xref: /titanic_44/usr/src/uts/sun4v/vm/mach_vm_dep.c (revision 207c561d680c931abe394588f09474c69152b253)
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 2007 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
24  */
25 
26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
27 /*	All Rights Reserved   */
28 
29 /*
30  * Portions of this source code were derived from Berkeley 4.3 BSD
31  * under license from the Regents of the University of California.
32  */
33 
34 #pragma ident	"%Z%%M%	%I%	%E% SMI"
35 
36 /*
37  * UNIX machine dependent virtual memory support.
38  */
39 
40 #include <sys/vm.h>
41 #include <sys/exec.h>
42 #include <sys/cmn_err.h>
43 #include <sys/cpu_module.h>
44 #include <sys/cpu.h>
45 #include <sys/elf_SPARC.h>
46 #include <sys/archsystm.h>
47 #include <vm/hat_sfmmu.h>
48 #include <sys/memnode.h>
49 #include <sys/mem_cage.h>
50 #include <vm/vm_dep.h>
51 #include <sys/error.h>
52 #include <sys/machsystm.h>
53 #include <vm/seg_kmem.h>
54 #include <sys/stack.h>
55 #include <sys/atomic.h>
56 
57 uint_t page_colors = 0;
58 uint_t page_colors_mask = 0;
59 uint_t page_coloring_shift = 0;
60 int consistent_coloring;
61 
62 uint_t mmu_page_sizes = MMU_PAGE_SIZES;
63 uint_t max_mmu_page_sizes = MMU_PAGE_SIZES;
64 uint_t mmu_hashcnt = MAX_HASHCNT;
65 uint_t max_mmu_hashcnt = MAX_HASHCNT;
66 size_t mmu_ism_pagesize = DEFAULT_ISM_PAGESIZE;
67 
68 /*
69  * A bitmask of the page sizes supported by hardware based upon szc.
70  * The base pagesize (p_szc == 0) must always be supported by the hardware.
71  */
72 int mmu_exported_pagesize_mask;
73 uint_t mmu_exported_page_sizes;
74 
75 uint_t szc_2_userszc[MMU_PAGE_SIZES];
76 uint_t userszc_2_szc[MMU_PAGE_SIZES];
77 
78 extern uint_t vac_colors_mask;
79 extern int vac_shift;
80 
81 hw_pagesize_t hw_page_array[] = {
82 	{MMU_PAGESIZE, MMU_PAGESHIFT, 0, MMU_PAGESIZE >> MMU_PAGESHIFT},
83 	{MMU_PAGESIZE64K, MMU_PAGESHIFT64K, 0,
84 	    MMU_PAGESIZE64K >> MMU_PAGESHIFT},
85 	{MMU_PAGESIZE512K, MMU_PAGESHIFT512K, 0,
86 	    MMU_PAGESIZE512K >> MMU_PAGESHIFT},
87 	{MMU_PAGESIZE4M, MMU_PAGESHIFT4M, 0, MMU_PAGESIZE4M >> MMU_PAGESHIFT},
88 	{MMU_PAGESIZE32M, MMU_PAGESHIFT32M, 0,
89 	    MMU_PAGESIZE32M >> MMU_PAGESHIFT},
90 	{MMU_PAGESIZE256M, MMU_PAGESHIFT256M, 0,
91 	    MMU_PAGESIZE256M >> MMU_PAGESHIFT},
92 	{0, 0, 0, 0}
93 };
94 
95 /*
96  * Maximum page size used to map 64-bit memory segment kmem64_base..kmem64_end
97  */
98 int	max_bootlp_tteszc = TTE256M;
99 
100 /*
101  * Maximum and default segment size tunables for user heap, stack, private
102  * and shared anonymous memory, and user text and initialized data.
