Commit Graph

89 Commits

Author SHA1 Message Date
Christian König
a2ab19fed9 drm/ttm: make eviction decision a driver callback v2
This way the driver can decide if it is valuable to evict a BO or not.

The current implementation is added as default to all existing drivers.

v2: fix some typos found during internal testing

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-10-25 14:44:04 -04:00
Christian König
585ffd6544 drm/ttm: fix coding style in ttm_bo_driver.h
A few 80chars issues and spaces at wrong places.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-10-25 14:44:03 -04:00
Alexandre Courbot
af1f85ddec drm/ttm: remove cpu_address member from ttm_tt
Patch 3d50d4dcb0 exposed the CPU address of DMA-allocated pages as
returned by dma_alloc_coherent because Nouveau on Tegra needed it.

This is not required anymore - as there were no other users for it,
remove it and save some memory for everyone.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-09-16 15:53:05 -04:00
Michel Dänzer
4499f2acd5 drm/ttm: Remove unused parameter evict from ttm_bo_move_memcpy
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-08-08 11:33:33 -04:00
Michel Dänzer
4e2f0caa39 drm/ttm: Remove unused parameter evict from ttm_bo_move_ttm
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-08-08 11:33:32 -04:00
Michel Dänzer
7b8082bc07 drm/ttm: Wait for a BO to become idle before unbinding it from GTT
Fixes hangs under memory pressure, e.g. running the piglit test
tex3d-maxsize concurrently with other tests.

Fixes: 17d33bc9d6 ("drm/ttm: drop waiting for idle in ttm_bo_evict.")
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-08-08 11:33:31 -04:00
Christian König
2ff2bf1e5c drm/ttm: partial revert "cleanup ttm_tt_(unbind|destroy)" v3
We still need to unbind explicitly during a move.

This partial reverts commit ff20caa0bcbfef9f7686f8d1868a3b990921afd6.

v2: remove unnecessary check and unused variable
v3: fix typo in commit message

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-29 14:37:04 -04:00
Christian König
3ddf4ad917 drm/ttm: add the infrastructure for pipelined evictions
Free up the memory immediately, remember the last eviction for each domain and
make new allocations depend on the last eviction to be completed.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-07 14:54:41 -04:00
Christian König
5bc730677b drm/ttm: remove TTM_BO_PRIV_FLAG_MOVING
Instead of using the flag just remember the fence of the last move operation.

This avoids waiting for command submissions pipelined after the move, but
before accessing the BO with the CPU again.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-07 14:54:40 -04:00
Christian König
74561cd4f1 drm/ttm: remove no_gpu_wait param from ttm_bo_move_accel_cleanup
It isn't used and not waiting for the GPU after scheduling a move is
actually quite dangerous.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-07 14:54:39 -04:00
Christian König
77dfc28bad drm/ttm: wait for BO idle in ttm_bo_move_memcpy
When we want to pipeline accelerated moves we need to wait in the fallback path.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-07 14:54:35 -04:00
Christian König
089f16c55b drm/ttm: cleanup ttm_tt_(unbind|destroy)
ttm_tt_destroy should be the only one unbinding the object.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-07-07 14:54:33 -04:00
Christian König
98c2872ae9 drm/ttm: implement LRU add callbacks v2
This allows fine grained control for the driver where to add a BO into the LRU.

v2: fix typo in comment

Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-05-04 20:21:38 -04:00
Christian König
c3ea576e05 drm/ttm: add optional LRU removal callback v2
Useful for driver specific LRU handling.

v2: fix typo in comment

Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-05-04 20:21:34 -04:00
Christian König
00cfd664f6 drm/ttm: remove unused validation sequence
Not used any more.

Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-05-04 20:21:30 -04:00
Christian König
dfd5e50ea4 drm/ttm: remove use_ticket parameter from ttm_bo_reserve
Not used any more.

Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2016-05-04 20:21:21 -04:00
Daniel Vetter
e6bf6e5799 drm/ttm: Remove TTM_HAS_AGP
It tries to do fancy things with excluding agp support if ttm is
built-in, but agp isn't. Instead just express this depency like drm
does and use CONFIG_AGP everywhere.

