From b67483b3c44eaef2f771fa4c712e13f452675a67 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Fri, 19 Apr 2024 17:54:45 +0100 Subject: iommu/dma: Centralise iommu_setup_dma_ops() It's somewhat hard to see, but arm64's arch_setup_dma_ops() should only ever call iommu_setup_dma_ops() after a successful iommu_probe_device(), which means there should be no harm in achieving the same order of operations by running it off the back of iommu_probe_device() itself. This then puts it in line with the x86 and s390 .probe_finalize bodges, letting us pull it all into the main flow properly. As a bonus this lets us fold in and de-scope the PCI workaround setup as well. At this point we can also then pull the call up inside the group mutex, and avoid having to think about whether iommu_group_store_type() could theoretically race and free the domain if iommu_setup_dma_ops() ran just *before* iommu_device_use_default_domain() claims it... Furthermore we replace one .probe_finalize call completely, since the only remaining implementations are now one which only needs to run once for the initial boot-time probe, and two which themselves render that path unreachable. This leaves us a big step closer to realistically being able to unpick the variety of different things that iommu_setup_dma_ops() has been muddling together, and further streamline iommu-dma into core API flows in future. Reviewed-by: Lu Baolu # For Intel IOMMU Reviewed-by: Jason Gunthorpe Tested-by: Hanjun Guo Signed-off-by: Robin Murphy Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/bebea331c1d688b34d9862eefd5ede47503961b8.1713523152.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel --- drivers/iommu/iommu.c | 20 +++++++------------- 1 file changed, 7 insertions(+), 13 deletions(-) (limited to 'drivers/iommu/iommu.c') diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 3183b0ed4cdb..9df7cc75c1bc 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -581,10 +581,11 @@ static int __iommu_probe_device(struct device *dev, struct list_head *group_list if (list_empty(&group->entry)) list_add_tail(&group->entry, group_list); } - mutex_unlock(&group->mutex); - if (dev_is_pci(dev)) - iommu_dma_set_pci_32bit_workaround(dev); + if (group->default_domain) + iommu_setup_dma_ops(dev); + + mutex_unlock(&group->mutex); return 0; @@ -1828,6 +1829,8 @@ int bus_iommu_probe(const struct bus_type *bus) mutex_unlock(&group->mutex); return ret; } + for_each_group_device(group, gdev) + iommu_setup_dma_ops(gdev->dev); mutex_unlock(&group->mutex); /* @@ -3066,18 +3069,9 @@ static ssize_t iommu_group_store_type(struct iommu_group *group, if (ret) goto out_unlock; - /* - * Release the mutex here because ops->probe_finalize() call-back of - * some vendor IOMMU drivers calls arm_iommu_attach_device() which - * in-turn might call back into IOMMU core code, where it tries to take - * group->mutex, resulting in a deadlock. - */ - mutex_unlock(&group->mutex); - /* Make sure dma_ops is appropriatley set */ for_each_group_device(group, gdev) - iommu_group_do_probe_finalize(gdev->dev); - return count; + iommu_setup_dma_ops(gdev->dev); out_unlock: mutex_unlock(&group->mutex); -- cgit v1.2.3