t);
219 void	hat_chgattr(struct hat *, caddr_t, size_t, uint_t);
220 uint_t	hat_getattr(struct hat *, caddr_t, uint_t *);
221 ssize_t	hat_getpagesize(struct hat *, caddr_t);
222 pfn_t	hat_getpfnum(struct hat *, caddr_t);
223 int	hat_probe(struct hat *, caddr_t);
224 int	hat_share(struct hat *, caddr_t, struct hat *, caddr_t, size_t, uint_t);
225 void	hat_unshare(struct hat *, caddr_t, size_t, uint_t);
226 void	hat_chgprot(struct hat *, caddr_t, size_t, uint_t);
227 void	hat_reserve(struct as *, caddr_t, size_t);
228 pfn_t	va_to_pfn(void *);
229 uint64_t va_to_pa(void *);
230 
231 /*
232  * hat_getkpfnum() is never supported on amd64 and will be
233  * removed from other platforms in future release
234  */
235 #if !defined(__amd64)
236 pfn_t	hat_getkpfnum(caddr_t);
237 #endif
238 
239 
240 /*
241  * Kernel Physical Mapping (segkpm) hat interface routines.
242  */
243 caddr_t	hat_kpm_mapin(struct page *, struct kpme *);
244 void	hat_kpm_mapout(struct page *, struct kpme *, caddr_t);
245 caddr_t	hat_kpm_page2va(struct page *, int);
246 struct page *hat_kpm_vaddr2page(caddr_t);
247 int	hat_kpm_fault(struct hat *, caddr_t);
248 void	hat_kpm_mseghash_clear(int);
249 void	hat_kpm_mseghash_update(pgcnt_t, struct memseg *);
250 void	hat_kpm_addmem_mseg_update(struct memseg *, pgcnt_t, offset_t);
251 void	hat_kpm_addmem_mseg_insert(struct memseg *);
252 void	hat_kpm_addmem_memsegs_update(struct memseg *);
253 caddr_t hat_kpm_mseg_reuse(struct memseg *);
254 void	hat_kpm_delmem_mseg_update(struct memseg *, struct memseg **);
255 void	hat_kpm_split_mseg_update(struct memseg *, struct memseg **,
256 			struct memseg *, struct memseg *, struct memseg *);
257 void	hat_kpm_walk(void (*)(void *, void *, size_t), void *);
258 
259 /*
260  * Operations on all translations for a given page(s)
261  *
262  * void hat_page_setattr(pp, flag)
263  * void hat_page_clrattr(pp, flag)
264  *	used to set/clr red/mod bits.
265  *
266  * uint hat_page_getattr(pp, flag)
267  *	If flag is specified, returns 0 if attribute is disabled
268  *	and non zero if enabled.  If flag specifes multiple attributs
269  *	then returns 0 if ALL atriibutes are disabled.  This is an advisory
270  *	call.
271  *
272  * int hat_pageunload(pp, forceflag)
273  *	unload all translations attached to pp.
274  *
275  * uint_t hat_pagesync(pp, flags)
276  *	get hw stats from hardware into page struct and reset hw stats
277  *	returns attributes of page
278  *
279  * ulong_t hat_page_getshare(pp)
280  *	returns approx number of mappings to this pp.  A return of 0 implies
281  *	there are no mappings to the page.
282  *
283  * faultcode_t hat_softlock(hat, addr, lenp, ppp, flags);
284  *	called to softlock pages for zero copy tcp
285  *
286  * void hat_page_demote(pp);
287  *	unload all large mappings to pp and decrease p_szc of all
288  *	constituent pages according to the remaining mappings.
289  */
290 
291 void	hat_page_setattr(struct page *, uint_t);
292 void	hat_page_clrattr(struct page *, uint_t);
293 uint_t	hat_page_getattr(struct page *, uint_t);
294 int	hat_pageunload(struct page *, uint_t);
295 uint_t	hat_pagesync(struct page *, uint_t);
296 ulong_t	hat_page_getshare(struct page *);
297 faultcode_t hat_softlock(struct hat *, caddr_t, size_t *,
298 			struct page **, uint_t);
299 void	hat_page_demote(struct page *);
300 
301 /*
302  * Rountine to expose supported HAT features to PIM.
