Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1 | /* |
| 2 | * linux/mm/percpu.c - percpu memory allocator |
| 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 |
| 10 | * areas. Percpu areas are allocated in chunks in vmalloc area. Each |
| 11 | * chunk is consisted of num_possible_cpus() units and the first chunk |
| 12 | * is used for static percpu variables in the kernel image (special |
| 13 | * boot time alloc/init handling necessary as these areas need to be |
| 14 | * brought up before allocation services are running). Unit grows as |
| 15 | * necessary and all units grow or shrink in unison. When a chunk is |
| 16 | * filled up, another chunk is allocated. ie. in vmalloc area |
| 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, |
| 25 | * c1:u1, c1:u2 and c1:u3. Percpu access can be done by configuring |
Christoph Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 26 | * percpu base registers pcpu_unit_size apart. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 27 | * |
| 28 | * There are usually many small percpu allocations many of them as |
| 29 | * small as 4 bytes. The allocator organizes chunks into lists |
| 30 | * according to free size and tries to allocate from the fullest one. |
| 31 | * Each chunk keeps the maximum contiguous area size hint which is |
| 32 | * guaranteed to be eqaul to or larger than the maximum contiguous |
| 33 | * area in the chunk. This helps the allocator not to iterate the |
| 34 | * chunk maps unnecessarily. |
| 35 | * |
| 36 | * Allocation state in each chunk is kept using an array of integers |
| 37 | * on chunk->map. A positive value in the map represents a free |
| 38 | * region and negative allocated. Allocation inside a chunk is done |
| 39 | * by scanning this map sequentially and serving the first matching |
| 40 | * entry. This is mostly copied from the percpu_modalloc() allocator. |
Christoph Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 41 | * Chunks can be determined from the address using the index field |
| 42 | * 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] | 43 | * |
| 44 | * To use this allocator, arch code should do the followings. |
| 45 | * |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 46 | * - drop CONFIG_HAVE_LEGACY_PER_CPU_AREA |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 47 | * |
| 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> |
| 58 | #include <linux/list.h> |
| 59 | #include <linux/mm.h> |
| 60 | #include <linux/module.h> |
| 61 | #include <linux/mutex.h> |
| 62 | #include <linux/percpu.h> |
| 63 | #include <linux/pfn.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 64 | #include <linux/slab.h> |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 65 | #include <linux/spinlock.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 66 | #include <linux/vmalloc.h> |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 67 | #include <linux/workqueue.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 68 | |
| 69 | #include <asm/cacheflush.h> |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 70 | #include <asm/sections.h> |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 71 | #include <asm/tlbflush.h> |
| 72 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 73 | #define PCPU_SLOT_BASE_SHIFT 5 /* 1-31 shares the same slot */ |
| 74 | #define PCPU_DFL_MAP_ALLOC 16 /* start a map with 16 ents */ |
| 75 | |
Tejun Heo | e010098 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 76 | /* default addr <-> pcpu_ptr mapping, override in asm/percpu.h if necessary */ |
| 77 | #ifndef __addr_to_pcpu_ptr |
| 78 | #define __addr_to_pcpu_ptr(addr) \ |
| 79 | (void *)((unsigned long)(addr) - (unsigned long)pcpu_base_addr \ |
| 80 | + (unsigned long)__per_cpu_start) |
| 81 | #endif |
| 82 | #ifndef __pcpu_ptr_to_addr |
| 83 | #define __pcpu_ptr_to_addr(ptr) \ |
| 84 | (void *)((unsigned long)(ptr) + (unsigned long)pcpu_base_addr \ |
| 85 | - (unsigned long)__per_cpu_start) |
| 86 | #endif |
| 87 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 88 | struct pcpu_chunk { |
| 89 | struct list_head list; /* linked to pcpu_slot lists */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 90 | int free_size; /* free bytes in the chunk */ |
| 91 | int contig_hint; /* max contiguous size hint */ |
| 92 | struct vm_struct *vm; /* mapped vmalloc region */ |
| 93 | int map_used; /* # of map entries used */ |
| 94 | int map_alloc; /* # of map entries allocated */ |
| 95 | int *map; /* allocation map */ |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 96 | bool immutable; /* no [de]population allowed */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 97 | unsigned long populated[]; /* populated bitmap */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 98 | }; |
| 99 | |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 100 | static int pcpu_unit_pages __read_mostly; |
| 101 | static int pcpu_unit_size __read_mostly; |
| 102 | static int pcpu_chunk_size __read_mostly; |
| 103 | static int pcpu_nr_slots __read_mostly; |
| 104 | static size_t pcpu_chunk_struct_size __read_mostly; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 105 | |
| 106 | /* 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] | 107 | void *pcpu_base_addr __read_mostly; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 108 | EXPORT_SYMBOL_GPL(pcpu_base_addr); |
| 109 | |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 110 | /* |
| 111 | * The first chunk which always exists. Note that unlike other |
| 112 | * chunks, this one can be allocated and mapped in several different |
| 113 | * ways and thus often doesn't live in the vmalloc area. |
| 114 | */ |
| 115 | static struct pcpu_chunk *pcpu_first_chunk; |
| 116 | |
| 117 | /* |
| 118 | * Optional reserved chunk. This chunk reserves part of the first |
| 119 | * chunk and serves it for reserved allocations. The amount of |
| 120 | * reserved offset is in pcpu_reserved_chunk_limit. When reserved |
| 121 | * area doesn't exist, the following variables contain NULL and 0 |
| 122 | * respectively. |
| 123 | */ |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 124 | static struct pcpu_chunk *pcpu_reserved_chunk; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 125 | static int pcpu_reserved_chunk_limit; |
| 126 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 127 | /* |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 128 | * Synchronization rules. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 129 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 130 | * There are two locks - pcpu_alloc_mutex and pcpu_lock. The former |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 131 | * protects allocation/reclaim paths, chunks, populated bitmap and |
| 132 | * vmalloc mapping. The latter is a spinlock and protects the index |
| 133 | * data structures - chunk slots, chunks and area maps in chunks. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 134 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 135 | * During allocation, pcpu_alloc_mutex is kept locked all the time and |
| 136 | * pcpu_lock is grabbed and released as necessary. All actual memory |
| 137 | * allocations are done using GFP_KERNEL with pcpu_lock released. |
| 138 | * |
| 139 | * Free path accesses and alters only the index data structures, so it |
| 140 | * can be safely called from atomic context. When memory needs to be |
| 141 | * returned to the system, free path schedules reclaim_work which |
| 142 | * grabs both pcpu_alloc_mutex and pcpu_lock, unlinks chunks to be |
| 143 | * reclaimed, release both locks and frees the chunks. Note that it's |
| 144 | * necessary to grab both locks to remove a chunk from circulation as |
| 145 | * allocation path might be referencing the chunk with only |
| 146 | * pcpu_alloc_mutex locked. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 147 | */ |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 148 | static DEFINE_MUTEX(pcpu_alloc_mutex); /* protects whole alloc and reclaim */ |
| 149 | static DEFINE_SPINLOCK(pcpu_lock); /* protects index data structures */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 150 | |
Tejun Heo | 40150d3 | 2009-02-24 12:32:28 +0900 | [diff] [blame] | 151 | static struct list_head *pcpu_slot __read_mostly; /* chunk list slots */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 152 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 153 | /* reclaim work to release fully free chunks, scheduled from free path */ |
| 154 | static void pcpu_reclaim(struct work_struct *work); |
| 155 | static DECLARE_WORK(pcpu_reclaim_work, pcpu_reclaim); |
| 156 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 157 | static int __pcpu_size_to_slot(int size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 158 | { |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 159 | int highbit = fls(size); /* size is in bytes */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 160 | return max(highbit - PCPU_SLOT_BASE_SHIFT + 2, 1); |
| 161 | } |
| 162 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 163 | static int pcpu_size_to_slot(int size) |
| 164 | { |
| 165 | if (size == pcpu_unit_size) |
| 166 | return pcpu_nr_slots - 1; |
| 167 | return __pcpu_size_to_slot(size); |
| 168 | } |
| 169 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 170 | static int pcpu_chunk_slot(const struct pcpu_chunk *chunk) |
| 171 | { |
| 172 | if (chunk->free_size < sizeof(int) || chunk->contig_hint < sizeof(int)) |
| 173 | return 0; |
| 174 | |
| 175 | return pcpu_size_to_slot(chunk->free_size); |
| 176 | } |
| 177 | |
| 178 | static int pcpu_page_idx(unsigned int cpu, int page_idx) |
| 179 | { |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 180 | return cpu * pcpu_unit_pages + page_idx; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 181 | } |
| 182 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 183 | static unsigned long pcpu_chunk_addr(struct pcpu_chunk *chunk, |
| 184 | unsigned int cpu, int page_idx) |
| 185 | { |
| 186 | return (unsigned long)chunk->vm->addr + |
| 187 | (pcpu_page_idx(cpu, page_idx) << PAGE_SHIFT); |
| 188 | } |
| 189 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 190 | static struct page *pcpu_chunk_page(struct pcpu_chunk *chunk, |
| 191 | unsigned int cpu, int page_idx) |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 192 | { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 193 | /* must not be used on pre-mapped chunk */ |
| 194 | WARN_ON(chunk->immutable); |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 195 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 196 | return vmalloc_to_page((void *)pcpu_chunk_addr(chunk, cpu, page_idx)); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 197 | } |
| 198 | |
