From 094cb98179f19b75acf9ff471daabf3948ce98e6 Mon Sep 17 00:00:00 2001 From: Ian Campbell Date: Tue, 25 Nov 2014 15:05:13 +0000 Subject: of/fdt: memblock_reserve /memreserve/ regions in the case of partial overlap 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 Signed-off-by: Grant Likely Cc: Rob Herring Cc: stable@vger.kernel.org # v3.16+ --- drivers/of/fdt.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 30e97bcc4f88..d134710de96d 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -964,8 +964,6 @@ void __init __weak early_init_dt_add_memory_arch(u64 base, u64 size) 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); -- cgit v1.2.3