Very Computer

by **Frank McGi** » Thu, 21 Jan 1999 04:00:00

I am developing a driver for RH 5.2 for a PCI-based adapter which
supports DMA. I have allocated a driver buffer using __get_dma_pages
and I would like to map this buffer to user space so as to be directly
accessible by a user process.

Has anyone seen any sample code to do this?? I would appreciate any
hints and/or help.

Frank McGirt

by **Frank McGi** » Wed, 27 Jan 1999 04:00:00

Thanks, Rob. I'll take a look.

Frank

>> I am developing a driver for RH 5.2 for a PCI-based adapter which
>> supports DMA. I have allocated a driver buffer using __get_dma_pages
>> and I would like to map this buffer to user space so as to be directly
>> accessible by a user process.

>> Has anyone seen any sample code to do this?? I would appreciate any
>> hints and/or help.

>I'm not sure this is possible with the standard kernel. What I have
>done in a similar situation is to have the user process allocate the
>buffer (e.g. malloc(), static data or whatever) and let the device
>driver DMA to that buffer directly. This worked fine, but it required
>a kernel patch which I've made available at ftp://ftp.sysgo.de/pub/Linux/

>Rob

>----------------------------------------------------------------
>Robert Kaiser email: rkaiser AT sysgo DOT de
>SYSGO RTS GmbH
>Carl-Zeiss-Str. 41
>D-55129 Mainz / Germany

Very Computer

Mapping driver buffer to user space

Mapping driver buffer to user space

Mapping driver buffer to user space