diff options
Diffstat (limited to 'Documentation/DocBook')
| -rw-r--r-- | Documentation/DocBook/Makefile | 2 | ||||
| -rw-r--r-- | Documentation/DocBook/kernel-api.tmpl | 1 | ||||
| -rw-r--r-- | Documentation/DocBook/libata.tmpl | 156 | ||||
| -rw-r--r-- | Documentation/DocBook/scsidrivers.tmpl | 193 |
4 files changed, 125 insertions, 227 deletions
diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index e69b3d2e788..87da3478fad 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -8,7 +8,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \ kernel-hacking.xml kernel-locking.xml deviceiobook.xml \ - procfs-guide.xml writing_usb_driver.xml scsidrivers.xml \ + procfs-guide.xml writing_usb_driver.xml \ sis900.xml kernel-api.xml journal-api.xml lsm.xml usb.xml \ gadget.xml libata.xml mtdnand.xml librs.xml diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index 757cef8f849..bb6a0106be1 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -338,7 +338,6 @@ X!Earch/i386/kernel/mca.c X!Iinclude/linux/device.h --> !Edrivers/base/driver.c -!Edrivers/base/class_simple.c !Edrivers/base/core.c !Edrivers/base/firmware_class.c !Edrivers/base/transport_class.c diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl index cf2fce7707d..6df1dfd18b6 100644 --- a/Documentation/DocBook/libata.tmpl +++ b/Documentation/DocBook/libata.tmpl @@ -14,7 +14,7 @@ </authorgroup> <copyright> - <year>2003</year> + <year>2003-2005</year> <holder>Jeff Garzik</holder> </copyright> @@ -44,30 +44,38 @@ <toc></toc> - <chapter id="libataThanks"> - <title>Thanks</title> + <chapter id="libataIntroduction"> + <title>Introduction</title> <para> - The bulk of the ATA knowledge comes thanks to long conversations with - Andre Hedrick (www.linux-ide.org). + libATA is a library used inside the Linux kernel to support ATA host + controllers and devices. libATA provides an ATA driver API, class + transports for ATA and ATAPI devices, and SCSI<->ATA translation + for ATA devices according to the T10 SAT specification. </para> <para> - Thanks to Alan Cox for pointing out similarities - between SATA and SCSI, and in general for motivation to hack on - libata. - </para> - <para> - libata's device detection - method, ata_pio_devchk, and in general all the early probing was - based on extensive study of Hale Landis's probe/reset code in his - ATADRVR driver (www.ata-atapi.com). + This Guide documents the libATA driver API, library functions, library + internals, and a couple sample ATA low-level drivers. </para> </chapter> <chapter id="libataDriverApi"> <title>libata Driver API</title> + <para> + struct ata_port_operations is defined for every low-level libata + hardware driver, and it controls how the low-level driver + interfaces with the ATA and SCSI layers. + </para> + <para> + FIS-based drivers will hook into the system with ->qc_prep() and + ->qc_issue() high-level hooks. Hardware which behaves in a manner + similar to PCI IDE hardware may utilize several generic helpers, + defining at a bare minimum the bus I/O addresses of the ATA shadow + register blocks. + </para> <sect1> <title>struct ata_port_operations</title> + <sect2><title>Disable ATA port</title> <programlisting> void (*port_disable) (struct ata_port *); </programlisting> @@ -78,6 +86,9 @@ void (*port_disable) (struct ata_port *); unplug). </para> + </sect2> + + <sect2><title>Post-IDENTIFY device configuration</title> <programlisting> void (*dev_config) (struct ata_port *, struct ata_device *); </programlisting> @@ -88,6 +99,9 @@ void (*dev_config) (struct ata_port *, struct ata_device *); issue of SET FEATURES - XFER MODE, and prior to operation. </para> + </sect2> + + <sect2><title>Set PIO/DMA mode</title> <programlisting> void (*set_piomode) (struct ata_port *, struct ata_device *); void (*set_dmamode) (struct ata_port *, struct ata_device *); @@ -108,6 +122,9 @@ void (*post_set_mode) (struct ata_port *ap); ->set_dma_mode() is only called if DMA is possible. </para> + </sect2> + + <sect2><title>Taskfile read/write</title> <programlisting> void (*tf_load) (struct ata_port *ap, struct ata_taskfile *tf); void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf); @@ -120,6 +137,9 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf); taskfile register values. </para> + </sect2> + + <sect2><title>ATA