Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1 | /* |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 2 | * mm/percpu.c - percpu memory allocator |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 3 | * |
| 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 Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 10 | * 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 Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 13 | * (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 Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 16 | * When a chunk is filled up, another chunk is allocated. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 17 | * |
| 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 Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 25 | * 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 Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 29 | * |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 30 | * There are usually many small percpu allocations many of them being |
| 31 | * as small as 4 bytes. The allocator organizes chunks into lists |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 32 | * according to free size and tries to allocate from the fullest one. |
| 33 | * Each chunk keeps the maximum contiguous area size hint which is |
| 34 | * guaranteed to be eqaul to or larger than the maximum contiguous |
| 35 | * 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 Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 43 | * 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 Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 45 | * |
| 46 | * To use this allocator, arch code should do the followings. |
| 47 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 48 | * - define __addr_to_pcpu_ptr() and __pcpu_ptr_to_addr() to translate |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 49 | * regular address to percpu pointer and back if they need to be |
| 50 | * different from the default |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 51 | * |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 52 | * - use pcpu_setup_first_chunk() during percpu area initialization to |
| 53 | * setup the first chunk containing the kernel static percpu area |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 54 | */ |
| 55 | |
| 56 | #include <linux/bitmap.h> |
| 57 | #include <linux/bootmem.h> |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 58 | #include <linux/err.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 59 | #include <linux/list.h> |
Tejun Heo | a530b79 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 60 | #include <linux/log2.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 61 | #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 Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 66 | #include <linux/slab.h> |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 67 | #include <linux/spinlock.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 68 | #include <linux/vmalloc.h> |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 69 | #include <linux/workqueue.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 70 | |
| 71 | #include <asm/cacheflush.h> |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 72 | #include <asm/sections.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 73 | #include <asm/tlbflush.h> |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 74 | #include <asm/io.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 75 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 76 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
| 77 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ |
| 78 | |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 79 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
| 80 | #ifndef __addr_to_pcpu_ptr |
| 81 | #define __addr_to_pcpu_ptr(addr) \ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 82 | (void __percpu *)((unsigned long)(addr) - \ |
| 83 | (unsigned long)pcpu_base_addr + \ |
| 84 | (unsigned long)__per_cpu_start) |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 85 | #endif |
| 86 | #ifndef __pcpu_ptr_to_addr |
| 87 | #define __pcpu_ptr_to_addr(ptr) \ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 88 | (void __force *)((unsigned long)(ptr) + \ |
| 89 | (unsigned long)pcpu_base_addr - \ |
| 90 | (unsigned long)__per_cpu_start) |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 91 | #endif |
| 92 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 93 | struct pcpu_chunk { |
| 94 | struct list_head list; /* linked to pcpu_slot lists */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 95 | int free_size; /* free bytes in the chunk */ |
| 96 | int contig_hint; /* max contiguous size hint */ |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 97 | void *base_addr; /* base address of this chunk */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 98 | int map_used; /* # of map entries used */ |
| 99 | int map_alloc; /* # of map entries allocated */ |
| 100 | int *map; /* allocation map */ |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 101 | void *data; /* chunk data */ |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 102 | bool immutable; /* no [de]population allowed */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 103 | unsigned long populated[]; /* populated bitmap */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 104 | }; |
| 105 | |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 106 | static int pcpu_unit_pages __read_mostly; |
| 107 | static int pcpu_unit_size __read_mostly; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 108 | static int pcpu_nr_units __read_mostly; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 109 | static int pcpu_atom_size __read_mostly; |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 110 | static int pcpu_nr_slots __read_mostly; |
| 111 | static size_t pcpu_chunk_struct_size __read_mostly; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 112 | |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 113 | /* cpus with the lowest and highest unit numbers */ |
| 114 | static unsigned int pcpu_first_unit_cpu __read_mostly; |
| 115 | static unsigned int pcpu_last_unit_cpu __read_mostly; |
| 116 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 117 | /* the address of the first chunk which starts with the kernel static area */ |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 118 | void *pcpu_base_addr __read_mostly; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 119 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
| 120 | |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 121 | static const int *pcpu_unit_map __read_mostly; /* cpu -> unit */ |
| 122 | const unsigned long *pcpu_unit_offsets __read_mostly; /* cpu -> unit offset */ |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 123 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 124 | /* group information, used for vm allocation */ |
| 125 | static int pcpu_nr_groups __read_mostly; |
| 126 | static const unsigned long *pcpu_group_offsets __read_mostly; |
| 127 | static const size_t *pcpu_group_sizes __read_mostly; |
| 128 | |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 129 | /* |
| 130 | * The first chunk which always exists. Note that unlike other |
| 131 | * chunks, this one can be allocated and mapped in several different |
| 132 | * ways and thus often doesn't live in the vmalloc area. |
| 133 | */ |
| 134 | static struct pcpu_chunk *pcpu_first_chunk; |
| 135 | |
| 136 | /* |
| 137 | * Optional reserved chunk. This chunk reserves part of the first |
| 138 | * chunk and serves it for reserved allocations. The amount of |
| 139 | * reserved offset is in pcpu_reserved_chunk_limit. When reserved |
| 140 | * area doesn't exist, the following variables contain NULL and 0 |
| 141 | * respectively. |
| 142 | */ |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 143 | static struct pcpu_chunk *pcpu_reserved_chunk; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 144 | static int pcpu_reserved_chunk_limit; |
| 145 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 146 | /* |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 147 | * Synchronization rules. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 148 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 149 | * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 150 | * protects allocation/reclaim paths, chunks, populated bitmap and |
| 151 | * vmalloc mapping. The latter is a spinlock and protects the index |
| 152 | * data structures - chunk slots, chunks and area maps in chunks. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 153 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 154 | * During allocation, pcpu_alloc_mutex is kept locked all the time and |
| 155 | * pcpu_lock is grabbed and released as necessary. All actual memory |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 156 | * allocations are done using GFP_KERNEL with pcpu_lock released. In |
| 157 | * general, percpu memory can't be allocated with irq off but |
| 158 | * irqsave/restore are still used in alloc path so that it can be used |
| 159 | * from early init path - sched_init() specifically. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 160 | * |
| 161 | * Free path accesses and alters only the index data structures, so it |
| 162 | * can be safely called from atomic context. When memory needs to be |
| 163 | * returned to the system, free path schedules reclaim_work which |
| 164 | * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be |
| 165 | * reclaimed, release both locks and frees the chunks. Note that it's |
| 166 | * necessary to grab both locks to remove a chunk from circulation as |
| 167 | * allocation path might be referencing the chunk with only |
| 168 | * pcpu_alloc_mutex locked. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 169 | */ |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 170 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ |
| 171 | static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 172 | |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 173 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 174 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 175 | /* reclaim work to release fully free chunks, scheduled from free path */ |
| 176 | static void pcpu_reclaim(struct work_struct *work); |
| 177 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); |
| 178 | |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 179 | static bool pcpu_addr_in_first_chunk(void *addr) |
| 180 | { |
| 181 | void *first_start = pcpu_first_chunk->base_addr; |
| 182 | |
| 183 | return addr >= first_start && addr < first_start + pcpu_unit_size; |
| 184 | } |
| 185 | |
| 186 | static bool pcpu_addr_in_reserved_chunk(void *addr) |
| 187 | { |
| 188 | void *first_start = pcpu_first_chunk->base_addr; |
| 189 | |
| 190 | return addr >= first_start && |
| 191 | addr < first_start + pcpu_reserved_chunk_limit; |
| 192 | } |
| 193 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 194 | static int __pcpu_size_to_slot(int size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 195 | { |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 196 | int highbit = fls(size); /* size is in bytes */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 197 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
| 198 | } |
| 199 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 200 | static int pcpu_size_to_slot(int size) |
| 201 | { |
| 202 | if (size == pcpu_unit_size) |
| 203 | return pcpu_nr_slots - 1; |
| 204 | return __pcpu_size_to_slot(size); |
| 205 | } |
| 206 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 207 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
| 208 | { |
| 209 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) |
| 210 | return 0; |
| 211 | |
| 212 | return pcpu_size_to_slot(chunk->free_size); |
| 213 | } |
| 214 | |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 215 | /* set the pointer to a chunk in a page struct */ |
