+static int mlx4_reset_slave(struct mlx4_dev *dev)
+{
+#define COM_CHAN_RST_REQ_OFFSET 0x10
+#define COM_CHAN_RST_ACK_OFFSET 0x08
+
+ u32 comm_flags;
+ u32 rst_req;
+ u32 rst_ack;
+ unsigned long end;
+ struct mlx4_priv *priv = mlx4_priv(dev);
+
+ if (pci_channel_offline(dev->persist->pdev))
+ return 0;
+
+ comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
+ MLX4_COMM_CHAN_FLAGS));
+ if (comm_flags == 0xffffffff) {
+ mlx4_err(dev, "VF reset is not needed\n");
+ return 0;
+ }
+
+ if (!(dev->caps.vf_caps & MLX4_VF_CAP_FLAG_RESET)) {
+ mlx4_err(dev, "VF reset is not supported\n");
+ return -EOPNOTSUPP;
+ }
+
+ rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
+ COM_CHAN_RST_REQ_OFFSET;
+ rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
+ COM_CHAN_RST_ACK_OFFSET;
+ if (rst_req != rst_ack) {
+ mlx4_err(dev, "Communication channel isn't sync, fail to send reset\n");
+ return -EIO;
+ }
+
+ rst_req ^= 1;
+ mlx4_warn(dev, "VF is sending reset request to Firmware\n");
+ comm_flags = rst_req << COM_CHAN_RST_REQ_OFFSET;
+ __raw_writel((__force u32)cpu_to_be32(comm_flags),
+ (__iomem char *)priv->mfunc.comm + MLX4_COMM_CHAN_FLAGS);
+ /* Make sure that our comm channel write doesn't
+ * get mixed in with writes from another CPU.
+ */
+ mmiowb();
+
+ end = msecs_to_jiffies(MLX4_COMM_TIME) + jiffies;
+ while (time_before(jiffies, end)) {
+ comm_flags = swab32(readl((__iomem char *)priv->mfunc.comm +
+ MLX4_COMM_CHAN_FLAGS));
+ rst_ack = (comm_flags & (u32)(1 << COM_CHAN_RST_ACK_OFFSET)) >>
+ COM_CHAN_RST_ACK_OFFSET;
+
+ /* Reading rst_req again since the communication channel can
+ * be reset at any time by the PF and all its bits will be
+ * set to zero.
+ */
+ rst_req = (comm_flags & (u32)(1 << COM_CHAN_RST_REQ_OFFSET)) >>
+ COM_CHAN_RST_REQ_OFFSET;
+
+ if (rst_ack == rst_req) {
+ mlx4_warn(dev, "VF Reset succeed\n");
+ return 0;
+ }
+ cond_resched();
+ }
+ mlx4_err(dev, "Fail to send reset over the communication channel\n");
+ return -ETIMEDOUT;
+}
+
+static int mlx4_comm_internal_err(u32 slave_read)
+{
+ return (u32)COMM_CHAN_EVENT_INTERNAL_ERR ==
+ (slave_read & (u32)COMM_CHAN_EVENT_INTERNAL_ERR) ? 1 : 0;
+}
+