Also use the neat Makefile magic to make the entire ttm_agp_backend
file optional.

v2: Use IS_ENABLED(CONFIG_AGP) as suggested by Ville

v3: Review from Emil.

v4: Actually get it right as spotted by 0-day.

Cc: Emil Velikov <emil.l.velikov@gmail.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1459337046-25882-1-git-send-email-daniel.vetter@ffwll.ch
2016-03-30 17:20:43 +02:00
Nicolai Hähnle
eb227c554e drm/ttm: fix documentation of ttm_bo_reserve
Previously, the comment was inconsistent. EDEADLK is what the ww_mutex
mechanism really returns.

Signed-off-by: Nicolai Hähnle <Nicolai.Haehnle@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-12-15 10:58:39 +10:00
Alex Deucher
54c4cd68ed drm/ttm: device address space != CPU address space
We need to store device offsets in 64 bit as the device
address space may be larger than the CPU's.

Fixes GPU init failures on radeons with 4GB or more of
vram on 32 bit kernels.  We put vram at the start of the
GPU's address space so the gart aperture starts at 4 GB
causing all GPU addresses in the gart aperture to get
truncated.

bug:
https://bugs.freedesktop.org/show_bug.cgi?id=89072

[airlied: fix warning on nouveau build]

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: thellstrom@vmware.com
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2015-03-05 09:04:39 +10:00
Maarten Lankhorst
f2c24b83ae drm/ttm: flip the switch, and convert to dma_fence
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
2014-09-02 16:41:50 +02:00
Maarten Lankhorst
dd7cfd6412 drm/ttm: kill fence_lock
No users are left, kill it off! :D
Conversion to the reservation api is next on the list, after
that the functionality can be restored with rcu.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
2014-09-01 10:16:43 +02:00
Christian König
f1217ed09f drm/ttm: move fpfn and lpfn into each placement v2
This allows us to more fine grained specify where to place the buffer object.

v2: rebased on drm-next, add bochs changes as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
2014-08-27 13:16:04 +02:00
Alexandre Courbot
3d50d4dcb0 drm/ttm: expose CPU address of DMA-allocated pages
Pages allocated using the DMA API have a coherent memory mapping. Make
this mapping visible to drivers so they can decide to use it instead of
creating their own redundant one.

Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: David Airlie <airlied@linux.ie>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
2014-08-10 01:08:03 +10:00
Christian König
e3f202798a drm/ttm: fix handling of TTM_PL_FLAG_TOPDOWN v2
bo->mem.placement is not initialized when ttm_bo_man_get_node is called,
so the flag had no effect at all.

v2: change nouveau and vmwgfx as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
2014-07-08 11:15:58 +10:00
Alexandre Courbot
15f8f65751 drm/ttm: remove declaration of ttm_tt_cache_flush
ttm_tt_cache_flush's implementation was removed in 2009 by commit
c9c97b8c, but its declaration has been hiding in ttm_bo_driver.h since
then.

It has been surviving in the dark for too long now ; give it the mercy
blow.

Reviewed-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
2014-07-08 00:29:57 +02:00
Thomas Hellstrom
c75230833c drm/ttm: Hide the implementation details of reservation
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
2014-04-04 08:00:59 +02:00
David Herrmann
44d847b743 drm: init TTM dev_mapping in ttm_bo_device_init()
With dev->anon_inode we have a global address_space ready for operation
right from the beginning. Therefore, there is no need to do a delayed
setup with TTM. Instead, set dev_mapping during initialization in
ttm_bo_device_init() and remove any "if (dev_mapping)" conditions.

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Alex Deucher <alexdeucher@gmail.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
2014-03-16 12:23:42 +01:00
Thomas Hellstrom
58aa6622d3 drm/ttm: Correctly set page mapping and -index members
Needed for some vm operations; most notably unmap_mapping_range() with
even_cows = 0.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Brian Paul <brianp@vmware.com>
2014-01-08 10:08:28 +01:00
David Herrmann
72525b3f33 drm/ttm: convert to unified vma offset manager
Use the new vma-manager infrastructure. This doesn't change any
implementation details as the vma-offset-manager is nearly copied 1-to-1
from TTM.