103  */
104 size_t max_uheap_lpsize = MMU_PAGESIZE64K;
105 size_t default_uheap_lpsize = MMU_PAGESIZE64K;
106 size_t max_ustack_lpsize = MMU_PAGESIZE64K;
107 size_t default_ustack_lpsize = MMU_PAGESIZE64K;
108 size_t max_privmap_lpsize = MMU_PAGESIZE64K;
109 size_t max_uidata_lpsize = MMU_PAGESIZE64K;
110 size_t max_utext_lpsize = MMU_PAGESIZE4M;
111 size_t max_shm_lpsize = MMU_PAGESIZE4M;
112 
113 /*
114  * Contiguous memory allocator data structures and variables.
115  *
116  * The sun4v kernel must provide a means to allocate physically
117  * contiguous, non-relocatable memory. The contig_mem_arena
118  * and contig_mem_slab_arena exist for this purpose. Allocations
119  * that require physically contiguous non-relocatable memory should
120  * be made using contig_mem_alloc() or contig_mem_alloc_align()
121  * which return memory from contig_mem_arena or contig_mem_reloc_arena.
122  * These arenas import memory from the contig_mem_slab_arena one
123  * contiguous chunk at a time.
124  *
125  * When importing slabs, an attempt is made to allocate a large page
126  * to use as backing. As a result of the non-relocatable requirement,
127  * slabs are allocated from the kernel cage freelists. If the cage does
128  * not contain any free contiguous chunks large enough to satisfy the
129  * slab allocation, the slab size will be downsized and the operation
130  * retried. Large slab sizes are tried first to minimize cage
131  * fragmentation. If the slab allocation is unsuccessful still, the slab
132  * is allocated from outside the kernel cage. This is undesirable because,
133  * until slabs are freed, it results in non-relocatable chunks scattered
134  * throughout physical memory.
135  *
136  * Allocations from the contig_mem_arena are backed by slabs from the
137  * cage. Allocations from the contig_mem_reloc_arena are backed by
138  * slabs allocated outside the cage. Slabs are left share locked while
139  * in use to prevent non-cage slabs from being relocated.
140  *
141  * Since there is no guarantee that large pages will be available in
142  * the kernel cage, contiguous memory is reserved and added to the
143  * contig_mem_arena at boot time, making it available for later
144  * contiguous memory allocations. This reserve will be used to satisfy
145  * contig_mem allocations first and it is only when the reserve is
146  * completely allocated that new slabs will need to be imported.
147  */
148 static	vmem_t		*contig_mem_slab_arena;
149 static	vmem_t		*contig_mem_arena;
150 static	vmem_t		*contig_mem_reloc_arena;
151 static	kmutex_t	contig_mem_lock;
152 #define	CONTIG_MEM_ARENA_QUANTUM	64
153 #define	CONTIG_MEM_SLAB_ARENA_QUANTUM	MMU_PAGESIZE64K
154 
155 /* contig_mem_arena import slab sizes, in decreasing size order */
156 static size_t contig_mem_import_sizes[] = {
157 	MMU_PAGESIZE4M,
158 	MMU_PAGESIZE512K,
159 	MMU_PAGESIZE64K
160 };
161 #define	NUM_IMPORT_SIZES	\
162 	(sizeof (contig_mem_import_sizes) / sizeof (size_t))
163 static size_t contig_mem_import_size_max	= MMU_PAGESIZE4M;
164 size_t contig_mem_slab_size			= MMU_PAGESIZE4M;
165 
166 /* Boot-time allocated buffer to pre-populate the contig_mem_arena */
167 static size_t prealloc_size;
168 static void *prealloc_buf;
169 
170 /*
171  * map_addr_proc() is the routine called when the system is to
172  * choose an address for the user.  We will pick an address
173  * range which is just below the current stack limit.  The
174  * algorithm used for cache consistency on machines with virtual
175  * address caches is such that offset 0 in the vnode is always
176  * on a shm_alignment'ed aligned address.  Unfortunately, this
177  * means that vnodes which are demand paged will not be mapped
178  * cache consistently with the executable images.  When the
179  * cache alignment for a given object is inconsistent, the
180  * lower level code must manage the translations so that this
181  * is not seen here (at the cost of efficiency, of course).
