iwlwifi: pcie: track rxb status

In MQ environment and new architecture in early stages
we may encounter DMA issues. Track RXB status and bail
out in case we receive index to an RXB that was not
mapped and handed over to HW.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

drivers/net/wireless/intel/iwlwifi/pcie/internal.h

@@ -68,12 +68,14 @@ struct iwl_host_cmd;
  * struct iwl_rx_mem_buffer
  * @page_dma: bus address of rxb page
  * @page: driver's pointer to the rxb page
+ * @invalid: rxb is in driver ownership - not owned by HW
  * @vid: index of this rxb in the global table
  */
 struct iwl_rx_mem_buffer {
 	dma_addr_t page_dma;
 	struct page *page;
 	u16 vid;
+	bool invalid;
 	struct list_head list;
 };
 

drivers/net/wireless/intel/iwlwifi/pcie/rx.c

@@ -266,7 +266,7 @@ static void iwl_pcie_rxmq_restock(struct iwl_trans *trans,
 		rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
 				       list);
 		list_del(&rxb->list);
-
+		rxb->invalid = false;
 		/* 12 first bits are expected to be empty */
 		WARN_ON(rxb->page_dma & DMA_BIT_MASK(12));
 		/* Point to Rx buffer via next RBD in circular buffer */
@@ -317,6 +317,7 @@ static void iwl_pcie_rxsq_restock(struct iwl_trans *trans,
 		rxb = list_first_entry(&rxq->rx_free, struct iwl_rx_mem_buffer,
 				       list);
 		list_del(&rxb->list);
+		rxb->invalid = false;
 
 		/* Point to Rx buffer via next RBD in circular buffer */
 		bd[rxq->write] = iwl_pcie_dma_addr2rbd_ptr(rxb->page_dma);
@@ -961,6 +962,7 @@ int iwl_pcie_rx_init(struct iwl_trans *trans)
 			list_add(&rxb->list, &def_rxq->rx_used);
 		trans_pcie->global_table[i] = rxb;
 		rxb->vid = (u16)(i + 1);
+		rxb->invalid = true;
 	}
 
 	iwl_pcie_rxq_alloc_rbs(trans, GFP_KERNEL, def_rxq);
@@ -1256,6 +1258,12 @@ static void iwl_pcie_rx_handle(struct iwl_trans *trans, int queue)
 				goto out;
 			}
 			rxb = trans_pcie->global_table[vid - 1];
+			if (WARN(rxb->invalid,
+				 "Invalid rxb from HW %u\n", (u32)vid)) {
+				iwl_force_nmi(trans);
+				goto out;
+			}
+			rxb->invalid = true;
 		} else {
 			rxb = rxq->queue[i];
 			rxq->queue[i] = NULL;