xref: /openbmc/linux/drivers/nvme/target/nvmet.h (revision f5b06569)
1 /*
2  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  */
13 
14 #ifndef _NVMET_H
15 #define _NVMET_H
16 
17 #include <linux/dma-mapping.h>
18 #include <linux/types.h>
19 #include <linux/device.h>
20 #include <linux/kref.h>
21 #include <linux/percpu-refcount.h>
22 #include <linux/list.h>
23 #include <linux/mutex.h>
24 #include <linux/nvme.h>
25 #include <linux/configfs.h>
26 #include <linux/rcupdate.h>
27 #include <linux/blkdev.h>
28 
29 #define NVMET_ASYNC_EVENTS		4
30 #define NVMET_ERROR_LOG_SLOTS		128
31 
32 /* Helper Macros when NVMe error is NVME_SC_CONNECT_INVALID_PARAM
33  * The 16 bit shift is to set IATTR bit to 1, which means offending
34  * offset starts in the data section of connect()
35  */
36 #define IPO_IATTR_CONNECT_DATA(x)	\
37 	(cpu_to_le32((1 << 16) | (offsetof(struct nvmf_connect_data, x))))
38 #define IPO_IATTR_CONNECT_SQE(x)	\
39 	(cpu_to_le32(offsetof(struct nvmf_connect_command, x)))
40 
41 struct nvmet_ns {
42 	struct list_head	dev_link;
43 	struct percpu_ref	ref;
44 	struct block_device	*bdev;
45 	u32			nsid;
46 	u32			blksize_shift;
47 	loff_t			size;
48 	u8			nguid[16];
49 
50 	struct nvmet_subsys	*subsys;
51 	const char		*device_path;
52 
53 	struct config_group	device_group;
54 	struct config_group	group;
55 
56 	struct completion	disable_done;
57 };
58 
59 static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
60 {
61 	return container_of(to_config_group(item), struct nvmet_ns, group);
62 }
63 
64 static inline bool nvmet_ns_enabled(struct nvmet_ns *ns)
65 {
66 	return !list_empty_careful(&ns->dev_link);
67 }
68 
69 struct nvmet_cq {
70 	u16			qid;
71 	u16			size;
72 };
73 
74 struct nvmet_sq {
75 	struct nvmet_ctrl	*ctrl;
76 	struct percpu_ref	ref;
77 	u16			qid;
78 	u16			size;
79 	struct completion	free_done;
80 };
81 
82 /**
83  * struct nvmet_port -	Common structure to keep port
84  *				information for the target.
85  * @entry:		List head for holding a list of these elements.
86  * @disc_addr:		Address information is stored in a format defined
87  *				for a discovery log page entry.
88  * @group:		ConfigFS group for this element's folder.
89  * @priv:		Private data for the transport.
90  */
91 struct nvmet_port {
92 	struct list_head		entry;
93 	struct nvmf_disc_rsp_page_entry	disc_addr;
94 	struct config_group		group;
95 	struct config_group		subsys_group;
96 	struct list_head		subsystems;
97 	struct config_group		referrals_group;
98 	struct list_head		referrals;
99 	void				*priv;
100 	bool				enabled;
101 };
102 
103 static inline struct nvmet_port *to_nvmet_port(struct config_item *item)
104 {
105 	return container_of(to_config_group(item), struct nvmet_port,
106 			group);
107 }
108 
109 struct nvmet_ctrl {
110 	struct nvmet_subsys	*subsys;
111 	struct nvmet_cq		**cqs;
112 	struct nvmet_sq		**sqs;
113 
114 	struct mutex		lock;
115 	u64			cap;
116 	u64			serial;
117 	u32			cc;
118 	u32			csts;
119 
120 	u16			cntlid;
121 	u32			kato;
122 
123 	struct nvmet_req	*async_event_cmds[NVMET_ASYNC_EVENTS];
124 	unsigned int		nr_async_event_cmds;
125 	struct list_head	async_events;
126 	struct work_struct	async_event_work;
127 
128 	struct list_head	subsys_entry;
129 	struct kref		ref;
130 	struct delayed_work	ka_work;
131 	struct work_struct	fatal_err_work;
132 
133 	struct nvmet_fabrics_ops *ops;
134 
135 	char			subsysnqn[NVMF_NQN_FIELD_LEN];
136 	char			hostnqn[NVMF_NQN_FIELD_LEN];
137 };
138 
139 struct nvmet_subsys {
140 	enum nvme_subsys_type	type;
141 
142 	struct mutex		lock;
143 	struct kref		ref;
144 
145 	struct list_head	namespaces;
146 	unsigned int		max_nsid;
147 
148 	struct list_head	ctrls;
149 	struct ida		cntlid_ida;
150 
151 	struct list_head	hosts;
152 	bool			allow_any_host;
153 
154 	u16			max_qid;
155 
156 	u64			ver;
157 	char			*subsysnqn;
158 
159 	struct config_group	group;
160 
161 	struct config_group	namespaces_group;
162 	struct config_group	allowed_hosts_group;
163 };
164 
165 static inline struct nvmet_subsys *to_subsys(struct config_item *item)
166 {
167 	return container_of(to_config_group(item), struct nvmet_subsys, group);
168 }
169 
170 static inline struct nvmet_subsys *namespaces_to_subsys(
171 		struct config_item *item)
172 {
173 	return container_of(to_config_group(item), struct nvmet_subsys,
174 			namespaces_group);
175 }
176 
177 struct nvmet_host {
178 	struct config_group	group;
179 };
180 
181 static inline struct nvmet_host *to_host(struct config_item *item)
182 {
183 	return container_of(to_config_group(item), struct nvmet_host, group);
184 }
185 
186 static inline char *nvmet_host_name(struct nvmet_host *host)
187 {
