1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _LINUX_MM_TYPES_H 3 #define _LINUX_MM_TYPES_H 4 5 #include <linux/mm_types_task.h> 6 7 #include <linux/auxvec.h> 8 #include <linux/kref.h> 9 #include <linux/list.h> 10 #include <linux/spinlock.h> 11 #include <linux/rbtree.h> 12 #include <linux/rwsem.h> 13 #include <linux/completion.h> 14 #include <linux/cpumask.h> 15 #include <linux/uprobes.h> 16 #include <linux/page-flags-layout.h> 17 #include <linux/workqueue.h> 18 #include <linux/seqlock.h> 19 #include <linux/android_kabi.h> 20 21 #include <asm/mmu.h> 22 23 #ifndef AT_VECTOR_SIZE_ARCH 24 #define AT_VECTOR_SIZE_ARCH 0 25 #endif 26 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 27 28 #define INIT_PASID 0 29 30 struct address_space; 31 struct mem_cgroup; 32 33 /* 34 * Each physical page in the system has a struct page associated with 35 * it to keep track of whatever it is we are using the page for at the 36 * moment. Note that we have no way to track which tasks are using 37 * a page, though if it is a pagecache page, rmap structures can tell us 38 * who is mapping it. 39 * 40 * If you allocate the page using alloc_pages(), you can use some of the 41 * space in struct page for your own purposes. The five words in the main 42 * union are available, except for bit 0 of the first word which must be 43 * kept clear. Many users use this word to store a pointer to an object 44 * which is guaranteed to be aligned. If you use the same storage as 45 * page->mapping, you must restore it to NULL before freeing the page. 46 * 47 * If your page will not be mapped to userspace, you can also use the four 48 * bytes in the mapcount union, but you must call page_mapcount_reset() 49 * before freeing it. 50 * 51 * If you want to use the refcount field, it must be used in such a way 52 * that other CPUs temporarily incrementing and then decrementing the 53 * refcount does not cause problems. On receiving the page from 54 * alloc_pages(), the refcount will be positive. 55 * 56 * If you allocate pages of order > 0, you can use some of the fields 57 * in each subpage, but you may need to restore some of their values 58 * afterwards. 59 * 60 * SLUB uses cmpxchg_double() to atomically update its freelist and 61 * counters. That requires that freelist & counters be adjacent and 62 * double-word aligned. We align all struct pages to double-word 63 * boundaries, and ensure that 'freelist' is aligned within the 64 * struct. 65 */ 66 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 67 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) 68 #else 69 #define _struct_page_alignment 70 #endif 71 72 struct page { 73 unsigned long flags; /* Atomic flags, some possibly 74 * updated asynchronously */ 75 /* 76 * Five words (20/40 bytes) are available in this union. 77 * WARNING: bit 0 of the first word is used for PageTail(). That 78 * means the other users of this union MUST NOT use the bit to 79 * avoid collision and false-positive PageTail(). 80 */ 81 union { 82 struct { /* Page cache and anonymous pages */ 83 union { 84 /** 85 * @lru: Pageout list, eg. active_list protected by 86 * lruvec->lru_lock. Sometimes used as a generic list 87 * by the page owner. 88 */ 89 struct list_head lru; 90 91 /* Or, free page */ 92 struct list_head buddy_list; 93 struct list_head pcp_list; 94 }; 95 /* See page-flags.h for PAGE_MAPPING_FLAGS */ 96 struct address_space *mapping; 97 pgoff_t index; /* Our offset within mapping. */ 98 /** 99 * @private: Mapping-private opaque data. 100 * Usually used for buffer_heads if PagePrivate. 101 * Used for swp_entry_t if PageSwapCache. 102 * Indicates order in the buddy system if PageBuddy. 103 */ 104 unsigned long private; 105 }; 106 struct { /* page_pool used by netstack */ 107 /** 108 * @pp_magic: magic value to avoid recycling non 109 * page_pool allocated pages. 