linux-kernel - [PATCH] drm/stm: drv: Improve data transfers

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-next>] [day] [month] [year] [list]

Message-ID: <20180122103335.12820-1-philippe.cornu@st.com>
Date:   Mon, 22 Jan 2018 11:33:35 +0100
From:   Philippe Cornu <philippe.cornu@...com>
To:     Yannick Fertre <yannick.fertre@...com>,
        Philippe Cornu <philippe.cornu@...com>,
        Benjamin Gaignard <benjamin.gaignard@...aro.org>,
        Vincent Abriou <vincent.abriou@...com>,
        David Airlie <airlied@...ux.ie>,
        <dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
        "Archit Taneja" <architt@...eaurora.org>,
        Andrzej Hajda <a.hajda@...sung.com>,
        "Laurent Pinchart" <Laurent.pinchart@...asonboard.com>
CC:     Fabien Dessenne <fabien.dessenne@...com>,
        Mickael Reulier <mickael.reulier@...com>,
        Ludovic Barre <ludovic.barre@...com>,
        "Alexandre Torgue" <alexandre.torgue@...com>,
        Maxime Coquelin <mcoquelin.stm32@...il.com>
Subject: [PATCH] drm/stm: drv: Improve data transfers

To optimize data transfers, align pitch on 128 bytes & height
on 4 bytes. This optimization is not applicable without MMU.

Signed-off-by: Yannick Fertre <yannick.fertre@...com>
Signed-off-by: Vincent Abriou <vincent.abriou@...com>
Signed-off-by: Philippe Cornu <philippe.cornu@...com>
---
 drivers/gpu/drm/stm/drv.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/gpu/drm/stm/drv.c b/drivers/gpu/drm/stm/drv.c
index 8fe954c27fba..c2bd9d882b93 100644
--- a/drivers/gpu/drm/stm/drv.c
+++ b/drivers/gpu/drm/stm/drv.c
@@ -31,6 +31,23 @@ static const struct drm_mode_config_funcs drv_mode_config_funcs = {
 	.atomic_commit = drm_atomic_helper_commit,
 };
 
+#ifdef CONFIG_MMU
+static int stm_dumb_create(struct drm_file *file, struct drm_device *dev,
+			   struct drm_mode_create_dumb *args)
+{
+	unsigned int min_pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+
+	/*
+	 * in order to optimize data transfer, pitch is aligned on
+	 * 128 bytes, height is aligned on 4 bytes
+	 */
+	args->pitch = roundup(min_pitch, 128);
+	args->height = roundup(args->height, 4);
+
+	return drm_gem_cma_dumb_create_internal(file, dev, args);
+}
+#endif
+
 DEFINE_DRM_GEM_CMA_FOPS(drv_driver_fops);
 
 static struct drm_driver drv_driver = {
@@ -44,7 +61,11 @@ static struct drm_driver drv_driver = {
 	.minor = 0,
 	.patchlevel = 0,
 	.fops = &drv_driver_fops,
+#ifdef CONFIG_MMU
+	.dumb_create = stm_dumb_create,
+#else
 	.dumb_create = drm_gem_cma_dumb_create,
+#endif
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_free_object_unlocked = drm_gem_cma_free_object,
-- 
2.15.1