xref: /freebsd/sys/dev/virtio/scsi/virtio_scsivar.h (revision a7623790fb345e6dc986dfd31df0ace115e6f2e4)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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  * $FreeBSD$
29  */
30 
31 #ifndef _VIRTIO_SCSIVAR_H
32 #define _VIRTIO_SCSIVAR_H
33 
34 struct vtscsi_softc;
35 struct vtscsi_request;
36 
37 typedef void vtscsi_request_cb_t(struct vtscsi_softc *,
38     struct vtscsi_request *);
39 
40 struct vtscsi_statistics {
41 	unsigned long		scsi_cmd_timeouts;
42 	unsigned long		dequeue_no_requests;
43 };
44 
45 struct vtscsi_softc {
46 	device_t		 vtscsi_dev;
47 	struct mtx		 vtscsi_mtx;
48 	uint64_t		 vtscsi_features;
49 
50 	uint16_t		 vtscsi_flags;
51 #define VTSCSI_FLAG_INDIRECT		0x0001
52 #define VTSCSI_FLAG_BIDIRECTIONAL	0x0002
53 #define VTSCSI_FLAG_HOTPLUG		0x0004
54 #define VTSCSI_FLAG_RESET		0x0008
55 #define VTSCSI_FLAG_DETACH		0x0010
56 
57 	uint16_t		 vtscsi_frozen;
58 #define VTSCSI_FROZEN_NO_REQUESTS	0x01
59 #define VTSCSI_FROZEN_REQUEST_VQ_FULL	0x02
60 
61 	struct sglist		*vtscsi_sglist;
62 
63 	struct virtqueue	*vtscsi_control_vq;
64 	struct virtqueue	*vtscsi_event_vq;
65 	struct virtqueue	*vtscsi_request_vq;
66 
67 	struct cam_sim		*vtscsi_sim;
68 	struct cam_path		*vtscsi_path;
69 
70 	int			 vtscsi_debug;
71 	int			 vtscsi_nrequests;
72 	int			 vtscsi_max_nsegs;
73 	int			 vtscsi_event_buf_size;
74 
75 	TAILQ_HEAD(,vtscsi_request)
76 				 vtscsi_req_free;
77 
78 	uint16_t		 vtscsi_max_channel;
79 	uint16_t		 vtscsi_max_target;
80 	uint32_t		 vtscsi_max_lun;
81 
82 #define VTSCSI_NUM_EVENT_BUFS	4
83 	struct virtio_scsi_event
84 				 vtscsi_event_bufs[VTSCSI_NUM_EVENT_BUFS];
85 
86 	struct vtscsi_statistics vtscsi_stats;
87 };
88 
89 enum vtscsi_request_state {
90 	VTSCSI_REQ_STATE_FREE,
91 	VTSCSI_REQ_STATE_INUSE,
92 	VTSCSI_REQ_STATE_ABORTED,
93 	VTSCSI_REQ_STATE_TIMEDOUT
94 };
95 
96 struct vtscsi_request {
97 	struct vtscsi_softc			*vsr_softc;
98 	union ccb				*vsr_ccb;
99 	vtscsi_request_cb_t			*vsr_complete;
100 
101 	void					*vsr_ptr0;
102 /* Request when aborting a timedout command. */
103 #define vsr_timedout_req	vsr_ptr0
104 
105 	enum vtscsi_request_state		 vsr_state;
106 
107 	uint16_t				 vsr_flags;
108 #define VTSCSI_REQ_FLAG_POLLED		0x01
109 #define VTSCSI_REQ_FLAG_COMPLETE	0x02
110 #define VTSCSI_REQ_FLAG_TIMEOUT_SET	0x04
111 
112 	union {
113 		struct virtio_scsi_cmd_req	 cmd;
114 		struct virtio_scsi_ctrl_tmf_req	 tmf;
115 		struct virtio_scsi_ctrl_an_req	 an;
116 	} vsr_ureq;
117 #define vsr_cmd_req 	vsr_ureq.cmd
118 #define vsr_tmf_req 	vsr_ureq.tmf
119 #define vsr_an_req	vsr_ureq.an
120 
121 	/* Make request and response non-contiguous. */
122 	uint32_t				 vsr_pad;
123 
124 	union {
125 		struct virtio_scsi_cmd_resp	 cmd;
126 		struct virtio_scsi_ctrl_tmf_resp tmf;
127 		struct virtio_scsi_ctrl_an_resp	 an;
128 	} vsr_uresp;
129 #define vsr_cmd_resp	vsr_uresp.cmd
130 #define vsr_tmf_resp	vsr_uresp.tmf
131 #define vsr_an_resp	vsr_uresp.an
