[PATCH 3/6] drm/fb-cma-helper: Support device unplug
Daniel Vetter
daniel at ffwll.ch
Mon Aug 28 21:46:16 UTC 2017
On Mon, Aug 28, 2017 at 07:17:45PM +0200, Noralf Trønnes wrote:
> Add drm_fbdev_cma_dev_unplug() and use the drm_fb_helper device unplug
> support. Pin driver module on fb_open().
>
> Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
> ---
> drivers/gpu/drm/drm_fb_cma_helper.c | 139 +++++++++++++++++-------------------
> include/drm/drm_fb_cma_helper.h | 1 +
> 2 files changed, 68 insertions(+), 72 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_fb_cma_helper.c b/drivers/gpu/drm/drm_fb_cma_helper.c
> index f2ee883..2b044be 100644
> --- a/drivers/gpu/drm/drm_fb_cma_helper.c
> +++ b/drivers/gpu/drm/drm_fb_cma_helper.c
> @@ -25,8 +25,6 @@
> #include <drm/drm_fb_cma_helper.h>
> #include <linux/module.h>
>
> -#define DEFAULT_FBDEFIO_DELAY_MS 50
> -
> struct drm_fbdev_cma {
> struct drm_fb_helper fb_helper;
> const struct drm_framebuffer_funcs *fb_funcs;
> @@ -238,6 +236,34 @@ int drm_fb_cma_debugfs_show(struct seq_file *m, void *arg)
> EXPORT_SYMBOL_GPL(drm_fb_cma_debugfs_show);
> #endif
>
> +static int drm_fbdev_cma_fb_open(struct fb_info *info, int user)
> +{
> + struct drm_fb_helper *fb_helper = info->par;
> + struct drm_device *dev = fb_helper->dev;
> +
> + /*
> + * The fb_ops definition resides in this library, meaning fb_open()
> + * will take a ref on the library instead of the driver. Make sure the
> + * driver module is pinned. Skip fbcon (user==0) since it can detach
> + * itself on unregister_framebuffer().
> + */
> + if (user && !try_module_get(dev->driver->fops->owner))
> + return -ENODEV;
I thought we've fixed this by redoing the fb_ops as a macro? Maybe tinydrm
isn't fixed yet, but then we need to fix up tinydrm. This here otoh kinda
smells a bit like a hack ...
If we need it, then I'd vote to put it into the fbdev helpers, not the cma
specific parts.
> +
> + return 0;
> +}
> +
> +static int drm_fbdev_cma_fb_release(struct fb_info *info, int user)
> +{
> + struct drm_fb_helper *fb_helper = info->par;
> + struct drm_device *dev = fb_helper->dev;
> +
> + if (user)
> + module_put(dev->driver->fops->owner);
> +
> + return 0;
> +}
> +
> static int drm_fb_cma_mmap(struct fb_info *info, struct vm_area_struct *vma)
> {
> return dma_mmap_writecombine(info->device, vma, info->screen_base,
> @@ -247,10 +273,13 @@ static int drm_fb_cma_mmap(struct fb_info *info, struct vm_area_struct *vma)
> static struct fb_ops drm_fbdev_cma_ops = {
> .owner = THIS_MODULE,
> DRM_FB_HELPER_DEFAULT_OPS,
> + .fb_open = drm_fbdev_cma_fb_open,
> + .fb_release = drm_fbdev_cma_fb_release,
> .fb_fillrect = drm_fb_helper_sys_fillrect,
> .fb_copyarea = drm_fb_helper_sys_copyarea,
> .fb_imageblit = drm_fb_helper_sys_imageblit,
> .fb_mmap = drm_fb_cma_mmap,
> + .fb_destroy = drm_fb_helper_fb_destroy,
> };
>
> static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
> @@ -262,52 +291,26 @@ static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
> return 0;
> }
>
> -static int drm_fbdev_cma_defio_init(struct fb_info *fbi,
> +static int drm_fbdev_cma_defio_init(struct drm_fb_helper *helper,
