[ALSA] Add volatile to IO pinters

ALSA Core
Add volatile prefix to IO pointers for copy_to_user_fromio() and
copy_from_user_toio() functions.
Signed-off-by: Takashi Iwai <tiwai@suse.de>

include/sound/core.h

@@ -307,8 +307,8 @@ void snd_hidden_vfree(void *obj);
 #define vfree_nocheck(obj) vfree(obj)
 #endif
 char *snd_kmalloc_strdup(const char *string, int flags);
-int copy_to_user_fromio(void __user *dst, const void __iomem *src, size_t count);
-int copy_from_user_toio(void __iomem *dst, const void __user *src, size_t count);
+int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count);
+int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count);
 
 /* init.c */
 

sound/core/memory.c

@@ -253,7 +253,7 @@ char *snd_kmalloc_strdup(const char *string, int flags)
  *
  * Returns zero if successful, or non-zero on failure.
  */
-int copy_to_user_fromio(void __user *dst, const void __iomem *src, size_t count)
+int copy_to_user_fromio(void __user *dst, const volatile void __iomem *src, size_t count)
 {
 #if defined(__i386__) || defined(CONFIG_SPARC32)
 	return copy_to_user(dst, (const void*)src, count) ? -EFAULT : 0;
@@ -284,7 +284,7 @@ int copy_to_user_fromio(void __user *dst, const void __iomem *src, size_t count)
  *
  * Returns zero if successful, or non-zero on failure.
  */
-int copy_from_user_toio(void __iomem *dst, const void __user *src, size_t count)
+int copy_from_user_toio(volatile void __iomem *dst, const void __user *src, size_t count)
 {
 #if defined(__i386__) || defined(CONFIG_SPARC32)
 	return copy_from_user((void*)dst, src, count) ? -EFAULT : 0;