1 #ifndef PAGE_ACTOR_H 2 #define PAGE_ACTOR_H 3 /* 4 * Copyright (c) 2013 5 * Phillip Lougher <phillip@squashfs.org.uk> 6 * 7 * This work is licensed under the terms of the GNU GPL, version 2. See 8 * the COPYING file in the top-level directory. 9 */ 10 11 #ifndef CONFIG_SQUASHFS_FILE_DIRECT 12 struct squashfs_page_actor { 13 void **page; 14 int pages; 15 int length; 16 int next_page; 17 }; 18 19 static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page, 20 int pages, int length) 21 { 22 struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL); 23 24 if (actor == NULL) 25 return NULL; 26 27 actor->length = length ? : pages * PAGE_CACHE_SIZE; 28 actor->page = page; 29 actor->pages = pages; 30 actor->next_page = 0; 31 return actor; 32 } 33 34 static inline void *squashfs_first_page(struct squashfs_page_actor *actor) 35 { 36 actor->next_page = 1; 37 return actor->page[0]; 38 } 39 40 static inline void *squashfs_next_page(struct squashfs_page_actor *actor) 41 { 42 return actor->next_page == actor->pages ? NULL : 43 actor->page[actor->next_page++]; 44 } 45 46 static inline void squashfs_finish_page(struct squashfs_page_actor *actor) 47 { 48 /* empty */ 49 } 50 #else 51 struct squashfs_page_actor { 52 union { 53 void **buffer; 54 struct page **page; 55 }; 56 void *pageaddr; 57 void *(*squashfs_first_page)(struct squashfs_page_actor *); 58 void *(*squashfs_next_page)(struct squashfs_page_actor *); 59 void (*squashfs_finish_page)(struct squashfs_page_actor *); 60 int pages; 61 int length; 62 int next_page; 63 }; 64 65 extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int); 66 extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page 67 **, int, int); 68 static inline void *squashfs_first_page(struct squashfs_page_actor *actor) 69 { 70 return actor->squashfs_first_page(actor); 71 } 72 static inline void *squashfs_next_page(struct squashfs_page_actor *actor) 73 { 74 return actor->squashfs_next_page(actor); 75 } 76 static inline void squashfs_finish_page(struct squashfs_page_actor *actor) 77 { 78 actor->squashfs_finish_page(actor); 79 } 80 #endif 81 #endif 82