[PATCH v1 10/18] ibmveth: Add queue-aware RX buffer submit helper for MQ

[Mingming Cao <mmc@linux.ibm.com>]

Replenish is the last open-path hypervisor call that still needs
per-queue awareness before MQ receive is enabled. Today
ibmveth_replenish_buffer_pool() calls h_add_logical_lan_buffer() or
h_add_logical_lan_buffers() directly; MQ posts via
H_ADD_LOGICAL_LAN_BUFFERS_QUEUE against adapter->queue_handle[].

Add ibmveth_add_logical_lan_buffers() to pick the hcall:
multi_queue uses h_add_logical_lan_buffers_queue() (up to 12 buffers,
IOBAs packed with odd counts in the upper 32 bits); legacy uses the
existing single- and multi-buffer hcalls. Count add_buf/add_bufs/
add_bufs_queue in hcall_stats.

Thread queue_index through replenish_task() and replenish_buffer_pool()
so they index rx_buff_pool[queue_index][pool]. All callers still pass
queue 0; legacy hcalls remain the live path until MQ probe enables
multi_queue.

Also split H_FUNCTION handling: legacy batch falls back to single-buffer
mode; multi_queue logs an error on unsupported firmware.

Signed-off-by: Mingming Cao <mmc@linux.ibm.com>
Reviewed-by: Dave Marquardt <davemarq@linux.ibm.com>
---
 drivers/net/ethernet/ibm/ibmveth.c | 134 ++++++++++++++++++++---------
 1 file changed, 94 insertions(+), 40 deletions(-)

diff --git a/drivers/net/ethernet/ibm/ibmveth.c b/drivers/net/ethernet/ibm/ibmveth.c
index fa2d4777ffc7..b3b3886c3eed 100644
--- a/drivers/net/ethernet/ibm/ibmveth.c
+++ b/drivers/net/ethernet/ibm/ibmveth.c
@@ -597,11 +597,73 @@ static inline void ibmveth_flush_buffer(void *addr, unsigned long length)
 		asm("dcbf %0,%1,1" :: "b" (addr), "r" (offset));
 }
 
+/**
+ * ibmveth_add_logical_lan_buffers - Add receive buffers to hypervisor
+ * @adapter: ibmveth adapter structure
+ * @descs: array of buffer descriptors to add
+ * @filled: number of valid descriptors in the array
+ * @buff_size: size of each buffer (multi-queue mode only)
+ * @queue_index: RX queue index
+ *
+ * Return: hypervisor return code
+ */
+static long ibmveth_add_logical_lan_buffers(struct ibmveth_adapter *adapter,
+					    union ibmveth_buf_desc *descs,
+					    int filled,
+					    unsigned long buff_size,
+					    int queue_index)
+{
+	struct vio_dev *vdev = adapter->vdev;
+	unsigned long rc;
+
+	if (adapter->multi_queue) {
+		unsigned long buffersznum = (buff_size << 32) | filled;
+		unsigned long ioba[IBMVETH_MAX_RX_PER_HCALL / 2] = {0};
+		int i;
+
+		/* Pack descriptor addresses into ioba pairs.
+		 * Each ioba holds two 32-bit addresses packed into 64 bits:
+		 * - Even descriptors (0,2,4...) go in high 32 bits
+		 * - Odd descriptors (1,3,5...) go in low 32 bits
+		 */
+		for (i = 0; i < filled && i < IBMVETH_MAX_RX_PER_HCALL; i++) {
+			int pair_idx = i / 2;           /* Which pair: 0-5 */
+			int is_high = (i % 2 == 0);     /* High or low 32 bits */
+
+			if (is_high)
+				ioba[pair_idx] = (unsigned long)descs[i].fields.address << 32;
+			else
+				ioba[pair_idx] |= descs[i].fields.address;
+		}
+
+		rc = h_add_logical_lan_buffers_queue(vdev->unit_address,
+						     adapter->queue_handle[queue_index],
+						     buffersznum,
+						     ioba[0], ioba[1], ioba[2],
+						     ioba[3], ioba[4], ioba[5]);
+		adapter->hcall_stats.add_bufs_queue++;
+	} else if (filled == 1) {
+		rc = h_add_logical_lan_buffer(vdev->unit_address,
+					      descs[0].desc);
+		adapter->hcall_stats.add_buf++;
+	} else {
+		rc = h_add_logical_lan_buffers(vdev->unit_address,
+					       descs[0].desc, descs[1].desc,
+					       descs[2].desc, descs[3].desc,
+					       descs[4].desc, descs[5].desc,
+					       descs[6].desc, descs[7].desc);
+		adapter->hcall_stats.add_bufs++;
+	}
+
+	return rc;
+}
+
 /* replenish the buffers for a pool.  note that we don't need to
  * skb_reserve these since they are used for incoming...
  */
 static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
-					  struct ibmveth_buff_pool *pool)
+					  struct ibmveth_buff_pool *pool,
+					  int queue_index)
 {
 	union ibmveth_buf_desc descs[IBMVETH_MAX_RX_PER_HCALL] = {0};
 	u32 remaining = pool->size - atomic_read(&pool->available);
@@ -687,24 +749,15 @@ static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
 		if (!filled)
 			break;
 
