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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 | /* SPDX-License-Identifier: GPL-2.0-only */ /* * Copyright (C) 2018 HUAWEI, Inc. * http://www.huawei.com/ * Created by Gao Xiang <gaoxiang25@huawei.com> */ #ifndef __EROFS_FS_ZPVEC_H #define __EROFS_FS_ZPVEC_H #include "tagptr.h" /* page type in pagevec for decompress subsystem */ enum z_erofs_page_type { /* including Z_EROFS_VLE_PAGE_TAIL_EXCLUSIVE */ Z_EROFS_PAGE_TYPE_EXCLUSIVE, Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED, Z_EROFS_VLE_PAGE_TYPE_HEAD, Z_EROFS_VLE_PAGE_TYPE_MAX }; extern void __compiletime_error("Z_EROFS_PAGE_TYPE_EXCLUSIVE != 0") __bad_page_type_exclusive(void); /* pagevec tagged pointer */ typedef tagptr2_t erofs_vtptr_t; /* pagevec collector */ struct z_erofs_pagevec_ctor { struct page *curr, *next; erofs_vtptr_t *pages; unsigned int nr, index; }; static inline void z_erofs_pagevec_ctor_exit(struct z_erofs_pagevec_ctor *ctor, bool atomic) { if (!ctor->curr) return; if (atomic) kunmap_atomic(ctor->pages); else kunmap(ctor->curr); } static inline struct page * z_erofs_pagevec_ctor_next_page(struct z_erofs_pagevec_ctor *ctor, unsigned int nr) { unsigned int index; /* keep away from occupied pages */ if (ctor->next) return ctor->next; for (index = 0; index < nr; ++index) { const erofs_vtptr_t t = ctor->pages[index]; const unsigned int tags = tagptr_unfold_tags(t); if (tags == Z_EROFS_PAGE_TYPE_EXCLUSIVE) return tagptr_unfold_ptr(t); } DBG_BUGON(nr >= ctor->nr); return NULL; } static inline void z_erofs_pagevec_ctor_pagedown(struct z_erofs_pagevec_ctor *ctor, bool atomic) { struct page *next = z_erofs_pagevec_ctor_next_page(ctor, ctor->nr); z_erofs_pagevec_ctor_exit(ctor, atomic); ctor->curr = next; ctor->next = NULL; ctor->pages = atomic ? kmap_atomic(ctor->curr) : kmap(ctor->curr); ctor->nr = PAGE_SIZE / sizeof(struct page *); ctor->index = 0; } static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor, unsigned int nr, erofs_vtptr_t *pages, unsigned int i) { ctor->nr = nr; ctor->curr = ctor->next = NULL; ctor->pages = pages; if (i >= nr) { i -= nr; z_erofs_pagevec_ctor_pagedown(ctor, false); while (i > ctor->nr) { i -= ctor->nr; z_erofs_pagevec_ctor_pagedown(ctor, false); } } ctor->next = z_erofs_pagevec_ctor_next_page(ctor, i); ctor->index = i; } static inline bool z_erofs_pagevec_enqueue(struct z_erofs_pagevec_ctor *ctor, struct page *page, enum z_erofs_page_type type, bool *occupied) { *occupied = false; if (!ctor->next && type) if (ctor->index + 1 == ctor->nr) return false; if (ctor->index >= ctor->nr) z_erofs_pagevec_ctor_pagedown(ctor, false); /* exclusive page type must be 0 */ if (Z_EROFS_PAGE_TYPE_EXCLUSIVE != (uintptr_t)NULL) __bad_page_type_exclusive(); /* should remind that collector->next never equal to 1, 2 */ if (type == (uintptr_t)ctor->next) { ctor->next = page; *occupied = true; } ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, page, type); return true; } static inline struct page * z_erofs_pagevec_dequeue(struct z_erofs_pagevec_ctor *ctor, enum z_erofs_page_type *type) { erofs_vtptr_t t; if (ctor->index >= ctor->nr) { DBG_BUGON(!ctor->next); z_erofs_pagevec_ctor_pagedown(ctor, true); } t = ctor->pages[ctor->index]; *type = tagptr_unfold_tags(t); /* should remind that collector->next never equal to 1, 2 */ if (*type == (uintptr_t)ctor->next) ctor->next = tagptr_unfold_ptr(t); ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, NULL, 0); return tagptr_unfold_ptr(t); } #endif |