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 struct page { 35 unsigned long flags; /* Atomic flags, some possibly 36 * updated asynchronously */ 37 atomic_t _count; /* Usage count, see below. */ 38 union { 39 atomic_t _mapcount; /* Count of ptes mapped in mms, 40 * to show when page is mapped 41 * & limit reverse map searches. 42 */ 43 struct { /* SLUB */ 44 u16 inuse; 45 u16 objects; 46 }; 47 }; 48 union { 49 struct { 50 unsigned long private; /* Mapping-private opaque data: 51 * usually used for buffer_heads 52 * if PagePrivate set; used for 53 * swp_entry_t if PageSwapCache; 54 * indicates order in the buddy 55 * system if PG_buddy is set. 56 */ 57 struct address_space *mapping; /* If low bit clear, points to 58 * inode address_space, or NULL. 59 * If page mapped as anonymous 60 * memory, low bit is set, and 61 * it points to anon_vma object: 62 * see PAGE_MAPPING_ANON below. 63 */ 64 }; 65 #if USE_SPLIT_PTLOCKS 66 spinlock_t ptl; 67 #endif 68 struct kmem_cache *slab; /* SLUB: Pointer to slab */ 69 struct page *first_page; /* Compound tail pages */ 70 }; 71 union { 72 pgoff_t index; /* Our offset within mapping. */ 73 void *freelist; /* SLUB: freelist req. slab lock */ 74 }; 75 struct list_head lru; /* Pageout list, eg. active_list 76 * protected by zone->lru_lock ! 77 */ 78 /* 79 * On machines where all RAM is mapped into kernel address space, 80 * we can simply calculate the virtual address. On machines with 81 * highmem some memory is mapped into kernel virtual memory 82 * dynamically, so we need a place to store that address. 83 * Note that this field could be 16 bits on x86 ... ;) 84 * 85 * Architectures with slow multiplication can define 86 * WANT_PAGE_VIRTUAL in asm/page.h 87 */ 88 #if defined(WANT_PAGE_VIRTUAL) 89 void *virtual; /* Kernel virtual address (NULL if 90 not kmapped, ie. highmem) */ 91 #endif /* WANT_PAGE_VIRTUAL */ 92 #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS 93 unsigned long debug_flags; /* Use atomic bitops on this */ 94 #endif 95 96 #ifdef CONFIG_KMEMCHECK 97 /* 98 * kmemcheck wants to track the status of each byte in a page; this 99 * is a pointer to such a status block. NULL if not tracked. 100 */ 101 void *shadow; 102 #endif 103 }; 104 105 typedef unsigned long __nocast vm_flags_t; 106 107 /* 108 * A region containing a mapping of a non-memory backed file under NOMMU 109 * conditions. These are held in a global tree and are pinned by the VMAs that 110 * map parts of them. 111 */ 112 struct vm_region { 113 struct rb_node vm_rb; /* link in global region tree */ 114 vm_flags_t vm_flags; /* VMA vm_flags */ 115 unsigned long vm_start; /* start address of region */ 116 unsigned long vm_end; /* region initialised to here */ 117 unsigned long vm_top; /* region allocated to here */ 118 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 119 struct file *vm_file; /* the backing file or NULL */ 120 121 int vm_usage; /* region usage count (access under nommu_region_sem) */ 122 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 123 * this region */ 124 }; 125 126 /* 127 * This struct defines a memory VMM memory area. There is one of these 128 * per VM-area/task. A VM area is any part of the process virtual memory 129 * space that has a special rule for the page-fault handlers (ie a shared 130 * library, the executable area etc). 131 */ 132 struct vm_area_struct { 133 struct mm_struct * vm_mm; /* The address space we belong to. */ 134 unsigned long vm_start; /* Our start address within vm_mm. */ 135 unsigned long vm_end; /* The first byte after our end address 136 within vm_mm. */ 137 138 /* linked list of VM areas per task, sorted by address */ 139 struct vm_area_struct *vm_next, *vm_prev; 140 141 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 142 unsigned long vm_flags; /* Flags, see mm.h. */ 143 144 struct rb_node vm_rb; 145 146 /* 147 * For areas with an address space and backing store, 148 * linkage into the address_space->i_mmap prio tree, or 149 * linkage to the list of like vmas hanging off its node, or 150 * linkage of vma in the address_space->i_mmap_nonlinear list. 151 */ 152 union { 153 struct { 154 struct list_head list; 155 void *parent; /* aligns with prio_tree_node parent */ 156 struct vm_area_struct *head; 157 } vm_set; 158 159 struct raw_prio_tree_node prio_tree_node; 160 } shared; 161 162 /* 163 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 164 * list, after a COW of one of the file pages. A MAP_SHARED vma 165 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 166 * or brk vma (with NULL file) can only be in an anon_vma list. 167 */ 168 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 169 * page_table_lock */ 170 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 171 172 /* Function pointers to deal with this struct. */ 173 const struct vm_operations_struct *vm_ops; 174 175 /* Information about our backing store: */ 176 