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authorNiklas Schnelle <schnelle@linux.ibm.com>2023-09-28 17:31:35 +0300
committerJoerg Roedel <jroedel@suse.de>2023-10-02 09:42:57 +0300
commitfa4c4507099f781ca89a748c480af9cf97629726 (patch)
treecbc571a65429151d3e53f8ae92e252d89d28f785 /drivers/iommu/msm_iommu.c
parentccb76c5751634541bfd2222374f46e1dea83d525 (diff)
downloadlinux-fa4c4507099f781ca89a748c480af9cf97629726.tar.xz
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 <baolu.lu@linux.intel.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun50i Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Link: https://lore.kernel.org/r/20230928-dma_iommu-v13-1-9e5fc4dacc36@linux.ibm.com Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/msm_iommu.c')
-rw-r--r--drivers/iommu/msm_iommu.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index a163cee0b724..f86af9815d6f 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -498,12 +498,13 @@ static int msm_iommu_map(struct iommu_domain *domain, unsigned long iova,
return ret;
}
-static void msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
- size_t size)
+static int msm_iommu_sync_map(struct iommu_domain *domain, unsigned long iova,
+ size_t size)
{
struct msm_priv *priv = to_msm_priv(domain);
__flush_iotlb_range(iova, size, SZ_4K, false, priv);
+ return 0;
}
static size_t msm_iommu_unmap(struct iommu_domain *domain, unsigned long iova,