1 /*
2  * Copyright (c) 1991 Regents of the University of California.
3  * Copyright (c) 1994 John S. Dyson
4  * Copyright (c) 1994 David Greenman
5  * Copyright (c) 2003 Peter Wemm
6  * Copyright (c) 2005-2008 Alan L. Cox <alc@cs.rice.edu>
7  * Copyright (c) 2008-2019 The DragonFly Project.
8  * Copyright (c) 2008, 2009 Jordan Gordeev.
9  * All rights reserved.
10  *
11  * This code is derived from software contributed to Berkeley by
12  * the Systems Programming Group of the University of Utah Computer
13  * Science Department and William Jolitz of UUNET Technologies Inc.
14  *
15  * Redistribution and use in source and binary forms, with or without
16  * modification, are permitted provided that the following conditions
17  * are met:
18  * 1. Redistributions of source code must retain the above copyright
19  *    notice, this list of conditions and the following disclaimer.
20  * 2. Redistributions in binary form must reproduce the above copyright
21  *    notice, this list of conditions and the following disclaimer in the
22  *    documentation and/or other materials provided with the distribution.
23  * 3. All advertising materials mentioning features or use of this software
24  *    must display the following acknowledgement:
25  *	This product includes software developed by the University of
26  *	California, Berkeley and its contributors.
27  * 4. Neither the name of the University nor the names of its contributors
28  *    may be used to endorse or promote products derived from this software
29  *    without specific prior written permission.
30  *
31  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
32  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
33  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
34  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
35  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
36  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
37  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
39  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
40  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
41  * SUCH DAMAGE.
42  *
43  *	from:	@(#)pmap.c	7.7 (Berkeley)	5/12/91
44  * $FreeBSD: src/sys/i386/i386/pmap.c,v 1.250.2.18 2002/03/06 22:48:53 silby Exp $
45  */
46 
47 /*
48  * Manages physical address maps.
49  */
50 
51 #include "opt_msgbuf.h"
52 
53 #include <sys/param.h>
54 #include <sys/systm.h>
55 #include <sys/kernel.h>
56 #include <sys/proc.h>
57 #include <sys/msgbuf.h>
58 #include <sys/vmmeter.h>
59 #include <sys/mman.h>
60 #include <sys/vmspace.h>
61 
62 #include <vm/vm.h>
63 #include <vm/vm_param.h>
64 #include <sys/sysctl.h>
65 #include <sys/lock.h>
66 #include <vm/vm_kern.h>
67 #include <vm/vm_page.h>
68 #include <vm/vm_map.h>
69 #include <vm/vm_object.h>
70 #include <vm/vm_extern.h>
71 #include <vm/vm_pageout.h>
72 #include <vm/vm_pager.h>
73 #include <vm/vm_zone.h>
74 
75 #include <sys/thread2.h>
76 #include <sys/spinlock2.h>
77 #include <vm/vm_page2.h>
78 
79 #include <machine/cputypes.h>
80 #include <machine/md_var.h>
81 #include <machine/specialreg.h>
82 #include <machine/smp.h>
83 #include <machine/globaldata.h>
84 #include <machine/pcb.h>
85 #include <machine/pmap.h>
86 #include <machine/pmap_inval.h>
87 
88 #include <ddb/ddb.h>
89 
90 #include <stdio.h>
91 #include <assert.h>
92 #include <stdlib.h>
93 #include <pthread.h>
94 
95 #define PMAP_KEEP_PDIRS
96 #ifndef PMAP_SHPGPERPROC
97 #define PMAP_SHPGPERPROC 1000
98 #endif
99 
100 #if defined(DIAGNOSTIC)
101 #define PMAP_DIAGNOSTIC
102 #endif
103 
104 #define MINPV 2048
105 
106 #if !defined(PMAP_DIAGNOSTIC)
107 #define PMAP_INLINE __inline
108 #else
109 #define PMAP_INLINE
110 #endif
111 
112 /*
113  * Get PDEs and PTEs for user/kernel address space
114  */
115 static pd_entry_t *pmap_pde(pmap_t pmap, vm_offset_t va);
116 #define pdir_pde(m, v) (m[(vm_offset_t)(v) >> PDRSHIFT])
117 
118 #define pmap_pde_v(pte)		((*(pd_entry_t *)pte & VPTE_V) != 0)
119 #define pmap_pte_w(pte)		((*(pt_entry_t *)pte & VPTE_WIRED) != 0)
120 #define pmap_pte_m(pte)		((*(pt_entry_t *)pte & VPTE_M) != 0)
121 #define pmap_pte_u(pte)		((*(pt_entry_t *)pte & VPTE_A) != 0)
122 #define pmap_pte_v(pte)		((*(pt_entry_t *)pte & VPTE_V) != 0)
123 
124 /*
125  * Given a map and a machine independent protection code,
126  * convert to a vax protection code.
127  */
128 #define pte_prot(m, p)		\
129 	(protection_codes[p & (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE)])
130 static uint64_t protection_codes[8];
131 
132 struct pmap kernel_pmap;
133 
134 static boolean_t pmap_initialized = FALSE;	/* Has pmap_init completed? */
135 
136 static struct vm_object kptobj;
137 static int nkpt;
138 
139 static uint64_t	KPDphys;	/* phys addr of kernel level 2 */
140 uint64_t		KPDPphys;	/* phys addr of kernel level 3 */
141 uint64_t		KPML4phys;	/* phys addr of kernel level 4 */
142 
143 extern int vmm_enabled;
144 extern void *vkernel_stack;
145 
146 /*
147  * Data for the pv entry allocation mechanism
148  */
149 static vm_zone_t pvzone;
150 static struct vm_zone pvzone_store;
151 static vm_pindex_t pv_entry_count = 0;
152 static vm_pindex_t pv_entry_max = 0;
153 static vm_pindex_t pv_entry_high_water = 0;
154 static int pmap_pagedaemon_waken = 0;
155 static struct pv_entry *pvinit;
156 
157 /*
158  * All those kernel PT submaps that BSD is so fond of
159  */
160 pt_entry_t *CMAP1 = NULL, *ptmmap;
161 caddr_t CADDR1 = NULL;
162 static pt_entry_t *msgbufmap;
163 
164 uint64_t KPTphys;
165 
166 static PMAP_INLINE void	free_pv_entry (pv_entry_t pv);
167 static pv_entry_t get_pv_entry (void);
168 static void	x86_64_protection_init (void);
169 static __inline void	pmap_clearbit (vm_page_t m, int bit);
170 
171 static void	pmap_remove_all (vm_page_t m);
172 static int pmap_remove_pte (struct pmap *pmap, pt_entry_t *ptq,
173 				pt_entry_t oldpte, vm_offset_t sva);
174 static void pmap_remove_page (struct pmap *pmap, vm_offset_t va);
175 static int pmap_remove_entry (struct pmap *pmap, vm_page_t m,
176 				vm_offset_t va);
177 static boolean_t pmap_testbit (vm_page_t m, int bit);
178 static void pmap_insert_entry (pmap_t pmap, vm_offset_t va,
179 				vm_page_t mpte, vm_page_t m, pv_entry_t);
180 
181 static vm_page_t pmap_allocpte (pmap_t pmap, vm_offset_t va);
182 
183 static int pmap_release_free_page (pmap_t pmap, vm_page_t p);
184 static vm_page_t _pmap_allocpte (pmap_t pmap, vm_pindex_t ptepindex);
185 static vm_page_t pmap_page_lookup (vm_object_t object, vm_pindex_t pindex);
186 static int pmap_unuse_pt (pmap_t, vm_offset_t, vm_page_t);
187 
188 static int
189 pv_entry_compare(pv_entry_t pv1, pv_entry_t pv2)
190 {
191 	if (pv1->pv_va < pv2->pv_va)
192 		return(-1);
193 	if (pv1->pv_va > pv2->pv_va)
194 		return(1);
195 	return(0);
196 }
197 
198 RB_GENERATE2(pv_entry_rb_tree, pv_entry, pv_entry,
199 	    pv_entry_compare, vm_offset_t, pv_va);
200 
201 static __inline vm_pindex_t
202 pmap_pt_pindex(vm_offset_t va)
203 {
204 	return va >> PDRSHIFT;
205 }
206 
207 static __inline vm_pindex_t
208 pmap_pte_index(vm_offset_t va)
209 {
210 	return ((va >> PAGE_SHIFT) & ((1ul << NPTEPGSHIFT) - 1));
211 }
212 
213 static __inline vm_pindex_t
214 pmap_pde_index(vm_offset_t va)
215 {
216 	return ((va >> PDRSHIFT) & ((1ul << NPDEPGSHIFT) - 1));
217 }
218 
219 static __inline vm_pindex_t
220 pmap_pdpe_index(vm_offset_t va)
221 {
222 	return ((va >> PDPSHIFT) & ((1ul << NPDPEPGSHIFT) - 1));
223 }
224 
225 static __inline vm_pindex_t
226 pmap_pml4e_index(vm_offset_t va)
227 {
228 	return ((va >> PML4SHIFT) & ((1ul << NPML4EPGSHIFT) - 1));
229 }
230 
231 /* Return a pointer to the PML4 slot that corresponds to a VA */
232 static __inline pml4_entry_t *
233 pmap_pml4e(pmap_t pmap, vm_offset_t va)
234 {
235 	return (&pmap->pm_pml4[pmap_pml4e_index(va)]);
236 }
237 
238 /* Return a pointer to the PDP slot that corresponds to a VA */
239 static __inline pdp_entry_t *
240 pmap_pml4e_to_pdpe(pml4_entry_t *pml4e, vm_offset_t va)
241 {
242 	pdp_entry_t *pdpe;
243 
244 	pdpe = (pdp_entry_t *)PHYS_TO_DMAP(*pml4e & VPTE_FRAME);
245 	return (&pdpe[pmap_pdpe_index(va)]);
246 }
247 
248 /* Return a pointer to the PDP slot that corresponds to a VA */
249 static __inline pdp_entry_t *
250 pmap_pdpe(pmap_t pmap, vm_offset_t va)
251 {
252 	pml4_entry_t *pml4e;
253 
254 	pml4e = pmap_pml4e(pmap, va);
255 	if ((*pml4e & VPTE_V) == 0)
256 		return NULL;
257 	return (pmap_pml4e_to_pdpe(pml4e, va));
258 }
259 
260 /* Return a pointer to the PD slot that corresponds to a VA */
261 static __inline pd_entry_t *
262 pmap_pdpe_to_pde(pdp_entry_t *pdpe, vm_offset_t va)
263 {
264 	pd_entry_t *pde;
265 
266 	pde = (pd_entry_t *)PHYS_TO_DMAP(*pdpe & VPTE_FRAME);
267 	return (&pde[pmap_pde_index(va)]);
268 }
269 
270 /* Return a pointer to the PD slot that corresponds to a VA */
271 static __inline pd_entry_t *
272 pmap_pde(pmap_t pmap, vm_offset_t va)
273 {
274 	pdp_entry_t *pdpe;
275 
276 	pdpe = pmap_pdpe(pmap, va);
277 	if (pdpe == NULL || (*pdpe & VPTE_V) == 0)
278 		 return NULL;
279 	return (pmap_pdpe_to_pde(pdpe, va));
280 }
281 
282 /* Return a pointer to the PT slot that corresponds to a VA */
283 static __inline pt_entry_t *
284 pmap_pde_to_pte(pd_entry_t *pde, vm_offset_t va)
285 {
286 	pt_entry_t *pte;
287 
288 	pte = (pt_entry_t *)PHYS_TO_DMAP(*pde & VPTE_FRAME);
289 	return (&pte[pmap_pte_index(va)]);
290 }
291 
292 /*
293  * Hold pt_m for page table scans to prevent it from getting reused out
294  * from under us across blocking conditions in the body of the loop.
295  */
296 static __inline
297 vm_page_t
298 pmap_hold_pt_page(pd_entry_t *pde, vm_offset_t va)
299 {
300 	pt_entry_t pte;
301 	vm_page_t pt_m;
302 
303 	pte = (pt_entry_t)*pde;
304 	KKASSERT(pte != 0);
305 	pt_m = PHYS_TO_VM_PAGE(pte & VPTE_FRAME);
306 	vm_page_hold(pt_m);
307 
308 	return pt_m;
309 }
310 
311 /* Return a pointer to the PT slot that corresponds to a VA */
312 static __inline pt_entry_t *
313 pmap_pte(pmap_t pmap, vm_offset_t va)
314 {
315 	pd_entry_t *pde;
316 
317 	pde = pmap_pde(pmap, va);
318 	if (pde == NULL || (*pde & VPTE_V) == 0)
319 		return NULL;
320 	if ((*pde & VPTE_PS) != 0)	/* compat with x86 pmap_pte() */
321 		return ((pt_entry_t *)pde);
322 	return (pmap_pde_to_pte(pde, va));
323 }
324 
325 static PMAP_INLINE pt_entry_t *
326 vtopte(vm_offset_t va)
327 {
328 	pt_entry_t *x;
329 	x = pmap_pte(&kernel_pmap, va);
330 	assert(x != NULL);
331 	return x;
332 }
333 
334 static __inline pd_entry_t *
335 vtopde(vm_offset_t va)
336 {
337 	pd_entry_t *x;
338 	x = pmap_pde(&kernel_pmap, va);
339 	assert(x != NULL);
340 	return x;
341 }
342 
343 /*
344  * Returns the physical address translation from va for a user address.
345  * (vm_paddr_t)-1 is returned on failure.
