[PATCH v2 1/4] iommu: Add private_data_owner to iommu_domain

[Nicolin Chen]

Steal two bits from the 32-bit "type" in struct iommu_domain to store a
new tag for private data owned by either dma-iommu or iommufd.

Set the domain->private_data_owner in dma-iommu and iommufd. These will
be used to replace the sw_msi function pointer.

Suggested-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Nicolin Chen <nicolinc@xxxxxxxxxx>
---
 include/linux/iommu.h                | 7 ++++++-
 drivers/iommu/dma-iommu.c            | 2 ++
 drivers/iommu/iommufd/hw_pagetable.c | 3 +++
 3 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index e93d2e918599..4f2774c08262 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -209,8 +209,13 @@ struct iommu_domain_geometry {
 #define IOMMU_DOMAIN_PLATFORM	(__IOMMU_DOMAIN_PLATFORM)
 #define IOMMU_DOMAIN_NESTED	(__IOMMU_DOMAIN_NESTED)
 
+#define IOMMU_DOMAIN_DATA_OWNER_NONE (0U)
+#define IOMMU_DOMAIN_DATA_OWNER_DMA (1U)
+#define IOMMU_DOMAIN_DATA_OWNER_IOMMUFD (2U)
+
 struct iommu_domain {
-	unsigned type;
+	u32 type : 30;
+	u32 private_data_owner : 2;
 	const struct iommu_domain_ops *ops;
 	const struct iommu_dirty_ops *dirty_ops;
 	const struct iommu_ops *owner; /* Whose domain_alloc we came from */
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 94263ed2c564..78915d74e8fa 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -403,6 +403,7 @@ int iommu_get_dma_cookie(struct iommu_domain *domain)
 
 	mutex_init(&domain->iova_cookie->mutex);
 	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
+	domain->private_data_owner = IOMMU_DOMAIN_DATA_OWNER_DMA;
 	return 0;
 }
 
@@ -435,6 +436,7 @@ int iommu_get_msi_cookie(struct iommu_domain *domain, dma_addr_t base)
 	cookie->msi_iova = base;
 	domain->iova_cookie = cookie;
 	iommu_domain_set_sw_msi(domain, iommu_dma_sw_msi);
+	domain->private_data_owner = IOMMU_DOMAIN_DATA_OWNER_DMA;
 	return 0;
 }
 EXPORT_SYMBOL(iommu_get_msi_cookie);
diff --git a/drivers/iommu/iommufd/hw_pagetable.c b/drivers/iommu/iommufd/hw_pagetable.c
index 7de6e914232e..5640444de475 100644
--- a/drivers/iommu/iommufd/hw_pagetable.c
+++ b/drivers/iommu/iommufd/hw_pagetable.c
@@ -157,6 +157,7 @@ iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
 		}
 	}
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
+	hwpt->domain->private_data_owner = IOMMU_DOMAIN_DATA_OWNER_IOMMUFD;
 
 	/*
 	 * Set the coherency mode before we do iopt_table_add_domain() as some
@@ -253,6 +254,7 @@ iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
 	}
 	hwpt->domain->owner = ops;
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
+	hwpt->domain->private_data_owner = IOMMU_DOMAIN_DATA_OWNER_IOMMUFD;
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;
@@ -310,6 +312,7 @@ iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
 	}
 	hwpt->domain->owner = viommu->iommu_dev->ops;
 	iommu_domain_set_sw_msi(hwpt->domain, iommufd_sw_msi);
+	hwpt->domain->private_data_owner = IOMMU_DOMAIN_DATA_OWNER_IOMMUFD;
 
 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
 		rc = -EINVAL;
-- 
2.43.0