diff options
| author | Paul Burton <paul.burton@mips.com> | 2018-11-08 21:14:38 +0100 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2018-11-09 19:23:19 +0100 |
| commit | 378ed6f0e3c525e3b12827e7b7fb0a078ee48a32 (patch) | |
| tree | 766bb2bdd18f7aa7fce8a9ccb428cfcad8cf2feb /arch/mips/include/asm/cmpxchg.h | |
| parent | MIPS: Allow FP support to be disabled (diff) | |
| download | linux-378ed6f0e3c525e3b12827e7b7fb0a078ee48a32.tar.xz linux-378ed6f0e3c525e3b12827e7b7fb0a078ee48a32.zip | |
MIPS: Avoid using .set mips0 to restore ISA
We currently have 2 commonly used methods for switching ISA within
assembly code, then restoring the original ISA.
1) Using a pair of .set push & .set pop directives. For example:
.set push
.set mips32r2
<some_insn>
.set pop
2) Using .set mips0 to restore the ISA originally specified on the
command line. For example:
.set mips32r2
<some_insn>
.set mips0
Unfortunately method 2 does not work with nanoMIPS toolchains, where the
assembler rejects the .set mips0 directive like so:
Error: cannot change ISA from nanoMIPS to mips0
In preparation for supporting nanoMIPS builds, switch all instances of
method 2 in generic non-platform-specific code to use push & pop as in
method 1 instead. The .set push & .set pop is arguably cleaner anyway,
and if nothing else it's good to consistently use one method.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/21037/
Cc: linux-mips@linux-mips.org
Diffstat (limited to 'arch/mips/include/asm/cmpxchg.h')
| -rw-r--r-- | arch/mips/include/asm/cmpxchg.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/mips/include/asm/cmpxchg.h b/arch/mips/include/asm/cmpxchg.h index 89e9fb7976fe..638de0c25249 100644 --- a/arch/mips/include/asm/cmpxchg.h +++ b/arch/mips/include/asm/cmpxchg.h @@ -47,9 +47,10 @@ extern unsigned long __xchg_called_with_bad_pointer(void) __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ + " .set push \n" \ " .set " MIPS_ISA_ARCH_LEVEL " \n" \ "1: " ld " %0, %2 # __xchg_asm \n" \ - " .set mips0 \n" \ + " .set pop \n" \ " move $1, %z3 \n" \ " .set " MIPS_ISA_ARCH_LEVEL " \n" \ " " st " $1, %1 \n" \ @@ -117,10 +118,11 @@ static inline unsigned long __xchg(volatile void *ptr, unsigned long x, __asm__ __volatile__( \ " .set push \n" \ " .set noat \n" \ + " .set push \n" \ " .set "MIPS_ISA_ARCH_LEVEL" \n" \ "1: " ld " %0, %2 # __cmpxchg_asm \n" \ " bne %0, %z3, 2f \n" \ - " .set mips0 \n" \ + " .set pop \n" \ " move $1, %z4 \n" \ " .set "MIPS_ISA_ARCH_LEVEL" \n" \ " " st " $1, %1 \n" \ |