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Commit 6f01cc69 authored by Alexey Kardashevskiy's avatar Alexey Kardashevskiy Committed by Michael Ellerman
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vfio/spapr: Add a helper to create default DMA window 



There is already a helper to create a DMA window which does allocate
a table and programs it to the IOMMU group. However
tce_iommu_take_ownership_ddw() did not use it and did these 2 calls
itself to simplify error path.

Since we are going to delay the default window creation till
the default window is accessed/removed or new window is added,
we need a helper to create a default window from all these cases.

This adds tce_iommu_create_default_window(). Since it relies on
a VFIO container to have at least one IOMMU group (for future use),
this changes tce_iommu_attach_group() to add a group to the container
first and then call the new helper.

Signed-off-by: default avatarAlexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: default avatarDavid Gibson <david@gibson.dropbear.id.au>
Acked-by: default avatarAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent 39701e56

drivers/vfio/vfio_iommu_spapr_tce.c

+42 −45
Original line number Diff line number Diff line
@@ -710,6 +710,29 @@ static long tce_iommu_remove_window(struct tce_container *container, 
	return 0;

}



static long tce_iommu_create_default_window(struct tce_container *container)

{

	long ret;

	__u64 start_addr = 0;

	struct tce_iommu_group *tcegrp;

	struct iommu_table_group *table_group;



	if (!tce_groups_attached(container))

		return -ENODEV;



	tcegrp = list_first_entry(&container->group_list,

			struct tce_iommu_group, next);

	table_group = iommu_group_get_iommudata(tcegrp->grp);

	if (!table_group)

		return -ENODEV;



	ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,

			table_group->tce32_size, 1, &start_addr);

	WARN_ON_ONCE(!ret && start_addr);



	return ret;

}



static long tce_iommu_ioctl(void *iommu_data,

				 unsigned int cmd, unsigned long arg)

{
@@ -1100,9 +1123,6 @@ static void tce_iommu_release_ownership_ddw(struct tce_container *container, 
static long tce_iommu_take_ownership_ddw(struct tce_container *container,

		struct iommu_table_group *table_group)

{

	long i, ret = 0;

	struct iommu_table *tbl = NULL;



	if (!table_group->ops->create_table || !table_group->ops->set_window ||

			!table_group->ops->release_ownership) {

		WARN_ON_ONCE(1);
@@ -1111,47 +1131,7 @@ static long tce_iommu_take_ownership_ddw(struct tce_container *container, 


	table_group->ops->take_ownership(table_group);



	/*

	 * If it the first group attached, check if there is

	 * a default DMA window and create one if none as

	 * the userspace expects it to exist.

	 */

	if (!tce_groups_attached(container) && !container->tables[0]) {

		ret = tce_iommu_create_table(container,

				table_group,

				0, /* window number */

				IOMMU_PAGE_SHIFT_4K,

				table_group->tce32_size,

				1, /* default levels */

				&tbl);

		if (ret)

			goto release_exit;

		else

			container->tables[0] = tbl;

	}



	/* Set all windows to the new group */

	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {

		tbl = container->tables[i];



		if (!tbl)

			continue;



		/* Set the default window to a new group */

		ret = table_group->ops->set_window(table_group, i, tbl);

		if (ret)

			goto release_exit;

	}



	return 0;



release_exit:

	for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)

		table_group->ops->unset_window(table_group, i);



	table_group->ops->release_ownership(table_group);



	return ret;

}



static int tce_iommu_attach_group(void *iommu_data,
@@ -1161,6 +1141,7 @@ static int tce_iommu_attach_group(void *iommu_data, 
	struct tce_container *container = iommu_data;

	struct iommu_table_group *table_group;

	struct tce_iommu_group *tcegrp = NULL;

	bool create_default_window = false;



	mutex_lock(&container->lock);
@@ -1203,14 +1184,30 @@ static int tce_iommu_attach_group(void *iommu_data, 
	}



	if (!table_group->ops || !table_group->ops->take_ownership ||

			!table_group->ops->release_ownership)

			!table_group->ops->release_ownership) {

		ret = tce_iommu_take_ownership(container, table_group);

	else

	} else {

		ret = tce_iommu_take_ownership_ddw(container, table_group);

		if (!tce_groups_attached(container) && !container->tables[0])

			create_default_window = true;

	}



	if (!ret) {

		tcegrp->grp = iommu_group;

		list_add(&tcegrp->next, &container->group_list);

		/*

		 * If it the first group attached, check if there is

		 * a default DMA window and create one if none as

		 * the userspace expects it to exist.

		 */

		if (create_default_window) {

			ret = tce_iommu_create_default_window(container);

			if (ret) {

				list_del(&tcegrp->next);

				tce_iommu_release_ownership_ddw(container,

						table_group);

			}

		}

	}



unlock_exit: