Add a function drivers can use to verify the MST payload state tracking
and compare this to the sink's payload table.
Cc: Lyude Paul <lyude@xxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
---
drivers/gpu/drm/display/drm_dp_mst_topology.c | 169 ++++++++++++++++++
include/drm/display/drm_dp.h | 3 +
include/drm/display/drm_dp_mst_helper.h | 3 +
3 files changed, 175 insertions(+)
diff --git a/drivers/gpu/drm/display/drm_dp_mst_topology.c b/drivers/gpu/drm/display/drm_dp_mst_topology.c
index 619f616d69e20..7597d27db4fa6 100644
--- a/drivers/gpu/drm/display/drm_dp_mst_topology.c
+++ b/drivers/gpu/drm/display/drm_dp_mst_topology.c
@@ -4834,6 +4834,175 @@ void drm_dp_mst_dump_topology(struct seq_file *m,
}
EXPORT_SYMBOL(drm_dp_mst_dump_topology);
+static bool verify_mst_payload_state(struct drm_dp_mst_topology_state *mst_state)
+{
+ struct drm_dp_mst_topology_mgr *mgr = mst_state->mgr;
+ struct drm_dp_mst_atomic_payload *payload;
+ int payload_count = 0;
+ u64 time_slot_mask = 0;
+ u32 vcpi_mask = 0;
+ int last_set;
+
+ if (BITS_PER_TYPE(time_slot_mask) < mst_state->total_avail_slots)
+ return false;
+
+ list_for_each_entry(payload, &mst_state->payloads, next) {
+ u64 mask;
+
+ if (payload->vc_start_slot == -1)
+ continue;
+
+ if (!payload->time_slots)
+ return false;
+
+ if (payload->vc_start_slot < mst_state->start_slot)
+ return false;
+
+ if (payload->vc_start_slot + payload->time_slots - mst_state->start_slot >
+ mst_state->total_avail_slots)
+ return false;
+
+ mask = GENMASK_ULL(payload->vc_start_slot + payload->time_slots - 1,
+ payload->vc_start_slot);
+
+ if (time_slot_mask & mask)
+ return false;
+
+ time_slot_mask |= mask;
+
+ if (payload->vcpi < 1 ||
+ payload->vcpi & ~DP_PAYLOAD_ID_MASK ||
+ payload->vcpi > BITS_PER_TYPE(vcpi_mask))
+ return false;
+ if (BIT(payload->vcpi - 1) & vcpi_mask)
+ return false;
+ vcpi_mask |= BIT(payload->vcpi - 1);
+
+ payload_count++;
+ }
+
+ if (payload_count != mgr->payload_count)
+ return false;
+
+ last_set = fls64(time_slot_mask);
+
+ if (last_set &&
+ GENMASK_ULL(last_set - 1, mst_state->start_slot) != time_slot_mask)
+ return false;
+
+ if (max(mst_state->start_slot, mgr->next_start_slot) !=
+ max_t(int, mst_state->start_slot, last_set))
+ return false;
+
+ return true;
+}
+
+static int get_payload_table_vcpi(const u8 *table, int slot)
+{
+ if (slot == 0)
+ return FIELD_GET(DP_PAYLOAD_ID_SLOT0_5_0_MASK, table[0]) |
+ (FIELD_GET(DP_PAYLOAD_ID_SLOT0_6, table[1]) << 6);
+ else
+ return FIELD_GET(DP_PAYLOAD_ID_MASK, table[slot]);
+}
+
+static bool verify_mst_payload_table(struct drm_dp_mst_topology_state *mst_state,
+ const u8 *payload_table)
+{
+ struct drm_dp_mst_topology_mgr *mgr = mst_state->mgr;
+ struct drm_dp_mst_atomic_payload *payload;
+ int i;
+
+ list_for_each_entry(payload, &mst_state->payloads, next) {
+ if (payload->vc_start_slot == -1)
+ continue;
+
+ if (payload->vc_start_slot + payload->time_slots > DP_PAYLOAD_TABLE_SIZE)
+ return false;
+
+ for (i = 0; i < payload->time_slots; i++)
+ if (get_payload_table_vcpi(payload_table,
+ payload->vc_start_slot + i) != payload->vcpi)
+ return false;
+ }
+
+ for (i = max(mgr->next_start_slot, mst_state->start_slot);
+ i < DP_PAYLOAD_TABLE_SIZE;
+ i++) {
+ if (get_payload_table_vcpi(payload_table, i) != 0)
+ return false;
+ }
+
+ return true;
+}
+
+static void print_mst_payload_state(struct drm_dp_mst_topology_mgr *mgr,