110 */ 111 unsigned long pp_magic; 112 struct page_pool *pp; 113 unsigned long _pp_mapping_pad; 114 unsigned long dma_addr; 115 union { 116 /** 117 * dma_addr_upper: might require a 64-bit 118 * value on 32-bit architectures. 119 */ 120 unsigned long dma_addr_upper; 121 /** 122 * For frag page support, not supported in 123 * 32-bit architectures with 64-bit DMA. 124 */ 125 atomic_long_t pp_frag_count; 126 }; 127 }; 128 struct { /* slab, slob and slub */ 129 union { 130 struct list_head slab_list; 131 struct { /* Partial pages */ 132 struct page *next; 133 #ifdef CONFIG_64BIT 134 int pages; /* Nr of pages left */ 135 int pobjects; /* Approximate count */ 136 #else 137 short int pages; 138 short int pobjects; 139 #endif 140 }; 141 }; 142 struct kmem_cache *slab_cache; /* not slob */ 143 /* Double-word boundary */ 144 void *freelist; /* first free object */ 145 union { 146 void *s_mem; /* slab: first object */ 147 unsigned long counters; /* SLUB */ 148 struct { /* SLUB */ 149 unsigned inuse:16; 150 unsigned objects:15; 151 unsigned frozen:1; 152 }; 153 }; 154 }; 155 struct { /* Tail pages of compound page */ 156 unsigned long compound_head; /* Bit zero is set */ 157 158 /* First tail page only */ 159 unsigned char compound_dtor; 160 unsigned char compound_order; 161 atomic_t compound_mapcount; 162 unsigned int compound_nr; /* 1 << compound_order */ 163 }; 164 struct { /* Second tail page of compound page */ 165 unsigned long _compound_pad_1; /* compound_head */ 166 atomic_t hpage_pinned_refcount; 167 /* For both global and memcg */ 168 struct list_head deferred_list; 169 }; 170 struct { /* Page table pages */ 171 unsigned long _pt_pad_1; /* compound_head */ 172 pgtable_t pmd_huge_pte; /* protected by page->ptl */ 173 unsigned long _pt_pad_2; /* mapping */ 174 union { 175 struct mm_struct *pt_mm; /* x86 pgds only */ 176 atomic_t pt_frag_refcount; /* powerpc */ 177 }; 178 #if ALLOC_SPLIT_PTLOCKS 179 spinlock_t *ptl; 180 #else 181 spinlock_t ptl; 182 #endif 183 }; 184 struct { /* ZONE_DEVICE pages */ 185 /** @pgmap: Points to the hosting device page map. */ 186 struct dev_pagemap *pgmap; 187 void *zone_device_data; 188 /* 189 * ZONE_DEVICE private pages are counted as being 190 * mapped so the next 3 words hold the mapping, index, 191 * and private fields from the source anonymous or 192 * page cache page while the page is migrated to device 193 * private memory. 194 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also 195 * use the mapping, index, and private fields when 196 * pmem backed DAX files are mapped. 197 */ 198 }; 199 200 /** @rcu_head: You can use this to free a page by RCU. */ 201 struct rcu_head rcu_head; 202 }; 203 204 union { /* This union is 4 bytes in size. */ 205 /* 206 * If the page can be mapped to userspace, encodes the number 207 * of times this page is referenced by a page table. 208 */ 209 atomic_t _mapcount; 210 211 /* 212 * If the page is neither PageSlab nor mappable to userspace, 213 * the value stored here may help determine what this page 214 * is used for. See page-flags.h for a list of page types 215 * which are currently stored here. 216 */ 217 unsigned int page_type; 218 219 unsigned int active; /* SLAB */ 220 int units; /* SLOB */ 221 }; 222 223 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ 224 atomic_t _refcount; 225 226 #ifdef CONFIG_MEMCG 227 unsigned long memcg_data; 228 #endif 229 230 /* 231 * On machines where all RAM is mapped into kernel address space, 232 * we can simply calculate the virtual address. On machines with 233 * highmem some memory is mapped into kernel virtual memory 234 * dynamically, so we need a place to store that address. 