drm/i915: Fix cmd parser desc matching with masks

[ Upstream commit e5f10d6385cda083037915c12b130887c8831d2b ]

Our variety of defined gpu commands have the actual
command id field and possibly length and flags applied.

We did start to apply the mask during initialization of
the cmd descriptors but forgot to also apply it on comparisons.

Fix comparisons in order to properly deny access with
associated commands.

v2: fix lri with correct mask (Chris)

References: 926abff2 ("drm/i915/cmdparser: Ignore Length operands during command matching")
Reported-by: Nicolai Stange <nstange@suse.de>
Cc: stable@vger.kernel.org # v5.4+
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Jon Bloomfield <jon.bloomfield@intel.com>
Cc: Chris Wilson <chris.p.wilson@intel.com>
Signed-off-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200817195926.12671-1-mika.kuoppala@linux.intel.com


(cherry picked from commit 3b4efa148da36f158cce3f662e831af2834b8e0f)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>