This is a note to let you know that I've just added the patch titled
of/fdt: memblock_reserve /memreserve/ regions in the case of partial overlap
to the 3.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
of-fdt-memblock_reserve-memreserve-regions-in-the-case-of-partial-overlap.patch
and it can be found in the queue-3.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 094cb98179f19b75acf9ff471daabf3948ce98e6 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ian.campbell@xxxxxxxxxx>
Date: Tue, 25 Nov 2014 15:05:13 +0000
Subject: of/fdt: memblock_reserve /memreserve/ regions in the case of partial overlap
From: Ian Campbell <ian.campbell@xxxxxxxxxx>
commit 094cb98179f19b75acf9ff471daabf3948ce98e6 upstream.
memblock_is_region_reserved() returns true in the case of a partial
overlap, meaning that the current code fails to reserve the
non-overlapping portion.
This call was introduced as part of d1552ce449eb "of/fdt: move
memreserve and dtb memory reservations into core" which went into
v3.16.
I observed this causing a Midway system with a buggy fdt (the header
declares itself to be larger than it really is) failing to boot
because the over-inflated size of the fdt was causing it to seem to
run into the swapper_pg_dir region, meaning the DT wasn't reserved.
The symptoms were failing to find an disks or network and failing to
boot.
However given the ambiguity of whether things like the initrd are
covered by /memreserve/ and similar I think it is best to also
register the region rather than just ignoring it.
Since memblock_reserve() handles overlaps just fine lets just warn and
carry on.
Signed-off-by: Ian Campbell <ian.campbell@xxxxxxxxxx>
Signed-off-by: Grant Likely <grant.likely@xxxxxxxxxx>
Cc: Rob Herring <robh+dt@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/of/fdt.c | 2 --
1 file changed, 2 deletions(-)
--- a/drivers/of/fdt.c
+++ b/drivers/of/fdt.c
@@ -964,8 +964,6 @@ void __init __weak early_init_dt_add_mem
int __init __weak early_init_dt_reserve_memory_arch(phys_addr_t base,
phys_addr_t size, bool nomap)
{
- if (memblock_is_region_reserved(base, size))
- return -EBUSY;
if (nomap)
return memblock_remove(base, size);
return memblock_reserve(base, size);
Patches currently in stable-queue which might be from ian.campbell@xxxxxxxxxx are
queue-3.17/of-fdt-memblock_reserve-memreserve-regions-in-the-case-of-partial-overlap.patch
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