xref: /linux/drivers/nvme/target/nvmet.h (revision 507e190946297c34a27d9366b0661d5e506fdd03)
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/uuid.h>
25 #include <linux/nvme.h>
26 #include <linux/configfs.h>
27 #include <linux/rcupdate.h>
28 #include <linux/blkdev.h>
29 
30 #define NVMET_ASYNC_EVENTS		4
31 #define NVMET_ERROR_LOG_SLOTS		128
32 
33 /* Helper Macros when NVMe error is NVME_SC_CONNECT_INVALID_PARAM
34  * The 16 bit shift is to set IATTR bit to 1, which means offending
35  * offset starts in the data section of connect()
36  */
37 #define IPO_IATTR_CONNECT_DATA(x)	\
38 	(cpu_to_le32((1 << 16) | (offsetof(struct nvmf_connect_data, x))))
39 #define IPO_IATTR_CONNECT_SQE(x)	\
40 	(cpu_to_le32(offsetof(struct nvmf_connect_command, x)))
41 
42 struct nvmet_ns {
43 	struct list_head	dev_link;
44 	struct percpu_ref	ref;
45 	struct block_device	*bdev;
46 	u32			nsid;
47 	u32			blksize_shift;
48 	loff_t			size;
49 	u8			nguid[16];
50 	uuid_t			uuid;
51 
52 	bool			enabled;
53 	struct nvmet_subsys	*subsys;
54 	const char		*device_path;
55 
56 	struct config_group	device_group;
57 	struct config_group	group;
58 
59 	struct completion	disable_done;
60 };
61 
62 static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
63 {
64 	return container_of(to_config_group(item), struct nvmet_ns, group);
65 }
66 
67 struct nvmet_cq {
68 	u16			qid;
69 	u16			size;
70 };
71 
72 struct nvmet_sq {
73 	struct nvmet_ctrl	*ctrl;
74 	struct percpu_ref	ref;
75 	u16			qid;
76 	u16			size;
77 	struct completion	free_done;
78 	struct completion	confirm_done;
79 };
80 
81 /**
82  * struct nvmet_port -	Common structure to keep port
83  *				information for the target.
84  * @entry:		List head for holding a list of these elements.
85  * @disc_addr:		Address information is stored in a format defined
86  *				for a discovery log page entry.
87  * @group:		ConfigFS group for this element's folder.
88  * @priv:		Private data for the transport.
89  */
90 struct nvmet_port {
91 	struct list_head		entry;
92 	struct nvmf_disc_rsp_page_entry	disc_addr;
93 	struct config_group		group;
94 	struct config_group		subsys_group;
95 	struct list_head		subsystems;
96 	struct config_group		referrals_group;
97 	struct list_head		referrals;
98 	void				*priv;
99 	bool				enabled;
100 };
101 
102 static inline struct nvmet_port *to_nvmet_port(struct config_item *item)
103 {
104 	return container_of(to_config_group(item), struct nvmet_port,
105 			group);
106 }
107 
108 struct nvmet_ctrl {
109 	struct nvmet_subsys	*subsys;
110 	struct nvmet_cq		**cqs;
111 	struct nvmet_sq		**sqs;
112 
113 	struct mutex		lock;
114 	u64			cap;
115 	u32			cc;
116 	u32			csts;
117 
118 	u16			cntlid;
119 	u32			kato;
120 
121 	struct nvmet_req	*async_event_cmds[NVMET_ASYNC_EVENTS];
122 	unsigned int		nr_async_event_cmds;
123 	struct list_head	async_events;
124 	struct work_struct	async_event_work;
125 
126 	struct list_head	subsys_entry;
127 	struct kref		ref;
128 	struct delayed_work	ka_work;
129 	struct work_struct	fatal_err_work;
130 
131 	struct nvmet_fabrics_ops *ops;
132 
133 	char			subsysnqn[NVMF_NQN_FIELD_LEN];
134 	char			hostnqn[NVMF_NQN_FIELD_LEN];
135 };
136 
137 struct nvmet_subsys {
138 	enum nvme_subsys_type	type;
139 
140 	struct mutex		lock;
141 	struct kref		ref;
142 
143 	struct list_head	namespaces;
144 	unsigned int		max_nsid;
145 
146 	struct list_head	ctrls;
147 
148 	struct list_head	hosts;
149 	bool			allow_any_host;
150 
151 	u16			max_qid;
152 
153 	u64			ver;
154 	u64			serial;
155 	char			*subsysnqn;
156 
157 	struct config_group	group;
158 
159 	struct config_group	namespaces_group;
160 	struct config_group	allowed_hosts_group;
161 };
162 
163 static inline struct nvmet_subsys *to_subsys(struct config_item *item)
164 {
165 	return container_of(to_config_group(item), struct nvmet_subsys, group);
166 }
167 
168 static inline struct nvmet_subsys *namespaces_to_subsys(
169 		struct config_item *item)
170 {
171 	return container_of(to_config_group(item), struct nvmet_subsys,
172 			namespaces_group);
173 }
174 
175 struct nvmet_host {
176 	struct config_group	group;
177 };
178 
179 static inline struct nvmet_host *to_host(struct config_item *item)
180 {
181 	return container_of(to_config_group(item), struct nvmet_host, group);
182 }
183 
184 static inline char *nvmet_host_name(struct nvmet_host *host)
185 {
186 	return config_item_name(&host->group.cg_item);
187 }
188 
189 struct nvmet_host_link {
190 	struct list_head	entry;
191 	struct nvmet_host	*host;
192 };
193 
194 struct nvmet_subsys_link {
195 	struct list_head	entry;
