xref: /illumos-gate/usr/src/uts/i86pc/vm/vm_machdep.c (revision 2c687d6826d5cbe1435931df7165d210c3336019)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
23  */
24 /*
25  * Copyright (c) 2010, Intel Corporation.
26  * All rights reserved.
27  * Copyright 2019, Joyent, Inc.
28  */
29 
30 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
31 /*	All Rights Reserved   */
32 
33 /*
34  * Portions of this source code were derived from Berkeley 4.3 BSD
35  * under license from the Regents of the University of California.
36  */
37 
38 /*
39  * UNIX machine dependent virtual memory support.
40  */
41 
42 #include <sys/types.h>
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #include <sys/user.h>
46 #include <sys/proc.h>
47 #include <sys/kmem.h>
48 #include <sys/vmem.h>
49 #include <sys/buf.h>
50 #include <sys/cpuvar.h>
51 #include <sys/lgrp.h>
52 #include <sys/disp.h>
53 #include <sys/vm.h>
54 #include <sys/mman.h>
55 #include <sys/vnode.h>
56 #include <sys/cred.h>
57 #include <sys/exec.h>
58 #include <sys/exechdr.h>
59 #include <sys/debug.h>
60 #include <sys/vmsystm.h>
61 #include <sys/swap.h>
62 #include <sys/dumphdr.h>
63 #include <sys/random.h>
64 
65 #include <vm/hat.h>
66 #include <vm/as.h>
67 #include <vm/seg.h>
68 #include <vm/seg_kp.h>
69 #include <vm/seg_vn.h>
70 #include <vm/page.h>
71 #include <vm/seg_kmem.h>
72 #include <vm/seg_kpm.h>
73 #include <vm/vm_dep.h>
74 
75 #include <sys/cpu.h>
76 #include <sys/vm_machparam.h>
77 #include <sys/memlist.h>
78 #include <sys/bootconf.h> /* XXX the memlist stuff belongs in memlist_plat.h */
79 #include <vm/hat_i86.h>
80 #include <sys/x86_archext.h>
81 #include <sys/elf_386.h>
82 #include <sys/cmn_err.h>
83 #include <sys/archsystm.h>
84 #include <sys/machsystm.h>
85 #include <sys/secflags.h>
86 
87 #include <sys/vtrace.h>
88 #include <sys/ddidmareq.h>
89 #include <sys/promif.h>
90 #include <sys/memnode.h>
91 #include <sys/stack.h>
92 #include <util/qsort.h>
93 #include <sys/taskq.h>
94 
95 #ifdef __xpv
96 
97 #include <sys/hypervisor.h>
98 #include <sys/xen_mmu.h>
99 #include <sys/balloon_impl.h>
100 
101 /*
102  * domain 0 pages usable for DMA are kept pre-allocated and kept in
103  * distinct lists, ordered by increasing mfn.
104  */
105 static kmutex_t io_pool_lock;
106 static kmutex_t contig_list_lock;
107 static page_t *io_pool_4g;	/* pool for 32 bit dma limited devices */
108 static page_t *io_pool_16m;	/* pool for 24 bit dma limited legacy devices */
109 static long io_pool_cnt;
110 static long io_pool_cnt_max = 0;
111 #define	DEFAULT_IO_POOL_MIN	128
112 static long io_pool_cnt_min = DEFAULT_IO_POOL_MIN;
113 static long io_pool_cnt_lowater = 0;
114 static long io_pool_shrink_attempts; /* how many times did we try to shrink */
115 static long io_pool_shrinks;	/* how many times did we really shrink */
116 static long io_pool_grows;	/* how many times did we grow */
117 static mfn_t start_mfn = 1;
118 static caddr_t io_pool_kva;	/* use to alloc pages when needed */
119 
120 static int create_contig_pfnlist(uint_t);
121 
122 /*
123  * percentage of phys mem to hold in the i/o pool
124  */
125 #define	DEFAULT_IO_POOL_PCT	2
126 static long io_pool_physmem_pct = DEFAULT_IO_POOL_PCT;
127 static void page_io_pool_sub(page_t **, page_t *, page_t *);
128 int ioalloc_dbg = 0;
129 
130 #endif /* __xpv */
131 
132 uint_t vac_colors = 1;
133 
134 int largepagesupport = 0;
135 extern uint_t page_create_new;
136 extern uint_t page_create_exists;
137 extern uint_t page_create_putbacks;
138 /*
139  * Allow users to disable the kernel's use of SSE.
140  */
141 extern int use_sse_pagecopy, use_sse_pagezero;
142 
143 /*
144  * combined memory ranges from mnode and memranges[] to manage single
145  * mnode/mtype dimension in the page lists.
146  */
147 typedef struct {
148 	pfn_t	mnr_pfnlo;
149 	pfn_t	mnr_pfnhi;
150 	int	mnr_mnode;
151 	int	mnr_memrange;		/* index into memranges[] */
152 	int	mnr_next;		/* next lower PA mnoderange */
153 	int	mnr_exists;
154 	/* maintain page list stats */
155 	pgcnt_t	mnr_mt_clpgcnt;		/* cache list cnt */
156 	pgcnt_t	mnr_mt_flpgcnt[MMU_PAGE_SIZES];	/* free list cnt per szc */
157 	pgcnt_t	mnr_mt_totcnt;		/* sum of cache and free lists */
158 #ifdef DEBUG
159 	struct mnr_mts {		/* mnode/mtype szc stats */
160 		pgcnt_t	mnr_mts_pgcnt;
161 		int	mnr_mts_colors;
162 		pgcnt_t *mnr_mtsc_pgcnt;
163 	}	*mnr_mts;
164 #endif
165 } mnoderange_t;
166 
167 #define	MEMRANGEHI(mtype)						\
168 	((mtype > 0) ? memranges[mtype - 1] - 1: physmax)
169 #define	MEMRANGELO(mtype)	(memranges[mtype])
170 
171 #define	MTYPE_FREEMEM(mt)	(mnoderanges[mt].mnr_mt_totcnt)
172 
173 /*
174  * As the PC architecture evolved memory up was clumped into several
175  * ranges for various historical I/O devices to do DMA.
176  * < 16Meg - ISA bus
177  * < 2Gig - ???
178  * < 4Gig - PCI bus or drivers that don't understand PAE mode
179  *
180  * These are listed in reverse order, so that we can skip over unused
181  * ranges on machines with small memories.
182  *
183  * For now under the Hypervisor, we'll only ever have one memrange.
184  */
185 #define	PFN_4GIG	0x100000
186 #define	PFN_16MEG	0x1000
187 /* Indices into the memory range (arch_memranges) array. */
188 #define	MRI_4G		0
189 #define	MRI_2G		1
190 #define	MRI_16M		2
191 #define	MRI_0		3
192 static pfn_t arch_memranges[NUM_MEM_RANGES] = {
193     PFN_4GIG,	/* pfn range for 4G and above */
194     0x80000,	/* pfn range for 2G-4G */
195     PFN_16MEG,	/* pfn range for 16M-2G */
196     0x00000,	/* pfn range for 0-16M */
197 };
198 pfn_t *memranges = &arch_memranges[0];
199 int nranges = NUM_MEM_RANGES;
200 
201 /*
202  * This combines mem_node_config and memranges into one data
203  * structure to be used for page list management.
204  */
205 static mnoderange_t *mnoderanges;
206 static int mnoderangecnt;
207 static int mtype4g;
208 static int mtype16m;
209 static int mtypetop;
210 
211 /*
212  * 4g memory management variables for systems with more than 4g of memory:
213  *
214  * physical memory below 4g is required for 32bit dma devices and, currently,
215  * for kmem memory. On systems with more than 4g of memory, the pool of memory
216  * below 4g can be depleted without any paging activity given that there is
217  * likely to be sufficient memory above 4g.
218  *
219  * physmax4g is set true if the largest pfn is over 4g. The rest of the
220  * 4g memory management code is enabled only when physmax4g is true.
221  *
222  * maxmem4g is the count of the maximum number of pages on the page lists
223  * with physical addresses below 4g. It can be a lot less then 4g given that
224  * BIOS may reserve large chunks of space below 4g for hot plug pci devices,
225  * agp aperture etc.
226  *
227  * freemem4g maintains the count of the number of available pages on the
228  * page lists with physical addresses below 4g.
229  *
230  * DESFREE4G specifies the desired amount of below 4g memory. It defaults to
231  * 6% (desfree4gshift = 4) of maxmem4g.
232  *
233  * RESTRICT4G_ALLOC returns true if freemem4g falls below DESFREE4G
234  * and the amount of physical memory above 4g is greater than freemem4g.
235  * In this case, page_get_* routines will restrict below 4g allocations
236  * for requests that don't specifically require it.
237  */
238 
239 #define	DESFREE4G	(maxmem4g >> desfree4gshift)
240 
241 #define	RESTRICT4G_ALLOC					\
242 	(physmax4g && (freemem4g < DESFREE4G) && ((freemem4g << 1) < freemem))
243 
244 static pgcnt_t	maxmem4g;
245 static pgcnt_t	freemem4g;
246 static int	physmax4g;
247 static int	desfree4gshift = 4;	/* maxmem4g shift to derive DESFREE4G */
248 
249 /*
250  * 16m memory management:
251  *
252  * reserve some amount of physical memory below 16m for legacy devices.
253  *
254  * RESTRICT16M_ALLOC returns true if an there are sufficient free pages above
255  * 16m or if the 16m pool drops below DESFREE16M.
256  *
257  * In this case, general page allocations via page_get_{free,cache}list
258  * routines will be restricted from allocating from the 16m pool. Allocations
259  * that require specific pfn ranges (page_get_anylist) and PG_PANIC allocations
260  * are not restricted.
261  */
262 
263 #define	FREEMEM16M	MTYPE_FREEMEM(mtype16m)
264 #define	DESFREE16M	desfree16m
265 #define	RESTRICT16M_ALLOC(freemem, pgcnt, flags) \
266 	(mtype16m != -1 && (freemem != 0) && ((flags & PG_PANIC) == 0) && \
267 	    ((freemem >= (FREEMEM16M)) || \
268 	    (FREEMEM16M  < (DESFREE16M + pgcnt))))
269 
270 static pgcnt_t	desfree16m = 0x380;
271 
272 /*
273  * This can be patched via /etc/system to allow old non-PAE aware device
274  * drivers to use kmem_alloc'd memory on 32 bit systems with > 4Gig RAM.
275  */
276 int restricted_kmemalloc = 0;
277 
278 #ifdef VM_STATS
279 struct {
280 	ulong_t	pga_alloc;
281 	ulong_t	pga_notfullrange;
282 	ulong_t	pga_nulldmaattr;
283 	ulong_t	pga_allocok;
284 	ulong_t	pga_allocfailed;
285 	ulong_t	pgma_alloc;
286 	ulong_t	pgma_allocok;
287 	ulong_t	pgma_allocfailed;
288 	ulong_t	pgma_allocempty;
289 } pga_vmstats;
290 #endif
291 
292 uint_t mmu_page_sizes;
293 
294 /* How many page sizes the users can see */
295 uint_t mmu_exported_page_sizes;
296 
297 /* page sizes that legacy applications can see */
298 uint_t mmu_legacy_page_sizes;
299 
300 /*
301  * Number of pages in 1 GB.  Don't enable automatic large pages if we have
302  * fewer than this many pages.
303  */
304 pgcnt_t shm_lpg_min_physmem = 1 << (30 - MMU_PAGESHIFT);
305 pgcnt_t privm_lpg_min_physmem = 1 << (30 - MMU_PAGESHIFT);
306 
307 /*
308  * Maximum and default segment size tunables for user private
309  * and shared anon memory, and user text and initialized data.
310  * These can be patched via /etc/system to allow large pages
311  * to be used for mapping application private and shared anon memory.
312  */
313 size_t mcntl0_lpsize = MMU_PAGESIZE;
314 size_t max_uheap_lpsize = MMU_PAGESIZE;
315 size_t default_uheap_lpsize = MMU_PAGESIZE;
316 size_t max_ustack_lpsize = MMU_PAGESIZE;
317 size_t default_ustack_lpsize = MMU_PAGESIZE;
318 size_t max_privmap_lpsize = MMU_PAGESIZE;
319 size_t max_uidata_lpsize = MMU_PAGESIZE;
320 size_t max_utext_lpsize = MMU_PAGESIZE;
321 size_t max_shm_lpsize = MMU_PAGESIZE;
322 
323 
324 /*
325  * initialized by page_coloring_init().
326  */
327 uint_t	page_colors;
328 uint_t	page_colors_mask;
329 uint_t	page_coloring_shift;
330 int	cpu_page_colors;
331 static uint_t	l2_colors;
332 
333 /*
334  * Page freelists and cachelists are dynamically allocated once mnoderangecnt
335  * and page_colors are calculated from the l2 cache n-way set size.  Within a
336  * mnode range, the page freelist and cachelist are hashed into bins based on
337  * color. This makes it easier to search for a page within a specific memory
338  * range.
339  */
340 #define	PAGE_COLORS_MIN	16
341 
342 page_t ****page_freelists;
343 page_t ***page_cachelists;
344 
345 
346 /*
347  * Used by page layer to know about page sizes
348  */
349 hw_pagesize_t hw_page_array[MAX_NUM_LEVEL + 1];
350 
351 kmutex_t	*fpc_mutex[NPC_MUTEX];
352 kmutex_t	*cpc_mutex[NPC_MUTEX];
353 
354 /* Lock to protect mnoderanges array for memory DR operations. */
355 static kmutex_t mnoderange_lock;
356 
357 /*
358  * Only let one thread at a time try to coalesce large pages, to
359  * prevent them from working against each other.
360  */
361 static kmutex_t	contig_lock;
362 #define	CONTIG_LOCK()	mutex_enter(&contig_lock);
363 #define	CONTIG_UNLOCK()	mutex_exit(&contig_lock);
364 
365 #define	PFN_16M		(mmu_btop((uint64_t)0x1000000))
366 
367 caddr_t
368 i86devmap(pfn_t pf, pgcnt_t pgcnt, uint_t prot)
369 {
370 	caddr_t addr;
371 	caddr_t addr1;
372 	page_t *pp;
373 
374 	addr1 = addr = vmem_alloc(heap_arena, mmu_ptob(pgcnt), VM_SLEEP);
375 
376 	for (; pgcnt != 0; addr += MMU_PAGESIZE, ++pf, --pgcnt) {
377 		pp = page_numtopp_nolock(pf);
378 		if (pp == NULL) {
379 			hat_devload(kas.a_hat, addr, MMU_PAGESIZE, pf,
380 			    prot | HAT_NOSYNC, HAT_LOAD_LOCK);
381 		} else {
382 			hat_memload(kas.a_hat, addr, pp,
383 			    prot | HAT_NOSYNC, HAT_LOAD_LOCK);
384 		}
385 	}
386 
387 	return (addr1);
388 }
389 
390 /*
391  * This routine is like page_numtopp, but accepts only free pages, which
392  * it allocates (unfrees) and returns with the exclusive lock held.
393  * It is used by machdep.c/dma_init() to find contiguous free pages.
394  */
395 page_t *
396 page_numtopp_alloc(pfn_t pfnum)
397 {
398 	page_t *pp;
399 
400 retry:
401 	pp = page_numtopp_nolock(pfnum);
402 	if (pp == NULL) {
403 		return (NULL);
404 	}
405 
406 	if (!page_trylock(pp, SE_EXCL)) {
407 		return (NULL);
408 	}
409 
410 	if (page_pptonum(pp) != pfnum) {
411 		page_unlock(pp);
412 		goto retry;
413 	}
414 
415 	if (!PP_ISFREE(pp)) {
416 		page_unlock(pp);
417 		return (NULL);
418 	}
419 	if (pp->p_szc) {
420 		page_demote_free_pages(pp);
421 		page_unlock(pp);
422 		goto retry;
423 	}
424 
425 	/* If associated with a vnode, destroy mappings */
426 
427 	if (pp->p_vnode) {
428 
429 		page_destroy_free(pp);
430 
431 		if (!page_lock(pp, SE_EXCL, (kmutex_t *)NULL, P_NO_RECLAIM)) {
432 			return (NULL);
433 		}
434 
435 		if (page_pptonum(pp) != pfnum) {
436 			page_unlock(pp);
437 			goto retry;
438 		}
439 	}
440 
441 	if (!PP_ISFREE(pp)) {
442 		page_unlock(pp);
443 		return (NULL);
444 	}
445 
446 	if (!page_reclaim(pp, (kmutex_t *)NULL))
447 		return (NULL);
448 
449 	return (pp);
450 }
451 
452 /*
453  * Return the optimum page size for a given mapping
454  */
455 /*ARGSUSED*/
456 size_t
457 map_pgsz(int maptype, struct proc *p, caddr_t addr, size_t len, int memcntl)
458 {
459 	level_t l = 0;
460 	size_t pgsz = MMU_PAGESIZE;
461 	size_t max_lpsize;
462 	uint_t mszc;
463 
464 	ASSERT(maptype != MAPPGSZ_VA);
465 
466 	if (maptype != MAPPGSZ_ISM && physmem < privm_lpg_min_physmem) {
467 		return (MMU_PAGESIZE);
468 	}
469 
470 	switch (maptype) {
471 	case MAPPGSZ_HEAP:
472 	case MAPPGSZ_STK:
473 		max_lpsize = memcntl ? mcntl0_lpsize : (maptype ==
474 		    MAPPGSZ_HEAP ? max_uheap_lpsize : max_ustack_lpsize);
475 		if (max_lpsize == MMU_PAGESIZE) {
476 			return (MMU_PAGESIZE);
477 		}
478 		if (len == 0) {
479 			len = (maptype == MAPPGSZ_HEAP) ? p->p_brkbase +
480 			    p->p_brksize - p->p_bssbase : p->p_stksize;
481 		}
482 		len = (maptype == MAPPGSZ_HEAP) ? MAX(len,
483 		    default_uheap_lpsize) : MAX(len, default_ustack_lpsize);
484 
485 		/*
486 		 * use the pages size that best fits len
487 		 */
488 		for (l = mmu.umax_page_level; l > 0; --l) {
489 			if (LEVEL_SIZE(l) > max_lpsize || len < LEVEL_SIZE(l)) {
490 				continue;
491 			} else {
492 				pgsz = LEVEL_SIZE(l);
493 			}
494 			break;
495 		}
496 
497 		mszc = (maptype == MAPPGSZ_HEAP ? p->p_brkpageszc :
498 		    p->p_stkpageszc);
499 		if (addr == 0 && (pgsz < hw_page_array[mszc].hp_size)) {
500 			pgsz = hw_page_array[mszc].hp_size;
501 		}
502 		return (pgsz);
503 
504 	case MAPPGSZ_ISM:
505 		for (l = mmu.umax_page_level; l > 0; --l) {
506 			if (len >= LEVEL_SIZE(l))
507 				return (LEVEL_SIZE(l));
508 		}
509 		return (LEVEL_SIZE(0));
510 	}
511 	return (pgsz);
512 }
513 
514 static uint_t
515 map_szcvec(caddr_t addr, size_t size, uintptr_t off, size_t max_lpsize,
516     size_t min_physmem)
517 {
518 	caddr_t eaddr = addr + size;
519 	uint_t szcvec = 0;
520 	caddr_t raddr;
521 	caddr_t readdr;
522 	size_t	pgsz;
523 	int i;
524 
525 	if (physmem < min_physmem || max_lpsize <= MMU_PAGESIZE) {
526 		return (0);
527 	}
528 
529 	for (i = mmu_exported_page_sizes - 1; i > 0; i--) {
530 		pgsz = page_get_pagesize(i);
531 		if (pgsz > max_lpsize) {
532 			continue;
533 		}
534 		raddr = (caddr_t)P2ROUNDUP((uintptr_t)addr, pgsz);
535 		readdr = (caddr_t)P2ALIGN((uintptr_t)eaddr, pgsz);
536 		if (raddr < addr || raddr >= readdr) {
537 			continue;
538 		}
539 		if (P2PHASE((uintptr_t)addr ^ off, pgsz)) {
540 			continue;
541 		}
542 		/*
543 		 * Set szcvec to the remaining page sizes.
