From fe3078fa5c367186c94a6652581ffbe9ccea4640 Mon Sep 17 00:00:00 2001 From: David Herrmann Date: Wed, 24 Jul 2013 21:06:15 +0200 Subject: 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 --- Documentation/DocBook/drm.tmpl | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'Documentation/DocBook') diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 7d1278e..87e22ec 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2212,6 +2212,12 @@ void intel_crt_init(struct drm_device *dev) !Iinclude/drm/drm_rect.h !Edrivers/gpu/drm/drm_rect.c + + VMA Offset Manager +!Pdrivers/gpu/drm/drm_vma_manager.c vma offset manager +!Edrivers/gpu/drm/drm_vma_manager.c +!Iinclude/drm/drm_vma_manager.h + -- cgit v1.1