Unverified Commit f05badde authored Apr 05, 2019 by Anup Patel Committed by Palmer Dabbelt Apr 10, 2019

RISC-V: Fix Maximum Physical Memory 2GiB option for 64bit systems



The Maximum Physical Memory 2GiB option for 64bit systems is currently
broken because kernel hangs at boot-time when this option is enabled
and the underlying system has more than 2GiB memory.

This issue can be easily reproduced on SiFive Unleashed board where
we have 8GiB of memory.

This patch fixes above issue by removing unusable memory region in
setup_bootmem().

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>

parent 6ec4bae1

arch/riscv/mm/init.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -121,6 +121,14 @@ void __init setup_bootmem(void)
		*/
		memblock_reserve(reg->base, vmlinux_end - reg->base);
		mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET);

		/*
		* Remove memblock from the end of usable area to the
		* end of region
		*/
		if (reg->base + mem_size < end)
		memblock_remove(reg->base + mem_size,
		end - reg->base - mem_size);
		}
		}
		BUG_ON(mem_size == 0);

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