Christoph Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 199 | /* set the pointer to a chunk in a page struct */ |
| 200 | static void pcpu_set_page_chunk(struct page *page, struct pcpu_chunk *pcpu) |
| 201 | { |
| 202 | page->index = (unsigned long)pcpu; |
| 203 | } |
| 204 | |
| 205 | /* obtain pointer to a chunk from a page struct */ |
| 206 | static struct pcpu_chunk *pcpu_get_page_chunk(struct page *page) |
| 207 | { |
| 208 | return (struct pcpu_chunk *)page->index; |
| 209 | } |
| 210 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 211 | static void pcpu_next_unpop(struct pcpu_chunk *chunk, int *rs, int *re, int end) |
| 212 | { |
| 213 | *rs = find_next_zero_bit(chunk->populated, end, *rs); |
| 214 | *re = find_next_bit(chunk->populated, end, *rs + 1); |
| 215 | } |
| 216 | |
| 217 | static void pcpu_next_pop(struct pcpu_chunk *chunk, int *rs, int *re, int end) |
| 218 | { |
| 219 | *rs = find_next_bit(chunk->populated, end, *rs); |
| 220 | *re = find_next_zero_bit(chunk->populated, end, *rs + 1); |
| 221 | } |
| 222 | |
| 223 | /* |
| 224 | * (Un)populated page region iterators. Iterate over (un)populated |
| 225 | * page regions betwen @start and @end in @chunk. @rs and @re should |
| 226 | * be integer variables and will be set to start and end page index of |
| 227 | * the current region. |
| 228 | */ |
| 229 | #define pcpu_for_each_unpop_region(chunk, rs, re, start, end) \ |
| 230 | for ((rs) = (start), pcpu_next_unpop((chunk), &(rs), &(re), (end)); \ |
| 231 | (rs) < (re); \ |
| 232 | (rs) = (re) + 1, pcpu_next_unpop((chunk), &(rs), &(re), (end))) |
| 233 | |
| 234 | #define pcpu_for_each_pop_region(chunk, rs, re, start, end) \ |
| 235 | for ((rs) = (start), pcpu_next_pop((chunk), &(rs), &(re), (end)); \ |
| 236 | (rs) < (re); \ |
| 237 | (rs) = (re) + 1, pcpu_next_pop((chunk), &(rs), &(re), (end))) |
| 238 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 239 | /** |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 240 | * pcpu_mem_alloc - allocate memory |
| 241 | * @size: bytes to allocate |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 242 | * |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 243 | * Allocate @size bytes. If @size is smaller than PAGE_SIZE, |
| 244 | * kzalloc() is used; otherwise, vmalloc() is used. The returned |
| 245 | * memory is always zeroed. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 246 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 247 | * CONTEXT: |
| 248 | * Does GFP_KERNEL allocation. |
| 249 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 250 | * RETURNS: |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 251 | * Pointer to the allocated area on success, NULL on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 252 | */ |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 253 | static void *pcpu_mem_alloc(size_t size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 254 | { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 255 | if (size <= PAGE_SIZE) |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 256 | return kzalloc(size, GFP_KERNEL); |
| 257 | else { |
| 258 | void *ptr = vmalloc(size); |
| 259 | if (ptr) |
| 260 | memset(ptr, 0, size); |
| 261 | return ptr; |
| 262 | } |
| 263 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 264 | |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 265 | /** |
| 266 | * pcpu_mem_free - free memory |
| 267 | * @ptr: memory to free |
| 268 | * @size: size of the area |
| 269 | * |
| 270 | * Free @ptr. @ptr should have been allocated using pcpu_mem_alloc(). |
| 271 | */ |
| 272 | static void pcpu_mem_free(void *ptr, size_t size) |
| 273 | { |
| 274 | if (size <= PAGE_SIZE) |
| 275 | kfree(ptr); |
| 276 | else |
| 277 | vfree(ptr); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 278 | } |
| 279 | |
| 280 | /** |
| 281 | * pcpu_chunk_relocate - put chunk in the appropriate chunk slot |
| 282 | * @chunk: chunk of interest |
| 283 | * @oslot: the previous slot it was on |
| 284 | * |
| 285 | * This function is called after an allocation or free changed @chunk. |
| 286 | * New slot according to the changed state is determined and @chunk is |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 287 | * moved to the slot. Note that the reserved chunk is never put on |
| 288 | * chunk slots. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 289 | * |
| 290 | * CONTEXT: |
| 291 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 292 | */ |
| 293 | static void pcpu_chunk_relocate(struct pcpu_chunk *chunk, int oslot) |
| 294 | { |
| 295 | int nslot = pcpu_chunk_slot(chunk); |
| 296 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 297 | if (chunk != pcpu_reserved_chunk && oslot != nslot) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 298 | if (oslot < nslot) |
| 299 | list_move(&chunk->list, &pcpu_slot[nslot]); |
| 300 | else |
| 301 | list_move_tail(&chunk->list, &pcpu_slot[nslot]); |
| 302 | } |
| 303 | } |
| 304 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 305 | /** |
Christoph Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 306 | * pcpu_chunk_addr_search - determine chunk containing specified address |
| 307 | * @addr: address for which the chunk needs to be determined. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 308 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 309 | * RETURNS: |
| 310 | * The address of the found chunk. |
| 311 | */ |
| 312 | static struct pcpu_chunk *pcpu_chunk_addr_search(void *addr) |
| 313 | { |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 314 | void *first_start = pcpu_first_chunk->vm->addr; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 315 | |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 316 | /* is it in the first chunk? */ |
Tejun Heo | 79ba6ac | 2009-07-04 08:10:58 +0900 | [diff] [blame] | 317 | if (addr >= first_start && addr < first_start + pcpu_unit_size) { |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 318 | /* is it in the reserved area? */ |
| 319 | if (addr < first_start + pcpu_reserved_chunk_limit) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 320 | return pcpu_reserved_chunk; |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 321 | return pcpu_first_chunk; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 322 | } |
| 323 | |
Christoph Lameter | e1b9aa3 | 2009-04-02 13:21:44 +0900 | [diff] [blame] | 324 | return pcpu_get_page_chunk(vmalloc_to_page(addr)); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 325 | } |
| 326 | |
| 327 | /** |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 328 | * pcpu_extend_area_map - extend area map for allocation |
| 329 | * @chunk: target chunk |
| 330 | * |
| 331 | * Extend area map of @chunk so that it can accomodate an allocation. |
| 332 | * A single allocation can split an area into three areas, so this |
| 333 | * function makes sure that @chunk->map has at least two extra slots. |
| 334 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 335 | * CONTEXT: |
| 336 | * pcpu_alloc_mutex, pcpu_lock. pcpu_lock is released and reacquired |
| 337 | * if area map is extended. |
| 338 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 339 | * RETURNS: |
| 340 | * 0 if noop, 1 if successfully extended, -errno on failure. |
| 341 | */ |
| 342 | static int pcpu_extend_area_map(struct pcpu_chunk *chunk) |
| 343 | { |
| 344 | int new_alloc; |
| 345 | int *new; |
| 346 | size_t size; |
| 347 | |
| 348 | /* has enough? */ |
| 349 | if (chunk->map_alloc >= chunk->map_used + 2) |
| 350 | return 0; |
| 351 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 352 | spin_unlock_irq(&pcpu_lock); |
| 353 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 354 | new_alloc = PCPU_DFL_MAP_ALLOC; |
| 355 | while (new_alloc < chunk->map_used + 2) |
| 356 | new_alloc *= 2; |
| 357 | |
| 358 | new = pcpu_mem_alloc(new_alloc * sizeof(new[0])); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 359 | if (!new) { |
| 360 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 361 | return -ENOMEM; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 362 | } |
| 363 | |
| 364 | /* |
| 365 | * Acquire pcpu_lock and switch to new area map. Only free |
| 366 | * could have happened inbetween, so map_used couldn't have |
| 367 | * grown. |
| 368 | */ |
| 369 | spin_lock_irq(&pcpu_lock); |
| 370 | BUG_ON(new_alloc < chunk->map_used + 2); |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 371 | |
| 372 | size = chunk->map_alloc * sizeof(chunk->map[0]); |
| 373 | memcpy(new, chunk->map, size); |
| 374 | |
| 375 | /* |
| 376 | * map_alloc < PCPU_DFL_MAP_ALLOC indicates that the chunk is |
| 377 | * one of the first chunks and still using static map. |
| 378 | */ |
| 379 | if (chunk->map_alloc >= PCPU_DFL_MAP_ALLOC) |
| 380 | pcpu_mem_free(chunk->map, size); |
| 381 | |
| 382 | chunk->map_alloc = new_alloc; |
| 383 | chunk->map = new; |
| 384 | return 0; |
| 385 | } |
| 386 | |
| 387 | /** |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 388 | * pcpu_split_block - split a map block |
| 389 | * @chunk: chunk of interest |
| 390 | * @i: index of map block to split |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 391 | * @head: head size in bytes (can be 0) |
| 392 | * @tail: tail size in bytes (can be 0) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 393 | * |
| 394 | * Split the @i'th map block into two or three blocks. If @head is |
| 395 | * non-zero, @head bytes block is inserted before block @i moving it |
| 396 | * to @i+1 and reducing its size by @head bytes. |
| 397 | * |
| 398 | * If @tail is non-zero, the target block, which can be @i or @i+1 |
| 399 | * depending on @head, is reduced by @tail bytes and @tail byte block |
| 400 | * is inserted after the target block. |
| 401 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 402 | * @chunk->map must have enough free slots to accomodate the split. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 403 | * |
| 404 | * CONTEXT: |
| 405 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 406 | */ |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 407 | static void pcpu_split_block(struct pcpu_chunk *chunk, int i, |
| 408 | int head, int tail) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 409 | { |
| 410 | int nr_extra = !!head + !!tail; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 411 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 412 | BUG_ON(chunk->map_alloc < chunk->map_used + nr_extra); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 413 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 414 | /* insert new subblocks */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 415 | memmove(&chunk->map[i + nr_extra], &chunk->map[i], |
| 416 | sizeof(chunk->map[0]) * (chunk->map_used - i)); |
| 417 | chunk->map_used += nr_extra; |
| 418 | |
| 419 | if (head) { |
| 420 | chunk->map[i + 1] = chunk->map[i] - head; |
