drivers/xen/xen-pciback/xenbus.c

Source file repositories/reference/linux-study-clean/drivers/xen/xen-pciback/xenbus.c

File Facts

System
Linux kernel
Corpus path
drivers/xen/xen-pciback/xenbus.c
Extension
.c
Size
19175 bytes
Lines
759
Domain
Driver Families
Bucket
drivers/xen
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 (unlikely(len >= (sizeof(str) - 1))) {
			err = -ENOMEM;
			goto out;
		}

		err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename,
				   str, "%x:%x", &d, &b);
		if (err < 0)
			goto out;
		if (err != 2) {
			err = -EINVAL;
			goto out;
		}

		if (d == domain && b == bus) {
			err = 0;
			goto out;
		}
	}

	len = snprintf(str, sizeof(str), "root-%d", root_num);
	if (unlikely(len >= (sizeof(str) - 1))) {
		err = -ENOMEM;
		goto out;
	}

	dev_dbg(&pdev->xdev->dev, "writing root %d at %04x:%02x\n",
		root_num, domain, bus);

	err = xenbus_printf(XBT_NIL, pdev->xdev->nodename, str,
			    "%04x:%02x", domain, bus);
	if (err)
		goto out;

	err = xenbus_printf(XBT_NIL, pdev->xdev->nodename,
			    "root_num", "%d", (root_num + 1));

out:
	return err;
}

static int xen_pcibk_reconfigure(struct xen_pcibk_device *pdev,
				 enum xenbus_state state)
{
	int err = 0;
	int num_devs;
	int domain, bus, slot, func;
	unsigned int substate;
	int i, len;
	char state_str[64];
	char dev_str[64];


	dev_dbg(&pdev->xdev->dev, "Reconfiguring device ...\n");

	mutex_lock(&pdev->dev_lock);
	if (xenbus_read_driver_state(pdev->xdev, pdev->xdev->nodename) != state)
		goto out;

	err = xenbus_scanf(XBT_NIL, pdev->xdev->nodename, "num_devs", "%d",
			   &num_devs);
	if (err != 1) {
		if (err >= 0)
			err = -EINVAL;
		xenbus_dev_fatal(pdev->xdev, err,
				 "Error reading number of devices");
		goto out;
	}

	for (i = 0; i < num_devs; i++) {
		len = snprintf(state_str, sizeof(state_str), "state-%d", i);
		if (unlikely(len >= (sizeof(state_str) - 1))) {
			err = -ENOMEM;
			xenbus_dev_fatal(pdev->xdev, err,
					 "String overflow while reading "
					 "configuration");
			goto out;
		}
		substate = xenbus_read_unsigned(pdev->xdev->nodename, state_str,
						XenbusStateUnknown);

		switch (substate) {
		case XenbusStateInitialising:
			dev_dbg(&pdev->xdev->dev, "Attaching dev-%d ...\n", i);

			len = snprintf(dev_str, sizeof(dev_str), "dev-%d", i);
			if (unlikely(len >= (sizeof(dev_str) - 1))) {
				err = -ENOMEM;
				xenbus_dev_fatal(pdev->xdev, err,
						 "String overflow while "

Annotation

Implementation Notes