xref: /openbmc/linux/drivers/nvme/target/nvmet.h (revision d236d361)
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 	bool			enabled;
51 	struct nvmet_subsys	*subsys;
52 	const char		*device_path;
53 
54 	struct config_group	device_group;
55 	struct config_group	group;
56 
57 	struct completion	disable_done;
58 };
59 
60 static inline struct nvmet_ns *to_nvmet_ns(struct config_item *item)
61 {
62 	return container_of(to_config_group(item), struct nvmet_ns, group);
63 }
64 
65 struct nvmet_cq {
66 	u16			qid;
67 	u16			size;
68 };
69 
70 struct nvmet_sq {
71 	struct nvmet_ctrl	*ctrl;
72 	struct percpu_ref	ref;
73 	u16			qid;
74 	u16			size;
75 	struct completion	free_done;
76 	struct completion	confirm_done;
77 };
78 
79 /**
80  * struct nvmet_port -	Common structure to keep port
81  *				information for the target.
82  * @entry:		List head for holding a list of these elements.
83  * @disc_addr:		Address information is stored in a format defined
84  *				for a discovery log page entry.
85  * @group:		ConfigFS group for this element's folder.
86  * @priv:		Private data for the transport.
87  */
88 struct nvmet_port {
89 	struct list_head		entry;
90 	struct nvmf_disc_rsp_page_entry	disc_addr;
91 	struct config_group		group;
92 	struct config_group		subsys_group;
93 	struct list_head		subsystems;
94 	struct config_group		referrals_group;
95 	struct list_head		referrals;
96 	void				*priv;
97 	bool				enabled;
98 };
99 
100 static inline struct nvmet_port *to_nvmet_port(struct config_item *item)
101 {
102 	return container_of(to_config_group(item), struct nvmet_port,
103 			group);
104 }
105 
106 struct nvmet_ctrl {
107 	struct nvmet_subsys	*subsys;
108 	struct nvmet_cq		**cqs;
109 	struct nvmet_sq		**sqs;
110 
111 	struct mutex		lock;
112 	u64			cap;
113 	u64			serial;
114 	u32			cc;
115 	u32			csts;
116 
117 	u16			cntlid;
118 	u32			kato;
119 
120 	struct nvmet_req	*async_event_cmds[NVMET_ASYNC_EVENTS];
121 	unsigned int		nr_async_event_cmds;
122 	struct list_head	async_events;
123 	struct work_struct	async_event_work;
124 
125 	struct list_head	subsys_entry;
126 	struct kref		ref;
127 	struct delayed_work	ka_work;
128 	struct work_struct	fatal_err_work;
129 
130 	struct nvmet_fabrics_ops *ops;
131 
132 	char			subsysnqn[NVMF_NQN_FIELD_LEN];
133 	char			hostnqn[NVMF_NQN_FIELD_LEN];
134 };
135 
136 struct nvmet_subsys {
137 	enum nvme_subsys_type	type;
138 
139 	struct mutex		lock;
140 	struct kref		ref;
141 
142 	struct list_head	namespaces;
143 	unsigned int		max_nsid;
144 
145 	struct list_head	ctrls;
146 
147 	struct list_head	hosts;
148 	bool			allow_any_host;
149 
150 	u16			max_qid;
151 
152 	u64			ver;
153 	char			*subsysnqn;
154 
155 	struct config_group	group;
156 
157 	struct config_group	namespaces_group;
158 	struct config_group	allowed_hosts_group;
159 };
160 
161 static inline struct nvmet_subsys *to_subsys(struct config_item *item)
162 {
163 	return container_of(to_config_group(item), struct nvmet_subsys, group);
164 }
165 
166 static inline struct nvmet_subsys *namespaces_to_subsys(
167 		struct config_item *item)
168 {
169 	return container_of(to_config_group(item), struct nvmet_subsys,
170 			namespaces_group);
171 }
172 
173 struct nvmet_host {
174 	struct config_group	group;
175 };
176 
177 static inline struct nvmet_host *to_host(struct config_item *item)
178 {
179 	return container_of(to_config_group(item), struct nvmet_host, group);
180 }
181 
182 static inline char *nvmet_host_name(struct nvmet_host *host)
183 {
184 	return config_item_name(&host->group.cg_item);
185 }
186 
187 struct nvmet_host_link {
188 	struct list_head	entry;
189 	struct nvmet_host	*host;
190 };
191 
192 struct nvmet_subsys_link {
193 	struct list_head	entry;
194 	struct nvmet_subsys	*subsys;
195 };
196 
197 struct nvmet_req;
198 struct nvmet_fabrics_ops {
199 	struct module *owner;
200 	unsigned int type;
201 	unsigned int sqe_inline_size;
202 	unsigned int msdbd;
203 	bool has_keyed_sgls : 1;
204 	void (*queue_response)(struct nvmet_req *req);
205 	int (*add_port)(struct nvmet_port *port);
206 	void (*remove_port)(struct nvmet_port *port);
207 	void (*delete_ctrl)(struct nvmet_ctrl *ctrl);
208 };
209 
210 #define NVMET_MAX_INLINE_BIOVEC	8
211 
212 struct nvmet_req {
213 	struct nvme_command	*cmd;
214 	struct nvme_completion	*rsp;
215 	struct nvmet_sq		*sq;
216 	struct nvmet_cq		*cq;
217 	struct nvmet_ns		*ns;
218 	struct scatterlist	*sg;
219 	struct bio		inline_bio;
220 	struct bio_vec		inline_bvec[NVMET_MAX_INLINE_BIOVEC];
221 	int			sg_cnt;
222 	size_t			data_len;
223 
224 	struct nvmet_port	*port;
225 
226 	void (*execute)(struct nvmet_req *req);
227 	struct nvmet_fabrics_ops *ops;
228 };
229 
230 static inline void nvmet_set_status(struct nvmet_req *req, u16 status)
231 {
232 	req->rsp->status = cpu_to_le16(status << 1);
233 }
234 
235 static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
236 {
237 	req->rsp->result.u32 = cpu_to_le32(result);
238 }
239 
240 /*
241  * NVMe command writes actually are DMA reads for us on the target side.