544 		 */
545 		szcvec = ((1 << (i + 1)) - 1) & ~1;
546 		break;
547 	}
548 	return (szcvec);
549 }
550 
551 /*
552  * Return a bit vector of large page size codes that
553  * can be used to map [addr, addr + len) region.
554  */
555 /*ARGSUSED*/
556 uint_t
557 map_pgszcvec(caddr_t addr, size_t size, uintptr_t off, int flags, int type,
558     int memcntl)
559 {
560 	size_t max_lpsize = mcntl0_lpsize;
561 
562 	if (mmu.max_page_level == 0)
563 		return (0);
564 
565 	if (flags & MAP_TEXT) {
566 		if (!memcntl)
567 			max_lpsize = max_utext_lpsize;
568 		return (map_szcvec(addr, size, off, max_lpsize,
569 		    shm_lpg_min_physmem));
570 
571 	} else if (flags & MAP_INITDATA) {
572 		if (!memcntl)
573 			max_lpsize = max_uidata_lpsize;
574 		return (map_szcvec(addr, size, off, max_lpsize,
575 		    privm_lpg_min_physmem));
576 
577 	} else if (type == MAPPGSZC_SHM) {
578 		if (!memcntl)
579 			max_lpsize = max_shm_lpsize;
580 		return (map_szcvec(addr, size, off, max_lpsize,
581 		    shm_lpg_min_physmem));
582 
583 	} else if (type == MAPPGSZC_HEAP) {
584 		if (!memcntl)
585 			max_lpsize = max_uheap_lpsize;
586 		return (map_szcvec(addr, size, off, max_lpsize,
587 		    privm_lpg_min_physmem));
588 
589 	} else if (type == MAPPGSZC_STACK) {
590 		if (!memcntl)
591 			max_lpsize = max_ustack_lpsize;
592 		return (map_szcvec(addr, size, off, max_lpsize,
593 		    privm_lpg_min_physmem));
594 
595 	} else {
596 		if (!memcntl)
597 			max_lpsize = max_privmap_lpsize;
598 		return (map_szcvec(addr, size, off, max_lpsize,
599 		    privm_lpg_min_physmem));
600 	}
601 }
602 
603 /*
604  * Handle a pagefault.
605  */
606 faultcode_t
607 pagefault(
608 	caddr_t addr,
609 	enum fault_type type,
610 	enum seg_rw rw,
611 	int iskernel)
612 {
613 	struct as *as;
614 	struct hat *hat;
615 	struct proc *p;
616 	kthread_t *t;
617 	faultcode_t res;
618 	caddr_t base;
619 	size_t len;
620 	int err;
621 	int mapped_red;
622 	uintptr_t ea;
623 
624 	ASSERT_STACK_ALIGNED();
625 
626 	if (INVALID_VADDR(addr))
627 		return (FC_NOMAP);
628 
629 	mapped_red = segkp_map_red();
630 
631 	if (iskernel) {
632 		as = &kas;
633 		hat = as->a_hat;
634 	} else {
635 		t = curthread;
636 		p = ttoproc(t);
637 		as = p->p_as;
638 		hat = as->a_hat;
639 	}
640 
641 	/*
642 	 * Dispatch pagefault.
643 	 */
644 	res = as_fault(hat, as, addr, 1, type, rw);
645 
646 	/*
647 	 * If this isn't a potential unmapped hole in the user's
648 	 * UNIX data or stack segments, just return status info.
649 	 */
650 	if (res != FC_NOMAP || iskernel)
651 		goto out;
652 
653 	/*
654 	 * Check to see if we happened to faulted on a currently unmapped
655 	 * part of the UNIX data or stack segments.  If so, create a zfod
656 	 * mapping there and then try calling the fault routine again.
657 	 */
658 	base = p->p_brkbase;
659 	len = p->p_brksize;
660 
661 	if (addr < base || addr >= base + len) {		/* data seg? */
662 		base = (caddr_t)p->p_usrstack - p->p_stksize;
663 		len = p->p_stksize;
664 		if (addr < base || addr >= p->p_usrstack) {	/* stack seg? */
665 			/* not in either UNIX data or stack segments */
666 			res = FC_NOMAP;
667 			goto out;
668 		}
669 	}
670 
671 	/*
672 	 * the rest of this function implements a 3.X 4.X 5.X compatibility
673 	 * This code is probably not needed anymore
674 	 */
675 	if (p->p_model == DATAMODEL_ILP32) {
676 
677 		/* expand the gap to the page boundaries on each side */
678 		ea = P2ROUNDUP((uintptr_t)base + len, MMU_PAGESIZE);
679 		base = (caddr_t)P2ALIGN((uintptr_t)base, MMU_PAGESIZE);
680 		len = ea - (uintptr_t)base;
681 
682 		as_rangelock(as);
683 		if (as_gap(as, MMU_PAGESIZE, &base, &len, AH_CONTAIN, addr) ==
684 		    0) {
685 			err = as_map(as, base, len, segvn_create, zfod_argsp);
686 			as_rangeunlock(as);
687 			if (err) {
688 				res = FC_MAKE_ERR(err);
689 				goto out;
690 			}
691 		} else {
692 			/*
693 			 * This page is already mapped by another thread after
694 			 * we returned from as_fault() above.  We just fall
695 			 * through as_fault() below.
696 			 */
697 			as_rangeunlock(as);
698 		}
699 
700 		res = as_fault(hat, as, addr, 1, F_INVAL, rw);
701 	}
702 
703 out:
704 	if (mapped_red)
705 		segkp_unmap_red();
706 
707 	return (res);
708 }
709 
710 void
711 map_addr(caddr_t *addrp, size_t len, offset_t off, int vacalign, uint_t flags)
712 {
713 	struct proc *p = curproc;
714 	caddr_t userlimit = (flags & _MAP_LOW32) ?
715 	    (caddr_t)_userlimit32 : p->p_as->a_userlimit;
716 
717 	map_addr_proc(addrp, len, off, vacalign, userlimit, curproc, flags);
718 }
719 
720 /*ARGSUSED*/
721 int
722 map_addr_vacalign_check(caddr_t addr, u_offset_t off)
723 {
724 	return (0);
725 }
726 
727 /*
728  * The maximum amount a randomized mapping will be slewed.  We should perhaps
729  * arrange things so these tunables can be separate for mmap, mmapobj, and
730  * ld.so
731  */
732 size_t aslr_max_map_skew = 256 * 1024 * 1024; /* 256MB */
733 
734 /*
735  * map_addr_proc() is the routine called when the system is to
736  * choose an address for the user.  We will pick an address
737  * range which is the highest available below userlimit.
738  *
739  * Every mapping will have a redzone of a single page on either side of
740  * the request. This is done to leave one page unmapped between segments.
741  * This is not required, but it's useful for the user because if their
742  * program strays across a segment boundary, it will catch a fault
743  * immediately making debugging a little easier.  Currently the redzone
744  * is mandatory.
745  *
746  * addrp is a value/result parameter.
747  *	On input it is a hint from the user to be used in a completely
748  *	machine dependent fashion.  We decide to completely ignore this hint.
749  *	If MAP_ALIGN was specified, addrp contains the minimal alignment, which
750  *	must be some "power of two" multiple of pagesize.
751  *
752  *	On output it is NULL if no address can be found in the current
753  *	processes address space or else an address that is currently
754  *	not mapped for len bytes with a page of red zone on either side.
755  *
756  *	vacalign is not needed on x86 (it's for viturally addressed caches)
757  */
758 /*ARGSUSED*/
759 void
760 map_addr_proc(
761 	caddr_t *addrp,
762 	size_t len,
763 	offset_t off,
764 	int vacalign,
765 	caddr_t userlimit,
766 	struct proc *p,
767 	uint_t flags)
768 {
769 	struct as *as = p->p_as;
770 	caddr_t addr;
771 	caddr_t base;
772 	size_t slen;
773 	size_t align_amount;
774 
775 	ASSERT32(userlimit == as->a_userlimit);
776 
777 	base = p->p_brkbase;
778 #if defined(__amd64)
779 	if (p->p_model == DATAMODEL_NATIVE) {
780 		if (userlimit < as->a_userlimit) {
781 			/*
782 			 * This happens when a program wants to map
783 			 * something in a range that's accessible to a
784 			 * program in a smaller address space.  For example,
785 			 * a 64-bit program calling mmap32(2) to guarantee
786 			 * that the returned address is below 4Gbytes.
787 			 */
788 			ASSERT((uintptr_t)userlimit < ADDRESS_C(0xffffffff));
789 
790 			if (userlimit > base)
791 				slen = userlimit - base;
792 			else {
793 				*addrp = NULL;
794 				return;
795 			}
796 		} else {
797 			/*
798 			 * With the stack positioned at a higher address than
799 			 * the heap for 64-bit processes, it is necessary to be
800 			 * mindful of its location and potential size.
801 			 *
802 			 * Unallocated space above the top of the stack (that
803 			 * is, at a lower address) but still within the bounds
804 			 * of the stack limit should be considered unavailable.
805 			 *
806 			 * As the 64-bit stack guard is mapped in immediately
807 			 * adjacent to the stack limit boundary, this prevents
808 			 * new mappings from having accidentally dangerous
809 			 * proximity to the stack.
810 			 */
811 			slen = p->p_usrstack - base -
812 			    ((p->p_stk_ctl + PAGEOFFSET) & PAGEMASK);
813 		}
814 	} else
815 #endif /* defined(__amd64) */
816 		slen = userlimit - base;
817 
818 	/* Make len be a multiple of PAGESIZE */
819 	len = (len + PAGEOFFSET) & PAGEMASK;
820 
821 	/*
822 	 * figure out what the alignment should be
823 	 *
824 	 * XX64 -- is there an ELF_AMD64_MAXPGSZ or is it the same????
825 	 */
826 	if (len <= ELF_386_MAXPGSZ) {
827 		/*
828 		 * Align virtual addresses to ensure that ELF shared libraries
829 		 * are mapped with the appropriate alignment constraints by
830 		 * the run-time linker.
831 		 */
832 		align_amount = ELF_386_MAXPGSZ;
833 	} else {
834 		/*
835 		 * For 32-bit processes, only those which have specified
836 		 * MAP_ALIGN and an addr will be aligned on a larger page size.
837 		 * Not doing so can potentially waste up to 1G of process
838 		 * address space.
839 		 */
840 		int lvl = (p->p_model == DATAMODEL_ILP32) ? 1 :
841 		    mmu.umax_page_level;
842 
843 		while (lvl && len < LEVEL_SIZE(lvl))
844 			--lvl;
845 
846 		align_amount = LEVEL_SIZE(lvl);
847 	}
848 	if ((flags & MAP_ALIGN) && ((uintptr_t)*addrp > align_amount))
849 		align_amount = (uintptr_t)*addrp;
850 
851 	ASSERT(ISP2(align_amount));
852 	ASSERT(align_amount == 0 || align_amount >= PAGESIZE);
853 
854 	off = off & (align_amount - 1);
855 
856 	/*
857 	 * Look for a large enough hole starting below userlimit.
858 	 * After finding it, use the upper part.
859 	 */
860 	if (as_gap_aligned(as, len, &base, &slen, AH_HI, NULL, align_amount,
861 	    PAGESIZE, off) == 0) {
862 		caddr_t as_addr;
863 
864 		/*
865 		 * addr is the highest possible address to use since we have
866 		 * a PAGESIZE redzone at the beginning and end.
867 		 */
868 		addr = base + slen - (PAGESIZE + len);
869 		as_addr = addr;
870 		/*
871 		 * Round address DOWN to the alignment amount and
872 		 * add the offset in.
873 		 * If addr is greater than as_addr, len would not be large
874 		 * enough to include the redzone, so we must adjust down
875 		 * by the alignment amount.
876 		 */
877 		addr = (caddr_t)((uintptr_t)addr & (~(align_amount - 1)));
878 		addr += (uintptr_t)off;
879 		if (addr > as_addr) {
880 			addr -= align_amount;
881 		}
882 
883 		/*
884 		 * If randomization is requested, slew the allocation
885 		 * backwards, within the same gap, by a random amount.
886 		 */
887 		if (flags & _MAP_RANDOMIZE) {
888 			uint32_t slew;
889 
890 			(void) random_get_pseudo_bytes((uint8_t *)&slew,
891 			    sizeof (slew));
892 
893 			slew = slew % MIN(aslr_max_map_skew, (addr - base));
894 			addr -= P2ALIGN(slew, align_amount);
895 		}
896 
897 		ASSERT(addr > base);
898 		ASSERT(addr + len < base + slen);
899 		ASSERT(((uintptr_t)addr & (align_amount - 1)) ==
900 		    ((uintptr_t)(off)));
901 		*addrp = addr;
902 	} else {
903 		*addrp = NULL;	/* no more virtual space */
904 	}
905 }
906 
907 int valid_va_range_aligned_wraparound;
908 
909 /*
910  * Determine whether [*basep, *basep + *lenp) contains a mappable range of
911  * addresses at least "minlen" long, where the base of the range is at "off"
912  * phase from an "align" boundary and there is space for a "redzone"-sized
913  * redzone on either side of the range.  On success, 1 is returned and *basep
914  * and *lenp are adjusted to describe the acceptable range (including
915  * the redzone).  On failure, 0 is returned.
916  */
917 /*ARGSUSED3*/
918 int
919 valid_va_range_aligned(caddr_t *basep, size_t *lenp, size_t minlen, int dir,
920     size_t align, size_t redzone, size_t off)
921 {
922 	uintptr_t hi, lo;
923 	size_t tot_len;
924 
925 	ASSERT(align == 0 ? off == 0 : off < align);
926 	ASSERT(ISP2(align));
927 	ASSERT(align == 0 || align >= PAGESIZE);
928 
929 	lo = (uintptr_t)*basep;
930 	hi = lo + *lenp;
931 	tot_len = minlen + 2 * redzone; /* need at least this much space */
932 
933 	/*
934 	 * If hi rolled over the top, try cutting back.
935 	 */
936 	if (hi < lo) {
937 		*lenp = 0UL - lo - 1UL;
938 		/* See if this really happens. If so, then we figure out why */
939 		valid_va_range_aligned_wraparound++;
940 		hi = lo + *lenp;
941 	}
942 	if (*lenp < tot_len) {
943 		return (0);
944 	}
945 
946 #if defined(__amd64)
947 	/*
948 	 * Deal with a possible hole in the address range between
949 	 * hole_start and hole_end that should never be mapped.
950 	 */
951 	if (lo < hole_start) {
952 		if (hi > hole_start) {
953 			if (hi < hole_end) {
954 				hi = hole_start;
955 			} else {
956 				/* lo < hole_start && hi >= hole_end */
957 				if (dir == AH_LO) {
958 					/*
959 					 * prefer lowest range
960 					 */
961 					if (hole_start - lo >= tot_len)
962 						hi = hole_start;
963 					else if (hi - hole_end >= tot_len)
964 						lo = hole_end;
965 					else
966 						return (0);
967 				} else {
968 					/*
969 					 * prefer highest range
970 					 */
971 					if (hi - hole_end >= tot_len)
972 						lo = hole_end;
973 					else if (hole_start - lo >= tot_len)
974 						hi = hole_start;
975 					else
976 						return (0);
977 				}
978 			}
979 		}
980 	} else {
981 		/* lo >= hole_start */
982 		if (hi < hole_end)
983 			return (0);
984 		if (lo < hole_end)
985 			lo = hole_end;
986 	}
987 #endif
988 
989 	if (hi - lo < tot_len)
990 		return (0);
991 
992 	if (align > 1) {
993 		uintptr_t tlo = lo + redzone;
994 		uintptr_t thi = hi - redzone;
995 		tlo = (uintptr_t)P2PHASEUP(tlo, align, off);
996 		if (tlo < lo + redzone) {
997 			return (0);
998 		}
999 		if (thi < tlo || thi - tlo < minlen) {
1000 			return (0);
1001 		}
1002 	}
1003 
1004 	*basep = (caddr_t)lo;
1005 	*lenp = hi - lo;
1006 	return (1);
1007 }
1008 
1009 /*
1010  * Determine whether [*basep, *basep + *lenp) contains a mappable range of
1011  * addresses at least "minlen" long.  On success, 1 is returned and *basep
1012  * and *lenp are adjusted to describe the acceptable range.  On failure, 0
1013  * is returned.
1014  */
1015 int
1016 valid_va_range(caddr_t *basep, size_t *lenp, size_t minlen, int dir)
1017 {
1018 	return (valid_va_range_aligned(basep, lenp, minlen, dir, 0, 0, 0));
1019 }
1020 
1021 /*
1022  * Default to forbidding the first 64k of address space.  This protects most
1023  * reasonably sized structures from dereferences through NULL:
1024  *     ((foo_t *)0)->bar
1025  */
1026 uintptr_t forbidden_null_mapping_sz = 0x10000;
1027 
1028 /*
1029  * Determine whether [addr, addr+len] are valid user addresses.
1030  */
1031 /*ARGSUSED*/
1032 int
1033 valid_usr_range(caddr_t addr, size_t len, uint_t prot, struct as *as,
1034     caddr_t userlimit)
1035 {
1036 	caddr_t eaddr = addr + len;
1037 
1038 	if (eaddr <= addr || addr >= userlimit || eaddr > userlimit)
1039 		return (RANGE_BADADDR);
1040 
1041 	if ((addr <= (caddr_t)forbidden_null_mapping_sz) &&
1042 	    as->a_proc != NULL &&
1043 	    secflag_enabled(as->a_proc, PROC_SEC_FORBIDNULLMAP))
1044 		return (RANGE_BADADDR);
1045 
1046 #if defined(__amd64)
1047 	/*
1048 	 * Check for the VA hole
1049 	 */
1050 	if (eaddr > (caddr_t)hole_start && addr < (caddr_t)hole_end)
1051 		return (RANGE_BADADDR);
1052 #endif
1053 
1054 	return (RANGE_OKAY);
1055 }
1056 
1057 /*
1058  * Return 1 if the page frame is onboard memory, else 0.
1059  */
1060 int
1061 pf_is_memory(pfn_t pf)
1062 {
1063 	if (pfn_is_foreign(pf))
1064 		return (0);
1065 	return (address_in_memlist(phys_install, pfn_to_pa(pf), 1));
1066 }
1067 
1068 /*
1069  * return the memrange containing pfn
1070  */
1071 int
1072 memrange_num(pfn_t pfn)
1073 {
1074 	int n;
1075 
1076 	for (n = 0; n < nranges - 1; ++n) {
1077 		if (pfn >= memranges[n])
1078 			break;
1079 	}
1080 	return (n);
1081 }
1082 
1083 /*
1084  * return the mnoderange containing pfn
1085  */
1086 /*ARGSUSED*/
1087 int
1088 pfn_2_mtype(pfn_t pfn)
1089 {
1090 #if defined(__xpv)
1091 	return (0);
1092 #else
1093 	int	n;
1094 
1095 	/* Always start from highest pfn and work our way down */
1096 	for (n = mtypetop; n != -1; n = mnoderanges[n].mnr_next) {
1097 		if (pfn >= mnoderanges[n].mnr_pfnlo) {
1098 			break;
1099 		}
1100 	}
1101 	return (n);
1102 #endif
1103 }
1104 
1105 #if !defined(__xpv)
1106 /*
1107  * is_contigpage_free:
1108  *	returns a page list of contiguous pages. It minimally has to return
1109  *	minctg pages. Caller determines minctg based on the scatter-gather
1110  *	list length.
