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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 <airlied@linux.ie> 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 <dh.herrmann@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@gmail.com> |
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media | ||
.gitignore | ||
80211.tmpl | ||
alsa-driver-api.tmpl | ||
debugobjects.tmpl | ||
device-drivers.tmpl | ||
deviceiobook.tmpl | ||
drm.tmpl | ||
filesystems.tmpl | ||
gadget.tmpl | ||
genericirq.tmpl | ||
kernel-api.tmpl | ||
kernel-hacking.tmpl | ||
kernel-locking.tmpl | ||
kgdb.tmpl | ||
libata.tmpl | ||
librs.tmpl | ||
lsm.tmpl | ||
Makefile | ||
media_api.tmpl | ||
mtdnand.tmpl | ||
networking.tmpl | ||
rapidio.tmpl | ||
regulator.tmpl | ||
s390-drivers.tmpl | ||
scsi.tmpl | ||
sh.tmpl | ||
stylesheet.xsl | ||
tracepoint.tmpl | ||
uio-howto.tmpl | ||
usb.tmpl | ||
writing_usb_driver.tmpl | ||
writing-an-alsa-driver.tmpl | ||
z8530book.tmpl |