[PATCH v2] arm: dma-mapping: Reset the device's dma_ops
From: Sricharan R <hidden>
Date: 2017-05-26 10:43:54
Also in:
linux-arch, linux-arm-msm, linux-iommu, lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
arch_teardown_dma_ops() being the inverse of arch_setup_dma_ops()
,dma_ops should be cleared in the teardown path. Currently, only the
device's iommu mapping structures are cleared in arch_teardown_dma_ops,
but not the dma_ops. So on the next reprobe, dma_ops left in place is
stale from the first IOMMU setup, but iommu mappings has been disposed
of. This is a problem when the probe of the device is deferred and
recalled with the IOMMU probe deferral.
So for fixing this, slightly refactor by moving the code from
__arm_iommu_detach_device to arm_iommu_detach_device and cleanup
the former. This takes care of resetting the dma_ops in the teardown
path.
Signed-off-by: Sricharan R <redacted>
Fixes: 09515ef5ddad ("of/acpi: Configure dma operations at probe time for platform/amba/pci bus devices")
---
arch/arm/mm/dma-mapping.c | 25 ++++++++++---------------
1 file changed, 10 insertions(+), 15 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c742dfd..6e82e87 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c@@ -2311,7 +2311,14 @@ int arm_iommu_attach_device(struct device *dev, } EXPORT_SYMBOL_GPL(arm_iommu_attach_device); -static void __arm_iommu_detach_device(struct device *dev) +/** + * arm_iommu_detach_device + * @dev: valid struct device pointer + * + * Detaches the provided device from a previously attached map. + * This voids the dma operations (dma_map_ops pointer) + */ +void arm_iommu_detach_device(struct device *dev) { struct dma_iommu_mapping *mapping;
@@ -2324,22 +2331,10 @@ static void __arm_iommu_detach_device(struct device *dev) iommu_detach_device(mapping->domain, dev); kref_put(&mapping->kref, release_iommu_mapping); to_dma_iommu_mapping(dev) = NULL; + set_dma_ops(dev, NULL); pr_debug("Detached IOMMU controller from %s device.\n", dev_name(dev)); } - -/** - * arm_iommu_detach_device - * @dev: valid struct device pointer - * - * Detaches the provided device from a previously attached map. - * This voids the dma operations (dma_map_ops pointer) - */ -void arm_iommu_detach_device(struct device *dev) -{ - __arm_iommu_detach_device(dev); - set_dma_ops(dev, NULL); -} EXPORT_SYMBOL_GPL(arm_iommu_detach_device); static const struct dma_map_ops *arm_get_iommu_dma_map_ops(bool coherent)
@@ -2379,7 +2374,7 @@ static void arm_teardown_iommu_dma_ops(struct device *dev) if (!mapping) return; - __arm_iommu_detach_device(dev); + arm_iommu_detach_device(dev); arm_iommu_release_mapping(mapping); }
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