include/linux/pfn_t.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _LINUX_PFN_T_H_
   3 #define _LINUX_PFN_T_H_
   4 #include <linux/mm.h>
   5
   6 /*
   7  * PFN_FLAGS_MASK - mask of all the possible valid pfn_t flags
   8  * PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry
   9  * PFN_SG_LAST - pfn references a page and is the last scatterlist entry
  10  * PFN_DEV - pfn is not covered by system memmap by default
  11  * PFN_MAP - pfn has a dynamic page mapping established by a device driver
  12  */
  13 #define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
  14 #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
  15 #define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2))
  16 #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
  17 #define PFN_MAP (1ULL << (BITS_PER_LONG_LONG - 4))
  18 #define PFN_SPECIAL (1ULL << (BITS_PER_LONG_LONG - 5))
  19
  20 #define PFN_FLAGS_TRACE \
  21         { PFN_SPECIAL,  "SPECIAL" }, \
  22         { PFN_SG_CHAIN, "SG_CHAIN" }, \
  23         { PFN_SG_LAST,  "SG_LAST" }, \
  24         { PFN_DEV,      "DEV" }, \
  25         { PFN_MAP,      "MAP" }
  26
  27 static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags)
  28 {
  29         pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), };
  30
  31         return pfn_t;
  32 }
  33
  34 /* a default pfn to pfn_t conversion assumes that @pfn is pfn_valid() */
  35 static inline pfn_t pfn_to_pfn_t(unsigned long pfn)
  36 {
  37         return __pfn_to_pfn_t(pfn, 0);
  38 }
  39
  40 static inline pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags)
  41 {
  42         return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
  43 }
  44
  45 static inline bool pfn_t_has_page(pfn_t pfn)
  46 {
  47         return (pfn.val & PFN_MAP) == PFN_MAP || (pfn.val & PFN_DEV) == 0;
  48 }
  49
  50 static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
  51 {
  52         return pfn.val & ~PFN_FLAGS_MASK;
  53 }
  54
  55 static inline struct page *pfn_t_to_page(pfn_t pfn)
  56 {
  57         if (pfn_t_has_page(pfn))
  58                 return pfn_to_page(pfn_t_to_pfn(pfn));
  59         return NULL;
  60 }
  61
  62 static inline phys_addr_t pfn_t_to_phys(pfn_t pfn)
  63 {
  64         return PFN_PHYS(pfn_t_to_pfn(pfn));
  65 }
  66
  67 static inline void *pfn_t_to_virt(pfn_t pfn)
  68 {
  69         if (pfn_t_has_page(pfn))
  70                 return __va(pfn_t_to_phys(pfn));
  71         return NULL;
  72 }
  73
  74 static inline pfn_t page_to_pfn_t(struct page *page)
  75 {
  76         return pfn_to_pfn_t(page_to_pfn(page));
  77 }
  78
  79 static inline int pfn_t_valid(pfn_t pfn)
  80 {
  81         return pfn_valid(pfn_t_to_pfn(pfn));
  82 }
  83
  84 #ifdef CONFIG_MMU
  85 static inline pte_t pfn_t_pte(pfn_t pfn, pgprot_t pgprot)
  86 {
  87         return pfn_pte(pfn_t_to_pfn(pfn), pgprot);
  88 }
  89 #endif
  90
  91 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  92 static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot)
  93 {
  94         return pfn_pmd(pfn_t_to_pfn(pfn), pgprot);
  95 }
  96
  97 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
  98 static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
  99 {
 100         return pfn_pud(pfn_t_to_pfn(pfn), pgprot);
 101 }
 102 #endif
 103 #endif
 104
 105 #ifdef __HAVE_ARCH_PTE_DEVMAP
 106 static inline bool pfn_t_devmap(pfn_t pfn)
 107 {
 108         const u64 flags = PFN_DEV|PFN_MAP;
 109
 110         return (pfn.val & flags) == flags;
 111 }
 112 #else
 113 static inline bool pfn_t_devmap(pfn_t pfn)
 114 {
 115         return false;
 116 }
 117 pte_t pte_mkdevmap(pte_t pte);
 118 pmd_t pmd_mkdevmap(pmd_t pmd);
 119 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
 120         defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
 121 pud_t pud_mkdevmap(pud_t pud);
 122 #endif
 123 #endif /* __HAVE_ARCH_PTE_DEVMAP */
 124
 125 #ifdef __HAVE_ARCH_PTE_SPECIAL
 126 static inline bool pfn_t_special(pfn_t pfn)
 127 {
 128         return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
 129 }
 130 #else
 131 static inline bool pfn_t_special(pfn_t pfn)
 132 {
 133         return false;
 134 }
 135 #endif /* __HAVE_ARCH_PTE_SPECIAL */
 136 #endif /* _LINUX_PFN_T_H_ */