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Diffstat (limited to 'include/linux/mm_types.h')
| -rw-r--r-- | include/linux/mm_types.h | 553 |
1 files changed, 553 insertions, 0 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h new file mode 100644 index 000000000..c54e67ec6 --- /dev/null +++ b/include/linux/mm_types.h @@ -0,0 +1,553 @@ +#ifndef _LINUX_MM_TYPES_H +#define _LINUX_MM_TYPES_H + +#include <linux/auxvec.h> +#include <linux/types.h> +#include <linux/threads.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/rbtree.h> +#include <linux/rwsem.h> +#include <linux/completion.h> +#include <linux/cpumask.h> +#include <linux/uprobes.h> +#include <linux/page-flags-layout.h> +#include <asm/page.h> +#include <asm/mmu.h> + +#ifndef AT_VECTOR_SIZE_ARCH +#define AT_VECTOR_SIZE_ARCH 0 +#endif +#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) + +struct address_space; +struct mem_cgroup; + +#define USE_SPLIT_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS) +#define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \ + IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK)) +#define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8) + +typedef void compound_page_dtor(struct page *); + +/* + * Each physical page in the system has a struct page associated with + * it to keep track of whatever it is we are using the page for at the + * moment. Note that we have no way to track which tasks are using + * a page, though if it is a pagecache page, rmap structures can tell us + * who is mapping it. + * + * The objects in struct page are organized in double word blocks in + * order to allows us to use atomic double word operations on portions + * of struct page. That is currently only used by slub but the arrangement + * allows the use of atomic double word operations on the flags/mapping + * and lru list pointers also. + */ +struct page { + /* First double word block */ + unsigned long flags; /* Atomic flags, some possibly + * updated asynchronously */ + union { + struct address_space *mapping; /* If low bit clear, points to + * inode address_space, or NULL. + * If page mapped as anonymous + * memory, low bit is set, and + * it points to anon_vma object: + * see PAGE_MAPPING_ANON below. + */ + void *s_mem; /* slab first object */ + }; + + /* Second double word */ + struct { + union { + pgoff_t index; /* Our offset within mapping. */ + void *freelist; /* sl[aou]b first free object */ + bool pfmemalloc; /* If set by the page allocator, + * ALLOC_NO_WATERMARKS was set + * and the low watermark was not + * met implying that the system + * is under some pressure. The + * caller should try ensure + * this page is only used to + * free other pages. + */ + }; + + union { +#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \ + defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE) + /* Used for cmpxchg_double in slub */ + unsigned long counters; +#else + /* + * Keep _count separate from slub cmpxchg_double data. + * As the rest of the double word is protected by + * slab_lock but _count is not. + */ + unsigned counters; +#endif + + struct { + + union { + /* + * Count of ptes mapped in + * mms, to show when page is + * mapped & limit reverse map + * searches. + * + * Used also for tail pages + * refcounting instead of + * _count. Tail pages cannot + * be mapped and keeping the + * tail page _count zero at + * all times guarantees + * get_page_unless_zero() will + * never succeed on tail + * pages. + */ + atomic_t _mapcount; + + struct { /* SLUB */ + unsigned inuse:16; + unsigned objects:15; + unsigned frozen:1; + }; + int units; /* SLOB */ + }; + atomic_t _count; /* Usage count, see below. */ + }; + unsigned int active; /* SLAB */ + }; + }; + + /* Third double word block */ + union { + struct list_head lru; /* Pageout list, eg. active_list + * protected by zone->lru_lock ! + * Can be used as a generic list + * by the page owner. + */ + struct { /* slub per cpu partial pages */ + struct page *next; /* Next partial slab */ +#ifdef CONFIG_64BIT + int pages; /* Nr of partial