drivers/usb/usbip/vhci_tx.c

Source file repositories/reference/linux-study-clean/drivers/usb/usbip/vhci_tx.c

File Facts

System
Linux kernel
Corpus path
drivers/usb/usbip/vhci_tx.c
Extension
.c
Size
6026 bytes
Lines
257
Domain
Driver Families
Bucket
drivers/usb
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!iov) {
			usbip_event_add(&vdev->ud, SDEV_EVENT_ERROR_MALLOC);
			return -ENOMEM;
		}

		if (urb->num_sgs)
			urb->transfer_flags |= URB_DMA_MAP_SG;

		/* 1. setup usbip_header */
		setup_cmd_submit_pdu(&pdu_header, urb);
		usbip_header_correct_endian(&pdu_header, 1);
		iovnum = 0;

		iov[iovnum].iov_base = &pdu_header;
		iov[iovnum].iov_len  = sizeof(pdu_header);
		txsize += sizeof(pdu_header);
		iovnum++;

		/* 2. setup transfer buffer */
		if (!usb_pipein(urb->pipe) && urb->transfer_buffer_length > 0) {
			if (urb->num_sgs &&
				      !usb_endpoint_xfer_isoc(&urb->ep->desc)) {
				for_each_sg(urb->sg, sg, urb->num_sgs, i) {
					iov[iovnum].iov_base = sg_virt(sg);
					iov[iovnum].iov_len = sg->length;
					iovnum++;
				}
			} else {
				iov[iovnum].iov_base = urb->transfer_buffer;
				iov[iovnum].iov_len  =
						urb->transfer_buffer_length;
				iovnum++;
			}
			txsize += urb->transfer_buffer_length;
		}

		/* 3. setup iso_packet_descriptor */
		if (usb_pipetype(urb->pipe) == PIPE_ISOCHRONOUS) {
			ssize_t len = 0;

			iso_buffer = usbip_alloc_iso_desc_pdu(urb, &len);
			if (!iso_buffer) {
				usbip_event_add(&vdev->ud,
						SDEV_EVENT_ERROR_MALLOC);
				goto err_iso_buffer;
			}

			iov[iovnum].iov_base = iso_buffer;
			iov[iovnum].iov_len  = len;
			iovnum++;
			txsize += len;
		}

		ret = kernel_sendmsg(vdev->ud.tcp_socket, &msg, iov, iovnum,
				     txsize);
		if (ret != txsize) {
			pr_err("sendmsg failed!, ret=%d for %zd\n", ret,
			       txsize);
			usbip_event_add(&vdev->ud, VDEV_EVENT_ERROR_TCP);
			err = -EPIPE;
			goto err_tx;
		}

		kfree(iov);
		/* This is only for isochronous case */
		kfree(iso_buffer);
		iso_buffer = NULL;

		usbip_dbg_vhci_tx("send txdata\n");

		total_size += txsize;
	}

	return total_size;

err_tx:
	kfree(iso_buffer);
err_iso_buffer:
	kfree(iov);

	return err;
}

static struct vhci_unlink *dequeue_from_unlink_tx(struct vhci_device *vdev)
{
	struct vhci_unlink *unlink, *tmp;
	unsigned long flags;

	spin_lock_irqsave(&vdev->priv_lock, flags);

Annotation

Implementation Notes