[PATCH 5/8] riscv: use memcpy based uaccess for nommu again

From: Christoph Hellwig
Date: Mon Sep 07 2020 - 01:59:21 EST


This reverts commit adccfb1a805ea84d2db38eb53032533279bdaa97.

Now that the generic uaccess by mempcy code handles unaligned addresses
the generic code can be used for all RISC-V CPUs.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
arch/riscv/Kconfig | 1 +
arch/riscv/include/asm/uaccess.h | 36 ++++++++++++++++----------------
arch/riscv/lib/Makefile | 2 +-
3 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 07d53044013ede..460e3971a80fde 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -87,6 +87,7 @@ config RISCV
select SYSCTL_EXCEPTION_TRACE
select THREAD_INFO_IN_TASK
select SET_FS
+ select UACCESS_MEMCPY if !MMU

config ARCH_MMAP_RND_BITS_MIN
default 18 if 64BIT
diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
index f56c66b3f5fe21..e8eedf22e90747 100644
--- a/arch/riscv/include/asm/uaccess.h
+++ b/arch/riscv/include/asm/uaccess.h
@@ -13,24 +13,6 @@
/*
* User space memory access functions
*/
-
-extern unsigned long __must_check __asm_copy_to_user(void __user *to,
- const void *from, unsigned long n);
-extern unsigned long __must_check __asm_copy_from_user(void *to,
- const void __user *from, unsigned long n);
-
-static inline unsigned long
-raw_copy_from_user(void *to, const void __user *from, unsigned long n)
-{
- return __asm_copy_from_user(to, from, n);
-}
-
-static inline unsigned long
-raw_copy_to_user(void __user *to, const void *from, unsigned long n)
-{
- return __asm_copy_to_user(to, from, n);
-}
-
#ifdef CONFIG_MMU
#include <linux/errno.h>
#include <linux/compiler.h>
@@ -385,6 +367,24 @@ do { \
-EFAULT; \
})

+
+unsigned long __must_check __asm_copy_to_user(void __user *to,
+ const void *from, unsigned long n);
+unsigned long __must_check __asm_copy_from_user(void *to,
+ const void __user *from, unsigned long n);
+
+static inline unsigned long
+raw_copy_from_user(void *to, const void __user *from, unsigned long n)
+{
+ return __asm_copy_from_user(to, from, n);
+}
+
+static inline unsigned long
+raw_copy_to_user(void __user *to, const void *from, unsigned long n)
+{
+ return __asm_copy_to_user(to, from, n);
+}
+
extern long strncpy_from_user(char *dest, const char __user *src, long count);

extern long __must_check strlen_user(const char __user *str);
diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile
index 0d0db80800c4ed..47e7a82044608d 100644
--- a/arch/riscv/lib/Makefile
+++ b/arch/riscv/lib/Makefile
@@ -2,5 +2,5 @@
lib-y += delay.o
lib-y += memcpy.o
lib-y += memset.o
-lib-y += uaccess.o
+lib-$(CONFIG_MMU) += uaccess.o
lib-$(CONFIG_64BIT) += tishift.o
--
2.28.0