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

Christoph Hellwig hch at lst.de
Mon Sep 7 01:58:22 EDT 2020


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 at lst.de>
---
 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




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