/* Reserve the lowmem memblock reserved regions in bootmem. */
for_each_memblock(reserved, reg) {
unsigned long start = memblock_region_reserved_base_pfn(reg);
unsigned long end = memblock_region_reserved_end_pfn(reg);
if (end >= end_pfn)
end = end_pfn;
if (start >= end)
break;
reserve_bootmem(__pfn_to_phys(start),
(end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
}
/* Reserve the lowmem memblock reserved regions in bootmem. */
for_each_memblock(reserved, reg) {
// for (reg = memblock.reserved.regions; reg < (memblock.reserved.regions + memblock.reserved.cnt), reg++)
unsigned long start = memblock_region_reserved_base_pfn(reg);
unsigned long end = memblock_region_reserved_end_pfn(reg);
if (end >= end_pfn)
end = end_pfn;
if (start >= end)
break;
// start : 0x20000000, (end - start) << PAGE_SHIFT : 0x2F800000
reserve_bootmem(__pfn_to_phys(start),
(end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
// start부터 end에 해당하는 bitmap 중 reserved 영역을 1로 설정
}
/* Reserve the lowmem memblock reserved regions in bootmem. */
for_each_memblock(reserved, reg) {
// start: 0x40004
unsigned long start = memblock_region_reserved_base_pfn(reg);
// end: 0x40008
unsigned long end = memblock_region_reserved_end_pfn(reg);
// end: 0x40008, end_pfn: 0x4f800
if (end >= end_pfn)
end = end_pfn;
// start: 0x40004, end: 0x40008
if (start >= end)
break;
// __pfn_to_phys(0x40004): 0x40004000, (end - start) << PAGE_SHIFT: 0x4000
// BOOTMEM_DEFAULT: 0
reserve_bootmem(__pfn_to_phys(start),
(end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
}
static void __init free_highpages(void)
{
unsigned long max_low = max_low_pfn;
struct memblock_region *mem, *res;
reset_all_zones_managed_pages();
/* set highmem page free */
for_each_memblock(memory, mem) {
unsigned long start = memblock_region_memory_base_pfn(mem);
unsigned long end = memblock_region_memory_end_pfn(mem);
/* Ignore complete lowmem entries */
if (end <= max_low)
continue;
if (memblock_is_nomap(mem))
continue;
/* Truncate partial highmem entries */
if (start < max_low)
start = max_low;
/* Find and exclude any reserved regions */
for_each_memblock(reserved, res) {
unsigned long res_start, res_end;
res_start = memblock_region_reserved_base_pfn(res);
res_end = memblock_region_reserved_end_pfn(res);
if (res_end < start)
continue;
if (res_start < start)
res_start = start;
if (res_start > end)
res_start = end;
if (res_end > end)
res_end = end;
if (res_start != start)
free_area_high(start, res_start);
start = res_end;
if (start == end)
break;
}