346  */
347 vm_paddr_t
348 uservtophys(vm_offset_t va)
349 {
350 	struct vmspace *vm = curproc->p_vmspace;
351 	vm_page_t m;
352 	vm_paddr_t pa;
353 	int error;
354 	int busy;
355 
356 	/* XXX No idea how to handle this case in a simple way, just abort */
357 	if (PAGE_SIZE - (va & PAGE_MASK) < sizeof(u_int))
358 		return ((vm_paddr_t)-1);
359 
360 	m = vm_fault_page(&vm->vm_map, trunc_page(va),
361 			  VM_PROT_READ|VM_PROT_WRITE,
362 			  VM_FAULT_NORMAL,
363 			  &error, &busy);
364 	if (error)
365 		return ((vm_paddr_t)-1);
366 
367 	pa = VM_PAGE_TO_PHYS(m) | (va & PAGE_MASK);
368 	if (busy)
369 		vm_page_wakeup(m);
370 	else
371 		vm_page_unhold(m);
372 
373 	return pa;
374 }
375 
376 static uint64_t
377 allocpages(vm_paddr_t *firstaddr, int n)
378 {
379 	uint64_t ret;
380 
381 	ret = *firstaddr;
382 	/*bzero((void *)ret, n * PAGE_SIZE); not mapped yet */
383 	*firstaddr += n * PAGE_SIZE;
384 	return (ret);
385 }
386 
387 static void
388 create_dmap_vmm(vm_paddr_t *firstaddr)
389 {
390 	void *stack_addr;
391 	int pml4_stack_index;
392 	int pdp_stack_index;
393 	int pd_stack_index;
394 	long i,j;
395 	int regs[4];
396 	int amd_feature;
397 
398 	uint64_t KPDP_DMAP_phys = allocpages(firstaddr, NDMPML4E);
399 	uint64_t KPDP_VSTACK_phys = allocpages(firstaddr, 1);
400 	uint64_t KPD_VSTACK_phys = allocpages(firstaddr, 1);
401 
402 	pml4_entry_t *KPML4virt = (pml4_entry_t *)PHYS_TO_DMAP(KPML4phys);
403 	pdp_entry_t *KPDP_DMAP_virt = (pdp_entry_t *)PHYS_TO_DMAP(KPDP_DMAP_phys);
404 	pdp_entry_t *KPDP_VSTACK_virt = (pdp_entry_t *)PHYS_TO_DMAP(KPDP_VSTACK_phys);
405 	pd_entry_t *KPD_VSTACK_virt = (pd_entry_t *)PHYS_TO_DMAP(KPD_VSTACK_phys);
406 
407 	bzero(KPDP_DMAP_virt, NDMPML4E * PAGE_SIZE);
408 	bzero(KPDP_VSTACK_virt, 1 * PAGE_SIZE);
409 	bzero(KPD_VSTACK_virt, 1 * PAGE_SIZE);
410 
411 	do_cpuid(0x80000001, regs);
412 	amd_feature = regs[3];
413 
414 	/* Build the mappings for the first 512GB */
415 	if (amd_feature & AMDID_PAGE1GB) {
416 		/* In pages of 1 GB, if supported */
417 		for (i = 0; i < NPDPEPG; i++) {
418 			KPDP_DMAP_virt[i] = ((uint64_t)i << PDPSHIFT);
419 			KPDP_DMAP_virt[i] |= VPTE_RW | VPTE_V | VPTE_PS | VPTE_U;
420 		}
421 	} else {
422 		/* In page of 2MB, otherwise */
423 		for (i = 0; i < NPDPEPG; i++) {
424 			uint64_t KPD_DMAP_phys;
425 			pd_entry_t *KPD_DMAP_virt;
426 
427 			KPD_DMAP_phys = allocpages(firstaddr, 1);
428 			KPD_DMAP_virt =
429 				(pd_entry_t *)PHYS_TO_DMAP(KPD_DMAP_phys);
430 
431 			bzero(KPD_DMAP_virt, PAGE_SIZE);
432 
433 			KPDP_DMAP_virt[i] = KPD_DMAP_phys;
434 			KPDP_DMAP_virt[i] |= VPTE_RW | VPTE_V | VPTE_U;
435 
436 			/* For each PD, we have to allocate NPTEPG PT */
437 			for (j = 0; j < NPTEPG; j++) {
438 				KPD_DMAP_virt[j] = (i << PDPSHIFT) |
439 						   (j << PDRSHIFT);
440 				KPD_DMAP_virt[j] |= VPTE_RW | VPTE_V |
441 						    VPTE_PS | VPTE_U;
442 			}
443 		}
444 	}
445 
446 	/* DMAP for the first 512G */
447 	KPML4virt[0] = KPDP_DMAP_phys;
448 	KPML4virt[0] |= VPTE_RW | VPTE_V | VPTE_U;
449 
450 	/* create a 2 MB map of the new stack */
451 	pml4_stack_index = (uint64_t)&stack_addr >> PML4SHIFT;
452 	KPML4virt[pml4_stack_index] = KPDP_VSTACK_phys;
453 	KPML4virt[pml4_stack_index] |= VPTE_RW | VPTE_V | VPTE_U;
454 
455 	pdp_stack_index = ((uint64_t)&stack_addr & PML4MASK) >> PDPSHIFT;
456 	KPDP_VSTACK_virt[pdp_stack_index] = KPD_VSTACK_phys;
457 	KPDP_VSTACK_virt[pdp_stack_index] |= VPTE_RW | VPTE_V | VPTE_U;
458 
459 	pd_stack_index = ((uint64_t)&stack_addr & PDPMASK) >> PDRSHIFT;
460 	KPD_VSTACK_virt[pd_stack_index] = (uint64_t) vkernel_stack;
461 	KPD_VSTACK_virt[pd_stack_index] |= VPTE_RW | VPTE_V | VPTE_U | VPTE_PS;
462 }
463 
464 static void
465 create_pagetables(vm_paddr_t *firstaddr, int64_t ptov_offset)
466 {
467 	int i;
468 	pml4_entry_t *KPML4virt;
469 	pdp_entry_t *KPDPvirt;
470 	pd_entry_t *KPDvirt;
471 	pt_entry_t *KPTvirt;
472 	int kpml4i = pmap_pml4e_index(ptov_offset);
473 	int kpdpi = pmap_pdpe_index(ptov_offset);
474 	int kpdi = pmap_pde_index(ptov_offset);
475 
476 	/*
477          * Calculate NKPT - number of kernel page tables.  We have to
478          * accomodoate prealloction of the vm_page_array, dump bitmap,
479          * MSGBUF_SIZE, and other stuff.  Be generous.
480          *
481          * Maxmem is in pages.
482          */
483         nkpt = (Maxmem * (sizeof(struct vm_page) * 2) + MSGBUF_SIZE) / NBPDR;
484 	/*
485 	 * Allocate pages
486 	 */
487 	KPML4phys = allocpages(firstaddr, 1);
488 	KPDPphys = allocpages(firstaddr, NKPML4E);
489 	KPDphys = allocpages(firstaddr, NKPDPE);
490 	KPTphys = allocpages(firstaddr, nkpt);
491 
492 	KPML4virt = (pml4_entry_t *)PHYS_TO_DMAP(KPML4phys);
493 	KPDPvirt = (pdp_entry_t *)PHYS_TO_DMAP(KPDPphys);
494 	KPDvirt = (pd_entry_t *)PHYS_TO_DMAP(KPDphys);
495 	KPTvirt = (pt_entry_t *)PHYS_TO_DMAP(KPTphys);
496 
497 	bzero(KPML4virt, 1 * PAGE_SIZE);
498 	bzero(KPDPvirt, NKPML4E * PAGE_SIZE);
499 	bzero(KPDvirt, NKPDPE * PAGE_SIZE);
500 	bzero(KPTvirt, nkpt * PAGE_SIZE);
501 
502 	/* Now map the page tables at their location within PTmap */
503 	for (i = 0; i < nkpt; i++) {
504 		KPDvirt[i + kpdi] = KPTphys + (i << PAGE_SHIFT);
505 		KPDvirt[i + kpdi] |= VPTE_RW | VPTE_V | VPTE_U;
506 	}
507 
508 	/* And connect up the PD to the PDP */
509 	for (i = 0; i < NKPDPE; i++) {
510 		KPDPvirt[i + kpdpi] = KPDphys + (i << PAGE_SHIFT);
511 		KPDPvirt[i + kpdpi] |= VPTE_RW | VPTE_V | VPTE_U;
512 	}
513 
514 	/* And recursively map PML4 to itself in order to get PTmap */
515 	KPML4virt[PML4PML4I] = KPML4phys;
516 	KPML4virt[PML4PML4I] |= VPTE_RW | VPTE_V | VPTE_U;
517 
518 	/* Connect the KVA slot up to the PML4 */
519 	KPML4virt[kpml4i] = KPDPphys;
520 	KPML4virt[kpml4i] |= VPTE_RW | VPTE_V | VPTE_U;
521 }
522 
523 /*
524  * Typically used to initialize a fictitious page by vm/device_pager.c
525  */
526 void
527 pmap_page_init(struct vm_page *m)
528 {
529 	vm_page_init(m);
530 	TAILQ_INIT(&m->md.pv_list);
531 }
532 
533 /*
534  *	Bootstrap the system enough to run with virtual memory.
535  *
536  *	On x86_64 this is called after mapping has already been enabled
537  *	and just syncs the pmap module with what has already been done.
538  *	[We can't call it easily with mapping off since the kernel is not
539  *	mapped with PA == VA, hence we would have to relocate every address
540  *	from the linked base (virtual) address "KERNBASE" to the actual
541  *	(physical) address starting relative to 0]
542  */
543 void
544 pmap_bootstrap(vm_paddr_t *firstaddr, int64_t ptov_offset)
545 {
546 	vm_offset_t va;
547 	pt_entry_t *pte;
548 
549 	/*
550 	 * Create an initial set of page tables to run the kernel in.
551 	 */
552 	create_pagetables(firstaddr, ptov_offset);
553 
554 	/* Create the DMAP for the VMM */
555 	if (vmm_enabled) {
556 		create_dmap_vmm(firstaddr);
557 	}
558 
559 	virtual_start = KvaStart;
560 	virtual_end = KvaEnd;
561 
562 	/*
563 	 * Initialize protection array.
564 	 */
565 	x86_64_protection_init();
566 
567 	/*
568 	 * The kernel's pmap is statically allocated so we don't have to use
569 	 * pmap_create, which is unlikely to work correctly at this part of
570 	 * the boot sequence (XXX and which no longer exists).
571 	 *
572 	 * The kernel_pmap's pm_pteobj is used only for locking and not
573 	 * for mmu pages.
574 	 */
575 	kernel_pmap.pm_pml4 = (pml4_entry_t *)PHYS_TO_DMAP(KPML4phys);
576 	kernel_pmap.pm_count = 1;
577 	/* don't allow deactivation */
578 	CPUMASK_ASSALLONES(kernel_pmap.pm_active);
579 	kernel_pmap.pm_pteobj = NULL;	/* see pmap_init */
580 	RB_INIT(&kernel_pmap.pm_pvroot);
581 	spin_init(&kernel_pmap.pm_spin, "pmapbootstrap");
582 
583 	/*
584 	 * Reserve some special page table entries/VA space for temporary
585 	 * mapping of pages.
586 	 */
587 #define	SYSMAP(c, p, v, n)	\
588 	v = (c)va; va += ((n)*PAGE_SIZE); p = pte; pte += (n);
589 
590 	va = virtual_start;
591 	pte = pmap_pte(&kernel_pmap, va);
592 	/*
593 	 * CMAP1/CMAP2 are used for zeroing and copying pages.
594 	 */
595 	SYSMAP(caddr_t, CMAP1, CADDR1, 1)
596 
597 #if 0 /* JGV */
598 	/*
599 	 * Crashdump maps.
600 	 */
601 	SYSMAP(caddr_t, pt_crashdumpmap, crashdumpmap, MAXDUMPPGS);
602 #endif
603 
604 	/*
605 	 * ptvmmap is used for reading arbitrary physical pages via
606 	 * /dev/mem.
607 	 */
608 	SYSMAP(caddr_t, ptmmap, ptvmmap, 1)
609 
610 	/*
611 	 * msgbufp is used to map the system message buffer.
612 	 * XXX msgbufmap is not used.
613 	 */
614 	SYSMAP(struct msgbuf *, msgbufmap, msgbufp,
615 	       atop(round_page(MSGBUF_SIZE)))
616 
617 	virtual_start = va;
618 
619 	*CMAP1 = 0;
620 	/* Not ready to do an invltlb yet for VMM*/
621 	if (!vmm_enabled)
622 		cpu_invltlb();
623 
624 }
625 
626 /*
627  *	Initialize the pmap module.
628  *	Called by vm_init, to initialize any structures that the pmap
629  *	system needs to map virtual memory.
630  *	pmap_init has been enhanced to support in a fairly consistant
631  *	way, discontiguous physical memory.
632  */
633 void
634 pmap_init(void)
635 {
636 	vm_pindex_t i;
637 	vm_pindex_t initial_pvs;
638 
639 	/*
640 	 * object for kernel page table pages
641 	 */
642 	/* JG I think the number can be arbitrary */
643 	vm_object_init(&kptobj, 5);
644 	kernel_pmap.pm_pteobj = &kptobj;
645 
646 	/*
647 	 * Allocate memory for random pmap data structures.  Includes the
648 	 * pv_head_table.
649 	 */
650 	for (i = 0; i < vm_page_array_size; i++) {
651 		vm_page_t m;
652 
653 		m = &vm_page_array[i];
654 		TAILQ_INIT(&m->md.pv_list);
655 		m->md.pv_list_count = 0;
656 	}
657 
658 	/*
659 	 * init the pv free list
660 	 */
661 	initial_pvs = vm_page_array_size;
662 	if (initial_pvs < MINPV)
663 		initial_pvs = MINPV;
664 	pvzone = &pvzone_store;
665 	pvinit = (struct pv_entry *)
666 		kmem_alloc(&kernel_map,
667 			   initial_pvs * sizeof (struct pv_entry),
668 			   VM_SUBSYS_PVENTRY);
669 	zbootinit(pvzone, "PV ENTRY", sizeof (struct pv_entry), pvinit,
670 		initial_pvs);
671 
672 	/*
673 	 * Now it is safe to enable pv_table recording.
674 	 */
675 	pmap_initialized = TRUE;
676 }
677 
678 /*
679  * Initialize the address space (zone) for the pv_entries.  Set a
680  * high water mark so that the system can recover from excessive
681  * numbers of pv entries.
682  */
683 void
684 pmap_init2(void)
685 {
686 	vm_pindex_t shpgperproc = PMAP_SHPGPERPROC;
687 
688 	TUNABLE_LONG_FETCH("vm.pmap.shpgperproc", &shpgperproc);
689 	pv_entry_max = shpgperproc * maxproc + vm_page_array_size;
690 	TUNABLE_LONG_FETCH("vm.pmap.pv_entries", &pv_entry_max);
691 	pv_entry_high_water = 9 * (pv_entry_max / 10);
692 	zinitna(pvzone, NULL, 0, pv_entry_max, ZONE_INTERRUPT);
693 }
694 
695 
696 /***************************************************
697  * Low level helper routines.....
698  ***************************************************/
699 
700 /*
701  * The modification bit is not tracked for any pages in this range. XXX
702  * such pages in this maps should always use pmap_k*() functions and not
703  * be managed anyhow.
704  *
705  * XXX User and kernel address spaces are independant for virtual kernels,
706  * this function only applies to the kernel pmap.
707  */
708 static void
709 pmap_track_modified(pmap_t pmap, vm_offset_t va)
710 {
711 	KKASSERT(pmap != &kernel_pmap ||
712 		 va < clean_sva || va >= clean_eva);
713 }
714 
715 /*
716  * Extract the physical page address associated with the map/VA pair.
717  *
718  * No requirements.
719  */
720 vm_paddr_t
721 pmap_extract(pmap_t pmap, vm_offset_t va, void **handlep)
722 {
723 	vm_paddr_t rtval;
724 	pt_entry_t *pte;
725 	pd_entry_t pde, *pdep;
726 
727 	vm_object_hold(pmap->pm_pteobj);
728 	rtval = 0;
729 	pdep = pmap_pde(pmap, va);
730 	if (pdep != NULL) {
731 		pde = *pdep;
732 		if (pde) {
733 			if ((pde & VPTE_PS) != 0) {
734 				/* JGV */
735 				rtval = (pde & PG_PS_FRAME) | (va & PDRMASK);
736 			} else {
737 				pte = pmap_pde_to_pte(pdep, va);
738 				rtval = (*pte & VPTE_FRAME) | (va & PAGE_MASK);
739 			}
740 		}
741 	}
742 	if (handlep)
743 		*handlep = NULL;	/* XXX */
744 	vm_object_drop(pmap->pm_pteobj);
745 
746 	return rtval;
747 }
748 
749 void
750 pmap_extract_done(void *handle)
751 {
752 	pmap_t pmap;
753 
754 	if (handle) {
755 		pmap = handle;
756 		vm_object_drop(pmap->pm_pteobj);
757 	}
758 }
759 
760 /*
761  * Similar to extract but checks protections, SMP-friendly short-cut for
762  * vm_fault_page[_quick]().
763  *
764  * WARNING! THE RETURNED PAGE IS ONLY HELD AND NEITHER IT NOR ITS TARGET
765  *	    DATA IS SUITABLE FOR WRITING.  Writing can interfere with
766  *	    pageouts flushes, msync, etc.  The hold_count is not enough
767  *	    to avoid races against pageouts and other flush code doesn't
768  *	    care about hold_count.
769  */
770 vm_page_t
771 pmap_fault_page_quick(pmap_t pmap __unused, vm_offset_t vaddr __unused,
772 		      vm_prot_t prot __unused, int *busyp __unused)
773 {
774 	return(NULL);
775 }
776 
777 /*
778  *	Routine:	pmap_kextract
779  *	Function:
780  *		Extract the physical page address associated
781  *		kernel virtual address.
782  */
783 vm_paddr_t
784 pmap_kextract(vm_offset_t va)
785 {
786 	pd_entry_t pde;
787 	vm_paddr_t pa;
788 
789 	KKASSERT(va >= KvaStart && va < KvaEnd);
790 
791 	/*
792 	 * The DMAP region is not included in [KvaStart, KvaEnd)
793 	 */
794 #if 0
795 	if (va >= DMAP_MIN_ADDRESS && va < DMAP_MAX_ADDRESS) {
796 		pa = DMAP_TO_PHYS(va);
797 	} else {
798 #endif
799 		pde = *vtopde(va);
800 		if (pde & VPTE_PS) {
801 			/* JGV */
802 			pa = (pde & PG_PS_FRAME) | (va & PDRMASK);
803 		} else {
804 			/*
805 			 * Beware of a concurrent promotion that changes the
806 			 * PDE at this point!  For example, vtopte() must not
807 			 * be used to access the PTE because it would use the
808 			 * new PDE.  It is, however, safe to use the old PDE
809 			 * because the page table page is preserved by the
810 			 * promotion.
811 			 */
812 			pa = *pmap_pde_to_pte(&pde, va);
813 			pa = (pa & VPTE_FRAME) | (va & PAGE_MASK);
814 		}
815 #if 0
816 	}
817 #endif
818 	return pa;
819 }
820 
821 /***************************************************
822  * Low level mapping routines.....
823  ***************************************************/
824 
825 /*
826  * Enter a mapping into kernel_pmap.  Mappings created in this fashion
827  * are not managed.  Mappings must be immediately accessible on all cpus.
828  *
829  * Call pmap_inval_pte() to invalidate the virtual pte and clean out the
830  * real pmap and handle related races before storing the new vpte.  The
831  * new semantics for kenter require use to do an UNCONDITIONAL invalidation,
832  * because the entry may have previously been cleared without an invalidation.
