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 struct list_head lru; /* Pageout list, eg. active_list 83 * protected by zone->lru_lock ! 84 */ 85 86 /* Remainder is not double word aligned */ 87 union { 88 unsigned long private; /* Mapping-private opaque data: 89 * usually used for buffer_heads 90 * if PagePrivate set; used for 91 * swp_entry_t if PageSwapCache; 92 * indicates order in the buddy 93 * system if PG_buddy is set. 94 */ 95 #if USE_SPLIT_PTLOCKS 96 spinlock_t ptl; 97 #endif 98 struct kmem_cache *slab; /* SLUB: Pointer to slab */ 99 struct page *first_page; /* Compound tail pages */ 100 }; 101 102 /* 103 * On machines where all RAM is mapped into kernel address space, 104 * we can simply calculate the virtual address. On machines with 105 * highmem some memory is mapped into kernel virtual memory 106 * dynamically, so we need a place to store that address. 107 * Note that this field could be 16 bits on x86 ... ;) 108 * 109 * Architectures with slow multiplication can define 110 * WANT_PAGE_VIRTUAL in asm/page.h 111 */ 112 #if defined(WANT_PAGE_VIRTUAL) 113 void *virtual; /* Kernel virtual address (NULL if 114 not kmapped, ie. highmem) */ 115 #endif /* WANT_PAGE_VIRTUAL */ 116 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 117 unsigned long debug_flags; /* Use atomic bitops on this */ 118 #endif 119 120 #ifdef CONFIG_KMEMCHECK 121 /* 122 * kmemcheck wants to track the status of each byte in a page; this 123 * is a pointer to such a status block. NULL if not tracked. 124 */ 125 void *shadow; 126 #endif 127 } 128 /* 129 * If another subsystem starts using the double word pairing for atomic 130 * operations on struct page then it must change the #if to ensure 131 * proper alignment of the page struct. 132 */ 133 #if defined(CONFIG_SLUB) && defined(CONFIG_CMPXCHG_LOCAL) 134 __attribute__((__aligned__(2*sizeof(unsigned long)))) 135 #endif 136 ; 137 138 typedef unsigned long __nocast vm_flags_t; 139 140 /* 141 * A region containing a mapping of a non-memory backed file under NOMMU 142 * conditions. These are held in a global tree and are pinned by the VMAs that 143 * map parts of them. 144 */ 145 struct vm_region { 146 struct rb_node vm_rb; /* link in global region tree */ 147 vm_flags_t vm_flags; /* VMA vm_flags */ 148 unsigned long vm_start; /* start address of region */ 149 unsigned long vm_end; /* region initialised to here */ 150 unsigned long vm_top; /* region allocated to here */ 151 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 152 struct file *vm_file; /* the backing file or NULL */ 153 154 int vm_usage; /* region usage count (access under nommu_region_sem) */ 155 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 156 * this region */ 157 }; 158 159 /* 160 * This struct defines a memory VMM memory area. There is one of these 161 * per VM-area/task. A VM area is any part of the process virtual memory 162 * space that has a special rule for the page-fault handlers (ie a shared 163 * library, the executable area etc). 164 */ 165 struct vm_area_struct { 166 struct mm_struct * vm_mm; /* The address space we belong to. */ 167 unsigned long vm_start; /* Our start address within vm_mm. */ 168 unsigned long vm_end; /* The first byte after our end address 169 within vm_mm. */ 170 171 /* linked list of VM areas per task, sorted by address */ 172 struct vm_area_struct *vm_next, *vm_prev; 173 174 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 175 unsigned long vm_flags; /* Flags, see mm.h. */ 176 177 struct rb_node vm_rb; 178 179 /* 180 * For areas with an address space and backing store, 181 * linkage into the address_space->i_mmap prio tree, or 182 * linkage to the list of like vmas hanging off its node, or 183 * linkage of vma in the address_space->i_mmap_nonlinear list. 184 */ 185 union { 186 struct { 187 struct list_head list; 188 void *parent; /* aligns with prio_tree_node parent */ 189 struct vm_area_struct *head; 190 } vm_set; 191 192 struct raw_prio_tree_node prio_tree_node; 193 } shared; 194 195 /* 196 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 197 * list, after a COW of one of the file pages. A MAP_SHARED vma 198 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 199 * or brk vma (with NULL file) can only be in an anon_vma list. 200 */ 201 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 202 * page_table_lock */ 203 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 204 205 /* Function pointers to deal with this struct. */ 206 const struct vm_operations_struct *vm_ops; 207 208 /* Information about our backing store: */ 209 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 210 units, *not* PAGE_CACHE_SIZE */ 211 struct file * vm_file; /* File we map