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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/mem_encrypt.h>
18 #include <linux/efi.h>
19 #include <linux/pgtable.h>
20 
21 #include <asm/set_memory.h>
22 #include <asm/e820/api.h>
23 #include <asm/efi.h>
24 #include <asm/fixmap.h>
25 #include <asm/tlbflush.h>
26 #include <asm/pgalloc.h>
27 #include <asm/memtype.h>
28 #include <asm/setup.h>
29 
30 #include "physaddr.h"
31 
32 /*
33  * Descriptor controlling ioremap() behavior.
34  */
35 struct ioremap_desc {
36 	unsigned int flags;
37 };
38 
39 /*
40  * Fix up the linear direct mapping of the kernel to avoid cache attribute
41  * conflicts.
42  */
ioremap_change_attr(unsigned long vaddr,unsigned long size,enum page_cache_mode pcm)43 int ioremap_change_attr(unsigned long vaddr, unsigned long size,
44 			enum page_cache_mode pcm)
45 {
46 	unsigned long nrpages = size >> PAGE_SHIFT;
47 	int err;
48 
49 	switch (pcm) {
50 	case _PAGE_CACHE_MODE_UC:
51 	default:
52 		err = _set_memory_uc(vaddr, nrpages);
53 		break;
54 	case _PAGE_CACHE_MODE_WC:
55 		err = _set_memory_wc(vaddr, nrpages);
56 		break;
57 	case _PAGE_CACHE_MODE_WT:
58 		err = _set_memory_wt(vaddr, nrpages);
59 		break;
60 	case _PAGE_CACHE_MODE_WB:
61 		err = _set_memory_wb(vaddr, nrpages);
62 		break;
63 	}
64 
65 	return err;
66 }
67 
68 /* Does the range (or a subset of) contain normal RAM? */
__ioremap_check_ram(struct resource * res)69 static unsigned int __ioremap_check_ram(struct resource *res)
70 {
71 	unsigned long start_pfn, stop_pfn;
72 	unsigned long i;
73 
74 	if ((res->flags & IORESOURCE_SYSTEM_RAM) != IORESOURCE_SYSTEM_RAM)
75 		return 0;
76 
77 	start_pfn = (res->start + PAGE_SIZE - 1) >> PAGE_SHIFT;
78 	stop_pfn = (res->end + 1) >> PAGE_SHIFT;
79 	if (stop_pfn > start_pfn) {
80 		for (i = 0; i < (stop_pfn - start_pfn); ++i)
81 			if (pfn_valid(start_pfn + i) &&
82 			    !PageReserved(pfn_to_page(start_pfn + i)))
83 				return IORES_MAP_SYSTEM_RAM;
84 	}
85 
86 	return 0;
87 }
88 
89 /*
90  * In a SEV guest, NONE and RESERVED should not be mapped encrypted because
91  * there the whole memory is already encrypted.
92  */
__ioremap_check_encrypted(struct resource * res)93 static unsigned int __ioremap_check_encrypted(struct resource *res)
94 {
95 	if (!sev_active())
96 		return 0;
97 
98 	switch (res->desc) {
99 	case IORES_DESC_NONE:
100 	case IORES_DESC_RESERVED:
101 		break;
102 	default:
103 		return IORES_MAP_ENCRYPTED;
104 	}
105 
106 	return 0;
107 }
108 
109 /*
110  * The EFI runtime services data area is not covered by walk_mem_res(), but must
111  * be mapped encrypted when SEV is active.
112  */
__ioremap_check_other(resource_size_t addr,struct ioremap_desc * desc)113 static void __ioremap_check_other(resource_size_t addr, struct ioremap_desc *desc)
114 {
115 	if (!sev_active())
116 		return;
117 
118 	if (!IS_ENABLED(CONFIG_EFI))
119 		return;
120 
121 	if (efi_mem_type(addr) == EFI_RUNTIME_SERVICES_DATA ||
122 	    (efi_mem_type(addr) == EFI_BOOT_SERVICES_DATA &&
123 	     efi_mem_attributes(addr) & EFI_MEMORY_RUNTIME))
124 		desc->flags |= IORES_MAP_ENCRYPTED;
125 }
126 
__ioremap_collect_map_flags(struct resource * res,void * arg)127 static int __ioremap_collect_map_flags(struct resource *res, void *arg)
128 {
129 	struct ioremap_desc *desc = arg;
130 
131 	if (!(desc->flags & IORES_MAP_SYSTEM_RAM))
132 		desc->flags |= __ioremap_check_ram(res);
133 
134 	if (!(desc->flags & IORES_MAP_ENCRYPTED))
135 		desc->flags |= __ioremap_check_encrypted(res);
136 
137 	return ((desc->flags & (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED)) ==
138 			       (IORES_MAP_SYSTEM_RAM | IORES_MAP_ENCRYPTED));
139 }
140 
141 /*
142  * To avoid multiple resource walks, this function walks resources marked as
143  * IORESOURCE_MEM and IORESOURCE_BUSY and looking for system RAM and/or a
144  * resource described not as IORES_DESC_NONE (e.g. IORES_DESC_ACPI_TABLES).