833  */
834 void
835 pmap_kenter(vm_offset_t va, vm_paddr_t pa)
836 {
837 	pt_entry_t *ptep;
838 	pt_entry_t npte;
839 
840 	KKASSERT(va >= KvaStart && va < KvaEnd);
841 	npte = pa | VPTE_RW | VPTE_V | VPTE_U;
842 	ptep = vtopte(va);
843 
844 #if 1
845 	pmap_inval_pte(ptep, &kernel_pmap, va);
846 #else
847 	if (*pte & VPTE_V)
848 		pmap_inval_pte(ptep, &kernel_pmap, va);
849 #endif
850 	atomic_swap_long(ptep, npte);
851 }
852 
853 /*
854  * Enter an unmanaged KVA mapping for the private use of the current
855  * cpu only.
856  *
857  * It is illegal for the mapping to be accessed by other cpus without
858  * proper invalidation.
859  */
860 int
861 pmap_kenter_quick(vm_offset_t va, vm_paddr_t pa)
862 {
863 	pt_entry_t *ptep;
864 	pt_entry_t npte;
865 	int res;
866 
867 	KKASSERT(va >= KvaStart && va < KvaEnd);
868 
869 	npte = (vpte_t)pa | VPTE_RW | VPTE_V | VPTE_U;
870 	ptep = vtopte(va);
871 
872 #if 1
873 	pmap_inval_pte_quick(ptep, &kernel_pmap, va);
874 	res = 1;
875 #else
876 	/* FUTURE */
877 	res = (*ptep != 0);
878 	if (*pte & VPTE_V)
879 		pmap_inval_pte(pte, &kernel_pmap, va);
880 #endif
881 	atomic_swap_long(ptep, npte);
882 
883 	return res;
884 }
885 
886 /*
887  * Invalidation will occur later, ok to be lazy here.
888  */
889 int
890 pmap_kenter_noinval(vm_offset_t va, vm_paddr_t pa)
891 {
892 	pt_entry_t *ptep;
893 	pt_entry_t npte;
894 	int res;
895 
896 	KKASSERT(va >= KvaStart && va < KvaEnd);
897 
898 	npte = (vpte_t)pa | VPTE_RW | VPTE_V | VPTE_U;
899 	ptep = vtopte(va);
900 #if 1
901 	res = 1;
902 #else
903 	/* FUTURE */
904 	res = (*ptep != 0);
905 #endif
906 	atomic_swap_long(ptep, npte);
907 
908 	return res;
909 }
910 
911 /*
912  * Remove an unmanaged mapping created with pmap_kenter*().
913  */
914 void
915 pmap_kremove(vm_offset_t va)
916 {
917 	pt_entry_t *ptep;
918 
919 	KKASSERT(va >= KvaStart && va < KvaEnd);
920 
921 	ptep = vtopte(va);
922 	atomic_swap_long(ptep, 0);
923 	pmap_inval_pte(ptep, &kernel_pmap, va);
924 }
925 
926 /*
927  * Remove an unmanaged mapping created with pmap_kenter*() but synchronize
928  * only with this cpu.
929  *
930  * Unfortunately because we optimize new entries by testing VPTE_V later
931  * on, we actually still have to synchronize with all the cpus.  XXX maybe
932  * store a junk value and test against 0 in the other places instead?
933  */
934 void
935 pmap_kremove_quick(vm_offset_t va)
936 {
937 	pt_entry_t *ptep;
938 
939 	KKASSERT(va >= KvaStart && va < KvaEnd);
940 
941 	ptep = vtopte(va);
942 	atomic_swap_long(ptep, 0);
943 	pmap_inval_pte(ptep, &kernel_pmap, va); /* NOT _quick */
944 }
945 
946 /*
947  * Invalidation will occur later, ok to be lazy here.
948  */
949 void
950 pmap_kremove_noinval(vm_offset_t va)
951 {
952 	pt_entry_t *ptep;
953 
954 	KKASSERT(va >= KvaStart && va < KvaEnd);
955 
956 	ptep = vtopte(va);
957 	atomic_swap_long(ptep, 0);
958 }
959 
960 /*
961  *	Used to map a range of physical addresses into kernel
962  *	virtual address space.
963  *
964  *	For now, VM is already on, we only need to map the
965  *	specified memory.
966  */
967 vm_offset_t
968 pmap_map(vm_offset_t *virtp, vm_paddr_t start, vm_paddr_t end, int prot)
969 {
970 	return PHYS_TO_DMAP(start);
971 }
972 
973 /*
974  * Map a set of unmanaged VM pages into KVM.
975  */
976 static __inline void
977 _pmap_qenter(vm_offset_t beg_va, vm_page_t *m, int count, int doinval)
978 {
979 	vm_offset_t end_va;
980 	vm_offset_t va;
981 
982 	end_va = beg_va + count * PAGE_SIZE;
983 	KKASSERT(beg_va >= KvaStart && end_va <= KvaEnd);
984 
985 	for (va = beg_va; va < end_va; va += PAGE_SIZE) {
986 		pt_entry_t *ptep;
987 
988 		ptep = vtopte(va);
989 		atomic_swap_long(ptep, VM_PAGE_TO_PHYS(*m) |
990 				       VPTE_RW | VPTE_V | VPTE_U);
991 		++m;
992 	}
993 	if (doinval)
994 		pmap_invalidate_range(&kernel_pmap, beg_va, end_va);
995 	/* pmap_inval_pte(pte, &kernel_pmap, va); */
996 }
997 
998 void
999 pmap_qenter(vm_offset_t beg_va, vm_page_t *m, int count)
1000 {
1001 	_pmap_qenter(beg_va, m, count, 1);
1002 }
1003 
1004 void
1005 pmap_qenter_noinval(vm_offset_t beg_va, vm_page_t *m, int count)
1006 {
1007 	_pmap_qenter(beg_va, m, count, 0);
1008 }
1009 
1010 /*
1011  * Undo the effects of pmap_qenter*().
1012  */
1013 void
1014 pmap_qremove(vm_offset_t beg_va, int count)
1015 {
1016 	vm_offset_t end_va;
1017 	vm_offset_t va;
1018 
1019 	end_va = beg_va + count * PAGE_SIZE;
1020 	KKASSERT(beg_va >= KvaStart && end_va < KvaEnd);
1021 
1022 	for (va = beg_va; va < end_va; va += PAGE_SIZE) {
1023 		pt_entry_t *ptep;
1024 
1025 		ptep = vtopte(va);
1026 		atomic_swap_long(ptep, 0);
1027 	}
1028 	pmap_invalidate_range(&kernel_pmap, beg_va, end_va);
1029 }
1030 
1031 /*
1032  * Unlike the real pmap code, we can't avoid calling the real-kernel.
1033  */
1034 void
1035 pmap_qremove_quick(vm_offset_t va, int count)
1036 {
1037 	pmap_qremove(va, count);
1038 }
1039 
1040 void
1041 pmap_qremove_noinval(vm_offset_t va, int count)
1042 {
1043 	pmap_qremove(va, count);
1044 }
1045 
1046 /*
1047  * This routine works like vm_page_lookup() but also blocks as long as the
1048  * page is busy.  This routine does not busy the page it returns.
1049  *
1050  * Unless the caller is managing objects whos pages are in a known state,
1051  * the call should be made with a critical section held so the page's object
1052  * association remains valid on return.
1053  */
1054 static vm_page_t
1055 pmap_page_lookup(vm_object_t object, vm_pindex_t pindex)
1056 {
1057 	vm_page_t m;
1058 
1059 	ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
1060 	m = vm_page_lookup_busy_wait(object, pindex, TRUE, "pplookp");
1061 
1062 	return(m);
1063 }
1064 
1065 /*
1066  * Create a new thread and optionally associate it with a (new) process.
1067  * NOTE! the new thread's cpu may not equal the current cpu.
1068  */
1069 void
1070 pmap_init_thread(thread_t td)
1071 {
1072 	/* enforce pcb placement */
1073 	td->td_pcb = (struct pcb *)(td->td_kstack + td->td_kstack_size) - 1;
1074 	td->td_savefpu = &td->td_pcb->pcb_save;
1075 	td->td_sp = (char *)td->td_pcb - 16; /* JG is -16 needed on x86_64? */
1076 }
1077 
1078 /*
1079  * This routine directly affects the fork perf for a process.
1080  */
1081 void
1082 pmap_init_proc(struct proc *p)
1083 {
1084 }
1085 
1086 /*
1087  * Unwire a page table which has been removed from the pmap.  We own the
1088  * wire_count, so the page cannot go away.  The page representing the page
1089  * table is passed in unbusied and must be busied if we cannot trivially
1090  * unwire it.
1091  *
1092  * XXX NOTE!  This code is not usually run because we do not currently
1093  *	      implement dynamic page table page removal.  The page in
1094  *	      its parent assumes at least 1 wire count, so no call to this
1095  *	      function ever sees a wire count less than 2.
1096  */
1097 static int
1098 pmap_unwire_pgtable(pmap_t pmap, vm_offset_t va, vm_page_t m)
1099 {
1100 	/*
1101 	 * Try to unwire optimally.  If non-zero is returned the wire_count
1102 	 * is 1 and we must busy the page to unwire it.
1103 	 */
1104 	if (vm_page_unwire_quick(m) == 0)
1105 		return 0;
1106 
1107 	vm_page_busy_wait(m, TRUE, "pmuwpt");
1108 	KASSERT(m->queue == PQ_NONE,
1109 		("_pmap_unwire_pgtable: %p->queue != PQ_NONE", m));
1110 
1111 	if (m->wire_count == 1) {
1112 		/*
1113 		 * Unmap the page table page.
1114 		 */
1115 		/* pmap_inval_add(info, pmap, -1); */
1116 
1117 		if (m->pindex >= (NUPT_TOTAL + NUPD_TOTAL)) {
1118 			/* PDP page */
1119 			pml4_entry_t *pml4;
1120 			pml4 = pmap_pml4e(pmap, va);
1121 			*pml4 = 0;
1122 		} else if (m->pindex >= NUPT_TOTAL) {
1123 			/* PD page */
1124 			pdp_entry_t *pdp;
1125 			pdp = pmap_pdpe(pmap, va);
1126 			*pdp = 0;
1127 		} else {
1128 			/* PT page */
1129 			pd_entry_t *pd;
1130 			pd = pmap_pde(pmap, va);
1131 			*pd = 0;
1132 		}
1133 
1134 		KKASSERT(pmap->pm_stats.resident_count > 0);
1135 		atomic_add_long(&pmap->pm_stats.resident_count, -1);
1136 
1137 		if (pmap->pm_ptphint == m)
1138 			pmap->pm_ptphint = NULL;
1139 
1140 		if (m->pindex < NUPT_TOTAL) {
1141 			/* We just released a PT, unhold the matching PD */
1142 			vm_page_t pdpg;
1143 
1144 			pdpg = PHYS_TO_VM_PAGE(*pmap_pdpe(pmap, va) &
1145 					       VPTE_FRAME);
1146 			pmap_unwire_pgtable(pmap, va, pdpg);
1147 		}
1148 		if (m->pindex >= NUPT_TOTAL &&
1149 		    m->pindex < (NUPT_TOTAL + NUPD_TOTAL)) {
1150 			/* We just released a PD, unhold the matching PDP */
1151 			vm_page_t pdppg;
1152 
1153 			pdppg = PHYS_TO_VM_PAGE(*pmap_pml4e(pmap, va) &
1154 						VPTE_FRAME);
1155 			pmap_unwire_pgtable(pmap, va, pdppg);
1156 		}
1157 
1158 		/*
1159 		 * This was our last wire, the page had better be unwired
1160 		 * after we decrement wire_count.
1161 		 *
1162 		 * FUTURE NOTE: shared page directory page could result in
1163 		 * multiple wire counts.
1164 		 */
1165 		vm_page_unwire(m, 0);
1166 		KKASSERT(m->wire_count == 0);
1167 		vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1168 		vm_page_flash(m);
1169 		vm_page_free(m);
1170 		return 1;
1171 	} else {
1172 		/* XXX SMP race to 1 if not holding vmobj */
1173 		vm_page_unwire(m, 0);
1174 		vm_page_wakeup(m);
1175 		return 0;
1176 	}
1177 }
1178 
1179 /*
1180  * After removing a page table entry, this routine is used to
1181  * conditionally free the page, and manage the hold/wire counts.
1182  *
1183  * If not NULL the caller owns a wire_count on mpte, so it can't disappear.
1184  * If NULL the caller owns a wire_count on what would be the mpte, we must
1185  * look it up.
1186  */
1187 static int
1188 pmap_unuse_pt(pmap_t pmap, vm_offset_t va, vm_page_t mpte)
1189 {
1190 	vm_pindex_t ptepindex;
1191 
1192 	ASSERT_LWKT_TOKEN_HELD(vm_object_token(pmap->pm_pteobj));
1193 
1194 	if (mpte == NULL) {
1195 		/*
1196 		 * page table pages in the kernel_pmap are not managed.
1197 		 */
1198 		if (pmap == &kernel_pmap)
1199 			return(0);
1200 		ptepindex = pmap_pt_pindex(va);
1201 		if (pmap->pm_ptphint &&
1202 		    (pmap->pm_ptphint->pindex == ptepindex)) {
1203 			mpte = pmap->pm_ptphint;
1204 		} else {
1205 			mpte = pmap_page_lookup(pmap->pm_pteobj, ptepindex);
1206 			pmap->pm_ptphint = mpte;
1207 			vm_page_wakeup(mpte);
1208 		}
1209 	}
1210 	return pmap_unwire_pgtable(pmap, va, mpte);
1211 }
1212 
1213 /*
1214  * Initialize pmap0/vmspace0 .  Since process 0 never enters user mode we
1215  * just dummy it up so it works well enough for fork().
1216  *
1217  * In DragonFly, process pmaps may only be used to manipulate user address
1218  * space, never kernel address space.
1219  */
1220 void
1221 pmap_pinit0(struct pmap *pmap)
1222 {
1223 	pmap_pinit(pmap);
1224 }
1225 
1226 /*
1227  * Initialize a preallocated and zeroed pmap structure,
1228  * such as one in a vmspace structure.
1229  */
1230 void
1231 pmap_pinit(struct pmap *pmap)
1232 {
1233 	vm_page_t ptdpg;
1234 
1235 	/*
1236 	 * No need to allocate page table space yet but we do need a valid
1237 	 * page directory table.
1238 	 */
1239 	if (pmap->pm_pml4 == NULL) {
1240 		pmap->pm_pml4 = (pml4_entry_t *)
1241 			kmem_alloc_pageable(&kernel_map, PAGE_SIZE,
1242 					    VM_SUBSYS_PML4);
1243 	}
1244 
1245 	/*
1246 	 * Allocate an object for the ptes
1247 	 */
1248 	if (pmap->pm_pteobj == NULL)
1249 		pmap->pm_pteobj = vm_object_allocate(OBJT_DEFAULT, NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL + 1);
1250 
1251 	/*
1252 	 * Allocate the page directory page, unless we already have
1253 	 * one cached.  If we used the cached page the wire_count will
1254 	 * already be set appropriately.
1255 	 */
1256 	if ((ptdpg = pmap->pm_pdirm) == NULL) {
1257 		ptdpg = vm_page_grab(pmap->pm_pteobj,
1258 				     NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL,
1259 				     VM_ALLOC_NORMAL | VM_ALLOC_RETRY |
1260 				     VM_ALLOC_ZERO);
1261 		pmap->pm_pdirm = ptdpg;
1262 		vm_page_flag_clear(ptdpg, PG_MAPPED | PG_WRITEABLE);
1263 		vm_page_wire(ptdpg);
1264 		vm_page_wakeup(ptdpg);
1265 		pmap_kenter((vm_offset_t)pmap->pm_pml4, VM_PAGE_TO_PHYS(ptdpg));
1266 	}
1267 	pmap->pm_count = 1;
1268 	CPUMASK_ASSZERO(pmap->pm_active);
1269 	pmap->pm_ptphint = NULL;
1270 	RB_INIT(&pmap->pm_pvroot);
1271 	spin_init(&pmap->pm_spin, "pmapinit");
1272 	bzero(&pmap->pm_stats, sizeof pmap->pm_stats);
1273 	pmap->pm_stats.resident_count = 1;
1274 	pmap->pm_stats.wired_count = 1;
1275 }
1276 
1277 /*
1278  * Clean up a pmap structure so it can be physically freed.  This routine
1279  * is called by the vmspace dtor function.  A great deal of pmap data is
1280  * left passively mapped to improve vmspace management so we have a bit
1281  * of cleanup work to do here.
1282  *
1283  * No requirements.
