diff options
| author | Ilija Hadzic <ihadzic@research.bell-labs.com> | 2011-10-28 17:43:28 -0400 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2012-01-05 14:43:02 +0000 |
| commit | 09b4ea47d1041612b101c369969db123ac2c1511 (patch) | |
| tree | 177a2cf53107d2451f47cf2680ce20db8af5f623 /drivers/gpu/drm/drm_drv.c | |
| parent | 53fead966a584cd2130e0c5565726dd56ccf7924 (diff) | |
drm: make DRM_UNLOCKED ioctls with their own mutex
drm_getclient, drm_getstats and drm_getmap (with a few minor
adjustments) do not need global mutex, so fix that and
make the said ioctls DRM_UNLOCKED. Details:
drm_getclient: the only thing that should be protected here
is dev->filelist and that is already protected everywhere with
dev->struct_mutex.
drm_getstats: there is no need for any mutex here because the
loop runs through quasi-static (set at load time only)
data, and the actual count access is done with atomic_read()
drm_getmap already uses dev->struct_mutex to protect
dev->maplist, which also used to protect the same structure
everywhere else except at three places:
* drm_getsarea, which doesn't grab *any* mutex before
touching dev->maplist (so no drm_global_mutex doesn't help
here either; different issue for a different patch).
However, drivers seem to call it only at
initialization time so it probably doesn't matter
* drm_master_destroy, which is called from drm_master_put,
which in turn is protected with dev->struct_mutex
everywhere else in drm module, so we are good here too.
* drm_getsareactx, which releases the dev->struct_mutex
too early, but this patch includes the fix for that.
v2: * incorporate comments received from Daniel Vetter
* include the (long) explanation above to make it clear what
we are doing (and why), also at Daniel Vetter's request
* tighten up mutex grab/release locations to only
encompass real critical sections, rather than some
random code around them
Signed-off-by: Ilija Hadzic <ihadzic@research.bell-labs.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Diffstat (limited to 'drivers/gpu/drm/drm_drv.c')
| -rw-r--r-- | drivers/gpu/drm/drm_drv.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c index 1919ef05d6d8..ebf7d3f68fc4 100644 --- a/drivers/gpu/drm/drm_drv.c +++ b/drivers/gpu/drm/drm_drv.c @@ -65,9 +65,9 @@ static struct drm_ioctl_desc drm_ioctls[] = { DRM_IOCTL_DEF(DRM_IOCTL_GET_UNIQUE, drm_getunique, 0), DRM_IOCTL_DEF(DRM_IOCTL_GET_MAGIC, drm_getmagic, 0), DRM_IOCTL_DEF(DRM_IOCTL_IRQ_BUSID, drm_irq_by_busid, DRM_MASTER|DRM_ROOT_ONLY), - DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, 0), - DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, 0), - DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, 0), + DRM_IOCTL_DEF(DRM_IOCTL_GET_MAP, drm_getmap, DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_GET_CLIENT, drm_getclient, DRM_UNLOCKED), + DRM_IOCTL_DEF(DRM_IOCTL_GET_STATS, drm_getstats, DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_GET_CAP, drm_getcap, DRM_UNLOCKED), DRM_IOCTL_DEF(DRM_IOCTL_SET_VERSION, drm_setversion, DRM_MASTER), |