xref: /freebsd/sys/powerpc/booke/pmap_64.c (revision bdd1243d)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (C) 2020 Justin Hibbits
5  * Copyright (C) 2007-2009 Semihalf, Rafal Jaworowski <raj@semihalf.com>
6  * Copyright (C) 2006 Semihalf, Marian Balakowicz <m8@semihalf.com>
7  * All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
21  * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
22  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
23  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
24  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * Some hw specific parts of this pmap were derived or influenced
30  * by NetBSD's ibm4xx pmap module. More generic code is shared with
31  * a few other pmap modules from the FreeBSD tree.
32  */
33 
34  /*
35   * VM layout notes:
36   *
37   * Kernel and user threads run within one common virtual address space
38   * defined by AS=0.
39   *
40   * 64-bit pmap:
41   * Virtual address space layout:
42   * -----------------------------
43   * 0x0000_0000_0000_0000 - 0x3fff_ffff_ffff_ffff      : user process
44   * 0x4000_0000_0000_0000 - 0x7fff_ffff_ffff_ffff      : unused
45   * 0x8000_0000_0000_0000 - 0xbfff_ffff_ffff_ffff      : mmio region
46   * 0xc000_0000_0000_0000 - 0xdfff_ffff_ffff_ffff      : direct map
47   * 0xe000_0000_0000_0000 - 0xffff_ffff_ffff_ffff      : KVA
48   */
49 
50 #include <sys/cdefs.h>
51 __FBSDID("$FreeBSD$");
52 
53 #include "opt_ddb.h"
54 #include "opt_kstack_pages.h"
55 
56 #include <sys/param.h>
57 #include <sys/conf.h>
58 #include <sys/malloc.h>
59 #include <sys/ktr.h>
60 #include <sys/proc.h>
61 #include <sys/user.h>
62 #include <sys/queue.h>
63 #include <sys/systm.h>
64 #include <sys/kernel.h>
65 #include <sys/kerneldump.h>
66 #include <sys/linker.h>
67 #include <sys/msgbuf.h>
68 #include <sys/lock.h>
69 #include <sys/mutex.h>
70 #include <sys/rwlock.h>
71 #include <sys/sched.h>
72 #include <sys/smp.h>
73 #include <sys/vmmeter.h>
74 
75 #include <vm/vm.h>
76 #include <vm/vm_page.h>
77 #include <vm/vm_kern.h>
78 #include <vm/vm_pageout.h>
79 #include <vm/vm_extern.h>
80 #include <vm/vm_object.h>
81 #include <vm/vm_param.h>
82 #include <vm/vm_map.h>
83 #include <vm/vm_pager.h>
84 #include <vm/vm_phys.h>
85 #include <vm/vm_pagequeue.h>
86 #include <vm/uma.h>
87 
88 #include <machine/_inttypes.h>
89 #include <machine/cpu.h>
90 #include <machine/pcb.h>
91 #include <machine/platform.h>
92 
93 #include <machine/tlb.h>
94 #include <machine/spr.h>
95 #include <machine/md_var.h>
96 #include <machine/mmuvar.h>
97 #include <machine/pmap.h>
98 #include <machine/pte.h>
99 
100 #include <ddb/ddb.h>
101 
102 #ifdef  DEBUG
103 #define debugf(fmt, args...) printf(fmt, ##args)
104 #else
105 #define debugf(fmt, args...)
106 #endif
107 
108 #define	PRI0ptrX	"016lx"
109 
110 /**************************************************************************/
111 /* PMAP */
112 /**************************************************************************/
113 
114 unsigned int kernel_pdirs;
115 static uma_zone_t ptbl_root_zone;
116 static pte_t ****kernel_ptbl_root;
117 
118 /*
119  * Base of the pmap_mapdev() region.  On 32-bit it immediately follows the
120  * userspace address range.  On On 64-bit it's far above, at (1 << 63), and
121  * ranges up to the DMAP, giving 62 bits of PA allowed.  This is far larger than
122  * the widest Book-E address bus, the e6500 has a 40-bit PA space.  This allows
123  * us to map akin to the DMAP, with addresses identical to the PA, offset by the
124  * base.
