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#include <asm/uaccess.h>
   8
   9#ifdef CONFIG_X86_PAT
  10/*
  11 * X86 PAT uses page flags WC and Uncached together to keep track of
  12 * memory type of pages that have backing page struct. X86 PAT supports 3
  13 * different memory types, _PAGE_CACHE_WB, _PAGE_CACHE_WC and
  14 * _PAGE_CACHE_UC_MINUS and fourth state where page's memory type has not
  15 * been changed from its default (value of -1 used to denote this).
  16 * Note we do not support _PAGE_CACHE_UC here.
  17 */
  18
  19#define _PGMT_DEFAULT           0
  20#define _PGMT_WC                (1UL << PG_arch_1)
  21#define _PGMT_UC_MINUS          (1UL << PG_uncached)
  22#define _PGMT_WB                (1UL << PG_uncached | 1UL << PG_arch_1)
  23#define _PGMT_MASK              (1UL << PG_uncached | 1UL << PG_arch_1)
  24#define _PGMT_CLEAR_MASK        (~_PGMT_MASK)
  25
  26static inline unsigned long get_page_memtype(struct page *pg)
  27{
  28        unsigned long pg_flags = pg->flags & _PGMT_MASK;
  29
  30        if (pg_flags == _PGMT_DEFAULT)
  31                return -1;
  32        else if (pg_flags == _PGMT_WC)
  33                return _PAGE_CACHE_WC;
  34        else if (pg_flags == _PGMT_UC_MINUS)
  35                return _PAGE_CACHE_UC_MINUS;
  36        else
  37                return _PAGE_CACHE_WB;
  38}
  39
  40static inline void set_page_memtype(struct page *pg, unsigned long memtype)
  41{
  42        unsigned long memtype_flags = _PGMT_DEFAULT;
  43        unsigned long old_flags;
  44        unsigned long new_flags;
  45
  46        switch (memtype) {
  47        case _PAGE_CACHE_WC:
  48                memtype_flags = _PGMT_WC;
  49                break;
  50        case _PAGE_CACHE_UC_MINUS:
  51                memtype_flags = _PGMT_UC_MINUS;
  52                break;
  53        case _PAGE_CACHE_WB:
  54                memtype_flags = _PGMT_WB;
  55                break;
  56        }
  57
  58        do {
  59                old_flags = pg->flags;
  60                new_flags = (old_flags & _PGMT_CLEAR_MASK) | memtype_flags;
  61        } while (cmpxchg(&pg->flags, old_flags, new_flags) != old_flags);
  62}
  63#else
  64static inline unsigned long get_page_memtype(struct page *pg) { return -1; }
  65static inline void set_page_memtype(struct page *pg, unsigned long memtype) { }
  66#endif
  67
  68/*
  69 * The set_memory_* API can be used to change various attributes of a virtual
  70 * address range. The attributes include:
  71 * Cachability   : UnCached, WriteCombining, WriteBack
  72 * Executability : eXeutable, NoteXecutable
  73 * Read/Write    : ReadOnly, ReadWrite
  74 * Presence      : NotPresent
  75 *
  76 * Within a category, the attributes are mutually exclusive.
  77 *
  78 * The implementation of this API will take care of various aspects that
  79 * are associated with changing such attributes, such as:
  80 * - Flushing TLBs
  81 * - Flushing CPU caches
  82 * - Making sure aliases of the memory behind the mapping don't violate
  83 *   coherency rules as defined by the CPU in the system.
  84 *
  85 * What this API does not do:
  86 * - Provide exclusion between various callers - including callers that
  87 *   operation on other mappings of the same physical page
  88 * - Restore default attributes when a page is freed
  89 * - Guarantee that mappings other than the requested one are
  90 *   in any state, other than that these do not violate rules for
  91 *   the CPU you have. Do not depend on any effects on other mappings,
  92 *   CPUs other than the one you have may have more relaxed rules.
  93 * The caller is required to take care of these.
  94 */
  95
  96int _set_memory_uc(unsigned long addr, int numpages);
  97int _set_memory_wc(unsigned long addr, int numpages);
  98int _set_memory_wb(unsigned long addr, int numpages);
  99int set_memory_uc(unsigned long addr, int numpages);
 100int set_memory_wc(unsigned long addr, int numpages);
 101int set_memory_wb(unsigned long addr, int numpages);
 102int set_memory_x(unsigned long addr, int numpages);
 103int set_memory_nx(unsigned long addr, int numpages);
 104int set_memory_ro(unsigned long addr, int numpages);
 105int set_memory_rw(unsigned long addr, int numpages);
 106int set_memory_np(unsigned long addr, int numpages);
 107int set_memory_4k(unsigned long addr, int numpages);
 108
 109int set_memory_array_uc(unsigned long *addr, int addrinarray);
 110int set_memory_array_wc(unsigned long *addr, int addrinarray);
 111int set_memory_array_wb(unsigned long *addr, int addrinarray);
 112
 113int set_pages_array_uc(struct page **pages, int addrinarray);
 114int set_pages_array_wc(struct page **pages, int addrinarray);
 115int set_pages_array_wb(struct page **pages, int addrinarray);
 116
 117/*
 118 * For legacy compatibility with the old APIs, a few functions
 119 * are provided that work on a "struct page".
 120 * These functions operate ONLY on the 1:1 kernel mapping of the
 121 * memory that the struct page represents, and internally just
 122 * call the set_memory_* function. See the description of the
 123 * set_memory_* function for more details on conventions.
 124 *
 125 * These APIs should be considered *deprecated* and are likely going to
 126 * be removed in the future.
 127 * The reason for this is the implicit operation on the 1:1 mapping only,
 128 * making this not a generally useful API.
 129 *
 130 * Specifically, many users of the old APIs had a virtual address,
 131 * called virt_to_page() or vmalloc_to_page() on that address to
 132 * get a struct page* that the old API required.
 133 * To convert these cases, use set_memory_*() on the original
 134 * virtual address, do not use these functions.
 135 */
 136
 137int set_pages_uc(struct page *page, int numpages);
 138int set_pages_wb(struct page *page, int numpages);
 139int set_pages_x(struct page *page, int numpages);
 140int set_pages_nx(struct page *page, int numpages);
 141int set_pages_ro(struct page *page, int numpages);
 142int set_pages_rw(struct page *page, int numpages);
 143
 144
 145void clflush_cache_range(void *addr, unsigned int size);
 146
 147#define mmio_flush_range(addr, size) clflush_cache_range(addr, size)
 148
 149#ifdef CONFIG_DEBUG_RODATA
 150void mark_rodata_ro(void);
 151extern const int rodata_test_data;
 152extern int kernel_set_to_readonly;
 153void set_kernel_text_rw(void);
 154void set_kernel_text_ro(void);
 155#else
 156static inline void set_kernel_text_rw(void) { }
 157static inline void set_kernel_text_ro(void) { }
 158#endif
 159
 160#ifdef CONFIG_DEBUG_RODATA_TEST
 161int rodata_test(void);
 162#else
 163static inline int rodata_test(void)
 164{
 165        return 0;
 166}
 167#endif
 168
 169#endif /* _ASM_X86_CACHEFLUSH_H */
 170