303  */
304 enum hat_features {
305 	HAT_SHARED_PT,		/* Shared page tables */
306 	HAT_DYNAMIC_ISM_UNMAP,	/* hat_pageunload() handles ISM pages */
307 	HAT_VMODSORT		/* support for VMODSORT flag of vnode */
308 };
309 
310 int hat_supported(enum hat_features, void *);
311 
312 /*
313  * Services provided to the hat:
314  *
315  * void as_signal_proc(as, siginfo)
316  *	deliver signal to all processes that have this as.
317  *
318  * int hat_setstat(as, addr, len, rmbits)
319  *	informs hatstat layer that ref/mod bits need to be updated for
320  *	address range. Returns 0 on success, 1 for failure.
321  */
322 void	as_signal_proc(struct as *, k_siginfo_t *siginfo);
323 void	hat_setstat(struct as *, caddr_t, size_t, uint_t);
324 
325 /*
326  * Flags to pass to hat routines.
327  *
328  * Certain flags only apply to some interfaces:
329  *
330  * 	HAT_LOAD	Default flags to load a translation to the page.
331  * 	HAT_LOAD_LOCK	Lock down mapping resources; hat_map(), hat_memload(),
332  *			and hat_devload().
333  *	HAT_LOAD_ADV	Advisory load - Load translation if and only if
334  *			sufficient MMU resources exist (i.e., do not steal).
335  *	HAT_LOAD_SHARE	A flag to hat_memload() to indicate h/w page tables
336  *			that map some user pages (not kas) is shared by more
337  *			than one process (eg. ISM).
338  *	HAT_LOAD_CONTIG	Pages are contigous
339  *	HAT_LOAD_NOCONSIST Do not add mapping to mapping list.
340  *	HAT_LOAD_REMAP	Reload a valid pte with a different page frame.
341  *	HAT_RELOAD_SHARE Reload a shared page table entry. Some platforms
342  *			 may require different actions than on the first
343  *			 load of a shared mapping.
344  *	HAT_NO_KALLOC	Do not kmem_alloc while creating the mapping; at this
345  *			point, it's setting up mapping to allocate internal
346  *			hat layer data structures.  This flag forces hat layer
347  *			to tap its reserves in order to prevent infinite
348  *			recursion.
349  *	HAT_LOAD_AUTOLPG Get MMU specific disable_auto_large_pages
350  */
351 
352 /*
353  * Flags for hat_memload/hat_devload
354  */
355 #define	HAT_FLAGS_RESV		0xFF000000	/* resv for hat impl */
356 #define	HAT_LOAD		0x00
357 #define	HAT_LOAD_LOCK		0x01
358 #define	HAT_LOAD_ADV		0x04
359 #define	HAT_LOAD_CONTIG		0x10
360 #define	HAT_LOAD_NOCONSIST	0x20
361 #define	HAT_LOAD_SHARE		0x40
362 #define	HAT_LOAD_REMAP		0x80
363 #define	HAT_RELOAD_SHARE	0x100
364 #define	HAT_NO_KALLOC		0x200
365 #define	HAT_LOAD_TEXT		0x400
366 #define	HAT_LOAD_AUTOLPG	0x800
367 
368 /*
369  * Attributes for hat_memload/hat_devload/hat_*attr
370  * are a superset of prot flags defined in mman.h.
371  */
372 #define	HAT_PLAT_ATTR_MASK	0xF00000
373 #define	HAT_PROT_MASK		0x0F
374 
375 #define	HAT_NOFAULT		0x10
376 #define	HAT_NOSYNC		0x20
377 
378 /*
379  * Advisory ordering attributes. Apply only to device mappings.
380  *
381  * HAT_STRICTORDER: the CPU must issue the references in order, as the
382  *	programmer specified.  This is the default.
383  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
384  *	of reordering; store or load with store or load).
385  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
386  *	to consecutive locations (for example, turn two consecutive byte
387  *	stores into one halfword store), and it may batch individual loads
388  *	(for example, turn two consecutive byte loads into one halfword load).
389  *	This also implies re-ordering.
390  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
391  *	until another store occurs.  The default is to fetch new data
392  *	on every load.  This also implies merging.
393  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
394  *	the device (perhaps with other data) at a later time.  The default is
395  *	to push the data right away.  This also implies load caching.
