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authorIlija Hadzic <ihadzic@research.bell-labs.com>2011-10-29 01:43:28 +0400
committerDave Airlie <airlied@redhat.com>2012-01-05 18:43:02 +0400
commit09b4ea47d1041612b101c369969db123ac2c1511 (patch)
tree177a2cf53107d2451f47cf2680ce20db8af5f623 /drivers/gpu/drm/drm_drv.c
parent53fead966a584cd2130e0c5565726dd56ccf7924 (diff)
downloadlinux-09b4ea47d1041612b101c369969db123ac2c1511.tar.xz
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.c6
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),