xref: /freebsd/sys/powerpc/aim/moea64_native.c (revision 47dd1d1b619cc035b82b49a91a25544309ff95ae)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD AND 4-Clause-BSD
3  *
4  * Copyright (c) 2001 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas <matt@3am-software.com> of Allegro Networks, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*-
32  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
33  * Copyright (C) 1995, 1996 TooLs GmbH.
34  * All rights reserved.
35  *
36  * Redistribution and use in source and binary forms, with or without
37  * modification, are permitted provided that the following conditions
38  * are met:
39  * 1. Redistributions of source code must retain the above copyright
40  *    notice, this list of conditions and the following disclaimer.
41  * 2. Redistributions in binary form must reproduce the above copyright
42  *    notice, this list of conditions and the following disclaimer in the
43  *    documentation and/or other materials provided with the distribution.
44  * 3. All advertising materials mentioning features or use of this software
45  *    must display the following acknowledgement:
46  *	This product includes software developed by TooLs GmbH.
47  * 4. The name of TooLs GmbH may not be used to endorse or promote products
48  *    derived from this software without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
51  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
52  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
53  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
54  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
55  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
56  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
57  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
58  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
59  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
60  *
61  * $NetBSD: pmap.c,v 1.28 2000/03/26 20:42:36 kleink Exp $
62  */
63 /*-
64  * Copyright (C) 2001 Benno Rice.
65  * All rights reserved.
66  *
67  * Redistribution and use in source and binary forms, with or without
68  * modification, are permitted provided that the following conditions
69  * are met:
70  * 1. Redistributions of source code must retain the above copyright
71  *    notice, this list of conditions and the following disclaimer.
72  * 2. Redistributions in binary form must reproduce the above copyright
73  *    notice, this list of conditions and the following disclaimer in the
74  *    documentation and/or other materials provided with the distribution.
75  *
76  * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
77  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
78  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
79  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
80  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
81  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
82  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
83  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
84  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
85  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
86  */
87 
88 #include <sys/cdefs.h>
89 __FBSDID("$FreeBSD$");
90 
91 /*
92  * Native 64-bit page table operations for running without a hypervisor.
93  */
94 
95 #include <sys/param.h>
96 #include <sys/kernel.h>
97 #include <sys/ktr.h>
98 #include <sys/lock.h>
99 #include <sys/mutex.h>
100 #include <sys/proc.h>
101 #include <sys/sched.h>
102 #include <sys/sysctl.h>
103 #include <sys/systm.h>
104 #include <sys/rwlock.h>
105 #include <sys/endian.h>
106 
107 #include <sys/kdb.h>
108 
109 #include <vm/vm.h>
110 #include <vm/vm_param.h>
111 #include <vm/vm_kern.h>
112 #include <vm/vm_page.h>
113 #include <vm/vm_map.h>
114 #include <vm/vm_object.h>
115 #include <vm/vm_extern.h>
116 #include <vm/vm_pageout.h>
117 
118 #include <machine/cpu.h>
119 #include <machine/md_var.h>
120 #include <machine/mmuvar.h>
121 
122 #include "mmu_oea64.h"
123 #include "mmu_if.h"
124 #include "moea64_if.h"
125 
126 #define	PTESYNC()	__asm __volatile("ptesync");
127 #define	TLBSYNC()	__asm __volatile("tlbsync; ptesync");
128 #define	SYNC()		__asm __volatile("sync");
129 #define	EIEIO()		__asm __volatile("eieio");
130 
131 #define	VSID_HASH_MASK	0x0000007fffffffffULL
132 
133 /* POWER9 only permits a 64k partition table size. */
134 #define	PART_SIZE	0x10000
135 
136 static __inline void
137 TLBIE(uint64_t vpn) {
138 #ifndef __powerpc64__
139 	register_t vpn_hi, vpn_lo;
140 	register_t msr;
141 	register_t scratch, intr;
142 #endif
143 
144 	static volatile u_int tlbie_lock = 0;
145 
146 	vpn <<= ADDR_PIDX_SHFT;
147 	vpn &= ~(0xffffULL << 48);
148 
149 	/* Hobo spinlock: we need stronger guarantees than mutexes provide */
150 	while (!atomic_cmpset_int(&tlbie_lock, 0, 1));
151 	isync(); /* Flush instruction queue once lock acquired */
152 
153 #ifdef __powerpc64__
154 	__asm __volatile("tlbie %0" :: "r"(vpn) : "memory");
155 	__asm __volatile("eieio; tlbsync; ptesync" ::: "memory");
156 #else
157 	vpn_hi = (uint32_t)(vpn >> 32);
158 	vpn_lo = (uint32_t)vpn;
159 
160 	intr = intr_disable();
161 	__asm __volatile("\
162 	    mfmsr %0; \
163 	    mr %1, %0; \
164 	    insrdi %1,%5,1,0; \
165 	    mtmsrd %1; isync; \
166 	    \
167 	    sld %1,%2,%4; \
168 	    or %1,%1,%3; \
169 	    tlbie %1; \
170 	    \
171 	    mtmsrd %0; isync; \
172 	    eieio; \
173 	    tlbsync; \
174 	    ptesync;"
175 	: "=r"(msr), "=r"(scratch) : "r"(vpn_hi), "r"(vpn_lo), "r"(32), "r"(1)
176 	    : "memory");
177 	intr_restore(intr);
178 #endif
179 
180 	/* No barriers or special ops -- taken care of by ptesync above */
181 	tlbie_lock = 0;
182 }
183 
184 #define DISABLE_TRANS(msr)	msr = mfmsr(); mtmsr(msr & ~PSL_DR)
185 #define ENABLE_TRANS(msr)	mtmsr(msr)
186 
187 /*
188  * PTEG data.