+ struct drm_dp_mst_topology_state *mst_state,
+ const u8 *payload_table)
+{
+ struct drm_dp_mst_atomic_payload *payload;
+ int i = 0;
+
+ drm_dbg(mgr->dev,
+ "Payload state: start_slot %d total_avail_slots %d next_start_slot %d payload_count %d\n",
+ mst_state->start_slot, mst_state->total_avail_slots,
+ mgr->next_start_slot, mgr->payload_count);
+
+ list_for_each_entry(payload, &mst_state->payloads, next) {
+ drm_dbg(mgr->dev,
+ " Payload#%d: port %p VCPI %d delete %d vc_start_slot %d time_slots %d\n",
+ i, payload->port, payload->vcpi,
+ payload->delete, payload->vc_start_slot, payload->time_slots);
+ i++;
+ }
+
+ if (!payload_table)
+ return;
+
+ drm_dbg(mgr->dev, "Payload table:\n");
+ print_hex_dump(KERN_DEBUG, " Ptbl ",
+ DUMP_PREFIX_OFFSET, 16, 1,
+ payload_table, DP_PAYLOAD_TABLE_SIZE, false);
+}
+
+/**
+ * drm_dp_mst_verify_payload_state - Verify the atomic state for payloads and the related sink payload table
+ * @state: atomic state
+ * @mgr: manager to verify the state for
+ * @verify_sink: %true if the sink payload table needs to be verified as well
+ *
+ * Verify @mgr's atomic state tracking all its payloads and optionally the
+ * related sink payload table.
+ */
+void drm_dp_mst_verify_payload_state(struct drm_atomic_state *state,
+ struct drm_dp_mst_topology_mgr *mgr,
+ bool verify_sink)
+{
+ struct drm_dp_mst_topology_state *mst_state;
+ u8 payload_table[DP_PAYLOAD_TABLE_SIZE];
+
+ mst_state = drm_atomic_get_new_mst_topology_state(state, mgr);
+ if (drm_WARN_ON(mgr->dev, !mst_state))
+ return;
+
+ if (drm_WARN_ON(mgr->dev, !verify_mst_payload_state(mst_state))) {
+ print_mst_payload_state(mgr, mst_state, NULL);
+ return;
+ }
+
+ if (!verify_sink)
+ return;
+
+ if (!dump_dp_payload_table(mgr, payload_table))
+ return;
+
+ if (!verify_mst_payload_table(mst_state, payload_table)) {
+ drm_err(mgr->dev, "MST payload state mismatches payload table\n");
+ print_mst_payload_state(mgr, mst_state, payload_table);
+ }
+}
+EXPORT_SYMBOL(drm_dp_mst_verify_payload_state);
+
static void drm_dp_tx_work(struct work_struct *work)
{
struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
diff --git a/include/drm/display/drm_dp.h b/include/drm/display/drm_dp.h
index 632376c291db6..bcc5183188a68 100644
--- a/include/drm/display/drm_dp.h
+++ b/include/drm/display/drm_dp.h
@@ -925,9 +925,12 @@
#define DP_PAYLOAD_TABLE_UPDATE_STATUS 0x2c0 /* 1.2 MST */
# define DP_PAYLOAD_TABLE_UPDATED (1 << 0)
# define DP_PAYLOAD_ACT_HANDLED (1 << 1)
+# define DP_PAYLOAD_ID_SLOT0_5_0_MASK (0x3f << 2)
#define DP_VC_PAYLOAD_ID_SLOT_1 0x2c1 /* 1.2 MST */
/* up to ID_SLOT_63 at 0x2ff */
+# define DP_PAYLOAD_ID_SLOT0_6 (1 << 7)
+# define DP_PAYLOAD_ID_MASK 0x7f
/* Source Device-specific */
#define DP_SOURCE_OUI 0x300
diff --git a/include/drm/display/drm_dp_mst_helper.h b/include/drm/display/drm_dp_mst_helper.h
index 32c764fb9cb56..44c6710ebf315 100644
--- a/include/drm/display/drm_dp_mst_helper.h
+++ b/include/drm/display/drm_dp_mst_helper.h
@@ -848,6 +848,9 @@ int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr);
void drm_dp_mst_dump_topology(struct seq_file *m,
struct drm_dp_mst_topology_mgr *mgr);
+void drm_dp_mst_verify_payload_state(struct drm_atomic_state *state,
+ struct drm_dp_mst_topology_mgr *mgr,
+ bool verify_sink);
void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr);
int __must_check
--
2.37.1
