[PATCH v2 02/22] drm/cma-helper: Add drm_fb_cma_fbdev_init/fini()

[Noralf Trønnes]

Laurent,

Can you please have a look at this and see if it's ok with you?

Noralf.


Den 15.11.2017 15.19, skrev Noralf Trønnes:
> Add functions drm_fb_cma_fbdev_init(), drm_fb_cma_fbdev_fini() and
> drm_fb_cma_fbdev_init_with_funcs(). These functions relies on the fact
> that the drm_fb_helper struct is stored in dev->drm_fb_helper_private
> so drivers don't need to store it.
>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>
> Changes since version 1:
> - Fix NULL pointer dereference in drm_fbdev_cma_create() (Benjamin)
>
>   drivers/gpu/drm/drm_fb_cma_helper.c | 119 +++++++++++++++++++++++++++++++++++-
>   include/drm/drm_fb_cma_helper.h     |   7 +++
>   2 files changed, 123 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
> index 35b56dfba929..186d00adfb5f 100644
> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> @@ -23,6 +23,7 @@
>   #include <drm/drm_gem_cma_helper.h>
>   #include <drm/drm_gem_framebuffer_helper.h>
>   #include <drm/drm_fb_cma_helper.h>
> +#include <drm/drm_print.h>
>   #include <linux/module.h>
>   
>   #define DEFAULT_FBDEFIO_DELAY_MS 50
> @@ -42,7 +43,7 @@ struct drm_fbdev_cma {
>    * callback function to create a cma backed framebuffer.
>    *
>    * An fbdev framebuffer backed by cma is also available by calling
> - * drm_fbdev_cma_init(). drm_fbdev_cma_fini() tears it down.
> + * drm_fb_cma_fbdev_init(). drm_fb_cma_fbdev_fini() tears it down.
>    * If the &drm_framebuffer_funcs.dirty callback is set, fb_deferred_io will be
>    * set up automatically. &drm_framebuffer_funcs.dirty is called by
>    * drm_fb_helper_deferred_io() in process context (&struct delayed_work).
> @@ -68,7 +69,7 @@ struct drm_fbdev_cma {
>    *
>    * Initialize::
>    *
> - *     fbdev = drm_fbdev_cma_init_with_funcs(dev, 16,
> + *     fbdev = drm_fb_cma_fbdev_init_with_funcs(dev, 16,
>    *                                           dev->mode_config.num_crtc,
>    *                                           dev->mode_config.num_connector,
>    *                                           &driver_fb_funcs);
> @@ -256,7 +257,7 @@ drm_fbdev_cma_create(struct drm_fb_helper *helper,
>   	fbi->screen_size = size;
>   	fbi->fix.smem_len = size;
>   
> -	if (fbdev_cma->fb_funcs->dirty) {
> +	if (fb->funcs->dirty) {
>   		ret = drm_fbdev_cma_defio_init(fbi, obj);
>   		if (ret)
>   			goto err_cma_destroy;
> @@ -277,6 +278,118 @@ static const struct drm_fb_helper_funcs drm_fb_cma_helper_funcs = {
>   	.fb_probe = drm_fbdev_cma_create,
>   };
>   
> +/**
> + * drm_fb_cma_fbdev_init_with_funcs() - Allocate and initialize fbdev emulation
> + * @dev: DRM device
> + * @preferred_bpp: Preferred bits per pixel for the device.
> + *                 @dev->mode_config.preferred_depth is used if this is zero.
> + * @max_conn_count: Maximum number of connectors.
> + *                  @dev->mode_config.num_connector is used if this is zero.
> + * @funcs: Framebuffer functions, in particular a custom dirty() callback.
> + *         Can be NULL.
> + *
> + * Returns:
> + * Zero on success or negative error code on failure.
> + */
> +int drm_fb_cma_fbdev_init_with_funcs(struct drm_device *dev,
> +	unsigned int preferred_bpp, unsigned int max_conn_count,
> +	const struct drm_framebuffer_funcs *funcs)
> +{
> +	struct drm_fbdev_cma *fbdev_cma;
> +	struct drm_fb_helper *fb_helper;
> +	int ret;
> +
> +	if (!preferred_bpp)
> +		preferred_bpp = dev->mode_config.preferred_depth;