1111  *
1112  *	pfnp is set to the next page frame to search on return.
1113  */
1114 static page_t *
1115 is_contigpage_free(
1116 	pfn_t *pfnp,
1117 	pgcnt_t *pgcnt,
1118 	pgcnt_t minctg,
1119 	uint64_t pfnseg,
1120 	int iolock)
1121 {
1122 	int	i = 0;
1123 	pfn_t	pfn = *pfnp;
1124 	page_t	*pp;
1125 	page_t	*plist = NULL;
1126 
1127 	/*
1128 	 * fail if pfn + minctg crosses a segment boundary.
1129 	 * Adjust for next starting pfn to begin at segment boundary.
1130 	 */
1131 
1132 	if (((*pfnp + minctg - 1) & pfnseg) < (*pfnp & pfnseg)) {
1133 		*pfnp = roundup(*pfnp, pfnseg + 1);
1134 		return (NULL);
1135 	}
1136 
1137 	do {
1138 retry:
1139 		pp = page_numtopp_nolock(pfn + i);
1140 		if ((pp == NULL) || IS_DUMP_PAGE(pp) ||
1141 		    (page_trylock(pp, SE_EXCL) == 0)) {
1142 			(*pfnp)++;
1143 			break;
1144 		}
1145 		if (page_pptonum(pp) != pfn + i) {
1146 			page_unlock(pp);
1147 			goto retry;
1148 		}
1149 
1150 		if (!(PP_ISFREE(pp))) {
1151 			page_unlock(pp);
1152 			(*pfnp)++;
1153 			break;
1154 		}
1155 
1156 		if (!PP_ISAGED(pp)) {
1157 			page_list_sub(pp, PG_CACHE_LIST);
1158 			page_hashout(pp, (kmutex_t *)NULL);
1159 		} else {
1160 			page_list_sub(pp, PG_FREE_LIST);
1161 		}
1162 
1163 		if (iolock)
1164 			page_io_lock(pp);
1165 		page_list_concat(&plist, &pp);
1166 
1167 		/*
1168 		 * exit loop when pgcnt satisfied or segment boundary reached.
1169 		 */
1170 
1171 	} while ((++i < *pgcnt) && ((pfn + i) & pfnseg));
1172 
1173 	*pfnp += i;		/* set to next pfn to search */
1174 
1175 	if (i >= minctg) {
1176 		*pgcnt -= i;
1177 		return (plist);
1178 	}
1179 
1180 	/*
1181 	 * failure: minctg not satisfied.
1182 	 *
1183 	 * if next request crosses segment boundary, set next pfn
1184 	 * to search from the segment boundary.
1185 	 */
1186 	if (((*pfnp + minctg - 1) & pfnseg) < (*pfnp & pfnseg))
1187 		*pfnp = roundup(*pfnp, pfnseg + 1);
1188 
1189 	/* clean up any pages already allocated */
1190 
1191 	while (plist) {
1192 		pp = plist;
1193 		page_sub(&plist, pp);
1194 		page_list_add(pp, PG_FREE_LIST | PG_LIST_TAIL);
1195 		if (iolock)
1196 			page_io_unlock(pp);
1197 		page_unlock(pp);
1198 	}
1199 
1200 	return (NULL);
1201 }
1202 #endif	/* !__xpv */
1203 
1204 /*
1205  * verify that pages being returned from allocator have correct DMA attribute
1206  */
1207 #ifndef DEBUG
1208 #define	check_dma(a, b, c) (void)(0)
1209 #else
1210 static void
1211 check_dma(ddi_dma_attr_t *dma_attr, page_t *pp, int cnt)
1212 {
1213 	if (dma_attr == NULL)
1214 		return;
1215 
1216 	while (cnt-- > 0) {
1217 		if (pa_to_ma(pfn_to_pa(pp->p_pagenum)) <
1218 		    dma_attr->dma_attr_addr_lo)
1219 			panic("PFN (pp=%p) below dma_attr_addr_lo", (void *)pp);
1220 		if (pa_to_ma(pfn_to_pa(pp->p_pagenum)) >=
1221 		    dma_attr->dma_attr_addr_hi)
1222 			panic("PFN (pp=%p) above dma_attr_addr_hi", (void *)pp);
1223 		pp = pp->p_next;
1224 	}
1225 }
1226 #endif
1227 
1228 #if !defined(__xpv)
1229 static page_t *
1230 page_get_contigpage(pgcnt_t *pgcnt, ddi_dma_attr_t *mattr, int iolock)
1231 {
1232 	pfn_t		pfn;
1233 	int		sgllen;
1234 	uint64_t	pfnseg;
1235 	pgcnt_t		minctg;
1236 	page_t		*pplist = NULL, *plist;
1237 	uint64_t	lo, hi;
1238 	pgcnt_t		pfnalign = 0;
1239 	static pfn_t	startpfn;
1240 	static pgcnt_t	lastctgcnt;
1241 	uintptr_t	align;
1242 
1243 	CONTIG_LOCK();
1244 
1245 	if (mattr) {
1246 		lo = mmu_btop((mattr->dma_attr_addr_lo + MMU_PAGEOFFSET));
1247 		hi = mmu_btop(mattr->dma_attr_addr_hi);
1248 		if (hi >= physmax)
1249 			hi = physmax - 1;
1250 		sgllen = mattr->dma_attr_sgllen;
1251 		pfnseg = mmu_btop(mattr->dma_attr_seg);
1252 
1253 		align = maxbit(mattr->dma_attr_align, mattr->dma_attr_minxfer);
1254 		if (align > MMU_PAGESIZE)
1255 			pfnalign = mmu_btop(align);
1256 
1257 		/*
1258 		 * in order to satisfy the request, must minimally
1259 		 * acquire minctg contiguous pages
1260 		 */
1261 		minctg = howmany(*pgcnt, sgllen);
1262 
1263 		ASSERT(hi >= lo);
1264 
1265 		/*
1266 		 * start from where last searched if the minctg >= lastctgcnt
1267 		 */
1268 		if (minctg < lastctgcnt || startpfn < lo || startpfn > hi)
1269 			startpfn = lo;
1270 	} else {
1271 		hi = physmax - 1;
1272 		lo = 0;
1273 		sgllen = 1;
1274 		pfnseg = mmu.highest_pfn;
1275 		minctg = *pgcnt;
1276 
1277 		if (minctg < lastctgcnt)
1278 			startpfn = lo;
1279 	}
1280 	lastctgcnt = minctg;
1281 
1282 	ASSERT(pfnseg + 1 >= (uint64_t)minctg);
1283 
1284 	/* conserve 16m memory - start search above 16m when possible */
1285 	if (hi > PFN_16M && startpfn < PFN_16M)
1286 		startpfn = PFN_16M;
1287 
1288 	pfn = startpfn;
1289 	if (pfnalign)
1290 		pfn = P2ROUNDUP(pfn, pfnalign);
1291 
1292 	while (pfn + minctg - 1 <= hi) {
1293 
1294 		plist = is_contigpage_free(&pfn, pgcnt, minctg, pfnseg, iolock);
1295 		if (plist) {
1296 			page_list_concat(&pplist, &plist);
1297 			sgllen--;
1298 			/*
1299 			 * return when contig pages no longer needed
1300 			 */
1301 			if (!*pgcnt || ((*pgcnt <= sgllen) && !pfnalign)) {
1302 				startpfn = pfn;
1303 				CONTIG_UNLOCK();
1304 				check_dma(mattr, pplist, *pgcnt);
1305 				return (pplist);
1306 			}
1307 			minctg = howmany(*pgcnt, sgllen);
1308 		}
1309 		if (pfnalign)
1310 			pfn = P2ROUNDUP(pfn, pfnalign);
1311 	}
1312 
1313 	/* cannot find contig pages in specified range */
1314 	if (startpfn == lo) {
1315 		CONTIG_UNLOCK();
1316 		return (NULL);
1317 	}
1318 
1319 	/* did not start with lo previously */
1320 	pfn = lo;
1321 	if (pfnalign)
1322 		pfn = P2ROUNDUP(pfn, pfnalign);
1323 
1324 	/* allow search to go above startpfn */
1325 	while (pfn < startpfn) {
1326 
1327 		plist = is_contigpage_free(&pfn, pgcnt, minctg, pfnseg, iolock);
1328 		if (plist != NULL) {
1329 
1330 			page_list_concat(&pplist, &plist);
1331 			sgllen--;
1332 
1333 			/*
1334 			 * return when contig pages no longer needed
1335 			 */
1336 			if (!*pgcnt || ((*pgcnt <= sgllen) && !pfnalign)) {
1337 				startpfn = pfn;
1338 				CONTIG_UNLOCK();
1339 				check_dma(mattr, pplist, *pgcnt);
1340 				return (pplist);
1341 			}
1342 			minctg = howmany(*pgcnt, sgllen);
1343 		}
1344 		if (pfnalign)
1345 			pfn = P2ROUNDUP(pfn, pfnalign);
1346 	}
1347 	CONTIG_UNLOCK();
1348 	return (NULL);
1349 }
1350 #endif	/* !__xpv */
1351 
1352 /*
1353  * mnode_range_cnt() calculates the number of memory ranges for mnode and
1354  * memranges[]. Used to determine the size of page lists and mnoderanges.
1355  */
1356 int
1357 mnode_range_cnt(int mnode)
1358 {
1359 #if defined(__xpv)
1360 	ASSERT(mnode == 0);
1361 	return (1);
1362 #else	/* __xpv */
1363 	int	mri;
1364 	int	mnrcnt = 0;
1365 
1366 	if (mem_node_config[mnode].exists != 0) {
1367 		mri = nranges - 1;
1368 
1369 		/* find the memranges index below contained in mnode range */
1370 
1371 		while (MEMRANGEHI(mri) < mem_node_config[mnode].physbase)
1372 			mri--;
1373 
1374 		/*
1375 		 * increment mnode range counter when memranges or mnode
1376 		 * boundary is reached.
1377 		 */
1378 		while (mri >= 0 &&
1379 		    mem_node_config[mnode].physmax >= MEMRANGELO(mri)) {
1380 			mnrcnt++;
1381 			if (mem_node_config[mnode].physmax > MEMRANGEHI(mri))
1382 				mri--;
1383 			else
1384 				break;
1385 		}
1386 	}
1387 	ASSERT(mnrcnt <= MAX_MNODE_MRANGES);
1388 	return (mnrcnt);
1389 #endif	/* __xpv */
1390 }
1391 
1392 static int
1393 mnoderange_cmp(const void *v1, const void *v2)
1394 {
1395 	const mnoderange_t *m1 = v1;
1396 	const mnoderange_t *m2 = v2;
1397 
1398 	if (m1->mnr_pfnlo < m2->mnr_pfnlo)
1399 		return (-1);
1400 	return (m1->mnr_pfnlo > m2->mnr_pfnlo);
1401 }
1402 
1403 void
1404 mnode_range_setup(mnoderange_t *mnoderanges)
1405 {
1406 	mnoderange_t *mp;
1407 	size_t nr_ranges;
1408 	size_t mnode;
1409 
1410 	for (mnode = 0, nr_ranges = 0, mp = mnoderanges;
1411 	    mnode < max_mem_nodes; mnode++) {
1412 		size_t mri = nranges - 1;
1413 
1414 		if (mem_node_config[mnode].exists == 0)
1415 			continue;
1416 
1417 		while (MEMRANGEHI(mri) < mem_node_config[mnode].physbase)
1418 			mri--;
1419 
1420 		while (mri >= 0 && mem_node_config[mnode].physmax >=
1421 		    MEMRANGELO(mri)) {
1422 			mp->mnr_pfnlo = MAX(MEMRANGELO(mri),
1423 			    mem_node_config[mnode].physbase);
1424 			mp->mnr_pfnhi = MIN(MEMRANGEHI(mri),
1425 			    mem_node_config[mnode].physmax);
1426 			mp->mnr_mnode = mnode;
1427 			mp->mnr_memrange = mri;
1428 			mp->mnr_next = -1;
1429 			mp->mnr_exists = 1;
1430 			mp++;
1431 			nr_ranges++;
1432 			if (mem_node_config[mnode].physmax > MEMRANGEHI(mri))
1433 				mri--;
1434 			else
1435 				break;
1436 		}
1437 	}
1438 
1439 	/*
1440 	 * mnoderangecnt can be larger than nr_ranges when memory DR is
1441 	 * supposedly supported.
1442 	 */
1443 	VERIFY3U(nr_ranges, <=, mnoderangecnt);
1444 
1445 	qsort(mnoderanges, nr_ranges, sizeof (mnoderange_t), mnoderange_cmp);
1446 
1447 	/*
1448 	 * If some intrepid soul takes the axe to the memory DR code, we can
1449 	 * remove ->mnr_next altogether, as we just sorted by ->mnr_pfnlo order.
1450 	 *
1451 	 * The VERIFY3U() above can be "==" then too.
1452 	 */
1453 	for (size_t i = 1; i < nr_ranges; i++)
1454 		mnoderanges[i].mnr_next = i - 1;
1455 
1456 	mtypetop = nr_ranges - 1;
1457 	mtype16m = pfn_2_mtype(PFN_16MEG - 1); /* Can be -1 ... */
1458 	if (physmax4g)
1459 		mtype4g = pfn_2_mtype(0xfffff);
1460 }
1461 
1462 #ifndef	__xpv
1463 /*
1464  * Update mnoderanges for memory hot-add DR operations.
1465  */
1466 static void
1467 mnode_range_add(int mnode)
1468 {
1469 	int	*prev;
1470 	int	n, mri;
1471 	pfn_t	start, end;
1472 	extern	void membar_sync(void);
1473 
1474 	ASSERT(0 <= mnode && mnode < max_mem_nodes);
1475 	ASSERT(mem_node_config[mnode].exists);
1476 	start = mem_node_config[mnode].physbase;
1477 	end = mem_node_config[mnode].physmax;
1478 	ASSERT(start <= end);
1479 	mutex_enter(&mnoderange_lock);
1480 
1481 #ifdef	DEBUG
1482 	/* Check whether it interleaves with other memory nodes. */
1483 	for (n = mtypetop; n != -1; n = mnoderanges[n].mnr_next) {
1484 		ASSERT(mnoderanges[n].mnr_exists);
1485 		if (mnoderanges[n].mnr_mnode == mnode)
1486 			continue;
1487 		ASSERT(start > mnoderanges[n].mnr_pfnhi ||
1488 		    end < mnoderanges[n].mnr_pfnlo);
1489 	}
1490 #endif	/* DEBUG */
1491 
1492 	mri = nranges - 1;
1493 	while (MEMRANGEHI(mri) < mem_node_config[mnode].physbase)
1494 		mri--;
1495 	while (mri >= 0 && mem_node_config[mnode].physmax >= MEMRANGELO(mri)) {
1496 		/* Check whether mtype already exists. */
1497 		for (n = mtypetop; n != -1; n = mnoderanges[n].mnr_next) {
1498 			if (mnoderanges[n].mnr_mnode == mnode &&
1499 			    mnoderanges[n].mnr_memrange == mri) {
1500 				mnoderanges[n].mnr_pfnlo = MAX(MEMRANGELO(mri),
1501 				    start);
1502 				mnoderanges[n].mnr_pfnhi = MIN(MEMRANGEHI(mri),
1503 				    end);
1504 				break;
1505 			}
1506 		}
1507 
1508 		/* Add a new entry if it doesn't exist yet. */
1509 		if (n == -1) {
1510 			/* Try to find an unused entry in mnoderanges array. */
1511 			for (n = 0; n < mnoderangecnt; n++) {
1512 				if (mnoderanges[n].mnr_exists == 0)
1513 					break;
1514 			}
1515 			ASSERT(n < mnoderangecnt);
1516 			mnoderanges[n].mnr_pfnlo = MAX(MEMRANGELO(mri), start);
1517 			mnoderanges[n].mnr_pfnhi = MIN(MEMRANGEHI(mri), end);
1518 			mnoderanges[n].mnr_mnode = mnode;
1519 			mnoderanges[n].mnr_memrange = mri;
1520 			mnoderanges[n].mnr_exists = 1;
1521 			/* Page 0 should always be present. */
1522 			for (prev = &mtypetop;
1523 			    mnoderanges[*prev].mnr_pfnlo > start;
1524 			    prev = &mnoderanges[*prev].mnr_next) {
1525 				ASSERT(mnoderanges[*prev].mnr_next >= 0);
1526 				ASSERT(mnoderanges[*prev].mnr_pfnlo > end);
1527 			}
1528 			mnoderanges[n].mnr_next = *prev;
1529 			membar_sync();
1530 			*prev = n;
1531 		}
1532 
1533 		if (mem_node_config[mnode].physmax > MEMRANGEHI(mri))
1534 			mri--;
1535 		else
1536 			break;
1537 	}
1538 
1539 	mutex_exit(&mnoderange_lock);
1540 }
1541 
1542 /*
1543  * Update mnoderanges for memory hot-removal DR operations.
1544  */
1545 static void
1546 mnode_range_del(int mnode)
1547 {
1548 	_NOTE(ARGUNUSED(mnode));
1549 	ASSERT(0 <= mnode && mnode < max_mem_nodes);
1550 	/* TODO: support deletion operation. */
1551 	ASSERT(0);
1552 }
1553 
1554 void
1555 plat_slice_add(pfn_t start, pfn_t end)
1556 {
1557 	mem_node_add_slice(start, end);
1558 	if (plat_dr_enabled()) {
1559 		mnode_range_add(PFN_2_MEM_NODE(start));
1560 	}
1561 }
1562 
1563 void
1564 plat_slice_del(pfn_t start, pfn_t end)
1565 {
1566 	ASSERT(PFN_2_MEM_NODE(start) == PFN_2_MEM_NODE(end));
1567 	ASSERT(plat_dr_enabled());
1568 	mnode_range_del(PFN_2_MEM_NODE(start));
1569 	mem_node_del_slice(start, end);
1570 }
1571 #endif	/* __xpv */
1572 
1573 /*ARGSUSED*/
1574 int
1575 mtype_init(vnode_t *vp, caddr_t vaddr, uint_t *flags, size_t pgsz)
1576 {
1577 	int mtype = mtypetop;
1578 
1579 #if !defined(__xpv)
1580 #if defined(__i386)
1581 	/*
1582 	 * set the mtype range
1583 	 * - kmem requests need to be below 4g if restricted_kmemalloc is set.
1584 	 * - for non kmem requests, set range to above 4g if memory below 4g
1585 	 * runs low.