1284  */
1285 void
1286 pmap_puninit(pmap_t pmap)
1287 {
1288 	vm_page_t p;
1289 
1290 	KKASSERT(CPUMASK_TESTZERO(pmap->pm_active));
1291 	if ((p = pmap->pm_pdirm) != NULL) {
1292 		KKASSERT(pmap->pm_pml4 != NULL);
1293 		pmap_kremove((vm_offset_t)pmap->pm_pml4);
1294 		vm_page_busy_wait(p, TRUE, "pgpun");
1295 		vm_page_unwire(p, 0);
1296 		vm_page_flag_clear(p, PG_MAPPED | PG_WRITEABLE);
1297 		vm_page_free(p);
1298 		pmap->pm_pdirm = NULL;
1299 		atomic_add_long(&pmap->pm_stats.wired_count, -1);
1300 		KKASSERT(pmap->pm_stats.wired_count == 0);
1301 	}
1302 	if (pmap->pm_pml4) {
1303 		kmem_free(&kernel_map, (vm_offset_t)pmap->pm_pml4, PAGE_SIZE);
1304 		pmap->pm_pml4 = NULL;
1305 	}
1306 	if (pmap->pm_pteobj) {
1307 		vm_object_deallocate(pmap->pm_pteobj);
1308 		pmap->pm_pteobj = NULL;
1309 	}
1310 }
1311 
1312 /*
1313  * This function is now unused (used to add the pmap to the pmap_list)
1314  */
1315 void
1316 pmap_pinit2(struct pmap *pmap)
1317 {
1318 }
1319 
1320 /*
1321  * Attempt to release and free a vm_page in a pmap.  Returns 1 on success,
1322  * 0 on failure (if the procedure had to sleep).
1323  *
1324  * When asked to remove the page directory page itself, we actually just
1325  * leave it cached so we do not have to incur the SMP inval overhead of
1326  * removing the kernel mapping.  pmap_puninit() will take care of it.
1327  */
1328 static int
1329 pmap_release_free_page(struct pmap *pmap, vm_page_t p)
1330 {
1331 	/*
1332 	 * This code optimizes the case of freeing non-busy
1333 	 * page-table pages.  Those pages are zero now, and
1334 	 * might as well be placed directly into the zero queue.
1335 	 */
1336 	if (vm_page_busy_try(p, TRUE)) {
1337 		vm_page_sleep_busy(p, TRUE, "pmaprl");
1338 		return 1;
1339 	}
1340 
1341 	/*
1342 	 * Remove the page table page from the processes address space.
1343 	 */
1344 	if (p->pindex == NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL) {
1345 		/*
1346 		 * We are the pml4 table itself.
1347 		 */
1348 		/* XXX anything to do here? */
1349 	} else if (p->pindex >= (NUPT_TOTAL + NUPD_TOTAL)) {
1350 		/*
1351 		 * We are a PDP page.
1352 		 * We look for the PML4 entry that points to us.
1353 		 */
1354 		vm_page_t m4;
1355 		pml4_entry_t *pml4;
1356 		int idx;
1357 
1358 		m4 = vm_page_lookup(pmap->pm_pteobj,
1359 				    NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL);
1360 		KKASSERT(m4 != NULL);
1361 		pml4 = (pml4_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m4));
1362 		idx = (p->pindex - (NUPT_TOTAL + NUPD_TOTAL)) % NPML4EPG;
1363 		KKASSERT(pml4[idx] != 0);
1364 		if (pml4[idx] == 0)
1365 			kprintf("pmap_release: Unmapped PML4\n");
1366 		pml4[idx] = 0;
1367 		vm_page_unwire_quick(m4);
1368 	} else if (p->pindex >= NUPT_TOTAL) {
1369 		/*
1370 		 * We are a PD page.
1371 		 * We look for the PDP entry that points to us.
1372 		 */
1373 		vm_page_t m3;
1374 		pdp_entry_t *pdp;
1375 		int idx;
1376 
1377 		m3 = vm_page_lookup(pmap->pm_pteobj,
1378 				    NUPT_TOTAL + NUPD_TOTAL +
1379 				     (p->pindex - NUPT_TOTAL) / NPDPEPG);
1380 		KKASSERT(m3 != NULL);
1381 		pdp = (pdp_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m3));
1382 		idx = (p->pindex - NUPT_TOTAL) % NPDPEPG;
1383 		KKASSERT(pdp[idx] != 0);
1384 		if (pdp[idx] == 0)
1385 			kprintf("pmap_release: Unmapped PDP %d\n", idx);
1386 		pdp[idx] = 0;
1387 		vm_page_unwire_quick(m3);
1388 	} else {
1389 		/* We are a PT page.
1390 		 * We look for the PD entry that points to us.
1391 		 */
1392 		vm_page_t m2;
1393 		pd_entry_t *pd;
1394 		int idx;
1395 
1396 		m2 = vm_page_lookup(pmap->pm_pteobj,
1397 				    NUPT_TOTAL + p->pindex / NPDEPG);
1398 		KKASSERT(m2 != NULL);
1399 		pd = (pd_entry_t *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m2));
1400 		idx = p->pindex % NPDEPG;
1401 		if (pd[idx] == 0)
1402 			kprintf("pmap_release: Unmapped PD %d\n", idx);
1403 		pd[idx] = 0;
1404 		vm_page_unwire_quick(m2);
1405 	}
1406 	KKASSERT(pmap->pm_stats.resident_count > 0);
1407 	atomic_add_long(&pmap->pm_stats.resident_count, -1);
1408 
1409 	if (p->wire_count > 1)  {
1410 		panic("pmap_release: freeing held pt page "
1411 		      "pmap=%p pg=%p dmap=%p pi=%ld {%ld,%ld,%ld}",
1412 		      pmap, p, (void *)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(p)),
1413 		      p->pindex, NUPT_TOTAL, NUPD_TOTAL, NUPDP_TOTAL);
1414 	}
1415 
1416 	if (pmap->pm_ptphint == p)
1417 		pmap->pm_ptphint = NULL;
1418 
1419 	/*
1420 	 * We leave the top-level page table page cached, wired, and mapped in
1421 	 * the pmap until the dtor function (pmap_puninit()) gets called.
1422 	 * However, still clean it up.
1423 	 */
1424 	if (p->pindex == NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL) {
1425 		bzero(pmap->pm_pml4, PAGE_SIZE);
1426 		vm_page_wakeup(p);
1427 	} else {
1428 		vm_page_unwire(p, 0);
1429 		vm_page_flag_clear(p, PG_MAPPED | PG_WRITEABLE);
1430 		vm_page_free(p);
1431 		atomic_add_long(&pmap->pm_stats.wired_count, -1);
1432 	}
1433 	return 0;
1434 }
1435 
1436 /*
1437  * Locate the requested PT, PD, or PDP page table page.
1438  *
1439  * Returns a busied page, caller must vm_page_wakeup() when done.
1440  */
1441 static vm_page_t
1442 _pmap_allocpte(pmap_t pmap, vm_pindex_t ptepindex)
1443 {
1444 	vm_page_t m;
1445 	vm_page_t pm;
1446 	vm_pindex_t pindex;
1447 	pt_entry_t *ptep;
1448 	pt_entry_t data;
1449 
1450 	/*
1451 	 * Find or fabricate a new pagetable page.  A non-zero wire_count
1452 	 * indicates that the page has already been mapped into its parent.
1453 	 */
1454 	m = vm_page_grab(pmap->pm_pteobj, ptepindex,
1455 			 VM_ALLOC_NORMAL | VM_ALLOC_ZERO | VM_ALLOC_RETRY);
1456 	if (m->wire_count != 0)
1457 		return m;
1458 
1459 	/*
1460 	 * Map the page table page into its parent, giving it 1 wire count.
1461 	 */
1462 	vm_page_wire(m);
1463 	vm_page_unqueue(m);
1464 	atomic_add_long(&pmap->pm_stats.resident_count, 1);
1465 	vm_page_flag_set(m, PG_MAPPED | PG_WRITEABLE);
1466 
1467 	data = VM_PAGE_TO_PHYS(m) |
1468 	       VPTE_RW | VPTE_V | VPTE_U | VPTE_A | VPTE_M | VPTE_WIRED;
1469 	atomic_add_long(&pmap->pm_stats.wired_count, 1);
1470 
1471 	if (ptepindex >= (NUPT_TOTAL + NUPD_TOTAL)) {
1472 		/*
1473 		 * Map PDP into the PML4
1474 		 */
1475 		pindex = ptepindex - (NUPT_TOTAL + NUPD_TOTAL);
1476 		pindex &= (NUPDP_TOTAL - 1);
1477 		ptep = (pt_entry_t *)pmap->pm_pml4;
1478 		pm = NULL;
1479 	} else if (ptepindex >= NUPT_TOTAL) {
1480 		/*
1481 		 * Map PD into its PDP
1482 		 */
1483 		pindex = (ptepindex - NUPT_TOTAL) >> NPDPEPGSHIFT;
1484 		pindex += NUPT_TOTAL + NUPD_TOTAL;
1485 		pm = _pmap_allocpte(pmap, pindex);
1486 		pindex = (ptepindex - NUPT_TOTAL) & (NPDPEPG - 1);
1487 		ptep = (void *)PHYS_TO_DMAP(pm->phys_addr);
1488 	} else {
1489 		/*
1490 		 * Map PT into its PD
1491 		 */
1492 		pindex = ptepindex >> NPDPEPGSHIFT;
1493 		pindex += NUPT_TOTAL;
1494 		pm = _pmap_allocpte(pmap, pindex);
1495 		pindex = ptepindex & (NPTEPG - 1);
1496 		ptep = (void *)PHYS_TO_DMAP(pm->phys_addr);
1497 	}
1498 
1499 	/*
1500 	 * Install the pte in (pm).  (m) prevents races.
1501 	 */
1502 	ptep += pindex;
1503 	data = atomic_swap_long(ptep, data);
1504 	if (pm) {
1505 		vm_page_wire_quick(pm);
1506 		vm_page_wakeup(pm);
1507 	}
1508 	pmap->pm_ptphint = pm;
1509 
1510 	return m;
1511 }
1512 
1513 /*
1514  * Determine the page table page required to access the VA in the pmap
1515  * and allocate it if necessary.  Return a held vm_page_t for the page.
1516  *
1517  * Only used with user pmaps.
1518  */
1519 static vm_page_t
1520 pmap_allocpte(pmap_t pmap, vm_offset_t va)
1521 {
1522 	vm_pindex_t ptepindex;
1523 	vm_page_t m;
1524 
1525 	ASSERT_LWKT_TOKEN_HELD(vm_object_token(pmap->pm_pteobj));
1526 
1527 	/*
1528 	 * Calculate pagetable page index, and return the PT page to
1529 	 * the caller.
1530 	 */
1531 	ptepindex = pmap_pt_pindex(va);
1532 	m = _pmap_allocpte(pmap, ptepindex);
1533 
1534 	return m;
1535 }
1536 
1537 /***************************************************
1538  * Pmap allocation/deallocation routines.
1539  ***************************************************/
1540 
1541 /*
1542  * Release any resources held by the given physical map.
1543  * Called when a pmap initialized by pmap_pinit is being released.
1544  * Should only be called if the map contains no valid mappings.
1545  */
1546 static int pmap_release_callback(struct vm_page *p, void *data);
1547 
1548 void
1549 pmap_release(struct pmap *pmap)
1550 {
1551 	vm_object_t object = pmap->pm_pteobj;
1552 	struct rb_vm_page_scan_info info;
1553 
1554 	KKASSERT(pmap != &kernel_pmap);
1555 
1556 #if defined(DIAGNOSTIC)
1557 	if (object->ref_count != 1)
1558 		panic("pmap_release: pteobj reference count != 1");
1559 #endif
1560 
1561 	info.pmap = pmap;
1562 	info.object = object;
1563 
1564 	KASSERT(CPUMASK_TESTZERO(pmap->pm_active),
1565 		("pmap %p still active! %016jx",
1566 		pmap,
1567 		(uintmax_t)CPUMASK_LOWMASK(pmap->pm_active)));
1568 
1569 	vm_object_hold(object);
1570 	do {
1571 		info.error = 0;
1572 		info.mpte = NULL;
1573 		info.limit = object->generation;
1574 
1575 		vm_page_rb_tree_RB_SCAN(&object->rb_memq, NULL,
1576 				        pmap_release_callback, &info);
1577 		if (info.error == 0 && info.mpte) {
1578 			if (pmap_release_free_page(pmap, info.mpte))
1579 				info.error = 1;
1580 		}
1581 	} while (info.error);
1582 
1583 	pmap->pm_ptphint = NULL;
1584 
1585 	KASSERT((pmap->pm_stats.wired_count == (pmap->pm_pdirm != NULL)),
1586 		("pmap_release: dangling count %p %ld",
1587 		pmap, pmap->pm_stats.wired_count));
1588 
1589 	vm_object_drop(object);
1590 }
1591 
1592 static int
1593 pmap_release_callback(struct vm_page *p, void *data)
1594 {
1595 	struct rb_vm_page_scan_info *info = data;
1596 
1597 	if (p->pindex == NUPT_TOTAL + NUPD_TOTAL + NUPDP_TOTAL) {
1598 		info->mpte = p;
1599 		return(0);
1600 	}
1601 	if (pmap_release_free_page(info->pmap, p)) {
1602 		info->error = 1;
1603 		return(-1);
1604 	}
1605 	if (info->object->generation != info->limit) {
1606 		info->error = 1;
1607 		return(-1);
1608 	}
1609 	return(0);
1610 }
1611 
1612 /*
1613  * Grow the number of kernel page table entries, if needed.
1614  *
1615  * kernel_map must be locked exclusively by the caller.
1616  */
1617 void
1618 pmap_growkernel(vm_offset_t kstart, vm_offset_t kend)
1619 {
1620 	vm_offset_t addr;
1621 	vm_paddr_t paddr;
1622 	vm_offset_t ptppaddr;
1623 	vm_page_t nkpg;
1624 	pd_entry_t *pde, newpdir;
1625 	pdp_entry_t newpdp;
1626 
1627 	addr = kend;
1628 
1629 	vm_object_hold(&kptobj);
1630 	if (kernel_vm_end == 0) {
1631 		kernel_vm_end = KvaStart;
1632 		nkpt = 0;
1633 		while ((*pmap_pde(&kernel_pmap, kernel_vm_end) & VPTE_V) != 0) {
1634 			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) & ~(PAGE_SIZE * NPTEPG - 1);
1635 			nkpt++;
1636 			if (kernel_vm_end - 1 >= vm_map_max(&kernel_map)) {
1637 				kernel_vm_end = vm_map_max(&kernel_map);
1638 				break;
1639 			}
1640 		}
1641 	}
1642 	addr = roundup2(addr, PAGE_SIZE * NPTEPG);
1643 	if (addr - 1 >= vm_map_max(&kernel_map))
1644 		addr = vm_map_max(&kernel_map);
1645 	while (kernel_vm_end < addr) {
1646 		pde = pmap_pde(&kernel_pmap, kernel_vm_end);
1647 		if (pde == NULL) {
1648 			/* We need a new PDP entry */
1649 			nkpg = vm_page_alloc(&kptobj, nkpt,
1650 			                     VM_ALLOC_NORMAL |
1651 					     VM_ALLOC_SYSTEM |
1652 					     VM_ALLOC_INTERRUPT);
1653 			if (nkpg == NULL) {
1654 				panic("pmap_growkernel: no memory to "
1655 				      "grow kernel");
1656 			}
1657 			paddr = VM_PAGE_TO_PHYS(nkpg);
1658 			pmap_zero_page(paddr);
1659 			newpdp = (pdp_entry_t)(paddr |
1660 					       VPTE_V | VPTE_RW | VPTE_U |
1661 					       VPTE_A | VPTE_M | VPTE_WIRED);
1662 			*pmap_pdpe(&kernel_pmap, kernel_vm_end) = newpdp;
1663 			atomic_add_long(&kernel_pmap.pm_stats.wired_count, 1);
1664 			nkpt++;
1665 			continue; /* try again */
1666 		}
1667 		if ((*pde & VPTE_V) != 0) {
1668 			kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) &
1669 					~(PAGE_SIZE * NPTEPG - 1);
1670 			if (kernel_vm_end - 1 >= vm_map_max(&kernel_map)) {
1671 				kernel_vm_end = vm_map_max(&kernel_map);
1672 				break;
1673 			}
1674 			continue;
1675 		}
1676 
1677 		/*
1678 		 * This index is bogus, but out of the way
1679 		 */
1680 		nkpg = vm_page_alloc(&kptobj, nkpt,
1681 				     VM_ALLOC_NORMAL |
1682 				     VM_ALLOC_SYSTEM |
1683 				     VM_ALLOC_INTERRUPT);
1684 		if (nkpg == NULL)
1685 			panic("pmap_growkernel: no memory to grow kernel");
1686 
1687 		vm_page_wire(nkpg);
1688 		ptppaddr = VM_PAGE_TO_PHYS(nkpg);
1689 		pmap_zero_page(ptppaddr);
1690 		newpdir = (pd_entry_t)(ptppaddr |
1691 				       VPTE_V | VPTE_RW | VPTE_U |
1692 				       VPTE_A | VPTE_M | VPTE_WIRED);
1693 		*pmap_pde(&kernel_pmap, kernel_vm_end) = newpdir;
1694 		atomic_add_long(&kernel_pmap.pm_stats.wired_count, 1);
1695 		nkpt++;
1696 
1697 		kernel_vm_end = (kernel_vm_end + PAGE_SIZE * NPTEPG) &
1698 				~(PAGE_SIZE * NPTEPG - 1);
1699 		if (kernel_vm_end - 1 >= vm_map_max(&kernel_map)) {
1700 			kernel_vm_end = vm_map_max(&kernel_map);
1701 			break;
1702 		}
1703 	}
1704 	vm_object_drop(&kptobj);
1705 }
1706 
1707 /*
1708  * Add a reference to the specified pmap.