command execute</title> <programlisting> void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf); </programlisting> @@ -129,17 +149,37 @@ void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf); ->tf_load(), to be initiated in hardware. </para> + </sect2> + + <sect2><title>Per-cmd ATAPI DMA capabilities filter</title> + <programlisting> +int (*check_atapi_dma) (struct ata_queued_cmd *qc); + </programlisting> + + <para> +Allow low-level driver to filter ATA PACKET commands, returning a status +indicating whether or not it is OK to use DMA for the supplied PACKET +command. + </para> + + </sect2> + + <sect2><title>Read specific ATA shadow registers</title> <programlisting> u8 (*check_status)(struct ata_port *ap); -void (*dev_select)(struct ata_port *ap, unsigned int device); +u8 (*check_altstatus)(struct ata_port *ap); +u8 (*check_err)(struct ata_port *ap); </programlisting> <para> - Reads the Status ATA shadow register from hardware. On some - hardware, this has the side effect of clearing the interrupt - condition. + Reads the Status/AltStatus/Error ATA shadow register from + hardware. On some hardware, reading the Status register has + the side effect of clearing the interrupt condition. </para> + </sect2> + + <sect2><title>Select ATA device on bus</title> <programlisting> void (*dev_select)(struct ata_port *ap, unsigned int device); </programlisting> @@ -147,9 +187,13 @@ void (*dev_select)(struct ata_port *ap, unsigned int device); <para> Issues the low-level hardware command(s) that causes one of N hardware devices to be considered 'selected' (active and - available for use) on the ATA bus. + available for use) on the ATA bus. This generally has no +meaning on FIS-based devices. </para> + </sect2> + + <sect2><title>Reset ATA bus</title> <programlisting> void (*phy_reset) (struct ata_port *ap); </programlisting> @@ -162,17 +206,31 @@ void (*phy_reset) (struct ata_port *ap); functions ata_bus_reset() or sata_phy_reset() for this hook. </para> + </sect2> + + <sect2><title>Control PCI IDE BMDMA engine</title> <programlisting> void (*bmdma_setup) (struct ata_queued_cmd *qc); void (*bmdma_start) (struct ata_queued_cmd *qc); +void (*bmdma_stop) (struct ata_port *ap); +u8 (*bmdma_status) (struct ata_port *ap); </programlisting> <para> - When setting up an IDE BMDMA transaction, these hooks arm - (->bmdma_setup) and fire (->bmdma_start) the hardware's DMA - engine. +When setting up an IDE BMDMA transaction, these hooks arm +(->bmdma_setup), fire (->bmdma_start), and halt (->bmdma_stop) +the hardware's DMA engine. ->bmdma_status is used to read the standard +PCI IDE DMA Status register. </para> + <para> +These hooks are typically either no-ops, or simply not implemented, in +FIS-based drivers. + </para> + + </sect2> + + <sect2><title>High-level taskfile hooks</title> <programlisting> void (*qc_prep) (struct ata_queued_cmd *qc); int (*qc_issue) (struct ata_queued_cmd *qc); @@ -190,20 +248,26 @@ int (*qc_issue) (struct ata_queued_cmd *qc); ->qc_issue is used to make a command active, once the hardware and S/G tables have been prepared. IDE BMDMA drivers use the helper function ata_qc_issue_prot() for taskfile protocol-based - dispatch. More advanced drivers roll their own ->qc_issue - implementation, using this as the "issue new ATA command to - hardware" hook. + dispatch. More advanced drivers implement their own ->qc_issue. </para> + </sect2> + + <sect2><title>Timeout (error) handling</title> <programlisting> void (*eng_timeout) (struct ata_port *ap); </programlisting> <para> - This is a high level error handling function, called from the - error handling thread, when a command times out. +This is a high level error handling function, called from the +error handling thread, when a command times out. Most newer +hardware will implement its own error handling code here. IDE BMDMA +drivers may use the helper function ata_eng_timeout(). </para> + </sect2> + + <sect2><title>Hardware interrupt handling</title> <programlisting> irqreturn_t (*irq_handler)(int, void *, struct pt_regs *); void (*irq_clear) (struct ata_port *); @@ -216,6 +280,9 @@ void (*irq_clear) (struct ata_port *); is quiet. </para> + </sect2> + + <sect2><title>SATA phy read/write</title> <programlisting> u32 (*scr_read) (struct ata_port *ap, unsigned int