125  */
126 #define	VM_MAPDEV_BASE		0x8000000000000000
127 #define	VM_MAPDEV_PA_MAX	0x4000000000000000 /* Don't encroach on DMAP */
128 
129 static void tid_flush(tlbtid_t tid);
130 static unsigned long ilog2(unsigned long);
131 
132 /**************************************************************************/
133 /* Page table management */
134 /**************************************************************************/
135 
136 #define PMAP_ROOT_SIZE	(sizeof(pte_t****) * PG_ROOT_NENTRIES)
137 static pte_t *ptbl_alloc(pmap_t pmap, vm_offset_t va,
138     bool nosleep, bool *is_new);
139 static void ptbl_hold(pmap_t, pte_t *);
140 static int ptbl_unhold(pmap_t, vm_offset_t);
141 
142 static vm_paddr_t pte_vatopa(pmap_t, vm_offset_t);
143 static int pte_enter(pmap_t, vm_page_t, vm_offset_t, uint32_t, boolean_t);
144 static int pte_remove(pmap_t, vm_offset_t, uint8_t);
145 static pte_t *pte_find(pmap_t, vm_offset_t);
146 static pte_t *pte_find_next(pmap_t, vm_offset_t *);
147 static void kernel_pte_alloc(vm_offset_t, vm_offset_t);
148 
149 /**************************************************************************/
150 /* Page table related */
151 /**************************************************************************/
152 
153 /* Allocate a page, to be used in a page table. */
154 static vm_offset_t
155 mmu_booke_alloc_page(pmap_t pmap, unsigned int idx, bool nosleep)
156 {
157 	vm_page_t	m;
158 	int		req;
159 
160 	req = VM_ALLOC_WIRED | VM_ALLOC_ZERO;
161 	while ((m = vm_page_alloc_noobj(req)) == NULL) {
162 		if (nosleep)
163 			return (0);
164 
165 		PMAP_UNLOCK(pmap);
166 		rw_wunlock(&pvh_global_lock);
167 		vm_wait(NULL);
168 		rw_wlock(&pvh_global_lock);
169 		PMAP_LOCK(pmap);
170 	}
171 	m->pindex = idx;
172 
173 	return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)));
174 }
175 
176 /* Initialize pool of kva ptbl buffers. */
177 static void
178 ptbl_init(void)
179 {
180 }
181 
182 /* Get a pointer to a PTE in a page table. */
183 static __inline pte_t *
184 pte_find(pmap_t pmap, vm_offset_t va)
185 {
186 	pte_t        ***pdir_l1;
187 	pte_t         **pdir;
188 	pte_t          *ptbl;
189 
190 	KASSERT((pmap != NULL), ("pte_find: invalid pmap"));
191 
192 	pdir_l1 = pmap->pm_root[PG_ROOT_IDX(va)];
193 	if (pdir_l1 == NULL)
194 		return (NULL);
195 	pdir = pdir_l1[PDIR_L1_IDX(va)];
196 	if (pdir == NULL)
197 		return (NULL);
198 	ptbl = pdir[PDIR_IDX(va)];
199 
200 	return ((ptbl != NULL) ? &ptbl[PTBL_IDX(va)] : NULL);
201 }
202 
203 /* Get a pointer to a PTE in a page table, or the next closest (greater) one. */
204 static __inline pte_t *
205 pte_find_next(pmap_t pmap, vm_offset_t *pva)
206 {
207 	vm_offset_t	va;
208 	pte_t	    ****pm_root;
209 	pte_t	       *pte;
210 	unsigned long	i, j, k, l;
211 
212 	KASSERT((pmap != NULL), ("pte_find: invalid pmap"));
213 
214 	va = *pva;
215 	i = PG_ROOT_IDX(va);
216 	j = PDIR_L1_IDX(va);
217 	k = PDIR_IDX(va);
218 	l = PTBL_IDX(va);
219 	pm_root = pmap->pm_root;
220 
221 	/* truncate the VA for later. */
222 	va &= ~((1UL << (PG_ROOT_H + 1)) - 1);
223 	for (; i < PG_ROOT_NENTRIES; i++, j = 0, k = 0, l = 0) {
224 		if (pm_root[i] == 0)
225 			continue;
226 		for (; j < PDIR_L1_NENTRIES; j++, k = 0, l = 0) {
227 			if (pm_root[i][j] == 0)
228 				continue;
229 			for (; k < PDIR_NENTRIES; k++, l = 0) {
230 				if (pm_root[i][j][k] == NULL)
231 					continue;
232 				for (; l < PTBL_NENTRIES; l++) {
233 					pte = &pm_root[i][j][k][l];
234 					if (!PTE_ISVALID(pte))
235 						continue;
236 					*pva = va + PG_ROOT_SIZE * i +
