1/*-
2 * Copyright (c) 1999 Michael Smith <msmith@freebsd.org>
3 * Copyright (c) 2017 The FreeBSD Foundation
4 * All rights reserved.
5 *
6 * Portions of this software were developed by Konstantin Belousov
7 * under sponsorship from the FreeBSD Foundation.
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 AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD: stable/11/sys/x86/x86/x86_mem.c 314591 2017-03-03 10:30:30Z kib $");
33
34#include <sys/param.h>
35#include <sys/kernel.h>
36#include <sys/systm.h>
37#include <sys/malloc.h>
38#include <sys/memrange.h>
39#include <sys/smp.h>
40#include <sys/sysctl.h>
41
42#include <vm/vm.h>
43#include <vm/vm_param.h>
44#include <vm/pmap.h>
45
46#include <machine/cputypes.h>
47#include <machine/md_var.h>
48#include <machine/specialreg.h>
49
50/*
51 * Pentium Pro+ memory range operations
52 *
53 * This code will probably be impenetrable without reference to the
54 * Intel Pentium Pro documentation or x86-64 programmers manual vol 2.
55 */
56
57static char *mem_owner_bios = "BIOS";
58
59#define	MR686_FIXMTRR	(1<<0)
60
61#define	mrwithin(mr, a)							\
62	(((a) >= (mr)->mr_base) && ((a) < ((mr)->mr_base + (mr)->mr_len)))
63#define	mroverlap(mra, mrb)						\
64	(mrwithin(mra, mrb->mr_base) || mrwithin(mrb, mra->mr_base))
65
66#define	mrvalid(base, len) 						\
67	((!(base & ((1 << 12) - 1))) &&	/* base is multiple of 4k */	\
68	    ((len) >= (1 << 12)) &&	/* length is >= 4k */		\
69	    powerof2((len)) &&		/* ... and power of two */	\
70	    !((base) & ((len) - 1)))	/* range is not discontiuous */
71
72#define	mrcopyflags(curr, new)						\
73	(((curr) & ~MDF_ATTRMASK) | ((new) & MDF_ATTRMASK))
74
75static int mtrrs_disabled;
76SYSCTL_INT(_machdep, OID_AUTO, disable_mtrrs, CTLFLAG_RDTUN,
77    &mtrrs_disabled, 0,
78    "Disable MTRRs.");
79
80static void	x86_mrinit(struct mem_range_softc *sc);
81static int	x86_mrset(struct mem_range_softc *sc,
82		    struct mem_range_desc *mrd, int *arg);
83static void	x86_mrAPinit(struct mem_range_softc *sc);
84static void	x86_mrreinit(struct mem_range_softc *sc);
85
86static struct mem_range_ops x86_mrops = {
87	x86_mrinit,
88	x86_mrset,
89	x86_mrAPinit,
90	x86_mrreinit
91};
92
93/* XXX for AP startup hook */
94static u_int64_t mtrrcap, mtrrdef;
95
96/* The bitmask for the PhysBase and PhysMask fields of the variable MTRRs. */
97static u_int64_t mtrr_physmask;
98
99static struct mem_range_desc *mem_range_match(struct mem_range_softc *sc,
100		    struct mem_range_desc *mrd);
101static void	x86_mrfetch(struct mem_range_softc *sc);
102static int	x86_mtrrtype(int flags);
103static int	x86_mrt2mtrr(int flags, int oldval);
104static int	x86_mtrrconflict(int flag1, int flag2);
105static void	x86_mrstore(struct mem_range_softc *sc);
106static void	x86_mrstoreone(void *arg);
107static struct mem_range_desc *x86_mtrrfixsearch(struct mem_range_softc *sc,
108		    u_int64_t addr);
109static int	x86_mrsetlow(struct mem_range_softc *sc,
110		    struct mem_range_desc *mrd, int *arg);
111static int	x86_mrsetvariable(struct mem_range_softc *sc,
112		    struct mem_range_desc *mrd, int *arg);
113
114/* ia32 MTRR type to memory range type conversion */
115static int x86_mtrrtomrt[] = {
116	MDF_UNCACHEABLE,
117	MDF_WRITECOMBINE,
118	MDF_UNKNOWN,
119	MDF_UNKNOWN,
120	MDF_WRITETHROUGH,
121	MDF_WRITEPROTECT,
122	MDF_WRITEBACK
123};
124
125#define	MTRRTOMRTLEN nitems(x86_mtrrtomrt)
126
127static int
128x86_mtrr2mrt(int val)
129{
130
131	if (val < 0 || val >= MTRRTOMRTLEN)
132		return (MDF_UNKNOWN);
133	return (x86_mtrrtomrt[val]);
134}
135
136/*
137 * x86 MTRR conflicts. Writeback and uncachable may overlap.
