On Tue, Aug 29, 2017 at 07:23:14PM +0200, Noralf Trønnes wrote: > > Den 28.08.2017 23.46, skrev Daniel Vetter: > > 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.pinch...@ideasonboard.com> > > > Signed-off-by: Noralf Trønnes <nor...@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. > > This is only necessary in this library atm because it contains this: > > static struct fb_ops drm_fbdev_cma_ops = { > .owner = THIS_MODULE, > > Other drivers have this definition in their own module, so fb_open() > takes a ref on the right module. > > My shmem gem library will also wrap struct fb_ops and needs to do this. > I can add them to drm_fb_helper with a note that they should only be > used by libraries. > > Yes it's kind of a hack, but I find the cma library is very nice in this > respect, that it makes fbdev emulation very easy for drivers. It wraps > up basic fbdev in 3 function calls. > > If we were to do this strictly by the book, we would have to add > something like this to every cma driver: > > DEFINE_DRM_FBDEV_CMA_FB_OPS(driver_fb_ops); > > static int driver_fb_probe(struct drm_fb_helper *helper, > struct drm_fb_helper_surface_size *sizes) > { > return drm_fbdev_cma_create(helper, sizes, &driver_fb_ops); > } > > static const struct drm_fb_helper_funcs driver_helper_funcs = { > .fb_probe = driver_fb_probe, > }; > > static int driver_fbdev_init() > { > - fbdev_cma = drm_fbdev_cma_init(dev, preferred_bpp, max_conn_count); > + fbdev_cma = drm_fbdev_cma_init(dev, preferred_bpp, max_conn_count, > + &driver_helper_funcs); > } > > Well, maybe not so bad after all :-) > Maybe I should do it like this in the shmem gem library.
Hm, this does add considerable amounts of boilerplate everywhere, so not sure it's a good idea. > I can't do refactoring like this, this time around. I need to do that > shmem gem library before I run out of steam. A refactoring like this > will have to wait to later. I think your fb_open/close hooks are just fine, but instead of putting them into cma helpers only let's just put them into the core helpers (and add them to DRM_FB_HELPER_DEFAULT_OPS). Them being a special case for cma only was what really irked me, not so much what they do. And doing the get/put module by default shouldn't really hurt (for drivers where the fb_ops and the drm_driver ops match it'll mean double refcounting, but that doesn't matter really). > > > > + > > > + 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? > > I agree, if we find a way to support unplug within the existing 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? > > Because struct drm_fbdev_cma is private to this file. > When tinydrm switches to shmem, we can remove the dirtyfb stuff from > this helper and we will end up with this: > > struct drm_fbdev_cma { > struct drm_fb_helper fb_helper; > }; > > Now it is possible to refactor and switch to using drm_fb_helper > directly and drop the fbdev wrappers. > > We can ofc avoid adding a wrapper by making struct drm_fbdev_cma public. Hm, no I understand. I'd vote to make struct drm_fbdev_cma public. We generally don't try to hide stuff in structs only in .c files, makes it easier to up/downcast and have static inline helpers. Moving the struct should be a separate patch I think. -Daniel > > > Noralf. > > > > +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 _______________________________________________ dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel