idpf: use reserved RDMA vectors from control plane

Fetch the number of reserved RDMA vectors from the control plane.
Adjust the number of reserved LAN vectors if necessary. Adjust the
minimum number of vectors the OS should reserve to include RDMA; and
fail if the OS cannot reserve enough vectors for the minimum number of
LAN and RDMA vectors required. Create a separate msix table for the
reserved RDMA vectors, which will just get handed off to the RDMA core
device to do with what it will.

Reviewed-by: Madhu Chittim <[email protected]>
Signed-off-by: Joshua Hay <[email protected]>
Signed-off-by: Tatyana Nikolova <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>

Author: jahay1

drivers/net/ethernet/intel/idpf/idpf.h

@@ -507,10 +507,11 @@ struct idpf_vc_xn_manager;
  * @flags: See enum idpf_flags
  * @reset_reg: See struct idpf_reset_reg
  * @hw: Device access data
- * @num_req_msix: Requested number of MSIX vectors
  * @num_avail_msix: Available number of MSIX vectors
  * @num_msix_entries: Number of entries in MSIX table
  * @msix_entries: MSIX table
+ * @num_rdma_msix_entries: Available number of MSIX vectors for RDMA
+ * @rdma_msix_entries: RDMA MSIX table
  * @req_vec_chunks: Requested vector chunk data
  * @mb_vector: Mailbox vector data
  * @vector_stack: Stack to store the msix vector indexes
@@ -561,10 +562,11 @@ struct idpf_adapter {
 	DECLARE_BITMAP(flags, IDPF_FLAGS_NBITS);
 	struct idpf_reset_reg reset_reg;
 	struct idpf_hw hw;
-	u16 num_req_msix;
 	u16 num_avail_msix;
 	u16 num_msix_entries;
 	struct msix_entry *msix_entries;
+	u16 num_rdma_msix_entries;
+	struct msix_entry *rdma_msix_entries;
 	struct virtchnl2_alloc_vectors *req_vec_chunks;
 	struct idpf_q_vector mb_vector;
 	struct idpf_vector_lifo vector_stack;
@@ -630,6 +632,17 @@ static inline int idpf_is_queue_model_split(u16 q_model)
 bool idpf_is_capability_ena(struct idpf_adapter *adapter, bool all,
 			    enum idpf_cap_field field, u64 flag);
 
+/**
+ * idpf_is_rdma_cap_ena - Determine if RDMA is supported
+ * @adapter: private data struct
+ *
+ * Return: true if RDMA capability is enabled, false otherwise
+ */
+static inline bool idpf_is_rdma_cap_ena(struct idpf_adapter *adapter)
+{
+	return idpf_is_cap_ena(adapter, IDPF_OTHER_CAPS, VIRTCHNL2_CAP_RDMA);
+}
+
 #define IDPF_CAP_RSS (\
 	VIRTCHNL2_CAP_RSS_IPV4_TCP	|\
 	VIRTCHNL2_CAP_RSS_IPV4_TCP	|\
@@ -682,6 +695,17 @@ static inline u16 idpf_get_reserved_vecs(struct idpf_adapter *adapter)
 	return le16_to_cpu(adapter->caps.num_allocated_vectors);
 }
 
+/**
+ * idpf_get_reserved_rdma_vecs - Get reserved RDMA vectors
+ * @adapter: private data struct
+ *
+ * Return: number of vectors reserved for RDMA
+ */
+static inline u16 idpf_get_reserved_rdma_vecs(struct idpf_adapter *adapter)
+{
+	return le16_to_cpu(adapter->caps.num_rdma_allocated_vectors);
+}
+
 /**
  * idpf_get_default_vports - Get default number of vports
  * @adapter: private data struct

drivers/net/ethernet/intel/idpf/idpf_lib.c

@@ -88,6 +88,8 @@ void idpf_intr_rel(struct idpf_adapter *adapter)
 	idpf_deinit_vector_stack(adapter);
 	kfree(adapter->msix_entries);
 	adapter->msix_entries = NULL;
+	kfree(adapter->rdma_msix_entries);
+	adapter->rdma_msix_entries = NULL;
 }
 