396  */
397 #define	HAT_STRICTORDER		0x0000
398 #define	HAT_UNORDERED_OK	0x0100
399 #define	HAT_MERGING_OK		0x0200
400 #define	HAT_LOADCACHING_OK	0x0300
401 #define	HAT_STORECACHING_OK	0x0400
402 #define	HAT_ORDER_MASK		0x0700
403 
404 /* endian attributes */
405 #define	HAT_NEVERSWAP		0x0000
406 #define	HAT_STRUCTURE_BE	0x1000
407 #define	HAT_STRUCTURE_LE	0x2000
408 #define	HAT_ENDIAN_MASK		0x3000
409 
410 /* flags for hat_softlock */
411 #define	HAT_COW			0x0001
412 
413 /*
414  * Flags for hat_unload
415  */
416 #define	HAT_UNLOAD		0x00
417 #define	HAT_UNLOAD_NOSYNC	0x02
418 #define	HAT_UNLOAD_UNLOCK	0x04
419 #define	HAT_UNLOAD_OTHER	0x08
420 #define	HAT_UNLOAD_UNMAP	0x10
421 
422 /*
423  * Flags for hat_pagesync, hat_getstat, hat_sync
424  */
425 #define	HAT_SYNC_DONTZERO	0x00
426 #define	HAT_SYNC_ZERORM		0x01
427 /* Additional flags for hat_pagesync */
428 #define	HAT_SYNC_STOPON_REF	0x02
429 #define	HAT_SYNC_STOPON_MOD	0x04
430 #define	HAT_SYNC_STOPON_RM	(HAT_SYNC_STOPON_REF | HAT_SYNC_STOPON_MOD)
431 #define	HAT_SYNC_STOPON_SHARED	0x08
432 
433 /*
434  * Flags for hat_dup
435  *
436  * HAT_DUP_ALL dup entire address space
437  * HAT_DUP_COW dup plus hat_clrattr(..PROT_WRITE) on newas
438  */
439 #define	HAT_DUP_ALL		1
440 #define	HAT_DUP_COW		2
441 
442 
443 /*
444  * Flags for hat_map
445  */
446 #define	HAT_MAP			0x00
447 
448 /*
449  * Flag for hat_pageunload
450  */
451 #define	HAT_ADV_PGUNLOAD	0x00
452 #define	HAT_FORCE_PGUNLOAD	0x01
453 
454 /*
455  * Attributes for hat_page_*attr, hat_setstats and
456  * returned by hat_pagesync.
457  */
458 #define	P_MOD	0x1		/* the modified bit */
459 #define	P_REF	0x2		/* the referenced bit */
460 #define	P_RO	0x4		/* Read only page */
461 
462 #define	hat_ismod(pp)		(hat_page_getattr(pp, P_MOD))
463 #define	hat_isref(pp)		(hat_page_getattr(pp, P_REF))
464 #define	hat_isro(pp)		(hat_page_getattr(pp, P_RO))
465 
466 #define	hat_setmod(pp)		(hat_page_setattr(pp, P_MOD))
467 #define	hat_setref(pp)		(hat_page_setattr(pp, P_REF))
468 #define	hat_setrefmod(pp)	(hat_page_setattr(pp, P_REF|P_MOD))
469 
470 #define	hat_clrmod(pp)		(hat_page_clrattr(pp, P_MOD))
471 #define	hat_clrref(pp)		(hat_page_clrattr(pp, P_REF))
472 #define	hat_clrrefmod(pp)	(hat_page_clrattr(pp, P_REF|P_MOD))
473 
474 #define	hat_page_is_mapped(pp)	(hat_page_getshare(pp))
475 
476 /*
477  * hat_setup is being used in sparc/os/sundep.c
478  */
479 void	hat_setup(struct hat *, int);
480 
481 /*
482  * Flags for hat_setup
483  */
484 #define	HAT_DONTALLOC		0
485 #define	HAT_ALLOC		1
486 #define	HAT_INIT		2
487 
488 /*
489  * Other routines, for statistics
490  */
491 int	hat_startstat(struct as *);
492 void	hat_getstat(struct as *, caddr_t, size_t, uint_t, char *, int);
493 void	hat_freestat(struct as *, int);
494 void	hat_resvstat(size_t, struct as *, caddr_t);
495 
496 /*
497  * Transitionary routine while we still allow hat_getkpfnum(caddr_t)
498  * to return a pfn for kernel memory, but want to warn the user that
499  * it isn't supported.
