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author | Joerg Roedel <jroedel@suse.de> | 2017-08-23 15:50:04 +0200 |
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committer | Joerg Roedel <jroedel@suse.de> | 2017-08-30 18:07:13 +0200 |
commit | add02cfdc9bc2987b0121861d5bb0c7392865be9 (patch) | |
tree | cb6fac974f4197968af1346bc13d6fce9f461cf7 /drivers/iommu | |
parent | 0688a09990986cd8c2fda26afb04ce0a599ced3f (diff) | |
download | linux-stable-add02cfdc9bc2987b0121861d5bb0c7392865be9.tar.gz linux-stable-add02cfdc9bc2987b0121861d5bb0c7392865be9.tar.bz2 linux-stable-add02cfdc9bc2987b0121861d5bb0c7392865be9.zip |
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.c | 32 |
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) { |