linux-kernel - [PATCH v2 1/2] drm/file: Rehabilitate the firstopen hook for non-legacy drivers

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20190320154809.14823-2-paul.kocialkowski@bootlin.com>
Date:   Wed, 20 Mar 2019 16:48:08 +0100
From:   Paul Kocialkowski <paul.kocialkowski@...tlin.com>
To:     dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Cc:     Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <maxime.ripard@...tlin.com>,
        Sean Paul <sean@...rly.run>, David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>, Eric Anholt <eric@...olt.net>,
        Eben Upton <eben@...pberrypi.org>,
        Thomas Petazzoni <thomas.petazzoni@...tlin.com>,
        Paul Kocialkowski <paul.kocialkowski@...tlin.com>
Subject: [PATCH v2 1/2] drm/file: Rehabilitate the firstopen hook for non-legacy drivers

The firstopen DRM driver hook was initially used to perform hardware
initialization, which is now considered legacy. Only a single user of
firstopen remains at this point (savage).

In some specific cases, non-legacy drivers may also need to implement
these hooks. For instance on VC4, we need to allocate a 16 MiB buffer
for the GPU. Because it's not required for fbcon, it's a waste to
allocate it before userspace starts using the DRM device.

Using firstopen and lastclose for this allocation seems like the best
fit, so re-habilitate the hook to allow it to be called for non-legacy
drivers.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@...tlin.com>
---
 drivers/gpu/drm/drm_file.c | 3 +--
 include/drm/drm_drv.h      | 2 +-
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index b1838a41ad43..c011b5cbfb6b 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -266,8 +266,7 @@ static int drm_setup(struct drm_device * dev)
 {
 	int ret;
 
-	if (dev->driver->firstopen &&
-	    drm_core_check_feature(dev, DRIVER_LEGACY)) {
+	if (dev->driver->firstopen) {
 		ret = dev->driver->firstopen(dev);
 		if (ret != 0)
 			return ret;
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index ca46a45a9cce..aa14607e54d4 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -236,7 +236,7 @@ struct drm_driver {
 	 * to set/unset the VT into raw mode.
 	 *
 	 * Legacy drivers initialize the hardware in the @firstopen callback,
-	 * which isn't even called for modern drivers.
+	 * modern drivers can use it for other purposes only.
 	 */
 	void (*lastclose) (struct drm_device *);
 
-- 
2.21.0