xref: /titanic_52/usr/src/uts/common/vm/hat.h (revision 24fe0b3bf671e123467ce1df0b67cadd3614c8e4)
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 (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
27 /*	  All Rights Reserved  	*/
28 
29 /*
30  * University Copyright- Copyright (c) 1982, 1986, 1988
31  * The Regents of the University of California
32  * All Rights Reserved
33  *
34  * University Acknowledgment- Portions of this document are derived from
35  * software developed by the University of California, Berkeley, and its
36  * contributors.
37  */
38 
39 #ifndef	_VM_HAT_H
40 #define	_VM_HAT_H
41 
42 #include <sys/types.h>
43 #include <sys/t_lock.h>
44 #include <vm/faultcode.h>
45 #include <sys/kstat.h>
46 #include <sys/siginfo.h>
47 
48 #ifdef	__cplusplus
49 extern "C" {
50 #endif
51 
52 /*
53  * VM - Hardware Address Translation management.
54  *
55  * This file describes the machine independent interfaces to
56  * the hardware address translation management routines.  Other
57  * machine specific interfaces and structures are defined
58  * in <vm/hat_xxx.h>.  The hat layer manages the address
59  * translation hardware as a cache driven by calls from the
60  * higher levels of the VM system.
61  */
62 
63 struct hat;
64 struct kpme;
65 struct memseg;
66 
67 #include <vm/page.h>
68 
69 /*
70  * a callback used with hat_unload_callback()
71  * start and end mark are set to a range of unloaded addresses
72  * and the function is invoked with a pointer to this data structure
73  */
74 typedef struct hat_callback {
75 	caddr_t	hcb_start_addr;
76 	caddr_t hcb_end_addr;
77 	void	(*hcb_function)(struct hat_callback *);
78 	void	*hcb_data;
79 } hat_callback_t;
80 
81 typedef void *hat_region_cookie_t;
82 
83 #ifdef	_KERNEL
84 
85 /*
86  * One time hat initialization
87  */
88 void	hat_init(void);
89 
90 /*
91  * Notify hat of a system dump
92  */
93 void	hat_dump(void);
94 
95 /*
96  * Operations on an address space:
97  *
98  * struct hat *hat_alloc(as)
99  *	allocated a hat structure for as.
100  *
101  * void hat_free_start(hat)
102  *	informs hat layer process has finished executing but as has not
103  *	been cleaned up yet.
104  *
105  * void hat_free_end(hat)
106  *	informs hat layer as is being destroyed.  hat layer cannot use as
107  *	pointer after this call.
108  *
109  * void hat_swapin(hat)
110  *	allocate any hat resources required for process being swapped in.
111  *
112  * void hat_swapout(hat)
113  *	deallocate hat resources for process being swapped out.
114  *
115  * size_t hat_get_mapped_size(hat)
116  *	returns number of bytes that have valid mappings in hat.
117  *
118  * void hat_stats_enable(hat)
119  * void hat_stats_disable(hat)
120  *	enables/disables collection of stats for hat.
121  *
122  * int hat_dup(parenthat, childhat, addr, len, flags)
123  *	Duplicate address translations of the parent to the child.  Supports
124  *	the entire address range or a range depending on flag,
125  *	zero returned on success, non-zero on error
126  *
127  * void hat_thread_exit(thread)
128  *	Notifies the HAT that a thread is exiting, called after it has been
129  *	reassigned to the kernel AS.
