133ff0eac9
HMM provides 3 separate types of functionality: - Mirroring: synchronize CPU page table and device page table - Device memory: allocating struct page for device memory - Migration: migrating regular memory to device memory This patch introduces some common helpers and definitions to all of those 3 functionality. Link: http://lkml.kernel.org/r/20170817000548.32038-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Evgeny Baskakov <ebaskakov@nvidia.com> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com> Signed-off-by: Sherry Cheung <SCheung@nvidia.com> Signed-off-by: Subhash Gutti <sgutti@nvidia.com> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Nellans <dnellans@nvidia.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Bob Liu <liubo95@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
663 lines
19 KiB
C
663 lines
19 KiB
C
#ifndef _LINUX_MM_TYPES_H
|
|
#define _LINUX_MM_TYPES_H
|
|
|
|
#include <linux/mm_types_task.h>
|
|
|
|
#include <linux/auxvec.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 <linux/workqueue.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;
|
|
struct hmm;
|
|
|
|
/*
|
|
* 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 */
|
|
atomic_t compound_mapcount; /* first tail page */
|
|
/* page_deferred_list().next -- second tail page */
|
|
};
|
|
|
|
/* Second double word */
|
|
union {
|
|
pgoff_t index; /* Our offset within mapping. */
|
|
void *freelist; /* sl[aou]b first free object */
|
|
/* page_deferred_list().prev -- second tail page */
|
|
};
|
|
|
|
union {
|
|
#if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
|
|
defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
|
|
/* Used for cmpxchg_double in slub */
|
|
unsigned long counters;
|
|
#else
|
|
/*
|
|
* Keep _refcount separate from slub cmpxchg_double data.
|
|
* As the rest of the double word is protected by slab_lock
|
|
* but _refcount is not.
|
|
*/
|
|
unsigned counters;
|
|
#endif
|
|
struct {
|
|
|
|
union {
|
|
/*
|
|
* Count of ptes mapped in mms, to show when
|
|
* page is mapped & limit reverse map searches.
|
|
*
|
|
* Extra information about page type may be
|
|
* stored here for pages that are never mapped,
|
|
* in which case the value MUST BE <= -2.
|
|
* See page-flags.h for more details.
|
|
*/
|
|
atomic_t _mapcount;
|
|
|
|
unsigned int active; /* SLAB */
|
|
struct { /* SLUB */
|
|
unsigned inuse:16;
|
|
unsigned objects:15;
|
|
unsigned frozen:1;
|
|
};
|
|
int units; /* SLOB */
|
|
};
|
|
/*
|
|
* Usage count, *USE WRAPPER FUNCTION* when manual
|
|
* accounting. See page_ref.h
|
|
*/
|
|
atomic_t _refcount;
|
|
};
|
|
};
|
|
|
|
/*
|
|
* Third double word block
|
|
*
|
|
* WARNING: bit 0 of the first word encode PageTail(). That means
|
|
* the rest users of the storage space MUST NOT use the bit to
|
|
* avoid collision and false-positive PageTail().
|
|
*/
|
|
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 dev_pagemap *pgmap; /* ZONE_DEVICE pages are never on an
|
|
* lru or handled by a slab
|
|
* allocator, this points to the
|
|
* hosting device page map.
|
|
*/
|
|
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 rcu_head rcu_head; /* Used by SLAB
|
|
* when destroying via RCU
|
|
*/
|
|
/* Tail pages of compound page */
|
|
struct {
|
|
unsigned long compound_head; /* If bit zero is set */
|
|
|
|
/* First tail page only */
|
|
#ifdef CONFIG_64BIT
|
|
/*
|
|
* On 64 bit system we have enough space in struct page
|
|
* to encode compound_dtor and compound_order with
|
|
* unsigned int. It can help compiler generate better or
|
|
* smaller code on some archtectures.
|
|
*/
|
|
unsigned int compound_dtor;
|
|
unsigned int compound_order;
|
|
#else
|
|
unsigned short int compound_dtor;
|
|
unsigned short int compound_order;
|
|
#endif
|
|
};
|
|
|
|
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && USE_SPLIT_PMD_PTLOCKS
|
|
struct {
|
|
unsigned long __pad; /* do not overlay pmd_huge_pte
|
|
* with compound_head to avoid
|
|
* possible bit 0 collision.
