xref: /freebsd/sys/powerpc/aim/moea64_native.c (revision d9f0ce31900a48d1a2bfc1c8c86f79d1e831451a)
1 /*-
2  * Copyright (c) 2001 The NetBSD Foundation, Inc.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to The NetBSD Foundation
6  * by Matt Thomas <matt@3am-software.com> of Allegro Networks, Inc.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 /*-
30  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
31  * Copyright (C) 1995, 1996 TooLs GmbH.
32  * All rights reserved.
33  *
34  * Redistribution and use in source and binary forms, with or without
35  * modification, are permitted provided that the following conditions
36  * are met:
37  * 1. Redistributions of source code must retain the above copyright
38  *    notice, this list of conditions and the following disclaimer.
39  * 2. Redistributions in binary form must reproduce the above copyright
40  *    notice, this list of conditions and the following disclaimer in the
41  *    documentation and/or other materials provided with the distribution.
42  * 3. All advertising materials mentioning features or use of this software
43  *    must display the following acknowledgement:
44  *	This product includes software developed by TooLs GmbH.
45  * 4. The name of TooLs GmbH may not be used to endorse or promote products
46  *    derived from this software without specific prior written permission.
47  *
48  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
49  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
50  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
51  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
52  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
53  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
54  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
55  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
56  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
57  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
58  *
59  * $NetBSD: pmap.c,v 1.28 2000/03/26 20:42:36 kleink Exp $
60  */
61 /*-
62  * Copyright (C) 2001 Benno Rice.
63  * All rights reserved.
64  *
65  * Redistribution and use in source and binary forms, with or without
66  * modification, are permitted provided that the following conditions
67  * are met:
68  * 1. Redistributions of source code must retain the above copyright
69  *    notice, this list of conditions and the following disclaimer.
70  * 2. Redistributions in binary form must reproduce the above copyright
71  *    notice, this list of conditions and the following disclaimer in the
72  *    documentation and/or other materials provided with the distribution.
73  *
74  * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
75  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
76  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
77  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
78  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
79  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
80  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
81  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
82  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
83  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
84  */
85 
86 #include <sys/cdefs.h>
87 __FBSDID("$FreeBSD$");
88 
89 /*
90  * Native 64-bit page table operations for running without a hypervisor.
91  */
