fabrics.h 6.5 KB

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  1. /*
  2. * NVMe over Fabrics common host code.
  3. * Copyright (c) 2015-2016 HGST, a Western Digital Company.
  4. *
  5. * This program is free software; you can redistribute it and/or modify it
  6. * under the terms and conditions of the GNU General Public License,
  7. * version 2, as published by the Free Software Foundation.
  8. *
  9. * This program is distributed in the hope it will be useful, but WITHOUT
  10. * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11. * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
  12. * more details.
  13. */
  14. #ifndef _NVME_FABRICS_H
  15. #define _NVME_FABRICS_H 1
  16. #include <linux/in.h>
  17. #include <linux/inet.h>
  18. #define NVMF_MIN_QUEUE_SIZE 16
  19. #define NVMF_MAX_QUEUE_SIZE 1024
  20. #define NVMF_DEF_QUEUE_SIZE 128
  21. #define NVMF_DEF_RECONNECT_DELAY 10
  22. /* default to 600 seconds of reconnect attempts before giving up */
  23. #define NVMF_DEF_CTRL_LOSS_TMO 600
  24. /*
  25. * Define a host as seen by the target. We allocate one at boot, but also
  26. * allow the override it when creating controllers. This is both to provide
  27. * persistence of the Host NQN over multiple boots, and to allow using
  28. * multiple ones, for example in a container scenario. Because we must not
  29. * use different Host NQNs with the same Host ID we generate a Host ID and
  30. * use this structure to keep track of the relation between the two.
  31. */
  32. struct nvmf_host {
  33. struct kref ref;
  34. struct list_head list;
  35. char nqn[NVMF_NQN_SIZE];
  36. uuid_t id;
  37. };
  38. /**
  39. * enum nvmf_parsing_opts - used to define the sysfs parsing options used.
  40. */
  41. enum {
  42. NVMF_OPT_ERR = 0,
  43. NVMF_OPT_TRANSPORT = 1 << 0,
  44. NVMF_OPT_NQN = 1 << 1,
  45. NVMF_OPT_TRADDR = 1 << 2,
  46. NVMF_OPT_TRSVCID = 1 << 3,
  47. NVMF_OPT_QUEUE_SIZE = 1 << 4,
  48. NVMF_OPT_NR_IO_QUEUES = 1 << 5,
  49. NVMF_OPT_TL_RETRY_COUNT = 1 << 6,
  50. NVMF_OPT_KATO = 1 << 7,
  51. NVMF_OPT_HOSTNQN = 1 << 8,
  52. NVMF_OPT_RECONNECT_DELAY = 1 << 9,
  53. NVMF_OPT_HOST_TRADDR = 1 << 10,
  54. NVMF_OPT_CTRL_LOSS_TMO = 1 << 11,
  55. NVMF_OPT_HOST_ID = 1 << 12,
  56. NVMF_OPT_DUP_CONNECT = 1 << 13,
  57. };
  58. /**
  59. * struct nvmf_ctrl_options - Used to hold the options specified
  60. * with the parsing opts enum.
  61. * @mask: Used by the fabrics library to parse through sysfs options
  62. * on adding a NVMe controller.
  63. * @transport: Holds the fabric transport "technology name" (for a lack of
  64. * better description) that will be used by an NVMe controller
  65. * being added.
  66. * @subsysnqn: Hold the fully qualified NQN subystem name (format defined
  67. * in the NVMe specification, "NVMe Qualified Names").
  68. * @traddr: The transport-specific TRADDR field for a port on the
  69. * subsystem which is adding a controller.
  70. * @trsvcid: The transport-specific TRSVCID field for a port on the
  71. * subsystem which is adding a controller.
  72. * @host_traddr: A transport-specific field identifying the NVME host port
  73. * to use for the connection to the controller.
  74. * @queue_size: Number of IO queue elements.
  75. * @nr_io_queues: Number of controller IO queues that will be established.
  76. * @reconnect_delay: Time between two consecutive reconnect attempts.
  77. * @discovery_nqn: indicates if the subsysnqn is the well-known discovery NQN.
  78. * @kato: Keep-alive timeout.
  79. * @host: Virtual NVMe host, contains the NQN and Host ID.
