Re: [PATCH v15 09/19] drm/etnaviv: Add constructor and destructor for the etnaviv_drm_private structure

From: Lucas Stach
Date: Tue Oct 01 2024 - 10:07:56 EST


Am Sonntag, dem 08.09.2024 um 17:43 +0800 schrieb Sui Jingfeng:
> Because there are a lot of data members in the struct etnaviv_drm_private,
> which are intended to be shared by all GPU cores. It can be lengthy and
> daunting on error handling, the 'gem_lock' of struct etnaviv_drm_private
> just be forgeten to destroy on driver leave.
>
As you seem to have based this patch on top of "drm/etnaviv: Fix
missing mutex_destroy()", the last part of the above sentence doesn't
match the code. Please drop.

> Switch to use the dedicated helpers introduced, etnaviv_bind() and
> etnaviv_unbind() gets simplified. Another potential benefit is that
> we could put the struct drm_device into struct etnaviv_drm_private
> in the future, which made them share the same life time.
>
> Signed-off-by: Sui Jingfeng <sui.jingfeng@xxxxxxxxx>
> ---
> drivers/gpu/drm/etnaviv/etnaviv_drv.c | 73 +++++++++++++++++----------
> 1 file changed, 46 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_drv.c b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> index 6591e420a051..809e5db85df4 100644
> --- a/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> +++ b/drivers/gpu/drm/etnaviv/etnaviv_drv.c
> @@ -41,6 +41,45 @@ static struct device_node *etnaviv_of_first_available_node(void)
> return NULL;
> }
>
> +static struct etnaviv_drm_private *etnaviv_alloc_private(struct device *dev)
> +{
> + struct etnaviv_drm_private *priv;
> +
> + priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return ERR_PTR(-ENOMEM);
> +
> + xa_init_flags(&priv->active_contexts, XA_FLAGS_ALLOC);
> +
> + mutex_init(&priv->gem_lock);
> + INIT_LIST_HEAD(&priv->gem_list);
> + priv->num_gpus = 0;
> + priv->shm_gfp_mask = GFP_HIGHUSER | __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
> +
> + priv->cmdbuf_suballoc = etnaviv_cmdbuf_suballoc_new(dev);
> + if (IS_ERR(priv->cmdbuf_suballoc)) {

If this is supposed to do everything by the books, we should also
destroy the gem_lock mutex and active_contexts xarray here.

Regards,
Lucas

> + kfree(priv);
> + dev_err(dev, "Failed to create cmdbuf suballocator\n");
> + return ERR_PTR(-ENOMEM);
> + }
> +
> + return priv;
> +}
> +
> +static void etnaviv_free_private(struct etnaviv_drm_private *priv)
> +{
> + if (!priv)
> + return;
> +
> + etnaviv_cmdbuf_suballoc_destroy(priv->cmdbuf_suballoc);
> +
> + xa_destroy(&priv->active_contexts);
> +
> + mutex_destroy(&priv->gem_lock);
> +
> + kfree(priv);
> +}
> +
> static void load_gpu(struct drm_device *dev)
> {
> struct etnaviv_drm_private *priv = dev->dev_private;
> @@ -521,35 +560,21 @@ static int etnaviv_bind(struct device *dev)
> if (IS_ERR(drm))
> return PTR_ERR(drm);
>
> - priv = kzalloc(sizeof(*priv), GFP_KERNEL);
> - if (!priv) {
> - dev_err(dev, "failed to allocate private data\n");
> - ret = -ENOMEM;
> + priv = etnaviv_alloc_private(dev);
> + if (IS_ERR(priv)) {
> + ret = PTR_ERR(priv);
> goto out_put;
> }
> +
> drm->dev_private = priv;
>
> dma_set_max_seg_size(dev, SZ_2G);
>
> - xa_init_flags(&priv->active_contexts, XA_FLAGS_ALLOC);
> -
> - mutex_init(&priv->gem_lock);
> - INIT_LIST_HEAD(&priv->gem_list);
> - priv->num_gpus = 0;
> - priv->shm_gfp_mask = GFP_HIGHUSER | __GFP_RETRY_MAYFAIL | __GFP_NOWARN;
> -
> - priv->cmdbuf_suballoc = etnaviv_cmdbuf_suballoc_new(drm->dev);
> - if (IS_ERR(priv->cmdbuf_suballoc)) {
> - dev_err(drm->dev, "Failed to create cmdbuf suballocator\n");
> - ret = PTR_ERR(priv->cmdbuf_suballoc);
> - goto out_free_priv;
> - }
> -
> dev_set_drvdata(dev, drm);
>
> ret = component_bind_all(dev, drm);
> if (ret < 0)
> - goto out_destroy_suballoc;
> + goto out_free_priv;
>
> load_gpu(drm);
>
> @@ -561,11 +586,8 @@ static int etnaviv_bind(struct device *dev)
>
> out_unbind:
> component_unbind_all(dev, drm);
> -out_destroy_suballoc:
> - etnaviv_cmdbuf_suballoc_destroy(priv->cmdbuf_suballoc);
> out_free_priv:
> - mutex_destroy(&priv->gem_lock);
> - kfree(priv);
> + etnaviv_free_private(priv);
> out_put:
> drm_dev_put(drm);
>
> @@ -581,12 +603,9 @@ static void etnaviv_unbind(struct device *dev)
>
> component_unbind_all(dev, drm);
>
> - etnaviv_cmdbuf_suballoc_destroy(priv->cmdbuf_suballoc);
> -
> - xa_destroy(&priv->active_contexts);
> + etnaviv_free_private(priv);
>
> drm->dev_private = NULL;
> - kfree(priv);
>
> drm_dev_put(drm);
> }