138 */
139static int
140x86_mtrrconflict(int flag1, int flag2)
141{
142
143	flag1 &= MDF_ATTRMASK;
144	flag2 &= MDF_ATTRMASK;
145	if ((flag1 & MDF_UNKNOWN) || (flag2 & MDF_UNKNOWN))
146		return (1);
147	if (flag1 == flag2 ||
148	    (flag1 == MDF_WRITEBACK && flag2 == MDF_UNCACHEABLE) ||
149	    (flag2 == MDF_WRITEBACK && flag1 == MDF_UNCACHEABLE))
150		return (0);
151	return (1);
152}
153
154/*
155 * Look for an exactly-matching range.
156 */
157static struct mem_range_desc *
158mem_range_match(struct mem_range_softc *sc, struct mem_range_desc *mrd)
159{
160	struct mem_range_desc *cand;
161	int i;
162
163	for (i = 0, cand = sc->mr_desc; i < sc->mr_ndesc; i++, cand++)
164		if ((cand->mr_base == mrd->mr_base) &&
165		    (cand->mr_len == mrd->mr_len))
166			return (cand);
167	return (NULL);
168}
169
170/*
171 * Ensure that the direct map region does not contain any mappings
172 * that span MTRRs of different types.  However, the fixed MTRRs can
173 * be ignored, because a large page mapping the first 1 MB of physical
174 * memory is a special case that the processor handles.  Invalidate
175 * any old TLB entries that might hold inconsistent memory type
176 * information.
177 */
178static void
179x86_mr_split_dmap(struct mem_range_softc *sc __unused)
180{
181#ifdef __amd64__
182	struct mem_range_desc *mrd;
183	int i;
184
185	i = (sc->mr_cap & MR686_FIXMTRR) ? MTRR_N64K + MTRR_N16K + MTRR_N4K : 0;
186	mrd = sc->mr_desc + i;
187	for (; i < sc->mr_ndesc; i++, mrd++) {
188		if ((mrd->mr_flags & (MDF_ACTIVE | MDF_BOGUS)) == MDF_ACTIVE)
189			pmap_demote_DMAP(mrd->mr_base, mrd->mr_len, TRUE);
190	}
191#endif
192}
193
194/*
195 * Fetch the current mtrr settings from the current CPU (assumed to
196 * all be in sync in the SMP case).  Note that if we are here, we
197 * assume that MTRRs are enabled, and we may or may not have fixed
198 * MTRRs.
199 */
200static void
201x86_mrfetch(struct mem_range_softc *sc)
202{
203	struct mem_range_desc *mrd;
204	u_int64_t msrv;
205	int i, j, msr;
206
207	mrd = sc->mr_desc;
208
209	/* Get fixed-range MTRRs. */
210	if (sc->mr_cap & MR686_FIXMTRR) {
211		msr = MSR_MTRR64kBase;
212		for (i = 0; i < (MTRR_N64K / 8); i++, msr++) {
213			msrv = rdmsr(msr);
214			for (j = 0; j < 8; j++, mrd++) {
215				mrd->mr_flags =
216				    (mrd->mr_flags & ~MDF_ATTRMASK) |
217				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
218				if (mrd->mr_owner[0] == 0)
219					strcpy(mrd->mr_owner, mem_owner_bios);
220				msrv = msrv >> 8;
221			}
222		}
223		msr = MSR_MTRR16kBase;
224		for (i = 0; i < MTRR_N16K / 8; i++, msr++) {
225			msrv = rdmsr(msr);
226			for (j = 0; j < 8; j++, mrd++) {
227				mrd->mr_flags =
228				    (mrd->mr_flags & ~MDF_ATTRMASK) |
229				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
230				if (mrd->mr_owner[0] == 0)
231					strcpy(mrd->mr_owner, mem_owner_bios);
232				msrv = msrv >> 8;
233			}
234		}
235		msr = MSR_MTRR4kBase;
236		for (i = 0; i < MTRR_N4K / 8; i++, msr++) {
237			msrv = rdmsr(msr);
238			for (j = 0; j < 8; j++, mrd++) {
239				mrd->mr_flags =
240				    (mrd->mr_flags & ~MDF_ATTRMASK) |
241				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
242				if (mrd->mr_owner[0] == 0)
243					strcpy(mrd->mr_owner, mem_owner_bios);
244				msrv = msrv >> 8;
245			}
246		}
247	}
248
249	/* Get remainder which must be variable MTRRs. */
250	msr = MSR_MTRRVarBase;
251	for (; mrd - sc->mr_desc < sc->mr_ndesc; msr += 2, mrd++) {
252		msrv = rdmsr(msr);
253		mrd->mr_flags = (mrd->mr_flags & ~MDF_ATTRMASK) |
254		    x86_mtrr2mrt(msrv & MTRR_PHYSBASE_TYPE);
255		mrd->mr_base = msrv & mtrr_physmask;
256		msrv = rdmsr(msr + 1);
257		mrd->mr_flags = (msrv & MTRR_PHYSMASK_VALID) ?
