On 05.11.2017 14:01, Mikko Perttunen wrote:
> To allow client drivers to free resources when jobs have completed,
> deliver job completion callbacks to them. This requires adding
> reference counting to context objects, as job completion can happen
> after the userspace application has closed the context. As such,
> also add kref-based refcounting for contexts.
>
It's very likely that we will need contexts kref'ing for other things as well,
would be nice if you could factor out kref addition into a standalone patch.
> Signed-off-by: Mikko Perttunen <mperttunen@xxxxxxxxxx>
> ---
> drivers/gpu/drm/tegra/drm.c | 27 ++++++++++++++++++++++++---
> drivers/gpu/drm/tegra/drm.h | 4 ++++
> 2 files changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/tegra/drm.c b/drivers/gpu/drm/tegra/drm.c
> index 2cdd054520bf..3e2a4a19412e 100644
> --- a/drivers/gpu/drm/tegra/drm.c
> +++ b/drivers/gpu/drm/tegra/drm.c
> @@ -281,8 +281,11 @@ static int tegra_drm_open(struct drm_device *drm, struct drm_file *filp)
> return 0;
> }
>
> -static void tegra_drm_context_free(struct tegra_drm_context *context)
> +static void tegra_drm_context_free(struct kref *ref)
> {
> + struct tegra_drm_context *context =
> + container_of(ref, struct tegra_drm_context, ref);
> +
> context->client->ops->close_channel(context);
> kfree(context);
> }
> @@ -379,6 +382,16 @@ static int host1x_waitchk_copy_from_user(struct host1x_waitchk *dest,
> return 0;
> }
>
> +static void tegra_drm_job_done(struct host1x_job *job)
> +{
> + struct tegra_drm_context *context = job->callback_data;
> +
> + if (context->client->ops->submit_done)
> + context->client->ops->submit_done(context);
> +
> + kref_put(&context->ref, tegra_drm_context_free);
> +}
> +
> int tegra_drm_submit(struct tegra_drm_context *context,
> struct drm_tegra_submit *args, struct drm_device *drm,
> struct drm_file *file)
> @@ -560,6 +573,9 @@ int tegra_drm_submit(struct tegra_drm_context *context,
> job->syncpt_id = syncpt.id;
> job->timeout = 10000;
>
> + job->done = tegra_drm_job_done;
> + job->callback_data = context;
> +
> if (args->timeout && args->timeout < 10000)
> job->timeout = args->timeout;
>
> @@ -567,8 +583,11 @@ int tegra_drm_submit(struct tegra_drm_context *context,
> if (err)
> goto fail;
>
> + kref_get(&context->ref);
> +
> err = host1x_job_submit(job);
> if (err) {
> + kref_put(&context->ref, tegra_drm_context_free);
> host1x_job_unpin(job);
> goto fail;
> }
> @@ -717,6 +736,8 @@ static int tegra_open_channel(struct drm_device *drm, void *data,
> if (err < 0)
> kfree(context);
>
> + kref_init(&context->ref);
> +
Would be a bit cleaner to move kref_init into tegra_client_open() where the rest
of context variables getting initialized.
> mutex_unlock(&fpriv->lock);
> return err;
> }
> @@ -738,7 +759,7 @@ static int tegra_close_channel(struct drm_device *drm, void *data,
> }
>
> idr_remove(&fpriv->contexts, context->id);
> - tegra_drm_context_free(context);
> + kref_put(&context->ref, tegra_drm_context_free);
>
> unlock:
> mutex_unlock(&fpriv->lock);
> @@ -1026,7 +1047,7 @@ static int tegra_drm_context_cleanup(int id, void *p, void *data)
> {
> struct tegra_drm_context *context = p;
>
> - tegra_drm_context_free(context);
> + kref_put(&context->ref, tegra_drm_context_free);
>
> return 0;
> }
> diff --git a/drivers/gpu/drm/tegra/drm.h b/drivers/gpu/drm/tegra/drm.h
> index 063f5d397526..079aebb3fb38 100644
> --- a/drivers/gpu/drm/tegra/drm.h
> +++ b/drivers/gpu/drm/tegra/drm.h
> @@ -13,6 +13,7 @@
> #include <uapi/drm/tegra_drm.h>
> #include <linux/host1x.h>
> #include <linux/iova.h>
> +#include <linux/kref.h>
> #include <linux/of_gpio.h>
>
> #include <drm/drmP.h>
> @@ -74,6 +75,8 @@ struct tegra_drm {
> struct tegra_drm_client;
>
> struct tegra_drm_context {
> + struct kref ref;
> +
> struct tegra_drm_client *client;
> struct host1x_channel *channel;
> unsigned int id;
> @@ -88,6 +91,7 @@ struct tegra_drm_client_ops {
> int (*submit)(struct tegra_drm_context *context,
> struct drm_tegra_submit *args, struct drm_device *drm,
> struct drm_file *file);
> + void (*submit_done)(struct tegra_drm_context *context);
> };
>
> int tegra_drm_submit(struct tegra_drm_context *context,
>
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