1709  *
1710  * No requirements.
1711  */
1712 void
1713 pmap_reference(pmap_t pmap)
1714 {
1715 	if (pmap)
1716 		atomic_add_int(&pmap->pm_count, 1);
1717 }
1718 
1719 /************************************************************************
1720  *	   		VMSPACE MANAGEMENT				*
1721  ************************************************************************
1722  *
1723  * The VMSPACE management we do in our virtual kernel must be reflected
1724  * in the real kernel.  This is accomplished by making vmspace system
1725  * calls to the real kernel.
1726  */
1727 void
1728 cpu_vmspace_alloc(struct vmspace *vm)
1729 {
1730 	int r;
1731 	void *rp;
1732 	vpte_t vpte;
1733 
1734 	/*
1735 	 * If VMM enable, don't do nothing, we
1736 	 * are able to use real page tables
1737 	 */
1738 	if (vmm_enabled)
1739 		return;
1740 
1741 #define USER_SIZE	(VM_MAX_USER_ADDRESS - VM_MIN_USER_ADDRESS)
1742 
1743 	if (vmspace_create(&vm->vm_pmap, 0, NULL) < 0)
1744 		panic("vmspace_create() failed");
1745 
1746 	rp = vmspace_mmap(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE,
1747 			  PROT_READ|PROT_WRITE|PROT_EXEC,
1748 			  MAP_FILE|MAP_SHARED|MAP_VPAGETABLE|MAP_FIXED,
1749 			  MemImageFd, 0);
1750 	if (rp == MAP_FAILED)
1751 		panic("vmspace_mmap: failed");
1752 	vmspace_mcontrol(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE,
1753 			 MADV_NOSYNC, 0);
1754 	vpte = VM_PAGE_TO_PHYS(vmspace_pmap(vm)->pm_pdirm) |
1755 			       VPTE_RW | VPTE_V | VPTE_U;
1756 	r = vmspace_mcontrol(&vm->vm_pmap, VM_MIN_USER_ADDRESS, USER_SIZE,
1757 			     MADV_SETMAP, vpte);
1758 	if (r < 0)
1759 		panic("vmspace_mcontrol: failed");
1760 }
1761 
1762 void
1763 cpu_vmspace_free(struct vmspace *vm)
1764 {
1765 	/*
1766 	 * If VMM enable, don't do nothing, we
1767 	 * are able to use real page tables
1768 	 */
1769 	if (vmm_enabled)
1770 		return;
1771 
1772 	if (vmspace_destroy(&vm->vm_pmap) < 0)
1773 		panic("vmspace_destroy() failed");
1774 }
1775 
1776 /***************************************************
1777 * page management routines.
1778  ***************************************************/
1779 
1780 /*
1781  * free the pv_entry back to the free list.  This function may be
1782  * called from an interrupt.
1783  */
1784 static __inline void
1785 free_pv_entry(pv_entry_t pv)
1786 {
1787 	atomic_add_long(&pv_entry_count, -1);
1788 	zfree(pvzone, pv);
1789 }
1790 
1791 /*
1792  * get a new pv_entry, allocating a block from the system
1793  * when needed.  This function may be called from an interrupt.
1794  */
1795 static pv_entry_t
1796 get_pv_entry(void)
1797 {
1798 	atomic_add_long(&pv_entry_count, 1);
1799 	if (pv_entry_high_water &&
1800 	    (pv_entry_count > pv_entry_high_water) &&
1801 	    atomic_swap_int(&pmap_pagedaemon_waken, 1) == 0) {
1802 		wakeup(&vm_pages_needed);
1803 	}
1804 	return zalloc(pvzone);
1805 }
1806 
1807 /*
1808  * This routine is very drastic, but can save the system
1809  * in a pinch.
1810  *
1811  * No requirements.
1812  */
1813 void
1814 pmap_collect(void)
1815 {
1816 	int i;
1817 	vm_page_t m;
1818 	static int warningdone=0;
1819 
1820 	if (pmap_pagedaemon_waken == 0)
1821 		return;
1822 	pmap_pagedaemon_waken = 0;
1823 
1824 	if (warningdone < 5) {
1825 		kprintf("pmap_collect: collecting pv entries -- "
1826 			"suggest increasing PMAP_SHPGPERPROC\n");
1827 		warningdone++;
1828 	}
1829 
1830 	for (i = 0; i < vm_page_array_size; i++) {
1831 		m = &vm_page_array[i];
1832 		if (m->wire_count || m->hold_count)
1833 			continue;
1834 		if (vm_page_busy_try(m, TRUE) == 0) {
1835 			if (m->wire_count == 0 && m->hold_count == 0) {
1836 				pmap_remove_all(m);
1837 			}
1838 			vm_page_wakeup(m);
1839 		}
1840 	}
1841 }
1842 
1843 
1844 /*
1845  * If it is the first entry on the list, it is actually
1846  * in the header and we must copy the following entry up
1847  * to the header.  Otherwise we must search the list for
1848  * the entry.  In either case we free the now unused entry.
1849  *
1850  * pmap->pm_pteobj must be held and (m) must be spin-locked by the caller.
1851  */
1852 static int
1853 pmap_remove_entry(struct pmap *pmap, vm_page_t m, vm_offset_t va)
1854 {
1855 	pv_entry_t pv;
1856 	int rtval;
1857 
1858 	vm_page_spin_lock(m);
1859 	pv = pv_entry_rb_tree_RB_LOOKUP(&pmap->pm_pvroot, va);
1860 
1861 	/*
1862 	 * Note that pv_ptem is NULL if the page table page itself is not
1863 	 * managed, even if the page being removed IS managed.
1864 	 */
1865 	rtval = 0;
1866 	if (pv) {
1867 		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
1868 		if (TAILQ_EMPTY(&m->md.pv_list))
1869 			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
1870 		m->md.pv_list_count--;
1871 		KKASSERT(m->md.pv_list_count >= 0);
1872 		pv_entry_rb_tree_RB_REMOVE(&pmap->pm_pvroot, pv);
1873 		atomic_add_int(&pmap->pm_generation, 1);
1874 		vm_page_spin_unlock(m);
1875 		rtval = pmap_unuse_pt(pmap, va, pv->pv_ptem);
1876 		free_pv_entry(pv);
1877 	} else {
1878 		vm_page_spin_unlock(m);
1879 		kprintf("pmap_remove_entry: could not find "
1880 			"pmap=%p m=%p va=%016jx\n",
1881 			pmap, m, va);
1882 	}
1883 	return rtval;
1884 }
1885 
1886 /*
1887  * Create a pv entry for page at pa for (pmap, va).  If the page table page
1888  * holding the VA is managed, mpte will be non-NULL.
1889  *
1890  * pmap->pm_pteobj must be held and (m) must be spin-locked by the caller.
1891  */
1892 static void
1893 pmap_insert_entry(pmap_t pmap, vm_offset_t va, vm_page_t mpte, vm_page_t m,
1894 		  pv_entry_t pv)
1895 {
1896 	pv->pv_va = va;
1897 	pv->pv_pmap = pmap;
1898 	pv->pv_ptem = mpte;
1899 
1900 	m->md.pv_list_count++;
1901 	TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
1902 	pv = pv_entry_rb_tree_RB_INSERT(&pmap->pm_pvroot, pv);
1903 	vm_page_flag_set(m, PG_MAPPED);
1904 	KKASSERT(pv == NULL);
1905 }
1906 
1907 /*
1908  * pmap_remove_pte: do the things to unmap a page in a process
1909  *
1910  * Caller holds pmap->pm_pteobj and holds the associated page table
1911  * page busy to prevent races.
1912  */
1913 static int
1914 pmap_remove_pte(struct pmap *pmap, pt_entry_t *ptq, pt_entry_t oldpte,
1915 		vm_offset_t va)
1916 {
1917 	vm_page_t m;
1918 	int error;
1919 
1920 	if (ptq)
1921 		oldpte = pmap_inval_loadandclear(ptq, pmap, va);
1922 
1923 	if (oldpte & VPTE_WIRED)
1924 		atomic_add_long(&pmap->pm_stats.wired_count, -1);
1925 	KKASSERT(pmap->pm_stats.wired_count >= 0);
1926 
1927 #if 0
1928 	/*
1929 	 * Machines that don't support invlpg, also don't support
1930 	 * PG_G.  XXX PG_G is disabled for SMP so don't worry about
1931 	 * the SMP case.
1932 	 */
1933 	if (oldpte & PG_G)
1934 		cpu_invlpg((void *)va);
1935 #endif
1936 	KKASSERT(pmap->pm_stats.resident_count > 0);
1937 	atomic_add_long(&pmap->pm_stats.resident_count, -1);
1938 	if (oldpte & VPTE_MANAGED) {
1939 		m = PHYS_TO_VM_PAGE(oldpte);
1940 
1941 		/*
1942 		 * NOTE: pmap_remove_entry() will spin-lock the page
1943 		 */
1944 		if (oldpte & VPTE_M) {
1945 #if defined(PMAP_DIAGNOSTIC)
1946 			if (pmap_nw_modified(oldpte)) {
1947 				kprintf("pmap_remove: modified page not "
1948 					"writable: va: 0x%lx, pte: 0x%lx\n",
1949 					va, oldpte);
1950 			}
1951 #endif
1952 			pmap_track_modified(pmap, va);
1953 			vm_page_dirty(m);
1954 		}
1955 		if (oldpte & VPTE_A)
1956 			vm_page_flag_set(m, PG_REFERENCED);
1957 		error = pmap_remove_entry(pmap, m, va);
1958 	} else {
1959 		error = pmap_unuse_pt(pmap, va, NULL);
1960 	}
1961 	return error;
1962 }
1963 
1964 /*
1965  * pmap_remove_page:
1966  *
1967  * Remove a single page from a process address space.
1968  *
1969  * This function may not be called from an interrupt if the pmap is
1970  * not kernel_pmap.
1971  *
1972  * Caller holds pmap->pm_pteobj
1973  */
1974 static void
1975 pmap_remove_page(struct pmap *pmap, vm_offset_t va)
1976 {
1977 	pt_entry_t *pte;
1978 
1979 	pte = pmap_pte(pmap, va);
1980 	if (pte == NULL)
1981 		return;
1982 	if ((*pte & VPTE_V) == 0)
1983 		return;
1984 	pmap_remove_pte(pmap, pte, 0, va);
1985 }
1986 
1987 /*
1988  * Remove the given range of addresses from the specified map.
1989  *
1990  * It is assumed that the start and end are properly rounded to
1991  * the page size.
1992  *
1993  * This function may not be called from an interrupt if the pmap is
1994  * not kernel_pmap.
1995  *
1996  * No requirements.
1997  */
1998 void
1999 pmap_remove(struct pmap *pmap, vm_offset_t sva, vm_offset_t eva)
2000 {
2001 	vm_offset_t va_next;
2002 	pml4_entry_t *pml4e;
2003 	pdp_entry_t *pdpe;
2004 	pd_entry_t ptpaddr, *pde;
2005 	pt_entry_t *pte;
2006 	vm_page_t pt_m;
2007 
2008 	if (pmap == NULL)
2009 		return;
2010 
2011 	vm_object_hold(pmap->pm_pteobj);
2012 	KKASSERT(pmap->pm_stats.resident_count >= 0);
2013 	if (pmap->pm_stats.resident_count == 0) {
2014 		vm_object_drop(pmap->pm_pteobj);
2015 		return;
2016 	}
2017 
2018 	/*
2019 	 * special handling of removing one page.  a very
2020 	 * common operation and easy to short circuit some
2021 	 * code.
2022 	 */
2023 	if (sva + PAGE_SIZE == eva) {
2024 		pde = pmap_pde(pmap, sva);
2025 		if (pde && (*pde & VPTE_PS) == 0) {
2026 			pmap_remove_page(pmap, sva);
2027 			vm_object_drop(pmap->pm_pteobj);
2028 			return;
2029 		}
2030 	}
2031 
2032 	for (; sva < eva; sva = va_next) {
2033 		pml4e = pmap_pml4e(pmap, sva);
2034 		if ((*pml4e & VPTE_V) == 0) {
2035 			va_next = (sva + NBPML4) & ~PML4MASK;
2036 			if (va_next < sva)
2037 				va_next = eva;
2038 			continue;
2039 		}
2040 
2041 		pdpe = pmap_pml4e_to_pdpe(pml4e, sva);
2042 		if ((*pdpe & VPTE_V) == 0) {
2043 			va_next = (sva + NBPDP) & ~PDPMASK;
2044 			if (va_next < sva)
2045 				va_next = eva;
2046 			continue;
2047 		}
2048 
2049 		/*
2050 		 * Calculate index for next page table.
2051 		 */
2052 		va_next = (sva + NBPDR) & ~PDRMASK;
2053 		if (va_next < sva)
2054 			va_next = eva;
2055 
2056 		pde = pmap_pdpe_to_pde(pdpe, sva);
2057 		ptpaddr = *pde;
2058 
2059 		/*
2060 		 * Weed out invalid mappings.
2061 		 */
2062 		if (ptpaddr == 0)
2063 			continue;
2064 
2065 		/*
2066 		 * Check for large page.
2067 		 */
2068 		if ((ptpaddr & VPTE_PS) != 0) {
2069 			/* JG FreeBSD has more complex treatment here */
2070 			KKASSERT(*pde != 0);
2071 			pmap_inval_pde(pde, pmap, sva);
2072 			atomic_add_long(&pmap->pm_stats.resident_count,
2073 				       -NBPDR / PAGE_SIZE);
2074 			continue;
2075 		}
2076 
2077 		/*
2078 		 * Limit our scan to either the end of the va represented
2079 		 * by the current page table page, or to the end of the
2080 		 * range being removed.
2081 		 */
2082 		if (va_next > eva)
2083 			va_next = eva;
2084 
2085 		/*
2086 		 * NOTE: pmap_remove_pte() can block.
2087 		 */
2088 		pt_m = pmap_hold_pt_page(pde, sva);
2089 		for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++,
2090 		     sva += PAGE_SIZE) {
2091 			if (*pte) {
2092 				if (pmap_remove_pte(pmap, pte, 0, sva))
2093 					break;
2094 			}
2095 		}
2096 		vm_page_unhold(pt_m);
2097 	}
2098 	vm_object_drop(pmap->pm_pteobj);
2099 }
2100 
2101 /*
2102  * Removes this physical page from all physical maps in which it resides.
2103  * Reflects back modify bits to the pager.
2104  *
2105  * This routine may not be called from an interrupt.
2106  *
2107  * No requirements.
2108  */
2109 static void
2110 pmap_remove_all(vm_page_t m)
2111 {
2112 	pt_entry_t *pte, tpte;
2113 	pv_entry_t pv;
2114 	vm_object_t pmobj;
2115 	pmap_t pmap;
2116 
2117 #if defined(PMAP_DIAGNOSTIC)
2118 	/*
2119 	 * XXX this makes pmap_page_protect(NONE) illegal for non-managed
2120 	 * pages!