| 421 | chunk->map[i++] = head; |
| 422 | } |
| 423 | if (tail) { |
| 424 | chunk->map[i++] -= tail; |
| 425 | chunk->map[i] = tail; |
| 426 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 427 | } |
| 428 | |
| 429 | /** |
| 430 | * pcpu_alloc_area - allocate area from a pcpu_chunk |
| 431 | * @chunk: chunk of interest |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 432 | * @size: wanted size in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 433 | * @align: wanted align |
| 434 | * |
| 435 | * Try to allocate @size bytes area aligned at @align from @chunk. |
| 436 | * Note that this function only allocates the offset. It doesn't |
| 437 | * populate or map the area. |
| 438 | * |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 439 | * @chunk->map must have at least two free slots. |
| 440 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 441 | * CONTEXT: |
| 442 | * pcpu_lock. |
| 443 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 444 | * RETURNS: |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 445 | * Allocated offset in @chunk on success, -1 if no matching area is |
| 446 | * found. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 447 | */ |
| 448 | static int pcpu_alloc_area(struct pcpu_chunk *chunk, int size, int align) |
| 449 | { |
| 450 | int oslot = pcpu_chunk_slot(chunk); |
| 451 | int max_contig = 0; |
| 452 | int i, off; |
| 453 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 454 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) { |
| 455 | bool is_last = i + 1 == chunk->map_used; |
| 456 | int head, tail; |
| 457 | |
| 458 | /* extra for alignment requirement */ |
| 459 | head = ALIGN(off, align) - off; |
| 460 | BUG_ON(i == 0 && head != 0); |
| 461 | |
| 462 | if (chunk->map[i] < 0) |
| 463 | continue; |
| 464 | if (chunk->map[i] < head + size) { |
| 465 | max_contig = max(chunk->map[i], max_contig); |
| 466 | continue; |
| 467 | } |
| 468 | |
| 469 | /* |
| 470 | * If head is small or the previous block is free, |
| 471 | * merge'em. Note that 'small' is defined as smaller |
| 472 | * than sizeof(int), which is very small but isn't too |
| 473 | * uncommon for percpu allocations. |
| 474 | */ |
| 475 | if (head && (head < sizeof(int) || chunk->map[i - 1] > 0)) { |
| 476 | if (chunk->map[i - 1] > 0) |
| 477 | chunk->map[i - 1] += head; |
| 478 | else { |
| 479 | chunk->map[i - 1] -= head; |
| 480 | chunk->free_size -= head; |
| 481 | } |
| 482 | chunk->map[i] -= head; |
| 483 | off += head; |
| 484 | head = 0; |
| 485 | } |
| 486 | |
| 487 | /* if tail is small, just keep it around */ |
| 488 | tail = chunk->map[i] - head - size; |
| 489 | if (tail < sizeof(int)) |
| 490 | tail = 0; |
| 491 | |
| 492 | /* split if warranted */ |
| 493 | if (head || tail) { |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 494 | pcpu_split_block(chunk, i, head, tail); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 495 | if (head) { |
| 496 | i++; |
| 497 | off += head; |
| 498 | max_contig = max(chunk->map[i - 1], max_contig); |
| 499 | } |
| 500 | if (tail) |
| 501 | max_contig = max(chunk->map[i + 1], max_contig); |
| 502 | } |
| 503 | |
| 504 | /* update hint and mark allocated */ |
| 505 | if (is_last) |
| 506 | chunk->contig_hint = max_contig; /* fully scanned */ |
| 507 | else |
| 508 | chunk->contig_hint = max(chunk->contig_hint, |
| 509 | max_contig); |
| 510 | |
| 511 | chunk->free_size -= chunk->map[i]; |
| 512 | chunk->map[i] = -chunk->map[i]; |
| 513 | |
| 514 | pcpu_chunk_relocate(chunk, oslot); |
| 515 | return off; |
| 516 | } |
| 517 | |
| 518 | chunk->contig_hint = max_contig; /* fully scanned */ |
| 519 | pcpu_chunk_relocate(chunk, oslot); |
| 520 | |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 521 | /* tell the upper layer that this chunk has no matching area */ |
| 522 | return -1; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 523 | } |
| 524 | |
| 525 | /** |
| 526 | * pcpu_free_area - free area to a pcpu_chunk |
| 527 | * @chunk: chunk of interest |
| 528 | * @freeme: offset of area to free |
| 529 | * |
| 530 | * Free area starting from @freeme to @chunk. Note that this function |
| 531 | * only modifies the allocation map. It doesn't depopulate or unmap |
| 532 | * the area. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 533 | * |
| 534 | * CONTEXT: |
| 535 | * pcpu_lock. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 536 | */ |
| 537 | static void pcpu_free_area(struct pcpu_chunk *chunk, int freeme) |
| 538 | { |
| 539 | int oslot = pcpu_chunk_slot(chunk); |
| 540 | int i, off; |
| 541 | |
| 542 | for (i = 0, off = 0; i < chunk->map_used; off += abs(chunk->map[i++])) |
| 543 | if (off == freeme) |
| 544 | break; |
| 545 | BUG_ON(off != freeme); |
| 546 | BUG_ON(chunk->map[i] > 0); |
| 547 | |
| 548 | chunk->map[i] = -chunk->map[i]; |
| 549 | chunk->free_size += chunk->map[i]; |
| 550 | |
| 551 | /* merge with previous? */ |
| 552 | if (i > 0 && chunk->map[i - 1] >= 0) { |
| 553 | chunk->map[i - 1] += chunk->map[i]; |
| 554 | chunk->map_used--; |
| 555 | memmove(&chunk->map[i], &chunk->map[i + 1], |
| 556 | (chunk->map_used - i) * sizeof(chunk->map[0])); |
| 557 | i--; |
| 558 | } |
| 559 | /* merge with next? */ |
| 560 | if (i + 1 < chunk->map_used && chunk->map[i + 1] >= 0) { |
| 561 | chunk->map[i] += chunk->map[i + 1]; |
| 562 | chunk->map_used--; |
| 563 | memmove(&chunk->map[i + 1], &chunk->map[i + 2], |
| 564 | (chunk->map_used - (i + 1)) * sizeof(chunk->map[0])); |
| 565 | } |
| 566 | |
| 567 | chunk->contig_hint = max(chunk->map[i], chunk->contig_hint); |
| 568 | pcpu_chunk_relocate(chunk, oslot); |
| 569 | } |
| 570 | |
| 571 | /** |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 572 | * pcpu_get_pages_and_bitmap - get temp pages array and bitmap |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 573 | * @chunk: chunk of interest |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 574 | * @bitmapp: output parameter for bitmap |
| 575 | * @may_alloc: may allocate the array |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 576 | * |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 577 | * Returns pointer to array of pointers to struct page and bitmap, |
| 578 | * both of which can be indexed with pcpu_page_idx(). The returned |
| 579 | * array is cleared to zero and *@bitmapp is copied from |
| 580 | * @chunk->populated. Note that there is only one array and bitmap |
| 581 | * and access exclusion is the caller's responsibility. |
| 582 | * |
| 583 | * CONTEXT: |
| 584 | * pcpu_alloc_mutex and does GFP_KERNEL allocation if @may_alloc. |
| 585 | * Otherwise, don't care. |
| 586 | * |
| 587 | * RETURNS: |
| 588 | * Pointer to temp pages array on success, NULL on failure. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 589 | */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 590 | static struct page **pcpu_get_pages_and_bitmap(struct pcpu_chunk *chunk, |
| 591 | unsigned long **bitmapp, |
| 592 | bool may_alloc) |
| 593 | { |
| 594 | static struct page **pages; |
| 595 | static unsigned long *bitmap; |
| 596 | size_t pages_size = num_possible_cpus() * pcpu_unit_pages * |
| 597 | sizeof(pages[0]); |
| 598 | size_t bitmap_size = BITS_TO_LONGS(pcpu_unit_pages) * |
| 599 | sizeof(unsigned long); |
| 600 | |
| 601 | if (!pages || !bitmap) { |
| 602 | if (may_alloc && !pages) |
| 603 | pages = pcpu_mem_alloc(pages_size); |
| 604 | if (may_alloc && !bitmap) |
| 605 | bitmap = pcpu_mem_alloc(bitmap_size); |
| 606 | if (!pages || !bitmap) |
| 607 | return NULL; |
| 608 | } |
| 609 | |
| 610 | memset(pages, 0, pages_size); |
| 611 | bitmap_copy(bitmap, chunk->populated, pcpu_unit_pages); |
| 612 | |
| 613 | *bitmapp = bitmap; |
| 614 | return pages; |
| 615 | } |
| 616 | |
| 617 | /** |
| 618 | * pcpu_free_pages - free pages which were allocated for @chunk |
| 619 | * @chunk: chunk pages were allocated for |
| 620 | * @pages: array of pages to be freed, indexed by pcpu_page_idx() |
| 621 | * @populated: populated bitmap |
| 622 | * @page_start: page index of the first page to be freed |
| 623 | * @page_end: page index of the last page to be freed + 1 |
| 624 | * |
| 625 | * Free pages [@page_start and @page_end) in @pages for all units. |
| 626 | * The pages were allocated for @chunk. |
| 627 | */ |
| 628 | static void pcpu_free_pages(struct pcpu_chunk *chunk, |
| 629 | struct page **pages, unsigned long *populated, |
| 630 | int page_start, int page_end) |
| 631 | { |
| 632 | unsigned int cpu; |
| 633 | int i; |
| 634 | |
| 635 | for_each_possible_cpu(cpu) { |
| 636 | for (i = page_start; i < page_end; i++) { |
| 637 | struct page *page = pages[pcpu_page_idx(cpu, i)]; |
| 638 | |
| 639 | if (page) |
| 640 | __free_page(page); |
| 641 | } |
| 642 | } |
| 643 | } |
| 644 | |
| 645 | /** |
| 646 | * pcpu_alloc_pages - allocates pages for @chunk |
| 647 | * @chunk: target chunk |
| 648 | * @pages: array to put the allocated pages into, indexed by pcpu_page_idx() |
| 649 | * @populated: populated bitmap |
| 650 | * @page_start: page index of the first page to be allocated |
| 651 | * @page_end: page index of the last page to be allocated + 1 |
| 652 | * |
| 653 | * Allocate pages [@page_start,@page_end) into @pages for all units. |
| 654 | * The allocation is for @chunk. Percpu core doesn't care about the |
| 655 | * content of @pages and will pass it verbatim to pcpu_map_pages(). |
| 656 | */ |
| 657 | static int pcpu_alloc_pages(struct pcpu_chunk *chunk, |
| 658 | struct page **pages, unsigned long *populated, |
| 659 | int page_start, int page_end) |
| 660 | { |
| 661 | const gfp_t gfp = GFP_KERNEL | __GFP_HIGHMEM | __GFP_COLD; |
| 662 | unsigned int cpu; |
| 663 | int i; |
| 664 | |
| 665 | for_each_possible_cpu(cpu) { |
| 666 | for (i = page_start; i < page_end; i++) { |
| 667 | struct page **pagep = &pages[pcpu_page_idx(cpu, i)]; |
| 668 | |
| 669 | *pagep = alloc_pages_node(cpu_to_node(cpu), gfp, 0); |
| 670 | if (!*pagep) { |
| 671 | pcpu_free_pages(chunk, pages, populated, |
| 672 | page_start, page_end); |
| 673 | return -ENOMEM; |
| 674 | } |
| 675 | } |
| 676 | } |
| 677 | return 0; |
| 678 | } |
| 679 | |
| 680 | /** |
| 681 | * pcpu_pre_unmap_flush - flush cache prior to unmapping |
| 682 | * @chunk: chunk the regions to be flushed belongs to |
| 683 | * @page_start: page index of the first page to be flushed |
| 684 | * @page_end: page index of the last page to be flushed + 1 |
| 685 | * |
| 686 | * Pages in [@page_start,@page_end) of @chunk are about to be |
| 687 | * unmapped. Flush cache. As each flushing trial can be very |
| 688 | * expensive, issue flush on the whole region at once rather than |
| 689 | * doing it for each cpu. This could be an overkill but is more |
| 690 | * scalable. |
| 691 | */ |
| 692 | static void pcpu_pre_unmap_flush(struct pcpu_chunk *chunk, |
