Re: [PATCH v2 1/6] drm/msm: Use drm_private_obj/state instead of subclassing

[Archit Taneja]

On Thursday 29 March 2018 12:36 AM, Sean Paul wrote:
> Now that we have private state handled by the core, we can use those
> instead of rolling our own swap_state for private data.
>
> Originally posted here: https://patchwork.freedesktop.org/patch/211361/
>
> Changes in v2:
>   - Use state->state in disp duplicate_state callback (Jeykumar)
> Changes in v3:
>   - Update comment describing msm_kms_state (Jeykumar)
> Changes in v4:
>   - Rebased on msm-next
>   - Don't always use private state from atomic state (Archit)
>   - Renamed some of the state accessors
>   - Tested on mdp5 db410c
> Changes in v5:
>   - None
>
> Cc: Jeykumar Sankaran <jsanka@xxxxxxxxxxxxxx>
> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c   | 77 ++++++++++---------
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h   | 11 +--
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c | 12 ++-
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c  | 28 ++++---
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c   | 19 +++--
>   drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.h   |  4 +-
>   drivers/gpu/drm/msm/msm_atomic.c           | 37 ---------
>   drivers/gpu/drm/msm/msm_drv.c              | 87 +++++++++++++++++++++-
>   drivers/gpu/drm/msm/msm_drv.h              |  3 -
>   drivers/gpu/drm/msm/msm_kms.h              | 21 ++++--
>   10 files changed, 183 insertions(+), 116 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> index 6d8e3a9a6fc0..366670043190 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.c
> @@ -70,60 +70,62 @@ static int mdp5_hw_init(struct msm_kms *kms)
>   	return 0;
>   }
>   
> -struct mdp5_state *mdp5_get_state(struct drm_atomic_state *s)
> +struct mdp5_state *mdp5_state_from_atomic(struct drm_atomic_state *state)
>   {
> -	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;
> +	struct msm_kms_state *kms_state = msm_kms_state_from_atomic(state);
>   
> -	if (state->state)
> -		return state->state;
> +	if (IS_ERR_OR_NULL(kms_state))
> +		return (struct mdp5_state *)kms_state; /* casting ERR_PTR */
>   
> -	ret = drm_modeset_lock(&mdp5_kms->state_lock, s->acquire_ctx);
> -	if (ret)
> -		return ERR_PTR(ret);
> +	return kms_state->state;
> +}
>   
> -	new_state = kmalloc(sizeof(*mdp5_kms->state), GFP_KERNEL);
> -	if (!new_state)
> -		return ERR_PTR(-ENOMEM);
> +struct mdp5_state *mdp5_state_from_dev(struct drm_device *dev)
> +{
> +	struct msm_kms_state *kms_state = msm_kms_state_from_dev(dev);
>   
> -	/* Copy state: */
> -	new_state->hwpipe = mdp5_kms->state->hwpipe;
> -	new_state->hwmixer = mdp5_kms->state->hwmixer;
> -	if (mdp5_kms->smp)
> -		new_state->smp = mdp5_kms->state->smp;
> +	if (IS_ERR_OR_NULL(kms_state))
> +		return (struct mdp5_state *)kms_state; /* casting ERR_PTR */
>   
> -	state->state = new_state;
> +	return kms_state->state;
> +}
> +
> +static void *mdp5_duplicate_state(void *state)
> +{
> +	if (!state)
> +		return kzalloc(sizeof(struct mdp5_state), GFP_KERNEL);
>   
> -	return new_state;
> +	return kmemdup(state, sizeof(struct mdp5_state), GFP_KERNEL);
>   }
>   
> -static void mdp5_swap_state(struct msm_kms *kms, struct drm_atomic_state *state)
> +static void mdp5_destroy_state(void *state)
>   {
> -	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> -	swap(to_kms_state(state)->state, mdp5_kms->state);
> +	struct mdp5_state *mdp_state = (struct mdp5_state *)state;
> +	kfree(mdp_state);
>   }
>   
> -static void mdp5_prepare_commit(struct msm_kms *kms, struct drm_atomic_state *state)
> +static void mdp5_prepare_commit(struct msm_kms *kms,
> +				struct drm_atomic_state *old_state)
>   {
