From fa4c4507099f781ca89a748c480af9cf97629726 Mon Sep 17 00:00:00 2001 From: Niklas Schnelle Date: Thu, 28 Sep 2023 16:31:35 +0200 Subject: iommu: Allow .iotlb_sync_map to fail and handle s390's -ENOMEM return On s390 when using a paging hypervisor, .iotlb_sync_map is used to sync mappings by letting the hypervisor inspect the synced IOVA range and updating a shadow table. This however means that .iotlb_sync_map can fail as the hypervisor may run out of resources while doing the sync. This can be due to the hypervisor being unable to pin guest pages, due to a limit on mapped addresses such as vfio_iommu_type1.dma_entry_limit or lack of other resources. Either way such a failure to sync a mapping should result in a DMA_MAPPING_ERROR. Now especially when running with batched IOTLB flushes for unmap it may be that some IOVAs have already been invalidated but not yet synced via .iotlb_sync_map. Thus if the hypervisor indicates running out of resources, first do a global flush allowing the hypervisor to free resources associated with these mappings as well a retry creating the new mappings and only if that also fails report this error to callers. Reviewed-by: Lu Baolu Reviewed-by: Matthew Rosato Acked-by: Jernej Skrabec # sun50i Signed-off-by: Niklas Schnelle Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-1-9e5fc4dacc36@linux.ibm.com Signed-off-by: Joerg Roedel --- drivers/iommu/sun50i-iommu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/iommu/sun50i-iommu.c') diff --git a/drivers/iommu/sun50i-iommu.c b/drivers/iommu/sun50i-iommu.c index 3c834854eda1..41484a5a399b 100644 --- a/drivers/iommu/sun50i-iommu.c +++ b/drivers/iommu/sun50i-iommu.c @@ -401,8 +401,8 @@ static void sun50i_iommu_flush_iotlb_all(struct iommu_domain *domain) spin_unlock_irqrestore(&iommu->iommu_lock, flags); } -static void sun50i_iommu_iotlb_sync_map(struct iommu_domain *domain, - unsigned long iova, size_t size) +static int sun50i_iommu_iotlb_sync_map(struct iommu_domain *domain, + unsigned long iova, size_t size) { struct sun50i_iommu_domain *sun50i_domain = to_sun50i_domain(domain); struct sun50i_iommu *iommu = sun50i_domain->iommu; @@ -411,6 +411,8 @@ static void sun50i_iommu_iotlb_sync_map(struct iommu_domain *domain, spin_lock_irqsave(&iommu->iommu_lock, flags); sun50i_iommu_zap_range(iommu, iova, size); spin_unlock_irqrestore(&iommu->iommu_lock, flags); + + return 0; } static void sun50i_iommu_iotlb_sync(struct iommu_domain *domain, -- cgit v1.2.3