237 					    PDIR_L1_SIZE * j +
238 					    PDIR_SIZE * k +
239 					    PAGE_SIZE * l;
240 					return (pte);
241 				}
242 			}
243 		}
244 	}
245 	return (NULL);
246 }
247 
248 static bool
249 unhold_free_page(pmap_t pmap, vm_page_t m)
250 {
251 
252 	if (vm_page_unwire_noq(m)) {
253 		vm_page_free_zero(m);
254 		return (true);
255 	}
256 
257 	return (false);
258 }
259 
260 static vm_offset_t
261 get_pgtbl_page(pmap_t pmap, vm_offset_t *ptr_tbl, uint32_t index,
262     bool nosleep, bool hold_parent, bool *isnew)
263 {
264 	vm_offset_t	page;
265 	vm_page_t	m;
266 
267 	page = ptr_tbl[index];
268 	KASSERT(page != 0 || pmap != kernel_pmap,
269 	    ("NULL page table page found in kernel pmap!"));
270 	if (page == 0) {
271 		page = mmu_booke_alloc_page(pmap, index, nosleep);
272 		if (ptr_tbl[index] == 0) {
273 			*isnew = true;
274 			ptr_tbl[index] = page;
275 			if (hold_parent) {
276 				m = PHYS_TO_VM_PAGE(pmap_kextract((vm_offset_t)ptr_tbl));
277 				m->ref_count++;
278 			}
279 			return (page);
280 		}
281 		m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS(page));
282 		page = ptr_tbl[index];
283 		vm_page_unwire_noq(m);
284 		vm_page_free_zero(m);
285 	}
286 
287 	*isnew = false;
288 
289 	return (page);
290 }
291 
292 /* Allocate page table. */
293 static pte_t*
294 ptbl_alloc(pmap_t pmap, vm_offset_t va, bool nosleep, bool *is_new)
295 {
296 	unsigned int	pg_root_idx = PG_ROOT_IDX(va);
297 	unsigned int	pdir_l1_idx = PDIR_L1_IDX(va);
298 	unsigned int	pdir_idx = PDIR_IDX(va);
299 	vm_offset_t	pdir_l1, pdir, ptbl;
300 
301 	/* When holding a parent, no need to hold the root index pages. */
302 	pdir_l1 = get_pgtbl_page(pmap, (vm_offset_t *)pmap->pm_root,
303 	    pg_root_idx, nosleep, false, is_new);
304 	if (pdir_l1 == 0)
305 		return (NULL);
306 	pdir = get_pgtbl_page(pmap, (vm_offset_t *)pdir_l1, pdir_l1_idx,
307 	    nosleep, !*is_new, is_new);
308 	if (pdir == 0)
309 		return (NULL);
310 	ptbl = get_pgtbl_page(pmap, (vm_offset_t *)pdir, pdir_idx,
311 	    nosleep, !*is_new, is_new);
312 
313 	return ((pte_t *)ptbl);
314 }
315 
316 /*
317  * Decrement ptbl pages hold count and attempt to free ptbl pages. Called
318  * when removing pte entry from ptbl.
319  *
320  * Return 1 if ptbl pages were freed.
321  */
322 static int
323 ptbl_unhold(pmap_t pmap, vm_offset_t va)
324 {
325 	pte_t          *ptbl;
326 	vm_page_t	m;
327 	u_int		pg_root_idx;
328 	pte_t        ***pdir_l1;
329 	u_int		pdir_l1_idx;
330 	pte_t         **pdir;
331 	u_int		pdir_idx;
332 
333 	pg_root_idx = PG_ROOT_IDX(va);
334 	pdir_l1_idx = PDIR_L1_IDX(va);
335 	pdir_idx = PDIR_IDX(va);
336 
337 	KASSERT((pmap != kernel_pmap),
338 		("ptbl_unhold: unholding kernel ptbl!"));
339 
340 	pdir_l1 = pmap->pm_root[pg_root_idx];
341 	pdir = pdir_l1[pdir_l1_idx];
342 	ptbl = pdir[pdir_idx];
343 
344 	/* decrement hold count */
345 	m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t) ptbl));
346 
347 	if (!unhold_free_page(pmap, m))
348 		return (0);
349 
350 	pdir[pdir_idx] = NULL;
351 	m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t) pdir));
352 
353 	if (!unhold_free_page(pmap, m))
354 		return (1);
355 
356 	pdir_l1[pdir_l1_idx] = NULL;
357 	m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t) pdir_l1));
358 
359 	if (!unhold_free_page(pmap, m))
360 		return (1);
361 	pmap->pm_root[pg_root_idx] = NULL;
362 
363 	return (1);
364 }
365 
366 /*
367  * Increment hold count for ptbl pages. This routine is used when new pte
368  * entry is being inserted into ptbl.
