[PATCH v2 05/13] powerpc: use linux/unaligned/le_struct.h on LE power7

Arnd Bergmann
2021-05-14T10:03:37Z

From: Arnd Bergmann <arnd@arndb.de>

Little-endian POWER7 kernels disable
CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS because that is not supported on
the hardware, but the kernel still uses direct load/store for explicti
get_unaligned()/put_unaligned().

I assume this is a mistake that leads to power7 having to trap and fix
up all these unaligned accesses at a noticeable performance cost.

The fix is completely trivial, just remove the file and use the
generic version that gets it right.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
arch/powerpc/include/asm/unaligned.h | 22 ----------------------
1 file changed, 22 deletions(-)
delete mode 100644 arch/powerpc/include/asm/unaligned.h

diff --git a/arch/powerpc/include/asm/unaligned.h b/arch/powerpc/include/asm/unaligned.h
deleted file mode 100644
index ce69c5eff95e..000000000000
--- a/arch/powerpc/include/asm/unaligned.h
+++ /dev/null
@@ -1,22 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_POWERPC_UNALIGNED_H
-#define _ASM_POWERPC_UNALIGNED_H
-
-#ifdef __KERNEL__
-
-/*
- * The PowerPC can do unaligned accesses itself based on its endian mode.
- */
-#include <linux/unaligned/access_ok.h>
-#include <linux/unaligned/generic.h>
-
-#ifdef __LITTLE_ENDIAN__
-#define get_unaligned __get_unaligned_le
-#define put_unaligned __put_unaligned_le
-#else
-#define get_unaligned __get_unaligned_be
-#define put_unaligned __put_unaligned_be
-#endif
-
-#endif /* __KERNEL__ */
-#endif /* _ASM_POWERPC_UNALIGNED_H */
--
2.29.2