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v6.2
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Re-map IO memory to kernel address space so that we can access it.
  4 * This is needed for high PCI addresses that aren't mapped in the
  5 * 640k-1MB IO memory area on PC's
  6 *
  7 * (C) Copyright 1995 1996 Linus Torvalds
  8 */
  9
 10#include <linux/memblock.h>
 11#include <linux/init.h>
 12#include <linux/io.h>
 13#include <linux/ioport.h>
 14#include <linux/slab.h>
 15#include <linux/vmalloc.h>
 16#include <linux/mmiotrace.h>
 17#include <linux/cc_platform.h>
 18#include <linux/efi.h>
 19#include <linux/pgtable.h>
 20#include <linux/kmsan.h>
 21
 22#include <asm/set_memory.h>
 23#include <asm/e820/api.h>
 24#include <asm/efi.h>
 25#include <asm/fixmap.h>
 
 26#include <asm/tlbflush.h>
 27#include <asm/pgalloc.h>
 28#include <asm/memtype.h>
 29#include <asm/setup.h>
 30
 31#include "physaddr.h"
 32
 33/*
 34 * Descriptor controlling ioremap() behavior.
 35 */
 36struct ioremap_desc {
 37	unsigned int flags;
 38};
 39
 40/*
 41 * Fix up the linear direct mapping of the kernel to avoid cache attribute
 42 * conflicts.
 43 */
 44int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 45			enum page_cache_mode pcm)
 46{
 47	unsigned long nrpages = size >> PAGE_SHIFT;
 48	int err;
 49
 50	switch (pcm) {
 51	case _PAGE_CACHE_MODE_UC:
 52	default:
 53		err = _set_memory_uc(vaddr, nrpages);
 54		break;
 55	case _PAGE_CACHE_MODE_WC:
 56		err = _set_memory_wc(vaddr, nrpages);
 57		break;
 58	case _PAGE_CACHE_MODE_WT:
 59		err = _set_memory_wt(vaddr, nrpages);
 60		break;
 61	case _PAGE_CACHE_MODE_WB:
 62		err = _set_memory_wb(vaddr, nrpages);
 63		break;
 64	}
 65
 66	return err;
 67}
 68
 69/* Does the range (or a subset of) contain normal RAM? */
 70static unsigned int __ioremap_check_ram(struct resource *res)
 71{
 72	unsigned long start_pfn, stop_pfn;
 73	unsigned long i;
 74
 75	if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM)
 76		return 0;
 77
 78	start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
 79	stop_pfn = (res->end + 1) >> PAGE_SHIFT;
 80	if (stop_pfn > start_pfn) {
 81		for (i = 0; i < (stop_pfn - start_pfn); ++i)
 82			if (pfn_valid(start_pfn + i) &&
 83			    !PageReserved(pfn_to_page(start_pfn + i)))
 84				return IORES_MAP_SYSTEM_RAM;
 85	}
 86
 87	return 0;
 88}
 89
 90/*
 91 * In a SEV guest, NONE and RESERVED should not be mapped encrypted because
 92 * there the whole memory is already encrypted.
 93 */
 94static unsigned int __ioremap_check_encrypted(struct resource *res)
 95{
 96	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
 97		return 0;
 98
 99	switch (res->desc) {
100	case IORES_DESC_NONE:
101	case IORES_DESC_RESERVED:
102		break;
103	default:
104		return IORES_MAP_ENCRYPTED;
105	}
106
107	return 0;
108}
109
110/*
111 * The EFI runtime services data area is not covered by walk_mem_res(), but must
112 * be mapped encrypted when SEV is active.
113 */
114static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *desc)
115{
116	if (!cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
117		return;
118
119	if (!IS_ENABLED(CONFIG_EFI))
120		return;
121
122	if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA ||
123	    (efi_mem_type(addr) == EFI_BOOT_SERVICES_DATA &&
124	     efi_mem_attributes(addr) & EFI_MEMORY_RUNTIME))
125		desc->flags |= IORES_MAP_ENCRYPTED;
126}
127
128static int __ioremap_collect_map_flags(struct resource *res, void *arg)
129{
130	struct ioremap_desc *desc = arg;
131
132	if (!(desc->flags & IORES_MAP_SYSTEM_RAM))
133		desc->flags |= __ioremap_check_ram(res);
134
135	if (!(desc->flags & IORES_MAP_ENCRYPTED))
136		desc->flags |= __ioremap_check_encrypted(res);
137
138	return ((desc->flags & (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)) ==
139			       (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED));
140}
141
142/*
143 * To avoid multiple resource walks, this function walks resources marked as
144 * IORESOURCE_MEM and IORESOURCE_BUSY and looking for system RAM and/or a
145 * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES).
146 *
147 * After that, deal with misc other ranges in __ioremap_check_other() which do
148 * not fall into the above category.
149 */
150static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
151				struct ioremap_desc *desc)
152{
153	u64 start, end;
154
155	start = (u64)addr;
156	end = start + size - 1;
157	memset(desc, 0, sizeof(struct ioremap_desc));
158
159	walk_mem_res(start, end, desc, __ioremap_collect_map_flags);
160
161	__ioremap_check_other(addr, desc);
162}
163
164/*
165 * Remap an arbitrary physical address space into the kernel virtual
166 * address space. It transparently creates kernel huge I/O mapping when
167 * the physical address is aligned by a huge page size (1GB or 2MB) and
168 * the requested size is at least the huge page size.
169 *
170 * NOTE: MTRRs can override PAT memory types with a 4KB granularity.
171 * Therefore, the mapping code falls back to use a smaller page toward 4KB
172 * when a mapping range is covered by non-WB type of MTRRs.
173 *
174 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
175 * have to convert them into an offset in a page-aligned mapping, but the
176 * caller shouldn't need to know that small detail.
177 */
178static void __iomem *
179__ioremap_caller(resource_size_t phys_addr, unsigned long size,
180		 enum page_cache_mode pcm, void *caller, bool encrypted)
181{
182	unsigned long offset, vaddr;
183	resource_size_t last_addr;
184	const resource_size_t unaligned_phys_addr = phys_addr;
185	const unsigned long unaligned_size = size;
186	struct ioremap_desc io_desc;
187	struct vm_struct *area;
188	enum page_cache_mode new_pcm;
189	pgprot_t prot;
190	int retval;
191	void __iomem *ret_addr;
192
193	/* Don't allow wraparound or zero size */
194	last_addr = phys_addr + size - 1;
195	if (!size || last_addr < phys_addr)
196		return NULL;
197
198	if (!phys_addr_valid(phys_addr)) {
199		printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
200		       (unsigned long long)phys_addr);
201		WARN_ON_ONCE(1);
202		return NULL;
203	}
204
205	__ioremap_check_mem(phys_addr, size, &io_desc);
 
