drivers/nvme/target/nvmet.h

   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         u32                     cc;
 117         u32                     csts;
 118
 119         u16                     cntlid;
 120         u32                     kato;
 121
 122         struct nvmet_req        *async_event_cmds[NVMET_ASYNC_EVENTS];
 123         unsigned int            nr_async_event_cmds;
 124         struct list_head        async_events;
 125         struct work_struct      async_event_work;
 126
 127         struct list_head        subsys_entry;
 128         struct kref             ref;
 129         struct delayed_work     ka_work;
 130         struct work_struct      fatal_err_work;
 131
 132         struct nvmet_fabrics_ops *ops;
 133
 134         char                    subsysnqn[NVMF_NQN_FIELD_LEN];
 135         char                    hostnqn[NVMF_NQN_FIELD_LEN];
 136 };
 137
 138 struct nvmet_subsys {
 139         enum nvme_subsys_type   type;
 140
 141         struct mutex            lock;
 142         struct kref             ref;
 143
 144         struct list_head        namespaces;
 145         unsigned int            max_nsid;
 146
 147         struct list_head        ctrls;
 148         struct ida              cntlid_ida;
 149
 150         struct list_head        hosts;
 151         bool                    allow_any_host;
 152
 153         u16                     max_qid;
 154
 155         u64                     ver;
 156         char                    *subsysnqn;
 157
 158         struct config_group     group;
 159
 160         struct config_group     namespaces_group;
 161         struct config_group     allowed_hosts_group;
 162 };
 163
 164 static inline struct nvmet_subsys *to_subsys(struct config_item *item)
 165 {
 166         return container_of(to_config_group(item), struct nvmet_subsys, group);
 167 }
 168
 169 static inline struct nvmet_subsys *namespaces_to_subsys(
 170                 struct config_item *item)
 171 {
 172         return container_of(to_config_group(item), struct nvmet_subsys,
 173                         namespaces_group);
 174 }
 175
 176 struct nvmet_host {
 177         struct config_group     group;
 178 };
 179
 180 static inline struct nvmet_host *to_host(struct config_item *item)
 181 {
 182         return container_of(to_config_group(item), struct nvmet_host, group);
 183 }
 184
 185 static inline char *nvmet_host_name(struct nvmet_host *host)
 186 {
 187         return config_item_name(&host->group.cg_item);
 188 }
 189
 190 struct nvmet_host_link {
 191         struct list_head        entry;
 192         struct nvmet_host       *host;
 193 };
 194
 195 struct nvmet_subsys_link {
 196         struct list_head        entry;
 197         struct nvmet_subsys     *subsys;
 198 };
 199
 200 struct nvmet_req;
 201 struct nvmet_fabrics_ops {
 202         struct module *owner;
 203         unsigned int type;
 204         unsigned int sqe_inline_size;
 205         unsigned int msdbd;
 206         bool has_keyed_sgls : 1;
 207         void (*queue_response)(struct nvmet_req *req);
 208         int (*add_port)(struct nvmet_port *port);
 209         void (*remove_port)(struct nvmet_port *port);
 210         void (*delete_ctrl)(struct nvmet_ctrl *ctrl);
 211 };
 212
 213 #define NVMET_MAX_INLINE_BIOVEC 8
 214
 215 struct nvmet_req {
 216         struct nvme_command     *cmd;
 217         struct nvme_completion  *rsp;
 218         struct nvmet_sq         *sq;
 219         struct nvmet_cq         *cq;
 220         struct nvmet_ns         *ns;
 221         struct scatterlist      *sg;
 222         struct bio              inline_bio;
 223         struct bio_vec          inline_bvec[NVMET_MAX_INLINE_BIOVEC];
 224         int                     sg_cnt;
 225         size_t                  data_len;
 226
 227         struct nvmet_port       *port;
 228
 229         void (*execute)(struct nvmet_req *req);
 230         struct nvmet_fabrics_ops *ops;
 231 };
 232
 233 static inline void nvmet_set_status(struct nvmet_req *req, u16 status)
 234 {
 235         req->rsp->status = cpu_to_le16(status << 1);
 236 }
 237
 238 static inline void nvmet_set_result(struct nvmet_req *req, u32 result)
 239 {
 240         req->rsp->result = cpu_to_le32(result);
 241 }
 242
 243 /*
 244  * NVMe command writes actually are DMA reads for us on the target side.
 245  */
 246 static inline enum dma_data_direction
 247 nvmet_data_dir(struct nvmet_req *req)
 248 {
 249         return nvme_is_write(req->cmd) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 250 }
 251
 252 struct nvmet_async_event {
 253         struct list_head        entry;
 254         u8                      event_type;
 255         u8                      event_info;
 256         u8                      log_page;
 257 };
 258
 259 int nvmet_parse_connect_cmd(struct nvmet_req *req);
 260 int nvmet_parse_io_cmd(struct nvmet_req *req);
 261 int nvmet_parse_admin_cmd(struct nvmet_req *req);
 262 int nvmet_parse_discovery_cmd(struct nvmet_req *req);
 263 int nvmet_parse_fabrics_cmd(struct nvmet_req *req);
 264
 265 bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 266                 struct nvmet_sq *sq, struct nvmet_fabrics_ops *ops);
 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
 285 struct nvmet_subsys *nvmet_subsys_alloc(const char *subsysnqn,
 286                 enum nvme_subsys_type type);
 287 void nvmet_subsys_put(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 */