1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3  * Copyright © 2003-2010 David Woodhouse <dwmw2@infradead.org>
4  */
5 
6 #ifndef __MTD_TRANS_H__
7 #define __MTD_TRANS_H__
8 
9 #include <linux/mutex.h>
10 #include <linux/kref.h>
11 #include <linux/sysfs.h>
12 
13 struct hd_geometry;
14 struct mtd_info;
15 struct mtd_blktrans_ops;
16 struct file;
17 struct inode;
18 
19 struct mtd_blktrans_dev {
20 	struct mtd_blktrans_ops *tr;
21 	struct list_head list;
22 	struct mtd_info *mtd;
23 	struct mutex lock;
24 	int devnum;
25 	bool bg_stop;
26 	unsigned long size;
27 	int readonly;
28 	int open;
29 	struct kref ref;
30 	struct gendisk *disk;
31 	struct attribute_group *disk_attributes;
32 	struct request_queue *rq;
33 	struct list_head rq_list;
34 	struct blk_mq_tag_set *tag_set;
35 	spinlock_t queue_lock;
36 	void *priv;
37 	fmode_t file_mode;
38 };
39 
40 struct mtd_blktrans_ops {
41 	char *name;
42 	int major;
43 	int part_bits;
44 	int blksize;
45 	int blkshift;
46 
47 	/* Access functions */
48 	int (*readsect)(struct mtd_blktrans_dev *dev,
49 		    unsigned long block, char *buffer);
50 	int (*writesect)(struct mtd_blktrans_dev *dev,
51 		     unsigned long block, char *buffer);
52 	int (*discard)(struct mtd_blktrans_dev *dev,
53 		       unsigned long block, unsigned nr_blocks);
54 	void (*background)(struct mtd_blktrans_dev *dev);
55 
56 	/* Block layer ioctls */
57 	int (*getgeo)(struct mtd_blktrans_dev *dev, struct hd_geometry *geo);
58 	int (*flush)(struct mtd_blktrans_dev *dev);
59 
60 	/* Called with mtd_table_mutex held; no race with add/remove */
61 	int (*open)(struct mtd_blktrans_dev *dev);
62 	void (*release)(struct mtd_blktrans_dev *dev);
63 
64 	/* Called on {de,}registration and on subsequent addition/removal
65 	   of devices, with mtd_table_mutex held. */
66 	void (*add_mtd)(struct mtd_blktrans_ops *tr, struct mtd_info *mtd);
67 	void (*remove_dev)(struct mtd_blktrans_dev *dev);
68 
69 	struct list_head devs;
70 	struct list_head list;
71 	struct module *owner;
72 };
73 
74 extern int register_mtd_blktrans(struct mtd_blktrans_ops *tr);
75 extern int deregister_mtd_blktrans(struct mtd_blktrans_ops *tr);
76 extern int add_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
77 extern int del_mtd_blktrans_dev(struct mtd_blktrans_dev *dev);
78 extern int mtd_blktrans_cease_background(struct mtd_blktrans_dev *dev);
79 
80 /**
81  * module_mtd_blktrans() - Helper macro for registering a mtd blktrans driver
82  * @__mtd_blktrans: mtd_blktrans_ops struct
83  *
84  * Helper macro for mtd blktrans drivers which do not do anything special in
85  * module init/exit. This eliminates a lot of boilerplate. Each module may only
86  * use this macro once, and calling it replaces module_init() and module_exit()
87  */
88 #define module_mtd_blktrans(__mtd_blktrans) \
89 	module_driver(__mtd_blktrans, register_mtd_blktrans, \
90 					deregister_mtd_blktrans)
91 
92 #endif /* __MTD_TRANS_H__ */
93