On 11/10/20 10:39 am, Ravi Bangoria wrote:
> From: Balamuruhan S <bal...@linux.ibm.com>
>
> Unconditional emulation of prefixed instructions will allow
> emulation of them on Power10 predecessors which might cause
> issues. Restrict that.
>
> Fixes: 3920742b92f5 ("powerpc sstep: Add support for prefixed fixed-point
> arithmetic")
> Fixes: 50b80a12e4cc ("powerpc sstep: Add support for prefixed load/stores")
> Signed-off-by: Balamuruhan S <bal...@linux.ibm.com>
> Signed-off-by: Ravi Bangoria <ravi.bango...@linux.ibm.com>
> ---
> arch/powerpc/lib/sstep.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index e9dcaba9a4f8..e6242744c71b 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -1346,6 +1346,9 @@ int analyse_instr(struct instruction_op *op, const
> struct pt_regs *regs,
> switch (opcode) {
> #ifdef __powerpc64__
> case 1:
> + if (!cpu_has_feature(CPU_FTR_ARCH_31))
> + return -1;
> +
> prefix_r = GET_PREFIX_R(word);
> ra = GET_PREFIX_RA(suffix);
> rd = (suffix >> 21) & 0x1f;
> @@ -2733,6 +2736,9 @@ int analyse_instr(struct instruction_op *op, const
> struct pt_regs *regs,
> }
> break;
> case 1: /* Prefixed instructions */
> + if (!cpu_has_feature(CPU_FTR_ARCH_31))
> + return -1;
> +
> prefix_r = GET_PREFIX_R(word);
> ra = GET_PREFIX_RA(suffix);
> op->update_reg = ra;
>
LGTM
Reviewed-by: Sandipan Das <sandi...@linux.ibm.com>
