diff options
| author | Joshua Kinard <kumba@gentoo.org> | 2017-11-19 06:29:56 +0300 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2018-07-12 21:14:10 +0300 |
| commit | a0a5ac3ce8fe6bf26694f49f9ba42ed859487424 (patch) | |
| tree | 32a04df6f500f91ea13a2d86e5a27989c90131ea | |
| parent | b5d69129ea2b86d8a357efe3eca664b44860406e (diff) | |
| download | linux-a0a5ac3ce8fe6bf26694f49f9ba42ed859487424.tar.xz | |
MIPS: Fix delay slot bug in `atomic*_sub_if_positive' for R10000_LLSC_WAR
This patch fixes an old bug in MIPS ll/sc atomics, in the
`atomic_sub_if_positive' and `atomic64_sub_if_positive' functions, for
the R10000_LLSC_WAR case where the result of the subu/dsubu instruction
would potentially not be made available to the sc/scd instruction due
to being in the delay-slot of the branch-likely (beqzl) instruction.
This also removes the need for the `noreorder' directive, allowing GAS
to use delay slot scheduling as needed.
The same fix is also applied to the standard branch (beqz) case in
preparation for a follow-up patch that will cleanup/merge the
R10000_LLSC_WAR and non-R10K sections together.
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Tested-by: Joshua Kinard <kumba@gentoo.org>
Patchwork: https://patchwork.linux-mips.org/patch/17735/
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: James Hogan <james.hogan@mips.com>
Cc: "Maciej W. Rozycki" <macro@mips.com>
Cc: linux-mips@linux-mips.org
| -rw-r--r-- | arch/mips/include/asm/atomic.h | 32 |
1 files changed, 12 insertions, 20 deletions
diff --git a/arch/mips/include/asm/atomic.h b/arch/mips/include/asm/atomic.h index 0ab176bdb8e8..0babf2775d8e 100644 --- a/arch/mips/include/asm/atomic.h +++ b/arch/mips/include/asm/atomic.h @@ -225,12 +225,10 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) " .set arch=r4000 \n" "1: ll %1, %2 # atomic_sub_if_positive\n" " subu %0, %1, %3 \n" + " move %1, %0 \n" " bltz %0, 1f \n" - " sc %0, %2 \n" - " .set noreorder \n" - " beqzl %0, 1b \n" - " subu %0, %1, %3 \n" - " .set reorder \n" + " sc %1, %2 \n" + " beqzl %1, 1b \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), @@ -244,12 +242,10 @@ static __inline__ int atomic_sub_if_positive(int i, atomic_t * v) " .set "MIPS_ISA_LEVEL" \n" "1: ll %1, %2 # atomic_sub_if_positive\n" " subu %0, %1, %3 \n" + " move %1, %0 \n" " bltz %0, 1f \n" - " sc %0, %2 \n" - " .set noreorder \n" - " beqz %0, 1b \n" - " subu %0, %1, %3 \n" - " .set reorder \n" + " sc %1, %2 \n" + " beqz %1, 1b \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), @@ -570,12 +566,10 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) " .set arch=r4000 \n" "1: lld %1, %2 # atomic64_sub_if_positive\n" " dsubu %0, %1, %3 \n" + " move %1, %0 \n" " bltz %0, 1f \n" - " scd %0, %2 \n" - " .set noreorder \n" - " beqzl %0, 1b \n" - " dsubu %0, %1, %3 \n" - " .set reorder \n" + " scd %1, %2 \n" + " beqzl %1, 1b \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), @@ -589,12 +583,10 @@ static __inline__ long atomic64_sub_if_positive(long i, atomic64_t * v) " .set "MIPS_ISA_LEVEL" \n" "1: lld %1, %2 # atomic64_sub_if_positive\n" " dsubu %0, %1, %3 \n" + " move %1, %0 \n" " bltz %0, 1f \n" - " scd %0, %2 \n" - " .set noreorder \n" - " beqz %0, 1b \n" - " dsubu %0, %1, %3 \n" - " .set reorder \n" + " scd %1, %2 \n" + " beqz %1, 1b \n" "1: \n" " .set mips0 \n" : "=&r" (result), "=&r" (temp), |