92 
93 #include <sys/param.h>
94 #include <sys/kernel.h>
95 #include <sys/ktr.h>
96 #include <sys/lock.h>
97 #include <sys/mutex.h>
98 #include <sys/proc.h>
99 #include <sys/sched.h>
100 #include <sys/sysctl.h>
101 #include <sys/systm.h>
102 #include <sys/rwlock.h>
103 #include <sys/endian.h>
104 
105 #include <sys/kdb.h>
106 
107 #include <vm/vm.h>
108 #include <vm/vm_param.h>
109 #include <vm/vm_kern.h>
110 #include <vm/vm_page.h>
111 #include <vm/vm_map.h>
112 #include <vm/vm_object.h>
113 #include <vm/vm_extern.h>
114 #include <vm/vm_pageout.h>
115 
116 #include <machine/md_var.h>
117 #include <machine/mmuvar.h>
118 
119 #include "mmu_oea64.h"
120 #include "mmu_if.h"
121 #include "moea64_if.h"
122 
123 #define	PTESYNC()	__asm __volatile("ptesync");
124 #define	TLBSYNC()	__asm __volatile("tlbsync; ptesync");
125 #define	SYNC()		__asm __volatile("sync");
126 #define	EIEIO()		__asm __volatile("eieio");
127 
128 #define	VSID_HASH_MASK	0x0000007fffffffffULL
129 
130 static __inline void
131 TLBIE(uint64_t vpn) {
132 #ifndef __powerpc64__
133 	register_t vpn_hi, vpn_lo;
134 	register_t msr;
135 	register_t scratch, intr;
136 #endif
137 
138 	static volatile u_int tlbie_lock = 0;
139 
140 	vpn <<= ADDR_PIDX_SHFT;
141 	vpn &= ~(0xffffULL << 48);
142 
143 	/* Hobo spinlock: we need stronger guarantees than mutexes provide */
144 	while (!atomic_cmpset_int(&tlbie_lock, 0, 1));
145 	isync(); /* Flush instruction queue once lock acquired */
146 
147 #ifdef __powerpc64__
148 	__asm __volatile("tlbie %0" :: "r"(vpn) : "memory");
149 	__asm __volatile("eieio; tlbsync; ptesync" ::: "memory");
150 #else
151 	vpn_hi = (uint32_t)(vpn >> 32);
152 	vpn_lo = (uint32_t)vpn;
153 
154 	intr = intr_disable();
155 	__asm __volatile("\
156 	    mfmsr %0; \
157 	    mr %1, %0; \
158 	    insrdi %1,%5,1,0; \
159 	    mtmsrd %1; isync; \
160 	    \
161 	    sld %1,%2,%4; \
162 	    or %1,%1,%3; \
163 	    tlbie %1; \
164 	    \
165 	    mtmsrd %0; isync; \
166 	    eieio; \
167 	    tlbsync; \
168 	    ptesync;"
169 	: "=r"(msr), "=r"(scratch) : "r"(vpn_hi), "r"(vpn_lo), "r"(32), "r"(1)
170 	    : "memory");
171 	intr_restore(intr);
172 #endif
173 
174 	/* No barriers or special ops -- taken care of by ptesync above */
175 	tlbie_lock = 0;
176 }
177 
178 #define DISABLE_TRANS(msr)	msr = mfmsr(); mtmsr(msr & ~PSL_DR)
179 #define ENABLE_TRANS(msr)	mtmsr(msr)
180 
181 /*
182  * PTEG data.
183  */
184 static volatile struct lpte *moea64_pteg_table;
185 static struct rwlock moea64_eviction_lock;
186 
187 /*
188  * PTE calls.
189  */
190 static int	moea64_pte_insert_native(mmu_t, struct pvo_entry *);
191 static int64_t	moea64_pte_synch_native(mmu_t, struct pvo_entry *);
192 static int64_t	moea64_pte_clear_native(mmu_t, struct pvo_entry *, uint64_t);
193 static int64_t	moea64_pte_replace_native(mmu_t, struct pvo_entry *, int);
194 static int64_t	moea64_pte_unset_native(mmu_t mmu, struct pvo_entry *);
195 
196 /*
197  * Utility routines.
198  */
199 static void	moea64_bootstrap_native(mmu_t mmup,
200 		    vm_offset_t kernelstart, vm_offset_t kernelend);
201 static void	moea64_cpu_bootstrap_native(mmu_t, int ap);
202 static void	tlbia(void);
203 
204 static mmu_method_t moea64_native_methods[] = {
205 	/* Internal interfaces */
206 	MMUMETHOD(mmu_bootstrap,	moea64_bootstrap_native),
207 	MMUMETHOD(mmu_cpu_bootstrap,	moea64_cpu_bootstrap_native),
208 
