powerpc: Fix build failure when MEMORY_HOTPLUG=y

[Michael Ellerman]

On Tue, 2014-19-08 at 21:01:05 UTC, Pranith Kumar wrote:
> ARCH_ENABLE_MEMORY_HOTPLUG is enabled by default for powerpc. This causes build
> failures when SPARSEMEM=n as memory hotplug needs definition which are defined
> only when SPARSEMEM=y. The error is as follows:

> arch/powerpc/platforms/pseries/hotplug-memory.c:27:31: error: 'SECTION_SIZE_BITS' undeclared (first use in this function)
> arch/powerpc/platforms/pseries/hotplug-memory.c:27:31: note: each undeclared identifier is reported only once for each function it appears in

I don't see how you can even build pseries without SPARSEMEM=y ?

The three options are:

	default DISCONTIGMEM_MANUAL if ARCH_DISCONTIGMEM_DEFAULT
	default SPARSEMEM_MANUAL if ARCH_SPARSEMEM_DEFAULT
	default FLATMEM_MANUAL

We don't have DISCONTIGMEM.

FLATMEM_MANUAL depends on !ARCH_SPARSEMEM_ENABLE.

We turn on ARCH_SPARSEMEM_ENABLE, and it's not user editable.

cheers