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Tejun Heofbf59bc2009-02-20 16:29:08 +09001/*
Tejun Heo88999a82010-04-09 18:57:01 +09002 * mm/percpu.c - percpu memory allocator
Tejun Heofbf59bc2009-02-20 16:29:08 +09003 *
4 * Copyright (C) 2009 SUSE Linux Products GmbH
5 * Copyright (C) 2009 Tejun Heo <tj@kernel.org>
6 *
7 * This file is released under the GPLv2.
8 *
9 * This is percpu allocator which can handle both static and dynamic
Tejun Heo88999a82010-04-09 18:57:01 +090010 * areas. Percpu areas are allocated in chunks. Each chunk is
11 * consisted of boot-time determined number of units and the first
12 * chunk is used for static percpu variables in the kernel image
Tejun Heo2f39e632009-07-04 08:11:00 +090013 * (special boot time alloc/init handling necessary as these areas
14 * need to be brought up before allocation services are running).
15 * Unit grows as necessary and all units grow or shrink in unison.
Tejun Heo88999a82010-04-09 18:57:01 +090016 * When a chunk is filled up, another chunk is allocated.
Tejun Heofbf59bc2009-02-20 16:29:08 +090017 *
18 * c0 c1 c2
19 * ------------------- ------------------- ------------
20 * | u0 | u1 | u2 | u3 | | u0 | u1 | u2 | u3 | | u0 | u1 | u
21 * ------------------- ...... ------------------- .... ------------
22 *
23 * Allocation is done in offset-size areas of single unit space. Ie,
24 * an area of 512 bytes at 6k in c1 occupies 512 bytes at 6k of c1:u0,
Tejun Heo2f39e632009-07-04 08:11:00 +090025 * c1:u1, c1:u2 and c1:u3. On UMA, units corresponds directly to
26 * cpus. On NUMA, the mapping can be non-linear and even sparse.
27 * Percpu access can be done by configuring percpu base registers
28 * according to cpu to unit mapping and pcpu_unit_size.
Tejun Heofbf59bc2009-02-20 16:29:08 +090029 *
Tejun Heo2f39e632009-07-04 08:11:00 +090030 * There are usually many small percpu allocations many of them being
31 * as small as 4 bytes. The allocator organizes chunks into lists
Tejun Heofbf59bc2009-02-20 16:29:08 +090032 * according to free size and tries to allocate from the fullest one.
33 * Each chunk keeps the maximum contiguous area size hint which is
Namhyung Kim47858792010-08-11 11:24:10 +090034 * guaranteed to be equal to or larger than the maximum contiguous
Tejun Heofbf59bc2009-02-20 16:29:08 +090035 * area in the chunk. This helps the allocator not to iterate the
36 * chunk maps unnecessarily.
37 *
38 * Allocation state in each chunk is kept using an array of integers
39 * on chunk->map. A positive value in the map represents a free
40 * region and negative allocated. Allocation inside a chunk is done
41 * by scanning this map sequentially and serving the first matching
42 * entry. This is mostly copied from the percpu_modalloc() allocator.
Christoph Lametere1b9aa32009-04-02 13:21:44 +090043 * Chunks can be determined from the address using the index field
44 * in the page struct. The index field contains a pointer to the chunk.
Tejun Heofbf59bc2009-02-20 16:29:08 +090045 *
46 * To use this allocator, arch code should do the followings.
47 *
Tejun Heofbf59bc2009-02-20 16:29:08 +090048 * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate
Tejun Heoe0100982009-03-10 16:27:48 +090049 * regular address to percpu pointer and back if they need to be
50 * different from the default
Tejun Heofbf59bc2009-02-20 16:29:08 +090051 *
Tejun Heo8d408b42009-02-24 11:57:21 +090052 * - use pcpu_setup_first_chunk() during percpu area initialization to
53 * setup the first chunk containing the kernel static percpu area
Tejun Heofbf59bc2009-02-20 16:29:08 +090054 */
55
56#include <linux/bitmap.h>
57#include <linux/bootmem.h>
Tejun Heofd1e8a12009-08-14 15:00:51 +090058#include <linux/err.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090059#include <linux/list.h>
Tejun Heoa530b792009-07-04 08:11:00 +090060#include <linux/log2.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090061#include <linux/mm.h>
62#include <linux/module.h>
63#include <linux/mutex.h>
64#include <linux/percpu.h>
65#include <linux/pfn.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090066#include <linux/slab.h>
Tejun Heoccea34b2009-03-07 00:44:13 +090067#include <linux/spinlock.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090068#include <linux/vmalloc.h>
Tejun Heoa56dbdd2009-03-07 00:44:11 +090069#include <linux/workqueue.h>
Catalin Marinasf528f0b2011-09-26 17:12:53 +010070#include <linux/kmemleak.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090071
72#include <asm/cacheflush.h>
Tejun Heoe0100982009-03-10 16:27:48 +090073#include <asm/sections.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090074#include <asm/tlbflush.h>
Vivek Goyal3b034b02009-11-24 15:50:03 +090075#include <asm/io.h>
Tejun Heofbf59bc2009-02-20 16:29:08 +090076
Tejun Heofbf59bc2009-02-20 16:29:08 +090077#define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */
78#define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */
79
Tejun Heobbddff02010-09-03 18:22:48 +020080#ifdef CONFIG_SMP
Tejun Heoe0100982009-03-10 16:27:48 +090081/* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */
82#ifndef __addr_to_pcpu_ptr
83#define __addr_to_pcpu_ptr(addr) \
Tejun Heo43cf38e2010-02-02 14:38:57 +090084 (void __percpu *)((unsigned long)(addr) - \
85 (unsigned long)pcpu_base_addr + \
86 (unsigned long)__per_cpu_start)
Tejun Heoe0100982009-03-10 16:27:48 +090087#endif
88#ifndef __pcpu_ptr_to_addr
89#define __pcpu_ptr_to_addr(ptr) \
Tejun Heo43cf38e2010-02-02 14:38:57 +090090 (void __force *)((unsigned long)(ptr) + \
91 (unsigned long)pcpu_base_addr - \
92 (unsigned long)__per_cpu_start)
Tejun Heoe0100982009-03-10 16:27:48 +090093#endif
Tejun Heobbddff02010-09-03 18:22:48 +020094#else /* CONFIG_SMP */
95/* on UP, it's always identity mapped */
96#define __addr_to_pcpu_ptr(addr) (void __percpu *)(addr)
97#define __pcpu_ptr_to_addr(ptr) (void __force *)(ptr)
98#endif /* CONFIG_SMP */
Tejun Heoe0100982009-03-10 16:27:48 +090099
Tejun Heofbf59bc2009-02-20 16:29:08 +0900100struct pcpu_chunk {
101 struct list_head list; /* linked to pcpu_slot lists */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900102 int free_size; /* free bytes in the chunk */
103 int contig_hint; /* max contiguous size hint */
Tejun Heobba174f2009-08-14 15:00:51 +0900104 void *base_addr; /* base address of this chunk */
Al Viro723ad1d2014-03-06 21:13:18 -0500105 int map_used; /* # of map entries used before the sentry */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900106 int map_alloc; /* # of map entries allocated */
107 int *map; /* allocation map */
Tejun Heo88999a82010-04-09 18:57:01 +0900108 void *data; /* chunk data */
Al Viro3d331ad2014-03-06 20:52:32 -0500109 int first_free; /* no free below this */
Tejun Heo8d408b42009-02-24 11:57:21 +0900110 bool immutable; /* no [de]population allowed */
Tejun Heoce3141a2009-07-04 08:11:00 +0900111 unsigned long populated[]; /* populated bitmap */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900112};
113
Tejun Heo40150d32009-02-24 12:32:28 +0900114static int pcpu_unit_pages __read_mostly;
115static int pcpu_unit_size __read_mostly;
Tejun Heo2f39e632009-07-04 08:11:00 +0900116static int pcpu_nr_units __read_mostly;
Tejun Heo65632972009-08-14 15:00:52 +0900117static int pcpu_atom_size __read_mostly;
Tejun Heo40150d32009-02-24 12:32:28 +0900118static int pcpu_nr_slots __read_mostly;
119static size_t pcpu_chunk_struct_size __read_mostly;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900120
Tejun Heoa855b842011-11-18 10:55:35 -0800121/* cpus with the lowest and highest unit addresses */
122static unsigned int pcpu_low_unit_cpu __read_mostly;
123static unsigned int pcpu_high_unit_cpu __read_mostly;
Tejun Heo2f39e632009-07-04 08:11:00 +0900124
Tejun Heofbf59bc2009-02-20 16:29:08 +0900125/* the address of the first chunk which starts with the kernel static area */
Tejun Heo40150d32009-02-24 12:32:28 +0900126void *pcpu_base_addr __read_mostly;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900127EXPORT_SYMBOL_GPL(pcpu_base_addr);
128
Tejun Heofb435d52009-08-14 15:00:51 +0900129static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */
130const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */
Tejun Heo2f39e632009-07-04 08:11:00 +0900131
Tejun Heo65632972009-08-14 15:00:52 +0900132/* group information, used for vm allocation */
133static int pcpu_nr_groups __read_mostly;
134static const unsigned long *pcpu_group_offsets __read_mostly;
135static const size_t *pcpu_group_sizes __read_mostly;
136
Tejun Heoae9e6bc92009-04-02 13:19:54 +0900137/*
138 * The first chunk which always exists. Note that unlike other
139 * chunks, this one can be allocated and mapped in several different
140 * ways and thus often doesn't live in the vmalloc area.
141 */
142static struct pcpu_chunk *pcpu_first_chunk;
143
144/*
145 * Optional reserved chunk. This chunk reserves part of the first
146 * chunk and serves it for reserved allocations. The amount of
147 * reserved offset is in pcpu_reserved_chunk_limit. When reserved
148 * area doesn't exist, the following variables contain NULL and 0
149 * respectively.
150 */
Tejun Heoedcb4632009-03-06 14:33:59 +0900151static struct pcpu_chunk *pcpu_reserved_chunk;
Tejun Heoedcb4632009-03-06 14:33:59 +0900152static int pcpu_reserved_chunk_limit;
153
Tejun Heofbf59bc2009-02-20 16:29:08 +0900154/*
Tejun Heoccea34b2009-03-07 00:44:13 +0900155 * Synchronization rules.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900156 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900157 * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former
Tejun Heoce3141a2009-07-04 08:11:00 +0900158 * protects allocation/reclaim paths, chunks, populated bitmap and
159 * vmalloc mapping. The latter is a spinlock and protects the index
160 * data structures - chunk slots, chunks and area maps in chunks.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900161 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900162 * During allocation, pcpu_alloc_mutex is kept locked all the time and
163 * pcpu_lock is grabbed and released as necessary. All actual memory
Jiri Kosina403a91b2009-10-29 00:25:59 +0900164 * allocations are done using GFP_KERNEL with pcpu_lock released. In
165 * general, percpu memory can't be allocated with irq off but
166 * irqsave/restore are still used in alloc path so that it can be used
167 * from early init path - sched_init() specifically.
Tejun Heoccea34b2009-03-07 00:44:13 +0900168 *
169 * Free path accesses and alters only the index data structures, so it
170 * can be safely called from atomic context. When memory needs to be
171 * returned to the system, free path schedules reclaim_work which
172 * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be
173 * reclaimed, release both locks and frees the chunks. Note that it's
174 * necessary to grab both locks to remove a chunk from circulation as
175 * allocation path might be referencing the chunk with only
176 * pcpu_alloc_mutex locked.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900177 */
Tejun Heoccea34b2009-03-07 00:44:13 +0900178static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */
179static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900180
Tejun Heo40150d32009-02-24 12:32:28 +0900181static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900182
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900183/* reclaim work to release fully free chunks, scheduled from free path */
184static void pcpu_reclaim(struct work_struct *work);
185static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim);
186
Tejun Heo020ec652010-04-09 18:57:00 +0900187static bool pcpu_addr_in_first_chunk(void *addr)
188{
189 void *first_start = pcpu_first_chunk->base_addr;
190
191 return addr >= first_start && addr < first_start + pcpu_unit_size;
192}
193
194static bool pcpu_addr_in_reserved_chunk(void *addr)
195{
196 void *first_start = pcpu_first_chunk->base_addr;
197
198 return addr >= first_start &&
199 addr < first_start + pcpu_reserved_chunk_limit;
200}
201
Tejun Heod9b55ee2009-02-24 11:57:21 +0900202static int __pcpu_size_to_slot(int size)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900203{
Tejun Heocae3aeb2009-02-21 16:56:23 +0900204 int highbit = fls(size); /* size is in bytes */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900205 return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1);
206}
207
Tejun Heod9b55ee2009-02-24 11:57:21 +0900208static int pcpu_size_to_slot(int size)
209{
210 if (size == pcpu_unit_size)
211 return pcpu_nr_slots - 1;
212 return __pcpu_size_to_slot(size);
213}
214
Tejun Heofbf59bc2009-02-20 16:29:08 +0900215static int pcpu_chunk_slot(const struct pcpu_chunk *chunk)
216{
217 if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int))
218 return 0;
219
220 return pcpu_size_to_slot(chunk->free_size);
221}
222
Tejun Heo88999a82010-04-09 18:57:01 +0900223/* set the pointer to a chunk in a page struct */
224static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu)
225{
226 page->index = (unsigned long)pcpu;
227}
228
229/* obtain pointer to a chunk from a page struct */
230static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page)
231{
232 return (struct pcpu_chunk *)page->index;
233}
234
235static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900236{
Tejun Heo2f39e632009-07-04 08:11:00 +0900237 return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900238}
239
Tejun Heo9983b6f02010-06-18 11:44:31 +0200240static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk,
241 unsigned int cpu, int page_idx)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900242{
Tejun Heobba174f2009-08-14 15:00:51 +0900243 return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] +
Tejun Heofb435d52009-08-14 15:00:51 +0900244 (page_idx << PAGE_SHIFT);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900245}
246
Tejun Heo88999a82010-04-09 18:57:01 +0900247static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk,
248 int *rs, int *re, int end)
Tejun Heoce3141a2009-07-04 08:11:00 +0900249{
250 *rs = find_next_zero_bit(chunk->populated, end, *rs);
251 *re = find_next_bit(chunk->populated, end, *rs + 1);
252}
253
Tejun Heo88999a82010-04-09 18:57:01 +0900254static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk,
255 int *rs, int *re, int end)
Tejun Heoce3141a2009-07-04 08:11:00 +0900256{
257 *rs = find_next_bit(chunk->populated, end, *rs);
258 *re = find_next_zero_bit(chunk->populated, end, *rs + 1);
259}
260
261/*
262 * (Un)populated page region iterators. Iterate over (un)populated
Uwe Kleine-Königb5950762010-11-01 15:38:34 -0400263 * page regions between @start and @end in @chunk. @rs and @re should
Tejun Heoce3141a2009-07-04 08:11:00 +0900264 * be integer variables and will be set to start and end page index of
265 * the current region.
266 */
267#define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \
268 for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \
269 (rs) < (re); \
270 (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end)))
271
272#define pcpu_for_each_pop_region(chunk, rs, re, start, end) \
273 for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \
274 (rs) < (re); \
275 (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end)))
276
Tejun Heofbf59bc2009-02-20 16:29:08 +0900277/**
Bob Liu90459ce02011-08-04 11:02:33 +0200278 * pcpu_mem_zalloc - allocate memory
Tejun Heo1880d932009-03-07 00:44:09 +0900279 * @size: bytes to allocate
Tejun Heofbf59bc2009-02-20 16:29:08 +0900280 *
Tejun Heo1880d932009-03-07 00:44:09 +0900281 * Allocate @size bytes. If @size is smaller than PAGE_SIZE,
Bob Liu90459ce02011-08-04 11:02:33 +0200282 * kzalloc() is used; otherwise, vzalloc() is used. The returned
Tejun Heo1880d932009-03-07 00:44:09 +0900283 * memory is always zeroed.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900284 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900285 * CONTEXT:
286 * Does GFP_KERNEL allocation.
287 *
Tejun Heofbf59bc2009-02-20 16:29:08 +0900288 * RETURNS:
Tejun Heo1880d932009-03-07 00:44:09 +0900289 * Pointer to the allocated area on success, NULL on failure.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900290 */
Bob Liu90459ce02011-08-04 11:02:33 +0200291static void *pcpu_mem_zalloc(size_t size)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900292{
Tejun Heo099a19d2010-06-27 18:50:00 +0200293 if (WARN_ON_ONCE(!slab_is_available()))
294 return NULL;
295
Tejun Heofbf59bc2009-02-20 16:29:08 +0900296 if (size <= PAGE_SIZE)
Tejun Heo1880d932009-03-07 00:44:09 +0900297 return kzalloc(size, GFP_KERNEL);
Jesper Juhl7af4c092010-10-30 15:56:54 +0200298 else
299 return vzalloc(size);
Tejun Heo1880d932009-03-07 00:44:09 +0900300}
Tejun Heofbf59bc2009-02-20 16:29:08 +0900301
Tejun Heo1880d932009-03-07 00:44:09 +0900302/**
303 * pcpu_mem_free - free memory
304 * @ptr: memory to free
305 * @size: size of the area
306 *
Bob Liu90459ce02011-08-04 11:02:33 +0200307 * Free @ptr. @ptr should have been allocated using pcpu_mem_zalloc().
Tejun Heo1880d932009-03-07 00:44:09 +0900308 */
309static void pcpu_mem_free(void *ptr, size_t size)
310{
311 if (size <= PAGE_SIZE)
312 kfree(ptr);
313 else
314 vfree(ptr);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900315}
316
317/**
318 * pcpu_chunk_relocate - put chunk in the appropriate chunk slot
319 * @chunk: chunk of interest
320 * @oslot: the previous slot it was on
321 *
322 * This function is called after an allocation or free changed @chunk.
323 * New slot according to the changed state is determined and @chunk is
Tejun Heoedcb4632009-03-06 14:33:59 +0900324 * moved to the slot. Note that the reserved chunk is never put on
325 * chunk slots.
Tejun Heoccea34b2009-03-07 00:44:13 +0900326 *
327 * CONTEXT:
328 * pcpu_lock.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900329 */
330static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot)
331{
332 int nslot = pcpu_chunk_slot(chunk);
333
Tejun Heoedcb4632009-03-06 14:33:59 +0900334 if (chunk != pcpu_reserved_chunk && oslot != nslot) {
Tejun Heofbf59bc2009-02-20 16:29:08 +0900335 if (oslot < nslot)
336 list_move(&chunk->list, &pcpu_slot[nslot]);
337 else
338 list_move_tail(&chunk->list, &pcpu_slot[nslot]);
339 }
340}
341
Tejun Heofbf59bc2009-02-20 16:29:08 +0900342/**
Tejun Heo833af842009-11-11 15:35:18 +0900343 * pcpu_need_to_extend - determine whether chunk area map needs to be extended
344 * @chunk: chunk of interest
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900345 *
Tejun Heo833af842009-11-11 15:35:18 +0900346 * Determine whether area map of @chunk needs to be extended to
Lucas De Marchi25985ed2011-03-30 22:57:33 -0300347 * accommodate a new allocation.
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900348 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900349 * CONTEXT:
Tejun Heo833af842009-11-11 15:35:18 +0900350 * pcpu_lock.
Tejun Heoccea34b2009-03-07 00:44:13 +0900351 *
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900352 * RETURNS:
Tejun Heo833af842009-11-11 15:35:18 +0900353 * New target map allocation length if extension is necessary, 0
354 * otherwise.
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900355 */
Tejun Heo833af842009-11-11 15:35:18 +0900356static int pcpu_need_to_extend(struct pcpu_chunk *chunk)
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900357{
358 int new_alloc;
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900359
Al Viro723ad1d2014-03-06 21:13:18 -0500360 if (chunk->map_alloc >= chunk->map_used + 3)
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900361 return 0;
362
363 new_alloc = PCPU_DFL_MAP_ALLOC;
Al Viro723ad1d2014-03-06 21:13:18 -0500364 while (new_alloc < chunk->map_used + 3)
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900365 new_alloc *= 2;
366
Tejun Heo833af842009-11-11 15:35:18 +0900367 return new_alloc;
368}
369
370/**
371 * pcpu_extend_area_map - extend area map of a chunk
372 * @chunk: chunk of interest
373 * @new_alloc: new target allocation length of the area map
374 *
375 * Extend area map of @chunk to have @new_alloc entries.
376 *
377 * CONTEXT:
378 * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock.
379 *
380 * RETURNS:
381 * 0 on success, -errno on failure.
382 */
383static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc)
384{
385 int *old = NULL, *new = NULL;
386 size_t old_size = 0, new_size = new_alloc * sizeof(new[0]);
387 unsigned long flags;
388
Bob Liu90459ce02011-08-04 11:02:33 +0200389 new = pcpu_mem_zalloc(new_size);
Tejun Heo833af842009-11-11 15:35:18 +0900390 if (!new)
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900391 return -ENOMEM;
Tejun Heoccea34b2009-03-07 00:44:13 +0900392
Tejun Heo833af842009-11-11 15:35:18 +0900393 /* acquire pcpu_lock and switch to new area map */
394 spin_lock_irqsave(&pcpu_lock, flags);
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900395
Tejun Heo833af842009-11-11 15:35:18 +0900396 if (new_alloc <= chunk->map_alloc)
397 goto out_unlock;
398
399 old_size = chunk->map_alloc * sizeof(chunk->map[0]);
Huang Shijiea002d142010-08-08 14:39:07 +0200400 old = chunk->map;
401
402 memcpy(new, old, old_size);
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900403
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900404 chunk->map_alloc = new_alloc;
405 chunk->map = new;
Tejun Heo833af842009-11-11 15:35:18 +0900406 new = NULL;
407
408out_unlock:
409 spin_unlock_irqrestore(&pcpu_lock, flags);
410
411 /*
412 * pcpu_mem_free() might end up calling vfree() which uses
413 * IRQ-unsafe lock and thus can't be called under pcpu_lock.
414 */
415 pcpu_mem_free(old, old_size);
416 pcpu_mem_free(new, new_size);
417
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900418 return 0;
419}
420
421/**
Tejun Heofbf59bc2009-02-20 16:29:08 +0900422 * pcpu_alloc_area - allocate area from a pcpu_chunk
423 * @chunk: chunk of interest
Tejun Heocae3aeb2009-02-21 16:56:23 +0900424 * @size: wanted size in bytes
Tejun Heofbf59bc2009-02-20 16:29:08 +0900425 * @align: wanted align
426 *
427 * Try to allocate @size bytes area aligned at @align from @chunk.
428 * Note that this function only allocates the offset. It doesn't
429 * populate or map the area.
430 *
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900431 * @chunk->map must have at least two free slots.
432 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900433 * CONTEXT:
434 * pcpu_lock.
435 *
Tejun Heofbf59bc2009-02-20 16:29:08 +0900436 * RETURNS:
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900437 * Allocated offset in @chunk on success, -1 if no matching area is
438 * found.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900439 */
440static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align)
441{
442 int oslot = pcpu_chunk_slot(chunk);
443 int max_contig = 0;
444 int i, off;
Al Viro3d331ad2014-03-06 20:52:32 -0500445 bool seen_free = false;
Al Viro723ad1d2014-03-06 21:13:18 -0500446 int *p;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900447
Al Viro3d331ad2014-03-06 20:52:32 -0500448 for (i = chunk->first_free, p = chunk->map + i; i < chunk->map_used; i++, p++) {
Tejun Heofbf59bc2009-02-20 16:29:08 +0900449 int head, tail;
Al Viro723ad1d2014-03-06 21:13:18 -0500450 int this_size;
451
452 off = *p;
453 if (off & 1)
454 continue;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900455
456 /* extra for alignment requirement */
457 head = ALIGN(off, align) - off;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900458
Al Viro723ad1d2014-03-06 21:13:18 -0500459 this_size = (p[1] & ~1) - off;
460 if (this_size < head + size) {
Al Viro3d331ad2014-03-06 20:52:32 -0500461 if (!seen_free) {
462 chunk->first_free = i;
463 seen_free = true;
464 }
Al Viro723ad1d2014-03-06 21:13:18 -0500465 max_contig = max(this_size, max_contig);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900466 continue;
467 }
468
469 /*
470 * If head is small or the previous block is free,
471 * merge'em. Note that 'small' is defined as smaller
472 * than sizeof(int), which is very small but isn't too
473 * uncommon for percpu allocations.
474 */
Al Viro723ad1d2014-03-06 21:13:18 -0500475 if (head && (head < sizeof(int) || !(p[-1] & 1))) {
Jianyu Zhan21ddfd32014-03-28 20:55:21 +0800476 *p = off += head;
Al Viro723ad1d2014-03-06 21:13:18 -0500477 if (p[-1] & 1)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900478 chunk->free_size -= head;
Jianyu Zhan21ddfd32014-03-28 20:55:21 +0800479 else
480 max_contig = max(*p - p[-1], max_contig);
Al Viro723ad1d2014-03-06 21:13:18 -0500481 this_size -= head;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900482 head = 0;
483 }
484
485 /* if tail is small, just keep it around */
Al Viro723ad1d2014-03-06 21:13:18 -0500486 tail = this_size - head - size;
487 if (tail < sizeof(int)) {
Tejun Heofbf59bc2009-02-20 16:29:08 +0900488 tail = 0;
Al Viro723ad1d2014-03-06 21:13:18 -0500489 size = this_size - head;
490 }
Tejun Heofbf59bc2009-02-20 16:29:08 +0900491
492 /* split if warranted */
493 if (head || tail) {
Al Viro706c16f2014-03-06 21:08:24 -0500494 int nr_extra = !!head + !!tail;
495
496 /* insert new subblocks */
Al Viro723ad1d2014-03-06 21:13:18 -0500497 memmove(p + nr_extra + 1, p + 1,
Al Viro706c16f2014-03-06 21:08:24 -0500498 sizeof(chunk->map[0]) * (chunk->map_used - i));
499 chunk->map_used += nr_extra;
500
Tejun Heofbf59bc2009-02-20 16:29:08 +0900501 if (head) {
Al Viro3d331ad2014-03-06 20:52:32 -0500502 if (!seen_free) {
503 chunk->first_free = i;
504 seen_free = true;
505 }
Al Viro723ad1d2014-03-06 21:13:18 -0500506 *++p = off += head;
507 ++i;
Al Viro706c16f2014-03-06 21:08:24 -0500508 max_contig = max(head, max_contig);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900509 }
Al Viro706c16f2014-03-06 21:08:24 -0500510 if (tail) {
Al Viro723ad1d2014-03-06 21:13:18 -0500511 p[1] = off + size;
Al Viro706c16f2014-03-06 21:08:24 -0500512 max_contig = max(tail, max_contig);
513 }
Tejun Heofbf59bc2009-02-20 16:29:08 +0900514 }
515
Al Viro3d331ad2014-03-06 20:52:32 -0500516 if (!seen_free)
517 chunk->first_free = i + 1;
518
Tejun Heofbf59bc2009-02-20 16:29:08 +0900519 /* update hint and mark allocated */
Al Viro723ad1d2014-03-06 21:13:18 -0500520 if (i + 1 == chunk->map_used)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900521 chunk->contig_hint = max_contig; /* fully scanned */
522 else
523 chunk->contig_hint = max(chunk->contig_hint,
524 max_contig);
525
Al Viro723ad1d2014-03-06 21:13:18 -0500526 chunk->free_size -= size;
527 *p |= 1;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900528
529 pcpu_chunk_relocate(chunk, oslot);
530 return off;
531 }
532
533 chunk->contig_hint = max_contig; /* fully scanned */
534 pcpu_chunk_relocate(chunk, oslot);
535
Tejun Heo9f7dcf22009-03-07 00:44:09 +0900536 /* tell the upper layer that this chunk has no matching area */
537 return -1;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900538}
539
540/**
541 * pcpu_free_area - free area to a pcpu_chunk
542 * @chunk: chunk of interest
543 * @freeme: offset of area to free
544 *
545 * Free area starting from @freeme to @chunk. Note that this function
546 * only modifies the allocation map. It doesn't depopulate or unmap
547 * the area.
