From: Jinyang He hejinyang@loongson.cn
[ Upstream commit b1ce9716f3b5ed3b49badf1f003b9e34b7ead0f9 ]
Use 0 as the align parameter in memblock_find_in_range() is incorrect when we reserve memory for Crash kernel.
The environment as follows: [ 0.000000] MIPS: machine is loongson,loongson64c-4core-rs780e ... [ 1.951016] crashkernel=64M@128M
The warning as follows: [ 0.000000] Invalid memory region reserved for crash kernel
And the iomem as follows: 00200000-0effffff : System RAM 04000000-0484009f : Kernel code 048400a0-04ad7fff : Kernel data 04b40000-05c4c6bf : Kernel bss 1a000000-1bffffff : pci@1a000000 ...
The align parameter may be finally used by round_down() or round_up(). Like the following call tree:
mips-next: mm/memblock.c
memblock_find_in_range └── memblock_find_in_range_node ├── __memblock_find_range_bottom_up │ └── round_up └── __memblock_find_range_top_down └── round_down #define round_up(x, y) ((((x)-1) | __round_mask(x, y))+1) #define round_down(x, y) ((x) & ~__round_mask(x, y)) #define __round_mask(x, y) ((__typeof__(x))((y)-1))
The round_down(or round_up)'s second parameter must be a power of 2. If the second parameter is 0, it both will return 0.
Use 1 as the parameter to fix the bug and the iomem as follows: 00200000-0effffff : System RAM 04000000-0484009f : Kernel code 048400a0-04ad7fff : Kernel data 04b40000-05c4c6bf : Kernel bss 08000000-0bffffff : Crash kernel 1a000000-1bffffff : pci@1a000000 ...
Signed-off-by: Jinyang He hejinyang@loongson.cn Reviewed-by: Jiaxun Yang jiaxun.yang@flygoat.com Signed-off-by: Thomas Bogendoerfer tsbogend@alpha.franken.de Signed-off-by: Sasha Levin sashal@kernel.org --- arch/mips/kernel/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index 7b06e6ee6817d..b8884de89c81e 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -494,7 +494,7 @@ static void __init mips_parse_crashkernel(void) if (ret != 0 || crash_size <= 0) return;
- if (!memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 0)) { + if (!memblock_find_in_range(crash_base, crash_base + crash_size, crash_size, 1)) { pr_warn("Invalid memory region reserved for crash kernel\n"); return; }