slabs left */ + int pobjects; /* Approximate # of objects */ +#else + short int pages; + short int pobjects; +#endif + }; + + struct slab *slab_page; /* slab fields */ + struct rcu_head rcu_head; /* Used by SLAB + * when destroying via RCU + */ + /* First tail page of compound page */ + struct { + compound_page_dtor *compound_dtor; + unsigned long compound_order; + }; + +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && USE_SPLIT_PMD_PTLOCKS + pgtable_t pmd_huge_pte; /* protected by page->ptl */ +#endif + }; + + /* Remainder is not double word aligned */ + union { + unsigned long private; /* Mapping-private opaque data: + * usually used for buffer_heads + * if PagePrivate set; used for + * swp_entry_t if PageSwapCache; + * indicates order in the buddy + * system if PG_buddy is set. + */ +#if USE_SPLIT_PTE_PTLOCKS +#if ALLOC_SPLIT_PTLOCKS + spinlock_t *ptl; +#else + spinlock_t ptl; +#endif +#endif + struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */ + struct page *first_page; /* Compound tail pages */ + }; + +#ifdef CONFIG_MEMCG + struct mem_cgroup *mem_cgroup; +#endif + + /* + * On machines where all RAM is mapped into kernel address space, + * we can simply calculate the virtual address. On machines with + * highmem some memory is mapped into kernel virtual memory + * dynamically, so we need a place to store that address. + * Note that this field could be 16 bits on x86 ... ;) + * + * Architectures with slow multiplication can define + * WANT_PAGE_VIRTUAL in asm/page.h + */ +#if defined(WANT_PAGE_VIRTUAL) + void *virtual; /* Kernel virtual address (NULL if + not kmapped, ie. highmem) */ +#endif /* WANT_PAGE_VIRTUAL */ + +#ifdef CONFIG_KMEMCHECK + /* + * kmemcheck wants to track the status of each byte in a page; this + * is a pointer to such a status block. NULL if not tracked. + */ + void *shadow; +#endif + +#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS + int _last_cpupid; +#endif +} +/* + * The struct page can be forced to be double word aligned so that atomic ops + * on double words work. The SLUB allocator can make use of such a feature. + */ +#ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE + __aligned(2 * sizeof(unsigned long)) +#endif +; + +struct page_frag { + struct page *page; +#if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536) + __u32 offset; + __u32 size; +#else + __u16 offset; + __u16 size; +#endif +}; + +typedef unsigned long __nocast vm_flags_t; + +/* + * A region containing a mapping of a non-memory backed file under NOMMU + * conditions. These are held in a global tree and are pinned by the VMAs that + * map parts of them. + */ +struct vm_region { + struct rb_node vm_rb; /* link in global region tree */ + vm_flags_t vm_flags; /* VMA vm_flags */ + unsigned long vm_start; /* start address of region */ + unsigned long vm_end; /* region initialised to here */ + unsigned long vm_top; /* region allocated to here */ + unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ + struct file *vm_file; /* the backing file or NULL */ + struct file *vm_prfile; /* the virtual backing file or NULL */ + + int vm_usage; /* region usage count (access under nommu_region_sem) */ + bool vm_icache_flushed : 1; /* true if the icache has been flushed for + * this region */ +}; + +/* + * This struct defines a memory VMM memory area. There is one of these + * per VM-area/task. A VM area is any part of the process virtual memory + * space that has a special rule for the page-fault handlers (ie a shared + * library, the executable area etc). + */ +struct vm_area_struct { + /* The first cache line has the info for VMA tree walking. */ + + unsigned long vm_start; /* Our start address within vm_mm. */ + unsigned long vm_end; /* The first byte after our end address + within vm_mm. */ + + /* linked list of VM areas per task, sorted by address */ + struct vm_area_struct *vm_next, *vm_prev; + + struct rb_node vm_rb; + + /* + * Largest free memory gap in bytes to the left of this VMA. + * Either between this VMA and vma->vm_prev, or between one of the + * VMAs below us