On Sat, 22 Feb 2014 07:41:26 Benjamin Herrenschmidt wrote: > On Fri, 2014-02-21 at 15:33 +0100, Arnd Bergmann wrote:
[...] > > Should we (provided it's possible in HW) create two ranges instead ? One > covering RAM and one covering MSIs ? To avoid stray DMAs whacking random > HW registers in the chip ... > The thought occurred to me but I figured if we had stray DMAs then they could already whack random bits of system memory which would likely break your system anyway so I wasn't sure how much we'd gain. I guess whacking random HW registers is arguably a bit worse though. I did a bit of digging into the HW documentation and it looks like it _may_ be possible to create a second range that would limit access to a subset of HW registers, although there doesn't seem to be much flexibility. Personally I'm not sure it justifies the work, but I'm happy to look into it a bit more if you feel it's important? - Alistair _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