to (can be NULL). */ 212 void * vm_private_data; /* was vm_pte (shared mem) */ 213 214 #ifndef CONFIG_MMU 215 struct vm_region *vm_region; /* NOMMU mapping region */ 216 #endif 217 #ifdef CONFIG_NUMA 218 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 219 #endif 220 }; 221 222 struct core_thread { 223 struct task_struct *task; 224 struct core_thread *next; 225 }; 226 227 struct core_state { 228 atomic_t nr_threads; 229 struct core_thread dumper; 230 struct completion startup; 231 }; 232 233 enum { 234 MM_FILEPAGES, 235 MM_ANONPAGES, 236 MM_SWAPENTS, 237 NR_MM_COUNTERS 238 }; 239 240 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 241 #define SPLIT_RSS_COUNTING 242 /* per-thread cached information, */ 243 struct task_rss_stat { 244 int events; /* for synchronization threshold */ 245 int count[NR_MM_COUNTERS]; 246 }; 247 #endif /* USE_SPLIT_PTLOCKS */ 248 249 struct mm_rss_stat { 250 atomic_long_t count[NR_MM_COUNTERS]; 251 }; 252 253 struct mm_struct { 254 struct vm_area_struct * mmap; /* list of VMAs */ 255 struct rb_root mm_rb; 256 struct vm_area_struct * mmap_cache; /* last find_vma result */ 257 #ifdef CONFIG_MMU 258 unsigned long (*get_unmapped_area) (struct file *filp, 259 unsigned long addr, unsigned long len, 260 unsigned long pgoff, unsigned long flags); 261 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 262 #endif 263 unsigned long mmap_base; /* base of mmap area */ 264 unsigned long task_size; /* size of task vm space */ 265 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 266 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 267 pgd_t * pgd; 268 atomic_t mm_users; /* How many users with user space? */ 269 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 270 int map_count; /* number of VMAs */ 271 272 spinlock_t page_table_lock; /* Protects page tables and some counters */ 273 struct rw_semaphore mmap_sem; 274 275 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 276 * together off init_mm.mmlist, and are protected 277 * by mmlist_lock 278 */ 279 280 281 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 282 unsigned long hiwater_vm; /* High-water virtual memory usage */ 283 284 unsigned long total_vm, locked_vm, shared_vm, exec_vm; 285 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes; 286 unsigned long start_code, end_code, start_data, end_data; 287 unsigned long start_brk, brk, start_stack; 288 unsigned long arg_start, arg_end, env_start, env_end; 289 290 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 291 292 /* 293 * Special counters, in some configurations protected by the 294 * page_table_lock, in other configurations by being atomic. 295 */ 296 struct mm_rss_stat rss_stat; 297 298 struct linux_binfmt *binfmt; 299 300 cpumask_var_t cpu_vm_mask_var; 301 302 /* Architecture-specific MM context */ 303 mm_context_t context; 304 305 /* Swap token stuff */ 306 /* 307 * Last value of global fault stamp as seen by this process. 308 * In other words, this value gives an indication of how long 309 * it has been since this task got the token. 310 * Look at mm/thrash.c 311 */ 312 unsigned int faultstamp; 313 unsigned int token_priority; 314 unsigned int last_interval; 315 316 /* How many tasks sharing this mm are OOM_DISABLE */ 317 atomic_t oom_disable_count; 318 319 unsigned long flags; /* Must use atomic bitops to access the bits */ 320 321 struct core_state *core_state; /* coredumping support */ 322 #ifdef CONFIG_AIO 323 spinlock_t ioctx_lock; 324 struct hlist_head ioctx_list; 325 #endif 326 #ifdef CONFIG_MM_OWNER 327 /* 328 * "owner" points to a task that is regarded as the canonical 329 * user/owner of this mm. All of the following must be true in 330 * order for it to be changed: 331 * 332 * current == mm->owner 333 * current->mm != mm 334 * new_owner->mm == mm 335 * new_owner->alloc_lock is held 336 */ 337 struct task_struct __rcu *owner; 338 #endif 339 340 /* store ref to file /proc/<pid>/exe symlink points to */ 341 struct file *exe_file; 342 unsigned long num_exe_file_vmas; 343 #ifdef CONFIG_MMU_NOTIFIER 344 struct mmu_notifier_mm *mmu_notifier_mm; 345 #endif 346 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 347 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 348 #endif 349 #ifdef CONFIG_CPUMASK_OFFSTACK 350 struct cpumask cpumask_allocation; 351 #endif 352 }; 353 354 static inline void mm_init_cpumask(struct mm_struct *mm) 355 { 356 #ifdef CONFIG_CPUMASK_OFFSTACK 357 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 358 #endif 359 } 360 361 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 362 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 363 { 364 return mm->cpu_vm_mask_var; 365 } 366 367 #endif /* _LINUX_MM_TYPES_H */ 368