xref: /openbmc/linux/arch/x86/include/asm/set_memory.h (revision 9a29f5fc)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SET_MEMORY_H
3 #define _ASM_X86_SET_MEMORY_H
4 
5 #include <linux/mm.h>
6 #include <asm/page.h>
7 #include <asm-generic/set_memory.h>
8 
9 /*
10  * The set_memory_* API can be used to change various attributes of a virtual
11  * address range. The attributes include:
12  * Cacheability  : UnCached, WriteCombining, WriteThrough, WriteBack
13  * Executability : eXecutable, NoteXecutable
14  * Read/Write    : ReadOnly, ReadWrite
15  * Presence      : NotPresent
16  * Encryption    : Encrypted, Decrypted
17  *
18  * Within a category, the attributes are mutually exclusive.
19  *
20  * The implementation of this API will take care of various aspects that
21  * are associated with changing such attributes, such as:
22  * - Flushing TLBs
23  * - Flushing CPU caches
24  * - Making sure aliases of the memory behind the mapping don't violate
25  *   coherency rules as defined by the CPU in the system.
26  *
27  * What this API does not do:
28  * - Provide exclusion between various callers - including callers that
29  *   operation on other mappings of the same physical page
30  * - Restore default attributes when a page is freed
31  * - Guarantee that mappings other than the requested one are
32  *   in any state, other than that these do not violate rules for
33  *   the CPU you have. Do not depend on any effects on other mappings,
34  *   CPUs other than the one you have may have more relaxed rules.
35  * The caller is required to take care of these.
36  */
37 
38 int __set_memory_prot(unsigned long addr, int numpages, pgprot_t prot);
39 int _set_memory_uc(unsigned long addr, int numpages);
40 int _set_memory_wc(unsigned long addr, int numpages);
41 int _set_memory_wt(unsigned long addr, int numpages);
42 int _set_memory_wb(unsigned long addr, int numpages);
43 int set_memory_uc(unsigned long addr, int numpages);
44 int set_memory_wc(unsigned long addr, int numpages);
45 int set_memory_wb(unsigned long addr, int numpages);
46 int set_memory_np(unsigned long addr, int numpages);
47 int set_memory_4k(unsigned long addr, int numpages);
48 int set_memory_encrypted(unsigned long addr, int numpages);
49 int set_memory_decrypted(unsigned long addr, int numpages);
50 int set_memory_np_noalias(unsigned long addr, int numpages);
51 int set_memory_nonglobal(unsigned long addr, int numpages);
52 int set_memory_global(unsigned long addr, int numpages);
53 
54 int set_pages_array_uc(struct page **pages, int addrinarray);
55 int set_pages_array_wc(struct page **pages, int addrinarray);
56 int set_pages_array_wb(struct page **pages, int addrinarray);
57 
58 /*
59  * For legacy compatibility with the old APIs, a few functions
60  * are provided that work on a "struct page".
61  * These functions operate ONLY on the 1:1 kernel mapping of the
62  * memory that the struct page represents, and internally just
63  * call the set_memory_* function. See the description of the
64  * set_memory_* function for more details on conventions.
65  *
66  * These APIs should be considered *deprecated* and are likely going to
67  * be removed in the future.
68  * The reason for this is the implicit operation on the 1:1 mapping only,
69  * making this not a generally useful API.
70  *
71  * Specifically, many users of the old APIs had a virtual address,
72  * called virt_to_page() or vmalloc_to_page() on that address to
73  * get a struct page* that the old API required.
74  * To convert these cases, use set_memory_*() on the original
75  * virtual address, do not use these functions.
76  */
77 
78 int set_pages_uc(struct page *page, int numpages);
79 int set_pages_wb(struct page *page, int numpages);
80 int set_pages_ro(struct page *page, int numpages);
81 int set_pages_rw(struct page *page, int numpages);
82 
83 int set_direct_map_invalid_noflush(struct page *page);
84 int set_direct_map_default_noflush(struct page *page);
85 bool kernel_page_present(struct page *page);
86 
87 extern int kernel_set_to_readonly;
88 
89 #endif /* _ASM_X86_SET_MEMORY_H */
90