| 216 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) |
| 217 | { |
| 218 | page->index = (unsigned long)pcpu; |
| 219 | } |
| 220 | |
| 221 | /* obtain pointer to a chunk from a page struct */ |
| 222 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) |
| 223 | { |
| 224 | return (struct pcpu_chunk *)page->index; |
| 225 | } |
| 226 | |
| 227 | static int __maybe_unused pcpu_page_idx(unsigned int cpu, int page_idx) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 228 | { |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 229 | return pcpu_unit_map[cpu] * pcpu_unit_pages + page_idx; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 230 | } |
| 231 | |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 232 | static unsigned long __maybe_unused pcpu_chunk_addr(struct pcpu_chunk *chunk, |
| 233 | unsigned int cpu, int page_idx) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 234 | { |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 235 | return (unsigned long)chunk->base_addr + pcpu_unit_offsets[cpu] + |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 236 | (page_idx << PAGE_SHIFT); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 237 | } |
| 238 | |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 239 | static void __maybe_unused pcpu_next_unpop(struct pcpu_chunk *chunk, |
| 240 | int *rs, int *re, int end) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 241 | { |
| 242 | *rs = find_next_zero_bit(chunk->populated, end, *rs); |
| 243 | *re = find_next_bit(chunk->populated, end, *rs + 1); |
| 244 | } |
| 245 | |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 246 | static void __maybe_unused pcpu_next_pop(struct pcpu_chunk *chunk, |
| 247 | int *rs, int *re, int end) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 248 | { |
| 249 | *rs = find_next_bit(chunk->populated, end, *rs); |
| 250 | *re = find_next_zero_bit(chunk->populated, end, *rs + 1); |
| 251 | } |
| 252 | |
| 253 | /* |
| 254 | * (Un)populated page region iterators. Iterate over (un)populated |
| 255 | * page regions betwen @start and @end in @chunk. @rs and @re should |
| 256 | * be integer variables and will be set to start and end page index of |
| 257 | * the current region. |
| 258 | */ |
| 259 | #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ |
| 260 | for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ |
| 261 | (rs) < (re); \ |
| 262 | (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) |
| 263 | |
| 264 | #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ |
| 265 | for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ |
| 266 | (rs) < (re); \ |
| 267 | (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) |
| 268 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 269 | /** |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 270 | * pcpu_mem_alloc - allocate memory |
| 271 | * @size: bytes to allocate |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 272 | * |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 273 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
| 274 | * kzalloc() is used; otherwise, vmalloc() is used. The returned |
| 275 | * memory is always zeroed. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 276 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 277 | * CONTEXT: |
| 278 | * Does GFP_KERNEL allocation. |
| 279 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 280 | * RETURNS: |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 281 | * Pointer to the allocated area on success, NULL on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 282 | */ |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 283 | static void *pcpu_mem_alloc(size_t size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 284 | { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 285 | if (size <= PAGE_SIZE) |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 286 | return kzalloc(size, GFP_KERNEL); |
| 287 | else { |
| 288 | void *ptr = vmalloc(size); |
| 289 | if (ptr) |
| 290 | memset(ptr, 0, size); |
| 291 | return ptr; |
| 292 | } |
| 293 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 294 | |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 295 | /** |
| 296 | * pcpu_mem_free - free memory |
| 297 | * @ptr: memory to free |
| 298 | * @size: size of the area |
| 299 | * |
| 300 | * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). |
| 301 | */ |
| 302 | static void pcpu_mem_free(void *ptr, size_t size) |
| 303 | { |
| 304 | if (size <= PAGE_SIZE) |
| 305 | kfree(ptr); |
| 306 | else |
| 307 | vfree(ptr); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 308 | } |
| 309 | |
| 310 | /** |
| 311 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot |
| 312 | * @chunk: chunk of interest |
| 313 | * @oslot: the previous slot it was on |
| 314 | * |
| 315 | * This function is called after an allocation or free changed @chunk. |
| 316 | * New slot according to the changed state is determined and @chunk is |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 317 | * moved to the slot. Note that the reserved chunk is never put on |
| 318 | * chunk slots. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 319 | * |
| 320 | * CONTEXT: |
| 321 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 322 | */ |
| 323 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) |
| 324 | { |
| 325 | int nslot = pcpu_chunk_slot(chunk); |
| 326 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 327 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 328 | if (oslot < nslot) |
| 329 | list_move(&chunk->list, &pcpu_slot[nslot]); |
| 330 | else |
| 331 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); |
| 332 | } |
| 333 | } |
| 334 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 335 | /** |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 336 | * pcpu_need_to_extend - determine whether chunk area map needs to be extended |
| 337 | * @chunk: chunk of interest |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 338 | * |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 339 | * Determine whether area map of @chunk needs to be extended to |
| 340 | * accomodate a new allocation. |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 341 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 342 | * CONTEXT: |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 343 | * pcpu_lock. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 344 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 345 | * RETURNS: |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 346 | * New target map allocation length if extension is necessary, 0 |
| 347 | * otherwise. |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 348 | */ |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 349 | static int pcpu_need_to_extend(struct pcpu_chunk *chunk) |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 350 | { |
| 351 | int new_alloc; |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 352 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 353 | if (chunk->map_alloc >= chunk->map_used + 2) |
| 354 | return 0; |
| 355 | |
| 356 | new_alloc = PCPU_DFL_MAP_ALLOC; |
| 357 | while (new_alloc < chunk->map_used + 2) |
| 358 | new_alloc *= 2; |
| 359 | |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 360 | return new_alloc; |
| 361 | } |
| 362 | |
| 363 | /** |
| 364 | * pcpu_extend_area_map - extend area map of a chunk |
| 365 | * @chunk: chunk of interest |
| 366 | * @new_alloc: new target allocation length of the area map |
| 367 | * |
| 368 | * Extend area map of @chunk to have @new_alloc entries. |
| 369 | * |
| 370 | * CONTEXT: |
| 371 | * Does GFP_KERNEL allocation. Grabs and releases pcpu_lock. |
| 372 | * |
| 373 | * RETURNS: |
| 374 | * 0 on success, -errno on failure. |
| 375 | */ |
| 376 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk, int new_alloc) |
| 377 | { |
| 378 | int *old = NULL, *new = NULL; |
| 379 | size_t old_size = 0, new_size = new_alloc * sizeof(new[0]); |
| 380 | unsigned long flags; |
| 381 | |
| 382 | new = pcpu_mem_alloc(new_size); |
| 383 | if (!new) |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 384 | return -ENOMEM; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 385 | |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 386 | /* acquire pcpu_lock and switch to new area map */ |
| 387 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 388 | |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 389 | if (new_alloc <= chunk->map_alloc) |
| 390 | goto out_unlock; |
| 391 | |
| 392 | old_size = chunk->map_alloc * sizeof(chunk->map[0]); |
| 393 | memcpy(new, chunk->map, old_size); |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 394 | |
| 395 | /* |
| 396 | * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is |
| 397 | * one of the first chunks and still using static map. |
| 398 | */ |
| 399 | if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC) |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 400 | old = chunk->map; |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 401 | |
| 402 | chunk->map_alloc = new_alloc; |
| 403 | chunk->map = new; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 404 | new = NULL; |
| 405 | |
| 406 | out_unlock: |
| 407 | spin_unlock_irqrestore(&pcpu_lock, flags); |
| 408 | |
| 409 | /* |
| 410 | * pcpu_mem_free() might end up calling vfree() which uses |
| 411 | * IRQ-unsafe lock and thus can't be called under pcpu_lock. |
| 412 | */ |
| 413 | pcpu_mem_free(old, old_size); |
| 414 | pcpu_mem_free(new, new_size); |
| 415 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 416 | return 0; |
| 417 | } |
| 418 | |
| 419 | /** |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 420 | * pcpu_split_block - split a map block |
| 421 | * @chunk: chunk of interest |
| 422 | * @i: index of map block to split |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 423 | * @head: head size in bytes (can be 0) |
| 424 | * @tail: tail size in bytes (can be 0) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 425 | * |
| 426 | * Split the @i'th map block into two or three blocks. If @head is |
| 427 | * non-zero, @head bytes block is inserted before block @i moving it |
| 428 | * to @i+1 and reducing its size by @head bytes. |
| 429 | * |
| 430 | * If @tail is non-zero, the target block, which can be @i or @i+1 |
| 431 | * depending on @head, is reduced by @tail bytes and @tail byte block |
| 432 | * is inserted after the target block. |
| 433 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 434 | * @chunk->map must have enough free slots to accomodate the split. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 435 | * |
| 436 | * CONTEXT: |
| 437 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 438 | */ |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 439 | static void pcpu_split_block(struct pcpu_chunk *chunk, int i, |
| 440 | int head, int tail) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 441 | { |
| 442 | int nr_extra = !!head + !!tail; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 443 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 444 | BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 445 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 446 | /* insert new subblocks */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 447 | memmove(&chunk->map[i + nr_extra], &chunk->map[i], |
| 448 | sizeof(chunk->map[0]) * (chunk->map_used - i)); |
| 449 | chunk->map_used += nr_extra; |
| 450 | |
| 451 | if (head) { |
| 452 | chunk->map[i + 1] = chunk->map[i] - head; |
| 453 | chunk->map[i++] = head; |
| 454 | } |
| 455 | if (tail) { |
| 456 | chunk->map[i++] -= tail; |
| 457 | chunk->map[i] = tail; |
| 458 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 459 | } |
| 460 | |
| 461 | /** |
| 462 | * pcpu_alloc_area - allocate area from a pcpu_chunk |
| 463 | * @chunk: chunk of interest |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 464 | * @size: wanted size in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 465 | * @align: wanted align |
