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 <linux/page-flags-layout.h> 16#include <asm/page.h> 17#include <asm/mmu.h> 18 19#ifndef AT_VECTOR_SIZE_ARCH 20#define AT_VECTOR_SIZE_ARCH 0 21#endif 22#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 23 24struct address_space; 25 26#define USE_SPLIT_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS) 27 28/* 29 * Each physical page in the system has a struct page associated with 30 * it to keep track of whatever it is we are using the page for at the 31 * moment. Note that we have no way to track which tasks are using 32 * a page, though if it is a pagecache page, rmap structures can tell us 33 * who is mapping it. 34 * 35 * The objects in struct page are organized in double word blocks in 36 * order to allows us to use atomic double word operations on portions 37 * of struct page. That is currently only used by slub but the arrangement 38 * allows the use of atomic double word operations on the flags/mapping 39 * and lru list pointers also. 40 */ 41struct page { 42 /* First double word block */ 43 unsigned long flags; /* Atomic flags, some possibly 44 * updated asynchronously */ 45 struct address_space *mapping; /* If low bit clear, points to 46 * inode address_space, or NULL. 47 * If page mapped as anonymous 48 * memory, low bit is set, and 49 * it points to anon_vma object: 50 * see PAGE_MAPPING_ANON below. 51 */ 52 /* Second double word */ 53 struct { 54 union { 55 pgoff_t index; /* Our offset within mapping. */ 56 void *freelist; /* slub/slob first free object */ 57 bool pfmemalloc; /* If set by the page allocator, 58 * ALLOC_NO_WATERMARKS was set 59 * and the low watermark was not 60 * met implying that the system 61 * is under some pressure. The 62 * caller should try ensure 63 * this page is only used to 64 * free other pages. 65 */ 66 }; 67 68 union { 69#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ 70 defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) 71 /* Used for cmpxchg_double in slub */ 72 unsigned long counters; 73#else 74 /* 75 * Keep _count separate from slub cmpxchg_double data. 76 * As the rest of the double word is protected by 77 * slab_lock but _count is not. 78 */ 79 unsigned counters; 80#endif 81 82 struct { 83 84 union { 85 /* 86 * Count of ptes mapped in 87 * mms, to show when page is 88 * mapped & limit reverse map 89 * searches. 90 * 91 * Used also for tail pages 92 * refcounting instead of 93 * _count. Tail pages cannot 94 * be mapped and keeping the 95 * tail page _count zero at 96 * all times guarantees 97 * get_page_unless_zero() will 98 * never succeed on tail 99 * pages. 100 */ 101 atomic_t _mapcount; 102 103 struct { /* SLUB */ 104 unsigned inuse:16; 105 unsigned objects:15; 106 unsigned frozen:1; 107 }; 108 int units; /* SLOB */ 109 }; 110 atomic_t _count; /* Usage count, see below. */ 111 }; 112 }; 113 }; 114 115 /* Third double word block */ 116 union { 117 struct list_head lru; /* Pageout list, eg. active_list 118 * protected by zone->lru_lock ! 119 */ 120 struct { /* slub per cpu partial pages */ 121 struct page *next; /* Next partial slab */ 122#ifdef CONFIG_64BIT 123 int pages; /* Nr of partial slabs left */ 124 int pobjects; /* Approximate # of objects */ 125#else 126 short int pages; 127 short int pobjects; 128#endif 129 }; 130 131 struct list_head list; /* slobs list of pages */ 132 struct slab *slab_page; /* slab fields */ 133 }; 134 135 /* Remainder is not double word aligned */ 136 union { 137 unsigned long private; /* Mapping-private opaque data: 138 * usually used for buffer_heads 139 * if PagePrivate set; used for 140 * swp_entry_t if PageSwapCache; 141 * indicates order in the buddy 142 * system if PG_buddy is set. 143 */ 144#if USE_SPLIT_PTLOCKS 145 spinlock_t ptl; 146#endif 147 struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */ 148 struct page *first_page; /* Compound tail pages */ 149 }; 150 151 /* 152 * On machines where all RAM is mapped into kernel address space, 153 * we can simply calculate the virtual address. On machines with 154 * highmem some memory is mapped into kernel virtual memory 155 * dynamically, so we need a place to store that address. 156 * Note that this field could be 16 bits on x86 ... ;) 157 * 158 * Architectures with slow multiplication can define 159 * WANT_PAGE_VIRTUAL in asm/page.h 160 */ 161#if defined(WANT_PAGE_VIRTUAL) 162 void *virtual; /* Kernel virtual address (NULL if 163 not kmapped, ie. highmem) */ 164#endif /* WANT_PAGE_VIRTUAL */ 165#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 166 unsigned long debug_flags; /* Use atomic bitops on this */ 167#endif 168 169#ifdef CONFIG_KMEMCHECK 170 /* 171 * kmemcheck wants to track the status of each byte in a page; this 172 * is a pointer to such a status block. NULL if not tracked. 