235 * Note that this field could be 16 bits on x86 ... ;) 236 * 237 * Architectures with slow multiplication can define 238 * WANT_PAGE_VIRTUAL in asm/page.h 239 */ 240 #if defined(WANT_PAGE_VIRTUAL) 241 void *virtual; /* Kernel virtual address (NULL if 242 not kmapped, ie. highmem) */ 243 #endif /* WANT_PAGE_VIRTUAL */ 244 245 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 246 int _last_cpupid; 247 #endif 248 } _struct_page_alignment; 249 compound_mapcount_ptr(struct page * page)250 static inline atomic_t *compound_mapcount_ptr(struct page *page) 251 { 252 return &page[1].compound_mapcount; 253 } 254 compound_pincount_ptr(struct page * page)255 static inline atomic_t *compound_pincount_ptr(struct page *page) 256 { 257 return &page[2].hpage_pinned_refcount; 258 } 259 260 /* 261 * Used for sizing the vmemmap region on some architectures 262 */ 263 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 264 265 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) 266 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) 267 268 #define page_private(page) ((page)->private) 269 set_page_private(struct page * page,unsigned long private)270 static inline void set_page_private(struct page *page, unsigned long private) 271 { 272 page->private = private; 273 } 274 275 struct page_frag_cache { 276 void * va; 277 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 278 __u16 offset; 279 __u16 size; 280 #else 281 __u32 offset; 282 #endif 283 /* we maintain a pagecount bias, so that we dont dirty cache line 284 * containing page->_refcount every time we allocate a fragment. 285 */ 286 unsigned int pagecnt_bias; 287 bool pfmemalloc; 288 }; 289 290 typedef unsigned long vm_flags_t; 291 292 /* 293 * A region containing a mapping of a non-memory backed file under NOMMU 294 * conditions. These are held in a global tree and are pinned by the VMAs that 295 * map parts of them. 296 */ 297 struct vm_region { 298 struct rb_node vm_rb; /* link in global region tree */ 299 vm_flags_t vm_flags; /* VMA vm_flags */ 300 unsigned long vm_start; /* start address of region */ 301 unsigned long vm_end; /* region initialised to here */ 302 unsigned long vm_top; /* region allocated to here */ 303 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 304 struct file *vm_file; /* the backing file or NULL */ 305 306 int vm_usage; /* region usage count (access under nommu_region_sem) */ 307 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 308 * this region */ 309 }; 310 311 #ifdef CONFIG_USERFAULTFD 312 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 313 struct vm_userfaultfd_ctx { 314 struct userfaultfd_ctx __rcu *ctx; 315 }; 316 #else /* CONFIG_USERFAULTFD */ 317 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 318 struct vm_userfaultfd_ctx {}; 319 #endif /* CONFIG_USERFAULTFD */ 320 321 struct anon_vma_name { 322 struct kref kref; 323 /* The name needs to be at the end because it is dynamically sized. */ 324 char name[]; 325 }; 326 327 /* 328 * This struct describes a virtual memory area. There is one of these 329 * per VM-area/task. A VM area is any part of the process virtual memory 330 * space that has a special rule for the page-fault handlers (ie a shared 331 * library, the executable area etc). 332 * 333 * Note that speculative page faults make an on-stack copy of the VMA, 334 * so the structure size matters. 335 * (TODO - it would be preferable to copy only the required vma attributes 336 * rather than the entire vma). 337 */ 338 struct vm_area_struct { 339 /* The first cache line has the info for VMA tree walking. */ 340 341 union { 342 struct { 343 /* VMA covers [vm_start; vm_end) addresses within mm */ 344 unsigned long vm_start, vm_end; 345 346 /* linked list of VMAs per task, sorted by address */ 347 struct vm_area_struct *vm_next, *vm_prev; 348 }; 349 #ifdef CONFIG_SPECULATIVE_PAGE_FAULT 350 struct rcu_head vm_rcu; /* Used for deferred freeing. */ 351 #endif 352 }; 353 354 struct rb_node vm_rb; 355 356 /* 357 * Largest free memory gap in bytes to the left of this VMA. 358 * Either between this VMA and vma->vm_prev, or between one of the 359 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps 360 * get_unmapped_area find a free area of the right size. 361 */ 362 unsigned long rb_subtree_gap; 363 364 /* Second cache line starts here. */ 365 366 struct mm_struct *vm_mm; /* The address space we belong to. */ 367 368 /* 369 * Access permissions of this VMA. 370 * See vmf_insert_mixed_prot() for discussion. 