130  */
131 
132 struct hat *hat_alloc(struct as *);
133 void	hat_free_start(struct hat *);
134 void	hat_free_end(struct hat *);
135 int	hat_dup(struct hat *, struct hat *, caddr_t, size_t, uint_t);
136 void	hat_swapin(struct hat *);
137 void	hat_swapout(struct hat *);
138 size_t	hat_get_mapped_size(struct hat *);
139 int	hat_stats_enable(struct hat *);
140 void	hat_stats_disable(struct hat *);
141 void	hat_thread_exit(kthread_t *);
142 
143 /*
144  * Operations on a named address within a segment:
145  *
146  * void hat_memload(hat, addr, pp, attr, flags)
147  *	load/lock the given page struct
148  *
149  * void hat_memload_array(hat, addr, len, ppa, attr, flags)
150  *	load/lock the given array of page structs
151  *
152  * void hat_devload(hat, addr, len, pf, attr, flags)
153  *	load/lock the given page frame number
154  *
155  * void hat_unlock(hat, addr, len)
156  *	unlock a given range of addresses
157  *
158  * void hat_unload(hat, addr, len, flags)
159  * void hat_unload_callback(hat, addr, len, flags, callback)
160  *	unload a given range of addresses (has optional callback)
161  *
162  * void hat_sync(hat, addr, len, flags)
163  *	synchronize mapping with software data structures
164  *
165  * void	hat_map(hat, addr, len, flags)
166  *
167  * void hat_setattr(hat, addr, len, attr)
168  * void hat_clrattr(hat, addr, len, attr)
169  * void hat_chgattr(hat, addr, len, attr)
170  *	modify attributes for a range of addresses. skips any invalid mappings
171  *
172  * uint_t hat_getattr(hat, addr, *attr)
173  *	returns attr for <hat,addr> in *attr.  returns 0 if there was a
174  *	mapping and *attr is valid, nonzero if there was no mapping and
175  *	*attr is not valid.
176  *
177  * size_t hat_getpagesize(hat, addr)
178  *	returns pagesize in bytes for <hat, addr>. returns -1 if there is
179  *	no mapping. This is an advisory call.
180  *
181  * pfn_t hat_getpfnum(hat, addr)
182  *	returns pfn for <hat, addr> or PFN_INVALID if mapping is invalid.
183  *
184  * pfn_t hat_getkpfnum(addr)
185  *	returns pfn for non-memory mapped addr in kernel address space
186  *	or PFN_INVALID if mapping is invalid or is kernel memory.
187  *
188  * int hat_probe(hat, addr)
189  *	return 0 if no valid mapping is present.  Faster version
190  *	of hat_getattr in certain architectures.
191  *
192  * int hat_share(dhat, daddr, shat, saddr, len, szc)
193  *
194  * void hat_unshare(hat, addr, len, szc)
195  *
196  * void hat_chgprot(hat, addr, len, vprot)
197  *	This is a deprecated call.  New segment drivers should store
198  *	all attributes and use hat_*attr calls.
199  *	Change the protections in the virtual address range
200  *	given to the specified virtual protection.  If vprot is ~PROT_WRITE,
201  *	then remove write permission, leaving the other permissions
202  *	unchanged.  If vprot is ~PROT_USER, remove user permissions.
203  */
204 
205 void	hat_memload(struct hat *, caddr_t, struct page *, uint_t, uint_t);
206 void	hat_memload_array(struct hat *, caddr_t, size_t, struct page **,
207 		uint_t, uint_t);
208 void	hat_memload_region(struct hat *, caddr_t, struct page *, uint_t,
209 		uint_t, hat_region_cookie_t);
210 void	hat_memload_array_region(struct hat *, caddr_t, size_t, struct page **,
211 		uint_t, uint_t, hat_region_cookie_t);
212 
213 void	hat_devload(struct hat *, caddr_t, size_t, pfn_t, uint_t, int);
214 
215 void	hat_unlock(struct hat *, caddr_t, size_t);
216 void	hat_unlock_region(struct hat *, caddr_t, size_t, hat_region_cookie_t);
217 
218 void	hat_unload(struct hat *, caddr_t, size_t, uint_t);
219 void	hat_unload_callback(struct hat *, caddr_t, size_t, uint_t,
220 		hat_callback_t *);
221 void	hat_sync(struct hat *, caddr_t, size_t, uint_t);
222 void	hat_map(struct hat *, caddr_t, size_t, uint_t);
223 void	hat_setattr(struct hat *, caddr_t, size_t, uint_t);
224 void	hat_clrattr(struct hat *, caddr_t, size_t, uint_t);
225 void	hat_chgattr(struct hat *, caddr_t, size_t, uint_t);
226 uint_t	hat_getattr(struct hat *, caddr_t, uint_t *);
227 ssize_t	hat_getpagesize(struct hat *, caddr_t);
228 pfn_t	hat_getpfnum(struct hat *, caddr_t);
229 int	hat_probe(struct hat *, caddr_t);
230 int	hat_share(struct hat *, caddr_t, struct hat *, caddr_t, size_t, uint_t);
231 void	hat_unshare(struct hat *, caddr_t, size_t, uint_t);
232 void	hat_chgprot(struct hat *, caddr_t, size_t, uint_t);
233 void	hat_reserve(struct as *, caddr_t, size_t);
234 pfn_t	va_to_pfn(void *);
235 uint64_t va_to_pa(void *);
236 
237 /*
238  * hat_getkpfnum() is never supported on amd64 and will be
239  * removed from other platforms in future release
240  */
241 #if !defined(__amd64)
242 pfn_t	hat_getkpfnum(caddr_t);
243 #endif
244 
245 
246 /*
247  * Kernel Physical Mapping (segkpm) hat interface routines.