2121 	 */
2122 	if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
2123 		panic("pmap_page_protect: illegal for unmanaged page, va: 0x%08llx", (long long)VM_PAGE_TO_PHYS(m));
2124 	}
2125 #endif
2126 
2127 restart:
2128 	vm_page_spin_lock(m);
2129 	while ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
2130 		pmap = pv->pv_pmap;
2131 		pmobj = pmap->pm_pteobj;
2132 
2133 		/*
2134 		 * Handle reversed lock ordering
2135 		 */
2136 		if (vm_object_hold_try(pmobj) == 0) {
2137 			refcount_acquire(&pmobj->hold_count);
2138 			vm_page_spin_unlock(m);
2139 			vm_object_lock(pmobj);
2140 			vm_page_spin_lock(m);
2141 			if (pv != TAILQ_FIRST(&m->md.pv_list) ||
2142 			    pmap != pv->pv_pmap ||
2143 			    pmobj != pmap->pm_pteobj) {
2144 				vm_page_spin_unlock(m);
2145 				vm_object_drop(pmobj);
2146 				goto restart;
2147 			}
2148 		}
2149 
2150 		KKASSERT(pmap->pm_stats.resident_count > 0);
2151 		atomic_add_long(&pmap->pm_stats.resident_count, -1);
2152 
2153 		pte = pmap_pte(pmap, pv->pv_va);
2154 		KKASSERT(pte != NULL);
2155 
2156 		tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
2157 		if (tpte & VPTE_WIRED)
2158 			atomic_add_long(&pmap->pm_stats.wired_count, -1);
2159 		KKASSERT(pmap->pm_stats.wired_count >= 0);
2160 
2161 		if (tpte & VPTE_A)
2162 			vm_page_flag_set(m, PG_REFERENCED);
2163 
2164 		/*
2165 		 * Update the vm_page_t clean and reference bits.
2166 		 */
2167 		if (tpte & VPTE_M) {
2168 #if defined(PMAP_DIAGNOSTIC)
2169 			if (pmap_nw_modified(tpte)) {
2170 				kprintf(
2171 	"pmap_remove_all: modified page not writable: va: 0x%lx, pte: 0x%lx\n",
2172 				    pv->pv_va, tpte);
2173 			}
2174 #endif
2175 			pmap_track_modified(pmap, pv->pv_va);
2176 			vm_page_dirty(m);
2177 		}
2178 		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2179 		if (TAILQ_EMPTY(&m->md.pv_list))
2180 			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2181 		m->md.pv_list_count--;
2182 		KKASSERT(m->md.pv_list_count >= 0);
2183 		pv_entry_rb_tree_RB_REMOVE(&pmap->pm_pvroot, pv);
2184 		atomic_add_int(&pmap->pm_generation, 1);
2185 		vm_page_spin_unlock(m);
2186 		pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem);
2187 		free_pv_entry(pv);
2188 
2189 		vm_object_drop(pmobj);
2190 		vm_page_spin_lock(m);
2191 	}
2192 	KKASSERT((m->flags & (PG_MAPPED|PG_WRITEABLE)) == 0);
2193 	vm_page_spin_unlock(m);
2194 }
2195 
2196 /*
2197  * Removes the page from a particular pmap
2198  */
2199 void
2200 pmap_remove_specific(pmap_t pmap, vm_page_t m)
2201 {
2202 	pt_entry_t *pte, tpte;
2203 	pv_entry_t pv;
2204 
2205 	vm_object_hold(pmap->pm_pteobj);
2206 again:
2207 	vm_page_spin_lock(m);
2208 	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2209 		if (pv->pv_pmap != pmap)
2210 			continue;
2211 
2212 		KKASSERT(pmap->pm_stats.resident_count > 0);
2213 		atomic_add_long(&pmap->pm_stats.resident_count, -1);
2214 
2215 		pte = pmap_pte(pmap, pv->pv_va);
2216 		KKASSERT(pte != NULL);
2217 
2218 		tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
2219 		if (tpte & VPTE_WIRED)
2220 			atomic_add_long(&pmap->pm_stats.wired_count, -1);
2221 		KKASSERT(pmap->pm_stats.wired_count >= 0);
2222 
2223 		if (tpte & VPTE_A)
2224 			vm_page_flag_set(m, PG_REFERENCED);
2225 
2226 		/*
2227 		 * Update the vm_page_t clean and reference bits.
2228 		 */
2229 		if (tpte & VPTE_M) {
2230 			pmap_track_modified(pmap, pv->pv_va);
2231 			vm_page_dirty(m);
2232 		}
2233 		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2234 		pv_entry_rb_tree_RB_REMOVE(&pmap->pm_pvroot, pv);
2235 		atomic_add_int(&pmap->pm_generation, 1);
2236 		m->md.pv_list_count--;
2237 		KKASSERT(m->md.pv_list_count >= 0);
2238 		if (TAILQ_EMPTY(&m->md.pv_list))
2239 			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2240 		pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem);
2241 		vm_page_spin_unlock(m);
2242 		free_pv_entry(pv);
2243 		goto again;
2244 	}
2245 	vm_page_spin_unlock(m);
2246 	vm_object_drop(pmap->pm_pteobj);
2247 }
2248 
2249 /*
2250  * Set the physical protection on the specified range of this map
2251  * as requested.
2252  *
2253  * This function may not be called from an interrupt if the map is
2254  * not the kernel_pmap.
2255  *
2256  * No requirements.
2257  */
2258 void
2259 pmap_protect(pmap_t pmap, vm_offset_t sva, vm_offset_t eva, vm_prot_t prot)
2260 {
2261 	vm_offset_t va_next;
2262 	pml4_entry_t *pml4e;
2263 	pdp_entry_t *pdpe;
2264 	pd_entry_t ptpaddr, *pde;
2265 	pt_entry_t *pte;
2266 	vm_page_t pt_m;
2267 
2268 	if (pmap == NULL)
2269 		return;
2270 
2271 	if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == VM_PROT_NONE) {
2272 		pmap_remove(pmap, sva, eva);
2273 		return;
2274 	}
2275 
2276 	if (prot & VM_PROT_WRITE)
2277 		return;
2278 
2279 	vm_object_hold(pmap->pm_pteobj);
2280 
2281 	for (; sva < eva; sva = va_next) {
2282 		pml4e = pmap_pml4e(pmap, sva);
2283 		if ((*pml4e & VPTE_V) == 0) {
2284 			va_next = (sva + NBPML4) & ~PML4MASK;
2285 			if (va_next < sva)
2286 				va_next = eva;
2287 			continue;
2288 		}
2289 
2290 		pdpe = pmap_pml4e_to_pdpe(pml4e, sva);
2291 		if ((*pdpe & VPTE_V) == 0) {
2292 			va_next = (sva + NBPDP) & ~PDPMASK;
2293 			if (va_next < sva)
2294 				va_next = eva;
2295 			continue;
2296 		}
2297 
2298 		va_next = (sva + NBPDR) & ~PDRMASK;
2299 		if (va_next < sva)
2300 			va_next = eva;
2301 
2302 		pde = pmap_pdpe_to_pde(pdpe, sva);
2303 		ptpaddr = *pde;
2304 
2305 #if 0
2306 		/*
2307 		 * Check for large page.
2308 		 */
2309 		if ((ptpaddr & VPTE_PS) != 0) {
2310 			/* JG correct? */
2311 			pmap_clean_pde(pde, pmap, sva);
2312 			atomic_add_long(&pmap->pm_stats.resident_count,
2313 					-NBPDR / PAGE_SIZE);
2314 			continue;
2315 		}
2316 #endif
2317 
2318 		/*
2319 		 * Weed out invalid mappings. Note: we assume that the page
2320 		 * directory table is always allocated, and in kernel virtual.
2321 		 */
2322 		if (ptpaddr == 0)
2323 			continue;
2324 
2325 		if (va_next > eva)
2326 			va_next = eva;
2327 
2328 		pt_m = pmap_hold_pt_page(pde, sva);
2329 		for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++,
2330 		    sva += PAGE_SIZE) {
2331 			/*
2332 			 * Clean managed pages and also check the accessed
2333 			 * bit.  Just remove write perms for unmanaged
2334 			 * pages.  Be careful of races, turning off write
2335 			 * access will force a fault rather then setting
2336 			 * the modified bit at an unexpected time.
2337 			 */
2338 			pmap_track_modified(pmap, sva);
2339 			pmap_clean_pte(pte, pmap, sva, NULL);
2340 		}
2341 		vm_page_unhold(pt_m);
2342 	}
2343 	vm_object_drop(pmap->pm_pteobj);
2344 }
2345 
2346 /*
2347  * Enter a managed page into a pmap.  If the page is not wired related pmap
2348  * data can be destroyed at any time for later demand-operation.
2349  *
2350  * Insert the vm_page (m) at virtual address (v) in (pmap), with the
2351  * specified protection, and wire the mapping if requested.
2352  *
2353  * NOTE: This routine may not lazy-evaluate or lose information.  The
2354  *	 page must actually be inserted into the given map NOW.
2355  *
2356  * NOTE: When entering a page at a KVA address, the pmap must be the
2357  *	 kernel_pmap.
2358  *
2359  * No requirements.
2360  */
2361 void
2362 pmap_enter(pmap_t pmap, vm_offset_t va, vm_page_t m, vm_prot_t prot,
2363 	   boolean_t wired, vm_map_entry_t entry __unused)
2364 {
2365 	vm_paddr_t pa;
2366 	pv_entry_t pv;
2367 	pt_entry_t *pte;
2368 	pt_entry_t origpte, newpte;
2369 	vm_paddr_t opa;
2370 	vm_page_t mpte;
2371 
2372 	if (pmap == NULL)
2373 		return;
2374 
2375 	va = trunc_page(va);
2376 
2377 	vm_object_hold(pmap->pm_pteobj);
2378 
2379 	/*
2380 	 * Get the page table page.   The kernel_pmap's page table pages
2381 	 * are preallocated and have no associated vm_page_t.
2382 	 *
2383 	 * If not NULL, mpte will be busied and we must vm_page_wakeup()
2384 	 * to cleanup.  There will already be at least one wire count from
2385 	 * it being mapped into its parent.
2386 	 */
2387 	if (pmap == &kernel_pmap) {
2388 		mpte = NULL;
2389 		pte = vtopte(va);
2390 	} else {
2391 		mpte = pmap_allocpte(pmap, va);
2392 		pte = (void *)PHYS_TO_DMAP(mpte->phys_addr);
2393 		pte += pmap_pte_index(va);
2394 	}
2395 
2396 	/*
2397 	 * Deal with races against the kernel's real MMU by cleaning the
2398 	 * page, even if we are re-entering the same page.
2399 	 */
2400 	pa = VM_PAGE_TO_PHYS(m);
2401 	origpte = pmap_inval_loadandclear(pte, pmap, va);
2402 	/*origpte = pmap_clean_pte(pte, pmap, va, NULL);*/
2403 	opa = origpte & VPTE_FRAME;
2404 
2405 	if (origpte & VPTE_PS)
2406 		panic("pmap_enter: attempted pmap_enter on 2MB page");
2407 
2408 	if ((origpte & (VPTE_MANAGED|VPTE_M)) == (VPTE_MANAGED|VPTE_M)) {
2409 		vm_page_t om;
2410 
2411 		pmap_track_modified(pmap, va);
2412 		om = PHYS_TO_VM_PAGE(opa);
2413 		vm_page_dirty(om);
2414 	}
2415 
2416 	/*
2417 	 * Mapping has not changed, must be protection or wiring change.
2418 	 */
2419 	if (origpte && (opa == pa)) {
2420 		/*
2421 		 * Wiring change, just update stats. We don't worry about
2422 		 * wiring PT pages as they remain resident as long as there
2423 		 * are valid mappings in them. Hence, if a user page is wired,
2424 		 * the PT page will be also.
2425 		 */
2426 		if (wired && ((origpte & VPTE_WIRED) == 0))
2427 			atomic_add_long(&pmap->pm_stats.wired_count, 1);
2428 		else if (!wired && (origpte & VPTE_WIRED))
2429 			atomic_add_long(&pmap->pm_stats.wired_count, -1);
2430 
2431 		if (origpte & VPTE_MANAGED) {
2432 			pa |= VPTE_MANAGED;
2433 			KKASSERT(m->flags & PG_MAPPED);
2434 			KKASSERT((m->flags & PG_FICTITIOUS) == 0);
2435 		} else {
2436 			KKASSERT((m->flags & PG_FICTITIOUS));
2437 		}
2438 		vm_page_spin_lock(m);
2439 		goto validate;
2440 	}
2441 
2442 	/*
2443 	 * Bump the wire_count for the page table page.
2444 	 */
2445 	if (mpte)
2446 		vm_page_wire_quick(mpte);
2447 
2448 	/*
2449 	 * Mapping has changed, invalidate old range and fall through to
2450 	 * handle validating new mapping.  Don't inherit anything from
2451 	 * oldpte.
2452 	 */
2453 	if (opa) {
2454 		int err;
2455 		err = pmap_remove_pte(pmap, NULL, origpte, va);
2456 		origpte = 0;
2457 		if (err)
2458 			panic("pmap_enter: pte vanished, va: 0x%lx", va);
2459 	}
2460 
2461 	/*
2462 	 * Enter on the PV list if part of our managed memory. Note that we
2463 	 * raise IPL while manipulating pv_table since pmap_enter can be
2464 	 * called at interrupt time.
2465 	 */
2466 	if (pmap_initialized) {
2467 		if ((m->flags & PG_FICTITIOUS) == 0) {
2468 			/*
2469 			 * WARNING!  We are using m's spin-lock as a
2470 			 *	     man's pte lock to interlock against
2471 			 *	     pmap_page_protect() operations.
2472 			 *
2473 			 *	     This is a bad hack (obviously).
2474 			 */
2475 			pv = get_pv_entry();
2476 			vm_page_spin_lock(m);
2477 			pmap_insert_entry(pmap, va, mpte, m, pv);
2478 			pa |= VPTE_MANAGED;
2479 			/* vm_page_spin_unlock(m); */
2480 		} else {
2481 			vm_page_spin_lock(m);
2482 		}
2483 	} else {
2484 		vm_page_spin_lock(m);
2485 	}
2486 
2487 	/*
2488 	 * Increment counters
2489 	 */
2490 	atomic_add_long(&pmap->pm_stats.resident_count, 1);
2491 	if (wired)
2492 		atomic_add_long(&pmap->pm_stats.wired_count, 1);
2493 
2494 validate:
2495 	/*
2496 	 * Now validate mapping with desired protection/wiring.
2497 	 */
2498 	newpte = (pt_entry_t)(pa | pte_prot(pmap, prot) | VPTE_V | VPTE_U);
2499 	newpte |= VPTE_A;
2500 
2501 	if (wired)
2502 		newpte |= VPTE_WIRED;
2503 //	if (pmap != &kernel_pmap)
2504 		newpte |= VPTE_U;
2505 	if (newpte & VPTE_RW)
2506 		vm_page_flag_set(m, PG_WRITEABLE);
2507 	KKASSERT((newpte & VPTE_MANAGED) == 0 || (m->flags & PG_MAPPED));
2508 
2509 	origpte = atomic_swap_long(pte, newpte);
2510 	if (origpte & VPTE_M) {
2511 		kprintf("pmap [M] race @ %016jx\n", va);
2512 		atomic_set_long(pte, VPTE_M);
2513 	}
2514 	vm_page_spin_unlock(m);
2515 
2516 	if (mpte)
2517 		vm_page_wakeup(mpte);
2518 	vm_object_drop(pmap->pm_pteobj);
2519 }
2520 
2521 /*
2522  * Make a temporary mapping for a physical address.  This is only intended
2523  * to be used for panic dumps.
2524  *
2525  * The caller is responsible for calling smp_invltlb().
2526  */
2527 void *
2528 pmap_kenter_temporary(vm_paddr_t pa, long i)
2529 {
2530 	pmap_kenter_quick(crashdumpmap + (i * PAGE_SIZE), pa);
2531 	return ((void *)crashdumpmap);
2532 }
2533 
2534 #define MAX_INIT_PT (96)
2535 
2536 /*
2537  * This routine preloads the ptes for a given object into the specified pmap.
2538  * This eliminates the blast of soft faults on process startup and
2539  * immediately after an mmap.
2540  *
2541  * No requirements.
2542  */
2543 static int pmap_object_init_pt_callback(vm_page_t p, void *data);
2544 
2545 void
2546 pmap_object_init_pt(pmap_t pmap, vm_map_entry_t entry,
2547 		    vm_offset_t addr, vm_size_t size, int limit)
2548 {
2549 	vm_prot_t prot = entry->protection;
2550 	vm_object_t object = entry->ba.object;
2551 	vm_pindex_t pindex = atop(entry->ba.offset + (addr - entry->ba.start));
2552 	struct rb_vm_page_scan_info info;
2553 	struct lwp *lp;
2554 	vm_size_t psize;
2555 
2556 	/*
2557 	 * We can't preinit if read access isn't set or there is no pmap
2558 	 * or object.
