xref: /freebsd/sys/x86/x86/x86_mem.c (revision 9eb4e0b42d7cf490254ccd2d725f2b0f6c396831)
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/param.h>
32 #include <sys/kernel.h>
33 #include <sys/systm.h>
34 #include <sys/malloc.h>
35 #include <sys/memrange.h>
36 #include <sys/smp.h>
37 #include <sys/sysctl.h>
38 
39 #include <vm/vm.h>
40 #include <vm/vm_param.h>
41 #include <vm/pmap.h>
42 
43 #include <machine/cputypes.h>
44 #include <machine/md_var.h>
45 #include <machine/specialreg.h>
46 
47 /*
48  * Pentium Pro+ memory range operations
49  *
50  * This code will probably be impenetrable without reference to the
51  * Intel Pentium Pro documentation or x86-64 programmers manual vol 2.
52  */
53 
54 static char *mem_owner_bios = "BIOS";
55 
56 #define	MR686_FIXMTRR	(1<<0)
57 
58 #define	mrwithin(mr, a)							\
59 	(((a) >= (mr)->mr_base) && ((a) < ((mr)->mr_base + (mr)->mr_len)))
60 #define	mroverlap(mra, mrb)						\
61 	(mrwithin(mra, mrb->mr_base) || mrwithin(mrb, mra->mr_base))
62 
63 #define	mrvalid(base, len) 						\
64 	((!(base & ((1 << 12) - 1))) &&	/* base is multiple of 4k */	\
65 	    ((len) >= (1 << 12)) &&	/* length is >= 4k */		\
66 	    powerof2((len)) &&		/* ... and power of two */	\
67 	    !((base) & ((len) - 1)))	/* range is not discontiuous */
68 
69 #define	mrcopyflags(curr, new)						\
70 	(((curr) & ~MDF_ATTRMASK) | ((new) & MDF_ATTRMASK))
71 
72 static int mtrrs_disabled;
73 SYSCTL_INT(_machdep, OID_AUTO, disable_mtrrs, CTLFLAG_RDTUN,
74     &mtrrs_disabled, 0,
75     "Disable MTRRs.");
76 
77 static void	x86_mrinit(struct mem_range_softc *sc);
78 static int	x86_mrset(struct mem_range_softc *sc,
79 		    struct mem_range_desc *mrd, int *arg);
80 static void	x86_mrAPinit(struct mem_range_softc *sc);
81 static void	x86_mrreinit(struct mem_range_softc *sc);
82 
83 static struct mem_range_ops x86_mrops = {
84 	x86_mrinit,
85 	x86_mrset,
86 	x86_mrAPinit,
87 	x86_mrreinit
88 };
89 
90 /* XXX for AP startup hook */
91 static u_int64_t mtrrcap, mtrrdef;
92 
93 /* The bitmask for the PhysBase and PhysMask fields of the variable MTRRs. */
94 static u_int64_t mtrr_physmask;
95 
96 static struct mem_range_desc *mem_range_match(struct mem_range_softc *sc,
97 		    struct mem_range_desc *mrd);
98 static void	x86_mrfetch(struct mem_range_softc *sc);
99 static int	x86_mtrrtype(int flags);
100 static int	x86_mrt2mtrr(int flags, int oldval);
101 static int	x86_mtrrconflict(int flag1, int flag2);
102 static void	x86_mrstore(struct mem_range_softc *sc);
103 static void	x86_mrstoreone(void *arg);
104 static struct mem_range_desc *x86_mtrrfixsearch(struct mem_range_softc *sc,
105 		    u_int64_t addr);
106 static int	x86_mrsetlow(struct mem_range_softc *sc,
107 		    struct mem_range_desc *mrd, int *arg);
108 static int	x86_mrsetvariable(struct mem_range_softc *sc,
109 		    struct mem_range_desc *mrd, int *arg);
110 
111 /* ia32 MTRR type to memory range type conversion */
112 static int x86_mtrrtomrt[] = {
113 	MDF_UNCACHEABLE,
114 	MDF_WRITECOMBINE,
115 	MDF_UNKNOWN,
116 	MDF_UNKNOWN,
117 	MDF_WRITETHROUGH,
118 	MDF_WRITEPROTECT,
119 	MDF_WRITEBACK
120 };
121 
122 #define	MTRRTOMRTLEN nitems(x86_mtrrtomrt)
123 
124 static int
x86_mtrr2mrt(int val)125 x86_mtrr2mrt(int val)
126 {
127 
128 	if (val < 0 || val >= MTRRTOMRTLEN)
129 		return (MDF_UNKNOWN);
130 	return (x86_mtrrtomrt[val]);
131 }
132 
133 /*
134  * x86 MTRR conflicts. Writeback and uncachable may overlap.