248  */
249 caddr_t	hat_kpm_mapin(struct page *, struct kpme *);
250 void	hat_kpm_mapout(struct page *, struct kpme *, caddr_t);
251 caddr_t hat_kpm_mapin_pfn(pfn_t);
252 void    hat_kpm_mapout_pfn(pfn_t);
253 caddr_t	hat_kpm_page2va(struct page *, int);
254 struct page *hat_kpm_vaddr2page(caddr_t);
255 int	hat_kpm_fault(struct hat *, caddr_t);
256 void	hat_kpm_mseghash_clear(int);
257 void	hat_kpm_mseghash_update(pgcnt_t, struct memseg *);
258 void	hat_kpm_addmem_mseg_update(struct memseg *, pgcnt_t, offset_t);
259 void	hat_kpm_addmem_mseg_insert(struct memseg *);
260 void	hat_kpm_addmem_memsegs_update(struct memseg *);
261 caddr_t hat_kpm_mseg_reuse(struct memseg *);
262 void	hat_kpm_delmem_mseg_update(struct memseg *, struct memseg **);
263 void	hat_kpm_split_mseg_update(struct memseg *, struct memseg **,
264 			struct memseg *, struct memseg *, struct memseg *);
265 void	hat_kpm_walk(void (*)(void *, void *, size_t), void *);
266 
267 /*
268  * Operations on all translations for a given page(s)
269  *
270  * void hat_page_setattr(pp, flag)
271  * void hat_page_clrattr(pp, flag)
272  *	used to set/clr red/mod bits.
273  *
274  * uint hat_page_getattr(pp, flag)
275  *	If flag is specified, returns 0 if attribute is disabled
276  *	and non zero if enabled.  If flag specifes multiple attributs
277  *	then returns 0 if ALL atriibutes are disabled.  This is an advisory
278  *	call.
279  *
280  * int hat_pageunload(pp, forceflag)
281  *	unload all translations attached to pp.
282  *
283  * uint_t hat_pagesync(pp, flags)
284  *	get hw stats from hardware into page struct and reset hw stats
285  *	returns attributes of page
286  *
287  * ulong_t hat_page_getshare(pp)
288  *	returns approx number of mappings to this pp.  A return of 0 implies
289  *	there are no mappings to the page.
290  *
291  * faultcode_t hat_softlock(hat, addr, lenp, ppp, flags);
292  *	called to softlock pages for zero copy tcp
293  *
294  * void hat_page_demote(pp);
295  *	unload all large mappings to pp and decrease p_szc of all
296  *	constituent pages according to the remaining mappings.
297  */
298 
299 void	hat_page_setattr(struct page *, uint_t);
300 void	hat_page_clrattr(struct page *, uint_t);
301 uint_t	hat_page_getattr(struct page *, uint_t);
302 int	hat_pageunload(struct page *, uint_t);
303 uint_t	hat_pagesync(struct page *, uint_t);
304 ulong_t	hat_page_getshare(struct page *);
305 int	hat_page_checkshare(struct page *, ulong_t);
306 faultcode_t hat_softlock(struct hat *, caddr_t, size_t *,
307 			struct page **, uint_t);
308 void	hat_page_demote(struct page *);
309 
310 /*
311  * Rountine to expose supported HAT features to PIM.