2559 	 */
2560 	if ((prot & VM_PROT_READ) == 0 || pmap == NULL || object == NULL)
2561 		return;
2562 
2563 	/*
2564 	 * We can't preinit if the pmap is not the current pmap
2565 	 */
2566 	lp = curthread->td_lwp;
2567 	if (lp == NULL || pmap != vmspace_pmap(lp->lwp_vmspace))
2568 		return;
2569 
2570 	/*
2571 	 * Misc additional checks
2572 	 */
2573 	psize = x86_64_btop(size);
2574 
2575 	if ((object->type != OBJT_VNODE) ||
2576 		((limit & MAP_PREFAULT_PARTIAL) && (psize > MAX_INIT_PT) &&
2577 			(object->resident_page_count > MAX_INIT_PT))) {
2578 		return;
2579 	}
2580 
2581 	if (psize + pindex > object->size) {
2582 		if (object->size < pindex)
2583 			return;
2584 		psize = object->size - pindex;
2585 	}
2586 
2587 	if (psize == 0)
2588 		return;
2589 
2590 	/*
2591 	 * Use a red-black scan to traverse the requested range and load
2592 	 * any valid pages found into the pmap.
2593 	 *
2594 	 * We cannot safely scan the object's memq unless we are in a
2595 	 * critical section since interrupts can remove pages from objects.
2596 	 */
2597 	info.start_pindex = pindex;
2598 	info.end_pindex = pindex + psize - 1;
2599 	info.limit = limit;
2600 	info.mpte = NULL;
2601 	info.addr = addr;
2602 	info.pmap = pmap;
2603 	info.entry = entry;
2604 
2605 	vm_object_hold_shared(object);
2606 	vm_page_rb_tree_RB_SCAN(&object->rb_memq, rb_vm_page_scancmp,
2607 				pmap_object_init_pt_callback, &info);
2608 	vm_object_drop(object);
2609 }
2610 
2611 static
2612 int
2613 pmap_object_init_pt_callback(vm_page_t p, void *data)
2614 {
2615 	struct rb_vm_page_scan_info *info = data;
2616 	vm_pindex_t rel_index;
2617 	/*
2618 	 * don't allow an madvise to blow away our really
2619 	 * free pages allocating pv entries.
2620 	 */
2621 	if ((info->limit & MAP_PREFAULT_MADVISE) &&
2622 		vmstats.v_free_count < vmstats.v_free_reserved) {
2623 		    return(-1);
2624 	}
2625 
2626 	/*
2627 	 * Ignore list markers and ignore pages we cannot instantly
2628 	 * busy (while holding the object token).
2629 	 */
2630 	if (p->flags & PG_MARKER)
2631 		return 0;
2632 	if (vm_page_busy_try(p, TRUE))
2633 		return 0;
2634 	if (((p->valid & VM_PAGE_BITS_ALL) == VM_PAGE_BITS_ALL) &&
2635 	    (p->flags & PG_FICTITIOUS) == 0) {
2636 		if ((p->queue - p->pc) == PQ_CACHE)
2637 			vm_page_deactivate(p);
2638 		rel_index = p->pindex - info->start_pindex;
2639 		pmap_enter(info->pmap, info->addr + x86_64_ptob(rel_index), p,
2640 			   VM_PROT_READ, FALSE, info->entry);
2641 	}
2642 	vm_page_wakeup(p);
2643 	return(0);
2644 }
2645 
2646 /*
2647  * Return TRUE if the pmap is in shape to trivially
2648  * pre-fault the specified address.
2649  *
2650  * Returns FALSE if it would be non-trivial or if a
2651  * pte is already loaded into the slot.
2652  *
2653  * No requirements.
2654  */
2655 int
2656 pmap_prefault_ok(pmap_t pmap, vm_offset_t addr)
2657 {
2658 	pt_entry_t *pte;
2659 	pd_entry_t *pde;
2660 	int ret;
2661 
2662 	vm_object_hold(pmap->pm_pteobj);
2663 	pde = pmap_pde(pmap, addr);
2664 	if (pde == NULL || *pde == 0) {
2665 		ret = 0;
2666 	} else {
2667 		pte = pmap_pde_to_pte(pde, addr);
2668 		ret = (*pte) ? 0 : 1;
2669 	}
2670 	vm_object_drop(pmap->pm_pteobj);
2671 
2672 	return (ret);
2673 }
2674 
2675 /*
2676  * Change the wiring attribute for a map/virtual-address pair.
2677  *
2678  * The mapping must already exist in the pmap.
2679  * No other requirements.
2680  */
2681 vm_page_t
2682 pmap_unwire(pmap_t pmap, vm_offset_t va)
2683 {
2684 	pt_entry_t *pte;
2685 	vm_paddr_t pa;
2686 	vm_page_t m;
2687 
2688 	if (pmap == NULL)
2689 		return NULL;
2690 
2691 	vm_object_hold(pmap->pm_pteobj);
2692 	pte = pmap_pte(pmap, va);
2693 
2694 	if (pte == NULL || (*pte & VPTE_V) == 0) {
2695 		vm_object_drop(pmap->pm_pteobj);
2696 		return NULL;
2697 	}
2698 
2699 	/*
2700 	 * Wiring is not a hardware characteristic so there is no need to
2701 	 * invalidate TLB.  However, in an SMP environment we must use
2702 	 * a locked bus cycle to update the pte (if we are not using
2703 	 * the pmap_inval_*() API that is)... it's ok to do this for simple
2704 	 * wiring changes.
2705 	 */
2706 	if (pmap_pte_w(pte))
2707 		atomic_add_long(&pmap->pm_stats.wired_count, -1);
2708 	/* XXX else return NULL so caller doesn't unwire m ? */
2709 	atomic_clear_long(pte, VPTE_WIRED);
2710 
2711 	pa = *pte & VPTE_FRAME;
2712 	m = PHYS_TO_VM_PAGE(pa);	/* held by wired count */
2713 
2714 	vm_object_drop(pmap->pm_pteobj);
2715 
2716 	return m;
2717 }
2718 
2719 /*
2720  *	Copy the range specified by src_addr/len
2721  *	from the source map to the range dst_addr/len
2722  *	in the destination map.
2723  *
2724  *	This routine is only advisory and need not do anything.
2725  */
2726 void
2727 pmap_copy(pmap_t dst_pmap, pmap_t src_pmap, vm_offset_t dst_addr,
2728 	vm_size_t len, vm_offset_t src_addr)
2729 {
2730 	/*
2731 	 * XXX BUGGY.  Amoung other things srcmpte is assumed to remain
2732 	 * valid through blocking calls, and that's just not going to
2733 	 * be the case.
2734 	 *
2735 	 * FIXME!
2736 	 */
2737 	return;
2738 }
2739 
2740 /*
2741  * pmap_zero_page:
2742  *
2743  *	Zero the specified physical page.
2744  *
2745  *	This function may be called from an interrupt and no locking is
2746  *	required.
2747  */
2748 void
2749 pmap_zero_page(vm_paddr_t phys)
2750 {
2751 	vm_offset_t va = PHYS_TO_DMAP(phys);
2752 
2753 	bzero((void *)va, PAGE_SIZE);
2754 }
2755 
2756 /*
2757  * pmap_zero_page:
2758  *
2759  *	Zero part of a physical page by mapping it into memory and clearing
2760  *	its contents with bzero.
2761  *
2762  *	off and size may not cover an area beyond a single hardware page.
2763  */
2764 void
2765 pmap_zero_page_area(vm_paddr_t phys, int off, int size)
2766 {
2767 	vm_offset_t virt = PHYS_TO_DMAP(phys);
2768 
2769 	bzero((char *)virt + off, size);
2770 }
2771 
2772 /*
2773  * pmap_copy_page:
2774  *
2775  *	Copy the physical page from the source PA to the target PA.
2776  *	This function may be called from an interrupt.  No locking
2777  *	is required.
2778  */
2779 void
2780 pmap_copy_page(vm_paddr_t src, vm_paddr_t dst)
2781 {
2782 	vm_offset_t src_virt, dst_virt;
2783 
2784 	src_virt = PHYS_TO_DMAP(src);
2785 	dst_virt = PHYS_TO_DMAP(dst);
2786 	bcopy((void *)src_virt, (void *)dst_virt, PAGE_SIZE);
2787 }
2788 
2789 /*
2790  * pmap_copy_page_frag:
2791  *
2792  *	Copy the physical page from the source PA to the target PA.
2793  *	This function may be called from an interrupt.  No locking
2794  *	is required.
2795  */
2796 void
2797 pmap_copy_page_frag(vm_paddr_t src, vm_paddr_t dst, size_t bytes)
2798 {
2799 	vm_offset_t src_virt, dst_virt;
2800 
2801 	src_virt = PHYS_TO_DMAP(src);
2802 	dst_virt = PHYS_TO_DMAP(dst);
2803 	bcopy((char *)src_virt + (src & PAGE_MASK),
2804 	      (char *)dst_virt + (dst & PAGE_MASK),
2805 	      bytes);
2806 }
2807 
2808 /*
2809  * Remove all pages from specified address space this aids process
2810  * exit speeds.  Also, this code is special cased for current
2811  * process only, but can have the more generic (and slightly slower)
2812  * mode enabled.  This is much faster than pmap_remove in the case
2813  * of running down an entire address space.
2814  *
2815  * No other requirements.
2816  */
2817 void
2818 pmap_remove_pages(pmap_t pmap, vm_offset_t sva, vm_offset_t eva)
2819 {
2820 	pmap_remove(pmap, sva, eva);
2821 #if 0
2822 	pt_entry_t *pte, tpte;
2823 	pv_entry_t pv, npv;
2824 	vm_page_t m;
2825 	int save_generation;
2826 
2827 	if (pmap->pm_pteobj)
2828 		vm_object_hold(pmap->pm_pteobj);
2829 
2830 	pmap_invalidate_range(pmap, sva, eva);
2831 
2832 	for (pv = TAILQ_FIRST(&pmap->pm_pvlist); pv; pv = npv) {
2833 		if (pv->pv_va >= eva || pv->pv_va < sva) {
2834 			npv = TAILQ_NEXT(pv, pv_plist);
2835 			continue;
2836 		}
2837 
2838 		KKASSERT(pmap == pv->pv_pmap);
2839 
2840 		pte = pmap_pte(pmap, pv->pv_va);
2841 
2842 		/*
2843 		 * We cannot remove wired pages from a process' mapping
2844 		 * at this time
2845 		 */
2846 		if (*pte & VPTE_WIRED) {
2847 			npv = TAILQ_NEXT(pv, pv_plist);
2848 			continue;
2849 		}
2850 		tpte = pmap_inval_loadandclear(pte, pmap, pv->pv_va);
2851 
2852 		m = PHYS_TO_VM_PAGE(tpte & VPTE_FRAME);
2853 		vm_page_spin_lock(m);
2854 
2855 		KASSERT(m < &vm_page_array[vm_page_array_size],
2856 			("pmap_remove_pages: bad tpte %lx", tpte));
2857 
2858 		KKASSERT(pmap->pm_stats.resident_count > 0);
2859 		atomic_add_long(&pmap->pm_stats.resident_count, -1);
2860 
2861 		/*
2862 		 * Update the vm_page_t clean and reference bits.
2863 		 */
2864 		if (tpte & VPTE_M) {
2865 			vm_page_dirty(m);
2866 		}
2867 
2868 		npv = TAILQ_NEXT(pv, pv_plist);
2869 		TAILQ_REMOVE(&pmap->pm_pvlist, pv, pv_plist);
2870 		atomic_add_int(&pmap->pm_generation, 1);
2871 		save_generation = pmap->pm_generation;
2872 		m->md.pv_list_count--;
2873 		TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
2874 		if (TAILQ_EMPTY(&m->md.pv_list))
2875 			vm_page_flag_clear(m, PG_MAPPED | PG_WRITEABLE);
2876 		vm_page_spin_unlock(m);
2877 
2878 		pmap_unuse_pt(pmap, pv->pv_va, pv->pv_ptem);
2879 		free_pv_entry(pv);
2880 
2881 		/*
2882 		 * Restart the scan if we blocked during the unuse or free
2883 		 * calls and other removals were made.
2884 		 */
2885 		if (save_generation != pmap->pm_generation) {
2886 			kprintf("Warning: pmap_remove_pages race-A avoided\n");
2887 			npv = TAILQ_FIRST(&pmap->pm_pvlist);
2888 		}
2889 	}
2890 	if (pmap->pm_pteobj)
2891 		vm_object_drop(pmap->pm_pteobj);
2892 	pmap_remove(pmap, sva, eva);
2893 #endif
2894 }
2895 
2896 /*
2897  * pmap_testbit tests bits in active mappings of a VM page.
2898  */
2899 static boolean_t
2900 pmap_testbit(vm_page_t m, int bit)
2901 {
2902 	pv_entry_t pv;
2903 	pt_entry_t *pte;
2904 
2905 	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
2906 		return FALSE;
2907 
2908 	if (TAILQ_FIRST(&m->md.pv_list) == NULL)
2909 		return FALSE;
2910 
2911 	vm_page_spin_lock(m);
2912 	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2913 		/*
2914 		 * if the bit being tested is the modified bit, then
2915 		 * mark clean_map and ptes as never
2916 		 * modified.
2917 		 */
2918 		if (bit & (VPTE_A|VPTE_M))
2919 			pmap_track_modified(pv->pv_pmap, pv->pv_va);
2920 
2921 #if defined(PMAP_DIAGNOSTIC)
2922 		if (pv->pv_pmap == NULL) {
2923 			kprintf("Null pmap (tb) at va: 0x%lx\n", pv->pv_va);
2924 			continue;
2925 		}
2926 #endif
2927 		pte = pmap_pte(pv->pv_pmap, pv->pv_va);
2928 		if (*pte & bit) {
2929 			vm_page_spin_unlock(m);
2930 			return TRUE;
2931 		}
2932 	}
2933 	vm_page_spin_unlock(m);
2934 	return (FALSE);
2935 }
2936 
2937 /*
2938  * This routine is used to clear bits in ptes.  Certain bits require special
2939  * handling, in particular (on virtual kernels) the VPTE_M (modify) bit.
2940  *
2941  * This routine is only called with certain VPTE_* bit combinations.
2942  */
2943 static __inline void
2944 pmap_clearbit(vm_page_t m, int bit)
2945 {
2946 	pv_entry_t pv;
2947 	pt_entry_t *pte;
2948 	pt_entry_t pbits;
2949 	vm_object_t pmobj;
2950 	pmap_t pmap;
2951 
2952 	if (!pmap_initialized || (m->flags & PG_FICTITIOUS)) {
2953 		if (bit == VPTE_RW)
2954 			vm_page_flag_clear(m, PG_WRITEABLE);
2955 		return;
2956 	}
2957 
2958 	/*
2959 	 * Loop over all current mappings setting/clearing as appropos If
2960 	 * setting RO do we need to clear the VAC?
2961 	 */
2962 restart:
2963 	vm_page_spin_lock(m);
2964 	TAILQ_FOREACH(pv, &m->md.pv_list, pv_list) {
2965 		/*
2966 		 * Need the pmap object lock(?)
2967 		 */
2968 		pmap = pv->pv_pmap;
2969 		pmobj = pmap->pm_pteobj;
2970 
2971 		if (vm_object_hold_try(pmobj) == 0) {
2972 			refcount_acquire(&pmobj->hold_count);
2973 			vm_page_spin_unlock(m);
2974 			vm_object_lock(pmobj);
2975 			vm_object_drop(pmobj);
2976 			goto restart;
2977 		}
2978 
2979 		/*
2980 		 * don't write protect pager mappings
2981 		 */
2982 		if (bit == VPTE_RW) {
2983 			pmap_track_modified(pv->pv_pmap, pv->pv_va);
2984 		}
2985 
2986 #if defined(PMAP_DIAGNOSTIC)
2987 		if (pv->pv_pmap == NULL) {
2988 			kprintf("Null pmap (cb) at va: 0x%lx\n", pv->pv_va);
2989 			vm_object_drop(pmobj);
2990 			continue;
2991 		}
2992 #endif
2993 
2994 		/*
2995 		 * Careful here.  We can use a locked bus instruction to
2996 		 * clear VPTE_A or VPTE_M safely but we need to synchronize
2997 		 * with the target cpus when we mess with VPTE_RW.
2998 		 *
2999 		 * On virtual kernels we must force a new fault-on-write
3000 		 * in the real kernel if we clear the Modify bit ourselves,
3001 		 * otherwise the real kernel will not get a new fault and
3002 		 * will never set our Modify bit again.
3003 		 */
3004 		pte = pmap_pte(pv->pv_pmap, pv->pv_va);
3005 		if (*pte & bit) {
3006 			if (bit == VPTE_RW) {
3007 				/*
3008 				 * We must also clear VPTE_M when clearing
3009 				 * VPTE_RW and synchronize its state to
3010 				 * the page.