145  *
146  * After that, deal with misc other ranges in __ioremap_check_other() which do
147  * not fall into the above category.
148  */
__ioremap_check_mem(resource_size_t addr,unsigned long size,struct ioremap_desc * desc)149 static void __ioremap_check_mem(resource_size_t addr, unsigned long size,
150 				struct ioremap_desc *desc)
151 {
152 	u64 start, end;
153 
154 	start = (u64)addr;
155 	end = start + size - 1;
156 	memset(desc, 0, sizeof(struct ioremap_desc));
157 
158 	walk_mem_res(start, end, desc, __ioremap_collect_map_flags);
159 
160 	__ioremap_check_other(addr, desc);
161 }
162 
163 /*
164  * Remap an arbitrary physical address space into the kernel virtual
165  * address space. It transparently creates kernel huge I/O mapping when
166  * the physical address is aligned by a huge page size (1GB or 2MB) and
167  * the requested size is at least the huge page size.
168  *
169  * NOTE: MTRRs can override PAT memory types with a 4KB granularity.
170  * Therefore, the mapping code falls back to use a smaller page toward 4KB
171  * when a mapping range is covered by non-WB type of MTRRs.
172  *
173  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
174  * have to convert them into an offset in a page-aligned mapping, but the
175  * caller shouldn't need to know that small detail.
176  */
177 static void __iomem *
__ioremap_caller(resource_size_t phys_addr,unsigned long size,enum page_cache_mode pcm,void * caller,bool encrypted)178 __ioremap_caller(resource_size_t phys_addr, unsigned long size,
179 		 enum page_cache_mode pcm, void *caller, bool encrypted)
180 {
181 	unsigned long offset, vaddr;
182 	resource_size_t last_addr;
183 	const resource_size_t unaligned_phys_addr = phys_addr;
184 	const unsigned long unaligned_size = size;
185 	struct ioremap_desc io_desc;
186 	struct vm_struct *area;
187 	enum page_cache_mode new_pcm;
188 	pgprot_t prot;
189 	int retval;
190 	void __iomem *ret_addr;
191 
192 	/* Don't allow wraparound or zero size */
193 	last_addr = phys_addr + size - 1;
194 	if (!size || last_addr < phys_addr)
195 		return NULL;
196 
197 	if (!phys_addr_valid(phys_addr)) {
198 		printk(KERN_WARNING "ioremap: invalid physical address %llx\n",
199 		       (unsigned long long)phys_addr);
200 		WARN_ON_ONCE(1);
201 		return NULL;
202 	}
203 
204 	__ioremap_check_mem(phys_addr, size, &io_desc);
205 
206 	/*
207 	 * Don't allow anybody to remap normal RAM that we're using..
208 	 */
209 	if (io_desc.flags & IORES_MAP_SYSTEM_RAM) {
210 		WARN_ONCE(1, "ioremap on RAM at %pa - %pa\n",
211 			  &phys_addr, &last_addr);
212 		return NULL;
213 	}
214 
215 	/*
216 	 * Mappings have to be page-aligned
217 	 */
218 	offset = phys_addr & ~PAGE_MASK;
219 	phys_addr &= PHYSICAL_PAGE_MASK;
220 	size = PAGE_ALIGN(last_addr+1) - phys_addr;
221 
222 	retval = memtype_reserve(phys_addr, (u64)phys_addr + size,
223 						pcm, &new_pcm);
224 	if (retval) {
225 		printk(KERN_ERR "ioremap memtype_reserve failed %d\n", retval);
226 		return NULL;
227 	}
228 
229 	if (pcm != new_pcm) {
230 		if (!is_new_memtype_allowed(phys_addr, size, pcm, new_pcm)) {
231 			printk(KERN_ERR
232 		"ioremap error for 0x%llx-0x%llx, requested 0x%x, got 0x%x\n",
233 				(unsigned long long)phys_addr,
234 				(unsigned long long)(phys_addr + size),
235 				pcm, new_pcm);
236 			goto err_free_memtype;
237 		}
238 		pcm = new_pcm;
239 	}
240 
241 	/*
242 	 * If the page being mapped is in memory and SEV is active then
243 	 * make sure the memory encryption attribute is enabled in the
244 	 * resulting mapping.
