Re: [PATCH 3/5] drm/msm/mdp5: add skeletal mdp5_state

[Archit Taneja <architt-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>]

On 11/05/2016 09:55 PM, Rob Clark wrote:
> Add basic state duplication/apply mechanism.  Following commits will
> move actual global hw state into this.
>
> The state_lock allows multiple concurrent updates to proceed as long as
> they don't both try to alter global state.  The ww_mutex mechanism will
> trigger backoff in case of deadlock between multiple threads trying to
> update state.
>
> Signed-off-by: Rob Clark <robdclark@gmail.com>
> ---
>  drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c | 43 +++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h | 22 +++++++++++++++++
>  2 files changed, 65 insertions(+)
>
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> index d3d45ed..ca6dfeb 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.c
> @@ -72,6 +72,39 @@ static int mdp5_hw_init(struct msm_kms *kms)
>  	return 0;
>  }
>
> +struct mdp5_state *mdp5_get_state(struct drm_atomic_state *s)
> +{
> +	struct msm_drm_private *priv = s->dev->dev_private;
> +	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> +	struct msm_kms_state *state = to_kms_state(s);
> +	struct mdp5_state *new_state;
> +	int ret;
> +
> +	if (state->state)
> +		return state->state;
> +
> +	ret = drm_modeset_lock(&mdp5_kms->state_lock, s->acquire_ctx);
> +	if (ret)
> +		return ERR_PTR(ret);
> +
> +	new_state = kmalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
> +	if (!new_state)
> +		return ERR_PTR(-ENOMEM);
> +
> +	/* Copy state: */
> +	/* TODO */
> +
> +	state->state = new_state;
> +
> +	return new_state;
> +}
> +
> +static void mdp5_swap_state(struct msm_kms *kms, struct drm_atomic_state *state)
> +{
> +	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> +	swap(to_kms_state(state)->state, mdp5_kms->state);
> +}
> +
>  static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *state)
>  {
>  	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> @@ -140,6 +173,7 @@ static const struct mdp_kms_funcs kms_funcs = {
>  		.irq             = mdp5_irq,
>  		.enable_vblank   = mdp5_enable_vblank,
>  		.disable_vblank  = mdp5_disable_vblank,
> +		.swap_state      = mdp5_swap_state,
>  		.prepare_commit  = mdp5_prepare_commit,
>  		.complete_commit = mdp5_complete_commit,
>  		.wait_for_crtc_commit_done = mdp5_wait_for_crtc_commit_done,
> @@ -645,6 +679,8 @@ static void mdp5_destroy(struct platform_device *pdev)
>
>  	if (mdp5_kms->rpm_enabled)
>  		pm_runtime_disable(&pdev->dev);
> +
> +	kfree(mdp5_kms->state);
>  }
>
>  static int construct_pipes(struct mdp5_kms *mdp5_kms, int cnt,
> @@ -729,6 +765,13 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
>  	mdp5_kms->dev = dev;
>  	mdp5_kms->pdev = pdev;
>
> +	drm_modeset_lock_init(&mdp5_kms->state_lock);
> +	mdp5_kms->state = kzalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
> +	if (!mdp5_kms->state) {
> +		ret = -ENOMEM;
> +		goto fail;
> +	}
> +

This would probably be better in mdp5_kms_init() since it's intializing kms stuff, and
not hw resources. Otherwise:

Reviewed-by: Archit Taneja <architt@codeaurora.org>


>  	mdp5_kms->mmio = msm_ioremap(pdev, "mdp_phys", "MDP5");
>  	if (IS_ERR(mdp5_kms->mmio)) {
>  		ret = PTR_ERR(mdp5_kms->mmio);
> diff --git a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> index 88120c5..52914ec 100644
> --- a/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> +++ b/drivers/gpu/drm/msm/mdp/mdp5/mdp5_kms.h
> @@ -27,6 +27,8 @@
>  #include "mdp5_pipe.h"
>  #include "mdp5_smp.h"
>
> +struct mdp5_state;
> +
>  struct mdp5_kms {
>  	struct mdp_kms base;
>
> @@ -40,6 +42,11 @@ struct mdp5_kms {
>  	struct mdp5_cfg_handler *cfg;
>  	uint32_t caps;	/* MDP capabilities (MDP_CAP_XXX bits) */
>
> +	/**
> +	 * Global atomic state.  Do not access directly, use mdp5_get_state()
> +	 */
> +	struct mdp5_state *state;
> +	struct drm_modeset_lock state_lock;
>
>  	/* mapper-id used to request GEM buffer mapped for scanout: */
>  	int id;
> @@ -69,6 +76,21 @@ struct mdp5_kms {
>  };
>  #define to_mdp5_kms(x) container_of(x, struct mdp5_kms, base)
>
> +/* Global atomic state for tracking resources that are shared across
> + * multiple kms objects (planes/crtcs/etc).
> + *
> + * For atomic updates which require modifying global state,
> + */
> +struct mdp5_state {
> +	uint32_t dummy;
> +};
> +
> +struct mdp5_state *__must_check
> +mdp5_get_state(struct drm_atomic_state *s);
> +
> +/* Atomic plane state.  Subclasses the base drm_plane_state in order to
> + * track assigned hwpipe and hw specific state.
> + */
>  struct mdp5_plane_state {
>  	struct drm_plane_state base;
>
>

-- 
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a Linux Foundation Collaborative Project
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