1586 	 */
1587 	if (restricted_kmemalloc && VN_ISKAS(vp) &&
1588 	    (caddr_t)(vaddr) >= kernelheap &&
1589 	    (caddr_t)(vaddr) < ekernelheap) {
1590 		ASSERT(physmax4g);
1591 		mtype = mtype4g;
1592 		if (RESTRICT16M_ALLOC(freemem4g - btop(pgsz),
1593 		    btop(pgsz), *flags)) {
1594 			*flags |= PGI_MT_RANGE16M;
1595 		} else {
1596 			VM_STAT_ADD(vmm_vmstats.unrestrict16mcnt);
1597 			VM_STAT_COND_ADD((*flags & PG_PANIC),
1598 			    vmm_vmstats.pgpanicalloc);
1599 			*flags |= PGI_MT_RANGE0;
1600 		}
1601 		return (mtype);
1602 	}
1603 #endif	/* __i386 */
1604 
1605 	if (RESTRICT4G_ALLOC) {
1606 		VM_STAT_ADD(vmm_vmstats.restrict4gcnt);
1607 		/* here only for > 4g systems */
1608 		*flags |= PGI_MT_RANGE4G;
1609 	} else if (RESTRICT16M_ALLOC(freemem, btop(pgsz), *flags)) {
1610 		*flags |= PGI_MT_RANGE16M;
1611 	} else {
1612 		VM_STAT_ADD(vmm_vmstats.unrestrict16mcnt);
1613 		VM_STAT_COND_ADD((*flags & PG_PANIC), vmm_vmstats.pgpanicalloc);
1614 		*flags |= PGI_MT_RANGE0;
1615 	}
1616 #endif /* !__xpv */
1617 	return (mtype);
1618 }
1619 
1620 
1621 /* mtype init for page_get_replacement_page */
1622 /*ARGSUSED*/
1623 int
1624 mtype_pgr_init(int *flags, page_t *pp, pgcnt_t pgcnt)
1625 {
1626 	int mtype = mtypetop;
1627 #if !defined(__xpv)
1628 	if (RESTRICT16M_ALLOC(freemem, pgcnt, *flags)) {
1629 		*flags |= PGI_MT_RANGE16M;
1630 	} else {
1631 		VM_STAT_ADD(vmm_vmstats.unrestrict16mcnt);
1632 		*flags |= PGI_MT_RANGE0;
1633 	}
1634 #endif
1635 	return (mtype);
1636 }
1637 
1638 /*
1639  * Determine if the mnode range specified in mtype contains memory belonging
1640  * to memory node mnode.  If flags & PGI_MT_RANGE is set then mtype contains
1641  * the range from high pfn to 0, 16m or 4g.
1642  *
1643  * Return first mnode range type index found otherwise return -1 if none found.
1644  */
1645 int
1646 mtype_func(int mnode, int mtype, uint_t flags)
1647 {
1648 	if (flags & PGI_MT_RANGE) {
1649 		int	mnr_lim = MRI_0;
1650 
1651 		if (flags & PGI_MT_NEXT) {
1652 			mtype = mnoderanges[mtype].mnr_next;
1653 		}
1654 		if (flags & PGI_MT_RANGE4G)
1655 			mnr_lim = MRI_4G;	/* exclude 0-4g range */
1656 		else if (flags & PGI_MT_RANGE16M)
1657 			mnr_lim = MRI_16M;	/* exclude 0-16m range */
1658 		while (mtype != -1 &&
1659 		    mnoderanges[mtype].mnr_memrange <= mnr_lim) {
1660 			if (mnoderanges[mtype].mnr_mnode == mnode)
1661 				return (mtype);
1662 			mtype = mnoderanges[mtype].mnr_next;
1663 		}
1664 	} else if (mnoderanges[mtype].mnr_mnode == mnode) {
1665 		return (mtype);
1666 	}
1667 	return (-1);
1668 }
1669 
1670 /*
1671  * Update the page list max counts with the pfn range specified by the
1672  * input parameters.
1673  */
1674 void
1675 mtype_modify_max(pfn_t startpfn, long cnt)
1676 {
1677 	int		mtype;
1678 	pgcnt_t		inc;
1679 	spgcnt_t	scnt = (spgcnt_t)(cnt);
1680 	pgcnt_t		acnt = ABS(scnt);
1681 	pfn_t		endpfn = startpfn + acnt;
1682 	pfn_t		pfn, lo;
1683 
1684 	if (!physmax4g)
1685 		return;
1686 
1687 	mtype = mtypetop;
1688 	for (pfn = endpfn; pfn > startpfn; ) {
1689 		ASSERT(mtype != -1);
1690 		lo = mnoderanges[mtype].mnr_pfnlo;
1691 		if (pfn > lo) {
1692 			if (startpfn >= lo) {
1693 				inc = pfn - startpfn;
1694 			} else {
1695 				inc = pfn - lo;
1696 			}
1697 			if (mnoderanges[mtype].mnr_memrange != MRI_4G) {
1698 				if (scnt > 0)
1699 					maxmem4g += inc;
1700 				else
1701 					maxmem4g -= inc;
1702 			}
1703 			pfn -= inc;
1704 		}
1705 		mtype = mnoderanges[mtype].mnr_next;
1706 	}
1707 }
1708 
1709 int
1710 mtype_2_mrange(int mtype)
1711 {
1712 	return (mnoderanges[mtype].mnr_memrange);
1713 }
1714 
1715 void
1716 mnodetype_2_pfn(int mnode, int mtype, pfn_t *pfnlo, pfn_t *pfnhi)
1717 {
1718 	_NOTE(ARGUNUSED(mnode));
1719 	ASSERT(mnoderanges[mtype].mnr_mnode == mnode);
1720 	*pfnlo = mnoderanges[mtype].mnr_pfnlo;
1721 	*pfnhi = mnoderanges[mtype].mnr_pfnhi;
1722 }
1723 
1724 size_t
1725 plcnt_sz(size_t ctrs_sz)
1726 {
1727 #ifdef DEBUG
1728 	int	szc, colors;
1729 
1730 	ctrs_sz += mnoderangecnt * sizeof (struct mnr_mts) * mmu_page_sizes;
1731 	for (szc = 0; szc < mmu_page_sizes; szc++) {
1732 		colors = page_get_pagecolors(szc);
1733 		ctrs_sz += mnoderangecnt * sizeof (pgcnt_t) * colors;
1734 	}
1735 #endif
1736 	return (ctrs_sz);
1737 }
1738 
1739 caddr_t
1740 plcnt_init(caddr_t addr)
1741 {
1742 #ifdef DEBUG
1743 	int	mt, szc, colors;
1744 
1745 	for (mt = 0; mt < mnoderangecnt; mt++) {
1746 		mnoderanges[mt].mnr_mts = (struct mnr_mts *)addr;
1747 		addr += (sizeof (struct mnr_mts) * mmu_page_sizes);
1748 		for (szc = 0; szc < mmu_page_sizes; szc++) {
1749 			colors = page_get_pagecolors(szc);
1750 			mnoderanges[mt].mnr_mts[szc].mnr_mts_colors = colors;
1751 			mnoderanges[mt].mnr_mts[szc].mnr_mtsc_pgcnt =
1752 			    (pgcnt_t *)addr;
1753 			addr += (sizeof (pgcnt_t) * colors);
1754 		}
1755 	}
1756 #endif
1757 	return (addr);
1758 }
1759 
1760 void
1761 plcnt_inc_dec(page_t *pp, int mtype, int szc, long cnt, int flags)
1762 {
1763 	_NOTE(ARGUNUSED(pp));
1764 #ifdef DEBUG
1765 	int	bin = PP_2_BIN(pp);
1766 
1767 	atomic_add_long(&mnoderanges[mtype].mnr_mts[szc].mnr_mts_pgcnt, cnt);
1768 	atomic_add_long(&mnoderanges[mtype].mnr_mts[szc].mnr_mtsc_pgcnt[bin],
1769 	    cnt);
1770 #endif
1771 	ASSERT(mtype == PP_2_MTYPE(pp));
1772 	if (physmax4g && mnoderanges[mtype].mnr_memrange != MRI_4G)
1773 		atomic_add_long(&freemem4g, cnt);
1774 	if (flags & PG_CACHE_LIST)
1775 		atomic_add_long(&mnoderanges[mtype].mnr_mt_clpgcnt, cnt);
1776 	else
1777 		atomic_add_long(&mnoderanges[mtype].mnr_mt_flpgcnt[szc], cnt);
1778 	atomic_add_long(&mnoderanges[mtype].mnr_mt_totcnt, cnt);
1779 }
1780 
1781 /*
1782  * Returns the free page count for mnode
1783  */
1784 int
1785 mnode_pgcnt(int mnode)
1786 {
1787 	int	mtype = mtypetop;
1788 	int	flags = PGI_MT_RANGE0;
1789 	pgcnt_t	pgcnt = 0;
1790 
1791 	mtype = mtype_func(mnode, mtype, flags);
1792 
1793 	while (mtype != -1) {
1794 		pgcnt += MTYPE_FREEMEM(mtype);
1795 		mtype = mtype_func(mnode, mtype, flags | PGI_MT_NEXT);
1796 	}
1797 	return (pgcnt);
1798 }
1799 
1800 /*
1801  * Initialize page coloring variables based on the l2 cache parameters.
1802  * Calculate and return memory needed for page coloring data structures.
1803  */
1804 size_t
1805 page_coloring_init(uint_t l2_sz, int l2_linesz, int l2_assoc)
1806 {
1807 	_NOTE(ARGUNUSED(l2_linesz));
1808 	size_t	colorsz = 0;
1809 	int	i;
1810 	int	colors;
1811 
1812 #if defined(__xpv)
1813 	/*
1814 	 * Hypervisor domains currently don't have any concept of NUMA.
1815 	 * Hence we'll act like there is only 1 memrange.
1816 	 */
1817 	i = memrange_num(1);
1818 #else /* !__xpv */
1819 	/*
1820 	 * Reduce the memory ranges lists if we don't have large amounts
1821 	 * of memory. This avoids searching known empty free lists.
1822 	 * To support memory DR operations, we need to keep memory ranges
1823 	 * for possible memory hot-add operations.
1824 	 */
1825 	if (plat_dr_physmax > physmax)
1826 		i = memrange_num(plat_dr_physmax);
1827 	else
1828 		i = memrange_num(physmax);
1829 #if defined(__i386)
1830 	if (i > MRI_4G)
1831 		restricted_kmemalloc = 0;
1832 #endif
1833 	/* physmax greater than 4g */
1834 	if (i == MRI_4G)
1835 		physmax4g = 1;
1836 #endif /* !__xpv */
1837 	memranges += i;
1838 	nranges -= i;
1839 
1840 	ASSERT(mmu_page_sizes <= MMU_PAGE_SIZES);
1841 
1842 	ASSERT(ISP2(l2_linesz));
1843 	ASSERT(l2_sz > MMU_PAGESIZE);
1844 
1845 	/* l2_assoc is 0 for fully associative l2 cache */
1846 	if (l2_assoc)
1847 		l2_colors = MAX(1, l2_sz / (l2_assoc * MMU_PAGESIZE));
1848 	else
1849 		l2_colors = 1;
1850 
1851 	ASSERT(ISP2(l2_colors));
1852 
1853 	/* for scalability, configure at least PAGE_COLORS_MIN color bins */
1854 	page_colors = MAX(l2_colors, PAGE_COLORS_MIN);
1855 
1856 	/*
1857 	 * cpu_page_colors is non-zero when a page color may be spread across
1858 	 * multiple bins.
1859 	 */
1860 	if (l2_colors < page_colors)
1861 		cpu_page_colors = l2_colors;
1862 
1863 	ASSERT(ISP2(page_colors));
1864 
1865 	page_colors_mask = page_colors - 1;
1866 
1867 	ASSERT(ISP2(CPUSETSIZE()));
1868 	page_coloring_shift = lowbit(CPUSETSIZE());
1869 
1870 	/* initialize number of colors per page size */
1871 	for (i = 0; i <= mmu.max_page_level; i++) {
1872 		hw_page_array[i].hp_size = LEVEL_SIZE(i);
1873 		hw_page_array[i].hp_shift = LEVEL_SHIFT(i);
1874 		hw_page_array[i].hp_pgcnt = LEVEL_SIZE(i) >> LEVEL_SHIFT(0);
1875 		hw_page_array[i].hp_colors = (page_colors_mask >>
1876 		    (hw_page_array[i].hp_shift - hw_page_array[0].hp_shift))
1877 		    + 1;
1878 		colorequivszc[i] = 0;
1879 	}
1880 
1881 	/*
1882 	 * The value of cpu_page_colors determines if additional color bins
1883 	 * need to be checked for a particular color in the page_get routines.
1884 	 */
1885 	if (cpu_page_colors != 0) {
1886 
1887 		int a = lowbit(page_colors) - lowbit(cpu_page_colors);
1888 		ASSERT(a > 0);
1889 		ASSERT(a < 16);
1890 
1891 		for (i = 0; i <= mmu.max_page_level; i++) {
1892 			if ((colors = hw_page_array[i].hp_colors) <= 1) {
1893 				colorequivszc[i] = 0;
1894 				continue;
1895 			}
1896 			while ((colors >> a) == 0)
1897 				a--;
1898 			ASSERT(a >= 0);
1899 
1900 			/* higher 4 bits encodes color equiv mask */
1901 			colorequivszc[i] = (a << 4);
1902 		}
1903 	}
1904 
1905 	/* factor in colorequiv to check additional 'equivalent' bins. */
1906 	if (colorequiv > 1) {
1907 
1908 		int a = lowbit(colorequiv) - 1;
1909 		if (a > 15)
1910 			a = 15;
1911 
1912 		for (i = 0; i <= mmu.max_page_level; i++) {
1913 			if ((colors = hw_page_array[i].hp_colors) <= 1) {
1914 				continue;
1915 			}
1916 			while ((colors >> a) == 0)
1917 				a--;
1918 			if ((a << 4) > colorequivszc[i]) {
1919 				colorequivszc[i] = (a << 4);
1920 			}
1921 		}
1922 	}
1923 
1924 	/* size for mnoderanges */
1925 	for (mnoderangecnt = 0, i = 0; i < max_mem_nodes; i++)
1926 		mnoderangecnt += mnode_range_cnt(i);
1927 	if (plat_dr_support_memory()) {
1928 		/*
1929 		 * Reserve enough space for memory DR operations.
1930 		 * Two extra mnoderanges for possbile fragmentations,
1931 		 * one for the 2G boundary and the other for the 4G boundary.
1932 		 * We don't expect a memory board crossing the 16M boundary
1933 		 * for memory hot-add operations on x86 platforms.
1934 		 */
1935 		mnoderangecnt += 2 + max_mem_nodes - lgrp_plat_node_cnt;
1936 	}
1937 	colorsz = mnoderangecnt * sizeof (mnoderange_t);
1938 
1939 	/* size for fpc_mutex and cpc_mutex */
1940 	colorsz += (2 * max_mem_nodes * sizeof (kmutex_t) * NPC_MUTEX);
1941 
1942 	/* size of page_freelists */
1943 	colorsz += mnoderangecnt * sizeof (page_t ***);
1944 	colorsz += mnoderangecnt * mmu_page_sizes * sizeof (page_t **);
1945 
1946 	for (i = 0; i < mmu_page_sizes; i++) {
1947 		colors = page_get_pagecolors(i);
1948 		colorsz += mnoderangecnt * colors * sizeof (page_t *);
1949 	}
1950 
1951 	/* size of page_cachelists */
1952 	colorsz += mnoderangecnt * sizeof (page_t **);
1953 	colorsz += mnoderangecnt * page_colors * sizeof (page_t *);
1954 
1955 	return (colorsz);
1956 }
1957 
1958 /*
1959  * Called once at startup to configure page_coloring data structures and
1960  * does the 1st page_free()/page_freelist_add().
1961  */
1962 void
1963 page_coloring_setup(caddr_t pcmemaddr)
1964 {
1965 	int	i;
1966 	int	j;
1967 	int	k;
1968 	caddr_t	addr;
1969 	int	colors;
1970 
1971 	/*
1972 	 * do page coloring setup
1973 	 */
1974 	addr = pcmemaddr;
1975 
1976 	mnoderanges = (mnoderange_t *)addr;
1977 	addr += (mnoderangecnt * sizeof (mnoderange_t));
1978 
1979 	mnode_range_setup(mnoderanges);
1980 
1981 	for (k = 0; k < NPC_MUTEX; k++) {
1982 		fpc_mutex[k] = (kmutex_t *)addr;
1983 		addr += (max_mem_nodes * sizeof (kmutex_t));
1984 	}
1985 	for (k = 0; k < NPC_MUTEX; k++) {
1986 		cpc_mutex[k] = (kmutex_t *)addr;
1987 		addr += (max_mem_nodes * sizeof (kmutex_t));
1988 	}
1989 	page_freelists = (page_t ****)addr;
1990 	addr += (mnoderangecnt * sizeof (page_t ***));
1991 
1992 	page_cachelists = (page_t ***)addr;
1993 	addr += (mnoderangecnt * sizeof (page_t **));
1994 
1995 	for (i = 0; i < mnoderangecnt; i++) {
1996 		page_freelists[i] = (page_t ***)addr;
1997 		addr += (mmu_page_sizes * sizeof (page_t **));
1998 
1999 		for (j = 0; j < mmu_page_sizes; j++) {
2000 			colors = page_get_pagecolors(j);
2001 			page_freelists[i][j] = (page_t **)addr;
2002 			addr += (colors * sizeof (page_t *));
2003 		}
2004 		page_cachelists[i] = (page_t **)addr;
2005 		addr += (page_colors * sizeof (page_t *));
2006 	}
2007 }
2008 
2009 #if defined(__xpv)
2010 /*
2011  * Give back 10% of the io_pool pages to the free list.
2012  * Don't shrink the pool below some absolute minimum.
2013  */
2014 static void
2015 page_io_pool_shrink()
2016 {
2017 	int retcnt;
2018 	page_t *pp, *pp_first, *pp_last, **curpool;
2019 	mfn_t mfn;
2020 	int bothpools = 0;
2021 
2022 	mutex_enter(&io_pool_lock);
2023 	io_pool_shrink_attempts++;	/* should be a kstat? */
2024 	retcnt = io_pool_cnt / 10;
2025 	if (io_pool_cnt - retcnt < io_pool_cnt_min)
2026 		retcnt = io_pool_cnt - io_pool_cnt_min;
2027 	if (retcnt <= 0)
2028 		goto done;
2029 	io_pool_shrinks++;	/* should be a kstat? */
2030 	curpool = &io_pool_4g;
2031 domore:
2032 	/*
2033 	 * Loop through taking pages from the end of the list
2034 	 * (highest mfns) till amount to return reached.
2035 	 */
2036 	for (pp = *curpool; pp && retcnt > 0; ) {
2037 		pp_first = pp_last = pp->p_prev;
2038 		if (pp_first == *curpool)
2039 			break;
2040 		retcnt--;
2041 		io_pool_cnt--;
2042 		page_io_pool_sub(curpool, pp_first, pp_last);
2043 		if ((mfn = pfn_to_mfn(pp->p_pagenum)) < start_mfn)
2044 			start_mfn = mfn;
2045 		page_free(pp_first, 1);
2046 		pp = *curpool;
2047 	}
2048 	if (retcnt != 0 && !bothpools) {
2049 		/*
2050 		 * If not enough found in less constrained pool try the
2051 		 * more constrained one.
2052 		 */
2053 		curpool = &io_pool_16m;
2054 		bothpools = 1;
2055 		goto domore;
2056 	}
2057 done:
2058 	mutex_exit(&io_pool_lock);
2059 }
2060 
2061 #endif	/* __xpv */
2062 
2063 uint_t
2064 page_create_update_flags_x86(uint_t flags)
2065 {
2066 #if defined(__xpv)
2067 	/*
2068 	 * Check this is an urgent allocation and free pages are depleted.
2069 	 */
2070 	if (!(flags & PG_WAIT) && freemem < desfree)
2071 		page_io_pool_shrink();
2072 #else /* !__xpv */
2073 	/*
2074 	 * page_create_get_something may call this because 4g memory may be
2075 	 * depleted. Set flags to allow for relocation of base page below
2076 	 * 4g if necessary.
