Use busdma unconditionally in iflib - Remove the complex mechanism to choose between using busdma and raw pmap_kextract at runtime. The reduced complexity makes the code easier to read and maintain. - Fix a bug in the small packet receive path where clusters were repeatedly mapped but never unmapped. We now store the cluster's bus address and avoid re-mapping the cluster each time a small packet is received. This patch fixes bugs I've seen where ixl(4) will not even respond to ping without seeing DMAR faults. I see a small improvement (14%) on packet forwarding tests using a Haswell based Xeon E5-2697 v3. Olivier sees a small regression (-3% to -6%) with lower end hardware.
Reviewed by: mmacy
Sponsored by: Netflix, Inc
Differential Revision: https://reviews.freebsd.org/D17901