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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#ifndef _LINUX_MMZONE_H
2#define _LINUX_MMZONE_H
3
4#ifdef __KERNEL__
5#ifndef __ASSEMBLY__
6
7#include <linux/config.h>
8#include <linux/spinlock.h>
9#include <linux/list.h>
10#include <linux/wait.h>
11#include <linux/cache.h>
12#include <linux/threads.h>
13#include <linux/numa.h>
14#include <linux/init.h>
Dave Hansenbdc8cb92005-10-29 18:16:53 -070015#include <linux/seqlock.h>
KAMEZAWA Hiroyuki8357f862006-03-27 01:15:57 -080016#include <linux/nodemask.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/atomic.h>
18
19/* Free memory management - zoned buddy allocator. */
20#ifndef CONFIG_FORCE_MAX_ZONEORDER
21#define MAX_ORDER 11
22#else
23#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
24#endif
25
26struct free_area {
27 struct list_head free_list;
28 unsigned long nr_free;
29};
30
31struct pglist_data;
32
33/*
34 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
35 * So add a wild amount of padding here to ensure that they fall into separate
36 * cachelines. There are very few zone structures in the machine, so space
37 * consumption is not a concern here.
38 */
39#if defined(CONFIG_SMP)
40struct zone_padding {
41 char x[0];
Ravikiran G Thirumalai22fc6ec2006-01-08 01:01:27 -080042} ____cacheline_internodealigned_in_smp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define ZONE_PADDING(name) struct zone_padding name;
44#else
45#define ZONE_PADDING(name)
46#endif
47
48struct per_cpu_pages {
49 int count; /* number of pages in the list */
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 int high; /* high watermark, emptying needed */
51 int batch; /* chunk size for buddy add/remove */
52 struct list_head list; /* the list of pages */
53};
54
55struct per_cpu_pageset {
56 struct per_cpu_pages pcp[2]; /* 0: hot. 1: cold */
57#ifdef CONFIG_NUMA
58 unsigned long numa_hit; /* allocated in intended node */
59 unsigned long numa_miss; /* allocated in non intended node */
60 unsigned long numa_foreign; /* was intended here, hit elsewhere */
61 unsigned long interleave_hit; /* interleaver prefered this zone */
62 unsigned long local_node; /* allocation from local node */
63 unsigned long other_node; /* allocation from other node */
64#endif
65} ____cacheline_aligned_in_smp;
66
Christoph Lametere7c8d5c2005-06-21 17:14:47 -070067#ifdef CONFIG_NUMA
68#define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
69#else
70#define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
71#endif
72
Linus Torvalds1da177e2005-04-16 15:20:36 -070073#define ZONE_DMA 0
Andi Kleena2f1b422005-11-05 17:25:53 +010074#define ZONE_DMA32 1
75#define ZONE_NORMAL 2
76#define ZONE_HIGHMEM 3
Linus Torvalds1da177e2005-04-16 15:20:36 -070077
Andi Kleena2f1b422005-11-05 17:25:53 +010078#define MAX_NR_ZONES 4 /* Sync this with ZONES_SHIFT */
Linus Torvalds1da177e2005-04-16 15:20:36 -070079#define ZONES_SHIFT 2 /* ceil(log2(MAX_NR_ZONES)) */
80
81
82/*
83 * When a memory allocation must conform to specific limitations (such
84 * as being suitable for DMA) the caller will pass in hints to the
85 * allocator in the gfp_mask, in the zone modifier bits. These bits
86 * are used to select a priority ordered list of memory zones which
87 * match the requested limits. GFP_ZONEMASK defines which bits within
88 * the gfp_mask should be considered as zone modifiers. Each valid
89 * combination of the zone modifier bits has a corresponding list
90 * of zones (in node_zonelists). Thus for two zone modifiers there
91 * will be a maximum of 4 (2 ** 2) zonelists, for 3 modifiers there will
92 * be 8 (2 ** 3) zonelists. GFP_ZONETYPES defines the number of possible
93 * combinations of zone modifiers in "zone modifier space".