189  */
190 static volatile struct pate *moea64_part_table;
191 static volatile struct lpte *moea64_pteg_table;
192 static struct rwlock moea64_eviction_lock;
193 
194 /*
195  * PTE calls.
196  */
197 static int	moea64_pte_insert_native(mmu_t, struct pvo_entry *);
198 static int64_t	moea64_pte_synch_native(mmu_t, struct pvo_entry *);
199 static int64_t	moea64_pte_clear_native(mmu_t, struct pvo_entry *, uint64_t);
200 static int64_t	moea64_pte_replace_native(mmu_t, struct pvo_entry *, int);
201 static int64_t	moea64_pte_unset_native(mmu_t mmu, struct pvo_entry *);
202 
203 /*
204  * Utility routines.
205  */
206 static void	moea64_bootstrap_native(mmu_t mmup,
207 		    vm_offset_t kernelstart, vm_offset_t kernelend);
208 static void	moea64_cpu_bootstrap_native(mmu_t, int ap);
209 static void	tlbia(void);
210 
211 static mmu_method_t moea64_native_methods[] = {
212 	/* Internal interfaces */
213 	MMUMETHOD(mmu_bootstrap,	moea64_bootstrap_native),
214 	MMUMETHOD(mmu_cpu_bootstrap,	moea64_cpu_bootstrap_native),
215 
216 	MMUMETHOD(moea64_pte_synch,	moea64_pte_synch_native),
217 	MMUMETHOD(moea64_pte_clear,	moea64_pte_clear_native),
218 	MMUMETHOD(moea64_pte_unset,	moea64_pte_unset_native),
219 	MMUMETHOD(moea64_pte_replace,	moea64_pte_replace_native),
220 	MMUMETHOD(moea64_pte_insert,	moea64_pte_insert_native),
221 
222 	{ 0, 0 }
223 };
224 
225 MMU_DEF_INHERIT(oea64_mmu_native, MMU_TYPE_G5, moea64_native_methods,
226     0, oea64_mmu);
227 
228 static int64_t
229 moea64_pte_synch_native(mmu_t mmu, struct pvo_entry *pvo)
230 {
231 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
232 	struct lpte properpt;
233 	uint64_t ptelo;
234 
235 	PMAP_LOCK_ASSERT(pvo->pvo_pmap, MA_OWNED);
236 
237 	moea64_pte_from_pvo(pvo, &properpt);
238 
239 	rw_rlock(&moea64_eviction_lock);
240 	if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
241 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
242 		/* Evicted */
243 		rw_runlock(&moea64_eviction_lock);
244 		return (-1);
245 	}
246 
247 	PTESYNC();
248 	ptelo = be64toh(pt->pte_lo);
249 
250 	rw_runlock(&moea64_eviction_lock);
251 
252 	return (ptelo & (LPTE_REF | LPTE_CHG));
253 }
254 
255 static int64_t
256 moea64_pte_clear_native(mmu_t mmu, struct pvo_entry *pvo, uint64_t ptebit)
257 {
258 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
259 	struct lpte properpt;
260 	uint64_t ptelo;
261 
262 	PMAP_LOCK_ASSERT(pvo->pvo_pmap, MA_OWNED);
263 
264 	moea64_pte_from_pvo(pvo, &properpt);
265 
266 	rw_rlock(&moea64_eviction_lock);
267 	if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
268 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
269 		/* Evicted */
270 		rw_runlock(&moea64_eviction_lock);
271 		return (-1);
272 	}
273 
274 	if (ptebit == LPTE_REF) {
275 		/* See "Resetting the Reference Bit" in arch manual */
276 		PTESYNC();
277 		/* 2-step here safe: precision is not guaranteed */
278 		ptelo = be64toh(pt->pte_lo);
279 
