Move the code to implement uaccess using memcpy or direct loads and
stores to asm-generic/uaccess.h and make it selectable kconfig option.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/h8300/Kconfig | 1 +
arch/h8300/include/asm/Kbuild | 1 +
arch/h8300/include/asm/uaccess.h | 55 --------------------------------
include/asm-generic/uaccess.h | 48 ++++++++++++++++++++++++++++
lib/Kconfig | 4 +++
5 files changed, 54 insertions(+), 55 deletions(-)
delete mode 100644 arch/h8300/include/asm/uaccess.h
diff --git a/arch/h8300/Kconfig b/arch/h8300/Kconfig
index c071da34e081..c24d36241503 100644
--- a/arch/h8300/Kconfig
+++ b/arch/h8300/Kconfig
@@ -23,6 +23,7 @@ config H8300
select HAVE_ARCH_KGDB
select HAVE_ARCH_HASH
select CPU_NO_EFFICIENT_FFS
+ select UACCESS_MEMCPY
config CPU_BIG_ENDIAN
def_bool y
diff --git a/arch/h8300/include/asm/Kbuild b/arch/h8300/include/asm/Kbuild
index e3dead402e5f..91533fc44b69 100644
--- a/arch/h8300/include/asm/Kbuild
+++ b/arch/h8300/include/asm/Kbuild
@@ -47,6 +47,7 @@ generic-y += timex.h
generic-y += tlbflush.h
generic-y += topology.h
generic-y += trace_clock.h
+generic-y += uaccess.h
generic-y += unaligned.h
generic-y += vga.h
generic-y += word-at-a-time.h
diff --git a/arch/h8300/include/asm/uaccess.h b/arch/h8300/include/asm/uaccess.h
deleted file mode 100644
index bc8031949d07..000000000000
--- a/arch/h8300/include/asm/uaccess.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_UACCESS_H
-#define _ASM_UACCESS_H
-
-#include <linux/string.h>
-
-static inline __must_check unsigned long
-raw_copy_from_user(void *to, const void __user * from, unsigned long n)
-{
- if (__builtin_constant_p(n)) {
- switch(n) {
- case 1:
- *(u8 *)to = *(u8 __force *)from;
- return 0;
- case 2:
- *(u16 *)to = *(u16 __force *)from;
- return 0;
- case 4:
- *(u32 *)to = *(u32 __force *)from;
- return 0;
- }
- }
-
- memcpy(to, (const void __force *)from, n);
- return 0;
-}
-
-static inline __must_check unsigned long
-raw_copy_to_user(void __user *to, const void *from, unsigned long n)
-{
- if (__builtin_constant_p(n)) {
- switch(n) {
- case 1:
- *(u8 __force *)to = *(u8 *)from;
- return 0;
- case 2:
- *(u16 __force *)to = *(u16 *)from;
- return 0;
- case 4:
- *(u32 __force *)to = *(u32 *)from;
- return 0;
- default:
- break;
- }
- }
-
- memcpy((void __force *)to, from, n);
- return 0;
-}
-#define INLINE_COPY_FROM_USER
-#define INLINE_COPY_TO_USER
-
-#include <asm-generic/uaccess.h>
-
-#endif
diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
index aac336831204..3dcabfceb21e 100644
--- a/include/asm-generic/uaccess.h
+++ b/include/asm-generic/uaccess.h
@@ -9,6 +9,54 @@
*/
#include <linux/string.h>
+#ifdef CONFIG_UACCESS_MEMCPY
+static inline __must_check unsigned long
+raw_copy_from_user(void *to, const void __user * from, unsigned long n)
+{
+ if (__builtin_constant_p(n)) {
+ switch(n) {
+ case 1:
+ *(u8 *)to = *(u8 __force *)from;
+ return 0;
+ case 2:
+ *(u16 *)to = *(u16 __force *)from;
+ return 0;
+ case 4:
+ *(u32 *)to = *(u32 __force *)from;
+ return 0;
+ }
+ }
+
+ memcpy(to, (const void __force *)from, n);
+ return 0;
+}
+
+static inline __must_check unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ if (__builtin_constant_p(n)) {
+ switch(n) {
+ case 1:
+ *(u8 __force *)to = *(u8 *)from;
+ return 0;
+ case 2:
+ *(u16 __force *)to = *(u16 *)from;
+ return 0;
+ case 4:
+ *(u32 __force *)to = *(u32 *)from;
+ return 0;
+ default:
+ break;
+ }
+ }
+
+ memcpy((void __force *)to, from, n);
+ return 0;
+}
+#define INLINE_COPY_FROM_USER
+#define INLINE_COPY_TO_USER
+#endif /* CONFIG_UACCESS_MEMCPY */
+
#define MAKE_MM_SEG(s) ((mm_segment_t) { (s) })
#ifndef KERNEL_DS
diff --git a/lib/Kconfig b/lib/Kconfig
index a9e56539bd11..7a3f01ac45e8 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -591,6 +591,10 @@ config ARCH_NO_SG_CHAIN
config ARCH_HAS_PMEM_API
bool
+# use memcpy to implement user copies for nommu architectures
+config UACCESS_MEMCPY
+ bool
+
config ARCH_HAS_UACCESS_FLUSHCACHE
bool
--
2.20.1
