[MIPS] Hook for platforms to define cachability of /dev/mem regions

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index abf99b1..81f925a 100644 (file)
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -6,6 +6,8 @@
  * Copyright (C) 1994 - 2003, 07 by Ralf Baechle (ralf@linux-mips.org)
  * Copyright (C) 2007 MIPS Technologies, Inc.
  */
+#include <linux/fs.h>
+#include <linux/fcntl.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -164,3 +166,11 @@ void __init cpu_cache_init(void)
 
        panic(cache_panic);
 }
+
+int __weak __uncached_access(struct file *file, unsigned long addr)
+{
+       if (file->f_flags & O_SYNC)
+               return 1;
+
+       return addr >= __pa(high_memory);
+}

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index cc9a9d0..7e082bc 100644 (file)
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -75,6 +75,13 @@ static inline int uncached_access(struct file *file, unsigned long addr)
         * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
         */
        return !(efi_mem_attributes(addr) & EFI_MEMORY_WB);
+#elif defined(CONFIG_MIPS)
+       {
+               extern int __uncached_access(struct file *file,
+                                            unsigned long addr);
+
+               return __uncached_access(file, addr);
+       }
 #else
        /*
         * Accessing memory above the top the kernel knows about or through a file pointer