369  */
370 static void
371 ptbl_hold(pmap_t pmap, pte_t *ptbl)
372 {
373 	vm_page_t	m;
374 
375 	KASSERT((pmap != kernel_pmap),
376 		("ptbl_hold: holding kernel ptbl!"));
377 
378 	m = PHYS_TO_VM_PAGE(DMAP_TO_PHYS((vm_offset_t) ptbl));
379 	m->ref_count++;
380 }
381 
382 /*
383  * Clean pte entry, try to free page table page if requested.
384  *
385  * Return 1 if ptbl pages were freed, otherwise return 0.
386  */
387 static int
388 pte_remove(pmap_t pmap, vm_offset_t va, u_int8_t flags)
389 {
390 	vm_page_t	m;
391 	pte_t          *pte;
392 
393 	pte = pte_find(pmap, va);
394 	KASSERT(pte != NULL, ("%s: NULL pte for va %#jx, pmap %p",
395 	    __func__, (uintmax_t)va, pmap));
396 
397 	if (!PTE_ISVALID(pte))
398 		return (0);
399 
400 	/* Get vm_page_t for mapped pte. */
401 	m = PHYS_TO_VM_PAGE(PTE_PA(pte));
402 
403 	if (PTE_ISWIRED(pte))
404 		pmap->pm_stats.wired_count--;
405 
406 	/* Handle managed entry. */
407 	if (PTE_ISMANAGED(pte)) {
408 		/* Handle modified pages. */
409 		if (PTE_ISMODIFIED(pte))
410 			vm_page_dirty(m);
411 
412 		/* Referenced pages. */
413 		if (PTE_ISREFERENCED(pte))
414 			vm_page_aflag_set(m, PGA_REFERENCED);
415 
416 		/* Remove pv_entry from pv_list. */
417 		pv_remove(pmap, va, m);
418 	} else if (pmap == kernel_pmap && m && m->md.pv_tracked) {
419 		pv_remove(pmap, va, m);
420 		if (TAILQ_EMPTY(&m->md.pv_list))
421 			m->md.pv_tracked = false;
422 	}
423 	mtx_lock_spin(&tlbivax_mutex);
424 	tlb_miss_lock();
425 
426 	tlb0_flush_entry(va);
427 	*pte = 0;
428 
429 	tlb_miss_unlock();
430 	mtx_unlock_spin(&tlbivax_mutex);
431 
432 	pmap->pm_stats.resident_count--;
433 
434 	if (flags & PTBL_UNHOLD) {
435 		return (ptbl_unhold(pmap, va));
436 	}
437 	return (0);
438 }
439 
440 /*
441  * Insert PTE for a given page and virtual address.
442  */
443 static int
444 pte_enter(pmap_t pmap, vm_page_t m, vm_offset_t va, uint32_t flags,
445     boolean_t nosleep)
446 {
447 	unsigned int	ptbl_idx = PTBL_IDX(va);
448 	pte_t          *ptbl, *pte, pte_tmp;
449 	bool		is_new;
450 
451 	/* Get the page directory pointer. */
452 	ptbl = ptbl_alloc(pmap, va, nosleep, &is_new);
453 	if (ptbl == NULL) {
454 		KASSERT(nosleep, ("nosleep and NULL ptbl"));
455 		return (ENOMEM);
456 	}
457 	if (is_new) {
458 		pte = &ptbl[ptbl_idx];
459 	} else {
460 		/*
461 		 * Check if there is valid mapping for requested va, if there
462 		 * is, remove it.
463 		 */
464 		pte = &ptbl[ptbl_idx];
465 		if (PTE_ISVALID(pte)) {
466 			pte_remove(pmap, va, PTBL_HOLD);
467 		} else {
468 			/*
469 			 * pte is not used, increment hold count for ptbl
470 			 * pages.
