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

Jason Gunthorpe
2023-02-25T00:28:17Z

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