pat.c 22.8 KB
Newer Older
1 2 3 4 5 6 7 8 9
/*
 * Handle caching attributes in page tables (PAT)
 *
 * Authors: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 *          Suresh B Siddha <suresh.b.siddha@intel.com>
 *
 * Loosely based on earlier PAT patchset from Eric Biederman and Andi Kleen.
 */

I
Ingo Molnar 已提交
10 11 12
#include <linux/seq_file.h>
#include <linux/bootmem.h>
#include <linux/debugfs.h>
13 14
#include <linux/kernel.h>
#include <linux/gfp.h>
I
Ingo Molnar 已提交
15
#include <linux/mm.h>
16 17
#include <linux/fs.h>

I
Ingo Molnar 已提交
18
#include <asm/cacheflush.h>
19
#include <asm/processor.h>
I
Ingo Molnar 已提交
20
#include <asm/tlbflush.h>
21 22
#include <asm/pgtable.h>
#include <asm/fcntl.h>
I
Ingo Molnar 已提交
23
#include <asm/e820.h>
24
#include <asm/mtrr.h>
I
Ingo Molnar 已提交
25 26 27
#include <asm/page.h>
#include <asm/msr.h>
#include <asm/pat.h>
28
#include <asm/io.h>
29

30
#ifdef CONFIG_X86_PAT
31
int __read_mostly pat_enabled = 1;
32

33
void __cpuinit pat_disable(char *reason)
34
{
35
	pat_enabled = 0;
36
	printk(KERN_INFO "%s\n", reason);
37 38
}

A
Andrew Morton 已提交
39
static int __init nopat(char *str)
40
{
41
	pat_disable("PAT support disabled.");
42 43
	return 0;
}
44 45 46
early_param("nopat", nopat);
#endif

47 48

static int debug_enable;
I
Ingo Molnar 已提交
49

50 51 52 53 54 55 56 57 58 59 60
static int __init pat_debug_setup(char *str)
{
	debug_enable = 1;
	return 0;
}
__setup("debugpat", pat_debug_setup);

#define dprintk(fmt, arg...) \
	do { if (debug_enable) printk(KERN_INFO fmt, ##arg); } while (0)


61
static u64 __read_mostly boot_pat_state;
62 63 64 65 66 67 68 69 70 71

enum {
	PAT_UC = 0,		/* uncached */
	PAT_WC = 1,		/* Write combining */
	PAT_WT = 4,		/* Write Through */
	PAT_WP = 5,		/* Write Protected */
	PAT_WB = 6,		/* Write Back (default) */
	PAT_UC_MINUS = 7,	/* UC, but can be overriden by MTRR */
};

72
#define PAT(x, y)	((u64)PAT_ ## y << ((x)*8))
73 74 75 76 77

void pat_init(void)
{
	u64 pat;

78
	if (!pat_enabled)
79 80
		return;

81
	/* Paranoia check. */
82
	if (!cpu_has_pat && boot_pat_state) {
83
		/*
84
		 * If this happens we are on a secondary CPU, but
85 86
		 * switched to PAT on the boot CPU. We have no way to
		 * undo PAT.
87 88 89 90
		 */
		printk(KERN_ERR "PAT enabled, "
		       "but not supported by secondary CPU\n");
		BUG();
91
	}
92 93 94 95 96 97 98 99 100 101 102 103 104 105

	/* Set PWT to Write-Combining. All other bits stay the same */
	/*
	 * PTE encoding used in Linux:
	 *      PAT
	 *      |PCD
	 *      ||PWT
	 *      |||
	 *      000 WB		_PAGE_CACHE_WB
	 *      001 WC		_PAGE_CACHE_WC
	 *      010 UC-		_PAGE_CACHE_UC_MINUS
	 *      011 UC		_PAGE_CACHE_UC
	 * PAT bit unused
	 */
106 107
	pat = PAT(0, WB) | PAT(1, WC) | PAT(2, UC_MINUS) | PAT(3, UC) |
	      PAT(4, WB) | PAT(5, WC) | PAT(6, UC_MINUS) | PAT(7, UC);
108 109

