1#ifndef _ASM_X86_CACHEFLUSH_H
  2#define _ASM_X86_CACHEFLUSH_H
  3
  4/* Caches aren't brain-dead on the intel. */
  5#include <asm-generic/cacheflush.h>
  6#include <asm/special_insns.h>
  7
  8#ifdef CONFIG_X86_PAT
  9/*
 10 * X86 PAT uses page flags WC and Uncached together to keep track of
 11 * memory type of pages that have backing page struct. X86 PAT supports 3
 12 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and
 13 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not
 14 * been changed from its default (value of -1 used to denote this).
 15 * Note we do not support _PAGE_CACHE_UC here.
 16 */
 17
 18#define _PGMT_DEFAULT		0
 19#define _PGMT_WC		(1UL << PG_arch_1)
 20#define _PGMT_UC_MINUS		(1UL << PG_uncached)
 21#define _PGMT_WB		(1UL << PG_uncached | 1UL << PG_arch_1)
 22#define _PGMT_MASK		(1UL << PG_uncached | 1UL << PG_arch_1)
 23#define _PGMT_CLEAR_MASK	(~_PGMT_MASK)
 24
 25static inline unsigned long get_page_memtype(struct page *pg)
 26{
 27	unsigned long pg_flags = pg->flags & _PGMT_MASK;
 28
 29	if (pg_flags == _PGMT_DEFAULT)
 30		return -1;
 31	else if (pg_flags == _PGMT_WC)
 32		return _PAGE_CACHE_WC;
 33	else if (pg_flags == _PGMT_UC_MINUS)
 34		return _PAGE_CACHE_UC_MINUS;
 35	else
 36		return _PAGE_CACHE_WB;
 37}
 38
 39static inline void set_page_memtype(struct page *pg, unsigned long memtype)
 40{
 41	unsigned long memtype_flags = _PGMT_DEFAULT;
 42	unsigned long old_flags;
 43	unsigned long new_flags;
 44
 45	switch (memtype) {
 46	case _PAGE_CACHE_WC:
 47		memtype_flags = _PGMT_WC;
 48		break;
 49	case _PAGE_CACHE_UC_MINUS:
 50		memtype_flags = _PGMT_UC_MINUS;
 51		break;
 52	case _PAGE_CACHE_WB:
 53		memtype_flags = _PGMT_WB;
 54		break;
 55	}
 56
 57	do {
 58		old_flags = pg->flags;
 59		new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags;
 60	} while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags);
 61}
 62#else
 63static inline unsigned long get_page_memtype(struct page *pg) { return -1; }
 64static inline void set_page_memtype(struct page *pg, unsigned long memtype) { }
 65#endif
 66
 67/*
 68 * The set_memory_* API can be used to change various attributes of a virtual
 69 * address range. The attributes include:
 70 * Cachability   : UnCached, WriteCombining, WriteBack
 71 * Executability : eXeutable, NoteXecutable
 72 * Read/Write    : ReadOnly, ReadWrite
 73 * Presence      : NotPresent
 74 *
 75 * Within a category, the attributes are mutually exclusive.
 76 *
 77 * The implementation of this API will take care of various aspects that
 78 * are associated with changing such attributes, such as:
 79 * - Flushing TLBs
 80 * - Flushing CPU caches
 81 * - Making sure aliases of the memory behind the mapping don't violate
 82 *   coherency rules as defined by the CPU in the system.
 83 *
 84 * What this API does not do:
 85 * - Provide exclusion between various callers - including callers that
 86 *   operation on other mappings of the same physical page
 87 * - Restore default attributes when a page is freed
 88 * - Guarantee that mappings other than the requested one are
 89 *   in any state, other than that these do not violate rules for
 90 *   the CPU you have. Do not depend on any effects on other mappings,
 91 *   CPUs other than the one you have may have more relaxed rules.
 92 * The caller is required to take care of these.
 93 */
 94
 95int _set_memory_uc(unsigned long addr, int numpages);
 96int _set_memory_wc(unsigned long addr, int numpages);
 97int _set_memory_wb(unsigned long addr, int numpages);
 98int set_memory_uc(unsigned long addr, int numpages);
 99int set_memory_wc(unsigned long addr, int numpages);
100int set_memory_wb(unsigned long addr, int numpages);
101int set_memory_x(unsigned long addr, int numpages);
102int set_memory_nx(unsigned long addr, int numpages);
103int set_memory_ro(unsigned long addr, int numpages);
104int set_memory_rw(unsigned long addr, int numpages);
105int set_memory_np(unsigned long addr, int numpages);
106int set_memory_4k(unsigned long addr, int numpages);
107
108int set_memory_array_uc(unsigned long *addr, int addrinarray);
109int set_memory_array_wc(unsigned long *addr, int addrinarray);
110int set_memory_array_wb(unsigned long *addr, int addrinarray);
111
112int set_pages_array_uc(struct page **pages, int addrinarray);
113int set_pages_array_wc(struct page **pages, int addrinarray);
114int set_pages_array_wb(struct page **pages, int addrinarray);
115
116/*
117 * For legacy compatibility with the old APIs, a few functions
118 * are provided that work on a "struct page".
119 * These functions operate ONLY on the 1:1 kernel mapping of the
120 * memory that the struct page represents, and internally just
121 * call the set_memory_* function. See the description of the
122 * set_memory_* function for more details on conventions.
123 *
124 * These APIs should be considered *deprecated* and are likely going to
125 * be removed in the future.
126 * The reason for this is the implicit operation on the 1:1 mapping only,
127 * making this not a generally useful API.
128 *
129 * Specifically, many users of the old APIs had a virtual address,
130 * called virt_to_page() or vmalloc_to_page() on that address to
131 * get a struct page* that the old API required.
132 * To convert these cases, use set_memory_*() on the original
133 * virtual address, do not use these functions.
134 */
135
136int set_pages_uc(struct page *page, int numpages);
137int set_pages_wb(struct page *page, int numpages);
138int set_pages_x(struct page *page, int numpages);
139int set_pages_nx(struct page *page, int numpages);
140int set_pages_ro(struct page *page, int numpages);
141int set_pages_rw(struct page *page, int numpages);
142
143
144void clflush_cache_range(void *addr, unsigned int size);
145
146#ifdef CONFIG_DEBUG_RODATA
147void mark_rodata_ro(void);
148extern const int rodata_test_data;
149extern int kernel_set_to_readonly;
150void set_kernel_text_rw(void);
151void set_kernel_text_ro(void);
152#else
153static inline void set_kernel_text_rw(void) { }
154static inline void set_kernel_text_ro(void) { }
155#endif
156
157#ifdef CONFIG_DEBUG_RODATA_TEST
158int rodata_test(void);
159#else
160static inline int rodata_test(void)
161{
162	return 0;
163}
164#endif
165
166#endif /* _ASM_X86_CACHEFLUSH_H */