3011 				 */
3012 				pmap_track_modified(pv->pv_pmap, pv->pv_va);
3013 				pbits = pmap_clean_pte(pte, pv->pv_pmap,
3014 						       pv->pv_va, m);
3015 			} else if (bit == VPTE_M) {
3016 				/*
3017 				 * We must invalidate the real-kernel pte
3018 				 * when clearing VPTE_M bit to force the
3019 				 * real-kernel to take a new fault to re-set
3020 				 * VPTE_M.
3021 				 */
3022 				atomic_clear_long(pte, VPTE_M);
3023 				if (*pte & VPTE_RW) {
3024 					pmap_invalidate_range(pv->pv_pmap,
3025 						      pv->pv_va,
3026 						      pv->pv_va + PAGE_SIZE);
3027 				}
3028 			} else if ((bit & (VPTE_RW|VPTE_M)) ==
3029 				   (VPTE_RW|VPTE_M)) {
3030 				/*
3031 				 * We've been asked to clear W & M, I guess
3032 				 * the caller doesn't want us to update
3033 				 * the dirty status of the VM page.
3034 				 */
3035 				pmap_track_modified(pv->pv_pmap, pv->pv_va);
3036 				pmap_clean_pte(pte, pv->pv_pmap, pv->pv_va, m);
3037 				panic("shouldn't be called");
3038 			} else {
3039 				/*
3040 				 * We've been asked to clear bits that do
3041 				 * not interact with hardware.
3042 				 */
3043 				atomic_clear_long(pte, bit);
3044 			}
3045 		}
3046 		vm_object_drop(pmobj);
3047 	}
3048 	if (bit == VPTE_RW)
3049 		vm_page_flag_clear(m, PG_WRITEABLE);
3050 	vm_page_spin_unlock(m);
3051 }
3052 
3053 /*
3054  * Lower the permission for all mappings to a given page.
3055  *
3056  * No other requirements.
3057  */
3058 void
3059 pmap_page_protect(vm_page_t m, vm_prot_t prot)
3060 {
3061 	if ((prot & VM_PROT_WRITE) == 0) {
3062 		if (prot & (VM_PROT_READ | VM_PROT_EXECUTE)) {
3063 			pmap_clearbit(m, VPTE_RW);
3064 		} else {
3065 			pmap_remove_all(m);
3066 		}
3067 	}
3068 }
3069 
3070 vm_paddr_t
3071 pmap_phys_address(vm_pindex_t ppn)
3072 {
3073 	return (x86_64_ptob(ppn));
3074 }
3075 
3076 /*
3077  * Return a count of reference bits for a page, clearing those bits.
3078  * It is not necessary for every reference bit to be cleared, but it
3079  * is necessary that 0 only be returned when there are truly no
3080  * reference bits set.
3081  *
3082  * XXX: The exact number of bits to check and clear is a matter that
3083  * should be tested and standardized at some point in the future for
3084  * optimal aging of shared pages.
3085  *
3086  * No other requirements.
3087  */
3088 int
3089 pmap_ts_referenced(vm_page_t m)
3090 {
3091 	pv_entry_t pv, pvf, pvn;
3092 	pt_entry_t *pte;
3093 	int rtval = 0;
3094 
3095 	if (!pmap_initialized || (m->flags & PG_FICTITIOUS))
3096 		return (rtval);
3097 
3098 	vm_page_spin_lock(m);
3099 	if ((pv = TAILQ_FIRST(&m->md.pv_list)) != NULL) {
3100 		pvf = pv;
3101 		do {
3102 			pvn = TAILQ_NEXT(pv, pv_list);
3103 			TAILQ_REMOVE(&m->md.pv_list, pv, pv_list);
3104 			TAILQ_INSERT_TAIL(&m->md.pv_list, pv, pv_list);
3105 
3106 			pmap_track_modified(pv->pv_pmap, pv->pv_va);
3107 			pte = pmap_pte(pv->pv_pmap, pv->pv_va);
3108 
3109 			if (pte && (*pte & VPTE_A)) {
3110 				atomic_clear_long(pte, VPTE_A);
3111 				rtval++;
3112 				if (rtval > 4) {
3113 					break;
3114 				}
3115 			}
3116 		} while ((pv = pvn) != NULL && pv != pvf);
3117 	}
3118 	vm_page_spin_unlock(m);
3119 
3120 	return (rtval);
3121 }
3122 
3123 /*
3124  * Return whether or not the specified physical page was modified
3125  * in any physical maps.
3126  *
3127  * No other requirements.
3128  */
3129 boolean_t
3130 pmap_is_modified(vm_page_t m)
3131 {
3132 	boolean_t res;
3133 
3134 	res = pmap_testbit(m, VPTE_M);
3135 
3136 	return (res);
3137 }
3138 
3139 /*
3140  * Clear the modify bits on the specified physical page.  For the vkernel
3141  * we really need to clean the page, which clears VPTE_RW and VPTE_M, in
3142  * order to ensure that we take a fault on the next write to the page.
3143  * Otherwise the page may become dirty without us knowing it.
3144  *
3145  * No other requirements.
3146  */
3147 void
3148 pmap_clear_modify(vm_page_t m)
3149 {
3150 	pmap_clearbit(m, VPTE_RW);
3151 }
3152 
3153 /*
3154  * Clear the reference bit on the specified physical page.
3155  *
3156  * No other requirements.
3157  */
3158 void
3159 pmap_clear_reference(vm_page_t m)
3160 {
3161 	pmap_clearbit(m, VPTE_A);
3162 }
3163 
3164 /*
3165  * Miscellaneous support routines follow
3166  */
3167 static void
3168 x86_64_protection_init(void)
3169 {
3170 	uint64_t *kp;
3171 	int prot;
3172 
3173 	kp = protection_codes;
3174 	for (prot = 0; prot < 8; prot++) {
3175 		if (prot & VM_PROT_READ)
3176 			*kp |= 0;			/* R */
3177 		if (prot & VM_PROT_WRITE)
3178 			*kp |= VPTE_RW;			/* R+W */
3179 		if (prot && (prot & VM_PROT_EXECUTE) == 0)
3180 			*kp |= VPTE_NX;			/* NX - !executable */
3181 		++kp;
3182 	}
3183 }
3184 
3185 /*
3186  * Sets the memory attribute for the specified page.
3187  */
3188 void
3189 pmap_page_set_memattr(vm_page_t m, vm_memattr_t ma)
3190 {
3191 	/* This is a vkernel, do nothing */
3192 }
3193 
3194 /*
3195  * Change the PAT attribute on an existing kernel memory map.  Caller
3196  * must ensure that the virtual memory in question is not accessed
3197  * during the adjustment.
3198  */
3199 void
3200 pmap_change_attr(vm_offset_t va, vm_size_t count, int mode)
3201 {
3202 	/* This is a vkernel, do nothing */
3203 }
3204 
3205 /*
3206  * Perform the pmap work for mincore
3207  *
3208  * No other requirements.
3209  */
3210 int
3211 pmap_mincore(pmap_t pmap, vm_offset_t addr)
3212 {
3213 	pt_entry_t *ptep, pte;
3214 	vm_page_t m;
3215 	int val = 0;
3216 
3217 	vm_object_hold(pmap->pm_pteobj);
3218 	ptep = pmap_pte(pmap, addr);
3219 
3220 	if (ptep && (pte = *ptep) != 0) {
3221 		vm_paddr_t pa;
3222 
3223 		val = MINCORE_INCORE;
3224 		if ((pte & VPTE_MANAGED) == 0)
3225 			goto done;
3226 
3227 		pa = pte & VPTE_FRAME;
3228 
3229 		m = PHYS_TO_VM_PAGE(pa);
3230 
3231 		/*
3232 		 * Modified by us
3233 		 */
3234 		if (pte & VPTE_M)
3235 			val |= MINCORE_MODIFIED|MINCORE_MODIFIED_OTHER;
3236 		/*
3237 		 * Modified by someone
3238 		 */
3239 		else if (m->dirty || pmap_is_modified(m))
3240 			val |= MINCORE_MODIFIED_OTHER;
3241 		/*
3242 		 * Referenced by us
3243 		 */
3244 		if (pte & VPTE_A)
3245 			val |= MINCORE_REFERENCED|MINCORE_REFERENCED_OTHER;
3246 
3247 		/*
3248 		 * Referenced by someone
3249 		 */
3250 		else if ((m->flags & PG_REFERENCED) || pmap_ts_referenced(m)) {
3251 			val |= MINCORE_REFERENCED_OTHER;
3252 			vm_page_flag_set(m, PG_REFERENCED);
3253 		}
3254 	}
3255 done:
3256 	vm_object_drop(pmap->pm_pteobj);
3257 
3258 	return val;
3259 }
3260 
3261 /*
3262  * Replace p->p_vmspace with a new one.  If adjrefs is non-zero the new
3263  * vmspace will be ref'd and the old one will be deref'd.
3264  *
3265  * Caller must hold vmspace->vm_map.token for oldvm and newvm
3266  */
3267 void
3268 pmap_replacevm(struct proc *p, struct vmspace *newvm, int adjrefs)
3269 {
3270 	struct vmspace *oldvm;
3271 	struct lwp *lp;
3272 
3273 	oldvm = p->p_vmspace;
3274 	if (oldvm != newvm) {
3275 		if (adjrefs)
3276 			vmspace_ref(newvm);
3277 		KKASSERT((newvm->vm_refcnt & VM_REF_DELETED) == 0);
3278 		p->p_vmspace = newvm;
3279 		KKASSERT(p->p_nthreads == 1);
3280 		lp = RB_ROOT(&p->p_lwp_tree);
3281 		pmap_setlwpvm(lp, newvm);
3282 		if (adjrefs)
3283 			vmspace_rel(oldvm);
3284 	}
3285 }
3286 
3287 /*
3288  * Set the vmspace for a LWP.  The vmspace is almost universally set the
3289  * same as the process vmspace, but virtual kernels need to swap out contexts
3290  * on a per-lwp basis.
3291  */
3292 void
3293 pmap_setlwpvm(struct lwp *lp, struct vmspace *newvm)
3294 {
3295 	struct vmspace *oldvm;
3296 	struct pmap *pmap;
3297 
3298 	oldvm = lp->lwp_vmspace;
3299 	if (oldvm != newvm) {
3300 		crit_enter();
3301 		KKASSERT((newvm->vm_refcnt & VM_REF_DELETED) == 0);
3302 		lp->lwp_vmspace = newvm;
3303 		if (curthread->td_lwp == lp) {
3304 			pmap = vmspace_pmap(newvm);
3305 			ATOMIC_CPUMASK_ORBIT(pmap->pm_active, mycpu->gd_cpuid);
3306 			if (pmap->pm_active_lock & CPULOCK_EXCL)
3307 				pmap_interlock_wait(newvm);
3308 #if defined(SWTCH_OPTIM_STATS)
3309 			tlb_flush_count++;
3310 #endif
3311 			pmap = vmspace_pmap(oldvm);
3312 			ATOMIC_CPUMASK_NANDBIT(pmap->pm_active,
3313 					       mycpu->gd_cpuid);
3314 		}
3315 		crit_exit();
3316 	}
3317 }
3318 
3319 /*
3320  * The swtch code tried to switch in a heavy weight process whos pmap
3321  * is locked by another cpu.  We have to wait for the lock to clear before
3322  * the pmap can be used.
3323  */
3324 void
3325 pmap_interlock_wait (struct vmspace *vm)
3326 {
3327 	pmap_t pmap = vmspace_pmap(vm);
3328 
3329 	if (pmap->pm_active_lock & CPULOCK_EXCL) {
3330 		crit_enter();
3331 		while (pmap->pm_active_lock & CPULOCK_EXCL) {
3332 			cpu_ccfence();
3333 			pthread_yield();
3334 		}
3335 		crit_exit();
3336 	}
3337 }
3338 
3339 vm_offset_t
3340 pmap_addr_hint(vm_object_t obj, vm_offset_t addr, vm_size_t size)
3341 {
3342 
3343 	if ((obj == NULL) || (size < NBPDR) || (obj->type != OBJT_DEVICE)) {
3344 		return addr;
3345 	}
3346 
3347 	addr = roundup2(addr, NBPDR);
3348 	return addr;
3349 }
3350 
3351 /*
3352  * Used by kmalloc/kfree, page already exists at va
3353  */
3354 vm_page_t
3355 pmap_kvtom(vm_offset_t va)
3356 {
3357 	vpte_t *ptep;
3358 
3359 	KKASSERT(va >= KvaStart && va < KvaEnd);
3360 	ptep = vtopte(va);
3361 	return(PHYS_TO_VM_PAGE(*ptep & PG_FRAME));
3362 }
3363 
3364 void
3365 pmap_object_init(vm_object_t object)
3366 {
3367 	/* empty */
3368 }
3369 
3370 void
3371 pmap_object_free(vm_object_t object)
3372 {
3373 	/* empty */
3374 }
3375 
3376 void
3377 pmap_pgscan(struct pmap_pgscan_info *pginfo)
3378 {
3379 	pmap_t pmap = pginfo->pmap;
3380 	vm_offset_t sva = pginfo->beg_addr;
3381 	vm_offset_t eva = pginfo->end_addr;
3382 	vm_offset_t va_next;
3383 	pml4_entry_t *pml4e;
3384 	pdp_entry_t *pdpe;
3385 	pd_entry_t ptpaddr, *pde;
3386 	pt_entry_t *pte;
3387 	vm_page_t pt_m;
3388 	int stop = 0;
3389 
3390 	vm_object_hold(pmap->pm_pteobj);
3391 
3392 	for (; sva < eva; sva = va_next) {
3393 		if (stop)
3394 			break;
3395 
3396 		pml4e = pmap_pml4e(pmap, sva);
3397 		if ((*pml4e & VPTE_V) == 0) {
3398 			va_next = (sva + NBPML4) & ~PML4MASK;
3399 			if (va_next < sva)
3400 				va_next = eva;
3401 			continue;
3402 		}
3403 
3404 		pdpe = pmap_pml4e_to_pdpe(pml4e, sva);
3405 		if ((*pdpe & VPTE_V) == 0) {
3406 			va_next = (sva + NBPDP) & ~PDPMASK;
3407 			if (va_next < sva)
3408 				va_next = eva;
3409 			continue;
3410 		}
3411 
3412 		va_next = (sva + NBPDR) & ~PDRMASK;
3413 		if (va_next < sva)
3414 			va_next = eva;
3415 
3416 		pde = pmap_pdpe_to_pde(pdpe, sva);
3417 		ptpaddr = *pde;
3418 
3419 #if 0
3420 		/*
3421 		 * Check for large page (ignore).
3422 		 */
3423 		if ((ptpaddr & VPTE_PS) != 0) {
3424 #if 0
3425 			pmap_clean_pde(pde, pmap, sva);
3426 			pmap->pm_stats.resident_count -= NBPDR / PAGE_SIZE;
3427 #endif
3428 			continue;
3429 		}
3430 #endif
3431 
3432 		/*
3433 		 * Weed out invalid mappings. Note: we assume that the page
3434 		 * directory table is always allocated, and in kernel virtual.
3435 		 */
3436 		if (ptpaddr == 0)
3437 			continue;
3438 
3439 		if (va_next > eva)
3440 			va_next = eva;
3441 
3442 		pt_m = pmap_hold_pt_page(pde, sva);
3443 		for (pte = pmap_pde_to_pte(pde, sva); sva != va_next; pte++,
3444 		    sva += PAGE_SIZE) {
3445 			vm_page_t m;
3446 
3447 			if (stop)
3448 				break;
3449 			if ((*pte & VPTE_MANAGED) == 0)
3450 				continue;
3451 
3452 			m = PHYS_TO_VM_PAGE(*pte & VPTE_FRAME);
3453 			if (vm_page_busy_try(m, TRUE) == 0) {
3454 				if (pginfo->callback(pginfo, sva, m) < 0)
3455 					stop = 1;
3456 			}
3457 		}
3458 		vm_page_unhold(pt_m);
3459 	}
3460 	vm_object_drop(pmap->pm_pteobj);
3461 }
3462 
3463 void
3464 pmap_maybethreaded(pmap_t pmap)
3465 {
3466 	/* nop */
3467 }
3468 
3469 /*
3470  * Called while page is hard-busied to clear the PG_MAPPED and PG_WRITEABLE
3471  * flags if able.
3472  *
3473  * vkernel code is using the old pmap style so the flags should already
3474  * be properly set.
3475  */
3476 int
3477 pmap_mapped_sync(vm_page_t m)
3478 {
3479 	return (m->flags);
3480 }
3481