135  */
136 static int
x86_mtrrconflict(int flag1,int flag2)137 x86_mtrrconflict(int flag1, int flag2)
138 {
139 
140 	flag1 &= MDF_ATTRMASK;
141 	flag2 &= MDF_ATTRMASK;
142 	if ((flag1 & MDF_UNKNOWN) || (flag2 & MDF_UNKNOWN))
143 		return (1);
144 	if (flag1 == flag2 ||
145 	    (flag1 == MDF_WRITEBACK && flag2 == MDF_UNCACHEABLE) ||
146 	    (flag2 == MDF_WRITEBACK && flag1 == MDF_UNCACHEABLE))
147 		return (0);
148 	return (1);
149 }
150 
151 /*
152  * Look for an exactly-matching range.
153  */
154 static struct mem_range_desc *
mem_range_match(struct mem_range_softc * sc,struct mem_range_desc * mrd)155 mem_range_match(struct mem_range_softc *sc, struct mem_range_desc *mrd)
156 {
157 	struct mem_range_desc *cand;
158 	int i;
159 
160 	for (i = 0, cand = sc->mr_desc; i < sc->mr_ndesc; i++, cand++)
161 		if ((cand->mr_base == mrd->mr_base) &&
162 		    (cand->mr_len == mrd->mr_len))
163 			return (cand);
164 	return (NULL);
165 }
166 
167 /*
168  * Ensure that the direct map region does not contain any mappings
169  * that span MTRRs of different types.  However, the fixed MTRRs can
170  * be ignored, because a large page mapping the first 1 MB of physical
171  * memory is a special case that the processor handles.  Invalidate
172  * any old TLB entries that might hold inconsistent memory type
173  * information.
174  */
175 static void
x86_mr_split_dmap(struct mem_range_softc * sc __unused)176 x86_mr_split_dmap(struct mem_range_softc *sc __unused)
177 {
178 #ifdef __amd64__
179 	struct mem_range_desc *mrd;
180 	int i;
181 
182 	i = (sc->mr_cap & MR686_FIXMTRR) ? MTRR_N64K + MTRR_N16K + MTRR_N4K : 0;
183 	mrd = sc->mr_desc + i;
184 	for (; i < sc->mr_ndesc; i++, mrd++) {
185 		if ((mrd->mr_flags & (MDF_ACTIVE | MDF_BOGUS)) == MDF_ACTIVE)
186 			pmap_demote_DMAP(mrd->mr_base, mrd->mr_len, true);
187 	}
188 #endif
189 }
190 
191 /*
192  * Fetch the current mtrr settings from the current CPU (assumed to
193  * all be in sync in the SMP case).  Note that if we are here, we
194  * assume that MTRRs are enabled, and we may or may not have fixed
195  * MTRRs.
