On Sat, Jan 12, 2019 at 04:16:27PM +0800, guoren@xxxxxxxxxx wrote: > From: Guo Ren <ren_guo@xxxxxxxxx> > > max_low_pfn should be pfn_size not byte_size. > > Signed-off-by: Guo Ren <ren_guo@xxxxxxxxx> > Signed-off-by: Mao Han <mao_han@xxxxxxxxx> > Cc: Palmer Dabbelt <palmer@xxxxxxxxxx> > Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx> > --- > arch/riscv/kernel/setup.c | 2 +- > arch/riscv/mm/init.c | 3 ++- > 2 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c > index fc8006a..5463e67 100644 > --- a/arch/riscv/kernel/setup.c > +++ b/arch/riscv/kernel/setup.c > @@ -174,7 +174,7 @@ static void __init setup_bootmem(void) > BUG_ON(mem_size == 0); > > set_max_mapnr(PFN_DOWN(mem_size)); > - max_low_pfn = memblock_end_of_DRAM(); > + max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); I know it is used just above, but can we please just switch this code to use >> PAGE_SHIFT instead of PFN_DOWN, which just horribly obsfucates what is going on? > > #ifdef CONFIG_BLK_DEV_INITRD > setup_initrd(); > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 1d9bfaf..658ebf6 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -28,7 +28,8 @@ static void __init zone_sizes_init(void) > unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; > > #ifdef CONFIG_ZONE_DMA32 > - max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, max_low_pfn)); > + max_zone_pfns[ZONE_DMA32] = PFN_DOWN(min(4UL * SZ_1G, > + (unsigned long) PFN_PHYS(max_low_pfn))); > #endif Same comment as above here, plus I think we should just use memblock_end_of_DRAM directly, e.g. something like: static const phys_addr_t max_dma32_addr = 4UL * SZ_1G; max_zone_pfns[ZONE_DMA32] = min(memblock_end_of_DRAM(), max_dma32_addr) >> PAGE_SHIFT;