diff options
Diffstat (limited to 'include/linux/dax.h')
| -rw-r--r-- | include/linux/dax.h | 55 |
1 files changed, 44 insertions, 11 deletions
diff --git a/include/linux/dax.h b/include/linux/dax.h index e9ea78c1cf98..8d1a5c47945f 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -9,20 +9,32 @@ struct iomap_ops; /* - * We use lowest available bit in exceptional entry for locking, other two - * bits to determine entry type. In total 3 special bits. + * We use lowest available bit in exceptional entry for locking, one bit for + * the entry size (PMD) and two more to tell us if the entry is a huge zero + * page (HZP) or an empty entry that is just used for locking. In total four + * special bits. + * + * If the PMD bit isn't set the entry has size PAGE_SIZE, and if the HZP and + * EMPTY bits aren't set the entry is a normal DAX entry with a filesystem + * block allocation. */ -#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 3) +#define RADIX_DAX_SHIFT (RADIX_TREE_EXCEPTIONAL_SHIFT + 4) #define RADIX_DAX_ENTRY_LOCK (1 << RADIX_TREE_EXCEPTIONAL_SHIFT) -#define RADIX_DAX_PTE (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1)) -#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2)) -#define RADIX_DAX_TYPE_MASK (RADIX_DAX_PTE | RADIX_DAX_PMD) -#define RADIX_DAX_TYPE(entry) ((unsigned long)entry & RADIX_DAX_TYPE_MASK) -#define RADIX_DAX_SECTOR(entry) (((unsigned long)entry >> RADIX_DAX_SHIFT)) -#define RADIX_DAX_ENTRY(sector, pmd) ((void *)((unsigned long)sector << \ - RADIX_DAX_SHIFT | (pmd ? RADIX_DAX_PMD : RADIX_DAX_PTE) | \ - RADIX_TREE_EXCEPTIONAL_ENTRY)) +#define RADIX_DAX_PMD (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 1)) +#define RADIX_DAX_HZP (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 2)) +#define RADIX_DAX_EMPTY (1 << (RADIX_TREE_EXCEPTIONAL_SHIFT + 3)) +static inline unsigned long dax_radix_sector(void *entry) +{ + return (unsigned long)entry >> RADIX_DAX_SHIFT; +} + +static inline void *dax_radix_locked_entry(sector_t sector, unsigned long flags) +{ + return (void *)(RADIX_TREE_EXCEPTIONAL_ENTRY | flags | + ((unsigned long)sector << RADIX_DAX_SHIFT) | + RADIX_DAX_ENTRY_LOCK); +} ssize_t dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, struct iomap_ops *ops); @@ -67,6 +79,27 @@ static inline int dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, return VM_FAULT_FALLBACK; } +#ifdef CONFIG_FS_DAX_PMD +static inline unsigned int dax_radix_order(void *entry) +{ + if ((unsigned long)entry & RADIX_DAX_PMD) + return PMD_SHIFT - PAGE_SHIFT; + return 0; +} +int dax_iomap_pmd_fault(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmd, unsigned int flags, struct iomap_ops *ops); +#else +static inline unsigned int dax_radix_order(void *entry) +{ + return 0; +} +static inline int dax_iomap_pmd_fault(struct vm_area_struct *vma, + unsigned long address, pmd_t *pmd, unsigned int flags, + struct iomap_ops *ops) +{ + return VM_FAULT_FALLBACK; +} +#endif int dax_pfn_mkwrite(struct vm_area_struct *, struct vm_fault *); #define dax_mkwrite(vma, vmf, gb) dax_fault(vma, vmf, gb) |