On Thu, Jul 13, 2017 at 01:25:46PM +1000, Matt Brown wrote:
> This adds emulation for the bpermd instruction.
>
> Signed-off-by: Matt Brown <matthew.brown....@gmail.com>
> ---
> arch/powerpc/lib/sstep.c | 23 +++++++++++++++++++++++
> 1 file changed, 23 insertions(+)
>
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index cf69987..603654d 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -637,6 +637,21 @@ static nokprobe_inline void do_popcnt(struct pt_regs
> *regs, unsigned long v1,
> regs->gpr[ra] = out_val;
> }
>
> +static nokprobe_inline void do_bpermd(struct pt_regs *regs, unsigned long v1,
> + unsigned long v2, int ra)
> +{
> + unsigned int idx, i;
> + unsigned char perm;
> +
> + perm = 0x0;
> + for (i = 0; i < 8; i++) {
> + idx = (v1 >> (i * 8)) & 0xff;
> + if (idx < 64)
> + perm |= (v2 & (1 << idx)) >> (idx - i);
> + }
> + regs->gpr[ra] = 0 | perm;
Huh? What's the point of doing an or with 0?
The compiler will eliminate it, but it just confuses the reader.
Gabriel
> +}
> +
> static nokprobe_inline int trap_compare(long v1, long v2)
> {
> int ret = 0;
> @@ -1274,6 +1289,14 @@ int analyse_instr(struct instruction_op *op, struct
> pt_regs *regs,
> goto logical_done;
> #endif
>
> +#ifdef __powerpc64__
> + case 2396736: /* bpermd */
> + val = regs->gpr[rd];
> + val2 = regs->gpr[rb];
> + do_bpermd(regs, val, val2, ra);
> + goto logical_done;
> +#endif
> +
> /*
> * Shift instructions
> */
> --
> 2.9.3