	/* Boot CPU check */
110
	if (!boot_pat_state)
111 112 113 114 115 116 117 118 119 120 121 122
		rdmsrl(MSR_IA32_CR_PAT, boot_pat_state);

	wrmsrl(MSR_IA32_CR_PAT, pat);
	printk(KERN_INFO "x86 PAT enabled: cpu %d, old 0x%Lx, new 0x%Lx\n",
	       smp_processor_id(), boot_pat_state, pat);
}

#undef PAT

static char *cattr_name(unsigned long flags)
{
	switch (flags & _PAGE_CACHE_MASK) {
123 124 125 126 127
	case _PAGE_CACHE_UC:		return "uncached";
	case _PAGE_CACHE_UC_MINUS:	return "uncached-minus";
	case _PAGE_CACHE_WB:		return "write-back";
	case _PAGE_CACHE_WC:		return "write-combining";
	default:			return "broken";
128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
	}
}

/*
 * The global memtype list keeps track of memory type for specific
 * physical memory areas. Conflicting memory types in different
 * mappings can cause CPU cache corruption. To avoid this we keep track.
 *
 * The list is sorted based on starting address and can contain multiple
 * entries for each address (this allows reference counting for overlapping
 * areas). All the aliases have the same cache attributes of course.
 * Zero attributes are represented as holes.
 *
 * Currently the data structure is a list because the number of mappings
 * are expected to be relatively small. If this should be a problem
 * it could be changed to a rbtree or similar.
 *
 * memtype_lock protects the whole list.
 */

struct memtype {
I
Ingo Molnar 已提交
149 150 151 152
	u64			start;
	u64			end;
	unsigned long		type;
	struct list_head	nd;
153 154 155
};

static LIST_HEAD(memtype_list);
I
Ingo Molnar 已提交
156
static DEFINE_SPINLOCK(memtype_lock);	/* protects memtype list */
157 158 159 160 161 162 163 164

/*
 * Does intersection of PAT memory type and MTRR memory type and returns
 * the resulting memory type as PAT understands it.
 * (Type in pat and mtrr will not have same value)
 * The intersection is based on "Effective Memory Type" tables in IA-32
 * SDM vol 3a
 */
165
static unsigned long pat_x_mtrr_type(u64 start, u64 end, unsigned long req_type)
166
{
167 168 169 170
	/*
	 * Look for MTRR hint to get the effective type in case where PAT
	 * request is for WB.
	 */
171 172 173 174 175 176 177 178 179 180 181
	if (req_type == _PAGE_CACHE_WB) {
		u8 mtrr_type;

		mtrr_type = mtrr_type_lookup(start, end);
		if (mtrr_type == MTRR_TYPE_UNCACHABLE)
			return _PAGE_CACHE_UC;
		if (mtrr_type == MTRR_TYPE_WRCOMB)
			return _PAGE_CACHE_WC;
	}

	return req_type;
182 183
}

I
Ingo Molnar 已提交
184 185
static int
chk_conflict(struct memtype *new, struct memtype *entry, unsigned long *type)
186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210
{
	if (new->type != entry->type) {
		if (type) {
			new->type = entry->type;
			*type = entry->type;
		} else
			goto conflict;
	}

	 /* check overlaps with more than one entry in the list */
	list_for_each_entry_continue(entry, &memtype_list, nd) {
		if (new->end <= entry->start)
			break;
		else if (new->type != entry->type)
			goto conflict;
	}
	return 0;

 conflict:
	printk(KERN_INFO "%s:%d conflicting memory types "
	       "%Lx-%Lx %s<->%s\n", current->comm, current->pid, new->start,
	       new->end, cattr_name(new->type), cattr_name(entry->type));
	return -EBUSY;
}

211 212 213
static struct memtype *cached_entry;
static u64 cached_start;

