Merge branch 'ena-fixes'

Netanel Belgazal says:

====================
bug fixes for ENA Ethernet driver
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/amazon/ena/ena_com.c

@@ -459,12 +459,12 @@ static void ena_com_handle_admin_completion(struct ena_com_admin_queue *admin_qu
 	cqe = &admin_queue->cq.entries[head_masked];
 
 	/* Go over all the completions */
-	while ((cqe->acq_common_descriptor.flags &
+	while ((READ_ONCE(cqe->acq_common_descriptor.flags) &
 			ENA_ADMIN_ACQ_COMMON_DESC_PHASE_MASK) == phase) {
 		/* Do not read the rest of the completion entry before the
 		 * phase bit was validated
 		 */
-		rmb();
+		dma_rmb();
 		ena_com_handle_single_admin_completion(admin_queue, cqe);
 
 		head_masked++;
@@ -627,17 +627,10 @@ static u32 ena_com_reg_bar_read32(struct ena_com_dev *ena_dev, u16 offset)
 	mmio_read_reg |= mmio_read->seq_num &
 			ENA_REGS_MMIO_REG_READ_REQ_ID_MASK;
 
-	/* make sure read_resp->req_id get updated before the hw can write
-	 * there
-	 */
-	wmb();
-
-	writel_relaxed(mmio_read_reg,
-		       ena_dev->reg_bar + ENA_REGS_MMIO_REG_READ_OFF);
+	writel(mmio_read_reg, ena_dev->reg_bar + ENA_REGS_MMIO_REG_READ_OFF);
 
-	mmiowb();
 	for (i = 0; i < timeout; i++) {
-		if (read_resp->req_id == mmio_read->seq_num)
+		if (READ_ONCE(read_resp->req_id) == mmio_read->seq_num)
 			break;
 
 		udelay(1);
@@ -1796,8 +1789,13 @@ void ena_com_aenq_intr_handler(struct ena_com_dev *dev, void *data)
 	aenq_common = &aenq_e->aenq_common_desc;
 
 	/* Go over all the events */
-	while ((aenq_common->flags & ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) ==
-	       phase) {
+	while ((READ_ONCE(aenq_common->flags) &
+		ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK) == phase) {
+		/* Make sure the phase bit (ownership) is as expected before
+		 * reading the rest of the descriptor.
+		 */
+		dma_rmb();
+
 		pr_debug("AENQ! Group[%x] Syndrom[%x] timestamp: [%llus]\n",
 			 aenq_common->group, aenq_common->syndrom,
 			 (u64)aenq_common->timestamp_low +

drivers/net/ethernet/amazon/ena/ena_eth_com.c

@@ -51,6 +51,11 @@ static inline struct ena_eth_io_rx_cdesc_base *ena_com_get_next_rx_cdesc(
 	if (desc_phase != expected_phase)
 		return NULL;
 
+	/* Make sure we read the rest of the descriptor after the phase bit
+	 * has been read
+	 */
+	dma_rmb();
+
 	return cdesc;
 }
 
@@ -493,6 +498,7 @@ int ena_com_tx_comp_req_id_get(struct ena_com_io_cq *io_cq, u16 *req_id)
 	if (cdesc_phase != expected_phase)
 		return -EAGAIN;
 
+	dma_rmb();
 	if (unlikely(cdesc->req_id >= io_cq->q_depth)) {
 		pr_err("Invalid req id %d\n", cdesc->req_id);
 		return -EINVAL;

drivers/net/ethernet/amazon/ena/ena_eth_com.h

@@ -107,8 +107,7 @@ static inline int ena_com_sq_empty_space(struct ena_com_io_sq *io_sq)
 	return io_sq->q_depth - 1 - cnt;
 }
 
-static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq,
-					    bool relaxed)
+static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq)
 {
 	u16 tail;
 
@@ -117,9 +116,6 @@ static inline int ena_com_write_sq_doorbell(struct ena_com_io_sq *io_sq,
 	pr_debug("write submission queue doorbell for queue: %d tail: %d\n",
 		 io_sq->qid, tail);
 
-	if (relaxed)
-		writel_relaxed(tail, io_sq->db_addr);
-	else
 	writel(tail, io_sq->db_addr);
 
 	return 0;

drivers/net/ethernet/amazon/ena/ena_netdev.c

@@ -76,7 +76,7 @@ MODULE_DEVICE_TABLE(pci, ena_pci_tbl);
 
 static int ena_rss_init_default(struct ena_adapter *adapter);
 static void check_for_admin_com_state(struct ena_adapter *adapter);
-static void ena_destroy_device(struct ena_adapter *adapter);
+static void ena_destroy_device(struct ena_adapter *adapter, bool graceful);
 static int ena_restore_device(struct ena_adapter *adapter);
 
 static void ena_tx_timeout(struct net_device *dev)
@@ -461,7 +461,7 @@ static inline int ena_alloc_rx_page(struct ena_ring *rx_ring,
 		return -ENOMEM;
 	}
 
