From eab309494ae2b9e15f85520f00de3893162c2e43 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Thu, 24 May 2012 00:45:21 -0700 Subject: memblock: Document memblock_is_region_{memory,reserved}() At first glance one would think that memblock_is_region_memory() and memblock_is_region_reserved() would be implemented in the same way. Unfortunately they aren't and the former returns whether the region specified is a subset of a memory bank while the latter returns whether the region specified intersects with reserved memory. Document the two functions so that users aren't tempted to make the implementation the same between them and to clarify the purpose of the functions. Signed-off-by: Stephen Boyd Cc: Tejun Heo Link: http://lkml.kernel.org/r/1337845521-32755-1-git-send-email-sboyd@codeaurora.org Signed-off-by: Ingo Molnar --- mm/memblock.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) (limited to 'mm/memblock.c') diff --git a/mm/memblock.c b/mm/memblock.c index 952123eba433..32a0a5e4d79d 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -867,6 +867,16 @@ int __init_memblock memblock_is_memory(phys_addr_t addr) return memblock_search(&memblock.memory, addr) != -1; } +/** + * memblock_is_region_memory - check if a region is a subset of memory + * @base: base of region to check + * @size: size of region to check + * + * Check if the region [@base, @base+@size) is a subset of a memory block. + * + * RETURNS: + * 0 if false, non-zero if true + */ int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size) { int idx = memblock_search(&memblock.memory, base); @@ -879,6 +889,16 @@ int __init_memblock memblock_is_region_memory(phys_addr_t base, phys_addr_t size memblock.memory.regions[idx].size) >= end; } +/** + * memblock_is_region_reserved - check if a region intersects reserved memory + * @base: base of region to check + * @size: size of region to check + * + * Check if the region [@base, @base+@size) intersects a reserved memory block. + * + * RETURNS: + * 0 if false, non-zero if true + */ int __init_memblock memblock_is_region_reserved(phys_addr_t base, phys_addr_t size) { memblock_cap_size(base, &size); -- cgit v1.2.2 From dad7557eb705688040aac134efa5418b66d5ed92 Mon Sep 17 00:00:00 2001 From: Wanpeng Li Date: Wed, 20 Jun 2012 12:53:01 -0700 Subject: mm: fix kernel-doc warnings Fix kernel-doc warnings such as Warning(../mm/page_cgroup.c:432): No description found for parameter 'id' Warning(../mm/page_cgroup.c:432): Excess function parameter 'mem' description in 'swap_cgroup_record' Signed-off-by: Wanpeng Li Cc: Randy Dunlap Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memblock.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'mm/memblock.c') diff --git a/mm/memblock.c b/mm/memblock.c index 32a0a5e4d79d..b65b687e2362 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -540,9 +540,9 @@ int __init_memblock memblock_reserve(phys_addr_t base, phys_addr_t size) * __next_free_mem_range - next function for for_each_free_mem_range() * @idx: pointer to u64 loop variable * @nid: nid: node selector, %MAX_NUMNODES for all nodes - * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL - * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL - * @p_nid: ptr to int for nid of the range, can be %NULL + * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL + * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL + * @out_nid: ptr to int for nid of the range, can be %NULL * * Find the first free area from *@idx which matches @nid, fill the out * parameters, and update *@idx for the next iteration. The lower 32bit of @@ -616,9 +616,9 @@ void __init_memblock __next_free_mem_range(u64 *idx, int nid, * __next_free_mem_range_rev - next function for for_each_free_mem_range_reverse() * @idx: pointer to u64 loop variable * @nid: nid: node selector, %MAX_NUMNODES for all nodes - * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL - * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL - * @p_nid: ptr to int for nid of the range, can be %NULL + * @out_start: ptr to phys_addr_t for start address of the range, can be %NULL + * @out_end: ptr to phys_addr_t for end address of the range, can be %NULL + * @out_nid: ptr to int for nid of the range, can be %NULL * * Reverse of __next_free_mem_range(). */ -- cgit v1.2.2 From 48c3b583bbddad2220ca4c22319ca5d1f78b2090 Mon Sep 17 00:00:00 2001 From: Greg Pearson Date: Wed, 20 Jun 2012 12:53:05 -0700 Subject: mm/memblock: fix overlapping allocation when doubling reserved array __alloc_memory_core_early() asks memblock for a range of memory then try to reserve it. If the reserved region array lacks space for the new range, memblock_double_array() is called to allocate more space for the array. If memblock is used to allocate memory for the new array it can end up using a range that overlaps with the range originally allocated in __alloc_memory_core_early(), leading to possible data corruption. With this patch memblock_double_array() now calls memblock_find_in_range() with a narrowed candidate range (in cases where the reserved.regions array is being doubled) so any memory allocated will not overlap with the original range that was being reserved. The range is narrowed by passing in the starting address and size of the previously allocated range. Then the range above the ending address is searched and if a candidate is not found, the range below the starting address is searched. Signed-off-by: Greg Pearson Signed-off-by: Yinghai Lu Acked-by: Tejun Heo Cc: Benjamin Herrenschmidt Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/memblock.c | 36 ++++++++++++++++++++++++++++++++---- 1 file changed, 32 insertions(+), 4 deletions(-) (limited to 'mm/memblock.c') diff --git a/mm/memblock.c b/mm/memblock.c index b65b687e2362..d4382095f8bd 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -184,7 +184,24 @@ static void __init_memblock memblock_remove_region(struct memblock_type *type, u } } -static int __init_memblock memblock_double_array(struct memblock_type *type) +/** + * memblock_double_array - double the size of the memblock regions array + * @type: memblock type of the regions array being doubled + * @new_area_start: starting address of memory range to avoid overlap with + * @new_area_size: size of memory range to avoid overlap with + * + * Double the size of the @type regions array. If memblock is being used to + * allocate memory for a new reserved regions array and there is a previously + * allocated memory range [@new_area_start,@new_area_start+@new_area_size] + * waiting to be reserved, ensure the memory used by the new array does + * not overlap. + * + * RETURNS: + * 0 on success, -1 on failure. + */ +static int __init_memblock memblock_double_array(struct memblock_type *type, + phys_addr_t new_area_start, + phys_addr_t new_area_size) { struct memblock_region *new_array, *old_array; phys_addr_t old_size, new_size, addr; @@ -222,7 +239,18 @@ static int __init_memblock memblock_double_array(struct memblock_type *type) new_array = kmalloc(new_size, GFP_KERNEL); addr = new_array ? __pa(new_array) : 0; } else { - addr = memblock_find_in_range(0, MEMBLOCK_ALLOC_ACCESSIBLE, new_size, sizeof(phys_addr_t)); + /* only exclude range when trying to double reserved.regions */ + if (type != &memblock.reserved) + new_area_start = new_area_size = 0; + + addr = memblock_find_in_range(new_area_start + new_area_size, + memblock.current_limit, + new_size, sizeof(phys_addr_t)); + if (!addr && new_area_size) + addr = memblock_find_in_range(0, + min(new_area_start, memblock.current_limit), + new_size, sizeof(phys_addr_t)); + new_array = addr ? __va(addr) : 0; } if (!addr) { @@ -399,7 +427,7 @@ repeat: */ if (!insert) { while (type->cnt + nr_new > type->max) - if (memblock_double_array(type) < 0) + if (memblock_double_array(type, obase, size) < 0) return -ENOMEM; insert = true; goto repeat; @@ -450,7 +478,7 @@ static int __init_memblock memblock_isolate_range(struct memblock_type *type, /* we'll create at most two more regions */ while (type->cnt + 2 > type->max) - if (memblock_double_array(type) < 0) + if (memblock_double_array(type, base, size) < 0) return -ENOMEM; for (i = 0; i < type->cnt; i++) { -- cgit v1.2.2