diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/blkdev.h | 5 | ||||
| -rw-r--r-- | include/linux/pfn.h | 9 | ||||
| -rw-r--r-- | include/linux/pfn_t.h | 67 |
3 files changed, 79 insertions, 2 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 88821fa..bfb64d6 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -15,6 +15,7 @@ #include <linux/backing-dev-defs.h> #include <linux/wait.h> #include <linux/mempool.h> +#include <linux/pfn.h> #include <linux/bio.h> #include <linux/stringify.h> #include <linux/gfp.h> @@ -1628,7 +1629,7 @@ struct blk_dax_ctl { sector_t sector; void __pmem *addr; long size; - unsigned long pfn; + pfn_t pfn; }; struct block_device_operations { @@ -1638,7 +1639,7 @@ struct block_device_operations { int (*ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); int (*compat_ioctl) (struct block_device *, fmode_t, unsigned, unsigned long); long (*direct_access)(struct block_device *, sector_t, void __pmem **, - unsigned long *pfn); + pfn_t *); unsigned int (*check_events) (struct gendisk *disk, unsigned int clearing); /* ->media_changed() is DEPRECATED, use ->check_events() instead */ diff --git a/include/linux/pfn.h b/include/linux/pfn.h index 97f3e88..2d8e497 100644 --- a/include/linux/pfn.h +++ b/include/linux/pfn.h @@ -3,6 +3,15 @@ #ifndef __ASSEMBLY__ #include <linux/types.h> + +/* + * pfn_t: encapsulates a page-frame number that is optionally backed + * by memmap (struct page). Whether a pfn_t has a 'struct page' + * backing is indicated by flags in the high bits of the value. + */ +typedef struct { + unsigned long val; +} pfn_t; #endif #define PFN_ALIGN(x) (((unsigned long)(x) + (PAGE_SIZE - 1)) & PAGE_MASK) diff --git a/include/linux/pfn_t.h b/include/linux/pfn_t.h new file mode 100644 index 0000000..c557a0e --- /dev/null +++ b/include/linux/pfn_t.h @@ -0,0 +1,67 @@ +#ifndef _LINUX_PFN_T_H_ +#define _LINUX_PFN_T_H_ +#include <linux/mm.h> + +/* + * PFN_FLAGS_MASK - mask of all the possible valid pfn_t flags + * PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry + * PFN_SG_LAST - pfn references a page and is the last scatterlist entry + * PFN_DEV - pfn is not covered by system memmap by default + * PFN_MAP - pfn has a dynamic page mapping established by a device driver + */ +#define PFN_FLAGS_MASK (((unsigned long) ~PAGE_MASK) \ + << (BITS_PER_LONG - PAGE_SHIFT)) +#define PFN_SG_CHAIN (1UL << (BITS_PER_LONG - 1)) +#define PFN_SG_LAST (1UL << (BITS_PER_LONG - 2)) +#define PFN_DEV (1UL << (BITS_PER_LONG - 3)) +#define PFN_MAP (1UL << (BITS_PER_LONG - 4)) + +static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, unsigned long flags) +{ + pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), }; + + return pfn_t; +} + +/* a default pfn to pfn_t conversion assumes that @pfn is pfn_valid() */ +static inline pfn_t pfn_to_pfn_t(unsigned long pfn) +{ + return __pfn_to_pfn_t(pfn, 0); +} + +extern pfn_t phys_to_pfn_t(dma_addr_t addr, unsigned long flags); + +static inline bool pfn_t_has_page(pfn_t pfn) +{ + return (pfn.val & PFN_MAP) == PFN_MAP || (pfn.val & PFN_DEV) == 0; +} + +static inline unsigned long pfn_t_to_pfn(pfn_t pfn) +{ + return pfn.val & ~PFN_FLAGS_MASK; +} + +static inline struct page *pfn_t_to_page(pfn_t pfn) +{ + if (pfn_t_has_page(pfn)) + return pfn_to_page(pfn_t_to_pfn(pfn)); + return NULL; +} + +static inline dma_addr_t pfn_t_to_phys(pfn_t pfn) +{ + return PFN_PHYS(pfn_t_to_pfn(pfn)); +} + +static inline void *pfn_t_to_virt(pfn_t pfn) +{ + if (pfn_t_has_page(pfn)) + return __va(pfn_t_to_phys(pfn)); + return NULL; +} + +static inline pfn_t page_to_pfn_t(struct page *page) +{ + return pfn_to_pfn_t(page_to_pfn(page)); +} +#endif /* _LINUX_PFN_T_H_ */ |