258		    (mrd->mr_flags | MDF_ACTIVE) :
259		    (mrd->mr_flags & ~MDF_ACTIVE);
260
261		/* Compute the range from the mask. Ick. */
262		mrd->mr_len = (~(msrv & mtrr_physmask) &
263		    (mtrr_physmask | 0xfff)) + 1;
264		if (!mrvalid(mrd->mr_base, mrd->mr_len))
265			mrd->mr_flags |= MDF_BOGUS;
266
267		/* If unclaimed and active, must be the BIOS. */
268		if ((mrd->mr_flags & MDF_ACTIVE) && (mrd->mr_owner[0] == 0))
269			strcpy(mrd->mr_owner, mem_owner_bios);
270	}
271}
272
273/*
274 * Return the MTRR memory type matching a region's flags
275 */
276static int
277x86_mtrrtype(int flags)
278{
279	int i;
280
281	flags &= MDF_ATTRMASK;
282
283	for (i = 0; i < MTRRTOMRTLEN; i++) {
284		if (x86_mtrrtomrt[i] == MDF_UNKNOWN)
285			continue;
286		if (flags == x86_mtrrtomrt[i])
287			return (i);
288	}
289	return (-1);
290}
291
292static int
293x86_mrt2mtrr(int flags, int oldval)
294{
295	int val;
296
297	if ((val = x86_mtrrtype(flags)) == -1)
298		return (oldval & 0xff);
299	return (val & 0xff);
300}
301
302/*
303 * Update running CPU(s) MTRRs to match the ranges in the descriptor
304 * list.
305 *
306 * Must be called with interrupts enabled.
307 */
308static void
309x86_mrstore(struct mem_range_softc *sc)
310{
311
312	smp_rendezvous(NULL, x86_mrstoreone, NULL, sc);
313}
314
315/*
316 * Update the current CPU's MTRRs with those represented in the
317 * descriptor list.  Note that we do this wholesale rather than just
318 * stuffing one entry; this is simpler (but slower, of course).
319 */
320static void
321x86_mrstoreone(void *arg)
322{
323	struct mem_range_softc *sc = arg;
324	struct mem_range_desc *mrd;
325	u_int64_t omsrv, msrv;
326	int i, j, msr;
327	u_long cr0, cr4;
328
329	mrd = sc->mr_desc;
330
331	critical_enter();
332
333	/* Disable PGE. */
334	cr4 = rcr4();
335	load_cr4(cr4 & ~CR4_PGE);
336
337	/* Disable caches (CD = 1, NW = 0). */
338	cr0 = rcr0();
339	load_cr0((cr0 & ~CR0_NW) | CR0_CD);
340
341	/* Flushes caches and TLBs. */
342	wbinvd();
343	invltlb();
344
345	/* Disable MTRRs (E = 0). */
346	wrmsr(MSR_MTRRdefType, rdmsr(MSR_MTRRdefType) & ~MTRR_DEF_ENABLE);
347
348	/* Set fixed-range MTRRs. */
349	if (sc->mr_cap & MR686_FIXMTRR) {
350		msr = MSR_MTRR64kBase;
351		for (i = 0; i < MTRR_N64K / 8; i++, msr++) {
352			msrv = 0;
353			omsrv = rdmsr(msr);
354			for (j = 7; j >= 0; j--) {
355				msrv = msrv << 8;
356				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
357				    omsrv >> (j * 8));
358			}
359			wrmsr(msr, msrv);
360			mrd += 8;
361		}
362		msr = MSR_MTRR16kBase;
363		for (i = 0; i < MTRR_N16K / 8; i++, msr++) {
364			msrv = 0;
365			omsrv = rdmsr(msr);
366			for (j = 7; j >= 0; j--) {
367				msrv = msrv << 8;
368				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
369				    omsrv >> (j * 8));
370			}
371			wrmsr(msr, msrv);
372			mrd += 8;
373		}
374		msr = MSR_MTRR4kBase;
375		for (i = 0; i < MTRR_N4K / 8; i++, msr++) {
376			msrv = 0;
377			omsrv = rdmsr(msr);