Tejun Heoccea34b2009-03-07 00:44:13 +0900548 *
549 * CONTEXT:
550 * pcpu_lock.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900551 */
552static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme)
553{
554 int oslot = pcpu_chunk_slot(chunk);
Al Viro723ad1d2014-03-06 21:13:18 -0500555 int off = 0;
556 unsigned i, j;
557 int to_free = 0;
558 int *p;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900559
Al Viro723ad1d2014-03-06 21:13:18 -0500560 freeme |= 1; /* we are searching for <given offset, in use> pair */
561
562 i = 0;
563 j = chunk->map_used;
564 while (i != j) {
565 unsigned k = (i + j) / 2;
566 off = chunk->map[k];
567 if (off < freeme)
568 i = k + 1;
569 else if (off > freeme)
570 j = k;
571 else
572 i = j = k;
573 }
Tejun Heofbf59bc2009-02-20 16:29:08 +0900574 BUG_ON(off != freeme);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900575
Al Viro3d331ad2014-03-06 20:52:32 -0500576 if (i < chunk->first_free)
577 chunk->first_free = i;
578
Al Viro723ad1d2014-03-06 21:13:18 -0500579 p = chunk->map + i;
580 *p = off &= ~1;
581 chunk->free_size += (p[1] & ~1) - off;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900582
Tejun Heofbf59bc2009-02-20 16:29:08 +0900583 /* merge with next? */
Al Viro723ad1d2014-03-06 21:13:18 -0500584 if (!(p[1] & 1))
585 to_free++;
586 /* merge with previous? */
587 if (i > 0 && !(p[-1] & 1)) {
588 to_free++;
589 i--;
590 p--;
591 }
592 if (to_free) {
593 chunk->map_used -= to_free;
594 memmove(p + 1, p + 1 + to_free,
595 (chunk->map_used - i) * sizeof(chunk->map[0]));
Tejun Heofbf59bc2009-02-20 16:29:08 +0900596 }
597
Al Viro723ad1d2014-03-06 21:13:18 -0500598 chunk->contig_hint = max(chunk->map[i + 1] - chunk->map[i] - 1, chunk->contig_hint);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900599 pcpu_chunk_relocate(chunk, oslot);
600}
601
Tejun Heo60810892010-04-09 18:57:01 +0900602static struct pcpu_chunk *pcpu_alloc_chunk(void)
603{
604 struct pcpu_chunk *chunk;
605
Bob Liu90459ce02011-08-04 11:02:33 +0200606 chunk = pcpu_mem_zalloc(pcpu_chunk_struct_size);
Tejun Heo60810892010-04-09 18:57:01 +0900607 if (!chunk)
608 return NULL;
609
Bob Liu90459ce02011-08-04 11:02:33 +0200610 chunk->map = pcpu_mem_zalloc(PCPU_DFL_MAP_ALLOC *
611 sizeof(chunk->map[0]));
Tejun Heo60810892010-04-09 18:57:01 +0900612 if (!chunk->map) {
613 kfree(chunk);
614 return NULL;
615 }
616
617 chunk->map_alloc = PCPU_DFL_MAP_ALLOC;
Al Viro723ad1d2014-03-06 21:13:18 -0500618 chunk->map[0] = 0;
619 chunk->map[1] = pcpu_unit_size | 1;
620 chunk->map_used = 1;
Tejun Heo60810892010-04-09 18:57:01 +0900621
622 INIT_LIST_HEAD(&chunk->list);
623 chunk->free_size = pcpu_unit_size;
624 chunk->contig_hint = pcpu_unit_size;
625
626 return chunk;
627}
628
629static void pcpu_free_chunk(struct pcpu_chunk *chunk)
630{
631 if (!chunk)
632 return;
633 pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0]));
Joonsoo Kimb4916cb2012-10-29 22:59:58 +0900634 pcpu_mem_free(chunk, pcpu_chunk_struct_size);
Tejun Heo60810892010-04-09 18:57:01 +0900635}
636
Tejun Heo9f645532010-04-09 18:57:01 +0900637/*
638 * Chunk management implementation.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900639 *
Tejun Heo9f645532010-04-09 18:57:01 +0900640 * To allow different implementations, chunk alloc/free and
641 * [de]population are implemented in a separate file which is pulled
642 * into this file and compiled together. The following functions
643 * should be implemented.
Tejun Heoce3141a2009-07-04 08:11:00 +0900644 *
Tejun Heo9f645532010-04-09 18:57:01 +0900645 * pcpu_populate_chunk - populate the specified range of a chunk
646 * pcpu_depopulate_chunk - depopulate the specified range of a chunk
647 * pcpu_create_chunk - create a new chunk
648 * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop
649 * pcpu_addr_to_page - translate address to physical address
650 * pcpu_verify_alloc_info - check alloc_info is acceptable during init
Tejun Heofbf59bc2009-02-20 16:29:08 +0900651 */
Tejun Heo9f645532010-04-09 18:57:01 +0900652static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size);
653static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size);
654static struct pcpu_chunk *pcpu_create_chunk(void);
655static void pcpu_destroy_chunk(struct pcpu_chunk *chunk);
656static struct page *pcpu_addr_to_page(void *addr);
657static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai);
Tejun Heoce3141a2009-07-04 08:11:00 +0900658
Tejun Heob0c97782010-04-09 18:57:01 +0900659#ifdef CONFIG_NEED_PER_CPU_KM
660#include "percpu-km.c"
661#else
Tejun Heo9f645532010-04-09 18:57:01 +0900662#include "percpu-vm.c"
Tejun Heob0c97782010-04-09 18:57:01 +0900663#endif
Tejun Heofbf59bc2009-02-20 16:29:08 +0900664
665/**
Tejun Heo88999a82010-04-09 18:57:01 +0900666 * pcpu_chunk_addr_search - determine chunk containing specified address
667 * @addr: address for which the chunk needs to be determined.
668 *
669 * RETURNS:
670 * The address of the found chunk.
671 */
672static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr)
673{
674 /* is it in the first chunk? */
675 if (pcpu_addr_in_first_chunk(addr)) {
676 /* is it in the reserved area? */
677 if (pcpu_addr_in_reserved_chunk(addr))
678 return pcpu_reserved_chunk;
679 return pcpu_first_chunk;
680 }
681
682 /*
683 * The address is relative to unit0 which might be unused and
684 * thus unmapped. Offset the address to the unit space of the
685 * current processor before looking it up in the vmalloc
686 * space. Note that any possible cpu id can be used here, so
687 * there's no need to worry about preemption or cpu hotplug.
688 */
689 addr += pcpu_unit_offsets[raw_smp_processor_id()];
Tejun Heo9f645532010-04-09 18:57:01 +0900690 return pcpu_get_page_chunk(pcpu_addr_to_page(addr));
Tejun Heo88999a82010-04-09 18:57:01 +0900691}
692
693/**
Tejun Heoedcb4632009-03-06 14:33:59 +0900694 * pcpu_alloc - the percpu allocator
Tejun Heocae3aeb2009-02-21 16:56:23 +0900695 * @size: size of area to allocate in bytes
Tejun Heofbf59bc2009-02-20 16:29:08 +0900696 * @align: alignment of area (max PAGE_SIZE)
Tejun Heoedcb4632009-03-06 14:33:59 +0900697 * @reserved: allocate from the reserved chunk if available
Tejun Heofbf59bc2009-02-20 16:29:08 +0900698 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900699 * Allocate percpu area of @size bytes aligned at @align.
700 *
701 * CONTEXT:
702 * Does GFP_KERNEL allocation.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900703 *
704 * RETURNS:
705 * Percpu pointer to the allocated area on success, NULL on failure.
706 */
Tejun Heo43cf38e2010-02-02 14:38:57 +0900707static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900708{
Tejun Heof2badb02009-09-29 09:17:58 +0900709 static int warn_limit = 10;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900710 struct pcpu_chunk *chunk;
Tejun Heof2badb02009-09-29 09:17:58 +0900711 const char *err;
Tejun Heo833af842009-11-11 15:35:18 +0900712 int slot, off, new_alloc;
Jiri Kosina403a91b2009-10-29 00:25:59 +0900713 unsigned long flags;
Catalin Marinasf528f0b2011-09-26 17:12:53 +0100714 void __percpu *ptr;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900715
Al Viro723ad1d2014-03-06 21:13:18 -0500716 /*
717 * We want the lowest bit of offset available for in-use/free
Viro2f69fa82014-03-17 16:01:27 -0400718 * indicator, so force >= 16bit alignment and make size even.
Al Viro723ad1d2014-03-06 21:13:18 -0500719 */
720 if (unlikely(align < 2))
721 align = 2;
722
Viro2f69fa82014-03-17 16:01:27 -0400723 if (unlikely(size & 1))
724 size++;
725
Tejun Heo8d408b42009-02-24 11:57:21 +0900726 if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) {
Tejun Heofbf59bc2009-02-20 16:29:08 +0900727 WARN(true, "illegal size (%zu) or align (%zu) for "
728 "percpu allocation\n", size, align);
729 return NULL;
730 }
731
Tejun Heoccea34b2009-03-07 00:44:13 +0900732 mutex_lock(&pcpu_alloc_mutex);
Jiri Kosina403a91b2009-10-29 00:25:59 +0900733 spin_lock_irqsave(&pcpu_lock, flags);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900734
Tejun Heoedcb4632009-03-06 14:33:59 +0900735 /* serve reserved allocations from the reserved chunk if available */
736 if (reserved && pcpu_reserved_chunk) {
737 chunk = pcpu_reserved_chunk;
Tejun Heo833af842009-11-11 15:35:18 +0900738
739 if (size > chunk->contig_hint) {
740 err = "alloc from reserved chunk failed";
Tejun Heoccea34b2009-03-07 00:44:13 +0900741 goto fail_unlock;
Tejun Heof2badb02009-09-29 09:17:58 +0900742 }
Tejun Heo833af842009-11-11 15:35:18 +0900743
744 while ((new_alloc = pcpu_need_to_extend(chunk))) {
745 spin_unlock_irqrestore(&pcpu_lock, flags);
746 if (pcpu_extend_area_map(chunk, new_alloc) < 0) {
747 err = "failed to extend area map of reserved chunk";
748 goto fail_unlock_mutex;
749 }
750 spin_lock_irqsave(&pcpu_lock, flags);
751 }
752
Tejun Heoedcb4632009-03-06 14:33:59 +0900753 off = pcpu_alloc_area(chunk, size, align);
754 if (off >= 0)
755 goto area_found;
Tejun Heo833af842009-11-11 15:35:18 +0900756
Tejun Heof2badb02009-09-29 09:17:58 +0900757 err = "alloc from reserved chunk failed";
Tejun Heoccea34b2009-03-07 00:44:13 +0900758 goto fail_unlock;
Tejun Heoedcb4632009-03-06 14:33:59 +0900759 }
760
Tejun Heoccea34b2009-03-07 00:44:13 +0900761restart:
Tejun Heoedcb4632009-03-06 14:33:59 +0900762 /* search through normal chunks */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900763 for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) {
764 list_for_each_entry(chunk, &pcpu_slot[slot], list) {
765 if (size > chunk->contig_hint)
766 continue;
Tejun Heoccea34b2009-03-07 00:44:13 +0900767
Tejun Heo833af842009-11-11 15:35:18 +0900768 new_alloc = pcpu_need_to_extend(chunk);
769 if (new_alloc) {
770 spin_unlock_irqrestore(&pcpu_lock, flags);
771 if (pcpu_extend_area_map(chunk,
772 new_alloc) < 0) {
773 err = "failed to extend area map";
774 goto fail_unlock_mutex;
775 }
776 spin_lock_irqsave(&pcpu_lock, flags);
777 /*
778 * pcpu_lock has been dropped, need to
779 * restart cpu_slot list walking.
