xref: /freebsd/sys/dev/virtio/scsi/virtio_scsivar.h (revision 95ee2897e98f5d444f26ed2334cc7c439f9c16c6)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012, Bryan Venteicher <bryanv@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice unmodified, this list of conditions, and the following
12  *    disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 #ifndef _VIRTIO_SCSIVAR_H
30 #define _VIRTIO_SCSIVAR_H
31 
32 struct vtscsi_softc;
33 struct vtscsi_request;
34 
35 typedef void vtscsi_request_cb_t(struct vtscsi_softc *,
36     struct vtscsi_request *);
37 
38 struct vtscsi_statistics {
39 	unsigned long		scsi_cmd_timeouts;
40 	unsigned long		dequeue_no_requests;
41 };
42 
43 struct vtscsi_softc {
44 	device_t		 vtscsi_dev;
45 	struct mtx		 vtscsi_mtx;
46 	uint64_t		 vtscsi_features;
47 
48 	uint16_t		 vtscsi_flags;
49 #define VTSCSI_FLAG_INDIRECT		0x0001
50 #define VTSCSI_FLAG_BIDIRECTIONAL	0x0002
51 #define VTSCSI_FLAG_HOTPLUG		0x0004
52 #define VTSCSI_FLAG_RESET		0x0008
53 #define VTSCSI_FLAG_DETACH		0x0010
54 
55 	uint16_t		 vtscsi_frozen;
56 #define VTSCSI_FROZEN_NO_REQUESTS	0x01
57 #define VTSCSI_FROZEN_REQUEST_VQ_FULL	0x02
58 
59 	struct sglist		*vtscsi_sglist;
60 
61 	struct virtqueue	*vtscsi_control_vq;
62 	struct virtqueue	*vtscsi_event_vq;
63 	struct virtqueue	*vtscsi_request_vq;
64 
65 	struct cam_sim		*vtscsi_sim;
66 	struct cam_path		*vtscsi_path;
67 
68 	int			 vtscsi_debug;
69 	int			 vtscsi_nrequests;
70 	int			 vtscsi_max_nsegs;
71 	int			 vtscsi_event_buf_size;
72 
73 	TAILQ_HEAD(,vtscsi_request)
74 				 vtscsi_req_free;
75 
76 	uint16_t		 vtscsi_max_channel;
77 	uint16_t		 vtscsi_max_target;
78 	uint32_t		 vtscsi_max_lun;
79 
80 #define VTSCSI_NUM_EVENT_BUFS	4
81 	struct virtio_scsi_event
82 				 vtscsi_event_bufs[VTSCSI_NUM_EVENT_BUFS];
83 
84 	struct vtscsi_statistics vtscsi_stats;
85 };
86 
87 enum vtscsi_request_state {
88 	VTSCSI_REQ_STATE_FREE,
89 	VTSCSI_REQ_STATE_INUSE,
90 	VTSCSI_REQ_STATE_ABORTED,
91 	VTSCSI_REQ_STATE_TIMEDOUT
92 };
93 
94 struct vtscsi_request {
95 	struct vtscsi_softc			*vsr_softc;
96 	union ccb				*vsr_ccb;
97 	vtscsi_request_cb_t			*vsr_complete;
98 
99 	void					*vsr_ptr0;
100 /* Request when aborting a timedout command. */
101 #define vsr_timedout_req	vsr_ptr0
102 
103 	enum vtscsi_request_state		 vsr_state;
104 
105 	uint16_t				 vsr_flags;
106 #define VTSCSI_REQ_FLAG_POLLED		0x01
107 #define VTSCSI_REQ_FLAG_COMPLETE	0x02
108 #define VTSCSI_REQ_FLAG_TIMEOUT_SET	0x04
109 
110 	union {
111 		struct virtio_scsi_cmd_req	 cmd;
112 		struct virtio_scsi_ctrl_tmf_req	 tmf;
113 		struct virtio_scsi_ctrl_an_req	 an;
114 	} vsr_ureq;
115 #define vsr_cmd_req 	vsr_ureq.cmd
116 #define vsr_tmf_req 	vsr_ureq.tmf
117 #define vsr_an_req	vsr_ureq.an
118 
119 	/* Make request and response non-contiguous. */
120 	uint32_t				 vsr_pad;
121 
122 	union {
123 		struct virtio_scsi_cmd_resp	 cmd;
124 		struct virtio_scsi_ctrl_tmf_resp tmf;
125 		struct virtio_scsi_ctrl_an_resp	 an;
126 	} vsr_uresp;
127 #define vsr_cmd_resp	vsr_uresp.cmd