The vm_lock is moved into the offset manager so we can drop it from TTM.
During lookup, we use the vma locking helpers to take a reference to the
found object.
In all other scenarios, locking stays the same as before. We always
guarantee that drm_vma_offset_remove() is called only during destruction.
Hence, helpers like drm_vma_node_offset_addr() are always safe as long as
the node has a valid offset.

This also drops the addr_space_offset member as it is a copy of vm_start
in vma_node objects. Use the accessor functions instead.

v4:
 - remove vm_lock
 - use drm_vma_offset_lock_lookup() to protect lookup (instead of vm_lock)

Cc: Dave Airlie <airlied@redhat.com>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Martin Peres <martin.peres@labri.fr>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
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>
2013-07-25 20:47:07 +10:00
Maarten Lankhorst
3482032457 drm/ttm: inline ttm_bo_reserve and related calls
Makes lockdep a lot more useful.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-06-28 12:04:09 +10:00
Maarten Lankhorst
ecff665f5e drm/ttm: make ttm reservation calls behave like reservation calls
This commit converts the source of the val_seq counter to
the ww_mutex api. The reservation objects are converted later,
because there is still a lockdep splat in nouveau that has to
resolved first.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-06-28 12:02:20 +10:00
Dave Airlie
afe6804c04 ttm: export functions to allow qxl do its own iomapping
qxl wants to use io mapping like i915 gem does, for now
just export the symbols so the driver can implement atomic
page maps using io mapping.

Signed-off-by: Dave Airlie <airlied@redhat.com>
2013-04-12 13:50:46 +10:00
Maarten Lankhorst
cc4c0c4de3 drm/ttm: unexport ttm_bo_wait_unreserved
All legitimate users of this function outside ttm_bo.c are gone, now
it's only an implementation detail.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
2013-01-15 16:49:39 +01:00
Maarten Lankhorst
5e45d7dfd7 drm/ttm: add ttm_bo_reserve_slowpath
Instead of dropping everything, waiting for the bo to be unreserved
and trying over, a better strategy would be to do a blocking wait.

This can be mapped a lot better to a mutex_lock-like call.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
2013-01-15 14:57:05 +01:00
Maarten Lankhorst
63d0a41955 drm/ttm: remove lru_lock around ttm_bo_reserve
There should no longer be assumptions that reserve will always succeed
with the lru lock held, so we can safely break the whole atomic
reserve/lru thing. As a bonus this fixes most lockdep annotations for
reservations.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
2013-01-15 14:56:37 +01:00
Maarten Lankhorst
97a875cbdf drm/ttm: remove no_wait_reserve, v3
All items on the lru list are always reservable, so this is a stupid
thing to keep. Not only that, it is used in a way which would
guarantee deadlocks if it were ever to be set to block on reserve.

This is a lot of churn, but mostly because of the removal of the
argument which can be nested arbitrarily deeply in many places.

No change of code in this patch except removal of the no_wait_reserve
argument, the previous patch removed the use of no_wait_reserve.

v2:
 - Warn if -EBUSY is returned on reservation, all objects on the list
   should be reservable. Adjusted patch slightly due to conflicts.
v3:
 - Focus on no_wait_reserve removal only.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-12-10 20:21:30 +10:00
Maarten Lankhorst
654aa79259 drm/ttm: alter cpu_writers to return -EBUSY in ttm_execbuf_util reservations
This is similar to other platforms that don't allow command submission
to buffers locked on the cpu.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-11-20 16:17:35 +10:00
Maarten Lankhorst
dedfdffd44 drm/ttm: remove sync_arg from driver functions
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-By: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-11-20 16:10:10 +10:00
Maarten Lankhorst
b03640b1de drm/ttm: remove sync_obj_arg from ttm_bo_move_accel_cleanup
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Reviewed-By: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-11-20 16:10:02 +10:00
Marcin Slusarz
830e2837f5 drm/ttm: remove ttm_bo_device->nice_mode
It's unused.

Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-11-20 16:06:21 +10:00
David Howells
a1ce39288e UAPI: (Scripted) Convert #include "..." to #include <path/...> in kernel system headers
Convert #include "..." to #include <path/...> in kernel system headers.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
2012-10-02 18:01:25 +01:00
Ilija Hadzic
b97ce28e9f drm/ttm: remove stale declaration and field
Patch 649bf3ca77 has completely
removed ttm_backend structure. Remove lingering declaration
and related (now stale) field in ttm_tt structure,

CC: Jerome Glisse <jglisse at redhat.com>
Signed-off-by: Ilija Hadzic <ihadzic at research.bell-labs.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-07-24 15:30:36 +10:00
Dave Airlie
129b78bfca ttm: add prime sharing support to TTM (v2)
This adds the ability for ttm common code to take an SG table
and use it as the backing for a slave TTM object.

The drivers can then populate their GTT tables using the SG object.

v2: make sure to setup VM for sg bos as well.

Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-05-23 10:46:27 +01:00
Jerome Glisse
dea7e0ac45 ttm: fix agp since ttm tt rework
ttm tt rework modified the way we allocate and populate the
ttm_tt structure, the AGP side was missing some bit to properly
work. Fix those and fix radeon and nouveau AGP support.

Tested on radeon only so far.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2012-01-06 09:34:03 +00:00
Jerome Glisse
57de4ba959 drm/ttm: simplify memory accounting for ttm user v2
Provide helper function to compute the kernel memory size needed
for each buffer object. Move all the accounting inside ttm, simplifying
driver and avoiding code duplication accross them.

v2 fix accounting of ghost object, one would have thought that i
   would have run into the issue since a longtime but it seems
   ghost object are rare when you have plenty of vram ;)

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:40:11 +00:00
Jerome Glisse
8e7e70522d drm/ttm: isolate dma data from ttm_tt V4
Move dma data to a superset ttm_dma_tt structure which herit
from ttm_tt. This allow driver that don't use dma functionalities
to not have to waste memory for it.

V2 Rebase on top of no memory account changes (where/when is my
   delorean when i need it ?)
V3 Make sure page list is initialized empty
V4 typo/syntax fixes

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:40:02 +00:00
Konrad Rzeszutek Wilk
2334b75ffb drm/ttm: provide dma aware ttm page pool code V9
In TTM world the pages for the graphic drivers are kept in three different
pools: write combined, uncached, and cached (write-back). When the pages
are used by the graphic driver the graphic adapter via its built in MMU
(or AGP) programs these pages in. The programming requires the virtual address
(from the graphic adapter perspective) and the physical address (either System RAM
or the memory on the card) which is obtained using the pci_map_* calls (which does the
virtual to physical - or bus address translation). During the graphic application's
"life" those pages can be shuffled around, swapped out to disk, moved from the
VRAM to System RAM or vice-versa. This all works with the existing TTM pool code
- except when we want to use the software IOTLB (SWIOTLB) code to "map" the physical
addresses to the graphic adapter MMU. We end up programming the bounce buffer's
physical address instead of the TTM pool memory's and get a non-worky driver.
There are two solutions:
1) using the DMA API to allocate pages that are screened by the DMA API, or
2) using the pci_sync_* calls to copy the pages from the bounce-buffer and back.

This patch fixes the issue by allocating pages using the DMA API. The second
is a viable option - but it has performance drawbacks and potential correctness
issues - think of the write cache page being bounced (SWIOTLB->TTM), the
WC is set on the TTM page and the copy from SWIOTLB not making it to the TTM
page until the page has been recycled in the pool (and used by another application).

The bounce buffer does not get activated often - only in cases where we have
a 32-bit capable card and we want to use a page that is allocated above the
4GB limit. The bounce buffer offers the solution of copying the contents
of that 4GB page to an location below 4GB and then back when the operation has been
completed (or vice-versa). This is done by using the 'pci_sync_*' calls.
Note: If you look carefully enough in the existing TTM page pool code you will
notice the GFP_DMA32 flag is used  - which should guarantee that the provided page
is under 4GB. It certainly is the case, except this gets ignored in two cases:
 - If user specifies 'swiotlb=force' which bounces _every_ page.
 - If user is using a Xen's PV Linux guest (which uses the SWIOTLB and the
   underlaying PFN's aren't necessarily under 4GB).

