xref: /freebsd/sys/dev/xen/blkfront/block.h (revision aa64588d28258aef88cc33b8043112e8856948d0)
1 /*
2  * XenBSD block device driver
3  *
4  * Copyright (c) 2009 Scott Long, Yahoo!
5  * Copyright (c) 2009 Frank Suchomel, Citrix
6  * Copyright (c) 2009 Doug F. Rabson, Citrix
7  * Copyright (c) 2005 Kip Macy
8  * Copyright (c) 2003-2004, Keir Fraser & Steve Hand
9  * Modifications by Mark A. Williamson are (c) Intel Research Cambridge
10  *
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy
13  * of this software and associated documentation files (the "Software"), to
14  * deal in the Software without restriction, including without limitation the
15  * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
16  * sell copies of the Software, and to permit persons to whom the Software is
17  * furnished to do so, subject to the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be included in
20  * all copies or substantial portions of the Software.
21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
22  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
23  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
24  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
25  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
26  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
27  * DEALINGS IN THE SOFTWARE.
28  *
29  * $FreeBSD$
30  */
31 
32 
33 #ifndef __XEN_DRIVERS_BLOCK_H__
34 #define __XEN_DRIVERS_BLOCK_H__
35 #include <xen/interface/io/blkif.h>
36 
37 struct xlbd_type_info
38 {
39 	int partn_shift;
40 	int disks_per_major;
41 	char *devname;
42 	char *diskname;
43 };
44 
45 struct xlbd_major_info
46 {
47 	int major;
48 	int index;
49 	int usage;
50 	struct xlbd_type_info *type;
51 };
52 
53 struct xb_command {
54 	TAILQ_ENTRY(xb_command)	cm_link;
55 	struct xb_softc		*cm_sc;
56 	u_int			cm_flags;
57 #define XB_CMD_FROZEN		(1<<0)
58 #define XB_CMD_POLLED		(1<<1)
59 #define XB_ON_XBQ_FREE		(1<<2)
60 #define XB_ON_XBQ_READY		(1<<3)
61 #define XB_ON_XBQ_BUSY		(1<<4)
62 #define XB_ON_XBQ_COMPLETE	(1<<5)
63 #define XB_ON_XBQ_MASK		((1<<2)|(1<<3)|(1<<4)|(1<<5))
64 	bus_dmamap_t		map;
65 	blkif_request_t		req;
66 	struct bio		*bp;
67 	grant_ref_t		gref_head;
68 	void			*data;
69 	size_t			datalen;
70 	int			operation;
71 	blkif_sector_t		sector_number;
72 	int			status;
73 	void			(* cm_complete)(struct xb_command *);
74 };
75 
76 #define BLK_RING_SIZE __RING_SIZE((blkif_sring_t *)0, PAGE_SIZE)
77 
78 #define XBQ_FREE	0
79 #define XBQ_BIO		1
80 #define XBQ_READY	2
81 #define XBQ_BUSY	3
82 #define XBQ_COMPLETE	4
83 #define XBQ_COUNT	5
84 
85 struct xb_qstat {
86 	uint32_t	q_length;
87 	uint32_t	q_max;
88 };
89 
90 union xb_statrequest {
91 	uint32_t		ms_item;
92 	struct xb_qstat		ms_qstat;
93 };
94 
95 /*
96  * We have one of these per vbd, whether ide, scsi or 'other'.
97  */
98 struct xb_softc {
99 	device_t		xb_dev;
100 	struct disk		*xb_disk;		/* disk params */
101 	struct bio_queue_head   xb_bioq;		/* sort queue */
102 	int			xb_unit;
103 	int			xb_flags;
104 #define XB_OPEN		(1<<0)		/* drive is open (can't shut down) */
105 #define XB_BARRIER	(1 << 1)	/* backend supports barriers */
106 #define XB_READY	(1 << 2)	/* Is ready */
107 #define XB_FROZEN	(1 << 3)	/* Waiting for resources */
108 	int			vdevice;
109 	blkif_vdev_t		handle;
110 	int			connected;
111 	int			ring_ref;
112 	blkif_front_ring_t	ring;
113 	unsigned int		irq;
114 	struct xlbd_major_info	*mi;
115 	struct gnttab_free_callback	callback;
116 	TAILQ_HEAD(,xb_command)	cm_free;
117 	TAILQ_HEAD(,xb_command)	cm_ready;
118 	TAILQ_HEAD(,xb_command)	cm_busy;
119 	TAILQ_HEAD(,xb_command)	cm_complete;
120 	struct xb_qstat		xb_qstat[XBQ_COUNT];
121 	bus_dma_tag_t		xb_io_dmat;
122 
123 	/**
124 	 * The number of people holding this device open.  We won't allow a
125 	 * hot-unplug unless this is 0.
