From 6ede1fd3cb404c0016de6ac529df46d561bd558b Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 22 Oct 2012 16:35:18 -0700 Subject: [PATCH] x86, mm: Trim memory in memblock to be page aligned We will not map partial pages, so need to make sure memblock allocation will not allocate those bytes out. Also we will use for_each_mem_pfn_range() to loop to map memory range to keep them consistent. Signed-off-by: Yinghai Lu Link: http://lkml.kernel.org/r/CAE9FiQVZirvaBMFYRfXMmWEcHbKSicQEHz4VAwUv0xFCk51ZNw@mail.gmail.com Acked-by: Jacob Shin Signed-off-by: H. Peter Anvin Cc: --- arch/x86/kernel/e820.c | 3 +++ include/linux/memblock.h | 1 + mm/memblock.c | 24 ++++++++++++++++++++++++ 3 files changed, 28 insertions(+) diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index ed858e9e9a7..df06ade26be 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -1077,6 +1077,9 @@ void __init memblock_x86_fill(void) memblock_add(ei->addr, ei->size); } + /* throw away partial pages */ + memblock_trim_memory(PAGE_SIZE); + memblock_dump_all(); } diff --git a/include/linux/memblock.h b/include/linux/memblock.h index 569d67d4243..d452ee19106 100644 --- a/include/linux/memblock.h +++ b/include/linux/memblock.h @@ -57,6 +57,7 @@ int memblock_add(phys_addr_t base, phys_addr_t size); int memblock_remove(phys_addr_t base, phys_addr_t size); int memblock_free(phys_addr_t base, phys_addr_t size); int memblock_reserve(phys_addr_t base, phys_addr_t size); +void memblock_trim_memory(phys_addr_t align); #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP void __next_mem_pfn_range(int *idx, int nid, unsigned long *out_start_pfn, diff --git a/mm/memblock.c b/mm/memblock.c index 931eef145af..625905523c2 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -930,6 +930,30 @@ int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t si return memblock_overlaps_region(&memblock.reserved, base, size) >= 0; } +void __init_memblock memblock_trim_memory(phys_addr_t align) +{ + int i; + phys_addr_t start, end, orig_start, orig_end; + struct memblock_type *mem = &memblock.memory; + + for (i = 0; i < mem->cnt; i++) { + orig_start = mem->regions[i].base; + orig_end = mem->regions[i].base + mem->regions[i].size; + start = round_up(orig_start, align); + end = round_down(orig_end, align); + + if (start == orig_start && end == orig_end) + continue; + + if (start < end) { + mem->regions[i].base = start; + mem->regions[i].size = end - start; + } else { + memblock_remove_region(mem, i); + i--; + } + } +} void __init_memblock memblock_set_current_limit(phys_addr_t limit) { -- 2.20.1