xref: /openbmc/linux/arch/x86/include/asm/set_memory.h (revision e2c75e76)
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 
50 int set_memory_array_uc(unsigned long *addr, int addrinarray);
51 int set_memory_array_wc(unsigned long *addr, int addrinarray);
52 int set_memory_array_wt(unsigned long *addr, int addrinarray);
53 int set_memory_array_wb(unsigned long *addr, int addrinarray);
54 
55 int set_pages_array_uc(struct page **pages, int addrinarray);
56 int set_pages_array_wc(struct page **pages, int addrinarray);
57 int set_pages_array_wt(struct page **pages, int addrinarray);
58 int set_pages_array_wb(struct page **pages, int addrinarray);
59 
60 /*
61  * For legacy compatibility with the old APIs, a few functions
62  * are provided that work on a "struct page".
63  * These functions operate ONLY on the 1:1 kernel mapping of the
64  * memory that the struct page represents, and internally just
65  * call the set_memory_* function. See the description of the
66  * set_memory_* function for more details on conventions.
67  *
68  * These APIs should be considered *deprecated* and are likely going to
69  * be removed in the future.
70  * The reason for this is the implicit operation on the 1:1 mapping only,
71  * making this not a generally useful API.
72  *
73  * Specifically, many users of the old APIs had a virtual address,
74  * called virt_to_page() or vmalloc_to_page() on that address to
75  * get a struct page* that the old API required.
76  * To convert these cases, use set_memory_*() on the original
77  * virtual address, do not use these functions.
78  */
79 
80 int set_pages_uc(struct page *page, int numpages);
81 int set_pages_wb(struct page *page, int numpages);
82 int set_pages_x(struct page *page, int numpages);
83 int set_pages_nx(struct page *page, int numpages);
84 int set_pages_ro(struct page *page, int numpages);
85 int set_pages_rw(struct page *page, int numpages);
86 
87 extern int kernel_set_to_readonly;
88 void set_kernel_text_rw(void);
89 void set_kernel_text_ro(void);
90 
91 #endif /* _ASM_X86_SET_MEMORY_H */
92