diff options
| author | Zhen Lei | 2018-09-20 17:10:23 +0100 |
|---|---|---|
| committer | Will Deacon | 2018-10-01 13:01:32 +0100 |
| commit | 68a6efe86f6a16e25556a2aff40efad41097b486 (patch) | |
| tree | d4422500a10c32ef7e40cc37598a92f6dd472222 /Documentation/admin-guide/kernel-parameters.txt | |
| parent | 2da274cdf998a1c12afa6b5975db2df1df01edf1 (diff) | |
iommu: Add "iommu.strict" command line option
Add a generic command line option to enable lazy unmapping via IOVA
flush queues, which will initally be suuported by iommu-dma. This echoes
the semantics of "intel_iommu=strict" (albeit with the opposite default
value), but in the driver-agnostic fashion of "iommu.passthrough".
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
[rm: move handling out of SMMUv3 driver, clean up documentation]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: dropped broken printk when parsing command-line option]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Diffstat (limited to 'Documentation/admin-guide/kernel-parameters.txt')
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 9871e649ffef..92ae12aeabf4 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1749,6 +1749,18 @@ nobypass [PPC/POWERNV] Disable IOMMU bypass, using IOMMU for PCI devices. + iommu.strict= [ARM64] Configure TLB invalidation behaviour + Format: { "0" | "1" } + 0 - Lazy mode. + Request that DMA unmap operations use deferred + invalidation of hardware TLBs, for increased + throughput at the cost of reduced device isolation. + Will fall back to strict mode if not supported by + the relevant IOMMU driver. + 1 - Strict mode (default). + DMA unmap operations invalidate IOMMU hardware TLBs + synchronously. + iommu.passthrough= [ARM64] Configure DMA to bypass the IOMMU by default. Format: { "0" | "1" } |