245 	 */
246 	prot = PAGE_KERNEL_IO;
247 	if ((io_desc.flags & IORES_MAP_ENCRYPTED) || encrypted)
248 		prot = pgprot_encrypted(prot);
249 
250 	switch (pcm) {
251 	case _PAGE_CACHE_MODE_UC:
252 	default:
253 		prot = __pgprot(pgprot_val(prot) |
254 				cachemode2protval(_PAGE_CACHE_MODE_UC));
255 		break;
256 	case _PAGE_CACHE_MODE_UC_MINUS:
257 		prot = __pgprot(pgprot_val(prot) |
258 				cachemode2protval(_PAGE_CACHE_MODE_UC_MINUS));
259 		break;
260 	case _PAGE_CACHE_MODE_WC:
261 		prot = __pgprot(pgprot_val(prot) |
262 				cachemode2protval(_PAGE_CACHE_MODE_WC));
263 		break;
264 	case _PAGE_CACHE_MODE_WT:
265 		prot = __pgprot(pgprot_val(prot) |
266 				cachemode2protval(_PAGE_CACHE_MODE_WT));
267 		break;
268 	case _PAGE_CACHE_MODE_WB:
269 		break;
270 	}
271 
272 	/*
273 	 * Ok, go for it..
274 	 */
275 	area = get_vm_area_caller(size, VM_IOREMAP, caller);
276 	if (!area)
277 		goto err_free_memtype;
278 	area->phys_addr = phys_addr;
279 	vaddr = (unsigned long) area->addr;
280 
281 	if (memtype_kernel_map_sync(phys_addr, size, pcm))
282 		goto err_free_area;
283 
284 	if (ioremap_page_range(vaddr, vaddr + size, phys_addr, prot))
285 		goto err_free_area;
286 
287 	ret_addr = (void __iomem *) (vaddr + offset);
288 	mmiotrace_ioremap(unaligned_phys_addr, unaligned_size, ret_addr);
289 
290 	/*
291 	 * Check if the request spans more than any BAR in the iomem resource
292 	 * tree.
293 	 */
294 	if (iomem_map_sanity_check(unaligned_phys_addr, unaligned_size))
295 		pr_warn("caller %pS mapping multiple BARs\n", caller);
296 
297 	return ret_addr;
298 err_free_area:
299 	free_vm_area(area);
300 err_free_memtype:
301 	memtype_free(phys_addr, phys_addr + size);
302 	return NULL;
303 }
304 
305 /**
306  * ioremap     -   map bus memory into CPU space
307  * @phys_addr:    bus address of the memory
308  * @size:      size of the resource to map
309  *
310  * ioremap performs a platform specific sequence of operations to
311  * make bus memory CPU accessible via the readb/readw/readl/writeb/
312  * writew/writel functions and the other mmio helpers. The returned
313  * address is not guaranteed to be usable directly as a virtual
314  * address.
315  *
316  * This version of ioremap ensures that the memory is marked uncachable
317  * on the CPU as well as honouring existing caching rules from things like
318  * the PCI bus. Note that there are other caches and buffers on many
319  * busses. In particular driver authors should read up on PCI writes
320  *
321  * It's useful if some control registers are in such an area and
322  * write combining or read caching is not desirable:
323  *
324  * Must be freed with iounmap.
325  */
ioremap(resource_size_t phys_addr,unsigned long size)326 void __iomem *ioremap(resource_size_t phys_addr, unsigned long size)
327 {
328 	/*
329 	 * Ideally, this should be:
330 	 *	pat_enabled() ? _PAGE_CACHE_MODE_UC : _PAGE_CACHE_MODE_UC_MINUS;
331 	 *
332 	 * Till we fix all X drivers to use ioremap_wc(), we will use
333 	 * UC MINUS. Drivers that are certain they need or can already
334 	 * be converted over to strong UC can use ioremap_uc().
