The {save,restore}_fp_context{,32} functions require that the assembler
allows the use of sdc instructions on any FP register, and this is
acomplished by setting the arch to r4000. However this has the effect
of enabling the assembler to use mips64 instructions in the expansion
of pseudo-instructions. This was done in the (now-reverted) commit
eec43a224cf1 "MIPS: Save/restore MSA context around signals" which
led to my mistakenly believing that there was an assembler bug, when
in reality the assembler was just emitting mips64 instructions. Avoid
the issue for future commits which will add code to r4k_fpu.S by
pushing the .set arch=r4000 directives into the functions that require
it, and remove the spurious assertion declaring the assembler bug.
Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
---
Changes in v2:
- Rebase atop v3.19-rc6.
---
arch/mips/include/asm/asmmacro.h | 12 ++++--------
arch/mips/kernel/r4k_fpu.S | 2 +-
2 files changed, 5 insertions(+), 9 deletions(-)
diff --git a/arch/mips/include/asm/asmmacro.h b/arch/mips/include/asm/asmmacro.h
index 6caf876..a4a5ec8 100644
--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -324,8 +324,7 @@
SET_HARDFLOAT
.insn
.word COPY_UW_MSA_INSN | (\n << 16) | (\ws << 11)
- /* move triggers an assembler bug... */
- or \rd, $1, zero
+ move \rd, $1
.set pop
.endm
@@ -335,8 +334,7 @@
SET_HARDFLOAT
.insn
.word COPY_UD_MSA_INSN | (\n << 16) | (\ws << 11)
- /* move triggers an assembler bug... */
- or \rd, $1, zero
+ move \rd, $1
.set pop
.endm
@@ -344,8 +342,7 @@
.set push
.set noat
SET_HARDFLOAT
- /* move triggers an assembler bug... */
- or $1, \rs, zero
+ move $1, \rs
.word INSERT_W_MSA_INSN | (\n << 16) | (\wd << 6)
.set pop
.endm
@@ -354,8 +351,7 @@
.set push
.set noat
SET_HARDFLOAT
- /* move triggers an assembler bug... */
- or $1, \rs, zero
+ move $1, \rs
.word INSERT_D_MSA_INSN | (\n << 16) | (\wd << 6)
.set pop
.endm
diff --git a/arch/mips/kernel/r4k_fpu.S b/arch/mips/kernel/r4k_fpu.S
index 6c160c6..02872df 100644
--- a/arch/mips/kernel/r4k_fpu.S
+++ b/arch/mips/kernel/r4k_fpu.S
@@ -34,7 +34,6 @@
.endm
.set noreorder
- .set arch=r4000
LEAF(_save_fp_context)
.set push
@@ -102,6 +101,7 @@ LEAF(_save_fp_context)
/* Save 32-bit process floating point context */
LEAF(_save_fp_context32)
.set push
+ .set arch=r4000
SET_HARDFLOAT
cfc1 t1, fcr31
--
2.2.2
