LXR linux/arch/x86/include/asm/cacheflush.h

   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 */
 167