378			for (j = 7; j >= 0; j--) {
379				msrv = msrv << 8;
380				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
381				    omsrv >> (j * 8));
382			}
383			wrmsr(msr, msrv);
384			mrd += 8;
385		}
386	}
387
388	/* Set remainder which must be variable MTRRs. */
389	msr = MSR_MTRRVarBase;
390	for (; mrd - sc->mr_desc < sc->mr_ndesc; msr += 2, mrd++) {
391		/* base/type register */
392		omsrv = rdmsr(msr);
393		if (mrd->mr_flags & MDF_ACTIVE) {
394			msrv = mrd->mr_base & mtrr_physmask;
395			msrv |= x86_mrt2mtrr(mrd->mr_flags, omsrv);
396		} else {
397			msrv = 0;
398		}
399		wrmsr(msr, msrv);
400
401		/* mask/active register */
402		if (mrd->mr_flags & MDF_ACTIVE) {
403			msrv = MTRR_PHYSMASK_VALID |
404			    rounddown2(mtrr_physmask, mrd->mr_len);
405		} else {
406			msrv = 0;
407		}
408		wrmsr(msr + 1, msrv);
409	}
410
411	/* Flush caches and TLBs. */
412	wbinvd();
413	invltlb();
414
415	/* Enable MTRRs. */
416	wrmsr(MSR_MTRRdefType, rdmsr(MSR_MTRRdefType) | MTRR_DEF_ENABLE);
417
418	/* Restore caches and PGE. */
419	load_cr0(cr0);
420	load_cr4(cr4);
421
422	critical_exit();
423}
424
425/*
426 * Hunt for the fixed MTRR referencing (addr)
427 */
428static struct mem_range_desc *
429x86_mtrrfixsearch(struct mem_range_softc *sc, u_int64_t addr)
430{
431	struct mem_range_desc *mrd;
432	int i;
433
434	for (i = 0, mrd = sc->mr_desc; i < MTRR_N64K + MTRR_N16K + MTRR_N4K;
435	     i++, mrd++)
436		if (addr >= mrd->mr_base &&
437		    addr < mrd->mr_base + mrd->mr_len)
438			return (mrd);
439	return (NULL);
440}
441
442/*
443 * Try to satisfy the given range request by manipulating the fixed
444 * MTRRs that cover low memory.
445 *
446 * Note that we try to be generous here; we'll bloat the range out to
447 * the next higher/lower boundary to avoid the consumer having to know
448 * too much about the mechanisms here.
449 *
450 * XXX note that this will have to be updated when we start supporting
451 * "busy" ranges.
452 */
453static int
454x86_mrsetlow(struct mem_range_softc *sc, struct mem_range_desc *mrd, int *arg)
455{
456	struct mem_range_desc *first_md, *last_md, *curr_md;
457
458	/* Range check. */
459	if ((first_md = x86_mtrrfixsearch(sc, mrd->mr_base)) == NULL ||
460	    (last_md = x86_mtrrfixsearch(sc, mrd->mr_base + mrd->mr_len - 1))
461	    == NULL)
462		return (EINVAL);
463
464	/* Check that we aren't doing something risky. */
465	if ((mrd->mr_flags & MDF_FORCE) == 0) {
466		for (curr_md = first_md; curr_md <= last_md; curr_md++) {
467			if ((curr_md->mr_flags & MDF_ATTRMASK) == MDF_UNKNOWN)
468				return (EACCES);
469		}
470	}
471
472	/* Set flags, clear set-by-firmware flag. */
473	for (curr_md = first_md; curr_md <= last_md; curr_md++) {
474		curr_md->mr_flags = mrcopyflags(curr_md->mr_flags &
475		    ~MDF_FIRMWARE, mrd->mr_flags);
476		bcopy(mrd->mr_owner, curr_md->mr_owner, sizeof(mrd->mr_owner));
477	}
478
479	return (0);
480}
481
482/*
483 * Modify/add a variable MTRR to satisfy the request.
