On Thu, Oct 12, 2017 at 06:56:29PM -0700, Keith Packard wrote:
This provides new data structures to hold "lease" information about drm mode setting objects, and provides for creating new drm_masters which have access to a subset of the available drm resources.
An 'owner' is a drm_master which is not leasing the objects from another drm_master, and hence 'owns' them.
A 'lessee' is a drm_master which is leasing objects from some other drm_master. Each lessee holds the set of objects which it is leasing from the lessor.
A 'lessor' is a drm_master which is leasing objects to another drm_master. This is the same as the owner in the current code.
The set of objects any drm_master 'controls' is limited to the set of objects it leases (for lessees) or all objects (for owners).
Objects not controlled by a drm_master cannot be modified through the various state manipulating ioctls, and any state reported back to user space will be edited to make them appear idle and/or unusable. For instance, connectors always report 'disconnected', while encoders report no possible crtcs or clones.
The full list of lessees leasing objects from an owner (either directly, or indirectly through another lessee), can be searched from an idr in the drm_master of the owner.
Changes for v2 as suggested by Daniel Vetter daniel.vetter@ffwll.ch:
Sub-leasing has been disabled.
BUG_ON for lock checking replaced with lockdep_assert_held
'change' ioctl has been removed.
Leased objects can always be controlled by the lessor; the 'mask_lease' flag has been removed
Checking for leased status has been simplified, replacing the drm_lease_check function with drm_lease_held.
Changes in v3, some suggested by Dave Airlie airlied@gmail.com
Add revocation. This allows leases to be effectively revoked by removing all of the objects they have access to. The lease itself hangs around as it's hanging off a file.
Free the leases IDR when the master is destroyed
_drm_lease_held should look at lessees, not lessor
Allow non-master files to check for lease status
Changes in v4, suggested by Dave Airlie airlied@gmail.com
- Formatting and whitespace changes
Signed-off-by: Keith Packard keithp@keithp.com
drivers/gpu/drm/Makefile | 2 +- drivers/gpu/drm/drm_auth.c | 29 +++- drivers/gpu/drm/drm_lease.c | 339 ++++++++++++++++++++++++++++++++++++++++++ include/drm/drm_auth.h | 20 +++ include/drm/drm_lease.h | 36 +++++ include/drm/drm_mode_object.h | 1 + 6 files changed, 425 insertions(+), 2 deletions(-) create mode 100644 drivers/gpu/drm/drm_lease.c create mode 100644 include/drm/drm_lease.h
<snip />
diff --git a/drivers/gpu/drm/drm_lease.c b/drivers/gpu/drm/drm_lease.c new file mode 100644 index 000000000000..6c3f2445254c --- /dev/null +++ b/drivers/gpu/drm/drm_lease.c
<snip />
+/**
- _drm_lease_revoke - revoke access to all leased objects
Can you add "(idr_mutex held)" like you have in _drm_lease_held()?
- @master: the master losing its lease
s/master/top/
- */
+void _drm_lease_revoke(struct drm_master *top) +{
- int object;
- void *entry;
- struct drm_master *master = top;
lockdep_assert_held(&top->dev->mode_config.idr_mutex);
With these nits fixed, Reviewed-by: Sean Paul seanpaul@chromium.org
- /*
* Walk the tree starting at 'top' emptying all leases. Because* the tree is fully connected, we can do this without recursing*/- for (;;) {
DRM_DEBUG_LEASE("revoke leases for %p %d\n", master, master->lessee_id);/* Evacuate the lease */idr_for_each_entry(&master->leases, entry, object)idr_remove(&master->leases, object);/* Depth-first list walk *//* Down */if (!list_empty(&master->lessees)) {master = list_first_entry(&master->lessees, struct drm_master, lessee_list);} else {/* Up */while (master != top && master == list_last_entry(&master->lessor->lessees, struct drm_master, lessee_list))master = master->lessor;if (master == top)break;/* Over */master = list_entry(master->lessee_list.next, struct drm_master, lessee_list);}- }
+}
<snip />
-- 2.15.0.rc0
dri-devel mailing list dri-devel@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/dri-devel