209 	MMUMETHOD(moea64_pte_synch,	moea64_pte_synch_native),
210 	MMUMETHOD(moea64_pte_clear,	moea64_pte_clear_native),
211 	MMUMETHOD(moea64_pte_unset,	moea64_pte_unset_native),
212 	MMUMETHOD(moea64_pte_replace,	moea64_pte_replace_native),
213 	MMUMETHOD(moea64_pte_insert,	moea64_pte_insert_native),
214 
215 	{ 0, 0 }
216 };
217 
218 MMU_DEF_INHERIT(oea64_mmu_native, MMU_TYPE_G5, moea64_native_methods,
219     0, oea64_mmu);
220 
221 static int64_t
222 moea64_pte_synch_native(mmu_t mmu, struct pvo_entry *pvo)
223 {
224 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
225 	struct lpte properpt;
226 	uint64_t ptelo;
227 
228 	PMAP_LOCK_ASSERT(pvo->pvo_pmap, MA_OWNED);
229 
230 	moea64_pte_from_pvo(pvo, &properpt);
231 
232 	rw_rlock(&moea64_eviction_lock);
233 	if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
234 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
235 		/* Evicted */
236 		rw_runlock(&moea64_eviction_lock);
237 		return (-1);
238 	}
239 
240 	PTESYNC();
241 	ptelo = be64toh(pt->pte_lo);
242 
243 	rw_runlock(&moea64_eviction_lock);
244 
245 	return (ptelo & (LPTE_REF | LPTE_CHG));
246 }
247 
248 static int64_t
249 moea64_pte_clear_native(mmu_t mmu, struct pvo_entry *pvo, uint64_t ptebit)
250 {
251 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
252 	struct lpte properpt;
253 	uint64_t ptelo;
254 
255 	PMAP_LOCK_ASSERT(pvo->pvo_pmap, MA_OWNED);
256 
257 	moea64_pte_from_pvo(pvo, &properpt);
258 
259 	rw_rlock(&moea64_eviction_lock);
260 	if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
261 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
262 		/* Evicted */
263 		rw_runlock(&moea64_eviction_lock);
264 		return (-1);
265 	}
266 
267 	if (ptebit == LPTE_REF) {
268 		/* See "Resetting the Reference Bit" in arch manual */
269 		PTESYNC();
270 		/* 2-step here safe: precision is not guaranteed */
271 		ptelo = be64toh(pt->pte_lo);
272 
273 		/* One-byte store to avoid touching the C bit */
274 		((volatile uint8_t *)(&pt->pte_lo))[6] =
275 #if BYTE_ORDER == BIG_ENDIAN
276 		    ((uint8_t *)(&properpt.pte_lo))[6];
277 #else
278 		    ((uint8_t *)(&properpt.pte_lo))[1];
279 #endif
280 		rw_runlock(&moea64_eviction_lock);
281 
282 		critical_enter();
283 		TLBIE(pvo->pvo_vpn);
284 		critical_exit();
285 	} else {
286 		rw_runlock(&moea64_eviction_lock);
287 		ptelo = moea64_pte_unset_native(mmu, pvo);
288 		moea64_pte_insert_native(mmu, pvo);
289 	}
290 
291 	return (ptelo & (LPTE_REF | LPTE_CHG));
292 }
293 
294 static int64_t
295 moea64_pte_unset_native(mmu_t mmu, struct pvo_entry *pvo)
296 {
297 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
298 	struct lpte properpt;
299 	uint64_t ptelo;
300 
301 	moea64_pte_from_pvo(pvo, &properpt);
302 
303 	rw_rlock(&moea64_eviction_lock);
304 	if ((be64toh(pt->pte_hi & LPTE_AVPN_MASK)) !=
305 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
306 		/* Evicted */
307 		moea64_pte_overflow--;
308 		rw_runlock(&moea64_eviction_lock);
309 		return (-1);
310 	}
311 
312 	/*
313 	 * Invalidate the pte, briefly locking it to collect RC bits. No
314 	 * atomics needed since this is protected against eviction by the lock.
315 	 */
316 	isync();
317 	critical_enter();
318 	pt->pte_hi = be64toh((pt->pte_hi & ~LPTE_VALID) | LPTE_LOCKED);
319 	PTESYNC();
320 	TLBIE(pvo->pvo_vpn);
321 	ptelo = be64toh(pt->pte_lo);
322 	*((volatile int32_t *)(&pt->pte_hi) + 1) = 0; /* Release lock */
