diff options
| author | Lu Baolu <baolu.lu@linux.intel.com> | 2023-06-14 10:47:05 +0800 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2023-06-16 16:38:33 +0200 |
| commit | b4da4e112ade4e7c59cf915c702b14d69b528824 (patch) | |
| tree | 45dc670fe40e324bded96e4fae3f2c2db2f9652b /drivers/iommu/intel/iommu.c | |
| parent | 3f13f72787bcd15792c01a34c2aed8bdf38397bb (diff) | |
iommu/vt-d: Remove commented-out code
These lines of code were commented out when they were first added in commit
ba39592764ed ("Intel IOMMU: Intel IOMMU driver"). We do not want to restore
them because the VT-d spec has deprecated the read/write draining hit.
VT-d spec (section 11.4.2):
"
Hardware implementation with Major Version 2 or higher (VER_REG), always
performs required drain without software explicitly requesting a drain in
IOTLB invalidation. This field is deprecated and hardware will always
report it as 1 to maintain backward compatibility with software.
"
Remove the code to make the code cleaner.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Link: https://lore.kernel.org/r/20230609060514.15154-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/intel/iommu.c')
| -rw-r--r-- | drivers/iommu/intel/iommu.c | 10 |
1 files changed, 1 insertions, 9 deletions
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c index 4c0b7424c45e..e5c111ff4dd9 100644 --- a/drivers/iommu/intel/iommu.c +++ b/drivers/iommu/intel/iommu.c @@ -1312,15 +1312,7 @@ static void __iommu_flush_iotlb(struct intel_iommu *iommu, u16 did, iommu->name, type); return; } - /* Note: set drain read/write */ -#if 0 - /* - * This is probably to be super secure.. Looks like we can - * ignore it without any impact. - */ - if (cap_read_drain(iommu->cap)) - val |= DMA_TLB_READ_DRAIN; -#endif + if (cap_write_drain(iommu->cap)) val |= DMA_TLB_WRITE_DRAIN; |