 /**
@@ -299,13 +301,33 @@ int idpf_req_rel_vector_indexes(struct idpf_adapter *adapter,
  */
 int idpf_intr_req(struct idpf_adapter *adapter)
 {
+	u16 num_lan_vecs, min_lan_vecs, num_rdma_vecs = 0, min_rdma_vecs = 0;
 	u16 default_vports = idpf_get_default_vports(adapter);
 	int num_q_vecs, total_vecs, num_vec_ids;
-	int min_vectors, v_actual, err;
+	int min_vectors, actual_vecs, err;
 	unsigned int vector;
 	u16 *vecids;
+	int i;
 
 	total_vecs = idpf_get_reserved_vecs(adapter);
+	num_lan_vecs = total_vecs;
+	if (idpf_is_rdma_cap_ena(adapter)) {
+		num_rdma_vecs = idpf_get_reserved_rdma_vecs(adapter);
+		min_rdma_vecs = IDPF_MIN_RDMA_VEC;
+
+		if (!num_rdma_vecs) {
+			/* If idpf_get_reserved_rdma_vecs is 0, vectors are
+			 * pulled from the LAN pool.
+			 */
+			num_rdma_vecs = min_rdma_vecs;
+		} else if (num_rdma_vecs < min_rdma_vecs) {
+			dev_err(&adapter->pdev->dev,
+				"Not enough vectors reserved for RDMA (min: %u, current: %u)\n",
+				min_rdma_vecs, num_rdma_vecs);
+			return -EINVAL;
+		}
+	}
+
 	num_q_vecs = total_vecs - IDPF_MBX_Q_VEC;
 
 	err = idpf_send_alloc_vectors_msg(adapter, num_q_vecs);
@@ -316,52 +338,76 @@ int idpf_intr_req(struct idpf_adapter *adapter)
 		return -EAGAIN;
 	}
 
-	min_vectors = IDPF_MBX_Q_VEC + IDPF_MIN_Q_VEC * default_vports;
-	v_actual = pci_alloc_irq_vectors(adapter->pdev, min_vectors,
-					 total_vecs, PCI_IRQ_MSIX);
-	if (v_actual < min_vectors) {
-		dev_err(&adapter->pdev->dev, "Failed to allocate MSIX vectors: %d\n",
-			v_actual);
-		err = -EAGAIN;
+	min_lan_vecs = IDPF_MBX_Q_VEC + IDPF_MIN_Q_VEC * default_vports;
+	min_vectors = min_lan_vecs + min_rdma_vecs;
+	actual_vecs = pci_alloc_irq_vectors(adapter->pdev, min_vectors,
+					    total_vecs, PCI_IRQ_MSIX);
+	if (actual_vecs < 0) {
+		dev_err(&adapter->pdev->dev, "Failed to allocate minimum MSIX vectors required: %d\n",
+			min_vectors);
+		err = actual_vecs;
 		goto send_dealloc_vecs;
 	}
 
-	adapter->msix_entries = kcalloc(v_actual, sizeof(struct msix_entry),
-					GFP_KERNEL);
+	if (idpf_is_rdma_cap_ena(adapter)) {
+		if (actual_vecs < total_vecs) {
+			dev_warn(&adapter->pdev->dev,
+				 "Warning: %d vectors requested, only %d available. Defaulting to minimum (%d) for RDMA and remaining for LAN.\n",
+				 total_vecs, actual_vecs, IDPF_MIN_RDMA_VEC);
+			num_rdma_vecs = IDPF_MIN_RDMA_VEC;
+		}
 
+		adapter->rdma_msix_entries = kcalloc(num_rdma_vecs,
+						     sizeof(struct msix_entry),
+						     GFP_KERNEL);
+		if (!adapter->rdma_msix_entries) {
+			err = -ENOMEM;
+			goto free_irq;
+		}
+	}
+
+	num_lan_vecs = actual_vecs - num_rdma_vecs;
+	adapter->msix_entries = kcalloc(num_lan_vecs, sizeof(struct msix_entry),
+					GFP_KERNEL);
 	if (!adapter->msix_entries) {
 		err = -ENOMEM;
-		goto free_irq;
+		goto free_rdma_msix;
 	}
 
 	adapter->mb_vector.v_idx = le16_to_cpu(adapter->caps.mailbox_vector_id);
 