Linus Torvaldsac3461a2005-11-22 19:39:30 -080094 *
Andy Whitcroft79046ae2006-02-01 03:05:26 -080095 * As an optimisation any zone modifier bits which are only valid when
96 * no other zone modifier bits are set (loners) should be placed in
97 * the highest order bits of this field. This allows us to reduce the
98 * extent of the zonelists thus saving space. For example in the case
99 * of three zone modifier bits, we could require up to eight zonelists.
100 * If the left most zone modifier is a "loner" then the highest valid
101 * zonelist would be four allowing us to allocate only five zonelists.
Andy Whitcroftce2ea892006-02-01 03:05:27 -0800102 * Use the first form for GFP_ZONETYPES when the left most bit is not
103 * a "loner", otherwise use the second.
Andy Whitcroft79046ae2006-02-01 03:05:26 -0800104 *
Linus Torvaldsac3461a2005-11-22 19:39:30 -0800105 * NOTE! Make sure this matches the zones in <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 */
Linus Torvaldsac3461a2005-11-22 19:39:30 -0800107#define GFP_ZONEMASK 0x07
Andy Whitcroftce2ea892006-02-01 03:05:27 -0800108/* #define GFP_ZONETYPES (GFP_ZONEMASK + 1) */ /* Non-loner */
109#define GFP_ZONETYPES ((GFP_ZONEMASK + 1) / 2 + 1) /* Loner */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110
111/*
112 * On machines where it is needed (eg PCs) we divide physical memory
Andi Kleen1f6818b2006-01-11 22:42:26 +0100113 * into multiple physical zones. On a 32bit PC we have 4 zones:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 *
115 * ZONE_DMA < 16 MB ISA DMA capable memory
Andi Kleena2f1b422005-11-05 17:25:53 +0100116 * ZONE_DMA32 0 MB Empty
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 * ZONE_NORMAL 16-896 MB direct mapped by the kernel
118 * ZONE_HIGHMEM > 896 MB only page cache and user processes
119 */
120
121struct zone {
122 /* Fields commonly accessed by the page allocator */
123 unsigned long free_pages;
124 unsigned long pages_min, pages_low, pages_high;
125 /*
126 * We don't know if the memory that we're going to allocate will be freeable
127 * or/and it will be released eventually, so to avoid totally wasting several
128 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
129 * to run OOM on the lower zones despite there's tons of freeable ram
130 * on the higher zones). This array is recalculated at runtime if the
131 * sysctl_lowmem_reserve_ratio sysctl changes.
132 */
133 unsigned long lowmem_reserve[MAX_NR_ZONES];
134
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700135#ifdef CONFIG_NUMA
136 struct per_cpu_pageset *pageset[NR_CPUS];
137#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138 struct per_cpu_pageset pageset[NR_CPUS];
Christoph Lametere7c8d5c2005-06-21 17:14:47 -0700139#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140 /*
141 * free areas of different sizes
142 */
143 spinlock_t lock;
Dave Hansenbdc8cb92005-10-29 18:16:53 -0700144#ifdef CONFIG_MEMORY_HOTPLUG
145 /* see spanned/present_pages for more description */
146 seqlock_t span_seqlock;
147#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 struct free_area free_area[MAX_ORDER];
149
150
151 ZONE_PADDING(_pad1_)
152
153 /* Fields commonly accessed by the page reclaim scanner */
154 spinlock_t lru_lock;
155 struct list_head active_list;
156 struct list_head inactive_list;
157 unsigned long nr_scan_active;
158 unsigned long nr_scan_inactive;
159 unsigned long nr_active;
160 unsigned long nr_inactive;
161 unsigned long pages_scanned; /* since last reclaim */
162 int all_unreclaimable; /* All pages pinned */
163
Martin Hicks1e7e5a92005-06-21 17:14:43 -0700164 /* A count of how many reclaimers are scanning this zone */
165 atomic_t reclaim_in_progress;
Martin Hicks753ee722005-06-21 17:14:41 -0700166
167 /*
Christoph Lameter9eeff232006-01-18 17:42:31 -0800168 * timestamp (in jiffies) of the last zone reclaim that did not
169 * result in freeing of pages. This is used to avoid repeated scans
170 * if all memory in the zone is in use.