280 		/* One-byte store to avoid touching the C bit */
281 		((volatile uint8_t *)(&pt->pte_lo))[6] =
282 #if BYTE_ORDER == BIG_ENDIAN
283 		    ((uint8_t *)(&properpt.pte_lo))[6];
284 #else
285 		    ((uint8_t *)(&properpt.pte_lo))[1];
286 #endif
287 		rw_runlock(&moea64_eviction_lock);
288 
289 		critical_enter();
290 		TLBIE(pvo->pvo_vpn);
291 		critical_exit();
292 	} else {
293 		rw_runlock(&moea64_eviction_lock);
294 		ptelo = moea64_pte_unset_native(mmu, pvo);
295 		moea64_pte_insert_native(mmu, pvo);
296 	}
297 
298 	return (ptelo & (LPTE_REF | LPTE_CHG));
299 }
300 
301 static int64_t
302 moea64_pte_unset_native(mmu_t mmu, struct pvo_entry *pvo)
303 {
304 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
305 	struct lpte properpt;
306 	uint64_t ptelo;
307 
308 	moea64_pte_from_pvo(pvo, &properpt);
309 
310 	rw_rlock(&moea64_eviction_lock);
311 	if ((be64toh(pt->pte_hi & LPTE_AVPN_MASK)) !=
312 	    (properpt.pte_hi & LPTE_AVPN_MASK)) {
313 		/* Evicted */
314 		moea64_pte_overflow--;
315 		rw_runlock(&moea64_eviction_lock);
316 		return (-1);
317 	}
318 
319 	/*
320 	 * Invalidate the pte, briefly locking it to collect RC bits. No
321 	 * atomics needed since this is protected against eviction by the lock.
322 	 */
323 	isync();
324 	critical_enter();
325 	pt->pte_hi = be64toh((pt->pte_hi & ~LPTE_VALID) | LPTE_LOCKED);
326 	PTESYNC();
327 	TLBIE(pvo->pvo_vpn);
328 	ptelo = be64toh(pt->pte_lo);
329 	*((volatile int32_t *)(&pt->pte_hi) + 1) = 0; /* Release lock */
330 	critical_exit();
331 	rw_runlock(&moea64_eviction_lock);
332 
333 	/* Keep statistics */
334 	moea64_pte_valid--;
335 
336 	return (ptelo & (LPTE_CHG | LPTE_REF));
337 }
338 
339 static int64_t
340 moea64_pte_replace_native(mmu_t mmu, struct pvo_entry *pvo, int flags)
341 {
342 	volatile struct lpte *pt = moea64_pteg_table + pvo->pvo_pte.slot;
343 	struct lpte properpt;
344 	int64_t ptelo;
345 
346 	if (flags == 0) {
347 		/* Just some software bits changing. */
348 		moea64_pte_from_pvo(pvo, &properpt);
349 
350 		rw_rlock(&moea64_eviction_lock);
351 		if ((be64toh(pt->pte_hi) & LPTE_AVPN_MASK) !=
352 		    (properpt.pte_hi & LPTE_AVPN_MASK)) {
353 			rw_runlock(&moea64_eviction_lock);
354 			return (-1);
355 		}
356 		pt->pte_hi = htobe64(properpt.pte_hi);
357 		ptelo = be64toh(pt->pte_lo);
358 		rw_runlock(&moea64_eviction_lock);
359 	} else {
360 		/* Otherwise, need reinsertion and deletion */
361 		ptelo = moea64_pte_unset_native(mmu, pvo);
362 		moea64_pte_insert_native(mmu, pvo);
363 	}
364 
365 	return (ptelo);
366 }
367 
368 static void
369 moea64_cpu_bootstrap_native(mmu_t mmup, int ap)
370 {
371 	int i = 0;
372 	#ifdef __powerpc64__
373 	struct slb *slb = PCPU_GET(aim.slb);
374 	register_t seg0;
375 	#endif
376 
377 	/*
378 	 * Initialize segment registers and MMU
379 	 */
380 
381 	mtmsr(mfmsr() & ~PSL_DR & ~PSL_IR);
382 
383 	/*
384 	 * Install kernel SLB entries
385 	 */
386 
387 	#ifdef __powerpc64__
388 		__asm __volatile ("slbia");