-	vecids = kcalloc(total_vecs, sizeof(u16), GFP_KERNEL);
+	vecids = kcalloc(actual_vecs, sizeof(u16), GFP_KERNEL);
 	if (!vecids) {
 		err = -ENOMEM;
 		goto free_msix;
 	}
 
-	num_vec_ids = idpf_get_vec_ids(adapter, vecids, total_vecs,
+	num_vec_ids = idpf_get_vec_ids(adapter, vecids, actual_vecs,
 				       &adapter->req_vec_chunks->vchunks);
-	if (num_vec_ids < v_actual) {
+	if (num_vec_ids < actual_vecs) {
 		err = -EINVAL;
 		goto free_vecids;
 	}
 
-	for (vector = 0; vector < v_actual; vector++) {
+	for (vector = 0; vector < num_lan_vecs; vector++) {
 		adapter->msix_entries[vector].entry = vecids[vector];
 		adapter->msix_entries[vector].vector =
 			pci_irq_vector(adapter->pdev, vector);
 	}
+	for (i = 0; i < num_rdma_vecs; vector++, i++) {
+		adapter->rdma_msix_entries[i].entry = vecids[vector];
+		adapter->rdma_msix_entries[i].vector =
+			pci_irq_vector(adapter->pdev, vector);
+	}
 
-	adapter->num_req_msix = total_vecs;
-	adapter->num_msix_entries = v_actual;
 	/* 'num_avail_msix' is used to distribute excess vectors to the vports
 	 * after considering the minimum vectors required per each default
 	 * vport
 	 */
-	adapter->num_avail_msix = v_actual - min_vectors;
+	adapter->num_avail_msix = num_lan_vecs - min_lan_vecs;
+	adapter->num_msix_entries = num_lan_vecs;
+	if (idpf_is_rdma_cap_ena(adapter))
+		adapter->num_rdma_msix_entries = num_rdma_vecs;
 
 	/* Fill MSIX vector lifo stack with vector indexes */
 	err = idpf_init_vector_stack(adapter);
@@ -383,6 +429,9 @@ int idpf_intr_req(struct idpf_adapter *adapter)
 free_msix:
 	kfree(adapter->msix_entries);
 	adapter->msix_entries = NULL;
+free_rdma_msix:
+	kfree(adapter->rdma_msix_entries);
+	adapter->rdma_msix_entries = NULL;
 free_irq:
 	pci_free_irq_vectors(adapter->pdev);
 send_dealloc_vecs:

drivers/net/ethernet/intel/idpf/idpf_txrx.h

@@ -57,6 +57,7 @@
 /* Default vector sharing */
 #define IDPF_MBX_Q_VEC		1
 #define IDPF_MIN_Q_VEC		1
+#define IDPF_MIN_RDMA_VEC	2
 
 #define IDPF_DFLT_TX_Q_DESC_COUNT		512
 #define IDPF_DFLT_TX_COMPLQ_DESC_COUNT		512

drivers/net/ethernet/intel/idpf/virtchnl2.h

@@ -483,6 +483,8 @@ VIRTCHNL2_CHECK_STRUCT_LEN(8, virtchnl2_version_info);
  *			segment offload.
  * @max_hdr_buf_per_lso: Max number of header buffers that can be used for
  *			 an LSO.
+ * @num_rdma_allocated_vectors: Maximum number of allocated RDMA vectors for
+ *				the device.
  * @pad1: Padding for future extensions.
  *
  * Dataplane driver sends this message to CP to negotiate capabilities and
@@ -530,7 +532,8 @@ struct virtchnl2_get_capabilities {
 	__le32 device_type;
 	u8 min_sso_packet_len;
 	u8 max_hdr_buf_per_lso;
-	u8 pad1[10];
+	__le16 num_rdma_allocated_vectors;
+	u8 pad1[8];
 };
 VIRTCHNL2_CHECK_STRUCT_LEN(80, virtchnl2_get_capabilities);