| 466 | * |
| 467 | * Try to allocate @size bytes area aligned at @align from @chunk. |
| 468 | * Note that this function only allocates the offset. It doesn't |
| 469 | * populate or map the area. |
| 470 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 471 | * @chunk->map must have at least two free slots. |
| 472 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 473 | * CONTEXT: |
| 474 | * pcpu_lock. |
| 475 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 476 | * RETURNS: |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 477 | * Allocated offset in @chunk on success, -1 if no matching area is |
| 478 | * found. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 479 | */ |
| 480 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) |
| 481 | { |
| 482 | int oslot = pcpu_chunk_slot(chunk); |
| 483 | int max_contig = 0; |
| 484 | int i, off; |
| 485 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 486 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { |
| 487 | bool is_last = i + 1 == chunk->map_used; |
| 488 | int head, tail; |
| 489 | |
| 490 | /* extra for alignment requirement */ |
| 491 | head = ALIGN(off, align) - off; |
| 492 | BUG_ON(i == 0 && head != 0); |
| 493 | |
| 494 | if (chunk->map[i] < 0) |
| 495 | continue; |
| 496 | if (chunk->map[i] < head + size) { |
| 497 | max_contig = max(chunk->map[i], max_contig); |
| 498 | continue; |
| 499 | } |
| 500 | |
| 501 | /* |
| 502 | * If head is small or the previous block is free, |
| 503 | * merge'em. Note that 'small' is defined as smaller |
| 504 | * than sizeof(int), which is very small but isn't too |
| 505 | * uncommon for percpu allocations. |
| 506 | */ |
| 507 | if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { |
| 508 | if (chunk->map[i - 1] > 0) |
| 509 | chunk->map[i - 1] += head; |
| 510 | else { |
| 511 | chunk->map[i - 1] -= head; |
| 512 | chunk->free_size -= head; |
| 513 | } |
| 514 | chunk->map[i] -= head; |
| 515 | off += head; |
| 516 | head = 0; |
| 517 | } |
| 518 | |
| 519 | /* if tail is small, just keep it around */ |
| 520 | tail = chunk->map[i] - head - size; |
| 521 | if (tail < sizeof(int)) |
| 522 | tail = 0; |
| 523 | |
| 524 | /* split if warranted */ |
| 525 | if (head || tail) { |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 526 | pcpu_split_block(chunk, i, head, tail); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 527 | if (head) { |
| 528 | i++; |
| 529 | off += head; |
| 530 | max_contig = max(chunk->map[i - 1], max_contig); |
| 531 | } |
| 532 | if (tail) |
| 533 | max_contig = max(chunk->map[i + 1], max_contig); |
| 534 | } |
| 535 | |
| 536 | /* update hint and mark allocated */ |
| 537 | if (is_last) |
| 538 | chunk->contig_hint = max_contig; /* fully scanned */ |
| 539 | else |
| 540 | chunk->contig_hint = max(chunk->contig_hint, |
| 541 | max_contig); |
| 542 | |
| 543 | chunk->free_size -= chunk->map[i]; |
| 544 | chunk->map[i] = -chunk->map[i]; |
| 545 | |
| 546 | pcpu_chunk_relocate(chunk, oslot); |
| 547 | return off; |
| 548 | } |
| 549 | |
| 550 | chunk->contig_hint = max_contig; /* fully scanned */ |
| 551 | pcpu_chunk_relocate(chunk, oslot); |
| 552 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 553 | /* tell the upper layer that this chunk has no matching area */ |
| 554 | return -1; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 555 | } |
| 556 | |
| 557 | /** |
| 558 | * pcpu_free_area - free area to a pcpu_chunk |
| 559 | * @chunk: chunk of interest |
| 560 | * @freeme: offset of area to free |
| 561 | * |
| 562 | * Free area starting from @freeme to @chunk. Note that this function |
| 563 | * only modifies the allocation map. It doesn't depopulate or unmap |
| 564 | * the area. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 565 | * |
| 566 | * CONTEXT: |
| 567 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 568 | */ |
| 569 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) |
| 570 | { |
| 571 | int oslot = pcpu_chunk_slot(chunk); |
| 572 | int i, off; |
| 573 | |
| 574 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) |
| 575 | if (off == freeme) |
| 576 | break; |
| 577 | BUG_ON(off != freeme); |
| 578 | BUG_ON(chunk->map[i] > 0); |
| 579 | |
| 580 | chunk->map[i] = -chunk->map[i]; |
| 581 | chunk->free_size += chunk->map[i]; |
| 582 | |
| 583 | /* merge with previous? */ |
| 584 | if (i > 0 && chunk->map[i - 1] >= 0) { |
| 585 | chunk->map[i - 1] += chunk->map[i]; |
| 586 | chunk->map_used--; |
| 587 | memmove(&chunk->map[i], &chunk->map[i + 1], |
| 588 | (chunk->map_used - i) * sizeof(chunk->map[0])); |
| 589 | i--; |
| 590 | } |
| 591 | /* merge with next? */ |
| 592 | if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { |
| 593 | chunk->map[i] += chunk->map[i + 1]; |
| 594 | chunk->map_used--; |
| 595 | memmove(&chunk->map[i + 1], &chunk->map[i + 2], |
| 596 | (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); |
| 597 | } |
| 598 | |
| 599 | chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); |
| 600 | pcpu_chunk_relocate(chunk, oslot); |
| 601 | } |
| 602 | |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 603 | static struct pcpu_chunk *pcpu_alloc_chunk(void) |
| 604 | { |
| 605 | struct pcpu_chunk *chunk; |
| 606 | |
| 607 | chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL); |
| 608 | if (!chunk) |
| 609 | return NULL; |
| 610 | |
| 611 | chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); |
| 612 | if (!chunk->map) { |
| 613 | kfree(chunk); |
| 614 | return NULL; |
| 615 | } |
| 616 | |
| 617 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; |
| 618 | chunk->map[chunk->map_used++] = pcpu_unit_size; |
| 619 | |
| 620 | INIT_LIST_HEAD(&chunk->list); |
| 621 | chunk->free_size = pcpu_unit_size; |
| 622 | chunk->contig_hint = pcpu_unit_size; |
| 623 | |
| 624 | return chunk; |
| 625 | } |
| 626 | |
| 627 | static void pcpu_free_chunk(struct pcpu_chunk *chunk) |
| 628 | { |
| 629 | if (!chunk) |
| 630 | return; |
| 631 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); |
| 632 | kfree(chunk); |
| 633 | } |
| 634 | |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 635 | /* |
| 636 | * Chunk management implementation. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 637 | * |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 638 | * To allow different implementations, chunk alloc/free and |
| 639 | * [de]population are implemented in a separate file which is pulled |
| 640 | * into this file and compiled together. The following functions |
| 641 | * should be implemented. |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 642 | * |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 643 | * pcpu_populate_chunk - populate the specified range of a chunk |
| 644 | * pcpu_depopulate_chunk - depopulate the specified range of a chunk |
| 645 | * pcpu_create_chunk - create a new chunk |
| 646 | * pcpu_destroy_chunk - destroy a chunk, always preceded by full depop |
| 647 | * pcpu_addr_to_page - translate address to physical address |
| 648 | * pcpu_verify_alloc_info - check alloc_info is acceptable during init |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 649 | */ |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 650 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size); |
| 651 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size); |
| 652 | static struct pcpu_chunk *pcpu_create_chunk(void); |
| 653 | static void pcpu_destroy_chunk(struct pcpu_chunk *chunk); |
| 654 | static struct page *pcpu_addr_to_page(void *addr); |
| 655 | static int __init pcpu_verify_alloc_info(const struct pcpu_alloc_info *ai); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 656 | |
Tejun Heo | b0c9778 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 657 | #ifdef CONFIG_NEED_PER_CPU_KM |
| 658 | #include "percpu-km.c" |
| 659 | #else |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 660 | #include "percpu-vm.c" |
Tejun Heo | b0c9778 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 661 | #endif |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 662 | |
| 663 | /** |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 664 | * pcpu_chunk_addr_search - determine chunk containing specified address |
| 665 | * @addr: address for which the chunk needs to be determined. |
| 666 | * |
| 667 | * RETURNS: |
| 668 | * The address of the found chunk. |
| 669 | */ |
| 670 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) |
| 671 | { |
| 672 | /* is it in the first chunk? */ |
| 673 | if (pcpu_addr_in_first_chunk(addr)) { |
| 674 | /* is it in the reserved area? */ |
| 675 | if (pcpu_addr_in_reserved_chunk(addr)) |
| 676 | return pcpu_reserved_chunk; |
| 677 | return pcpu_first_chunk; |
| 678 | } |
| 679 | |
| 680 | /* |
| 681 | * The address is relative to unit0 which might be unused and |
| 682 | * thus unmapped. Offset the address to the unit space of the |
| 683 | * current processor before looking it up in the vmalloc |
| 684 | * space. Note that any possible cpu id can be used here, so |
| 685 | * there's no need to worry about preemption or cpu hotplug. |
| 686 | */ |
| 687 | addr += pcpu_unit_offsets[raw_smp_processor_id()]; |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 688 | return pcpu_get_page_chunk(pcpu_addr_to_page(addr)); |
Tejun Heo | 88999a8 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 689 | } |
| 690 | |
| 691 | /** |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 692 | * pcpu_alloc - the percpu allocator |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 693 | * @size: size of area to allocate in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 694 | * @align: alignment of area (max PAGE_SIZE) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 695 | * @reserved: allocate from the reserved chunk if available |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 696 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 697 | * Allocate percpu area of @size bytes aligned at @align. |
| 698 | * |
| 699 | * CONTEXT: |
| 700 | * Does GFP_KERNEL allocation. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 701 | * |
| 702 | * RETURNS: |
| 703 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 704 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 705 | static void __percpu *pcpu_alloc(size_t size, size_t align, bool reserved) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 706 | { |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 707 | static int warn_limit = 10; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 708 | struct pcpu_chunk *chunk; |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 709 | const char *err; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 710 | int slot, off, new_alloc; |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 711 | unsigned long flags; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 712 | |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 713 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 714 | WARN(true, "illegal size (%zu) or align (%zu) for " |
| 715 | "percpu allocation\n", size, align); |
| 716 | return NULL; |
| 717 | } |
| 718 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 719 | mutex_lock(&pcpu_alloc_mutex); |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 720 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 721 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 722 | /* serve reserved allocations from the reserved chunk if available */ |
| 723 | if (reserved && pcpu_reserved_chunk) { |
| 724 | chunk = pcpu_reserved_chunk; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 725 | |
| 726 | if (size > chunk->contig_hint) { |
| 727 | err = "alloc from reserved chunk failed"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 728 | goto fail_unlock; |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 729 | } |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 730 | |
| 731 | while ((new_alloc = pcpu_need_to_extend(chunk))) { |
| 732 | spin_unlock_irqrestore(&pcpu_lock, flags); |
| 733 | if (pcpu_extend_area_map(chunk, new_alloc) < 0) { |
| 734 | err = "failed to extend area map of reserved chunk"; |