 
 
 
206
207	/*
208	 * Don't allow anybody to remap normal RAM that we're using..
209	 */
210	if (io_desc.flags & IORES_MAP_SYSTEM_RAM) {
 
 
 
211		WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
212			  &phys_addr, &last_addr);
213		return NULL;
214	}
215
216	/*
217	 * Mappings have to be page-aligned
218	 */
219	offset = phys_addr & ~PAGE_MASK;
220	phys_addr &= PAGE_MASK;
221	size = PAGE_ALIGN(last_addr+1) - phys_addr;
222
223	/*
224	 * Mask out any bits not part of the actual physical
225	 * address, like memory encryption bits.
226	 */
227	phys_addr &= PHYSICAL_PAGE_MASK;
 
228
229	retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
230						pcm, &new_pcm);
231	if (retval) {
232		printk(KERN_ERR "ioremap memtype_reserve failed %d\n", retval);
233		return NULL;
234	}
235
236	if (pcm != new_pcm) {
237		if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) {
238			printk(KERN_ERR
239		"ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n",
240				(unsigned long long)phys_addr,
241				(unsigned long long)(phys_addr + size),
242				pcm, new_pcm);
243			goto err_free_memtype;
244		}
245		pcm = new_pcm;
246	}
247
248	/*
249	 * If the page being mapped is in memory and SEV is active then
250	 * make sure the memory encryption attribute is enabled in the
251	 * resulting mapping.
252	 * In TDX guests, memory is marked private by default. If encryption
253	 * is not requested (using encrypted), explicitly set decrypt
254	 * attribute in all IOREMAPPED memory.
255	 */
256	prot = PAGE_KERNEL_IO;
257	if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted)
258		prot = pgprot_encrypted(prot);
259	else
260		prot = pgprot_decrypted(prot);
261
262	switch (pcm) {
263	case _PAGE_CACHE_MODE_UC:
264	default:
265		prot = __pgprot(pgprot_val(prot) |
266				cachemode2protval(_PAGE_CACHE_MODE_UC));
267		break;
268	case _PAGE_CACHE_MODE_UC_MINUS:
269		prot = __pgprot(pgprot_val(prot) |
270				cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
271		break;
272	case _PAGE_CACHE_MODE_WC:
273		prot = __pgprot(pgprot_val(prot) |
274				cachemode2protval(_PAGE_CACHE_MODE_WC));
275		break;
276	case _PAGE_CACHE_MODE_WT:
277		prot = __pgprot(pgprot_val(prot) |
278				cachemode2protval(_PAGE_CACHE_MODE_WT));
279		break;
280	case _PAGE_CACHE_MODE_WB:
281		break;
282	}
283
284	/*
285	 * Ok, go for it..
286	 */
287	area = get_vm_area_caller(size, VM_IOREMAP, caller);
288	if (!area)
289		goto err_free_memtype;
290	area->phys_addr = phys_addr;
291	vaddr = (unsigned long) area->addr;
292
293	if (memtype_kernel_map_sync(phys_addr, size, pcm))
294		goto err_free_area;
295
296	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
297		goto err_free_area;
298
299	ret_addr = (void __iomem *) (vaddr + offset);
300	mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
301
302	/*
303	 * Check if the request spans more than any BAR in the iomem resource
304	 * tree.
305	 */
306	if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size))
307		pr_warn("caller %pS mapping multiple BARs\n", caller);
308
309	return ret_addr;
310err_free_area:
311	free_vm_area(area);
312err_free_memtype:
313	memtype_free(phys_addr, phys_addr + size);
314	return NULL;
315}
316
317/**
318 * ioremap     -   map bus memory into CPU space
319 * @phys_addr:    bus address of the memory
320 * @size:      size of the resource to map
321 *
322 * ioremap performs a platform specific sequence of operations to
323 * make bus memory CPU accessible via the readb/readw/readl/writeb/
324 * writew/writel functions and the other mmio helpers. The returned
325 * address is not guaranteed to be usable directly as a virtual
326 * address.
327 *
328 * This version of ioremap ensures that the memory is marked uncachable
329 * on the CPU as well as honouring existing caching rules from things like
330 * the PCI bus. Note that there are other caches and buffers on many
331 * busses. In particular driver authors should read up on PCI writes
332 *
333 * It's useful if some control registers are in such an area and
334 * write combining or read caching is not desirable:
335 *
336 * Must be freed with iounmap.
337 */
338void __iomem *ioremap(resource_size_t phys_addr, unsigned long size)
339{
340	/*
341	 * Ideally, this should be:
342	 *	pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS;
343	 *
344	 * Till we fix all X drivers to use ioremap_wc(), we will use
345	 * UC MINUS. Drivers that are certain they need or can already
346	 * be converted over to strong UC can use ioremap_uc().
347	 */
348	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
349
350	return __ioremap_caller(phys_addr, size, pcm,
351				__builtin_return_address(0), false);
352}
353EXPORT_SYMBOL(ioremap);
354
355/**
356 * ioremap_uc     -   map bus memory into CPU space as strongly uncachable
357 * @phys_addr:    bus address of the memory
358 * @size:      size of the resource to map
359 *
360 * ioremap_uc performs a platform specific sequence of operations to
361 * make bus memory CPU accessible via the readb/readw/readl/writeb/
362 * writew/writel functions and the other mmio helpers. The returned