335 	 */
336 	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC_MINUS;
337 
338 	return __ioremap_caller(phys_addr, size, pcm,
339 				__builtin_return_address(0), false);
340 }
341 EXPORT_SYMBOL(ioremap);
342 
343 /**
344  * ioremap_uc     -   map bus memory into CPU space as strongly uncachable
345  * @phys_addr:    bus address of the memory
346  * @size:      size of the resource to map
347  *
348  * ioremap_uc performs a platform specific sequence of operations to
349  * make bus memory CPU accessible via the readb/readw/readl/writeb/
350  * writew/writel functions and the other mmio helpers. The returned
351  * address is not guaranteed to be usable directly as a virtual
352  * address.
353  *
354  * This version of ioremap ensures that the memory is marked with a strong
355  * preference as completely uncachable on the CPU when possible. For non-PAT
356  * systems this ends up setting page-attribute flags PCD=1, PWT=1. For PAT
357  * systems this will set the PAT entry for the pages as strong UC.  This call
358  * will honor existing caching rules from things like the PCI bus. Note that
359  * there are other caches and buffers on many busses. In particular driver
360  * authors should read up on PCI writes.
361  *
362  * It's useful if some control registers are in such an area and
363  * write combining or read caching is not desirable:
364  *
365  * Must be freed with iounmap.
366  */
ioremap_uc(resource_size_t phys_addr,unsigned long size)367 void __iomem *ioremap_uc(resource_size_t phys_addr, unsigned long size)
368 {
369 	enum page_cache_mode pcm = _PAGE_CACHE_MODE_UC;
370 
371 	return __ioremap_caller(phys_addr, size, pcm,
372 				__builtin_return_address(0), false);
373 }
374 EXPORT_SYMBOL_GPL(ioremap_uc);
375 
376 /**
377  * ioremap_wc	-	map memory into CPU space write combined
378  * @phys_addr:	bus address of the memory
379  * @size:	size of the resource to map
380  *
381  * This version of ioremap ensures that the memory is marked write combining.
382  * Write combining allows faster writes to some hardware devices.
383  *
384  * Must be freed with iounmap.
385  */
ioremap_wc(resource_size_t phys_addr,unsigned long size)386 void __iomem *ioremap_wc(resource_size_t phys_addr, unsigned long size)
387 {
388 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WC,
389 					__builtin_return_address(0), false);
390 }
391 EXPORT_SYMBOL(ioremap_wc);
392 
393 /**
394  * ioremap_wt	-	map memory into CPU space write through
395  * @phys_addr:	bus address of the memory
396  * @size:	size of the resource to map
397  *
398  * This version of ioremap ensures that the memory is marked write through.
399  * Write through stores data into memory while keeping the cache up-to-date.
400  *
401  * Must be freed with iounmap.
402  */
ioremap_wt(resource_size_t phys_addr,unsigned long size)403 void __iomem *ioremap_wt(resource_size_t phys_addr, unsigned long size)
404 {
405 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WT,
406 					__builtin_return_address(0), false);
407 }
408 EXPORT_SYMBOL(ioremap_wt);
409 
ioremap_encrypted(resource_size_t phys_addr,unsigned long size)410 void __iomem *ioremap_encrypted(resource_size_t phys_addr, unsigned long size)
411 {
412 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
413 				__builtin_return_address(0), true);
414 }
415 EXPORT_SYMBOL(ioremap_encrypted);
416 
ioremap_cache(resource_size_t phys_addr,unsigned long size)417 void __iomem *ioremap_cache(resource_size_t phys_addr, unsigned long size)
418 {
419 	return __ioremap_caller(phys_addr, size, _PAGE_CACHE_MODE_WB,
420 				__builtin_return_address(0), false);
421 }
422 EXPORT_SYMBOL(ioremap_cache);
423 
ioremap_prot(resource_size_t phys_addr,unsigned long size,unsigned long prot_val)424 void __iomem *ioremap_prot(resource_size_t phys_addr, unsigned long size,
425 				unsigned long prot_val)
426 {
427 	return __ioremap_caller(phys_addr, size,
428 				pgprot2cachemode(__pgprot(prot_val)),
429 				__builtin_return_address(0), false);
430 }
431 EXPORT_SYMBOL(ioremap_prot);
432 
433 /**
434  * iounmap - Free a IO remapping
435  * @addr: virtual address from ioremap_*
436  *
437  * Caller must ensure there is only one unmapping for the same pointer.