196  */
197 static void
x86_mrfetch(struct mem_range_softc * sc)198 x86_mrfetch(struct mem_range_softc *sc)
199 {
200 	struct mem_range_desc *mrd;
201 	u_int64_t msrv;
202 	int i, j, msr;
203 
204 	mrd = sc->mr_desc;
205 
206 	/* Get fixed-range MTRRs. */
207 	if (sc->mr_cap & MR686_FIXMTRR) {
208 		msr = MSR_MTRR64kBase;
209 		for (i = 0; i < (MTRR_N64K / 8); i++, msr++) {
210 			msrv = rdmsr(msr);
211 			for (j = 0; j < 8; j++, mrd++) {
212 				mrd->mr_flags =
213 				    (mrd->mr_flags & ~MDF_ATTRMASK) |
214 				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
215 				if (mrd->mr_owner[0] == 0)
216 					strcpy(mrd->mr_owner, mem_owner_bios);
217 				msrv = msrv >> 8;
218 			}
219 		}
220 		msr = MSR_MTRR16kBase;
221 		for (i = 0; i < MTRR_N16K / 8; i++, msr++) {
222 			msrv = rdmsr(msr);
223 			for (j = 0; j < 8; j++, mrd++) {
224 				mrd->mr_flags =
225 				    (mrd->mr_flags & ~MDF_ATTRMASK) |
226 				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
227 				if (mrd->mr_owner[0] == 0)
228 					strcpy(mrd->mr_owner, mem_owner_bios);
229 				msrv = msrv >> 8;
230 			}
231 		}
232 		msr = MSR_MTRR4kBase;
233 		for (i = 0; i < MTRR_N4K / 8; i++, msr++) {
234 			msrv = rdmsr(msr);
235 			for (j = 0; j < 8; j++, mrd++) {
236 				mrd->mr_flags =
237 				    (mrd->mr_flags & ~MDF_ATTRMASK) |
238 				    x86_mtrr2mrt(msrv & 0xff) | MDF_ACTIVE;
239 				if (mrd->mr_owner[0] == 0)
240 					strcpy(mrd->mr_owner, mem_owner_bios);
241 				msrv = msrv >> 8;
242 			}
243 		}
244 	}
245 
246 	/* Get remainder which must be variable MTRRs. */
247 	msr = MSR_MTRRVarBase;
248 	for (; mrd - sc->mr_desc < sc->mr_ndesc; msr += 2, mrd++) {
249 		msrv = rdmsr(msr);
250 		mrd->mr_flags = (mrd->mr_flags & ~MDF_ATTRMASK) |
251 		    x86_mtrr2mrt(msrv & MTRR_PHYSBASE_TYPE);
252 		mrd->mr_base = msrv & mtrr_physmask;
253 		msrv = rdmsr(msr + 1);
254 		mrd->mr_flags = (msrv & MTRR_PHYSMASK_VALID) ?
255 		    (mrd->mr_flags | MDF_ACTIVE) :
256 		    (mrd->mr_flags & ~MDF_ACTIVE);
257 
258 		/* Compute the range from the mask. Ick. */
259 		mrd->mr_len = (~(msrv & mtrr_physmask) &
260 		    (mtrr_physmask | 0xfff)) + 1;
261 		if (!mrvalid(mrd->mr_base, mrd->mr_len))
262 			mrd->mr_flags |= MDF_BOGUS;
263 
264 		/* If unclaimed and active, must be the BIOS. */
265 		if ((mrd->mr_flags & MDF_ACTIVE) && (mrd->mr_owner[0] == 0))
266 			strcpy(mrd->mr_owner, mem_owner_bios);
267 	}
268 }
269 
270 /*
271  * Return the MTRR memory type matching a region's flags
272  */
273 static int
x86_mtrrtype(int flags)274 x86_mtrrtype(int flags)
275 {
276 	int i;
277 
278 	flags &= MDF_ATTRMASK;
279 
280 	for (i = 0; i < MTRRTOMRTLEN; i++) {
281 		if (x86_mtrrtomrt[i] == MDF_UNKNOWN)
282 			continue;
283 		if (flags == x86_mtrrtomrt[i])
284 			return (i);
285 	}
286 	return (-1);
287 }
288 
289 static int
x86_mrt2mtrr(int flags,int oldval)290 x86_mrt2mtrr(int flags, int oldval)
291 {
292 	int val;
293 
294 	if ((val = x86_mtrrtype(flags)) == -1)
295 		return (oldval & 0xff);
296 	return (val & 0xff);
297 }
298 
299 /*
300  * Update running CPU(s) MTRRs to match the ranges in the descriptor
301  * list.
302  *
303  * Must be called with interrupts enabled.
304  */
305 static void
x86_mrstore(struct mem_range_softc * sc)306 x86_mrstore(struct mem_range_softc *sc)
307 {
308 
309 	smp_rendezvous(NULL, x86_mrstoreone, NULL, sc);
310 }
311 
312 /*
313  * Update the current CPU's MTRRs with those represented in the
314  * descriptor list.  Note that we do this wholesale rather than just
315  * stuffing one entry; this is simpler (but slower, of course).