363 * address is not guaranteed to be usable directly as a virtual
364 * address.
365 *
366 * This version of ioremap ensures that the memory is marked with a strong
367 * preference as completely uncachable on the CPU when possible. For non-PAT
368 * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT
369 * systems this will set the PAT entry for the pages as strong UC.  This call
370 * will honor existing caching rules from things like the PCI bus. Note that
371 * there are other caches and buffers on many busses. In particular driver
372 * authors should read up on PCI writes.
373 *
374 * It's useful if some control registers are in such an area and
375 * write combining or read caching is not desirable:
376 *
377 * Must be freed with iounmap.
378 */
379void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size)
380{
381	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC;
382
383	return __ioremap_caller(phys_addr, size, pcm,
384				__builtin_return_address(0), false);
385}
386EXPORT_SYMBOL_GPL(ioremap_uc);
387
388/**
389 * ioremap_wc	-	map memory into CPU space write combined
390 * @phys_addr:	bus address of the memory
391 * @size:	size of the resource to map
392 *
393 * This version of ioremap ensures that the memory is marked write combining.
394 * Write combining allows faster writes to some hardware devices.
395 *
396 * Must be freed with iounmap.
397 */
398void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
399{
400	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
401					__builtin_return_address(0), false);
402}
403EXPORT_SYMBOL(ioremap_wc);
404
405/**
406 * ioremap_wt	-	map memory into CPU space write through
407 * @phys_addr:	bus address of the memory
408 * @size:	size of the resource to map
409 *
410 * This version of ioremap ensures that the memory is marked write through.
411 * Write through stores data into memory while keeping the cache up-to-date.
412 *
413 * Must be freed with iounmap.
414 */
415void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size)
416{
417	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT,
418					__builtin_return_address(0), false);
419}
420EXPORT_SYMBOL(ioremap_wt);
421
422void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size)
423{
424	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
425				__builtin_return_address(0), true);
426}
427EXPORT_SYMBOL(ioremap_encrypted);
428
429void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
430{
431	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
432				__builtin_return_address(0), false);
433}
434EXPORT_SYMBOL(ioremap_cache);
435
436void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
437				unsigned long prot_val)
438{
439	return __ioremap_caller(phys_addr, size,
440				pgprot2cachemode(__pgprot(prot_val)),
441				__builtin_return_address(0), false);
442}
443EXPORT_SYMBOL(ioremap_prot);
444
445/**
446 * iounmap - Free a IO remapping
447 * @addr: virtual address from ioremap_*
448 *
449 * Caller must ensure there is only one unmapping for the same pointer.
450 */
451void iounmap(volatile void __iomem *addr)
452{
453	struct vm_struct *p, *o;
454
455	if ((void __force *)addr <= high_memory)
456		return;
457
458	/*
459	 * The PCI/ISA range special-casing was removed from __ioremap()
460	 * so this check, in theory, can be removed. However, there are
461	 * cases where iounmap() is called for addresses not obtained via
462	 * ioremap() (vga16fb for example). Add a warning so that these
463	 * cases can be caught and fixed.
464	 */
465	if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
466	    (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) {
467		WARN(1, "iounmap() called for ISA range not obtained using ioremap()\n");
468		return;
469	}
470
471	mmiotrace_iounmap(addr);
472
473	addr = (volatile void __iomem *)
474		(PAGE_MASK & (unsigned long __force)addr);
475
 
 
476	/* Use the vm area unlocked, assuming the caller
477	   ensures there isn't another iounmap for the same address
478	   in parallel. Reuse of the virtual address is prevented by
479	   leaving it in the global lists until we're done with it.
480	   cpa takes care of the direct mappings. */
481	p = find_vm_area((void __force *)addr);
482
483	if (!p) {
484		printk(KERN_ERR "iounmap: bad address %p\n", addr);
485		dump_stack();
486		return;
487	}
488
489	kmsan_iounmap_page_range((unsigned long)addr,
490		(unsigned long)addr + get_vm_area_size(p));
491	memtype_free(p->phys_addr, p->phys_addr + get_vm_area_size(p));
492
493	/* Finally remove it */
494	o = remove_vm_area((void __force *)addr);
495	BUG_ON(p != o || o == NULL);
496	kfree(p);
497}
498EXPORT_SYMBOL(iounmap);
499
 
 
 
 
 
 
 
 
 
 
 
 
 
 
500/*
501 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
502 * access
503 */
504void *xlate_dev_mem_ptr(phys_addr_t phys)
505{
506	unsigned long start  = phys &  PAGE_MASK;
507	unsigned long offset = phys & ~PAGE_MASK;
508	void *vaddr;
509
510	/* memremap() maps if RAM, otherwise falls back to ioremap() */
511	vaddr = memremap(start, PAGE_SIZE, MEMREMAP_WB);
 