312  */
313 enum hat_features {
314 	HAT_SHARED_PT,		/* Shared page tables */
315 	HAT_DYNAMIC_ISM_UNMAP,	/* hat_pageunload() handles ISM pages */
316 	HAT_VMODSORT,		/* support for VMODSORT flag of vnode */
317 	HAT_SHARED_REGIONS	/* shared regions support */
318 };
319 
320 int hat_supported(enum hat_features, void *);
321 
322 /*
323  * Services provided to the hat:
324  *
325  * void as_signal_proc(as, siginfo)
326  *	deliver signal to all processes that have this as.
327  *
328  * int hat_setstat(as, addr, len, rmbits)
329  *	informs hatstat layer that ref/mod bits need to be updated for
330  *	address range. Returns 0 on success, 1 for failure.
331  */
332 void	as_signal_proc(struct as *, k_siginfo_t *siginfo);
333 void	hat_setstat(struct as *, caddr_t, size_t, uint_t);
334 
335 /*
336  * Flags to pass to hat routines.
337  *
338  * Certain flags only apply to some interfaces:
339  *
340  * 	HAT_LOAD	Default flags to load a translation to the page.
341  * 	HAT_LOAD_LOCK	Lock down mapping resources; hat_map(), hat_memload(),
342  *			and hat_devload().
343  *	HAT_LOAD_ADV	Advisory load - Load translation if and only if
344  *			sufficient MMU resources exist (i.e., do not steal).
345  *	HAT_LOAD_SHARE	A flag to hat_memload() to indicate h/w page tables
346  *			that map some user pages (not kas) is shared by more
347  *			than one process (eg. ISM).
348  *	HAT_LOAD_CONTIG	Pages are contigous
349  *	HAT_LOAD_NOCONSIST Do not add mapping to mapping list.
350  *	HAT_LOAD_REMAP	Reload a valid pte with a different page frame.
351  *	HAT_RELOAD_SHARE Reload a shared page table entry. Some platforms
352  *			 may require different actions than on the first
353  *			 load of a shared mapping.
354  *	HAT_NO_KALLOC	Do not kmem_alloc while creating the mapping; at this
355  *			point, it's setting up mapping to allocate internal
356  *			hat layer data structures.  This flag forces hat layer
357  *			to tap its reserves in order to prevent infinite
358  *			recursion.
359  *	HAT_LOAD_TEXT	A flag to hat_memload() to indicate loading text pages.
360  */
361 
362 /*
363  * Flags for hat_memload/hat_devload
364  */
365 #define	HAT_FLAGS_RESV		0xFF000000	/* resv for hat impl */
366 #define	HAT_LOAD		0x00
367 #define	HAT_LOAD_LOCK		0x01
368 #define	HAT_LOAD_ADV		0x04
369 #define	HAT_LOAD_CONTIG		0x10
370 #define	HAT_LOAD_NOCONSIST	0x20
371 #define	HAT_LOAD_SHARE		0x40
372 #define	HAT_LOAD_REMAP		0x80
373 #define	HAT_RELOAD_SHARE	0x100
374 #define	HAT_NO_KALLOC		0x200
375 #define	HAT_LOAD_TEXT		0x400
376 
377 /*
378  * Flags for initializing disable_*large_pages.
379  *
380  *	HAT_AUTO_TEXT	Get MMU specific disable_auto_text_large_pages
381  *	HAT_AUTO_DATA	Get MMU specific disable_auto_data_large_pages
382  */
383 #define	HAT_AUTO_TEXT		0x800
384 #define	HAT_AUTO_DATA		0x1000
385 
386 /*
387  * Attributes for hat_memload/hat_devload/hat_*attr
388  * are a superset of prot flags defined in mman.h.
