From 7a3e97b0dc4bbac2ba7803564ab0057722689921 Mon Sep 17 00:00:00 2001 From: Santosh Yaraganavi Date: Wed, 29 Feb 2012 12:11:50 +0530 Subject: [SCSI] ufshcd: UFS Host controller driver This patch adds support for Universal Flash Storage(UFS) host controllers. The UFS host controller driver includes host controller initialization method. The Initialization process involves following steps: - Initiate UFS Host Controller initialization process by writing to Host controller enable register - Configure UFS Host controller registers with host memory space datastructure offsets. - Unipro link startup procedure - Check for connected device - Configure UFS host controller to process requests - Enable required interrupts - Configure interrupt aggregation [jejb: fix warnings in 32 bit compile] Signed-off-by: Santosh Yaraganavi Signed-off-by: Vinayak Holikatti Reviewed-by: Arnd Bergmann Reviewed-by: Vishak G Reviewed-by: Girish K S Reviewed-by: Namjae Jeon Signed-off-by: James Bottomley --- Documentation/scsi/00-INDEX | 2 + Documentation/scsi/ufs.txt | 133 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 135 insertions(+) create mode 100644 Documentation/scsi/ufs.txt (limited to 'Documentation/scsi') 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 tmscsim.txt - info on driver for AM53c974 based adapters +ufs.txt + - info on Universal Flash Storage(UFS) and UFS host controller driver. 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 + ======================= + + +Contents +-------- + +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 -- cgit v1.2.3 From c743e44fbb1f8668941e83de07662b1ecd33d083 Mon Sep 17 00:00:00 2001 From: Lee Duncan Date: Thu, 1 Mar 2012 12:41:01 -0800 Subject: [SCSI] st: expand ability to write immediate filemarks The st tape driver recently added the MTWEOFI ioctl, which writes a tape filemark (EOF), like the MTWEOF ioctl, except that MTWEOFI returns immediately. This makes certain applications, like backup software, run much more quickly on buffered tape drives. Since legacy applications do not know about this new MTWEOFI ioctl, this patch adds a new ioctl option that tells the st driver to return immediately when writing an EOF (i.e. a filemark). This new flag is much like the existing flag that tells the st driver to perform writes (and certain other IOs) immediately, but this new flag only applies to writing EOFs. This new feature is controlled via the MTSETDRVBUFFER ioctl, using the newly-defined MT_ST_NOWAIT_EOF flag. Use of this new feature is displayed via the sysfs tape "options" attribute. The st documentation was updated to mention this new flag, as well as the problems that can occur from using it. Signed-off-by: Lee Duncan Acked-by: Kai Makisara Signed-off-by: James Bottomley --- Documentation/scsi/st.txt | 4 ++++ drivers/scsi/st.c | 21 ++++++++++++++++++--- drivers/scsi/st.h | 1 + include/linux/mtio.h | 1 + 4 files changed, 24 insertions(+), 3 deletions(-) (limited to 'Documentation/scsi') 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/drivers/scsi/st.c b/drivers/scsi/st.c index 9262cdfa4b23..8c663e16fd02 100644 --- a/drivers/scsi/st.c +++ b/drivers/scsi/st.c @@ -1106,6 +1106,12 @@ static int check_tape(struct scsi_tape *STp, struct file *filp) STp->drv_buffer)); } STp->drv_write_prot = ((STp->buffer)->b_data[2] & 0x80) != 0; + if (!STp->drv_buffer && STp->immediate_filemark) { + printk(KERN_WARNING + "%s: non-buffered tape: disabling writing immediate filemarks\n", + name); + STp->immediate_filemark = 