-	dma = dma_map_page(rx_ring->dev, page, 0, PAGE_SIZE,
+	dma = dma_map_page(rx_ring->dev, page, 0, ENA_PAGE_SIZE,
 			   DMA_FROM_DEVICE);
 	if (unlikely(dma_mapping_error(rx_ring->dev, dma))) {
 		u64_stats_update_begin(&rx_ring->syncp);
@@ -478,7 +478,7 @@ static inline int ena_alloc_rx_page(struct ena_ring *rx_ring,
 	rx_info->page_offset = 0;
 	ena_buf = &rx_info->ena_buf;
 	ena_buf->paddr = dma;
-	ena_buf->len = PAGE_SIZE;
+	ena_buf->len = ENA_PAGE_SIZE;
 
 	return 0;
 }
@@ -495,7 +495,7 @@ static void ena_free_rx_page(struct ena_ring *rx_ring,
 		return;
 	}
 
-	dma_unmap_page(rx_ring->dev, ena_buf->paddr, PAGE_SIZE,
+	dma_unmap_page(rx_ring->dev, ena_buf->paddr, ENA_PAGE_SIZE,
 		       DMA_FROM_DEVICE);
 
 	__free_page(page);
@@ -551,14 +551,9 @@ static int ena_refill_rx_bufs(struct ena_ring *rx_ring, u32 num)
 			    rx_ring->qid, i, num);
 	}
 
-	if (likely(i)) {
-		/* Add memory barrier to make sure the desc were written before
-		 * issue a doorbell
-		 */
-		wmb();
-		ena_com_write_sq_doorbell(rx_ring->ena_com_io_sq, true);
-		mmiowb();
-	}
+	/* ena_com_write_sq_doorbell issues a wmb() */
+	if (likely(i))
+		ena_com_write_sq_doorbell(rx_ring->ena_com_io_sq);
 
 	rx_ring->next_to_use = next_to_use;
 
@@ -916,10 +911,10 @@ static struct sk_buff *ena_rx_skb(struct ena_ring *rx_ring,
 	do {
 		dma_unmap_page(rx_ring->dev,
 			       dma_unmap_addr(&rx_info->ena_buf, paddr),
-			       PAGE_SIZE, DMA_FROM_DEVICE);
+			       ENA_PAGE_SIZE, DMA_FROM_DEVICE);
 
 		skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, rx_info->page,
-				rx_info->page_offset, len, PAGE_SIZE);
+				rx_info->page_offset, len, ENA_PAGE_SIZE);
 
 		netif_dbg(rx_ring->adapter, rx_status, rx_ring->netdev,
 			  "rx skb updated. len %d. data_len %d\n",
@@ -1900,7 +1895,7 @@ static int ena_close(struct net_device *netdev)
 			  "Destroy failure, restarting device\n");
 		ena_dump_stats_to_dmesg(adapter);
 		/* rtnl lock already obtained in dev_ioctl() layer */
-		ena_destroy_device(adapter);
+		ena_destroy_device(adapter, false);
 		ena_restore_device(adapter);
 	}
 
@@ -2112,12 +2107,6 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	tx_ring->next_to_use = ENA_TX_RING_IDX_NEXT(next_to_use,
 		tx_ring->ring_size);
 
-	/* This WMB is aimed to:
-	 * 1 - perform smp barrier before reading next_to_completion
-	 * 2 - make sure the desc were written before trigger DB
-	 */
-	wmb();
-
 	/* stop the queue when no more space available, the packet can have up
 	 * to sgl_size + 2. one for the meta descriptor and one for header
 	 * (if the header is larger than tx_max_header_size).
@@ -2136,10 +2125,11 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
 		 * stop the queue but meanwhile clean_tx_irq updates
 		 * next_to_completion and terminates.
 		 * The queue will remain stopped forever.
-		 * To solve this issue this function perform rmb, check
-		 * the wakeup condition and wake up the queue if needed.
+		 * To solve this issue add a mb() to make sure that
+		 * netif_tx_stop_queue() write is vissible before checking if
+		 * there is additional space in the queue.
 		 */
-		smp_rmb();
+		smp_mb();
 
 		if (ena_com_sq_empty_space(tx_ring->ena_com_io_sq)
 				> ENA_TX_WAKEUP_THRESH) {
@@ -2151,8 +2141,10 @@ static netdev_tx_t ena_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	}
 
 	if (netif_xmit_stopped(txq) || !skb->xmit_more) {
-		/* trigger the dma engine */
-		ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq, false);
+		/* trigger the dma engine. ena_com_write_sq_doorbell()
+		 * has a mb
+		 */
+		ena_com_write_sq_doorbell(tx_ring->ena_com_io_sq);
 		u64_stats_update_begin(&tx_ring->syncp);
 		tx_ring->tx_stats.doorbells++;
 		u64_stats_update_end(&tx_ring->syncp);
@@ -2550,12 +2542,15 @@ static int ena_enable_msix_and_set_admin_interrupts(struct ena_adapter *adapter,
 	return rc;
 }
 
