diff options
Diffstat (limited to 'Documentation')
| -rwxr-xr-x | Documentation/target/tcm_mod_builder.py | 79 | ||||
| -rw-r--r-- | Documentation/target/tcmu-design.txt | 43 |
2 files changed, 40 insertions, 82 deletions
diff --git a/Documentation/target/tcm_mod_builder.py b/Documentation/target/tcm_mod_builder.py index 2b47704f75cb..2ba71cea0172 100755 --- a/Documentation/target/tcm_mod_builder.py +++ b/Documentation/target/tcm_mod_builder.py @@ -237,8 +237,7 @@ def tcm_mod_build_configfs(proto_ident, fabric_mod_dir_var, fabric_mod_name): buf += "#include \"" + fabric_mod_name + "_base.h\"\n" buf += "#include \"" + fabric_mod_name + "_fabric.h\"\n\n" - buf += "/* Local pointer to allocated TCM configfs fabric module */\n" - buf += "struct target_fabric_configfs *" + fabric_mod_name + "_fabric_configfs;\n\n" + buf += "static const struct target_core_fabric_ops " + fabric_mod_name + "_ops;\n\n" buf += "static struct se_node_acl *" + fabric_mod_name + "_make_nodeacl(\n" buf += " struct se_portal_group *se_tpg,\n" @@ -309,8 +308,8 @@ def tcm_mod_build_configfs(proto_ident, fabric_mod_dir_var, fabric_mod_name): buf += " }\n" buf += " tpg->" + fabric_mod_port + " = " + fabric_mod_port + ";\n" buf += " tpg->" + fabric_mod_port + "_tpgt = tpgt;\n\n" - buf += " ret = core_tpg_register(&" + fabric_mod_name + "_fabric_configfs->tf_ops, wwn,\n" - buf += " &tpg->se_tpg, (void *)tpg,\n" + buf += " ret = core_tpg_register(&" + fabric_mod_name + "_ops, wwn,\n" + buf += " &tpg->se_tpg, tpg,\n" buf += " TRANSPORT_TPG_TYPE_NORMAL);\n" buf += " if (ret < 0) {\n" buf += " kfree(tpg);\n" @@ -370,7 +369,10 @@ def tcm_mod_build_configfs(proto_ident, fabric_mod_dir_var, fabric_mod_name): buf += " NULL,\n" buf += "};\n\n" - buf += "static struct target_core_fabric_ops " + fabric_mod_name + "_ops = {\n" + buf += "static const struct target_core_fabric_ops " + fabric_mod_name + "_ops = {\n" + buf += " .module = THIS_MODULE,\n" + buf += " .name = " + fabric_mod_name + ",\n" + buf += " .get_fabric_proto_ident = " + fabric_mod_name + "_get_fabric_proto_ident,\n" buf += " .get_fabric_name = " + fabric_mod_name + "_get_fabric_name,\n" buf += " .get_fabric_proto_ident = " + fabric_mod_name + "_get_fabric_proto_ident,\n" buf += " .tpg_get_wwn = " + fabric_mod_name + "_get_fabric_wwn,\n" @@ -413,75 +415,18 @@ def tcm_mod_build_configfs(proto_ident, fabric_mod_dir_var, fabric_mod_name): buf += " .fabric_drop_np = NULL,\n" buf += " .fabric_make_nodeacl = " + fabric_mod_name + "_make_nodeacl,\n" buf += " .fabric_drop_nodeacl = " + fabric_mod_name + "_drop_nodeacl,\n" - buf += "};\n\n" - - buf += "static int " + fabric_mod_name + "_register_configfs(void)\n" - buf += "{\n" - buf += " struct target_fabric_configfs *fabric;\n" - buf += " int ret;\n\n" - buf += " printk(KERN_INFO \"" + fabric_mod_name.upper() + " fabric module %s on %s/%s\"\n" - buf += " \" on \"UTS_RELEASE\"\\n\"," + fabric_mod_name.upper() + "_VERSION, utsname()->sysname,\n" - buf += " utsname()->machine);\n" - buf += " /*\n" - buf += " * Register the top level struct config_item_type with TCM core\n" - buf += " */\n" - buf += " fabric = target_fabric_configfs_init(THIS_MODULE, \"" + fabric_mod_name + "\");\n" - buf += " if (IS_ERR(fabric)) {\n" - buf += " printk(KERN_ERR \"target_fabric_configfs_init() failed\\n\");\n" - buf += " return PTR_ERR(fabric);\n" - buf += " }\n" - buf += " /*\n" - buf += " * Setup fabric->tf_ops from our local " + fabric_mod_name + "_ops\n" - buf += " */\n" - buf += " fabric->tf_ops = " + fabric_mod_name + "_ops;\n" - buf += " /*\n" - buf += " * Setup default attribute lists for various fabric->tf_cit_tmpl\n" - buf += " */\n" - buf += " fabric->tf_cit_tmpl.tfc_wwn_cit.ct_attrs = " + fabric_mod_name + "_wwn_attrs;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_base_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_attrib_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_param_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_np_base_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_nacl_base_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_nacl_attrib_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_nacl_auth_cit.ct_attrs = NULL;\n" - buf += " fabric->tf_cit_tmpl.tfc_tpg_nacl_param_cit.ct_attrs = NULL;\n" - buf += " /*\n" - buf += " * Register the fabric for use within TCM\n" - buf += " */\n" - buf += " ret = target_fabric_configfs_register(fabric);\n" - buf += " if (ret < 0) {\n" - buf += " printk(KERN_ERR \"target_fabric_configfs_register() failed\"\n" - buf += " \" for " + fabric_mod_name.upper() + "\\n\");\n" - buf += " return ret;\n" - buf += " }\n" - buf += " /*\n" - buf += " * Setup our local pointer to *fabric\n" - buf += " */\n" - buf += " " + fabric_mod_name + "_fabric_configfs = fabric;\n" - buf += " printk(KERN_INFO \"" + fabric_mod_name.upper() + "[0] - Set fabric -> " + fabric_mod_name + "_fabric_configfs\\n\");\n" - buf += " return 0;\n" - buf += "};\n\n" - buf += "static void __exit " + fabric_mod_name + "_deregister_configfs(void)\n" - buf += "{\n" - buf += " if (!" + fabric_mod_name + "_fabric_configfs)\n" - buf += " return;\n\n" - buf += " target_fabric_configfs_deregister(" + fabric_mod_name + "_fabric_configfs);\n" - buf += " " + fabric_mod_name + "_fabric_configfs = NULL;\n" - buf += " printk(KERN_INFO \"" + fabric_mod_name.upper() + "[0] - Cleared " + fabric_mod_name + "_fabric_configfs\\n\");\n" + buf += "\n" + buf += " .tfc_wwn_attrs = " + fabric_mod_name + "_wwn_attrs;\n" buf += "};\n\n" buf += "static int __init " + fabric_mod_name + "_init(void)\n" buf += "{\n" - buf += " int ret;\n\n" - buf += " ret = " + fabric_mod_name + "_register_configfs();\n" - buf += " if (ret < 0)\n" - buf += " return ret;\n\n" - buf += " return 0;\n" + buf += " return target_register_template(" + fabric_mod_name + "_ops);\n" buf += "};\n\n" + buf += "static void __exit " + fabric_mod_name + "_exit(void)\n" buf += "{\n" - buf += " " + fabric_mod_name + "_deregister_configfs();\n" + buf += " target_unregister_template(" + fabric_mod_name + "_ops);\n" buf += "};\n\n" buf += "MODULE_DESCRIPTION(\"" + fabric_mod_name.upper() + " series fabric driver\");\n" diff --git a/Documentation/target/tcmu-design.txt b/Documentation/target/tcmu-design.txt index 5518465290bf..43e94ea6d2ca 100644 --- a/Documentation/target/tcmu-design.txt +++ b/Documentation/target/tcmu-design.txt @@ -138,27 +138,40 @@ signals the kernel via a 4-byte write(). When cmd_head equals cmd_tail, the ring is empty -- no commands are currently waiting to be processed by userspace. -TCMU commands start with a common header containing "len_op", a 32-bit -value that stores the length, as well as the opcode in the lowest -unused bits. Currently only two opcodes are defined, TCMU_OP_PAD and -TCMU_OP_CMD. When userspace encounters a command with PAD opcode, it -should skip ahead by the bytes in "length". (The kernel inserts PAD -entries to ensure each CMD entry fits contigously into the circular -buffer.) - -When userspace handles a CMD, it finds the SCSI CDB (Command Data -Block) via tcmu_cmd_entry.req.cdb_off. This is an offset from the -start of the overall shared memory region, not the entry. The data -in/out buffers are accessible via tht req.iov[] array. Note that -each iov.iov_base is also an offset from the start of the region. - -TCMU currently does not support BIDI operations. +TCMU commands are 8-byte aligned. They start with a common header +containing "len_op", a 32-bit value that stores the length, as well as +the opcode in the lowest unused bits. It also contains cmd_id and +flags fields for setting by the kernel (kflags) and userspace +(uflags). + +Currently only two opcodes are defined, TCMU_OP_CMD and TCMU_OP_PAD. + +When the opcode is CMD, the entry in the command ring is a struct +tcmu_cmd_entry. Userspace finds the SCSI CDB (Command Data Block) via +tcmu_cmd_entry.req.cdb_off. This is an offset from the start of the +overall shared memory region, not the entry. The data in/out buffers +are accessible via tht req.iov[] array. iov_cnt contains the number of +entries in iov[] needed to describe either the Data-In or Data-Out +buffers. For bidirectional commands, iov_cnt specifies how many iovec +entries cover the Data-Out area, and iov_bidi_count specifies how many +iovec entries immediately after that in iov[] cover the Data-In +area. Just like other fields, iov.iov_base is an offset from the start +of the region. When completing a command, userspace sets rsp.scsi_status, and rsp.sense_buffer if necessary. Userspace then increments mailbox.cmd_tail by entry.hdr.length (mod cmdr_size) and signals the kernel via the UIO method, a 4-byte write to the file descriptor. +When the opcode is PAD, userspace only updates cmd_tail as above -- +it's a no-op. (The kernel inserts PAD entries to ensure each CMD entry +is contiguous within the command ring.) + +More opcodes may be added in the future. If userspace encounters an +opcode it does not handle, it must set UNKNOWN_OP bit (bit 0) in +hdr.uflags, update cmd_tail, and proceed with processing additional +commands, if any. + The Data Area: This is shared-memory space after the command ring. The organization |