scsi: fnic: Adding devcmd2 init and posting interfaces

This patch adds fnic devcmd2 interfaces for initialization and posting
commands to fw.

Signed-off-by: Satish Kharat <[e-mail]>
Signed-off-by: Martin K. Petersen <[e-mail]>

drivers/scsi/fnic/vnic_dev.c

···
 	return -ETIMEDOUT;
 }
 
+int vnic_dev_cmd2(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
+		int wait)
+{
+	struct devcmd2_controller *dc2c = vdev->devcmd2;
+	struct devcmd2_result *result;
+	u8 color;
+	unsigned int i;
+	int delay;
+	int err;
+	u32 fetch_index;
+	u32 posted;
+	u32 new_posted;
+
+	posted = ioread32(&dc2c->wq_ctrl->posted_index);
+	fetch_index = ioread32(&dc2c->wq_ctrl->fetch_index);
+
+	if (posted == 0xFFFFFFFF || fetch_index == 0xFFFFFFFF) {
+		/* Hardware surprise removal: return error */
+		pr_err("%s: devcmd2 invalid posted or fetch index on cmd %d\n",
+				pci_name(vdev->pdev), _CMD_N(cmd));
+		pr_err("%s: fetch index: %u, posted index: %u\n",
+				pci_name(vdev->pdev), fetch_index, posted);
+
+		return -ENODEV;
+
+	}
+
+	new_posted = (posted + 1) % DEVCMD2_RING_SIZE;
+
+	if (new_posted == fetch_index) {
+		pr_err("%s: devcmd2 wq full while issuing cmd %d\n",
+				pci_name(vdev->pdev), _CMD_N(cmd));
+		pr_err("%s: fetch index: %u, posted index: %u\n",
+				pci_name(vdev->pdev), fetch_index, posted);
+		return -EBUSY;
+
+	}
+	dc2c->cmd_ring[posted].cmd = cmd;
+	dc2c->cmd_ring[posted].flags = 0;
+
+	if ((_CMD_FLAGS(cmd) & _CMD_FLAGS_NOWAIT))
+		dc2c->cmd_ring[posted].flags |= DEVCMD2_FNORESULT;
+	if (_CMD_DIR(cmd) & _CMD_DIR_WRITE) {
+		for (i = 0; i < VNIC_DEVCMD_NARGS; i++)
+			dc2c->cmd_ring[posted].args[i] = vdev->args[i];
+
+	}
+
+	/* Adding write memory barrier prevents compiler and/or CPU
+	 * reordering, thus avoiding descriptor posting before
+	 * descriptor is initialized. Otherwise, hardware can read
+	 * stale descriptor fields.
+	 */
+	wmb();
+	iowrite32(new_posted, &dc2c->wq_ctrl->posted_index);
+
+	if (dc2c->cmd_ring[posted].flags & DEVCMD2_FNORESULT)
+		return 0;
+
+	result = dc2c->result + dc2c->next_result;
+	color = dc2c->color;
+
+	dc2c->next_result++;
+	if (dc2c->next_result == dc2c->result_size) {
+		dc2c->next_result = 0;
+		dc2c->color = dc2c->color ? 0 : 1;
+	}
+
+	for (delay = 0; delay < wait; delay++) {
+		udelay(100);
+		if (result->color == color) {
+			if (result->error) {
+				err = -(int) result->error;
+				if (err != ERR_ECMDUNKNOWN ||
+						cmd != CMD_CAPABILITY)
+					pr_err("%s:Error %d devcmd %d\n",
+						pci_name(vdev->pdev),
+						err, _CMD_N(cmd));
+				return err;
+			}
+			if (_CMD_DIR(cmd) & _CMD_DIR_READ) {
+				rmb(); /*prevent reorder while reding result*/
+				for (i = 0; i < VNIC_DEVCMD_NARGS; i++)
+					vdev->args[i] = result->results[i];
+			}
+			return 0;
+		}
+	}
+
+	pr_err("%s:Timed out devcmd %d\n", pci_name(vdev->pdev), _CMD_N(cmd));
+
+	return -ETIMEDOUT;
+}
+
+
+int vnic_dev_init_devcmd1(struct vnic_dev *vdev)
+{
+	vdev->devcmd = vnic_dev_get_res(vdev, RES_TYPE_DEVCMD, 0);
+	if (!vdev->devcmd)
+		return -ENODEV;
+
+	vdev->devcmd_rtn = &vnic_dev_cmd1;
+	return 0;
+}
+
+
+int vnic_dev_init_devcmd2(struct vnic_dev *vdev)
