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 <linux/uprobes.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 fields */ 133 struct kmem_cache *slab_cache; 134 struct slab *slab_page; 135 }; 136 }; 137 138 /* Remainder is not double word aligned */ 139 union { 140 unsigned long private; /* Mapping-private opaque data: 141 * usually used for buffer_heads 142 * if PagePrivate set; used for 143 * swp_entry_t if PageSwapCache; 144 * indicates order in the buddy 145 * system if PG_buddy is set. 146 */ 147#if USE_SPLIT_PTLOCKS 148 spinlock_t ptl; 149#endif 150 struct kmem_cache *slab; /* SLUB: Pointer to slab */ 151 struct page *first_page; /* Compound tail pages */ 152 }; 153 154 /* 155 * On machines where all RAM is mapped into kernel address space, 156 * we can simply calculate the virtual address. On machines with 157 * highmem some memory is mapped into kernel virtual memory 158 * dynamically, so we need a place to store that address. 159 * Note that this field could be 16 bits on x86 ... ;) 160 * 161 * Architectures with slow multiplication can define 162 * WANT_PAGE_VIRTUAL in asm/page.h 163 */ 164#if defined(WANT_PAGE_VIRTUAL) 165 void *virtual; /* Kernel virtual address (NULL if 166 not kmapped, ie. highmem) */ 167#endif /* WANT_PAGE_VIRTUAL */ 168#ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 169 unsigned long debug_flags; /* Use atomic bitops on this */ 170#endif 171 172#ifdef CONFIG_KMEMCHECK 173 /* 174 * kmemcheck wants to track the status of each byte in a page; this 175 * is a pointer to such a status block. NULL if not tracked. 176 */ 177 void *shadow; 178#endif 179} 180/* 181 * The struct page can be forced to be double word aligned so that atomic ops 182 * on double words work. The SLUB allocator can make use of such a feature. 183 */ 184#ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 185 __aligned(2 * sizeof(unsigned long)) 186#endif 187; 188 189struct page_frag { 190 struct page *page; 191#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) 192 __u32 offset; 193 __u32 size; 194#else 195 __u16 offset; 196 __u16 size; 197#endif 198}; 199 200typedef unsigned long __nocast vm_flags_t; 201 202/* 203 * A region containing a mapping of a non-memory backed file under NOMMU 204 * conditions. These are held in a global tree and are pinned by the VMAs that 205 * map parts of them. 206 */ 207struct vm_region { 208 struct rb_node vm_rb; /* link in global region tree */ 209 vm_flags_t vm_flags; /* VMA vm_flags */ 210 unsigned long vm_start; /* start address of region */ 211 unsigned long vm_end; /* region initialised to here */ 212 unsigned long vm_top; /* region allocated to here */ 213 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 214 struct file *vm_file; /* the backing file or NULL */ 215 216 int vm_usage; /* region usage count (access under nommu_region_sem) */ 217 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 218 * this region */ 219}; 220 221/* 222 * This struct defines a memory VMM memory area. There is one of these 223 * per VM-area/task. A VM area is any part of the process virtual memory 224 * space that has a special rule for the page-fault handlers (ie a shared 225 * library, the executable area etc). 226 */ 227struct vm_area_struct { 228 struct mm_struct * vm_mm; /* The address space we belong to. */ 229 unsigned long vm_start; /* Our start address within vm_mm. */ 230 unsigned long vm_end; /* The first byte after our end address 231 within vm_mm. */ 232 233 /* linked list of VM areas per task, sorted by address */ 234 struct vm_area_struct *vm_next, *vm_prev; 235 236 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 237 unsigned long vm_flags; /* Flags, see mm.h. */ 238 239 struct rb_node vm_rb; 240 241 /* 242 * For areas with an address space and backing store, 243 * linkage into the address_space->i_mmap prio tree, or 244 * linkage to the list of like vmas hanging off its node, or 245 * linkage of vma in the address_space->i_mmap_nonlinear list. 246 */ 247 union { 248 struct { 249 struct list_head list; 250 void *parent; /* aligns with prio_tree_node parent */ 251 struct vm_area_struct *head; 252 } vm_set; 253 254 struct raw_prio_tree_node prio_tree_node; 255 } shared; 256 257 /* 258 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 259 * list, after a COW of one of the file pages. A MAP_SHARED vma 260 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 261 * or brk vma (with NULL file) can only be in an anon_vma list. 262 */ 263 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 264 * page_table_lock */ 265 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 266 267 /* Function pointers to deal with this struct. */ 268 const struct vm_operations_struct *vm_ops; 269 270 /* Information about our backing