|
|
*/
|
|
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 */
|
|
};
|
|
|
|
#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
|
|
;
|
|
|
|
#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
|
|
#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
|
|
|
|
struct page_frag_cache {
|
|
void * va;
|
|
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
|
|
__u16 offset;
|
|
__u16 size;
|
|
#else
|
|
__u32 offset;
|
|
#endif
|
|
/* we maintain a pagecount bias, so that we dont dirty cache line
|
|
* containing page->_refcount every time we allocate a fragment.
|
|
*/
|
|
unsigned int pagecnt_bias;
|
|
bool pfmemalloc;
|
|
};
|
|
|
|
typedef unsigned long 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 */
|
|
|
|
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 */
|
|
};
|
|
|
|
#ifdef CONFIG_USERFAULTFD
|
|
#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
|
|
struct vm_userfaultfd_ctx {
|
|
struct userfaultfd_ctx *ctx;
|
|
};
|
|
#else /* CONFIG_USERFAULTFD */
|
|
#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
|
|
struct vm_userfaultfd_ctx {};
|
|
#endif /* CONFIG_USERFAULTFD */
|
|
|
|
/*
|
|
* 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 */
|
|
struct file * vm_file; /* File we map to (can be NULL). */
|
|
void * vm_private_data; /* was vm_pte (shared mem) */
|
|
|
|
atomic_long_t swap_readahead_info;
|
|
#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
|
|
struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
|
|
} __randomize_layout;
|
|
|
|
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;
|
|
};
|
|
|
|
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 */
|
|
#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
|
|
/* Base adresses for compatible mmap() */
|
|
unsigned long mmap_compat_base;
|
|
unsigned long mmap_compat_legacy_base;
|
|
#endif
|
|
unsigned long task_size; /* size of task vm space */
|
|
unsigned long highest_vm_end; /* highest vma end address */
|
|
pgd_t * pgd;
|
|
|
|
/**
|
|
* @mm_users: The number of users including userspace.
|
|
*
|
|
* Use mmget()/mmget_not_zero()/mmput() to modify. When this drops
|
|
* to 0 (i.e. when the task exits and there are no other temporary
|
|
* reference holders), we also release a reference on @mm_count
|
|
* (which may then free the &struct mm_struct if @mm_count also
|
|
* drops to 0).
|
|
*/
|
|
atomic_t mm_users;
|
|
|
|
/**
|
|
* @mm_count: The number of references to &struct mm_struct
|
|
* (@mm_users count as 1).
|
|
*
|
|
* Use mmgrab()/mmdrop() to modify. When this drops to 0, the
|
|
* &struct mm_struct is freed.
|
|
*/
|
|
atomic_t mm_count;
|
|
|
|
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 data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
|
|
unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
|
|
unsigned long stack_vm; /* VM_STACK */
|
|
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
|
|
struct user_namespace *user_ns;
|
|
|
|
/* 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
|
|
/*
|
|
* 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.
|
|
*/
|
|
atomic_t tlb_flush_pending;
|
|
#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
|
|
/* See flush_tlb_batched_pending() */
|
|
bool tlb_flush_batched;
|
|
#endif
|
|
struct uprobes_state uprobes_state;
|
|
#ifdef CONFIG_HUGETLB_PAGE
|
|
atomic_long_t hugetlb_usage;
|
|
#endif
|
|
struct work_struct async_put_work;
|
|
|
|
#if IS_ENABLED(CONFIG_HMM)
|
|
/* HMM needs to track a few things per mm */
|
|
struct hmm *hmm;
|
|
#endif
|
|
} __randomize_layout;
|
|
|
|
extern struct mm_struct init_mm;
|
|
|
|
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;
|
|
}
|
|
|
|
struct mmu_gather;
|
|
extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm,
|
|
unsigned long start, unsigned long end);
|
|
extern void tlb_finish_mmu(struct mmu_gather *tlb,
|
|
unsigned long start, unsigned long end);
|
|
|
|
static inline void init_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
atomic_set(&mm->tlb_flush_pending, 0);
|
|
}
|
|
|
|
static inline void inc_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
atomic_inc(&mm->tlb_flush_pending);
|
|
/*
|
|
* The only time this value is relevant is when there are indeed pages
|
|
* to flush. And we'll only flush pages after changing them, which
|
|
* requires the PTL.