371 */ 372 pgprot_t vm_page_prot; 373 unsigned long vm_flags; /* Flags, see mm.h. */ 374 375 /* 376 * For areas with an address space and backing store, 377 * linkage into the address_space->i_mmap interval tree. 378 * 379 * For private anonymous mappings, a pointer to a null terminated string 380 * containing the name given to the vma, or NULL if unnamed. 381 */ 382 383 union { 384 struct { 385 struct rb_node rb; 386 unsigned long rb_subtree_last; 387 } shared; 388 /* 389 * Serialized by mmap_sem. Never use directly because it is 390 * valid only when vm_file is NULL. Use anon_vma_name instead. 391 */ 392 struct anon_vma_name *anon_name; 393 }; 394 395 /* 396 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 397 * list, after a COW of one of the file pages. A MAP_SHARED vma 398 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 399 * or brk vma (with NULL file) can only be in an anon_vma list. 400 */ 401 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 402 * page_table_lock */ 403 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 404 405 /* Function pointers to deal with this struct. */ 406 const struct vm_operations_struct *vm_ops; 407 408 /* Information about our backing store: */ 409 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 410 units */ 411 struct file * vm_file; /* File we map to (can be NULL). */ 412 void * vm_private_data; /* was vm_pte (shared mem) */ 413 414 #ifdef CONFIG_SWAP 415 atomic_long_t swap_readahead_info; 416 #endif 417 #ifndef CONFIG_MMU 418 struct vm_region *vm_region; /* NOMMU mapping region */ 419 #endif 420 #ifdef CONFIG_NUMA 421 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 422 #endif 423 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 424 #ifdef CONFIG_SPECULATIVE_PAGE_FAULT 425 /* 426 * The name does not reflect the usage and is not renamed to keep 427 * the ABI intact. 428 * This is used to refcount VMA in get_vma/put_vma. 429 */ 430 atomic_t file_ref_count; 431 #endif 432 433 ANDROID_KABI_RESERVE(1); 434 ANDROID_KABI_RESERVE(2); 435 ANDROID_KABI_RESERVE(3); 436 ANDROID_KABI_RESERVE(4); 437 } __randomize_layout; 438 439 struct core_thread { 440 struct task_struct *task; 441 struct core_thread *next; 442 }; 443 444 struct core_state { 445 atomic_t nr_threads; 446 struct core_thread dumper; 447 struct completion startup; 448 }; 449 450 struct kioctx_table; 451 struct percpu_rw_semaphore; 452 struct mm_struct { 453 struct { 454 struct vm_area_struct *mmap; /* list of VMAs */ 455 struct rb_root mm_rb; 456 u64 vmacache_seqnum; /* per-thread vmacache */ 457 #ifdef CONFIG_MMU 458 unsigned long (*get_unmapped_area) (struct file *filp, 459 unsigned long addr, unsigned long len, 460 unsigned long pgoff, unsigned long flags); 461 #endif 462 unsigned long mmap_base; /* base of mmap area */ 463 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 464 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 465 /* Base addresses for compatible mmap() */ 466 unsigned long mmap_compat_base; 467 unsigned long mmap_compat_legacy_base; 468 #endif 469 unsigned long task_size; /* size of task vm space */ 470 unsigned long highest_vm_end; /* highest vma end address */ 471 pgd_t * pgd; 472 473 #ifdef CONFIG_MEMBARRIER 474 /** 475 * @membarrier_state: Flags controlling membarrier behavior. 476 * 477 * This field is close to @pgd to hopefully fit in the same 478 * cache-line, which needs to be touched by switch_mm(). 479 */ 480 atomic_t membarrier_state; 481 #endif 482 483 /** 484 * @mm_users: The number of users including userspace. 