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| author | Ilija Hadzic <ihadzic@research.bell-labs.com> | 2012-05-16 00:40:10 +0400 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-07-25 08:09:30 +0400 |
| commit | 949c4a34afacfe800fc442afac117aba15284962 (patch) | |
| tree | ee7c6ebc5d8b05fbca1113b8c9147fbee7e26321 /drivers/gpu/drm/radeon/radeon_ttm.c | |
| parent | b97ce28e9f6d65a800e5c2ee3a2a99c7795bef65 (diff) | |
| download | linux-949c4a34afacfe800fc442afac117aba15284962.tar.xz | |
drm: track dev_mapping in more robust and flexible way
Setting dev_mapping (pointer to the address_space structure
used for memory mappings) to the address_space of the first
opener's inode and then failing if other openers come in
through a different inode has a few restrictions that are
eliminated by this patch.
If we already have valid dev_mapping and we spot an opener
with different i_node, we force its i_mapping pointer to the
already established address_space structure (first opener's
inode). This will make all mappings from drm device hang off
the same address_space object.
Some benefits (things that now work and didn't work
before) of this patch are:
* user space can mknod and use any number of device
nodes and they will all work fine as long as the major
device number is that of the drm module.
* user space can even remove the first opener's device
nodes and mknod the new one and the applications and
windowing system will still work.
* GPU drivers can safely assume that dev->dev_mapping is
correct address_space and just blindly copy it
into their (private) bdev.dev_mapping
For reference, some discussion that lead to this patch can
be found here:
http://lists.freedesktop.org/archives/dri-devel/2012-April/022283.html
Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/radeon/radeon_ttm.c')
| -rw-r--r-- | drivers/gpu/drm/radeon/radeon_ttm.c | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/drivers/gpu/drm/radeon/radeon_ttm.c b/drivers/gpu/drm/radeon/radeon_ttm.c index 0881131a0388..5b71c716d83f 100644 --- a/drivers/gpu/drm/radeon/radeon_ttm.c +++ b/drivers/gpu/drm/radeon/radeon_ttm.c @@ -734,9 +734,7 @@ int radeon_ttm_init(struct radeon_device *rdev) } DRM_INFO("radeon: %uM of GTT memory ready.\n", (unsigned)(rdev->mc.gtt_size / (1024 * 1024))); - if (unlikely(rdev->mman.bdev.dev_mapping == NULL)) { - rdev->mman.bdev.dev_mapping = rdev->ddev->dev_mapping; - } + rdev->mman.bdev.dev_mapping = rdev->ddev->dev_mapping; r = radeon_ttm_debugfs_init(rdev); if (r) { |