196 	struct nvmet_subsys	*subsys;
197 };
198 
199 struct nvmet_req;
200 struct nvmet_fabrics_ops {
201 	struct module *owner;
202 	unsigned int type;
203 	unsigned int sqe_inline_size;
204 	unsigned int msdbd;
205 	bool has_keyed_sgls : 1;
206 	void (*queue_response)(struct nvmet_req *req);
207 	int (*add_port)(struct nvmet_port *port);
208 	void (*remove_port)(struct nvmet_port *port);
209 	void (*delete_ctrl)(struct nvmet_ctrl *ctrl);
210 };
211 
212 #define NVMET_MAX_INLINE_BIOVEC	8
213 
214 struct nvmet_req {
215 	struct nvme_command	*cmd;
216 	struct nvme_completion	*rsp;
217 	struct nvmet_sq		*sq;
218 	struct nvmet_cq		*cq;
219 	struct nvmet_ns		*ns;
220 	struct scatterlist	*sg;
221 	struct bio		inline_bio;
222 	struct bio_vec		inline_bvec[NVMET_MAX_INLINE_BIOVEC];
223 	int			sg_cnt;
224 	size_t			data_len;
225 
226 	struct nvmet_port	*port;
227 
228 	void (*execute)(struct nvmet_req *req);
229 	struct nvmet_fabrics_ops *ops;
230 };
231 
232 static inline void nvmet_set_status(struct nvmet_req *req, u16 status)
233 {
234 	req->rsp->status = cpu_to_le16(status << 1);
235 }
236 
237 static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
238 {
239 	req->rsp->result.u32 = cpu_to_le32(result);
240 }
241 
242 /*
243  * NVMe command writes actually are DMA reads for us on the target side.
244  */
245 static inline enum dma_data_direction
246 nvmet_data_dir(struct nvmet_req *req)
247 {
248 	return nvme_is_write(req->cmd) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
249 }
250 
251 struct nvmet_async_event {
252 	struct list_head	entry;
253 	u8			event_type;
254 	u8			event_info;
255 	u8			log_page;
256 };
257 
258 u16 nvmet_parse_connect_cmd(struct nvmet_req *req);
259 u16 nvmet_parse_io_cmd(struct nvmet_req *req);
260 u16 nvmet_parse_admin_cmd(struct nvmet_req *req);
261 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req);
262 u16 nvmet_parse_fabrics_cmd(struct nvmet_req *req);
263 
264 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
265 		struct nvmet_sq *sq, struct nvmet_fabrics_ops *ops);
266 void nvmet_req_uninit(struct nvmet_req *req);
267 void nvmet_req_complete(struct nvmet_req *req, u16 status);
268 
269 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq, u16 qid,
270 		u16 size);
271 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq, u16 qid,
272 		u16 size);
273 void nvmet_sq_destroy(struct nvmet_sq *sq);
274 int nvmet_sq_init(struct nvmet_sq *sq);
275 
276 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl);
277 
278 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new);
279 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
280 		struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp);
281 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
282 		struct nvmet_req *req, struct nvmet_ctrl **ret);
283 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl);
284 u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd);
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 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys);
290 
291 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid);
292 void nvmet_put_namespace(struct nvmet_ns *ns);
293 int nvmet_ns_enable(struct nvmet_ns *ns);
294 void nvmet_ns_disable(struct nvmet_ns *ns);
295 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid);
296 void nvmet_ns_free(struct nvmet_ns *ns);
297 
298 int nvmet_register_transport(struct nvmet_fabrics_ops *ops);
299 void nvmet_unregister_transport(struct nvmet_fabrics_ops *ops);
300 
301 int nvmet_enable_port(struct nvmet_port *port);
302 void nvmet_disable_port(struct nvmet_port *port);
303 
304 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port);
305 void nvmet_referral_disable(struct nvmet_port *port);
306 
307 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
308 		size_t len);
309 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
310 		size_t len);
311 
312 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
313 
314 #define NVMET_QUEUE_SIZE	1024
315 #define NVMET_NR_QUEUES		64
316 #define NVMET_MAX_CMD		NVMET_QUEUE_SIZE
317 #define NVMET_KAS		10
318 #define NVMET_DISC_KATO		120
319 
320 int __init nvmet_init_configfs(void);
321 void __exit nvmet_exit_configfs(void);
322 
323 int __init nvmet_init_discovery(void);
324 void nvmet_exit_discovery(void);
325 
326 extern struct nvmet_subsys *nvmet_disc_subsys;
327 extern u64 nvmet_genctr;
328 extern struct rw_semaphore nvmet_config_sem;
329 
330 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
331 		const char *hostnqn);
332 
333 #endif /* _NVMET_H */
334