Date: Wed, 1 Sep 2010 19:33:40 +0000 (UTC) From: Pyun YongHyeon <yongari@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/dev/sis if_sis.c if_sisreg.h Message-ID: <201009011933.o81JXvvu027809@repoman.freebsd.org>
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yongari 2010-09-01 19:33:40 UTC
FreeBSD src repository
Modified files:
sys/dev/sis if_sis.c if_sisreg.h
Log:
SVN rev 212109 on 2010-09-01 19:33:40Z by yongari
bus_dma(9) cleanup.
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.
Revision Changes Path
1.14 +462 -396 src/sys/dev/sis/if_sis.c
1.4 +36 -25 src/sys/dev/sis/if_sisreg.h
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