diff options
Diffstat (limited to 'Documentation/DocBook/libata.tmpl')
| -rw-r--r-- | Documentation/DocBook/libata.tmpl | 243 |
1 files changed, 166 insertions, 77 deletions
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl index d260d92089a..d7fcdc5a437 100644 --- a/Documentation/DocBook/libata.tmpl +++ b/Documentation/DocBook/libata.tmpl @@ -14,7 +14,7 @@ </authorgroup> <copyright> - <year>2003-2005</year> + <year>2003-2006</year> <holder>Jeff Garzik</holder> </copyright> @@ -22,8 +22,8 @@ <para> The contents of this file are subject to the Open Software License version 1.1 that can be found at - <ulink url="http://www.opensource.org/licenses/osl-1.1.txt">http://www.opensource.org/licenses/osl-1.1.txt</ulink> and is included herein - by reference. + <ulink url="http://fedoraproject.org/wiki/Licensing:OSL1.1">http://fedoraproject.org/wiki/Licensing:OSL1.1</ulink> + and is included herein by reference. </para> <para> @@ -81,16 +81,14 @@ void (*port_disable) (struct ata_port *); </programlisting> <para> - Called from ata_bus_probe() and ata_bus_reset() error paths, - as well as when unregistering from the SCSI module (rmmod, hot - unplug). + Called from ata_bus_probe() error path, as well as when + unregistering from the SCSI module (rmmod, hot unplug). This function should do whatever needs to be done to take the port out of use. In most cases, ata_port_disable() can be used as this hook. </para> <para> Called from ata_bus_probe() on a failed probe. - Called from ata_bus_reset() on a failed bus reset. Called from ata_scsi_release(). </para> @@ -107,10 +105,6 @@ void (*dev_config) (struct ata_port *, struct ata_device *); issue of SET FEATURES - XFER MODE, and prior to operation. </para> <para> - Called by ata_device_add() after ata_dev_identify() determines - a device is present. - </para> - <para> This entry may be specified as NULL in ata_port_operations. </para> @@ -120,14 +114,27 @@ void (*dev_config) (struct ata_port *, struct ata_device *); <programlisting> void (*set_piomode) (struct ata_port *, struct ata_device *); void (*set_dmamode) (struct ata_port *, struct ata_device *); -void (*post_set_mode) (struct ata_port *ap); +void (*post_set_mode) (struct ata_port *); +unsigned int (*mode_filter) (struct ata_port *, struct ata_device *, unsigned int); </programlisting> <para> Hooks called prior to the issue of SET FEATURES - XFER MODE - command. dev->pio_mode is guaranteed to be valid when - ->set_piomode() is called, and dev->dma_mode is guaranteed to be - valid when ->set_dmamode() is called. ->post_set_mode() is + command. The optional ->mode_filter() hook is called when libata + has built a mask of the possible modes. This is passed to the + ->mode_filter() function which should return a mask of valid modes + after filtering those unsuitable due to hardware limits. It is not + valid to use this interface to add modes. + </para> + <para> + dev->pio_mode and dev->dma_mode are guaranteed to be valid when + ->set_piomode() and when ->set_dmamode() is called. The timings for + any other drive sharing the cable will also be valid at this point. + That is the library records the decisions for the modes of each + drive on a channel before it attempts to set any of them. + </para> + <para> + ->post_set_mode() is called unconditionally, after the SET FEATURES - XFER MODE command completes successfully. </para> @@ -141,8 +148,8 @@ void (*post_set_mode) (struct ata_port *ap); <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); +void (*sff_tf_load) (struct ata_port *ap, struct ata_taskfile *tf); +void (*sff_tf_read) (struct ata_port *ap, struct ata_taskfile *tf); </programlisting> <para> @@ -151,20 +158,35 @@ void (*tf_read) (struct ata_port *ap, struct ata_taskfile *tf); hardware registers / DMA buffers, to obtain the current set of taskfile register values. Most drivers for taskfile-based hardware (PIO or MMIO) use - ata_tf_load() and ata_tf_read() for these hooks. + ata_sff_tf_load() and ata_sff_tf_read() for these hooks. + </para> + + </sect2> + + <sect2><title>PIO data read/write</title> + <programlisting> +void (*sff_data_xfer) (struct ata_device *, unsigned char *, unsigned int, int); + </programlisting> + + <para> +All