Date: Sat, 25 Oct 2008 02:36:08 +0000 (UTC) From: Pyun YongHyeon <yongari@FreeBSD.org> To: cvs-src-old@freebsd.org Subject: cvs commit: src/sys/pci if_rl.c if_rlreg.h Message-ID: <200810251818.m9PII2RD001472@repoman.freebsd.org>
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yongari 2008-10-25 02:36:08 UTC
FreeBSD src repository
Modified files:
sys/pci if_rl.c if_rlreg.h
Log:
SVN rev 184240 on 2008-10-25 02:36:08Z by yongari
Various bus_dma(9) fixes.
- The hardware does not support DAC so limit DMA address space to
4GB.
- Removed BUS_DMA_ALLOC_NOW flag.
- Created separated Tx buffer and Rx buffer DMA tags. Previously
it used to single DMA tag and it was not possible to specify
different DMA restrictions.
- Apply 4 bytes alignment limitation of Tx buffer.
- Apply 8 bytes alignment limitation of Rx buffer.
- Tx side bus_dmamap_load_mbuf_sg(9) support.
- Preallocate Tx DMA maps as creating DMA maps take very long time
on architectures that require real DMA maps.
- Adjust guard buffer size to 1522 + 8 as it should include VLAN
and additional reserved bytes in Rx buffer.
- Plug memory leak in device detach. Previously wrong buffer
address was used to free allocated memory.
- Added rl_list_rx_init() to clear Rx buffer and cleared the
buffer.
- Don't destroy DMA maps in rl_txeof() as the DMA map should be
reused. There is no reason to destroy/recreate the DMA maps in
this driver.
- Removed rl_dma_map_rxbuf()/rl_dma_map_txbuf() callbacks.
- The hardware does not support descriptor based DMA on Tx side
and the Tx buffer address should be aligned on 4 bytes boundary
as well as manual padding for short frames. Because of this
hardware limitation rl(4) always used to invoke m_defrag(9) to
get a 4 bytes aligned single buffer. However m_defrag(9) takes
a lot of CPU cycles on slow machines and not all packets need
the help of m_defrag(9). Armed with the information, don't
invoke m_defrag(9) if the following conditions are true.
1. Buffer is not fragmented.
2. Buffer is aligned on 4 bytes boundary.
3. Manual padding is not necessary.
4. Or padding is necessary but upper stack passed a writable
buffer and the space needed for padding is satisfied.
This change combined with preallocated DMA maps greatly
increased Tx performance of driver on sparc64.
- Moved bus_dmamap_sync(9) in rl_start_locked() to rl_encap() and
corrected memory synchronization operation specifier of
bus_dmamap_sync(9).
- Removed bus_dmamap_unload(9) in rl_stop(). There is no need to
reload/unload Rx buffer as rl(4) always have to copy from the
buffer. It just needs proper bus_dmamap_sync(9) calls before
copying the received frame.
With this change rl(4) should work on systems with more than 4GB
memory.
PR: kern/128143
Revision Changes Path
1.176 +247 -118 src/sys/pci/if_rl.c
1.82 +9 -2 src/sys/pci/if_rlreg.h
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