Hi Daniel,
Thank you for the patch.
On Wed, Feb 19, 2020 at 11:20:53AM +0100, Daniel Vetter wrote:
> The cleanup here is somewhat tricky, since we can't tell apart the
> allocated minor index from 0. So register a cleanup action first, and
> if the index allocation fails, unregister that cleanup action again to
> avoid bad mistakes.
>
> The kdev for the minor already handles NULL, so no problem there.
>
> Hence add drmm_remove_action() to the drm_managed library.
>
> Signed-off-by: Daniel Vetter <daniel.vet...@intel.com>
> ---
> drivers/gpu/drm/drm_drv.c | 74 +++++++++++++----------------------
> drivers/gpu/drm/drm_managed.c | 28 +++++++++++++
> include/drm/drm_managed.h | 4 ++
> 3 files changed, 59 insertions(+), 47 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
> index 1f7ab88d9435..03a1fb377830 100644
> --- a/drivers/gpu/drm/drm_drv.c
> +++ b/drivers/gpu/drm/drm_drv.c
> @@ -93,19 +93,35 @@ static struct drm_minor **drm_minor_get_slot(struct
> drm_device *dev,
> }
> }
>
> +static void drm_minor_alloc_release(struct drm_device *dev, void *data)
> +{
> + struct drm_minor *minor = data;
> + unsigned long flags;
> +
> + put_device(minor->kdev);
> +
> + spin_lock_irqsave(&drm_minor_lock, flags);
> + idr_remove(&drm_minors_idr, minor->index);
> + spin_unlock_irqrestore(&drm_minor_lock, flags);
> +}
> +
> static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
> {
> struct drm_minor *minor;
> unsigned long flags;
> int r;
>
> - minor = kzalloc(sizeof(*minor), GFP_KERNEL);
> + minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
> if (!minor)
> return -ENOMEM;
>
> minor->type = type;
> minor->dev = dev;
>
> + r = drmm_add_action(dev, drm_minor_alloc_release, minor);
> + if (r)
> + return r;
> +
> idr_preload(GFP_KERNEL);
> spin_lock_irqsave(&drm_minor_lock, flags);
> r = idr_alloc(&drm_minors_idr,
> @@ -116,47 +132,18 @@ static int drm_minor_alloc(struct drm_device *dev,
> unsigned int type)
> spin_unlock_irqrestore(&drm_minor_lock, flags);
> idr_preload_end();
>
> - if (r < 0)
> - goto err_free;
> + if (r < 0) {
> + drmm_remove_action(dev, drm_minor_alloc_release, minor);
> + return r;
> + }
>
> minor->index = r;
> -
> minor->kdev = drm_sysfs_minor_alloc(minor);
> - if (IS_ERR(minor->kdev)) {
> - r = PTR_ERR(minor->kdev);
> - goto err_index;
> - }
> + if (IS_ERR(minor->kdev))
> + return PTR_ERR(minor->kdev);
>
> *drm_minor_get_slot(dev, type) = minor;
> return 0;
> -
> -err_index:
> - spin_lock_irqsave(&drm_minor_lock, flags);
> - idr_remove(&drm_minors_idr, minor->index);
> - spin_unlock_irqrestore(&drm_minor_lock, flags);
The need to do the drmm_remove_action() dance, with the need for
drmm_remove_action() in the first place, just to remove those three
lines of manual cleanup really seems overkill to me. Automation is nice,
but not everything is a nail even if all you have is a hammer.
