Messages in this thread Patch in this message | | | From | Lu Baolu <> | Subject | [PATCH v4 1/6] iommu/ipmmu-vmsa: Call arm_iommu_release_mapping() in release path | Date | Wed, 22 Mar 2023 14:49:51 +0800 |
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In the iommu driver's release_device operation, the driver should detach the device from any attached domain and release the resources allocated in the probe_device and probe_finalize paths.
Replace arm_iommu_detach_device() with arm_iommu_release_mapping() in the release path of the ipmmu-vmsa driver. The device_release callback is called in device_del(), this device is not coming back. Zeroing out pointers and testing for a condition which cannot be true by construction is simply a waste of time and code.
The bonus is that it also removes a obstacle of arm_iommu_detach_device() re-entering the iommu core during release_device. With this removed, the iommu core code could be simplified a lot.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com> Suggested-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/linux-iommu/7b248ba1-3967-5cd8-82e9-0268c706d320@arm.com/ Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> --- drivers/iommu/ipmmu-vmsa.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c index bdf1a4e5eae0..bc135679523a 100644 --- a/drivers/iommu/ipmmu-vmsa.c +++ b/drivers/iommu/ipmmu-vmsa.c @@ -30,7 +30,6 @@ #define arm_iommu_create_mapping(...) NULL #define arm_iommu_attach_device(...) -ENODEV #define arm_iommu_release_mapping(...) do {} while (0) -#define arm_iommu_detach_device(...) do {} while (0) #endif #define IPMMU_CTX_MAX 16U @@ -820,7 +819,18 @@ static void ipmmu_probe_finalize(struct device *dev) static void ipmmu_release_device(struct device *dev) { - arm_iommu_detach_device(dev); + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + struct ipmmu_vmsa_device *mmu = to_ipmmu(dev); + unsigned int i; + + for (i = 0; i < fwspec->num_ids; ++i) { + unsigned int utlb = fwspec->ids[i]; + + ipmmu_imuctr_write(mmu, utlb, 0); + mmu->utlb_ctx[utlb] = IPMMU_CTX_INVALID; + } + + arm_iommu_release_mapping(mmu->mapping); } static struct iommu_group *ipmmu_find_group(struct device *dev) -- 2.34.1
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