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> +	struct mdp5_state *mdp5_state = mdp5_state_from_dev(mdp5_kms->dev);
>   	struct device *dev = &mdp5_kms->pdev->dev;
>   
>   	pm_runtime_get_sync(dev);
>   
>   	if (mdp5_kms->smp)
> -		mdp5_smp_prepare_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
> +		mdp5_smp_prepare_commit(mdp5_kms->smp, &mdp5_state->smp);
>   }
>   
> -static void mdp5_complete_commit(struct msm_kms *kms, struct drm_atomic_state *state)
> +static void mdp5_complete_commit(struct msm_kms *kms,
> +				 struct drm_atomic_state *old_state)
>   {
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(kms));
> +	struct mdp5_state *mdp5_state = mdp5_state_from_dev(mdp5_kms->dev);
>   	struct device *dev = &mdp5_kms->pdev->dev;
>   
>   	if (mdp5_kms->smp)
> -		mdp5_smp_complete_commit(mdp5_kms->smp, &mdp5_kms->state->smp);
> +		mdp5_smp_complete_commit(mdp5_kms->smp, &mdp5_state->smp);
>   
>   	pm_runtime_put_sync(dev);
>   }
> @@ -229,7 +231,8 @@ 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,
> +		.duplicate_state = mdp5_duplicate_state,
> +		.destroy_state	 = mdp5_destroy_state,
>   		.prepare_commit  = mdp5_prepare_commit,
>   		.complete_commit = mdp5_complete_commit,
>   		.wait_for_crtc_commit_done = mdp5_wait_for_crtc_commit_done,
> @@ -726,8 +729,6 @@ 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,
> @@ -859,7 +860,8 @@ static int interface_init(struct mdp5_kms *mdp5_kms)
>   	return 0;
>   }
>   
> -static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
> +static int mdp5_init(struct platform_device *pdev, struct drm_device *dev,
> +		     struct msm_kms_state *initial_state)
>   {
>   	struct msm_drm_private *priv = dev->dev_private;
>   	struct mdp5_kms *mdp5_kms;
> @@ -880,9 +882,8 @@ 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) {
> +	initial_state->state = mdp5_duplicate_state(NULL);
> +	if (!initial_state->state) {
>   		ret = -ENOMEM;
>   		goto fail;
>   	}
> @@ -940,7 +941,8 @@ static int mdp5_init(struct platform_device *pdev, struct drm_device *dev)
>   	 * this section initializes the SMP:
>   	 */
>   	if (mdp5_kms->caps & MDP_CAP_SMP) {
> -		mdp5_kms->smp = mdp5_smp_init(mdp5_kms, &config->hw->smp);
> +		mdp5_kms->smp = mdp5_smp_init(mdp5_kms, &config->hw->smp,
> +					      initial_state->state);
>   		if (IS_ERR(mdp5_kms->smp)) {
>   			ret = PTR_ERR(mdp5_kms->smp);
>   			mdp5_kms->smp = NULL;
> @@ -980,10 +982,11 @@ static int mdp5_bind(struct device *dev, struct device *master, void *data)
>   {
>   	struct drm_device *ddev = dev_get_drvdata(master);
>   	struct platform_device *pdev = to_platform_device(dev);
> +	struct msm_kms_state *initial_state = (struct msm_kms_state *)data;
>   
>   	DBG("");
>   
> -	return mdp5_init(pdev, ddev);
> +	return mdp5_init(pdev, ddev, initial_state);
>   }
>   
>   static void mdp5_unbind(struct device *dev, struct device *master,
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> index 425a03d213e5..e23117b82aad 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_kms.h
> @@ -28,8 +28,6 @@
>   #include "mdp5_ctl.h"
>   #include "mdp5_smp.h"
>   
> -struct mdp5_state;
> -
>   struct mdp5_kms {
>   	struct mdp_kms base;
>   
> @@ -49,12 +47,6 @@ 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;
> -
>   	struct mdp5_smp *smp;
>   	struct mdp5_ctl_manager *ctlm;
>   
> @@ -93,7 +85,8 @@ struct mdp5_state {
>   };
>   
>   struct mdp5_state *__must_check
> -mdp5_get_state(struct drm_atomic_state *s);
> +mdp5_state_from_atomic(struct drm_atomic_state *s);
> +struct mdp5_state *__must_check mdp5_state_from_dev(struct drm_device *dev);
>   
>   /* Atomic plane state.  Subclasses the base drm_plane_state in order to
>    * track assigned hwpipe and hw specific state.