132 
133 	struct callout				 vsr_callout;
134 
135 	TAILQ_ENTRY(vtscsi_request)		 vsr_link;
136 };
137 
138 /* Private field in the CCB header that points to our request. */
139 #define ccbh_vtscsi_req	spriv_ptr0
140 
141 /* Features desired/implemented by this driver. */
142 #define VTSCSI_FEATURES \
143     (VIRTIO_SCSI_F_HOTPLUG		| \
144      VIRTIO_RING_F_INDIRECT_DESC)
145 
146 #define VTSCSI_MTX(_sc)			&(_sc)->vtscsi_mtx
147 #define VTSCSI_LOCK_INIT(_sc, _name) 	mtx_init(VTSCSI_MTX(_sc), _name, \
148 					    "VTSCSI Lock", MTX_DEF)
149 #define VTSCSI_LOCK(_sc)		mtx_lock(VTSCSI_MTX(_sc))
150 #define VTSCSI_UNLOCK(_sc)		mtx_unlock(VTSCSI_MTX(_sc))
151 #define VTSCSI_LOCK_OWNED(_sc)		mtx_assert(VTSCSI_MTX(_sc), MA_OWNED)
152 #define VTSCSI_LOCK_NOTOWNED(_sc) 	mtx_assert(VTSCSI_MTX(_sc), MA_NOTOWNED)
153 #define VTSCSI_LOCK_DESTROY(_sc)	mtx_destroy(VTSCSI_MTX(_sc))
154 
155 /*
156  * Reasons for either freezing or thawing the SIMQ.
157  *
158  * VirtIO SCSI is a bit unique in the sense that SCSI and TMF
159  * commands go over different queues. Both queues are fed by
160  * the same SIMQ, but we only freeze the SIMQ when the request
161  * (SCSI) virtqueue is full, not caring if the control (TMF)
162  * virtqueue unlikely gets full. However, both queues share the
163  * same pool of requests, so the completion of a TMF command
164  * could cause the SIMQ to be unfrozen.
165  */
166 #define VTSCSI_REQUEST		0x01
167 #define VTSCSI_REQUEST_VQ	0x02
168 
169 /* Debug trace levels. */
170 #define VTSCSI_INFO	0x01
171 #define VTSCSI_ERROR	0x02
172 #define VTSCSI_TRACE	0x04
173 
174 #define vtscsi_dprintf(_sc, _level, _msg, _args ...) do { 		\
175 	if ((_sc)->vtscsi_debug & (_level))				\
176 		device_printf((_sc)->vtscsi_dev, "%s: "_msg,		\
177 		    __FUNCTION__, ##_args);				\
178 } while (0)
179 
180 #define vtscsi_dprintf_req(_req, _level, _msg, _args ...) do {		\
181 	struct vtscsi_softc *__sc = (_req)->vsr_softc;			\
182 	if ((__sc)->vtscsi_debug & (_level))				\
183 		vtscsi_printf_req(_req, __FUNCTION__, _msg, ##_args);	\
184 } while (0)
185 
186 /*
187  * Set the status field in a CCB, optionally clearing non CCB_STATUS_* flags.
188  */
189 #define vtscsi_set_ccb_status(_ccbh, _status, _mask) do {		\
190 	KASSERT(((_mask) & CAM_STATUS_MASK) == 0,			\
191 	    ("%s:%d bad mask: 0x%x", __FUNCTION__, __LINE__, (_mask)));	\
192 	(_ccbh)->status &= ~(CAM_STATUS_MASK | (_mask));		\
193 	(_ccbh)->status |= (_status);					\
194 } while (0)
195 
196 /*
197  * One segment each for the request and the response.
198  */
199 #define VTSCSI_MIN_SEGMENTS	2
200 
201 /*
202  * Allocate additional requests for internal use such
203  * as TM commands (e.g. aborting timedout commands).
204  */
205 #define VTSCSI_RESERVED_REQUESTS	10
206 
207 /*
208  * How to wait (or not) for request completion.
209  */
210 #define VTSCSI_EXECUTE_ASYNC	0
211 #define VTSCSI_EXECUTE_POLL	1
212 
213 #endif /* _VIRTIO_SCSIVAR_H */
214