Reserving large amounts of RAM for busmastering PCI card.

[John P. Hartmann]

 RE:  Reserving large amounts of RAM for busmastering PCI card.

 Please CC [e-mail] on your replies.

 I have an IBM P390 card, which will use up to 512M of contiguous
 RAM for "expanded storage", which can be thought of as a swap device.

 On the 2.2 kernels I modified setup.c to parse RESERVE=nnnM and take
 that amount off the top of the bios-reported memory size.  My module
 then picks the address and size up from a place where I left them at
 boot time.

 Since the 2.4 kernels introduce the e820map structure, I'd like to
 plug into that infrastructure, and create a new type memory segment
 for this storage (I envisage having more than one segment), but in the
 2.4.4 kernel (which I am forced to remain with for quite a while) it
 seems not to be used apart from set up at boot time.

 I'm quite happy to do the work to generalise this, if I could get a
 pointer as to the direction that is envisaged.

 Thanks,

     j.                                                [e-mail]