| 693 | int page_start, int page_end) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 694 | { |
| 695 | unsigned int last = num_possible_cpus() - 1; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 696 | |
Tejun Heo | 85ae87c | 2009-06-22 11:56:23 +0900 | [diff] [blame] | 697 | flush_cache_vunmap(pcpu_chunk_addr(chunk, 0, page_start), |
| 698 | pcpu_chunk_addr(chunk, last, page_end)); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 699 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 700 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 701 | static void __pcpu_unmap_pages(unsigned long addr, int nr_pages) |
| 702 | { |
| 703 | unmap_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT); |
| 704 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 705 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 706 | /** |
| 707 | * pcpu_unmap_pages - unmap pages out of a pcpu_chunk |
| 708 | * @chunk: chunk of interest |
| 709 | * @pages: pages array which can be used to pass information to free |
| 710 | * @populated: populated bitmap |
| 711 | * @page_start: page index of the first page to unmap |
| 712 | * @page_end: page index of the last page to unmap + 1 |
| 713 | * |
| 714 | * For each cpu, unmap pages [@page_start,@page_end) out of @chunk. |
| 715 | * Corresponding elements in @pages were cleared by the caller and can |
| 716 | * be used to carry information to pcpu_free_pages() which will be |
| 717 | * called after all unmaps are finished. The caller should call |
| 718 | * proper pre/post flush functions. |
| 719 | */ |
| 720 | static void pcpu_unmap_pages(struct pcpu_chunk *chunk, |
| 721 | struct page **pages, unsigned long *populated, |
| 722 | int page_start, int page_end) |
| 723 | { |
| 724 | unsigned int cpu; |
| 725 | int i; |
| 726 | |
| 727 | for_each_possible_cpu(cpu) { |
| 728 | for (i = page_start; i < page_end; i++) { |
| 729 | struct page *page; |
| 730 | |
| 731 | page = pcpu_chunk_page(chunk, cpu, i); |
| 732 | WARN_ON(!page); |
| 733 | pages[pcpu_page_idx(cpu, i)] = page; |
| 734 | } |
| 735 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, cpu, page_start), |
| 736 | page_end - page_start); |
| 737 | } |
| 738 | |
| 739 | for (i = page_start; i < page_end; i++) |
| 740 | __clear_bit(i, populated); |
| 741 | } |
| 742 | |
| 743 | /** |
| 744 | * pcpu_post_unmap_tlb_flush - flush TLB after unmapping |
| 745 | * @chunk: pcpu_chunk the regions to be flushed belong to |
| 746 | * @page_start: page index of the first page to be flushed |
| 747 | * @page_end: page index of the last page to be flushed + 1 |
| 748 | * |
| 749 | * Pages [@page_start,@page_end) of @chunk have been unmapped. Flush |
| 750 | * TLB for the regions. This can be skipped if the area is to be |
| 751 | * returned to vmalloc as vmalloc will handle TLB flushing lazily. |
| 752 | * |
| 753 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once |
| 754 | * for the whole region. |
| 755 | */ |
| 756 | static void pcpu_post_unmap_tlb_flush(struct pcpu_chunk *chunk, |
| 757 | int page_start, int page_end) |
| 758 | { |
| 759 | unsigned int last = num_possible_cpus() - 1; |
| 760 | |
| 761 | flush_tlb_kernel_range(pcpu_chunk_addr(chunk, 0, page_start), |
| 762 | pcpu_chunk_addr(chunk, last, page_end)); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 763 | } |
| 764 | |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 765 | static int __pcpu_map_pages(unsigned long addr, struct page **pages, |
| 766 | int nr_pages) |
| 767 | { |
| 768 | return map_kernel_range_noflush(addr, nr_pages << PAGE_SHIFT, |
| 769 | PAGE_KERNEL, pages); |
| 770 | } |
| 771 | |
| 772 | /** |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 773 | * pcpu_map_pages - map pages into a pcpu_chunk |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 774 | * @chunk: chunk of interest |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 775 | * @pages: pages array containing pages to be mapped |
| 776 | * @populated: populated bitmap |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 777 | * @page_start: page index of the first page to map |
| 778 | * @page_end: page index of the last page to map + 1 |
| 779 | * |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 780 | * For each cpu, map pages [@page_start,@page_end) into @chunk. The |
| 781 | * caller is responsible for calling pcpu_post_map_flush() after all |
| 782 | * mappings are complete. |
| 783 | * |
| 784 | * This function is responsible for setting corresponding bits in |
| 785 | * @chunk->populated bitmap and whatever is necessary for reverse |
| 786 | * lookup (addr -> chunk). |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 787 | */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 788 | static int pcpu_map_pages(struct pcpu_chunk *chunk, |
| 789 | struct page **pages, unsigned long *populated, |
| 790 | int page_start, int page_end) |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 791 | { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 792 | unsigned int cpu, tcpu; |
| 793 | int i, err; |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 794 | |
| 795 | for_each_possible_cpu(cpu) { |
| 796 | err = __pcpu_map_pages(pcpu_chunk_addr(chunk, cpu, page_start), |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 797 | &pages[pcpu_page_idx(cpu, page_start)], |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 798 | page_end - page_start); |
| 799 | if (err < 0) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 800 | goto err; |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 801 | } |
| 802 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 803 | /* mapping successful, link chunk and mark populated */ |
| 804 | for (i = page_start; i < page_end; i++) { |
| 805 | for_each_possible_cpu(cpu) |
| 806 | pcpu_set_page_chunk(pages[pcpu_page_idx(cpu, i)], |
| 807 | chunk); |
| 808 | __set_bit(i, populated); |
| 809 | } |
| 810 | |
| 811 | return 0; |
| 812 | |
| 813 | err: |
| 814 | for_each_possible_cpu(tcpu) { |
| 815 | if (tcpu == cpu) |
| 816 | break; |
| 817 | __pcpu_unmap_pages(pcpu_chunk_addr(chunk, tcpu, page_start), |
| 818 | page_end - page_start); |
| 819 | } |
| 820 | return err; |
| 821 | } |
| 822 | |
| 823 | /** |
| 824 | * pcpu_post_map_flush - flush cache after mapping |
| 825 | * @chunk: pcpu_chunk the regions to be flushed belong to |
| 826 | * @page_start: page index of the first page to be flushed |
| 827 | * @page_end: page index of the last page to be flushed + 1 |
| 828 | * |
| 829 | * Pages [@page_start,@page_end) of @chunk have been mapped. Flush |
| 830 | * cache. |
| 831 | * |
| 832 | * As with pcpu_pre_unmap_flush(), TLB flushing also is done at once |
| 833 | * for the whole region. |
| 834 | */ |
| 835 | static void pcpu_post_map_flush(struct pcpu_chunk *chunk, |
| 836 | int page_start, int page_end) |
| 837 | { |
| 838 | unsigned int last = num_possible_cpus() - 1; |
| 839 | |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 840 | /* flush at once, please read comments in pcpu_unmap() */ |
| 841 | flush_cache_vmap(pcpu_chunk_addr(chunk, 0, page_start), |
| 842 | pcpu_chunk_addr(chunk, last, page_end)); |
Tejun Heo | c8a51be | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 843 | } |
| 844 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 845 | /** |
| 846 | * pcpu_depopulate_chunk - depopulate and unmap an area of a pcpu_chunk |
| 847 | * @chunk: chunk to depopulate |
| 848 | * @off: offset to the area to depopulate |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 849 | * @size: size of the area to depopulate in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 850 | * @flush: whether to flush cache and tlb or not |
| 851 | * |
| 852 | * For each cpu, depopulate and unmap pages [@page_start,@page_end) |
| 853 | * from @chunk. If @flush is true, vcache is flushed before unmapping |
| 854 | * and tlb after. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 855 | * |
| 856 | * CONTEXT: |
| 857 | * pcpu_alloc_mutex. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 858 | */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 859 | static void pcpu_depopulate_chunk(struct pcpu_chunk *chunk, int off, int size) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 860 | { |
| 861 | int page_start = PFN_DOWN(off); |
| 862 | int page_end = PFN_UP(off + size); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 863 | struct page **pages; |
| 864 | unsigned long *populated; |
| 865 | int rs, re; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 866 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 867 | /* quick path, check whether it's empty already */ |
| 868 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { |
| 869 | if (rs == page_start && re == page_end) |
| 870 | return; |
| 871 | break; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 872 | } |
| 873 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 874 | /* immutable chunks can't be depopulated */ |
| 875 | WARN_ON(chunk->immutable); |
| 876 | |
| 877 | /* |
| 878 | * If control reaches here, there must have been at least one |
| 879 | * successful population attempt so the temp pages array must |
| 880 | * be available now. |
| 881 | */ |
| 882 | pages = pcpu_get_pages_and_bitmap(chunk, &populated, false); |
| 883 | BUG_ON(!pages); |
| 884 | |
| 885 | /* unmap and free */ |
| 886 | pcpu_pre_unmap_flush(chunk, page_start, page_end); |
| 887 | |
| 888 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) |
| 889 | pcpu_unmap_pages(chunk, pages, populated, rs, re); |
| 890 | |
| 891 | /* no need to flush tlb, vmalloc will handle it lazily */ |
| 892 | |
| 893 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) |
| 894 | pcpu_free_pages(chunk, pages, populated, rs, re); |
| 895 | |
| 896 | /* commit new bitmap */ |
| 897 | bitmap_copy(chunk->populated, populated, pcpu_unit_pages); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 898 | } |
| 899 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 900 | /** |
| 901 | * pcpu_populate_chunk - populate and map an area of a pcpu_chunk |
| 902 | * @chunk: chunk of interest |
| 903 | * @off: offset to the area to populate |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 904 | * @size: size of the area to populate in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 905 | * |
| 906 | * For each cpu, populate and map pages [@page_start,@page_end) into |
| 907 | * @chunk. The area is cleared on return. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 908 | * |
| 909 | * CONTEXT: |
| 910 | * pcpu_alloc_mutex, does GFP_KERNEL allocation. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 911 | */ |
| 912 | static int pcpu_populate_chunk(struct pcpu_chunk *chunk, int off, int size) |
| 913 | { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 914 | int page_start = PFN_DOWN(off); |
