Arch code can define ARCH_DISCARD_MEMBLOCK in asm/memblock.h,
which in turns causes memblock code and data to go respectively
into the .init and .initdata sections. This will be used by the
x86 architecture.

If ARCH_DISCARD_MEMBLOCK is defined, the debugfs files to inspect
the memblock arrays after boot are not created.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This should make it easier to catch/debug incorrect use when
the CONFIG_ option isn't set.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

And ensure we don't hand out 0 as a valid allocation. We put the
low limit at PAGE_SIZE arbitrarily.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

will used by x86 memblock_x86_find_in_range_node and nobootmem replacement
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Print out the location info in addition to which array is being
resized. Also use memblocK_dbg() to put that under control of
the memblock_debug flag.
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This exposes memblock_debug and associated memblock_dbg() macro,
along with memblock_can_resize so that x86 can use these when
ported to use memblock
Signed-off-by: NYinghai Lu <yinghai@kernel.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

memblock_alloc_nid() used to fallback to allocating anywhere by using
memblock_alloc() as a fallback.

However, some of my previous patches limit memblock_alloc() to the region
covered by MEMBLOCK_ALLOC_ACCESSIBLE which is not quite what we want
for memblock_alloc_try_nid().

So we fix it by explicitely using MEMBLOCK_ALLOC_ANYWHERE.

Not that so far only sparc uses memblock_alloc_nid() and it hasn't been updated
to clamp the accessible zone yet. Thus the temporary "breakage" should have
no effect.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The former is now strict, it will fail if it cannot honor the allocation
within the node, while the later implements the previous semantic which
falls back to allocating anywhere.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

We now provide a default (weak) implementation of memblock_nid_range()
which uses the early_pfn_map[] if CONFIG_ARCH_POPULATES_NODE_MAP
is set. Sparc still needs to use its own method due to the way
the pages can be scattered between nodes.

This implementation is inefficient due to our main algorithm and
callback construct wanting to work on an ascending addresses bases
while early_pfn_map[] would rather work with nid's (it's unsorted
at that stage). But it should work and we can look into improving
it subsequently, possibly using arch compile options to chose a
different algorithm alltogether.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

To constraint the search of a region between two boundaries,
which will be used by the new NUMA aware allocator among others.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some archs such as ARM want to avoid coalescing accross things such
as the lowmem/highmem boundary or similar. This provides the option
to control it via an arch callback for which a weak default is provided
which always allows coalescing.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

When one of the array gets full, we resize it. After much thinking and
a few iterations of that code, I went back to on-demand resizing using
the (new) internal memblock_find_base() function, which is pretty much what
Yinghai initially proposed, though there some differences in the details.

To work this relies on the default alloc limit being set sensibly by
the architecture.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Some shuffling is needed for doing array resize so we may as well
put some sense into the ordering of the functions in the whole memblock.c
file. No code change. Added some comments.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This will be used by the array resize code and might prove useful
to some arch code as well at which point it can be made non-static.

Also add comment as to why aligning size is important
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
---

v2. Fix loss of size alignment
v3. Fix result code

It's a real PITA to have to search for it in the middle
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This function will be used to locate a free area to put the new memblock
arrays when attempting to resize them. memblock_alloc_region() is gone,
the two callsites now call memblock_add_region().
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
---
v2. Fix membase_alloc_nid_region() conversion

Since we allocate one more than needed, why not do a bit of sanity checking
here to ensure we don't walk past the end of the array ?
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This is in preparation for having resizable arrays.

Note that we still allocate one more than needed, this is unchanged from
the previous implementation.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Right now, both the "memory" and "reserved" memblock_type structures have
a "size" member. It represents the calculated memory size in the former
case and is unused in the latter.

This moves it out to the main memblock structure instead
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Let's not waste space and cycles on archs that don't support >32-bit
physical address space.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The RMA (RMO is a misnomer) is a concept specific to ppc64 (in fact
server ppc64 though I hijack it on embedded ppc64 for similar purposes)
and represents the area of memory that can be accessed in real mode
(aka with MMU off), or on embedded, from the exception vectors (which
is bolted in the TLB) which pretty much boils down to the same thing.

We take that out of the generic MEMBLOCK data structure and move it into
arch/powerpc where it belongs, renaming it to "RMA" while at it.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

This introduce memblock.current_limit which is used to limit allocations
from memblock_alloc() or memblock_alloc_base(..., MEMBLOCK_ALLOC_ACCESSIBLE).

The old MEMBLOCK_ALLOC_ANYWHERE changes value from 0 to ~(u64)0 and can still
be used with memblock_alloc_base() to allocate really anywhere.

It is -no-longer- cropped to MEMBLOCK_REAL_LIMIT which disappears.

Note to archs: I'm leaving the default limit to MEMBLOCK_ALLOC_ANYWHERE. I
strongly recommend that you ensure that you set an appropriate limit
during boot in order to guarantee that an memblock_alloc() at any time
results in something that is accessible with a simple __va().

The reason is that a subsequent patch will introduce the ability for
the array to resize itself by reallocating itself. The MEMBLOCK core will
honor the current limit when performing those allocations.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Nobody uses it anymore. It's semantics were ... weird
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

CC: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

CC: David S. Miller <davem@davemloft.net>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

CC: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

CC: Michal Simek <monstr@monstr.eu>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Walk memblock's using for_each_memblock() and use memblock_region_base/end_pfn() for
getting to PFNs.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Instead of the deprecated memblock_find()
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

The implementation is pretty much similar. There is a -small- added
overhead by having another function call and the address shift.

If that becomes a concern, I suppose we could actually have memblock
itself expose a memblock_pfn_valid() which then ARM can use directly
with an appropriate #define...
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

To make it fast, we steal ARM's binary search for memblock_is_memory()
and we use that to also the replace existing implementation of
memblock_is_reserved().
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>