[PATCH v8 30/30] powerpc sstep: Add support for prefixed fixed-point arithmetic

[Christophe Leroy]

Le 06/05/2020 à 05:40, Jordan Niethe a écrit :
> This adds emulation support for the following prefixed Fixed-Point
> Arithmetic instructions:
>    * Prefixed Add Immediate (paddi)

Shouldn't this patch go before patch 23 ?

Christophe

> 
> Reviewed-by: Balamuruhan S <bala24 at linux.ibm.com>
> Signed-off-by: Jordan Niethe <jniethe5 at gmail.com>
> ---
> v3: Since we moved the prefixed loads/stores into the load/store switch
> statement it no longer makes sense to have paddi in there, so move it
> out.
> ---
>   arch/powerpc/lib/sstep.c | 20 ++++++++++++++++++++
>   1 file changed, 20 insertions(+)
> 
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index 6794a7672ad5..964fe7bbfce3 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -1337,6 +1337,26 @@ int analyse_instr(struct instruction_op *op, const struct pt_regs *regs,
>   
>   	switch (opcode) {
>   #ifdef __powerpc64__
> +	case 1:
> +		prefix_r = word & (1ul << 20);
> +		ra = (suffix >> 16) & 0x1f;
> +		rd = (suffix >> 21) & 0x1f;
> +		op->reg = rd;
> +		op->val = regs->gpr[rd];
> +		suffixopcode = suffix >> 26;
> +		prefixtype = (word >> 24) & 0x3;
> +		switch (prefixtype) {
> +		case 2:
> +			if (prefix_r && ra)
> +				return 0;
> +			switch (suffixopcode) {
> +			case 14:	/* paddi */
> +				op->type = COMPUTE | PREFIXED;
> +				op->val = mlsd_8lsd_ea(word, suffix, regs);
> +				goto compute_done;
> +			}
> +		}
> +		break;
>   	case 2:		/* tdi */
>   		if (rd & trap_compare(regs->gpr[ra], (short) word))
>   			goto trap;
>