summaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 19:22:09 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-24 19:22:09 +0200
commitc6668726d2c2c581e6c417448c472c994d026f5f (patch)
treeccbc5a73b9dfe09a065cb5d8627aa2297e730ec0 /Documentation
parentMerge tag 'pwm/for-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff)
parenttarget: Put TCMU under a new config option (diff)
downloadlinux-c6668726d2c2c581e6c417448c472c994d026f5f.tar.xz
linux-c6668726d2c2c581e6c417448c472c994d026f5f.zip
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger: "Lots of activity in target land the last months. The highlights include: - Convert fabric drivers tree-wide to target_register_template() (hch + bart) - iser-target hardening fixes + v1.0 improvements (sagi) - Convert iscsi_thread_set usage to kthread.h + kill iscsi_target_tq.c (sagi + nab) - Add support for T10-PI WRITE_STRIP + READ_INSERT operation (mkp + sagi + nab) - DIF fixes for CONFIG_DEBUG_SG=y + UNMAP file emulation (akinobu + sagi + mkp) - Extended TCMU ABI v2 for future BIDI + DIF support (andy + ilias) - Fix COMPARE_AND_WRITE handling for NO_ALLLOC drivers (hch + nab) Thanks to everyone who contributed this round with new features, bug-reports, fixes, cleanups and improvements. Looking forward, it's currently shaping up to be a busy v4.2 as well" * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending: (69 commits) target: Put TCMU under a new config option target: Version 2 of TCMU ABI target: fix tcm_mod_builder.py target/file: Fix UNMAP with DIF protection support target/file: Fix SG table for prot_buf initialization target/file: Fix BUG() when CONFIG_DEBUG_SG=y and DIF protection enabled target: Make core_tmr_abort_task() skip TMFs target/sbc: Update sbc_dif_generate pr_debug output target/sbc: Make internal DIF emulation honor ->prot_checks target/sbc: Return INVALID_CDB_FIELD if DIF + sess_prot_type disabled target: Ensure sess_prot_type is saved across session restart target/rd: Don't pass incomplete scatterlist entries to sbc_dif_verify_* target: Remove the unused flag SCF_ACK_KREF target: Fix two sparse warnings target: Fix COMPARE_AND_WRITE with SG_TO_MEM_NOALLOC handling target: simplify the target template registration API target: simplify target_xcopy_init_pt_lun target: remove the unused SCF_CMD_XCOPY_PASSTHROUGH flag target/rd: reduce code duplication in rd_execute_rw() tcm_loop: fixup tpgt string to integer conversion ...
Diffstat (limited to 'Documentation')
-rwxr-xr-xDocumentation/target/tcm_mod_builder.py79
-rw-r--r--Documentation/target/tcmu-design.txt43
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