[PATCH 05/14] iommufd: Make sw_msi_start a group global

[Jason Gunthorpe <jgg@nvidia.com>]

The sw_msi_start is only set by the ARM drivers and it is always constant.
Due to the way vfio/iommufd allow domains to be re-used between
devices we have a built in assumption that there is only one value
for sw_msi_start and it is global to the system.

To make replace simpler where we may not reparse the
iommu_get_group_resv_regions() move the sw_msi_start to the iommufd_group
so it is always available once any HWPT has been attached.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
 drivers/iommu/iommufd/device.c          | 13 +++++++------
 drivers/iommu/iommufd/iommufd_private.h |  1 +
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index 75e8d79678736f..ea34dc5b0fd1e4 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -74,6 +74,7 @@ static struct iommufd_group *iommufd_get_group(struct iommufd_ctx *ictx,
 
 	kref_init(&new_igroup->ref);
 	mutex_init(&new_igroup->lock);
+	new_igroup->sw_msi_start = PHYS_ADDR_MAX;
 	/* group reference moves into new_igroup */
 	new_igroup->group = group;
 
@@ -238,9 +239,9 @@ void iommufd_device_unbind(struct iommufd_device *idev)
 EXPORT_SYMBOL_NS_GPL(iommufd_device_unbind, IOMMUFD);
 
 static int iommufd_device_setup_msi(struct iommufd_device *idev,
-				    struct iommufd_hw_pagetable *hwpt,
-				    phys_addr_t sw_msi_start)
+				    struct iommufd_hw_pagetable *hwpt)
 {
+	phys_addr_t sw_msi_start = idev->igroup->sw_msi_start;
 	int rc;
 
 	/*
@@ -273,7 +274,6 @@ static int iommufd_device_setup_msi(struct iommufd_device *idev,
 int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 				struct iommufd_device *idev)
 {
-	phys_addr_t sw_msi_start = PHYS_ADDR_MAX;
 	int rc;
 
 	lockdep_assert_held(&idev->igroup->lock);
@@ -310,12 +310,13 @@ int iommufd_hw_pagetable_attach(struct iommufd_hw_pagetable *hwpt,
 		return 0;
 	}
 
-	rc = iopt_table_enforce_group_resv_regions(
-		&hwpt->ioas->iopt, idev->igroup->group, &sw_msi_start);
+	rc = iopt_table_enforce_group_resv_regions(&hwpt->ioas->iopt,
+						   idev->igroup->group,
+						   &idev->igroup->sw_msi_start);
 	if (rc)
 		return rc;
 
-	rc = iommufd_device_setup_msi(idev, hwpt, sw_msi_start);
+	rc = iommufd_device_setup_msi(idev, hwpt);
 	if (rc)
 		goto err_unresv;
 
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index dbecdff013d082..0497d6190fd1b3 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -267,6 +267,7 @@ struct iommufd_group {
 	struct iommu_group *group;
 	struct iommufd_hw_pagetable *hwpt;
 	unsigned int devices;
+	phys_addr_t sw_msi_start;
 };
 
 /*
-- 
2.39.1