On 31/08/2026 16:59, Michael Kelly wrote:
On 31/08/2026 13:01, Alperen Erkan wrote:
1. As far as I can see, |bus_dmamap_load()|,
|bus_dmamap_load_mbuf()|, and |bus_dmamap_load_uio()| have been
considered, but no equivalent bounce-threshold check has been
added to |bus_dmamap_load_raw()|.
If raw segments contain DMA addresses directly, a segment above the
32-bit limit may be able to bypass the new mechanism. Even if
applying a bounce buffer to the raw-loading path is not possible,
should the supplied segments not at least be checked against
|_dm_bounce_thresh|, with an error returned when they exceed it?
I don't know but will check
arch/x86/bus_dma.c does not implement bounce buffer support in
_bus_dmamap_load_raw(). There is a comment:
/* XXX TBD bounce */
It's not an issue for NetBSD so I think it's irrelevant at this time for
GNU/Hurd.
Thanks,
MIke.
