include/linux/pfn_t.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 #ifndef _LINUX_PFN_T_H_
0003 #define _LINUX_PFN_T_H_
0004 #include <linux/mm.h>
0005
0006 /*
0007  * PFN_FLAGS_MASK - mask of all the possible valid pfn_t flags
0008  * PFN_SG_CHAIN - pfn is a pointer to the next scatterlist entry
0009  * PFN_SG_LAST - pfn references a page and is the last scatterlist entry
0010  * PFN_DEV - pfn is not covered by system memmap by default
0011  * PFN_MAP - pfn has a dynamic page mapping established by a device driver
0012  * PFN_SPECIAL - for CONFIG_FS_DAX_LIMITED builds to allow XIP, but not
0013  *       get_user_pages
0014  */
0015 #define PFN_FLAGS_MASK (((u64) (~PAGE_MASK)) << (BITS_PER_LONG_LONG - PAGE_SHIFT))
0016 #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1))
0017 #define PFN_SG_LAST (1ULL << (BITS_PER_LONG_LONG - 2))
0018 #define PFN_DEV (1ULL << (BITS_PER_LONG_LONG - 3))
0019 #define PFN_MAP (1ULL << (BITS_PER_LONG_LONG - 4))
0020 #define PFN_SPECIAL (1ULL << (BITS_PER_LONG_LONG - 5))
0021
0022 #define PFN_FLAGS_TRACE \
0023     { PFN_SPECIAL,  "SPECIAL" }, \
0024     { PFN_SG_CHAIN, "SG_CHAIN" }, \
0025     { PFN_SG_LAST,  "SG_LAST" }, \
0026     { PFN_DEV,  "DEV" }, \
0027     { PFN_MAP,  "MAP" }
0028
0029 static inline pfn_t __pfn_to_pfn_t(unsigned long pfn, u64 flags)
0030 {
0031     pfn_t pfn_t = { .val = pfn | (flags & PFN_FLAGS_MASK), };
0032
0033     return pfn_t;
0034 }
0035
0036 /* a default pfn to pfn_t conversion assumes that @pfn is pfn_valid() */
0037 static inline pfn_t pfn_to_pfn_t(unsigned long pfn)
0038 {
0039     return __pfn_to_pfn_t(pfn, 0);
0040 }
0041
0042 static inline pfn_t phys_to_pfn_t(phys_addr_t addr, u64 flags)
0043 {
0044     return __pfn_to_pfn_t(addr >> PAGE_SHIFT, flags);
0045 }
0046
0047 static inline bool pfn_t_has_page(pfn_t pfn)
0048 {
0049     return (pfn.val & PFN_MAP) == PFN_MAP || (pfn.val & PFN_DEV) == 0;
0050 }
0051
0052 static inline unsigned long pfn_t_to_pfn(pfn_t pfn)
0053 {
0054     return pfn.val & ~PFN_FLAGS_MASK;
0055 }
0056
0057 static inline struct page *pfn_t_to_page(pfn_t pfn)
0058 {
0059     if (pfn_t_has_page(pfn))
0060         return pfn_to_page(pfn_t_to_pfn(pfn));
0061     return NULL;
0062 }
0063
0064 static inline phys_addr_t pfn_t_to_phys(pfn_t pfn)
0065 {
0066     return PFN_PHYS(pfn_t_to_pfn(pfn));
0067 }
0068
0069 static inline pfn_t page_to_pfn_t(struct page *page)
0070 {
0071     return pfn_to_pfn_t(page_to_pfn(page));
0072 }
0073
0074 static inline int pfn_t_valid(pfn_t pfn)
0075 {
0076     return pfn_valid(pfn_t_to_pfn(pfn));
0077 }
0078
0079 #ifdef CONFIG_MMU
0080 static inline pte_t pfn_t_pte(pfn_t pfn, pgprot_t pgprot)
0081 {
0082     return pfn_pte(pfn_t_to_pfn(pfn), pgprot);
0083 }
0084 #endif
0085
0086 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
0087 static inline pmd_t pfn_t_pmd(pfn_t pfn, pgprot_t pgprot)
0088 {
0089     return pfn_pmd(pfn_t_to_pfn(pfn), pgprot);
0090 }
0091
0092 #ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
0093 static inline pud_t pfn_t_pud(pfn_t pfn, pgprot_t pgprot)
0094 {
0095     return pfn_pud(pfn_t_to_pfn(pfn), pgprot);
0096 }
0097 #endif
0098 #endif
0099
0100 #ifdef CONFIG_ARCH_HAS_PTE_DEVMAP
0101 static inline bool pfn_t_devmap(pfn_t pfn)
0102 {
0103     const u64 flags = PFN_DEV|PFN_MAP;
0104
0105     return (pfn.val & flags) == flags;
0106 }
0107 #else
0108 static inline bool pfn_t_devmap(pfn_t pfn)
0109 {
0110     return false;
0111 }
0112 pte_t pte_mkdevmap(pte_t pte);
0113 pmd_t pmd_mkdevmap(pmd_t pmd);
0114 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
0115     defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
0116 pud_t pud_mkdevmap(pud_t pud);
0117 #endif
0118 #endif /* CONFIG_ARCH_HAS_PTE_DEVMAP */
0119
0120 #ifdef CONFIG_ARCH_HAS_PTE_SPECIAL
0121 static inline bool pfn_t_special(pfn_t pfn)
0122 {
0123     return (pfn.val & PFN_SPECIAL) == PFN_SPECIAL;
0124 }
0125 #else
0126 static inline bool pfn_t_special(pfn_t pfn)
0127 {
0128     return false;
0129 }
0130 #endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
0131 #endif /* _LINUX_PFN_T_H_ */