mirror of https://gitee.com/openkylin/linux.git
89 lines
2.7 KiB
C
89 lines
2.7 KiB
C
#ifndef PAGE_FLAGS_LAYOUT_H
|
|
#define PAGE_FLAGS_LAYOUT_H
|
|
|
|
#include <linux/numa.h>
|
|
#include <generated/bounds.h>
|
|
|
|
/*
|
|
* When a memory allocation must conform to specific limitations (such
|
|
* as being suitable for DMA) the caller will pass in hints to the
|
|
* allocator in the gfp_mask, in the zone modifier bits. These bits
|
|
* are used to select a priority ordered list of memory zones which
|
|
* match the requested limits. See gfp_zone() in include/linux/gfp.h
|
|
*/
|
|
#if MAX_NR_ZONES < 2
|
|
#define ZONES_SHIFT 0
|
|
#elif MAX_NR_ZONES <= 2
|
|
#define ZONES_SHIFT 1
|
|
#elif MAX_NR_ZONES <= 4
|
|
#define ZONES_SHIFT 2
|
|
#else
|
|
#error ZONES_SHIFT -- too many zones configured adjust calculation
|
|
#endif
|
|
|
|
#ifdef CONFIG_SPARSEMEM
|
|
#include <asm/sparsemem.h>
|
|
|
|
/* SECTION_SHIFT #bits space required to store a section # */
|
|
#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
|
|
|
|
#endif /* CONFIG_SPARSEMEM */
|
|
|
|
/*
|
|
* page->flags layout:
|
|
*
|
|
* There are five possibilities for how page->flags get laid out. The first
|
|
* pair is for the normal case without sparsemem. The second pair is for
|
|
* sparsemem when there is plenty of space for node and section information.
|
|
* The last is when there is insufficient space in page->flags and a separate
|
|
* lookup is necessary.
|
|
*
|
|
* No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS |
|
|
* " plus space for last_nid: | NODE | ZONE | LAST_NID ... | FLAGS |
|
|
* classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
|
|
* " plus space for last_nid: | SECTION | NODE | ZONE | LAST_NID ... | FLAGS |
|
|
* classic sparse no space for node: | SECTION | ZONE | ... | FLAGS |
|
|
*/
|
|
#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
|
|
#define SECTIONS_WIDTH SECTIONS_SHIFT
|
|
#else
|
|
#define SECTIONS_WIDTH 0
|
|
#endif
|
|
|
|
#define ZONES_WIDTH ZONES_SHIFT
|
|
|
|
#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
|
|
#define NODES_WIDTH NODES_SHIFT
|
|
#else
|
|
#ifdef CONFIG_SPARSEMEM_VMEMMAP
|
|
#error "Vmemmap: No space for nodes field in page flags"
|
|
#endif
|
|
#define NODES_WIDTH 0
|
|
#endif
|
|
|
|
#ifdef CONFIG_NUMA_BALANCING
|
|
#define LAST_NID_SHIFT NODES_SHIFT
|
|
#else
|
|
#define LAST_NID_SHIFT 0
|
|
#endif
|
|
|
|
#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_NID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
|
|
#define LAST_NID_WIDTH LAST_NID_SHIFT
|
|
#else
|
|
#define LAST_NID_WIDTH 0
|
|
#endif
|
|
|
|
/*
|
|
* We are going to use the flags for the page to node mapping if its in
|
|
* there. This includes the case where there is no node, so it is implicit.
|
|
*/
|
|
#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
|
|
#define NODE_NOT_IN_PAGE_FLAGS
|
|
#endif
|
|
|
|
#if defined(CONFIG_NUMA_BALANCING) && LAST_NID_WIDTH == 0
|
|
#define LAST_NID_NOT_IN_PAGE_FLAGS
|
|
#endif
|
|
|
|
#endif /* _LINUX_PAGE_FLAGS_LAYOUT */
|