485 * 486 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 487 * drops to 0 (i.e. when the task exits and there are no other 488 * temporary reference holders), we also release a reference on 489 * @mm_count (which may then free the &struct mm_struct if 490 * @mm_count also drops to 0). 491 */ 492 atomic_t mm_users; 493 494 /** 495 * @mm_count: The number of references to &struct mm_struct 496 * (@mm_users count as 1). 497 * 498 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the 499 * &struct mm_struct is freed. 500 */ 501 atomic_t mm_count; 502 503 #ifdef CONFIG_MMU 504 atomic_long_t pgtables_bytes; /* PTE page table pages */ 505 #endif 506 int map_count; /* number of VMAs */ 507 508 spinlock_t page_table_lock; /* Protects page tables and some 509 * counters 510 */ 511 /* 512 * With some kernel config, the current mmap_lock's offset 513 * inside 'mm_struct' is at 0x120, which is very optimal, as 514 * its two hot fields 'count' and 'owner' sit in 2 different 515 * cachelines, and when mmap_lock is highly contended, both 516 * of the 2 fields will be accessed frequently, current layout 517 * will help to reduce cache bouncing. 518 * 519 * So please be careful with adding new fields before 520 * mmap_lock, which can easily push the 2 fields into one 521 * cacheline. 522 */ 523 struct rw_semaphore mmap_lock; 524 #ifdef CONFIG_SPECULATIVE_PAGE_FAULT 525 unsigned long mmap_seq; 526 #endif 527 528 529 struct list_head mmlist; /* List of maybe swapped mm's. These 530 * are globally strung together off 531 * init_mm.mmlist, and are protected 532 * by mmlist_lock 533 */ 534 535 536 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 537 unsigned long hiwater_vm; /* High-water virtual memory usage */ 538 539 unsigned long total_vm; /* Total pages mapped */ 540 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 541 atomic64_t pinned_vm; /* Refcount permanently increased */ 542 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 543 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 544 unsigned long stack_vm; /* VM_STACK */ 545 unsigned long def_flags; 546 547 /** 548 * @write_protect_seq: Locked when any thread is write 549 * protecting pages mapped by this mm to enforce a later COW, 550 * for instance during page table copying for fork(). 551 */ 552 seqcount_t write_protect_seq; 553 554 spinlock_t arg_lock; /* protect the below fields */ 555 556 unsigned long start_code, end_code, start_data, end_data; 557 unsigned long start_brk, brk, start_stack; 558 unsigned long arg_start, arg_end, env_start, env_end; 559 560 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 561 562 /* 563 * Special counters, in some configurations protected by the 564 * page_table_lock, in other configurations by being atomic. 565 */ 566 struct mm_rss_stat rss_stat; 567 568 struct linux_binfmt *binfmt; 569 570 /* Architecture-specific MM context */ 571 mm_context_t context; 572 573 unsigned long flags; /* Must use atomic bitops to access */ 574 575 struct core_state *core_state; /* coredumping support */ 576 577 #ifdef CONFIG_AIO 578 spinlock_t ioctx_lock; 579 struct kioctx_table __rcu *ioctx_table; 580 #endif 581 #ifdef CONFIG_MEMCG 582 /* 583 * "owner" points to a task that is regarded as the canonical 584 * user/owner of this mm. All of the following must be true in 585 * order for it to be changed: 586 * 587 * current == mm->owner 588 * current->mm != mm 589 * new_owner->mm == mm 590 * new_owner->alloc_lock is held 591 */ 592 struct task_struct __rcu *owner; 593 #endif 594 struct user_namespace *user_ns; 595 596 /* store ref to file /proc/<pid>/exe symlink points to */ 597 struct file __rcu *exe_file; 598 #ifdef CONFIG_MMU_NOTIFIER 599 struct mmu_notifier_subscriptions *notifier_subscriptions; 600 #ifdef CONFIG_SPECULATIVE_PAGE_FAULT 601 struct percpu_rw_semaphore *mmu_notifier_lock; 602 #endif /* CONFIG_SPECULATIVE_PAGE_FAULT */ 603 #endif /* CONFIG_MMU_NOTIFIER */ 604 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS 605 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 606 #endif 607 #ifdef CONFIG_NUMA_BALANCING 608 /* 609 * numa_next_scan is the next time that the PTEs will be marked 610 * pte_numa. NUMA hinting faults will gather statistics and 611 * migrate pages to new nodes if necessary. 