471 			 */
472 			if (pmap != kernel_pmap)
473 				ptbl_hold(pmap, ptbl);
474 		}
475 	}
476 
477 	/*
478 	 * Insert pv_entry into pv_list for mapped page if part of managed
479 	 * memory.
480 	 */
481 	if ((m->oflags & VPO_UNMANAGED) == 0) {
482 		flags |= PTE_MANAGED;
483 
484 		/* Create and insert pv entry. */
485 		pv_insert(pmap, va, m);
486 	}
487 
488 	pmap->pm_stats.resident_count++;
489 
490 	pte_tmp = PTE_RPN_FROM_PA(VM_PAGE_TO_PHYS(m));
491 	pte_tmp |= (PTE_VALID | flags);
492 
493 	mtx_lock_spin(&tlbivax_mutex);
494 	tlb_miss_lock();
495 
496 	tlb0_flush_entry(va);
497 	*pte = pte_tmp;
498 
499 	tlb_miss_unlock();
500 	mtx_unlock_spin(&tlbivax_mutex);
501 
502 	return (0);
503 }
504 
505 /* Return the pa for the given pmap/va. */
506 static	vm_paddr_t
507 pte_vatopa(pmap_t pmap, vm_offset_t va)
508 {
509 	vm_paddr_t	pa = 0;
510 	pte_t          *pte;
511 
512 	pte = pte_find(pmap, va);
513 	if ((pte != NULL) && PTE_ISVALID(pte))
514 		pa = (PTE_PA(pte) | (va & PTE_PA_MASK));
515 	return (pa);
516 }
517 
518 /* allocate pte entries to manage (addr & mask) to (addr & mask) + size */
519 static void
520 kernel_pte_alloc(vm_offset_t data_end, vm_offset_t addr)
521 {
522 	pte_t		*pte;
523 	vm_size_t	kva_size;
524 	int		kernel_pdirs, kernel_pgtbls, pdir_l1s;
525 	vm_offset_t	va, l1_va, pdir_va, ptbl_va;
526 	int		i, j, k;
527 
528 	kva_size = VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS;
529 	kernel_pmap->pm_root = kernel_ptbl_root;
530 	pdir_l1s = howmany(kva_size, PG_ROOT_SIZE);
531 	kernel_pdirs = howmany(kva_size, PDIR_L1_SIZE);
532 	kernel_pgtbls = howmany(kva_size, PDIR_SIZE);
533 
534 	/* Initialize kernel pdir */
535 	l1_va = (vm_offset_t)kernel_ptbl_root +
536 	    round_page(PG_ROOT_NENTRIES * sizeof(pte_t ***));
537 	pdir_va = l1_va + pdir_l1s * PAGE_SIZE;
538 	ptbl_va = pdir_va + kernel_pdirs * PAGE_SIZE;
539 	if (bootverbose) {
540 		printf("ptbl_root_va: %#lx\n", (vm_offset_t)kernel_ptbl_root);
541 		printf("l1_va: %#lx (%d entries)\n", l1_va, pdir_l1s);
542 		printf("pdir_va: %#lx(%d entries)\n", pdir_va, kernel_pdirs);
543 		printf("ptbl_va: %#lx(%d entries)\n", ptbl_va, kernel_pgtbls);
544 	}
545 
546 	va = VM_MIN_KERNEL_ADDRESS;
547 	for (i = PG_ROOT_IDX(va); i < PG_ROOT_IDX(va) + pdir_l1s;
548 	    i++, l1_va += PAGE_SIZE) {
549 		kernel_pmap->pm_root[i] = (pte_t ***)l1_va;
550 		for (j = 0;
551 		    j < PDIR_L1_NENTRIES && va < VM_MAX_KERNEL_ADDRESS;
552 		    j++, pdir_va += PAGE_SIZE) {
553 			kernel_pmap->pm_root[i][j] = (pte_t **)pdir_va;
554 			for (k = 0;
555 			    k < PDIR_NENTRIES && va < VM_MAX_KERNEL_ADDRESS;
556 			    k++, va += PDIR_SIZE, ptbl_va += PAGE_SIZE)
557 				kernel_pmap->pm_root[i][j][k] = (pte_t *)ptbl_va;
558 		}
559 	}
560 	/*
561 	 * Fill in PTEs covering kernel code and data. They are not required
562 	 * for address translation, as this area is covered by static TLB1
563 	 * entries, but for pte_vatopa() to work correctly with kernel area
564 	 * addresses.
