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/rbtree.h> 10 #include <linux/rwsem.h> 11 #include <linux/completion.h> 12 #include <linux/cpumask.h> 13 #include <linux/page-debug-flags.h> 14 #include <linux/uprobes.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/slob first free object */ 56 bool pfmemalloc; /* If set by the page allocator, 57 * ALLOC_NO_WATERMARKS was set 58 * and the low watermark was not 59 * met implying that the system 60 * is under some pressure. The 61 * caller should try ensure 62 * this page is only used to 63 * free other pages. 64 */ 65 }; 66 67 union { 68 #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ 69 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) 70 /* Used for cmpxchg_double in slub */ 71 unsigned long counters; 72 #else 73 /* 74 * Keep _count separate from slub cmpxchg_double data. 75 * As the rest of the double word is protected by 76 * slab_lock but _count is not. 77 */ 78 unsigned counters; 79 #endif 80 81 struct { 82 83 union { 84 /* 85 * Count of ptes mapped in 86 * mms, to show when page is 87 * mapped & limit reverse map 88 * searches. 89 * 90 * Used also for tail pages 91 * refcounting instead of 92 * _count. Tail pages cannot 93 * be mapped and keeping the 94 * tail page _count zero at 95 * all times guarantees 96 * get_page_unless_zero() will 97 * never succeed on tail 98 * pages. 99 */ 100 atomic_t _mapcount; 101 102 struct { /* SLUB */ 103 unsigned inuse:16; 104 unsigned objects:15; 105 unsigned frozen:1; 106 }; 107 int units; /* SLOB */ 108 }; 109 atomic_t _count; /* Usage count, see below. */ 110 }; 111 }; 112 }; 113 114 /* Third double word block */ 115 union { 116 struct list_head lru; /* Pageout list, eg. active_list 117 * protected by zone->lru_lock ! 118 */ 119 struct { /* slub per cpu partial pages */ 120 struct page *next; /* Next partial slab */ 121 #ifdef CONFIG_64BIT 122 int pages; /* Nr of partial slabs left */ 123 int pobjects; /* Approximate # of objects */ 124 #else 125 short int pages; 126 short int pobjects; 127 #endif 128 }; 129 130 struct list_head list; /* slobs list of pages */ 131 struct { /* slab fields */ 132 struct kmem_cache *slab_cache; 133 struct slab *slab_page; 134 }; 135 }; 136 137 /* Remainder is not double word aligned */ 138 union { 139 unsigned long private; /* Mapping-private opaque data: 140 * usually used for buffer_heads 141 * if PagePrivate set; used for 142 * swp_entry_t if PageSwapCache; 143 * indicates order in the buddy 144 * system if PG_buddy is set. 145 */ 146 #if USE_SPLIT_PTLOCKS 147 spinlock_t ptl; 148 #endif 149 struct kmem_cache *slab; /* SLUB: Pointer to slab */ 150 struct page *first_page; /* Compound tail pages */ 151 }; 152 153 /* 154 * On machines where all RAM is mapped into kernel address space, 155 * we can simply calculate the virtual address. On machines with 156 * highmem some memory is mapped into kernel virtual memory 157 * dynamically, so we need a place to store that address. 158 * Note that this field could be 16 bits on x86 ... ;) 159 * 160 * Architectures with slow multiplication can define 161 * WANT_PAGE_VIRTUAL in asm/page.h 162 */ 163 #if defined(WANT_PAGE_VIRTUAL) 164 void *virtual; /* Kernel virtual address (NULL if 165 not kmapped, ie. highmem) */ 166 #endif /* WANT_PAGE_VIRTUAL */ 167 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 168 unsigned long debug_flags; /* Use atomic bitops on this */ 169 #endif 170 171 #ifdef CONFIG_KMEMCHECK 172 /* 173 * kmemcheck wants to track the status of each byte in a page; this 174 * is a pointer to such a status block. NULL if not tracked. 175 */ 176 void *shadow; 177 #endif 178 } 179 /* 180 * The struct page can be forced to be double word aligned so that atomic ops 181 * on double words work. The SLUB allocator can make use of such a feature. 182 */ 183 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 184 __aligned(2 * sizeof(unsigned long)) 185 #endif 186 ; 187 188 struct page_frag { 189 struct page *page; 190 #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 191 __u32 offset; 192 __u32 size; 193 #else 194 __u16 offset; 195 __u16 size; 196 #endif 197 }; 198 199 typedef unsigned long __nocast vm_flags_t; 200 201 /* 202 * A region containing a mapping of a non-memory backed file under NOMMU 203 * conditions. These are held in a global tree and are pinned by the VMAs that 204 * map parts of them. 205 */ 206 struct vm_region { 207 struct rb_node vm_rb; /* link in global region tree */ 208 vm_flags_t vm_flags; /* VMA vm_flags */ 209 unsigned long vm_start; /* start address of region */ 210 unsigned long vm_end; /* region initialised to here */ 211 unsigned long vm_top; /* region allocated to here */ 212 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 213 struct file *vm_file; /* the backing file or NULL */ 214 215 int vm_usage; /* region usage count (access under nommu_region_sem) */ 216 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 217 * this region */ 218 }; 219 220 /* 221 * This struct defines a memory VMM memory area. There is one of these 222 * per VM-area/task. A VM area is any part of the process virtual memory 223 * space that has a special rule for the page-fault handlers (ie a shared 224 * library, the executable area etc). 