drm/tegra: gr2d: Add IOMMU support

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

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --git a/drivers/gpu/drm/tegra/gr2d.c b/drivers/gpu/drm/tegra/gr2d.c
index 9a8ea93016a97bf03bb135fd4dfb6fa581054d6b..8eb530a85dd05e27ea98c1b94a0f3554947783fc 100644 (file)
--- 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;
 }