+{
+	int err;
+	unsigned int fetch_index;
+
+	if (vdev->devcmd2)
+		return 0;
+
+	vdev->devcmd2 = kzalloc(sizeof(*vdev->devcmd2), GFP_ATOMIC);
+	if (!vdev->devcmd2)
+		return -ENOMEM;
+
+	vdev->devcmd2->color = 1;
+	vdev->devcmd2->result_size = DEVCMD2_RING_SIZE;
+	err = vnic_wq_devcmd2_alloc(vdev, &vdev->devcmd2->wq,
+				DEVCMD2_RING_SIZE, DEVCMD2_DESC_SIZE);
+	if (err)
+		goto err_free_devcmd2;
+
+	fetch_index = ioread32(&vdev->devcmd2->wq.ctrl->fetch_index);
+	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
+		pr_err("error in devcmd2 init");
+		return -ENODEV;
+	}
+
+	/*
+	 * Don't change fetch_index ever and
+	 * set posted_index same as fetch_index
+	 * when setting up the WQ for devcmd2.
+	 */
+	vnic_wq_init_start(&vdev->devcmd2->wq, 0, fetch_index,
+			fetch_index, 0, 0);
+
+	vnic_wq_enable(&vdev->devcmd2->wq);
+
+	err = vnic_dev_alloc_desc_ring(vdev, &vdev->devcmd2->results_ring,
+			DEVCMD2_RING_SIZE, DEVCMD2_DESC_SIZE);
+	if (err)
+		goto err_free_wq;
+
+	vdev->devcmd2->result =
+		(struct devcmd2_result *) vdev->devcmd2->results_ring.descs;
+	vdev->devcmd2->cmd_ring =
+		(struct vnic_devcmd2 *) vdev->devcmd2->wq.ring.descs;
+	vdev->devcmd2->wq_ctrl = vdev->devcmd2->wq.ctrl;
+	vdev->args[0] = (u64) vdev->devcmd2->results_ring.base_addr |
+				VNIC_PADDR_TARGET;
+	vdev->args[1] = DEVCMD2_RING_SIZE;
+
+	err = vnic_dev_cmd2(vdev, CMD_INITIALIZE_DEVCMD2, 1000);
+	if (err)
+		goto err_free_desc_ring;
+
+	vdev->devcmd_rtn = &vnic_dev_cmd2;
+
+	return 0;
+
+err_free_desc_ring:
+	vnic_dev_free_desc_ring(vdev, &vdev->devcmd2->results_ring);
+err_free_wq:
+	vnic_wq_disable(&vdev->devcmd2->wq);
+	vnic_wq_free(&vdev->devcmd2->wq);
+err_free_devcmd2:
+	kfree(vdev->devcmd2);
+	vdev->devcmd2 = NULL;
+
+	return err;
+}
+
+
+void vnic_dev_deinit_devcmd2(struct vnic_dev *vdev)
+{
+	vnic_dev_free_desc_ring(vdev, &vdev->devcmd2->results_ring);
+	vnic_wq_disable(&vdev->devcmd2->wq);
+	vnic_wq_free(&vdev->devcmd2->wq);
+	kfree(vdev->devcmd2);
+	vdev->devcmd2 = NULL;
+	vdev->devcmd_rtn = &vnic_dev_cmd1;
+}
+
+
+int vnic_dev_cmd_no_proxy(struct vnic_dev *vdev,
+	enum vnic_devcmd_cmd cmd, u64 *a0, u64 *a1, int wait)
+{
+	int err;
+
+	vdev->args[0] = *a0;
+	vdev->args[1] = *a1;
+
+	err = (*vdev->devcmd_rtn)(vdev, cmd, wait);
+
+	*a0 = vdev->args[0];
+	*a1 = vdev->args[1];
+
+	return err;
+}
+
+
+int vnic_dev_cmd(struct vnic_dev *vdev, enum vnic_devcmd_cmd cmd,
+	u64 *a0, u64 *a1, int wait)
+{
+	memset(vdev->args, 0, sizeof(vdev->args));
+
+	switch (vdev->proxy) {
+	case PROXY_NONE:
+	default:
+		return vnic_dev_cmd_no_proxy(vdev, cmd, a0, a1, wait);
+	}
+}
+
+
 int vnic_dev_fw_info(struct vnic_dev *vdev,
 	struct vnic_devcmd_fw_info **fw_info)
 {
···
 			dma_free_coherent(&vdev->pdev->dev,
 				sizeof(struct vnic_devcmd_fw_info),
 				vdev->fw_info, vdev->fw_info_pa);
+		if (vdev->devcmd2)
+			vnic_dev_deinit_devcmd2(vdev);
 		kfree(vdev);
 	}
 }
···
 	vdev->pdev = pdev;
 
 	if (vnic_dev_discover_res(vdev, bar))
-		goto err_out;
-
-	vdev->devcmd = vnic_dev_get_res(vdev, RES_TYPE_DEVCMD, 0);
-	if (!vdev->devcmd)
 		goto err_out;
 
 	return vdev;