780 */
781 goto restart;
Tejun Heoccea34b2009-03-07 00:44:13 +0900782 }
783
Tejun Heofbf59bc2009-02-20 16:29:08 +0900784 off = pcpu_alloc_area(chunk, size, align);
785 if (off >= 0)
786 goto area_found;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900787 }
788 }
789
790 /* hmmm... no space left, create a new chunk */
Jiri Kosina403a91b2009-10-29 00:25:59 +0900791 spin_unlock_irqrestore(&pcpu_lock, flags);
Tejun Heoccea34b2009-03-07 00:44:13 +0900792
Tejun Heo60810892010-04-09 18:57:01 +0900793 chunk = pcpu_create_chunk();
Tejun Heof2badb02009-09-29 09:17:58 +0900794 if (!chunk) {
795 err = "failed to allocate new chunk";
Tejun Heoccea34b2009-03-07 00:44:13 +0900796 goto fail_unlock_mutex;
Tejun Heof2badb02009-09-29 09:17:58 +0900797 }
Tejun Heoccea34b2009-03-07 00:44:13 +0900798
Jiri Kosina403a91b2009-10-29 00:25:59 +0900799 spin_lock_irqsave(&pcpu_lock, flags);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900800 pcpu_chunk_relocate(chunk, -1);
Tejun Heoccea34b2009-03-07 00:44:13 +0900801 goto restart;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900802
803area_found:
Jiri Kosina403a91b2009-10-29 00:25:59 +0900804 spin_unlock_irqrestore(&pcpu_lock, flags);
Tejun Heoccea34b2009-03-07 00:44:13 +0900805
Tejun Heofbf59bc2009-02-20 16:29:08 +0900806 /* populate, map and clear the area */
807 if (pcpu_populate_chunk(chunk, off, size)) {
Jiri Kosina403a91b2009-10-29 00:25:59 +0900808 spin_lock_irqsave(&pcpu_lock, flags);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900809 pcpu_free_area(chunk, off);
Tejun Heof2badb02009-09-29 09:17:58 +0900810 err = "failed to populate";
Tejun Heoccea34b2009-03-07 00:44:13 +0900811 goto fail_unlock;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900812 }
813
Tejun Heoccea34b2009-03-07 00:44:13 +0900814 mutex_unlock(&pcpu_alloc_mutex);
815
Tejun Heobba174f2009-08-14 15:00:51 +0900816 /* return address relative to base address */
Catalin Marinasf528f0b2011-09-26 17:12:53 +0100817 ptr = __addr_to_pcpu_ptr(chunk->base_addr + off);
818 kmemleak_alloc_percpu(ptr, size);
819 return ptr;
Tejun Heoccea34b2009-03-07 00:44:13 +0900820
821fail_unlock:
Jiri Kosina403a91b2009-10-29 00:25:59 +0900822 spin_unlock_irqrestore(&pcpu_lock, flags);
Tejun Heoccea34b2009-03-07 00:44:13 +0900823fail_unlock_mutex:
824 mutex_unlock(&pcpu_alloc_mutex);
Tejun Heof2badb02009-09-29 09:17:58 +0900825 if (warn_limit) {
826 pr_warning("PERCPU: allocation failed, size=%zu align=%zu, "
827 "%s\n", size, align, err);
828 dump_stack();
829 if (!--warn_limit)
830 pr_info("PERCPU: limit reached, disable warning\n");
831 }
Tejun Heoccea34b2009-03-07 00:44:13 +0900832 return NULL;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900833}
Tejun Heoedcb4632009-03-06 14:33:59 +0900834
835/**
836 * __alloc_percpu - allocate dynamic percpu area
837 * @size: size of area to allocate in bytes
838 * @align: alignment of area (max PAGE_SIZE)
839 *
Tejun Heo9329ba92010-09-10 11:01:56 +0200840 * Allocate zero-filled percpu area of @size bytes aligned at @align.
841 * Might sleep. Might trigger writeouts.
Tejun Heoedcb4632009-03-06 14:33:59 +0900842 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900843 * CONTEXT:
844 * Does GFP_KERNEL allocation.
845 *
Tejun Heoedcb4632009-03-06 14:33:59 +0900846 * RETURNS:
847 * Percpu pointer to the allocated area on success, NULL on failure.
848 */
Tejun Heo43cf38e2010-02-02 14:38:57 +0900849void __percpu *__alloc_percpu(size_t size, size_t align)
Tejun Heoedcb4632009-03-06 14:33:59 +0900850{
851 return pcpu_alloc(size, align, false);
852}
Tejun Heofbf59bc2009-02-20 16:29:08 +0900853EXPORT_SYMBOL_GPL(__alloc_percpu);
854
Tejun Heoedcb4632009-03-06 14:33:59 +0900855/**
856 * __alloc_reserved_percpu - allocate reserved percpu area
857 * @size: size of area to allocate in bytes
858 * @align: alignment of area (max PAGE_SIZE)
859 *
Tejun Heo9329ba92010-09-10 11:01:56 +0200860 * Allocate zero-filled percpu area of @size bytes aligned at @align
861 * from reserved percpu area if arch has set it up; otherwise,
862 * allocation is served from the same dynamic area. Might sleep.
863 * Might trigger writeouts.
Tejun Heoedcb4632009-03-06 14:33:59 +0900864 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900865 * CONTEXT:
866 * Does GFP_KERNEL allocation.
867 *
Tejun Heoedcb4632009-03-06 14:33:59 +0900868 * RETURNS:
869 * Percpu pointer to the allocated area on success, NULL on failure.
870 */
Tejun Heo43cf38e2010-02-02 14:38:57 +0900871void __percpu *__alloc_reserved_percpu(size_t size, size_t align)
Tejun Heoedcb4632009-03-06 14:33:59 +0900872{
873 return pcpu_alloc(size, align, true);
874}
875
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900876/**
877 * pcpu_reclaim - reclaim fully free chunks, workqueue function
878 * @work: unused
879 *
880 * Reclaim all fully free chunks except for the first one.
Tejun Heoccea34b2009-03-07 00:44:13 +0900881 *
882 * CONTEXT:
883 * workqueue context.
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900884 */
885static void pcpu_reclaim(struct work_struct *work)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900886{
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900887 LIST_HEAD(todo);
888 struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1];
889 struct pcpu_chunk *chunk, *next;
890
Tejun Heoccea34b2009-03-07 00:44:13 +0900891 mutex_lock(&pcpu_alloc_mutex);
892 spin_lock_irq(&pcpu_lock);
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900893
894 list_for_each_entry_safe(chunk, next, head, list) {
895 WARN_ON(chunk->immutable);
896
897 /* spare the first one */
898 if (chunk == list_first_entry(head, struct pcpu_chunk, list))
899 continue;
900
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900901 list_move(&chunk->list, &todo);
902 }
903
Tejun Heoccea34b2009-03-07 00:44:13 +0900904 spin_unlock_irq(&pcpu_lock);
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900905
906 list_for_each_entry_safe(chunk, next, &todo, list) {
Tejun Heoce3141a2009-07-04 08:11:00 +0900907 pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size);
Tejun Heo60810892010-04-09 18:57:01 +0900908 pcpu_destroy_chunk(chunk);
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900909 }
Tejun Heo971f3912009-08-14 15:00:49 +0900910
911 mutex_unlock(&pcpu_alloc_mutex);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900912}
913
914/**
915 * free_percpu - free percpu area
916 * @ptr: pointer to area to free
917 *
Tejun Heoccea34b2009-03-07 00:44:13 +0900918 * Free percpu area @ptr.
919 *
920 * CONTEXT:
921 * Can be called from atomic context.
Tejun Heofbf59bc2009-02-20 16:29:08 +0900922 */
Tejun Heo43cf38e2010-02-02 14:38:57 +0900923void free_percpu(void __percpu *ptr)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900924{
Andrew Morton129182e2010-01-08 14:42:39 -0800925 void *addr;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900926 struct pcpu_chunk *chunk;
Tejun Heoccea34b2009-03-07 00:44:13 +0900927 unsigned long flags;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900928 int off;
929
930 if (!ptr)
931 return;
932
Catalin Marinasf528f0b2011-09-26 17:12:53 +0100933 kmemleak_free_percpu(ptr);
934
Andrew Morton129182e2010-01-08 14:42:39 -0800935 addr = __pcpu_ptr_to_addr(ptr);
936
Tejun Heoccea34b2009-03-07 00:44:13 +0900937 spin_lock_irqsave(&pcpu_lock, flags);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900938
939 chunk = pcpu_chunk_addr_search(addr);
Tejun Heobba174f2009-08-14 15:00:51 +0900940 off = addr - chunk->base_addr;
Tejun Heofbf59bc2009-02-20 16:29:08 +0900941
942 pcpu_free_area(chunk, off);
943
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900944 /* if there are more than one fully free chunks, wake up grim reaper */
Tejun Heofbf59bc2009-02-20 16:29:08 +0900945 if (chunk->free_size == pcpu_unit_size) {
946 struct pcpu_chunk *pos;
947
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900948 list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list)
Tejun Heofbf59bc2009-02-20 16:29:08 +0900949 if (pos != chunk) {
Tejun Heoa56dbdd2009-03-07 00:44:11 +0900950 schedule_work(&pcpu_reclaim_work);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900951 break;
952 }
953 }
954
Tejun Heoccea34b2009-03-07 00:44:13 +0900955 spin_unlock_irqrestore(&pcpu_lock, flags);
Tejun Heofbf59bc2009-02-20 16:29:08 +0900956}
957EXPORT_SYMBOL_GPL(free_percpu);
958
Vivek Goyal3b034b02009-11-24 15:50:03 +0900959/**
Tejun Heo10fad5e2010-03-10 18:57:54 +0900960 * is_kernel_percpu_address - test whether address is from static percpu area
961 * @addr: address to test
962 *
963 * Test whether @addr belongs to in-kernel static percpu area. Module
964 * static percpu areas are not considered. For those, use
965 * is_module_percpu_address().
966 *
967 * RETURNS:
968 * %true if @addr is from in-kernel static percpu area, %false otherwise.
969 */
970bool is_kernel_percpu_address(unsigned long addr)
971{
Tejun Heobbddff02010-09-03 18:22:48 +0200972#ifdef CONFIG_SMP
Tejun Heo10fad5e2010-03-10 18:57:54 +0900973 const size_t static_size = __per_cpu_end - __per_cpu_start;
974 void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
975 unsigned int cpu;
976
977 for_each_possible_cpu(cpu) {
978 void *start = per_cpu_ptr(base, cpu);
979
980 if ((void *)addr >= start && (void *)addr < start + static_size)
981 return true;
982 }
Tejun Heobbddff02010-09-03 18:22:48 +0200983#endif
984 /* on UP, can't distinguish from other static vars, always false */
Tejun Heo10fad5e2010-03-10 18:57:54 +0900985 return false;
986}
987
988/**
Vivek Goyal3b034b02009-11-24 15:50:03 +0900989 * per_cpu_ptr_to_phys - convert translated percpu address to physical address
990 * @addr: the address to be converted to physical address
991 *
992 * Given @addr which is dereferenceable address obtained via one of
993 * percpu access macros, this function translates it into its physical
994 * address. The caller is responsible for ensuring @addr stays valid
995 * until this function finishes.
996 *
Dave Young67589c72011-11-23 08:20:53 -0800997 * percpu allocator has special setup for the first chunk, which currently
998 * supports either embedding in linear address space or vmalloc mapping,
999 * and, from the second one, the backing allocator (currently either vm or
1000 * km) provides translation.
1001 *
1002 * The addr can be tranlated simply without checking if it falls into the
1003 * first chunk. But the current code reflects better how percpu allocator
1004 * actually works, and the verification can discover both bugs in percpu
1005 * allocator itself and per_cpu_ptr_to_phys() callers. So we keep current
1006 * code.
1007 *
Vivek Goyal3b034b02009-11-24 15:50:03 +09001008 * RETURNS:
1009 * The physical address for @addr.
1010 */
1011phys_addr_t per_cpu_ptr_to_phys(void *addr)
1012{
Tejun Heo9983b6f02010-06-18 11:44:31 +02001013 void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr);
1014 bool in_first_chunk = false;
Tejun Heoa855b842011-11-18 10:55:35 -08001015 unsigned long first_low, first_high;
Tejun Heo9983b6f02010-06-18 11:44:31 +02001016 unsigned int cpu;
1017
1018 /*
Tejun Heoa855b842011-11-18 10:55:35 -08001019 * The following test on unit_low/high isn't strictly
Tejun Heo9983b6f02010-06-18 11:44:31 +02001020 * necessary but will speed up lookups of addresses which
1021 * aren't in the first chunk.
1022 */
Tejun Heoa855b842011-11-18 10:55:35 -08001023 first_low = pcpu_chunk_addr(pcpu_first_chunk, pcpu_low_unit_cpu, 0);
1024 first_high = pcpu_chunk_addr(pcpu_first_chunk, pcpu_high_unit_cpu,
1025 pcpu_unit_pages);
1026 if ((unsigned long)addr >= first_low &&
1027 (unsigned long)addr < first_high) {
Tejun Heo9983b6f02010-06-18 11:44:31 +02001028 for_each_possible_cpu(cpu) {
1029 void *start = per_cpu_ptr(base, cpu);
1030
1031 if (addr >= start && addr < start + pcpu_unit_size) {
1032 in_first_chunk = true;
1033 break;
1034 }
1035 }
1036 }
1037
1038 if (in_first_chunk) {
David Howellseac522e2011-03-28 12:53:29 +01001039 if (!is_vmalloc_addr(addr))
Tejun Heo020ec652010-04-09 18:57:00 +09001040 return __pa(addr);
1041 else
Eugene Surovegin9f57bd42011-12-15 11:25:59 -08001042 return page_to_phys(vmalloc_to_page(addr)) +
1043 offset_in_page(addr);
Tejun Heo020ec652010-04-09 18:57:00 +09001044 } else
Eugene Surovegin9f57bd42011-12-15 11:25:59 -08001045 return page_to_phys(pcpu_addr_to_page(addr)) +
1046 offset_in_page(addr);
Vivek Goyal3b034b02009-11-24 15:50:03 +09001047}
1048
Tejun Heofbf59bc2009-02-20 16:29:08 +09001049/**
Tejun Heofd1e8a12009-08-14 15:00:51 +09001050 * pcpu_alloc_alloc_info - allocate percpu allocation info
1051 * @nr_groups: the number of groups
1052 * @nr_units: the number of units
Tejun Heo033e48f2009-08-14 15:00:51 +09001053 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001054 * Allocate ai which is large enough for @nr_groups groups containing
1055 * @nr_units units. The returned ai's groups[0].cpu_map points to the
1056 * cpu_map array which is long enough for @nr_units and filled with
1057 * NR_CPUS. It's the caller's responsibility to initialize cpu_map
1058 * pointer of other groups.
Tejun Heo033e48f2009-08-14 15:00:51 +09001059 *
1060 * RETURNS:
Tejun Heofd1e8a12009-08-14 15:00:51 +09001061 * Pointer to the allocated pcpu_alloc_info on success, NULL on
1062 * failure.
Tejun Heo033e48f2009-08-14 15:00:51 +09001063 */
Tejun Heofd1e8a12009-08-14 15:00:51 +09001064struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups,
1065 int nr_units)
1066{
1067 struct pcpu_alloc_info *ai;
1068 size_t base_size, ai_size;
1069 void *ptr;
1070 int unit;
1071
1072 base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]),
1073 __alignof__(ai->groups[0].cpu_map[0]));
1074 ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]);
1075
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001076 ptr = memblock_virt_alloc_nopanic(PFN_ALIGN(ai_size), 0);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001077 if (!ptr)
1078 return NULL;
1079 ai = ptr;
1080 ptr += base_size;
1081
1082 ai->groups[0].cpu_map = ptr;
1083
1084 for (unit = 0; unit < nr_units; unit++)
1085 ai->groups[0].cpu_map[unit] = NR_CPUS;
1086
1087 ai->nr_groups = nr_groups;
1088 ai->__ai_size = PFN_ALIGN(ai_size);
1089
1090 return ai;
1091}
1092
1093/**
1094 * pcpu_free_alloc_info - free percpu allocation info
1095 * @ai: pcpu_alloc_info to free
1096 *
1097 * Free @ai which was allocated by pcpu_alloc_alloc_info().
1098 */
1099void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai)
1100{
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001101 memblock_free_early(__pa(ai), ai->__ai_size);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001102}
1103
1104/**
Tejun Heofd1e8a12009-08-14 15:00:51 +09001105 * pcpu_dump_alloc_info - print out information about pcpu_alloc_info
1106 * @lvl: loglevel
1107 * @ai: allocation info to dump
1108 *
1109 * Print out information about @ai using loglevel @lvl.
1110 */
1111static void pcpu_dump_alloc_info(const char *lvl,
1112 const struct pcpu_alloc_info *ai)
Tejun Heo033e48f2009-08-14 15:00:51 +09001113{
Tejun Heofd1e8a12009-08-14 15:00:51 +09001114 int group_width = 1, cpu_width = 1, width;
Tejun Heo033e48f2009-08-14 15:00:51 +09001115 char empty_str[] = "--------";
Tejun Heofd1e8a12009-08-14 15:00:51 +09001116 int alloc = 0, alloc_end = 0;
1117 int group, v;
1118 int upa, apl; /* units per alloc, allocs per line */
Tejun Heo033e48f2009-08-14 15:00:51 +09001119
Tejun Heofd1e8a12009-08-14 15:00:51 +09001120 v = ai->nr_groups;
Tejun Heo033e48f2009-08-14 15:00:51 +09001121 while (v /= 10)
Tejun Heofd1e8a12009-08-14 15:00:51 +09001122 group_width++;
Tejun Heo033e48f2009-08-14 15:00:51 +09001123
Tejun Heofd1e8a12009-08-14 15:00:51 +09001124 v = num_possible_cpus();
1125 while (v /= 10)
1126 cpu_width++;
1127 empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0';
Tejun Heo033e48f2009-08-14 15:00:51 +09001128
Tejun Heofd1e8a12009-08-14 15:00:51 +09001129 upa = ai->alloc_size / ai->unit_size;
1130 width = upa * (cpu_width + 1) + group_width + 3;
1131 apl = rounddown_pow_of_two(max(60 / width, 1));
Tejun Heo033e48f2009-08-14 15:00:51 +09001132
Tejun Heofd1e8a12009-08-14 15:00:51 +09001133 printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu",
1134 lvl, ai->static_size, ai->reserved_size, ai->dyn_size,
1135 ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size);
1136
1137 for (group = 0; group < ai->nr_groups; group++) {
1138 const struct pcpu_group_info *gi = &ai->groups[group];
1139 int unit = 0, unit_end = 0;
1140
1141 BUG_ON(gi->nr_units % upa);
1142 for (alloc_end += gi->nr_units / upa;
1143 alloc < alloc_end; alloc++) {
1144 if (!(alloc % apl)) {
Tejun Heocb129822012-03-29 09:45:58 -07001145 printk(KERN_CONT "\n");
Tejun Heofd1e8a12009-08-14 15:00:51 +09001146 printk("%spcpu-alloc: ", lvl);
1147 }
Tejun Heocb129822012-03-29 09:45:58 -07001148 printk(KERN_CONT "[%0*d] ", group_width, group);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001149
1150 for (unit_end += upa; unit < unit_end; unit++)
1151 if (gi->cpu_map[unit] != NR_CPUS)
Tejun Heocb129822012-03-29 09:45:58 -07001152 printk(KERN_CONT "%0*d ", cpu_width,
Tejun Heofd1e8a12009-08-14 15:00:51 +09001153 gi->cpu_map[unit]);
1154 else
Tejun Heocb129822012-03-29 09:45:58 -07001155 printk(KERN_CONT "%s ", empty_str);
Tejun Heo033e48f2009-08-14 15:00:51 +09001156 }
Tejun Heo033e48f2009-08-14 15:00:51 +09001157 }
Tejun Heocb129822012-03-29 09:45:58 -07001158 printk(KERN_CONT "\n");
Tejun Heo033e48f2009-08-14 15:00:51 +09001159}
Tejun Heo033e48f2009-08-14 15:00:51 +09001160
Tejun Heofbf59bc2009-02-20 16:29:08 +09001161/**
Tejun Heo8d408b42009-02-24 11:57:21 +09001162 * pcpu_setup_first_chunk - initialize the first percpu chunk
Tejun Heofd1e8a12009-08-14 15:00:51 +09001163 * @ai: pcpu_alloc_info describing how to percpu area is shaped
Tejun Heo38a6be52009-07-04 08:10:59 +09001164 * @base_addr: mapped address
Tejun Heofbf59bc2009-02-20 16:29:08 +09001165 *
Tejun Heo8d408b42009-02-24 11:57:21 +09001166 * Initialize the first percpu chunk which contains the kernel static
1167 * perpcu area. This function is to be called from arch percpu area
Tejun Heo38a6be52009-07-04 08:10:59 +09001168 * setup path.
Tejun Heo8d408b42009-02-24 11:57:21 +09001169 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001170 * @ai contains all information necessary to initialize the first
1171 * chunk and prime the dynamic percpu allocator.
Tejun Heo8d408b42009-02-24 11:57:21 +09001172 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001173 * @ai->static_size is the size of static percpu area.
1174 *
1175 * @ai->reserved_size, if non-zero, specifies the amount of bytes to
Tejun Heoedcb4632009-03-06 14:33:59 +09001176 * reserve after the static area in the first chunk. This reserves
1177 * the first chunk such that it's available only through reserved
1178 * percpu allocation. This is primarily used to serve module percpu
1179 * static areas on architectures where the addressing model has
1180 * limited offset range for symbol relocations to guarantee module
1181 * percpu symbols fall inside the relocatable range.
1182 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001183 * @ai->dyn_size determines the number of bytes available for dynamic
1184 * allocation in the first chunk. The area between @ai->static_size +
1185 * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused.
Tejun Heo6074d5b2009-03-10 16:27:48 +09001186 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001187 * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE
1188 * and equal to or larger than @ai->static_size + @ai->reserved_size +
1189 * @ai->dyn_size.
Tejun Heo8d408b42009-02-24 11:57:21 +09001190 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001191 * @ai->atom_size is the allocation atom size and used as alignment
1192 * for vm areas.
Tejun Heo8d408b42009-02-24 11:57:21 +09001193 *
Tejun Heofd1e8a12009-08-14 15:00:51 +09001194 * @ai->alloc_size is the allocation size and always multiple of
1195 * @ai->atom_size. This is larger than @ai->atom_size if
1196 * @ai->unit_size is larger than @ai->atom_size.
1197 *
1198 * @ai->nr_groups and @ai->groups describe virtual memory layout of
1199 * percpu areas. Units which should be colocated are put into the
1200 * same group. Dynamic VM areas will be allocated according to these
1201 * groupings. If @ai->nr_groups is zero, a single group containing
1202 * all units is assumed.
Tejun Heo8d408b42009-02-24 11:57:21 +09001203 *
Tejun Heo38a6be52009-07-04 08:10:59 +09001204 * The caller should have mapped the first chunk at @base_addr and
1205 * copied static data to each unit.
Tejun Heofbf59bc2009-02-20 16:29:08 +09001206 *
Tejun Heoedcb4632009-03-06 14:33:59 +09001207 * If the first chunk ends up with both reserved and dynamic areas, it
1208 * is served by two chunks - one to serve the core static and reserved
1209 * areas and the other for the dynamic area. They share the same vm
1210 * and page map but uses different area allocation map to stay away
1211 * from each other. The latter chunk is circulated in the chunk slots
1212 * and available for dynamic allocation like any other chunks.
1213 *
Tejun Heofbf59bc2009-02-20 16:29:08 +09001214 * RETURNS:
Tejun Heofb435d52009-08-14 15:00:51 +09001215 * 0 on success, -errno on failure.
Tejun Heofbf59bc2009-02-20 16:29:08 +09001216 */
Tejun Heofb435d52009-08-14 15:00:51 +09001217int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai,
1218 void *base_addr)
Tejun Heofbf59bc2009-02-20 16:29:08 +09001219{
Tejun Heo635b75f2009-09-24 09:43:11 +09001220 static char cpus_buf[4096] __initdata;
Tejun Heo099a19d2010-06-27 18:50:00 +02001221 static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
1222 static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001223 size_t dyn_size = ai->dyn_size;
1224 size_t size_sum = ai->static_size + ai->reserved_size + dyn_size;
Tejun Heoedcb4632009-03-06 14:33:59 +09001225 struct pcpu_chunk *schunk, *dchunk = NULL;
Tejun Heo65632972009-08-14 15:00:52 +09001226 unsigned long *group_offsets;
1227 size_t *group_sizes;
Tejun Heofb435d52009-08-14 15:00:51 +09001228 unsigned long *unit_off;
Tejun Heofbf59bc2009-02-20 16:29:08 +09001229 unsigned int cpu;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001230 int *unit_map;
1231 int group, unit, i;
Tejun Heofbf59bc2009-02-20 16:29:08 +09001232
Tejun Heo635b75f2009-09-24 09:43:11 +09001233 cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask);
1234
1235#define PCPU_SETUP_BUG_ON(cond) do { \
1236 if (unlikely(cond)) { \
1237 pr_emerg("PERCPU: failed to initialize, %s", #cond); \
1238 pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \
1239 pcpu_dump_alloc_info(KERN_EMERG, ai); \
1240 BUG(); \
1241 } \
1242} while (0)
1243
Tejun Heo2f39e632009-07-04 08:11:00 +09001244 /* sanity checks */
Tejun Heo635b75f2009-09-24 09:43:11 +09001245 PCPU_SETUP_BUG_ON(ai->nr_groups <= 0);
Tejun Heobbddff02010-09-03 18:22:48 +02001246#ifdef CONFIG_SMP
Tejun Heo635b75f2009-09-24 09:43:11 +09001247 PCPU_SETUP_BUG_ON(!ai->static_size);
Tejun Heo0415b00d12011-03-24 18:50:09 +01001248 PCPU_SETUP_BUG_ON((unsigned long)__per_cpu_start & ~PAGE_MASK);
Tejun Heobbddff02010-09-03 18:22:48 +02001249#endif
Tejun Heo635b75f2009-09-24 09:43:11 +09001250 PCPU_SETUP_BUG_ON(!base_addr);
Tejun Heo0415b00d12011-03-24 18:50:09 +01001251 PCPU_SETUP_BUG_ON((unsigned long)base_addr & ~PAGE_MASK);
Tejun Heo635b75f2009-09-24 09:43:11 +09001252 PCPU_SETUP_BUG_ON(ai->unit_size < size_sum);
1253 PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK);
1254 PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE);
Tejun Heo099a19d2010-06-27 18:50:00 +02001255 PCPU_SETUP_BUG_ON(ai->dyn_size < PERCPU_DYNAMIC_EARLY_SIZE);
Tejun Heo9f645532010-04-09 18:57:01 +09001256 PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0);
Tejun Heo8d408b42009-02-24 11:57:21 +09001257
Tejun Heo65632972009-08-14 15:00:52 +09001258 /* process group information and build config tables accordingly */
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001259 group_offsets = memblock_virt_alloc(ai->nr_groups *
1260 sizeof(group_offsets[0]), 0);
1261 group_sizes = memblock_virt_alloc(ai->nr_groups *
1262 sizeof(group_sizes[0]), 0);
1263 unit_map = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_map[0]), 0);
1264 unit_off = memblock_virt_alloc(nr_cpu_ids * sizeof(unit_off[0]), 0);
Tejun Heo2f39e632009-07-04 08:11:00 +09001265
Tejun Heofd1e8a12009-08-14 15:00:51 +09001266 for (cpu = 0; cpu < nr_cpu_ids; cpu++)
Tejun Heoffe0d5a2009-09-29 09:17:56 +09001267 unit_map[cpu] = UINT_MAX;
Tejun Heoa855b842011-11-18 10:55:35 -08001268
1269 pcpu_low_unit_cpu = NR_CPUS;
1270 pcpu_high_unit_cpu = NR_CPUS;
Tejun Heo2f39e632009-07-04 08:11:00 +09001271
Tejun Heofd1e8a12009-08-14 15:00:51 +09001272 for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) {
1273 const struct pcpu_group_info *gi = &ai->groups[group];
Tejun Heo2f39e632009-07-04 08:11:00 +09001274
Tejun Heo65632972009-08-14 15:00:52 +09001275 group_offsets[group] = gi->base_offset;
1276 group_sizes[group] = gi->nr_units * ai->unit_size;
1277
Tejun Heofd1e8a12009-08-14 15:00:51 +09001278 for (i = 0; i < gi->nr_units; i++) {
1279 cpu = gi->cpu_map[i];
1280 if (cpu == NR_CPUS)
1281 continue;
1282
Tejun Heo635b75f2009-09-24 09:43:11 +09001283 PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids);
1284 PCPU_SETUP_BUG_ON(!cpu_possible(cpu));
1285 PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001286
1287 unit_map[cpu] = unit + i;
Tejun Heofb435d52009-08-14 15:00:51 +09001288 unit_off[cpu] = gi->base_offset + i * ai->unit_size;
1289
Tejun Heoa855b842011-11-18 10:55:35 -08001290 /* determine low/high unit_cpu */
1291 if (pcpu_low_unit_cpu == NR_CPUS ||
1292 unit_off[cpu] < unit_off[pcpu_low_unit_cpu])
1293 pcpu_low_unit_cpu = cpu;
1294 if (pcpu_high_unit_cpu == NR_CPUS ||
1295 unit_off[cpu] > unit_off[pcpu_high_unit_cpu])
1296 pcpu_high_unit_cpu = cpu;
Tejun Heo2f39e632009-07-04 08:11:00 +09001297 }
Tejun Heo2f39e632009-07-04 08:11:00 +09001298 }
Tejun Heofd1e8a12009-08-14 15:00:51 +09001299 pcpu_nr_units = unit;
1300
1301 for_each_possible_cpu(cpu)
Tejun Heo635b75f2009-09-24 09:43:11 +09001302 PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX);
1303
1304 /* we're done parsing the input, undefine BUG macro and dump config */
1305#undef PCPU_SETUP_BUG_ON
Tejun Heobcbea792010-12-22 14:19:14 +01001306 pcpu_dump_alloc_info(KERN_DEBUG, ai);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001307
Tejun Heo65632972009-08-14 15:00:52 +09001308 pcpu_nr_groups = ai->nr_groups;
1309 pcpu_group_offsets = group_offsets;
1310 pcpu_group_sizes = group_sizes;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001311 pcpu_unit_map = unit_map;
Tejun Heofb435d52009-08-14 15:00:51 +09001312 pcpu_unit_offsets = unit_off;
Tejun Heo2f39e632009-07-04 08:11:00 +09001313
1314 /* determine basic parameters */
Tejun Heofd1e8a12009-08-14 15:00:51 +09001315 pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT;
Tejun Heod9b55ee2009-02-24 11:57:21 +09001316 pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT;
Tejun Heo65632972009-08-14 15:00:52 +09001317 pcpu_atom_size = ai->atom_size;
Tejun Heoce3141a2009-07-04 08:11:00 +09001318 pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) +
1319 BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long);
Tejun Heocafe8812009-03-06 14:33:59 +09001320
Tejun Heod9b55ee2009-02-24 11:57:21 +09001321 /*
1322 * Allocate chunk slots. The additional last slot is for
1323 * empty chunks.