389  */
390 #define	HAT_PLAT_ATTR_MASK	0xF00000
391 #define	HAT_PROT_MASK		0x0F
392 
393 #define	HAT_NOFAULT		0x10
394 #define	HAT_NOSYNC		0x20
395 
396 /*
397  * Advisory ordering attributes. Apply only to device mappings.
398  *
399  * HAT_STRICTORDER: the CPU must issue the references in order, as the
400  *	programmer specified.  This is the default.
401  * HAT_UNORDERED_OK: the CPU may reorder the references (this is all kinds
402  *	of reordering; store or load with store or load).
403  * HAT_MERGING_OK: merging and batching: the CPU may merge individual stores
404  *	to consecutive locations (for example, turn two consecutive byte
405  *	stores into one halfword store), and it may batch individual loads
406  *	(for example, turn two consecutive byte loads into one halfword load).
407  *	This also implies re-ordering.
408  * HAT_LOADCACHING_OK: the CPU may cache the data it fetches and reuse it
409  *	until another store occurs.  The default is to fetch new data
410  *	on every load.  This also implies merging.
411  * HAT_STORECACHING_OK: the CPU may keep the data in the cache and push it to
412  *	the device (perhaps with other data) at a later time.  The default is
413  *	to push the data right away.  This also implies load caching.
414  */
415 #define	HAT_STRICTORDER		0x0000
416 #define	HAT_UNORDERED_OK	0x0100
417 #define	HAT_MERGING_OK		0x0200
418 #define	HAT_LOADCACHING_OK	0x0300
419 #define	HAT_STORECACHING_OK	0x0400
420 #define	HAT_ORDER_MASK		0x0700
421 
422 /* endian attributes */
423 #define	HAT_NEVERSWAP		0x0000
424 #define	HAT_STRUCTURE_BE	0x1000
425 #define	HAT_STRUCTURE_LE	0x2000
426 #define	HAT_ENDIAN_MASK		0x3000
427 
428 /*
429  * Attributes for non-coherent I-cache support.
430  *
431  * We detect if an I-cache has been filled by first resetting
432  * execute permission in a tte entry. This forces a trap when
433  * an instruction fetch first occurs in that page. In "soft
434  * execute mode", the hardware execute permission is cleared
435  * and a different software execution bit is set in the tte.
436  *
437  * HAT_ATTR_TEXT: set this flag to avoid the extra trap associated
438  * with soft execute mode. Same meaning as HAT_LOAD_TEXT.
439  *
440  * HAT_ATTR_NOSOFTEXEC: set this flag when installing a permanent
441  * mapping, or installing a mapping that will never be
442  * freed. Overrides soft execute mode.
443  */
444 #define	HAT_ATTR_TEXT		0x4000
445 #define	HAT_ATTR_NOSOFTEXEC	0x8000
446 
447 /* flags for hat_softlock */
448 #define	HAT_COW			0x0001
449 
450 /*
451  * Flags for hat_unload
452  */
453 #define	HAT_UNLOAD		0x00
454 #define	HAT_UNLOAD_NOSYNC	0x02
455 #define	HAT_UNLOAD_UNLOCK	0x04
456 #define	HAT_UNLOAD_OTHER	0x08
457 #define	HAT_UNLOAD_UNMAP	0x10
458 
459 /*
460  * Flags for hat_pagesync, hat_getstat, hat_sync
461  */
462 #define	HAT_SYNC_DONTZERO	0x00
463 #define	HAT_SYNC_ZERORM		0x01
464 /* Additional flags for hat_pagesync */
465 #define	HAT_SYNC_STOPON_REF	0x02
466 #define	HAT_SYNC_STOPON_MOD	0x04
467 #define	HAT_SYNC_STOPON_RM	(HAT_SYNC_STOPON_REF | HAT_SYNC_STOPON_MOD)
468 #define	HAT_SYNC_STOPON_SHARED	0x08
469 
470 /*
471  * Flags for hat_dup
472  *
473  * HAT_DUP_ALL dup entire address space
474  * HAT_DUP_COW dup plus hat_clrattr(..PROT_WRITE) on newas
475  */
476 #define	HAT_DUP_ALL		1
477 #define	HAT_DUP_COW		2
478 #define	HAT_DUP_SRD		3
479 
480 
481 /*
482  * Flags for hat_map
483  */
484 #define	HAT_MAP			0x00
485 
486 /*
487  * Flag for hat_pageunload
488  */
489 #define	HAT_ADV_PGUNLOAD	0x00
490 #define	HAT_FORCE_PGUNLOAD	0x01
491 
492 /*
493  * Attributes for hat_page_*attr, hat_setstats and
494  * returned by hat_pagesync.