182  *
183  * addrp is a value/result parameter.
184  *	On input it is a hint from the user to be used in a completely
185  *	machine dependent fashion.  For MAP_ALIGN, addrp contains the
186  *	minimal alignment.
187  *
188  *	On output it is NULL if no address can be found in the current
189  *	processes address space or else an address that is currently
190  *	not mapped for len bytes with a page of red zone on either side.
191  *	If vacalign is true, then the selected address will obey the alignment
192  *	constraints of a vac machine based on the given off value.
193  */
194 /*ARGSUSED3*/
195 void
196 map_addr_proc(caddr_t *addrp, size_t len, offset_t off, int vacalign,
197     caddr_t userlimit, struct proc *p, uint_t flags)
198 {
199 	struct as *as = p->p_as;
200 	caddr_t addr;
201 	caddr_t base;
202 	size_t slen;
203 	uintptr_t align_amount;
204 	int allow_largepage_alignment = 1;
205 
206 	base = p->p_brkbase;
207 	if (userlimit < as->a_userlimit) {
208 		/*
209 		 * This happens when a program wants to map something in
210 		 * a range that's accessible to a program in a smaller
211 		 * address space.  For example, a 64-bit program might
212 		 * be calling mmap32(2) to guarantee that the returned
213 		 * address is below 4Gbytes.
214 		 */
215 		ASSERT(userlimit > base);
216 		slen = userlimit - base;
217 	} else {
218 		slen = p->p_usrstack - base - (((size_t)rctl_enforced_value(
219 		    rctlproc_legacy[RLIMIT_STACK], p->p_rctls, p) + PAGEOFFSET)
220 		    & PAGEMASK);
221 	}
222 	len = (len + PAGEOFFSET) & PAGEMASK;
223 
224 	/*
225 	 * Redzone for each side of the request. This is done to leave
226 	 * one page unmapped between segments. This is not required, but
227 	 * it's useful for the user because if their program strays across
228 	 * a segment boundary, it will catch a fault immediately making
229 	 * debugging a little easier.
230 	 */
231 	len += (2 * PAGESIZE);
232 
233 	/*
234 	 *  If the request is larger than the size of a particular
235 	 *  mmu level, then we use that level to map the request.
236 	 *  But this requires that both the virtual and the physical
237 	 *  addresses be aligned with respect to that level, so we
238 	 *  do the virtual bit of nastiness here.
239 	 *
240 	 *  For 32-bit processes, only those which have specified
241 	 *  MAP_ALIGN or an addr will be aligned on a page size > 4MB. Otherwise
242 	 *  we can potentially waste up to 256MB of the 4G process address
243 	 *  space just for alignment.
244 	 *
245 	 * XXXQ Should iterate trough hw_page_array here to catch
246 	 * all supported pagesizes
247 	 */
248 	if (p->p_model == DATAMODEL_ILP32 && ((flags & MAP_ALIGN) == 0 ||
249 	    ((uintptr_t)*addrp) != 0)) {
250 		allow_largepage_alignment = 0;
251 	}
252 	if ((mmu_page_sizes == max_mmu_page_sizes) &&
253 	    allow_largepage_alignment &&
254 		(len >= MMU_PAGESIZE256M)) {	/* 256MB mappings */
255 		align_amount = MMU_PAGESIZE256M;
256 	} else if ((mmu_page_sizes == max_mmu_page_sizes) &&
257 	    allow_largepage_alignment &&
258 		(len >= MMU_PAGESIZE32M)) {	/* 32MB mappings */
259 		align_amount = MMU_PAGESIZE32M;
260 	} else if (len >= MMU_PAGESIZE4M) {  /* 4MB mappings */
261 		align_amount = MMU_PAGESIZE4M;
262 	} else if (len >= MMU_PAGESIZE512K) { /* 512KB mappings */
263 		align_amount = MMU_PAGESIZE512K;
264 	} else if (len >= MMU_PAGESIZE64K) { /* 64KB mappings */
265 		align_amount = MMU_PAGESIZE64K;
266 	} else  {
267 		/*
268 		 * Align virtual addresses on a 64K boundary to ensure
269 		 * that ELF shared libraries are mapped with the appropriate
270 		 * alignment constraints by the run-time linker.