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 177 units, *not* PAGE_CACHE_SIZE */ 178 struct file * vm_file; /* File we map to (can be NULL). */ 179 void * vm_private_data; /* was vm_pte (shared mem) */ 180 181 #ifndef CONFIG_MMU 182 struct vm_region *vm_region; /* NOMMU mapping region */ 183 #endif 184 #ifdef CONFIG_NUMA 185 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 186 #endif 187 }; 188 189 struct core_thread { 190 struct task_struct *task; 191 struct core_thread *next; 192 }; 193 194 struct core_state { 195 atomic_t nr_threads; 196 struct core_thread dumper; 197 struct completion startup; 198 }; 199 200 enum { 201 MM_FILEPAGES, 202 MM_ANONPAGES, 203 MM_SWAPENTS, 204 NR_MM_COUNTERS 205 }; 206 207 #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU) 208 #define SPLIT_RSS_COUNTING 209 /* per-thread cached information, */ 210 struct task_rss_stat { 211 int events; /* for synchronization threshold */ 212 int count[NR_MM_COUNTERS]; 213 }; 214 #endif /* USE_SPLIT_PTLOCKS */ 215 216 struct mm_rss_stat { 217 atomic_long_t count[NR_MM_COUNTERS]; 218 }; 219 220 struct mm_struct { 221 struct vm_area_struct * mmap; /* list of VMAs */ 222 struct rb_root mm_rb; 223 struct vm_area_struct * mmap_cache; /* last find_vma result */ 224 #ifdef CONFIG_MMU 225 unsigned long (*get_unmapped_area) (struct file *filp, 226 unsigned long addr, unsigned long len, 227 unsigned long pgoff, unsigned long flags); 228 void (*unmap_area) (struct mm_struct *mm, unsigned long addr); 229 #endif 230 unsigned long mmap_base; /* base of mmap area */ 231 unsigned long task_size; /* size of task vm space */ 232 unsigned long cached_hole_size; /* if non-zero, the largest hole below free_area_cache */ 233 unsigned long free_area_cache; /* first hole of size cached_hole_size or larger */ 234 pgd_t * pgd; 235 atomic_t mm_users; /* How many users with user space? */ 236 atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ 237 int map_count; /* number of VMAs */ 238 239 spinlock_t page_table_lock; /* Protects page tables and some counters */ 240 struct rw_semaphore mmap_sem; 241 242 struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung 243 * together off init_mm.mmlist, and are protected 244 * by mmlist_lock 245 */ 246 247 248 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 249 unsigned long hiwater_vm; /* High-water virtual memory usage */ 250 251 unsigned long total_vm, locked_vm, shared_vm, exec_vm; 252 unsigned long stack_vm, reserved_vm, def_flags, nr_ptes; 253 unsigned long start_code, end_code, start_data, end_data; 254 unsigned long start_brk, brk, start_stack; 255 unsigned long arg_start, arg_end, env_start, env_end; 256 257 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 258 259 /* 260 * Special counters, in some configurations protected by the 261 * page_table_lock, in other configurations by being atomic. 262 */ 263 struct mm_rss_stat rss_stat; 264 265 struct linux_binfmt *binfmt; 266 267 cpumask_var_t cpu_vm_mask_var; 268 269 /* Architecture-specific MM context */ 270 mm_context_t context; 271 272 /* Swap token stuff */ 273 /* 274 * Last value of global fault stamp as seen by this process. 275 * In other words, this value gives an indication of how long 276 * it has been since this task got the token. 277 * Look at mm/thrash.c 278 */ 279 unsigned int faultstamp; 280 unsigned int token_priority; 281 unsigned int last_interval; 282 283 /* How many tasks sharing this mm are OOM_DISABLE */ 284 atomic_t oom_disable_count; 285 286 unsigned long flags; /* Must use atomic bitops to access the bits */ 287 288 struct core_state *core_state; /* coredumping support */ 289 #ifdef CONFIG_AIO 290 spinlock_t ioctx_lock; 291 struct hlist_head ioctx_list; 292 #endif 293 #ifdef CONFIG_MM_OWNER 294 /* 295 * "owner" points to a task that is regarded as the canonical 296 * user/owner of this mm. All of the following must be true in 297 * order for it to be changed: 298 * 299 * current == mm->owner 300 * current->mm != mm 301 * new_owner->mm == mm 302 * new_owner->alloc_lock is held 303 */ 304 struct task_struct __rcu *owner; 305 #endif 306 307 /* store ref to file /proc/<pid>/exe symlink points to */ 308 struct file *exe_file; 309 unsigned long num_exe_file_vmas; 310 #ifdef CONFIG_MMU_NOTIFIER 311 struct mmu_notifier_mm *mmu_notifier_mm; 312 #endif 313 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 314 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 315 #endif 316 #ifdef CONFIG_CPUMASK_OFFSTACK 317 struct cpumask cpumask_allocation; 318 #endif 319 }; 320 321 static inline void mm_init_cpumask(struct mm_struct *mm) 322 { 323 #ifdef CONFIG_CPUMASK_OFFSTACK 324 mm->cpu_vm_mask_var = &mm->cpumask_allocation; 325 #endif 326 } 327 328 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 329 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 330 { 331 return mm->cpu_vm_mask_var; 332 } 333 334 #endif /* _LINUX_MM_TYPES_H */ 335