214 215 216 217 218 219 220 221 222 223 224 225 226
/*
 * For RAM pages, mark the pages as non WB memory type using
 * PageNonWB (PG_arch_1). We allow only one set_memory_uc() or
 * set_memory_wc() on a RAM page at a time before marking it as WB again.
 * This is ok, because only one driver will be owning the page and
 * doing set_memory_*() calls.
 *
 * For now, we use PageNonWB to track that the RAM page is being mapped
 * as non WB. In future, we will have to use one more flag
 * (or some other mechanism in page_struct) to distinguish between
 * UC and WC mapping.
 */
static int reserve_ram_pages_type(u64 start, u64 end, unsigned long req_type,
I
Ingo Molnar 已提交
227
				  unsigned long *new_type)
228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273
{
	struct page *page;
	u64 pfn, end_pfn;

	for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
		page = pfn_to_page(pfn);
		if (page_mapped(page) || PageNonWB(page))
			goto out;

		SetPageNonWB(page);
	}
	return 0;

out:
	end_pfn = pfn;
	for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) {
		page = pfn_to_page(pfn);
		ClearPageNonWB(page);
	}

	return -EINVAL;
}

static int free_ram_pages_type(u64 start, u64 end)
{
	struct page *page;
	u64 pfn, end_pfn;

	for (pfn = (start >> PAGE_SHIFT); pfn < (end >> PAGE_SHIFT); ++pfn) {
		page = pfn_to_page(pfn);
		if (page_mapped(page) || !PageNonWB(page))
			goto out;

		ClearPageNonWB(page);
	}
	return 0;

out:
	end_pfn = pfn;
	for (pfn = (start >> PAGE_SHIFT); pfn < end_pfn; ++pfn) {
		page = pfn_to_page(pfn);
		SetPageNonWB(page);
	}
	return -EINVAL;
}

274 275 276 277 278 279 280 281 282 283
/*
 * req_type typically has one of the:
 * - _PAGE_CACHE_WB
 * - _PAGE_CACHE_WC
 * - _PAGE_CACHE_UC_MINUS
 * - _PAGE_CACHE_UC
 *
 * req_type will have a special case value '-1', when requester want to inherit
 * the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS.
 *
284 285 286
 * If new_type is NULL, function will return an error if it cannot reserve the
 * region with req_type. If new_type is non-NULL, function will return
 * available type in new_type in case of no error. In case of any error
287 288
 * it will return a negative return value.
 */
289
int reserve_memtype(u64 start, u64 end, unsigned long req_type,
I
Ingo Molnar 已提交
290
		    unsigned long *new_type)
291
{
292
	struct memtype *new, *entry;
293
	unsigned long actual_type;
294
	struct list_head *where;
295
	int is_range_ram;
I
Ingo Molnar 已提交
296
	int err = 0;
297

I
Ingo Molnar 已提交
298
	BUG_ON(start >= end); /* end is exclusive */
299

300
	if (!pat_enabled) {
301
		/* This is identical to page table setting without PAT */
302 303 304 305 306
		if (new_type) {
			if (req_type == -1)
				*new_type = _PAGE_CACHE_WB;
			else
				*new_type = req_type & _PAGE_CACHE_MASK;
307
		}
308 309 310 311
		return 0;
	}

	/* Low ISA region is always mapped WB in page table. No need to track */
312
	if (is_ISA_range(start, end - 1)) {
313 314
		if (new_type)
			*new_type = _PAGE_CACHE_WB;
315 316 317
		return 0;
	}

318 319
	if (req_type == -1) {
		/*
320 321 322 323
		 * Call mtrr_lookup to get the type hint. This is an
		 * optimization for /dev/mem mmap'ers into WB memory (BIOS
		 * tools and ACPI tools). Use WB request for WB memory and use
		 * UC_MINUS otherwise.
324 325 326
		 */
		u8 mtrr_type = mtrr_type_lookup(start, end);

