diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 6c14b6179727..2925da23505d 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -332,6 +332,7 @@ phys_addr_t memblock_mem_size(unsigned long limit_pfn); phys_addr_t memblock_start_of_DRAM(void); phys_addr_t memblock_end_of_DRAM(void); void memblock_enforce_memory_limit(phys_addr_t memory_limit); +void memblock_mem_limit_remove_map(phys_addr_t limit); bool memblock_is_memory(phys_addr_t addr); int memblock_is_map_memory(phys_addr_t addr); int memblock_is_region_memory(phys_addr_t base, phys_addr_t size); diff --git a/mm/memblock.c b/mm/memblock.c index d8a79dfbf891..4884a162e3ad 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1465,15 +1465,16 @@ phys_addr_t __init_memblock memblock_end_of_DRAM(void) return (memblock.memory.regions[idx].base + memblock.memory.regions[idx].size); } -void __init memblock_enforce_memory_limit(phys_addr_t limit) +static phys_addr_t __init_memblock __find_max_addr(phys_addr_t limit) { phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX; struct memblock_region *r; - if (!limit) - return; - - /* find out max address */ + /* + * translate the memory @limit size into the max address within one of + * the memory memblock regions, if the @limit exceeds the total size + * of those regions, max_addr will keep original value ULLONG_MAX + */ for_each_memblock(memory, r) { if (limit <= r->size) { max_addr = r->base + limit; @@ -1482,6 +1483,22 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) limit -= r->size; } + return max_addr; +} + +void __init memblock_enforce_memory_limit(phys_addr_t limit) +{ + phys_addr_t max_addr = (phys_addr_t)ULLONG_MAX; + + if (!limit) + return; + + max_addr = __find_max_addr(limit); + + /* @limit exceeds the total size of the memory, do nothing */ + if (max_addr == (phys_addr_t)ULLONG_MAX) + return; + /* truncate both memory and reserved regions */ memblock_remove_range(&memblock.memory, max_addr, (phys_addr_t)ULLONG_MAX); @@ -1489,6 +1506,36 @@ void __init memblock_enforce_memory_limit(phys_addr_t limit) (phys_addr_t)ULLONG_MAX); } +void __init memblock_mem_limit_remove_map(phys_addr_t limit) +{ + struct memblock_type *type = &memblock.memory; + phys_addr_t max_addr; + int i, ret, start_rgn, end_rgn; + + if (!limit) + return; + + max_addr = __find_max_addr(limit); + + /* @limit exceeds the total size of the memory, do nothing */ + if (max_addr == (phys_addr_t)ULLONG_MAX) + return; + + ret = memblock_isolate_range(type, max_addr, (phys_addr_t)ULLONG_MAX, + &start_rgn, &end_rgn); + if (ret) + return; + + /* remove all the MAP regions above the limit */ + for (i = end_rgn - 1; i >= start_rgn; i--) { + if (!memblock_is_nomap(&type->regions[i])) + memblock_remove_region(type, i); + } + /* truncate the reserved regions */ + memblock_remove_range(&memblock.reserved, max_addr, + (phys_addr_t)ULLONG_MAX); +} + static int __init_memblock memblock_search(struct memblock_type *type, phys_addr_t addr) { unsigned int left = 0, right = type->cnt;