512
513	/* Only add the offset on success and return NULL if memremap() failed */
 
514	if (vaddr)
515		vaddr += offset;
516
517	return vaddr;
518}
519
520void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
521{
522	memunmap((void *)((unsigned long)addr & PAGE_MASK));
523}
524
525#ifdef CONFIG_AMD_MEM_ENCRYPT
526/*
527 * Examine the physical address to determine if it is an area of memory
528 * that should be mapped decrypted.  If the memory is not part of the
529 * kernel usable area it was accessed and created decrypted, so these
530 * areas should be mapped decrypted. And since the encryption key can
531 * change across reboots, persistent memory should also be mapped
532 * decrypted.
533 *
534 * If SEV is active, that implies that BIOS/UEFI also ran encrypted so
535 * only persistent memory should be mapped decrypted.
536 */
537static bool memremap_should_map_decrypted(resource_size_t phys_addr,
538					  unsigned long size)
539{
540	int is_pmem;
541
542	/*
543	 * Check if the address is part of a persistent memory region.
544	 * This check covers areas added by E820, EFI and ACPI.
545	 */
546	is_pmem = region_intersects(phys_addr, size, IORESOURCE_MEM,
547				    IORES_DESC_PERSISTENT_MEMORY);
548	if (is_pmem != REGION_DISJOINT)
549		return true;
550
551	/*
552	 * Check if the non-volatile attribute is set for an EFI
553	 * reserved area.
554	 */
555	if (efi_enabled(EFI_BOOT)) {
556		switch (efi_mem_type(phys_addr)) {
557		case EFI_RESERVED_TYPE:
558			if (efi_mem_attributes(phys_addr) & EFI_MEMORY_NV)
559				return true;
560			break;
561		default:
562			break;
563		}
564	}
565
566	/* Check if the address is outside kernel usable area */
567	switch (e820__get_entry_type(phys_addr, phys_addr + size - 1)) {
568	case E820_TYPE_RESERVED:
569	case E820_TYPE_ACPI:
570	case E820_TYPE_NVS:
571	case E820_TYPE_UNUSABLE:
572		/* For SEV, these areas are encrypted */
573		if (cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT))
574			break;
575		fallthrough;
576
577	case E820_TYPE_PRAM:
578		return true;
579	default:
580		break;
581	}
582
583	return false;
584}
585
586/*
587 * Examine the physical address to determine if it is EFI data. Check
588 * it against the boot params structure and EFI tables and memory types.
589 */
590static bool memremap_is_efi_data(resource_size_t phys_addr,
591				 unsigned long size)
592{
593	u64 paddr;
594
595	/* Check if the address is part of EFI boot/runtime data */
596	if (!efi_enabled(EFI_BOOT))
597		return false;
598
599	paddr = boot_params.efi_info.efi_memmap_hi;
600	paddr <<= 32;
601	paddr |= boot_params.efi_info.efi_memmap;
602	if (phys_addr == paddr)
603		return true;
604
605	paddr = boot_params.efi_info.efi_systab_hi;
606	paddr <<= 32;
607	paddr |= boot_params.efi_info.efi_systab;
608	if (phys_addr == paddr)
609		return true;
610
611	if (efi_is_table_address(phys_addr))
612		return true;
613
614	switch (efi_mem_type(phys_addr)) {
615	case EFI_BOOT_SERVICES_DATA:
616	case EFI_RUNTIME_SERVICES_DATA:
617		return true;
618	default:
619		break;
620	}
621
622	return false;
623}
624
625/*
626 * Examine the physical address to determine if it is boot data by checking
627 * it against the boot params setup_data chain.
628 */
629static bool memremap_is_setup_data(resource_size_t phys_addr,
630				   unsigned long size)
631{
632	struct setup_indirect *indirect;
633	struct setup_data *data;
634	u64 paddr, paddr_next;
635
636	paddr = boot_params.hdr.setup_data;
637	while (paddr) {
638		unsigned int len;
639
640		if (phys_addr == paddr)
641			return true;
642
643		data = memremap(paddr, sizeof(*data),
644				MEMREMAP_WB | MEMREMAP_DEC);
645		if (!data) {
646			pr_warn("failed to memremap setup_data entry\n");
647			return false;
648		}
649
650		paddr_next = data->next;
651		len = data->len;
652
653		if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
654			memunmap(data);
655			return true;
656		}
657
658		if (data->type == SETUP_INDIRECT) {
659			memunmap(data);
660			data = memremap(paddr, sizeof(*data) + len,
661					MEMREMAP_WB | MEMREMAP_DEC);
662			if (!data) {
663				pr_warn("failed to memremap indirect setup_data\n");
664				return false;
665			}
666
667			indirect = (struct setup_indirect *)data->data;
668
669			if (indirect->type != SETUP_INDIRECT) {
670				paddr = indirect->addr;
671				len = indirect->len;
672			}
673		}
674
675		memunmap(data);
676
677		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
678			return true;
679
680		paddr = paddr_next;
681	}
682
683	return false;
684}
685
686/*
687 * Examine the physical address to determine if it is boot data by checking
688 * it against the boot params setup_data chain (early boot version).
689 */
690static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
691						unsigned long size)
692{
693	struct setup_indirect *indirect;
694	struct setup_data *data;
695	u64 paddr, paddr_next;
696
697	paddr = boot_params.hdr.setup_data;
698	while (paddr) {
699		unsigned int len, size;
700
701		if (phys_addr == paddr)
702			return true;
703
704		data = early_memremap_decrypted(paddr, sizeof(*data));
705		if (!data) {
706			pr_warn("failed to early memremap setup_data entry\n");
707			return false;
708		}
709
710		size = sizeof(*data);
711
712		paddr_next = data->next;
713		len = data->len;
714
715		if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
716			early_memunmap(data, sizeof(*data));
717			return true;
718		}
719
720		if (data->type == SETUP_INDIRECT) {
721			size += len;
722			early_memunmap(data, sizeof(*data));
723			data = early_memremap_decrypted(paddr, size);
724			if (!data) {
725				pr_warn("failed to early memremap indirect setup_data\n");
726				return false;
727			}
728
729			indirect = (struct setup_indirect *)data->data;
730
731			if (indirect->type != SETUP_INDIRECT) {