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c
> index 8a00991f03c7..fdd5e12a9d56 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_mixer.c
> @@ -52,10 +52,11 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
>   {
>   	struct msm_drm_private *priv = s->dev->dev_private;
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> -	struct mdp5_state *state = mdp5_get_state(s);
> +	struct mdp5_state *state;
>   	struct mdp5_hw_mixer_state *new_state;
>   	int i;
>   
> +	state = mdp5_state_from_atomic(s);
>   	if (IS_ERR(state))
>   		return PTR_ERR(state);
>   
> @@ -129,12 +130,17 @@ int mdp5_mixer_assign(struct drm_atomic_state *s, struct drm_crtc *crtc,
>   
>   void mdp5_mixer_release(struct drm_atomic_state *s, struct mdp5_hw_mixer *mixer)
>   {
> -	struct mdp5_state *state = mdp5_get_state(s);
> -	struct mdp5_hw_mixer_state *new_state = &state->hwmixer;
> +	struct mdp5_state *state;
> +	struct mdp5_hw_mixer_state *new_state;
>   
>   	if (!mixer)
>   		return;
>   
> +	state = mdp5_state_from_atomic(s);
> +	if (IS_ERR(state))
> +		return;
> +
> +	new_state = &state->hwmixer;
>   	if (WARN_ON(!new_state->hwmixer_to_crtc[mixer->idx]))
>   		return;
>   
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c
> index ff52c49095f9..dc66ab9fdd50 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_pipe.c
> @@ -24,17 +24,20 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane,
>   {
>   	struct msm_drm_private *priv = s->dev->dev_private;
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> -	struct mdp5_state *state;
> +	struct mdp5_state *old_mdp5_state, *new_mdp5_state;
>   	struct mdp5_hw_pipe_state *old_state, *new_state;
>   	int i, j;
>   
> -	state = mdp5_get_state(s);
> -	if (IS_ERR(state))
> -		return PTR_ERR(state);
> +	new_mdp5_state = mdp5_state_from_atomic(s);
> +	if (IS_ERR(new_mdp5_state))
> +		return PTR_ERR(new_mdp5_state);
>   
> -	/* grab old_state after mdp5_get_state(), since now we hold lock: */
> -	old_state = &mdp5_kms->state->hwpipe;
> -	new_state = &state->hwpipe;
> +	old_mdp5_state = mdp5_state_from_dev(s->dev);
> +	if (IS_ERR(old_mdp5_state))
> +		return PTR_ERR(old_mdp5_state);
> +
> +	old_state = &old_mdp5_state->hwpipe;
> +	new_state = &new_mdp5_state->hwpipe;
>   
>   	for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
>   		struct mdp5_hw_pipe *cur = mdp5_kms->hwpipes[i];
> @@ -107,7 +110,7 @@ int mdp5_pipe_assign(struct drm_atomic_state *s, struct drm_plane *plane,
>   		WARN_ON(r_hwpipe);
>   
>   		DBG("%s: alloc SMP blocks", (*hwpipe)->name);
> -		ret = mdp5_smp_assign(mdp5_kms->smp, &state->smp,
> +		ret = mdp5_smp_assign(mdp5_kms->smp, &new_mdp5_state->smp,
>   				(*hwpipe)->pipe, blkcfg);
>   		if (ret)
>   			return -ENOMEM;
> @@ -132,12 +135,17 @@ void mdp5_pipe_release(struct drm_atomic_state *s, struct mdp5_hw_pipe *hwpipe)
>   {
>   	struct msm_drm_private *priv = s->dev->dev_private;
>   	struct mdp5_kms *mdp5_kms = to_mdp5_kms(to_mdp_kms(priv->kms));
> -	struct mdp5_state *state = mdp5_get_state(s);
> -	struct mdp5_hw_pipe_state *new_state = &state->hwpipe;