484 *
485 * XXX needs to be updated to properly support "busy" ranges.
486 */
487static int
488x86_mrsetvariable(struct mem_range_softc *sc, struct mem_range_desc *mrd,
489    int *arg)
490{
491	struct mem_range_desc *curr_md, *free_md;
492	int i;
493
494	/*
495	 * Scan the currently active variable descriptors, look for
496	 * one we exactly match (straight takeover) and for possible
497	 * accidental overlaps.
498	 *
499	 * Keep track of the first empty variable descriptor in case
500	 * we can't perform a takeover.
501	 */
502	i = (sc->mr_cap & MR686_FIXMTRR) ? MTRR_N64K + MTRR_N16K + MTRR_N4K : 0;
503	curr_md = sc->mr_desc + i;
504	free_md = NULL;
505	for (; i < sc->mr_ndesc; i++, curr_md++) {
506		if (curr_md->mr_flags & MDF_ACTIVE) {
507			/* Exact match? */
508			if (curr_md->mr_base == mrd->mr_base &&
509			    curr_md->mr_len == mrd->mr_len) {
510
511				/* Whoops, owned by someone. */
512				if (curr_md->mr_flags & MDF_BUSY)
513					return (EBUSY);
514
515				/* Check that we aren't doing something risky */
516				if (!(mrd->mr_flags & MDF_FORCE) &&
517				    (curr_md->mr_flags & MDF_ATTRMASK) ==
518				    MDF_UNKNOWN)
519					return (EACCES);
520
521				/* Ok, just hijack this entry. */
522				free_md = curr_md;
523				break;
524			}
525
526			/* Non-exact overlap? */
527			if (mroverlap(curr_md, mrd)) {
528				/* Between conflicting region types? */
529				if (x86_mtrrconflict(curr_md->mr_flags,
530				    mrd->mr_flags))
531					return (EINVAL);
532			}
533		} else if (free_md == NULL) {
534			free_md = curr_md;
535		}
536	}
537
538	/* Got somewhere to put it? */
539	if (free_md == NULL)
540		return (ENOSPC);
541
542	/* Set up new descriptor. */
543	free_md->mr_base = mrd->mr_base;
544	free_md->mr_len = mrd->mr_len;
545	free_md->mr_flags = mrcopyflags(MDF_ACTIVE, mrd->mr_flags);
546	bcopy(mrd->mr_owner, free_md->mr_owner, sizeof(mrd->mr_owner));
547	return (0);
548}
549
550/*
551 * Handle requests to set memory range attributes by manipulating MTRRs.
552 */
553static int
554x86_mrset(struct mem_range_softc *sc, struct mem_range_desc *mrd, int *arg)
555{
556	struct mem_range_desc *targ;
557	int error;
558
559	switch (*arg) {
560	case MEMRANGE_SET_UPDATE:
561		/*
562		 * Make sure that what's being asked for is even
563		 * possible at all.
564		 */
565		if (!mrvalid(mrd->mr_base, mrd->mr_len) ||
566		    x86_mtrrtype(mrd->mr_flags) == -1)
567			return (EINVAL);
568
569#define	FIXTOP	\
570    ((MTRR_N64K * 0x10000) + (MTRR_N16K * 0x4000) + (MTRR_N4K * 0x1000))
571
572		/* Are the "low memory" conditions applicable? */
573		if ((sc->mr_cap & MR686_FIXMTRR) != 0 &&
574		    mrd->mr_base + mrd->mr_len <= FIXTOP) {
575			if ((error = x86_mrsetlow(sc, mrd, arg)) != 0)
576				return (error);
577		} else {
578			/* It's time to play with variable MTRRs. */
579			if ((error = x86_mrsetvariable(sc, mrd, arg)) != 0)
580				return (error);
581		}
582		break;
583
584	case MEMRANGE_SET_REMOVE:
585		if ((targ = mem_range_match(sc, mrd)) == NULL)
586			return (ENOENT);
587		if (targ->mr_flags & MDF_FIXACTIVE)
588			return (EPERM);
589		if (targ->mr_flags & MDF_BUSY)
590			return (EBUSY);
591		targ->mr_flags &= ~MDF_ACTIVE;
592		targ->mr_owner[0] = 0;
593		break;
594
595	default:
596		return (EOPNOTSUPP);
597	}
598
599	x86_mr_split_dmap(sc);
600
601	/* Update the hardware. */
602	x86_mrstore(sc);
603
604	/* Refetch to see where we're at. */
605	x86_mrfetch(sc);
606	return (0);
607}
608
609/*
610 * Work out how many ranges we support, initialise storage for them,
611 * and fetch the initial settings.