1324 */
1325 pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2;
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001326 pcpu_slot = memblock_virt_alloc(
1327 pcpu_nr_slots * sizeof(pcpu_slot[0]), 0);
Tejun Heofbf59bc2009-02-20 16:29:08 +09001328 for (i = 0; i < pcpu_nr_slots; i++)
1329 INIT_LIST_HEAD(&pcpu_slot[i]);
1330
Tejun Heoedcb4632009-03-06 14:33:59 +09001331 /*
1332 * Initialize static chunk. If reserved_size is zero, the
1333 * static chunk covers static area + dynamic allocation area
1334 * in the first chunk. If reserved_size is not zero, it
1335 * covers static area + reserved area (mostly used for module
1336 * static percpu allocation).
1337 */
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001338 schunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0);
Tejun Heo2441d152009-03-06 14:33:59 +09001339 INIT_LIST_HEAD(&schunk->list);
Tejun Heobba174f2009-08-14 15:00:51 +09001340 schunk->base_addr = base_addr;
Tejun Heo61ace7f2009-03-06 14:33:59 +09001341 schunk->map = smap;
1342 schunk->map_alloc = ARRAY_SIZE(smap);
Tejun Heo38a6be52009-07-04 08:10:59 +09001343 schunk->immutable = true;
Tejun Heoce3141a2009-07-04 08:11:00 +09001344 bitmap_fill(schunk->populated, pcpu_unit_pages);
Tejun Heoedcb4632009-03-06 14:33:59 +09001345
Tejun Heofd1e8a12009-08-14 15:00:51 +09001346 if (ai->reserved_size) {
1347 schunk->free_size = ai->reserved_size;
Tejun Heoae9e6bc92009-04-02 13:19:54 +09001348 pcpu_reserved_chunk = schunk;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001349 pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size;
Tejun Heoedcb4632009-03-06 14:33:59 +09001350 } else {
1351 schunk->free_size = dyn_size;
1352 dyn_size = 0; /* dynamic area covered */
1353 }
Tejun Heo2441d152009-03-06 14:33:59 +09001354 schunk->contig_hint = schunk->free_size;
Tejun Heofbf59bc2009-02-20 16:29:08 +09001355
Al Viro723ad1d2014-03-06 21:13:18 -05001356 schunk->map[0] = 1;
1357 schunk->map[1] = ai->static_size;
1358 schunk->map_used = 1;
Tejun Heo61ace7f2009-03-06 14:33:59 +09001359 if (schunk->free_size)
Al Viro723ad1d2014-03-06 21:13:18 -05001360 schunk->map[++schunk->map_used] = 1 | (ai->static_size + schunk->free_size);
1361 else
1362 schunk->map[1] |= 1;
Tejun Heo61ace7f2009-03-06 14:33:59 +09001363
Tejun Heoedcb4632009-03-06 14:33:59 +09001364 /* init dynamic chunk if necessary */
1365 if (dyn_size) {
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001366 dchunk = memblock_virt_alloc(pcpu_chunk_struct_size, 0);
Tejun Heoedcb4632009-03-06 14:33:59 +09001367 INIT_LIST_HEAD(&dchunk->list);
Tejun Heobba174f2009-08-14 15:00:51 +09001368 dchunk->base_addr = base_addr;
Tejun Heoedcb4632009-03-06 14:33:59 +09001369 dchunk->map = dmap;
1370 dchunk->map_alloc = ARRAY_SIZE(dmap);
Tejun Heo38a6be52009-07-04 08:10:59 +09001371 dchunk->immutable = true;
Tejun Heoce3141a2009-07-04 08:11:00 +09001372 bitmap_fill(dchunk->populated, pcpu_unit_pages);
Tejun Heoedcb4632009-03-06 14:33:59 +09001373
1374 dchunk->contig_hint = dchunk->free_size = dyn_size;
Al Viro723ad1d2014-03-06 21:13:18 -05001375 dchunk->map[0] = 1;
1376 dchunk->map[1] = pcpu_reserved_chunk_limit;
1377 dchunk->map[2] = (pcpu_reserved_chunk_limit + dchunk->free_size) | 1;
1378 dchunk->map_used = 2;
Tejun Heoedcb4632009-03-06 14:33:59 +09001379 }
1380
Tejun Heo2441d152009-03-06 14:33:59 +09001381 /* link the first chunk in */
Tejun Heoae9e6bc92009-04-02 13:19:54 +09001382 pcpu_first_chunk = dchunk ?: schunk;
1383 pcpu_chunk_relocate(pcpu_first_chunk, -1);
Tejun Heofbf59bc2009-02-20 16:29:08 +09001384
1385 /* we're done */
Tejun Heobba174f2009-08-14 15:00:51 +09001386 pcpu_base_addr = base_addr;
Tejun Heofb435d52009-08-14 15:00:51 +09001387 return 0;
Tejun Heofbf59bc2009-02-20 16:29:08 +09001388}
Tejun Heo66c3a752009-03-10 16:27:48 +09001389
Tejun Heobbddff02010-09-03 18:22:48 +02001390#ifdef CONFIG_SMP
1391
Andi Kleen17f36092012-10-04 17:12:07 -07001392const char * const pcpu_fc_names[PCPU_FC_NR] __initconst = {
Tejun Heof58dc012009-08-14 15:00:50 +09001393 [PCPU_FC_AUTO] = "auto",
1394 [PCPU_FC_EMBED] = "embed",
1395 [PCPU_FC_PAGE] = "page",
Tejun Heof58dc012009-08-14 15:00:50 +09001396};
Tejun Heo66c3a752009-03-10 16:27:48 +09001397
Tejun Heof58dc012009-08-14 15:00:50 +09001398enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO;
1399
1400static int __init percpu_alloc_setup(char *str)
Tejun Heo66c3a752009-03-10 16:27:48 +09001401{
Cyrill Gorcunov5479c782012-11-25 01:17:13 +04001402 if (!str)
1403 return -EINVAL;
1404
Tejun Heof58dc012009-08-14 15:00:50 +09001405 if (0)
1406 /* nada */;
1407#ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK
1408 else if (!strcmp(str, "embed"))
1409 pcpu_chosen_fc = PCPU_FC_EMBED;
1410#endif
1411#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
1412 else if (!strcmp(str, "page"))
1413 pcpu_chosen_fc = PCPU_FC_PAGE;
1414#endif
Tejun Heof58dc012009-08-14 15:00:50 +09001415 else
1416 pr_warning("PERCPU: unknown allocator %s specified\n", str);
Tejun Heo66c3a752009-03-10 16:27:48 +09001417
Tejun Heof58dc012009-08-14 15:00:50 +09001418 return 0;
Tejun Heo66c3a752009-03-10 16:27:48 +09001419}
Tejun Heof58dc012009-08-14 15:00:50 +09001420early_param("percpu_alloc", percpu_alloc_setup);
Tejun Heo66c3a752009-03-10 16:27:48 +09001421
Tejun Heo3c9a0242010-09-09 18:00:15 +02001422/*
1423 * pcpu_embed_first_chunk() is used by the generic percpu setup.
1424 * Build it if needed by the arch config or the generic setup is going
1425 * to be used.
1426 */
Tejun Heo08fc4582009-08-14 15:00:49 +09001427#if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \
1428 !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA)
Tejun Heo3c9a0242010-09-09 18:00:15 +02001429#define BUILD_EMBED_FIRST_CHUNK
1430#endif
1431
1432/* build pcpu_page_first_chunk() iff needed by the arch config */
1433#if defined(CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK)
1434#define BUILD_PAGE_FIRST_CHUNK
1435#endif
1436
1437/* pcpu_build_alloc_info() is used by both embed and page first chunk */
1438#if defined(BUILD_EMBED_FIRST_CHUNK) || defined(BUILD_PAGE_FIRST_CHUNK)
1439/**
Tejun Heofbf59bc2009-02-20 16:29:08 +09001440 * pcpu_build_alloc_info - build alloc_info considering distances between CPUs
1441 * @reserved_size: the size of reserved percpu area in bytes
1442 * @dyn_size: minimum free size for dynamic allocation in bytes
1443 * @atom_size: allocation atom size
1444 * @cpu_distance_fn: callback to determine distance between cpus, optional
1445 *
1446 * This function determines grouping of units, their mappings to cpus
1447 * and other parameters considering needed percpu size, allocation
1448 * atom size and distances between CPUs.
1449 *
1450 * Groups are always mutliples of atom size and CPUs which are of
1451 * LOCAL_DISTANCE both ways are grouped together and share space for
1452 * units in the same group. The returned configuration is guaranteed
1453 * to have CPUs on different nodes on different groups and >=75% usage
1454 * of allocated virtual address space.
1455 *
1456 * RETURNS:
1457 * On success, pointer to the new allocation_info is returned. On
1458 * failure, ERR_PTR value is returned.
1459 */
1460static struct pcpu_alloc_info * __init pcpu_build_alloc_info(
1461 size_t reserved_size, size_t dyn_size,
1462 size_t atom_size,
1463 pcpu_fc_cpu_distance_fn_t cpu_distance_fn)
1464{
1465 static int group_map[NR_CPUS] __initdata;
1466 static int group_cnt[NR_CPUS] __initdata;
1467 const size_t static_size = __per_cpu_end - __per_cpu_start;
1468 int nr_groups = 1, nr_units = 0;
1469 size_t size_sum, min_unit_size, alloc_size;
1470 int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */
1471 int last_allocs, group, unit;
1472 unsigned int cpu, tcpu;
1473 struct pcpu_alloc_info *ai;
1474 unsigned int *cpu_map;
1475
1476 /* this function may be called multiple times */
1477 memset(group_map, 0, sizeof(group_map));
1478 memset(group_cnt, 0, sizeof(group_cnt));
1479
1480 /* calculate size_sum and ensure dyn_size is enough for early alloc */
1481 size_sum = PFN_ALIGN(static_size + reserved_size +
1482 max_t(size_t, dyn_size, PERCPU_DYNAMIC_EARLY_SIZE));
1483 dyn_size = size_sum - static_size - reserved_size;
1484
1485 /*
1486 * Determine min_unit_size, alloc_size and max_upa such that
1487 * alloc_size is multiple of atom_size and is the smallest
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001488 * which can accommodate 4k aligned segments which are equal to
Tejun Heofbf59bc2009-02-20 16:29:08 +09001489 * or larger than min_unit_size.