327
		if (mtrr_type == MTRR_TYPE_WRBACK)
328
			actual_type = _PAGE_CACHE_WB;
329
		else
330
			actual_type = _PAGE_CACHE_UC_MINUS;
I
Ingo Molnar 已提交
331
	} else {
332 333
		actual_type = pat_x_mtrr_type(start, end,
					      req_type & _PAGE_CACHE_MASK);
I
Ingo Molnar 已提交
334
	}
335

336 337 338 339 340 341
	is_range_ram = pagerange_is_ram(start, end);
	if (is_range_ram == 1)
		return reserve_ram_pages_type(start, end, req_type, new_type);
	else if (is_range_ram < 0)
		return -EINVAL;

342 343
	new  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
	if (!new)
344 345
		return -ENOMEM;

I
Ingo Molnar 已提交
346 347 348
	new->start	= start;
	new->end	= end;
	new->type	= actual_type;
349

350 351
	if (new_type)
		*new_type = actual_type;
352 353 354

	spin_lock(&memtype_lock);

355 356 357 358 359
	if (cached_entry && start >= cached_start)
		entry = cached_entry;
	else
		entry = list_entry(&memtype_list, struct memtype, nd);

360
	/* Search for existing mapping that overlaps the current range */
361
	where = NULL;
362
	list_for_each_entry_continue(entry, &memtype_list, nd) {
363
		if (end <= entry->start) {
364
			where = entry->nd.prev;
365
			cached_entry = list_entry(where, struct memtype, nd);
366
			break;
367
		} else if (start <= entry->start) { /* end > entry->start */
368
			err = chk_conflict(new, entry, new_type);
369 370 371 372
			if (!err) {
				dprintk("Overlap at 0x%Lx-0x%Lx\n",
					entry->start, entry->end);
				where = entry->nd.prev;
373 374
				cached_entry = list_entry(where,
							struct memtype, nd);
375 376
			}
			break;
377
		} else if (start < entry->end) { /* start > entry->start */
378
			err = chk_conflict(new, entry, new_type);
379 380 381
			if (!err) {
				dprintk("Overlap at 0x%Lx-0x%Lx\n",
					entry->start, entry->end);
382 383 384 385 386 387 388 389 390 391 392 393 394 395
				cached_entry = list_entry(entry->nd.prev,
							struct memtype, nd);

				/*
				 * Move to right position in the linked
				 * list to add this new entry
				 */
				list_for_each_entry_continue(entry,
							&memtype_list, nd) {
					if (start <= entry->start) {
						where = entry->nd.prev;
						break;
					}
				}
396 397 398 399 400 401
			}
			break;
		}
	}

	if (err) {
402 403 404
		printk(KERN_INFO "reserve_memtype failed 0x%Lx-0x%Lx, "
		       "track %s, req %s\n",
		       start, end, cattr_name(new->type), cattr_name(req_type));
405
		kfree(new);
406
		spin_unlock(&memtype_lock);
I
Ingo Molnar 已提交
407

408 409 410
		return err;
	}

411 412
	cached_start = start;

413 414 415
	if (where)
		list_add(&new->nd, where);
	else
416
		list_add_tail(&new->nd, &memtype_list);
417

418
	spin_unlock(&memtype_lock);
419 420 421 422 423

	dprintk("reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
		start, end, cattr_name(new->type), cattr_name(req_type),
		new_type ? cattr_name(*new_type) : "-");

424 425 426 427 428
	return err;
}

int free_memtype(u64 start, u64 end)
{
429
	struct memtype *entry;
430
	int err = -EINVAL;
431
	int is_range_ram;
432

433
	if (!pat_enabled)
434 435 436
		return 0;

	/* Low ISA region is always mapped WB. No need to track */
437
	if (is_ISA_range(start, end - 1))
438 439
		return 0;

440 441 442 443 444 445
	is_range_ram = pagerange_is_ram(start, end);
	if (is_range_ram == 1)
		return free_ram_pages_type(start, end);
	else if (is_range_ram < 0)
		return -EINVAL;

