]> git.karo-electronics.de Git - karo-tx-linux.git/commit
iommu/arm-smmu: Set SMTNMB_TLBEN in ACR to enable caching of bypass entries
authorNipun Gupta <nipun.gupta@nxp.com>
Fri, 4 Nov 2016 09:55:23 +0000 (15:25 +0530)
committerWill Deacon <will.deacon@arm.com>
Tue, 29 Nov 2016 15:57:41 +0000 (15:57 +0000)
commit6eb18d4a2b860ad259763c5e6d632839dcf974a1
tree5a3f94d9a5a84109af05a1946d1bfb9967c54544
parentdfed5f01e2461af2e5f05b87868c22fe8dff6762
iommu/arm-smmu: Set SMTNMB_TLBEN in ACR to enable caching of bypass entries

The SMTNMB_TLBEN in the Auxiliary Configuration Register (ACR) provides an
option to enable the updation of TLB in case of bypass transactions due to
no stream match in the stream match table. This reduces the latencies of
the subsequent transactions with the same stream-id which bypasses the SMMU.
This provides a significant performance benefit for certain networking
workloads.

With this change substantial performance improvement of ~9% is observed with
DPDK l3fwd application (http://dpdk.org/doc/guides/sample_app_ug/l3_forward.html)
on NXP's LS2088a platform.

Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
drivers/iommu/arm-smmu.c