171 */
172 unsigned long last_unsuccessful_zone_reclaim;
173
174 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175 * prev_priority holds the scanning priority for this zone. It is
176 * defined as the scanning priority at which we achieved our reclaim
177 * target at the previous try_to_free_pages() or balance_pgdat()
178 * invokation.
179 *
180 * We use prev_priority as a measure of how much stress page reclaim is
181 * under - it drives the swappiness decision: whether to unmap mapped
182 * pages.
183 *
184 * temp_priority is used to remember the scanning priority at which
185 * this zone was successfully refilled to free_pages == pages_high.
186 *
187 * Access to both these fields is quite racy even on uniprocessor. But
188 * it is expected to average out OK.
189 */
190 int temp_priority;
191 int prev_priority;
192
193
194 ZONE_PADDING(_pad2_)
195 /* Rarely used or read-mostly fields */
196
197 /*
198 * wait_table -- the array holding the hash table
199 * wait_table_size -- the size of the hash table array
200 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
201 *
202 * The purpose of all these is to keep track of the people
203 * waiting for a page to become available and make them
204 * runnable again when possible. The trouble is that this
205 * consumes a lot of space, especially when so few things
206 * wait on pages at a given time. So instead of using
207 * per-page waitqueues, we use a waitqueue hash table.
208 *
209 * The bucket discipline is to sleep on the same queue when
210 * colliding and wake all in that wait queue when removing.
211 * When something wakes, it must check to be sure its page is
212 * truly available, a la thundering herd. The cost of a
213 * collision is great, but given the expected load of the
214 * table, they should be so rare as to be outweighed by the
215 * benefits from the saved space.
216 *
217 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
218 * primary users of these fields, and in mm/page_alloc.c
219 * free_area_init_core() performs the initialization of them.
220 */
221 wait_queue_head_t * wait_table;
222 unsigned long wait_table_size;
223 unsigned long wait_table_bits;
224
225 /*
226 * Discontig memory support fields.
227 */
228 struct pglist_data *zone_pgdat;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
230 unsigned long zone_start_pfn;
231
Dave Hansenbdc8cb92005-10-29 18:16:53 -0700232 /*
233 * zone_start_pfn, spanned_pages and present_pages are all
234 * protected by span_seqlock. It is a seqlock because it has
235 * to be read outside of zone->lock, and it is done in the main
236 * allocator path. But, it is written quite infrequently.
237 *
238 * The lock is declared along with zone->lock because it is
239 * frequently read in proximity to zone->lock. It's good to
240 * give them a chance of being in the same cacheline.
241 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 unsigned long spanned_pages; /* total size, including holes */
243 unsigned long present_pages; /* amount of memory (excluding holes) */
244
245 /*
246 * rarely used fields:
247 */
248 char *name;
Ravikiran G Thirumalai22fc6ec2006-01-08 01:01:27 -0800249} ____cacheline_internodealigned_in_smp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250
251
252/*
253 * The "priority" of VM scanning is how much of the queues we will scan in one
254 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
255 * queues ("queue_length >> 12") during an aging round.
256 */
257#define DEF_PRIORITY 12
258
259/*
260 * One allocation request operates on a zonelist. A zonelist
261 * is a list of zones, the first one is the 'goal' of the
262 * allocation, the other zones are fallback zones, in decreasing
263 * priority.
264 *
265 * Right now a zonelist takes up less than a cacheline. We never
266 * modify it apart from boot-up, and only a few indices are used,
267 * so despite the zonelist table being relatively big, the cache
268 * footprint of this construct is very small.
269 */
270struct zonelist {
271 struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited
272};
273
274
275/*
276 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
277 * (mostly NUMA machines?) to denote a higher-level memory zone than the
278 * zone denotes.
279 *
280 * On NUMA machines, each NUMA node would have a pg_data_t to describe
281 * it's memory layout.
282 *
283 * Memory statistics and page replacement data structures are maintained on a
284 * per-zone basis.
