drivers/s390/cio/vfio_ccw_ops.c

Source file repositories/reference/linux-study-clean/drivers/s390/cio/vfio_ccw_ops.c

File Facts

System
Linux kernel
Corpus path
drivers/s390/cio/vfio_ccw_ops.c
Extension
.c
Size
15226 bytes
Lines
615
Domain
Driver Families
Bucket
drivers/s390
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 (fd == -1) {
			if (*ctx)
				eventfd_ctx_put(*ctx);
			*ctx = NULL;
		} else if (fd >= 0) {
			struct eventfd_ctx *efdctx;

			efdctx = eventfd_ctx_fdget(fd);
			if (IS_ERR(efdctx))
				return PTR_ERR(efdctx);

			if (*ctx)
				eventfd_ctx_put(*ctx);

			*ctx = efdctx;
		} else
			return -EINVAL;

		return 0;
	}
	default:
		return -EINVAL;
	}
}

int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
				 unsigned int subtype,
				 const struct vfio_ccw_regops *ops,
				 size_t size, u32 flags, void *data)
{
	struct vfio_ccw_region *region;

	region = krealloc(private->region,
			  (private->num_regions + 1) * sizeof(*region),
			  GFP_KERNEL);
	if (!region)
		return -ENOMEM;

	private->region = region;
	private->region[private->num_regions].type = VFIO_REGION_TYPE_CCW;
	private->region[private->num_regions].subtype = subtype;
	private->region[private->num_regions].ops = ops;
	private->region[private->num_regions].size = size;
	private->region[private->num_regions].flags = flags;
	private->region[private->num_regions].data = data;

	private->num_regions++;

	return 0;
}

void vfio_ccw_unregister_dev_regions(struct vfio_ccw_private *private)
{
	int i;

	for (i = 0; i < private->num_regions; i++)
		private->region[i].ops->release(private, &private->region[i]);
	private->num_regions = 0;
	kfree(private->region);
	private->region = NULL;
}

static ssize_t vfio_ccw_mdev_ioctl(struct vfio_device *vdev,
				   unsigned int cmd,
				   unsigned long arg)
{
	struct vfio_ccw_private *private =
		container_of(vdev, struct vfio_ccw_private, vdev);
	int ret = 0;
	unsigned long minsz;

	switch (cmd) {
	case VFIO_DEVICE_GET_INFO:
	{
		struct vfio_device_info info;

		minsz = offsetofend(struct vfio_device_info, num_irqs);

		if (copy_from_user(&info, (void __user *)arg, minsz))
			return -EFAULT;

		if (info.argsz < minsz)
			return -EINVAL;

		ret = vfio_ccw_mdev_get_device_info(private, &info);
		if (ret)
			return ret;

		return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
	}

Annotation

Implementation Notes