1 #ifndef _LINUX_MM_TYPES_H 2 #define _LINUX_MM_TYPES_H 3 4 #include <linux/auxvec.h> 5 #include <linux/types.h> 6 #include <linux/threads.h> 7 #include <linux/list.h> 8 #include <linux/spinlock.h> 9 #include <linux/prio_tree.h> 10 #include <linux/rbtree.h> 11 #include <linux/rwsem.h> 12 #include <linux/completion.h> 13 #include <linux/cpumask.h> 14 #include <linux/page-debug-flags.h> 15 #include <asm/page.h> 16 #include <asm/mmu.h> 17 18 #ifndef AT_VECTOR_SIZE_ARCH 19 #define AT_VECTOR_SIZE_ARCH 0 20 #endif 21 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 22 23 struct address_space; 24 25 #define USE_SPLIT_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS) 26 27 /* 28 * Each physical page in the system has a struct page associated with 29 * it to keep track of whatever it is we are using the page for at the 30 * moment. Note that we have no way to track which tasks are using 31 * a page, though if it is a pagecache page, rmap structures can tell us 32 * who is mapping it. 33 * 34 * The objects in struct page are organized in double word blocks in 35 * order to allows us to use atomic double word operations on portions 36 * of struct page. That is currently only used by slub but the arrangement 37 * allows the use of atomic double word operations on the flags/mapping 38 * and lru list pointers also. 39 */ 40 struct page { 41 /* First double word block */ 42 unsigned long flags; /* Atomic flags, some possibly 43 * updated asynchronously */ 44 struct address_space *mapping; /* If low bit clear, points to 45 * inode address_space, or NULL. 46 * If page mapped as anonymous 47 * memory, low bit is set, and 48 * it points to anon_vma object: 49 * see PAGE_MAPPING_ANON below. 50 */ 51 /* Second double word */ 52 struct { 53 union { 54 pgoff_t index; /* Our offset within mapping. */ 55 void *freelist; /* slub first free object */ 56 }; 57 58 union { 59 /* Used for cmpxchg_double in slub */ 60 unsigned long counters; 61 62 struct { 63 64 union { 65 atomic_t _mapcount; /* Count of ptes mapped in mms, 66 * to show when page is mapped 67 * & limit reverse map searches. 68 */ 69 70 struct { 71 unsigned inuse:16; 72 unsigned objects:15; 73 unsigned frozen:1; 74 }; 75 }; 76 atomic_t _count; /* Usage count, see below. */ 77 }; 78 }; 79 }; 80 81 /* Third double word block */ 82 union { 83 struct list_head lru; /* Pageout list, eg. active_list 84 * protected by zone->lru_lock ! 85 */ 86 struct { /* slub per cpu partial pages */ 87 struct page *next; /* Next partial slab */ 88 #ifdef CONFIG_64BIT 89 int pages; /* Nr of partial slabs left */ 90 int pobjects; /* Approximate # of objects */ 91 #else 92 short int pages; 93 short int pobjects; 94 #endif 95 }; 96 }; 97 98 /* Remainder is not double word aligned */ 99 union { 100 unsigned long private; /* Mapping-private opaque data: 101 * usually used for buffer_heads 102 * if PagePrivate set; used for 103 * swp_entry_t if PageSwapCache; 104 * indicates order in the buddy 105 * system if PG_buddy is set. 106 */ 107 #if USE_SPLIT_PTLOCKS 108 spinlock_t ptl; 109 #endif 110 struct kmem_cache *slab; /* SLUB: Pointer to slab */ 111 struct page *first_page; /* Compound tail pages */ 112 }; 113 114 /* 115 * On machines where all RAM is mapped into kernel address space, 116 * we can simply calculate the virtual address. On machines with 117 * highmem some memory is mapped into kernel virtual memory 118 * dynamically, so we need a place to store that address. 119 * Note that this field could be 16 bits on x86 ... ;) 120 * 121 * Architectures with slow multiplication can define 122 * WANT_PAGE_VIRTUAL in asm/page.h 123 */ 124 #if defined(WANT_PAGE_VIRTUAL) 125 void *virtual; /* Kernel virtual address (NULL if 126 not kmapped, ie. highmem) */ 127 #endif /* WANT_PAGE_VIRTUAL */ 128 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 129 unsigned long debug_flags; /* Use atomic bitops on this */ 130 #endif 131 132 #ifdef CONFIG_KMEMCHECK 133 /* 134 * kmemcheck wants to track the status of each byte in a page; this 135 * is a pointer to such a status block. NULL if not tracked. 