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  * PFN_SPECIAL - for CONFIG_FS_DAX_LIMITED builds to allow XIP, but not
  13  *               get_user_pages
  14  */
  15 #define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
  16 #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
  17 #define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2))
  18 #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
  19 #define PFN_MAP (1ULL << (BITS_PER_LONG_LONG - 4))
  20 #define PFN_SPECIAL (1ULL << (BITS_PER_LONG_LONG - 5))
  21
  22 #define PFN_FLAGS_TRACE \
  23         { PFN_SPECIAL,  "SPECIAL" }, \
  24         { PFN_SG_CHAIN, "SG_CHAIN" }, \
  25         { PFN_SG_LAST,  "SG_LAST" }, \
  26         { PFN_DEV,      "DEV" }, \
  27         { PFN_MAP,      "MAP" }
  28
  29 static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags)
  30 {
  31         pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), };
  32
  33         return pfn_t;
  34 }
  35
  36 /* a default pfn to pfn_t conversion assumes that @pfn is pfn_valid() */
  37 static inline pfn_t pfn_to_pfn_t(unsigned long pfn)
  38 {
  39         return __pfn_to_pfn_t(pfn, 0);
  40 }
  41
  42 static inline pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags)
  43 {
  44         return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
  45 }
  46
  47 static inline bool pfn_t_has_page(pfn_t pfn)
  48 {
  49         return (pfn.val & PFN_MAP) == PFN_MAP || (pfn.val & PFN_DEV) == 0;
  50 }
  51
  52 static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
  53 {
  54         return pfn.val & ~PFN_FLAGS_MASK;
  55 }
  56
  57 static inline struct page *pfn_t_to_page(pfn_t pfn)
  58 {
  59         if (pfn_t_has_page(pfn))
  60                 return pfn_to_page(pfn_t_to_pfn(pfn));
  61         return NULL;
  62 }
  63
  64 static inline phys_addr_t pfn_t_to_phys(pfn_t pfn)
  65 {
  66         return PFN_PHYS(pfn_t_to_pfn(pfn));
  67 }
  68
  69 static inline pfn_t page_to_pfn_t(struct page *page)
  70 {
  71         return pfn_to_pfn_t(page_to_pfn(page));
  72 }
  73
  74 static inline int pfn_t_valid(pfn_t pfn)
  75 {
  76         return pfn_valid(pfn_t_to_pfn(pfn));
  77 }
  78
  79 #ifdef CONFIG_MMU
  80 static inline pte_t pfn_t_pte(pfn_t pfn, pgprot_t pgprot)
  81 {
  82         return pfn_pte(pfn_t_to_pfn(pfn), pgprot);
  83 }
  84 #endif
  85
  86 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  87 static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot)
  88 {
  89         return pfn_pmd(pfn_t_to_pfn(pfn), pgprot);
  90 }
  91
  92 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
  93 static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
  94 {
  95         return pfn_pud(pfn_t_to_pfn(pfn), pgprot);
  96 }
  97 #endif
  98 #endif
  99
 100 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
 101 static inline bool pfn_t_devmap(pfn_t pfn)
 102 {
 103         const u64 flags = PFN_DEV|PFN_MAP;
 104
 105         return (pfn.val & flags) == flags;
 106 }
 107 #else
 108 static inline bool pfn_t_devmap(pfn_t pfn)
 109 {
 110         return false;
 111 }
 112 pte_t pte_mkdevmap(pte_t pte);
 113 pmd_t pmd_mkdevmap(pmd_t pmd);
 114 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
 115         defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
 116 pud_t pud_mkdevmap(pud_t pud);
 117 #endif
 118 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
 119
 120 #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
 121 static inline bool pfn_t_special(pfn_t pfn)
 122 {
 123         return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
 124 }
 125 #else
 126 static inline bool pfn_t_special(pfn_t pfn)
 127 {
 128         return false;
 129 }
 130 #endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
 131 #endif /* _LINUX_PFN_T_H_ */