drm_dp_atomic_find_vcpi_slots() should be called from ->atomic_check() to check there are sufficient vcpi slots for a mode and to add that to the state. This should be followed by a call to drm_dp_mst_allocate_vcpi() in ->atomic_commit() to initialize a struct vcpi for the port.
drm_dp_atomic_release_vcpi_slots() should be called from ->atomic_check() to release a port's vcpi slot allocation from the state.
Drivers that do not make use of this atomic helper are expected to call drm_dp_find_vcpi_slots() instead before calling drm_dp_mst_allocate_vcpi().
v2: Added checks for verifying the port reference is valid Moved get_mst_topology_state() into the helpers (Daniel) Changed find_vcpi_slots() to not depend on current allocation
Signed-off-by: Dhinakaran Pandiyan dhinakaran.pandiyan@intel.com --- drivers/gpu/drm/drm_dp_mst_topology.c | 75 +++++++++++++++++++++++++++++++++++ include/drm/drm_dp_mst_helper.h | 6 +++ 2 files changed, 81 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index a891c36..93de257 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -2498,6 +2498,81 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr, }
/** + * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state + * @state: global atomic state + * @mgr: MST topology manager for the port + * @port: port to find vcpi slots for + * @pbn: bandwidth required for the mode in PBN + * + * RETURNS: + * Total slots in the atomic state assigned for this port or error + */ +int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, int pbn) +{ + struct drm_dp_mst_topology_state *topology_state; + int req_slots; + + topology_state = drm_atomic_get_mst_topology_state(state, mgr); + if (topology_state == NULL) + return -ENOMEM; + + port = drm_dp_get_validated_port_ref(mgr, port); + if (port == NULL) + return -EINVAL; + req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div); + DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n", + req_slots, topology_state->avail_slots); + + if (req_slots > topology_state->avail_slots) { + drm_dp_put_port(port); + return -ENOSPC; + } + + topology_state->avail_slots -= req_slots; + DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots); + + drm_dp_put_port(port); + return req_slots; +} +EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots); + +/** + * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots + * @state: global atomic state + * @mgr: MST topology manager for the port + * @port: port to release the vcpi slots for + * + * RETURNS: + * Number of slots released from the atomic state for this port + */ +int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port) +{ + struct drm_dp_mst_topology_state *topology_state; + int curr_slots; + + topology_state = drm_atomic_get_mst_topology_state(state, mgr); + if (topology_state == NULL) + return -ENOMEM; + + port = drm_dp_get_validated_port_ref(mgr, port); + if (port == NULL) + return -EINVAL; + + curr_slots = port->vcpi.num_slots; + topology_state->avail_slots += curr_slots; + DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n", + curr_slots, topology_state->avail_slots); + + drm_dp_put_port(port); + return curr_slots; +} +EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots); + +/** * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel * @mgr: manager for this port * @port: port to allocate a virtual channel for. diff --git a/include/drm/drm_dp_mst_helper.h b/include/drm/drm_dp_mst_helper.h index 0b371df..64e7dac 100644 --- a/include/drm/drm_dp_mst_helper.h +++ b/include/drm/drm_dp_mst_helper.h @@ -615,5 +615,11 @@ void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr); int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr); struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr); +int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port, int pbn); +int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state, + struct drm_dp_mst_topology_mgr *mgr, + struct drm_dp_mst_port *port);
#endif