On Mon, Mar 25, 2019 at 09:23:09AM +0000, Anup Patel wrote: > Currently, the setup_bootmem() reserves memory from RAM start to the > kernel end. This prevents us from exploring ways to use the RAM below > (or before) the kernel start hence this patch updates setup_bootmem() > to only reserve memory from the kernel start to the kernel end. > > Signed-off-by: Mike Rapoport <[email protected]>
Suggested-by: please :) > Signed-off-by: Anup Patel <[email protected]> > Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Mike Rapoport <[email protected]> > --- > arch/riscv/mm/init.c | 17 ++++++++--------- > 1 file changed, 8 insertions(+), 9 deletions(-) > > diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c > index 8cf9ff1f9058..3e66b7cb3a61 100644 > --- a/arch/riscv/mm/init.c > +++ b/arch/riscv/mm/init.c > @@ -29,6 +29,8 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned > long)] > __page_aligned_bss; > EXPORT_SYMBOL(empty_zero_page); > > +extern char _start[]; > + > static void __init zone_sizes_init(void) > { > unsigned long max_zone_pfns[MAX_NR_ZONES] = { 0, }; > @@ -108,23 +110,21 @@ void __init setup_bootmem(void) > { > struct memblock_region *reg; > phys_addr_t mem_size = 0; > + phys_addr_t vmlinux_end = __pa(&_end); > + phys_addr_t vmlinux_start = __pa(&_start); > > /* Find the memory region containing the kernel */ > for_each_memblock(memory, reg) { > - phys_addr_t vmlinux_end = __pa(_end); > phys_addr_t end = reg->base + reg->size; > > - if (reg->base <= vmlinux_end && vmlinux_end <= end) { > - /* > - * Reserve from the start of the region to the end of > - * the kernel > - */ > - memblock_reserve(reg->base, vmlinux_end - reg->base); > + if (reg->base <= vmlinux_end && vmlinux_end <= end) > mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); > - } > } > BUG_ON(mem_size == 0); > > + /* Reserve from the start of the kernel to the end of the kernel */ > + memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); > + > set_max_mapnr(PFN_DOWN(mem_size)); > max_low_pfn = PFN_DOWN(memblock_end_of_DRAM()); > > @@ -196,7 +196,6 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t > phys, pgprot_t prot) > */ > asmlinkage void __init setup_vm(void) > { > - extern char _start; > uintptr_t i; > uintptr_t pa = (uintptr_t) &_start; > pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC); > -- > 2.17.1 > -- Sincerely yours, Mike.
