On Mon, Jan 16, 2017 at 05:25:07PM +0900, AKASHI Takahiro wrote: > On Fri, Jan 13, 2017 at 11:17:56AM +0000, Mark Rutland wrote: > > On Fri, Jan 13, 2017 at 06:13:49PM +0900, AKASHI Takahiro wrote: > > > On Thu, Jan 12, 2017 at 03:39:45PM +0000, Mark Rutland wrote: > > > > arm64 we should either ensure that /proc/iomem is consistently usable > > > > (and have userspace consistently use it), or we should expose a new file > > > > specifically to expose this information. > > > > > > The thing that I had in my mind when adding this property is that > > > /proc/iomem would be obsolete in the future, then we should have > > > an alternative in hand. > > > > Ok. > > > > My disagreement is with using the DT as a channel to convey information > > from the kernel to userspace. > > > > I'm more than happy for a new file or other mechanism to express this > > information. For example, we could add > > /sys/kernel/kexec_crash_{base,size} or similar. > > It may make sense because /sys/kernel/kexec_crash_size already exists, > so why not kexec_crash_base? > My concern, however, is that this kind of interface might prevent us from > allowing multiple regions to be reserved for crash dump kernel in the future. > (There is an assumption that we have only one region at least on arm64 though.) Ok. If we need to handle that, we should also update the description of linux,usable-memory-range to allow multiple entries (and probably s/range/ranges). Thanks, Mark. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html