Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: Question regarding DMA xfer to user space directly | From | Alan Cox <> | Date | 08 Jul 2003 16:22:23 +0100 |
| |
On Maw, 2003-07-08 at 15:50, Alan Shih wrote: > Is there a provision in MM for DMA transfer to user space directly without > allocating a kernel buffer?
Yes. Its used both for O_DIRECT I/O (direct to disk I/O from userspace) and for things like tv capture cards. The kernel allows a driver to pin user pages and obtain mappings for them. Note that for large systems user pages may be above the 32bit boundary so you need DAC capable hardware to get the best results
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| ![\](/images/icornerr.gif) |