225 */ 226 struct vm_area_struct { 227 struct mm_struct * vm_mm; /* The address space we belong to. */ 228 unsigned long vm_start; /* Our start address within vm_mm. */ 229 unsigned long vm_end; /* The first byte after our end address 230 within vm_mm. */ 231 232 /* linked list of VM areas per task, sorted by address */ 233 struct vm_area_struct *vm_next, *vm_prev; 234 235 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 236 unsigned long vm_flags; /* Flags, see mm.h. */ 237 238 struct rb_node vm_rb; 239 240 /* 241 * For areas with an address space and backing store, 242 * linkage into the address_space->i_mmap interval tree, or 243 * linkage of vma in the address_space->i_mmap_nonlinear list. 244 */ 245 union { 246 struct { 247 struct rb_node rb; 248 unsigned long rb_subtree_last; 249 } linear; 250 struct list_head nonlinear; 251 } shared; 252 253 /* 254 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 255 * list, after a COW of one of the file pages. A MAP_SHARED vma 256 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 257 * or brk vma (with NULL file) can only be in an anon_vma list. 258 */ 259 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 260 * page_table_lock */ 261 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 262 263 /* Function pointers to deal with this struct. */ 264 const struct vm_operations_struct *vm_ops; 265 266 /* Information about our backing store: */ 267 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 268 units, *not* PAGE_CACHE_SIZE */ 269 struct file * vm_file; /* File we map to (can be NULL). */ 270 void * vm_private_data; /* was vm_pte (shared mem) */ 271 272 #ifndef CONFIG_MMU 273 struct vm_region *vm_region; /* NOMMU mapping region */ 274 #endif 275 #ifdef CONFIG_NUMA 276 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 277 #endif 278 }; 279 280 struct core_thread { 281 struct task_struct *task; 282 struct core_thread *next; 283 }; 284 285 struct core_state { 286 atomic_t nr_threads; 287 struct core_thread dumper; 288 struct completion startup; 289 }; 290 291 enum { 292 MM_FILEPAGES, 293 MM_ANONPAGES, 294 MM_SWAPENTS, 295 NR_MM_COUNTERS 296 }; 297 298 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 299 #define SPLIT_RSS_COUNTING 300 /* per-thread cached information, */ 301 struct task_rss_stat { 302 int events; /* for synchronization threshold */ 303 int count[NR_MM_COUNTERS]; 304 }; 305 #endif /* USE_SPLIT_PTLOCKS */ 306 307 struct mm_rss_stat { 308 atomic_long_t count[NR_MM_COUNTERS]; 309 }; 310 311 struct mm_struct { 312 struct vm_area_struct * mmap; /* list of VMAs */ 313 struct rb_root mm_rb; 314 struct vm_area_struct * mmap_cache; /* last find_vma result */ 315 #ifdef CONFIG_MMU 316 unsigned long (*get_unmapped_area) (struct file *filp, 317 unsigned long addr, unsigned long len, 318 unsigned long pgoff, unsigned long flags); 319 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 320 #endif 321 unsigned long mmap_base; /* base of mmap area */ 322 unsigned long task_size; /* size of task vm space */ 323 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 324 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 325 pgd_t * pgd; 326 atomic_t mm_users; /* How many users with user space? */ 327 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 328 int map_count; /* number of VMAs */ 329 330 spinlock_t page_table_lock; /* Protects page tables and some counters */ 331 struct rw_semaphore mmap_sem; 332 333 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 334 * together off init_mm.mmlist, and are protected 335 * by mmlist_lock 336 */ 337 338 339 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 340 unsigned long hiwater_vm; /* High-water virtual memory usage */ 341 342 unsigned long total_vm; /* Total pages mapped */ 343 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 344 unsigned long pinned_vm; /* Refcount permanently increased */ 345 unsigned long shared_vm; /* Shared pages (files) */ 346 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */ 347 unsigned long stack_vm; /* VM_GROWSUP/DOWN */ 348 unsigned long def_flags; 349 unsigned long nr_ptes; /* Page table pages */ 350 unsigned long start_code, end_code, start_data, end_data; 351 unsigned long start_brk, brk, start_stack; 352 unsigned long arg_start, arg_end, env_start, env_end; 353 354 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 355 356 /* 357 * Special counters, in some configurations protected by the 358 * page_table_lock, in other configurations by being atomic. 359 */ 360 struct mm_rss_stat rss_stat; 361 362 struct linux_binfmt *binfmt; 363 364 cpumask_var_t cpu_vm_mask_var; 365 366 /* Architecture-specific MM context */ 367 mm_context_t context; 368 369 unsigned long flags; /* Must use atomic bitops to access the bits */ 370 371 struct core_state *core_state; /* coredumping support */ 372 #ifdef CONFIG_AIO 373 spinlock_t ioctx_lock; 374 struct hlist_head ioctx_list; 375 #endif 376 #ifdef CONFIG_MM_OWNER 377 /* 378 * "owner" points to a task that is regarded as the canonical 379 * user/owner of this mm. All of the following must be true in 380 * order for it to be changed: 381 * 382 * current == mm->owner 383 * current->mm != mm 384 * new_owner->mm == mm 385 * new_owner->alloc_lock is held 386 */ 387 struct task_struct __rcu *owner; 388 #endif 389 390 /* store ref to file /proc/<pid>/exe symlink points to */ 391 struct file *exe_file; 392 #ifdef CONFIG_MMU_NOTIFIER 393 struct mmu_notifier_mm *mmu_notifier_mm; 394 #endif 395 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 396 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 397 #endif 398 #ifdef CONFIG_CPUMASK_OFFSTACK 399 struct cpumask cpumask_allocation; 400 #endif 401 struct uprobes_state uprobes_state; 402 }; 403 404 static inline void mm_init_cpumask(struct mm_struct *mm) 405 { 406 #ifdef CONFIG_CPUMASK_OFFSTACK 407 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 408 #endif 409 } 410 411 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 412 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 413 { 414 return mm->cpu_vm_mask_var; 415 } 416 417 #endif /* _LINUX_MM_TYPES_H */ 418