[PATCH v5 18/21] drm/tegra: Allocate per-engine channel in core code

Mikko Perttunen
2021-01-11T13:02:14Z

To avoid duplication, allocate the per-engine shared channel in the
core code instead. Once MLOCKs are implemented on Host1x side, we
can also update this to avoid allocating a shared channel when
MLOCKs are enabled.

Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
---
drivers/gpu/drm/tegra/drm.c | 11 +++++++++++
drivers/gpu/drm/tegra/drm.h | 4 ++++
2 files changed, 15 insertions(+)

diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
index cd81b52a9e06..afd3f143c5e0 100644
--- a/drivers/gpu/drm/tegra/drm.c
+++ b/drivers/gpu/drm/tegra/drm.c
@@ -880,6 +880,14 @@ static const struct drm_driver tegra_drm_driver = {
int tegra_drm_register_client(struct tegra_drm *tegra,
struct tegra_drm_client *client)
{
+ /*
+ * When MLOCKs are implemented, change to allocate a shared channel
+ * only when MLOCKs are disabled.
+ */
+ client->shared_channel = host1x_channel_request(&client->base);
+ if (!client->shared_channel)
+ return -EBUSY;
+
mutex_lock(&tegra->clients_lock);
list_add_tail(&client->list, &tegra->clients);
client->drm = tegra;
@@ -896,6 +904,9 @@ int tegra_drm_unregister_client(struct tegra_drm *tegra,
client->drm = NULL;
mutex_unlock(&tegra->clients_lock);

+ if (client->shared_channel)
+ host1x_channel_put(client->shared_channel);
+
return 0;
}

diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
index f38de08e0c95..0f38f159aa8e 100644
--- a/drivers/gpu/drm/tegra/drm.h
+++ b/drivers/gpu/drm/tegra/drm.h
@@ -87,8 +87,12 @@ struct tegra_drm_client {
struct list_head list;
struct tegra_drm *drm;

+ /* Set by driver */
unsigned int version;
const struct tegra_drm_client_ops *ops;
+
+ /* Set by TegraDRM core */
+ struct host1x_channel *shared_channel;
};

static inline struct tegra_drm_client *
--
2.30.0