565 	 */
566 	for (va = addr; va < data_end; va += PAGE_SIZE) {
567 		pte = &(kernel_pmap->pm_root[PG_ROOT_IDX(va)][PDIR_L1_IDX(va)][PDIR_IDX(va)][PTBL_IDX(va)]);
568 		*pte = PTE_RPN_FROM_PA(kernload + (va - kernstart));
569 		*pte |= PTE_M | PTE_SR | PTE_SW | PTE_SX | PTE_WIRED |
570 		    PTE_VALID | PTE_PS_4KB;
571 	}
572 }
573 
574 static vm_offset_t
575 mmu_booke_alloc_kernel_pgtables(vm_offset_t data_end)
576 {
577 	vm_size_t kva_size = VM_MAX_KERNEL_ADDRESS - VM_MIN_KERNEL_ADDRESS;
578 	kernel_ptbl_root = (pte_t ****)data_end;
579 
580 	data_end += round_page(PG_ROOT_NENTRIES * sizeof(pte_t ***));
581 	data_end += howmany(kva_size, PG_ROOT_SIZE) * PAGE_SIZE;
582 	data_end += howmany(kva_size, PDIR_L1_SIZE) * PAGE_SIZE;
583 	data_end += howmany(kva_size, PDIR_SIZE) * PAGE_SIZE;
584 
585 	return (data_end);
586 }
587 
588 /*
589  * Initialize a preallocated and zeroed pmap structure,
590  * such as one in a vmspace structure.
591  */
592 static int
593 mmu_booke_pinit(pmap_t pmap)
594 {
595 	int i;
596 
597 	CTR4(KTR_PMAP, "%s: pmap = %p, proc %d '%s'", __func__, pmap,
598 	    curthread->td_proc->p_pid, curthread->td_proc->p_comm);
599 
600 	KASSERT((pmap != kernel_pmap), ("pmap_pinit: initializing kernel_pmap"));
601 
602 	for (i = 0; i < MAXCPU; i++)
603 		pmap->pm_tid[i] = TID_NONE;
604 	CPU_ZERO(&kernel_pmap->pm_active);
605 	bzero(&pmap->pm_stats, sizeof(pmap->pm_stats));
606 	pmap->pm_root = uma_zalloc(ptbl_root_zone, M_WAITOK);
607 	bzero(pmap->pm_root, sizeof(pte_t **) * PG_ROOT_NENTRIES);
608 
609 	return (1);
610 }
611 
612 /*
613  * Release any resources held by the given physical map.
614  * Called when a pmap initialized by mmu_booke_pinit is being released.
615  * Should only be called if the map contains no valid mappings.
616  */
617 static void
618 mmu_booke_release(pmap_t pmap)
619 {
620 
621 	KASSERT(pmap->pm_stats.resident_count == 0,
622 	    ("pmap_release: pmap resident count %ld != 0",
623 	    pmap->pm_stats.resident_count));
624 #ifdef INVARIANTS
625 	/*
626 	 * Verify that all page directories are gone.
627 	 * Protects against reference count leakage.
628 	 */
629 	for (int i = 0; i < PG_ROOT_NENTRIES; i++)
630 		KASSERT(pmap->pm_root[i] == 0,
631 		    ("Index %d on root page %p is non-zero!\n", i, pmap->pm_root));
632 #endif
633 	uma_zfree(ptbl_root_zone, pmap->pm_root);
634 }
635 
636 static void
637 mmu_booke_sync_icache(pmap_t pm, vm_offset_t va, vm_size_t sz)
638 {
639 	pte_t *pte;
640 	vm_paddr_t pa = 0;
641 	int sync_sz, valid;
642 
643 	while (sz > 0) {
644 		PMAP_LOCK(pm);
645 		pte = pte_find(pm, va);
646 		valid = (pte != NULL && PTE_ISVALID(pte)) ? 1 : 0;
647 		if (valid)
648 			pa = PTE_PA(pte);
649 		PMAP_UNLOCK(pm);
650 		sync_sz = PAGE_SIZE - (va & PAGE_MASK);
651 		sync_sz = min(sync_sz, sz);
652 		if (valid) {
653 			pa += (va & PAGE_MASK);
654 			__syncicache((void *)PHYS_TO_DMAP(pa), sync_sz);
655 		}
656 		va += sync_sz;
657 		sz -= sync_sz;
658 	}
659 }
660 
661 /*
662  * mmu_booke_zero_page_area zeros the specified hardware page by
663  * mapping it into virtual memory and using bzero to clear
664  * its contents.