2077 	 */
2078 	if (physmax4g)
2079 		flags |= (PGI_PGCPSZC0 | PGI_PGCPHIPRI);
2080 #endif /* __xpv */
2081 	return (flags);
2082 }
2083 
2084 /*ARGSUSED*/
2085 int
2086 bp_color(struct buf *bp)
2087 {
2088 	return (0);
2089 }
2090 
2091 #if defined(__xpv)
2092 
2093 /*
2094  * Take pages out of an io_pool
2095  */
2096 static void
2097 page_io_pool_sub(page_t **poolp, page_t *pp_first, page_t *pp_last)
2098 {
2099 	if (*poolp == pp_first) {
2100 		*poolp = pp_last->p_next;
2101 		if (*poolp == pp_first)
2102 			*poolp = NULL;
2103 	}
2104 	pp_first->p_prev->p_next = pp_last->p_next;
2105 	pp_last->p_next->p_prev = pp_first->p_prev;
2106 	pp_first->p_prev = pp_last;
2107 	pp_last->p_next = pp_first;
2108 }
2109 
2110 /*
2111  * Put a page on the io_pool list. The list is ordered by increasing MFN.
2112  */
2113 static void
2114 page_io_pool_add(page_t **poolp, page_t *pp)
2115 {
2116 	page_t	*look;
2117 	mfn_t	mfn = mfn_list[pp->p_pagenum];
2118 
2119 	if (*poolp == NULL) {
2120 		*poolp = pp;
2121 		pp->p_next = pp;
2122 		pp->p_prev = pp;
2123 		return;
2124 	}
2125 
2126 	/*
2127 	 * Since we try to take pages from the high end of the pool
2128 	 * chances are good that the pages to be put on the list will
2129 	 * go at or near the end of the list. so start at the end and
2130 	 * work backwards.
2131 	 */
2132 	look = (*poolp)->p_prev;
2133 	while (mfn < mfn_list[look->p_pagenum]) {
2134 		look = look->p_prev;
2135 		if (look == (*poolp)->p_prev)
2136 			break; /* backed all the way to front of list */
2137 	}
2138 
2139 	/* insert after look */
2140 	pp->p_prev = look;
2141 	pp->p_next = look->p_next;
2142 	pp->p_next->p_prev = pp;
2143 	look->p_next = pp;
2144 	if (mfn < mfn_list[(*poolp)->p_pagenum]) {
2145 		/*
2146 		 * we inserted a new first list element
2147 		 * adjust pool pointer to newly inserted element
2148 		 */
2149 		*poolp = pp;
2150 	}
2151 }
2152 
2153 /*
2154  * Add a page to the io_pool.  Setting the force flag will force the page
2155  * into the io_pool no matter what.
2156  */
2157 static void
2158 add_page_to_pool(page_t *pp, int force)
2159 {
2160 	page_t *highest;
2161 	page_t *freep = NULL;
2162 
2163 	mutex_enter(&io_pool_lock);
2164 	/*
2165 	 * Always keep the scarce low memory pages
2166 	 */
2167 	if (mfn_list[pp->p_pagenum] < PFN_16MEG) {
2168 		++io_pool_cnt;
2169 		page_io_pool_add(&io_pool_16m, pp);
2170 		goto done;
2171 	}
2172 	if (io_pool_cnt < io_pool_cnt_max || force || io_pool_4g == NULL) {
2173 		++io_pool_cnt;
2174 		page_io_pool_add(&io_pool_4g, pp);
2175 	} else {
2176 		highest = io_pool_4g->p_prev;
2177 		if (mfn_list[pp->p_pagenum] < mfn_list[highest->p_pagenum]) {
2178 			page_io_pool_sub(&io_pool_4g, highest, highest);
2179 			page_io_pool_add(&io_pool_4g, pp);
2180 			freep = highest;
2181 		} else {
2182 			freep = pp;
2183 		}
2184 	}
2185 done:
2186 	mutex_exit(&io_pool_lock);
2187 	if (freep)
2188 		page_free(freep, 1);
2189 }
2190 
2191 
2192 int contig_pfn_cnt;	/* no of pfns in the contig pfn list */
2193 int contig_pfn_max;	/* capacity of the contig pfn list */
2194 int next_alloc_pfn;	/* next position in list to start a contig search */
2195 int contig_pfnlist_updates;	/* pfn list update count */
2196 int contig_pfnlist_builds;	/* how many times have we (re)built list */
2197 int contig_pfnlist_buildfailed;	/* how many times has list build failed */
2198 int create_contig_pending;	/* nonzero means taskq creating contig list */
2199 pfn_t *contig_pfn_list = NULL;	/* list of contig pfns in ascending mfn order */
2200 
2201 /*
2202  * Function to use in sorting a list of pfns by their underlying mfns.
2203  */
2204 static int
2205 mfn_compare(const void *pfnp1, const void *pfnp2)
2206 {
2207 	mfn_t mfn1 = mfn_list[*(pfn_t *)pfnp1];
2208 	mfn_t mfn2 = mfn_list[*(pfn_t *)pfnp2];
2209 
2210 	if (mfn1 > mfn2)
2211 		return (1);
2212 	if (mfn1 < mfn2)
2213 		return (-1);
2214 	return (0);
2215 }
2216 
2217 /*
2218  * Compact the contig_pfn_list by tossing all the non-contiguous
2219  * elements from the list.
2220  */
2221 static void
2222 compact_contig_pfn_list(void)
2223 {
2224 	pfn_t pfn, lapfn, prev_lapfn;
2225 	mfn_t mfn;
2226 	int i, newcnt = 0;
2227 
2228 	prev_lapfn = 0;
2229 	for (i = 0; i < contig_pfn_cnt - 1; i++) {
2230 		pfn = contig_pfn_list[i];
2231 		lapfn = contig_pfn_list[i + 1];
2232 		mfn = mfn_list[pfn];
2233 		/*
2234 		 * See if next pfn is for a contig mfn
2235 		 */
2236 		if (mfn_list[lapfn] != mfn + 1)
2237 			continue;
2238 		/*
2239 		 * pfn and lookahead are both put in list
2240 		 * unless pfn is the previous lookahead.
2241 		 */
2242 		if (pfn != prev_lapfn)
2243 			contig_pfn_list[newcnt++] = pfn;
2244 		contig_pfn_list[newcnt++] = lapfn;
2245 		prev_lapfn = lapfn;
2246 	}
2247 	for (i = newcnt; i < contig_pfn_cnt; i++)
2248 		contig_pfn_list[i] = 0;
2249 	contig_pfn_cnt = newcnt;
2250 }
2251 
2252 /*ARGSUSED*/
2253 static void
2254 call_create_contiglist(void *arg)
2255 {
2256 	(void) create_contig_pfnlist(PG_WAIT);
2257 }
2258 
2259 /*
2260  * Create list of freelist pfns that have underlying
2261  * contiguous mfns.  The list is kept in ascending mfn order.
2262  * returns 1 if list created else 0.
2263  */
2264 static int
2265 create_contig_pfnlist(uint_t flags)
2266 {
2267 	pfn_t pfn;
2268 	page_t *pp;
2269 	int ret = 1;
2270 
2271 	mutex_enter(&contig_list_lock);
2272 	if (contig_pfn_list != NULL)
2273 		goto out;
2274 	contig_pfn_max = freemem + (freemem / 10);
2275 	contig_pfn_list = kmem_zalloc(contig_pfn_max * sizeof (pfn_t),
2276 	    (flags & PG_WAIT) ? KM_SLEEP : KM_NOSLEEP);
2277 	if (contig_pfn_list == NULL) {
2278 		/*
2279 		 * If we could not create the contig list (because
2280 		 * we could not sleep for memory).  Dispatch a taskq that can
2281 		 * sleep to get the memory.
2282 		 */
2283 		if (!create_contig_pending) {
2284 			if (taskq_dispatch(system_taskq, call_create_contiglist,
2285 			    NULL, TQ_NOSLEEP) != TASKQID_INVALID)
2286 				create_contig_pending = 1;
2287 		}
2288 		contig_pfnlist_buildfailed++;	/* count list build failures */
2289 		ret = 0;
2290 		goto out;
2291 	}
2292 	create_contig_pending = 0;
2293 	ASSERT(contig_pfn_cnt == 0);
2294 	for (pfn = 0; pfn < mfn_count; pfn++) {
2295 		pp = page_numtopp_nolock(pfn);
2296 		if (pp == NULL || !PP_ISFREE(pp))
2297 			continue;
2298 		contig_pfn_list[contig_pfn_cnt] = pfn;
2299 		if (++contig_pfn_cnt == contig_pfn_max)
2300 			break;
2301 	}
2302 	/*
2303 	 * Sanity check the new list.
2304 	 */
2305 	if (contig_pfn_cnt < 2) { /* no contig pfns */
2306 		contig_pfn_cnt = 0;
2307 		contig_pfnlist_buildfailed++;
2308 		kmem_free(contig_pfn_list, contig_pfn_max * sizeof (pfn_t));
2309 		contig_pfn_list = NULL;
2310 		contig_pfn_max = 0;
2311 		ret = 0;
2312 		goto out;
2313 	}
2314 	qsort(contig_pfn_list, contig_pfn_cnt, sizeof (pfn_t), mfn_compare);
2315 	compact_contig_pfn_list();
2316 	/*
2317 	 * Make sure next search of the newly created contiguous pfn
2318 	 * list starts at the beginning of the list.
2319 	 */
2320 	next_alloc_pfn = 0;
2321 	contig_pfnlist_builds++;	/* count list builds */
2322 out:
2323 	mutex_exit(&contig_list_lock);
2324 	return (ret);
2325 }
2326 
2327 
2328 /*
2329  * Toss the current contig pfnlist.  Someone is about to do a massive
2330  * update to pfn<->mfn mappings.  So we have them destroy the list and lock
2331  * it till they are done with their update.
2332  */
2333 void
2334 clear_and_lock_contig_pfnlist()
2335 {
2336 	pfn_t *listp = NULL;
2337 	size_t listsize;
2338 
2339 	mutex_enter(&contig_list_lock);
2340 	if (contig_pfn_list != NULL) {
2341 		listp = contig_pfn_list;
2342 		listsize = contig_pfn_max * sizeof (pfn_t);
2343 		contig_pfn_list = NULL;
2344 		contig_pfn_max = contig_pfn_cnt = 0;
2345 	}
2346 	if (listp != NULL)
2347 		kmem_free(listp, listsize);
2348 }
2349 
2350 /*
2351  * Unlock the contig_pfn_list.  The next attempted use of it will cause
2352  * it to be re-created.
2353  */
2354 void
2355 unlock_contig_pfnlist()
2356 {
2357 	mutex_exit(&contig_list_lock);
2358 }
2359 
2360 /*
2361  * Update the contiguous pfn list in response to a pfn <-> mfn reassignment
2362  */
2363 void
2364 update_contig_pfnlist(pfn_t pfn, mfn_t oldmfn, mfn_t newmfn)
2365 {
2366 	int probe_hi, probe_lo, probe_pos, insert_after, insert_point;
2367 	pfn_t probe_pfn;
2368 	mfn_t probe_mfn;
2369 	int drop_lock = 0;
2370 
2371 	if (mutex_owner(&contig_list_lock) != curthread) {
2372 		drop_lock = 1;
2373 		mutex_enter(&contig_list_lock);
2374 	}
2375 	if (contig_pfn_list == NULL)
2376 		goto done;
2377 	contig_pfnlist_updates++;
2378 	/*
2379 	 * Find the pfn in the current list.  Use a binary chop to locate it.
2380 	 */
2381 	probe_hi = contig_pfn_cnt - 1;
2382 	probe_lo = 0;
2383 	probe_pos = (probe_hi + probe_lo) / 2;
2384 	while ((probe_pfn = contig_pfn_list[probe_pos]) != pfn) {
2385 		if (probe_pos == probe_lo) { /* pfn not in list */
2386 			probe_pos = -1;
2387 			break;
2388 		}
2389 		if (pfn_to_mfn(probe_pfn) <= oldmfn)
2390 			probe_lo = probe_pos;
2391 		else
2392 			probe_hi = probe_pos;
2393 		probe_pos = (probe_hi + probe_lo) / 2;
2394 	}
2395 	if (probe_pos >= 0) {
2396 		/*
2397 		 * Remove pfn from list and ensure next alloc
2398 		 * position stays in bounds.
2399 		 */
2400 		if (--contig_pfn_cnt <= next_alloc_pfn)
2401 			next_alloc_pfn = 0;
2402 		if (contig_pfn_cnt < 2) { /* no contig pfns */
2403 			contig_pfn_cnt = 0;
2404 			kmem_free(contig_pfn_list,
2405 			    contig_pfn_max * sizeof (pfn_t));
2406 			contig_pfn_list = NULL;
2407 			contig_pfn_max = 0;
2408 			goto done;
2409 		}
2410 		ovbcopy(&contig_pfn_list[probe_pos + 1],
2411 		    &contig_pfn_list[probe_pos],
2412 		    (contig_pfn_cnt - probe_pos) * sizeof (pfn_t));
2413 	}
2414 	if (newmfn == MFN_INVALID)
2415 		goto done;
2416 	/*
2417 	 * Check if new mfn has adjacent mfns in the list
2418 	 */
2419 	probe_hi = contig_pfn_cnt - 1;
2420 	probe_lo = 0;
2421 	insert_after = -2;
2422 	do {
2423 		probe_pos = (probe_hi + probe_lo) / 2;
2424 		probe_mfn = pfn_to_mfn(contig_pfn_list[probe_pos]);
2425 		if (newmfn == probe_mfn + 1)
2426 			insert_after = probe_pos;
2427 		else if (newmfn == probe_mfn - 1)
2428 			insert_after = probe_pos - 1;
2429 		if (probe_pos == probe_lo)
2430 			break;
2431 		if (probe_mfn <= newmfn)
2432 			probe_lo = probe_pos;
2433 		else
2434 			probe_hi = probe_pos;
2435 	} while (insert_after == -2);
2436 	/*
2437 	 * If there is space in the list and there are adjacent mfns
2438 	 * insert the pfn in to its proper place in the list.
2439 	 */
2440 	if (insert_after != -2 && contig_pfn_cnt + 1 <= contig_pfn_max) {
2441 		insert_point = insert_after + 1;
2442 		ovbcopy(&contig_pfn_list[insert_point],
2443 		    &contig_pfn_list[insert_point + 1],
2444 		    (contig_pfn_cnt - insert_point) * sizeof (pfn_t));
2445 		contig_pfn_list[insert_point] = pfn;
2446 		contig_pfn_cnt++;
2447 	}
2448 done:
2449 	if (drop_lock)
2450 		mutex_exit(&contig_list_lock);
2451 }
2452 
2453 /*
2454  * Called to (re-)populate the io_pool from the free page lists.
2455  */
2456 long
2457 populate_io_pool(void)
2458 {
2459 	pfn_t pfn;
2460 	mfn_t mfn, max_mfn;
2461 	page_t *pp;
2462 
2463 	/*
2464 	 * Figure out the bounds of the pool on first invocation.
2465 	 * We use a percentage of memory for the io pool size.
2466 	 * we allow that to shrink, but not to less than a fixed minimum
2467 	 */
2468 	if (io_pool_cnt_max == 0) {
2469 		io_pool_cnt_max = physmem / (100 / io_pool_physmem_pct);
2470 		io_pool_cnt_lowater = io_pool_cnt_max;
2471 		/*
2472 		 * This is the first time in populate_io_pool, grab a va to use
2473 		 * when we need to allocate pages.
2474 		 */
2475 		io_pool_kva = vmem_alloc(heap_arena, PAGESIZE, VM_SLEEP);
2476 	}
2477 	/*
2478 	 * If we are out of pages in the pool, then grow the size of the pool
2479 	 */
2480 	if (io_pool_cnt == 0) {
2481 		/*
2482 		 * Grow the max size of the io pool by 5%, but never more than
2483 		 * 25% of physical memory.
2484 		 */
2485 		if (io_pool_cnt_max < physmem / 4)
2486 			io_pool_cnt_max += io_pool_cnt_max / 20;
2487 	}
2488 	io_pool_grows++;	/* should be a kstat? */
2489 
2490 	/*
2491 	 * Get highest mfn on this platform, but limit to the 32 bit DMA max.
2492 	 */
2493 	(void) mfn_to_pfn(start_mfn);
2494 	max_mfn = MIN(cached_max_mfn, PFN_4GIG);
2495 	for (mfn = start_mfn; mfn < max_mfn; start_mfn = ++mfn) {
2496 		pfn = mfn_to_pfn(mfn);
2497 		if (pfn & PFN_IS_FOREIGN_MFN)
2498 			continue;
2499 		/*
2500 		 * try to allocate it from free pages
2501 		 */
2502 		pp = page_numtopp_alloc(pfn);
2503 		if (pp == NULL)
2504 			continue;
2505 		PP_CLRFREE(pp);
2506 		add_page_to_pool(pp, 1);
2507 		if (io_pool_cnt >= io_pool_cnt_max)
2508 			break;
2509 	}
2510 
2511 	return (io_pool_cnt);
2512 }
2513 
2514 /*
2515  * Destroy a page that was being used for DMA I/O. It may or
2516  * may not actually go back to the io_pool.
2517  */
2518 void
2519 page_destroy_io(page_t *pp)
2520 {
2521 	mfn_t mfn = mfn_list[pp->p_pagenum];
2522 
2523 	/*
2524 	 * When the page was alloc'd a reservation was made, release it now
2525 	 */
2526 	page_unresv(1);
2527 	/*
2528 	 * Unload translations, if any, then hash out the
2529 	 * page to erase its identity.
2530 	 */
2531 	(void) hat_pageunload(pp, HAT_FORCE_PGUNLOAD);
2532 	page_hashout(pp, NULL);
2533 
2534 	/*
2535 	 * If the page came from the free lists, just put it back to them.
2536 	 * DomU pages always go on the free lists as well.
2537 	 */
2538 	if (!DOMAIN_IS_INITDOMAIN(xen_info) || mfn >= PFN_4GIG) {
2539 		page_free(pp, 1);
2540 		return;
2541 	}
2542 
2543 	add_page_to_pool(pp, 0);
2544 }
2545 
2546 
2547 long contig_searches;		/* count of times contig pages requested */
2548 long contig_search_restarts;	/* count of contig ranges tried */
2549 long contig_search_failed;	/* count of contig alloc failures */
2550 
2551 /*
2552  * Free partial page list
2553  */
2554 static void
2555 free_partial_list(page_t **pplist)
2556 {
2557 	page_t *pp;
2558 
2559 	while (*pplist != NULL) {
2560 		pp = *pplist;
2561 		page_io_pool_sub(pplist, pp, pp);
2562 		page_free(pp, 1);
2563 	}
2564 }
2565 
2566 /*
2567  * Look thru the contiguous pfns that are not part of the io_pool for
2568  * contiguous free pages.  Return a list of the found pages or NULL.
2569  */
2570 page_t *
2571 find_contig_free(uint_t npages, uint_t flags, uint64_t pfnseg,
2572     pgcnt_t pfnalign)
2573 {
2574 	page_t *pp, *plist = NULL;
2575 	mfn_t mfn, prev_mfn, start_mfn;
2576 	pfn_t pfn;
2577 	int pages_needed, pages_requested;
2578 	int search_start;
2579 
2580 	/*
2581 	 * create the contig pfn list if not already done
2582 	 */
2583 retry:
2584 	mutex_enter(&contig_list_lock);
2585 	if (contig_pfn_list == NULL) {
2586 		mutex_exit(&contig_list_lock);
2587 		if (!create_contig_pfnlist(flags)) {
2588 			return (NULL);
2589 		}
2590 		goto retry;
2591 	}
2592 	contig_searches++;
2593 	/*
2594 	 * Search contiguous pfn list for physically contiguous pages not in
2595 	 * the io_pool.  Start the search where the last search left off.
