@@ -367,6 +367,9 @@ extern int nx_enabled;
#define pgprot_writecombine pgprot_writecombine
extern pgprot_t pgprot_writecombine(pgprot_t prot);
+#define pgprot_writethrough pgprot_writethrough
+extern pgprot_t pgprot_writethrough(pgprot_t prot);
+
/* Indicate that x86 has its own track and untrack pfn vma functions */
#define __HAVE_PFNMAP_TRACKING
@@ -987,6 +987,13 @@ pgprot_t pgprot_writecombine(pgprot_t prot)
}
EXPORT_SYMBOL_GPL(pgprot_writecombine);
+pgprot_t pgprot_writethrough(pgprot_t prot)
+{
+ return __pgprot(pgprot_val(prot) |
+ cachemode2protval(_PAGE_CACHE_MODE_WT));
+}
+EXPORT_SYMBOL_GPL(pgprot_writethrough);
+
#if defined(CONFIG_DEBUG_FS) && defined(CONFIG_X86_PAT)
static struct memtype *memtype_get_idx(loff_t pos)
@@ -262,6 +262,10 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
#define pgprot_writecombine pgprot_noncached
#endif
+#ifndef pgprot_writethrough
+#define pgprot_writethrough pgprot_noncached
+#endif
+
#ifndef pgprot_device
#define pgprot_device pgprot_noncached
#endif