diff options
| author | Robin Murphy <robin.murphy@arm.com> | 2021-08-11 15:21:28 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-08-18 14:25:32 +0300 |
| commit | 7a7c5badf85806eab75e31ab8d45021f1545b0e3 (patch) | |
| tree | 426957aa85d006744de240c29724cf91b190389e /drivers/iommu/iova.c | |
| parent | 8d971243a9a7d73a410450951a21f298f1394dc7 (diff) | |
| download | linux-7a7c5badf85806eab75e31ab8d45021f1545b0e3.tar.xz | |
iommu: Indicate queued flushes via gather data
Since iommu_iotlb_gather exists to help drivers optimise flushing for a
given unmap request, it is also the logical place to indicate whether
the unmap is strict or not, and thus help them further optimise for
whether to expect a sync or a flush_all subsequently. As part of that,
it also seems fair to make the flush queue code take responsibility for
enforcing the really subtle ordering requirement it brings, so that we
don't need to worry about forgetting that if new drivers want to add
flush queue support, and can consolidate the existing versions.
While we're adding to the kerneldoc, also fill in some info for
@freelist which was overlooked previously.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Link: https://lore.kernel.org/r/bf5f8e2ad84e48c712ccbf80fa8c610594c7595f.1628682049.git.robin.murphy@arm.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/iova.c')
| -rw-r--r-- | drivers/iommu/iova.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c index b6cf5f16123b..2ad73fb2e94e 100644 --- a/drivers/iommu/iova.c +++ b/drivers/iommu/iova.c @@ -637,6 +637,13 @@ void queue_iova(struct iova_domain *iovad, unsigned long flags; unsigned idx; + /* + * Order against the IOMMU driver's pagetable update from unmapping + * @pte, to guarantee that iova_domain_flush() observes that if called + * from a different CPU before we release the lock below. + */ + smp_wmb(); + spin_lock_irqsave(&fq->lock, flags); /* |