path: root/Documentation
diff options
authorLinus Torvalds <torvalds@linux-foundation.org>2012-03-31 13:31:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2012-03-31 13:31:23 -0700
commita75ee6ecd411a50bf4da927c2fdb2cb56246a2bd (patch)
treefcb06e1940152b115901fda68e7eea1cc1196ff3 /Documentation
parentc9651e70ad0aa499814817cbf3cc1d0b806ed3a1 (diff)
parent699316948628dab9e813c415640fe5b9f65cd5e3 (diff)
Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6
Pull SCSI updates from James Bottomley: "This is primarily another round of driver updates (lpfc, bfa, fcoe, ipr) plus a new ufshcd driver. There shouldn't be anything controversial in here (The final deletion of scsi proc_ops which caused some build breakage has been held over until the next merge window to give us more time to stabilise it). I'm afraid, with me moving continents at exactly the wrong time, anything submitted after the merge window opened has been held over to the next merge window." * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (63 commits) [SCSI] ipr: Driver version 2.5.3 [SCSI] ipr: Increase alignment boundary of command blocks [SCSI] ipr: Increase max concurrent oustanding commands [SCSI] ipr: Remove unnecessary memory barriers [SCSI] ipr: Remove unnecessary interrupt clearing on new adapters [SCSI] ipr: Fix target id allocation re-use problem [SCSI] atp870u, mpt2sas, qla4xxx use pci_dev->revision [SCSI] fcoe: Drop the rtnl_mutex before calling fcoe_ctlr_link_up [SCSI] bfa: Update the driver version to [SCSI] bfa: BSG and User interface fixes. [SCSI] bfa: Fix to avoid vport delete hang on request queue full scenario. [SCSI] bfa: Move service parameter programming logic into firmware. [SCSI] bfa: Revised Fabric Assigned Address(FAA) feature implementation. [SCSI] bfa: Flash controller IOC pll init fixes. [SCSI] bfa: Serialize the IOC hw semaphore unlock logic. [SCSI] bfa: Modify ISR to process pending completions [SCSI] bfa: Add fc host issue lip support [SCSI] mpt2sas: remove extraneous sas_log_info messages [SCSI] libfc: fcoe_transport_create fails in single-CPU environment [SCSI] fcoe: reduce contention for fcoe_rx_list lock [v2] ...
Diffstat (limited to 'Documentation')
3 files changed, 139 insertions, 0 deletions
diff --git a/Documentation/scsi/00-INDEX b/Documentation/scsi/00-INDEX
index b48ded55b555..b7dd6502bec5 100644
--- a/Documentation/scsi/00-INDEX
+++ b/Documentation/scsi/00-INDEX
@@ -94,3 +94,5 @@ sym53c8xx_2.txt
- info on second generation driver for sym53c8xx based adapters
- info on driver for AM53c974 based adapters
+ - info on Universal Flash Storage(UFS) and UFS host controller driver.
diff --git a/Documentation/scsi/st.txt b/Documentation/scsi/st.txt
index 691ca292c24d..685bf3582abe 100644
--- a/Documentation/scsi/st.txt
+++ b/Documentation/scsi/st.txt
@@ -390,6 +390,10 @@ MTSETDRVBUFFER
MT_ST_SYSV sets the SYSV semantics (mode)
MT_ST_NOWAIT enables immediate mode (i.e., don't wait for
the command to finish) for some commands (e.g., rewind)
+ MT_ST_NOWAIT_EOF enables immediate filemark mode (i.e. when
+ writing a filemark, don't wait for it to complete). Please
+ see the BASICS note about MTWEOFI with respect to the
+ possible dangers of writing immediate filemarks.
MT_ST_SILI enables setting the SILI bit in SCSI commands when
reading in variable block mode to enhance performance when
reading blocks shorter than the byte count; set this only
diff --git a/Documentation/scsi/ufs.txt b/Documentation/scsi/ufs.txt
new file mode 100644
index 000000000000..41a6164592aa
--- /dev/null
+++ b/Documentation/scsi/ufs.txt
@@ -0,0 +1,133 @@
+ Universal Flash Storage
+ =======================
+1. Overview
+2. UFS Architecture Overview
+ 2.1 Application Layer
+ 2.2 UFS Transport Protocol(UTP) layer
+ 2.3 UFS Interconnect(UIC) Layer
+3. UFSHCD Overview
+ 3.1 UFS controller initialization
+ 3.2 UTP Transfer requests
+ 3.3 UFS error handling
+ 3.4 SCSI Error handling
+1. Overview
+Universal Flash Storage(UFS) is a storage specification for flash devices.