> +	struct mdp5_state *state;
> +	struct mdp5_hw_pipe_state *new_state;
>   
>   	if (!hwpipe)
>   		return;
>   
> +	state = mdp5_state_from_atomic(s);
> +	if (IS_ERR(state))
> +		return;
> +
> +	new_state = &state->hwpipe;
>   	if (WARN_ON(!new_state->hwpipe_to_plane[hwpipe->idx]))
>   		return;
>   
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> index ae4983d9d0a5..918e4123e781 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.c
> @@ -338,6 +338,7 @@ void mdp5_smp_complete_commit(struct mdp5_smp *smp, struct mdp5_smp_state *state
>   void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
>   {
>   	struct mdp5_kms *mdp5_kms = get_kms(smp);
> +	struct mdp5_state *mdp5_state;
>   	struct mdp5_hw_pipe_state *hwpstate;
>   	struct mdp5_smp_state *state;
>   	int total = 0, i, j;
> @@ -346,11 +347,12 @@ void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
>   	drm_printf(p, "----\t-----\t-----\n");
>   
>   	if (drm_can_sleep())
> -		drm_modeset_lock(&mdp5_kms->state_lock, NULL);
> +		drm_modeset_lock_all(mdp5_kms->dev);
>   
> -	/* grab these *after* we hold the state_lock */
> -	hwpstate = &mdp5_kms->state->hwpipe;
> -	state = &mdp5_kms->state->smp;
> +	/* grab these *after* we hold the modeset_lock */
> +	mdp5_state = mdp5_state_from_dev(mdp5_kms->dev);
> +	hwpstate = &mdp5_state->hwpipe;
> +	state = &mdp5_state->smp;
>   
>   	for (i = 0; i < mdp5_kms->num_hwpipes; i++) {
>   		struct mdp5_hw_pipe *hwpipe = mdp5_kms->hwpipes[i];
> @@ -374,7 +376,7 @@ void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p)
>   			bitmap_weight(state->state, smp->blk_cnt));
>   
>   	if (drm_can_sleep())
> -		drm_modeset_unlock(&mdp5_kms->state_lock);
> +		drm_modeset_unlock_all(mdp5_kms->dev);
>   }
>   
>   void mdp5_smp_destroy(struct mdp5_smp *smp)
> @@ -382,12 +384,15 @@ void mdp5_smp_destroy(struct mdp5_smp *smp)
>   	kfree(smp);
>   }
>   
> -struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms, const struct mdp5_smp_block *cfg)
> +struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms,
> +			       const struct mdp5_smp_block *cfg,
> +			       struct mdp5_state *mdp5_state)
>   {
> -	struct mdp5_smp_state *state = &mdp5_kms->state->smp;
> +	struct mdp5_smp_state *state;
>   	struct mdp5_smp *smp = NULL;
>   	int ret;
>   
> +	state = &mdp5_state->smp;
>   	smp = kzalloc(sizeof(*smp), GFP_KERNEL);
>   	if (unlikely(!smp)) {
>   		ret = -ENOMEM;
> diff --git a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.h b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.h
> index b41d0448fbe8..1bfa22b63a2d 100644
> --- a/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.h
> +++ b/drivers/gpu/drm/msm/disp/mdp5/mdp5_smp.h
> @@ -69,6 +69,7 @@ struct mdp5_smp_state {
>   };
>   
>   struct mdp5_kms;
> +struct mdp5_state;
>   struct mdp5_smp;
>   
>   /*
> @@ -78,7 +79,8 @@ struct mdp5_smp;
>    */
>   
>   struct mdp5_smp *mdp5_smp_init(struct mdp5_kms *mdp5_kms,
> -		const struct mdp5_smp_block *cfg);
> +		const struct mdp5_smp_block *cfg,
> +		struct mdp5_state *mdp5_state);