| 735 | goto fail_unlock_mutex; |
| 736 | } |
| 737 | spin_lock_irqsave(&pcpu_lock, flags); |
| 738 | } |
| 739 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 740 | off = pcpu_alloc_area(chunk, size, align); |
| 741 | if (off >= 0) |
| 742 | goto area_found; |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 743 | |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 744 | err = "alloc from reserved chunk failed"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 745 | goto fail_unlock; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 746 | } |
| 747 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 748 | restart: |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 749 | /* search through normal chunks */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 750 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
| 751 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { |
| 752 | if (size > chunk->contig_hint) |
| 753 | continue; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 754 | |
Tejun Heo | 833af84 | 2009-11-11 15:35:18 +0900 | [diff] [blame] | 755 | new_alloc = pcpu_need_to_extend(chunk); |
| 756 | if (new_alloc) { |
| 757 | spin_unlock_irqrestore(&pcpu_lock, flags); |
| 758 | if (pcpu_extend_area_map(chunk, |
| 759 | new_alloc) < 0) { |
| 760 | err = "failed to extend area map"; |
| 761 | goto fail_unlock_mutex; |
| 762 | } |
| 763 | spin_lock_irqsave(&pcpu_lock, flags); |
| 764 | /* |
| 765 | * pcpu_lock has been dropped, need to |
| 766 | * restart cpu_slot list walking. |
| 767 | */ |
| 768 | goto restart; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 769 | } |
| 770 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 771 | off = pcpu_alloc_area(chunk, size, align); |
| 772 | if (off >= 0) |
| 773 | goto area_found; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 774 | } |
| 775 | } |
| 776 | |
| 777 | /* hmmm... no space left, create a new chunk */ |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 778 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 779 | |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 780 | chunk = pcpu_create_chunk(); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 781 | if (!chunk) { |
| 782 | err = "failed to allocate new chunk"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 783 | goto fail_unlock_mutex; |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 784 | } |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 785 | |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 786 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 787 | pcpu_chunk_relocate(chunk, -1); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 788 | goto restart; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 789 | |
| 790 | area_found: |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 791 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 792 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 793 | /* populate, map and clear the area */ |
| 794 | if (pcpu_populate_chunk(chunk, off, size)) { |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 795 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 796 | pcpu_free_area(chunk, off); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 797 | err = "failed to populate"; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 798 | goto fail_unlock; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 799 | } |
| 800 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 801 | mutex_unlock(&pcpu_alloc_mutex); |
| 802 | |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 803 | /* return address relative to base address */ |
| 804 | return __addr_to_pcpu_ptr(chunk->base_addr + off); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 805 | |
| 806 | fail_unlock: |
Jiri Kosina | 403a91b | 2009-10-29 00:25:59 +0900 | [diff] [blame] | 807 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 808 | fail_unlock_mutex: |
| 809 | mutex_unlock(&pcpu_alloc_mutex); |
Tejun Heo | f2badb0 | 2009-09-29 09:17:58 +0900 | [diff] [blame] | 810 | if (warn_limit) { |
| 811 | pr_warning("PERCPU: allocation failed, size=%zu align=%zu, " |
| 812 | "%s\n", size, align, err); |
| 813 | dump_stack(); |
| 814 | if (!--warn_limit) |
| 815 | pr_info("PERCPU: limit reached, disable warning\n"); |
| 816 | } |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 817 | return NULL; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 818 | } |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 819 | |
| 820 | /** |
| 821 | * __alloc_percpu - allocate dynamic percpu area |
| 822 | * @size: size of area to allocate in bytes |
| 823 | * @align: alignment of area (max PAGE_SIZE) |
| 824 | * |
| 825 | * Allocate percpu area of @size bytes aligned at @align. Might |
| 826 | * sleep. Might trigger writeouts. |
| 827 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 828 | * CONTEXT: |
| 829 | * Does GFP_KERNEL allocation. |
| 830 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 831 | * RETURNS: |
| 832 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 833 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 834 | void __percpu *__alloc_percpu(size_t size, size_t align) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 835 | { |
| 836 | return pcpu_alloc(size, align, false); |
| 837 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 838 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
| 839 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 840 | /** |
| 841 | * __alloc_reserved_percpu - allocate reserved percpu area |
| 842 | * @size: size of area to allocate in bytes |
| 843 | * @align: alignment of area (max PAGE_SIZE) |
| 844 | * |
| 845 | * Allocate percpu area of @size bytes aligned at @align from reserved |
| 846 | * percpu area if arch has set it up; otherwise, allocation is served |
| 847 | * from the same dynamic area. Might sleep. Might trigger writeouts. |
| 848 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 849 | * CONTEXT: |
| 850 | * Does GFP_KERNEL allocation. |
| 851 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 852 | * RETURNS: |
| 853 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 854 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 855 | void __percpu *__alloc_reserved_percpu(size_t size, size_t align) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 856 | { |
| 857 | return pcpu_alloc(size, align, true); |
| 858 | } |
| 859 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 860 | /** |
| 861 | * pcpu_reclaim - reclaim fully free chunks, workqueue function |
| 862 | * @work: unused |
| 863 | * |
| 864 | * Reclaim all fully free chunks except for the first one. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 865 | * |
| 866 | * CONTEXT: |
| 867 | * workqueue context. |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 868 | */ |
| 869 | static void pcpu_reclaim(struct work_struct *work) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 870 | { |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 871 | LIST_HEAD(todo); |
| 872 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; |
| 873 | struct pcpu_chunk *chunk, *next; |
| 874 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 875 | mutex_lock(&pcpu_alloc_mutex); |
| 876 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 877 | |
| 878 | list_for_each_entry_safe(chunk, next, head, list) { |
| 879 | WARN_ON(chunk->immutable); |
| 880 | |
| 881 | /* spare the first one */ |
| 882 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) |
| 883 | continue; |
| 884 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 885 | list_move(&chunk->list, &todo); |
| 886 | } |
| 887 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 888 | spin_unlock_irq(&pcpu_lock); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 889 | |
| 890 | list_for_each_entry_safe(chunk, next, &todo, list) { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 891 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); |
Tejun Heo | 6081089 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 892 | pcpu_destroy_chunk(chunk); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 893 | } |
Tejun Heo | 971f391 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 894 | |
| 895 | mutex_unlock(&pcpu_alloc_mutex); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 896 | } |
| 897 | |
| 898 | /** |
| 899 | * free_percpu - free percpu area |
| 900 | * @ptr: pointer to area to free |
| 901 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 902 | * Free percpu area @ptr. |
| 903 | * |
| 904 | * CONTEXT: |
| 905 | * Can be called from atomic context. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 906 | */ |
Tejun Heo | 43cf38e | 2010-02-02 14:38:57 +0900 | [diff] [blame] | 907 | void free_percpu(void __percpu *ptr) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 908 | { |
Andrew Morton | 129182e | 2010-01-08 14:42:39 -0800 | [diff] [blame] | 909 | void *addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 910 | struct pcpu_chunk *chunk; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 911 | unsigned long flags; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 912 | int off; |
| 913 | |
| 914 | if (!ptr) |
| 915 | return; |
| 916 | |
Andrew Morton | 129182e | 2010-01-08 14:42:39 -0800 | [diff] [blame] | 917 | addr = __pcpu_ptr_to_addr(ptr); |
| 918 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 919 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 920 | |
| 921 | chunk = pcpu_chunk_addr_search(addr); |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 922 | off = addr - chunk->base_addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 923 | |
| 924 | pcpu_free_area(chunk, off); |
| 925 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 926 | /* if there are more than one fully free chunks, wake up grim reaper */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 927 | if (chunk->free_size == pcpu_unit_size) { |
| 928 | struct pcpu_chunk *pos; |
| 929 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 930 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 931 | if (pos != chunk) { |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 932 | schedule_work(&pcpu_reclaim_work); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 933 | break; |
| 934 | } |
| 935 | } |
| 936 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 937 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 938 | } |
| 939 | EXPORT_SYMBOL_GPL(free_percpu); |
| 940 | |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 941 | /** |
Tejun Heo | 10fad5e | 2010-03-10 18:57:54 +0900 | [diff] [blame] | 942 | * is_kernel_percpu_address - test whether address is from static percpu area |
| 943 | * @addr: address to test |
| 944 | * |
| 945 | * Test whether @addr belongs to in-kernel static percpu area. Module |
| 946 | * static percpu areas are not considered. For those, use |
| 947 | * is_module_percpu_address(). |
| 948 | * |
| 949 | * RETURNS: |
| 950 | * %true if @addr is from in-kernel static percpu area, %false otherwise. |
| 951 | */ |
| 952 | bool is_kernel_percpu_address(unsigned long addr) |
| 953 | { |
| 954 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
| 955 | void __percpu *base = __addr_to_pcpu_ptr(pcpu_base_addr); |
| 956 | unsigned int cpu; |
| 957 | |
| 958 | for_each_possible_cpu(cpu) { |
| 959 | void *start = per_cpu_ptr(base, cpu); |
| 960 | |
| 961 | if ((void *)addr >= start && (void *)addr < start + static_size) |
| 962 | return true; |
| 963 | } |
| 964 | return false; |
| 965 | } |
| 966 | |
| 967 | /** |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 968 | * per_cpu_ptr_to_phys - convert translated percpu address to physical address |
| 969 | * @addr: the address to be converted to physical address |
| 970 | * |
| 971 | * Given @addr which is dereferenceable address obtained via one of |
| 972 | * percpu access macros, this function translates it into its physical |
| 973 | * address. The caller is responsible for ensuring @addr stays valid |
| 974 | * until this function finishes. |
| 975 | * |
