diff options
Diffstat (limited to 'include/linux/mm_types.h')
| -rw-r--r-- | include/linux/mm_types.h | 156 |
1 files changed, 145 insertions, 11 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 3b7d05e7169c..9f6de068295d 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -286,6 +286,31 @@ typedef struct { unsigned long val; } swp_entry_t; +/** + * typedef softleaf_t - Describes a page table software leaf entry, abstracted + * from its architecture-specific encoding. + * + * Page table leaf entries are those which do not reference any descendent page + * tables but rather either reference a data page, are an empty (or 'none' + * entry), or contain a non-present entry. + * + * If referencing another page table or a data page then the page table entry is + * pertinent to hardware - that is it tells the hardware how to decode the page + * table entry. + * + * Otherwise it is a software-defined leaf page table entry, which this type + * describes. See leafops.h and specifically @softleaf_type for a list of all + * possible kinds of software leaf entry. + * + * A softleaf_t entry is abstracted from the hardware page table entry, so is + * not architecture-specific. + * + * NOTE: While we transition from the confusing swp_entry_t type used for this + * purpose, we simply alias this type. This will be removed once the + * transition is complete. + */ +typedef swp_entry_t softleaf_t; + #if defined(CONFIG_MEMCG) || defined(CONFIG_SLAB_OBJ_EXT) /* We have some extra room after the refcount in tail pages. */ #define NR_PAGES_IN_LARGE_FOLIO @@ -774,6 +799,65 @@ struct pfnmap_track_ctx { }; #endif +/* What action should be taken after an .mmap_prepare call is complete? */ +enum mmap_action_type { + MMAP_NOTHING, /* Mapping is complete, no further action. */ + MMAP_REMAP_PFN, /* Remap PFN range. */ + MMAP_IO_REMAP_PFN, /* I/O remap PFN range. */ +}; + +/* + * Describes an action an mmap_prepare hook can instruct to be taken to complete + * the mapping of a VMA. Specified in vm_area_desc. + */ +struct mmap_action { + union { + /* Remap range. */ + struct { + unsigned long start; + unsigned long start_pfn; + unsigned long size; + pgprot_t pgprot; + } remap; + }; + enum mmap_action_type type; + + /* + * If specified, this hook is invoked after the selected action has been + * successfully completed. Note that the VMA write lock still held. + * + * The absolute minimum ought to be done here. + * + * Returns 0 on success, or an error code. + */ + int (*success_hook)(const struct vm_area_struct *vma); + + /* + * If specified, this hook is invoked when an error occurred when + * attempting the selection action. + * + * The hook can return an error code in order to filter the error, but + * it is not valid to clear the error here. + */ + int (*error_hook)(int err); + + /* + * This should be set in rare instances where the operation required + * that the rmap should not be able to access the VMA until + * completely set up. + */ + bool hide_from_rmap_until_complete :1; +}; + +/* + * Opaque type representing current VMA (vm_area_struct) flag state. Must be + * accessed via vma_flags_xxx() helper functions. + */ +#define NUM_VMA_FLAG_BITS BITS_PER_LONG +typedef struct { + DECLARE_BITMAP(__vma_flags, NUM_VMA_FLAG_BITS); +} __private vma_flags_t; + /* * Describes a VMA that is about to be mmap()'ed. Drivers may choose to * manipulate mutable fields which will cause those fields to be updated in the @@ -791,12 +875,18 @@ struct vm_area_desc { /* Mutable fields. Populated with initial state. */ pgoff_t pgoff; struct file *vm_file; - vm_flags_t vm_flags; + union { + vm_flags_t vm_flags; + vma_flags_t vma_flags; + }; pgprot_t page_prot; /* Write-only fields. */ const struct vm_operations_struct *vm_ops; void *private_data; + + /* Take further action? */ + struct mmap_action action; }; /* @@ -833,10 +923,12 @@ struct vm_area_struct { /* * Flags, see mm.h. * To modify use vm_flags_{init|reset|set|clear|mod} functions. + * Preferably, use vma_flags_xxx() functions. */ union { + /* Temporary while VMA flags are being converted. */ const vm_flags_t vm_flags; - vm_flags_t __private __vm_flags; + vma_flags_t flags; }; #ifdef CONFIG_PER_VMA_LOCK @@ -917,6 +1009,52 @@ struct vm_area_struct { #endif } __randomize_layout; +/* Clears all bits in the VMA flags bitmap, non-atomically. */ +static inline void vma_flags_clear_all(vma_flags_t *flags) +{ + bitmap_zero(ACCESS_PRIVATE(flags, __vma_flags), NUM_VMA_FLAG_BITS); +} + +/* + * Copy value to the first system word of VMA flags, non-atomically. + * + * IMPORTANT: This does not overwrite bytes past the first system word. The + * caller must account for this. + */ +static inline void vma_flags_overwrite_word(vma_flags_t *flags, unsigned long value) +{ + *ACCESS_PRIVATE(flags, __vma_flags) = value; +} + +/* + * Copy value to the first system word of VMA flags ONCE, non-atomically. + * + * IMPORTANT: This does not overwrite bytes past the first system word. The + * caller must account for this. + */ +static inline void vma_flags_overwrite_word_once(vma_flags_t *flags, unsigned long value) +{ + unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags); + + WRITE_ONCE(*bitmap, value); +} + +/* Update the first system word of VMA flags setting bits, non-atomically. */ +static inline void vma_flags_set_word(vma_flags_t *flags, unsigned long value) +{ + unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags); + + *bitmap |= value; +} + +/* Update the first system word of VMA flags clearing bits, non-atomically. */ +static inline void vma_flags_clear_word(vma_flags_t *flags, unsigned long value) +{ + unsigned long *bitmap = ACCESS_PRIVATE(flags, __vma_flags); + + *bitmap &= ~value; +} + #ifdef CONFIG_NUMA #define vma_policy(vma) ((vma)->vm_policy) #else @@ -1194,15 +1332,13 @@ struct mm_struct { unsigned long cpu_bitmap[]; }; -/* Set the first system word of mm flags, non-atomically. */ -static inline void __mm_flags_set_word(struct mm_struct *mm, unsigned long value) +/* Copy value to the first system word of mm flags, non-atomically. */ +static inline void __mm_flags_overwrite_word(struct mm_struct *mm, unsigned long value) { - unsigned long *bitmap = ACCESS_PRIVATE(&mm->flags, __mm_flags); - - bitmap_copy(bitmap, &value, BITS_PER_LONG); + *ACCESS_PRIVATE(&mm->flags, __mm_flags) = value; } -/* Obtain a read-only view of the bitmap. */ +/* Obtain a read-only view of the mm flags bitmap. */ static inline const unsigned long *__mm_flags_get_bitmap(const struct mm_struct *mm) { return (const unsigned long *)ACCESS_PRIVATE(&mm->flags, __mm_flags); @@ -1211,9 +1347,7 @@ static inline const unsigned long *__mm_flags_get_bitmap(const struct mm_struct /* Read the first system word of mm flags, non-atomically. */ static inline unsigned long __mm_flags_get_word(const struct mm_struct *mm) { - const unsigned long *bitmap = __mm_flags_get_bitmap(mm); - - return bitmap_read(bitmap, 0, BITS_PER_LONG); + return *__mm_flags_get_bitmap(mm); } /* |