>   void  mdp5_smp_destroy(struct mdp5_smp *smp);
>   
>   void mdp5_smp_dump(struct mdp5_smp *smp, struct drm_printer *p);
> diff --git a/drivers/gpu/drm/msm/msm_atomic.c b/drivers/gpu/drm/msm/msm_atomic.c
> index bf5f8c39f34d..e792158676aa 100644
> --- a/drivers/gpu/drm/msm/msm_atomic.c
> +++ b/drivers/gpu/drm/msm/msm_atomic.c
> @@ -220,16 +220,6 @@ int msm_atomic_commit(struct drm_device *dev,
>   
>   	BUG_ON(drm_atomic_helper_swap_state(state, false) < 0);
>   
> -	/*
> -	 * This is the point of no return - everything below never fails except
> -	 * when the hw goes bonghits. Which means we can commit the new state on
> -	 * the software side now.
> -	 *
> -	 * swap driver private state while still holding state_lock
> -	 */
> -	if (to_kms_state(state)->state)
> -		priv->kms->funcs->swap_state(priv->kms, state);
> -
>   	/*
>   	 * Everything below can be run asynchronously without the need to grab
>   	 * any modeset locks at all under one conditions: It must be guaranteed
> @@ -262,30 +252,3 @@ int msm_atomic_commit(struct drm_device *dev,
>   	drm_atomic_helper_cleanup_planes(dev, state);
>   	return ret;
>   }
> -
> -struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev)
> -{
> -	struct msm_kms_state *state = kzalloc(sizeof(*state), GFP_KERNEL);
> -
> -	if (!state || drm_atomic_state_init(dev, &state->base) < 0) {
> -		kfree(state);
> -		return NULL;
> -	}
> -
> -	return &state->base;
> -}
> -
> -void msm_atomic_state_clear(struct drm_atomic_state *s)
> -{
> -	struct msm_kms_state *state = to_kms_state(s);
> -	drm_atomic_state_default_clear(&state->base);
> -	kfree(state->state);
> -	state->state = NULL;
> -}
> -
> -void msm_atomic_state_free(struct drm_atomic_state *state)
> -{
> -	kfree(to_kms_state(state)->state);
> -	drm_atomic_state_default_release(state);
> -	kfree(state);
> -}
> diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
> index 30cd514d8f7c..7e8f640062ef 100644
> --- a/drivers/gpu/drm/msm/msm_drv.c
> +++ b/drivers/gpu/drm/msm/msm_drv.c
> @@ -42,11 +42,79 @@ static const struct drm_mode_config_funcs mode_config_funcs = {
>   	.output_poll_changed = drm_fb_helper_output_poll_changed,
>   	.atomic_check = drm_atomic_helper_check,
>   	.atomic_commit = msm_atomic_commit,
> -	.atomic_state_alloc = msm_atomic_state_alloc,
> -	.atomic_state_clear = msm_atomic_state_clear,
> -	.atomic_state_free = msm_atomic_state_free,
>   };
>   
> +static inline
> +struct msm_kms *msm_kms_from_obj(struct drm_private_obj *obj)
> +{
> +	return container_of(obj, struct msm_kms, base);
> +}
> +
> +static inline
> +struct msm_kms_state *msm_kms_state_from_priv(struct drm_private_state *priv)
> +{
> +	return container_of(priv, struct msm_kms_state, base);
> +}
> +
> +
> +struct msm_kms_state *msm_kms_state_from_atomic(struct drm_atomic_state *state)
> +{
> +	struct msm_drm_private *priv = state->dev->dev_private;
> +	struct drm_private_obj *obj = &priv->kms->base;
> +	struct drm_private_state *priv_state;
> +
> +	priv_state = drm_atomic_get_private_obj_state(state, obj);