271 		 */
272 		align_amount = ELF_SPARC_MAXPGSZ;
273 		if ((flags & MAP_ALIGN) && ((uintptr_t)*addrp != 0) &&
274 			((uintptr_t)*addrp < align_amount))
275 			align_amount = (uintptr_t)*addrp;
276 	}
277 
278 	/*
279 	 * 64-bit processes require 1024K alignment of ELF shared libraries.
280 	 */
281 	if (p->p_model == DATAMODEL_LP64)
282 		align_amount = MAX(align_amount, ELF_SPARCV9_MAXPGSZ);
283 #ifdef VAC
284 	if (vac && vacalign && (align_amount < shm_alignment))
285 		align_amount = shm_alignment;
286 #endif
287 
288 	if ((flags & MAP_ALIGN) && ((uintptr_t)*addrp > align_amount)) {
289 		align_amount = (uintptr_t)*addrp;
290 	}
291 	len += align_amount;
292 
293 	/*
294 	 * Look for a large enough hole starting below the stack limit.
295 	 * After finding it, use the upper part.  Addition of PAGESIZE is
296 	 * for the redzone as described above.
297 	 */
298 	as_purge(as);
299 	if (as_gap(as, len, &base, &slen, AH_HI, NULL) == 0) {
300 		caddr_t as_addr;
301 
302 		addr = base + slen - len + PAGESIZE;
303 		as_addr = addr;
304 		/*
305 		 * Round address DOWN to the alignment amount,
306 		 * add the offset, and if this address is less
307 		 * than the original address, add alignment amount.
308 		 */
309 		addr = (caddr_t)((uintptr_t)addr & (~(align_amount - 1l)));
310 		addr += (long)(off & (align_amount - 1l));
311 		if (addr < as_addr) {
312 			addr += align_amount;
313 		}
314 
315 		ASSERT(addr <= (as_addr + align_amount));
316 		ASSERT(((uintptr_t)addr & (align_amount - 1l)) ==
317 		    ((uintptr_t)(off & (align_amount - 1l))));
318 		*addrp = addr;
319 
320 	} else {
321 		*addrp = NULL;	/* no more virtual space */
322 	}
323 }
324 
325 /*
326  * Platform-dependent page scrub call.
327  * We call hypervisor to scrub the page.
328  */
329 void
330 pagescrub(page_t *pp, uint_t off, uint_t len)
331 {
332 	uint64_t pa, length;
333 
334 	pa = (uint64_t)(pp->p_pagenum << MMU_PAGESHIFT + off);
335 	length = (uint64_t)len;
336 
337 	(void) mem_scrub(pa, length);
338 }
339 
340 void
341 sync_data_memory(caddr_t va, size_t len)
342 {
343 	/* Call memory sync function */
344 	(void) mem_sync(va, len);
345 }
346 
347 size_t
348 mmu_get_kernel_lpsize(size_t lpsize)
349 {
350 	extern int mmu_exported_pagesize_mask;
351 	uint_t tte;
352 
353 	if (lpsize == 0) {
354 		/* no setting for segkmem_lpsize in /etc/system: use default */
355 		if (mmu_exported_pagesize_mask & (1 << TTE256M)) {
356 			lpsize = MMU_PAGESIZE256M;
357 		} else if (mmu_exported_pagesize_mask & (1 << TTE4M)) {
358 			lpsize = MMU_PAGESIZE4M;
359 		} else if (mmu_exported_pagesize_mask & (1 << TTE64K)) {
360 			lpsize = MMU_PAGESIZE64K;
361 		} else {
362 			lpsize = MMU_PAGESIZE;
363 		}
364 
365 		return (lpsize);
366 	}
367 
368 	for (tte = TTE8K; tte <= TTE256M; tte++) {
369 
370 		if ((mmu_exported_pagesize_mask & (1 << tte)) == 0)