| 915 | int page_end = PFN_UP(off + size); |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 916 | int free_end = page_start, unmap_end = page_start; |
| 917 | struct page **pages; |
| 918 | unsigned long *populated; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 919 | unsigned int cpu; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 920 | int rs, re, rc; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 921 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 922 | /* quick path, check whether all pages are already there */ |
| 923 | pcpu_for_each_pop_region(chunk, rs, re, page_start, page_end) { |
| 924 | if (rs == page_start && re == page_end) |
| 925 | goto clear; |
| 926 | break; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 927 | } |
| 928 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 929 | /* need to allocate and map pages, this chunk can't be immutable */ |
| 930 | WARN_ON(chunk->immutable); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 931 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 932 | pages = pcpu_get_pages_and_bitmap(chunk, &populated, true); |
| 933 | if (!pages) |
| 934 | return -ENOMEM; |
| 935 | |
| 936 | /* alloc and map */ |
| 937 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { |
| 938 | rc = pcpu_alloc_pages(chunk, pages, populated, rs, re); |
| 939 | if (rc) |
| 940 | goto err_free; |
| 941 | free_end = re; |
| 942 | } |
| 943 | |
| 944 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, page_end) { |
| 945 | rc = pcpu_map_pages(chunk, pages, populated, rs, re); |
| 946 | if (rc) |
| 947 | goto err_unmap; |
| 948 | unmap_end = re; |
| 949 | } |
| 950 | pcpu_post_map_flush(chunk, page_start, page_end); |
| 951 | |
| 952 | /* commit new bitmap */ |
| 953 | bitmap_copy(chunk->populated, populated, pcpu_unit_pages); |
| 954 | clear: |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 955 | for_each_possible_cpu(cpu) |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 956 | memset(chunk->vm->addr + cpu * pcpu_unit_size + off, 0, |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 957 | size); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 958 | return 0; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 959 | |
| 960 | err_unmap: |
| 961 | pcpu_pre_unmap_flush(chunk, page_start, unmap_end); |
| 962 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, unmap_end) |
| 963 | pcpu_unmap_pages(chunk, pages, populated, rs, re); |
| 964 | pcpu_post_unmap_tlb_flush(chunk, page_start, unmap_end); |
| 965 | err_free: |
| 966 | pcpu_for_each_unpop_region(chunk, rs, re, page_start, free_end) |
| 967 | pcpu_free_pages(chunk, pages, populated, rs, re); |
| 968 | return rc; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 969 | } |
| 970 | |
| 971 | static void free_pcpu_chunk(struct pcpu_chunk *chunk) |
| 972 | { |
| 973 | if (!chunk) |
| 974 | return; |
| 975 | if (chunk->vm) |
| 976 | free_vm_area(chunk->vm); |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 977 | pcpu_mem_free(chunk->map, chunk->map_alloc * sizeof(chunk->map[0])); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 978 | kfree(chunk); |
| 979 | } |
| 980 | |
| 981 | static struct pcpu_chunk *alloc_pcpu_chunk(void) |
| 982 | { |
| 983 | struct pcpu_chunk *chunk; |
| 984 | |
| 985 | chunk = kzalloc(pcpu_chunk_struct_size, GFP_KERNEL); |
| 986 | if (!chunk) |
| 987 | return NULL; |
| 988 | |
Tejun Heo | 1880d93 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 989 | chunk->map = pcpu_mem_alloc(PCPU_DFL_MAP_ALLOC * sizeof(chunk->map[0])); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 990 | chunk->map_alloc = PCPU_DFL_MAP_ALLOC; |
| 991 | chunk->map[chunk->map_used++] = pcpu_unit_size; |
| 992 | |
| 993 | chunk->vm = get_vm_area(pcpu_chunk_size, GFP_KERNEL); |
| 994 | if (!chunk->vm) { |
| 995 | free_pcpu_chunk(chunk); |
| 996 | return NULL; |
| 997 | } |
| 998 | |
| 999 | INIT_LIST_HEAD(&chunk->list); |
| 1000 | chunk->free_size = pcpu_unit_size; |
| 1001 | chunk->contig_hint = pcpu_unit_size; |
| 1002 | |
| 1003 | return chunk; |
| 1004 | } |
| 1005 | |
| 1006 | /** |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1007 | * pcpu_alloc - the percpu allocator |
Tejun Heo | cae3aeb | 2009-02-21 16:56:23 +0900 | [diff] [blame] | 1008 | * @size: size of area to allocate in bytes |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1009 | * @align: alignment of area (max PAGE_SIZE) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1010 | * @reserved: allocate from the reserved chunk if available |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1011 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1012 | * Allocate percpu area of @size bytes aligned at @align. |
| 1013 | * |
| 1014 | * CONTEXT: |
| 1015 | * Does GFP_KERNEL allocation. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1016 | * |
| 1017 | * RETURNS: |
| 1018 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1019 | */ |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1020 | static void *pcpu_alloc(size_t size, size_t align, bool reserved) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1021 | { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1022 | struct pcpu_chunk *chunk; |
| 1023 | int slot, off; |
| 1024 | |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1025 | if (unlikely(!size || size > PCPU_MIN_UNIT_SIZE || align > PAGE_SIZE)) { |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1026 | WARN(true, "illegal size (%zu) or align (%zu) for " |
| 1027 | "percpu allocation\n", size, align); |
| 1028 | return NULL; |
| 1029 | } |
| 1030 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1031 | mutex_lock(&pcpu_alloc_mutex); |
| 1032 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1033 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1034 | /* serve reserved allocations from the reserved chunk if available */ |
| 1035 | if (reserved && pcpu_reserved_chunk) { |
| 1036 | chunk = pcpu_reserved_chunk; |
Tejun Heo | 9f7dcf2 | 2009-03-07 00:44:09 +0900 | [diff] [blame] | 1037 | if (size > chunk->contig_hint || |
| 1038 | pcpu_extend_area_map(chunk) < 0) |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1039 | goto fail_unlock; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1040 | off = pcpu_alloc_area(chunk, size, align); |
| 1041 | if (off >= 0) |
| 1042 | goto area_found; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1043 | goto fail_unlock; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1044 | } |
| 1045 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1046 | restart: |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1047 | /* search through normal chunks */ |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1048 | for (slot = pcpu_size_to_slot(size); slot < pcpu_nr_slots; slot++) { |
| 1049 | list_for_each_entry(chunk, &pcpu_slot[slot], list) { |
| 1050 | if (size > chunk->contig_hint) |
| 1051 | continue; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1052 | |
| 1053 | switch (pcpu_extend_area_map(chunk)) { |
| 1054 | case 0: |
| 1055 | break; |
| 1056 | case 1: |
| 1057 | goto restart; /* pcpu_lock dropped, restart */ |
| 1058 | default: |
| 1059 | goto fail_unlock; |
| 1060 | } |
| 1061 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1062 | off = pcpu_alloc_area(chunk, size, align); |
| 1063 | if (off >= 0) |
| 1064 | goto area_found; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1065 | } |
| 1066 | } |
| 1067 | |
| 1068 | /* hmmm... no space left, create a new chunk */ |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1069 | spin_unlock_irq(&pcpu_lock); |
| 1070 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1071 | chunk = alloc_pcpu_chunk(); |
| 1072 | if (!chunk) |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1073 | goto fail_unlock_mutex; |
| 1074 | |
| 1075 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1076 | pcpu_chunk_relocate(chunk, -1); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1077 | goto restart; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1078 | |
| 1079 | area_found: |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1080 | spin_unlock_irq(&pcpu_lock); |
| 1081 | |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1082 | /* populate, map and clear the area */ |
| 1083 | if (pcpu_populate_chunk(chunk, off, size)) { |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1084 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1085 | pcpu_free_area(chunk, off); |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1086 | goto fail_unlock; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1087 | } |
| 1088 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1089 | mutex_unlock(&pcpu_alloc_mutex); |
| 1090 | |
| 1091 | return __addr_to_pcpu_ptr(chunk->vm->addr + off); |
| 1092 | |
| 1093 | fail_unlock: |
| 1094 | spin_unlock_irq(&pcpu_lock); |
| 1095 | fail_unlock_mutex: |
| 1096 | mutex_unlock(&pcpu_alloc_mutex); |
| 1097 | return NULL; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1098 | } |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1099 | |
| 1100 | /** |
| 1101 | * __alloc_percpu - allocate dynamic percpu area |
| 1102 | * @size: size of area to allocate in bytes |
| 1103 | * @align: alignment of area (max PAGE_SIZE) |
| 1104 | * |
| 1105 | * Allocate percpu area of @size bytes aligned at @align. Might |
| 1106 | * sleep. Might trigger writeouts. |
| 1107 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1108 | * CONTEXT: |
| 1109 | * Does GFP_KERNEL allocation. |
| 1110 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1111 | * RETURNS: |
| 1112 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1113 | */ |
| 1114 | void *__alloc_percpu(size_t size, size_t align) |
| 1115 | { |
| 1116 | return pcpu_alloc(size, align, false); |
| 1117 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1118 | EXPORT_SYMBOL_GPL(__alloc_percpu); |
| 1119 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1120 | /** |
| 1121 | * __alloc_reserved_percpu - allocate reserved percpu area |
| 1122 | * @size: size of area to allocate in bytes |
| 1123 | * @align: alignment of area (max PAGE_SIZE) |
| 1124 | * |
| 1125 | * Allocate percpu area of @size bytes aligned at @align from reserved |
| 1126 | * percpu area if arch has set it up; otherwise, allocation is served |
| 1127 | * from the same dynamic area. Might sleep. Might trigger writeouts. |
| 1128 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1129 | * CONTEXT: |
| 1130 | * Does GFP_KERNEL allocation. |
| 1131 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1132 | * RETURNS: |
| 1133 | * Percpu pointer to the allocated area on success, NULL on failure. |
| 1134 | */ |
| 1135 | void *__alloc_reserved_percpu(size_t size, size_t align) |
| 1136 | { |
| 1137 | return pcpu_alloc(size, align, true); |
| 1138 | } |
| 1139 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1140 | /** |