316  */
317 static void
x86_mrstoreone(void * arg)318 x86_mrstoreone(void *arg)
319 {
320 	struct mem_range_softc *sc = arg;
321 	struct mem_range_desc *mrd;
322 	u_int64_t omsrv, msrv;
323 	int i, j, msr;
324 	u_long cr0, cr4;
325 
326 	mrd = sc->mr_desc;
327 
328 	critical_enter();
329 
330 	/* Disable PGE. */
331 	cr4 = rcr4();
332 	load_cr4(cr4 & ~CR4_PGE);
333 
334 	/* Disable caches (CD = 1, NW = 0). */
335 	cr0 = rcr0();
336 	load_cr0((cr0 & ~CR0_NW) | CR0_CD);
337 
338 	/* Flushes caches and TLBs. */
339 	wbinvd();
340 	invltlb();
341 
342 	/* Disable MTRRs (E = 0). */
343 	wrmsr(MSR_MTRRdefType, rdmsr(MSR_MTRRdefType) & ~MTRR_DEF_ENABLE);
344 
345 	/* Set fixed-range MTRRs. */
346 	if (sc->mr_cap & MR686_FIXMTRR) {
347 		msr = MSR_MTRR64kBase;
348 		for (i = 0; i < MTRR_N64K / 8; i++, msr++) {
349 			msrv = 0;
350 			omsrv = rdmsr(msr);
351 			for (j = 7; j >= 0; j--) {
352 				msrv = msrv << 8;
353 				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
354 				    omsrv >> (j * 8));
355 			}
356 			wrmsr(msr, msrv);
357 			mrd += 8;
358 		}
359 		msr = MSR_MTRR16kBase;
360 		for (i = 0; i < MTRR_N16K / 8; i++, msr++) {
361 			msrv = 0;
362 			omsrv = rdmsr(msr);
363 			for (j = 7; j >= 0; j--) {
364 				msrv = msrv << 8;
365 				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
366 				    omsrv >> (j * 8));
367 			}
368 			wrmsr(msr, msrv);
369 			mrd += 8;
370 		}
371 		msr = MSR_MTRR4kBase;
372 		for (i = 0; i < MTRR_N4K / 8; i++, msr++) {
373 			msrv = 0;
374 			omsrv = rdmsr(msr);
375 			for (j = 7; j >= 0; j--) {
376 				msrv = msrv << 8;
377 				msrv |= x86_mrt2mtrr((mrd + j)->mr_flags,
378 				    omsrv >> (j * 8));
379 			}
380 			wrmsr(msr, msrv);
381 			mrd += 8;
382 		}
383 	}
384 
385 	/* Set remainder which must be variable MTRRs. */
386 	msr = MSR_MTRRVarBase;
387 	for (; mrd - sc->mr_desc < sc->mr_ndesc; msr += 2, mrd++) {
388 		/* base/type register */
389 		omsrv = rdmsr(msr);
390 		if (mrd->mr_flags & MDF_ACTIVE) {
391 			msrv = mrd->mr_base & mtrr_physmask;
392 			msrv |= x86_mrt2mtrr(mrd->mr_flags, omsrv);
393 		} else {
394 			msrv = 0;
395 		}
396 		wrmsr(msr, msrv);
397 
398 		/* mask/active register */
399 		if (mrd->mr_flags & MDF_ACTIVE) {
400 			msrv = MTRR_PHYSMASK_VALID |
401 			    rounddown2(mtrr_physmask, mrd->mr_len);
402 		} else {
403 			msrv = 0;
404 		}
405 		wrmsr(msr + 1, msrv);
406 	}
407 
408 	/* Flush caches and TLBs. */
409 	wbinvd();
410 	invltlb();
411 
412 	/* Enable MTRRs. */
413 	wrmsr(MSR_MTRRdefType, rdmsr(MSR_MTRRdefType) | MTRR_DEF_ENABLE);
414 
415 	/* Restore caches and PGE. */
416 	load_cr0(cr0);
417 	load_cr4(cr4);
418 
419 	critical_exit();
420 }
421 
422 /*
423  * Hunt for the fixed MTRR referencing (addr)
424  */
425 static struct mem_range_desc *
x86_mtrrfixsearch(struct mem_range_softc * sc,u_int64_t addr)426 x86_mtrrfixsearch(struct mem_range_softc *sc, u_int64_t addr)
427 {
428 	struct mem_range_desc *mrd;
429 	int i;
430 
431 	for (i = 0, mrd = sc->mr_desc; i < MTRR_N64K + MTRR_N16K + MTRR_N4K;
432 	     i++, mrd++)
433 		if (addr >= mrd->mr_base &&
434 		    addr < mrd->mr_base + mrd->mr_len)
435 			return (mrd);
436 	return (NULL);
437 }
438 
439 /*
440  * Try to satisfy the given range request by manipulating the fixed
441  * MTRRs that cover low memory.