371 			continue;
372 
373 		if (lpsize == TTEBYTES(tte))
374 			return (lpsize);
375 	}
376 
377 	lpsize = TTEBYTES(TTE8K);
378 	return (lpsize);
379 }
380 
381 void
382 mmu_init_kcontext()
383 {
384 }
385 
386 /*ARGSUSED*/
387 void
388 mmu_init_kernel_pgsz(struct hat *hat)
389 {
390 }
391 
392 static void *
393 contig_mem_span_alloc(vmem_t *vmp, size_t size, int vmflag)
394 {
395 	page_t *ppl;
396 	page_t *rootpp;
397 	caddr_t addr = NULL;
398 	pgcnt_t npages = btopr(size);
399 	page_t **ppa;
400 	int pgflags;
401 	spgcnt_t i = 0;
402 
403 
404 	ASSERT(size <= contig_mem_import_size_max);
405 	ASSERT((size & (size - 1)) == 0);
406 
407 	if ((addr = vmem_xalloc(vmp, size, size, 0, 0,
408 	    NULL, NULL, vmflag)) == NULL) {
409 		return (NULL);
410 	}
411 
412 	/* The address should be slab-size aligned. */
413 	ASSERT(((uintptr_t)addr & (size - 1)) == 0);
414 
415 	if (page_resv(npages, vmflag & VM_KMFLAGS) == 0) {
416 		vmem_xfree(vmp, addr, size);
417 		return (NULL);
418 	}
419 
420 	pgflags = PG_EXCL;
421 	if (vmflag & VM_NORELOC)
422 		pgflags |= PG_NORELOC;
423 
424 	ppl = page_create_va_large(&kvp, (u_offset_t)(uintptr_t)addr, size,
425 	    pgflags, &kvseg, addr, NULL);
426 
427 	if (ppl == NULL) {
428 		vmem_xfree(vmp, addr, size);
429 		page_unresv(npages);
430 		return (NULL);
431 	}
432 
433 	rootpp = ppl;
434 	ppa = kmem_zalloc(npages * sizeof (page_t *), KM_SLEEP);
435 	while (ppl != NULL) {
436 		page_t *pp = ppl;
437 		ppa[i++] = pp;
438 		page_sub(&ppl, pp);
439 		ASSERT(page_iolock_assert(pp));
440 		ASSERT(PAGE_EXCL(pp));
441 		page_io_unlock(pp);
442 	}
443 
444 	/*
445 	 * Load the locked entry.  It's OK to preload the entry into
446 	 * the TSB since we now support large mappings in the kernel TSB.
447 	 */
448 	hat_memload_array(kas.a_hat, (caddr_t)rootpp->p_offset, size,
449 	    ppa, (PROT_ALL & ~PROT_USER) | HAT_NOSYNC, HAT_LOAD_LOCK);
450 
451 	ASSERT(i == page_get_pagecnt(ppa[0]->p_szc));
452 	for (--i; i >= 0; --i) {
453 		ASSERT(ppa[i]->p_szc == ppa[0]->p_szc);
454 		ASSERT(page_pptonum(ppa[i]) == page_pptonum(ppa[0]) + i);
455 		(void) page_pp_lock(ppa[i], 0, 1);
456 		/*
457 		 * Leave the page share locked. For non-cage pages,
458 		 * this would prevent memory DR if it were supported
459 		 * on sun4v.
460 		 */
461 		page_downgrade(ppa[i]);
462 	}
463 
464 	kmem_free(ppa, npages * sizeof (page_t *));
465 	return (addr);
466 }
467 
468 /*
469  * Allocates a slab by first trying to use the largest slab size
470  * in contig_mem_import_sizes and then falling back to smaller slab
471  * sizes still large enough for the allocation. The sizep argument
472  * is a pointer to the requested size. When a slab is successfully
473  * allocated, the slab size, which must be >= *sizep and <=
474  * contig_mem_import_size_max, is returned in the *sizep argument.