389 		__asm __volatile ("slbmfee %0,%1; slbie %0;" : "=r"(seg0) :
390 		    "r"(0));
391 
392 		for (i = 0; i < n_slbs; i++) {
393 			if (!(slb[i].slbe & SLBE_VALID))
394 				continue;
395 
396 			__asm __volatile ("slbmte %0, %1" ::
397 			    "r"(slb[i].slbv), "r"(slb[i].slbe));
398 		}
399 	#else
400 		for (i = 0; i < 16; i++)
401 			mtsrin(i << ADDR_SR_SHFT, kernel_pmap->pm_sr[i]);
402 	#endif
403 
404 	/*
405 	 * Install page table
406 	 */
407 
408 	if (cpu_features2 & PPC_FEATURE2_ARCH_3_00) {
409 		mtspr(SPR_PTCR,
410 		    ((uintptr_t)moea64_part_table & ~DMAP_BASE_ADDRESS) |
411 		     flsl((PART_SIZE >> 12) - 1));
412 	} else {
413 		__asm __volatile ("ptesync; mtsdr1 %0; isync"
414 		    :: "r"(((uintptr_t)moea64_pteg_table & ~DMAP_BASE_ADDRESS)
415 			     | (uintptr_t)(flsl(moea64_pteg_mask >> 11))));
416 	}
417 	tlbia();
418 }
419 
420 static void
421 moea64_bootstrap_native(mmu_t mmup, vm_offset_t kernelstart,
422     vm_offset_t kernelend)
423 {
424 	vm_size_t	size;
425 	vm_offset_t	off;
426 	vm_paddr_t	pa;
427 	register_t	msr;
428 
429 	moea64_early_bootstrap(mmup, kernelstart, kernelend);
430 
431 	/*
432 	 * Allocate PTEG table.
433 	 */
434 
435 	size = moea64_pteg_count * sizeof(struct lpteg);
436 	CTR2(KTR_PMAP, "moea64_bootstrap: %d PTEGs, %d bytes",
437 	    moea64_pteg_count, size);
438 	rw_init(&moea64_eviction_lock, "pte eviction");
439 
440 	/*
441 	 * We now need to allocate memory. This memory, to be allocated,
442 	 * has to reside in a page table. The page table we are about to
443 	 * allocate. We don't have BAT. So drop to data real mode for a minute
444 	 * as a measure of last resort. We do this a couple times.
445 	 */
446 
447 	if (cpu_features2 & PPC_FEATURE2_ARCH_3_00) {
448 		moea64_part_table =
449 		    (struct pate *)moea64_bootstrap_alloc(PART_SIZE, PART_SIZE);
450 		if (hw_direct_map)
451 			moea64_part_table =
452 			    (struct pate *)PHYS_TO_DMAP((vm_offset_t)moea64_part_table);
453 	}
454 	/*
455 	 * PTEG table must be aligned on a 256k boundary, but can be placed
456 	 * anywhere with that alignment.
457 	 */
458 	moea64_pteg_table = (struct lpte *)moea64_bootstrap_alloc(size, 256*1024);
459 	if (hw_direct_map)
460 		moea64_pteg_table =
461 		    (struct lpte *)PHYS_TO_DMAP((vm_offset_t)moea64_pteg_table);
462 	DISABLE_TRANS(msr);
463 	if (cpu_features2 & PPC_FEATURE2_ARCH_3_00) {
464 		bzero(__DEVOLATILE(void *, moea64_part_table), PART_SIZE);
465 		moea64_part_table[0].pagetab =
466 		    ((uintptr_t)moea64_pteg_table & ~DMAP_BASE_ADDRESS) |
467 		    (uintptr_t)(flsl((moea64_pteg_count - 1) >> 11));
468 	}
469 	bzero(__DEVOLATILE(void *, moea64_pteg_table), moea64_pteg_count *
470 	    sizeof(struct lpteg));
471 	ENABLE_TRANS(msr);
472 
473 	CTR1(KTR_PMAP, "moea64_bootstrap: PTEG table at %p", moea64_pteg_table);
474 
475 	moea64_mid_bootstrap(mmup, kernelstart, kernelend);
476 
477 	/*
478 	 * Add a mapping for the page table itself if there is no direct map.