612 */ 613 unsigned long numa_next_scan; 614 615 /* Restart point for scanning and setting pte_numa */ 616 unsigned long numa_scan_offset; 617 618 /* numa_scan_seq prevents two threads setting pte_numa */ 619 int numa_scan_seq; 620 #endif 621 /* 622 * An operation with batched TLB flushing is going on. Anything 623 * that can move process memory needs to flush the TLB when 624 * moving a PROT_NONE or PROT_NUMA mapped page. 625 */ 626 atomic_t tlb_flush_pending; 627 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 628 /* See flush_tlb_batched_pending() */ 629 bool tlb_flush_batched; 630 #endif 631 struct uprobes_state uprobes_state; 632 #ifdef CONFIG_HUGETLB_PAGE 633 atomic_long_t hugetlb_usage; 634 #endif 635 struct work_struct async_put_work; 636 637 #ifdef CONFIG_IOMMU_SUPPORT 638 u32 pasid; 639 #endif 640 #ifdef CONFIG_LRU_GEN 641 struct { 642 /* this mm_struct is on lru_gen_mm_list */ 643 struct list_head list; 644 /* 645 * Set when switching to this mm_struct, as a hint of 646 * whether it has been used since the last time per-node 647 * page table walkers cleared the corresponding bits. 648 */ 649 unsigned long bitmap; 650 #ifdef CONFIG_MEMCG 651 /* points to the memcg of "owner" above */ 652 struct mem_cgroup *memcg; 653 #endif 654 } lru_gen; 655 #endif /* CONFIG_LRU_GEN */ 656 657 ANDROID_KABI_RESERVE(1); 658 } __randomize_layout; 659 660 /* 661 * The mm_cpumask needs to be at the end of mm_struct, because it 662 * is dynamically sized based on nr_cpu_ids. 663 */ 664 unsigned long cpu_bitmap[]; 665 }; 666 667 extern struct mm_struct init_mm; 668 669 /* Pointer magic because the dynamic array size confuses some compilers. */ mm_init_cpumask(struct mm_struct * mm)670 static inline void mm_init_cpumask(struct mm_struct *mm) 671 { 672 unsigned long cpu_bitmap = (unsigned long)mm; 673 674 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 675 cpumask_clear((struct cpumask *)cpu_bitmap); 676 } 677 678 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ mm_cpumask(struct mm_struct * mm)679 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 680 { 681 return (struct cpumask *)&mm->cpu_bitmap; 682 } 683 684 #ifdef CONFIG_LRU_GEN 685 686 struct lru_gen_mm_list { 687 /* mm_struct list for page table walkers */ 688 struct list_head fifo; 689 /* protects the list above */ 690 spinlock_t lock; 691 }; 692 693 void lru_gen_add_mm(struct mm_struct *mm); 694 void lru_gen_del_mm(struct mm_struct *mm); 695 #ifdef CONFIG_MEMCG 696 void lru_gen_migrate_mm(struct mm_struct *mm); 697 #endif 698 lru_gen_init_mm(struct mm_struct * mm)699 static inline void lru_gen_init_mm(struct mm_struct *mm) 700 { 701 INIT_LIST_HEAD(&mm->lru_gen.list); 702 mm->lru_gen.bitmap = 0; 703 #ifdef CONFIG_MEMCG 704 mm->lru_gen.memcg = NULL; 705 #endif 706 } 707 lru_gen_use_mm(struct mm_struct * mm)708 static inline void lru_gen_use_mm(struct mm_struct *mm) 709 { 710 /* 711 * When the bitmap is set, page reclaim knows this mm_struct has been 712 * used since the last time it cleared the bitmap. So it might be worth 713 * walking the page tables of this mm_struct to clear the accessed bit. 714 */ 715 WRITE_ONCE(mm->lru_gen.bitmap, -1); 716 } 717 718 #else /* !CONFIG_LRU_GEN */ 719 lru_gen_add_mm(struct mm_struct * mm)720 static inline void lru_gen_add_mm(struct mm_struct *mm) 721 { 722 } 723 lru_gen_del_mm(struct mm_struct * mm)724 static inline void lru_gen_del_mm(struct mm_struct *mm) 725 { 726 } 727 728 #ifdef CONFIG_MEMCG lru_gen_migrate_mm(struct mm_struct * mm)729 static inline void lru_gen_migrate_mm(struct mm_struct *mm) 730 { 731 } 732 #endif 733 lru_gen_init_mm(struct mm_struct * mm)734 static inline void lru_gen_init_mm(struct mm_struct *mm) 735 { 736 } 737 lru_gen_use_mm(struct mm_struct * mm)738 static inline void lru_gen_use_mm(struct mm_struct *mm) 739 { 740 } 741 742 #endif /* CONFIG_LRU_GEN */ 743 744 struct mmu_gather; 745 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); 746 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); 747 extern void tlb_finish_mmu(struct mmu_gather *tlb); 748 init_tlb_flush_pending(struct mm_struct * mm)749 static inline void init_tlb_flush_pending(struct mm_struct *mm) 750 { 751 atomic_set(&mm->tlb_flush_pending, 0); 752 } 753 inc_tlb_flush_pending(struct mm_struct * mm)754 static inline void inc_tlb_flush_pending(struct mm_struct *mm) 755 { 756 atomic_inc(&mm->tlb_flush_pending); 757 /* 758 * The only time this value is relevant is when there are indeed pages 759 * to flush. And we'll only flush pages after changing them, which 760 * requires the PTL. 761 * 762 * So the ordering here is: 763 * 764 * atomic_inc(&mm->tlb_flush_pending); 765 * spin_lock(&ptl); 766 * ... 767 * set_pte_at(); 768 * spin_unlock(&ptl); 769 * 770 * spin_lock(&ptl) 771 * mm_tlb_flush_pending(); 772 * .... 773 * spin_unlock(&ptl); 774 * 775 * flush_tlb_range(); 776 * atomic_dec(&mm->tlb_flush_pending); 777 * 778 * Where the increment if constrained by the PTL unlock, it thus 779 * ensures that the increment is visible if the PTE modification is 780 * visible. After all, if there is no PTE modification, nobody cares 781 * about TLB flushes either. 782 * 783 * This very much relies on users (mm_tlb_flush_pending() and 784 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and 785 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc 786 * locks (PPC) the unlock of one doesn't order against the lock of 787 * another PTL. 788 * 789 * The decrement is ordered by the flush_tlb_range(), such that 790 * mm_tlb_flush_pending() will not return false unless all flushes have 791 * completed. 792 */ 793 } 794 dec_tlb_flush_pending(struct mm_struct * mm)795 static inline void dec_tlb_flush_pending(struct mm_struct *mm) 796 { 797 /* 798 * See inc_tlb_flush_pending(). 799 * 800 * This cannot be smp_mb__before_atomic() because smp_mb() simply does 801 * not order against TLB invalidate completion, which is what we need. 802 * 803 * Therefore we must rely on tlb_flush_*() to guarantee order. 804 */ 805 atomic_dec(&mm->tlb_flush_pending); 806 } 807 mm_tlb_flush_pending(struct mm_struct * mm)808 static inline bool mm_tlb_flush_pending(struct mm_struct *mm) 809 { 810 /* 811 * Must be called after having acquired the PTL; orders against that 812 * PTLs release and therefore ensures that if we observe the modified 813 * PTE we must also observe the increment from inc_tlb_flush_pending(). 814 * 815 * That is, it only guarantees to return true if there is a flush 816 * pending for _this_ PTL. 817 */ 818 return atomic_read(&mm->tlb_flush_pending); 819 } 820 mm_tlb_flush_nested(struct mm_struct * mm)821 static inline bool mm_tlb_flush_nested(struct mm_struct *mm) 822 { 823 /* 824 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL 825 * for which there is a TLB flush pending in order to guarantee 826 * we've seen both that PTE modification and the increment. 827 * 828 * (no requirement on actually still holding the PTL, that is irrelevant) 829 */ 830 return atomic_read(&mm->tlb_flush_pending) > 1; 831 } 832 833 struct vm_fault; 834 835 /** 836 * typedef vm_fault_t - Return type for page fault handlers. 837 * 838 * Page fault handlers return a bitmask of %VM_FAULT values. 