475  * Returns the virtual address of the new slab.
476  */
477 static void *
478 span_alloc_downsize(vmem_t *vmp, size_t *sizep, size_t align, int vmflag)
479 {
480 	int i;
481 
482 	ASSERT(*sizep <= contig_mem_import_size_max);
483 
484 	for (i = 0; i < NUM_IMPORT_SIZES; i++) {
485 		size_t page_size = contig_mem_import_sizes[i];
486 
487 		/*
488 		 * Check that the alignment is also less than the
489 		 * import (large page) size. In the case where the
490 		 * alignment is larger than the size, a large page
491 		 * large enough for the allocation is not necessarily
492 		 * physical-address aligned to satisfy the requested
493 		 * alignment. Since alignment is required to be a
494 		 * power-of-2, any large page >= size && >= align will
495 		 * suffice.
496 		 */
497 		if (*sizep <= page_size && align <= page_size) {
498 			void *addr;
499 			addr = contig_mem_span_alloc(vmp, page_size, vmflag);
500 			if (addr == NULL)
501 				continue;
502 			*sizep = page_size;
503 			return (addr);
504 		}
505 		return (NULL);
506 	}
507 
508 	return (NULL);
509 }
510 
511 static void *
512 contig_mem_span_xalloc(vmem_t *vmp, size_t *sizep, size_t align, int vmflag)
513 {
514 	return (span_alloc_downsize(vmp, sizep, align, vmflag | VM_NORELOC));
515 }
516 
517 static void *
518 contig_mem_reloc_span_xalloc(vmem_t *vmp, size_t *sizep, size_t align,
519     int vmflag)
520 {
521 	ASSERT((vmflag & VM_NORELOC) == 0);
522 	return (span_alloc_downsize(vmp, sizep, align, vmflag));
523 }
524 
525 /*
526  * Free a span, which is always exactly one large page.
527  */
528 static void
529 contig_mem_span_free(vmem_t *vmp, void *inaddr, size_t size)
530 {
531 	page_t *pp;
532 	caddr_t addr = inaddr;
533 	caddr_t eaddr;
534 	pgcnt_t npages = btopr(size);
535 	page_t *rootpp = NULL;
536 
537 	ASSERT(size <= contig_mem_import_size_max);
538 	/* All slabs should be size aligned */
539 	ASSERT(((uintptr_t)addr & (size - 1)) == 0);
540 
541 	hat_unload(kas.a_hat, addr, size, HAT_UNLOAD_UNLOCK);
542 
543 	for (eaddr = addr + size; addr < eaddr; addr += PAGESIZE) {
544 		pp = page_find(&kvp, (u_offset_t)(uintptr_t)addr);
545 		if (pp == NULL) {
546 			panic("contig_mem_span_free: page not found");
547 		}
548 		if (!page_tryupgrade(pp)) {
549 			page_unlock(pp);
550 			pp = page_lookup(&kvp,
551 			    (u_offset_t)(uintptr_t)addr, SE_EXCL);
552 			if (pp == NULL)
553 				panic("contig_mem_span_free: page not found");
554 		}
555 
556 		ASSERT(PAGE_EXCL(pp));
557 		ASSERT(size == page_get_pagesize(pp->p_szc));
558 		ASSERT(rootpp == NULL || rootpp->p_szc == pp->p_szc);
559 		ASSERT(rootpp == NULL || (page_pptonum(rootpp) +
560 		    (pgcnt_t)btop(addr - (caddr_t)inaddr) == page_pptonum(pp)));
561 
562 		page_pp_unlock(pp, 0, 1);
563 
564 		if (rootpp == NULL)
565 			rootpp = pp;
566 	}
567 	page_destroy_pages(rootpp);
568 	page_unresv(npages);
569 
570 	if (vmp != NULL)
571 		vmem_xfree(vmp, inaddr, size);
572 }
573 
574 static void *
575 contig_vmem_xalloc_aligned_wrapper(vmem_t *vmp, size_t *sizep, size_t align,
576     int vmflag)
577 {
578 	ASSERT((align & (align - 1)) == 0);
579 	return (vmem_xalloc(vmp, *sizep, align, 0, 0, NULL, NULL, vmflag));
580 }
581 
582 /*
583  * contig_mem_alloc, contig_mem_alloc_align
584  *
585  * Caution: contig_mem_alloc and contig_mem_alloc_align should be
586  * used only when physically contiguous non-relocatable memory is
587  * required. Furthermore, use of these allocation routines should be
588  * minimized as well as should the allocation size. As described in the
589  * contig_mem_arena comment block above, slab allocations fall back to
590  * being outside of the cage. Therefore, overuse of these allocation
591  * routines can lead to non-relocatable large pages being allocated
592  * outside the cage. Such pages prevent the allocation of a larger page
593  * occupying overlapping pages. This can impact performance for
594  * applications that utilize e.g. 256M large pages.