479 	 */
480 	if (!hw_direct_map) {
481 		size = moea64_pteg_count * sizeof(struct lpteg);
482 		off = (vm_offset_t)(moea64_pteg_table);
483 		DISABLE_TRANS(msr);
484 		for (pa = off; pa < off + size; pa += PAGE_SIZE)
485 			pmap_kenter(pa, pa);
486 		ENABLE_TRANS(msr);
487 	}
488 
489 	/* Bring up virtual memory */
490 	moea64_late_bootstrap(mmup, kernelstart, kernelend);
491 }
492 
493 static void
494 tlbia(void)
495 {
496 	vm_offset_t i;
497 	#ifndef __powerpc64__
498 	register_t msr, scratch;
499 	#endif
500 
501 	i = 0xc00; /* IS = 11 */
502 	switch (mfpvr() >> 16) {
503 	case IBM970:
504 	case IBM970FX:
505 	case IBM970MP:
506 	case IBM970GX:
507 	case IBMPOWER4:
508 	case IBMPOWER4PLUS:
509 	case IBMPOWER5:
510 	case IBMPOWER5PLUS:
511 		i = 0; /* IS not supported */
512 		break;
513 	}
514 
515 	TLBSYNC();
516 
517 	for (; i < 0x200000; i += 0x00001000) {
518 		#ifdef __powerpc64__
519 		__asm __volatile("tlbiel %0" :: "r"(i));
520 		#else
521 		__asm __volatile("\
522 		    mfmsr %0; \
523 		    mr %1, %0; \
524 		    insrdi %1,%3,1,0; \
525 		    mtmsrd %1; \
526 		    isync; \
527 		    \
528 		    tlbiel %2; \
529 		    \
530 		    mtmsrd %0; \
531 		    isync;"
532 		: "=r"(msr), "=r"(scratch) : "r"(i), "r"(1));
533 		#endif
534 	}
535 
536 	EIEIO();
537 	TLBSYNC();
538 }
539 
540 static int
541 atomic_pte_lock(volatile struct lpte *pte, uint64_t bitmask, uint64_t *oldhi)
542 {
543 	int	ret;
544 	uint32_t oldhihalf;
545 
546 	/*
547 	 * Note: in principle, if just the locked bit were set here, we
548 	 * could avoid needing the eviction lock. However, eviction occurs
549 	 * so rarely that it isn't worth bothering about in practice.
550 	 */
551 
552 	__asm __volatile (
553 		"1:\tlwarx %1, 0, %3\n\t"	/* load old value */
554 		"and. %0,%1,%4\n\t"		/* check if any bits set */
555 		"bne 2f\n\t"			/* exit if any set */
556 		"stwcx. %5, 0, %3\n\t"      	/* attempt to store */
557 		"bne- 1b\n\t"			/* spin if failed */
558 		"li %0, 1\n\t"			/* success - retval = 1 */
559 		"b 3f\n\t"			/* we've succeeded */
560 		"2:\n\t"
561 		"stwcx. %1, 0, %3\n\t"       	/* clear reservation (74xx) */
562 		"li %0, 0\n\t"			/* failure - retval = 0 */
563 		"3:\n\t"
564 		: "=&r" (ret), "=&r"(oldhihalf), "=m" (pte->pte_hi)
565 		: "r" ((volatile char *)&pte->pte_hi + 4),
566 		  "r" ((uint32_t)bitmask), "r" ((uint32_t)LPTE_LOCKED),
567 		  "m" (pte->pte_hi)
568 		: "cr0", "cr1", "cr2", "memory");
569 
570 	*oldhi = (pte->pte_hi & 0xffffffff00000000ULL) | oldhihalf;
571 
572 	return (ret);
573 }
574 
575 static uintptr_t
576 moea64_insert_to_pteg_native(struct lpte *pvo_pt, uintptr_t slotbase,
577     uint64_t mask)
578 {
579 	volatile struct lpte *pt;
580 	uint64_t oldptehi, va;
581 	uintptr_t k;
582 	int i, j;
583 
584 	/* Start at a random slot */
585 	i = mftb() % 8;
586 	for (j = 0; j < 8; j++) {
587 		k = slotbase + (i + j) % 8;
588 		pt = &moea64_pteg_table[k];
589 		/* Invalidate and seize lock only if no bits in mask set */
590 		if (atomic_pte_lock(pt, mask, &oldptehi)) /* Lock obtained */
591 			break;
592 	}
593 
594 	if (j == 8)
595 		return (-1);
596 
597 	if (oldptehi & LPTE_VALID) {
598 		KASSERT(!(oldptehi & LPTE_WIRED), ("Unmapped wired entry"));
599 		/*
600 		 * Need to invalidate old entry completely: see
601 		 * "Modifying a Page Table Entry". Need to reconstruct
602 		 * the virtual address for the outgoing entry to do that.