442  *
443  * Note that we try to be generous here; we'll bloat the range out to
444  * the next higher/lower boundary to avoid the consumer having to know
445  * too much about the mechanisms here.
446  *
447  * XXX note that this will have to be updated when we start supporting
448  * "busy" ranges.
449  */
450 static int
x86_mrsetlow(struct mem_range_softc * sc,struct mem_range_desc * mrd,int * arg)451 x86_mrsetlow(struct mem_range_softc *sc, struct mem_range_desc *mrd, int *arg)
452 {
453 	struct mem_range_desc *first_md, *last_md, *curr_md;
454 
455 	/* Range check. */
456 	if ((first_md = x86_mtrrfixsearch(sc, mrd->mr_base)) == NULL ||
457 	    (last_md = x86_mtrrfixsearch(sc, mrd->mr_base + mrd->mr_len - 1))
458 	    == NULL)
459 		return (EINVAL);
460 
461 	/* Check that we aren't doing something risky. */
462 	if ((mrd->mr_flags & MDF_FORCE) == 0) {
463 		for (curr_md = first_md; curr_md <= last_md; curr_md++) {
464 			if ((curr_md->mr_flags & MDF_ATTRMASK) == MDF_UNKNOWN)
465 				return (EACCES);
466 		}
467 	}
468 
469 	/* Set flags, clear set-by-firmware flag. */
470 	for (curr_md = first_md; curr_md <= last_md; curr_md++) {
471 		curr_md->mr_flags = mrcopyflags(curr_md->mr_flags &
472 		    ~MDF_FIRMWARE, mrd->mr_flags);
473 		bcopy(mrd->mr_owner, curr_md->mr_owner, sizeof(mrd->mr_owner));
474 	}
475 
476 	return (0);
477 }
478 
479 /*
480  * Modify/add a variable MTRR to satisfy the request.
481  *
482  * XXX needs to be updated to properly support "busy" ranges.
483  */
484 static int
x86_mrsetvariable(struct mem_range_softc * sc,struct mem_range_desc * mrd,int * arg)485 x86_mrsetvariable(struct mem_range_softc *sc, struct mem_range_desc *mrd,
486     int *arg)
487 {
488 	struct mem_range_desc *curr_md, *free_md;
489 	int i;
490 
491 	/*
492 	 * Scan the currently active variable descriptors, look for
493 	 * one we exactly match (straight takeover) and for possible
494 	 * accidental overlaps.
495 	 *
496 	 * Keep track of the first empty variable descriptor in case
497 	 * we can't perform a takeover.