> struct drm_gem_cma_object *cma_obj)
> {
> - struct fb_deferred_io *fbdefio;
> - struct fb_ops *fbops;
> + struct fb_info *fbi = helper->fbdev;
> + int ret;
>
> - /*
> - * Per device structures are needed because:
> - * fbops: fb_deferred_io_cleanup() clears fbops.fb_mmap
> - * fbdefio: individual delays
> - */
> - fbdefio = kzalloc(sizeof(*fbdefio), GFP_KERNEL);
> - fbops = kzalloc(sizeof(*fbops), GFP_KERNEL);
> - if (!fbdefio || !fbops) {
> - kfree(fbdefio);
> - kfree(fbops);
> - return -ENOMEM;
> - }
> + ret = drm_fb_helper_defio_init(helper);
> + if (ret)
> + return ret;
>
> /* can't be offset from vaddr since dirty() uses cma_obj */
> fbi->screen_buffer = cma_obj->vaddr;
> /* fb_deferred_io_fault() needs a physical address */
> fbi->fix.smem_start = page_to_phys(virt_to_page(fbi->screen_buffer));
>
> - *fbops = *fbi->fbops;
> - fbi->fbops = fbops;
> -
> - fbdefio->delay = msecs_to_jiffies(DEFAULT_FBDEFIO_DELAY_MS);
> - fbdefio->deferred_io = drm_fb_helper_deferred_io;
> - fbi->fbdefio = fbdefio;
> - fb_deferred_io_init(fbi);
> fbi->fbops->fb_mmap = drm_fbdev_cma_deferred_io_mmap;
>
> return 0;
> }
>
> -static void drm_fbdev_cma_defio_fini(struct fb_info *fbi)
> -{
> - if (!fbi->fbdefio)
> - return;
> -
> - fb_deferred_io_cleanup(fbi);
> - kfree(fbi->fbdefio);
> - kfree(fbi->fbops);
> -}
> -
Above changes look like unrelated cleanup? Should be a separate patch I
think.
> static int
> drm_fbdev_cma_create(struct drm_fb_helper *helper,
> struct drm_fb_helper_surface_size *sizes)
> @@ -365,7 +368,7 @@ drm_fbdev_cma_create(struct drm_fb_helper *helper,
> fbi->fix.smem_len = size;
>
> if (fbdev_cma->fb_funcs->dirty) {
> - ret = drm_fbdev_cma_defio_init(fbi, obj);
> + ret = drm_fbdev_cma_defio_init(helper, obj);
> if (ret)
> goto err_cma_destroy;
> }
> @@ -399,7 +402,6 @@ struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
> const struct drm_framebuffer_funcs *funcs)
> {
> struct drm_fbdev_cma *fbdev_cma;
> - struct drm_fb_helper *helper;
> int ret;
>
> fbdev_cma = kzalloc(sizeof(*fbdev_cma), GFP_KERNEL);
> @@ -409,37 +411,15 @@ struct drm_fbdev_cma *drm_fbdev_cma_init_with_funcs(struct drm_device *dev,
> }
> fbdev_cma->fb_funcs = funcs;
>
> - helper = &fbdev_cma->fb_helper;
> -
> - drm_fb_helper_prepare(dev, helper, &drm_fb_cma_helper_funcs);
> -
> - ret = drm_fb_helper_init(dev, helper, max_conn_count);
> - if (ret < 0) {
> - dev_err(dev->dev, "Failed to initialize drm fb helper.\n");
> - goto err_free;
> - }
> -
> - ret = drm_fb_helper_single_add_all_connectors(helper);
> - if (ret < 0) {
> - dev_err(dev->dev, "Failed to add connectors.\n");
> - goto err_drm_fb_helper_fini;
> -
> - }
> -
> - ret = drm_fb_helper_initial_config(helper, preferred_bpp);
> - if (ret < 0) {
> - dev_err(dev->dev, "Failed to set initial hw configuration.\n");
> - goto err_drm_fb_helper_fini;
> + ret = drm_fb_helper_simple_init(dev, &fbdev_cma->fb_helper,
> + preferred_bpp, max_conn_count,
> + &drm_fb_cma_helper_funcs);
Yeah the conversion to simple* should be split out I think. But then I
thought more of this will be unified with the overall fbdev helpers?