173 */ 174 void *shadow; 175#endif 176 177#ifdef LAST_NID_NOT_IN_PAGE_FLAGS 178 int _last_nid; 179#endif 180} 181/* 182 * The struct page can be forced to be double word aligned so that atomic ops 183 * on double words work. The SLUB allocator can make use of such a feature. 184 */ 185#ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 186 __aligned(2 * sizeof(unsigned long)) 187#endif 188; 189 190struct page_frag { 191 struct page *page; 192#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 193 __u32 offset; 194 __u32 size; 195#else 196 __u16 offset; 197 __u16 size; 198#endif 199}; 200 201typedef unsigned long __nocast vm_flags_t; 202 203/* 204 * A region containing a mapping of a non-memory backed file under NOMMU 205 * conditions. These are held in a global tree and are pinned by the VMAs that 206 * map parts of them. 207 */ 208struct vm_region { 209 struct rb_node vm_rb; /* link in global region tree */ 210 vm_flags_t vm_flags; /* VMA vm_flags */ 211 unsigned long vm_start; /* start address of region */ 212 unsigned long vm_end; /* region initialised to here */ 213 unsigned long vm_top; /* region allocated to here */ 214 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 215 struct file *vm_file; /* the backing file or NULL */ 216 217 int vm_usage; /* region usage count (access under nommu_region_sem) */ 218 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 219 * this region */ 220}; 221 222/* 223 * This struct defines a memory VMM memory area. There is one of these 224 * per VM-area/task. A VM area is any part of the process virtual memory 225 * space that has a special rule for the page-fault handlers (ie a shared 226 * library, the executable area etc). 227 */ 228struct vm_area_struct { 229 /* The first cache line has the info for VMA tree walking. */ 230 231 unsigned long vm_start; /* Our start address within vm_mm. */ 232 unsigned long vm_end; /* The first byte after our end address 233 within vm_mm. */ 234 235 /* linked list of VM areas per task, sorted by address */ 236 struct vm_area_struct *vm_next, *vm_prev; 237 238 struct rb_node vm_rb; 239 240 /* 241 * Largest free memory gap in bytes to the left of this VMA. 242 * Either between this VMA and vma->vm_prev, or between one of the 243 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps 244 * get_unmapped_area find a free area of the right size. 245 */ 246 unsigned long rb_subtree_gap; 247 248 /* Second cache line starts here. */ 249 250 struct mm_struct *vm_mm; /* The address space we belong to. */ 251 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 252 unsigned long vm_flags; /* Flags, see mm.h. */ 253 254 /* 255 * For areas with an address space and backing store, 256 * linkage into the address_space->i_mmap interval tree, or 257 * linkage of vma in the address_space->i_mmap_nonlinear list. 258 */ 259 union { 260 struct { 261 struct rb_node rb; 262 unsigned long rb_subtree_last; 263 } linear; 264 struct list_head nonlinear; 265 } shared; 266 267 /* 268 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 269 * list, after a COW of one of the file pages. A MAP_SHARED vma 270 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 271 * or brk vma (with NULL file) can only be in an anon_vma list. 272 */ 273 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 274 * page_table_lock */ 275 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 276 277 /* Function pointers to deal with this struct. */ 278 const struct vm_operations_struct *vm_ops; 279 280 /* Information about our backing store: */ 281 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 282 units, *not* PAGE_CACHE_SIZE */ 283 struct file * vm_file; /* File we map to (can be NULL). */ 284 void * vm_private_data; /* was vm_pte (shared mem) */ 285 286#ifndef CONFIG_MMU 287 struct vm_region *vm_region; /* NOMMU mapping region */ 288#endif 289#ifdef CONFIG_NUMA 290 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 291#endif 292}; 293 294struct core_thread { 295 struct task_struct *task; 296 struct core_thread *next; 297}; 298 299struct core_state { 300 atomic_t nr_threads; 301 struct core_thread dumper; 302 struct completion startup; 303}; 304 305enum { 306 MM_FILEPAGES, 307 MM_ANONPAGES, 308 MM_SWAPENTS, 309 NR_MM_COUNTERS 310}; 311 312#if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 313#define SPLIT_RSS_COUNTING 314/* per-thread cached information, */ 315struct