| 976 | * RETURNS: |
| 977 | * The physical address for @addr. |
| 978 | */ |
| 979 | phys_addr_t per_cpu_ptr_to_phys(void *addr) |
| 980 | { |
Tejun Heo | 020ec65 | 2010-04-09 18:57:00 +0900 | [diff] [blame] | 981 | if (pcpu_addr_in_first_chunk(addr)) { |
| 982 | if ((unsigned long)addr < VMALLOC_START || |
| 983 | (unsigned long)addr >= VMALLOC_END) |
| 984 | return __pa(addr); |
| 985 | else |
| 986 | return page_to_phys(vmalloc_to_page(addr)); |
| 987 | } else |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 988 | return page_to_phys(pcpu_addr_to_page(addr)); |
Vivek Goyal | 3b034b0 | 2009-11-24 15:50:03 +0900 | [diff] [blame] | 989 | } |
| 990 | |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 991 | static inline size_t pcpu_calc_fc_sizes(size_t static_size, |
| 992 | size_t reserved_size, |
| 993 | ssize_t *dyn_sizep) |
| 994 | { |
| 995 | size_t size_sum; |
| 996 | |
| 997 | size_sum = PFN_ALIGN(static_size + reserved_size + |
| 998 | (*dyn_sizep >= 0 ? *dyn_sizep : 0)); |
| 999 | if (*dyn_sizep != 0) |
| 1000 | *dyn_sizep = size_sum - static_size - reserved_size; |
| 1001 | |
| 1002 | return size_sum; |
| 1003 | } |
| 1004 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1005 | /** |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1006 | * pcpu_alloc_alloc_info - allocate percpu allocation info |
| 1007 | * @nr_groups: the number of groups |
| 1008 | * @nr_units: the number of units |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1009 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1010 | * Allocate ai which is large enough for @nr_groups groups containing |
| 1011 | * @nr_units units. The returned ai's groups[0].cpu_map points to the |
| 1012 | * cpu_map array which is long enough for @nr_units and filled with |
| 1013 | * NR_CPUS. It's the caller's responsibility to initialize cpu_map |
| 1014 | * pointer of other groups. |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1015 | * |
| 1016 | * RETURNS: |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1017 | * Pointer to the allocated pcpu_alloc_info on success, NULL on |
| 1018 | * failure. |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1019 | */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1020 | struct pcpu_alloc_info * __init pcpu_alloc_alloc_info(int nr_groups, |
| 1021 | int nr_units) |
| 1022 | { |
| 1023 | struct pcpu_alloc_info *ai; |
| 1024 | size_t base_size, ai_size; |
| 1025 | void *ptr; |
| 1026 | int unit; |
| 1027 | |
| 1028 | base_size = ALIGN(sizeof(*ai) + nr_groups * sizeof(ai->groups[0]), |
| 1029 | __alignof__(ai->groups[0].cpu_map[0])); |
| 1030 | ai_size = base_size + nr_units * sizeof(ai->groups[0].cpu_map[0]); |
| 1031 | |
| 1032 | ptr = alloc_bootmem_nopanic(PFN_ALIGN(ai_size)); |
| 1033 | if (!ptr) |
| 1034 | return NULL; |
| 1035 | ai = ptr; |
| 1036 | ptr += base_size; |
| 1037 | |
| 1038 | ai->groups[0].cpu_map = ptr; |
| 1039 | |
| 1040 | for (unit = 0; unit < nr_units; unit++) |
| 1041 | ai->groups[0].cpu_map[unit] = NR_CPUS; |
| 1042 | |
| 1043 | ai->nr_groups = nr_groups; |
| 1044 | ai->__ai_size = PFN_ALIGN(ai_size); |
| 1045 | |
| 1046 | return ai; |
| 1047 | } |
| 1048 | |
| 1049 | /** |
| 1050 | * pcpu_free_alloc_info - free percpu allocation info |
| 1051 | * @ai: pcpu_alloc_info to free |
| 1052 | * |
| 1053 | * Free @ai which was allocated by pcpu_alloc_alloc_info(). |
| 1054 | */ |
| 1055 | void __init pcpu_free_alloc_info(struct pcpu_alloc_info *ai) |
| 1056 | { |
| 1057 | free_bootmem(__pa(ai), ai->__ai_size); |
| 1058 | } |
| 1059 | |
| 1060 | /** |
| 1061 | * pcpu_build_alloc_info - build alloc_info considering distances between CPUs |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1062 | * @reserved_size: the size of reserved percpu area in bytes |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1063 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1064 | * @atom_size: allocation atom size |
| 1065 | * @cpu_distance_fn: callback to determine distance between cpus, optional |
| 1066 | * |
| 1067 | * This function determines grouping of units, their mappings to cpus |
| 1068 | * and other parameters considering needed percpu size, allocation |
| 1069 | * atom size and distances between CPUs. |
| 1070 | * |
| 1071 | * Groups are always mutliples of atom size and CPUs which are of |
| 1072 | * LOCAL_DISTANCE both ways are grouped together and share space for |
| 1073 | * units in the same group. The returned configuration is guaranteed |
| 1074 | * to have CPUs on different nodes on different groups and >=75% usage |
| 1075 | * of allocated virtual address space. |
| 1076 | * |
| 1077 | * RETURNS: |
| 1078 | * On success, pointer to the new allocation_info is returned. On |
| 1079 | * failure, ERR_PTR value is returned. |
| 1080 | */ |
| 1081 | struct pcpu_alloc_info * __init pcpu_build_alloc_info( |
| 1082 | size_t reserved_size, ssize_t dyn_size, |
| 1083 | size_t atom_size, |
| 1084 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn) |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1085 | { |
| 1086 | static int group_map[NR_CPUS] __initdata; |
| 1087 | static int group_cnt[NR_CPUS] __initdata; |
| 1088 | const size_t static_size = __per_cpu_end - __per_cpu_start; |
Pavel V. Panteleev | a92d3ff | 2010-06-17 10:07:25 +0200 | [diff] [blame^] | 1089 | int nr_groups = 1, nr_units = 0; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1090 | size_t size_sum, min_unit_size, alloc_size; |
| 1091 | int upa, max_upa, uninitialized_var(best_upa); /* units_per_alloc */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1092 | int last_allocs, group, unit; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1093 | unsigned int cpu, tcpu; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1094 | struct pcpu_alloc_info *ai; |
| 1095 | unsigned int *cpu_map; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1096 | |
Tejun Heo | fb59e72 | 2009-09-24 18:50:34 +0900 | [diff] [blame] | 1097 | /* this function may be called multiple times */ |
| 1098 | memset(group_map, 0, sizeof(group_map)); |
Pavel V. Panteleev | a92d3ff | 2010-06-17 10:07:25 +0200 | [diff] [blame^] | 1099 | memset(group_cnt, 0, sizeof(group_cnt)); |
Tejun Heo | fb59e72 | 2009-09-24 18:50:34 +0900 | [diff] [blame] | 1100 | |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1101 | /* |
| 1102 | * Determine min_unit_size, alloc_size and max_upa such that |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1103 | * alloc_size is multiple of atom_size and is the smallest |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1104 | * which can accomodate 4k aligned segments which are equal to |
| 1105 | * or larger than min_unit_size. |
| 1106 | */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1107 | size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1108 | min_unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); |
| 1109 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1110 | alloc_size = roundup(min_unit_size, atom_size); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1111 | upa = alloc_size / min_unit_size; |
| 1112 | while (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) |
| 1113 | upa--; |
| 1114 | max_upa = upa; |
| 1115 | |
| 1116 | /* group cpus according to their proximity */ |
| 1117 | for_each_possible_cpu(cpu) { |
| 1118 | group = 0; |
| 1119 | next_group: |
| 1120 | for_each_possible_cpu(tcpu) { |
| 1121 | if (cpu == tcpu) |
| 1122 | break; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1123 | if (group_map[tcpu] == group && cpu_distance_fn && |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1124 | (cpu_distance_fn(cpu, tcpu) > LOCAL_DISTANCE || |
| 1125 | cpu_distance_fn(tcpu, cpu) > LOCAL_DISTANCE)) { |
| 1126 | group++; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1127 | nr_groups = max(nr_groups, group + 1); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1128 | goto next_group; |
| 1129 | } |
| 1130 | } |
| 1131 | group_map[cpu] = group; |
| 1132 | group_cnt[group]++; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1133 | } |
| 1134 | |
| 1135 | /* |
| 1136 | * Expand unit size until address space usage goes over 75% |
| 1137 | * and then as much as possible without using more address |
| 1138 | * space. |
| 1139 | */ |
| 1140 | last_allocs = INT_MAX; |
| 1141 | for (upa = max_upa; upa; upa--) { |
| 1142 | int allocs = 0, wasted = 0; |
| 1143 | |
| 1144 | if (alloc_size % upa || ((alloc_size / upa) & ~PAGE_MASK)) |
| 1145 | continue; |
| 1146 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1147 | for (group = 0; group < nr_groups; group++) { |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1148 | int this_allocs = DIV_ROUND_UP(group_cnt[group], upa); |
| 1149 | allocs += this_allocs; |
| 1150 | wasted += this_allocs * upa - group_cnt[group]; |
| 1151 | } |
| 1152 | |
| 1153 | /* |
| 1154 | * Don't accept if wastage is over 25%. The |
| 1155 | * greater-than comparison ensures upa==1 always |
| 1156 | * passes the following check. |
| 1157 | */ |
| 1158 | if (wasted > num_possible_cpus() / 3) |
| 1159 | continue; |
| 1160 | |
| 1161 | /* and then don't consume more memory */ |
| 1162 | if (allocs > last_allocs) |
| 1163 | break; |
| 1164 | last_allocs = allocs; |
| 1165 | best_upa = upa; |
| 1166 | } |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1167 | upa = best_upa; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1168 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1169 | /* allocate and fill alloc_info */ |
| 1170 | for (group = 0; group < nr_groups; group++) |
| 1171 | nr_units += roundup(group_cnt[group], upa); |
| 1172 | |
| 1173 | ai = pcpu_alloc_alloc_info(nr_groups, nr_units); |
| 1174 | if (!ai) |
| 1175 | return ERR_PTR(-ENOMEM); |
| 1176 | cpu_map = ai->groups[0].cpu_map; |
| 1177 | |
| 1178 | for (group = 0; group < nr_groups; group++) { |
| 1179 | ai->groups[group].cpu_map = cpu_map; |
| 1180 | cpu_map += roundup(group_cnt[group], upa); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1181 | } |
| 1182 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1183 | ai->static_size = static_size; |
| 1184 | ai->reserved_size = reserved_size; |
| 1185 | ai->dyn_size = dyn_size; |
| 1186 | ai->unit_size = alloc_size / upa; |
| 1187 | ai->atom_size = atom_size; |
| 1188 | ai->alloc_size = alloc_size; |
| 1189 | |
| 1190 | for (group = 0, unit = 0; group_cnt[group]; group++) { |
| 1191 | struct pcpu_group_info *gi = &ai->groups[group]; |
| 1192 | |
| 1193 | /* |
| 1194 | * Initialize base_offset as if all groups are located |
| 1195 | * back-to-back. The caller should update this to |
| 1196 | * reflect actual allocation. |
| 1197 | */ |
| 1198 | gi->base_offset = unit * ai->unit_size; |
| 1199 | |
| 1200 | for_each_possible_cpu(cpu) |
| 1201 | if (group_map[cpu] == group) |
| 1202 | gi->cpu_map[gi->nr_units++] = cpu; |
| 1203 | gi->nr_units = roundup(gi->nr_units, upa); |
| 1204 | unit += gi->nr_units; |
| 1205 | } |
| 1206 | BUG_ON(unit != nr_units); |
| 1207 | |
| 1208 | return ai; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1209 | } |
| 1210 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1211 | /** |
| 1212 | * pcpu_dump_alloc_info - print out information about pcpu_alloc_info |
| 1213 | * @lvl: loglevel |
| 1214 | * @ai: allocation info to dump |
| 1215 | * |
| 1216 | * Print out information about @ai using loglevel @lvl. |
| 1217 | */ |
| 1218 | static void pcpu_dump_alloc_info(const char *lvl, |
| 1219 | const struct pcpu_alloc_info *ai) |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1220 | { |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1221 | int group_width = 1, cpu_width = 1, width; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1222 | char empty_str[] = "--------"; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1223 | int alloc = 0, alloc_end = 0; |
| 1224 | int group, v; |
| 1225 | int upa, apl; /* units per alloc, allocs per line */ |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1226 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1227 | v = ai->nr_groups; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1228 | while (v /= 10) |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1229 | group_width++; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1230 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1231 | v = num_possible_cpus(); |