136 */ 137 void *shadow; 138 #endif 139 } 140 /* 141 * If another subsystem starts using the double word pairing for atomic 142 * operations on struct page then it must change the #if to ensure 143 * proper alignment of the page struct. 144 */ 145 #if defined(CONFIG_SLUB) && defined(CONFIG_CMPXCHG_LOCAL) 146 __attribute__((__aligned__(2*sizeof(unsigned long)))) 147 #endif 148 ; 149 150 struct page_frag { 151 struct page *page; 152 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 153 __u32 offset; 154 __u32 size; 155 #else 156 __u16 offset; 157 __u16 size; 158 #endif 159 }; 160 161 typedef unsigned long __nocast vm_flags_t; 162 163 /* 164 * A region containing a mapping of a non-memory backed file under NOMMU 165 * conditions. These are held in a global tree and are pinned by the VMAs that 166 * map parts of them. 167 */ 168 struct vm_region { 169 struct rb_node vm_rb; /* link in global region tree */ 170 vm_flags_t vm_flags; /* VMA vm_flags */ 171 unsigned long vm_start; /* start address of region */ 172 unsigned long vm_end; /* region initialised to here */ 173 unsigned long vm_top; /* region allocated to here */ 174 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 175 struct file *vm_file; /* the backing file or NULL */ 176 177 int vm_usage; /* region usage count (access under nommu_region_sem) */ 178 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 179 * this region */ 180 }; 181 182 /* 183 * This struct defines a memory VMM memory area. There is one of these 184 * per VM-area/task. A VM area is any part of the process virtual memory 185 * space that has a special rule for the page-fault handlers (ie a shared 186 * library, the executable area etc). 187 */ 188 struct vm_area_struct { 189 struct mm_struct * vm_mm; /* The address space we belong to. */ 190 unsigned long vm_start; /* Our start address within vm_mm. */ 191 unsigned long vm_end; /* The first byte after our end address 192 within vm_mm. */ 193 194 /* linked list of VM areas per task, sorted by address */ 195 struct vm_area_struct *vm_next, *vm_prev; 196 197 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 198 unsigned long vm_flags; /* Flags, see mm.h. */ 199 200 struct rb_node vm_rb; 201 202 /* 203 * For areas with an address space and backing store, 204 * linkage into the address_space->i_mmap prio tree, or 205 * linkage to the list of like vmas hanging off its node, or 206 * linkage of vma in the address_space->i_mmap_nonlinear list. 207 */ 208 union { 209 struct { 210 struct list_head list; 211 void *parent; /* aligns with prio_tree_node parent */ 212 struct vm_area_struct *head; 213 } vm_set; 214 215 struct raw_prio_tree_node prio_tree_node; 216 } shared; 217 218 /* 219 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 220 * list, after a COW of one of the file pages. A MAP_SHARED vma 221 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 222 * or brk vma (with NULL file) can only be in an anon_vma list. 223 */ 224 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 225 * page_table_lock */ 226 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 227 228 /* Function pointers to deal with this struct. */ 229 const struct vm_operations_struct *vm_ops; 230 231 /* Information about our backing store: */ 232 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 233 units, *not* PAGE_CACHE_SIZE */ 234 struct file * vm_file; /* File we map to (can be NULL). */ 235 void * vm_private_data; /* was vm_pte (shared mem) */ 236 237 #ifndef CONFIG_MMU 238 struct vm_region *vm_region; /* NOMMU mapping region */ 239 #endif 240 #ifdef CONFIG_NUMA 241 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 242 #endif 243 }; 244 245 struct core_thread { 246 struct task_struct *task; 247 struct core_thread *next; 248 }; 249 250 struct core_state { 251 atomic_t nr_threads; 252 struct core_thread dumper; 253 struct completion startup; 254 }; 255 256 enum { 257 MM_FILEPAGES, 258 MM_ANONPAGES, 259 MM_SWAPENTS, 260 NR_MM_COUNTERS 261 }; 262 263 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 