x86, pat: Update the page flags for memtype atomically instead of using memtype_lock

[linux-2.6.git] / arch / x86 / include / asm / cacheflush.h

diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index 5b301b7..c70068d 100644 (file)
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -12,6 +12,7 @@ static inline void flush_cache_range(struct vm_area_struct *vma,
                                     unsigned long start, unsigned long end) { }
 static inline void flush_cache_page(struct vm_area_struct *vma,
                                    unsigned long vmaddr, unsigned long pfn) { }
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 static inline void flush_dcache_page(struct page *page) { }
 static inline void flush_dcache_mmap_lock(struct address_space *mapping) { }
 static inline void flush_dcache_mmap_unlock(struct address_space *mapping) { }
@@ -43,8 +44,64 @@ static inline void copy_from_user_page(struct vm_area_struct *vma,
        memcpy(dst, src, len);
 }
 
-#define PG_non_WB                              PG_arch_1
-PAGEFLAG(NonWB, non_WB)
+#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
@@ -90,6 +147,9 @@ int set_memory_4k(unsigned long addr, int numpages);
 int set_memory_array_uc(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_wb(struct page **pages, int addrinarray);
+
 /*
  * For legacy compatibility with the old APIs, a few functions
  * are provided that work on a "struct page".
@@ -123,6 +183,12 @@ 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