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_wt(unsigned long addr, int numpages); |
44 | int set_memory_wb(unsigned long addr, int numpages); |
45 | int set_memory_np(unsigned long addr, int numpages); |
46 | int set_memory_4k(unsigned long addr, int numpages); |
47 | int set_memory_encrypted(unsigned long addr, int numpages); |
48 | int set_memory_decrypted(unsigned long addr, int numpages); |
49 | int set_memory_np_noalias(unsigned long addr, int numpages); |
50 | |
51 | int set_memory_array_uc(unsigned long *addr, int addrinarray); |
52 | int set_memory_array_wc(unsigned long *addr, int addrinarray); |
53 | int set_memory_array_wt(unsigned long *addr, int addrinarray); |
54 | int set_memory_array_wb(unsigned long *addr, int addrinarray); |
55 | |
56 | int set_pages_array_uc(struct page **pages, int addrinarray); |
57 | int set_pages_array_wc(struct page **pages, int addrinarray); |
58 | int set_pages_array_wt(struct page **pages, int addrinarray); |
59 | int set_pages_array_wb(struct page **pages, int addrinarray); |
60 | |
61 | /* |
62 | * For legacy compatibility with the old APIs, a few functions |
63 | * are provided that work on a "struct page". |
64 | * These functions operate ONLY on the 1:1 kernel mapping of the |
65 | * memory that the struct page represents, and internally just |
66 | * call the set_memory_* function. See the description of the |
67 | * set_memory_* function for more details on conventions. |
68 | * |
69 | * These APIs should be considered *deprecated* and are likely going to |
70 | * be removed in the future. |
71 | * The reason for this is the implicit operation on the 1:1 mapping only, |
72 | * making this not a generally useful API. |
73 | * |
74 | * Specifically, many users of the old APIs had a virtual address, |
75 | * called virt_to_page() or vmalloc_to_page() on that address to |
76 | * get a struct page* that the old API required. |
77 | * To convert these cases, use set_memory_*() on the original |
78 | * virtual address, do not use these functions. |
79 | */ |
80 | |
81 | int set_pages_uc(struct page *page, int numpages); |
82 | int set_pages_wb(struct page *page, int numpages); |
83 | int set_pages_x(struct page *page, int numpages); |
84 | int set_pages_nx(struct page *page, int numpages); |
85 | int set_pages_ro(struct page *page, int numpages); |
86 | int set_pages_rw(struct page *page, int numpages); |
87 | |
88 | extern int kernel_set_to_readonly; |
89 | void set_kernel_text_rw(void); |
90 | void set_kernel_text_ro(void); |
91 | |
92 | #ifdef CONFIG_X86_64 |
93 | static inline int set_mce_nospec(unsigned long pfn) |
94 | { |
95 | unsigned long decoy_addr; |
96 | int rc; |
97 | |
98 | /* |
99 | * Mark the linear address as UC to make sure we don't log more |
100 | * errors because of speculative access to the page. |
101 | * We would like to just call: |
102 | * set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1); |
103 | * but doing that would radically increase the odds of a |
104 | * speculative access to the poison page because we'd have |
105 | * the virtual address of the kernel 1:1 mapping sitting |
106 | * around in registers. |
107 | * Instead we get tricky. We create a non-canonical address |
108 | * that looks just like the one we want, but has bit 63 flipped. |
109 | * This relies on set_memory_uc() properly sanitizing any __pa() |
110 | * results with __PHYSICAL_MASK or PTE_PFN_MASK. |
111 | */ |
112 | decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63)); |
113 | |
114 | rc = set_memory_uc(decoy_addr, 1); |
115 | if (rc) |
116 | pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n" , pfn); |
117 | return rc; |
118 | } |
119 | #define set_mce_nospec set_mce_nospec |
120 | |
121 | /* Restore full speculative operation to the pfn. */ |
122 | static inline int clear_mce_nospec(unsigned long pfn) |
123 | { |
124 | return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1); |
125 | } |
126 | #define clear_mce_nospec clear_mce_nospec |
127 | #else |
128 | /* |
129 | * Few people would run a 32-bit kernel on a machine that supports |
130 | * recoverable errors because they have too much memory to boot 32-bit. |
131 | */ |
132 | #endif |
133 | |
134 | #endif /* _ASM_X86_SET_MEMORY_H */ |
135 | |