188 	return config_item_name(&host->group.cg_item);
189 }
190 
191 struct nvmet_host_link {
192 	struct list_head	entry;
193 	struct nvmet_host	*host;
194 };
195 
196 struct nvmet_subsys_link {
197 	struct list_head	entry;
198 	struct nvmet_subsys	*subsys;
199 };
200 
201 struct nvmet_req;
202 struct nvmet_fabrics_ops {
203 	struct module *owner;
204 	unsigned int type;
205 	unsigned int sqe_inline_size;
206 	unsigned int msdbd;
207 	bool has_keyed_sgls : 1;
208 	void (*queue_response)(struct nvmet_req *req);
209 	int (*add_port)(struct nvmet_port *port);
210 	void (*remove_port)(struct nvmet_port *port);
211 	void (*delete_ctrl)(struct nvmet_ctrl *ctrl);
212 };
213 
214 #define NVMET_MAX_INLINE_BIOVEC	8
215 
216 struct nvmet_req {
217 	struct nvme_command	*cmd;
218 	struct nvme_completion	*rsp;
219 	struct nvmet_sq		*sq;
220 	struct nvmet_cq		*cq;
221 	struct nvmet_ns		*ns;
222 	struct scatterlist	*sg;
223 	struct bio		inline_bio;
224 	struct bio_vec		inline_bvec[NVMET_MAX_INLINE_BIOVEC];
225 	int			sg_cnt;
226 	size_t			data_len;
227 
228 	struct nvmet_port	*port;
229 
230 	void (*execute)(struct nvmet_req *req);
231 	struct nvmet_fabrics_ops *ops;
232 };
233 
234 static inline void nvmet_set_status(struct nvmet_req *req, u16 status)
235 {
236 	req->rsp->status = cpu_to_le16(status << 1);
237 }
238 
239 static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
240 {
241 	req->rsp->result = cpu_to_le32(result);
242 }
243 
244 /*
245  * NVMe command writes actually are DMA reads for us on the target side.
246  */
247 static inline enum dma_data_direction
248 nvmet_data_dir(struct nvmet_req *req)
249 {
250 	return nvme_is_write(req->cmd) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
251 }
252 
253 struct nvmet_async_event {
254 	struct list_head	entry;
255 	u8			event_type;
256 	u8			event_info;
257 	u8			log_page;
258 };
259 
260 int nvmet_parse_connect_cmd(struct nvmet_req *req);
261 int nvmet_parse_io_cmd(struct nvmet_req *req);
262 int nvmet_parse_admin_cmd(struct nvmet_req *req);
263 int nvmet_parse_discovery_cmd(struct nvmet_req *req);
264 int nvmet_parse_fabrics_cmd(struct nvmet_req *req);
265 
266 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
267 		struct nvmet_sq *sq, struct nvmet_fabrics_ops *ops);
268 void nvmet_req_complete(struct nvmet_req *req, u16 status);
269 
270 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq, u16 qid,
271 		u16 size);
272 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq, u16 qid,
273 		u16 size);
274 void nvmet_sq_destroy(struct nvmet_sq *sq);
275 int nvmet_sq_init(struct nvmet_sq *sq);
276 
277 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl);
278 
279 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new);
280 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
281 		struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp);
282 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
283 		struct nvmet_req *req, struct nvmet_ctrl **ret);
284 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl);
285 
286 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
287 		enum nvme_subsys_type type);
288 void nvmet_subsys_put(struct nvmet_subsys *subsys);
289 
290 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid);
291 void nvmet_put_namespace(struct nvmet_ns *ns);
292 int nvmet_ns_enable(struct nvmet_ns *ns);
293 void nvmet_ns_disable(struct nvmet_ns *ns);
294 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid);
295 void nvmet_ns_free(struct nvmet_ns *ns);
296 
297 int nvmet_register_transport(struct nvmet_fabrics_ops *ops);
298 void nvmet_unregister_transport(struct nvmet_fabrics_ops *ops);
299 
300 int nvmet_enable_port(struct nvmet_port *port);
301 void nvmet_disable_port(struct nvmet_port *port);
302 
303 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port);
304 void nvmet_referral_disable(struct nvmet_port *port);
305 
306 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
307 		size_t len);
308 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
309 		size_t len);
310 
311 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
312 
313 #define NVMET_QUEUE_SIZE	1024
314 #define NVMET_NR_QUEUES		64
315 #define NVMET_MAX_CMD		NVMET_QUEUE_SIZE
316 #define NVMET_KAS		10
317 #define NVMET_DISC_KATO		120
318 
319 int __init nvmet_init_configfs(void);
320 void __exit nvmet_exit_configfs(void);
321 
322 int __init nvmet_init_discovery(void);
323 void nvmet_exit_discovery(void);
324 
325 extern struct nvmet_subsys *nvmet_disc_subsys;
326 extern u64 nvmet_genctr;
327 extern struct rw_semaphore nvmet_config_sem;
328 
329 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
330 		const char *hostnqn);
331 
332 #endif /* _NVMET_H */
333