446
	spin_lock(&memtype_lock);
447 448
	list_for_each_entry(entry, &memtype_list, nd) {
		if (entry->start == start && entry->end == end) {
449 450 451
			if (cached_entry == entry || cached_start == start)
				cached_entry = NULL;

452 453
			list_del(&entry->nd);
			kfree(entry);
454 455 456 457 458 459 460
			err = 0;
			break;
		}
	}
	spin_unlock(&memtype_lock);

	if (err) {
I
Ingo Molnar 已提交
461
		printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n",
462 463
			current->comm, current->pid, start, end);
	}
464

465
	dprintk("free_memtype request 0x%Lx-0x%Lx\n", start, end);
I
Ingo Molnar 已提交
466

467 468 469
	return err;
}

470 471 472 473 474 475 476

pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
				unsigned long size, pgprot_t vma_prot)
{
	return vma_prot;
}

477 478
#ifdef CONFIG_STRICT_DEVMEM
/* This check is done in drivers/char/mem.c in case of STRICT_DEVMEM*/
479 480 481 482 483
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
	return 1;
}
#else
484
/* This check is needed to avoid cache aliasing when PAT is enabled */
485 486 487 488 489 490
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
	u64 from = ((u64)pfn) << PAGE_SHIFT;
	u64 to = from + size;
	u64 cursor = from;

491 492 493
	if (!pat_enabled)
		return 1;

494 495 496 497 498 499 500 501 502 503 504 505
	while (cursor < to) {
		if (!devmem_is_allowed(pfn)) {
			printk(KERN_INFO
		"Program %s tried to access /dev/mem between %Lx->%Lx.\n",
				current->comm, from, to);
			return 0;
		}
		cursor += PAGE_SIZE;
		pfn++;
	}
	return 1;
}
506
#endif /* CONFIG_STRICT_DEVMEM */
507

508 509 510
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
				unsigned long size, pgprot_t *vma_prot)
{
511
	u64 offset = ((u64) pfn) << PAGE_SHIFT;
512
	unsigned long flags = -1;
513
	int retval;
514

515 516 517
	if (!range_is_allowed(pfn, size))
		return 0;

518
	if (file->f_flags & O_SYNC) {
519
		flags = _PAGE_CACHE_UC_MINUS;
520 521 522 523 524 525 526 527 528 529 530
	}

#ifdef CONFIG_X86_32
	/*
	 * On the PPro and successors, the MTRRs are used to set
	 * memory types for physical addresses outside main memory,
	 * so blindly setting UC or PWT on those pages is wrong.
	 * For Pentiums and earlier, the surround logic should disable
	 * caching for the high addresses through the KEN pin, but
	 * we maintain the tradition of paranoia in this code.
	 */
531
	if (!pat_enabled &&
532 533 534 535 536
	    !(boot_cpu_has(X86_FEATURE_MTRR) ||
	      boot_cpu_has(X86_FEATURE_K6_MTRR) ||
	      boot_cpu_has(X86_FEATURE_CYRIX_ARR) ||
	      boot_cpu_has(X86_FEATURE_CENTAUR_MCR)) &&
	    (pfn << PAGE_SHIFT) >= __pa(high_memory)) {
537
		flags = _PAGE_CACHE_UC;
538 539 540
	}
#endif

541
	/*
542 543
	 * With O_SYNC, we can only take UC_MINUS mapping. Fail if we cannot.
	 *
544 545 546 547 548
	 * Without O_SYNC, we want to get
	 * - WB for WB-able memory and no other conflicting mappings
	 * - UC_MINUS for non-WB-able memory with no other conflicting mappings
	 * - Inherit from confliting mappings otherwise
	 */
549
	if (flags != -1) {
550 551
		retval = reserve_memtype(offset, offset + size, flags, NULL);
	} else {
I
Ingo Molnar 已提交
552
		retval = reserve_memtype(offset, offset + size, -1, &flags);
553 554 555 556 557
	}

	if (retval < 0)
		return 0;

