[PATCH v3] LoongArch: Remove vcsr in loongarch_fpu

From: huqi
Date: Wed Jul 06 2022 - 07:29:54 EST


From: Qi Hu <huqi@xxxxxxxxxxx>

The `vcsr` is not used anymore. Remove this member from `loongarch_fpu`.

>From 3A5000(LoongArch), `vcsr` is removed in hardware. FP and LSX/LASX
both use `fcsr` as their csr.

Particularly, fcsr from $r16 to $r31 are reserved for LSX/LASX, an
using the registers in this area will cause SXD/ASXD if LSX/LASX is
not enabled.

Signed-off-by: Qi Hu <huqi@xxxxxxxxxxx>
---
V3:
- Modify commit message to conform to the format.
V2:
- Add more details in the commit message.
---
arch/loongarch/include/asm/fpregdef.h | 1 -
arch/loongarch/include/asm/processor.h | 2 --
arch/loongarch/kernel/asm-offsets.c | 1 -
arch/loongarch/kernel/fpu.S | 10 ----------
4 files changed, 14 deletions(-)

diff --git a/arch/loongarch/include/asm/fpregdef.h b/arch/loongarch/include/asm/fpregdef.h
index adb16e4b43b0..b6be527831dd 100644
--- a/arch/loongarch/include/asm/fpregdef.h
+++ b/arch/loongarch/include/asm/fpregdef.h
@@ -48,6 +48,5 @@
#define fcsr1 $r1
#define fcsr2 $r2
#define fcsr3 $r3
-#define vcsr16 $r16

#endif /* _ASM_FPREGDEF_H */
diff --git a/arch/loongarch/include/asm/processor.h b/arch/loongarch/include/asm/processor.h
index 1d63c934b289..57ec45aa078e 100644
--- a/arch/loongarch/include/asm/processor.h
+++ b/arch/loongarch/include/asm/processor.h
@@ -80,7 +80,6 @@ BUILD_FPR_ACCESS(64)

struct loongarch_fpu {
unsigned int fcsr;
- unsigned int vcsr;
uint64_t fcc; /* 8x8 */
union fpureg fpr[NUM_FPU_REGS];
};
@@ -161,7 +160,6 @@ struct thread_struct {
*/ \
.fpu = { \
.fcsr = 0, \
- .vcsr = 0, \
.fcc = 0, \
.fpr = {{{0,},},}, \
}, \
diff --git a/arch/loongarch/kernel/asm-offsets.c b/arch/loongarch/kernel/asm-offsets.c
index bfb65eb2844f..20cd9e16a95a 100644
--- a/arch/loongarch/kernel/asm-offsets.c
+++ b/arch/loongarch/kernel/asm-offsets.c
@@ -166,7 +166,6 @@ void output_thread_fpu_defines(void)

OFFSET(THREAD_FCSR, loongarch_fpu, fcsr);
OFFSET(THREAD_FCC, loongarch_fpu, fcc);
- OFFSET(THREAD_VCSR, loongarch_fpu, vcsr);
BLANK();
}

diff --git a/arch/loongarch/kernel/fpu.S b/arch/loongarch/kernel/fpu.S
index 75c6ce0682a2..a631a7137667 100644
--- a/arch/loongarch/kernel/fpu.S
+++ b/arch/loongarch/kernel/fpu.S
@@ -146,16 +146,6 @@
movgr2fcsr fcsr0, \tmp0
.endm

- .macro sc_save_vcsr base, tmp0
- movfcsr2gr \tmp0, vcsr16
- EX st.w \tmp0, \base, 0
- .endm
-
- .macro sc_restore_vcsr base, tmp0
- EX ld.w \tmp0, \base, 0
- movgr2fcsr vcsr16, \tmp0
- .endm
-
/*
* Save a thread's fp context.
*/
--
2.36.1