On Tue, Jun 18, 2019 at 6:49 AM Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote: > > Hi, > > > > While most callbacks are pretty straight forward (just hook the same > > > callbacks into the drm_gem_object_funcs. struct) the mmap bits are a > > > bit more obscure. > > > > > > First, there seem to be two ways to mmap a gem buffer: > > > > > > (1) drm_driver->fops->mmap, and > > > (2) drm_driver->gem_prime_mmap. > > > > > > drm_gem_object_funcs has just a single vm_ops ... > > > > > > Also it is not obvious how one would convert something which basically > > > calls ttm_bo_mmap() in drm_driver->fops->mmap to the new interface. > > > > Yeah the mmap side is still a mess, but my series here was getting a bit > > too long already. There's a bunch of problems here: > > > > drm_driver->gem_prime_mmap could be nuked and instead we use > > drm_gem_prime_mmap everywhere. Especially the various versions in helpers > > really don't add much. > > Well, everything using ttm has the problem that we have another > duplication here: both gem and ttm have a vma_node ... > > So (for example) drm_gem_vram_driver_gem_prime_mmap() is a thin wrapper > which does (a) copy vm_node.start from ttm to gem vma_node and (b) calls > drm_gem_prime_mmap(). Hm ... maybe we should ditch the ttm vma offset stuff and fold that over entirely to the gem way of doing things. The only thing you're going to loose is the ->verify_access callback, which again is just to get back to gem I think. You would need a slightly differrent vm_ops structure though, since the ttm vm ops expect a ttm_buffer_object, whereas gem gives you a drm_gem_buffer_object. So either need to overwrite all those, or maybe it's inded time to just make ttm_bo a subclass of gem_bo. > > Second one is drm_driver->fops->mmap. That one we need to keep, but this > > isn't mmap on a buffer, but mmap on the entire drm_device. The one which > > should be replaced by drm_gem_object_funcs.vm_ops is > > drm_driver->gem_vm_ops. > > Hmm, seems ttm hasn't something I can hook into drm_driver->gem_vm_ops ... ttm_bo_vm_ops seems to be the thing you want. Cheers, Daniel -- Daniel Vetter Software Engineer, Intel Corporation +41 (0) 79 365 57 48 - http://blog.ffwll.ch _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