| 1141 | * pcpu_reclaim - reclaim fully free chunks, workqueue function |
| 1142 | * @work: unused |
| 1143 | * |
| 1144 | * Reclaim all fully free chunks except for the first one. |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1145 | * |
| 1146 | * CONTEXT: |
| 1147 | * workqueue context. |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1148 | */ |
| 1149 | static void pcpu_reclaim(struct work_struct *work) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1150 | { |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1151 | LIST_HEAD(todo); |
| 1152 | struct list_head *head = &pcpu_slot[pcpu_nr_slots - 1]; |
| 1153 | struct pcpu_chunk *chunk, *next; |
| 1154 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1155 | mutex_lock(&pcpu_alloc_mutex); |
| 1156 | spin_lock_irq(&pcpu_lock); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1157 | |
| 1158 | list_for_each_entry_safe(chunk, next, head, list) { |
| 1159 | WARN_ON(chunk->immutable); |
| 1160 | |
| 1161 | /* spare the first one */ |
| 1162 | if (chunk == list_first_entry(head, struct pcpu_chunk, list)) |
| 1163 | continue; |
| 1164 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1165 | list_move(&chunk->list, &todo); |
| 1166 | } |
| 1167 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1168 | spin_unlock_irq(&pcpu_lock); |
| 1169 | mutex_unlock(&pcpu_alloc_mutex); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1170 | |
| 1171 | list_for_each_entry_safe(chunk, next, &todo, list) { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1172 | pcpu_depopulate_chunk(chunk, 0, pcpu_unit_size); |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1173 | free_pcpu_chunk(chunk); |
| 1174 | } |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1175 | } |
| 1176 | |
| 1177 | /** |
| 1178 | * free_percpu - free percpu area |
| 1179 | * @ptr: pointer to area to free |
| 1180 | * |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1181 | * Free percpu area @ptr. |
| 1182 | * |
| 1183 | * CONTEXT: |
| 1184 | * Can be called from atomic context. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1185 | */ |
| 1186 | void free_percpu(void *ptr) |
| 1187 | { |
| 1188 | void *addr = __pcpu_ptr_to_addr(ptr); |
| 1189 | struct pcpu_chunk *chunk; |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1190 | unsigned long flags; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1191 | int off; |
| 1192 | |
| 1193 | if (!ptr) |
| 1194 | return; |
| 1195 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1196 | spin_lock_irqsave(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1197 | |
| 1198 | chunk = pcpu_chunk_addr_search(addr); |
| 1199 | off = addr - chunk->vm->addr; |
| 1200 | |
| 1201 | pcpu_free_area(chunk, off); |
| 1202 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1203 | /* 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] | 1204 | if (chunk->free_size == pcpu_unit_size) { |
| 1205 | struct pcpu_chunk *pos; |
| 1206 | |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1207 | list_for_each_entry(pos, &pcpu_slot[pcpu_nr_slots - 1], list) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1208 | if (pos != chunk) { |
Tejun Heo | a56dbdd | 2009-03-07 00:44:11 +0900 | [diff] [blame] | 1209 | schedule_work(&pcpu_reclaim_work); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1210 | break; |
| 1211 | } |
| 1212 | } |
| 1213 | |
Tejun Heo | ccea34b | 2009-03-07 00:44:13 +0900 | [diff] [blame] | 1214 | spin_unlock_irqrestore(&pcpu_lock, flags); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1215 | } |
| 1216 | EXPORT_SYMBOL_GPL(free_percpu); |
| 1217 | |
| 1218 | /** |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1219 | * pcpu_setup_first_chunk - initialize the first percpu chunk |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1220 | * @static_size: the size of static percpu area in bytes |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1221 | * @reserved_size: the size of reserved percpu area in bytes, 0 for none |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1222 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1223 | * @unit_size: unit size in bytes, must be multiple of PAGE_SIZE |
| 1224 | * @base_addr: mapped address |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1225 | * |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1226 | * Initialize the first percpu chunk which contains the kernel static |
| 1227 | * perpcu area. This function is to be called from arch percpu area |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1228 | * setup path. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1229 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1230 | * @reserved_size, if non-zero, specifies the amount of bytes to |
| 1231 | * reserve after the static area in the first chunk. This reserves |
| 1232 | * the first chunk such that it's available only through reserved |
| 1233 | * percpu allocation. This is primarily used to serve module percpu |
| 1234 | * static areas on architectures where the addressing model has |
| 1235 | * limited offset range for symbol relocations to guarantee module |
| 1236 | * percpu symbols fall inside the relocatable range. |
| 1237 | * |
Tejun Heo | 6074d5b | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1238 | * @dyn_size, if non-negative, determines the number of bytes |
| 1239 | * available for dynamic allocation in the first chunk. Specifying |
| 1240 | * non-negative value makes percpu leave alone the area beyond |
| 1241 | * @static_size + @reserved_size + @dyn_size. |
| 1242 | * |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1243 | * @unit_size specifies unit size and must be aligned to PAGE_SIZE and |
| 1244 | * equal to or larger than @static_size + @reserved_size + if |
| 1245 | * non-negative, @dyn_size. |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1246 | * |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1247 | * The caller should have mapped the first chunk at @base_addr and |
| 1248 | * copied static data to each unit. |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1249 | * |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1250 | * If the first chunk ends up with both reserved and dynamic areas, it |
| 1251 | * is served by two chunks - one to serve the core static and reserved |
| 1252 | * areas and the other for the dynamic area. They share the same vm |
| 1253 | * and page map but uses different area allocation map to stay away |
| 1254 | * from each other. The latter chunk is circulated in the chunk slots |
| 1255 | * and available for dynamic allocation like any other chunks. |
| 1256 | * |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1257 | * RETURNS: |
| 1258 | * The determined pcpu_unit_size which can be used to initialize |
| 1259 | * percpu access. |
| 1260 | */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1261 | size_t __init pcpu_setup_first_chunk(size_t static_size, size_t reserved_size, |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1262 | ssize_t dyn_size, size_t unit_size, |
| 1263 | void *base_addr) |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1264 | { |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1265 | static struct vm_struct first_vm; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1266 | static int smap[2], dmap[2]; |
Tejun Heo | 6074d5b | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1267 | size_t size_sum = static_size + reserved_size + |
| 1268 | (dyn_size >= 0 ? dyn_size : 0); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1269 | struct pcpu_chunk *schunk, *dchunk = NULL; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1270 | int i; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1271 | |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1272 | /* santiy checks */ |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1273 | BUILD_BUG_ON(ARRAY_SIZE(smap) >= PCPU_DFL_MAP_ALLOC || |
| 1274 | ARRAY_SIZE(dmap) >= PCPU_DFL_MAP_ALLOC); |
Tejun Heo | 8d408b4 | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1275 | BUG_ON(!static_size); |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1276 | BUG_ON(!base_addr); |
| 1277 | BUG_ON(unit_size < size_sum); |
| 1278 | BUG_ON(unit_size & ~PAGE_MASK); |
| 1279 | BUG_ON(unit_size < PCPU_MIN_UNIT_SIZE); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1280 | |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1281 | pcpu_unit_pages = unit_size >> PAGE_SHIFT; |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1282 | pcpu_unit_size = pcpu_unit_pages << PAGE_SHIFT; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1283 | pcpu_chunk_size = num_possible_cpus() * pcpu_unit_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1284 | pcpu_chunk_struct_size = sizeof(struct pcpu_chunk) + |
| 1285 | BITS_TO_LONGS(pcpu_unit_pages) * sizeof(unsigned long); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1286 | |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1287 | if (dyn_size < 0) |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1288 | dyn_size = pcpu_unit_size - static_size - reserved_size; |
Tejun Heo | cafe881 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1289 | |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1290 | first_vm.flags = VM_ALLOC; |
| 1291 | first_vm.size = pcpu_chunk_size; |
| 1292 | first_vm.addr = base_addr; |
| 1293 | |
Tejun Heo | d9b55ee | 2009-02-24 11:57:21 +0900 | [diff] [blame] | 1294 | /* |
| 1295 | * Allocate chunk slots. The additional last slot is for |
| 1296 | * empty chunks. |
| 1297 | */ |
| 1298 | pcpu_nr_slots = __pcpu_size_to_slot(pcpu_unit_size) + 2; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1299 | pcpu_slot = alloc_bootmem(pcpu_nr_slots * sizeof(pcpu_slot[0])); |
| 1300 | for (i = 0; i < pcpu_nr_slots; i++) |
| 1301 | INIT_LIST_HEAD(&pcpu_slot[i]); |
| 1302 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1303 | /* |
| 1304 | * Initialize static chunk. If reserved_size is zero, the |
| 1305 | * static chunk covers static area + dynamic allocation area |
| 1306 | * in the first chunk. If reserved_size is not zero, it |
| 1307 | * covers static area + reserved area (mostly used for module |
| 1308 | * static percpu allocation). |
| 1309 | */ |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1310 | schunk = alloc_bootmem(pcpu_chunk_struct_size); |
| 1311 | INIT_LIST_HEAD(&schunk->list); |
| 1312 | schunk->vm = &first_vm; |
Tejun Heo | 61ace7f | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1313 | schunk->map = smap; |
| 1314 | schunk->map_alloc = ARRAY_SIZE(smap); |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1315 | schunk->immutable = true; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1316 | bitmap_fill(schunk->populated, pcpu_unit_pages); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1317 | |