bmdma-style drivers must implement this hook. This is the low-level +operation that actually copies the data bytes during a PIO data +transfer. +Typically the driver will choose one of ata_sff_data_xfer_noirq(), +ata_sff_data_xfer(), or ata_sff_data_xfer32(). </para> </sect2> <sect2><title>ATA command execute</title> <programlisting> -void (*exec_command)(struct ata_port *ap, struct ata_taskfile *tf); +void (*sff_exec_command)(struct ata_port *ap, struct ata_taskfile *tf); </programlisting> <para> causes an ATA command, previously loaded with ->tf_load(), to be initiated in hardware. - Most drivers for taskfile-based hardware use ata_exec_command() + Most drivers for taskfile-based hardware use ata_sff_exec_command() for this hook. </para> @@ -189,30 +211,35 @@ command. <sect2><title>Read specific ATA shadow registers</title> <programlisting> -u8 (*check_status)(struct ata_port *ap); -u8 (*check_altstatus)(struct ata_port *ap); -u8 (*check_err)(struct ata_port *ap); +u8 (*sff_check_status)(struct ata_port *ap); +u8 (*sff_check_altstatus)(struct ata_port *ap); </programlisting> <para> - Reads the Status/AltStatus/Error ATA shadow register from + Reads the Status/AltStatus ATA shadow register from hardware. On some hardware, reading the Status register has the side effect of clearing the interrupt condition. Most drivers for taskfile-based hardware use - ata_check_status() for this hook. + ata_sff_check_status() for this hook. </para> + + </sect2> + + <sect2><title>Write specific ATA shadow register</title> + <programlisting> +void (*sff_set_devctl)(struct ata_port *ap, u8 ctl); + </programlisting> + <para> - Note that because this is called from ata_device_add(), at - least a dummy function that clears device interrupts must be - provided for all drivers, even if the controller doesn't - actually have a taskfile status register. + Write the device control ATA shadow register to the hardware. + Most drivers don't need to define this. </para> </sect2> <sect2><title>Select ATA device on bus</title> <programlisting> -void (*dev_select)(struct ata_port *ap, unsigned int device); +void (*sff_dev_select)(struct ata_port *ap, unsigned int device); </programlisting> <para> @@ -223,28 +250,35 @@ void (*dev_select)(struct ata_port *ap, unsigned int device); </para> <para> Most drivers for taskfile-based hardware use - ata_std_dev_select() for this hook. Controllers which do not - support second drives on a port (such as SATA contollers) will - use ata_noop_dev_select(). + ata_sff_dev_select() for this hook. </para> </sect2> - <sect2><title>Reset ATA bus</title> + <sect2><title>Private tuning method</title> <programlisting> -void (*phy_reset) (struct ata_port *ap); +void (*set_mode) (struct ata_port *ap); </programlisting> <para> - The very first step in the probe phase. Actions vary depending - on the bus type, typically. After waking up the device and probing - for device presence (PATA and SATA), typically a soft reset - (SRST) will be performed. Drivers typically use the helper - functions ata_bus_reset() or sata_phy_reset() for this hook. - Many SATA drivers use sata_phy_reset() or call it from within - their own phy_reset() functions. + By default libata performs drive and controller tuning in + accordance with the ATA timing rules and also applies blacklists + and cable limits. Some controllers need special handling and have + custom tuning rules, typically raid controllers that use ATA + commands but do not actually do drive timing. </para> + <warning> + <para> + This hook should not be used to replace the standard controller + tuning logic when a controller has quirks. Replacing the default + tuning logic in that case would bypass handling for drive and + bridge quirks that may be important to data reliability. If a + controller needs to filter the mode selection it should use the + mode_filter hook instead. + </para> + </warning> + </sect2> <sect2><title>Control PCI IDE BMDMA engine</title> @@ -315,16 +349,74 @@ int (*qc_issue) (struct ata_queued_cmd *qc); </sect2> - <sect2><title>Timeout (error) handling</title> + <sect2><title>Exception and probe handling (EH)</title> <programlisting> void (*eng_timeout) (struct ata_port *ap); +void (*phy_reset) (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. Most newer -hardware will implement its own error handling code here. IDE BMDMA -drivers may use the helper function ata_eng_timeout(). +Deprecated. Use ->error_handler() instead. + </para> + + <programlisting> +void (*freeze) (struct ata_port *ap); +void (*thaw) (struct ata_port *ap); + </programlisting> + + <para> +ata_port_freeze() is called when HSM violations or some other +condition disrupts normal operation of the port. A frozen port +is not allowed to perform any operation until the port is +thawed, which usually follows a successful reset. + </para> + + <para> +The optional ->freeze() callback can be used for freezing the port +hardware-wise (e.g. mask interrupt and stop DMA engine). If a +port cannot be frozen hardware-wise, the interrupt handler +must ack and clear interrupts unconditionally while the port +is frozen. + </para> + <para> +The optional ->thaw() callback is called to perform the opposite of ->freeze(): +prepare the port for normal operation once again. Unmask interrupts, +start DMA engine, etc. + </para> + + <programlisting> +void (*error_handler) (struct ata_port *ap); + </programlisting> + + <para> +->error_handler() is a driver's hook into probe, hotplug, and recovery +and other exceptional conditions. The primary responsibility of an +implementation is to call ata_do_eh() or ata_bmdma_drive_eh() with a set +of EH hooks as arguments: + </para> + + <para> +'prereset' hook (may be NULL) is called during an EH reset, before any other actions +are taken. + </para> + + <para> +'postreset' hook (may be NULL) is called after the EH reset is performed. Based on +existing conditions, severity of the problem, and hardware capabilities, + </para> + + <para> +Either 'softreset' (may be NULL) or 'hardreset' (may be NULL) will be +called to perform the low-level EH reset. + </para> + + <programlisting> +void (*post_internal_cmd) (struct ata_queued_cmd *qc); + </programlisting> + + <para> +Perform any hardware-specific actions necessary to finish processing +after executing a probe-time or EH-time command via ata_exec_internal(). </para> </sect2> @@ -346,13 +438,13 @@ void (*irq_clear) (struct ata_port *); to struct ata_host_set. </para> <para> - Most legacy IDE drivers use ata_interrupt() for the + Most legacy IDE drivers use ata_sff_interrupt() for the irq_handler hook, which scans all ports in the host_set, determines which queued command was active (if any), and calls - ata_host_intr(ap,qc). + ata_sff_host_intr(ap,qc). </para> <para> - Most legacy IDE drivers use ata_bmdma_irq_clear() for the + Most legacy IDE drivers use ata_sff_irq_clear() for the irq_clear() hook, which simply clears the interrupt and error flags in the DMA status register. </para> @@ -361,8 +453,9 @@ void (*irq_clear) (struct ata_port *); <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, +int (*scr_read) (struct ata_port *ap, unsigned int sc_reg, + u32 *val); +int (*scr_write) (struct ata_port *ap, unsigned int sc_reg, u32 val); </programlisting> @@ -394,16 +487,12 @@ void (*host_stop) (struct ata_host_set *host_set); allocates space for a legacy IDE PRD table and returns. </para> <para> - ->port_stop() is called after ->host_stop(). It's sole function + ->port_stop() is called after ->host_stop(). Its sole function is to release DMA/memory resources, now that they are no longer actively being used. Many drivers also free driver-private data from port at this time. </para> <para> - Many drivers use ata_port_stop() as this hook, which frees the - PRD table. - </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. @@ -588,7 +677,7 @@ and other resources, etc. <listitem> <para> - ATA_QCFLAG_ACTIVE is clared from qc->flags. + ATA_QCFLAG_ACTIVE is cleared from qc->flags. </para> </listitem> @@ -619,7 +708,7 @@ and other resources, etc. <listitem> <para> - qc->waiting is claread & completed (in that order). + qc->waiting is cleared & completed (in that order). </para> </listitem> @@ -666,7 +755,7 @@ and other resources, etc. <sect1><title>ata_scsi_error()</title> <para> - ata_scsi_error() is the current hostt->eh_strategy_handler() + ata_scsi_error() is the current