On 07/27/2010 11:01 PM, David Miller wrote: > From: "H. Peter Anvin" <hpa@xxxxxxxxx> > Date: Tue, 27 Jul 2010 22:53:21 -0700 > >> On 07/27/2010 10:19 PM, Benjamin Herrenschmidt wrote: >>> >>> Screw it, I don't like it but I'll just split your patch in two for now >>> and keep 0. It's a bit fishy but memblock does mostly top-down >>> allocations and so shouldn't hit 0, and in practice the region at 0 is, >>> I beleive, reserved, but we need to be extra careful and might need to >>> revisit that a bit. >>> >>> That's an area where I don't completely agree with Linus, ie, 0 is a >>> perfectly valid physical address for memblock to return :-) >>> >> >> On x86, physical address 0 contains the real-mode IVT and will thus be >> reserved, at least for the forseeable future. Other architectures may >> very well have non-special RAM there. > > 0 is very much possible on sparc64 So still keep MEMBLOCK_ERROR to (~(phys_addr_t)0) ? We can change some variable from unsigned long to phys_addr_t that will be assigned by memblock_find_base(). that could avoid casting too. Thanks Yinghai -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html