Re: [PATCH] MIPS: Loongson-3: Fix fp register access if MSA enabled

[Huacai Chen <chenhuacai@xxxxxxxxx>]

Ping?

On Mon, Aug 24, 2020 at 3:40 PM Huacai Chen <chenhc@xxxxxxxxxx> wrote:
>
> 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>
> ---
>  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 f130f62..00055d4 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)
> --
> 2.7.0
>