From: munisekharrms@gmail.com (Muni Sekhar)
To: kernelnewbies@lists.kernelnewbies.org
Subject: scatter-gather doubt?
Date: Sat, 24 Sep 2016 19:03:50 +0530 [thread overview]
Message-ID: <CAHhAz+j3f=TELfXbR3gdmKk-bQr41aRpxqHSRkSiA0KkZ3i6Dw@mail.gmail.com> (raw)
Hi All,
I am working on a xilinx PCIe endpoint with DMA reference block.
The DMA reference block design has 2 Scatter-Gather engines, one for
each DMA channel.
Channel 0 is for HostMemory -> DMA_REF FIFO transfers
Channel 1 is for DMA_REF FIFO -> HostMemory transfers
Each scatter-gather engine works through a linked list of Descriptors
from which it generates the required DMA activity.
The format of these descriptors is depicted as below:
Offset @ 0x00 - LSBs of pointer to DMA data
Offset @ 0x04 - MSBs of pointer to DMA data
Offset @ 0x08 - Number of data bytes to be transferred. (note: only 8
byte aligned transfers supported)
Offset @ 0x0C - LSBs of pointer to next Descriptor (Set this field &
MSBs to zero to indicate end of descriptor list)
Offset @ 0x10 - MSBs of pointer to next Descriptor
Does the Linux kernel has any data structure to support the above
mentioned scatter-gather descriptor?
Will it be possible to use the kernel scatterlist API?s for this hardware?
--
Thanks,
Sekhar
next reply other threads:[~2016-09-24 13:33 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-24 13:33 Muni Sekhar [this message]
2016-09-24 19:32 ` scatter-gather doubt? Greg Freemyer
2016-09-26 10:25 ` Muni Sekhar
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