  80. * @max_reconnects: maximum number of allowed reconnect attempts before removing
  81. * the controller, (-1) means reconnect forever, zero means remove
  82. * immediately;
  83. */
  84. struct nvmf_ctrl_options {
  85. unsigned mask;
  86. char *transport;
  87. char *subsysnqn;
  88. char *traddr;
  89. char *trsvcid;
  90. char *host_traddr;
  91. size_t queue_size;
  92. unsigned int nr_io_queues;
  93. unsigned int reconnect_delay;
  94. bool discovery_nqn;
  95. bool duplicate_connect;
  96. unsigned int kato;
  97. struct nvmf_host *host;
  98. int max_reconnects;
  99. };
  100. /*
  101. * struct nvmf_transport_ops - used to register a specific
  102. * fabric implementation of NVMe fabrics.
  103. * @entry: Used by the fabrics library to add the new
  104. * registration entry to its linked-list internal tree.
  105. * @module: Transport module reference
  106. * @name: Name of the NVMe fabric driver implementation.
  107. * @required_opts: sysfs command-line options that must be specified
  108. * when adding a new NVMe controller.
  109. * @allowed_opts: sysfs command-line options that can be specified
  110. * when adding a new NVMe controller.
  111. * @create_ctrl(): function pointer that points to a non-NVMe
  112. * implementation-specific fabric technology
  113. * that would go into starting up that fabric
  114. * for the purpose of conneciton to an NVMe controller
  115. * using that fabric technology.
  116. *
  117. * Notes:
  118. * 1. At minimum, 'required_opts' and 'allowed_opts' should
  119. * be set to the same enum parsing options defined earlier.
  120. * 2. create_ctrl() must be defined (even if it does nothing)
  121. * 3. struct nvmf_transport_ops must be statically allocated in the
  122. * modules .bss section so that a pure module_get on @module
  123. * prevents the memory from beeing freed.
  124. */
  125. struct nvmf_transport_ops {
  126. struct list_head entry;
  127. struct module *module;
  128. const char *name;
  129. int required_opts;
  130. int allowed_opts;
  131. struct nvme_ctrl *(*create_ctrl)(struct device *dev,
  132. struct nvmf_ctrl_options *opts);
  133. };
  134. static inline bool
  135. nvmf_ctlr_matches_baseopts(struct nvme_ctrl *ctrl,
  136. struct nvmf_ctrl_options *opts)
  137. {
  138. if (ctrl->state == NVME_CTRL_DELETING ||
  139. ctrl->state == NVME_CTRL_DEAD ||
  140. strcmp(opts->subsysnqn, ctrl->opts->subsysnqn) ||
  141. strcmp(opts->host->nqn, ctrl->opts->host->nqn) ||
  142. memcmp(&opts->host->id, &ctrl->opts->host->id, sizeof(uuid_t)))
  143. return false;
  144. return true;
  145. }
  146. int nvmf_reg_read32(struct nvme_ctrl *ctrl, u32 off, u32 *val);
  147. int nvmf_reg_read64(struct nvme_ctrl *ctrl, u32 off, u64 *val);
  148. int nvmf_reg_write32(struct nvme_ctrl *ctrl, u32 off, u32 val);
  149. int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl);
  150. int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid);
  151. int nvmf_register_transport(struct nvmf_transport_ops *ops);
  152. void nvmf_unregister_transport(struct nvmf_transport_ops *ops);
  153. void nvmf_free_options(struct nvmf_ctrl_options *opts);
  154. int nvmf_get_address(struct nvme_ctrl *ctrl, char *buf, int size);
  155. bool nvmf_should_reconnect(struct nvme_ctrl *ctrl);
  156. blk_status_t nvmf_fail_nonready_command(struct nvme_ctrl *ctrl,
  157. struct request *rq);
  158. bool __nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
  159. bool queue_live);
  160. static inline bool nvmf_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
  161. bool queue_live)
  162. {
  163. if (likely(ctrl->state == NVME_CTRL_LIVE ||
  164. ctrl->state == NVME_CTRL_ADMIN_ONLY))
  165. return true;
  166. return __nvmf_check_ready(ctrl, rq, queue_live);
  167. }
  168. #endif /* _NVME_FABRICS_H */