[PATCH v1 2/5] drm/tegra: gr2d: Add IOMMU support

From: Dmitry Osipenko
Date: Thu May 03 2018 - 19:52:30 EST


Attach GR2D to the display IOMMU group in order to provide GR2D access
to BO's IOVA.

Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
drivers/gpu/drm/tegra/gr2d.c | 31 +++++++++++++++++++++++++++++--
1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index 9a8ea93016a9..8eb530a85dd0 100644
--- a/drivers/gpu/drm/tegra/gr2d.c
+++ b/drivers/gpu/drm/tegra/gr2d.c
@@ -7,12 +7,14 @@
*/

#include <linux/clk.h>
+#include <linux/iommu.h>

#include "drm.h"
#include "gem.h"
#include "gr2d.h"

struct gr2d {
+ struct iommu_group *group;
struct tegra_drm_client client;
struct host1x_channel *channel;
struct clk *clk;
@@ -30,7 +32,9 @@ static int gr2d_init(struct host1x_client *client)
struct tegra_drm_client *drm = host1x_to_drm_client(client);
struct drm_device *dev = dev_get_drvdata(client->parent);
unsigned long flags = HOST1X_SYNCPT_HAS_BASE;
+ struct tegra_drm *tegra = dev->dev_private;
struct gr2d *gr2d = to_gr2d(drm);
+ int err;

gr2d->channel = host1x_channel_request(client->dev);
if (!gr2d->channel)
@@ -42,23 +46,46 @@ static int gr2d_init(struct host1x_client *client)
return -ENOMEM;
}

- return tegra_drm_register_client(dev->dev_private, drm);
+ if (tegra->domain) {
+ gr2d->group = iommu_group_get(client->dev);
+
+ if (gr2d->group) {
+ err = iommu_attach_group(tegra->domain, gr2d->group);
+ if (err < 0) {
+ dev_err(client->dev,
+ "failed to attach to domain: %d\n",
+ err);
+ host1x_syncpt_free(client->syncpts[0]);
+ host1x_channel_put(gr2d->channel);
+ iommu_group_put(gr2d->group);
+ return err;
+ }
+ }
+ }
+
+ return tegra_drm_register_client(tegra, drm);
}

static int gr2d_exit(struct host1x_client *client)
{
struct tegra_drm_client *drm = host1x_to_drm_client(client);
struct drm_device *dev = dev_get_drvdata(client->parent);
+ struct tegra_drm *tegra = dev->dev_private;
struct gr2d *gr2d = to_gr2d(drm);
int err;

- err = tegra_drm_unregister_client(dev->dev_private, drm);
+ err = tegra_drm_unregister_client(tegra, drm);
if (err < 0)
return err;

host1x_syncpt_free(client->syncpts[0]);
host1x_channel_put(gr2d->channel);

+ if (gr2d->group) {
+ iommu_detach_group(tegra->domain, gr2d->group);
+ iommu_group_put(gr2d->group);
+ }
+
return 0;
}

--
2.17.0