diff options
Diffstat (limited to 'fs/erofs/zpvec.h')
| -rw-r--r-- | fs/erofs/zpvec.h | 159 |
1 files changed, 0 insertions, 159 deletions
diff --git a/fs/erofs/zpvec.h b/fs/erofs/zpvec.h deleted file mode 100644 index b05464f4a808..000000000000 --- a/fs/erofs/zpvec.h +++ /dev/null @@ -1,159 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Copyright (C) 2018 HUAWEI, Inc. - * https://www.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 pvec_safereuse) -{ - if (!ctor->next) { - /* some pages cannot be reused as pvec safely without I/O */ - if (type == Z_EROFS_PAGE_TYPE_EXCLUSIVE && !pvec_safereuse) - type = Z_EROFS_VLE_PAGE_TYPE_TAIL_SHARED; - - if (type != Z_EROFS_PAGE_TYPE_EXCLUSIVE && - 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; - } - 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 |