1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_SET_MEMORY_H
#define _ASM_X86_SET_MEMORY_H
#include <asm/page.h>
#include <asm-generic/set_memory.h>
/*
* The set_memory_* API can be used to change various attributes of a virtual
* address range. The attributes include:
* Cachability : UnCached, WriteCombining, WriteThrough, WriteBack
* Executability : eXeutable, NoteXecutable
* Read/Write : ReadOnly, ReadWrite
* Presence : NotPresent
* Encryption : Encrypted, Decrypted
*
* Within a category, the attributes are mutually exclusive.
*
* The implementation of this API will take care of various aspects that
* are associated with changing such attributes, such as:
* - Flushing TLBs
* - Flushing CPU caches
* - Making sure aliases of the memory behind the mapping don't violate
* coherency rules as defined by the CPU in the system.
*
* What this API does not do:
* - Provide exclusion between various callers - including callers that
* operation on other mappings of the same physical page
* - Restore default attributes when a page is freed
* - Guarantee that mappings other than the requested one are
* in any state, other than that these do not violate rules for
* the CPU you have. Do not depend on any effects on other mappings,
* CPUs other than the one you have may have more relaxed rules.
* The caller is required to take care of these.
*/
int _set_memory_uc(unsigned long addr, int numpages);
int _set_memory_wc(unsigned long addr, int numpages);
int _set_memory_wt(unsigned long addr, int numpages);
int _set_memory_wb(unsigned long addr, int numpages);
int set_memory_uc(unsigned long addr, int numpages);
int set_memory_wc(unsigned long addr, int numpages);
int set_memory_wb(unsigned long addr, int numpages);
int set_memory_np(unsigned long addr, int numpages);
int set_memory_4k(unsigned long addr, int numpages);
int set_memory_encrypted(unsigned long addr, int numpages);
int set_memory_decrypted(unsigned long addr, int numpages);
int set_memory_np_noalias(unsigned long addr, int numpages);
int set_pages_array_uc(struct page **pages, int addrinarray);
int set_pages_array_wc(struct page **pages, int addrinarray);
int set_pages_array_wt(struct page **pages, int addrinarray);
int set_pages_array_wb(struct page **pages, int addrinarray);
/*
* For legacy compatibility with the old APIs, a few functions
* are provided that work on a "struct page".
* These functions operate ONLY on the 1:1 kernel mapping of the
* memory that the struct page represents, and internally just
* call the set_memory_* function. See the description of the
* set_memory_* function for more details on conventions.
*
* These APIs should be considered *deprecated* and are likely going to
* be removed in the future.
* The reason for this is the implicit operation on the 1:1 mapping only,
* making this not a generally useful API.
*
* Specifically, many users of the old APIs had a virtual address,
* called virt_to_page() or vmalloc_to_page() on that address to
* get a struct page* that the old API required.
* To convert these cases, use set_memory_*() on the original
* virtual address, do not use these functions.
*/
int set_pages_uc(struct page *page, int numpages);
int set_pages_wb(struct page *page, int numpages);
int set_pages_ro(struct page *page, int numpages);
int set_pages_rw(struct page *page, int numpages);
int set_direct_map_invalid_noflush(struct page *page);
int set_direct_map_default_noflush(struct page *page);
extern int kernel_set_to_readonly;
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
#ifdef CONFIG_X86_64
static inline int set_mce_nospec(unsigned long pfn)
{
unsigned long decoy_addr;
int rc;
/*
* Mark the linear address as UC to make sure we don't log more
* errors because of speculative access to the page.
* We would like to just call:
* set_memory_uc((unsigned long)pfn_to_kaddr(pfn), 1);
* but doing that would radically increase the odds of a
* speculative access to the poison page because we'd have
* the virtual address of the kernel 1:1 mapping sitting
* around in registers.
* Instead we get tricky. We create a non-canonical address
* that looks just like the one we want, but has bit 63 flipped.
* This relies on set_memory_uc() properly sanitizing any __pa()
* results with __PHYSICAL_MASK or PTE_PFN_MASK.
*/
decoy_addr = (pfn << PAGE_SHIFT) + (PAGE_OFFSET ^ BIT(63));
rc = set_memory_uc(decoy_addr, 1);
if (rc)
pr_warn("Could not invalidate pfn=0x%lx from 1:1 map\n", pfn);
return rc;
}
#define set_mce_nospec set_mce_nospec
/* Restore full speculative operation to the pfn. */
static inline int clear_mce_nospec(unsigned long pfn)
{
return set_memory_wb((unsigned long) pfn_to_kaddr(pfn), 1);
}
#define clear_mce_nospec clear_mce_nospec
#else
/*
* Few people would run a 32-bit kernel on a machine that supports
* recoverable errors because they have too much memory to boot 32-bit.
*/
#endif
#endif /* _ASM_X86_SET_MEMORY_H */
|