323 	critical_exit();
324 	rw_runlock(&moea64_eviction_lock);
325 
326 	/* Keep statistics */
327 	moea64_pte_valid--;
328 
329 	return (ptelo & (LPTE_CHG | LPTE_REF));
330 }
331 
332 static int64_t
333 moea64_pte_replace_native(mmu_t mmu, struct pvo_entry *pvo, int flags)
334 {
335 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
336 	struct lpte properpt;
337 	int64_t ptelo;
338 
339 	if (flags == 0) {
340 		/* Just some software bits changing. */
341 		moea64_pte_from_pvo(pvo, &properpt);
342 
343 		rw_rlock(&moea64_eviction_lock);
344 		if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
345 		    (properpt.pte_hi & LPTE_AVPN_MASK)) {
346 			rw_runlock(&moea64_eviction_lock);
347 			return (-1);
348 		}
349 		pt->pte_hi = htobe64(properpt.pte_hi);
350 		ptelo = be64toh(pt->pte_lo);
351 		rw_runlock(&moea64_eviction_lock);
352 	} else {
353 		/* Otherwise, need reinsertion and deletion */
354 		ptelo = moea64_pte_unset_native(mmu, pvo);
355 		moea64_pte_insert_native(mmu, pvo);
356 	}
357 
358 	return (ptelo);
359 }
360 
361 static void
362 moea64_cpu_bootstrap_native(mmu_t mmup, int ap)
363 {
364 	int i = 0;
365 	#ifdef __powerpc64__
366 	struct slb *slb = PCPU_GET(slb);
367 	register_t seg0;
368 	#endif
369 
370 	/*
371 	 * Initialize segment registers and MMU
372 	 */
373 
374 	mtmsr(mfmsr() & ~PSL_DR & ~PSL_IR);
375 
376 	/*
377 	 * Install kernel SLB entries
378 	 */
379 
380 	#ifdef __powerpc64__
381 		__asm __volatile ("slbia");
382 		__asm __volatile ("slbmfee %0,%1; slbie %0;" : "=r"(seg0) :
383 		    "r"(0));
384 
385 		for (i = 0; i < 64; i++) {
386 			if (!(slb[i].slbe & SLBE_VALID))
387 				continue;
388 
389 			__asm __volatile ("slbmte %0, %1" ::
390 			    "r"(slb[i].slbv), "r"(slb[i].slbe));
391 		}
392 	#else
393 		for (i = 0; i < 16; i++)
394 			mtsrin(i << ADDR_SR_SHFT, kernel_pmap->pm_sr[i]);
395 	#endif
396 
397 	/*
398 	 * Install page table
399 	 */
400 
401 	__asm __volatile ("ptesync; mtsdr1 %0; isync"
402 	    :: "r"((uintptr_t)moea64_pteg_table
403 		     | (uintptr_t)(flsl(moea64_pteg_mask >> 11))));
404 	tlbia();
405 }
406 
407 static void
408 moea64_bootstrap_native(mmu_t mmup, vm_offset_t kernelstart,
409     vm_offset_t kernelend)
410 {
411 	vm_size_t	size;
412 	vm_offset_t	off;
413 	vm_paddr_t	pa;
414 	register_t	msr;
415 
416 	moea64_early_bootstrap(mmup, kernelstart, kernelend);
417 
418 	/*
419 	 * Allocate PTEG table.
420 	 */
421 
422 	size = moea64_pteg_count * sizeof(struct lpteg);
423 	CTR2(KTR_PMAP, "moea64_bootstrap: %d PTEGs, %d bytes",
424 	    moea64_pteg_count, size);
425 	rw_init(&moea64_eviction_lock, "pte eviction");
426 
427 	/*
428 	 * We now need to allocate memory. This memory, to be allocated,
429 	 * has to reside in a page table. The page table we are about to
430 	 * allocate. We don't have BAT. So drop to data real mode for a minute
431 	 * as a measure of last resort. We do this a couple times.
432 	 */
433 
434 	moea64_pteg_table = (struct lpte *)moea64_bootstrap_alloc(size, size);
435 	DISABLE_TRANS(msr);
436 	bzero(__DEVOLATILE(void *, moea64_pteg_table), moea64_pteg_count *
437 	    sizeof(struct lpteg));
438 	ENABLE_TRANS(msr);
439 
440 	CTR1(KTR_PMAP, "moea64_bootstrap: PTEG table at %p", moea64_pteg_table);
441 
442 	moea64_mid_bootstrap(mmup, kernelstart, kernelend);
443 
444 	/*
445 	 * Add a mapping for the page table itself if there is no direct map.