595  */
596 
597 /*
598  * Allocates size aligned contiguous memory up to contig_mem_import_size_max.
599  * Size must be a power of 2.
600  */
601 void *
602 contig_mem_alloc(size_t size)
603 {
604 	ASSERT((size & (size - 1)) == 0);
605 	return (contig_mem_alloc_align(size, size));
606 }
607 
608 /*
609  * contig_mem_alloc_align allocates real contiguous memory with the specified
610  * alignment up to contig_mem_import_size_max. The alignment must be a
611  * power of 2 and no greater than contig_mem_import_size_max. We assert
612  * the aligment is a power of 2. For non-debug, vmem_xalloc will panic
613  * for non power of 2 alignments.
614  */
615 void *
616 contig_mem_alloc_align(size_t size, size_t align)
617 {
618 	void *buf;
619 
620 	ASSERT(size <= contig_mem_import_size_max);
621 	ASSERT(align <= contig_mem_import_size_max);
622 	ASSERT((align & (align - 1)) == 0);
623 
624 	if (align < CONTIG_MEM_ARENA_QUANTUM)
625 		align = CONTIG_MEM_ARENA_QUANTUM;
626 
627 	/*
628 	 * We take the lock here to serialize span allocations.
629 	 * We do not lose concurrency for the common case, since
630 	 * allocations that don't require new span allocations
631 	 * are serialized by vmem_xalloc. Serializing span
632 	 * allocations also prevents us from trying to allocate
633 	 * more spans that necessary.
634 	 */
635 	mutex_enter(&contig_mem_lock);
636 
637 	buf = vmem_xalloc(contig_mem_arena, size, align, 0, 0,
638 	    NULL, NULL, VM_NOSLEEP | VM_NORELOC);
639 
640 	if ((buf == NULL) && (size <= MMU_PAGESIZE)) {
641 		mutex_exit(&contig_mem_lock);
642 		return (vmem_xalloc(static_alloc_arena, size, align, 0, 0,
643 		    NULL, NULL, VM_NOSLEEP));
644 	}
645 
646 	if (buf == NULL) {
647 		buf = vmem_xalloc(contig_mem_reloc_arena, size, align, 0, 0,
648 		    NULL, NULL, VM_NOSLEEP);
649 	}
650 
651 	mutex_exit(&contig_mem_lock);
652 
653 	return (buf);
654 }
655 
656 void
657 contig_mem_free(void *vaddr, size_t size)
658 {
659 	if (vmem_contains(contig_mem_arena, vaddr, size)) {
660 		vmem_xfree(contig_mem_arena, vaddr, size);
661 	} else if (size > MMU_PAGESIZE) {
662 		vmem_xfree(contig_mem_reloc_arena, vaddr, size);
663 	} else {
664 		vmem_xfree(static_alloc_arena, vaddr, size);
665 	}
666 }
667 
668 /*
669  * We create a set of stacked vmem arenas to enable us to
670  * allocate large >PAGESIZE chucks of contiguous Real Address space.
