In order to support snoopable memory on non-LLC architectures (so that
we can bind vgem objects into the i915 GATT for example), we have to
avoid the prefetcher on the GPU from crossing memory domains and so
prevent allocation of a snoopable PTE immediately following an uncached
PTE. To do that, we need to extend the range allocator with support for
tracking and segregating different node colours.
This will be used by i915 to segregate memory domains within the GTT.
v2: Now with more drm_mm helpers and less driver interference.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Dave Airlie <airlied@redhat.com
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@gmail.com>
The looping helper didn't do anything due to a superficial
semicolon. Furthermore one of the two dump functions suffered
from copy&paste fail.
While staring at the code I've also noticed that the replace
helper (currently unused) is a bit broken.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
With the switch to implicit free space accounting one pointer
got unused when scanning. Use it to create a single-linked list
to ensure correct unwinding of the scan state.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The old api has a two-step process: First search for a suitable
free hole, then allocate from that specific hole. No user used
this to do anything clever. So drop it for the embeddable variant
of the drm_mm api (the old one retains this ability, for the time
being).
With struct drm_mm_node embedded, we cannot track allocations
anymore by checking for a NULL pointer. So keep track of this
and add a small helper drm_mm_node_allocated.
Also add a function to move allocations between different struct
drm_mm_node.
v2: Implement suggestions by Chris Wilson.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
The idea is to track free holes implicitly by marking the allocation
immediatly preceeding a hole.
To avoid an ugly corner case add a dummy head_node to struct drm_mm
to track the hole that spans to complete allocation area when the
memory manager is empty.
To guarantee that there's always a preceeding/following node (that might
be marked as hole_follows == 1), move the mm->node_list list_head to the
head_node.
The main allocator and fair-lru scan code actually becomes simpler.
Only the debug code slightly suffers because free areas are no longer
explicit.
Also add drm_mm_for_each_node (which will be much more useful when
struct drm_mm_node is embeddable).
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Nouveau was checking drm_mm internals on teardown to see whether the
memory manager was initialized. Hide these internals in a small
inline helper function.
Acked-by: Ben Skeggs <bskeggs@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
These helper functions can be used to efficiently scan lru list
for eviction. Eviction becomes a three stage process:
1. Scanning through the lru list until a suitable hole has been found.
2. Scan backwards to restore drm_mm consistency and find out which
objects fall into the hole.
3. Evict the objects that fall into the hole.
These helper functions don't allocate any memory (at the price of
not allowing any other concurrent operations). Hence this can also be
used for ttm (which does lru scanning under a spinlock).
Evicting objects in this fashion should be more fair than the current
approach by i915 (scan the lru for a object large enough to contain
the new object). It's also more efficient than the current approach used
by ttm (uncoditionally evict objects from the lru until there's enough
free space).
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Thomas Hellstrom <thellstrom@vmwgfx.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Yeah, I've kinda noticed that fl_entry is the free stack. Still
give it (and the memory node list ml_entry) decent names.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Thomas Hellstrom <thellstrom@vmwgfx.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Only ever assigned, never used.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[glisse: I will re-add if needed for range-restricted allocations]
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
drm_mm_debug_table will print the memory manager state
in table allowing to give a snapshot of the manager at
given point in time. Usefull for debugging.
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This adds code to the drm_mm to talk to debugfs, and adds
support to radeon to add the VRAM and GTT mm lists to debugfs.
I tested with spinlock debugging and it doesn't give out.
Signed-off-by: Dave Airlie <airlied@redhat.com>
also for the atomic path by using a common code-path.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
this is a TTM preparation patch, it rearranges the mm and
add operations needed to do mm operations in atomic context.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