store: */ 271 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 272 units, *not* PAGE_CACHE_SIZE */ 273 struct file * vm_file; /* File we map to (can be NULL). */ 274 void * vm_private_data; /* was vm_pte (shared mem) */ 275 276#ifndef CONFIG_MMU 277 struct vm_region *vm_region; /* NOMMU mapping region */ 278#endif 279#ifdef CONFIG_NUMA 280 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 281#endif 282}; 283 284struct core_thread { 285 struct task_struct *task; 286 struct core_thread *next; 287}; 288 289struct core_state { 290 atomic_t nr_threads; 291 struct core_thread dumper; 292 struct completion startup; 293}; 294 295enum { 296 MM_FILEPAGES, 297 MM_ANONPAGES, 298 MM_SWAPENTS, 299 NR_MM_COUNTERS 300}; 301 302#if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 303#define SPLIT_RSS_COUNTING 304/* per-thread cached information, */ 305struct task_rss_stat { 306 int events; /* for synchronization threshold */ 307 int count[NR_MM_COUNTERS]; 308}; 309#endif /* USE_SPLIT_PTLOCKS */ 310 311struct mm_rss_stat { 312 atomic_long_t count[NR_MM_COUNTERS]; 313}; 314 315struct mm_struct { 316 struct vm_area_struct * mmap; /* list of VMAs */ 317 struct rb_root mm_rb; 318 struct vm_area_struct * mmap_cache; /* last find_vma result */ 319#ifdef CONFIG_MMU 320 unsigned long (*get_unmapped_area) (struct file *filp, 321 unsigned long addr, unsigned long len, 322 unsigned long pgoff, unsigned long flags); 323 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 324#endif 325 unsigned long mmap_base; /* base of mmap area */ 326 unsigned long task_size; /* size of task vm space */ 327 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 328 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 329 pgd_t * pgd; 330 atomic_t mm_users; /* How many users with user space? */ 331 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 332 int map_count; /* number of VMAs */ 333 334 spinlock_t page_table_lock; /* Protects page tables and some counters */ 335 struct rw_semaphore mmap_sem; 336 337 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 338 * together off init_mm.mmlist, and are protected 339 * by mmlist_lock 340 */ 341 342 343 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 344 unsigned long hiwater_vm; /* High-water virtual memory usage */ 345 346 unsigned long total_vm; /* Total pages mapped */ 347 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 348 unsigned long pinned_vm; /* Refcount permanently increased */ 349 unsigned long shared_vm; /* Shared pages (files) */ 350 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */ 351 unsigned long stack_vm; /* VM_GROWSUP/DOWN */ 352 unsigned long reserved_vm; /* VM_RESERVED|VM_IO pages */ 353 unsigned long def_flags; 354 unsigned long nr_ptes; /* Page table pages */ 355 unsigned long start_code, end_code, start_data, end_data; 356 unsigned long start_brk, brk, start_stack; 357 unsigned long arg_start, arg_end, env_start, env_end; 358 359 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 360 361 /* 362 * Special counters, in some configurations protected by the 363 * page_table_lock, in other configurations by being atomic. 364 */ 365 struct mm_rss_stat rss_stat; 366 367 struct linux_binfmt *binfmt; 368 369 cpumask_var_t cpu_vm_mask_var; 370 371 /* Architecture-specific MM context */ 372 mm_context_t context; 373 374 unsigned long flags; /* Must use atomic bitops to access the bits */ 375 376 struct core_state *core_state; /* coredumping support */ 377#ifdef CONFIG_AIO 378 spinlock_t ioctx_lock; 379 struct hlist_head ioctx_list; 380#endif 381#ifdef CONFIG_MM_OWNER 382 /* 383 * "owner" points to a task that is regarded as the canonical 384 * user/owner of this mm. All of the following must be true in 385 * order for it to be changed: 386 * 387 * current == mm->owner 388 * current->mm != mm 389 * new_owner->mm == mm 390 * new_owner->alloc_lock is held 391 */ 392 struct task_struct __rcu *owner; 393#endif 394 395 /* store ref to file /proc/<pid>/exe symlink points to */ 396 struct file *exe_file; 397 unsigned long num_exe_file_vmas; 398#ifdef CONFIG_MMU_NOTIFIER 399 struct mmu_notifier_mm *mmu_notifier_mm; 400#endif 401#ifdef CONFIG_TRANSPARENT_HUGEPAGE 402 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 403#endif 404#ifdef CONFIG_CPUMASK_OFFSTACK 405 struct cpumask cpumask_allocation; 406#endif 407 struct uprobes_state uprobes_state; 408}; 409 410static inline void mm_init_cpumask(struct mm_struct *mm) 411{ 412#ifdef CONFIG_CPUMASK_OFFSTACK 413 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 414#endif 415} 416 417/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 418static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 419{ 420 return mm->cpu_vm_mask_var; 421} 422 423#endif /* _LINUX_MM_TYPES_H */ 424