atomic_long_add(count, &_totalram_pages);
}
-static inline void totalram_pages_set(long val)
-{
- atomic_long_set(&_totalram_pages, val);
-}
-
extern void * high_memory;
extern int page_cluster;
* On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
* is no special casing required.
*/
-static inline bool is_vmalloc_addr(const void *x)
-{
-#ifdef CONFIG_MMU
- unsigned long addr = (unsigned long)x;
-
- return addr >= VMALLOC_START && addr < VMALLOC_END;
-#else
- return false;
-#endif
-}
#ifndef is_ioremap_addr
#define is_ioremap_addr(x) is_vmalloc_addr(x)
#endif
#ifdef CONFIG_MMU
+extern bool is_vmalloc_addr(const void *x);
extern int is_vmalloc_or_module_addr(const void *x);
#else
+static inline bool is_vmalloc_addr(const void *x)
+{
+ return false;
+}
static inline int is_vmalloc_or_module_addr(const void *x)
{
return 0;
#define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
-#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
-#error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
-#endif
-
#define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
#define NODES_MASK ((1UL << NODES_WIDTH) - 1)
#define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
#endif
#ifdef CONFIG_DEV_PAGEMAP_OPS
-void __put_devmap_managed_page(struct page *page);
+void free_devmap_managed_page(struct page *page);
DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
-static inline bool put_devmap_managed_page(struct page *page)
+
+static inline bool page_is_devmap_managed(struct page *page)
{
if (!static_branch_unlikely(&devmap_managed_key))
return false;
switch (page->pgmap->type) {
case MEMORY_DEVICE_PRIVATE:
case MEMORY_DEVICE_FS_DAX:
- __put_devmap_managed_page(page);
return true;
default:
break;
return false;
}
+void put_devmap_managed_page(struct page *page);
+
#else /* CONFIG_DEV_PAGEMAP_OPS */
-static inline bool put_devmap_managed_page(struct page *page)
+static inline bool page_is_devmap_managed(struct page *page)
{
return false;
}
+
+static inline void put_devmap_managed_page(struct page *page)
+{
+}
#endif /* CONFIG_DEV_PAGEMAP_OPS */
static inline bool is_device_private_page(const struct page *page)
* need to inform the device driver through callback. See
* include/linux/memremap.h and HMM for details.
*/
- if (put_devmap_managed_page(page))
+ if (page_is_devmap_managed(page)) {
+ put_devmap_managed_page(page);
return;
+ }
if (put_page_testzero(page))
__put_page(page);
}
/**
- * put_user_page() - release a gup-pinned page
+ * unpin_user_page() - release a gup-pinned page
* @page: pointer to page to be released
*
- * Pages that were pinned via get_user_pages*() must be released via
- * either put_user_page(), or one of the put_user_pages*() routines
- * below. This is so that eventually, pages that are pinned via
- * get_user_pages*() can be separately tracked and uniquely handled. In
- * particular, interactions with RDMA and filesystems need special
- * handling.
+ * Pages that were pinned via pin_user_pages*() must be released via either
+ * unpin_user_page(), or one of the unpin_user_pages*() routines. This is so
+ * that eventually such pages can be separately tracked and uniquely handled. In
+ * particular, interactions with RDMA and filesystems need special handling.
*
- * put_user_page() and put_page() are not interchangeable, despite this early
- * implementation that makes them look the same. put_user_page() calls must
- * be perfectly matched up with get_user_page() calls.
+ * unpin_user_page() and put_page() are not interchangeable, despite this early
+ * implementation that makes them look the same. unpin_user_page() calls must
+ * be perfectly matched up with pin*() calls.