285 */
286struct bootmem_data;
287typedef struct pglist_data {
288 struct zone node_zones[MAX_NR_ZONES];
289 struct zonelist node_zonelists[GFP_ZONETYPES];
290 int nr_zones;
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700291#ifdef CONFIG_FLAT_NODE_MEM_MAP
Linus Torvalds1da177e2005-04-16 15:20:36 -0700292 struct page *node_mem_map;
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700293#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 struct bootmem_data *bdata;
Dave Hansen208d54e2005-10-29 18:16:52 -0700295#ifdef CONFIG_MEMORY_HOTPLUG
296 /*
297 * Must be held any time you expect node_start_pfn, node_present_pages
298 * or node_spanned_pages stay constant. Holding this will also
299 * guarantee that any pfn_valid() stays that way.
300 *
301 * Nests above zone->lock and zone->size_seqlock.
302 */
303 spinlock_t node_size_lock;
304#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 unsigned long node_start_pfn;
306 unsigned long node_present_pages; /* total number of physical pages */
307 unsigned long node_spanned_pages; /* total size of physical page
308 range, including holes */
309 int node_id;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 wait_queue_head_t kswapd_wait;
311 struct task_struct *kswapd;
312 int kswapd_max_order;
313} pg_data_t;
314
315#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
316#define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700317#ifdef CONFIG_FLAT_NODE_MEM_MAP
Dave Hansen408fde82005-06-23 00:07:37 -0700318#define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700319#else
320#define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
321#endif
Dave Hansen408fde82005-06-23 00:07:37 -0700322#define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323
Dave Hansen208d54e2005-10-29 18:16:52 -0700324#include <linux/memory_hotplug.h>
325
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326void __get_zone_counts(unsigned long *active, unsigned long *inactive,
327 unsigned long *free, struct pglist_data *pgdat);
328void get_zone_counts(unsigned long *active, unsigned long *inactive,
329 unsigned long *free);
330void build_all_zonelists(void);
331void wakeup_kswapd(struct zone *zone, int order);
332int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
Rohit Seth7fb1d9f2005-11-13 16:06:43 -0800333 int classzone_idx, int alloc_flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334
335#ifdef CONFIG_HAVE_MEMORY_PRESENT
336void memory_present(int nid, unsigned long start, unsigned long end);
337#else
338static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
339#endif
340
341#ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
342unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
343#endif
344
345/*
346 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
347 */
348#define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
349
Con Kolivasf3fe6512006-01-06 00:11:15 -0800350static inline int populated_zone(struct zone *zone)
351{
352 return (!!zone->present_pages);
353}
354
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355static inline int is_highmem_idx(int idx)
356{
357 return (idx == ZONE_HIGHMEM);
358}
359
360static inline int is_normal_idx(int idx)
361{
362 return (idx == ZONE_NORMAL);
363}
Nick Piggin9328b8f2006-01-06 00:11:10 -0800364
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365/**
366 * is_highmem - helper function to quickly check if a struct zone is a
367 * highmem zone or not. This is an attempt to keep references
368 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
369 * @zone - pointer to struct zone variable
370 */
371static inline int is_highmem(struct zone *zone)
372{
373 return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM;
374}
375
376static inline int is_normal(struct zone *zone)
377{
378 return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
379}
380
Nick Piggin9328b8f2006-01-06 00:11:10 -0800381static inline int is_dma32(struct zone *zone)
382{
383 return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
384}
385
386static inline int is_dma(struct zone *zone)
387{
388 return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
389}
390
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391/* These two functions are used to setup the per zone pages min values */
392struct ctl_table;
393struct file;
394int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
395 void __user *, size_t *, loff_t *);
396extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
397int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
398 void __user *, size_t *, loff_t *);
Rohit Seth8ad4b1f2006-01-08 01:00:40 -0800399int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
