include/linux/pfn_t.h

   1 #ifndef _LINUX_PFN_T_H_
   2 #define _LINUX_PFN_T_H_
   3 #include <linux/mm.h>
   4
   5 /*
   6  * PFN_FLAGS_MASK - mask of all the possible valid pfn_t flags
   7  * PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry
   8  * PFN_SG_LAST - pfn references a page and is the last scatterlist entry
   9  * PFN_DEV - pfn is not covered by system memmap by default
  10  * PFN_MAP - pfn has a dynamic page mapping established by a device driver
  11  */
  12 #define PFN_FLAGS_MASK (((unsigned long) ~PAGE_MASK) \
  13                 << (BITS_PER_LONG - PAGE_SHIFT))
  14 #define PFN_SG_CHAIN (1UL << (BITS_PER_LONG - 1))
  15 #define PFN_SG_LAST (1UL << (BITS_PER_LONG - 2))
  16 #define PFN_DEV (1UL << (BITS_PER_LONG - 3))
  17 #define PFN_MAP (1UL << (BITS_PER_LONG - 4))
  18
  19 static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, unsigned long flags)
  20 {
  21         pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), };
  22
  23         return pfn_t;
  24 }
  25
  26 /* a default pfn to pfn_t conversion assumes that @pfn is pfn_valid() */
  27 static inline pfn_t pfn_to_pfn_t(unsigned long pfn)
  28 {
  29         return __pfn_to_pfn_t(pfn, 0);
  30 }
  31
  32 extern pfn_t phys_to_pfn_t(dma_addr_t addr, unsigned long flags);
  33
  34 static inline bool pfn_t_has_page(pfn_t pfn)
  35 {
  36         return (pfn.val & PFN_MAP) == PFN_MAP || (pfn.val & PFN_DEV) == 0;
  37 }
  38
  39 static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
  40 {
  41         return pfn.val & ~PFN_FLAGS_MASK;
  42 }
  43
  44 static inline struct page *pfn_t_to_page(pfn_t pfn)
  45 {
  46         if (pfn_t_has_page(pfn))
  47                 return pfn_to_page(pfn_t_to_pfn(pfn));
  48         return NULL;
  49 }
  50
  51 static inline dma_addr_t pfn_t_to_phys(pfn_t pfn)
  52 {
  53         return PFN_PHYS(pfn_t_to_pfn(pfn));
  54 }
  55
  56 static inline void *pfn_t_to_virt(pfn_t pfn)
  57 {
  58         if (pfn_t_has_page(pfn))
  59                 return __va(pfn_t_to_phys(pfn));
  60         return NULL;
  61 }
  62
  63 static inline pfn_t page_to_pfn_t(struct page *page)
  64 {
  65         return pfn_to_pfn_t(page_to_pfn(page));
  66 }
  67
  68 static inline int pfn_t_valid(pfn_t pfn)
  69 {
  70         return pfn_valid(pfn_t_to_pfn(pfn));
  71 }
  72
  73 #ifdef CONFIG_MMU
  74 static inline pte_t pfn_t_pte(pfn_t pfn, pgprot_t pgprot)
  75 {
  76         return pfn_pte(pfn_t_to_pfn(pfn), pgprot);
  77 }
  78 #endif
  79
  80 #ifdef __HAVE_ARCH_PTE_DEVMAP
  81 static inline bool pfn_t_devmap(pfn_t pfn)
  82 {
  83         const unsigned long flags = PFN_DEV|PFN_MAP;
  84
  85         return (pfn.val & flags) == flags;
  86 }
  87 #else
  88 static inline bool pfn_t_devmap(pfn_t pfn)
  89 {
  90         return false;
  91 }
  92 pte_t pte_mkdevmap(pte_t pte);
  93 #endif
  94 #endif /* _LINUX_PFN_T_H_ */