Hello. My device has a dedicated memory to put packets buffer inside and save CPU RAM space. The issue is I do not know how to allocate a mbuf inside this physical memory. Is mmap able to do such ? Is that the purpose of its "addr" parameter ? Once again, thank you very much for your help. Guillaume.
I doubt this is a good idea. mbuf being hold all the time, buffering, waiting for client application come to read it out of the stack, ... The memory in your device may run out very quickly. I would suggest do a copy in the driver layer. -xtang On Wed, 2009-06-24 at 09:42 -0400, Guillaume Varlet wrote: > Hello. > > My device has a dedicated memory to put packets buffer inside and save > CPU RAM space. > > The issue is I do not know how to allocate a mbuf inside this physical > memory. > Is mmap able to do such ? > Is that the purpose of its "addr" parameter ? > > Once again, thank you very much for your help. > Guillaume. > > _______________________________________________ > Networking Drivers > http://community.qnx.com/sf/go/post32441 > > >
On Wed, Jun 24, 2009 at 09:42:19AM -0400, Guillaume Varlet wrote: > Hello. > > My device has a dedicated memory to put packets buffer inside and save CPU RAM space. > > The issue is I do not know how to allocate a mbuf inside this physical memory. > Is mmap able to do such ? > Is that the purpose of its "addr" parameter ? > > Once again, thank you very much for your help. This is for receive right? If you know the physical offset you can mmap it in with or use mmap_device_memory(). For an example of pointing an mbuf in it and reusing it after mfree() grep for MEXTADD in the wpi driver which also uses its own receive pool. http://community.qnx.com/integration/viewcvs/viewcvs.cgi/trunk/sys/dev/pci/if_wpi.c?root=core_networking&rev=904&system= exsy1001&view=log -seanb