839 */ 840 typedef __bitwise unsigned int vm_fault_t; 841 842 /** 843 * enum vm_fault_reason - Page fault handlers return a bitmask of 844 * these values to tell the core VM what happened when handling the 845 * fault. Used to decide whether a process gets delivered SIGBUS or 846 * just gets major/minor fault counters bumped up. 847 * 848 * @VM_FAULT_OOM: Out Of Memory 849 * @VM_FAULT_SIGBUS: Bad access 850 * @VM_FAULT_MAJOR: Page read from storage 851 * @VM_FAULT_WRITE: Special case for get_user_pages 852 * @VM_FAULT_HWPOISON: Hit poisoned small page 853 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 854 * in upper bits 855 * @VM_FAULT_SIGSEGV: segmentation fault 856 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 857 * @VM_FAULT_LOCKED: ->fault locked the returned page 858 * @VM_FAULT_RETRY: ->fault blocked, must retry 859 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 860 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 861 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 862 * fsync() to complete (for synchronous page faults 863 * in DAX) 864 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 865 * 866 */ 867 enum vm_fault_reason { 868 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 869 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 870 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 871 VM_FAULT_WRITE = (__force vm_fault_t)0x000008, 872 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 873 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 874 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 875 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 876 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 877 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 878 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 879 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 880 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 881 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 882 }; 883 884 /* Encode hstate index for a hwpoisoned large page */ 885 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 886 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 887 888 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 889 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 890 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 891 892 #define VM_FAULT_RESULT_TRACE \ 893 { VM_FAULT_OOM, "OOM" }, \ 894 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 895 { VM_FAULT_MAJOR, "MAJOR" }, \ 896 { VM_FAULT_WRITE, "WRITE" }, \ 897 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 898 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 899 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 900 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 901 { VM_FAULT_LOCKED, "LOCKED" }, \ 902 { VM_FAULT_RETRY, "RETRY" }, \ 903 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 904 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 905 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } 906 907 struct vm_special_mapping { 908 const char *name; /* The name, e.g. "[vdso]". */ 909 910 /* 911 * If .fault is not provided, this points to a 912 * NULL-terminated array of pages that back the special mapping. 913 * 914 * This must not be NULL unless .fault is provided. 915 */ 916 struct page **pages; 917 918 /* 919 * If non-NULL, then this is called to resolve page faults 920 * on the special mapping. If used, .pages is not checked. 921 */ 922 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 923 struct vm_area_struct *vma, 924 struct vm_fault *vmf); 925 926 int (*mremap)(const struct vm_special_mapping *sm, 927 struct vm_area_struct *new_vma); 928 }; 929 930 enum tlb_flush_reason { 931 TLB_FLUSH_ON_TASK_SWITCH, 932 TLB_REMOTE_SHOOTDOWN, 933 TLB_LOCAL_SHOOTDOWN, 934 TLB_LOCAL_MM_SHOOTDOWN, 935 TLB_REMOTE_SEND_IPI, 936 NR_TLB_FLUSH_REASONS, 937 }; 938 939 /* 940 * A swap entry has to fit into a "unsigned long", as the entry is hidden 941 * in the "index" field of the swapper address space. 942 */ 943 typedef struct { 944 unsigned long val; 945 } swp_entry_t; 946 947 #endif /* _LINUX_MM_TYPES_H */ 948