transportt->eh_strategy_handler() for libata. As discussed above, this will be entered in two cases - timeout and ATAPI error completion. This function calls low level libata driver's eng_timeout() callback, the @@ -773,22 +862,22 @@ and other resources, etc. <chapter id="libataExt"> <title>libata Library</title> -!Edrivers/scsi/libata-core.c +!Edrivers/ata/libata-core.c </chapter> <chapter id="libataInt"> <title>libata Core Internals</title> -!Idrivers/scsi/libata-core.c +!Idrivers/ata/libata-core.c </chapter> <chapter id="libataScsiInt"> <title>libata SCSI translation/emulation</title> -!Edrivers/scsi/libata-scsi.c -!Idrivers/scsi/libata-scsi.c +!Edrivers/ata/libata-scsi.c +!Idrivers/ata/libata-scsi.c </chapter> <chapter id="ataExceptions"> - <title>ATA errors & exceptions</title> + <title>ATA errors and exceptions</title> <para> This chapter tries to identify what error/exception conditions exist @@ -829,7 +918,7 @@ and other resources, etc. <title>HSM violation</title> <para> This error is indicated when STATUS value doesn't match HSM - requirement during issuing or excution any ATA/ATAPI command. + requirement during issuing or execution any ATA/ATAPI command. </para> <itemizedlist> @@ -856,7 +945,7 @@ and other resources, etc. <listitem> <para> - !BSY && ERR after CDB tranfer starts but before the + !BSY && ERR after CDB transfer starts but before the last byte of CDB is transferred. ATA/ATAPI standard states that "The device shall not terminate the PACKET command with an error before the last byte of the command packet has @@ -943,7 +1032,7 @@ and other resources, etc. <listitem> <para> This is indicated by ICRC bit in the ERROR register and - means that corruption occurred during data transfer. Upto + means that corruption occurred during data transfer. Up to ATA/ATAPI-7, the standard specifies that this bit is only applicable to UDMA transfers but ATA/ATAPI-8 draft revision 1f says that the bit may be applicable to multiword DMA and @@ -956,12 +1045,12 @@ and other resources, etc. <term>ABRT error during data transfer or on completion</term> <listitem> <para> - Upto ATA/ATAPI-7, the standard specifies that ABRT could be + Up to ATA/ATAPI-7, the standard specifies that ABRT could be set on ICRC errors and on cases where a device is not able to complete a command. Combined with the fact that MWDMA - and PIO transfer errors aren't allowed to use ICRC bit upto + and PIO transfer errors aren't allowed to use ICRC bit up to ATA/ATAPI-7, it seems to imply that ABRT bit alone could - indicate tranfer errors. + indicate transfer errors. </para> <para> However, ATA/ATAPI-8 draft revision 1f removes the part @@ -1033,7 +1122,7 @@ and other resources, etc. <para> Depending on commands, not all STATUS/ERROR bits are applicable. These non-applicable bits are marked with - "na" in the output descriptions but upto ATA/ATAPI-7 + "na" in the output descriptions but up to ATA/ATAPI-7 no definition of "na" can be found. However, ATA/ATAPI-8 draft revision 1f describes "N/A" as follows. @@ -1074,7 +1163,7 @@ and other resources, etc. <para> Once sense data is acquired, this type of errors can be - handled similary to other SCSI errors. Note that sense data + handled similarly to other SCSI errors. Note that sense data may indicate ATA bus error (e.g. Sense Key 04h HARDWARE ERROR && ASC/ASCQ 47h/00h SCSI PARITY ERROR). In such cases, the error should be considered as an ATA bus error and @@ -1305,7 +1394,7 @@ and other resources, etc. <listitem> <para> When it's known that HBA is in ready state but ATA/ATAPI - device in in unknown state, reset only device. + device is in unknown state, reset only device. </para> </listitem> @@ -1418,7 +1507,7 @@ and other resources, etc. <listitem> <para> - CHS set up with INITIALIZE DEVICE PARAMETERS (seldomly used) + CHS set up with INITIALIZE DEVICE PARAMETERS (seldom used) </para> </listitem> @@ -1505,12 +1594,12 @@ and other resources, etc. <chapter id="PiixInt"> <title>ata_piix Internals</title> -!Idrivers/scsi/ata_piix.c +!Idrivers/ata/ata_piix.c </chapter> <chapter id="SILInt"> <title>sata_sil Internals</title> -!Idrivers/scsi/sata_sil.c +!Idrivers/ata/sata_sil.c </chapter> <chapter id="libataThanks"> |