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libata: doc updates
This commit is contained in:
Jeff Garzik
parent
780a87f718
commit
0cba632b73
@ -58,26 +58,6 @@
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</para>
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</chapter>
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<chapter id="libataThanks">
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<title>Thanks</title>
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<para>
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The bulk of the ATA knowledge comes thanks to long conversations with
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Andre Hedrick (www.linux-ide.org), and long hours pondering the ATA
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and SCSI specifications.
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</para>
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<para>
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Thanks to Alan Cox for pointing out similarities
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between SATA and SCSI, and in general for motivation to hack on
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libata.
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</para>
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<para>
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libata's device detection
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method, ata_pio_devchk, and in general all the early probing was
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based on extensive study of Hale Landis's probe/reset code in his
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ATADRVR driver (www.ata-atapi.com).
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</para>
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</chapter>
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<chapter id="libataDriverApi">
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<title>libata Driver API</title>
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<sect1>
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@ -314,4 +294,24 @@ and other resources, etc.
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!Idrivers/scsi/sata_sil.c
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</chapter>
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<chapter id="libataThanks">
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<title>Thanks</title>
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<para>
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The bulk of the ATA knowledge comes thanks to long conversations with
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Andre Hedrick (www.linux-ide.org), and long hours pondering the ATA
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and SCSI specifications.
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</para>
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<para>
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Thanks to Alan Cox for pointing out similarities
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between SATA and SCSI, and in general for motivation to hack on
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libata.
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</para>
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<para>
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libata's device detection
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method, ata_pio_devchk, and in general all the early probing was
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based on extensive study of Hale Landis's probe/reset code in his
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ATADRVR driver (www.ata-atapi.com).
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</para>
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</chapter>
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</book>
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@ -663,15 +663,6 @@ static int piix_init_one (struct pci_dev *pdev, const struct pci_device_id *ent)
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return ata_pci_init_one(pdev, port_info, n_ports);
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}
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/**
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* piix_init -
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*
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* LOCKING:
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*
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* RETURNS:
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*
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*/
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static int __init piix_init(void)
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{
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int rc;
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@ -687,13 +678,6 @@ static int __init piix_init(void)
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return 0;
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}
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/**
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* piix_exit -
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*
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* LOCKING:
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*
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*/
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static void __exit piix_exit(void)
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{
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pci_unregister_driver(&piix_pci_driver);
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@ -1190,7 +1190,12 @@ err_out:
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* ata_bus_probe - Reset and probe ATA bus
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* @ap: Bus to probe
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*
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* Master ATA bus probing function. Initiates a hardware-dependent
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* bus reset, then attempts to identify any devices found on
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* the bus.
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*
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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* RETURNS:
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* Zero on success, non-zero on error.
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@ -1229,10 +1234,14 @@ err_out:
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}
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/**
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* ata_port_probe -
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* @ap:
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* ata_port_probe - Mark port as enabled
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* @ap: Port for which we indicate enablement
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*
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* LOCKING:
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* Modify @ap data structure such that the system
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* thinks that the entire port is enabled.
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*
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* LOCKING: host_set lock, or some other form of
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* serialization.
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*/
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void ata_port_probe(struct ata_port *ap)
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@ -1248,7 +1257,8 @@ void ata_port_probe(struct ata_port *ap)
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* PHY registers, to wake up the phy (and device), and
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* clear any reset condition.
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*
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* LOCKING: None. Serialized during ata_bus_probe().
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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*/
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void __sata_phy_reset(struct ata_port *ap)
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@ -1299,7 +1309,8 @@ void __sata_phy_reset(struct ata_port *ap)
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* This function resets the SATA bus, and then probes
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* the bus for devices.
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*
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* LOCKING: None. Serialized during ata_bus_probe().
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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*/
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void sata_phy_reset(struct ata_port *ap)
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@ -1431,7 +1442,8 @@ static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode,
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*
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* Set ATA device disk transfer mode (PIO3, UDMA6, etc.).
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*
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* LOCKING: None. Serialized during ata_bus_probe().
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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*/
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static void ata_set_mode(struct ata_port *ap)
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@ -1571,10 +1583,14 @@ static void ata_bus_post_reset(struct ata_port *ap, unsigned int devmask)
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}
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/**
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* ata_bus_edd -
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* @ap:
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* ata_bus_edd - Issue EXECUTE DEVICE DIAGNOSTIC command.
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* @ap: Port to reset and probe
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*
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* LOCKING: None. Serialized during ata_bus_probe().