> +	if (IS_ERR_OR_NULL(priv_state))
> +		return (struct msm_kms_state *)state; /* casting ERR_PTR */
> +
> +	return msm_kms_state_from_priv(priv_state);
> +}
> +
> +struct msm_kms_state *msm_kms_state_from_dev(struct drm_device *dev)
> +{
> +	struct msm_drm_private *priv = dev->dev_private;
> +	struct drm_private_obj *obj = &priv->kms->base;
> +	struct drm_private_state *priv_state = obj->state;
> +
> +	return msm_kms_state_from_priv(priv_state);
> +}
> +
> +static struct drm_private_state *
> +msm_kms_duplicate_state(struct drm_private_obj *obj)
> +{
> +	struct msm_kms *kms = msm_kms_from_obj(obj);
> +	struct msm_kms_state *state = msm_kms_state_from_priv(obj->state);
> +	struct msm_kms_state *new_state;
> +
> +	new_state = kzalloc(sizeof(*new_state), GFP_KERNEL);
> +	if (!new_state)
> +		return NULL;
> +
> +	if (kms->funcs->duplicate_state)
> +		new_state->state = kms->funcs->duplicate_state(state->state);
> +
> +	__drm_atomic_helper_private_obj_duplicate_state(obj, &new_state->base);
> +
> +	return &new_state->base;
> +}
> +
> +static void msm_kms_destroy_state(struct drm_private_obj *obj,
> +				  struct drm_private_state *priv_state)
> +{
> +	struct msm_kms *kms = msm_kms_from_obj(obj);
> +	struct msm_kms_state *state = msm_kms_state_from_priv(priv_state);
> +
> +	if (kms->funcs->destroy_state)
> +		kms->funcs->destroy_state(state->state);
> +	kfree(state);
> +}
> +
> +static const struct drm_private_state_funcs kms_state_funcs = {
> +	.atomic_duplicate_state = msm_kms_duplicate_state,
> +	.atomic_destroy_state = msm_kms_destroy_state,
> +};
> +
> +

Minor nit: Two blank lines here^

>   #ifdef CONFIG_DRM_MSM_REGISTER_LOGGING
>   static bool reglog = false;
>   MODULE_PARM_DESC(reglog, "Enable register read/write logging");
> @@ -245,6 +313,8 @@ static int msm_drm_uninit(struct device *dev)
>   	flush_workqueue(priv->atomic_wq);
>   	destroy_workqueue(priv->atomic_wq);
>   
> +	drm_atomic_private_obj_fini(&kms->base);
> +
>   	if (kms && kms->funcs)
>   		kms->funcs->destroy(kms);
>   
> @@ -356,6 +426,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>   	struct drm_device *ddev;
>   	struct msm_drm_private *priv;
>   	struct msm_kms *kms;
> +	struct msm_kms_state *initial_state;
>   	int ret;
>   
>   	ddev = drm_dev_alloc(drv, dev);
> @@ -364,6 +435,10 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>   		return PTR_ERR(ddev);
>   	}
>   
> +	initial_state = kzalloc(sizeof(*initial_state), GFP_KERNEL);
> +	if (!initial_state)
> +		return -ENOMEM;
> +
>   	platform_set_drvdata(pdev, ddev);
>   
>   	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> @@ -394,7 +469,7 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>   	drm_mode_config_init(ddev);
>   
>   	/* Bind all our sub-components: */
> -	ret = component_bind_all(dev, ddev);
> +	ret = component_bind_all(dev, initial_state);

Only the core kms component (mdp4/mdp5/dpu) will use initial_state,
and the encoders drivers (DSI/HDMI) would discard it, right? I guess
it's still better than passing ddev, which can be derived from the
component master.