126 	 */
127 	int			users;
128 	struct mtx		xb_io_lock;
129 	struct xb_command	shadow[BLK_RING_SIZE];
130 };
131 
132 int xlvbd_add(struct xb_softc *, blkif_sector_t capacity, int device,
133 	      uint16_t vdisk_info, uint16_t sector_size);
134 void xlvbd_del(struct xb_softc *);
135 
136 #define XBQ_ADD(sc, qname)					\
137 	do {							\
138 		struct xb_qstat *qs;				\
139 								\
140 		qs = &(sc)->xb_qstat[qname];			\
141 		qs->q_length++;					\
142 		if (qs->q_length > qs->q_max)			\
143 			qs->q_max = qs->q_length;		\
144 	} while (0)
145 
146 #define XBQ_REMOVE(sc, qname)	(sc)->xb_qstat[qname].q_length--
147 
148 #define XBQ_INIT(sc, qname)					\
149 	do {							\
150 		sc->xb_qstat[qname].q_length = 0;		\
151 		sc->xb_qstat[qname].q_max = 0;			\
152 	} while (0)
153 
154 #define XBQ_COMMAND_QUEUE(name, index)					\
155 	static __inline void						\
156 	xb_initq_ ## name (struct xb_softc *sc)				\
157 	{								\
158 		TAILQ_INIT(&sc->cm_ ## name);				\
159 		XBQ_INIT(sc, index);					\
160 	}								\
161 	static __inline void						\
162 	xb_enqueue_ ## name (struct xb_command *cm)			\
163 	{								\
164 		if ((cm->cm_flags & XB_ON_XBQ_MASK) != 0) {		\
165 			printf("command %p is on another queue, "	\
166 			    "flags = %#x\n", cm, cm->cm_flags);		\
167 			panic("command is on another queue");		\
168 		}							\
169 		TAILQ_INSERT_TAIL(&cm->cm_sc->cm_ ## name, cm, cm_link); \
170 		cm->cm_flags |= XB_ON_ ## index;			\
171 		XBQ_ADD(cm->cm_sc, index);				\
172 	}								\
173 	static __inline void						\
174 	xb_requeue_ ## name (struct xb_command *cm)			\
175 	{								\
176 		if ((cm->cm_flags & XB_ON_XBQ_MASK) != 0) {		\
177 			printf("command %p is on another queue, "	\
178 			    "flags = %#x\n", cm, cm->cm_flags);		\
179 			panic("command is on another queue");		\
180 		}							\
181 		TAILQ_INSERT_HEAD(&cm->cm_sc->cm_ ## name, cm, cm_link); \
182 		cm->cm_flags |= XB_ON_ ## index;			\
183 		XBQ_ADD(cm->cm_sc, index);				\
184 	}								\
185 	static __inline struct xb_command *				\
186 	xb_dequeue_ ## name (struct xb_softc *sc)			\
187 	{								\
188 		struct xb_command *cm;					\
189 									\
190 		if ((cm = TAILQ_FIRST(&sc->cm_ ## name)) != NULL) {	\
191 			if ((cm->cm_flags & XB_ON_ ## index) == 0) {	\
192 				printf("command %p not in queue, "	\
193 				    "flags = %#x, bit = %#x\n", cm,	\
194 				    cm->cm_flags, XB_ON_ ## index);	\
195 				panic("command not in queue");		\
196 			}						\
197 			TAILQ_REMOVE(&sc->cm_ ## name, cm, cm_link);	\
198 			cm->cm_flags &= ~XB_ON_ ## index;		\
199 			XBQ_REMOVE(sc, index);				\
200 		}							\
201 		return (cm);						\
202 	}								\
203 	static __inline void						\
204 	xb_remove_ ## name (struct xb_command *cm)			\
205 	{								\
206 		if ((cm->cm_flags & XB_ON_ ## index) == 0) {		\
207 			printf("command %p not in queue, flags = %#x, " \
208 			    "bit = %#x\n", cm, cm->cm_flags,		\
209 			    XB_ON_ ## index);				\
210 			panic("command not in queue");			\
211 		}							\
212 		TAILQ_REMOVE(&cm->cm_sc->cm_ ## name, cm, cm_link);	\
213 		cm->cm_flags &= ~XB_ON_ ## index;			\
214 		XBQ_REMOVE(cm->cm_sc, index);				\
215 	}								\
216 struct hack
217 
218 XBQ_COMMAND_QUEUE(free, XBQ_FREE);
219 XBQ_COMMAND_QUEUE(ready, XBQ_READY);
220 XBQ_COMMAND_QUEUE(busy, XBQ_BUSY);
221 XBQ_COMMAND_QUEUE(complete, XBQ_COMPLETE);
222 
223 static __inline void
224 xb_initq_bio(struct xb_softc *sc)
225 {
226 	bioq_init(&sc->xb_bioq);
227 	XBQ_INIT(sc, XBQ_BIO);
228 }
229 
230 static __inline void
231 xb_enqueue_bio(struct xb_softc *sc, struct bio *bp)
232 {
233 	bioq_insert_tail(&sc->xb_bioq, bp);
234 	XBQ_ADD(sc, XBQ_BIO);
235 }
236 
237 static __inline void
238 xb_requeue_bio(struct xb_softc *sc, struct bio *bp)
239 {
240 	bioq_insert_head(&sc->xb_bioq, bp);
241 	XBQ_ADD(sc, XBQ_BIO);
242 }
243 
244 static __inline struct bio *
245 xb_dequeue_bio(struct xb_softc *sc)
246 {
247 	struct bio *bp;
248 
249 	if ((bp = bioq_first(&sc->xb_bioq)) != NULL) {
250 		bioq_remove(&sc->xb_bioq, bp);
251 		XBQ_REMOVE(sc, XBQ_BIO);
252 	}
253 	return (bp);
254 }
255 
256 #endif /* __XEN_DRIVERS_BLOCK_H__ */
257 
258