1490 */
1491 min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE);
1492
1493 alloc_size = roundup(min_unit_size, atom_size);
1494 upa = alloc_size / min_unit_size;
1495 while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
1496 upa--;
1497 max_upa = upa;
1498
1499 /* group cpus according to their proximity */
1500 for_each_possible_cpu(cpu) {
1501 group = 0;
1502 next_group:
1503 for_each_possible_cpu(tcpu) {
1504 if (cpu == tcpu)
1505 break;
1506 if (group_map[tcpu] == group && cpu_distance_fn &&
1507 (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE ||
1508 cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) {
1509 group++;
1510 nr_groups = max(nr_groups, group + 1);
1511 goto next_group;
1512 }
1513 }
1514 group_map[cpu] = group;
1515 group_cnt[group]++;
1516 }
1517
1518 /*
1519 * Expand unit size until address space usage goes over 75%
1520 * and then as much as possible without using more address
1521 * space.
1522 */
1523 last_allocs = INT_MAX;
1524 for (upa = max_upa; upa; upa--) {
1525 int allocs = 0, wasted = 0;
1526
1527 if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK))
1528 continue;
1529
1530 for (group = 0; group < nr_groups; group++) {
1531 int this_allocs = DIV_ROUND_UP(group_cnt[group], upa);
1532 allocs += this_allocs;
1533 wasted += this_allocs * upa - group_cnt[group];
1534 }
1535
1536 /*
1537 * Don't accept if wastage is over 1/3. The
1538 * greater-than comparison ensures upa==1 always
1539 * passes the following check.
1540 */
1541 if (wasted > num_possible_cpus() / 3)
1542 continue;
1543
1544 /* and then don't consume more memory */
1545 if (allocs > last_allocs)
1546 break;
1547 last_allocs = allocs;
1548 best_upa = upa;
1549 }
1550 upa = best_upa;
1551
1552 /* allocate and fill alloc_info */
1553 for (group = 0; group < nr_groups; group++)
1554 nr_units += roundup(group_cnt[group], upa);
1555
1556 ai = pcpu_alloc_alloc_info(nr_groups, nr_units);
1557 if (!ai)
1558 return ERR_PTR(-ENOMEM);
1559 cpu_map = ai->groups[0].cpu_map;
1560
1561 for (group = 0; group < nr_groups; group++) {
1562 ai->groups[group].cpu_map = cpu_map;
1563 cpu_map += roundup(group_cnt[group], upa);
1564 }
1565
1566 ai->static_size = static_size;
1567 ai->reserved_size = reserved_size;
1568 ai->dyn_size = dyn_size;
1569 ai->unit_size = alloc_size / upa;
1570 ai->atom_size = atom_size;
1571 ai->alloc_size = alloc_size;
1572
1573 for (group = 0, unit = 0; group_cnt[group]; group++) {
1574 struct pcpu_group_info *gi = &ai->groups[group];
1575
1576 /*
1577 * Initialize base_offset as if all groups are located
1578 * back-to-back. The caller should update this to
1579 * reflect actual allocation.
1580 */
1581 gi->base_offset = unit * ai->unit_size;
1582
1583 for_each_possible_cpu(cpu)
1584 if (group_map[cpu] == group)
1585 gi->cpu_map[gi->nr_units++] = cpu;
1586 gi->nr_units = roundup(gi->nr_units, upa);
1587 unit += gi->nr_units;
1588 }
1589 BUG_ON(unit != nr_units);
1590
1591 return ai;
1592}
Tejun Heo3c9a0242010-09-09 18:00:15 +02001593#endif /* BUILD_EMBED_FIRST_CHUNK || BUILD_PAGE_FIRST_CHUNK */
Tejun Heofbf59bc2009-02-20 16:29:08 +09001594
Tejun Heo3c9a0242010-09-09 18:00:15 +02001595#if defined(BUILD_EMBED_FIRST_CHUNK)
Tejun Heo66c3a752009-03-10 16:27:48 +09001596/**
1597 * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem
Tejun Heo66c3a752009-03-10 16:27:48 +09001598 * @reserved_size: the size of reserved percpu area in bytes
Tejun Heo4ba6ce22010-06-27 18:49:59 +02001599 * @dyn_size: minimum free size for dynamic allocation in bytes
Tejun Heoc8826dd2009-08-14 15:00:52 +09001600 * @atom_size: allocation atom size
1601 * @cpu_distance_fn: callback to determine distance between cpus, optional
1602 * @alloc_fn: function to allocate percpu page
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001603 * @free_fn: function to free percpu page
Tejun Heo66c3a752009-03-10 16:27:48 +09001604 *
1605 * This is a helper to ease setting up embedded first percpu chunk and
1606 * can be called where pcpu_setup_first_chunk() is expected.
1607 *
1608 * If this function is used to setup the first chunk, it is allocated
Tejun Heoc8826dd2009-08-14 15:00:52 +09001609 * by calling @alloc_fn and used as-is without being mapped into
1610 * vmalloc area. Allocations are always whole multiples of @atom_size
1611 * aligned to @atom_size.
1612 *
1613 * This enables the first chunk to piggy back on the linear physical
1614 * mapping which often uses larger page size. Please note that this
1615 * can result in very sparse cpu->unit mapping on NUMA machines thus
1616 * requiring large vmalloc address space. Don't use this allocator if
1617 * vmalloc space is not orders of magnitude larger than distances
1618 * between node memory addresses (ie. 32bit NUMA machines).
Tejun Heo66c3a752009-03-10 16:27:48 +09001619 *
Tejun Heo4ba6ce22010-06-27 18:49:59 +02001620 * @dyn_size specifies the minimum dynamic area size.
Tejun Heo66c3a752009-03-10 16:27:48 +09001621 *
1622 * If the needed size is smaller than the minimum or specified unit
Tejun Heoc8826dd2009-08-14 15:00:52 +09001623 * size, the leftover is returned using @free_fn.
Tejun Heo66c3a752009-03-10 16:27:48 +09001624 *
1625 * RETURNS:
Tejun Heofb435d52009-08-14 15:00:51 +09001626 * 0 on success, -errno on failure.
Tejun Heo66c3a752009-03-10 16:27:48 +09001627 */
Tejun Heo4ba6ce22010-06-27 18:49:59 +02001628int __init pcpu_embed_first_chunk(size_t reserved_size, size_t dyn_size,
Tejun Heoc8826dd2009-08-14 15:00:52 +09001629 size_t atom_size,
1630 pcpu_fc_cpu_distance_fn_t cpu_distance_fn,
1631 pcpu_fc_alloc_fn_t alloc_fn,
1632 pcpu_fc_free_fn_t free_fn)
Tejun Heo66c3a752009-03-10 16:27:48 +09001633{
Tejun Heoc8826dd2009-08-14 15:00:52 +09001634 void *base = (void *)ULONG_MAX;
1635 void **areas = NULL;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001636 struct pcpu_alloc_info *ai;
Tejun Heo6ea529a2009-09-24 18:46:01 +09001637 size_t size_sum, areas_size, max_distance;
Tejun Heoc8826dd2009-08-14 15:00:52 +09001638 int group, i, rc;
Tejun Heo66c3a752009-03-10 16:27:48 +09001639
Tejun Heoc8826dd2009-08-14 15:00:52 +09001640 ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size,
1641 cpu_distance_fn);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001642 if (IS_ERR(ai))
1643 return PTR_ERR(ai);
Tejun Heo66c3a752009-03-10 16:27:48 +09001644
Tejun Heofd1e8a12009-08-14 15:00:51 +09001645 size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
Tejun Heoc8826dd2009-08-14 15:00:52 +09001646 areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *));
Tejun Heo66c3a752009-03-10 16:27:48 +09001647
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001648 areas = memblock_virt_alloc_nopanic(areas_size, 0);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001649 if (!areas) {
Tejun Heofb435d52009-08-14 15:00:51 +09001650 rc = -ENOMEM;
Tejun Heoc8826dd2009-08-14 15:00:52 +09001651 goto out_free;
Tejun Heofa8a7092009-06-22 11:56:24 +09001652 }
Tejun Heo66c3a752009-03-10 16:27:48 +09001653
Tejun Heoc8826dd2009-08-14 15:00:52 +09001654 /* allocate, copy and determine base address */
1655 for (group = 0; group < ai->nr_groups; group++) {
1656 struct pcpu_group_info *gi = &ai->groups[group];
1657 unsigned int cpu = NR_CPUS;
1658 void *ptr;
Tejun Heo66c3a752009-03-10 16:27:48 +09001659
Tejun Heoc8826dd2009-08-14 15:00:52 +09001660 for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++)
1661 cpu = gi->cpu_map[i];
1662 BUG_ON(cpu == NR_CPUS);
1663
1664 /* allocate space for the whole group */
1665 ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size);
1666 if (!ptr) {
1667 rc = -ENOMEM;
1668 goto out_free_areas;
1669 }
Catalin Marinasf528f0b2011-09-26 17:12:53 +01001670 /* kmemleak tracks the percpu allocations separately */
1671 kmemleak_free(ptr);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001672 areas[group] = ptr;
1673
1674 base = min(ptr, base);
Tejun Heo42b64282012-04-27 08:42:53 -07001675 }
1676
1677 /*
1678 * Copy data and free unused parts. This should happen after all
1679 * allocations are complete; otherwise, we may end up with
1680 * overlapping groups.
1681 */
1682 for (group = 0; group < ai->nr_groups; group++) {
1683 struct pcpu_group_info *gi = &ai->groups[group];
1684 void *ptr = areas[group];
Tejun Heoc8826dd2009-08-14 15:00:52 +09001685
1686 for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) {
1687 if (gi->cpu_map[i] == NR_CPUS) {
1688 /* unused unit, free whole */
1689 free_fn(ptr, ai->unit_size);
1690 continue;
1691 }
1692 /* copy and return the unused part */
1693 memcpy(ptr, __per_cpu_load, ai->static_size);
1694 free_fn(ptr + size_sum, ai->unit_size - size_sum);
1695 }
Tejun Heo66c3a752009-03-10 16:27:48 +09001696 }
1697
Tejun Heoc8826dd2009-08-14 15:00:52 +09001698 /* base address is now known, determine group base offsets */
Tejun Heo6ea529a2009-09-24 18:46:01 +09001699 max_distance = 0;
1700 for (group = 0; group < ai->nr_groups; group++) {
Tejun Heoc8826dd2009-08-14 15:00:52 +09001701 ai->groups[group].base_offset = areas[group] - base;
Tejun Heo1a0c3292009-10-04 09:31:05 +09001702 max_distance = max_t(size_t, max_distance,
1703 ai->groups[group].base_offset);
Tejun Heo6ea529a2009-09-24 18:46:01 +09001704 }
1705 max_distance += ai->unit_size;
1706
1707 /* warn if maximum distance is further than 75% of vmalloc space */
Laura Abbott8a092172014-01-02 13:53:21 -08001708 if (max_distance > VMALLOC_TOTAL * 3 / 4) {
Tejun Heo1a0c3292009-10-04 09:31:05 +09001709 pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc "
Mike Frysinger787e5b02011-03-23 08:23:52 +01001710 "space 0x%lx\n", max_distance,
Laura Abbott8a092172014-01-02 13:53:21 -08001711 VMALLOC_TOTAL);
Tejun Heo6ea529a2009-09-24 18:46:01 +09001712#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK
1713 /* and fail if we have fallback */
1714 rc = -EINVAL;
1715 goto out_free;
1716#endif
1717 }
Tejun Heoc8826dd2009-08-14 15:00:52 +09001718
Tejun Heo004018e2009-08-14 15:00:49 +09001719 pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n",
Tejun Heofd1e8a12009-08-14 15:00:51 +09001720 PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size,
1721 ai->dyn_size, ai->unit_size);
Tejun Heo66c3a752009-03-10 16:27:48 +09001722
Tejun Heofb435d52009-08-14 15:00:51 +09001723 rc = pcpu_setup_first_chunk(ai, base);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001724 goto out_free;
1725
1726out_free_areas:
1727 for (group = 0; group < ai->nr_groups; group++)
Michael Holzheuf851c8d2013-09-17 16:57:34 +02001728 if (areas[group])
1729 free_fn(areas[group],
1730 ai->groups[group].nr_units * ai->unit_size);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001731out_free:
Tejun Heofd1e8a12009-08-14 15:00:51 +09001732 pcpu_free_alloc_info(ai);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001733 if (areas)
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001734 memblock_free_early(__pa(areas), areas_size);
Tejun Heofb435d52009-08-14 15:00:51 +09001735 return rc;
Tejun Heod4b95f82009-07-04 08:10:59 +09001736}
Tejun Heo3c9a0242010-09-09 18:00:15 +02001737#endif /* BUILD_EMBED_FIRST_CHUNK */
Tejun Heod4b95f82009-07-04 08:10:59 +09001738
Tejun Heo3c9a0242010-09-09 18:00:15 +02001739#ifdef BUILD_PAGE_FIRST_CHUNK
Tejun Heod4b95f82009-07-04 08:10:59 +09001740/**
Tejun Heo00ae4062009-08-14 15:00:49 +09001741 * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages
Tejun Heod4b95f82009-07-04 08:10:59 +09001742 * @reserved_size: the size of reserved percpu area in bytes
1743 * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE
Lucas De Marchi25985ed2011-03-30 22:57:33 -03001744 * @free_fn: function to free percpu page, always called with PAGE_SIZE
Tejun Heod4b95f82009-07-04 08:10:59 +09001745 * @populate_pte_fn: function to populate pte
1746 *
Tejun Heo00ae4062009-08-14 15:00:49 +09001747 * This is a helper to ease setting up page-remapped first percpu
1748 * chunk and can be called where pcpu_setup_first_chunk() is expected.