264 #define SPLIT_RSS_COUNTING 265 /* per-thread cached information, */ 266 struct task_rss_stat { 267 int events; /* for synchronization threshold */ 268 int count[NR_MM_COUNTERS]; 269 }; 270 #endif /* USE_SPLIT_PTLOCKS */ 271 272 struct mm_rss_stat { 273 atomic_long_t count[NR_MM_COUNTERS]; 274 }; 275 276 struct mm_struct { 277 struct vm_area_struct * mmap; /* list of VMAs */ 278 struct rb_root mm_rb; 279 struct vm_area_struct * mmap_cache; /* last find_vma result */ 280 #ifdef CONFIG_MMU 281 unsigned long (*get_unmapped_area) (struct file *filp, 282 unsigned long addr, unsigned long len, 283 unsigned long pgoff, unsigned long flags); 284 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 285 #endif 286 unsigned long mmap_base; /* base of mmap area */ 287 unsigned long task_size; /* size of task vm space */ 288 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 289 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 290 pgd_t * pgd; 291 atomic_t mm_users; /* How many users with user space? */ 292 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 293 int map_count; /* number of VMAs */ 294 295 spinlock_t page_table_lock; /* Protects page tables and some counters */ 296 struct rw_semaphore mmap_sem; 297 298 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 299 * together off init_mm.mmlist, and are protected 300 * by mmlist_lock 301 */ 302 303 304 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 305 unsigned long hiwater_vm; /* High-water virtual memory usage */ 306 307 unsigned long total_vm, locked_vm, shared_vm, exec_vm; 308 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes; 309 unsigned long start_code, end_code, start_data, end_data; 310 unsigned long start_brk, brk, start_stack; 311 unsigned long arg_start, arg_end, env_start, env_end; 312 313 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 314 315 /* 316 * Special counters, in some configurations protected by the 317 * page_table_lock, in other configurations by being atomic. 318 */ 319 struct mm_rss_stat rss_stat; 320 321 struct linux_binfmt *binfmt; 322 323 cpumask_var_t cpu_vm_mask_var; 324 325 /* Architecture-specific MM context */ 326 mm_context_t context; 327 328 /* Swap token stuff */ 329 /* 330 * Last value of global fault stamp as seen by this process. 331 * In other words, this value gives an indication of how long 332 * it has been since this task got the token. 333 * Look at mm/thrash.c 334 */ 335 unsigned int faultstamp; 336 unsigned int token_priority; 337 unsigned int last_interval; 338 339 /* How many tasks sharing this mm are OOM_DISABLE */ 340 atomic_t oom_disable_count; 341 342 unsigned long flags; /* Must use atomic bitops to access the bits */ 343 344 struct core_state *core_state; /* coredumping support */ 345 #ifdef CONFIG_AIO 346 spinlock_t ioctx_lock; 347 struct hlist_head ioctx_list; 348 #endif 349 #ifdef CONFIG_MM_OWNER 350 /* 351 * "owner" points to a task that is regarded as the canonical 352 * user/owner of this mm. All of the following must be true in 353 * order for it to be changed: 354 * 355 * current == mm->owner 356 * current->mm != mm 357 * new_owner->mm == mm 358 * new_owner->alloc_lock is held 359 */ 360 struct task_struct __rcu *owner; 361 #endif 362 363 /* store ref to file /proc/<pid>/exe symlink points to */ 364 struct file *exe_file; 365 unsigned long num_exe_file_vmas; 366 #ifdef CONFIG_MMU_NOTIFIER 367 struct mmu_notifier_mm *mmu_notifier_mm; 368 #endif 369 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 370 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 371 #endif 372 #ifdef CONFIG_CPUMASK_OFFSTACK 373 struct cpumask cpumask_allocation; 374 #endif 375 }; 376 377 static inline void mm_init_cpumask(struct mm_struct *mm) 378 { 379 #ifdef CONFIG_CPUMASK_OFFSTACK 380 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 381 #endif 382 } 383 384 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 385 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 386 { 387 return mm->cpu_vm_mask_var; 388 } 389 390 #endif /* _LINUX_MM_TYPES_H */ 391