sc_reg); void (*scr_write) (struct ata_port *ap, unsigned int sc_reg, @@ -227,6 +294,9 @@ void (*scr_write) (struct ata_port *ap, unsigned int sc_reg, if ->phy_reset hook called the sata_phy_reset() helper function. </para> + </sect2> + + <sect2><title>Init and shutdown</title> <programlisting> int (*port_start) (struct ata_port *ap); void (*port_stop) (struct ata_port *ap); @@ -240,15 +310,17 @@ void (*host_stop) (struct ata_host_set *host_set); tasks. </para> <para> - ->host_stop() is called when the rmmod or hot unplug process - begins. The hook must stop all hardware interrupts, DMA - engines, etc. - </para> - <para> ->port_stop() is called after ->host_stop(). It's sole function is to release DMA/memory resources, now that they are no longer actively being used. </para> + <para> + ->host_stop() is called after all ->port_stop() calls +have completed. The hook must finalize hardware shutdown, release DMA +and other resources, etc. + </para> + + </sect2> </sect1> </chapter> @@ -279,4 +351,24 @@ void (*host_stop) (struct ata_host_set *host_set); !Idrivers/scsi/sata_sil.c </chapter> + <chapter id="libataThanks"> + <title>Thanks</title> + <para> + The bulk of the ATA knowledge comes thanks to long conversations with + Andre Hedrick (www.linux-ide.org), and long hours pondering the ATA + and SCSI specifications. + </para> + <para> + Thanks to Alan Cox for pointing out similarities + between SATA and SCSI, and in general for motivation to hack on + libata. + </para> + <para> + libata's device detection + method, ata_pio_devchk, and in general all the early probing was + based on extensive study of Hale Landis's probe/reset code in his + ATADRVR driver (www.ata-atapi.com). + </para> + </chapter> + </book> diff --git a/Documentation/DocBook/scsidrivers.tmpl b/Documentation/DocBook/scsidrivers.tmpl deleted file mode 100644 index d058e65daf1..00000000000 --- a/Documentation/DocBook/scsidrivers.tmpl +++ /dev/null @@ -1,193 +0,0 @@ -<?xml version="1.0" encoding="UTF-8"?> -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" - "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> - -<book id="scsidrivers"> - <bookinfo> - <title>SCSI Subsystem Interfaces</title> - - <authorgroup> - <author> - <firstname>Douglas</firstname> - <surname>Gilbert</surname> - <affiliation> - <address> - <email>dgilbert@interlog.com</email> - </address> - </affiliation> - </author> - </authorgroup> - <pubdate>2003-08-11</pubdate> - - <copyright> - <year>2002</year> - <year>2003</year> - <holder>Douglas Gilbert</holder> - </copyright> - - <legalnotice> - <para> - This documentation is free software; you can redistribute - it and/or modify it under the terms of the GNU General Public - License as published by the Free Software Foundation; either - version 2 of the License, or (at your option) any later - version. - </para> - - <para> - This program is distributed in the hope that it will be - useful, but WITHOUT ANY WARRANTY; without even the implied - warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. - See the GNU General Public License for more details. - </para> - - <para> - You should have received a copy of the GNU General Public - License along with this program; if not, write to the Free - Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, - MA 02111-1307 USA - </para> - - <para> - For more details see the file COPYING in the source - distribution of Linux. - </para> - </legalnotice> - - </bookinfo> - -<toc></toc> - - <chapter id="intro"> - <title>Introduction</title> - <para> -This document outlines the interface between the Linux scsi mid level -and lower level drivers. Lower level drivers are variously called HBA -(host bus adapter) drivers, host drivers (HD) or pseudo adapter drivers. -The latter alludes to the fact that a lower level driver may be a -bridge to another IO subsystem (and the "ide-scsi" driver is an example -of this). There can be many lower level drivers active in a running -system, but only one per hardware type. For example, the aic7xxx driver -controls adaptec controllers based on the 7xxx chip series. Most lower -level drivers can control one or more scsi hosts (a.k.a. scsi initiators). - </para> -<para> -This document can been found in an ASCII text file in the linux kernel -source: <filename>Documentation/scsi/scsi_mid_low_api.txt</filename> . -It