*/
-static inline void put_user_page(struct page *page)
+static inline void unpin_user_page(struct page *page)
{
put_page(page);
}
-void put_user_pages_dirty_lock(struct page **pages, unsigned long npages,
- bool make_dirty);
+void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
+ bool make_dirty);
-void put_user_pages(struct page **pages, unsigned long npages);
+void unpin_user_pages(struct page **pages, unsigned long npages);
#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
#define SECTION_IN_PAGE_FLAGS
unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
struct vm_area_struct **vmas, int *locked);
+long pin_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
+ unsigned long start, unsigned long nr_pages,
+ unsigned int gup_flags, struct page **pages,
+ struct vm_area_struct **vmas, int *locked);
long get_user_pages(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages,
struct vm_area_struct **vmas);
+long pin_user_pages(unsigned long start, unsigned long nr_pages,
+ unsigned int gup_flags, struct page **pages,
+ struct vm_area_struct **vmas);
long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
unsigned int gup_flags, struct page **pages, int *locked);
long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
int get_user_pages_fast(unsigned long start, int nr_pages,
unsigned int gup_flags, struct page **pages);
+int pin_user_pages_fast(unsigned long start, int nr_pages,
+ unsigned int gup_flags, struct page **pages);
int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc);
int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc,
struct mminit_pfnnid_cache *state);
#endif
-#if !defined(CONFIG_FLAT_NODE_MEM_MAP)
-void zero_resv_unavail(void);
-#else
-static inline void zero_resv_unavail(void) {}
-#endif
-
extern void set_dma_reserve(unsigned long new_dma_reserve);
extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long,
enum memmap_context, struct vmem_altmap *);
struct list_head *uf, bool downgrade);
extern int do_munmap(struct mm_struct *, unsigned long, size_t,
struct list_head *uf);
+extern int do_madvise(unsigned long start, size_t len_in, int behavior);
static inline unsigned long
do_mmap_pgoff(struct file *file, unsigned long addr,
#define FOLL_ANON 0x8000 /* don't do file mappings */
#define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */
#define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */
+#define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */
/*
- * NOTE on FOLL_LONGTERM:
+ * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
+ * other. Here is what they mean, and how to use them:
*
* FOLL_LONGTERM indicates that the page will be held for an indefinite time
- * period _often_ under userspace control. This is contrasted with
- * iov_iter_get_pages() where usages which are transient.
+ * period _often_ under userspace control. This is in contrast to
+ * iov_iter_get_pages(), whose usages are transient.
*
* FIXME: For pages which are part of a filesystem, mappings are subject to the
* lifetime enforced by the filesystem and we need guarantees that longterm
* Currently only get_user_pages() and get_user_pages_fast() support this flag
* and calls to get_user_pages_[un]locked are specifically not allowed. This
* is due to an incompatibility with the FS DAX check and
- * FAULT_FLAG_ALLOW_RETRY
+ * FAULT_FLAG_ALLOW_RETRY.
*
- * In the CMA case: longterm pins in a CMA region would unnecessarily fragment
- * that region. And so CMA attempts to migrate the page before pinning when
+ * In the CMA case: long term pins in a CMA region would unnecessarily fragment
+ * that region. And so, CMA attempts to migrate the page before pinning, when
* FOLL_LONGTERM is specified.
+ *
+ * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount,
+ * but an additional pin counting system) will be invoked. This is intended for
+ * anything that gets a page reference and then touches page data (for example,
+ * Direct IO). This lets the filesystem know that some non-file-system entity is
+ * potentially changing the pages' data. In contrast to FOLL_GET (whose pages
+ * are released via put_page()), FOLL_PIN pages must be released, ultimately, by
+ * a call to unpin_user_page().
+ *
+ * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different
+ * and separate refcounting mechanisms, however, and that means that each has
+ * its own acquire and release mechanisms:
+ *
+ * FOLL_GET: get_user_pages*() to acquire, and put_page() to release.
+ *
+ * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release.
+ *
+ * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call.
+ * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based
+ * calls applied to them, and that's perfectly OK. This is a constraint on the
+ * callers, not on the pages.)
+ *
+ * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never
+ * directly by the caller. That's in order to help avoid mismatches when
+ * releasing pages: get_user_pages*() pages must be released via put_page(),
+ * while pin_user_pages*() pages must be released via unpin_user_page().
+ *
+ * Please see Documentation/vm/pin_user_pages.rst for more information.
*/
static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_ARCH_HAS_SET_DIRECT_MAP)
extern void __kernel_map_pages(struct page *page, int numpages, int enable);
+/*
+ * When called in DEBUG_PAGEALLOC context, the call should most likely be
+ * guarded by debug_pagealloc_enabled() or debug_pagealloc_enabled_static()
+ */
static inline void
kernel_map_pages(struct page *page, int numpages, int enable)
{
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