diff options
| author | Jason Gunthorpe | 2022-04-11 12:16:07 -0300 |
|---|---|---|
| committer | Joerg Roedel | 2022-04-28 17:24:57 +0200 |
| commit | f78dc1dad829e505d83e33dc0879887f074c52e1 (patch) | |
| tree | d94ad09234bbe08afd5699160c66edc009260d2c /drivers/iommu | |
| parent | 71cfafda9c9bd9812cdb62ddb94daf65a1af12c1 (diff) | |
iommu: Redefine IOMMU_CAP_CACHE_COHERENCY as the cap flag for IOMMU_CACHE
While the comment was correct that this flag was intended to convey the
block no-snoop support in the IOMMU, it has become widely implemented and
used to mean the IOMMU supports IOMMU_CACHE as a map flag. Only the Intel
driver was different.
Now that the Intel driver is using enforce_cache_coherency() update the
comment to make it clear that IOMMU_CAP_CACHE_COHERENCY is only about
IOMMU_CACHE. Fix the Intel driver to return true since IOMMU_CACHE always
works.
The two places that test this flag, usnic and vdpa, are both assigning
userspace pages to a driver controlled iommu_domain and require
IOMMU_CACHE behavior as they offer no way for userspace to synchronize
caches.
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/3-v3-2cf356649677+a32-intel_no_snoop_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 38441cb06c8c..efcecfa5952a 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -4556,7 +4556,7 @@ static bool intel_iommu_enforce_cache_coherency(struct iommu_domain *domain) static bool intel_iommu_capable(enum iommu_cap cap) { if (cap == IOMMU_CAP_CACHE_COHERENCY) - return domain_update_iommu_snooping(NULL); + return true; if (cap == IOMMU_CAP_INTR_REMAP) return irq_remapping_enabled == 1; if (cap == IOMMU_CAP_PRE_BOOT_PROTECTION) |