446 	 */
447 	if (!hw_direct_map) {
448 		size = moea64_pteg_count * sizeof(struct lpteg);
449 		off = (vm_offset_t)(moea64_pteg_table);
450 		DISABLE_TRANS(msr);
451 		for (pa = off; pa < off + size; pa += PAGE_SIZE)
452 			pmap_kenter(pa, pa);
453 		ENABLE_TRANS(msr);
454 	}
455 
456 	/* Bring up virtual memory */
457 	moea64_late_bootstrap(mmup, kernelstart, kernelend);
458 }
459 
460 static void
461 tlbia(void)
462 {
463 	vm_offset_t i;
464 	#ifndef __powerpc64__
465 	register_t msr, scratch;
466 	#endif
467 
468 	TLBSYNC();
469 
470 	for (i = 0; i < 0xFF000; i += 0x00001000) {
471 		#ifdef __powerpc64__
472 		__asm __volatile("tlbiel %0" :: "r"(i));
473 		#else
474 		__asm __volatile("\
475 		    mfmsr %0; \
476 		    mr %1, %0; \
477 		    insrdi %1,%3,1,0; \
478 		    mtmsrd %1; \
479 		    isync; \
480 		    \
481 		    tlbiel %2; \
482 		    \
483 		    mtmsrd %0; \
484 		    isync;"
485 		: "=r"(msr), "=r"(scratch) : "r"(i), "r"(1));
486 		#endif
487 	}
488 
489 	EIEIO();
490 	TLBSYNC();
491 }
492 
493 static int
494 atomic_pte_lock(volatile struct lpte *pte, uint64_t bitmask, uint64_t *oldhi)
495 {
496 	int	ret;
497 	uint32_t oldhihalf;
498 
499 	/*
500 	 * Note: in principle, if just the locked bit were set here, we
501 	 * could avoid needing the eviction lock. However, eviction occurs
502 	 * so rarely that it isn't worth bothering about in practice.
503 	 */
504 
505 	__asm __volatile (
506 		"1:\tlwarx %1, 0, %3\n\t"	/* load old value */
507 		"and. %0,%1,%4\n\t"		/* check if any bits set */
508 		"bne 2f\n\t"			/* exit if any set */
509 		"stwcx. %5, 0, %3\n\t"      	/* attempt to store */
510 		"bne- 1b\n\t"			/* spin if failed */
511 		"li %0, 1\n\t"			/* success - retval = 1 */
512 		"b 3f\n\t"			/* we've succeeded */
513 		"2:\n\t"
514 		"stwcx. %1, 0, %3\n\t"       	/* clear reservation (74xx) */
515 		"li %0, 0\n\t"			/* failure - retval = 0 */
516 		"3:\n\t"
517 		: "=&r" (ret), "=&r"(oldhihalf), "=m" (pte->pte_hi)
518 		: "r" ((volatile char *)&pte->pte_hi + 4),
519 		  "r" ((uint32_t)bitmask), "r" ((uint32_t)LPTE_LOCKED),
520 		  "m" (pte->pte_hi)
521 		: "cr0", "cr1", "cr2", "memory");
522 
523 	*oldhi = (pte->pte_hi & 0xffffffff00000000ULL) | oldhihalf;
524 
525 	return (ret);
526 }
527 
528 static uintptr_t
529 moea64_insert_to_pteg_native(struct lpte *pvo_pt, uintptr_t slotbase,
530     uint64_t mask)
531 {
532 	volatile struct lpte *pt;
533 	uint64_t oldptehi, va;
534 	uintptr_t k;
535 	int i, j;
536 
537 	/* Start at a random slot */
538 	i = mftb() % 8;
539 	for (j = 0; j < 8; j++) {
540 		k = slotbase + (i + j) % 8;
541 		pt = &moea64_pteg_table[k];
542 		/* Invalidate and seize lock only if no bits in mask set */
543 		if (atomic_pte_lock(pt, mask, &oldptehi)) /* Lock obtained */
544 			break;
545 	}
546 
547 	if (j == 8)
548 		return (-1);
549 
550 	if (oldptehi & LPTE_VALID) {
551 		KASSERT(!(oldptehi & LPTE_WIRED), ("Unmapped wired entry"));
552 		/*
553 		 * Need to invalidate old entry completely: see
554 		 * "Modifying a Page Table Entry". Need to reconstruct
555 		 * the virtual address for the outgoing entry to do that.