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* Use the EXECUTE DEVICE DIAGNOSTIC command to reset and
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* probe the bus. Not often used these days.
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*
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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*/
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@ -1651,8 +1667,8 @@ static unsigned int ata_bus_softreset(struct ata_port *ap,
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* the device is ATA or ATAPI.
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*
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* LOCKING:
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* Inherited from caller. Some functions called by this function
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* obtain the host_set lock.
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* PCI/etc. bus probe sem.
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* Obtains host_set lock.
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*
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* SIDE EFFECTS:
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* Sets ATA_FLAG_PORT_DISABLED if bus reset fails.
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@ -1894,7 +1910,11 @@ static int fgb(u32 bitmap)
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* @xfer_mode_out: (output) SET FEATURES - XFER MODE code
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* @xfer_shift_out: (output) bit shift that selects this mode
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*
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* Based on host and device capabilities, determine the
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* maximum transfer mode that is amenable to all.
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*
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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* RETURNS:
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* Zero on success, negative on error.
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@ -1930,7 +1950,8 @@ static int ata_choose_xfer_mode(struct ata_port *ap,
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* Issue SET FEATURES - XFER MODE command to device @dev
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* on port @ap.
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*
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* LOCKING: None. Serialized during ata_bus_probe().
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* LOCKING:
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* PCI/etc. bus probe sem.
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*/
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static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev)
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@ -1968,10 +1989,13 @@ static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev)
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}
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/**
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* ata_sg_clean -
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* @qc:
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* ata_sg_clean - Unmap DMA memory associated with command
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* @qc: Command containing DMA memory to be released
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*
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* Unmap all mapped DMA memory associated with this command.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*/
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static void ata_sg_clean(struct ata_queued_cmd *qc)
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@ -2058,6 +2082,8 @@ static void ata_fill_sg(struct ata_queued_cmd *qc)
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* supplied PACKET command.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*
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* RETURNS: 0 when ATAPI DMA can be used
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* nonzero otherwise
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*/
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@ -2088,6 +2114,19 @@ void ata_qc_prep(struct ata_queued_cmd *qc)
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ata_fill_sg(qc);
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}
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/**
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* ata_sg_init_one - Associate command with memory buffer
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* @qc: Command to be associated
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* @buf: Memory buffer
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* @buflen: Length of memory buffer, in bytes.
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*
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* Initialize the data-related elements of queued_cmd @qc
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* to point to a single memory buffer, @buf of byte length @buflen.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*/
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void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
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{
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struct scatterlist *sg;
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@ -2105,6 +2144,20 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
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sg->length = buflen;
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}
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/**
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* ata_sg_init - Associate command with scatter-gather table.
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* @qc: Command to be associated
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* @sg: Scatter-gather table.
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* @n_elem: Number of elements in s/g table.
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*
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* Initialize the data-related elements of queued_cmd @qc
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* to point to a scatter-gather table @sg, containing @n_elem
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* elements.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*/
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void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
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unsigned int n_elem)
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{
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@ -2114,14 +2167,16 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
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}
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/**
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* ata_sg_setup_one -
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* @qc:
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* ata_sg_setup_one - DMA-map the memory buffer associated with a command.
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* @qc: Command with memory buffer to be mapped.
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*
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* DMA-map the memory buffer associated with queued_cmd @qc.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*
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* RETURNS:
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*
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* Zero on success, negative on error.
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*/
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static int ata_sg_setup_one(struct ata_queued_cmd *qc)
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@ -2146,13 +2201,16 @@ static int ata_sg_setup_one(struct ata_queued_cmd *qc)
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}
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/**
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* ata_sg_setup -
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* @qc:
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* ata_sg_setup - DMA-map the scatter-gather table associated with a command.
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* @qc: Command with scatter-gather table to be mapped.
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*
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* DMA-map the scatter-gather table associated with queued_cmd @qc.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*
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* RETURNS:
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* Zero on success, negative on error.
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*
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*/
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@ -2182,6 +2240,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc)
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* @ap:
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*
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* LOCKING:
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* None. (executing in kernel thread context)
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*
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* RETURNS:
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*
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@ -2229,6 +2288,7 @@ static unsigned long ata_pio_poll(struct ata_port *ap)
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* @ap:
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*
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* LOCKING:
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* None. (executing in kernel thread context)
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*/
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static void ata_pio_complete (struct ata_port *ap)
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@ -2446,6 +2506,7 @@ err_out:
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* @ap:
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*
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* LOCKING:
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* None. (executing in kernel thread context)
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*/
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static void ata_pio_block(struct ata_port *ap)
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@ -2614,6 +2675,7 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev,
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* transaction completed successfully.