242  */
243 static inline enum dma_data_direction
244 nvmet_data_dir(struct nvmet_req *req)
245 {
246 	return nvme_is_write(req->cmd) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
247 }
248 
249 struct nvmet_async_event {
250 	struct list_head	entry;
251 	u8			event_type;
252 	u8			event_info;
253 	u8			log_page;
254 };
255 
256 u16 nvmet_parse_connect_cmd(struct nvmet_req *req);
257 u16 nvmet_parse_io_cmd(struct nvmet_req *req);
258 u16 nvmet_parse_admin_cmd(struct nvmet_req *req);
259 u16 nvmet_parse_discovery_cmd(struct nvmet_req *req);
260 u16 nvmet_parse_fabrics_cmd(struct nvmet_req *req);
261 
262 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
263 		struct nvmet_sq *sq, struct nvmet_fabrics_ops *ops);
264 void nvmet_req_uninit(struct nvmet_req *req);
265 void nvmet_req_complete(struct nvmet_req *req, u16 status);
266 
267 void nvmet_cq_setup(struct nvmet_ctrl *ctrl, struct nvmet_cq *cq, u16 qid,
268 		u16 size);
269 void nvmet_sq_setup(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq, u16 qid,
270 		u16 size);
271 void nvmet_sq_destroy(struct nvmet_sq *sq);
272 int nvmet_sq_init(struct nvmet_sq *sq);
273 
274 void nvmet_ctrl_fatal_error(struct nvmet_ctrl *ctrl);
275 
276 void nvmet_update_cc(struct nvmet_ctrl *ctrl, u32 new);
277 u16 nvmet_alloc_ctrl(const char *subsysnqn, const char *hostnqn,
278 		struct nvmet_req *req, u32 kato, struct nvmet_ctrl **ctrlp);
279 u16 nvmet_ctrl_find_get(const char *subsysnqn, const char *hostnqn, u16 cntlid,
280 		struct nvmet_req *req, struct nvmet_ctrl **ret);
281 void nvmet_ctrl_put(struct nvmet_ctrl *ctrl);
282 u16 nvmet_check_ctrl_status(struct nvmet_req *req, struct nvme_command *cmd);
283 
284 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
285 		enum nvme_subsys_type type);
286 void nvmet_subsys_put(struct nvmet_subsys *subsys);
287 void nvmet_subsys_del_ctrls(struct nvmet_subsys *subsys);
288 
289 struct nvmet_ns *nvmet_find_namespace(struct nvmet_ctrl *ctrl, __le32 nsid);
290 void nvmet_put_namespace(struct nvmet_ns *ns);
291 int nvmet_ns_enable(struct nvmet_ns *ns);
292 void nvmet_ns_disable(struct nvmet_ns *ns);
293 struct nvmet_ns *nvmet_ns_alloc(struct nvmet_subsys *subsys, u32 nsid);
294 void nvmet_ns_free(struct nvmet_ns *ns);
295 
296 int nvmet_register_transport(struct nvmet_fabrics_ops *ops);
297 void nvmet_unregister_transport(struct nvmet_fabrics_ops *ops);
298 
299 int nvmet_enable_port(struct nvmet_port *port);
300 void nvmet_disable_port(struct nvmet_port *port);
301 
302 void nvmet_referral_enable(struct nvmet_port *parent, struct nvmet_port *port);
303 void nvmet_referral_disable(struct nvmet_port *port);
304 
305 u16 nvmet_copy_to_sgl(struct nvmet_req *req, off_t off, const void *buf,
306 		size_t len);
307 u16 nvmet_copy_from_sgl(struct nvmet_req *req, off_t off, void *buf,
308 		size_t len);
309 
310 u32 nvmet_get_log_page_len(struct nvme_command *cmd);
311 
312 #define NVMET_QUEUE_SIZE	1024
313 #define NVMET_NR_QUEUES		64
314 #define NVMET_MAX_CMD		NVMET_QUEUE_SIZE
315 #define NVMET_KAS		10
316 #define NVMET_DISC_KATO		120
317 
318 int __init nvmet_init_configfs(void);
319 void __exit nvmet_exit_configfs(void);
320 
321 int __init nvmet_init_discovery(void);
322 void nvmet_exit_discovery(void);
323 
324 extern struct nvmet_subsys *nvmet_disc_subsys;
325 extern u64 nvmet_genctr;
326 extern struct rw_semaphore nvmet_config_sem;
327 
328 bool nvmet_host_allowed(struct nvmet_req *req, struct nvmet_subsys *subsys,
329 		const char *hostnqn);
330 
331 #endif /* _NVMET_H */
332