o Enforce TX/RX descriptor ring alignment. NS data sheet says the controller needs 4 bytes alignment but use 16 to cover both SiS and NS controllers. I don't have SiS data sheet so I'm not sure what is alignment restriction of SiS controller but 16 would be enough because it's larger than the size of a TX/RX descriptor. Previously sis(4) ignored the alignment restriction. o Enforce RX buffer alignment, 4. Previously sis(4) ignored RX buffer alignment restriction. o Limit number of TX DMA segment to be used to 16. It seems controller has no restriction on number of DMA segments but using more than 16 looks resource waste. o Collapse long mbuf chains with m_collapse(9) instead of calling expensive m_defrag(9). o TX/RX side bus_dmamap_load_mbuf_sg(9) support and remove unnecessary callbacks. o Initial endianness support. o Prefer local alignment fixup code to m_devget(9). o Pre-allocate TX/RX mbuf DMA maps instead of creating/destroying these maps in fast TX/RX path. On non-x86 architectures, this is very expensive operation and there is no need to do that. o Add missing bus_dmamap_sync(9) in TX/RX path. o watchdog is now unarmed only when there are no pending frames on controller. Previously sis(4) blindly unarmed watchdog without checking the number of queued frames. o For efficiency, loaded DMA map is reused for error frames. o DMA map loading failure is now gracefully handled. Previously sis(4) ignored any DMA map loading errors. o Nuke unused macros which are not appropriate for endianness operation. o Stop embedding driver maintained structures into descriptor rings. Because TX/RX descriptor structures are shared between host and controller, frequent bus_dmamap_sync(9) operations are required in fast path. Embedding driver structures will increase the size of DMA map which in turn will slow down performance. |
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if_sis.c | ||
if_sisreg.h |