400 void __user *, size_t *, loff_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401
402#include <linux/topology.h>
403/* Returns the number of the current Node. */
Andi Kleen69d81fc2005-11-05 17:25:53 +0100404#ifndef numa_node_id
Ingo Molnar39c715b2005-06-21 17:14:34 -0700405#define numa_node_id() (cpu_to_node(raw_smp_processor_id()))
Andi Kleen69d81fc2005-11-05 17:25:53 +0100406#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
Dave Hansen93b75042005-06-23 00:07:47 -0700408#ifndef CONFIG_NEED_MULTIPLE_NODES
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
410extern struct pglist_data contig_page_data;
411#define NODE_DATA(nid) (&contig_page_data)
412#define NODE_MEM_MAP(nid) mem_map
413#define MAX_NODES_SHIFT 1
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Dave Hansen93b75042005-06-23 00:07:47 -0700415#else /* CONFIG_NEED_MULTIPLE_NODES */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
417#include <asm/mmzone.h>
418
Dave Hansen93b75042005-06-23 00:07:47 -0700419#endif /* !CONFIG_NEED_MULTIPLE_NODES */
Dave Hansen348f8b62005-06-23 00:07:40 -0700420
KAMEZAWA Hiroyuki95144c72006-03-27 01:16:02 -0800421extern struct pglist_data *first_online_pgdat(void);
422extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
423extern struct zone *next_zone(struct zone *zone);
KAMEZAWA Hiroyuki8357f862006-03-27 01:15:57 -0800424
425/**
426 * for_each_pgdat - helper macro to iterate over all nodes
427 * @pgdat - pointer to a pg_data_t variable
428 */
429#define for_each_online_pgdat(pgdat) \
430 for (pgdat = first_online_pgdat(); \
431 pgdat; \
432 pgdat = next_online_pgdat(pgdat))
KAMEZAWA Hiroyuki8357f862006-03-27 01:15:57 -0800433/**
434 * for_each_zone - helper macro to iterate over all memory zones
435 * @zone - pointer to struct zone variable
436 *
437 * The user only needs to declare the zone variable, for_each_zone
438 * fills it in.
439 */
440#define for_each_zone(zone) \
441 for (zone = (first_online_pgdat())->node_zones; \
442 zone; \
443 zone = next_zone(zone))
444
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700445#ifdef CONFIG_SPARSEMEM
446#include <asm/sparsemem.h>
447#endif
448
Andi Kleen07808b72005-11-05 17:25:53 +0100449#if BITS_PER_LONG == 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450/*
Andi Kleena2f1b422005-11-05 17:25:53 +0100451 * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
452 * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453 */
Andi Kleena2f1b422005-11-05 17:25:53 +0100454#define FLAGS_RESERVED 9
Dave Hansen348f8b62005-06-23 00:07:40 -0700455
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456#elif BITS_PER_LONG == 64
457/*
458 * with 64 bit flags field, there's plenty of room.
459 */
Dave Hansen348f8b62005-06-23 00:07:40 -0700460#define FLAGS_RESERVED 32
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461
Dave Hansen348f8b62005-06-23 00:07:40 -0700462#else
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463
Dave Hansen348f8b62005-06-23 00:07:40 -0700464#error BITS_PER_LONG not defined
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466#endif
467
Andy Whitcroftb159d432005-06-23 00:07:52 -0700468#ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
469#define early_pfn_to_nid(nid) (0UL)
470#endif
471
Andy Whitcroft2bdaf112006-01-06 00:10:53 -0800472#ifdef CONFIG_FLATMEM
473#define pfn_to_nid(pfn) (0)
474#endif
475
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700476#define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
477#define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
478
479#ifdef CONFIG_SPARSEMEM
480
481/*
482 * SECTION_SHIFT #bits space required to store a section #
483 *
484 * PA_SECTION_SHIFT physical address to/from section number
485 * PFN_SECTION_SHIFT pfn to/from section number
486 */
487#define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
488
489#define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
490#define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
491
492#define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
493
494#define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
495#define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
496
497#if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
498#error Allocator MAX_ORDER exceeds SECTION_SIZE
499#endif
500
501struct page;
502struct mem_section {
Andy Whitcroft29751f62005-06-23 00:08:00 -0700503 /*
504 * This is, logically, a pointer to an array of struct
505 * pages. However, it is stored with some other magic.
506 * (see sparse.c::sparse_init_one_section())
507 *
508 * Making it a UL at least makes someone do a cast
509 * before using it wrong.