495  */
496 #define	P_MOD	0x1		/* the modified bit */
497 #define	P_REF	0x2		/* the referenced bit */
498 #define	P_RO	0x4		/* Read only page */
499 #define	P_NSH	0x8		/* Not to shuffle v_pages */
500 
501 #define	hat_ismod(pp)		(hat_page_getattr(pp, P_MOD))
502 #define	hat_isref(pp)		(hat_page_getattr(pp, P_REF))
503 #define	hat_isro(pp)		(hat_page_getattr(pp, P_RO))
504 
505 #define	hat_setmod(pp)		(hat_page_setattr(pp, P_MOD))
506 #define	hat_setmod_only(pp)	(hat_page_setattr(pp, P_MOD|P_NSH))
507 #define	hat_setref(pp)		(hat_page_setattr(pp, P_REF))
508 #define	hat_setrefmod(pp)	(hat_page_setattr(pp, P_REF|P_MOD))
509 
510 #define	hat_clrmod(pp)		(hat_page_clrattr(pp, P_MOD))
511 #define	hat_clrref(pp)		(hat_page_clrattr(pp, P_REF))
512 #define	hat_clrrefmod(pp)	(hat_page_clrattr(pp, P_REF|P_MOD))
513 
514 #define	hat_page_is_mapped(pp)	(hat_page_getshare(pp))
515 
516 /*
517  * hat_setup is being used in sparc/os/sundep.c
518  */
519 void	hat_setup(struct hat *, int);
520 
521 /*
522  * Flags for hat_setup
523  */
524 #define	HAT_DONTALLOC		0
525 #define	HAT_ALLOC		1
526 #define	HAT_INIT		2
527 
528 /*
529  * Other routines, for statistics
530  */
531 int	hat_startstat(struct as *);
532 void	hat_getstat(struct as *, caddr_t, size_t, uint_t, char *, int);
533 void	hat_freestat(struct as *, int);
534 void	hat_resvstat(size_t, struct as *, caddr_t);
535 
536 /*
537  * Transitionary routine while we still allow hat_getkpfnum(caddr_t)
538  * to return a pfn for kernel memory, but want to warn the user that
539  * it isn't supported.
540  */
541 void	hat_getkpfnum_badcall(void *caller);
542 
543 /*
544  * Relocation callback routines. Currently only sfmmu HAT supports
545  * these.
546  */
547 extern int	hat_add_callback(id_t, caddr_t, uint_t, uint_t, void *,
548 	pfn_t *, void **);
549 extern id_t	hat_register_callback(int,
550 	int (*prehandler)(caddr_t, uint_t, uint_t, void *),
551 	int (*posthandler)(caddr_t, uint_t, uint_t, void *, pfn_t),
552 	int (*errhandler)(caddr_t, uint_t, uint_t, void *), int);
553 extern void	hat_delete_callback(caddr_t, uint_t, void *, uint_t, void *);
554 
555 /*
556  * hat_add_callback()/hat_delete_callback() flags.
557  */
558 #define	HAC_NOSLEEP	0x0
559 #define	HAC_SLEEP	0x1
560 #define	HAC_PAGELOCK	0x2
561 
562 /*
563  * Suspend/unsuspend handler callback arguments.
564  */
565 #define	HAT_SUSPEND		0x0010
566 #define	HAT_UNSUSPEND		0x0010
567 #define	HAT_PRESUSPEND		0x0020
568 #define	HAT_POSTUNSUSPEND	0x0020
569 
570 /*
571  * Error handler callback arguments. See the block comments
572  * before the implementation of hat_add_callback() for an
573  * explanation of what these mean.