| 1232 | while (v /= 10) |
| 1233 | cpu_width++; |
| 1234 | empty_str[min_t(int, cpu_width, sizeof(empty_str) - 1)] = '\0'; |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1235 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1236 | upa = ai->alloc_size / ai->unit_size; |
| 1237 | width = upa * (cpu_width + 1) + group_width + 3; |
| 1238 | apl = rounddown_pow_of_two(max(60 / width, 1)); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1239 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1240 | printk("%spcpu-alloc: s%zu r%zu d%zu u%zu alloc=%zu*%zu", |
| 1241 | lvl, ai->static_size, ai->reserved_size, ai->dyn_size, |
| 1242 | ai->unit_size, ai->alloc_size / ai->atom_size, ai->atom_size); |
| 1243 | |
| 1244 | for (group = 0; group < ai->nr_groups; group++) { |
| 1245 | const struct pcpu_group_info *gi = &ai->groups[group]; |
| 1246 | int unit = 0, unit_end = 0; |
| 1247 | |
| 1248 | BUG_ON(gi->nr_units % upa); |
| 1249 | for (alloc_end += gi->nr_units / upa; |
| 1250 | alloc < alloc_end; alloc++) { |
| 1251 | if (!(alloc % apl)) { |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1252 | printk("\n"); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1253 | printk("%spcpu-alloc: ", lvl); |
| 1254 | } |
| 1255 | printk("[%0*d] ", group_width, group); |
| 1256 | |
| 1257 | for (unit_end += upa; unit < unit_end; unit++) |
| 1258 | if (gi->cpu_map[unit] != NR_CPUS) |
| 1259 | printk("%0*d ", cpu_width, |
| 1260 | gi->cpu_map[unit]); |
| 1261 | else |
| 1262 | printk("%s ", empty_str); |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1263 | } |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1264 | } |
| 1265 | printk("\n"); |
| 1266 | } |
Tejun Heo | 033e48f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1267 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1268 | /** |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1269 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1270 | * @ai: pcpu_alloc_info describing how to percpu area is shaped |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1271 | * @base_addr: mapped address |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1272 | * |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1273 | * Initialize the first percpu chunk which contains the kernel static |
| 1274 | * perpcu area. This function is to be called from arch percpu area |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1275 | * setup path. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1276 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1277 | * @ai contains all information necessary to initialize the first |
| 1278 | * chunk and prime the dynamic percpu allocator. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1279 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1280 | * @ai->static_size is the size of static percpu area. |
| 1281 | * |
| 1282 | * @ai->reserved_size, if non-zero, specifies the amount of bytes to |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1283 | * reserve after the static area in the first chunk. This reserves |
| 1284 | * the first chunk such that it's available only through reserved |
| 1285 | * percpu allocation. This is primarily used to serve module percpu |
| 1286 | * static areas on architectures where the addressing model has |
| 1287 | * limited offset range for symbol relocations to guarantee module |
| 1288 | * percpu symbols fall inside the relocatable range. |
| 1289 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1290 | * @ai->dyn_size determines the number of bytes available for dynamic |
| 1291 | * allocation in the first chunk. The area between @ai->static_size + |
| 1292 | * @ai->reserved_size + @ai->dyn_size and @ai->unit_size is unused. |
Tejun Heo | 6074d5b | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1293 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1294 | * @ai->unit_size specifies unit size and must be aligned to PAGE_SIZE |
| 1295 | * and equal to or larger than @ai->static_size + @ai->reserved_size + |
| 1296 | * @ai->dyn_size. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1297 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1298 | * @ai->atom_size is the allocation atom size and used as alignment |
| 1299 | * for vm areas. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1300 | * |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1301 | * @ai->alloc_size is the allocation size and always multiple of |
| 1302 | * @ai->atom_size. This is larger than @ai->atom_size if |
| 1303 | * @ai->unit_size is larger than @ai->atom_size. |
| 1304 | * |
| 1305 | * @ai->nr_groups and @ai->groups describe virtual memory layout of |
| 1306 | * percpu areas. Units which should be colocated are put into the |
| 1307 | * same group. Dynamic VM areas will be allocated according to these |
| 1308 | * groupings. If @ai->nr_groups is zero, a single group containing |
| 1309 | * all units is assumed. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1310 | * |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1311 | * The caller should have mapped the first chunk at @base_addr and |
| 1312 | * copied static data to each unit. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1313 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1314 | * If the first chunk ends up with both reserved and dynamic areas, it |
| 1315 | * is served by two chunks - one to serve the core static and reserved |
| 1316 | * areas and the other for the dynamic area. They share the same vm |
| 1317 | * and page map but uses different area allocation map to stay away |
| 1318 | * from each other. The latter chunk is circulated in the chunk slots |
| 1319 | * and available for dynamic allocation like any other chunks. |
| 1320 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1321 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1322 | * 0 on success, -errno on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1323 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1324 | int __init pcpu_setup_first_chunk(const struct pcpu_alloc_info *ai, |
| 1325 | void *base_addr) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1326 | { |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 1327 | static char cpus_buf[4096] __initdata; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1328 | static int smap[2], dmap[2]; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1329 | size_t dyn_size = ai->dyn_size; |
| 1330 | size_t size_sum = ai->static_size + ai->reserved_size + dyn_size; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1331 | struct pcpu_chunk *schunk, *dchunk = NULL; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1332 | unsigned long *group_offsets; |
| 1333 | size_t *group_sizes; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1334 | unsigned long *unit_off; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1335 | unsigned int cpu; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1336 | int *unit_map; |
| 1337 | int group, unit, i; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1338 | |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 1339 | cpumask_scnprintf(cpus_buf, sizeof(cpus_buf), cpu_possible_mask); |
| 1340 | |
| 1341 | #define PCPU_SETUP_BUG_ON(cond) do { \ |
| 1342 | if (unlikely(cond)) { \ |
| 1343 | pr_emerg("PERCPU: failed to initialize, %s", #cond); \ |
| 1344 | pr_emerg("PERCPU: cpu_possible_mask=%s\n", cpus_buf); \ |
| 1345 | pcpu_dump_alloc_info(KERN_EMERG, ai); \ |
| 1346 | BUG(); \ |
| 1347 | } \ |
| 1348 | } while (0) |
| 1349 | |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1350 | /* sanity checks */ |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1351 | BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || |
| 1352 | ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 1353 | PCPU_SETUP_BUG_ON(ai->nr_groups <= 0); |
| 1354 | PCPU_SETUP_BUG_ON(!ai->static_size); |
| 1355 | PCPU_SETUP_BUG_ON(!base_addr); |
| 1356 | PCPU_SETUP_BUG_ON(ai->unit_size < size_sum); |
| 1357 | PCPU_SETUP_BUG_ON(ai->unit_size & ~PAGE_MASK); |
| 1358 | PCPU_SETUP_BUG_ON(ai->unit_size < PCPU_MIN_UNIT_SIZE); |
Tejun Heo | 9f64553 | 2010-04-09 18:57:01 +0900 | [diff] [blame] | 1359 | PCPU_SETUP_BUG_ON(pcpu_verify_alloc_info(ai) < 0); |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1360 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1361 | /* process group information and build config tables accordingly */ |
| 1362 | group_offsets = alloc_bootmem(ai->nr_groups * sizeof(group_offsets[0])); |
| 1363 | group_sizes = alloc_bootmem(ai->nr_groups * sizeof(group_sizes[0])); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1364 | unit_map = alloc_bootmem(nr_cpu_ids * sizeof(unit_map[0])); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1365 | unit_off = alloc_bootmem(nr_cpu_ids * sizeof(unit_off[0])); |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1366 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1367 | for (cpu = 0; cpu < nr_cpu_ids; cpu++) |
Tejun Heo | ffe0d5a | 2009-09-29 09:17:56 +0900 | [diff] [blame] | 1368 | unit_map[cpu] = UINT_MAX; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1369 | pcpu_first_unit_cpu = NR_CPUS; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1370 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1371 | for (group = 0, unit = 0; group < ai->nr_groups; group++, unit += i) { |
| 1372 | const struct pcpu_group_info *gi = &ai->groups[group]; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1373 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1374 | group_offsets[group] = gi->base_offset; |
| 1375 | group_sizes[group] = gi->nr_units * ai->unit_size; |
| 1376 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1377 | for (i = 0; i < gi->nr_units; i++) { |
| 1378 | cpu = gi->cpu_map[i]; |
| 1379 | if (cpu == NR_CPUS) |
| 1380 | continue; |
| 1381 | |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 1382 | PCPU_SETUP_BUG_ON(cpu > nr_cpu_ids); |
| 1383 | PCPU_SETUP_BUG_ON(!cpu_possible(cpu)); |
| 1384 | PCPU_SETUP_BUG_ON(unit_map[cpu] != UINT_MAX); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1385 | |
| 1386 | unit_map[cpu] = unit + i; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1387 | unit_off[cpu] = gi->base_offset + i * ai->unit_size; |
| 1388 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1389 | if (pcpu_first_unit_cpu == NR_CPUS) |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1390 | pcpu_first_unit_cpu = cpu; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1391 | } |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1392 | } |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1393 | pcpu_last_unit_cpu = cpu; |
| 1394 | pcpu_nr_units = unit; |
| 1395 | |
| 1396 | for_each_possible_cpu(cpu) |
Tejun Heo | 635b75f | 2009-09-24 09:43:11 +0900 | [diff] [blame] | 1397 | PCPU_SETUP_BUG_ON(unit_map[cpu] == UINT_MAX); |
| 1398 | |
| 1399 | /* we're done parsing the input, undefine BUG macro and dump config */ |
| 1400 | #undef PCPU_SETUP_BUG_ON |
| 1401 | pcpu_dump_alloc_info(KERN_INFO, ai); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1402 | |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1403 | pcpu_nr_groups = ai->nr_groups; |
| 1404 | pcpu_group_offsets = group_offsets; |
| 1405 | pcpu_group_sizes = group_sizes; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1406 | pcpu_unit_map = unit_map; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1407 | pcpu_unit_offsets = unit_off; |
Tejun Heo | 2f39e63 | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1408 | |
| 1409 | /* determine basic parameters */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1410 | pcpu_unit_pages = ai->unit_size >> PAGE_SHIFT; |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1411 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
