liquidio: fix ndo_change_mtu to always return correct status to the caller

In a scenario where the command queued to firmware get dropped or times
out, MTU change from host will not propagate to firmware. So, it is
required for host driver to wait for response from firmware or timeout
and then return correct status to caller of ndo_change_mtu.

Also moved the common code for MTU change from PF and VF driver files to
common file lio_core.c

Signed-off-by: Veerasenareddy Burru <veerasenareddy.burru@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 85 insertions, 9 deletions

diff --git a/drivers/net/ethernet/cavium/liquidio/lio_core.c b/drivers/net/ethernet/cavium/liquidio/lio_core.c
index 8b1ee83134e3..e7b6eb87ab14 100644
--- a/drivers/net/ethernet/cavium/liquidio/lio_core.c
+++ b/drivers/net/ethernet/cavium/liquidio/lio_core.c
@@ -164,15 +164,6 @@ void liquidio_link_ctrl_cmd_completion(void *nctrl_ptr)
 		}
 		break;
 
-	case OCTNET_CMD_CHANGE_MTU:
-		/* If command is successful, change the MTU. */
-		netif_info(lio, probe, lio->netdev, "MTU Changed from %d to %d\n",
-			   netdev->mtu, nctrl->ncmd.s.param1);
-		netdev->mtu = nctrl->ncmd.s.param1;
-		queue_delayed_work(lio->link_status_wq.wq,
-				   &lio->link_status_wq.wk.work, 0);
-		break;
-
 	case OCTNET_CMD_GPIO_ACCESS:
 		netif_info(lio, probe, lio->netdev, "LED Flashing visual identification\n");
 
@@ -1081,3 +1072,88 @@ int octeon_setup_interrupt(struct octeon_device *oct, u32 num_ioqs)
 	}
 	return 0;
 }
+
+static void liquidio_change_mtu_completion(struct octeon_device *oct,
+					   u32 status, void *buf)
+{
+	struct octeon_soft_command *sc = (struct octeon_soft_command *)buf;
+	struct liquidio_if_cfg_context *ctx;
+
+	ctx  = (struct liquidio_if_cfg_context *)sc->ctxptr;
+
+	if (status) {
+		dev_err(&oct->pci_dev->dev, "MTU change failed. Status: %llx\n",
+			CVM_CAST64(status));
+		WRITE_ONCE(ctx->cond, LIO_CHANGE_MTU_FAIL);
+	} else {
+		WRITE_ONCE(ctx->cond, LIO_CHANGE_MTU_SUCCESS);
+	}
+
+	/* This barrier is required to be sure that the response has been
+	 * written fully before waking up the handler
+	 */
+	wmb();
+
+	wake_up_interruptible(&ctx->wc);
+}
+
+/**
+ * \brief Net device change_mtu
+ * @param netdev network device
+ */
+int liquidio_change_mtu(struct net_device *netdev, int new_mtu)
+{
+	struct lio *lio = GET_LIO(netdev);
+	struct octeon_device *oct = lio->oct_dev;
+	struct liquidio_if_cfg_context *ctx;
+	struct octeon_soft_command *sc;
+	union octnet_cmd *ncmd;
+	int ctx_size;
+	int ret = 0;
+
+	ctx_size = sizeof(struct liquidio_if_cfg_context);
+	sc = (struct octeon_soft_command *)
+		octeon_alloc_soft_command(oct, OCTNET_CMD_SIZE, 16, ctx_size);
+
+	ncmd = (union octnet_cmd *)sc->virtdptr;
+	ctx  = (struct liquidio_if_cfg_context *)sc->ctxptr;
+
+	WRITE_ONCE(ctx->cond, 0);
+	ctx->octeon_id = lio_get_device_id(oct);
+	init_waitqueue_head(&ctx->wc);
+
+	ncmd->u64 = 0;
+	ncmd->s.cmd = OCTNET_CMD_CHANGE_MTU;
+	ncmd->s.param1 = new_mtu;
+
+	octeon_swap_8B_data((u64 *)ncmd, (OCTNET_CMD_SIZE >> 3));
+
+	sc->iq_no = lio->linfo.txpciq[0].s.q_no;
+
+	octeon_prepare_soft_command(oct, sc, OPCODE_NIC,
+				    OPCODE_NIC_CMD, 0, 0, 0);
+
+	sc->callback = liquidio_change_mtu_completion;
+	sc->callback_arg = sc;
+	sc->wait_time = 100;
+
+	ret = octeon_send_soft_command(oct, sc);
+	if (ret == IQ_SEND_FAILED) {
+		netif_info(lio, rx_err, lio->netdev, "Failed to change MTU\n");
+		return -EINVAL;
+	}
+	/* Sleep on a wait queue till the cond flag indicates that the
+	 * response arrived or timed-out.
+	 */
+	if (sleep_cond(&ctx->wc, &ctx->cond) == -EINTR ||
+	    ctx->cond == LIO_CHANGE_MTU_FAIL) {
+		octeon_free_soft_command(oct, sc);
+		return -EINVAL;
+	}
+
+	netdev->mtu = new_mtu;
+	lio->mtu = new_mtu;
+
+	octeon_free_soft_command(oct, sc);
+	return 0;
+}