556 		 */
557 		if (oldptehi & LPTE_BIG)
558 			va = oldptehi >> moea64_large_page_shift;
559 		else
560 			va = oldptehi >> ADDR_PIDX_SHFT;
561 		if (oldptehi & LPTE_HID)
562 			va = (((k >> 3) ^ moea64_pteg_mask) ^ va) &
563 			    VSID_HASH_MASK;
564 		else
565 			va = ((k >> 3) ^ va) & VSID_HASH_MASK;
566 		va |= (oldptehi & LPTE_AVPN_MASK) <<
567 		    (ADDR_API_SHFT64 - ADDR_PIDX_SHFT);
568 		PTESYNC();
569 		TLBIE(va);
570 		moea64_pte_valid--;
571 		moea64_pte_overflow++;
572 	}
573 
574 	/*
575 	 * Update the PTE as per "Adding a Page Table Entry". Lock is released
576 	 * by setting the high doubleworld.
577 	 */
578 	pt->pte_lo = htobe64(pvo_pt->pte_lo);
579 	EIEIO();
580 	pt->pte_hi = htobe64(pvo_pt->pte_hi);
581 	PTESYNC();
582 
583 	/* Keep statistics */
584 	moea64_pte_valid++;
585 
586 	return (k);
587 }
588 
589 static int
590 moea64_pte_insert_native(mmu_t mmu, struct pvo_entry *pvo)
591 {
592 	struct lpte insertpt;
593 	uintptr_t slot;
594 
595 	/* Initialize PTE */
596 	moea64_pte_from_pvo(pvo, &insertpt);
597 
598 	/* Make sure further insertion is locked out during evictions */
599 	rw_rlock(&moea64_eviction_lock);
600 
601 	/*
602 	 * First try primary hash.
603 	 */
604 	pvo->pvo_pte.slot &= ~7ULL; /* Base slot address */
605 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
606 	    LPTE_VALID | LPTE_WIRED | LPTE_LOCKED);
607 	if (slot != -1) {
608 		rw_runlock(&moea64_eviction_lock);
609 		pvo->pvo_pte.slot = slot;
610 		return (0);
611 	}
612 
613 	/*
614 	 * Now try secondary hash.
615 	 */
616 	pvo->pvo_vaddr ^= PVO_HID;
617 	insertpt.pte_hi ^= LPTE_HID;
618 	pvo->pvo_pte.slot ^= (moea64_pteg_mask << 3);
619 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
620 	    LPTE_VALID | LPTE_WIRED | LPTE_LOCKED);
621 	if (slot != -1) {
622 		rw_runlock(&moea64_eviction_lock);
623 		pvo->pvo_pte.slot = slot;
624 		return (0);
625 	}
626 
627 	/*
628 	 * Out of luck. Find a PTE to sacrifice.
629 	 */
630 
631 	/* Lock out all insertions for a bit */
632 	if (!rw_try_upgrade(&moea64_eviction_lock)) {
633 		rw_runlock(&moea64_eviction_lock);
634 		rw_wlock(&moea64_eviction_lock);
635 	}
636 
637 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
638 	    LPTE_WIRED | LPTE_LOCKED);
639 	if (slot != -1) {
640 		rw_wunlock(&moea64_eviction_lock);
641 		pvo->pvo_pte.slot = slot;
642 		return (0);
643 	}
644 
645 	/* Try other hash table. Now we're getting desperate... */
646 	pvo->pvo_vaddr ^= PVO_HID;
647 	insertpt.pte_hi ^= LPTE_HID;
648 	pvo->pvo_pte.slot ^= (moea64_pteg_mask << 3);
649 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
650 	    LPTE_WIRED | LPTE_LOCKED);
651 	if (slot != -1) {
652 		rw_wunlock(&moea64_eviction_lock);
653 		pvo->pvo_pte.slot = slot;
654 		return (0);
655 	}
656 
657 	/* No freeable slots in either PTEG? We're hosed. */
658 	rw_wunlock(&moea64_eviction_lock);
659 	panic("moea64_pte_insert: overflow");
660 	return (-1);
661 }
662 
663