498 	 */
499 	i = (sc->mr_cap & MR686_FIXMTRR) ? MTRR_N64K + MTRR_N16K + MTRR_N4K : 0;
500 	curr_md = sc->mr_desc + i;
501 	free_md = NULL;
502 	for (; i < sc->mr_ndesc; i++, curr_md++) {
503 		if (curr_md->mr_flags & MDF_ACTIVE) {
504 			/* Exact match? */
505 			if (curr_md->mr_base == mrd->mr_base &&
506 			    curr_md->mr_len == mrd->mr_len) {
507 				/* Whoops, owned by someone. */
508 				if (curr_md->mr_flags & MDF_BUSY)
509 					return (EBUSY);
510 
511 				/* Check that we aren't doing something risky */
512 				if (!(mrd->mr_flags & MDF_FORCE) &&
513 				    (curr_md->mr_flags & MDF_ATTRMASK) ==
514 				    MDF_UNKNOWN)
515 					return (EACCES);
516 
517 				/* Ok, just hijack this entry. */
518 				free_md = curr_md;
519 				break;
520 			}
521 
522 			/* Non-exact overlap? */
523 			if (mroverlap(curr_md, mrd)) {
524 				/* Between conflicting region types? */
525 				if (x86_mtrrconflict(curr_md->mr_flags,
526 				    mrd->mr_flags))
527 					return (EINVAL);
528 			}
529 		} else if (free_md == NULL) {
530 			free_md = curr_md;
531 		}
532 	}
533 
534 	/* Got somewhere to put it? */
535 	if (free_md == NULL)
536 		return (ENOSPC);
537 
538 	/* Set up new descriptor. */
539 	free_md->mr_base = mrd->mr_base;
540 	free_md->mr_len = mrd->mr_len;
541 	free_md->mr_flags = mrcopyflags(MDF_ACTIVE, mrd->mr_flags);
542 	bcopy(mrd->mr_owner, free_md->mr_owner, sizeof(mrd->mr_owner));
543 	return (0);
544 }
545 
546 /*
547  * Handle requests to set memory range attributes by manipulating MTRRs.
548  */
549 static int
x86_mrset(struct mem_range_softc * sc,struct mem_range_desc * mrd,int * arg)550 x86_mrset(struct mem_range_softc *sc, struct mem_range_desc *mrd, int *arg)
551 {
552 	struct mem_range_desc *targ;
553 	int error;
554 
555 	switch (*arg) {
556 	case MEMRANGE_SET_UPDATE:
557 		/*
558 		 * Make sure that what's being asked for is even
559 		 * possible at all.
560 		 */
561 		if (!mrvalid(mrd->mr_base, mrd->mr_len) ||
562 		    x86_mtrrtype(mrd->mr_flags) == -1)
563 			return (EINVAL);
564 
565 #define	FIXTOP	\
566     ((MTRR_N64K * 0x10000) + (MTRR_N16K * 0x4000) + (MTRR_N4K * 0x1000))
567 
568 		/* Are the "low memory" conditions applicable? */
569 		if ((sc->mr_cap & MR686_FIXMTRR) != 0 &&
570 		    mrd->mr_base + mrd->mr_len <= FIXTOP) {
571 			if ((error = x86_mrsetlow(sc, mrd, arg)) != 0)
572 				return (error);
573 		} else {
574 			/* It's time to play with variable MTRRs. */
575 			if ((error = x86_mrsetvariable(sc, mrd, arg)) != 0)
576 				return (error);
577 		}
578 		break;
579 
580 	case MEMRANGE_SET_REMOVE:
581 		if ((targ = mem_range_match(sc, mrd)) == NULL)
582 			return (ENOENT);
583 		if (targ->mr_flags & MDF_FIXACTIVE)
584 			return (EPERM);
585 		if (targ->mr_flags & MDF_BUSY)
586 			return (EBUSY);
587 		targ->mr_flags &= ~MDF_ACTIVE;
588 		targ->mr_owner[0] = 0;
589 		break;
590 
591 	default:
592 		return (EOPNOTSUPP);
593 	}
594 
595 	x86_mr_split_dmap(sc);
596 
597 	/* Update the hardware. */
598 	x86_mrstore(sc);
599 
600 	/* Refetch to see where we're at. */
601 	x86_mrfetch(sc);
602 	return (0);
603 }
604 
605 /*
606  * Work out how many ranges we support, initialise storage for them,
607  * and fetch the initial settings.
608  */
609 static void
x86_mrinit(struct mem_range_softc * sc)610 x86_mrinit(struct mem_range_softc *sc)
611 {
612 	struct mem_range_desc *mrd;
613 	int i, nmdesc;
614 
615 	if (sc->mr_desc != NULL)
616 		/* Already initialized. */
617 		return;
618 
619 	nmdesc = 0;
620 	mtrrcap = rdmsr(MSR_MTRRcap);
621 	mtrrdef = rdmsr(MSR_MTRRdefType);
622 
623 	/* For now, bail out if MTRRs are not enabled. */
624 	if (!(mtrrdef & MTRR_DEF_ENABLE)) {
625 		if (bootverbose)
626 			printf("CPU supports MTRRs but not enabled\n");
627 		return;
628 	}
629 	nmdesc = mtrrcap & MTRR_CAP_VCNT;
630 	if (bootverbose)
631 		printf("Pentium Pro MTRR support enabled\n");
632 
633 	/*
634 	 * Determine the size of the PhysMask and PhysBase fields in
635 	 * the variable range MTRRs.