732				paddr = indirect->addr;
733				len = indirect->len;
734			}
735		}
736
737		early_memunmap(data, size);
738
739		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
740			return true;
741
742		paddr = paddr_next;
743	}
744
745	return false;
746}
747
748/*
749 * Architecture function to determine if RAM remap is allowed. By default, a
750 * RAM remap will map the data as encrypted. Determine if a RAM remap should
751 * not be done so that the data will be mapped decrypted.
752 */
753bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size,
754				 unsigned long flags)
755{
756	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
757		return true;
758
759	if (flags & MEMREMAP_ENC)
760		return true;
761
762	if (flags & MEMREMAP_DEC)
763		return false;
764
765	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
766		if (memremap_is_setup_data(phys_addr, size) ||
767		    memremap_is_efi_data(phys_addr, size))
768			return false;
769	}
770
771	return !memremap_should_map_decrypted(phys_addr, size);
772}
773
774/*
775 * Architecture override of __weak function to adjust the protection attributes
776 * used when remapping memory. By default, early_memremap() will map the data
777 * as encrypted. Determine if an encrypted mapping should not be done and set
778 * the appropriate protection attributes.
779 */
780pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
781					     unsigned long size,
782					     pgprot_t prot)
783{
784	bool encrypted_prot;
785
786	if (!cc_platform_has(CC_ATTR_MEM_ENCRYPT))
787		return prot;
788
789	encrypted_prot = true;
790
791	if (cc_platform_has(CC_ATTR_HOST_MEM_ENCRYPT)) {
792		if (early_memremap_is_setup_data(phys_addr, size) ||
793		    memremap_is_efi_data(phys_addr, size))
794			encrypted_prot = false;
795	}
796
797	if (encrypted_prot && memremap_should_map_decrypted(phys_addr, size))
798		encrypted_prot = false;
799
800	return encrypted_prot ? pgprot_encrypted(prot)
801			      : pgprot_decrypted(prot);
802}
803
804bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size)
805{
806	return arch_memremap_can_ram_remap(phys_addr, size, 0);
807}
808
809/* Remap memory with encryption */
810void __init *early_memremap_encrypted(resource_size_t phys_addr,
811				      unsigned long size)
812{
813	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC);
814}
815
816/*
817 * Remap memory with encryption and write-protected - cannot be called
818 * before pat_init() is called
819 */
820void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
821					 unsigned long size)
822{
823	if (!x86_has_pat_wp())
824		return NULL;
825	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP);
826}
827
828/* Remap memory without encryption */
829void __init *early_memremap_decrypted(resource_size_t phys_addr,
830				      unsigned long size)
831{
832	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC);
833}
834
835/*
836 * Remap memory without encryption and write-protected - cannot be called
837 * before pat_init() is called
838 */
839void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
840					 unsigned long size)
841{
842	if (!x86_has_pat_wp())
843		return NULL;
844	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP);
845}
846#endif	/* CONFIG_AMD_MEM_ENCRYPT */
847
848static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
849
850static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
851{
852	/* Don't assume we're using swapper_pg_dir at this point */
853	pgd_t *base = __va(read_cr3_pa());
854	pgd_t *pgd = &base[pgd_index(addr)];
855	p4d_t *p4d = p4d_offset(pgd, addr);
856	pud_t *pud = pud_offset(p4d, addr);
857	pmd_t *pmd = pmd_offset(pud, addr);
858
859	return pmd;
860}
861
862static inline pte_t * __init early_ioremap_pte(unsigned long addr)
863{
864	return &bm_pte[pte_index(addr)];
865}
866
867bool __init is_early_ioremap_ptep(pte_t *ptep)
868{
869	return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
870}
871
872void __init early_ioremap_init(void)
873{
874	pmd_t *pmd;
875
876#ifdef CONFIG_X86_64
877	BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
878#else
879	WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
880#endif
881
882	early_ioremap_setup();
883
884	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
885	memset(bm_pte, 0, sizeof(bm_pte));
886	pmd_populate_kernel(&init_mm, pmd, bm_pte);
887
888	/*
889	 * The boot-ioremap range spans multiple pmds, for which
890	 * we are not prepared:
891	 */
892#define __FIXADDR_TOP (-PAGE_SIZE)
893	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
894		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
895#undef __FIXADDR_TOP
896	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
897		WARN_ON(1);
898		printk(KERN_WARNING "pmd %p != %p\n",
899		       pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
900		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
901			fix_to_virt(FIX_BTMAP_BEGIN));
902		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
903			fix_to_virt(FIX_BTMAP_END));
904
905		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
906		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
907		       FIX_BTMAP_BEGIN);
908	}
909}
910
911void __init __early_set_fixmap(enum fixed_addresses idx,
912			       phys_addr_t phys, pgprot_t flags)
913{
914	unsigned long addr = __fix_to_virt(idx);
915	pte_t *pte;
916
917	if (idx >= __end_of_fixed_addresses) {
918		BUG();
919		return;
920	}
921	pte = early_ioremap_pte(addr);
922
923	/* Sanitize 'prot' against any unsupported bits: */
924	pgprot_val(flags) &= __supported_pte_mask;
925
926	if (pgprot_val(flags))
927		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
928	else
929		pte_clear(&init_mm, addr, pte);
930	flush_tlb_one_kernel(addr);
931}
v4.6
 
