linux-arm-kernel.lists.infradead.org archive mirror
 help / color / mirror / Atom feed
* ARM DMA Zones (coherent memory pool)
       [not found] <1706190290.100315.1358858042869.JavaMail.root@elliptictech.com>
@ 2013-01-22 12:36 ` Tom St Denis
  0 siblings, 0 replies; only message in thread
From: Tom St Denis @ 2013-01-22 12:36 UTC (permalink / raw)
  To: linux-arm-kernel

Hi all,

I was wondering if there was a proper way of instructing the init code (atomic_pool_init) for the DMA coherent subsystem to point to a fixed location instead of using alloc_pages()?

I ask because on our system (Zynq702/706 boards) DDR has a high latency (~25-30 cycles) whereas FPGA memory can be much quicker.  What I'd like to do is create a 256Kbyte memory in FPGA BRAMs and then have the CPU point at it for the DMA zone.

Is that at all possible through a simple kernel cmdline or patch?

Tom

^ permalink raw reply	[flat|nested] only message in thread

only message in thread, other threads:[~2013-01-22 12:36 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
     [not found] <1706190290.100315.1358858042869.JavaMail.root@elliptictech.com>
2013-01-22 12:36 ` ARM DMA Zones (coherent memory pool) Tom St Denis

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).