128 #define vsr_tmf_resp	vsr_uresp.tmf
129 #define vsr_an_resp	vsr_uresp.an
130 
131 	struct callout				 vsr_callout;
132 
133 	TAILQ_ENTRY(vtscsi_request)		 vsr_link;
134 };
135 
136 /* Private field in the CCB header that points to our request. */
137 #define ccbh_vtscsi_req	spriv_ptr0
138 
139 /* Features desired/implemented by this driver. */
140 #define VTSCSI_FEATURES \
141     (VIRTIO_SCSI_F_HOTPLUG		| \
142      VIRTIO_RING_F_INDIRECT_DESC)
143 
144 #define VTSCSI_MTX(_sc)			&(_sc)->vtscsi_mtx
145 #define VTSCSI_LOCK_INIT(_sc, _name) 	mtx_init(VTSCSI_MTX(_sc), _name, \
146 					    "VTSCSI Lock", MTX_DEF)
147 #define VTSCSI_LOCK(_sc)		mtx_lock(VTSCSI_MTX(_sc))
148 #define VTSCSI_UNLOCK(_sc)		mtx_unlock(VTSCSI_MTX(_sc))
149 #define VTSCSI_LOCK_OWNED(_sc)		mtx_assert(VTSCSI_MTX(_sc), MA_OWNED)
150 #define VTSCSI_LOCK_NOTOWNED(_sc) 	mtx_assert(VTSCSI_MTX(_sc), MA_NOTOWNED)
151 #define VTSCSI_LOCK_DESTROY(_sc)	mtx_destroy(VTSCSI_MTX(_sc))
152 
153 /*
154  * Reasons for either freezing or thawing the SIMQ.
155  *
156  * VirtIO SCSI is a bit unique in the sense that SCSI and TMF
157  * commands go over different queues. Both queues are fed by
158  * the same SIMQ, but we only freeze the SIMQ when the request
159  * (SCSI) virtqueue is full, not caring if the control (TMF)
160  * virtqueue unlikely gets full. However, both queues share the
161  * same pool of requests, so the completion of a TMF command
162  * could cause the SIMQ to be unfrozen.
163  */
164 #define VTSCSI_REQUEST		0x01
165 #define VTSCSI_REQUEST_VQ	0x02
166 
167 /* Debug trace levels. */
168 #define VTSCSI_INFO	0x01
169 #define VTSCSI_ERROR	0x02
170 #define VTSCSI_TRACE	0x04
171 
172 #define vtscsi_dprintf(_sc, _level, _msg, _args ...) do { 		\
173 	if ((_sc)->vtscsi_debug & (_level))				\
174 		device_printf((_sc)->vtscsi_dev, "%s: "_msg,		\
175 		    __FUNCTION__, ##_args);				\
176 } while (0)
177 
178 #define vtscsi_dprintf_req(_req, _level, _msg, _args ...) do {		\
179 	struct vtscsi_softc *__sc = (_req)->vsr_softc;			\
180 	if ((__sc)->vtscsi_debug & (_level))				\
181 		vtscsi_printf_req(_req, __FUNCTION__, _msg, ##_args);	\
182 } while (0)
183 
184 /*
185  * Set the status field in a CCB, optionally clearing non CCB_STATUS_* flags.
186  */
187 #define vtscsi_set_ccb_status(_ccbh, _status, _mask) do {		\
188 	KASSERT(((_mask) & CAM_STATUS_MASK) == 0,			\
189 	    ("%s:%d bad mask: 0x%x", __FUNCTION__, __LINE__, (_mask)));	\
190 	(_ccbh)->status &= ~(CAM_STATUS_MASK | (_mask));		\
191 	(_ccbh)->status |= (_status);					\
192 } while (0)
193 
194 /*
195  * One segment each for the request and the response.
196  */
197 #define VTSCSI_MIN_SEGMENTS	2
198 
199 /*
200  * Allocate additional requests for internal use such
201  * as TM commands (e.g. aborting timedout commands).
202  */
203 #define VTSCSI_RESERVED_REQUESTS	10
204 
205 /*
206  * How to wait (or not) for request completion.
207  */
208 #define VTSCSI_EXECUTE_ASYNC	0
209 #define VTSCSI_EXECUTE_POLL	1
210 
211 #endif /* _VIRTIO_SCSIVAR_H */
212