  1/*
  2 * Re-map IO memory to kernel address space so that we can access it.
  3 * This is needed for high PCI addresses that aren't mapped in the
  4 * 640k-1MB IO memory area on PC's
  5 *
  6 * (C) Copyright 1995 1996 Linus Torvalds
  7 */
  8
  9#include <linux/bootmem.h>
 10#include <linux/init.h>
 11#include <linux/io.h>
 12#include <linux/module.h>
 13#include <linux/slab.h>
 14#include <linux/vmalloc.h>
 15#include <linux/mmiotrace.h>
 16
 17#include <asm/cacheflush.h>
 18#include <asm/e820.h>
 
 
 
 
 
 19#include <asm/fixmap.h>
 20#include <asm/pgtable.h>
 21#include <asm/tlbflush.h>
 22#include <asm/pgalloc.h>
 23#include <asm/pat.h>
 
 24
 25#include "physaddr.h"
 26
 27/*
 
 
 
 
 
 
 
 28 * Fix up the linear direct mapping of the kernel to avoid cache attribute
 29 * conflicts.
 30 */
 31int ioremap_change_attr(unsigned long vaddr, unsigned long size,
 32			enum page_cache_mode pcm)
 33{
 34	unsigned long nrpages = size >> PAGE_SHIFT;
 35	int err;
 36
 37	switch (pcm) {
 38	case _PAGE_CACHE_MODE_UC:
 39	default:
 40		err = _set_memory_uc(vaddr, nrpages);
 41		break;
 42	case _PAGE_CACHE_MODE_WC:
 43		err = _set_memory_wc(vaddr, nrpages);
 44		break;
 45	case _PAGE_CACHE_MODE_WT:
 46		err = _set_memory_wt(vaddr, nrpages);
 47		break;
 48	case _PAGE_CACHE_MODE_WB:
 49		err = _set_memory_wb(vaddr, nrpages);
 50		break;
 51	}
 52
 53	return err;
 54}
 55
 56static int __ioremap_check_ram(unsigned long start_pfn, unsigned long nr_pages,
 57			       void *arg)
 58{
 
 59	unsigned long i;
 60
 61	for (i = 0; i < nr_pages; ++i)
 62		if (pfn_valid(start_pfn + i) &&
 63		    !PageReserved(pfn_to_page(start_pfn + i)))
 64			return 1;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 65
 66	return 0;
 67}
 68
 69/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 70 * Remap an arbitrary physical address space into the kernel virtual
 71 * address space. It transparently creates kernel huge I/O mapping when
 72 * the physical address is aligned by a huge page size (1GB or 2MB) and
 73 * the requested size is at least the huge page size.
 74 *
 75 * NOTE: MTRRs can override PAT memory types with a 4KB granularity.
 76 * Therefore, the mapping code falls back to use a smaller page toward 4KB
 77 * when a mapping range is covered by non-WB type of MTRRs.
 78 *
 79 * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 80 * have to convert them into an offset in a page-aligned mapping, but the
 81 * caller shouldn't need to know that small detail.
 82 */
 83static void __iomem *__ioremap_caller(resource_size_t phys_addr,
 84		unsigned long size, enum page_cache_mode pcm, void *caller)
 
 85{
 86	unsigned long offset, vaddr;
 87	resource_size_t pfn, last_pfn, last_addr;
 88	const resource_size_t unaligned_phys_addr = phys_addr;
 89	const unsigned long unaligned_size = size;
 
 90	struct vm_struct *area;
 91	enum page_cache_mode new_pcm;
 92	pgprot_t prot;
 93	int retval;
 94	void __iomem *ret_addr;
 95
 96	/* Don't allow wraparound or zero size */
 97	last_addr = phys_addr + size - 1;
 98	if (!size || last_addr < phys_addr)
 99		return NULL;
100
101	if (!phys_addr_valid(phys_addr)) {
102		printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
103		       (unsigned long long)phys_addr);
104		WARN_ON_ONCE(1);
105		return NULL;
106	}
107
108	/*
109	 * Don't remap the low PCI/ISA area, it's always mapped..
110	 */
111	if (is_ISA_range(phys_addr, last_addr))
112		return (__force void __iomem *)phys_to_virt(phys_addr);
113
114	/*
115	 * Don't allow anybody to remap normal RAM that we're using..
116	 */
117	pfn      = phys_addr >> PAGE_SHIFT;
118	last_pfn = last_addr >> PAGE_SHIFT;
119	if (walk_system_ram_range(pfn, last_pfn - pfn + 1, NULL,
120					  __ioremap_check_ram) == 1) {
121		WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
122			  &phys_addr, &last_addr);
123		return NULL;
124	}
125
126	/*
127	 * Mappings have to be page-aligned
128	 */
129	offset = phys_addr & ~PAGE_MASK;
 
 
 
 
 
 
 
130	phys_addr &= PHYSICAL_PAGE_MASK;
131	size = PAGE_ALIGN(last_addr+1) - phys_addr;
132
133	retval = reserve_memtype(phys_addr, (u64)phys_addr + size,
134						pcm, &new_pcm);
135	if (retval) {
136		printk(KERN_ERR "ioremap reserve_memtype failed %d\n", retval);
137		return NULL;
138	}
139
140	if (pcm != new_pcm) {
141		if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) {
142			printk(KERN_ERR
143		"ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n",
144				(unsigned long long)phys_addr,
145				(unsigned long long)(phys_addr + size),
146				pcm, new_pcm);
147			goto err_free_memtype;
148		}
149		pcm = new_pcm;
150	}
151
 