671  * The vmem_xcreate interface is used to create the contig_mem_arena
672  * allowing the import routine to downsize the requested slab size
673  * and return a smaller slab.
674  */
675 void
676 contig_mem_init(void)
677 {
678 	mutex_init(&contig_mem_lock, NULL, MUTEX_DEFAULT, NULL);
679 
680 	contig_mem_slab_arena = vmem_xcreate("contig_mem_slab_arena", NULL, 0,
681 	    CONTIG_MEM_SLAB_ARENA_QUANTUM, contig_vmem_xalloc_aligned_wrapper,
682 	    vmem_xfree, heap_arena, 0, VM_SLEEP | VMC_XALIGN);
683 
684 	contig_mem_arena = vmem_xcreate("contig_mem_arena", NULL, 0,
685 	    CONTIG_MEM_ARENA_QUANTUM, contig_mem_span_xalloc,
686 	    contig_mem_span_free, contig_mem_slab_arena, 0,
687 	    VM_SLEEP | VM_BESTFIT | VMC_XALIGN);
688 
689 	contig_mem_reloc_arena = vmem_xcreate("contig_mem_reloc_arena", NULL, 0,
690 	    CONTIG_MEM_ARENA_QUANTUM, contig_mem_reloc_span_xalloc,
691 	    contig_mem_span_free, contig_mem_slab_arena, 0,
692 	    VM_SLEEP | VM_BESTFIT | VMC_XALIGN);
693 
694 	if (vmem_add(contig_mem_arena, prealloc_buf, prealloc_size,
695 	    VM_SLEEP) == NULL)
696 		cmn_err(CE_PANIC, "Failed to pre-populate contig_mem_arena");
697 }
698 
699 /*
700  * In calculating how much memory to pre-allocate, we include a small
701  * amount per-CPU to account for per-CPU buffers in line with measured
702  * values for different size systems. contig_mem_prealloc_base is the
703  * base fixed amount to be preallocated before considering per-CPU
704  * requirements and memory size. We take the minimum of
705  * contig_mem_prealloc_base and a small percentage of physical memory
706  * to prevent allocating too much on smaller systems.
707  */
708 #define	PREALLOC_PER_CPU	(256 * 1024)		/* 256K */
709 #define	PREALLOC_PERCENT	(4)			/* 4% */
710 #define	PREALLOC_MIN		(16 * 1024 * 1024)	/* 16M */
711 size_t contig_mem_prealloc_base = 0;
712 
713 /*
714  * Called at boot-time allowing pre-allocation of contiguous memory.
715  * The argument 'alloc_base' is the requested base address for the
716  * allocation and originates in startup_memlist.
717  */
718 caddr_t
719 contig_mem_prealloc(caddr_t alloc_base, pgcnt_t npages)
720 {
721 	prealloc_size = MIN((PREALLOC_PER_CPU * ncpu_guest_max) +
722 	    contig_mem_prealloc_base, (ptob(npages) * PREALLOC_PERCENT) / 100);
723 	prealloc_size = MAX(prealloc_size, PREALLOC_MIN);
724 	prealloc_size = P2ROUNDUP(prealloc_size, MMU_PAGESIZE4M);
725 
726 	alloc_base = (caddr_t)roundup((uintptr_t)alloc_base, MMU_PAGESIZE4M);
727 	prealloc_buf = alloc_base;
728 	alloc_base += prealloc_size;
729 
730 	return (alloc_base);
731 }
732 
733 static uint_t sp_color_stride = 16;
734 static uint_t sp_color_mask = 0x1f;
735 static uint_t sp_current_color = (uint_t)-1;
736 
737 size_t
738 exec_get_spslew(void)
739 {
740 	uint_t spcolor = atomic_inc_32_nv(&sp_current_color);
741 	return ((size_t)((spcolor & sp_color_mask) * SA(sp_color_stride)));
742 }
743