From a66fd7daec1f40c1f0eac466f0da9206b615fe2a Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 23 Jul 2008 21:28:01 -0700 Subject: [PATCH] bootmem: add documentation to API functions Signed-off-by: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/bootmem.c | 150 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 149 insertions(+), 1 deletion(-) diff --git a/mm/bootmem.c b/mm/bootmem.c index 286e12c536a..105ad4cff2e 100644 --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -47,7 +47,10 @@ static unsigned long __init get_mapsize(bootmem_data_t *bdata) return ALIGN(mapsize, sizeof(long)); } -/* return the number of _pages_ that will be allocated for the boot bitmap */ +/** + * bootmem_bootmap_pages - calculate bitmap size in pages + * @pages: number of pages the bitmap has to represent + */ unsigned long __init bootmem_bootmap_pages(unsigned long pages) { unsigned long mapsize; @@ -104,12 +107,28 @@ static unsigned long __init init_bootmem_core(bootmem_data_t *bdata, return mapsize; } +/** + * init_bootmem_node - register a node as boot memory + * @pgdat: node to register + * @freepfn: pfn where the bitmap for this node is to be placed + * @startpfn: first pfn on the node + * @endpfn: first pfn after the node + * + * Returns the number of bytes needed to hold the bitmap for this node. + */ unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn) { return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn); } +/** + * init_bootmem - register boot memory + * @start: pfn where the bitmap is to be placed + * @pages: number of available physical pages + * + * Returns the number of bytes needed to hold the bitmap. + */ unsigned long __init init_bootmem(unsigned long start, unsigned long pages) { max_low_pfn = pages; @@ -182,12 +201,23 @@ static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata) return count; } +/** + * free_all_bootmem_node - release a node's free pages to the buddy allocator + * @pgdat: node to be released + * + * Returns the number of pages actually released. + */ unsigned long __init free_all_bootmem_node(pg_data_t *pgdat) { register_page_bootmem_info_node(pgdat); return free_all_bootmem_core(pgdat->bdata); } +/** + * free_all_bootmem - release free pages to the buddy allocator + * + * Returns the number of pages actually released. + */ unsigned long __init free_all_bootmem(void) { return free_all_bootmem_core(NODE_DATA(0)->bdata); @@ -231,12 +261,32 @@ static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, } } +/** + * free_bootmem_node - mark a page range as usable + * @pgdat: node the range resides on + * @physaddr: starting address of the range + * @size: size of the range in bytes + * + * Partial pages will be considered reserved and left as they are. + * + * Only physical pages that actually reside on @pgdat are marked. + */ void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size) { free_bootmem_core(pgdat->bdata, physaddr, size); } +/** + * free_bootmem - mark a page range as usable + * @addr: starting address of the range + * @size: size of the range in bytes + * + * Partial pages will be considered reserved and left as they are. + * + * All physical pages within the range are marked, no matter what + * node they reside on. + */ void __init free_bootmem(unsigned long addr, unsigned long size) { bootmem_data_t *bdata; @@ -319,6 +369,17 @@ static void __init reserve_bootmem_core(bootmem_data_t *bdata, } } +/** + * reserve_bootmem_node - mark a page range as reserved + * @pgdat: node the range resides on + * @physaddr: starting address of the range + * @size: size of the range in bytes + * @flags: reservation flags (see linux/bootmem.h) + * + * Partial pages will be reserved. + * + * Only physical pages that actually reside on @pgdat are marked. + */ int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, unsigned long size, int flags) { @@ -332,6 +393,17 @@ int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr, } #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE +/** + * reserve_bootmem - mark a page range as usable + * @addr: starting address of the range + * @size: size of the range in bytes + * @flags: reservation flags (see linux/bootmem.h) + * + * Partial pages will be reserved. + * + * All physical pages within the range are marked, no matter what + * node they reside on. + */ int __init reserve_bootmem(unsigned long addr, unsigned long size, int flags) { @@ -500,6 +572,19 @@ found: return ret; } +/** + * __alloc_bootmem_nopanic - allocate boot memory without panicking + * @size: size of the request in bytes + * @align: alignment of the region + * @goal: preferred starting address of the region + * + * The goal is dropped if it can not be satisfied and the allocation will + * fall back to memory below @goal. + * + * Allocation may happen on any node in the system. + * + * Returns NULL on failure. + */ void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, unsigned long goal) { @@ -514,6 +599,19 @@ void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align, return NULL; } +/** + * __alloc_bootmem - allocate boot memory + * @size: size of the request in bytes + * @align: alignment of the region + * @goal: preferred starting address of the region + * + * The goal is dropped if it can not be satisfied and the allocation will + * fall back to memory below @goal. + * + * Allocation may happen on any node in the system. + * + * The function panics if the request can not be satisfied. + */ void * __init __alloc_bootmem(unsigned long size, unsigned long align, unsigned long goal) { @@ -529,6 +627,21 @@ void * __init __alloc_bootmem(unsigned long size, unsigned long align, return NULL; } +/** + * __alloc_bootmem_node - allocate boot memory from a specific node + * @pgdat: node to allocate from + * @size: size of the request in bytes + * @align: alignment of the region + * @goal: preferred starting address of the region + * + * The goal is dropped if it can not be satisfied and the allocation will + * fall back to memory below @goal. + * + * Allocation may fall back to any node in the system if the specified node + * can not hold the requested memory. + * + * The function panics if the request can not be satisfied. + */ void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal) { @@ -542,6 +655,13 @@ void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size, } #ifdef CONFIG_SPARSEMEM +/** + * alloc_bootmem_section - allocate boot memory from a specific section + * @size: size of the request in bytes + * @section_nr: sparse map section to allocate from + * + * Return NULL on failure. + */ void * __init alloc_bootmem_section(unsigned long size, unsigned long section_nr) { @@ -588,6 +708,19 @@ void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size, #define ARCH_LOW_ADDRESS_LIMIT 0xffffffffUL #endif +/** + * __alloc_bootmem_low - allocate low boot memory + * @size: size of the request in bytes + * @align: alignment of the region + * @goal: preferred starting address of the region + * + * The goal is dropped if it can not be satisfied and the allocation will + * fall back to memory below @goal. + * + * Allocation may happen on any node in the system. + * + * The function panics if the request can not be satisfied. + */ void * __init __alloc_bootmem_low(unsigned long size, unsigned long align, unsigned long goal) { @@ -609,6 +742,21 @@ void * __init __alloc_bootmem_low(unsigned long size, unsigned long align, return NULL; } +/** + * __alloc_bootmem_low_node - allocate low boot memory from a specific node + * @pgdat: node to allocate from + * @size: size of the request in bytes + * @align: alignment of the region + * @goal: preferred starting address of the region + * + * The goal is dropped if it can not be satisfied and the allocation will + * fall back to memory below @goal. + * + * Allocation may fall back to any node in the system if the specified node + * can not hold the requested memory. + * + * The function panics if the request can not be satisfied. + */ void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal) { -- 2.41.1