612 */
613static void
614x86_mrinit(struct mem_range_softc *sc)
615{
616	struct mem_range_desc *mrd;
617	int i, nmdesc;
618
619	if (sc->mr_desc != NULL)
620		/* Already initialized. */
621		return;
622
623	nmdesc = 0;
624	mtrrcap = rdmsr(MSR_MTRRcap);
625	mtrrdef = rdmsr(MSR_MTRRdefType);
626
627	/* For now, bail out if MTRRs are not enabled. */
628	if (!(mtrrdef & MTRR_DEF_ENABLE)) {
629		if (bootverbose)
630			printf("CPU supports MTRRs but not enabled\n");
631		return;
632	}
633	nmdesc = mtrrcap & MTRR_CAP_VCNT;
634	if (bootverbose)
635		printf("Pentium Pro MTRR support enabled\n");
636
637	/*
638	 * Determine the size of the PhysMask and PhysBase fields in
639	 * the variable range MTRRs.
640	 */
641	mtrr_physmask = (((uint64_t)1 << cpu_maxphyaddr) - 1) &
642	    ~(uint64_t)0xfff;
643
644	/* If fixed MTRRs supported and enabled. */
645	if ((mtrrcap & MTRR_CAP_FIXED) && (mtrrdef & MTRR_DEF_FIXED_ENABLE)) {
646		sc->mr_cap = MR686_FIXMTRR;
647		nmdesc += MTRR_N64K + MTRR_N16K + MTRR_N4K;
648	}
649
650	sc->mr_desc = malloc(nmdesc * sizeof(struct mem_range_desc), M_MEMDESC,
651	    M_WAITOK | M_ZERO);
652	sc->mr_ndesc = nmdesc;
653
654	mrd = sc->mr_desc;
655
656	/* Populate the fixed MTRR entries' base/length. */
657	if (sc->mr_cap & MR686_FIXMTRR) {
658		for (i = 0; i < MTRR_N64K; i++, mrd++) {
659			mrd->mr_base = i * 0x10000;
660			mrd->mr_len = 0x10000;
661			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
662			    MDF_FIXACTIVE;
663		}
664		for (i = 0; i < MTRR_N16K; i++, mrd++) {
665			mrd->mr_base = i * 0x4000 + 0x80000;
666			mrd->mr_len = 0x4000;
667			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
668			    MDF_FIXACTIVE;
669		}
670		for (i = 0; i < MTRR_N4K; i++, mrd++) {
671			mrd->mr_base = i * 0x1000 + 0xc0000;
672			mrd->mr_len = 0x1000;
673			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
674			    MDF_FIXACTIVE;
675		}
676	}
677
678	/*
679	 * Get current settings, anything set now is considered to
680	 * have been set by the firmware. (XXX has something already
681	 * played here?)
682	 */
683	x86_mrfetch(sc);
684	mrd = sc->mr_desc;
685	for (i = 0; i < sc->mr_ndesc; i++, mrd++) {
686		if (mrd->mr_flags & MDF_ACTIVE)
687			mrd->mr_flags |= MDF_FIRMWARE;
688	}
689
690	x86_mr_split_dmap(sc);
691}
692
693/*
694 * Initialise MTRRs on an AP after the BSP has run the init code.
695 */
696static void
697x86_mrAPinit(struct mem_range_softc *sc)
698{
699
700	x86_mrstoreone(sc);
701	wrmsr(MSR_MTRRdefType, mtrrdef);
702}
703
704/*
705 * Re-initialise running CPU(s) MTRRs to match the ranges in the descriptor
706 * list.
707 *
708 * Must be called with interrupts enabled.
709 */
710static void
711x86_mrreinit(struct mem_range_softc *sc)
712{
713
714	smp_rendezvous(NULL, (void (*)(void *))x86_mrAPinit, NULL, sc);
715}
716
717static void
718x86_mem_drvinit(void *unused)
719{
720
721	if (mtrrs_disabled)
722		return;
723	if (!(cpu_feature & CPUID_MTRR))
724		return;
725	mem_range_softc.mr_op = &x86_mrops;
726	x86_mrinit(&mem_range_softc);
727}
728SYSINIT(x86memdev, SI_SUB_CPU, SI_ORDER_ANY, x86_mem_drvinit, NULL);
729