Tejun Heod4b95f82009-07-04 08:10:59 +09001749 *
1750 * This is the basic allocator. Static percpu area is allocated
1751 * page-by-page into vmalloc area.
1752 *
1753 * RETURNS:
Tejun Heofb435d52009-08-14 15:00:51 +09001754 * 0 on success, -errno on failure.
Tejun Heod4b95f82009-07-04 08:10:59 +09001755 */
Tejun Heofb435d52009-08-14 15:00:51 +09001756int __init pcpu_page_first_chunk(size_t reserved_size,
1757 pcpu_fc_alloc_fn_t alloc_fn,
1758 pcpu_fc_free_fn_t free_fn,
1759 pcpu_fc_populate_pte_fn_t populate_pte_fn)
Tejun Heod4b95f82009-07-04 08:10:59 +09001760{
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001761 static struct vm_struct vm;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001762 struct pcpu_alloc_info *ai;
Tejun Heo00ae4062009-08-14 15:00:49 +09001763 char psize_str[16];
Tejun Heoce3141a2009-07-04 08:11:00 +09001764 int unit_pages;
Tejun Heod4b95f82009-07-04 08:10:59 +09001765 size_t pages_size;
Tejun Heoce3141a2009-07-04 08:11:00 +09001766 struct page **pages;
Tejun Heofb435d52009-08-14 15:00:51 +09001767 int unit, i, j, rc;
Tejun Heod4b95f82009-07-04 08:10:59 +09001768
Tejun Heo00ae4062009-08-14 15:00:49 +09001769 snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10);
1770
Tejun Heo4ba6ce22010-06-27 18:49:59 +02001771 ai = pcpu_build_alloc_info(reserved_size, 0, PAGE_SIZE, NULL);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001772 if (IS_ERR(ai))
1773 return PTR_ERR(ai);
1774 BUG_ON(ai->nr_groups != 1);
1775 BUG_ON(ai->groups[0].nr_units != num_possible_cpus());
1776
1777 unit_pages = ai->unit_size >> PAGE_SHIFT;
Tejun Heod4b95f82009-07-04 08:10:59 +09001778
1779 /* unaligned allocations can't be freed, round up to page size */
Tejun Heofd1e8a12009-08-14 15:00:51 +09001780 pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() *
1781 sizeof(pages[0]));
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001782 pages = memblock_virt_alloc(pages_size, 0);
Tejun Heod4b95f82009-07-04 08:10:59 +09001783
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001784 /* allocate pages */
Tejun Heod4b95f82009-07-04 08:10:59 +09001785 j = 0;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001786 for (unit = 0; unit < num_possible_cpus(); unit++)
Tejun Heoce3141a2009-07-04 08:11:00 +09001787 for (i = 0; i < unit_pages; i++) {
Tejun Heofd1e8a12009-08-14 15:00:51 +09001788 unsigned int cpu = ai->groups[0].cpu_map[unit];
Tejun Heod4b95f82009-07-04 08:10:59 +09001789 void *ptr;
1790
Tejun Heo3cbc8562009-08-14 15:00:50 +09001791 ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE);
Tejun Heod4b95f82009-07-04 08:10:59 +09001792 if (!ptr) {
Tejun Heo00ae4062009-08-14 15:00:49 +09001793 pr_warning("PERCPU: failed to allocate %s page "
1794 "for cpu%u\n", psize_str, cpu);
Tejun Heod4b95f82009-07-04 08:10:59 +09001795 goto enomem;
1796 }
Catalin Marinasf528f0b2011-09-26 17:12:53 +01001797 /* kmemleak tracks the percpu allocations separately */
1798 kmemleak_free(ptr);
Tejun Heoce3141a2009-07-04 08:11:00 +09001799 pages[j++] = virt_to_page(ptr);
Tejun Heod4b95f82009-07-04 08:10:59 +09001800 }
1801
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001802 /* allocate vm area, map the pages and copy static data */
1803 vm.flags = VM_ALLOC;
Tejun Heofd1e8a12009-08-14 15:00:51 +09001804 vm.size = num_possible_cpus() * ai->unit_size;
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001805 vm_area_register_early(&vm, PAGE_SIZE);
1806
Tejun Heofd1e8a12009-08-14 15:00:51 +09001807 for (unit = 0; unit < num_possible_cpus(); unit++) {
Tejun Heo1d9d3252009-08-14 15:00:50 +09001808 unsigned long unit_addr =
Tejun Heofd1e8a12009-08-14 15:00:51 +09001809 (unsigned long)vm.addr + unit * ai->unit_size;
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001810
Tejun Heoce3141a2009-07-04 08:11:00 +09001811 for (i = 0; i < unit_pages; i++)
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001812 populate_pte_fn(unit_addr + (i << PAGE_SHIFT));
1813
1814 /* pte already populated, the following shouldn't fail */
Tejun Heofb435d52009-08-14 15:00:51 +09001815 rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages],
1816 unit_pages);
1817 if (rc < 0)
1818 panic("failed to map percpu area, err=%d\n", rc);
Tejun Heo8f05a6a2009-07-04 08:10:59 +09001819
1820 /*
1821 * FIXME: Archs with virtual cache should flush local
1822 * cache for the linear mapping here - something
1823 * equivalent to flush_cache_vmap() on the local cpu.
1824 * flush_cache_vmap() can't be used as most supporting
1825 * data structures are not set up yet.
1826 */
1827
1828 /* copy static data */
Tejun Heofd1e8a12009-08-14 15:00:51 +09001829 memcpy((void *)unit_addr, __per_cpu_load, ai->static_size);
Tejun Heo66c3a752009-03-10 16:27:48 +09001830 }
1831
1832 /* we're ready, commit */
Tejun Heo1d9d3252009-08-14 15:00:50 +09001833 pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n",
Tejun Heofd1e8a12009-08-14 15:00:51 +09001834 unit_pages, psize_str, vm.addr, ai->static_size,
1835 ai->reserved_size, ai->dyn_size);
Tejun Heo66c3a752009-03-10 16:27:48 +09001836
Tejun Heofb435d52009-08-14 15:00:51 +09001837 rc = pcpu_setup_first_chunk(ai, vm.addr);
Tejun Heod4b95f82009-07-04 08:10:59 +09001838 goto out_free_ar;
1839
1840enomem:
1841 while (--j >= 0)
Tejun Heoce3141a2009-07-04 08:11:00 +09001842 free_fn(page_address(pages[j]), PAGE_SIZE);
Tejun Heofb435d52009-08-14 15:00:51 +09001843 rc = -ENOMEM;
Tejun Heod4b95f82009-07-04 08:10:59 +09001844out_free_ar:
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001845 memblock_free_early(__pa(pages), pages_size);
Tejun Heofd1e8a12009-08-14 15:00:51 +09001846 pcpu_free_alloc_info(ai);
Tejun Heofb435d52009-08-14 15:00:51 +09001847 return rc;
Tejun Heo66c3a752009-03-10 16:27:48 +09001848}
Tejun Heo3c9a0242010-09-09 18:00:15 +02001849#endif /* BUILD_PAGE_FIRST_CHUNK */
Tejun Heod4b95f82009-07-04 08:10:59 +09001850
Tejun Heobbddff02010-09-03 18:22:48 +02001851#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
Tejun Heo8c4bfc62009-07-04 08:10:59 +09001852/*
Tejun Heobbddff02010-09-03 18:22:48 +02001853 * Generic SMP percpu area setup.
Tejun Heoe74e3962009-03-30 19:07:44 +09001854 *
1855 * The embedding helper is used because its behavior closely resembles
1856 * the original non-dynamic generic percpu area setup. This is
1857 * important because many archs have addressing restrictions and might
1858 * fail if the percpu area is located far away from the previous
1859 * location. As an added bonus, in non-NUMA cases, embedding is
1860 * generally a good idea TLB-wise because percpu area can piggy back
1861 * on the physical linear memory mapping which uses large page
1862 * mappings on applicable archs.
1863 */
Tejun Heoe74e3962009-03-30 19:07:44 +09001864unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
1865EXPORT_SYMBOL(__per_cpu_offset);
1866
Tejun Heoc8826dd2009-08-14 15:00:52 +09001867static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size,
1868 size_t align)
1869{
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001870 return memblock_virt_alloc_from_nopanic(
1871 size, align, __pa(MAX_DMA_ADDRESS));
Tejun Heoc8826dd2009-08-14 15:00:52 +09001872}
1873
1874static void __init pcpu_dfl_fc_free(void *ptr, size_t size)
1875{
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001876 memblock_free_early(__pa(ptr), size);
Tejun Heoc8826dd2009-08-14 15:00:52 +09001877}
1878
Tejun Heoe74e3962009-03-30 19:07:44 +09001879void __init setup_per_cpu_areas(void)
1880{
Tejun Heoe74e3962009-03-30 19:07:44 +09001881 unsigned long delta;
1882 unsigned int cpu;
Tejun Heofb435d52009-08-14 15:00:51 +09001883 int rc;
Tejun Heoe74e3962009-03-30 19:07:44 +09001884
1885 /*
1886 * Always reserve area for module percpu variables. That's
1887 * what the legacy allocator did.
1888 */
Tejun Heofb435d52009-08-14 15:00:51 +09001889 rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
Tejun Heoc8826dd2009-08-14 15:00:52 +09001890 PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL,
1891 pcpu_dfl_fc_alloc, pcpu_dfl_fc_free);
Tejun Heofb435d52009-08-14 15:00:51 +09001892 if (rc < 0)
Tejun Heobbddff02010-09-03 18:22:48 +02001893 panic("Failed to initialize percpu areas.");
Tejun Heoe74e3962009-03-30 19:07:44 +09001894
1895 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
1896 for_each_possible_cpu(cpu)
Tejun Heofb435d52009-08-14 15:00:51 +09001897 __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
Tejun Heoe74e3962009-03-30 19:07:44 +09001898}
Tejun Heobbddff02010-09-03 18:22:48 +02001899#endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */
1900
1901#else /* CONFIG_SMP */
1902
1903/*
1904 * UP percpu area setup.
1905 *
1906 * UP always uses km-based percpu allocator with identity mapping.
1907 * Static percpu variables are indistinguishable from the usual static
1908 * variables and don't require any special preparation.
1909 */
1910void __init setup_per_cpu_areas(void)
1911{
1912 const size_t unit_size =
1913 roundup_pow_of_two(max_t(size_t, PCPU_MIN_UNIT_SIZE,
1914 PERCPU_DYNAMIC_RESERVE));
1915 struct pcpu_alloc_info *ai;
1916 void *fc;
1917
1918 ai = pcpu_alloc_alloc_info(1, 1);
Santosh Shilimkar999c17e2014-01-21 15:50:40 -08001919 fc = memblock_virt_alloc_from_nopanic(unit_size,
1920 PAGE_SIZE,
1921 __pa(MAX_DMA_ADDRESS));
Tejun Heobbddff02010-09-03 18:22:48 +02001922 if (!ai || !fc)
1923 panic("Failed to allocate memory for percpu areas.");
Catalin Marinas100d13c2012-05-09 16:55:19 +01001924 /* kmemleak tracks the percpu allocations separately */
1925 kmemleak_free(fc);
Tejun Heobbddff02010-09-03 18:22:48 +02001926
1927 ai->dyn_size = unit_size;
1928 ai->unit_size = unit_size;
1929 ai->atom_size = unit_size;
1930 ai->alloc_size = unit_size;
1931 ai->groups[0].nr_units = 1;
1932 ai->groups[0].cpu_map[0] = 0;
1933
1934 if (pcpu_setup_first_chunk(ai, fc) < 0)
1935 panic("Failed to initialize percpu areas.");
1936}
1937
1938#endif /* CONFIG_SMP */
Tejun Heo099a19d2010-06-27 18:50:00 +02001939
1940/*
1941 * First and reserved chunks are initialized with temporary allocation
1942 * map in initdata so that they can be used before slab is online.
1943 * This function is called after slab is brought up and replaces those
1944 * with properly allocated maps.
1945 */
1946void __init percpu_init_late(void)
1947{
1948 struct pcpu_chunk *target_chunks[] =
1949 { pcpu_first_chunk, pcpu_reserved_chunk, NULL };
1950 struct pcpu_chunk *chunk;
1951 unsigned long flags;
1952 int i;
1953
1954 for (i = 0; (chunk = target_chunks[i]); i++) {
1955 int *map;
1956 const size_t size = PERCPU_DYNAMIC_EARLY_SLOTS * sizeof(map[0]);
1957
1958 BUILD_BUG_ON(size > PAGE_SIZE);
1959
Bob Liu90459ce02011-08-04 11:02:33 +02001960 map = pcpu_mem_zalloc(size);
Tejun Heo099a19d2010-06-27 18:50:00 +02001961 BUG_ON(!map);
1962
1963 spin_lock_irqsave(&pcpu_lock, flags);
1964 memcpy(map, chunk->map, size);
1965 chunk->map = map;
1966 spin_unlock_irqrestore(&pcpu_lock, flags);
1967 }
1968}