Y
Yinghai Lu 已提交
558 559
	if (((pfn < max_low_pfn_mapped) ||
	     (pfn >= (1UL<<(32 - PAGE_SHIFT)) && pfn < max_pfn_mapped)) &&
560
	    ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
561
		free_memtype(offset, offset + size);
I
Ingo Molnar 已提交
562
		printk(KERN_INFO
563 564 565
		"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
			current->comm, current->pid,
			cattr_name(flags),
566
			offset, (unsigned long long)(offset + size));
567 568 569 570 571
		return 0;
	}

	*vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
			     flags);
572 573
	return 1;
}
574 575 576

void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
{
I
Ingo Molnar 已提交
577
	unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
578 579 580 581 582
	u64 addr = (u64)pfn << PAGE_SHIFT;
	unsigned long flags;

	reserve_memtype(addr, addr + size, want_flags, &flags);
	if (flags != want_flags) {
I
Ingo Molnar 已提交
583
		printk(KERN_INFO
584 585 586
		"%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",
			current->comm, current->pid,
			cattr_name(want_flags),
587
			addr, (unsigned long long)(addr + size),
588 589 590 591 592 593 594 595 596 597 598
			cattr_name(flags));
	}
}

void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
{
	u64 addr = (u64)pfn << PAGE_SHIFT;

	free_memtype(addr, addr + size);
}

599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686
/*
 * Internal interface to reserve a range of physical memory with prot.
 * Reserved non RAM regions only and after successful reserve_memtype,
 * this func also keeps identity mapping (if any) in sync with this new prot.
 */
static int reserve_pfn_range(u64 paddr, unsigned long size, pgprot_t vma_prot)
{
	int is_ram = 0;
	int id_sz, ret;
	unsigned long flags;
	unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);

	is_ram = pagerange_is_ram(paddr, paddr + size);

	if (is_ram != 0) {
		/*
		 * For mapping RAM pages, drivers need to call
		 * set_memory_[uc|wc|wb] directly, for reserve and free, before
		 * setting up the PTE.
		 */
		WARN_ON_ONCE(1);
		return 0;
	}

	ret = reserve_memtype(paddr, paddr + size, want_flags, &flags);
	if (ret)
		return ret;

	if (flags != want_flags) {
		free_memtype(paddr, paddr + size);
		printk(KERN_ERR
		"%s:%d map pfn expected mapping type %s for %Lx-%Lx, got %s\n",
			current->comm, current->pid,
			cattr_name(want_flags),
			(unsigned long long)paddr,
			(unsigned long long)(paddr + size),
			cattr_name(flags));
		return -EINVAL;
	}

	/* Need to keep identity mapping in sync */
	if (paddr >= __pa(high_memory))
		return 0;

	id_sz = (__pa(high_memory) < paddr + size) ?
				__pa(high_memory) - paddr :
				size;

	if (ioremap_change_attr((unsigned long)__va(paddr), id_sz, flags) < 0) {
		free_memtype(paddr, paddr + size);
		printk(KERN_ERR
			"%s:%d reserve_pfn_range ioremap_change_attr failed %s "
			"for %Lx-%Lx\n",
			current->comm, current->pid,
			cattr_name(flags),
			(unsigned long long)paddr,
			(unsigned long long)(paddr + size));
		return -EINVAL;
	}
	return 0;
}

/*
 * Internal interface to free a range of physical memory.
 * Frees non RAM regions only.
 */
static void free_pfn_range(u64 paddr, unsigned long size)
{
	int is_ram;

	is_ram = pagerange_is_ram(paddr, paddr + size);
	if (is_ram == 0)
		free_memtype(paddr, paddr + size);
}