636 	 */
637 	mtrr_physmask = (((uint64_t)1 << cpu_maxphyaddr) - 1) &
638 	    ~(uint64_t)0xfff;
639 
640 	/* If fixed MTRRs supported and enabled. */
641 	if ((mtrrcap & MTRR_CAP_FIXED) && (mtrrdef & MTRR_DEF_FIXED_ENABLE)) {
642 		sc->mr_cap = MR686_FIXMTRR;
643 		nmdesc += MTRR_N64K + MTRR_N16K + MTRR_N4K;
644 	}
645 
646 	sc->mr_desc = malloc(nmdesc * sizeof(struct mem_range_desc), M_MEMDESC,
647 	    M_WAITOK | M_ZERO);
648 	sc->mr_ndesc = nmdesc;
649 
650 	mrd = sc->mr_desc;
651 
652 	/* Populate the fixed MTRR entries' base/length. */
653 	if (sc->mr_cap & MR686_FIXMTRR) {
654 		for (i = 0; i < MTRR_N64K; i++, mrd++) {
655 			mrd->mr_base = i * 0x10000;
656 			mrd->mr_len = 0x10000;
657 			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
658 			    MDF_FIXACTIVE;
659 		}
660 		for (i = 0; i < MTRR_N16K; i++, mrd++) {
661 			mrd->mr_base = i * 0x4000 + 0x80000;
662 			mrd->mr_len = 0x4000;
663 			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
664 			    MDF_FIXACTIVE;
665 		}
666 		for (i = 0; i < MTRR_N4K; i++, mrd++) {
667 			mrd->mr_base = i * 0x1000 + 0xc0000;
668 			mrd->mr_len = 0x1000;
669 			mrd->mr_flags = MDF_FIXBASE | MDF_FIXLEN |
670 			    MDF_FIXACTIVE;
671 		}
672 	}
673 
674 	/*
675 	 * Get current settings, anything set now is considered to
676 	 * have been set by the firmware. (XXX has something already
677 	 * played here?)
678 	 */
679 	x86_mrfetch(sc);
680 	mrd = sc->mr_desc;
681 	for (i = 0; i < sc->mr_ndesc; i++, mrd++) {
682 		if (mrd->mr_flags & MDF_ACTIVE)
683 			mrd->mr_flags |= MDF_FIRMWARE;
684 	}
685 
686 	x86_mr_split_dmap(sc);
687 }
688 
689 /*
690  * Initialise MTRRs on an AP after the BSP has run the init code.
691  */
692 static void
x86_mrAPinit(struct mem_range_softc * sc)693 x86_mrAPinit(struct mem_range_softc *sc)
694 {
695 
696 	x86_mrstoreone(sc);
697 	wrmsr(MSR_MTRRdefType, mtrrdef);
698 }
699 
700 /*
701  * Re-initialise running CPU(s) MTRRs to match the ranges in the descriptor
702  * list.
703  *
704  * Must be called with interrupts enabled.
705  */
706 static void
x86_mrreinit(struct mem_range_softc * sc)707 x86_mrreinit(struct mem_range_softc *sc)
708 {
709 
710 	smp_rendezvous(NULL, (void (*)(void *))x86_mrAPinit, NULL, sc);
711 }
712 
713 static void
x86_mem_drvinit(void * unused)714 x86_mem_drvinit(void *unused)
715 {
716 
717 	if (mtrrs_disabled)
718 		return;
719 	if (!(cpu_feature & CPUID_MTRR))
720 		return;
721 	mem_range_softc.mr_op = &x86_mrops;
722 	x86_mrinit(&mem_range_softc);
723 }
724 SYSINIT(x86memdev, SI_SUB_CPU, SI_ORDER_ANY, x86_mem_drvinit, NULL);
725