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