2596 	 */
2597 	pages_requested = pages_needed = npages;
2598 	search_start = next_alloc_pfn;
2599 	start_mfn = prev_mfn = 0;
2600 	while (pages_needed) {
2601 		pfn = contig_pfn_list[next_alloc_pfn];
2602 		mfn = pfn_to_mfn(pfn);
2603 		/*
2604 		 * Check if mfn is first one or contig to previous one and
2605 		 * if page corresponding to mfn is free and that mfn
2606 		 * range is not crossing a segment boundary.
2607 		 */
2608 		if ((prev_mfn == 0 || mfn == prev_mfn + 1) &&
2609 		    (pp = page_numtopp_alloc(pfn)) != NULL &&
2610 		    !((mfn & pfnseg) < (start_mfn & pfnseg))) {
2611 			PP_CLRFREE(pp);
2612 			page_io_pool_add(&plist, pp);
2613 			pages_needed--;
2614 			if (prev_mfn == 0) {
2615 				if (pfnalign &&
2616 				    mfn != P2ROUNDUP(mfn, pfnalign)) {
2617 					/*
2618 					 * not properly aligned
2619 					 */
2620 					contig_search_restarts++;
2621 					free_partial_list(&plist);
2622 					pages_needed = pages_requested;
2623 					start_mfn = prev_mfn = 0;
2624 					goto skip;
2625 				}
2626 				start_mfn = mfn;
2627 			}
2628 			prev_mfn = mfn;
2629 		} else {
2630 			contig_search_restarts++;
2631 			free_partial_list(&plist);
2632 			pages_needed = pages_requested;
2633 			start_mfn = prev_mfn = 0;
2634 		}
2635 skip:
2636 		if (++next_alloc_pfn == contig_pfn_cnt)
2637 			next_alloc_pfn = 0;
2638 		if (next_alloc_pfn == search_start)
2639 			break; /* all pfns searched */
2640 	}
2641 	mutex_exit(&contig_list_lock);
2642 	if (pages_needed) {
2643 		contig_search_failed++;
2644 		/*
2645 		 * Failed to find enough contig pages.
2646 		 * free partial page list
2647 		 */
2648 		free_partial_list(&plist);
2649 	}
2650 	return (plist);
2651 }
2652 
2653 /*
2654  * Search the reserved io pool pages for a page range with the
2655  * desired characteristics.
2656  */
2657 page_t *
2658 page_io_pool_alloc(ddi_dma_attr_t *mattr, int contig, pgcnt_t minctg)
2659 {
2660 	page_t *pp_first, *pp_last;
2661 	page_t *pp, **poolp;
2662 	pgcnt_t nwanted, pfnalign;
2663 	uint64_t pfnseg;
2664 	mfn_t mfn, tmfn, hi_mfn, lo_mfn;
2665 	int align, attempt = 0;
2666 
2667 	if (minctg == 1)
2668 		contig = 0;
2669 	lo_mfn = mmu_btop(mattr->dma_attr_addr_lo);
2670 	hi_mfn = mmu_btop(mattr->dma_attr_addr_hi);
2671 	pfnseg = mmu_btop(mattr->dma_attr_seg);
2672 	align = maxbit(mattr->dma_attr_align, mattr->dma_attr_minxfer);
2673 	if (align > MMU_PAGESIZE)
2674 		pfnalign = mmu_btop(align);
2675 	else
2676 		pfnalign = 0;
2677 
2678 try_again:
2679 	/*
2680 	 * See if we want pages for a legacy device
2681 	 */
2682 	if (hi_mfn < PFN_16MEG)
2683 		poolp = &io_pool_16m;
2684 	else
2685 		poolp = &io_pool_4g;
2686 try_smaller:
2687 	/*
2688 	 * Take pages from I/O pool. We'll use pages from the highest
2689 	 * MFN range possible.
2690 	 */
2691 	pp_first = pp_last = NULL;
2692 	mutex_enter(&io_pool_lock);
2693 	nwanted = minctg;
2694 	for (pp = *poolp; pp && nwanted > 0; ) {
2695 		pp = pp->p_prev;
2696 
2697 		/*
2698 		 * skip pages above allowable range
2699 		 */
2700 		mfn = mfn_list[pp->p_pagenum];
2701 		if (hi_mfn < mfn)
2702 			goto skip;
2703 
2704 		/*
2705 		 * stop at pages below allowable range
2706 		 */
2707 		if (lo_mfn > mfn)
2708 			break;
2709 restart:
2710 		if (pp_last == NULL) {
2711 			/*
2712 			 * Check alignment
2713 			 */
2714 			tmfn = mfn - (minctg - 1);
2715 			if (pfnalign && tmfn != P2ROUNDUP(tmfn, pfnalign))
2716 				goto skip; /* not properly aligned */
2717 			/*
2718 			 * Check segment
2719 			 */
2720 			if ((mfn & pfnseg) < (tmfn & pfnseg))
2721 				goto skip; /* crosses seg boundary */
2722 			/*
2723 			 * Start building page list
2724 			 */
2725 			pp_first = pp_last = pp;
2726 			nwanted--;
2727 		} else {
2728 			/*
2729 			 * check physical contiguity if required
2730 			 */
2731 			if (contig &&
2732 			    mfn_list[pp_first->p_pagenum] != mfn + 1) {
2733 				/*
2734 				 * not a contiguous page, restart list.
2735 				 */
2736 				pp_last = NULL;
2737 				nwanted = minctg;
2738 				goto restart;
2739 			} else { /* add page to list */
2740 				pp_first = pp;
2741 				nwanted--;
2742 			}
2743 		}
2744 skip:
2745 		if (pp == *poolp)
2746 			break;
2747 	}
2748 
2749 	/*
2750 	 * If we didn't find memory. Try the more constrained pool, then
2751 	 * sweep free pages into the DMA pool and try again.
2752 	 */
2753 	if (nwanted != 0) {
2754 		mutex_exit(&io_pool_lock);
2755 		/*
2756 		 * If we were looking in the less constrained pool and
2757 		 * didn't find pages, try the more constrained pool.
2758 		 */
2759 		if (poolp == &io_pool_4g) {
2760 			poolp = &io_pool_16m;
2761 			goto try_smaller;
2762 		}
2763 		kmem_reap();
2764 		if (++attempt < 4) {
2765 			/*
2766 			 * Grab some more io_pool pages
2767 			 */
2768 			(void) populate_io_pool();
2769 			goto try_again; /* go around and retry */
2770 		}
2771 		return (NULL);
2772 	}
2773 	/*
2774 	 * Found the pages, now snip them from the list
2775 	 */
2776 	page_io_pool_sub(poolp, pp_first, pp_last);
2777 	io_pool_cnt -= minctg;
2778 	/*
2779 	 * reset low water mark
2780 	 */
2781 	if (io_pool_cnt < io_pool_cnt_lowater)
2782 		io_pool_cnt_lowater = io_pool_cnt;
2783 	mutex_exit(&io_pool_lock);
2784 	return (pp_first);
2785 }
2786 
2787 page_t *
2788 page_swap_with_hypervisor(struct vnode *vp, u_offset_t off, caddr_t vaddr,
2789     ddi_dma_attr_t *mattr, uint_t flags, pgcnt_t minctg)
2790 {
2791 	uint_t kflags;
2792 	int order, extra, extpages, i, contig, nbits, extents;
2793 	page_t *pp, *expp, *pp_first, **pplist = NULL;
2794 	mfn_t *mfnlist = NULL;
2795 
2796 	contig = flags & PG_PHYSCONTIG;
2797 	if (minctg == 1)
2798 		contig = 0;
2799 	flags &= ~PG_PHYSCONTIG;
2800 	kflags = flags & PG_WAIT ? KM_SLEEP : KM_NOSLEEP;
2801 	/*
2802 	 * Hypervisor will allocate extents, if we want contig
2803 	 * pages extent must be >= minctg
2804 	 */
2805 	if (contig) {
2806 		order = highbit(minctg) - 1;
2807 		if (minctg & ((1 << order) - 1))
2808 			order++;
2809 		extpages = 1 << order;
2810 	} else {
2811 		order = 0;
2812 		extpages = minctg;
2813 	}
2814 	if (extpages > minctg) {
2815 		extra = extpages - minctg;
2816 		if (!page_resv(extra, kflags))
2817 			return (NULL);
2818 	}
2819 	pp_first = NULL;
2820 	pplist = kmem_alloc(extpages * sizeof (page_t *), kflags);
2821 	if (pplist == NULL)
2822 		goto balloon_fail;
2823 	mfnlist = kmem_alloc(extpages * sizeof (mfn_t), kflags);
2824 	if (mfnlist == NULL)
2825 		goto balloon_fail;
2826 	pp = page_create_va(vp, off, minctg * PAGESIZE, flags, &kvseg, vaddr);
2827 	if (pp == NULL)
2828 		goto balloon_fail;
2829 	pp_first = pp;
2830 	if (extpages > minctg) {
2831 		/*
2832 		 * fill out the rest of extent pages to swap
2833 		 * with the hypervisor
2834 		 */
2835 		for (i = 0; i < extra; i++) {
2836 			expp = page_create_va(vp,
2837 			    (u_offset_t)(uintptr_t)io_pool_kva,
2838 			    PAGESIZE, flags, &kvseg, io_pool_kva);
2839 			if (expp == NULL)
2840 				goto balloon_fail;
2841 			(void) hat_pageunload(expp, HAT_FORCE_PGUNLOAD);
2842 			page_io_unlock(expp);
2843 			page_hashout(expp, NULL);
2844 			page_io_lock(expp);
2845 			/*
2846 			 * add page to end of list
2847 			 */
2848 			expp->p_prev = pp_first->p_prev;
2849 			expp->p_next = pp_first;
2850 			expp->p_prev->p_next = expp;
2851 			pp_first->p_prev = expp;
2852 		}
2853 
2854 	}
2855 	for (i = 0; i < extpages; i++) {
2856 		pplist[i] = pp;
2857 		pp = pp->p_next;
2858 	}
2859 	nbits = highbit(mattr->dma_attr_addr_hi);
2860 	extents = contig ? 1 : minctg;
2861 	if (balloon_replace_pages(extents, pplist, nbits, order,
2862 	    mfnlist) != extents) {
2863 		if (ioalloc_dbg)
2864 			cmn_err(CE_NOTE, "request to hypervisor"
2865 			    " for %d pages, maxaddr %" PRIx64 " failed",
2866 			    extpages, mattr->dma_attr_addr_hi);
2867 		goto balloon_fail;
2868 	}
2869 
2870 	kmem_free(pplist, extpages * sizeof (page_t *));
2871 	kmem_free(mfnlist, extpages * sizeof (mfn_t));
2872 	/*
2873 	 * Return any excess pages to free list
2874 	 */
2875 	if (extpages > minctg) {
2876 		for (i = 0; i < extra; i++) {
2877 			pp = pp_first->p_prev;
2878 			page_sub(&pp_first, pp);
2879 			page_io_unlock(pp);
2880 			page_unresv(1);
2881 			page_free(pp, 1);
2882 		}
2883 	}
2884 	return (pp_first);
2885 balloon_fail:
2886 	/*
2887 	 * Return pages to free list and return failure
2888 	 */
2889 	while (pp_first != NULL) {
2890 		pp = pp_first;
2891 		page_sub(&pp_first, pp);
2892 		page_io_unlock(pp);
2893 		if (pp->p_vnode != NULL)
2894 			page_hashout(pp, NULL);
2895 		page_free(pp, 1);
2896 	}
2897 	if (pplist)
2898 		kmem_free(pplist, extpages * sizeof (page_t *));
2899 	if (mfnlist)
2900 		kmem_free(mfnlist, extpages * sizeof (mfn_t));
2901 	page_unresv(extpages - minctg);
2902 	return (NULL);
2903 }
2904 
2905 static void
2906 return_partial_alloc(page_t *plist)
2907 {
2908 	page_t *pp;
2909 
2910 	while (plist != NULL) {
2911 		pp = plist;
2912 		page_sub(&plist, pp);
2913 		page_io_unlock(pp);
2914 		page_destroy_io(pp);
2915 	}
2916 }
2917 
2918 static page_t *
2919 page_get_contigpages(
2920 	struct vnode	*vp,
2921 	u_offset_t	off,
2922 	int		*npagesp,
2923 	uint_t		flags,
2924 	caddr_t		vaddr,
2925 	ddi_dma_attr_t	*mattr)
2926 {
2927 	mfn_t	max_mfn = HYPERVISOR_memory_op(XENMEM_maximum_ram_page, NULL);
2928 	page_t	*plist;	/* list to return */
2929 	page_t	*pp, *mcpl;
2930 	int	contig, anyaddr, npages, getone = 0;
2931 	mfn_t	lo_mfn;
2932 	mfn_t	hi_mfn;
2933 	pgcnt_t	pfnalign = 0;
2934 	int	align, sgllen;
2935 	uint64_t pfnseg;
2936 	pgcnt_t	minctg;
2937 
2938 	npages = *npagesp;
2939 	ASSERT(mattr != NULL);
2940 	lo_mfn = mmu_btop(mattr->dma_attr_addr_lo);
2941 	hi_mfn = mmu_btop(mattr->dma_attr_addr_hi);
2942 	sgllen = mattr->dma_attr_sgllen;
2943 	pfnseg = mmu_btop(mattr->dma_attr_seg);
2944 	align = maxbit(mattr->dma_attr_align, mattr->dma_attr_minxfer);
2945 	if (align > MMU_PAGESIZE)
2946 		pfnalign = mmu_btop(align);
2947 
2948 	contig = flags & PG_PHYSCONTIG;
2949 	if (npages == -1) {
2950 		npages = 1;
2951 		pfnalign = 0;
2952 	}
2953 	/*
2954 	 * Clear the contig flag if only one page is needed.
2955 	 */
2956 	if (npages == 1) {
2957 		getone = 1;
2958 		contig = 0;
2959 	}
2960 
2961 	/*
2962 	 * Check if any page in the system is fine.
2963 	 */
2964 	anyaddr = lo_mfn == 0 && hi_mfn >= max_mfn;
2965 	if (!contig && anyaddr && !pfnalign) {
2966 		flags &= ~PG_PHYSCONTIG;
2967 		plist = page_create_va(vp, off, npages * MMU_PAGESIZE,
2968 		    flags, &kvseg, vaddr);
2969 		if (plist != NULL) {
2970 			*npagesp = 0;
2971 			return (plist);
2972 		}
2973 	}
2974 	plist = NULL;
2975 	minctg = howmany(npages, sgllen);
2976 	while (npages > sgllen || getone) {
2977 		if (minctg > npages)
2978 			minctg = npages;
2979 		mcpl = NULL;
2980 		/*
2981 		 * We could want contig pages with no address range limits.
2982 		 */
2983 		if (anyaddr && contig) {
2984 			/*
2985 			 * Look for free contig pages to satisfy the request.
2986 			 */
2987 			mcpl = find_contig_free(minctg, flags, pfnseg,
2988 			    pfnalign);
2989 		}
2990 		/*
2991 		 * Try the reserved io pools next
2992 		 */
2993 		if (mcpl == NULL)
2994 			mcpl = page_io_pool_alloc(mattr, contig, minctg);
2995 		if (mcpl != NULL) {
2996 			pp = mcpl;
2997 			do {
2998 				if (!page_hashin(pp, vp, off, NULL)) {
2999 					panic("page_get_contigpages:"
3000 					    " hashin failed"
3001 					    " pp %p, vp %p, off %llx",
3002 					    (void *)pp, (void *)vp, off);
3003 				}
3004 				off += MMU_PAGESIZE;
3005 				PP_CLRFREE(pp);
3006 				PP_CLRAGED(pp);
3007 				page_set_props(pp, P_REF);
3008 				page_io_lock(pp);
3009 				pp = pp->p_next;
3010 			} while (pp != mcpl);
3011 		} else {
3012 			/*
3013 			 * Hypervisor exchange doesn't handle segment or
3014 			 * alignment constraints
3015 			 */
3016 			if (mattr->dma_attr_seg < mattr->dma_attr_addr_hi ||
3017 			    pfnalign)
3018 				goto fail;
3019 			/*
3020 			 * Try exchanging pages with the hypervisor
3021 			 */
3022 			mcpl = page_swap_with_hypervisor(vp, off, vaddr, mattr,
3023 			    flags, minctg);
3024 			if (mcpl == NULL)
3025 				goto fail;
3026 			off += minctg * MMU_PAGESIZE;
3027 		}
3028 		check_dma(mattr, mcpl, minctg);
3029 		/*
3030 		 * Here with a minctg run of contiguous pages, add them to the
3031 		 * list we will return for this request.
3032 		 */
3033 		page_list_concat(&plist, &mcpl);
3034 		npages -= minctg;
3035 		*npagesp = npages;
3036 		sgllen--;
3037 		if (getone)
3038 			break;
3039 	}
3040 	return (plist);
3041 fail:
3042 	return_partial_alloc(plist);
3043 	return (NULL);
3044 }
3045 
3046 /*
3047  * Allocator for domain 0 I/O pages. We match the required
3048  * DMA attributes and contiguity constraints.
3049  */
3050 /*ARGSUSED*/
3051 page_t *
3052 page_create_io(
3053 	struct vnode	*vp,
3054 	u_offset_t	off,
3055 	uint_t		bytes,
3056 	uint_t		flags,
3057 	struct as	*as,
3058 	caddr_t		vaddr,
3059 	ddi_dma_attr_t	*mattr)
3060 {
3061 	page_t	*plist = NULL, *pp;
3062 	int	npages = 0, contig, anyaddr, pages_req;
3063 	mfn_t	lo_mfn;
3064 	mfn_t	hi_mfn;
3065 	pgcnt_t	pfnalign = 0;
3066 	int	align;
3067 	int	is_domu = 0;
3068 	int	dummy, bytes_got;
3069 	mfn_t	max_mfn = HYPERVISOR_memory_op(XENMEM_maximum_ram_page, NULL);
3070 
3071 	ASSERT(mattr != NULL);
3072 	lo_mfn = mmu_btop(mattr->dma_attr_addr_lo);
3073 	hi_mfn = mmu_btop(mattr->dma_attr_addr_hi);
3074 	align = maxbit(mattr->dma_attr_align, mattr->dma_attr_minxfer);
3075 	if (align > MMU_PAGESIZE)
3076 		pfnalign = mmu_btop(align);
3077 
3078 	/*
3079 	 * Clear the contig flag if only one page is needed or the scatter
3080 	 * gather list length is >= npages.
3081 	 */
3082 	pages_req = npages = mmu_btopr(bytes);
3083 	contig = (flags & PG_PHYSCONTIG);
3084 	bytes = P2ROUNDUP(bytes, MMU_PAGESIZE);
3085 	if (bytes == MMU_PAGESIZE || mattr->dma_attr_sgllen >= npages)
3086 		contig = 0;
3087 
3088 	/*
3089 	 * Check if any old page in the system is fine.
3090 	 * DomU should always go down this path.
3091 	 */
3092 	is_domu = !DOMAIN_IS_INITDOMAIN(xen_info);
3093 	anyaddr = lo_mfn == 0 && hi_mfn >= max_mfn && !pfnalign;
3094 	if ((!contig && anyaddr) || is_domu) {
3095 		flags &= ~PG_PHYSCONTIG;
3096 		plist = page_create_va(vp, off, bytes, flags, &kvseg, vaddr);
3097 		if (plist != NULL)
3098 			return (plist);
3099 		else if (is_domu)
3100 			return (NULL); /* no memory available */
3101 	}
3102 	/*
3103 	 * DomU should never reach here
3104 	 */
3105 	if (contig) {
3106 		plist = page_get_contigpages(vp, off, &npages, flags, vaddr,
3107 		    mattr);
3108 		if (plist == NULL)
3109 			goto fail;
3110 		bytes_got = (pages_req - npages) << MMU_PAGESHIFT;
3111 		vaddr += bytes_got;
3112 		off += bytes_got;
3113 		/*
3114 		 * We now have all the contiguous pages we need, but
3115 		 * we may still need additional non-contiguous pages.