> +	if (!preferred_bpp)
> +		preferred_bpp = 32;
> +
> +	if (!max_conn_count)
> +		max_conn_count = dev->mode_config.num_connector;
> +
> +	fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
> +	if (!fbdev_cma)
> +		return -ENOMEM;
> +
> +	fbdev_cma->fb_funcs = funcs;
> +	fb_helper = &fbdev_cma->fb_helper;
> +
> +	drm_fb_helper_prepare(dev, fb_helper, &drm_fb_cma_helper_funcs);
> +
> +	ret = drm_fb_helper_init(dev, fb_helper, max_conn_count);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev, "Failed to initialize fbdev helper.\n");
> +		goto err_free;
> +	}
> +
> +	ret = drm_fb_helper_single_add_all_connectors(fb_helper);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev, "Failed to add connectors.\n");
> +		goto err_drm_fb_helper_fini;
> +	}
> +
> +	ret = drm_fb_helper_initial_config(fb_helper, preferred_bpp);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(dev->dev, "Failed to set fbdev configuration.\n");
> +		goto err_drm_fb_helper_fini;
> +	}
> +
> +	return 0;
> +
> +err_drm_fb_helper_fini:
> +	drm_fb_helper_fini(fb_helper);
> +err_free:
> +	kfree(fbdev_cma);
> +
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init_with_funcs);
> +
> +/**
> + * drm_fb_cma_fbdev_init() - Allocate and initialize fbdev emulation
> + * @dev: DRM device
> + * @preferred_bpp: Preferred bits per pixel for the device.
> + *                 @dev->mode_config.preferred_depth is used if this is zero.
> + * @max_conn_count: Maximum number of connectors.
> + *                  @dev->mode_config.num_connector is used if this is zero.
> + *
> + * Returns:
> + * Zero on success or negative error code on failure.
> + */
> +int drm_fb_cma_fbdev_init(struct drm_device *dev, unsigned int preferred_bpp,
> +			  unsigned int max_conn_count)
> +{
> +	return drm_fb_cma_fbdev_init_with_funcs(dev, preferred_bpp,
> +						max_conn_count, NULL);
> +}
> +EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_init);
> +
> +/**
> + * drm_fb_cma_fbdev_fini() - Teardown fbdev emulation
> + * @dev: DRM device
> + */
> +void drm_fb_cma_fbdev_fini(struct drm_device *dev)
> +{
> +	struct drm_fb_helper *fb_helper = dev->fb_helper;
> +
> +	if (!fb_helper)
> +		return;
> +
> +	/* Unregister if it hasn't been done already */
> +	if (fb_helper->fbdev && fb_helper->fbdev->dev)
> +		drm_fb_helper_unregister_fbi(fb_helper);
> +
> +	if (fb_helper->fbdev)
> +		drm_fbdev_cma_defio_fini(fb_helper->fbdev);
> +
> +	if (fb_helper->fb)
> +		drm_framebuffer_remove(fb_helper->fb);
> +
> +	drm_fb_helper_fini(fb_helper);
> +	kfree(to_fbdev_cma(fb_helper));
> +}
> +EXPORT_SYMBOL_GPL(drm_fb_cma_fbdev_fini);
> +
>   /**
>    * drm_fbdev_cma_init_with_funcs() - Allocate and initializes a drm_fbdev_cma struct
>    * @dev: DRM device
> diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
> index a613ff022e6c..4fb2d5563420 100644
> --- a/include/drm/drm_fb_cma_helper.h
> +++ b/include/drm/drm_fb_cma_helper.h
> @@ -15,6 +15,13 @@ struct drm_mode_fb_cmd2;
>   struct drm_plane;
>   struct drm_plane_state;
>   
> +int drm_fb_cma_fbdev_init_with_funcs(struct drm_device *dev,
> +	unsigned int preferred_bpp, unsigned int max_conn_count,
> +	const struct drm_framebuffer_funcs *funcs);
> +int drm_fb_cma_fbdev_init(struct drm_device *dev, unsigned int preferred_bpp,
> +			  unsigned int max_conn_count);
> +void drm_fb_cma_fbdev_fini(struct drm_device *dev);
> +
>   struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
>   	unsigned int preferred_bpp, unsigned int max_conn_count,
>   	const struct drm_framebuffer_funcs *funcs);