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152 lines
3.4 KiB
152 lines
3.4 KiB
/* SPDX-License-Identifier: GPL-2.0-only */ |
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/* |
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* Copyright (C) 2018 HUAWEI, Inc. |
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* https://www.huawei.com/ |
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*/ |
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#ifndef __EROFS_FS_ZPVEC_H |
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#define __EROFS_FS_ZPVEC_H |
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#include "tagptr.h" |
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/* page type in pagevec for decompress subsystem */ |
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enum z_erofs_page_type { |
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/* including Z_EROFS_VLE_PAGE_TAIL_EXCLUSIVE */ |
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Z_EROFS_PAGE_TYPE_EXCLUSIVE, |
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Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED, |
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Z_EROFS_VLE_PAGE_TYPE_HEAD, |
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Z_EROFS_VLE_PAGE_TYPE_MAX |
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}; |
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extern void __compiletime_error("Z_EROFS_PAGE_TYPE_EXCLUSIVE != 0") |
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__bad_page_type_exclusive(void); |
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/* pagevec tagged pointer */ |
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typedef tagptr2_t erofs_vtptr_t; |
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/* pagevec collector */ |
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struct z_erofs_pagevec_ctor { |
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struct page *curr, *next; |
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erofs_vtptr_t *pages; |
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unsigned int nr, index; |
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}; |
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static inline void z_erofs_pagevec_ctor_exit(struct z_erofs_pagevec_ctor *ctor, |
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bool atomic) |
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{ |
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if (!ctor->curr) |
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return; |
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if (atomic) |
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kunmap_atomic(ctor->pages); |
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else |
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kunmap(ctor->curr); |
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} |
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static inline struct page * |
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z_erofs_pagevec_ctor_next_page(struct z_erofs_pagevec_ctor *ctor, |
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unsigned int nr) |
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{ |
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unsigned int index; |
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/* keep away from occupied pages */ |
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if (ctor->next) |
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return ctor->next; |
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for (index = 0; index < nr; ++index) { |
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const erofs_vtptr_t t = ctor->pages[index]; |
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const unsigned int tags = tagptr_unfold_tags(t); |
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if (tags == Z_EROFS_PAGE_TYPE_EXCLUSIVE) |
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return tagptr_unfold_ptr(t); |
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} |
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DBG_BUGON(nr >= ctor->nr); |
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return NULL; |
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} |
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static inline void |
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z_erofs_pagevec_ctor_pagedown(struct z_erofs_pagevec_ctor *ctor, |
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bool atomic) |
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{ |
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struct page *next = z_erofs_pagevec_ctor_next_page(ctor, ctor->nr); |
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z_erofs_pagevec_ctor_exit(ctor, atomic); |
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ctor->curr = next; |
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ctor->next = NULL; |
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ctor->pages = atomic ? |
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kmap_atomic(ctor->curr) : kmap(ctor->curr); |
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ctor->nr = PAGE_SIZE / sizeof(struct page *); |
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ctor->index = 0; |
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} |
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static inline void z_erofs_pagevec_ctor_init(struct z_erofs_pagevec_ctor *ctor, |
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unsigned int nr, |
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erofs_vtptr_t *pages, |
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unsigned int i) |
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{ |
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ctor->nr = nr; |
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ctor->curr = ctor->next = NULL; |
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ctor->pages = pages; |
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if (i >= nr) { |
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i -= nr; |
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z_erofs_pagevec_ctor_pagedown(ctor, false); |
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while (i > ctor->nr) { |
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i -= ctor->nr; |
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z_erofs_pagevec_ctor_pagedown(ctor, false); |
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} |
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} |
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ctor->next = z_erofs_pagevec_ctor_next_page(ctor, i); |
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ctor->index = i; |
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} |
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static inline bool z_erofs_pagevec_enqueue(struct z_erofs_pagevec_ctor *ctor, |
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struct page *page, |
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enum z_erofs_page_type type) |
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{ |
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if (!ctor->next && type) |
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if (ctor->index + 1 == ctor->nr) |
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return false; |
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if (ctor->index >= ctor->nr) |
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z_erofs_pagevec_ctor_pagedown(ctor, false); |
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/* exclusive page type must be 0 */ |
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if (Z_EROFS_PAGE_TYPE_EXCLUSIVE != (uintptr_t)NULL) |
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__bad_page_type_exclusive(); |
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/* should remind that collector->next never equal to 1, 2 */ |
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if (type == (uintptr_t)ctor->next) { |
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ctor->next = page; |
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} |
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ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, page, type); |
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return true; |
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} |
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static inline struct page * |
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z_erofs_pagevec_dequeue(struct z_erofs_pagevec_ctor *ctor, |
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enum z_erofs_page_type *type) |
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{ |
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erofs_vtptr_t t; |
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if (ctor->index >= ctor->nr) { |
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DBG_BUGON(!ctor->next); |
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z_erofs_pagevec_ctor_pagedown(ctor, true); |
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} |
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t = ctor->pages[ctor->index]; |
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*type = tagptr_unfold_tags(t); |
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/* should remind that collector->next never equal to 1, 2 */ |
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if (*type == (uintptr_t)ctor->next) |
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ctor->next = tagptr_unfold_ptr(t); |
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ctor->pages[ctor->index++] = tagptr_fold(erofs_vtptr_t, NULL, 0); |
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return tagptr_unfold_ptr(t); |
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} |
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#endif
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