From: David Herrmann Date: Wed, 24 Jul 2013 19:06:15 +0000 (+0200) Subject: drm: add unified vma offset manager X-Git-Tag: v3.12-rc1~136^2~145 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fe3078fa5c367186c94a6652581ffbe9ccea4640;p=pandora-kernel.git drm: add unified vma offset manager If we want to map GPU memory into user-space, we need to linearize the addresses to not confuse mm-core. Currently, GEM and TTM both implement their own offset-managers to assign a pgoff to each object for user-space CPU access. GEM uses a hash-table, TTM uses an rbtree. This patch provides a unified implementation that can be used to replace both. TTM allows partial mmaps with a given offset, so we cannot use hashtables as the start address may not be known at mmap time. Hence, we use the rbtree-implementation of TTM. We could easily update drm_mm to use an rbtree instead of a linked list for it's object list and thus drop the rbtree from the vma-manager. However, this would slow down drm_mm object allocation for all other use-cases (rbtree insertion) and add another 4-8 bytes to each mm node. Hence, use the separate tree but allow for later migration. This is a rewrite of the 2012-proposal by David Airlie v2: - fix Docbook integration - drop drm_mm_node_linked() and use drm_mm_node_allocated() - remove unjustified likely/unlikely usage (but keep for rbtree paths) - remove BUG_ON() as drm_mm already does that - clarify page-based vs. byte-based addresses - use drm_vma_node_reset() for initialization, too v4: - allow external locking via drm_vma_offset_un/lock_lookup() - add locked lookup helper drm_vma_offset_lookup_locked() v5: - fix drm_vma_offset_lookup() to correctly validate range-mismatches (fix (offset > start + pages)) - fix drm_vma_offset_exact_lookup() to actually do what it says - remove redundant vm_pages member (add drm_vma_node_size() helper) - remove unneeded goto - fix documentation Signed-off-by: David Herrmann Reviewed-by: Daniel Vetter Signed-off-by: Dave Airlie --- Reading git-diff-tree failed