500  */
501 void	hat_getkpfnum_badcall(void *caller);
502 
503 /*
504  * Relocation callback routines. Currently only sfmmu HAT supports
505  * these.
506  */
507 extern int	hat_add_callback(id_t, caddr_t, uint_t, uint_t, void *,
508 	pfn_t *);
509 extern id_t	hat_register_callback(int,
510 	int (*prehandler)(caddr_t, uint_t, uint_t, void *),
511 	int (*posthandler)(caddr_t, uint_t, uint_t, void *, pfn_t),
512 	int (*errhandler)(caddr_t, uint_t, uint_t, void *), int);
513 extern void	hat_delete_callback(caddr_t, uint_t, void *, uint_t);
514 
515 /*
516  * hat_add_callback()/hat_delete_callback() flags.
517  */
518 #define	HAC_NOSLEEP	0x0
519 #define	HAC_SLEEP	0x1
520 #define	HAC_PAGELOCK	0x2
521 
522 /*
523  * Suspend/unsuspend handler callback arguments.
524  */
525 #define	HAT_SUSPEND		0x0010
526 #define	HAT_UNSUSPEND		0x0010
527 #define	HAT_PRESUSPEND		0x0020
528 #define	HAT_POSTUNSUSPEND	0x0020
529 
530 /*
531  * Error handler callback arguments. See the block comments
532  * before the implementation of hat_add_callback() for an
533  * explanation of what these mean.
534  */
535 #define	HAT_CB_ERR_LEAKED	0x1
536 
537 #endif /* _KERNEL */
538 
539 /*
540  * The size of the bit array for ref and mod bit storage must be a power of 2.
541  * 2 bits are collected for each page.  Below the power used is 4,
542  * which is 16 8-bit characters = 128 bits, ref and mod bit information
543  * for 64 pages.
544  */
545 #define	HRM_SHIFT		4
546 #define	HRM_BYTES		(1 << HRM_SHIFT)
547 #define	HRM_PAGES		((HRM_BYTES * NBBY) / 2)
548 #define	HRM_PGPERBYTE		(NBBY/2)
549 #define	HRM_PGBYTEMASK		(HRM_PGPERBYTE-1)
550 
551 #define	HRM_PGOFFMASK		((HRM_PGPERBYTE-1) << MMU_PAGESHIFT)
552 #define	HRM_BASEOFFSET		(((MMU_PAGESIZE * HRM_PAGES) - 1))
553 #define	HRM_BASEMASK		(~(HRM_BASEOFFSET))
554 
555 #define	HRM_BASESHIFT		(MMU_PAGESHIFT + (HRM_SHIFT + 2))
556 #define	HRM_PAGEMASK		(MMU_PAGEMASK ^ HRM_BASEMASK)
557 
558 #define	HRM_HASHSIZE		0x200
559 #define	HRM_HASHMASK		(HRM_HASHSIZE - 1)
560 
561 #define	HRM_BLIST_INCR		0x200
562 
563 /*
564  * The structure for maintaining referenced and modified information
565  */
566 struct hrmstat {
567 	struct as	*hrm_as;	/* stat block belongs to this as */
568 	uintptr_t	hrm_base;	/* base of block */
569 	ushort_t	hrm_id;		/* opaque identifier, one of a_vbits */
570 	struct hrmstat	*hrm_anext;	/* as statistics block list */
571 	struct hrmstat	*hrm_hnext;	/* list for hashed blocks */
572 	uchar_t		hrm_bits[HRM_BYTES]; /* the ref and mod bits */
573 };
574 
575 /*
576  * For global monitoring of the reference and modified bits
577  * of all address spaces we reserve one id bit.
578  */
579 #define	HRM_SWSMONID	1
580 
581 
582 #ifdef _KERNEL
583 
584 /*
585  * Hat locking functions
586  * XXX - these two functions are currently being used by hatstats
587  * 	they can be removed by using a per-as mutex for hatstats.
588  */
589 void	hat_enter(struct hat *);
590 void	hat_exit(struct hat *);
591 
592 #endif /* _KERNEL */
593 
594 #ifdef	__cplusplus
595 }
596 #endif
597 
598 #endif	/* _VM_HAT_H */
599