665  *
666  * off and size must reside within a single page.
667  */
668 static void
669 mmu_booke_zero_page_area(vm_page_t m, int off, int size)
670 {
671 	vm_offset_t va;
672 
673 	/* XXX KASSERT off and size are within a single page? */
674 
675 	va = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
676 	bzero((caddr_t)va + off, size);
677 }
678 
679 /*
680  * mmu_booke_zero_page zeros the specified hardware page.
681  */
682 static void
683 mmu_booke_zero_page(vm_page_t m)
684 {
685 	vm_offset_t off, va;
686 
687 	va = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m));
688 
689 	for (off = 0; off < PAGE_SIZE; off += cacheline_size)
690 		__asm __volatile("dcbz 0,%0" :: "r"(va + off));
691 }
692 
693 /*
694  * mmu_booke_copy_page copies the specified (machine independent) page by
695  * mapping the page into virtual memory and using memcopy to copy the page,
696  * one machine dependent page at a time.
697  */
698 static void
699 mmu_booke_copy_page(vm_page_t sm, vm_page_t dm)
700 {
701 	vm_offset_t sva, dva;
702 
703 	sva = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(sm));
704 	dva = PHYS_TO_DMAP(VM_PAGE_TO_PHYS(dm));
705 	memcpy((caddr_t)dva, (caddr_t)sva, PAGE_SIZE);
706 }
707 
708 static inline void
709 mmu_booke_copy_pages(vm_page_t *ma, vm_offset_t a_offset,
710     vm_page_t *mb, vm_offset_t b_offset, int xfersize)
711 {
712 	void *a_cp, *b_cp;
713 	vm_offset_t a_pg_offset, b_pg_offset;
714 	int cnt;
715 
716 	vm_page_t pa, pb;
717 
718 	while (xfersize > 0) {
719 		a_pg_offset = a_offset & PAGE_MASK;
720 		pa = ma[a_offset >> PAGE_SHIFT];
721 		b_pg_offset = b_offset & PAGE_MASK;
722 		pb = mb[b_offset >> PAGE_SHIFT];
723 		cnt = min(xfersize, PAGE_SIZE - a_pg_offset);
724 		cnt = min(cnt, PAGE_SIZE - b_pg_offset);
725 		a_cp = (caddr_t)((uintptr_t)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(pa)) +
726 		    a_pg_offset);
727 		b_cp = (caddr_t)((uintptr_t)PHYS_TO_DMAP(VM_PAGE_TO_PHYS(pb)) +
728 		    b_pg_offset);
729 		bcopy(a_cp, b_cp, cnt);
730 		a_offset += cnt;
731 		b_offset += cnt;
732 		xfersize -= cnt;
733 	}
734 }
735 
736 static vm_offset_t
737 mmu_booke_quick_enter_page(vm_page_t m)
738 {
739 	return (PHYS_TO_DMAP(VM_PAGE_TO_PHYS(m)));
740 }
741 
742 static void
743 mmu_booke_quick_remove_page(vm_offset_t addr)
744 {
745 }
746 
747 /**************************************************************************/
748 /* TID handling */
749 /**************************************************************************/
750 
751 /*
752  * Return the largest uint value log such that 2^log <= num.
753  */
754 static unsigned long
755 ilog2(unsigned long num)
756 {
757 	long lz;
758 
759 	__asm ("cntlzd %0, %1" : "=r" (lz) : "r" (num));
760 	return (63 - lz);
761 }
762 
763 /*
764  * Invalidate all TLB0 entries which match the given TID. Note this is
765  * dedicated for cases when invalidations should NOT be propagated to other
766  * CPUs.
767  */
768 static void
769 tid_flush(tlbtid_t tid)
770 {
771 	register_t msr;
772 
773 	/* Don't evict kernel translations */
774 	if (tid == TID_KERNEL)
775 		return;
776 
777 	msr = mfmsr();
778 	__asm __volatile("wrteei 0");
779 
780 	/*
781 	 * Newer (e500mc and later) have tlbilx, which doesn't broadcast, so use
782 	 * it for PID invalidation.
783 	 */
784 	mtspr(SPR_MAS6, tid << MAS6_SPID0_SHIFT);
785 	__asm __volatile("isync; .long 0x7c200024; isync; msync");
786 
787 	__asm __volatile("wrtee %0" :: "r"(msr));
788 }
789