Re: [PATCH 2/3] lib/rendercopy: Convert rendercopy_gen9 to use genxml pack headers

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Fri, Apr 24, 2026 at 12:21:37PM +0200, Zbigniew Kempczyński wrote:
> On Tue, Apr 07, 2026 at 06:00:49PM +0300, Ville Syrjälä wrote:
> 
> <cut>
> 
> > > +	/* MOCS encoding: genxml has a single 7-bit MOCS field (bits 30:24).
> > > +	 * The old struct had mocs_index:6 at bits 30:25 and pxp:1 at bit 24.
> > > +	 * Reproduce the same bit layout. */
> > > +	mocs = (buf->mocs_index << 1) | (intel_buf_pxp(buf) ? 1 : 0);
> > 
> > This annoying mocs_index stuff should be nuked throughout igt,
> > and replaced with the full mocs field. I've already gotten
> > confused by this multiple times when it looked like the 
> > relevant macros were off by one bit when compared to the spec.
> 
> IMO we can't stop using mocs index. BLOCK_COPY for Xe2+ has mocs index
> on bits[27:24] and encrypt is on bit[21]. Bits[23-22] are reserved.

If that's the exception then it would be better to handle it there.
Everything else just has a single MOCS field, and the encryption bit
(if it exists) is just part of it. The current thing makes zero sense
for platforms that don't have the encrypt bit, and for the platforms
where the encrypt bit is part of MOCS the whole thing is just
intentionally confusing.

-- 
Ville Syrjälä
Intel