> -err_free:
> - kfree(minor);
> - return r;
> -}
> -
> -static void drm_minor_free(struct drm_device *dev, unsigned int type)
> -{
> - struct drm_minor **slot, *minor;
> - unsigned long flags;
> -
> - slot = drm_minor_get_slot(dev, type);
> - minor = *slot;
> - if (!minor)
> - return;
> -
> - put_device(minor->kdev);
> -
> - spin_lock_irqsave(&drm_minor_lock, flags);
> - idr_remove(&drm_minors_idr, minor->index);
> - spin_unlock_irqrestore(&drm_minor_lock, flags);
> -
> - kfree(minor);
> - *slot = NULL;
> }
>
> static int drm_minor_register(struct drm_device *dev, unsigned int type)
> @@ -678,16 +665,16 @@ int drm_dev_init(struct drm_device *dev,
> if (drm_core_check_feature(dev, DRIVER_RENDER)) {
> ret = drm_minor_alloc(dev, DRM_MINOR_RENDER);
> if (ret)
> - goto err_minors;
> + goto err;
> }
>
> ret = drm_minor_alloc(dev, DRM_MINOR_PRIMARY);
> if (ret)
> - goto err_minors;
> + goto err;
>
> ret = drm_legacy_create_map_hash(dev);
> if (ret)
> - goto err_minors;
> + goto err;
>
> drm_legacy_ctxbitmap_init(dev);
>
> @@ -695,7 +682,7 @@ int drm_dev_init(struct drm_device *dev,
> ret = drm_gem_init(dev);
> if (ret) {
> DRM_ERROR("Cannot initialize graphics execution manager
> (GEM)\n");
> - goto err_ctxbitmap;
> + goto err;
> }
> }
>
> @@ -708,10 +695,6 @@ int drm_dev_init(struct drm_device *dev,
> err_setunique:
> if (drm_core_check_feature(dev, DRIVER_GEM))
> drm_gem_destroy(dev);
> -err_ctxbitmap:
> -err_minors:
> - drm_minor_free(dev, DRM_MINOR_PRIMARY);
> - drm_minor_free(dev, DRM_MINOR_RENDER);
> err:
> drm_managed_release(dev);
>
> @@ -776,9 +759,6 @@ void drm_dev_fini(struct drm_device *dev)
>
> if (drm_core_check_feature(dev, DRIVER_GEM))
> drm_gem_destroy(dev);
> -
> - drm_minor_free(dev, DRM_MINOR_PRIMARY);
> - drm_minor_free(dev, DRM_MINOR_RENDER);
> }
> EXPORT_SYMBOL(drm_dev_fini);
>
> diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
> index d8a484e19830..fb44fe65c2cd 100644
> --- a/drivers/gpu/drm/drm_managed.c
> +++ b/drivers/gpu/drm/drm_managed.c
> @@ -132,6 +132,34 @@ int __drmm_add_action(struct drm_device *dev,
> }
> EXPORT_SYMBOL(__drmm_add_action);
>
> +void drmm_remove_action(struct drm_device *dev,
> + drmres_release_t action,
> + void *data)
> +{
> + struct drmres *dr = NULL, *tmp;
> + unsigned long flags;
> +
> + if (!data)
> + return;
> +
> + spin_lock_irqsave(&dev->managed.lock, flags);
> + list_for_each_entry(tmp, &dev->managed.resources, node.entry) {
> + if (tmp->node.release == action &&
> + * (void **) tmp->data == data) {
As before, &tmp->data, and let's rename tmp.
> + dr = tmp;
> + del_dr(dev, dr);
> + break;
> + }
> + }
> + spin_unlock_irqrestore(&dev->managed.lock, flags);
> +
> + if (WARN_ON(!dr))
> + return;
> +
> + kfree(dr);
> +}
> +EXPORT_SYMBOL(drmm_remove_action);
> +
> void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
> {
> struct drmres *dr;
> diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
> index 240edd395e88..df30f9355902 100644
> --- a/include/drm/drm_managed.h
> +++ b/include/drm/drm_managed.h
> @@ -14,6 +14,10 @@ int __must_check __drmm_add_action(struct drm_device *dev,
> drmres_release_t action,
> void *data, const char *name);
>
> +void drmm_remove_action(struct drm_device *dev,
> + drmres_release_t action,
> + void *data);
> +
> void drmm_add_final_kfree(struct drm_device *dev, void *parent);
>
> void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp) __malloc;
--
Regards,
Laurent Pinchart
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