|
|
*
|
|
* So the ordering here is:
|
|
*
|
|
* atomic_inc(&mm->tlb_flush_pending);
|
|
* spin_lock(&ptl);
|
|
* ...
|
|
* set_pte_at();
|
|
* spin_unlock(&ptl);
|
|
*
|
|
* spin_lock(&ptl)
|
|
* mm_tlb_flush_pending();
|
|
* ....
|
|
* spin_unlock(&ptl);
|
|
*
|
|
* flush_tlb_range();
|
|
* atomic_dec(&mm->tlb_flush_pending);
|
|
*
|
|
* Where the increment if constrained by the PTL unlock, it thus
|
|
* ensures that the increment is visible if the PTE modification is
|
|
* visible. After all, if there is no PTE modification, nobody cares
|
|
* about TLB flushes either.
|
|
*
|
|
* This very much relies on users (mm_tlb_flush_pending() and
|
|
* mm_tlb_flush_nested()) only caring about _specific_ PTEs (and
|
|
* therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc
|
|
* locks (PPC) the unlock of one doesn't order against the lock of
|
|
* another PTL.
|
|
*
|
|
* The decrement is ordered by the flush_tlb_range(), such that
|
|
* mm_tlb_flush_pending() will not return false unless all flushes have
|
|
* completed.
|
|
*/
|
|
}
|
|
|
|
static inline void dec_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* See inc_tlb_flush_pending().
|
|
*
|
|
* This cannot be smp_mb__before_atomic() because smp_mb() simply does
|
|
* not order against TLB invalidate completion, which is what we need.
|
|
*
|
|
* Therefore we must rely on tlb_flush_*() to guarantee order.
|
|
*/
|
|
atomic_dec(&mm->tlb_flush_pending);
|
|
}
|
|
|
|
static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* Must be called after having acquired the PTL; orders against that
|
|
* PTLs release and therefore ensures that if we observe the modified
|
|
* PTE we must also observe the increment from inc_tlb_flush_pending().
|
|
*
|
|
* That is, it only guarantees to return true if there is a flush
|
|
* pending for _this_ PTL.
|
|
*/
|
|
return atomic_read(&mm->tlb_flush_pending);
|
|
}
|
|
|
|
static inline bool mm_tlb_flush_nested(struct mm_struct *mm)
|
|
{
|
|
/*
|
|
* Similar to mm_tlb_flush_pending(), we must have acquired the PTL
|
|
* for which there is a TLB flush pending in order to guarantee
|
|
* we've seen both that PTE modification and the increment.
|
|
*
|
|
* (no requirement on actually still holding the PTL, that is irrelevant)
|
|
*/
|
|
return atomic_read(&mm->tlb_flush_pending) > 1;
|
|
}
|
|
|
|
struct vm_fault;
|
|
|
|
struct vm_special_mapping {
|
|
const char *name; /* The name, e.g. "[vdso]". */
|
|
|
|
/*
|
|
* If .fault is not provided, this points to a
|
|
* NULL-terminated array of pages that back the special mapping.
|
|
*
|
|
* This must not be NULL unless .fault is provided.
|
|
*/
|
|
struct page **pages;
|
|
|
|
/*
|
|
* If non-NULL, then this is called to resolve page faults
|
|
* on the special mapping. If used, .pages is not checked.
|
|
*/
|
|
int (*fault)(const struct vm_special_mapping *sm,
|
|
struct vm_area_struct *vma,
|
|
struct vm_fault *vmf);
|
|
|
|
int (*mremap)(const struct vm_special_mapping *sm,
|
|
struct vm_area_struct *new_vma);
|
|
};
|
|
|
|
enum tlb_flush_reason {
|
|
TLB_FLUSH_ON_TASK_SWITCH,
|
|
TLB_REMOTE_SHOOTDOWN,
|
|
TLB_LOCAL_SHOOTDOWN,
|
|
TLB_LOCAL_MM_SHOOTDOWN,
|
|
TLB_REMOTE_SEND_IPI,
|
|
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 */
|