 
 
 
 
 
 
 
152	prot = PAGE_KERNEL_IO;
 
 
 
 
 
153	switch (pcm) {
154	case _PAGE_CACHE_MODE_UC:
155	default:
156		prot = __pgprot(pgprot_val(prot) |
157				cachemode2protval(_PAGE_CACHE_MODE_UC));
158		break;
159	case _PAGE_CACHE_MODE_UC_MINUS:
160		prot = __pgprot(pgprot_val(prot) |
161				cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
162		break;
163	case _PAGE_CACHE_MODE_WC:
164		prot = __pgprot(pgprot_val(prot) |
165				cachemode2protval(_PAGE_CACHE_MODE_WC));
166		break;
167	case _PAGE_CACHE_MODE_WT:
168		prot = __pgprot(pgprot_val(prot) |
169				cachemode2protval(_PAGE_CACHE_MODE_WT));
170		break;
171	case _PAGE_CACHE_MODE_WB:
172		break;
173	}
174
175	/*
176	 * Ok, go for it..
177	 */
178	area = get_vm_area_caller(size, VM_IOREMAP, caller);
179	if (!area)
180		goto err_free_memtype;
181	area->phys_addr = phys_addr;
182	vaddr = (unsigned long) area->addr;
183
184	if (kernel_map_sync_memtype(phys_addr, size, pcm))
185		goto err_free_area;
186
187	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
188		goto err_free_area;
189
190	ret_addr = (void __iomem *) (vaddr + offset);
191	mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
192
193	/*
194	 * Check if the request spans more than any BAR in the iomem resource
195	 * tree.
196	 */
197	if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size))
198		pr_warn("caller %pS mapping multiple BARs\n", caller);
199
200	return ret_addr;
201err_free_area:
202	free_vm_area(area);
203err_free_memtype:
204	free_memtype(phys_addr, phys_addr + size);
205	return NULL;
206}
207
208/**
209 * ioremap_nocache     -   map bus memory into CPU space
210 * @phys_addr:    bus address of the memory
211 * @size:      size of the resource to map
212 *
213 * ioremap_nocache performs a platform specific sequence of operations to
214 * make bus memory CPU accessible via the readb/readw/readl/writeb/
215 * writew/writel functions and the other mmio helpers. The returned
216 * address is not guaranteed to be usable directly as a virtual
217 * address.
218 *
219 * This version of ioremap ensures that the memory is marked uncachable
220 * on the CPU as well as honouring existing caching rules from things like
221 * the PCI bus. Note that there are other caches and buffers on many
222 * busses. In particular driver authors should read up on PCI writes
223 *
224 * It's useful if some control registers are in such an area and
225 * write combining or read caching is not desirable:
226 *
227 * Must be freed with iounmap.
228 */
229void __iomem *ioremap_nocache(resource_size_t phys_addr, unsigned long size)
230{
231	/*
232	 * Ideally, this should be:
233	 *	pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS;
234	 *
235	 * Till we fix all X drivers to use ioremap_wc(), we will use
236	 * UC MINUS. Drivers that are certain they need or can already
237	 * be converted over to strong UC can use ioremap_uc().
238	 */
239	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
240
241	return __ioremap_caller(phys_addr, size, pcm,
242				__builtin_return_address(0));
243}
244EXPORT_SYMBOL(ioremap_nocache);
245
246/**
247 * ioremap_uc     -   map bus memory into CPU space as strongly uncachable
248 * @phys_addr:    bus address of the memory
249 * @size:      size of the resource to map
250 *
251 * ioremap_uc performs a platform specific sequence of operations to
252 * make bus memory CPU accessible via the readb/readw/readl/writeb/
253 * writew/writel functions and the other mmio helpers. The returned
254 * address is not guaranteed to be usable directly as a virtual
255 * address.
256 *
257 * This version of ioremap ensures that the memory is marked with a strong
258 * preference as completely uncachable on the CPU when possible. For non-PAT
259 * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT
260 * systems this will set the PAT entry for the pages as strong UC.  This call
261 * will honor existing caching rules from things like the PCI bus. Note that
262 * there are other caches and buffers on many busses. In particular driver
263 * authors should read up on PCI writes.
264 *
265 * It's useful if some control registers are in such an area and
266 * write combining or read caching is not desirable:
267 *
268 * Must be freed with iounmap.
269 */
270void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size)
271{
272	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC;
273
274	return __ioremap_caller(phys_addr, size, pcm,
275				__builtin_return_address(0));
276}
277EXPORT_SYMBOL_GPL(ioremap_uc);
278
279/**
280 * ioremap_wc	-	map memory into CPU space write combined
281 * @phys_addr:	bus address of the memory
282 * @size:	size of the resource to map
283 *
284 * This version of ioremap ensures that the memory is marked write combining.
285 * Write combining allows faster writes to some hardware devices.
286 *
287 * Must be freed with iounmap.
288 */
289void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
290{
291	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
292					__builtin_return_address(0));
293}
294EXPORT_SYMBOL(ioremap_wc);
295
296/**
297 * ioremap_wt	-	map memory into CPU space write through
298 * @phys_addr:	bus address of the memory
299 * @size:	size of the resource to map
300 *
301 * This version of ioremap ensures that the memory is marked write through.
302 * Write through stores data into memory while keeping the cache up-to-date.
303 *
304 * Must be freed with iounmap.
305 */
306void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size)
307{
308	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT,
309					__builtin_return_address(0));
310}
311EXPORT_SYMBOL(ioremap_wt);
312
 
