On Wed, 2016-07-06 at 16:52 +0900, AKASHI Takahiro wrote: > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -136,6 +137,57 @@ static void __init reserve_crashkernel(void) > } > #endif /* CONFIG_KEXEC_CORE */ > > +#ifdef CONFIG_CRASH_DUMP > +static int __init early_init_dt_scan_elfcorehdr(unsigned long node, > +> > > const char *uname, int depth, void *data) > +{ > +> > const __be32 *reg; > +> > int len; > + > +> > if (depth != 1 || strcmp(uname, "chosen") != 0) > +> > > return 0; > + > +> > reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len); > +> > if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells))) > +> > > return 1; > + > +> > elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, ?); > +> > elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, ?); > + > +> > return 1; > +} > + > +/* > + * reserve_elfcorehdr() - reserves memory for elf core header > + * > + * This function reserves elf core header given in "elfcorehdr=" kernel > + * command line parameter. This region contains all the information about > + * primary kernel's core image and is used by a dump capture kernel to > + * access the system memory on primary kernel. > + */ > +static void __init reserve_elfcorehdr(void) > +{ It seems like you could get rid of all these conditionals by just putting this here: if (!IS_ENABLED(CONFIG_CRASH_DUMP)) return; > +> > of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL); > + > +> > if (!elfcorehdr_size) > +> > > return; > + > +> > if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) { > +> > > pr_warn("elfcorehdr is overlapped\n"); > +> > > return; > +> > } > + > +> > memblock_reserve(elfcorehdr_addr, elfcorehdr_size); > + > +> > pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n", > +> > > elfcorehdr_size >> 10, elfcorehdr_addr); > +} > +#else > +static void __init reserve_elfcorehdr(void) > +{ > +> > ; > +} > +#endif /* CONFIG_CRASH_DUMP */ > /* > * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It > * currently assumes that for memory starting above 4G, 32-bit devices will > @@ -389,6 +441,8 @@ void __init arm64_memblock_init(void) > > > > reserve_crashkernel(); > > +> > reserve_elfcorehdr(); > + > > > early_init_fdt_scan_reserved_mem(); > > > > /* 4GB maximum for 32-bit only capable devices */