-		/* single buffer case*/
-		if (filled == 1)
-			lpar_rc = h_add_logical_lan_buffer(vdev->unit_address,
-							   descs[0].desc);
-		else
-			/* Multi-buffer hcall */
-			lpar_rc = h_add_logical_lan_buffers(vdev->unit_address,
-							    descs[0].desc,
-							    descs[1].desc,
-							    descs[2].desc,
-							    descs[3].desc,
-							    descs[4].desc,
-							    descs[5].desc,
-							    descs[6].desc,
-							    descs[7].desc);
+		lpar_rc = ibmveth_add_logical_lan_buffers(adapter, descs,
+							  filled,
+							  pool->buff_size,
+							  queue_index);
+
 		if (lpar_rc != H_SUCCESS) {
 			dev_warn_ratelimited(dev,
-					     "RX h_add_logical_lan failed: filled=%u, rc=%lu, batch=%u\n",
+					     "RX h_add_logical_lan %s failed: filled=%u, rc=%lu, batch=%u\n",
+					     adapter->multi_queue ? "_queue" : "",
 					     filled, lpar_rc, batch);
 			goto hcall_failure;
 		}
@@ -745,24 +798,19 @@ static void ibmveth_replenish_buffer_pool(struct ibmveth_adapter *adapter,
 		}
 		adapter->replenish_add_buff_failure += filled;
 
-		/*
-		 * If multi rx buffers hcall is no longer supported by FW
-		 * e.g. in the case of Live Partition Migration
-		 */
-		if (batch > 1 && lpar_rc == H_FUNCTION) {
-			/*
-			 * Instead of retry submit single buffer individually
-			 * here just set the max rx buffer per hcall to 1
-			 * buffers will be respleshed next time
-			 * when ibmveth_replenish_buffer_pool() is called again
-			 * with single-buffer case
-			 */
-			netdev_info(adapter->netdev,
-				    "RX Multi buffers not supported by FW, rc=%lu\n",
-				    lpar_rc);
-			adapter->rx_buffers_per_hcall = 1;
-			netdev_info(adapter->netdev,
-				    "Next rx replesh will fall back to single-buffer hcall\n");
+		if (lpar_rc == H_FUNCTION) {
+			if (adapter->multi_queue) {
+				netdev_err(adapter->netdev,
+					   "Unexpected H_FUNCTION from multi-queue buffer add (queue=%d, batch=%d)\n",
+					   queue_index, batch);
+				break;
+			} else if (batch > 1) {
+				netdev_warn(adapter->netdev,
+					    "H_FUNCTION from legacy batch buffer add (batch=%d), falling back to single buffer mode\n",
+					    batch);
+				adapter->rx_buffers_per_hcall = 1;
+				continue;
+			}
 		}
 		break;
 	}
@@ -784,18 +832,24 @@ static void ibmveth_update_rx_no_buffer(struct ibmveth_adapter *adapter)
 }
 
 /* replenish routine */
-static void ibmveth_replenish_task(struct ibmveth_adapter *adapter)
+static void ibmveth_replenish_task(struct ibmveth_adapter *adapter,
+				   int queue_index)
 {
 	int i;
 
+	if (queue_index >= adapter->num_rx_queues)
+		return;
+
 	adapter->replenish_task_cycles++;
 
 	for (i = (IBMVETH_NUM_BUFF_POOLS - 1); i >= 0; i--) {
-		struct ibmveth_buff_pool *pool = &adapter->rx_buff_pool[0][i];
+		struct ibmveth_buff_pool *pool =
+			&adapter->rx_buff_pool[queue_index][i];
 
 		if (pool->active &&
 		    (atomic_read(&pool->available) < pool->threshold))
-			ibmveth_replenish_buffer_pool(adapter, pool);
+			ibmveth_replenish_buffer_pool(adapter, pool,
+						      queue_index);
 	}
 
 	ibmveth_update_rx_no_buffer(adapter);
@@ -2307,7 +2361,7 @@ static int ibmveth_poll(struct napi_struct *napi, int budget)
 		}
 	}
 
-	ibmveth_replenish_task(adapter);
+	ibmveth_replenish_task(adapter, 0);
 
 	if (frames_processed == budget)
 		goto out;
@@ -2458,7 +2512,7 @@ static void ibmveth_poll_controller(struct net_device *dev)
 {
 	struct ibmveth_adapter *adapter = netdev_priv(dev);
 
-	ibmveth_replenish_task(adapter);
+	ibmveth_replenish_task(adapter, 0);
 	ibmveth_interrupt(dev->irq, &adapter->napi[0]);
 }
 #endif
-- 
2.39.3 (Apple Git-146)