in the VMA rbtree and its ->vm_prev. This helps + * get_unmapped_area find a free area of the right size. + */ + unsigned long rb_subtree_gap; + + /* Second cache line starts here. */ + + struct mm_struct *vm_mm; /* The address space we belong to. */ + pgprot_t vm_page_prot; /* Access permissions of this VMA. */ + unsigned long vm_flags; /* Flags, see mm.h. */ + + /* + * For areas with an address space and backing store, + * linkage into the address_space->i_mmap interval tree. + */ + struct { + struct rb_node rb; + unsigned long rb_subtree_last; + } shared; + + /* + * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma + * list, after a COW of one of the file pages. A MAP_SHARED vma + * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack + * or brk vma (with NULL file) can only be in an anon_vma list. + */ + struct list_head anon_vma_chain; /* Serialized by mmap_sem & + * page_table_lock */ + struct anon_vma *anon_vma; /* Serialized by page_table_lock */ + + /* Function pointers to deal with this struct. */ + const struct vm_operations_struct *vm_ops; + + /* Information about our backing store: */ + unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE + units, *not* PAGE_CACHE_SIZE */ + struct file * vm_file; /* File we map to (can be NULL). */ + struct file *vm_prfile; /* shadow of vm_file */ + void * vm_private_data; /* was vm_pte (shared mem) */ + +#ifndef CONFIG_MMU + struct vm_region *vm_region; /* NOMMU mapping region */ +#endif +#ifdef CONFIG_NUMA + struct mempolicy *vm_policy; /* NUMA policy for the VMA */ +#endif +#ifdef CONFIG_UKSM + struct vma_slot *uksm_vma_slot; +#endif +}; + +struct core_thread { + struct task_struct *task; + struct core_thread *next; +}; + +struct core_state { + atomic_t nr_threads; + struct core_thread dumper; + struct completion startup; +}; + +enum { + MM_FILEPAGES, + MM_ANONPAGES, + MM_SWAPENTS, + NR_MM_COUNTERS +}; + +#if USE_SPLIT_PTE_PTLOCKS && defined(CONFIG_MMU) +#define SPLIT_RSS_COUNTING +/* per-thread cached information, */ +struct task_rss_stat { + int events; /* for synchronization threshold */ + int count[NR_MM_COUNTERS]; +}; +#endif /* USE_SPLIT_PTE_PTLOCKS */ + +struct mm_rss_stat { + atomic_long_t count[NR_MM_COUNTERS]; +}; + +struct kioctx_table; +struct mm_struct { + struct vm_area_struct *mmap; /* list of VMAs */ + struct rb_root mm_rb; + u32 vmacache_seqnum; /* per-thread vmacache */ +#ifdef CONFIG_MMU + unsigned long (*get_unmapped_area) (struct file *filp, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags); +#endif + unsigned long mmap_base; /* base of mmap area */ + unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ + unsigned long task_size; /* size of task vm space */ + unsigned long highest_vm_end; /* highest vma end address */ + pgd_t * pgd; + atomic_t mm_users; /* How many users with user space? */ + atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */ + atomic_long_t nr_ptes; /* PTE page table pages */ +#if CONFIG_PGTABLE_LEVELS > 2 + atomic_long_t nr_pmds; /* PMD page table pages */ +#endif + int map_count; /* number of VMAs */ + + spinlock_t page_table_lock; /* Protects page tables and some counters */ + struct rw_semaphore mmap_sem; + + struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung + * together off init_mm.mmlist, and are protected + * by mmlist_lock + */ + + + unsigned long hiwater_rss; /* High-watermark of RSS usage */ + unsigned long hiwater_vm; /* High-water virtual memory usage */ + + unsigned long total_vm; /* Total pages mapped */ + unsigned long locked_vm; /* Pages that have PG_mlocked set */ + unsigned long pinned_vm; /* Refcount permanently increased */ + unsigned long shared_vm; /* Shared pages (files) */ + unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */ + unsigned long stack_vm; /* VM_GROWSUP/DOWN */ + unsigned long def_flags; + unsigned long start_code, end_code, start_data, end_data; + unsigned long start_brk, brk, start_stack; + unsigned long arg_start, arg_end, env_start, env_end; + + unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ + + /* + * Special