Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Copyright (c) 2013
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  * Phillip Lougher <phillip@squashfs.org.uk>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) #include <linux/pagemap.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include "page_actor.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)  * This file contains implementations of page_actor for decompressing into
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14)  * an intermediate buffer, and for decompressing directly into the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)  * page cache.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17)  * Calling code should avoid sleeping between calls to squashfs_first_page()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)  * and squashfs_finish_page().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) /* Implementation of page_actor for decompressing into intermediate buffer */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) static void *cache_first_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 	actor->next_page = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 	return actor->buffer[0];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) static void *cache_next_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 	if (actor->next_page == actor->pages)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	return actor->buffer[actor->next_page++];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) static void cache_finish_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	/* empty */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 	int pages, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	if (actor == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	actor->length = length ? : pages * PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	actor->buffer = buffer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	actor->pages = pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 	actor->next_page = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	actor->squashfs_first_page = cache_first_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 	actor->squashfs_next_page = cache_next_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	actor->squashfs_finish_page = cache_finish_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	return actor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) /* Implementation of page_actor for decompressing directly into page cache. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) static void *direct_first_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 	actor->next_page = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 	return actor->pageaddr = kmap_atomic(actor->page[0]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) static void *direct_next_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	if (actor->pageaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 		kunmap_atomic(actor->pageaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 	return actor->pageaddr = actor->next_page == actor->pages ? NULL :
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 		kmap_atomic(actor->page[actor->next_page++]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) static void direct_finish_page(struct squashfs_page_actor *actor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) 	if (actor->pageaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) 		kunmap_atomic(actor->pageaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) struct squashfs_page_actor *squashfs_page_actor_init_special(struct page **page,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) 	int pages, int length)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) 	struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) 	if (actor == NULL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) 		return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) 	actor->length = length ? : pages * PAGE_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) 	actor->page = page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) 	actor->pages = pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) 	actor->next_page = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) 	actor->pageaddr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) 	actor->squashfs_first_page = direct_first_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) 	actor->squashfs_next_page = direct_next_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) 	actor->squashfs_finish_page = direct_finish_page;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) 	return actor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) }