+It is aimed to provide a universal storage interface for both
+embedded and removable flash memory based storage in mobile
+devices such as smart phones and tablet computers. The specification
+is defined by JEDEC Solid State Technology Association. UFS is based
+on MIPI M-PHY physical layer standard. UFS uses MIPI M-PHY as the
+physical layer and MIPI Unipro as the link layer.
+The main goals of UFS is to provide,
+ * Optimized performance:
+ For UFS version 1.0 and 1.1 the target performance is as follows,
+ Support for Gear1 is mandatory (rate A: 1248Mbps, rate B: 1457.6Mbps)
+ Support for Gear2 is optional (rate A: 2496Mbps, rate B: 2915.2Mbps)
+ Future version of the standard,
+ Gear3 (rate A: 4992Mbps, rate B: 5830.4Mbps)
+ * Low power consumption
+ * High random IOPs and low latency
+2. UFS Architecture Overview
+UFS has a layered communication architecture which is based on SCSI
+SAM-5 architectural model.
+UFS communication architecture consists of following layers,
+2.1 Application Layer
+ The Application layer is composed of UFS command set layer(UCS),
+ Task Manager and Device manager. The UFS interface is designed to be
+ protocol agnostic, however SCSI has been selected as a baseline
+ protocol for versions 1.0 and 1.1 of UFS protocol layer.
+ UFS supports subset of SCSI commands defined by SPC-4 and SBC-3.
+ * UCS: It handles SCSI commands supported by UFS specification.
+ * Task manager: It handles task management functions defined by the
+ UFS which are meant for command queue control.
+ * Device manager: It handles device level operations and device
+ configuration operations. Device level operations mainly involve
+ device power management operations and commands to Interconnect
+ layers. Device level configurations involve handling of query
+ requests which are used to modify and retrieve configuration
+ information of the device.
+2.2 UFS Transport Protocol(UTP) layer
+ UTP layer provides services for
+ the higher layers through Service Access Points. UTP defines 3
+ service access points for higher layers.
+ * UDM_SAP: Device manager service access point is exposed to device
+ manager for device level operations. These device level operations
+ are done through query requests.
+ * UTP_CMD_SAP: Command service access point is exposed to UFS command
+ set layer(UCS) to transport commands.
+ * UTP_TM_SAP: Task management service access point is exposed to task
+ manager to transport task management functions.
+ UTP transports messages through UFS protocol information unit(UPIU).
+2.3 UFS Interconnect(UIC) Layer
+ UIC is the lowest layer of UFS layered architecture. It handles
+ connection between UFS host and UFS device. UIC consists of
+ MIPI UniPro and MIPI M-PHY. UIC provides 2 service access points
+ to upper layer,
+ * UIC_SAP: To transport UPIU between UFS host and UFS device.
+ * UIO_SAP: To issue commands to Unipro layers.
+3. UFSHCD Overview
+The UFS host controller driver is based on Linux SCSI Framework.
+UFSHCD is a low level device driver which acts as an interface between
+SCSI Midlayer and PCIe based UFS host controllers.
+The current UFSHCD implementation supports following functionality,
+3.1 UFS controller initialization
+ The initialization module brings UFS host controller to active state
+ and prepares the controller to transfer commands/response between
+ UFSHCD and UFS device.
+3.2 UTP Transfer requests
+ Transfer request handling module of UFSHCD receives SCSI commands
+ from SCSI Midlayer, forms UPIUs and issues the UPIUs to UFS Host
+ controller. Also, the module decodes, responses received from UFS
+ host controller in the form of UPIUs and intimates the SCSI Midlayer
+ of the status of the command.
+3.3 UFS error handling
+ Error handling module handles Host controller fatal errors,
+ Device fatal errors and UIC interconnect layer related errors.
+3.4 SCSI Error handling
+ This is done through UFSHCD SCSI error handling routines registered
+ with SCSI Midlayer. Examples of some of the error handling commands
+ issues by SCSI Midlayer are Abort task, Lun reset and host reset.
+ UFSHCD Routines to perform these tasks are registered with
+ SCSI Midlayer through .eh_abort_handler, .eh_device_reset_handler and
+ .eh_host_reset_handler.
+In this version of UFSHCD Query requests and power management
+functionality are not implemented.
+UFS Specifications can be found at,
+UFS - http://www.jedec.org/sites/default/files/docs/JESD220.pdf
+UFSHCI - http://www.jedec.org/sites/default/files/docs/JESD223.pdf

Privacy Policy