drm/nouveau/tegra: Use iommu_paging_domain_alloc()

Commit <421be3ee36a4> ("drm/rockchip: Refactor IOMMU initialisation") has refactored rockchip_drm_init_iommu() to pass a device that the domain is allocated for. Replace iommu_domain_alloc() with iommu_paging_domain_alloc() to retire the former.

Signed-off-by Lu Baolu <[email protected]>

Reviewed-by Jason Gunthorpe <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

---
drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 10 +++++++---

1 file changed, 7 insertions(+), 3 deletions(-)

drivers/gpu/drm/rockchip/rockchip_drm_drv.c +7 -3

index 44d769d9234d..11e5d10de4d7 100644
@@ -103,13 +103,17 @@ static int rockchip_drm_init_iommu(struct drm_device *drm_dev)
 	struct rockchip_drm_private *private = drm_dev->dev_private;
 	struct iommu_domain_geometry *geometry;
 	u64 start, end;
+	int ret;
 
 	if (IS_ERR_OR_NULL(private->iommu_dev))
 		return 0;
 
-	private->domain = iommu_domain_alloc(private->iommu_dev->bus);
-	if (!private->domain)
-		return -ENOMEM;
+	private->domain = iommu_paging_domain_alloc(private->iommu_dev);
+	if (IS_ERR(private->domain)) {
+		ret = PTR_ERR(private->domain);
+		private->domain = NULL;
+		return ret;
+	}
 
 	geometry = &private->domain->geometry;
 	start = geometry->aperture_start;

Signature · 1 line

2.34.1

Commit <17de3f5fdd35> ("iommu: Retire bus ops") removes iommu ops from the bus structure. The iommu subsystem no longer relies on bus for operations. So iommu_domain_alloc() interface is no longer relevant.

Normally, iommu_paging_domain_alloc() could be a replacement for iommu_domain_alloc() if the caller has the right device for IOMMU API use. Unfortunately, this is not the case for this driver.

Iterate the devices on the platform bus and find a suitable device whose device DMA is translated by an IOMMU. Then use this device to allocate an iommu domain. The iommu subsystem prevents domains allocated by one iommu driver from being attached to devices managed by any different iommu driver.

Signed-off-by Lu Baolu <[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

---
 drivers/gpu/drm/tegra/drm.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

Quoted 14 lines · Lu Baolu

Commit <17de3f5fdd35> ("iommu: Retire bus ops") removes iommu ops from the bus structure. The iommu subsystem no longer relies on bus for operations. So iommu_domain_alloc() interface is no longer relevant.

Normally, iommu_paging_domain_alloc() could be a replacement for iommu_domain_alloc() if the caller has the right device for IOMMU API use. Unfortunately, this is not the case for this driver.

Iterate the devices on the platform bus and find a suitable device whose device DMA is translated by an IOMMU. Then use this device to allocate an iommu domain. The iommu subsystem prevents domains allocated by one iommu driver from being attached to devices managed by any different iommu driver.

Quoted 5 lines

Signed-off-by Lu Baolu<[email protected]>

Link https://lore.kernel.org/r/[email protected] open here

---
  drivers/gpu/drm/tegra/drm.c | 34 +++++++++++++++++++++++++---------
  1 file changed, 25 insertions(+), 9 deletions(-)

Actually I think we can just do something like this:

--- >8 ---

drivers/gpu/drm/tegra/drm.c +1 -2

index d9f0728c3afd..d35e411d536b 100644
@@ -1150,7 +1150,7 @@ static int host1x_drm_probe(struct host1x_device *dev)
  	}
 
  	if (host1x_drm_wants_iommu(dev) && iommu_present(&platform_bus_type)) {
-		tegra->domain = iommu_domain_alloc(&platform_bus_type);
+		tegra->domain = iommu_paging_domain_alloc(dev->dev.parent);
  		if (!tegra->domain) {
  			err = -ENOMEM;
  			goto free;
--- >8 ---

That refers to the physical device that the host1x_device virtual device was instantiated from and is a common parent to all physical devices that are part of the virtual device.