On Wed, 12 Nov 2008 15:37:43 +1100 Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> wrote: > On Tue, 2008-11-11 at 18:06 -0600, Hollis Blanchard wrote: > > The current CHIP11 errata truncates the device tree memory node, and subtracts > > (hardcoded) 4096 bytes. This breaks kernels with larger PAGE_SIZE, since the > > bootmem allocator assumes that total memory is a multiple of PAGE_SIZE. > > > > Instead, use a device tree memory reservation to reserve only the 256 bytes > > actually affected by the errata, leaving the total memory size unaltered. > > > > Signed-off-by: Hollis Blanchard <hollisb@xxxxxxxxxx> > > While I prefer this approach, won't it break kexec ? Break it how? Particularly given that kexec doesn't work on 4xx (yet). > I don't understand why we don't just have a bit of code in the kernel > itself that reserve that page on 44x at boot time and be done with it. > > It's like we are trying to be too smart and over-engineer the solution. I don't think that's it. I think it's more that we're opportunistic and the wrapper is the easiest place to do this, given that U-Boot itself will be doing the reserve for platforms that don't require the wrapper. So we could do the fixup in-kernel, but how do you do that deterministically given that U-Boot might have already done it? josh -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
