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authorJoerg Roedel <jroedel@suse.de>2017-08-23 15:50:04 +0200
committerJoerg Roedel <jroedel@suse.de>2017-08-30 18:07:13 +0200
commitadd02cfdc9bc2987b0121861d5bb0c7392865be9 (patch)
treecb6fac974f4197968af1346bc13d6fce9f461cf7 /drivers/iommu
parent0688a09990986cd8c2fda26afb04ce0a599ced3f (diff)
downloadlinux-add02cfdc9bc2987b0121861d5bb0c7392865be9.tar.bz2
iommu: Introduce Interface for IOMMU TLB Flushing
With the current IOMMU-API the hardware TLBs have to be flushed in every iommu_ops->unmap() call-back. For unmapping large amounts of address space, like it happens when a KVM domain with assigned devices is destroyed, this causes thousands of unnecessary TLB flushes in the IOMMU hardware because the unmap call-back runs for every unmapped physical page. With the TLB Flush Interface and the new iommu_unmap_fast() function introduced here the need to clean the hardware TLBs is removed from the unmapping code-path. Users of iommu_unmap_fast() have to explicitly call the TLB-Flush functions to sync the page-table changes to the hardware. Three functions for TLB-Flushes are introduced: * iommu_flush_tlb_all() - Flushes all TLB entries associated with that domain. TLBs entries are flushed when this function returns. * iommu_tlb_range_add() - This will add a given range to the flush queue for this domain. * iommu_tlb_sync() - Flushes all queued ranges from the hardware TLBs. Returns when the flush is finished. The semantic of this interface is intentionally similar to the iommu_gather_ops from the io-pgtable code. Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iommu.c32
1 files changed, 28 insertions, 4 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 5499a0387349..31c2b1dc8cfd 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -527,6 +527,8 @@ static int iommu_group_create_direct_mappings(struct iommu_group *group,
}
+ iommu_flush_tlb_all(domain);
+
out:
iommu_put_resv_regions(dev, &mappings);
@@ -1547,13 +1549,16 @@ int iommu_map(struct iommu_domain *domain, unsigned long iova,
}
EXPORT_SYMBOL_GPL(iommu_map);
-size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
+static size_t __iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size,
+ bool sync)
{
+ const struct iommu_ops *ops = domain->ops;
size_t unmapped_page, unmapped = 0;
- unsigned int min_pagesz;
unsigned long orig_iova = iova;
+ unsigned int min_pagesz;
- if (unlikely(domain->ops->unmap == NULL ||
+ if (unlikely(ops->unmap == NULL ||
domain->pgsize_bitmap == 0UL))
return -ENODEV;
@@ -1583,10 +1588,13 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
while (unmapped < size) {
size_t pgsize = iommu_pgsize(domain, iova, size - unmapped);
- unmapped_page = domain->ops->unmap(domain, iova, pgsize);
+ unmapped_page = ops->unmap(domain, iova, pgsize);
if (!unmapped_page)
break;
+ if (sync && ops->iotlb_range_add)
+ ops->iotlb_range_add(domain, iova, pgsize);
+
pr_debug("unmapped: iova 0x%lx size 0x%zx\n",
iova, unmapped_page);
@@ -1594,11 +1602,27 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size)
unmapped += unmapped_page;
}
+ if (sync && ops->iotlb_sync)
+ ops->iotlb_sync(domain);
+
trace_unmap(orig_iova, size, unmapped);
return unmapped;
}
+
+size_t iommu_unmap(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ return __iommu_unmap(domain, iova, size, true);
+}
EXPORT_SYMBOL_GPL(iommu_unmap);
+size_t iommu_unmap_fast(struct iommu_domain *domain,
+ unsigned long iova, size_t size)
+{
+ return __iommu_unmap(domain, iova, size, false);
+}
+EXPORT_SYMBOL_GPL(iommu_unmap_fast);
+
size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova,
struct scatterlist *sg, unsigned int nents, int prot)
{