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1 : : /* SPDX-License-Identifier: GPL-2.0 */ 2 : : #ifndef _ASM_X86_SET_MEMORY_H 3 : : #define _ASM_X86_SET_MEMORY_H 4 : : 5 : : #include <asm/page.h> 6 : : #include <asm-generic/set_memory.h> 7 : : 8 : : /* 9 : : * The set_memory_* API can be used to change various attributes of a virtual 10 : : * address range. The attributes include: 11 : : * Cachability : UnCached, WriteCombining, WriteThrough, WriteBack 12 : : * Executability : eXeutable, NoteXecutable 13 : : * Read/Write : ReadOnly, ReadWrite 14 : : * Presence : NotPresent 15 : : * Encryption : Encrypted, Decrypted 16 : : * 17 : : * Within a category, the attributes are mutually exclusive. 18 : : * 19 : : * The implementation of this API will take care of various aspects that 20 : : * are associated with changing such attributes, such as: 21 : : * - Flushing TLBs 22 : : * - Flushing CPU caches 23 : : * - Making sure aliases of the memory behind the mapping don't violate 24 : : * coherency rules as defined by the CPU in the system. 25 : : * 26 : : * What this API does not do: 27 : : * - Provide exclusion between various callers - including callers that 28 : : * operation on other mappings of the same physical page 29 : : * - Restore default attributes when a page is freed 30 : : * - Guarantee that mappings other than the requested one are 31 : : * in any state, other than that these do not violate rules for 32 : : * the CPU you have. Do not depend on any effects on other mappings, 33 : : * CPUs other than the one you have may have more relaxed rules. 34 : : * The caller is required to take care of these. 35 : : */ 36 : : 37 : : int _set_memory_uc(unsigned long addr, int numpages); 38 : : int _set_memory_wc(unsigned long addr, int numpages); 39 : : int _set_memory_wt(unsigned long addr, int numpages); 40 : : int _set_memory_wb(unsigned long addr, int numpages); 41 : : int set_memory_uc(unsigned long addr, int numpages); 42 : : int set_memory_wc(unsigned long addr, int numpages); 43 : : int set_memory_wb(unsigned long addr, int numpages); 44 : : int set_memory_np(unsigned long addr, int numpages); 45 : : int set_memory_4k(unsigned long addr, int numpages); 46 : : int set_memory_encrypted(unsigned long addr, int numpages); 47 : : int set_memory_decrypted(unsigned long addr, int numpages); 48 : : int set_memory_np_noalias(unsigned long addr, int numpages); 49 : : 50 : : int set_pages_array_uc(struct page **pages, int addrinarray); 51 : : int set_pages_array_wc(struct page **pages, int addrinarray); 52 : : int set_pages_array_wt(struct page **pages, int addrinarray); 53 : : int set_pages_array_wb(struct page **pages, int addrinarray); 54 : : 55 : : /* 56 : : * For legacy compatibility with the old APIs, a few functions 57 : : * are provided that work on a "struct page". 58 : : * These functions operate ONLY on the 1:1 kernel mapping of the 59 : : * memory that the struct page represents, and internally just 60 : : * call the set_memory_* function. See the description of the 61 : : * set_memory_* function for more details on conventions. 62 : : * 63 : : * These APIs should be considered *deprecated* and are likely going to 64 : : * be removed in the future. 65 : : * The reason for this is the implicit operation on the 1:1 mapping only, 66 : : * making this not a generally useful API. 67 : : * 68 : : * Specifically, many users of the old APIs had a virtual address, 69 : : * called virt_to_page() or vmalloc_to_page() on that address to 70 : : * get a struct page* that the old API required. 71 : : * To convert these cases, use set_memory_*() on the original 72 : : * virtual address, do not use these functions. 73 : : */ 74 : : 75 : : int set_pages_uc(struct page *page, int numpages); 76 : : int set_pages_wb(struct page *page, int numpages); 77 : : int set_pages_ro(struct page *page, int numpages); 78 : : int set_pages_rw(struct page *page, int numpages); 79 : : 80 : : int set_direct_map_invalid_noflush(struct page *page); 81 : : int set_direct_map_default_noflush(struct page *page); 82 : : 83 : : extern int kernel_set_to_readonly; 84 : : 85 : : #ifdef CONFIG_X86_64 86 : 0 : static inline int set_mce_nospec(unsigned long pfn) 87 : : { 88 : 0 : unsigned long decoy_addr; 89 : 0 : int rc; 90 : : 91 : : /* 92 : : * Mark the linear address as UC to make sure we don't log more 93 : : * errors because of speculative access to the page. 94 : : * We would like to just call: 95 : : * set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1); 96 : : * but doing that would radically increase the odds of a 97 : : * speculative access to the poison page because we'd have 98 : : * the virtual address of the kernel 1:1 mapping sitting 99 : : * around in registers. 100 : : * Instead we get tricky. We create a non-canonical address 101 : : * that looks just like the one we want, but has bit 63 flipped. 102 : : * This relies on set_memory_uc() properly sanitizing any __pa() 103 : : * results with __PHYSICAL_MASK or PTE_PFN_MASK. 104 : : */ 105 : 0 : decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); 106 : : 107 : 0 : rc = set_memory_uc(decoy_addr, 1); 108 [ # # ]: 0 : if (rc) 109 : 0 : pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn); 110 : 0 : return rc; 111 : : } 112 : : #define set_mce_nospec set_mce_nospec 113 : : 114 : : /* Restore full speculative operation to the pfn. */ 115 : : static inline int clear_mce_nospec(unsigned long pfn) 116 : : { 117 : : return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1); 118 : : } 119 : : #define clear_mce_nospec clear_mce_nospec 120 : : #else 121 : : /* 122 : : * Few people would run a 32-bit kernel on a machine that supports 123 : : * recoverable errors because they have too much memory to boot 32-bit. 124 : : */ 125 : : #endif 126 : : 127 : : #endif /* _ASM_X86_SET_MEMORY_H */