603 		 */
604 		if (oldptehi & LPTE_BIG)
605 			va = oldptehi >> moea64_large_page_shift;
606 		else
607 			va = oldptehi >> ADDR_PIDX_SHFT;
608 		if (oldptehi & LPTE_HID)
609 			va = (((k >> 3) ^ moea64_pteg_mask) ^ va) &
610 			    VSID_HASH_MASK;
611 		else
612 			va = ((k >> 3) ^ va) & VSID_HASH_MASK;
613 		va |= (oldptehi & LPTE_AVPN_MASK) <<
614 		    (ADDR_API_SHFT64 - ADDR_PIDX_SHFT);
615 		PTESYNC();
616 		TLBIE(va);
617 		moea64_pte_valid--;
618 		moea64_pte_overflow++;
619 	}
620 
621 	/*
622 	 * Update the PTE as per "Adding a Page Table Entry". Lock is released
623 	 * by setting the high doubleworld.
624 	 */
625 	pt->pte_lo = htobe64(pvo_pt->pte_lo);
626 	EIEIO();
627 	pt->pte_hi = htobe64(pvo_pt->pte_hi);
628 	PTESYNC();
629 
630 	/* Keep statistics */
631 	moea64_pte_valid++;
632 
633 	return (k);
634 }
635 
636 static int
637 moea64_pte_insert_native(mmu_t mmu, struct pvo_entry *pvo)
638 {
639 	struct lpte insertpt;
640 	uintptr_t slot;
641 
642 	/* Initialize PTE */
643 	moea64_pte_from_pvo(pvo, &insertpt);
644 
645 	/* Make sure further insertion is locked out during evictions */
646 	rw_rlock(&moea64_eviction_lock);
647 
648 	/*
649 	 * First try primary hash.
650 	 */
651 	pvo->pvo_pte.slot &= ~7ULL; /* Base slot address */
652 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
653 	    LPTE_VALID | LPTE_WIRED | LPTE_LOCKED);
654 	if (slot != -1) {
655 		rw_runlock(&moea64_eviction_lock);
656 		pvo->pvo_pte.slot = slot;
657 		return (0);
658 	}
659 
660 	/*
661 	 * Now try secondary hash.
662 	 */
663 	pvo->pvo_vaddr ^= PVO_HID;
664 	insertpt.pte_hi ^= LPTE_HID;
665 	pvo->pvo_pte.slot ^= (moea64_pteg_mask << 3);
666 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
667 	    LPTE_VALID | LPTE_WIRED | LPTE_LOCKED);
668 	if (slot != -1) {
669 		rw_runlock(&moea64_eviction_lock);
670 		pvo->pvo_pte.slot = slot;
671 		return (0);
672 	}
673 
674 	/*
675 	 * Out of luck. Find a PTE to sacrifice.
676 	 */
677 
678 	/* Lock out all insertions for a bit */
679 	if (!rw_try_upgrade(&moea64_eviction_lock)) {
680 		rw_runlock(&moea64_eviction_lock);
681 		rw_wlock(&moea64_eviction_lock);
682 	}
683 
684 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
685 	    LPTE_WIRED | LPTE_LOCKED);
686 	if (slot != -1) {
687 		rw_wunlock(&moea64_eviction_lock);
688 		pvo->pvo_pte.slot = slot;
689 		return (0);
690 	}
691 
692 	/* Try other hash table. Now we're getting desperate... */
693 	pvo->pvo_vaddr ^= PVO_HID;
694 	insertpt.pte_hi ^= LPTE_HID;
695 	pvo->pvo_pte.slot ^= (moea64_pteg_mask << 3);
696 	slot = moea64_insert_to_pteg_native(&insertpt, pvo->pvo_pte.slot,
697 	    LPTE_WIRED | LPTE_LOCKED);
698 	if (slot != -1) {
699 		rw_wunlock(&moea64_eviction_lock);
700 		pvo->pvo_pte.slot = slot;
701 		return (0);
702 	}
703 
704 	/* No freeable slots in either PTEG? We're hosed. */
705 	rw_wunlock(&moea64_eviction_lock);
706 	panic("moea64_pte_insert: overflow");
707 	return (-1);
708 }
709 
710