[PATCH 4.9 010/104] MIPS: fix mem=X@Y commandline processing

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Marcin Nowakowski <marcin.nowakowski@imgtec.com>


[ Upstream commit 73fbc1eba7ffa3bf0ad12486232a8a1edb4e4411 ]

When a memory offset is specified through the commandline, add the
memory in range PHYS_OFFSET:Y as reserved memory area.
Otherwise the bootmem allocator is initialised with low page equal to
min_low_pfn = PHYS_OFFSET, and in free_all_bootmem will process pages
starting from min_low_pfn instead of PFN(Y).

Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/14613/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/mips/kernel/setup.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/arch/mips/kernel/setup.c
+++ b/arch/mips/kernel/setup.c
@@ -589,6 +589,10 @@ static int __init early_parse_mem(char *
 		start = memparse(p + 1, &p);
 
 	add_memory_region(start, size, BOOT_MEM_RAM);
+
+	if (start && start > PHYS_OFFSET)
+		add_memory_region(PHYS_OFFSET, start - PHYS_OFFSET,
+				BOOT_MEM_RESERVED);
 	return 0;
 }
 early_param("mem", early_parse_mem);