Reviewed-by: Archit Taneja <architt@xxxxxxxxxxxxxx>

>   	if (ret) {
>   		msm_mdss_destroy(ddev);
>   		kfree(priv);
> @@ -433,6 +508,10 @@ static int msm_drm_init(struct device *dev, struct drm_driver *drv)
>   		goto fail;
>   	}
>   
> +	drm_atomic_private_obj_init(&kms->base,
> +				    &initial_state->base,
> +				    &kms_state_funcs);
> +
>   	if (kms) {
>   		ret = kms->funcs->hw_init(kms);
>   		if (ret) {
> diff --git a/drivers/gpu/drm/msm/msm_drv.h b/drivers/gpu/drm/msm/msm_drv.h
> index 48ed5b9a8580..c5b8c989b859 100644
> --- a/drivers/gpu/drm/msm/msm_drv.h
> +++ b/drivers/gpu/drm/msm/msm_drv.h
> @@ -162,9 +162,6 @@ struct msm_format {
>   
>   int msm_atomic_commit(struct drm_device *dev,
>   		struct drm_atomic_state *state, bool nonblock);
> -struct drm_atomic_state *msm_atomic_state_alloc(struct drm_device *dev);
> -void msm_atomic_state_clear(struct drm_atomic_state *state);
> -void msm_atomic_state_free(struct drm_atomic_state *state);
>   
>   void msm_gem_unmap_vma(struct msm_gem_address_space *aspace,
>   		struct msm_gem_vma *vma, struct sg_table *sgt);
> diff --git a/drivers/gpu/drm/msm/msm_kms.h b/drivers/gpu/drm/msm/msm_kms.h
> index 17d5824417ad..24d09fcebf16 100644
> --- a/drivers/gpu/drm/msm/msm_kms.h
> +++ b/drivers/gpu/drm/msm/msm_kms.h
> @@ -42,6 +42,8 @@ struct msm_kms_funcs {
>   	void (*disable_vblank)(struct msm_kms *kms, struct drm_crtc *crtc);
>   	/* swap global atomic state: */
>   	void (*swap_state)(struct msm_kms *kms, struct drm_atomic_state *state);
> +	void *(*duplicate_state)(void *state);
> +	void (*destroy_state)(void *state);
>   	/* modeset, bracketing atomic_commit(): */
>   	void (*prepare_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
>   	void (*complete_commit)(struct msm_kms *kms, struct drm_atomic_state *state);
> @@ -68,6 +70,8 @@ struct msm_kms_funcs {
>   };
>   
>   struct msm_kms {
> +	struct drm_private_obj base;
> +
>   	const struct msm_kms_funcs *funcs;
>   
>   	/* irq number to be passed on to drm_irq_install */
> @@ -78,16 +82,23 @@ struct msm_kms {
>   };
>   
>   /**
> - * Subclass of drm_atomic_state, to allow kms backend to have driver
> + * Subclass of drm_private_state, to allow kms backend to have driver
>    * private global state.  The kms backend can do whatever it wants
> - * with the ->state ptr.  On ->atomic_state_clear() the ->state ptr
> - * is kfree'd and set back to NULL.
> + * with the ->state ptr.
>    */
>   struct msm_kms_state {
> -	struct drm_atomic_state base;
> +	struct drm_private_state base;
>   	void *state;
>   };
> -#define to_kms_state(x) container_of(x, struct msm_kms_state, base)
> +
> +/**
> + * Extracts the msm_kms_state from either an atomic state, or the current
> + * device. One or the other might be desirable depending on whether you want the
> + * currently configured msm_kms_state (from_dev), or you would like the state
> + * which is about to be applied (from_atomic).
> + */
> +struct msm_kms_state *msm_kms_state_from_dev(struct drm_device *dev);
> +struct msm_kms_state *msm_kms_state_from_atomic(struct drm_atomic_state *state);
>   
>   static inline void msm_kms_init(struct msm_kms *kms,
>   		const struct msm_kms_funcs *funcs)