Merge tag 'topic/amdgpu-dp2.0-mst-2021-10-27' of git://anongit.freedesktop.org/drm/drm-misc into drm-next

UAPI Changes:
Nope!

Cross-subsystem Changes:
drm_dp_update_payload_part1() takes a new argument for specifying what the
VCPI slot start is

Core Changes:
Make the DP MST helpers aware of the current starting VCPI slot/VCPI total
slot count...

Driver Changes:
...and then add support for taking advantage of this for 128b/132b links on DP
2.0 for amdgpu

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/bf8e724cc0c8803d58a8d730fd6883c991376a76.camel@redhat.com

1 files changed, 33 insertions, 9 deletions

diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c
index 86d13d6bc463..571da0c2f39f 100644
--- a/drivers/gpu/drm/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/drm_dp_mst_topology.c
@@ -3355,6 +3355,10 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
 /**
  * drm_dp_update_payload_part1() - Execute payload update part 1
  * @mgr: manager to use.
+ * @start_slot: this is the cur slot
+ *
+ * NOTE: start_slot is a temporary workaround for non-atomic drivers,
+ * this will be removed when non-atomic mst helpers are moved out of the helper
  *
  * This iterates over all proposed virtual channels, and tries to
  * allocate space in the link for them. For 0->slots transitions,
@@ -3365,12 +3369,12 @@ static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
  * after calling this the driver should generate ACT and payload
  * packets.
  */
-int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
+int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr, int start_slot)
 {
 	struct drm_dp_payload req_payload;
 	struct drm_dp_mst_port *port;
 	int i, j;
-	int cur_slots = 1;
+	int cur_slots = start_slot;
 	bool skip;
 
 	mutex_lock(&mgr->payload_lock);
@@ -4334,10 +4338,6 @@ static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
 {
 	int ret;
 
-	/* max. time slots - one slot for MTP header */
-	if (slots > 63)
-		return -ENOSPC;
-
 	vcpi->pbn = pbn;
 	vcpi->aligned_pbn = slots * mgr->pbn_div;
 	vcpi->num_slots = slots;
@@ -4510,6 +4510,27 @@ int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
 
 /**
+ * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
+ * @mst_state: mst_state to update
+ * @link_encoding_cap: the ecoding format on the link
+ */
+void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
+{
+	if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
+		mst_state->total_avail_slots = 64;
+		mst_state->start_slot = 0;
+	} else {
+		mst_state->total_avail_slots = 63;
+		mst_state->start_slot = 1;
+	}
+
+	DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
+		      (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
+		      mst_state);
+}
+EXPORT_SYMBOL(drm_dp_mst_update_slots);
+
+/**
  * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
  * @mgr: manager for this port
  * @port: port to allocate a virtual channel for.
@@ -4540,7 +4561,7 @@ bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
 
 	ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
 	if (ret) {
-		drm_dbg_kms(mgr->dev, "failed to init vcpi slots=%d max=63 ret=%d\n",
+		drm_dbg_kms(mgr->dev, "failed to init vcpi slots=%d ret=%d\n",
 			    DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
 		drm_dp_mst_topology_put_port(port);
 		goto out;
@@ -5228,7 +5249,7 @@ drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
 					 struct drm_dp_mst_topology_state *mst_state)
 {
 	struct drm_dp_vcpi_allocation *vcpi;
-	int avail_slots = 63, payload_count = 0;
+	int avail_slots = mst_state->total_avail_slots, payload_count = 0;
 
 	list_for_each_entry(vcpi, &mst_state->vcpis, next) {
 		/* Releasing VCPI is always OK-even if the port is gone */
@@ -5257,7 +5278,7 @@ drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
 		}
 	}
 	drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
-		       mgr, mst_state, avail_slots, 63 - avail_slots);
+		       mgr, mst_state, avail_slots, mst_state->total_avail_slots - avail_slots);
 
 	return 0;
 }
@@ -5534,6 +5555,9 @@ int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
 	if (mst_state == NULL)
 		return -ENOMEM;
 
+	mst_state->total_avail_slots = 63;
+	mst_state->start_slot = 1;
+
 	mst_state->mgr = mgr;
 	INIT_LIST_HEAD(&mst_state->vcpis);