[PATCH 3.2 17/74] MIPS: Fix mips_atomic_set() retry condition

[Ben Hutchings]

3.2.94-rc1 review patch.  If anyone has any objections, please let me know.

--

From: James Hogan 

commit 2ec420b26f7b6ff332393f0bb5a7d245f7ad87f0 upstream.

The inline asm retry check in the MIPS_ATOMIC_SET operation of the
sysmips system call has been backwards since commit f1e39a4a616c ("MIPS:
Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
merged in v2.6.32, resulting in the non R1_LLSC_WAR case retrying
until the operation was inatomic, before returning the new value that
was probably just written multiple times instead of the old value.

Invert the branch condition to fix that particular issue.

Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with 
inline assembler")
Signed-off-by: James Hogan 
Cc: linux-m...@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16148/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings 
---
 arch/mips/kernel/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -203,7 +203,7 @@ static inline int mips_atomic_set(struct
"1: ll  %[old], (%[addr])   \n"
"   move%[tmp], %[new]  \n"
"2: sc  %[tmp], (%[addr])   \n"
-   "   bnez%[tmp], 4f  \n"
+   "   beqz%[tmp], 4f  \n"
"3: \n"
"   .subsection 2   \n"
"4: b   1b  \n"

[PATCH 3.2 17/74] MIPS: Fix mips_atomic_set() retry condition

[Ben Hutchings]

3.2.94-rc1 review patch.  If anyone has any objections, please let me know.

--

From: James Hogan 

commit 2ec420b26f7b6ff332393f0bb5a7d245f7ad87f0 upstream.

The inline asm retry check in the MIPS_ATOMIC_SET operation of the
sysmips system call has been backwards since commit f1e39a4a616c ("MIPS:
Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with inline assembler")
merged in v2.6.32, resulting in the non R1_LLSC_WAR case retrying
until the operation was inatomic, before returning the new value that
was probably just written multiple times instead of the old value.

Invert the branch condition to fix that particular issue.

Fixes: f1e39a4a616c ("MIPS: Rewrite sysmips(MIPS_ATOMIC_SET, ...) in C with 
inline assembler")
Signed-off-by: James Hogan 
Cc: linux-m...@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16148/
Signed-off-by: Ralf Baechle 
Signed-off-by: Ben Hutchings 
---
 arch/mips/kernel/syscall.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/syscall.c
+++ b/arch/mips/kernel/syscall.c
@@ -203,7 +203,7 @@ static inline int mips_atomic_set(struct
"1: ll  %[old], (%[addr])   \n"
"   move%[tmp], %[new]  \n"
"2: sc  %[tmp], (%[addr])   \n"
-   "   bnez%[tmp], 4f  \n"
+   "   beqz%[tmp], 4f  \n"
"3: \n"
"   .subsection 2   \n"
"4: b   1b  \n"