Commit c9133112 authored by Juergen Gross's avatar Juergen Gross
Browse files

xen/virtio: restructure xen grant dma setup 



In order to prepare supporting other means than device tree for
setting up virtio devices under Xen, restructure the functions
xen_is_grant_dma_device() and xen_grant_setup_dma_ops() a little bit.

Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
Reviewed-by: default avatarOleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Tested-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> # Arm64 only
Acked-by: default avatarStefano Stabellini <sstabellini@kernel.org>
Signed-off-by: default avatarJuergen Gross <jgross@suse.com>
parent 2849752f

drivers/xen/grant-dma-ops.c

+43 −25
Original line number Diff line number Diff line
@@ -289,22 +289,28 @@ static const struct dma_map_ops xen_grant_dma_ops = { 
	.dma_supported = xen_grant_dma_supported,

};



bool xen_is_grant_dma_device(struct device *dev)

static bool xen_is_dt_grant_dma_device(struct device *dev)

{

	struct device_node *iommu_np;

	bool has_iommu;



	/* XXX Handle only DT devices for now */

	if (!dev->of_node)

		return false;



	iommu_np = of_parse_phandle(dev->of_node, "iommus", 0);

	has_iommu = iommu_np && of_device_is_compatible(iommu_np, "xen,grant-dma");

	has_iommu = iommu_np &&

		    of_device_is_compatible(iommu_np, "xen,grant-dma");

	of_node_put(iommu_np);



	return has_iommu;

}



bool xen_is_grant_dma_device(struct device *dev)

{

	/* XXX Handle only DT devices for now */

	if (dev->of_node)

		return xen_is_dt_grant_dma_device(dev);



	return false;

}



bool xen_virtio_mem_acc(struct virtio_device *dev)

{

	if (IS_ENABLED(CONFIG_XEN_VIRTIO_FORCE_GRANT))
@@ -313,45 +319,56 @@ bool xen_virtio_mem_acc(struct virtio_device *dev) 
	return xen_is_grant_dma_device(dev->dev.parent);

}



void xen_grant_setup_dma_ops(struct device *dev)

static int xen_dt_grant_init_backend_domid(struct device *dev,

					   struct xen_grant_dma_data *data)

{

	struct xen_grant_dma_data *data;

	struct of_phandle_args iommu_spec;



	data = find_xen_grant_dma_data(dev);

	if (data) {

		dev_err(dev, "Xen grant DMA data is already created\n");

		return;

	}



	/* XXX ACPI device unsupported for now */

	if (!dev->of_node)

		goto err;



	if (of_parse_phandle_with_args(dev->of_node, "iommus", "#iommu-cells",

			0, &iommu_spec)) {

		dev_err(dev, "Cannot parse iommus property\n");

		goto err;

		return -ESRCH;

	}



	if (!of_device_is_compatible(iommu_spec.np, "xen,grant-dma") ||

			iommu_spec.args_count != 1) {

		dev_err(dev, "Incompatible IOMMU node\n");

		of_node_put(iommu_spec.np);

		goto err;

		return -ESRCH;

	}



	of_node_put(iommu_spec.np);



	/*

	 * The endpoint ID here means the ID of the domain where the

	 * corresponding backend is running

	 */

	data->backend_domid = iommu_spec.args[0];



	return 0;

}



void xen_grant_setup_dma_ops(struct device *dev)

{

	struct xen_grant_dma_data *data;



	data = find_xen_grant_dma_data(dev);

	if (data) {

		dev_err(dev, "Xen grant DMA data is already created\n");

		return;

	}



	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);

	if (!data)

		goto err;



	/*

	 * The endpoint ID here means the ID of the domain where the corresponding

	 * backend is running

	 */

	data->backend_domid = iommu_spec.args[0];

	if (dev->of_node) {

		if (xen_dt_grant_init_backend_domid(dev, data))

			goto err;

	} else {

		/* XXX ACPI device unsupported for now */

		goto err;

	}



	if (store_xen_grant_dma_data(dev, data)) {

		dev_err(dev, "Cannot store Xen grant DMA data\n");
@@ -363,6 +380,7 @@ void xen_grant_setup_dma_ops(struct device *dev) 
	return;



err:

	devm_kfree(dev, data);

	dev_err(dev, "Cannot set up Xen grant DMA ops, retain platform DMA ops\n");

}