[PATCH 5.8 63/99] MIPS: Loongson-3: Fix fp register access if MSA enabled

From: Greg Kroah-Hartman
Date: Tue Sep 29 2020 - 07:52:07 EST


From: Huacai Chen <chenhc@xxxxxxxxxx>

[ Upstream commit 01ce6d4d2c8157b076425e3dd8319948652583c5 ]

If MSA is enabled, FPU_REG_WIDTH is 128 rather than 64, then get_fpr64()
/set_fpr64() in the original unaligned instruction emulation code access
the wrong fp registers. This is because the current code doesn't specify
the correct index field, so fix it.

Fixes: f83e4f9896eff614d0f2547a ("MIPS: Loongson-3: Add some unaligned instructions emulation")
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
Signed-off-by: Pei Huang <huangpei@xxxxxxxxxxx>
Signed-off-by: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
arch/mips/loongson64/cop2-ex.c | 24 ++++++++----------------
1 file changed, 8 insertions(+), 16 deletions(-)

diff --git a/arch/mips/loongson64/cop2-ex.c b/arch/mips/loongson64/cop2-ex.c
index f130f62129b86..00055d4b6042f 100644
--- a/arch/mips/loongson64/cop2-ex.c
+++ b/arch/mips/loongson64/cop2-ex.c
@@ -95,10 +95,8 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
if (res)
goto fault;

- set_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lswc2_format.rt, value);
- set_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lswc2_format.rq, value_next);
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rt], 0, value);
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rq], 0, value_next);
compute_return_epc(regs);
own_fpu(1);
}
@@ -130,15 +128,13 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
goto sigbus;

lose_fpu(1);
- value_next = get_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lswc2_format.rq);
+ value_next = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rq], 0);

StoreDW(addr + 8, value_next, res);
if (res)
goto fault;

- value = get_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lswc2_format.rt);
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lswc2_format.rt], 0);

StoreDW(addr, value, res);
if (res)
@@ -204,8 +200,7 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
if (res)
goto fault;

- set_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lsdc2_format.rt, value);
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0, value);
compute_return_epc(regs);
own_fpu(1);

@@ -221,8 +216,7 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
if (res)
goto fault;

- set_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lsdc2_format.rt, value);
+ set_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0, value);
compute_return_epc(regs);
own_fpu(1);
break;
@@ -286,8 +280,7 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
goto sigbus;

lose_fpu(1);
- value = get_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lsdc2_format.rt);
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0);

StoreW(addr, value, res);
if (res)
@@ -305,8 +298,7 @@ static int loongson_cu2_call(struct notifier_block *nfb, unsigned long action,
goto sigbus;

lose_fpu(1);
- value = get_fpr64(current->thread.fpu.fpr,
- insn.loongson3_lsdc2_format.rt);
+ value = get_fpr64(&current->thread.fpu.fpr[insn.loongson3_lsdc2_format.rt], 0);

StoreDW(addr, value, res);
if (res)
--
2.25.1