/*
 * track_pfn_vma_copy is called when vma that is covering the pfnmap gets
 * copied through copy_page_range().
 *
 * If the vma has a linear pfn mapping for the entire range, we get the prot
 * from pte and reserve the entire vma range with single reserve_pfn_range call.
 * Otherwise, we reserve the entire vma range, my ging through the PTEs page
 * by page to get physical address and protection.
 */
int track_pfn_vma_copy(struct vm_area_struct *vma)
{
	int retval = 0;
	unsigned long i, j;
687
	resource_size_t paddr;
688
	unsigned long prot;
689 690 691 692 693 694 695 696 697
	unsigned long vma_start = vma->vm_start;
	unsigned long vma_end = vma->vm_end;
	unsigned long vma_size = vma_end - vma_start;

	if (!pat_enabled)
		return 0;

	if (is_linear_pfn_mapping(vma)) {
		/*
698 699
		 * reserve the whole chunk covered by vma. We need the
		 * starting address and protection from pte.
700
		 */
701
		if (follow_phys(vma, vma_start, 0, &prot, &paddr)) {
702
			WARN_ON_ONCE(1);
703
			return -EINVAL;
704
		}
705
		return reserve_pfn_range(paddr, vma_size, __pgprot(prot));
706 707 708 709
	}

	/* reserve entire vma page by page, using pfn and prot from pte */
	for (i = 0; i < vma_size; i += PAGE_SIZE) {
710
		if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
711 712
			continue;

713
		retval = reserve_pfn_range(paddr, PAGE_SIZE, __pgprot(prot));
714 715 716 717 718 719 720 721
		if (retval)
			goto cleanup_ret;
	}
	return 0;

cleanup_ret:
	/* Reserve error: Cleanup partial reservation and return error */
	for (j = 0; j < i; j += PAGE_SIZE) {
722
		if (follow_phys(vma, vma_start + j, 0, &prot, &paddr))
723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743
			continue;

		free_pfn_range(paddr, PAGE_SIZE);
	}

	return retval;
}

/*
 * track_pfn_vma_new is called when a _new_ pfn mapping is being established
 * for physical range indicated by pfn and size.
 *
 * prot is passed in as a parameter for the new mapping. If the vma has a
 * linear pfn mapping for the entire range reserve the entire vma range with
 * single reserve_pfn_range call.
 * Otherwise, we look t the pfn and size and reserve only the specified range
 * page by page.
 *
 * Note that this function can be called with caller trying to map only a
 * subrange/page inside the vma.
 */
744
int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t *prot,
745 746 747 748
			unsigned long pfn, unsigned long size)
{
	int retval = 0;
	unsigned long i, j;
749 750
	resource_size_t base_paddr;
	resource_size_t paddr;
751 752 753 754 755 756 757 758 759
	unsigned long vma_start = vma->vm_start;
	unsigned long vma_end = vma->vm_end;
	unsigned long vma_size = vma_end - vma_start;

	if (!pat_enabled)
		return 0;

	if (is_linear_pfn_mapping(vma)) {
		/* reserve the whole chunk starting from vm_pgoff */
760
		paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
761
		return reserve_pfn_range(paddr, vma_size, *prot);
762 763 764
	}

	/* reserve page by page using pfn and size */
765
	base_paddr = (resource_size_t)pfn << PAGE_SHIFT;
766 767
	for (i = 0; i < size; i += PAGE_SIZE) {
		paddr = base_paddr + i;
768
		retval = reserve_pfn_range(paddr, PAGE_SIZE, *prot);
769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792
		if (retval)
			goto cleanup_ret;
	}
	return 0;

cleanup_ret:
	/* Reserve error: Cleanup partial reservation and return error */
	for (j = 0; j < i; j += PAGE_SIZE) {
		paddr = base_paddr + j;
		free_pfn_range(paddr, PAGE_SIZE);
	}

	return retval;
}

/*
 * untrack_pfn_vma is called while unmapping a pfnmap for a region.
 * untrack can be called for a specific region indicated by pfn and size or
 * can be for the entire vma (in which case size can be zero).
 */
void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn,
			unsigned long size)
{
	unsigned long i;
793
	resource_size_t paddr;
794
	unsigned long prot;
795 796 797 798 799 800 801 802 803
	unsigned long vma_start = vma->vm_start;
	unsigned long vma_end = vma->vm_end;
	unsigned long vma_size = vma_end - vma_start;

