drivers/net/netdevsim/bus.c

Source file repositories/reference/linux-study-clean/drivers/net/netdevsim/bus.c

File Facts

System
Linux kernel
Corpus path
drivers/net/netdevsim/bus.c
Extension
.c
Size
13146 bytes
Lines
541
Domain
Driver Families
Bucket
drivers/net
Inferred role
Driver Families: operation-table or driver-model contract
Status
pattern 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

new_device_store(const struct bus_type *bus, const char *buf, size_t count)
{
	unsigned int id, port_count, num_queues;
	struct nsim_bus_dev *nsim_bus_dev;
	int err;

	err = sscanf(buf, "%u %u %u", &id, &port_count, &num_queues);
	switch (err) {
	case 1:
		port_count = 1;
		fallthrough;
	case 2:
		num_queues = 1;
		fallthrough;
	case 3:
		if (id > INT_MAX) {
			pr_err("Value of \"id\" is too big.\n");
			return -EINVAL;
		}
		break;
	default:
		pr_err("Format for adding new device is \"id port_count num_queues\" (uint uint uint).\n");
		return -EINVAL;
	}

	mutex_lock(&nsim_bus_dev_list_lock);
	/* Prevent to use resource before initialization. */
	if (!smp_load_acquire(&nsim_bus_enable)) {
		err = -EBUSY;
		goto err;
	}

	nsim_bus_dev = nsim_bus_dev_new(id, port_count, num_queues);
	if (IS_ERR(nsim_bus_dev)) {
		err = PTR_ERR(nsim_bus_dev);
		goto err;
	}

	refcount_inc(&nsim_bus_devs);
	/* Allow using nsim_bus_dev */
	smp_store_release(&nsim_bus_dev->init, true);

	list_add_tail(&nsim_bus_dev->list, &nsim_bus_dev_list);
	mutex_unlock(&nsim_bus_dev_list_lock);

	return count;
err:
	mutex_unlock(&nsim_bus_dev_list_lock);
	return err;
}
static BUS_ATTR_WO(new_device);

static void nsim_bus_dev_del(struct nsim_bus_dev *nsim_bus_dev);

static ssize_t
del_device_store(const struct bus_type *bus, const char *buf, size_t count)
{
	struct nsim_bus_dev *nsim_bus_dev, *tmp;
	unsigned int id;
	int err;

	err = sscanf(buf, "%u", &id);
	switch (err) {
	case 1:
		if (id > INT_MAX) {
			pr_err("Value of \"id\" is too big.\n");
			return -EINVAL;
		}
		break;
	default:
		pr_err("Format for deleting device is \"id\" (uint).\n");
		return -EINVAL;
	}

	err = -ENOENT;
	mutex_lock(&nsim_bus_dev_list_lock);
	/* Prevent to use resource before initialization. */
	if (!smp_load_acquire(&nsim_bus_enable)) {
		mutex_unlock(&nsim_bus_dev_list_lock);
		return -EBUSY;
	}
	list_for_each_entry_safe(nsim_bus_dev, tmp, &nsim_bus_dev_list, list) {
		if (nsim_bus_dev->dev.id != id)
			continue;
		list_del(&nsim_bus_dev->list);
		nsim_bus_dev_del(nsim_bus_dev);
		err = 0;
		break;
	}
	mutex_unlock(&nsim_bus_dev_list_lock);

Annotation

Implementation Notes