New implementation for IO memcpy and IO memset

The IO memcpy and IO memset functions in asm-generic/io.h simply call
memcpy and memset. This can lead to alignment problems or faults on
architectures that do not define their own version and fall back to
these defaults.
This patch introduces new implementations for IO memcpy and IO memset,
that use read{l,q} accessor functions, align accesses to machine word
size, and resort to byte accesses when the target memory is not aligned.
For new architectures and existing ones that were using the old
fallbacks these functions are save to use, because IO memory constraints
are taken into account. Moreover, architectures with similar
implementations can now use these new versions, not needing to implement
their own.

Reviewed-by: Yann Sionneau <ysionneau@kalrayinc.com>
Signed-off-by: Julian Vetter <jvetter@kalrayinc.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 3 insertions, 19 deletions

diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
index 1027be6a62bc..a5cbbf3e26ec 100644
--- a/include/asm-generic/io.h
+++ b/include/asm-generic/io.h
@@ -1211,7 +1211,6 @@ static inline void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
 #endif
 
 #ifndef memset_io
-#define memset_io memset_io
 /**
  * memset_io	Set a range of I/O memory to a constant value
  * @addr:	The beginning of the I/O-memory range to set
@@ -1220,15 +1219,10 @@ static inline void unxlate_dev_mem_ptr(phys_addr_t phys, void *addr)
  *
  * Set a range of I/O memory to a given value.
  */
-static inline void memset_io(volatile void __iomem *addr, int value,
-			     size_t size)
-{
-	memset(__io_virt(addr), value, size);
-}
+void memset_io(volatile void __iomem *addr, int val, size_t count);
 #endif
 
 #ifndef memcpy_fromio
-#define memcpy_fromio memcpy_fromio
 /**
  * memcpy_fromio	Copy a block of data from I/O memory
  * @dst:		The (RAM) destination for the copy
@@ -1237,16 +1231,10 @@ static inline void memset_io(volatile void __iomem *addr, int value,
  *
  * Copy a block of data from I/O memory.
  */
-static inline void memcpy_fromio(void *buffer,
-				 const volatile void __iomem *addr,
-				 size_t size)
-{
-	memcpy(buffer, __io_virt(addr), size);
-}
+void memcpy_fromio(void *dst, const volatile void __iomem *src, size_t count);
 #endif
 
 #ifndef memcpy_toio
-#define memcpy_toio memcpy_toio
 /**
  * memcpy_toio		Copy a block of data into I/O memory
  * @dst:		The (I/O memory) destination for the copy
@@ -1255,11 +1243,7 @@ static inline void memcpy_fromio(void *buffer,
  *
  * Copy a block of data to I/O memory.
  */
-static inline void memcpy_toio(volatile void __iomem *addr, const void *buffer,
-			       size_t size)
-{
-	memcpy(__io_virt(addr), buffer, size);
-}
+void memcpy_toio(volatile void __iomem *dst, const void *src, size_t count);
 #endif
 
 extern int devmem_is_allowed(unsigned long pfn);