| 1318 | if (reserved_size) { |
| 1319 | schunk->free_size = reserved_size; |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 1320 | pcpu_reserved_chunk = schunk; |
| 1321 | pcpu_reserved_chunk_limit = static_size + reserved_size; |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1322 | } else { |
| 1323 | schunk->free_size = dyn_size; |
| 1324 | dyn_size = 0; /* dynamic area covered */ |
| 1325 | } |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1326 | schunk->contig_hint = schunk->free_size; |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1327 | |
Tejun Heo | 61ace7f | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1328 | schunk->map[schunk->map_used++] = -static_size; |
| 1329 | if (schunk->free_size) |
| 1330 | schunk->map[schunk->map_used++] = schunk->free_size; |
| 1331 | |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1332 | /* init dynamic chunk if necessary */ |
| 1333 | if (dyn_size) { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1334 | dchunk = alloc_bootmem(pcpu_chunk_struct_size); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1335 | INIT_LIST_HEAD(&dchunk->list); |
| 1336 | dchunk->vm = &first_vm; |
| 1337 | dchunk->map = dmap; |
| 1338 | dchunk->map_alloc = ARRAY_SIZE(dmap); |
Tejun Heo | 38a6be5 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1339 | dchunk->immutable = true; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1340 | bitmap_fill(dchunk->populated, pcpu_unit_pages); |
Tejun Heo | edcb463 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1341 | |
| 1342 | dchunk->contig_hint = dchunk->free_size = dyn_size; |
| 1343 | dchunk->map[dchunk->map_used++] = -pcpu_reserved_chunk_limit; |
| 1344 | dchunk->map[dchunk->map_used++] = dchunk->free_size; |
| 1345 | } |
| 1346 | |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1347 | /* link the first chunk in */ |
Tejun Heo | ae9e6bc | 2009-04-02 13:19:54 +0900 | [diff] [blame] | 1348 | pcpu_first_chunk = dchunk ?: schunk; |
| 1349 | pcpu_chunk_relocate(pcpu_first_chunk, -1); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1350 | |
| 1351 | /* we're done */ |
Tejun Heo | 2441d15 | 2009-03-06 14:33:59 +0900 | [diff] [blame] | 1352 | pcpu_base_addr = (void *)pcpu_chunk_addr(schunk, 0, 0); |
Tejun Heo | fbf59bc | 2009-02-20 16:29:08 +0900 | [diff] [blame] | 1353 | return pcpu_unit_size; |
| 1354 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1355 | |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1356 | static size_t pcpu_calc_fc_sizes(size_t static_size, size_t reserved_size, |
| 1357 | ssize_t *dyn_sizep) |
| 1358 | { |
| 1359 | size_t size_sum; |
| 1360 | |
| 1361 | size_sum = PFN_ALIGN(static_size + reserved_size + |
| 1362 | (*dyn_sizep >= 0 ? *dyn_sizep : 0)); |
| 1363 | if (*dyn_sizep != 0) |
| 1364 | *dyn_sizep = size_sum - static_size - reserved_size; |
| 1365 | |
| 1366 | return size_sum; |
| 1367 | } |
| 1368 | |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1369 | /** |
| 1370 | * pcpu_embed_first_chunk - embed the first percpu chunk into bootmem |
| 1371 | * @static_size: the size of static percpu area in bytes |
| 1372 | * @reserved_size: the size of reserved percpu area in bytes |
| 1373 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1374 | * |
| 1375 | * This is a helper to ease setting up embedded first percpu chunk and |
| 1376 | * can be called where pcpu_setup_first_chunk() is expected. |
| 1377 | * |
| 1378 | * If this function is used to setup the first chunk, it is allocated |
| 1379 | * as a contiguous area using bootmem allocator and used as-is without |
| 1380 | * being mapped into vmalloc area. This enables the first chunk to |
| 1381 | * piggy back on the linear physical mapping which often uses larger |
| 1382 | * page size. |
| 1383 | * |
| 1384 | * When @dyn_size is positive, dynamic area might be larger than |
Tejun Heo | 788e5ab | 2009-07-04 08:10:58 +0900 | [diff] [blame] | 1385 | * specified to fill page alignment. When @dyn_size is auto, |
| 1386 | * @dyn_size is just big enough to fill page alignment after static |
| 1387 | * and reserved areas. |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1388 | * |
| 1389 | * If the needed size is smaller than the minimum or specified unit |
| 1390 | * size, the leftover is returned to the bootmem allocator. |
| 1391 | * |
| 1392 | * RETURNS: |
| 1393 | * The determined pcpu_unit_size which can be used to initialize |
| 1394 | * percpu access on success, -errno on failure. |
| 1395 | */ |
| 1396 | ssize_t __init pcpu_embed_first_chunk(size_t static_size, size_t reserved_size, |
Tejun Heo | 788e5ab | 2009-07-04 08:10:58 +0900 | [diff] [blame] | 1397 | ssize_t dyn_size) |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1398 | { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1399 | size_t size_sum, unit_size, chunk_size; |
| 1400 | void *base; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1401 | unsigned int cpu; |
| 1402 | |
| 1403 | /* determine parameters and allocate */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1404 | size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1405 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1406 | unit_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); |
| 1407 | chunk_size = unit_size * num_possible_cpus(); |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 1408 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1409 | base = __alloc_bootmem_nopanic(chunk_size, PAGE_SIZE, |
| 1410 | __pa(MAX_DMA_ADDRESS)); |
| 1411 | if (!base) { |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 1412 | pr_warning("PERCPU: failed to allocate %zu bytes for " |
| 1413 | "embedding\n", chunk_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1414 | return -ENOMEM; |
Tejun Heo | fa8a709 | 2009-06-22 11:56:24 +0900 | [diff] [blame] | 1415 | } |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1416 | |
| 1417 | /* return the leftover and copy */ |
| 1418 | for_each_possible_cpu(cpu) { |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1419 | void *ptr = base + cpu * unit_size; |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1420 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1421 | free_bootmem(__pa(ptr + size_sum), unit_size - size_sum); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1422 | memcpy(ptr, __per_cpu_load, static_size); |
| 1423 | } |
| 1424 | |
| 1425 | /* we're ready, commit */ |
| 1426 | pr_info("PERCPU: Embedded %zu pages at %p, static data %zu bytes\n", |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1427 | size_sum >> PAGE_SHIFT, base, static_size); |
Tejun Heo | 66c3a75 | 2009-03-10 16:27:48 +0900 | [diff] [blame] | 1428 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1429 | return pcpu_setup_first_chunk(static_size, reserved_size, dyn_size, |
| 1430 | unit_size, base); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1431 | } |
| 1432 | |
| 1433 | /** |
| 1434 | * pcpu_4k_first_chunk - map the first chunk using PAGE_SIZE pages |
| 1435 | * @static_size: the size of static percpu area in bytes |
| 1436 | * @reserved_size: the size of reserved percpu area in bytes |
| 1437 | * @alloc_fn: function to allocate percpu page, always called with PAGE_SIZE |
| 1438 | * @free_fn: funtion to free percpu page, always called with PAGE_SIZE |
| 1439 | * @populate_pte_fn: function to populate pte |
| 1440 | * |
| 1441 | * This is a helper to ease setting up embedded first percpu chunk and |
| 1442 | * can be called where pcpu_setup_first_chunk() is expected. |
| 1443 | * |
| 1444 | * This is the basic allocator. Static percpu area is allocated |
| 1445 | * page-by-page into vmalloc area. |
| 1446 | * |
| 1447 | * RETURNS: |
| 1448 | * The determined pcpu_unit_size which can be used to initialize |
| 1449 | * percpu access on success, -errno on failure. |
| 1450 | */ |
| 1451 | ssize_t __init pcpu_4k_first_chunk(size_t static_size, size_t reserved_size, |
| 1452 | pcpu_fc_alloc_fn_t alloc_fn, |
| 1453 | pcpu_fc_free_fn_t free_fn, |
| 1454 | pcpu_fc_populate_pte_fn_t populate_pte_fn) |
| 1455 | { |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1456 | static struct vm_struct vm; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1457 | int unit_pages; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1458 | size_t pages_size; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1459 | struct page **pages; |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1460 | unsigned int cpu; |
| 1461 | int i, j; |
| 1462 | ssize_t ret; |
| 1463 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1464 | unit_pages = PFN_UP(max_t(size_t, static_size + reserved_size, |
| 1465 | PCPU_MIN_UNIT_SIZE)); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1466 | |
| 1467 | /* unaligned allocations can't be freed, round up to page size */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1468 | pages_size = PFN_ALIGN(unit_pages * num_possible_cpus() * |
| 1469 | sizeof(pages[0])); |
| 1470 | pages = alloc_bootmem(pages_size); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1471 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1472 | /* allocate pages */ |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1473 | j = 0; |
| 1474 | for_each_possible_cpu(cpu) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1475 | for (i = 0; i < unit_pages; i++) { |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1476 | void *ptr; |
| 1477 | |
| 1478 | ptr = alloc_fn(cpu, PAGE_SIZE); |
| 1479 | if (!ptr) { |
| 1480 | pr_warning("PERCPU: failed to allocate " |
| 1481 | "4k page for cpu%u\n", cpu); |
| 1482 | goto enomem; |
| 1483 | } |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1484 | pages[j++] = virt_to_page(ptr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1485 | } |
| 1486 | |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1487 | /* allocate vm area, map the pages and copy static data */ |
| 1488 | vm.flags = VM_ALLOC; |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1489 | vm.size = num_possible_cpus() * unit_pages << PAGE_SHIFT; |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1490 | vm_area_register_early(&vm, PAGE_SIZE); |
| 1491 | |
| 1492 | for_each_possible_cpu(cpu) { |
| 1493 | unsigned long unit_addr = (unsigned long)vm.addr + |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1494 | (cpu * unit_pages << PAGE_SHIFT); |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1495 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1496 | for (i = 0; i < unit_pages; i++) |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1497 | populate_pte_fn(unit_addr + (i << PAGE_SHIFT)); |
| 1498 | |
| 1499 | /* pte already populated, the following shouldn't fail */ |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1500 | ret = __pcpu_map_pages(unit_addr, &pages[cpu * unit_pages], |