currently hold a little more information than this document. The -<filename>drivers/scsi/hosts.h</filename> and <filename> -drivers/scsi/scsi.h</filename> headers contain descriptions of members -of important structures for the scsi subsystem. -</para> - </chapter> - - <chapter id="driver-struct"> - <title>Driver structure</title> - <para> -Traditionally a lower level driver for the scsi subsystem has been -at least two files in the drivers/scsi directory. For example, a -driver called "xyz" has a header file "xyz.h" and a source file -"xyz.c". [Actually there is no good reason why this couldn't all -be in one file.] Some drivers that have been ported to several operating -systems (e.g. aic7xxx which has separate files for generic and -OS-specific code) have more than two files. Such drivers tend to have -their own directory under the drivers/scsi directory. - </para> - <para> -scsi_module.c is normally included at the end of a lower -level driver. For it to work a declaration like this is needed before -it is included: -<programlisting> - static Scsi_Host_Template driver_template = DRIVER_TEMPLATE; - /* DRIVER_TEMPLATE should contain pointers to supported interface - functions. Scsi_Host_Template is defined hosts.h */ - #include "scsi_module.c" -</programlisting> - </para> - <para> -The scsi_module.c assumes the name "driver_template" is appropriately -defined. It contains 2 functions: -<orderedlist> -<listitem><para> - init_this_scsi_driver() called during builtin and module driver - initialization: invokes mid level's scsi_register_host() -</para></listitem> -<listitem><para> - exit_this_scsi_driver() called during closedown: invokes - mid level's scsi_unregister_host() -</para></listitem> -</orderedlist> - </para> -<para> -When a new, lower level driver is being added to Linux, the following -files (all found in the drivers/scsi directory) will need some attention: -Makefile, Config.help and Config.in . It is probably best to look at what -an existing lower level driver does in this regard. -</para> - </chapter> - - <chapter id="intfunctions"> - <title>Interface Functions</title> -!EDocumentation/scsi/scsi_mid_low_api.txt - </chapter> - - <chapter id="locks"> - <title>Locks</title> -<para> -Each Scsi_Host instance has a spin_lock called Scsi_Host::default_lock -which is initialized in scsi_register() [found in hosts.c]. Within the -same function the Scsi_Host::host_lock pointer is initialized to point -at default_lock with the scsi_assign_lock() function. Thereafter -lock and unlock operations performed by the mid level use the -Scsi_Host::host_lock pointer. -</para> -<para> -Lower level drivers can override the use of Scsi_Host::default_lock by -using scsi_assign_lock(). The earliest opportunity to do this would -be in the detect() function after it has invoked scsi_register(). It -could be replaced by a coarser grain lock (e.g. per driver) or a -lock of equal granularity (i.e. per host). Using finer grain locks -(e.g. per scsi device) may be possible by juggling locks in -queuecommand(). -</para> - </chapter> - - <chapter id="changes"> - <title>Changes since lk 2.4 series</title> -<para> -io_request_lock has been replaced by several finer grained locks. The lock -relevant to lower level drivers is Scsi_Host::host_lock and there is one -per scsi host. -</para> -<para> -The older error handling mechanism has been removed. This means the -lower level interface functions abort() and reset() have been removed. -</para> -<para> -In the 2.4 series the scsi subsystem configuration descriptions were -aggregated with the configuration descriptions from all other Linux -subsystems in the Documentation/Configure.help file. In the 2.5 series, -the scsi subsystem now has its own (much smaller) drivers/scsi/Config.help -file. -</para> - </chapter> - - <chapter id="credits"> - <title>Credits</title> -<para> -The following people have contributed to this document: -<orderedlist> -<listitem><para> -Mike Anderson <email>andmike@us.ibm.com</email> -</para></listitem> -<listitem><para> -James Bottomley <email>James.Bottomley@steeleye.com</email> -</para></listitem> -<listitem><para> -Patrick Mansfield <email>patmans@us.ibm.com</email> -</para></listitem> -</orderedlist> -</para> - </chapter> - -</book> |