	if (!pat_enabled)
		return;

	if (is_linear_pfn_mapping(vma)) {
		/* free the whole chunk starting from vm_pgoff */
804
		paddr = (resource_size_t)vma->vm_pgoff << PAGE_SHIFT;
805 806 807 808 809 810
		free_pfn_range(paddr, vma_size);
		return;
	}

	if (size != 0 && size != vma_size) {
		/* free page by page, using pfn and size */
811
		paddr = (resource_size_t)pfn << PAGE_SHIFT;
812 813 814 815 816 817 818
		for (i = 0; i < size; i += PAGE_SIZE) {
			paddr = paddr + i;
			free_pfn_range(paddr, PAGE_SIZE);
		}
	} else {
		/* free entire vma, page by page, using the pfn from pte */
		for (i = 0; i < vma_size; i += PAGE_SIZE) {
819
			if (follow_phys(vma, vma_start + i, 0, &prot, &paddr))
820 821 822 823 824 825 826
				continue;

			free_pfn_range(paddr, PAGE_SIZE);
		}
	}
}

827 828 829 830 831 832 833 834
pgprot_t pgprot_writecombine(pgprot_t prot)
{
	if (pat_enabled)
		return __pgprot(pgprot_val(prot) | _PAGE_CACHE_WC);
	else
		return pgprot_noncached(prot);
}

835
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857

/* get Nth element of the linked list */
static struct memtype *memtype_get_idx(loff_t pos)
{
	struct memtype *list_node, *print_entry;
	int i = 1;

	print_entry  = kmalloc(sizeof(struct memtype), GFP_KERNEL);
	if (!print_entry)
		return NULL;

	spin_lock(&memtype_lock);
	list_for_each_entry(list_node, &memtype_list, nd) {
		if (pos == i) {
			*print_entry = *list_node;
			spin_unlock(&memtype_lock);
			return print_entry;
		}
		++i;
	}
	spin_unlock(&memtype_lock);
	kfree(print_entry);
I
Ingo Molnar 已提交
858

859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888
	return NULL;
}

static void *memtype_seq_start(struct seq_file *seq, loff_t *pos)
{
	if (*pos == 0) {
		++*pos;
		seq_printf(seq, "PAT memtype list:\n");
	}

	return memtype_get_idx(*pos);
}

static void *memtype_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
	++*pos;
	return memtype_get_idx(*pos);
}

static void memtype_seq_stop(struct seq_file *seq, void *v)
{
}

static int memtype_seq_show(struct seq_file *seq, void *v)
{
	struct memtype *print_entry = (struct memtype *)v;

	seq_printf(seq, "%s @ 0x%Lx-0x%Lx\n", cattr_name(print_entry->type),
			print_entry->start, print_entry->end);
	kfree(print_entry);
I
Ingo Molnar 已提交
889

890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920
	return 0;
}

static struct seq_operations memtype_seq_ops = {
	.start = memtype_seq_start,
	.next  = memtype_seq_next,
	.stop  = memtype_seq_stop,
	.show  = memtype_seq_show,
};

static int memtype_seq_open(struct inode *inode, struct file *file)
{
	return seq_open(file, &memtype_seq_ops);
}

static const struct file_operations memtype_fops = {
	.open    = memtype_seq_open,
	.read    = seq_read,
	.llseek  = seq_lseek,
	.release = seq_release,
};

static int __init pat_memtype_list_init(void)
{
	debugfs_create_file("pat_memtype_list", S_IRUSR, arch_debugfs_dir,
				NULL, &memtype_fops);
	return 0;
}

late_initcall(pat_memtype_list_init);

921
#endif /* CONFIG_DEBUG_FS && CONFIG_X86_PAT */