[PATCH v2 4/4] iommu: dev->iommu->iommu_dev must be set before ops->device_group()

[Jason Gunthorpe <jgg@xxxxxxxxxx>]

As generic_single_device_group() requires it. Otherwise it crashes:

  generic_single_device_group+0x24/0x88
  __iommu_probe_device+0xe8/0x444
  iommu_probe_device+0x1c/0x54
  of_iommu_configure+0x10c/0x200
  of_dma_configure_id+0x1e0/0x3b4
  platform_dma_configure+0x30/0x78
  really_probe+0x70/0x2b4
  __driver_probe_device+0x78/0x12c
  driver_probe_device+0x3c/0x160
  __driver_attach+0x9c/0x1ac
  bus_for_each_dev+0x74/0xd4
  driver_attach+0x24/0x30
  bus_add_driver+0xe4/0x1e8
  driver_register+0x60/0x128
  __platform_driver_register+0x28/0x34
  hantro_driver_init+0x20/0x1000 [hantro_vpu]
  do_one_initcall+0x74/0x2f0
  do_init_module+0x58/0x1ec
  load_module+0x1a20/0x1c64
  init_module_from_file+0x84/0xc0
  idempotent_init_module+0x180/0x250
  __arm64_sys_finit_module+0x64/0xa0
  invoke_syscall+0x48/0x114
  el0_svc_common.constprop.0+0xec/0x10c
  do_el0_svc+0x38/0xa4
  el0_svc+0x40/0xac
  el0t_64_sync_handler+0xc0/0xc4
  el0t_64_sync+0x190/0x194

Fixes: 5dd59857af60 ("iommu: Add generic_single_device_group()")
Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Closes: https://lore.kernel.org/all/e5e75222-13a9-ee01-0c25-8311b622fe0d@xxxxxxxxxxx/
Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
---
 drivers/iommu/iommu.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 3ff365c9117850..18162049bd2294 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -366,6 +366,7 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
 		ret = PTR_ERR(iommu_dev);
 		goto err_module_put;
 	}
+	dev->iommu->iommu_dev = iommu_dev;
 
 	ret = iommu_device_link(iommu_dev, dev);
 	if (ret)
@@ -383,7 +384,6 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
 	dev->iommu_group = group;
 	mutex_unlock(&dev_iommu_group_lock);
 
-	dev->iommu->iommu_dev = iommu_dev;
 	dev->iommu->max_pasids = dev_iommu_get_max_pasids(dev);
 	if (ops->is_attach_deferred)
 		dev->iommu->attach_deferred = ops->is_attach_deferred(dev);
@@ -397,6 +397,7 @@ static int iommu_init_device(struct device *dev, const struct iommu_ops *ops)
 err_module_put:
 	module_put(ops->owner);
 err_free:
+	dev->iommu->iommu_dev = NULL;
 	dev_iommu_free(dev);
 	return ret;
 }
-- 
2.41.0