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*
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* LOCKING:
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* Inherited from SCSI layer (none, can sleep)
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*/
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static void ata_qc_timeout(struct ata_queued_cmd *qc)
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@ -2723,6 +2785,7 @@ out:
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* @dev: Device from whom we request an available command structure
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*
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* LOCKING:
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* None.
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*/
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static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
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@ -2748,6 +2811,7 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
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* @dev: Device from whom we request an available command structure
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*
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* LOCKING:
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* None.
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*/
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struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,
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@ -2812,6 +2876,7 @@ static void __ata_qc_complete(struct ata_queued_cmd *qc)
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* in case something prevents using it.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*
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*/
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void ata_qc_free(struct ata_queued_cmd *qc)
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@ -2825,9 +2890,13 @@ void ata_qc_free(struct ata_queued_cmd *qc)
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/**
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* ata_qc_complete - Complete an active ATA command
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* @qc: Command to complete
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* @drv_stat: ATA status register contents
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* @drv_stat: ATA Status register contents
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*
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* Indicate to the mid and upper layers that an ATA
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* command has completed, with either an ok or not-ok status.
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*
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* LOCKING:
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* spin_lock_irqsave(host_set lock)
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*
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*/
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@ -3234,13 +3303,18 @@ idle_irq:
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/**
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* ata_interrupt - Default ATA host interrupt handler
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* @irq: irq line
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* @dev_instance: pointer to our host information structure
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* @irq: irq line (unused)
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* @dev_instance: pointer to our ata_host_set information structure
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* @regs: unused
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*
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* Default interrupt handler for PCI IDE devices. Calls
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* ata_host_intr() for each port that is not disabled.
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*
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* LOCKING:
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* Obtains host_set lock during operation.
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*
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* RETURNS:
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* IRQ_NONE or IRQ_HANDLED.
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*
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*/
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@ -3381,7 +3455,11 @@ static void ata_host_remove(struct ata_port *ap, unsigned int do_unregister)
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* @ent: Probe information provided by low-level driver
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* @port_no: Port number associated with this ata_port
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*
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* Initialize a new ata_port structure, and its associated
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* scsi_host.
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*
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* LOCKING:
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* Inherited from caller.
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*
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*/
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@ -3436,9 +3514,13 @@ static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host,
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* @host_set: Collections of ports to which we add
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* @port_no: Port number associated with this host
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*
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* Attach low-level ATA driver to system.
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*
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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* RETURNS:
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* New ata_port on success, for NULL on error.
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*
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*/
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@ -3471,12 +3553,22 @@ err_out:
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}
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/**
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* ata_device_add -
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* @ent:
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* ata_device_add - Register hardware device with ATA and SCSI layers
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* @ent: Probe information describing hardware device to be registered
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*
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* This function processes the information provided in the probe
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* information struct @ent, allocates the necessary ATA and SCSI
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* host information structures, initializes them, and registers
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* everything with requisite kernel subsystems.
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*
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* This function requests irqs, probes the ATA bus, and probes
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* the SCSI bus.
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*
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* LOCKING:
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* PCI/etc. bus probe sem.
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*
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* RETURNS:
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* Number of ports registered. Zero on error (no ports registered).
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*
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*/
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@ -3755,6 +3847,7 @@ ata_pci_init_legacy_mode(struct pci_dev *pdev, struct ata_port_info **port,
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* Inherited from PCI layer (may sleep).
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*
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* RETURNS:
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* Zero on success, negative on errno-based value on error.
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*
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*/
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@ -3974,15 +4067,6 @@ int pci_test_config_bits(struct pci_dev *pdev, struct pci_bits *bits)
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#endif /* CONFIG_PCI */
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/**
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* ata_init -
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*
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* LOCKING:
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*
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* RETURNS:
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*
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*/
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static int __init ata_init(void)
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{
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ata_wq = create_workqueue("ata");
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@ -947,7 +947,7 @@ unsigned int ata_scsiop_inq_83(struct ata_scsi_args *args, u8 *rbuf,
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}
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/**
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* ata_scsiop_noop -
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* ata_scsiop_noop - Command handler that simply returns success.
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* @args: device IDENTIFY data / SCSI command of interest.
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* @rbuf: Response buffer, to which simulated SCSI cmd output is sent.
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* @buflen: Response buffer length.
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