> + if (ret) {
> + kfree(fbdev_cma);
> + return ERR_PTR(ret);
> }
>
> return fbdev_cma;
> -
> -err_drm_fb_helper_fini:
> - drm_fb_helper_fini(helper);
> -err_free:
> - kfree(fbdev_cma);
> -
> - return ERR_PTR(ret);
> }
> EXPORT_SYMBOL_GPL(drm_fbdev_cma_init_with_funcs);
>
> @@ -468,17 +448,15 @@ EXPORT_SYMBOL_GPL(drm_fbdev_cma_init);
> /**
> * drm_fbdev_cma_fini() - Free drm_fbdev_cma struct
> * @fbdev_cma: The drm_fbdev_cma struct
> + *
> + * This function calls drm_fb_helper_simple_fini() and frees @fbdev_cma.
> + *
> + * Don't use this function together with drm_fbdev_cma_dev_unplug().
> */
> void drm_fbdev_cma_fini(struct drm_fbdev_cma *fbdev_cma)
> {
> - drm_fb_helper_unregister_fbi(&fbdev_cma->fb_helper);
> - if (fbdev_cma->fb_helper.fbdev)
> - drm_fbdev_cma_defio_fini(fbdev_cma->fb_helper.fbdev);
> -
> - if (fbdev_cma->fb_helper.fb)
> - drm_framebuffer_remove(fbdev_cma->fb_helper.fb);
> -
> - drm_fb_helper_fini(&fbdev_cma->fb_helper);
> + if (fbdev_cma)
> + drm_fb_helper_simple_fini(&fbdev_cma->fb_helper);
> kfree(fbdev_cma);
> }
> EXPORT_SYMBOL_GPL(drm_fbdev_cma_fini);
> @@ -542,3 +520,20 @@ void drm_fbdev_cma_set_suspend_unlocked(struct drm_fbdev_cma *fbdev_cma,
> state);
> }
> EXPORT_SYMBOL(drm_fbdev_cma_set_suspend_unlocked);
> +
> +/**
> + * drm_fbdev_cma_dev_unplug - wrapper around drm_fb_helper_dev_unplug
> + * @fbdev_cma: The drm_fbdev_cma struct, may be NULL
> + *
> + * This unplugs the fbdev emulation for a hotpluggable DRM device. See
> + * drm_fb_helper_dev_unplug() for details.
> + *
> + * Drivers must call drm_mode_config_cleanup() and free @fbdev_cma in their
> + * &drm_driver->release callback.
> + */
> +void drm_fbdev_cma_dev_unplug(struct drm_fbdev_cma *fbdev_cma)
> +{
> + if (fbdev_cma)
> + drm_fb_helper_dev_unplug(&fbdev_cma->fb_helper);
> +}
I thought we're trying to phase out the cma helpers, why do we need a
wrapper for a wrapper?
> +EXPORT_SYMBOL(drm_fbdev_cma_dev_unplug);
> diff --git a/include/drm/drm_fb_cma_helper.h b/include/drm/drm_fb_cma_helper.h
> index a323781..a6aafae 100644
> --- a/include/drm/drm_fb_cma_helper.h
> +++ b/include/drm/drm_fb_cma_helper.h
> @@ -27,6 +27,7 @@ void drm_fbdev_cma_hotplug_event(struct drm_fbdev_cma *fbdev_cma);
> void drm_fbdev_cma_set_suspend(struct drm_fbdev_cma *fbdev_cma, bool state);
> void drm_fbdev_cma_set_suspend_unlocked(struct drm_fbdev_cma *fbdev_cma,
> bool state);
> +void drm_fbdev_cma_dev_unplug(struct drm_fbdev_cma *fbdev_cma);
>
> void drm_fb_cma_destroy(struct drm_framebuffer *fb);
> int drm_fb_cma_create_handle(struct drm_framebuffer *fb,
> --
> 2.7.4
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
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