-static void ena_destroy_device(struct ena_adapter *adapter)
+static void ena_destroy_device(struct ena_adapter *adapter, bool graceful)
 {
 	struct net_device *netdev = adapter->netdev;
 	struct ena_com_dev *ena_dev = adapter->ena_dev;
 	bool dev_up;
 
+	if (!test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
+		return;
+
 	netif_carrier_off(netdev);
 
 	del_timer_sync(&adapter->timer_service);
@@ -2563,6 +2558,7 @@ static void ena_destroy_device(struct ena_adapter *adapter)
 	dev_up = test_bit(ENA_FLAG_DEV_UP, &adapter->flags);
 	adapter->dev_up_before_reset = dev_up;
 
+	if (!graceful)
 		ena_com_set_admin_running_state(ena_dev, false);
 
 	if (test_bit(ENA_FLAG_DEV_UP, &adapter->flags))
@@ -2591,6 +2587,7 @@ static void ena_destroy_device(struct ena_adapter *adapter)
 	adapter->reset_reason = ENA_REGS_RESET_NORMAL;
 
 	clear_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
+	clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
 }
 
 static int ena_restore_device(struct ena_adapter *adapter)
@@ -2635,6 +2632,7 @@ static int ena_restore_device(struct ena_adapter *adapter)
 		}
 	}
 
+	set_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
 	mod_timer(&adapter->timer_service, round_jiffies(jiffies + HZ));
 	dev_err(&pdev->dev, "Device reset completed successfully\n");
 
@@ -2665,7 +2663,7 @@ static void ena_fw_reset_device(struct work_struct *work)
 		return;
 	}
 	rtnl_lock();
-	ena_destroy_device(adapter);
+	ena_destroy_device(adapter, false);
 	ena_restore_device(adapter);
 	rtnl_unlock();
 }
@@ -3409,30 +3407,24 @@ static void ena_remove(struct pci_dev *pdev)
 		netdev->rx_cpu_rmap = NULL;
 	}
 #endif /* CONFIG_RFS_ACCEL */
-
-	unregister_netdev(netdev);
 	del_timer_sync(&adapter->timer_service);
 
 	cancel_work_sync(&adapter->reset_task);
 
-	/* Reset the device only if the device is running. */
-	if (test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
-		ena_com_dev_reset(ena_dev, adapter->reset_reason);
+	unregister_netdev(netdev);
 
-	ena_free_mgmnt_irq(adapter);
+	/* If the device is running then we want to make sure the device will be
+	 * reset to make sure no more events will be issued by the device.
+	 */
+	if (test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
+		set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
 
-	ena_disable_msix(adapter);
+	rtnl_lock();
+	ena_destroy_device(adapter, true);
+	rtnl_unlock();
 
 	free_netdev(netdev);
 
-	ena_com_mmio_reg_read_request_destroy(ena_dev);
-
-	ena_com_abort_admin_commands(ena_dev);
-
-	ena_com_wait_for_abort_completion(ena_dev);
-
-	ena_com_admin_destroy(ena_dev);
-
 	ena_com_rss_destroy(ena_dev);
 
 	ena_com_delete_debug_area(ena_dev);
@@ -3467,7 +3459,7 @@ static int ena_suspend(struct pci_dev *pdev,  pm_message_t state)
 			"ignoring device reset request as the device is being suspended\n");
 		clear_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
 	}
-	ena_destroy_device(adapter);
+	ena_destroy_device(adapter, true);
 	rtnl_unlock();
 	return 0;
 }

drivers/net/ethernet/amazon/ena/ena_netdev.h

@@ -355,4 +355,15 @@ void ena_dump_stats_to_buf(struct ena_adapter *adapter, u8 *buf);
 
 int ena_get_sset_count(struct net_device *netdev, int sset);
 
+/* The ENA buffer length fields is 16 bit long. So when PAGE_SIZE == 64kB the
+ * driver passas 0.
+ * Since the max packet size the ENA handles is ~9kB limit the buffer length to
+ * 16kB.
+ */
+#if PAGE_SIZE > SZ_16K
+#define ENA_PAGE_SIZE SZ_16K
+#else
+#define ENA_PAGE_SIZE PAGE_SIZE
+#endif
+
 #endif /* !(ENA_H) */