510 */
511 unsigned long section_mem_map;
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700512};
513
Bob Picco3e347262005-09-03 15:54:28 -0700514#ifdef CONFIG_SPARSEMEM_EXTREME
515#define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
Bob Picco802f1922005-09-03 15:54:26 -0700516#else
Bob Picco3e347262005-09-03 15:54:28 -0700517#define SECTIONS_PER_ROOT 1
518#endif
Bob Picco802f1922005-09-03 15:54:26 -0700519
Bob Picco3e347262005-09-03 15:54:28 -0700520#define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
521#define NR_SECTION_ROOTS (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
522#define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
523
524#ifdef CONFIG_SPARSEMEM_EXTREME
525extern struct mem_section *mem_section[NR_SECTION_ROOTS];
526#else
527extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
528#endif
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700529
Andy Whitcroft29751f62005-06-23 00:08:00 -0700530static inline struct mem_section *__nr_to_section(unsigned long nr)
531{
Bob Picco3e347262005-09-03 15:54:28 -0700532 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
533 return NULL;
534 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
Andy Whitcroft29751f62005-06-23 00:08:00 -0700535}
Dave Hansen4ca644d2005-10-29 18:16:51 -0700536extern int __section_nr(struct mem_section* ms);
Andy Whitcroft29751f62005-06-23 00:08:00 -0700537
538/*
539 * We use the lower bits of the mem_map pointer to store
540 * a little bit of information. There should be at least
541 * 3 bits here due to 32-bit alignment.
542 */
543#define SECTION_MARKED_PRESENT (1UL<<0)
544#define SECTION_HAS_MEM_MAP (1UL<<1)
545#define SECTION_MAP_LAST_BIT (1UL<<2)
546#define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
547
548static inline struct page *__section_mem_map_addr(struct mem_section *section)
549{
550 unsigned long map = section->section_mem_map;
551 map &= SECTION_MAP_MASK;
552 return (struct page *)map;
553}
554
555static inline int valid_section(struct mem_section *section)
556{
Bob Picco802f1922005-09-03 15:54:26 -0700557 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
Andy Whitcroft29751f62005-06-23 00:08:00 -0700558}
559
560static inline int section_has_mem_map(struct mem_section *section)
561{
Bob Picco802f1922005-09-03 15:54:26 -0700562 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
Andy Whitcroft29751f62005-06-23 00:08:00 -0700563}
564
565static inline int valid_section_nr(unsigned long nr)
566{
567 return valid_section(__nr_to_section(nr));
568}
569
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700570static inline struct mem_section *__pfn_to_section(unsigned long pfn)
571{
Andy Whitcroft29751f62005-06-23 00:08:00 -0700572 return __nr_to_section(pfn_to_section_nr(pfn));
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700573}
574
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700575static inline int pfn_valid(unsigned long pfn)
576{
577 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
578 return 0;
Andy Whitcroft29751f62005-06-23 00:08:00 -0700579 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700580}
581
582/*
583 * These are _only_ used during initialisation, therefore they
584 * can use __initdata ... They could have names to indicate
585 * this restriction.
586 */
587#ifdef CONFIG_NUMA
Andy Whitcroft161599f2006-01-06 00:10:54 -0800588#define pfn_to_nid(pfn) \
589({ \
590 unsigned long __pfn_to_nid_pfn = (pfn); \
591 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
592})
Andy Whitcroft2bdaf112006-01-06 00:10:53 -0800593#else
594#define pfn_to_nid(pfn) (0)
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700595#endif
596
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700597#define early_pfn_valid(pfn) pfn_valid(pfn)
598void sparse_init(void);
599#else
600#define sparse_init() do {} while (0)
Dave Hansen28ae55c2005-09-03 15:54:29 -0700601#define sparse_index_init(_sec, _nid) do {} while (0)
Andy Whitcroftd41dee32005-06-23 00:07:54 -0700602#endif /* CONFIG_SPARSEMEM */
603
604#ifndef early_pfn_valid
605#define early_pfn_valid(pfn) (1)
606#endif
607
608void memory_present(int nid, unsigned long start, unsigned long end);
609unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
610
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611#endif /* !__ASSEMBLY__ */
612#endif /* __KERNEL__ */
613#endif /* _LINUX_MMZONE_H */