counters, in some configurations protected by the + * page_table_lock, in other configurations by being atomic. + */ + struct mm_rss_stat rss_stat; + + struct linux_binfmt *binfmt; + + cpumask_var_t cpu_vm_mask_var; + + /* Architecture-specific MM context */ + mm_context_t context; + + unsigned long flags; /* Must use atomic bitops to access the bits */ + + struct core_state *core_state; /* coredumping support */ +#ifdef CONFIG_AIO + spinlock_t ioctx_lock; + struct kioctx_table __rcu *ioctx_table; +#endif +#ifdef CONFIG_MEMCG + /* + * "owner" points to a task that is regarded as the canonical + * user/owner of this mm. All of the following must be true in + * order for it to be changed: + * + * current == mm->owner + * current->mm != mm + * new_owner->mm == mm + * new_owner->alloc_lock is held + */ + struct task_struct __rcu *owner; +#endif + + /* store ref to file /proc/<pid>/exe symlink points to */ + struct file __rcu *exe_file; +#ifdef CONFIG_MMU_NOTIFIER + struct mmu_notifier_mm *mmu_notifier_mm; +#endif +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS + pgtable_t pmd_huge_pte; /* protected by page_table_lock */ +#endif +#ifdef CONFIG_CPUMASK_OFFSTACK + struct cpumask cpumask_allocation; +#endif +#ifdef CONFIG_NUMA_BALANCING + /* + * numa_next_scan is the next time that the PTEs will be marked + * pte_numa. NUMA hinting faults will gather statistics and migrate + * pages to new nodes if necessary. + */ + unsigned long numa_next_scan; + + /* Restart point for scanning and setting pte_numa */ + unsigned long numa_scan_offset; + + /* numa_scan_seq prevents two threads setting pte_numa */ + int numa_scan_seq; +#endif +#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION) + /* + * An operation with batched TLB flushing is going on. Anything that + * can move process memory needs to flush the TLB when moving a + * PROT_NONE or PROT_NUMA mapped page. + */ + bool tlb_flush_pending; +#endif + struct uprobes_state uprobes_state; +#ifdef CONFIG_X86_INTEL_MPX + /* address of the bounds directory */ + void __user *bd_addr; +#endif +}; + +static inline void mm_init_cpumask(struct mm_struct *mm) +{ +#ifdef CONFIG_CPUMASK_OFFSTACK + mm->cpu_vm_mask_var = &mm->cpumask_allocation; +#endif + cpumask_clear(mm->cpu_vm_mask_var); +} + +/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ +static inline cpumask_t *mm_cpumask(struct mm_struct *mm) +{ + return mm->cpu_vm_mask_var; +} + +#if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION) +/* + * Memory barriers to keep this state in sync are graciously provided by + * the page table locks, outside of which no page table modifications happen. + * The barriers below prevent the compiler from re-ordering the instructions + * around the memory barriers that are already present in the code. + */ +static inline bool mm_tlb_flush_pending(struct mm_struct *mm) +{ + barrier(); + return mm->tlb_flush_pending; +} +static inline void set_tlb_flush_pending(struct mm_struct *mm) +{ + mm->tlb_flush_pending = true; + + /* + * Guarantee that the tlb_flush_pending store does not leak into the + * critical section updating the page tables + */ + smp_mb__before_spinlock(); +} +/* Clearing is done after a TLB flush, which also provides a barrier. */ +static inline void clear_tlb_flush_pending(struct mm_struct *mm) +{ + barrier(); + mm->tlb_flush_pending = false; +} +#else +static inline bool mm_tlb_flush_pending(struct mm_struct *mm) +{ + return false; +} +static inline void set_tlb_flush_pending(struct mm_struct *mm) +{ +} +static inline void clear_tlb_flush_pending(struct mm_struct *mm) +{ +} +#endif + +struct vm_special_mapping +{ + const char *name; + struct page **pages; +}; + +enum tlb_flush_reason { + TLB_FLUSH_ON_TASK_SWITCH, + TLB_REMOTE_SHOOTDOWN, + TLB_LOCAL_SHOOTDOWN, + TLB_LOCAL_MM_SHOOTDOWN, + NR_TLB_FLUSH_REASONS, +}; + + /* + * A swap entry has to fit into a "unsigned long", as the entry is hidden + * in the "index" field of the swapper address space. + */ +typedef struct { + unsigned long val; +} swp_entry_t; + +#endif /* _LINUX_MM_TYPES_H */ |