574  */
575 #define	HAT_CB_ERR_LEAKED	0x1
576 
577 #endif /* _KERNEL */
578 
579 /*
580  * The size of the bit array for ref and mod bit storage must be a power of 2.
581  * 2 bits are collected for each page.  Below the power used is 4,
582  * which is 16 8-bit characters = 128 bits, ref and mod bit information
583  * for 64 pages.
584  */
585 #define	HRM_SHIFT		4
586 #define	HRM_BYTES		(1 << HRM_SHIFT)
587 #define	HRM_PAGES		((HRM_BYTES * NBBY) / 2)
588 #define	HRM_PGPERBYTE		(NBBY/2)
589 #define	HRM_PGBYTEMASK		(HRM_PGPERBYTE-1)
590 
591 #define	HRM_PGOFFMASK		((HRM_PGPERBYTE-1) << MMU_PAGESHIFT)
592 #define	HRM_BASEOFFSET		(((MMU_PAGESIZE * HRM_PAGES) - 1))
593 #define	HRM_BASEMASK		(~(HRM_BASEOFFSET))
594 
595 #define	HRM_BASESHIFT		(MMU_PAGESHIFT + (HRM_SHIFT + 2))
596 #define	HRM_PAGEMASK		(MMU_PAGEMASK ^ HRM_BASEMASK)
597 
598 #define	HRM_HASHSIZE		0x200
599 #define	HRM_HASHMASK		(HRM_HASHSIZE - 1)
600 
601 #define	HRM_BLIST_INCR		0x200
602 
603 /*
604  * The structure for maintaining referenced and modified information
605  */
606 struct hrmstat {
607 	struct as	*hrm_as;	/* stat block belongs to this as */
608 	uintptr_t	hrm_base;	/* base of block */
609 	ushort_t	hrm_id;		/* opaque identifier, one of a_vbits */
610 	struct hrmstat	*hrm_anext;	/* as statistics block list */
611 	struct hrmstat	*hrm_hnext;	/* list for hashed blocks */
612 	uchar_t		hrm_bits[HRM_BYTES]; /* the ref and mod bits */
613 };
614 
615 extern struct hrmstat **hrm_hashtab;
616 
617 /*
618  * For global monitoring of the reference and modified bits
619  * of all address spaces we reserve one id bit.
620  */
621 #define	HRM_SWSMONID	1
622 
623 
624 #ifdef _KERNEL
625 
626 /*
627  * Hat locking functions
628  * XXX - these two functions are currently being used by hatstats
629  * 	they can be removed by using a per-as mutex for hatstats.
630  */
631 void	hat_enter(struct hat *);
632 void	hat_exit(struct hat *);
633 
634 typedef void (*hat_rgn_cb_func_t)(caddr_t, caddr_t, caddr_t,
635     size_t, void *, u_offset_t);
636 
637 void			hat_join_srd(struct hat *, vnode_t *);
638 
639 hat_region_cookie_t	hat_join_region(struct hat *, caddr_t, size_t, void *,
640 			    u_offset_t, uchar_t, uchar_t, hat_rgn_cb_func_t,
641 			    uint_t);
642 void			hat_leave_region(struct hat *, hat_region_cookie_t,
643 			    uint_t);
644 void			hat_dup_region(struct hat *, hat_region_cookie_t);
645 
646 #define	HAT_INVALID_REGION_COOKIE	((hat_region_cookie_t)-1)
647 #define	HAT_IS_REGION_COOKIE_VALID(c)	((c) != HAT_INVALID_REGION_COOKIE)
648 
649 /* hat_join_region() flags */
650 
651 #define	HAT_REGION_TEXT	0x1	/* passed by segvn */
652 #define	HAT_REGION_ISM	0x2	/* for hat_share()/hat_unshare() */
653 
654 #define	HAT_REGION_TYPE_MASK	(0x7)
655 
656 #endif /* _KERNEL */
657 
658 #ifdef	__cplusplus
659 }
660 #endif
661 
662 #endif	/* _VM_HAT_H */
663