[PATCH 3.16 26/26] MIPS: wrap cfcmsa & ctcmsa accesses for toolchains with MSA support

From: Ben Hutchings
Date: Sat Apr 01 2017 - 23:11:52 EST


3.16.43-rc2 review patch. If anyone has any objections, please let me know.

------------------

From: Paul Burton <paul.burton@xxxxxxxxxx>

commit e1bebbab1eaecac77d77033010b5e0f51b737e64 upstream.

Uses of the cfcmsa & ctcmsa instructions were not being wrapped by a
macro in the case where the toolchain supports MSA, since the arguments
exactly match a typical use of the instructions. However using current
toolchains this leads to errors such as:

arch/mips/kernel/genex.S:437: Error: opcode not supported on this processor: mips32r2 (mips32r2) `cfcmsa $5,1'

Thus uses of the instructions must be in the context of a ".set msa"
directive, however doing that from the users of the instructions would
be messy due to the possibility that the toolchain does not support
MSA. Fix this by renaming the macros (prepending an underscore) in order
to avoid recursion when attempting to emit the instructions, and provide
implementations for the TOOLCHAIN_SUPPORTS_MSA case which ".set msa" as
appropriate.

Signed-off-by: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/9163/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
arch/mips/include/asm/asmmacro.h | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)

--- a/arch/mips/include/asm/asmmacro.h
+++ b/arch/mips/include/asm/asmmacro.h
@@ -209,6 +209,22 @@
.endm

#ifdef TOOLCHAIN_SUPPORTS_MSA
+ .macro _cfcmsa rd, cs
+ .set push
+ .set mips32r2
+ .set msa
+ cfcmsa \rd, $\cs
+ .set pop
+ .endm
+
+ .macro _ctcmsa cd, rs
+ .set push
+ .set mips32r2
+ .set msa
+ ctcmsa $\cd, \rs
+ .set pop
+ .endm
+
.macro ld_d wd, off, base
.set push
.set mips32r2
@@ -281,7 +297,7 @@
/*
* Temporary until all toolchains in use include MSA support.
*/
- .macro cfcmsa rd, cs
+ .macro _cfcmsa rd, cs
.set push
.set noat
SET_HARDFLOAT
@@ -291,7 +307,7 @@
.set pop
.endm

- .macro ctcmsa cd, rs
+ .macro _ctcmsa cd, rs
.set push
.set noat
SET_HARDFLOAT
@@ -389,7 +405,7 @@
.set push
.set noat
SET_HARDFLOAT
- cfcmsa $1, MSA_CSR
+ _cfcmsa $1, MSA_CSR
sw $1, THREAD_MSA_CSR(\thread)
.set pop
.endm
@@ -399,7 +415,7 @@
.set noat
SET_HARDFLOAT
lw $1, THREAD_MSA_CSR(\thread)
- ctcmsa MSA_CSR, $1
+ _ctcmsa MSA_CSR, $1
.set pop
ld_d 0, THREAD_FPR0, \thread
ld_d 1, THREAD_FPR1, \thread