On Fri, 8 Nov 2013 18:41:45 -0500 Santosh Shilimkar <santosh.shilimkar@xxxxxx> wrote:
> Introduce memblock memory allocation APIs which allow to support
> PAE or LPAE extension on 32 bits archs where the physical memory start
> address can be beyond 4GB. In such cases, existing bootmem APIs which
> operate on 32 bit addresses won't work and needs memblock layer which
> operates on 64 bit addresses.
>
> So we add equivalent APIs so that we can replace usage of bootmem
> with memblock interfaces. Architectures already converted to NO_BOOTMEM
> use these new interfaces and other which still uses bootmem, these new
> APIs just fallback to exiting bootmem APIs. So no functional change as
> such.
>
> In long run, once all the achitectures moves to NO_BOOTMEM, we can get rid of
> bootmem layer completely. This is one step to remove the core code dependency
> with bootmem and also gives path for architectures to move away from bootmem.
>
> The proposed interface will became active if both CONFIG_HAVE_MEMBLOCK
> and CONFIG_NO_BOOTMEM are specified by arch. In case !CONFIG_NO_BOOTMEM,
> the memblock() wrappers will fallback to the existing bootmem apis so
> that arch's not converted to NO_BOOTMEM continue to work as is.
>
> The meaning of MEMBLOCK_ALLOC_ACCESSIBLE and MEMBLOCK_ALLOC_ANYWHERE is
> kept same.
>
> ...
>
> +static void * __init _memblock_virt_alloc_try_nid_nopanic(
> + phys_addr_t size, phys_addr_t align,
> + phys_addr_t from, phys_addr_t max_addr,
> + int nid)
> +{
> + phys_addr_t alloc;
> + void *ptr;
> +
> + if (WARN_ON_ONCE(slab_is_available())) {
> + if (nid == MAX_NUMNODES)
> + return kzalloc(size, GFP_NOWAIT);
> + else
> + return kzalloc_node(size, GFP_NOWAIT, nid);
> + }
The use of MAX_NUMNODES is a bit unconventional here. I *think* we
generally use NUMA_NO_NODE to indicate "don't care". I Also *think*
that if this code did s/MAX_NUMNODES/NUMA_NO_NODE/g then the above
simply becomes
return kzalloc_node(size, GFP_NOWAIT, nid);
and kzalloc_node() handles NUMA_NO_NODE appropriately.
I *think* ;) Please check all this.
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