3116 		 */
3117 	}
3118 	/*
3119 	 * now loop collecting the requested number of pages, these do
3120 	 * not have to be contiguous pages but we will use the contig
3121 	 * page alloc code to get the pages since it will honor any
3122 	 * other constraints the pages may have.
3123 	 */
3124 	while (npages--) {
3125 		dummy = -1;
3126 		pp = page_get_contigpages(vp, off, &dummy, flags, vaddr, mattr);
3127 		if (pp == NULL)
3128 			goto fail;
3129 		page_add(&plist, pp);
3130 		vaddr += MMU_PAGESIZE;
3131 		off += MMU_PAGESIZE;
3132 	}
3133 	return (plist);
3134 fail:
3135 	/*
3136 	 * Failed to get enough pages, return ones we did get
3137 	 */
3138 	return_partial_alloc(plist);
3139 	return (NULL);
3140 }
3141 
3142 /*
3143  * Lock and return the page with the highest mfn that we can find.  last_mfn
3144  * holds the last one found, so the next search can start from there.  We
3145  * also keep a counter so that we don't loop forever if the machine has no
3146  * free pages.
3147  *
3148  * This is called from the balloon thread to find pages to give away.  new_high
3149  * is used when new mfn's have been added to the system - we will reset our
3150  * search if the new mfn's are higher than our current search position.
3151  */
3152 page_t *
3153 page_get_high_mfn(mfn_t new_high)
3154 {
3155 	static mfn_t last_mfn = 0;
3156 	pfn_t pfn;
3157 	page_t *pp;
3158 	ulong_t loop_count = 0;
3159 
3160 	if (new_high > last_mfn)
3161 		last_mfn = new_high;
3162 
3163 	for (; loop_count < mfn_count; loop_count++, last_mfn--) {
3164 		if (last_mfn == 0) {
3165 			last_mfn = cached_max_mfn;
3166 		}
3167 
3168 		pfn = mfn_to_pfn(last_mfn);
3169 		if (pfn & PFN_IS_FOREIGN_MFN)
3170 			continue;
3171 
3172 		/* See if the page is free.  If so, lock it. */
3173 		pp = page_numtopp_alloc(pfn);
3174 		if (pp == NULL)
3175 			continue;
3176 		PP_CLRFREE(pp);
3177 
3178 		ASSERT(PAGE_EXCL(pp));
3179 		ASSERT(pp->p_vnode == NULL);
3180 		ASSERT(!hat_page_is_mapped(pp));
3181 		last_mfn--;
3182 		return (pp);
3183 	}
3184 	return (NULL);
3185 }
3186 
3187 #else /* !__xpv */
3188 
3189 /*
3190  * get a page from any list with the given mnode
3191  */
3192 static page_t *
3193 page_get_mnode_anylist(ulong_t origbin, uchar_t szc, uint_t flags,
3194     int mnode, int mtype, ddi_dma_attr_t *dma_attr)
3195 {
3196 	kmutex_t		*pcm;
3197 	int			i;
3198 	page_t			*pp;
3199 	page_t			*first_pp;
3200 	uint64_t		pgaddr;
3201 	ulong_t			bin;
3202 	int			mtypestart;
3203 	int			plw_initialized;
3204 	page_list_walker_t	plw;
3205 
3206 	VM_STAT_ADD(pga_vmstats.pgma_alloc);
3207 
3208 	ASSERT((flags & PG_MATCH_COLOR) == 0);
3209 	ASSERT(szc == 0);
3210 	ASSERT(dma_attr != NULL);
3211 
3212 	MTYPE_START(mnode, mtype, flags);
3213 	if (mtype < 0) {
3214 		VM_STAT_ADD(pga_vmstats.pgma_allocempty);
3215 		return (NULL);
3216 	}
3217 
3218 	mtypestart = mtype;
3219 
3220 	bin = origbin;
3221 
3222 	/*
3223 	 * check up to page_colors + 1 bins - origbin may be checked twice
3224 	 * because of BIN_STEP skip
3225 	 */
3226 	do {
3227 		plw_initialized = 0;
3228 
3229 		for (plw.plw_count = 0;
3230 		    plw.plw_count < page_colors; plw.plw_count++) {
3231 
3232 			if (PAGE_FREELISTS(mnode, szc, bin, mtype) == NULL)
3233 				goto nextfreebin;
3234 
3235 			pcm = PC_BIN_MUTEX(mnode, bin, PG_FREE_LIST);
3236 			mutex_enter(pcm);
3237 			pp = PAGE_FREELISTS(mnode, szc, bin, mtype);
3238 			first_pp = pp;
3239 			while (pp != NULL) {
3240 				if (IS_DUMP_PAGE(pp) || page_trylock(pp,
3241 				    SE_EXCL) == 0) {
3242 					pp = pp->p_next;
3243 					if (pp == first_pp) {
3244 						pp = NULL;
3245 					}
3246 					continue;
3247 				}
3248 
3249 				ASSERT(PP_ISFREE(pp));
3250 				ASSERT(PP_ISAGED(pp));
3251 				ASSERT(pp->p_vnode == NULL);
3252 				ASSERT(pp->p_hash == NULL);
3253 				ASSERT(pp->p_offset == (u_offset_t)-1);
3254 				ASSERT(pp->p_szc == szc);
3255 				ASSERT(PFN_2_MEM_NODE(pp->p_pagenum) == mnode);
3256 				/* check if page within DMA attributes */
3257 				pgaddr = pa_to_ma(pfn_to_pa(pp->p_pagenum));
3258 				if ((pgaddr >= dma_attr->dma_attr_addr_lo) &&
3259 				    (pgaddr + MMU_PAGESIZE - 1 <=
3260 				    dma_attr->dma_attr_addr_hi)) {
3261 					break;
3262 				}
3263 
3264 				/* continue looking */
3265 				page_unlock(pp);
3266 				pp = pp->p_next;
3267 				if (pp == first_pp)
3268 					pp = NULL;
3269 
3270 			}
3271 			if (pp != NULL) {
3272 				ASSERT(mtype == PP_2_MTYPE(pp));
3273 				ASSERT(pp->p_szc == 0);
3274 
3275 				/* found a page with specified DMA attributes */
3276 				page_sub(&PAGE_FREELISTS(mnode, szc, bin,
3277 				    mtype), pp);
3278 				page_ctr_sub(mnode, mtype, pp, PG_FREE_LIST);
3279 
3280 				if ((PP_ISFREE(pp) == 0) ||
3281 				    (PP_ISAGED(pp) == 0)) {
3282 					cmn_err(CE_PANIC, "page %p is not free",
3283 					    (void *)pp);
3284 				}
3285 
3286 				mutex_exit(pcm);
3287 				check_dma(dma_attr, pp, 1);
3288 				VM_STAT_ADD(pga_vmstats.pgma_allocok);
3289 				return (pp);
3290 			}
3291 			mutex_exit(pcm);
3292 nextfreebin:
3293 			if (plw_initialized == 0) {
3294 				page_list_walk_init(szc, 0, bin, 1, 0, &plw);
3295 				ASSERT(plw.plw_ceq_dif == page_colors);
3296 				plw_initialized = 1;
3297 			}
3298 
3299 			if (plw.plw_do_split) {
3300 				pp = page_freelist_split(szc, bin, mnode,
3301 				    mtype,
3302 				    mmu_btop(dma_attr->dma_attr_addr_lo),
3303 				    mmu_btop(dma_attr->dma_attr_addr_hi + 1),
3304 				    &plw);
3305 				if (pp != NULL) {
3306 					check_dma(dma_attr, pp, 1);
3307 					return (pp);
3308 				}
3309 			}
3310 
3311 			bin = page_list_walk_next_bin(szc, bin, &plw);
3312 		}
3313 
3314 		MTYPE_NEXT(mnode, mtype, flags);
3315 	} while (mtype >= 0);
3316 
3317 	/* failed to find a page in the freelist; try it in the cachelist */
3318 
3319 	/* reset mtype start for cachelist search */
3320 	mtype = mtypestart;
3321 	ASSERT(mtype >= 0);
3322 
3323 	/* start with the bin of matching color */
3324 	bin = origbin;
3325 
3326 	do {
3327 		for (i = 0; i <= page_colors; i++) {
3328 			if (PAGE_CACHELISTS(mnode, bin, mtype) == NULL)
3329 				goto nextcachebin;
3330 			pcm = PC_BIN_MUTEX(mnode, bin, PG_CACHE_LIST);
3331 			mutex_enter(pcm);
3332 			pp = PAGE_CACHELISTS(mnode, bin, mtype);
3333 			first_pp = pp;
3334 			while (pp != NULL) {
3335 				if (IS_DUMP_PAGE(pp) || page_trylock(pp,
3336 				    SE_EXCL) == 0) {
3337 					pp = pp->p_next;
3338 					if (pp == first_pp)
3339 						pp = NULL;
3340 					continue;
3341 				}
3342 				ASSERT(pp->p_vnode);
3343 				ASSERT(PP_ISAGED(pp) == 0);
3344 				ASSERT(pp->p_szc == 0);
3345 				ASSERT(PFN_2_MEM_NODE(pp->p_pagenum) == mnode);
3346 
3347 				/* check if page within DMA attributes */
3348 
3349 				pgaddr = pa_to_ma(pfn_to_pa(pp->p_pagenum));
3350 				if ((pgaddr >= dma_attr->dma_attr_addr_lo) &&
3351 				    (pgaddr + MMU_PAGESIZE - 1 <=
3352 				    dma_attr->dma_attr_addr_hi)) {
3353 					break;
3354 				}
3355 
3356 				/* continue looking */
3357 				page_unlock(pp);
3358 				pp = pp->p_next;
3359 				if (pp == first_pp)
3360 					pp = NULL;
3361 			}
3362 
3363 			if (pp != NULL) {
3364 				ASSERT(mtype == PP_2_MTYPE(pp));
3365 				ASSERT(pp->p_szc == 0);
3366 
3367 				/* found a page with specified DMA attributes */
3368 				page_sub(&PAGE_CACHELISTS(mnode, bin,
3369 				    mtype), pp);
3370 				page_ctr_sub(mnode, mtype, pp, PG_CACHE_LIST);
3371 
3372 				mutex_exit(pcm);
3373 				ASSERT(pp->p_vnode);
3374 				ASSERT(PP_ISAGED(pp) == 0);
3375 				check_dma(dma_attr, pp, 1);
3376 				VM_STAT_ADD(pga_vmstats.pgma_allocok);
3377 				return (pp);
3378 			}
3379 			mutex_exit(pcm);
3380 nextcachebin:
3381 			bin += (i == 0) ? BIN_STEP : 1;
3382 			bin &= page_colors_mask;
3383 		}
3384 		MTYPE_NEXT(mnode, mtype, flags);
3385 	} while (mtype >= 0);
3386 
3387 	VM_STAT_ADD(pga_vmstats.pgma_allocfailed);
3388 	return (NULL);
3389 }
3390 
3391 /*
3392  * This function is similar to page_get_freelist()/page_get_cachelist()
3393  * but it searches both the lists to find a page with the specified
3394  * color (or no color) and DMA attributes. The search is done in the
3395  * freelist first and then in the cache list within the highest memory
3396  * range (based on DMA attributes) before searching in the lower
3397  * memory ranges.
3398  *
3399  * Note: This function is called only by page_create_io().
3400  */
3401 /*ARGSUSED*/
3402 static page_t *
3403 page_get_anylist(struct vnode *vp, u_offset_t off, struct as *as, caddr_t vaddr,
3404     size_t size, uint_t flags, ddi_dma_attr_t *dma_attr, lgrp_t	*lgrp)
3405 {
3406 	uint_t		bin;
3407 	int		mtype;
3408 	page_t		*pp;
3409 	int		n;
3410 	int		m;
3411 	int		szc;
3412 	int		fullrange;
3413 	int		mnode;
3414 	int		local_failed_stat = 0;
3415 	lgrp_mnode_cookie_t	lgrp_cookie;
3416 
3417 	VM_STAT_ADD(pga_vmstats.pga_alloc);
3418 
3419 	/* only base pagesize currently supported */
3420 	if (size != MMU_PAGESIZE)
3421 		return (NULL);
3422 
3423 	/*
3424 	 * If we're passed a specific lgroup, we use it.  Otherwise,
3425 	 * assume first-touch placement is desired.
3426 	 */
3427 	if (!LGRP_EXISTS(lgrp))
3428 		lgrp = lgrp_home_lgrp();
3429 
3430 	/* LINTED */
3431 	AS_2_BIN(as, seg, vp, vaddr, bin, 0);
3432 
3433 	/*
3434 	 * Only hold one freelist or cachelist lock at a time, that way we
3435 	 * can start anywhere and not have to worry about lock
3436 	 * ordering.
3437 	 */
3438 	if (dma_attr == NULL) {
3439 		n = mtype16m;
3440 		m = mtypetop;
3441 		fullrange = 1;
3442 		VM_STAT_ADD(pga_vmstats.pga_nulldmaattr);
3443 	} else {
3444 		pfn_t pfnlo = mmu_btop(dma_attr->dma_attr_addr_lo);
3445 		pfn_t pfnhi = mmu_btop(dma_attr->dma_attr_addr_hi);
3446 
3447 		/*
3448 		 * We can guarantee alignment only for page boundary.
3449 		 */
3450 		if (dma_attr->dma_attr_align > MMU_PAGESIZE)
3451 			return (NULL);
3452 
3453 		/* Sanity check the dma_attr */
3454 		if (pfnlo > pfnhi)
3455 			return (NULL);
3456 
3457 		n = pfn_2_mtype(pfnlo);
3458 		m = pfn_2_mtype(pfnhi);
3459 
3460 		fullrange = ((pfnlo == mnoderanges[n].mnr_pfnlo) &&
3461 		    (pfnhi >= mnoderanges[m].mnr_pfnhi));
3462 	}
3463 	VM_STAT_COND_ADD(fullrange == 0, pga_vmstats.pga_notfullrange);
3464 
3465 	szc = 0;
3466 
3467 	/* cylcing thru mtype handled by RANGE0 if n == mtype16m */
3468 	if (n == mtype16m) {
3469 		flags |= PGI_MT_RANGE0;
3470 		n = m;
3471 	}
3472 
3473 	/*
3474 	 * Try local memory node first, but try remote if we can't
3475 	 * get a page of the right color.
3476 	 */
3477 	LGRP_MNODE_COOKIE_INIT(lgrp_cookie, lgrp, LGRP_SRCH_HIER);
3478 	while ((mnode = lgrp_memnode_choose(&lgrp_cookie)) >= 0) {
3479 		/*
3480 		 * allocate pages from high pfn to low.
3481 		 */
3482 		mtype = m;
3483 		do {
3484 			if (fullrange != 0) {
3485 				pp = page_get_mnode_freelist(mnode,
3486 				    bin, mtype, szc, flags);
3487 				if (pp == NULL) {
3488 					pp = page_get_mnode_cachelist(
3489 					    bin, flags, mnode, mtype);
3490 				}
3491 			} else {
3492 				pp = page_get_mnode_anylist(bin, szc,
3493 				    flags, mnode, mtype, dma_attr);
3494 			}
3495 			if (pp != NULL) {
3496 				VM_STAT_ADD(pga_vmstats.pga_allocok);
3497 				check_dma(dma_attr, pp, 1);
3498 				return (pp);
3499 			}
3500 		} while (mtype != n &&
3501 		    (mtype = mnoderanges[mtype].mnr_next) != -1);
3502 		if (!local_failed_stat) {
3503 			lgrp_stat_add(lgrp->lgrp_id, LGRP_NUM_ALLOC_FAIL, 1);
3504 			local_failed_stat = 1;
3505 		}
3506 	}
3507 	VM_STAT_ADD(pga_vmstats.pga_allocfailed);
3508 
3509 	return (NULL);
3510 }
3511 
3512 /*
3513  * page_create_io()
3514  *
3515  * This function is a copy of page_create_va() with an additional
3516  * argument 'mattr' that specifies DMA memory requirements to
3517  * the page list functions. This function is used by the segkmem
3518  * allocator so it is only to create new pages (i.e PG_EXCL is
3519  * set).
3520  *
3521  * Note: This interface is currently used by x86 PSM only and is
3522  *	 not fully specified so the commitment level is only for
3523  *	 private interface specific to x86. This interface uses PSM
3524  *	 specific page_get_anylist() interface.
3525  */
3526 
3527 #define	PAGE_HASH_SEARCH(index, pp, vp, off) { \
3528 	for ((pp) = page_hash[(index)]; (pp); (pp) = (pp)->p_hash) { \
3529 		if ((pp)->p_vnode == (vp) && (pp)->p_offset == (off)) \
3530 			break; \
3531 	} \
3532 }
3533 
3534 
3535 page_t *
3536 page_create_io(
3537 	struct vnode	*vp,
3538 	u_offset_t	off,
3539 	uint_t		bytes,
3540 	uint_t		flags,
3541 	struct as	*as,
3542 	caddr_t		vaddr,
3543 	ddi_dma_attr_t	*mattr)	/* DMA memory attributes if any */
3544 {
3545 	page_t		*plist = NULL;
3546 	uint_t		plist_len = 0;
3547 	pgcnt_t		npages;
3548 	page_t		*npp = NULL;
3549 	uint_t		pages_req;
3550 	page_t		*pp;
3551 	kmutex_t	*phm = NULL;
3552 	uint_t		index;
3553 
3554 	TRACE_4(TR_FAC_VM, TR_PAGE_CREATE_START,
3555 	    "page_create_start:vp %p off %llx bytes %u flags %x",
3556 	    vp, off, bytes, flags);
3557 
3558 	ASSERT((flags & ~(PG_EXCL | PG_WAIT | PG_PHYSCONTIG)) == 0);
3559 
3560 	pages_req = npages = mmu_btopr(bytes);
3561 
3562 	/*
3563 	 * Do the freemem and pcf accounting.
3564 	 */
3565 	if (!page_create_wait(npages, flags)) {
3566 		return (NULL);
3567 	}
3568 
3569 	TRACE_2(TR_FAC_VM, TR_PAGE_CREATE_SUCCESS,
3570 	    "page_create_success:vp %p off %llx", vp, off);
3571 
3572 	/*
3573 	 * If satisfying this request has left us with too little
3574 	 * memory, start the wheels turning to get some back.  The
3575 	 * first clause of the test prevents waking up the pageout
3576 	 * daemon in situations where it would decide that there's
3577 	 * nothing to do.
3578 	 */
3579 	if (nscan < desscan && freemem < minfree) {
3580 		TRACE_1(TR_FAC_VM, TR_PAGEOUT_CV_SIGNAL,
3581 		    "pageout_cv_signal:freemem %ld", freemem);
3582 		cv_signal(&proc_pageout->p_cv);
3583 	}
3584 
3585 	if (flags & PG_PHYSCONTIG) {
3586 
3587 		plist = page_get_contigpage(&npages, mattr, 1);
3588 		if (plist == NULL) {
3589 			page_create_putback(npages);
3590 			return (NULL);
3591 		}
3592 
3593 		pp = plist;
3594 
3595 		do {
3596 			if (!page_hashin(pp, vp, off, NULL)) {
3597 				panic("pg_creat_io: hashin failed %p %p %llx",
3598 				    (void *)pp, (void *)vp, off);
3599 			}
3600 			VM_STAT_ADD(page_create_new);
3601 			off += MMU_PAGESIZE;
3602 			PP_CLRFREE(pp);
3603 			PP_CLRAGED(pp);
3604 			page_set_props(pp, P_REF);
3605 			pp = pp->p_next;
3606 		} while (pp != plist);
3607 
3608 		if (!npages) {
3609 			check_dma(mattr, plist, pages_req);
3610 			return (plist);
3611 		} else {
3612 			vaddr += (pages_req - npages) << MMU_PAGESHIFT;
3613 		}
3614 
3615 		/*
3616 		 * fall-thru:
3617 		 *
3618 		 * page_get_contigpage returns when npages <= sgllen.