438  */
iounmap(volatile void __iomem * addr)439 void iounmap(volatile void __iomem *addr)
440 {
441 	struct vm_struct *p, *o;
442 
443 	if ((void __force *)addr <= high_memory)
444 		return;
445 
446 	/*
447 	 * The PCI/ISA range special-casing was removed from __ioremap()
448 	 * so this check, in theory, can be removed. However, there are
449 	 * cases where iounmap() is called for addresses not obtained via
450 	 * ioremap() (vga16fb for example). Add a warning so that these
451 	 * cases can be caught and fixed.
452 	 */
453 	if ((void __force *)addr >= phys_to_virt(ISA_START_ADDRESS) &&
454 	    (void __force *)addr < phys_to_virt(ISA_END_ADDRESS)) {
455 		WARN(1, "iounmap() called for ISA range not obtained using ioremap()\n");
456 		return;
457 	}
458 
459 	mmiotrace_iounmap(addr);
460 
461 	addr = (volatile void __iomem *)
462 		(PAGE_MASK & (unsigned long __force)addr);
463 
464 	/* Use the vm area unlocked, assuming the caller
465 	   ensures there isn't another iounmap for the same address
466 	   in parallel. Reuse of the virtual address is prevented by
467 	   leaving it in the global lists until we're done with it.
468 	   cpa takes care of the direct mappings. */
469 	p = find_vm_area((void __force *)addr);
470 
471 	if (!p) {
472 		printk(KERN_ERR "iounmap: bad address %p\n", addr);
473 		dump_stack();
474 		return;
475 	}
476 
477 	memtype_free(p->phys_addr, p->phys_addr + get_vm_area_size(p));
478 
479 	/* Finally remove it */
480 	o = remove_vm_area((void __force *)addr);
481 	BUG_ON(p != o || o == NULL);
482 	kfree(p);
483 }
484 EXPORT_SYMBOL(iounmap);
485 
arch_ioremap_p4d_supported(void)486 int __init arch_ioremap_p4d_supported(void)
487 {
488 	return 0;
489 }
490 
arch_ioremap_pud_supported(void)491 int __init arch_ioremap_pud_supported(void)
492 {
493 #ifdef CONFIG_X86_64
494 	return boot_cpu_has(X86_FEATURE_GBPAGES);
495 #else
496 	return 0;
497 #endif
498 }
499 
arch_ioremap_pmd_supported(void)500 int __init arch_ioremap_pmd_supported(void)
501 {
502 	return boot_cpu_has(X86_FEATURE_PSE);
503 }
504 
505 /*
506  * Convert a physical pointer to a virtual kernel pointer for /dev/mem
507  * access
508  */
xlate_dev_mem_ptr(phys_addr_t phys)509 void *xlate_dev_mem_ptr(phys_addr_t phys)
510 {
511 	unsigned long start  = phys &  PAGE_MASK;
512 	unsigned long offset = phys & ~PAGE_MASK;
513 	void *vaddr;
514 
515 	/* memremap() maps if RAM, otherwise falls back to ioremap() */
516 	vaddr = memremap(start, PAGE_SIZE, MEMREMAP_WB);
517 
518 	/* Only add the offset on success and return NULL if memremap() failed */
519 	if (vaddr)
520 		vaddr += offset;
521 
522 	return vaddr;
523 }
524 
unxlate_dev_mem_ptr(phys_addr_t phys,void * addr)525 void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
526 {
527 	memunmap((void *)((unsigned long)addr & PAGE_MASK));
528 }
529 
530 /*
531  * Examine the physical address to determine if it is an area of memory
532  * that should be mapped decrypted.  If the memory is not part of the
533  * kernel usable area it was accessed and created decrypted, so these
534  * areas should be mapped decrypted. And since the encryption key can
535  * change across reboots, persistent memory should also be mapped
536  * decrypted.
537  *
538  * If SEV is active, that implies that BIOS/UEFI also ran encrypted so
539  * only persistent memory should be mapped decrypted.
540  */
memremap_should_map_decrypted(resource_size_t phys_addr,unsigned long size)541 static bool memremap_should_map_decrypted(resource_size_t phys_addr,
542 					  unsigned long size)
543 {
544 	int is_pmem;
545 
546 	/*
547 	 * Check if the address is part of a persistent memory region.