task_rss_stat { 316 int events; /* for synchronization threshold */ 317 int count[NR_MM_COUNTERS]; 318}; 319#endif /* USE_SPLIT_PTLOCKS */ 320 321struct mm_rss_stat { 322 atomic_long_t count[NR_MM_COUNTERS]; 323}; 324 325struct mm_struct { 326 struct vm_area_struct * mmap; /* list of VMAs */ 327 struct rb_root mm_rb; 328 struct vm_area_struct * mmap_cache; /* last find_vma result */ 329#ifdef CONFIG_MMU 330 unsigned long (*get_unmapped_area) (struct file *filp, 331 unsigned long addr, unsigned long len, 332 unsigned long pgoff, unsigned long flags); 333#endif 334 unsigned long mmap_base; /* base of mmap area */ 335 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 336 unsigned long task_size; /* size of task vm space */ 337 unsigned long highest_vm_end; /* highest vma end address */ 338 pgd_t * pgd; 339 atomic_t mm_users; /* How many users with user space? */ 340 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 341 int map_count; /* number of VMAs */ 342 343 spinlock_t page_table_lock; /* Protects page tables and some counters */ 344 struct rw_semaphore mmap_sem; 345 346 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 347 * together off init_mm.mmlist, and are protected 348 * by mmlist_lock 349 */ 350 351 352 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 353 unsigned long hiwater_vm; /* High-water virtual memory usage */ 354 355 unsigned long total_vm; /* Total pages mapped */ 356 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 357 unsigned long pinned_vm; /* Refcount permanently increased */ 358 unsigned long shared_vm; /* Shared pages (files) */ 359 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */ 360 unsigned long stack_vm; /* VM_GROWSUP/DOWN */ 361 unsigned long def_flags; 362 unsigned long nr_ptes; /* Page table pages */ 363 unsigned long start_code, end_code, start_data, end_data; 364 unsigned long start_brk, brk, start_stack; 365 unsigned long arg_start, arg_end, env_start, env_end; 366 367 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 368 369 /* 370 * Special counters, in some configurations protected by the 371 * page_table_lock, in other configurations by being atomic. 372 */ 373 struct mm_rss_stat rss_stat; 374 375 struct linux_binfmt *binfmt; 376 377 cpumask_var_t cpu_vm_mask_var; 378 379 /* Architecture-specific MM context */ 380 mm_context_t context; 381 382 unsigned long flags; /* Must use atomic bitops to access the bits */ 383 384 struct core_state *core_state; /* coredumping support */ 385#ifdef CONFIG_AIO 386 spinlock_t ioctx_lock; 387 struct hlist_head ioctx_list; 388#endif 389#ifdef CONFIG_MM_OWNER 390 /* 391 * "owner" points to a task that is regarded as the canonical 392 * user/owner of this mm. All of the following must be true in 393 * order for it to be changed: 394 * 395 * current == mm->owner 396 * current->mm != mm 397 * new_owner->mm == mm 398 * new_owner->alloc_lock is held 399 */ 400 struct task_struct __rcu *owner; 401#endif 402 403 /* store ref to file /proc/<pid>/exe symlink points to */ 404 struct file *exe_file; 405#ifdef CONFIG_MMU_NOTIFIER 406 struct mmu_notifier_mm *mmu_notifier_mm; 407#endif 408#ifdef CONFIG_TRANSPARENT_HUGEPAGE 409 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 410#endif 411#ifdef CONFIG_CPUMASK_OFFSTACK 412 struct cpumask cpumask_allocation; 413#endif 414#ifdef CONFIG_NUMA_BALANCING 415 /* 416 * numa_next_scan is the next time that the PTEs will be marked 417 * pte_numa. NUMA hinting faults will gather statistics and migrate 418 * pages to new nodes if necessary. 419 */ 420 unsigned long numa_next_scan; 421 422 /* numa_next_reset is when the PTE scanner period will be reset */ 423 unsigned long numa_next_reset; 424 425 /* Restart point for scanning and setting pte_numa */ 426 unsigned long numa_scan_offset; 427 428 /* numa_scan_seq prevents two threads setting pte_numa */ 429 int numa_scan_seq; 430 431 /* 432 * The first node a task was scheduled on. If a task runs on 433 * a different node than Make PTE Scan Go Now. 434 */ 435 int first_nid; 436#endif 437 struct uprobes_state uprobes_state; 438}; 439 440/* first nid will either be a valid NID or one of these values */ 441#define NUMA_PTE_SCAN_INIT -1 442#define NUMA_PTE_SCAN_ACTIVE -2 443 444static inline void mm_init_cpumask(struct mm_struct *mm) 445{ 446#ifdef CONFIG_CPUMASK_OFFSTACK 447 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 448#endif 449} 450 451/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 452static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 453{ 454 return mm->cpu_vm_mask_var; 455} 456 457#endif /* _LINUX_MM_TYPES_H */ 458