| 1501 | unit_pages); |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1502 | if (ret < 0) |
| 1503 | panic("failed to map percpu area, err=%zd\n", ret); |
| 1504 | |
| 1505 | /* |
| 1506 | * FIXME: Archs with virtual cache should flush local |
| 1507 | * cache for the linear mapping here - something |
| 1508 | * equivalent to flush_cache_vmap() on the local cpu. |
| 1509 | * flush_cache_vmap() can't be used as most supporting |
| 1510 | * data structures are not set up yet. |
| 1511 | */ |
| 1512 | |
| 1513 | /* copy static data */ |
| 1514 | memcpy((void *)unit_addr, __per_cpu_load, static_size); |
| 1515 | } |
| 1516 | |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1517 | /* we're ready, commit */ |
Tejun Heo | 8f05a6a | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1518 | pr_info("PERCPU: %d 4k pages per cpu, static data %zu bytes\n", |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1519 | unit_pages, static_size); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1520 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1521 | ret = pcpu_setup_first_chunk(static_size, reserved_size, -1, |
| 1522 | unit_pages << PAGE_SHIFT, vm.addr); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1523 | goto out_free_ar; |
| 1524 | |
| 1525 | enomem: |
| 1526 | while (--j >= 0) |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1527 | free_fn(page_address(pages[j]), PAGE_SIZE); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1528 | ret = -ENOMEM; |
| 1529 | out_free_ar: |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1530 | free_bootmem(__pa(pages), pages_size); |
Tejun Heo | d4b95f8 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1531 | return ret; |
| 1532 | } |
| 1533 | |
| 1534 | /* |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1535 | * Large page remapping first chunk setup helper |
| 1536 | */ |
| 1537 | #ifdef CONFIG_NEED_MULTIPLE_NODES |
| 1538 | struct pcpul_ent { |
| 1539 | unsigned int cpu; |
| 1540 | void *ptr; |
| 1541 | }; |
| 1542 | |
| 1543 | static size_t pcpul_size; |
| 1544 | static size_t pcpul_unit_size; |
| 1545 | static struct pcpul_ent *pcpul_map; |
| 1546 | static struct vm_struct pcpul_vm; |
| 1547 | |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1548 | /** |
| 1549 | * pcpu_lpage_first_chunk - remap the first percpu chunk using large page |
| 1550 | * @static_size: the size of static percpu area in bytes |
| 1551 | * @reserved_size: the size of reserved percpu area in bytes |
| 1552 | * @dyn_size: free size for dynamic allocation in bytes, -1 for auto |
| 1553 | * @lpage_size: the size of a large page |
| 1554 | * @alloc_fn: function to allocate percpu lpage, always called with lpage_size |
| 1555 | * @free_fn: function to free percpu memory, @size <= lpage_size |
| 1556 | * @map_fn: function to map percpu lpage, always called with lpage_size |
| 1557 | * |
| 1558 | * This allocator uses large page as unit. A large page is allocated |
| 1559 | * for each cpu and each is remapped into vmalloc area using large |
| 1560 | * page mapping. As large page can be quite large, only part of it is |
| 1561 | * used for the first chunk. Unused part is returned to the bootmem |
| 1562 | * allocator. |
| 1563 | * |
| 1564 | * So, the large pages are mapped twice - once to the physical mapping |
| 1565 | * and to the vmalloc area for the first percpu chunk. The double |
| 1566 | * mapping does add one more large TLB entry pressure but still is |
| 1567 | * much better than only using 4k mappings while still being NUMA |
| 1568 | * friendly. |
| 1569 | * |
| 1570 | * RETURNS: |
| 1571 | * The determined pcpu_unit_size which can be used to initialize |
| 1572 | * percpu access on success, -errno on failure. |
| 1573 | */ |
| 1574 | ssize_t __init pcpu_lpage_first_chunk(size_t static_size, size_t reserved_size, |
| 1575 | ssize_t dyn_size, size_t lpage_size, |
| 1576 | pcpu_fc_alloc_fn_t alloc_fn, |
| 1577 | pcpu_fc_free_fn_t free_fn, |
| 1578 | pcpu_fc_map_fn_t map_fn) |
| 1579 | { |
| 1580 | size_t size_sum; |
| 1581 | size_t map_size; |
| 1582 | unsigned int cpu; |
| 1583 | int i, j; |
| 1584 | ssize_t ret; |
| 1585 | |
| 1586 | /* |
| 1587 | * Currently supports only single page. Supporting multiple |
| 1588 | * pages won't be too difficult if it ever becomes necessary. |
| 1589 | */ |
| 1590 | size_sum = pcpu_calc_fc_sizes(static_size, reserved_size, &dyn_size); |
| 1591 | |
| 1592 | pcpul_unit_size = lpage_size; |
| 1593 | pcpul_size = max_t(size_t, size_sum, PCPU_MIN_UNIT_SIZE); |
| 1594 | if (pcpul_size > pcpul_unit_size) { |
| 1595 | pr_warning("PERCPU: static data is larger than large page, " |
| 1596 | "can't use large page\n"); |
| 1597 | return -EINVAL; |
| 1598 | } |
| 1599 | |
| 1600 | /* allocate pointer array and alloc large pages */ |
| 1601 | map_size = PFN_ALIGN(num_possible_cpus() * sizeof(pcpul_map[0])); |
| 1602 | pcpul_map = alloc_bootmem(map_size); |
| 1603 | |
| 1604 | for_each_possible_cpu(cpu) { |
| 1605 | void *ptr; |
| 1606 | |
| 1607 | ptr = alloc_fn(cpu, lpage_size); |
| 1608 | if (!ptr) { |
| 1609 | pr_warning("PERCPU: failed to allocate large page " |
| 1610 | "for cpu%u\n", cpu); |
| 1611 | goto enomem; |
| 1612 | } |
| 1613 | |
| 1614 | /* |
| 1615 | * Only use pcpul_size bytes and give back the rest. |
| 1616 | * |
| 1617 | * Ingo: The lpage_size up-rounding bootmem is needed |
| 1618 | * to make sure the partial lpage is still fully RAM - |
| 1619 | * it's not well-specified to have a incompatible area |
| 1620 | * (unmapped RAM, device memory, etc.) in that hole. |
| 1621 | */ |
| 1622 | free_fn(ptr + pcpul_size, lpage_size - pcpul_size); |
| 1623 | |
| 1624 | pcpul_map[cpu].cpu = cpu; |
| 1625 | pcpul_map[cpu].ptr = ptr; |
| 1626 | |
| 1627 | memcpy(ptr, __per_cpu_load, static_size); |
| 1628 | } |
| 1629 | |
| 1630 | /* allocate address and map */ |
| 1631 | pcpul_vm.flags = VM_ALLOC; |
| 1632 | pcpul_vm.size = num_possible_cpus() * pcpul_unit_size; |
| 1633 | vm_area_register_early(&pcpul_vm, pcpul_unit_size); |
| 1634 | |
| 1635 | for_each_possible_cpu(cpu) |
| 1636 | map_fn(pcpul_map[cpu].ptr, pcpul_unit_size, |
| 1637 | pcpul_vm.addr + cpu * pcpul_unit_size); |
| 1638 | |
| 1639 | /* we're ready, commit */ |
| 1640 | pr_info("PERCPU: Remapped at %p with large pages, static data " |
| 1641 | "%zu bytes\n", pcpul_vm.addr, static_size); |
| 1642 | |
Tejun Heo | ce3141a | 2009-07-04 08:11:00 +0900 | [diff] [blame^] | 1643 | ret = pcpu_setup_first_chunk(static_size, reserved_size, dyn_size, |
| 1644 | pcpul_unit_size, pcpul_vm.addr); |
Tejun Heo | 8c4bfc6 | 2009-07-04 08:10:59 +0900 | [diff] [blame] | 1645 | |
| 1646 | /* sort pcpul_map array for pcpu_lpage_remapped() */ |
| 1647 | for (i = 0; i < num_possible_cpus() - 1; i++) |
| 1648 | for (j = i + 1; j < num_possible_cpus(); j++) |
| 1649 | if (pcpul_map[i].ptr > pcpul_map[j].ptr) { |
| 1650 | struct pcpul_ent tmp = pcpul_map[i]; |
| 1651 | pcpul_map[i] = pcpul_map[j]; |
| 1652 | pcpul_map[j] = tmp; |
| 1653 | } |
| 1654 | |
| 1655 | return ret; |
| 1656 | |
| 1657 | enomem: |
| 1658 | for_each_possible_cpu(cpu) |
| 1659 | if (pcpul_map[cpu].ptr) |
| 1660 | free_fn(pcpul_map[cpu].ptr, pcpul_size); |
| 1661 | free_bootmem(__pa(pcpul_map), map_size); |
| 1662 | return -ENOMEM; |
| 1663 | } |
| 1664 | |
| 1665 | /** |
| 1666 | * pcpu_lpage_remapped - determine whether a kaddr is in pcpul recycled area |
| 1667 | * @kaddr: the kernel address in question |
| 1668 | * |
| 1669 | * Determine whether @kaddr falls in the pcpul recycled area. This is |
| 1670 | * used by pageattr to detect VM aliases and break up the pcpu large |
| 1671 | * page mapping such that the same physical page is not mapped under |
| 1672 | * different attributes. |
| 1673 | * |
| 1674 | * The recycled area is always at the tail of a partially used large |
| 1675 | * page. |
| 1676 | * |
| 1677 | * RETURNS: |
| 1678 | * Address of corresponding remapped pcpu address if match is found; |
| 1679 | * otherwise, NULL. |
| 1680 | */ |
| 1681 | void *pcpu_lpage_remapped(void *kaddr) |
| 1682 | { |
| 1683 | unsigned long unit_mask = pcpul_unit_size - 1; |
| 1684 | void *lpage_addr = (void *)((unsigned long)kaddr & ~unit_mask); |
| 1685 | unsigned long offset = (unsigned long)kaddr & unit_mask; |
| 1686 | int left = 0, right = num_possible_cpus() - 1; |
| 1687 | int pos; |
| 1688 | |
| 1689 | /* pcpul in use at all? */ |
| 1690 | if (!pcpul_map) |
| 1691 | return NULL; |
| 1692 | |
| 1693 | /* okay, perform binary search */ |
| 1694 | while (left <= right) { |
| 1695 | pos = (left + right) / 2; |
| 1696 | |
| 1697 | if (pcpul_map[pos].ptr < lpage_addr) |
| 1698 | left = pos + 1; |
| 1699 | else if (pcpul_map[pos].ptr > lpage_addr) |
| 1700 | right = pos - 1; |
| 1701 | else { |
| 1702 | /* it shouldn't be in the area for the first chunk */ |
| 1703 | WARN_ON(offset < pcpul_size); |
| 1704 | |
| 1705 | return pcpul_vm.addr + |
| 1706 | pcpul_map[pos].cpu * pcpul_unit_size + offset; |
| 1707 | } |
| 1708 | } |
| 1709 | |
| 1710 | return NULL; |
| 1711 | } |
| 1712 | #endif |
| 1713 | |
| 1714 | /* |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1715 | * Generic percpu area setup. |
| 1716 | * |
| 1717 | * The embedding helper is used because its behavior closely resembles |
| 1718 | * the original non-dynamic generic percpu area setup. This is |
| 1719 | * important because many archs have addressing restrictions and might |
| 1720 | * fail if the percpu area is located far away from the previous |
| 1721 | * location. As an added bonus, in non-NUMA cases, embedding is |
| 1722 | * generally a good idea TLB-wise because percpu area can piggy back |
| 1723 | * on the physical linear memory mapping which uses large page |
| 1724 | * mappings on applicable archs. |
| 1725 | */ |
| 1726 | #ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA |
| 1727 | unsigned long __per_cpu_offset[NR_CPUS] __read_mostly; |
| 1728 | EXPORT_SYMBOL(__per_cpu_offset); |
| 1729 | |
| 1730 | void __init setup_per_cpu_areas(void) |
| 1731 | { |
| 1732 | size_t static_size = __per_cpu_end - __per_cpu_start; |
| 1733 | ssize_t unit_size; |
| 1734 | unsigned long delta; |
| 1735 | unsigned int cpu; |
| 1736 | |
| 1737 | /* |
| 1738 | * Always reserve area for module percpu variables. That's |
| 1739 | * what the legacy allocator did. |
| 1740 | */ |
| 1741 | unit_size = pcpu_embed_first_chunk(static_size, PERCPU_MODULE_RESERVE, |
Tejun Heo | 788e5ab | 2009-07-04 08:10:58 +0900 | [diff] [blame] | 1742 | PERCPU_DYNAMIC_RESERVE); |
Tejun Heo | e74e396 | 2009-03-30 19:07:44 +0900 | [diff] [blame] | 1743 | if (unit_size < 0) |
| 1744 | panic("Failed to initialized percpu areas."); |
| 1745 | |
| 1746 | delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start; |
| 1747 | for_each_possible_cpu(cpu) |
| 1748 | __per_cpu_offset[cpu] = delta + cpu * unit_size; |
| 1749 | } |
| 1750 | #endif /* CONFIG_HAVE_SETUP_PER_CPU_AREA */ |