548 	 * This check covers areas added by E820, EFI and ACPI.
549 	 */
550 	is_pmem = region_intersects(phys_addr, size, IORESOURCE_MEM,
551 				    IORES_DESC_PERSISTENT_MEMORY);
552 	if (is_pmem != REGION_DISJOINT)
553 		return true;
554 
555 	/*
556 	 * Check if the non-volatile attribute is set for an EFI
557 	 * reserved area.
558 	 */
559 	if (efi_enabled(EFI_BOOT)) {
560 		switch (efi_mem_type(phys_addr)) {
561 		case EFI_RESERVED_TYPE:
562 			if (efi_mem_attributes(phys_addr) & EFI_MEMORY_NV)
563 				return true;
564 			break;
565 		default:
566 			break;
567 		}
568 	}
569 
570 	/* Check if the address is outside kernel usable area */
571 	switch (e820__get_entry_type(phys_addr, phys_addr + size - 1)) {
572 	case E820_TYPE_RESERVED:
573 	case E820_TYPE_ACPI:
574 	case E820_TYPE_NVS:
575 	case E820_TYPE_UNUSABLE:
576 		/* For SEV, these areas are encrypted */
577 		if (sev_active())
578 			break;
579 		fallthrough;
580 
581 	case E820_TYPE_PRAM:
582 		return true;
583 	default:
584 		break;
585 	}
586 
587 	return false;
588 }
589 
590 /*
591  * Examine the physical address to determine if it is EFI data. Check
592  * it against the boot params structure and EFI tables and memory types.
593  */
memremap_is_efi_data(resource_size_t phys_addr,unsigned long size)594 static bool memremap_is_efi_data(resource_size_t phys_addr,
595 				 unsigned long size)
596 {
597 	u64 paddr;
598 
599 	/* Check if the address is part of EFI boot/runtime data */
600 	if (!efi_enabled(EFI_BOOT))
601 		return false;
602 
603 	paddr = boot_params.efi_info.efi_memmap_hi;
604 	paddr <<= 32;
605 	paddr |= boot_params.efi_info.efi_memmap;
606 	if (phys_addr == paddr)
607 		return true;
608 
609 	paddr = boot_params.efi_info.efi_systab_hi;
610 	paddr <<= 32;
611 	paddr |= boot_params.efi_info.efi_systab;
612 	if (phys_addr == paddr)
613 		return true;
614 
615 	if (efi_is_table_address(phys_addr))
616 		return true;
617 
618 	switch (efi_mem_type(phys_addr)) {
619 	case EFI_BOOT_SERVICES_DATA:
620 	case EFI_RUNTIME_SERVICES_DATA:
621 		return true;
622 	default:
623 		break;
624 	}
625 
626 	return false;
627 }
628 
629 /*
630  * Examine the physical address to determine if it is boot data by checking
631  * it against the boot params setup_data chain.
632  */
memremap_is_setup_data(resource_size_t phys_addr,unsigned long size)633 static bool memremap_is_setup_data(resource_size_t phys_addr,
634 				   unsigned long size)
635 {
636 	struct setup_data *data;
637 	u64 paddr, paddr_next;
638 
639 	paddr = boot_params.hdr.setup_data;
640 	while (paddr) {
641 		unsigned int len;
642 
643 		if (phys_addr == paddr)
644 			return true;
645 
646 		data = memremap(paddr, sizeof(*data),
647 				MEMREMAP_WB | MEMREMAP_DEC);
648 
649 		paddr_next = data->next;
650 		len = data->len;
651 
652 		if ((phys_addr > paddr) && (phys_addr < (paddr + len))) {
653 			memunmap(data);
654 			return true;
655 		}
656 
657 		if (data->type == SETUP_INDIRECT &&
658 		    ((struct setup_indirect *)data->data)->type != SETUP_INDIRECT) {
659 			paddr = ((struct setup_indirect *)data->data)->addr;
660 			len = ((struct setup_indirect *)data->data)->len;
661 		}
662 
663 		memunmap(data);
664 
665 		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
666 			return true;
667 
668 		paddr = paddr_next;
669 	}
670 
671 	return false;
672 }
673 
674 /*
675  * Examine the physical address to determine if it is boot data by checking
676  * it against the boot params setup_data chain (early boot version).