Tejun Heo | 6563297 | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1412 | pcpu_atom_size = ai->atom_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1413 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
| 1414 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1415 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1416 | /* |
| 1417 | * Allocate chunk slots. The additional last slot is for |
| 1418 | * empty chunks. |
| 1419 | */ |
| 1420 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1421 | pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); |
| 1422 | for (i = 0; i < pcpu_nr_slots; i++) |
| 1423 | INIT_LIST_HEAD(&pcpu_slot[i]); |
| 1424 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1425 | /* |
| 1426 | * Initialize static chunk. If reserved_size is zero, the |
| 1427 | * static chunk covers static area + dynamic allocation area |
| 1428 | * in the first chunk. If reserved_size is not zero, it |
| 1429 | * covers static area + reserved area (mostly used for module |
| 1430 | * static percpu allocation). |
| 1431 | */ |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1432 | schunk = alloc_bootmem(pcpu_chunk_struct_size); |
| 1433 | INIT_LIST_HEAD(&schunk->list); |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1434 | schunk->base_addr = base_addr; |
Tejun Heo | 61ace7f | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1435 | schunk->map = smap; |
| 1436 | schunk->map_alloc = ARRAY_SIZE(smap); |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1437 | schunk->immutable = true; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1438 | bitmap_fill(schunk->populated, pcpu_unit_pages); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1439 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1440 | if (ai->reserved_size) { |
| 1441 | schunk->free_size = ai->reserved_size; |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 1442 | pcpu_reserved_chunk = schunk; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1443 | pcpu_reserved_chunk_limit = ai->static_size + ai->reserved_size; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1444 | } else { |
| 1445 | schunk->free_size = dyn_size; |
| 1446 | dyn_size = 0; /* dynamic area covered */ |
| 1447 | } |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1448 | schunk->contig_hint = schunk->free_size; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1449 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1450 | schunk->map[schunk->map_used++] = -ai->static_size; |
Tejun Heo | 61ace7f | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1451 | if (schunk->free_size) |
| 1452 | schunk->map[schunk->map_used++] = schunk->free_size; |
| 1453 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1454 | /* init dynamic chunk if necessary */ |
| 1455 | if (dyn_size) { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1456 | dchunk = alloc_bootmem(pcpu_chunk_struct_size); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1457 | INIT_LIST_HEAD(&dchunk->list); |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1458 | dchunk->base_addr = base_addr; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1459 | dchunk->map = dmap; |
| 1460 | dchunk->map_alloc = ARRAY_SIZE(dmap); |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1461 | dchunk->immutable = true; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1462 | bitmap_fill(dchunk->populated, pcpu_unit_pages); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1463 | |
| 1464 | dchunk->contig_hint = dchunk->free_size = dyn_size; |
| 1465 | dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; |
| 1466 | dchunk->map[dchunk->map_used++] = dchunk->free_size; |
| 1467 | } |
| 1468 | |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1469 | /* link the first chunk in */ |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 1470 | pcpu_first_chunk = dchunk ?: schunk; |
| 1471 | pcpu_chunk_relocate(pcpu_first_chunk, -1); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1472 | |
| 1473 | /* we're done */ |
Tejun Heo | bba174f | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1474 | pcpu_base_addr = base_addr; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1475 | return 0; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1476 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1477 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1478 | const char *pcpu_fc_names[PCPU_FC_NR] __initdata = { |
| 1479 | [PCPU_FC_AUTO] = "auto", |
| 1480 | [PCPU_FC_EMBED] = "embed", |
| 1481 | [PCPU_FC_PAGE] = "page", |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1482 | }; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1483 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1484 | enum pcpu_fc pcpu_chosen_fc __initdata = PCPU_FC_AUTO; |
| 1485 | |
| 1486 | static int __init percpu_alloc_setup(char *str) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1487 | { |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1488 | if (0) |
| 1489 | /* nada */; |
| 1490 | #ifdef CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK |
| 1491 | else if (!strcmp(str, "embed")) |
| 1492 | pcpu_chosen_fc = PCPU_FC_EMBED; |
| 1493 | #endif |
| 1494 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
| 1495 | else if (!strcmp(str, "page")) |
| 1496 | pcpu_chosen_fc = PCPU_FC_PAGE; |
| 1497 | #endif |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1498 | else |
| 1499 | pr_warning("PERCPU: unknown allocator %s specified\n", str); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1500 | |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1501 | return 0; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1502 | } |
Tejun Heo | f58dc01 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1503 | early_param("percpu_alloc", percpu_alloc_setup); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1504 | |
Tejun Heo | 08fc458 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1505 | #if defined(CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK) || \ |
| 1506 | !defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1507 | /** |
| 1508 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1509 | * @reserved_size: the size of reserved percpu area in bytes |
| 1510 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1511 | * @atom_size: allocation atom size |
| 1512 | * @cpu_distance_fn: callback to determine distance between cpus, optional |
| 1513 | * @alloc_fn: function to allocate percpu page |
| 1514 | * @free_fn: funtion to free percpu page |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1515 | * |
| 1516 | * This is a helper to ease setting up embedded first percpu chunk and |
| 1517 | * can be called where pcpu_setup_first_chunk() is expected. |
| 1518 | * |
| 1519 | * If this function is used to setup the first chunk, it is allocated |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1520 | * by calling @alloc_fn and used as-is without being mapped into |
| 1521 | * vmalloc area. Allocations are always whole multiples of @atom_size |
| 1522 | * aligned to @atom_size. |
| 1523 | * |
| 1524 | * This enables the first chunk to piggy back on the linear physical |
| 1525 | * mapping which often uses larger page size. Please note that this |
| 1526 | * can result in very sparse cpu->unit mapping on NUMA machines thus |
| 1527 | * requiring large vmalloc address space. Don't use this allocator if |
| 1528 | * vmalloc space is not orders of magnitude larger than distances |
| 1529 | * between node memory addresses (ie. 32bit NUMA machines). |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1530 | * |
| 1531 | * When @dyn_size is positive, dynamic area might be larger than |
Tejun Heo | 788e5ab | 2009-07-04 08:10:58 +0900 | [diff] [blame] | 1532 | * specified to fill page alignment. When @dyn_size is auto, |
| 1533 | * @dyn_size is just big enough to fill page alignment after static |
| 1534 | * and reserved areas. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1535 | * |
| 1536 | * If the needed size is smaller than the minimum or specified unit |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1537 | * size, the leftover is returned using @free_fn. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1538 | * |
| 1539 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1540 | * 0 on success, -errno on failure. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1541 | */ |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1542 | int __init pcpu_embed_first_chunk(size_t reserved_size, ssize_t dyn_size, |
| 1543 | size_t atom_size, |
| 1544 | pcpu_fc_cpu_distance_fn_t cpu_distance_fn, |
| 1545 | pcpu_fc_alloc_fn_t alloc_fn, |
| 1546 | pcpu_fc_free_fn_t free_fn) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1547 | { |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1548 | void *base = (void *)ULONG_MAX; |
| 1549 | void **areas = NULL; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1550 | struct pcpu_alloc_info *ai; |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 1551 | size_t size_sum, areas_size, max_distance; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1552 | int group, i, rc; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1553 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1554 | ai = pcpu_build_alloc_info(reserved_size, dyn_size, atom_size, |
| 1555 | cpu_distance_fn); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1556 | if (IS_ERR(ai)) |
| 1557 | return PTR_ERR(ai); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1558 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1559 | size_sum = ai->static_size + ai->reserved_size + ai->dyn_size; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1560 | areas_size = PFN_ALIGN(ai->nr_groups * sizeof(void *)); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1561 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1562 | areas = alloc_bootmem_nopanic(areas_size); |
| 1563 | if (!areas) { |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1564 | rc = -ENOMEM; |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1565 | goto out_free; |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 1566 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1567 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1568 | /* allocate, copy and determine base address */ |
| 1569 | for (group = 0; group < ai->nr_groups; group++) { |
| 1570 | struct pcpu_group_info *gi = &ai->groups[group]; |
| 1571 | unsigned int cpu = NR_CPUS; |
| 1572 | void *ptr; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1573 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1574 | for (i = 0; i < gi->nr_units && cpu == NR_CPUS; i++) |
| 1575 | cpu = gi->cpu_map[i]; |
| 1576 | BUG_ON(cpu == NR_CPUS); |
| 1577 | |
| 1578 | /* allocate space for the whole group */ |
| 1579 | ptr = alloc_fn(cpu, gi->nr_units * ai->unit_size, atom_size); |
| 1580 | if (!ptr) { |
| 1581 | rc = -ENOMEM; |
| 1582 | goto out_free_areas; |
| 1583 | } |
| 1584 | areas[group] = ptr; |
| 1585 | |
| 1586 | base = min(ptr, base); |
| 1587 | |
| 1588 | for (i = 0; i < gi->nr_units; i++, ptr += ai->unit_size) { |
| 1589 | if (gi->cpu_map[i] == NR_CPUS) { |
| 1590 | /* unused unit, free whole */ |
| 1591 | free_fn(ptr, ai->unit_size); |
| 1592 | continue; |
| 1593 | } |
| 1594 | /* copy and return the unused part */ |
| 1595 | memcpy(ptr, __per_cpu_load, ai->static_size); |
| 1596 | free_fn(ptr + size_sum, ai->unit_size - size_sum); |
| 1597 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1598 | } |
| 1599 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1600 | /* base address is now known, determine group base offsets */ |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 1601 | max_distance = 0; |
| 1602 | for (group = 0; group < ai->nr_groups; group++) { |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1603 | ai->groups[group].base_offset = areas[group] - base; |
Tejun Heo | 1a0c329 | 2009-10-04 09:31:05 +0900 | [diff] [blame] | 1604 | max_distance = max_t(size_t, max_distance, |
| 1605 | ai->groups[group].base_offset); |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 1606 | } |
| 1607 | max_distance += ai->unit_size; |
| 1608 | |