3619 		 * Grab the rest of the non-contig pages below from anylist.
3620 		 */
3621 	}
3622 
3623 	/*
3624 	 * Loop around collecting the requested number of pages.
3625 	 * Most of the time, we have to `create' a new page. With
3626 	 * this in mind, pull the page off the free list before
3627 	 * getting the hash lock.  This will minimize the hash
3628 	 * lock hold time, nesting, and the like.  If it turns
3629 	 * out we don't need the page, we put it back at the end.
3630 	 */
3631 	while (npages--) {
3632 		phm = NULL;
3633 
3634 		index = PAGE_HASH_FUNC(vp, off);
3635 top:
3636 		ASSERT(phm == NULL);
3637 		ASSERT(index == PAGE_HASH_FUNC(vp, off));
3638 		ASSERT(MUTEX_NOT_HELD(page_vnode_mutex(vp)));
3639 
3640 		if (npp == NULL) {
3641 			/*
3642 			 * Try to get the page of any color either from
3643 			 * the freelist or from the cache list.
3644 			 */
3645 			npp = page_get_anylist(vp, off, as, vaddr, MMU_PAGESIZE,
3646 			    flags & ~PG_MATCH_COLOR, mattr, NULL);
3647 			if (npp == NULL) {
3648 				if (mattr == NULL) {
3649 					/*
3650 					 * Not looking for a special page;
3651 					 * panic!
3652 					 */
3653 					panic("no page found %d", (int)npages);
3654 				}
3655 				/*
3656 				 * No page found! This can happen
3657 				 * if we are looking for a page
3658 				 * within a specific memory range
3659 				 * for DMA purposes. If PG_WAIT is
3660 				 * specified then we wait for a
3661 				 * while and then try again. The
3662 				 * wait could be forever if we
3663 				 * don't get the page(s) we need.
3664 				 *
3665 				 * Note: XXX We really need a mechanism
3666 				 * to wait for pages in the desired
3667 				 * range. For now, we wait for any
3668 				 * pages and see if we can use it.
3669 				 */
3670 
3671 				if ((mattr != NULL) && (flags & PG_WAIT)) {
3672 					delay(10);
3673 					goto top;
3674 				}
3675 				goto fail; /* undo accounting stuff */
3676 			}
3677 
3678 			if (PP_ISAGED(npp) == 0) {
3679 				/*
3680 				 * Since this page came from the
3681 				 * cachelist, we must destroy the
3682 				 * old vnode association.
3683 				 */
3684 				page_hashout(npp, (kmutex_t *)NULL);
3685 			}
3686 		}
3687 
3688 		/*
3689 		 * We own this page!
3690 		 */
3691 		ASSERT(PAGE_EXCL(npp));
3692 		ASSERT(npp->p_vnode == NULL);
3693 		ASSERT(!hat_page_is_mapped(npp));
3694 		PP_CLRFREE(npp);
3695 		PP_CLRAGED(npp);
3696 
3697 		/*
3698 		 * Here we have a page in our hot little mits and are
3699 		 * just waiting to stuff it on the appropriate lists.
3700 		 * Get the mutex and check to see if it really does
3701 		 * not exist.
3702 		 */
3703 		phm = PAGE_HASH_MUTEX(index);
3704 		mutex_enter(phm);
3705 		PAGE_HASH_SEARCH(index, pp, vp, off);
3706 		if (pp == NULL) {
3707 			VM_STAT_ADD(page_create_new);
3708 			pp = npp;
3709 			npp = NULL;
3710 			if (!page_hashin(pp, vp, off, phm)) {
3711 				/*
3712 				 * Since we hold the page hash mutex and
3713 				 * just searched for this page, page_hashin
3714 				 * had better not fail.  If it does, that
3715 				 * means somethread did not follow the
3716 				 * page hash mutex rules.  Panic now and
3717 				 * get it over with.  As usual, go down
3718 				 * holding all the locks.
3719 				 */
3720 				ASSERT(MUTEX_HELD(phm));
3721 				panic("page_create: hashin fail %p %p %llx %p",
3722 				    (void *)pp, (void *)vp, off, (void *)phm);
3723 
3724 			}
3725 			ASSERT(MUTEX_HELD(phm));
3726 			mutex_exit(phm);
3727 			phm = NULL;
3728 
3729 			/*
3730 			 * Hat layer locking need not be done to set
3731 			 * the following bits since the page is not hashed
3732 			 * and was on the free list (i.e., had no mappings).
3733 			 *
3734 			 * Set the reference bit to protect
3735 			 * against immediate pageout
3736 			 *
3737 			 * XXXmh modify freelist code to set reference
3738 			 * bit so we don't have to do it here.
3739 			 */
3740 			page_set_props(pp, P_REF);
3741 		} else {
3742 			ASSERT(MUTEX_HELD(phm));
3743 			mutex_exit(phm);
3744 			phm = NULL;
3745 			/*
3746 			 * NOTE: This should not happen for pages associated
3747 			 *	 with kernel vnode 'kvp'.
3748 			 */
3749 			/* XX64 - to debug why this happens! */
3750 			ASSERT(!VN_ISKAS(vp));
3751 			if (VN_ISKAS(vp))
3752 				cmn_err(CE_NOTE,
3753 				    "page_create: page not expected "
3754 				    "in hash list for kernel vnode - pp 0x%p",
3755 				    (void *)pp);
3756 			VM_STAT_ADD(page_create_exists);
3757 			goto fail;
3758 		}
3759 
3760 		/*
3761 		 * Got a page!  It is locked.  Acquire the i/o
3762 		 * lock since we are going to use the p_next and
3763 		 * p_prev fields to link the requested pages together.
3764 		 */
3765 		page_io_lock(pp);
3766 		page_add(&plist, pp);
3767 		plist = plist->p_next;
3768 		off += MMU_PAGESIZE;
3769 		vaddr += MMU_PAGESIZE;
3770 	}
3771 
3772 	check_dma(mattr, plist, pages_req);
3773 	return (plist);
3774 
3775 fail:
3776 	if (npp != NULL) {
3777 		/*
3778 		 * Did not need this page after all.
3779 		 * Put it back on the free list.
3780 		 */
3781 		VM_STAT_ADD(page_create_putbacks);
3782 		PP_SETFREE(npp);
3783 		PP_SETAGED(npp);
3784 		npp->p_offset = (u_offset_t)-1;
3785 		page_list_add(npp, PG_FREE_LIST | PG_LIST_TAIL);
3786 		page_unlock(npp);
3787 	}
3788 
3789 	/*
3790 	 * Give up the pages we already got.
3791 	 */
3792 	while (plist != NULL) {
3793 		pp = plist;
3794 		page_sub(&plist, pp);
3795 		page_io_unlock(pp);
3796 		plist_len++;
3797 		/*LINTED: constant in conditional ctx*/
3798 		VN_DISPOSE(pp, B_INVAL, 0, kcred);
3799 	}
3800 
3801 	/*
3802 	 * VN_DISPOSE does freemem accounting for the pages in plist
3803 	 * by calling page_free. So, we need to undo the pcf accounting
3804 	 * for only the remaining pages.
3805 	 */
3806 	VM_STAT_ADD(page_create_putbacks);
3807 	page_create_putback(pages_req - plist_len);
3808 
3809 	return (NULL);
3810 }
3811 #endif /* !__xpv */
3812 
3813 
3814 /*
3815  * Copy the data from the physical page represented by "frompp" to
3816  * that represented by "topp". ppcopy uses CPU->cpu_caddr1 and
3817  * CPU->cpu_caddr2.  It assumes that no one uses either map at interrupt
3818  * level and no one sleeps with an active mapping there.
3819  *
3820  * Note that the ref/mod bits in the page_t's are not affected by
3821  * this operation, hence it is up to the caller to update them appropriately.
3822  */
3823 int
3824 ppcopy(page_t *frompp, page_t *topp)
3825 {
3826 	caddr_t		pp_addr1;
3827 	caddr_t		pp_addr2;
3828 	hat_mempte_t	pte1;
3829 	hat_mempte_t	pte2;
3830 	kmutex_t	*ppaddr_mutex;
3831 	label_t		ljb;
3832 	int		ret = 1;
3833 
3834 	ASSERT_STACK_ALIGNED();
3835 	ASSERT(PAGE_LOCKED(frompp));
3836 	ASSERT(PAGE_LOCKED(topp));
3837 
3838 	if (kpm_enable) {
3839 		pp_addr1 = hat_kpm_page2va(frompp, 0);
3840 		pp_addr2 = hat_kpm_page2va(topp, 0);
3841 		kpreempt_disable();
3842 	} else {
3843 		/*
3844 		 * disable pre-emption so that CPU can't change
3845 		 */
3846 		kpreempt_disable();
3847 
3848 		pp_addr1 = CPU->cpu_caddr1;
3849 		pp_addr2 = CPU->cpu_caddr2;
3850 		pte1 = CPU->cpu_caddr1pte;
3851 		pte2 = CPU->cpu_caddr2pte;
3852 
3853 		ppaddr_mutex = &CPU->cpu_ppaddr_mutex;
3854 		mutex_enter(ppaddr_mutex);
3855 
3856 		hat_mempte_remap(page_pptonum(frompp), pp_addr1, pte1,
3857 		    PROT_READ | HAT_STORECACHING_OK, HAT_LOAD_NOCONSIST);
3858 		hat_mempte_remap(page_pptonum(topp), pp_addr2, pte2,
3859 		    PROT_READ | PROT_WRITE | HAT_STORECACHING_OK,
3860 		    HAT_LOAD_NOCONSIST);
3861 	}
3862 
3863 	if (on_fault(&ljb)) {
3864 		ret = 0;
3865 		goto faulted;
3866 	}
3867 	if (use_sse_pagecopy)
3868 #ifdef __xpv
3869 		page_copy_no_xmm(pp_addr2, pp_addr1);
3870 #else
3871 		hwblkpagecopy(pp_addr1, pp_addr2);
3872 #endif
3873 	else
3874 		bcopy(pp_addr1, pp_addr2, PAGESIZE);
3875 
3876 	no_fault();
3877 faulted:
3878 	if (!kpm_enable) {
3879 #ifdef __xpv
3880 		/*
3881 		 * We can't leave unused mappings laying about under the
3882 		 * hypervisor, so blow them away.
3883 		 */
3884 		if (HYPERVISOR_update_va_mapping((uintptr_t)pp_addr1, 0,
3885 		    UVMF_INVLPG | UVMF_LOCAL) < 0)
3886 			panic("HYPERVISOR_update_va_mapping() failed");
3887 		if (HYPERVISOR_update_va_mapping((uintptr_t)pp_addr2, 0,
3888 		    UVMF_INVLPG | UVMF_LOCAL) < 0)
3889 			panic("HYPERVISOR_update_va_mapping() failed");
3890 #endif
3891 		mutex_exit(ppaddr_mutex);
3892 	}
3893 	kpreempt_enable();
3894 	return (ret);
3895 }
3896 
3897 void
3898 pagezero(page_t *pp, uint_t off, uint_t len)
3899 {
3900 	ASSERT(PAGE_LOCKED(pp));
3901 	pfnzero(page_pptonum(pp), off, len);
3902 }
3903 
3904 /*
3905  * Zero the physical page from off to off + len given by pfn
3906  * without changing the reference and modified bits of page.
3907  *
3908  * We use this using CPU private page address #2, see ppcopy() for more info.
3909  * pfnzero() must not be called at interrupt level.
3910  */
3911 void
3912 pfnzero(pfn_t pfn, uint_t off, uint_t len)
3913 {
3914 	caddr_t		pp_addr2;
3915 	hat_mempte_t	pte2;
3916 	kmutex_t	*ppaddr_mutex = NULL;
3917 
3918 	ASSERT_STACK_ALIGNED();
3919 	ASSERT(len <= MMU_PAGESIZE);
3920 	ASSERT(off <= MMU_PAGESIZE);
3921 	ASSERT(off + len <= MMU_PAGESIZE);
3922 
3923 	if (kpm_enable && !pfn_is_foreign(pfn)) {
3924 		pp_addr2 = hat_kpm_pfn2va(pfn);
3925 		kpreempt_disable();
3926 	} else {
3927 		kpreempt_disable();
3928 
3929 		pp_addr2 = CPU->cpu_caddr2;
3930 		pte2 = CPU->cpu_caddr2pte;
3931 
3932 		ppaddr_mutex = &CPU->cpu_ppaddr_mutex;
3933 		mutex_enter(ppaddr_mutex);
3934 
3935 		hat_mempte_remap(pfn, pp_addr2, pte2,
3936 		    PROT_READ | PROT_WRITE | HAT_STORECACHING_OK,
3937 		    HAT_LOAD_NOCONSIST);
3938 	}
3939 
3940 	if (use_sse_pagezero) {
3941 #ifdef __xpv
3942 		uint_t rem;
3943 
3944 		/*
3945 		 * zero a byte at a time until properly aligned for
3946 		 * block_zero_no_xmm().
3947 		 */
3948 		while (!P2NPHASE(off, ((uint_t)BLOCKZEROALIGN)) && len-- > 0)
3949 			pp_addr2[off++] = 0;
3950 
3951 		/*
3952 		 * Now use faster block_zero_no_xmm() for any range
3953 		 * that is properly aligned and sized.
3954 		 */
3955 		rem = P2PHASE(len, ((uint_t)BLOCKZEROALIGN));
3956 		len -= rem;
3957 		if (len != 0) {
3958 			block_zero_no_xmm(pp_addr2 + off, len);
3959 			off += len;
3960 		}
3961 
3962 		/*
3963 		 * zero remainder with byte stores.
3964 		 */
3965 		while (rem-- > 0)
3966 			pp_addr2[off++] = 0;
3967 #else
3968 		hwblkclr(pp_addr2 + off, len);
3969 #endif
3970 	} else {
3971 		bzero(pp_addr2 + off, len);
3972 	}
3973 
3974 	if (!kpm_enable || pfn_is_foreign(pfn)) {
3975 #ifdef __xpv
3976 		/*
3977 		 * On the hypervisor this page might get used for a page
3978 		 * table before any intervening change to this mapping,
3979 		 * so blow it away.
3980 		 */
3981 		if (HYPERVISOR_update_va_mapping((uintptr_t)pp_addr2, 0,
3982 		    UVMF_INVLPG) < 0)
3983 			panic("HYPERVISOR_update_va_mapping() failed");
3984 #endif
3985 		mutex_exit(ppaddr_mutex);
3986 	}
3987 
3988 	kpreempt_enable();
3989 }
3990 
3991 /*
3992  * Platform-dependent page scrub call.
3993  */
3994 void
3995 pagescrub(page_t *pp, uint_t off, uint_t len)
3996 {
3997 	/*
3998 	 * For now, we rely on the fact that pagezero() will
3999 	 * always clear UEs.
4000 	 */
4001 	pagezero(pp, off, len);
4002 }
4003 
4004 /*
4005  * set up two private addresses for use on a given CPU for use in ppcopy()
4006  */
4007 void
4008 setup_vaddr_for_ppcopy(struct cpu *cpup)
4009 {
4010 	void *addr;
4011 	hat_mempte_t pte_pa;
4012 
4013 	addr = vmem_alloc(heap_arena, mmu_ptob(1), VM_SLEEP);
4014 	pte_pa = hat_mempte_setup(addr);
4015 	cpup->cpu_caddr1 = addr;
4016 	cpup->cpu_caddr1pte = pte_pa;
4017 
4018 	addr = vmem_alloc(heap_arena, mmu_ptob(1), VM_SLEEP);
4019 	pte_pa = hat_mempte_setup(addr);
4020 	cpup->cpu_caddr2 = addr;
4021 	cpup->cpu_caddr2pte = pte_pa;
4022 
4023 	mutex_init(&cpup->cpu_ppaddr_mutex, NULL, MUTEX_DEFAULT, NULL);
4024 }
4025 
4026 /*
4027  * Undo setup_vaddr_for_ppcopy
4028  */
4029 void
4030 teardown_vaddr_for_ppcopy(struct cpu *cpup)
4031 {
4032 	mutex_destroy(&cpup->cpu_ppaddr_mutex);
4033 
4034 	hat_mempte_release(cpup->cpu_caddr2, cpup->cpu_caddr2pte);
4035 	cpup->cpu_caddr2pte = 0;
4036 	vmem_free(heap_arena, cpup->cpu_caddr2, mmu_ptob(1));
4037 	cpup->cpu_caddr2 = 0;
4038 
4039 	hat_mempte_release(cpup->cpu_caddr1, cpup->cpu_caddr1pte);
4040 	cpup->cpu_caddr1pte = 0;
4041 	vmem_free(heap_arena, cpup->cpu_caddr1, mmu_ptob(1));
4042 	cpup->cpu_caddr1 = 0;
4043 }
4044 
4045 /*
4046  * Function for flushing D-cache when performing module relocations
4047  * to an alternate mapping.  Unnecessary on Intel / AMD platforms.
4048  */
4049 void
4050 dcache_flushall()
4051 {}
4052 
4053 /*
4054  * Allocate a memory page.  The argument 'seed' can be any pseudo-random
4055  * number to vary where the pages come from.  This is quite a hacked up
4056  * method -- it works for now, but really needs to be fixed up a bit.
4057  *
4058  * We currently use page_create_va() on the kvp with fake offsets,
4059  * segments and virt address.  This is pretty bogus, but was copied from the
4060  * old hat_i86.c code.  A better approach would be to specify either mnode
4061  * random or mnode local and takes a page from whatever color has the MOST
4062  * available - this would have a minimal impact on page coloring.
4063  */
4064 page_t *
4065 page_get_physical(uintptr_t seed)
4066 {
4067 	page_t *pp;
4068 	u_offset_t offset;
4069 	static struct seg tmpseg;
4070 	static uintptr_t ctr = 0;
4071 
4072 	/*
4073 	 * This code is gross, we really need a simpler page allocator.
4074 	 *
4075 	 * We need to assign an offset for the page to call page_create_va()
4076 	 * To avoid conflicts with other pages, we get creative with the offset.
4077 	 * For 32 bits, we need an offset > 4Gig
4078 	 * For 64 bits, need an offset somewhere in the VA hole.
4079 	 */
4080 	offset = seed;
4081 	if (offset > kernelbase)
4082 		offset -= kernelbase;
4083 	offset <<= MMU_PAGESHIFT;
4084 #if defined(__amd64)
4085 	offset += mmu.hole_start;	/* something in VA hole */
4086 #else
4087 	offset += 1ULL << 40;	/* something > 4 Gig */
4088 #endif
4089 
4090 	if (page_resv(1, KM_NOSLEEP) == 0)
4091 		return (NULL);
4092 
4093 #ifdef	DEBUG
4094 	pp = page_exists(&kvp, offset);
4095 	if (pp != NULL)
4096 		panic("page already exists %p", (void *)pp);
4097 #endif
4098 
4099 	pp = page_create_va(&kvp, offset, MMU_PAGESIZE, PG_EXCL,
4100 	    &tmpseg, (caddr_t)(ctr += MMU_PAGESIZE));	/* changing VA usage */
4101 	if (pp != NULL) {
4102 		page_io_unlock(pp);
4103 		page_downgrade(pp);
4104 	}
4105 	return (pp);
4106 }
4107