677  */
early_memremap_is_setup_data(resource_size_t phys_addr,unsigned long size)678 static bool __init early_memremap_is_setup_data(resource_size_t phys_addr,
679 						unsigned long size)
680 {
681 	struct setup_data *data;
682 	u64 paddr, paddr_next;
683 
684 	paddr = boot_params.hdr.setup_data;
685 	while (paddr) {
686 		unsigned int len;
687 
688 		if (phys_addr == paddr)
689 			return true;
690 
691 		data = early_memremap_decrypted(paddr, sizeof(*data));
692 
693 		paddr_next = data->next;
694 		len = data->len;
695 
696 		early_memunmap(data, sizeof(*data));
697 
698 		if ((phys_addr > paddr) && (phys_addr < (paddr + len)))
699 			return true;
700 
701 		paddr = paddr_next;
702 	}
703 
704 	return false;
705 }
706 
707 /*
708  * Architecture function to determine if RAM remap is allowed. By default, a
709  * RAM remap will map the data as encrypted. Determine if a RAM remap should
710  * not be done so that the data will be mapped decrypted.
711  */
arch_memremap_can_ram_remap(resource_size_t phys_addr,unsigned long size,unsigned long flags)712 bool arch_memremap_can_ram_remap(resource_size_t phys_addr, unsigned long size,
713 				 unsigned long flags)
714 {
715 	if (!mem_encrypt_active())
716 		return true;
717 
718 	if (flags & MEMREMAP_ENC)
719 		return true;
720 
721 	if (flags & MEMREMAP_DEC)
722 		return false;
723 
724 	if (sme_active()) {
725 		if (memremap_is_setup_data(phys_addr, size) ||
726 		    memremap_is_efi_data(phys_addr, size))
727 			return false;
728 	}
729 
730 	return !memremap_should_map_decrypted(phys_addr, size);
731 }
732 
733 /*
734  * Architecture override of __weak function to adjust the protection attributes
735  * used when remapping memory. By default, early_memremap() will map the data
736  * as encrypted. Determine if an encrypted mapping should not be done and set
737  * the appropriate protection attributes.
738  */
early_memremap_pgprot_adjust(resource_size_t phys_addr,unsigned long size,pgprot_t prot)739 pgprot_t __init early_memremap_pgprot_adjust(resource_size_t phys_addr,
740 					     unsigned long size,
741 					     pgprot_t prot)
742 {
743 	bool encrypted_prot;
744 
745 	if (!mem_encrypt_active())
746 		return prot;
747 
748 	encrypted_prot = true;
749 
750 	if (sme_active()) {
751 		if (early_memremap_is_setup_data(phys_addr, size) ||
752 		    memremap_is_efi_data(phys_addr, size))
753 			encrypted_prot = false;
754 	}
755 
756 	if (encrypted_prot && memremap_should_map_decrypted(phys_addr, size))
757 		encrypted_prot = false;
758 
759 	return encrypted_prot ? pgprot_encrypted(prot)
760 			      : pgprot_decrypted(prot);
761 }
762 
phys_mem_access_encrypted(unsigned long phys_addr,unsigned long size)763 bool phys_mem_access_encrypted(unsigned long phys_addr, unsigned long size)
764 {
765 	return arch_memremap_can_ram_remap(phys_addr, size, 0);
766 }
767 
768 #ifdef CONFIG_AMD_MEM_ENCRYPT
769 /* Remap memory with encryption */
early_memremap_encrypted(resource_size_t phys_addr,unsigned long size)770 void __init *early_memremap_encrypted(resource_size_t phys_addr,
771 				      unsigned long size)
772 {
773 	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC);
774 }
775 
776 /*
777  * Remap memory with encryption and write-protected - cannot be called
778  * before pat_init() is called
779  */
early_memremap_encrypted_wp(resource_size_t phys_addr,unsigned long size)780 void __init *early_memremap_encrypted_wp(resource_size_t phys_addr,
781 					 unsigned long size)
782 {
783 	if (!x86_has_pat_wp())
784 		return NULL;
785 	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_ENC_WP);
786 }
787 
788 /* Remap memory without encryption */
early_memremap_decrypted(resource_size_t phys_addr,unsigned long size)789 void __init *early_memremap_decrypted(resource_size_t phys_addr,
790 				      unsigned long size)
791 {
792 	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC);
793 }
794 
795 /*
796  * Remap memory without encryption and write-protected - cannot be called
797  * before pat_init() is called
798  */
early_memremap_decrypted_wp(resource_size_t phys_addr,unsigned long size)799 void __init *early_memremap_decrypted_wp(resource_size_t phys_addr,
800 					 unsigned long size)
801 {
802 	if (!x86_has_pat_wp())
803 		return NULL;
804 	return early_memremap_prot(phys_addr, size, __PAGE_KERNEL_NOENC_WP);
805 }
806 #endif	/* CONFIG_AMD_MEM_ENCRYPT */
807 
808 static pte_t bm_pte[PAGE_SIZE/sizeof(pte_t)] __page_aligned_bss;
809 
early_ioremap_pmd(unsigned long addr)810 static inline pmd_t * __init early_ioremap_pmd(unsigned long addr)
811 {
812 	/* Don't assume we're using swapper_pg_dir at this point */
813 	pgd_t *base = __va(read_cr3_pa());
814 	pgd_t *pgd = &base[pgd_index(addr)];
815 	p4d_t *p4d = p4d_offset(pgd, addr);
816 	pud_t *pud = pud_offset(p4d, addr);
817 	pmd_t *pmd = pmd_offset(pud, addr);
818 
819 	return pmd;
820 }
821 
early_ioremap_pte(unsigned long addr)822 static inline pte_t * __init early_ioremap_pte(unsigned long addr)
823 {
824 	return &bm_pte[pte_index(addr)];
825 }
826 
is_early_ioremap_ptep(pte_t * ptep)827 bool __init is_early_ioremap_ptep(pte_t *ptep)
828 {
829 	return ptep >= &bm_pte[0] && ptep < &bm_pte[PAGE_SIZE/sizeof(pte_t)];
830 }
831 
early_ioremap_init(void)832 void __init early_ioremap_init(void)
833 {
834 	pmd_t *pmd;
835 
836 #ifdef CONFIG_X86_64
837 	BUILD_BUG_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
838 #else
839 	WARN_ON((fix_to_virt(0) + PAGE_SIZE) & ((1 << PMD_SHIFT) - 1));
840 #endif
841 
842 	early_ioremap_setup();
843 
844 	pmd = early_ioremap_pmd(fix_to_virt(FIX_BTMAP_BEGIN));
845 	memset(bm_pte, 0, sizeof(bm_pte));
846 	pmd_populate_kernel(&init_mm, pmd, bm_pte);
847 
848 	/*
849 	 * The boot-ioremap range spans multiple pmds, for which
850 	 * we are not prepared:
851 	 */
852 #define __FIXADDR_TOP (-PAGE_SIZE)
853 	BUILD_BUG_ON((__fix_to_virt(FIX_BTMAP_BEGIN) >> PMD_SHIFT)
854 		     != (__fix_to_virt(FIX_BTMAP_END) >> PMD_SHIFT));
855 #undef __FIXADDR_TOP
856 	if (pmd != early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END))) {
857 		WARN_ON(1);
858 		printk(KERN_WARNING "pmd %p != %p\n",
859 		       pmd, early_ioremap_pmd(fix_to_virt(FIX_BTMAP_END)));
860 		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_BEGIN): %08lx\n",
861 			fix_to_virt(FIX_BTMAP_BEGIN));
862 		printk(KERN_WARNING "fix_to_virt(FIX_BTMAP_END):   %08lx\n",
863 			fix_to_virt(FIX_BTMAP_END));
864 
865 		printk(KERN_WARNING "FIX_BTMAP_END:       %d\n", FIX_BTMAP_END);
866 		printk(KERN_WARNING "FIX_BTMAP_BEGIN:     %d\n",
867 		       FIX_BTMAP_BEGIN);
868 	}
869 }
870 
__early_set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)871 void __init __early_set_fixmap(enum fixed_addresses idx,
872 			       phys_addr_t phys, pgprot_t flags)
873 {
874 	unsigned long addr = __fix_to_virt(idx);
875 	pte_t *pte;
876 
877 	if (idx >= __end_of_fixed_addresses) {
878 		BUG();
879 		return;
880 	}
881 	pte = early_ioremap_pte(addr);
882 
883 	/* Sanitize 'prot' against any unsupported bits: */
884 	pgprot_val(flags) &= __supported_pte_mask;
885 
886 	if (pgprot_val(flags))
887 		set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, flags));
888 	else
889 		pte_clear(&init_mm, addr, pte);
890 	flush_tlb_one_kernel(addr);
891 }
892