0; + } } st_release_request(SRpnt); SRpnt = NULL; @@ -1314,6 +1320,8 @@ static int st_flush(struct file *filp, fl_owner_t id) memset(cmd, 0, MAX_COMMAND_SIZE); cmd[0] = WRITE_FILEMARKS; + if (STp->immediate_filemark) + cmd[1] = 1; cmd[4] = 1 + STp->two_fm; SRpnt = st_do_scsi(NULL, STp, cmd, 0, DMA_NONE, @@ -2181,8 +2189,9 @@ static void st_log_options(struct scsi_tape * STp, struct st_modedef * STm, char name, STm->defaults_for_writes, STp->omit_blklims, STp->can_partitions, STp->scsi2_logical); printk(KERN_INFO - "%s: sysv: %d nowait: %d sili: %d\n", name, STm->sysv, STp->immediate, - STp->sili); + "%s: sysv: %d nowait: %d sili: %d nowait_filemark: %d\n", + name, STm->sysv, STp->immediate, STp->sili, + STp->immediate_filemark); printk(KERN_INFO "%s: debugging: %d\n", name, debugging); } @@ -2224,6 +2233,7 @@ static int st_set_options(struct scsi_tape *STp, long options) STp->can_partitions = (options & MT_ST_CAN_PARTITIONS) != 0; STp->scsi2_logical = (options & MT_ST_SCSI2LOGICAL) != 0; STp->immediate = (options & MT_ST_NOWAIT) != 0; + STp->immediate_filemark = (options & MT_ST_NOWAIT_EOF) != 0; STm->sysv = (options & MT_ST_SYSV) != 0; STp->sili = (options & MT_ST_SILI) != 0; DEB( debugging = (options & MT_ST_DEBUGGING) != 0; @@ -2255,6 +2265,8 @@ static int st_set_options(struct scsi_tape *STp, long options) STp->scsi2_logical = value; if ((options & MT_ST_NOWAIT) != 0) STp->immediate = value; + if ((options & MT_ST_NOWAIT_EOF) != 0) + STp->immediate_filemark = value; if ((options & MT_ST_SYSV) != 0) STm->sysv = value; if ((options & MT_ST_SILI) != 0) @@ -2714,7 +2726,8 @@ static int st_int_ioctl(struct scsi_tape *STp, unsigned int cmd_in, unsigned lon cmd[0] = WRITE_FILEMARKS; if (cmd_in == MTWSM) cmd[1] = 2; - if (cmd_in == MTWEOFI) + if (cmd_in == MTWEOFI || + (cmd_in == MTWEOF && STp->immediate_filemark)) cmd[1] |= 1; cmd[2] = (arg >> 16); cmd[3] = (arg >> 8); @@ -4093,6 +4106,7 @@ static int st_probe(struct device *dev) tpnt->scsi2_logical = ST_SCSI2LOGICAL; tpnt->sili = ST_SILI; tpnt->immediate = ST_NOWAIT; + tpnt->immediate_filemark = 0; tpnt->default_drvbuffer = 0xff; /* No forced buffering */ tpnt->partition = 0; tpnt->new_partition = 0; @@ -4478,6 +4492,7 @@ st_options_show(struct device *dev, struct device_attribute *attr, char *buf) options |= STp->scsi2_logical ? MT_ST_SCSI2LOGICAL : 0; options |= STm->sysv ? MT_ST_SYSV : 0; options |= STp->immediate ? MT_ST_NOWAIT : 0; + options |= STp->immediate_filemark ? MT_ST_NOWAIT_EOF : 0; options |= STp->sili ? MT_ST_SILI : 0; l = snprintf(buf, PAGE_SIZE, "0x%08x\n", options); diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h index f91a67c6d968..ea35632b986c 100644 --- a/drivers/scsi/st.h +++ b/drivers/scsi/st.h @@ -120,6 +120,7 @@ struct scsi_tape { unsigned char c_algo; /* compression algorithm */ unsigned char pos_unknown; /* after reset position unknown */ unsigned char sili; /* use SILI when reading in variable b mode */ + unsigned char immediate_filemark; /* write filemark immediately */ int tape_type; int long_timeout; /* timeout for commands known to take long time */ diff --git a/include/linux/mtio.h b/include/linux/mtio.h index 8f825756c459..18543e2db06f 100644 --- a/include/linux/mtio.h +++ b/include/linux/mtio.h @@ -194,6 +194,7 @@ struct mtpos { #define MT_ST_SYSV 0x1000 #define MT_ST_NOWAIT 0x2000 #define MT_ST_SILI 0x4000 +#define MT_ST_NOWAIT_EOF 0x8000 /* The mode parameters to be controlled. Parameter chosen with bits 20-28 */ #define MT_ST_CLEAR_DEFAULT 0xfffff -- cgit v1.2.3