summaryrefslogtreecommitdiffstats
path: root/arch/x86/include/asm/cacheflush.h
blob: 62f084478f7e08448050cac33152f8f62bed8b72 (plain)
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
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
#ifndef _ASM_X86_CACHEFLUSH_H
#define _ASM_X86_CACHEFLUSH_H

/* Caches aren't brain-dead on the intel. */
#include <asm-generic/cacheflush.h>

#ifdef CONFIG_X86_PAT
/*
 * X86 PAT uses page flags WC and Uncached together to keep track of
 * memory type of pages that have backing page struct. X86 PAT supports 3
 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and
 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not
 * been changed from its default (value of -1 used to denote this).
 * Note we do not support _PAGE_CACHE_UC here.
 */

#define _PGMT_DEFAULT		0
#define _PGMT_WC		(1UL << PG_arch_1)
#define _PGMT_UC_MINUS		(1UL << PG_uncached)
#define _PGMT_WB		(1UL << PG_uncached | 1UL << PG_arch_1)
#define _PGMT_MASK		(1UL << PG_uncached | 1UL << PG_arch_1)
#define _PGMT_CLEAR_MASK	(~_PGMT_MASK)

static inline unsigned long get_page_memtype(struct page *pg)
{
	unsigned long pg_flags = pg->flags & _PGMT_MASK;

	if (pg_flags == _PGMT_DEFAULT)
		return -1;
	else if (pg_flags == _PGMT_WC)
		return _PAGE_CACHE_WC;
	else if (pg_flags == _PGMT_UC_MINUS)
		return _PAGE_CACHE_UC_MINUS;
	else
		return _PAGE_CACHE_WB;
}

static inline void set_page_memtype(struct page *pg, unsigned long memtype)
{
	unsigned long memtype_flags = _PGMT_DEFAULT;
	unsigned long old_flags;
	unsigned long new_flags;

	switch (memtype) {
	case _PAGE_CACHE_WC:
		memtype_flags = _PGMT_WC;
		break;
	case _PAGE_CACHE_UC_MINUS:
		memtype_flags = _PGMT_UC_MINUS;
		break;
	case _PAGE_CACHE_WB:
		memtype_flags = _PGMT_WB;
		break;
	}

	do {
		old_flags = pg->flags;
		new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags;
	} while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags);
}
#else
static inline unsigned long get_page_memtype(struct page *pg) { return -1; }
static inline void set_page_memtype(struct page *pg, unsigned long memtype) { }
#endif

/*
 * The set_memory_* API can be used to change various attributes of a virtual
 * address range. The attributes include:
 * Cachability   : UnCached, WriteCombining, WriteBack
 * Executability : eXeutable, NoteXecutable
 * Read/Write    : ReadOnly, ReadWrite
 * Presence      : NotPresent
 *
 * Within a catagory, 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_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_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(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_array_uc(unsigned long *addr, int addrinarray);
int set_memory_array_wc(unsigned long *addr, int addrinarray);
int set_memory_array_wb(unsigned long *addr, int addrinarray);

int set_pages_array_uc(struct page **pages, int addrinarray);
int set_pages_array_wc(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_x(struct page *page, int numpages);
int set_pages_nx(struct page *page, int numpages);
int set_pages_ro(struct page *page, int numpages);
int set_pages_rw(struct page *page, int numpages);


void clflush_cache_range(void *addr, unsigned int size);

#ifdef CONFIG_DEBUG_RODATA
void mark_rodata_ro(void);
extern const int rodata_test_data;
extern int kernel_set_to_readonly;
void set_kernel_text_rw(void);
void set_kernel_text_ro(void);
#else
static inline void set_kernel_text_rw(void) { }
static inline void set_kernel_text_ro(void) { }
#endif

#ifdef CONFIG_DEBUG_RODATA_TEST
int rodata_test(void);
#else
static inline int rodata_test(void)
{
	return 0;
}
#endif

#endif /* _ASM_X86_CACHEFLUSH_H */
OpenPOWER on IntegriCloud