To not have this extra copying done the other option is to allocate the pages
using the DMA API so that there is not need to map the page and perform the
expensive 'pci_sync_*' calls.

This DMA API capable TTM pool requires for this the 'struct device' to
properly call the DMA API. It also has to track the virtual and bus address of
the page being handed out in case it ends up being swapped out or de-allocated -
to make sure it is de-allocated using the proper's 'struct device'.

Implementation wise the code keeps two lists: one that is attached to the
'struct device' (via the dev->dma_pools list) and a global one to be used when
the 'struct device' is unavailable (think shrinker code). The global list can
iterate over all of the 'struct device' and its associated dma_pool. The list
in dev->dma_pools can only iterate the device's dma_pool.
                                                            /[struct device_pool]\
        /---------------------------------------------------| dev                |
       /                                            +-------| dma_pool           |
 /-----+------\                                    /        \--------------------/
 |struct device|     /-->[struct dma_pool for WC]</         /[struct device_pool]\
 | dma_pools   +----+                                     /-| dev                |
 |  ...        |    \--->[struct dma_pool for uncached]<-/--| dma_pool           |
 \-----+------/                                         /   \--------------------/
        \----------------------------------------------/
[Two pools associated with the device (WC and UC), and the parallel list
containing the 'struct dev' and 'struct dma_pool' entries]

The maximum amount of dma pools a device can have is six: write-combined,
uncached, and cached; then there are the DMA32 variants which are:
write-combined dma32, uncached dma32, and cached dma32.

Currently this code only gets activated when any variant of the SWIOTLB IOMMU
code is running (Intel without VT-d, AMD without GART, IBM Calgary and Xen PV
with PCI devices).

Tested-by: Michel Dänzer <michel@daenzer.net>
[v1: Using swiotlb_nr_tbl instead of swiotlb_enabled]
[v2: Major overhaul - added 'inuse_list' to seperate used from inuse and reorder
the order of lists to get better performance.]
[v3: Added comments/and some logic based on review, Added Jerome tag]
[v4: rebase on top of ttm_tt & ttm_backend merge]
[v5: rebase on top of ttm memory accounting overhaul]
[v6: New rebase on top of more memory accouting changes]
[v7: well rebase on top of no memory accounting changes]
[v8: make sure pages list is initialized empty]
[v9: calll ttm_mem_global_free_page in unpopulate for accurate accountg]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Jerome Glisse <jglisse@redhat.com>
Acked-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:39:33 +00:00
Jerome Glisse
b1e5f17232 drm/ttm: introduce callback for ttm_tt populate & unpopulate V4
Move the page allocation and freeing to driver callback and
provide ttm code helper function for those.

Most intrusive change, is the fact that we now only fully
populate an object this simplify some of code designed around
the page fault design.

V2 Rebase on top of memory accounting overhaul
V3 New rebase on top of more memory accouting changes
V4 Rebase on top of no memory account changes (where/when is my
   delorean when i need it ?)

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:39:24 +00:00
Jerome Glisse
649bf3ca77 drm/ttm: merge ttm_backend and ttm_tt V5
ttm_backend will only exist with a ttm_tt, and ttm_tt
will only be of interest when bound to a backend. Merge them
to avoid code and data duplication.

V2 Rebase on top of memory accounting overhaul
V3 Rebase on top of more memory accounting changes
V4 Rebase on top of no memory account changes (where/when is my
   delorean when i need it ?)
V5 make sure ttm is unbound before destroying, change commit
   message on suggestion from Tormod Volden

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:39:17 +00:00
Jerome Glisse
a14af87b0b drm/ttm: remove unused backend flags field
This field is not use by any of the driver just drop it.

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
2011-12-06 10:38:48 +00:00