 
 
 
 
 
 
313void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
314{
315	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
316				__builtin_return_address(0));
317}
318EXPORT_SYMBOL(ioremap_cache);
319
320void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
321				unsigned long prot_val)
322{
323	return __ioremap_caller(phys_addr, size,
324				pgprot2cachemode(__pgprot(prot_val)),
325				__builtin_return_address(0));
326}
327EXPORT_SYMBOL(ioremap_prot);
328
329/**
330 * iounmap - Free a IO remapping
331 * @addr: virtual address from ioremap_*
332 *
333 * Caller must ensure there is only one unmapping for the same pointer.
334 */
335void iounmap(volatile void __iomem *addr)
336{
337	struct vm_struct *p, *o;
338
339	if ((void __force *)addr <= high_memory)
340		return;
341
342	/*
343	 * __ioremap special-cases the PCI/ISA range by not instantiating a
344	 * vm_area and by simply returning an address into the kernel mapping
345	 * of ISA space.   So handle that here.
 
 
346	 */
347	if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
348	    (void __force *)addr < phys_to_virt(ISA_END_ADDRESS))
 
349		return;
 
 
 
350
351	addr = (volatile void __iomem *)
352		(PAGE_MASK & (unsigned long __force)addr);
353
354	mmiotrace_iounmap(addr);
355
356	/* Use the vm area unlocked, assuming the caller
357	   ensures there isn't another iounmap for the same address
358	   in parallel. Reuse of the virtual address is prevented by
359	   leaving it in the global lists until we're done with it.
360	   cpa takes care of the direct mappings. */
361	p = find_vm_area((void __force *)addr);
362
363	if (!p) {
364		printk(KERN_ERR "iounmap: bad address %p\n", addr);
365		dump_stack();
366		return;
367	}
368
369	free_memtype(p->phys_addr, p->phys_addr + get_vm_area_size(p));
 
 
370
371	/* Finally remove it */
372	o = remove_vm_area((void __force *)addr);
373	BUG_ON(p != o || o == NULL);
374	kfree(p);
375}
376EXPORT_SYMBOL(iounmap);
377
378int __init arch_ioremap_pud_supported(void)
379{
380#ifdef CONFIG_X86_64
381	return cpu_has_gbpages;
382#else
383	return 0;
384#endif
385}
386
387int __init arch_ioremap_pmd_supported(void)
388{
389	return cpu_has_pse;
390}
391
392/*
393 * Convert a physical pointer to a virtual kernel pointer for /dev/mem
394 * access
395 */
396void *xlate_dev_mem_ptr(phys_addr_t phys)
397{
398	unsigned long start  = phys &  PAGE_MASK;
399	unsigned long offset = phys & ~PAGE_MASK;
400	void *vaddr;
401
402	/* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
403	if (page_is_ram(start >> PAGE_SHIFT))
404		return __va(phys);
405
406	vaddr = ioremap_cache(start, PAGE_SIZE);
407	/* Only add the offset on success and return NULL if the ioremap() failed: */
408	if (vaddr)
409		vaddr += offset;
410
411	return vaddr;
412}
413
414void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
415{
416	if (page_is_ram(phys >> PAGE_SHIFT))
417		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
418
419	iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
 
 
 
 
420}
421
 
 
 
 
 
 
 
 
 
 
 
 
 
422static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
423
424static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
425{
426	/* Don't assume we're using swapper_pg_dir at this point */
427	pgd_t *base = __va(read_cr3());
428	pgd_t *pgd = &base[pgd_index(addr)];
429	pud_t *pud = pud_offset(pgd, addr);
 
430	pmd_t *pmd = pmd_offset(pud, addr);
431
432	return pmd;
433}
434
435static inline pte_t * __init early_ioremap_pte(unsigned long addr)
436{
437	return &bm_pte[pte_index(addr)];
438}
439
440bool __init is_early_ioremap_ptep(pte_t *ptep)
441{
442	return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
443}
444
445void __init early_ioremap_init(void)
446{
447	pmd_t *pmd;
448
449#ifdef CONFIG_X86_64
450	BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
451#else
452	WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
453#endif
454
455	early_ioremap_setup();
456
457	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
458	memset(bm_pte, 0, sizeof(bm_pte));
459	pmd_populate_kernel(&init_mm, pmd, bm_pte);
460
461	/*
462	 * The boot-ioremap range spans multiple pmds, for which
463	 * we are not prepared:
464	 */
465#define __FIXADDR_TOP (-PAGE_SIZE)
466	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
467		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
468#undef __FIXADDR_TOP
469	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
470		WARN_ON(1);
471		printk(KERN_WARNING "pmd %p != %p\n",
472		       pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
473		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
474			fix_to_virt(FIX_BTMAP_BEGIN));
475		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
476			fix_to_virt(FIX_BTMAP_END));
477
478		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
479		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
480		       FIX_BTMAP_BEGIN);
481	}
482}
483
484void __init __early_set_fixmap(enum fixed_addresses idx,
485			       phys_addr_t phys, pgprot_t flags)
486{
487	unsigned long addr = __fix_to_virt(idx);
488	pte_t *pte;
489
490	if (idx >= __end_of_fixed_addresses) {
491		BUG();
492		return;
493	}
494	pte = early_ioremap_pte(addr);
495
 
 
 
496	if (pgprot_val(flags))
497		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
498	else
499		pte_clear(&init_mm, addr, pte);
500	__flush_tlb_one(addr);
501}