| 1609 | /* warn if maximum distance is further than 75% of vmalloc space */ |
| 1610 | if (max_distance > (VMALLOC_END - VMALLOC_START) * 3 / 4) { |
Tejun Heo | 1a0c329 | 2009-10-04 09:31:05 +0900 | [diff] [blame] | 1611 | pr_warning("PERCPU: max_distance=0x%zx too large for vmalloc " |
Tejun Heo | 6ea529a | 2009-09-24 18:46:01 +0900 | [diff] [blame] | 1612 | "space 0x%lx\n", |
| 1613 | max_distance, VMALLOC_END - VMALLOC_START); |
| 1614 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
| 1615 | /* and fail if we have fallback */ |
| 1616 | rc = -EINVAL; |
| 1617 | goto out_free; |
| 1618 | #endif |
| 1619 | } |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1620 | |
Tejun Heo | 004018e | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1621 | pr_info("PERCPU: Embedded %zu pages/cpu @%p s%zu r%zu d%zu u%zu\n", |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1622 | PFN_DOWN(size_sum), base, ai->static_size, ai->reserved_size, |
| 1623 | ai->dyn_size, ai->unit_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1624 | |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1625 | rc = pcpu_setup_first_chunk(ai, base); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1626 | goto out_free; |
| 1627 | |
| 1628 | out_free_areas: |
| 1629 | for (group = 0; group < ai->nr_groups; group++) |
| 1630 | free_fn(areas[group], |
| 1631 | ai->groups[group].nr_units * ai->unit_size); |
| 1632 | out_free: |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1633 | pcpu_free_alloc_info(ai); |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1634 | if (areas) |
| 1635 | free_bootmem(__pa(areas), areas_size); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1636 | return rc; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1637 | } |
Tejun Heo | 08fc458 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1638 | #endif /* CONFIG_NEED_PER_CPU_EMBED_FIRST_CHUNK || |
| 1639 | !CONFIG_HAVE_SETUP_PER_CPU_AREA */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1640 | |
Tejun Heo | 08fc458 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1641 | #ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1642 | /** |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1643 | * pcpu_page_first_chunk - map the first chunk using PAGE_SIZE pages |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1644 | * @reserved_size: the size of reserved percpu area in bytes |
| 1645 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE |
| 1646 | * @free_fn: funtion to free percpu page, always called with PAGE_SIZE |
| 1647 | * @populate_pte_fn: function to populate pte |
| 1648 | * |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1649 | * This is a helper to ease setting up page-remapped first percpu |
| 1650 | * chunk and can be called where pcpu_setup_first_chunk() is expected. |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1651 | * |
| 1652 | * This is the basic allocator. Static percpu area is allocated |
| 1653 | * page-by-page into vmalloc area. |
| 1654 | * |
| 1655 | * RETURNS: |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1656 | * 0 on success, -errno on failure. |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1657 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1658 | int __init pcpu_page_first_chunk(size_t reserved_size, |
| 1659 | pcpu_fc_alloc_fn_t alloc_fn, |
| 1660 | pcpu_fc_free_fn_t free_fn, |
| 1661 | pcpu_fc_populate_pte_fn_t populate_pte_fn) |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1662 | { |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1663 | static struct vm_struct vm; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1664 | struct pcpu_alloc_info *ai; |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1665 | char psize_str[16]; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1666 | int unit_pages; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1667 | size_t pages_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1668 | struct page **pages; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1669 | int unit, i, j, rc; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1670 | |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1671 | snprintf(psize_str, sizeof(psize_str), "%luK", PAGE_SIZE >> 10); |
| 1672 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1673 | ai = pcpu_build_alloc_info(reserved_size, -1, PAGE_SIZE, NULL); |
| 1674 | if (IS_ERR(ai)) |
| 1675 | return PTR_ERR(ai); |
| 1676 | BUG_ON(ai->nr_groups != 1); |
| 1677 | BUG_ON(ai->groups[0].nr_units != num_possible_cpus()); |
| 1678 | |
| 1679 | unit_pages = ai->unit_size >> PAGE_SHIFT; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1680 | |
| 1681 | /* unaligned allocations can't be freed, round up to page size */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1682 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
| 1683 | sizeof(pages[0])); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1684 | pages = alloc_bootmem(pages_size); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1685 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1686 | /* allocate pages */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1687 | j = 0; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1688 | for (unit = 0; unit < num_possible_cpus(); unit++) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1689 | for (i = 0; i < unit_pages; i++) { |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1690 | unsigned int cpu = ai->groups[0].cpu_map[unit]; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1691 | void *ptr; |
| 1692 | |
Tejun Heo | 3cbc856 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1693 | ptr = alloc_fn(cpu, PAGE_SIZE, PAGE_SIZE); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1694 | if (!ptr) { |
Tejun Heo | 00ae406 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1695 | pr_warning("PERCPU: failed to allocate %s page " |
| 1696 | "for cpu%u\n", psize_str, cpu); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1697 | goto enomem; |
| 1698 | } |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1699 | pages[j++] = virt_to_page(ptr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1700 | } |
| 1701 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1702 | /* allocate vm area, map the pages and copy static data */ |
| 1703 | vm.flags = VM_ALLOC; |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1704 | vm.size = num_possible_cpus() * ai->unit_size; |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1705 | vm_area_register_early(&vm, PAGE_SIZE); |
| 1706 | |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1707 | for (unit = 0; unit < num_possible_cpus(); unit++) { |
Tejun Heo | 1d9d325 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1708 | unsigned long unit_addr = |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1709 | (unsigned long)vm.addr + unit * ai->unit_size; |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1710 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1711 | for (i = 0; i < unit_pages; i++) |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1712 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
| 1713 | |
| 1714 | /* pte already populated, the following shouldn't fail */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1715 | rc = __pcpu_map_pages(unit_addr, &pages[unit * unit_pages], |
| 1716 | unit_pages); |
| 1717 | if (rc < 0) |
| 1718 | panic("failed to map percpu area, err=%d\n", rc); |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1719 | |
| 1720 | /* |
| 1721 | * FIXME: Archs with virtual cache should flush local |
| 1722 | * cache for the linear mapping here - something |
| 1723 | * equivalent to flush_cache_vmap() on the local cpu. |
| 1724 | * flush_cache_vmap() can't be used as most supporting |
| 1725 | * data structures are not set up yet. |
| 1726 | */ |
| 1727 | |
| 1728 | /* copy static data */ |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1729 | memcpy((void *)unit_addr, __per_cpu_load, ai->static_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1730 | } |
| 1731 | |
| 1732 | /* we're ready, commit */ |
Tejun Heo | 1d9d325 | 2009-08-14 15:00:50 +0900 | [diff] [blame] | 1733 | pr_info("PERCPU: %d %s pages/cpu @%p s%zu r%zu d%zu\n", |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1734 | unit_pages, psize_str, vm.addr, ai->static_size, |
| 1735 | ai->reserved_size, ai->dyn_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1736 | |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1737 | rc = pcpu_setup_first_chunk(ai, vm.addr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1738 | goto out_free_ar; |
| 1739 | |
| 1740 | enomem: |
| 1741 | while (--j >= 0) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1742 | free_fn(page_address(pages[j]), PAGE_SIZE); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1743 | rc = -ENOMEM; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1744 | out_free_ar: |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame] | 1745 | free_bootmem(__pa(pages), pages_size); |
Tejun Heo | fd1e8a1 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1746 | pcpu_free_alloc_info(ai); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1747 | return rc; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1748 | } |
Tejun Heo | 08fc458 | 2009-08-14 15:00:49 +0900 | [diff] [blame] | 1749 | #endif /* CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1750 | |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1751 | /* |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1752 | * Generic percpu area setup. |
| 1753 | * |
| 1754 | * The embedding helper is used because its behavior closely resembles |
| 1755 | * the original non-dynamic generic percpu area setup. This is |
| 1756 | * important because many archs have addressing restrictions and might |
| 1757 | * fail if the percpu area is located far away from the previous |
| 1758 | * location. As an added bonus, in non-NUMA cases, embedding is |
| 1759 | * generally a good idea TLB-wise because percpu area can piggy back |
| 1760 | * on the physical linear memory mapping which uses large page |
| 1761 | * mappings on applicable archs. |
| 1762 | */ |
| 1763 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
| 1764 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
| 1765 | EXPORT_SYMBOL(__per_cpu_offset); |
| 1766 | |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1767 | static void * __init pcpu_dfl_fc_alloc(unsigned int cpu, size_t size, |
| 1768 | size_t align) |
| 1769 | { |
| 1770 | return __alloc_bootmem_nopanic(size, align, __pa(MAX_DMA_ADDRESS)); |
| 1771 | } |
| 1772 | |
| 1773 | static void __init pcpu_dfl_fc_free(void *ptr, size_t size) |
| 1774 | { |
| 1775 | free_bootmem(__pa(ptr), size); |
| 1776 | } |
| 1777 | |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1778 | void __init setup_per_cpu_areas(void) |
| 1779 | { |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1780 | unsigned long delta; |
| 1781 | unsigned int cpu; |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1782 | int rc; |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1783 | |
| 1784 | /* |
| 1785 | * Always reserve area for module percpu variables. That's |
| 1786 | * what the legacy allocator did. |
| 1787 | */ |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1788 | rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE, |
Tejun Heo | c8826dd | 2009-08-14 15:00:52 +0900 | [diff] [blame] | 1789 | PERCPU_DYNAMIC_RESERVE, PAGE_SIZE, NULL, |
| 1790 | pcpu_dfl_fc_alloc, pcpu_dfl_fc_free); |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1791 | if (rc < 0) |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1792 | panic("Failed to initialized percpu areas."); |
| 1793 | |
| 1794 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; |
| 1795 | for_each_possible_cpu(cpu) |
Tejun Heo | fb435d5 | 2009-08-14 15:00:51 +0900 | [diff] [blame] | 1796 | __per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu]; |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1797 | } |
| 1798 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |