diff options
Diffstat (limited to 'drivers/scsi/libata-core.c')
| -rw-r--r-- | drivers/scsi/libata-core.c | 150 |
1 files changed, 117 insertions, 33 deletions
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c index 4d707d06a5d1..31b2984f379a 100644 --- a/drivers/scsi/libata-core.c +++ b/drivers/scsi/libata-core.c @@ -1190,7 +1190,12 @@ err_out: * ata_bus_probe - Reset and probe ATA bus * @ap: Bus to probe * + * Master ATA bus probing function. Initiates a hardware-dependent + * bus reset, then attempts to identify any devices found on + * the bus. + * * LOCKING: + * PCI/etc. bus probe sem. * * RETURNS: * Zero on success, non-zero on error. @@ -1229,10 +1234,14 @@ err_out: } /** - * ata_port_probe - - * @ap: + * ata_port_probe - Mark port as enabled + * @ap: Port for which we indicate enablement * - * LOCKING: + * Modify @ap data structure such that the system + * thinks that the entire port is enabled. + * + * LOCKING: host_set lock, or some other form of + * serialization. */ void ata_port_probe(struct ata_port *ap) @@ -1248,7 +1257,8 @@ void ata_port_probe(struct ata_port *ap) * PHY registers, to wake up the phy (and device), and * clear any reset condition. * - * LOCKING: None. Serialized during ata_bus_probe(). + * LOCKING: + * PCI/etc. bus probe sem. * */ void __sata_phy_reset(struct ata_port *ap) @@ -1299,7 +1309,8 @@ void __sata_phy_reset(struct ata_port *ap) * This function resets the SATA bus, and then probes * the bus for devices. * - * LOCKING: None. Serialized during ata_bus_probe(). + * LOCKING: + * PCI/etc. bus probe sem. * */ void sata_phy_reset(struct ata_port *ap) @@ -1431,7 +1442,8 @@ static void ata_host_set_dma(struct ata_port *ap, u8 xfer_mode, * * Set ATA device disk transfer mode (PIO3, UDMA6, etc.). * - * LOCKING: None. Serialized during ata_bus_probe(). + * LOCKING: + * PCI/etc. bus probe sem. * */ static void ata_set_mode(struct ata_port *ap) @@ -1571,10 +1583,14 @@ static void ata_bus_post_reset(struct ata_port *ap, unsigned int devmask) } /** - * ata_bus_edd - - * @ap: + * ata_bus_edd - Issue EXECUTE DEVICE DIAGNOSTIC command. + * @ap: Port to reset and probe + * + * Use the EXECUTE DEVICE DIAGNOSTIC command to reset and + * probe the bus. Not often used these days. * - * LOCKING: None. Serialized during ata_bus_probe(). + * LOCKING: + * PCI/etc. bus probe sem. * */ @@ -1651,8 +1667,8 @@ static unsigned int ata_bus_softreset(struct ata_port *ap, * the device is ATA or ATAPI. * * LOCKING: - * Inherited from caller. Some functions called by this function - * obtain the host_set lock. + * PCI/etc. bus probe sem. + * Obtains host_set lock. * * SIDE EFFECTS: * Sets ATA_FLAG_PORT_DISABLED if bus reset fails. @@ -1894,7 +1910,11 @@ static int fgb(u32 bitmap) * @xfer_mode_out: (output) SET FEATURES - XFER MODE code * @xfer_shift_out: (output) bit shift that selects this mode * + * Based on host and device capabilities, determine the + * maximum transfer mode that is amenable to all. + * * LOCKING: + * PCI/etc. bus probe sem. * * RETURNS: * Zero on success, negative on error. @@ -1930,7 +1950,8 @@ static int ata_choose_xfer_mode(struct ata_port *ap, * Issue SET FEATURES - XFER MODE command to device @dev * on port @ap. * - * LOCKING: None. Serialized during ata_bus_probe(). + * LOCKING: + * PCI/etc. bus probe sem. */ static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev) @@ -1968,10 +1989,13 @@ static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev) } /** - * ata_sg_clean - - * @qc: + * ata_sg_clean - Unmap DMA memory associated with command + * @qc: Command containing DMA memory to be released + * + * Unmap all mapped DMA memory associated with this command. * * LOCKING: + * spin_lock_irqsave(host_set lock) */ static void ata_sg_clean(struct ata_queued_cmd *qc) @@ -2058,6 +2082,8 @@ static void ata_fill_sg(struct ata_queued_cmd *qc) * supplied PACKET command. * * LOCKING: + * spin_lock_irqsave(host_set lock) + * * RETURNS: 0 when ATAPI DMA can be used * nonzero otherwise */ @@ -2088,6 +2114,19 @@ void ata_qc_prep(struct ata_queued_cmd *qc) ata_fill_sg(qc); } +/** + * ata_sg_init_one - Associate command with memory buffer + * @qc: Command to be associated + * @buf: Memory buffer + * @buflen: Length of memory buffer, in bytes. + * + * Initialize the data-related elements of queued_cmd @qc + * to point to a single memory buffer, @buf of byte length @buflen. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + */ + void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen) { struct scatterlist *sg; @@ -2105,6 +2144,20 @@ void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen) sg->length = buflen; } +/** + * ata_sg_init - Associate command with scatter-gather table. + * @qc: Command to be associated + * @sg: Scatter-gather table. + * @n_elem: Number of elements in s/g table. + * + * Initialize the data-related elements of queued_cmd @qc + * to point to a scatter-gather table @sg, containing @n_elem + * elements. + * + * LOCKING: + * spin_lock_irqsave(host_set lock) + */ + void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg, unsigned int n_elem) { @@ -2114,14 +2167,16 @@ void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg, } /** - * ata_sg_setup_one - - * @qc: + * ata_sg_setup_one - DMA-map the memory buffer associated with a command. + * @qc: Command with memory buffer to be mapped. + * + * DMA-map the memory buffer associated with queued_cmd @qc. * * LOCKING: * spin_lock_irqsave(host_set lock) * * RETURNS: - * + * Zero on success, negative on error. */ static int ata_sg_setup_one(struct ata_queued_cmd *qc) @@ -2146,13 +2201,16 @@ static int ata_sg_setup_one(struct ata_queued_cmd *qc) } /** - * ata_sg_setup - - * @qc: + * ata_sg_setup - DMA-map the scatter-gather table associated with a command. + * @qc: Command with scatter-gather table to be mapped. + * + * DMA-map the scatter-gather table associated with queued_cmd @qc. * * LOCKING: * spin_lock_irqsave(host_set lock) * * RETURNS: + * Zero on success, negative on error. * */ @@ -2182,6 +2240,7 @@ static int ata_sg_setup(struct ata_queued_cmd *qc) * @ap: * * LOCKING: + * None. (executing in kernel thread context) * * RETURNS: * @@ -2229,6 +2288,7 @@ static unsigned long ata_pio_poll(struct ata_port *ap) * @ap: * * LOCKING: + * None. (executing in kernel thread context) */ static void ata_pio_complete (struct ata_port *ap) @@ -2446,6 +2506,7 @@ err_out: * @ap: * * LOCKING: + * None. (executing in kernel thread context) */ static void ata_pio_block(struct ata_port *ap) @@ -2614,6 +2675,7 @@ static void atapi_request_sense(struct ata_port *ap, struct ata_device *dev, * transaction completed successfully. * * LOCKING: + * Inherited from SCSI layer (none, can sleep) */ static void ata_qc_timeout(struct ata_queued_cmd *qc) @@ -2723,6 +2785,7 @@ out: * @dev: Device from whom we request an available command structure * * LOCKING: + * None. */ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap) @@ -2748,6 +2811,7 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap) * @dev: Device from whom we request an available command structure * * LOCKING: + * None. */ struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap, @@ -2812,6 +2876,7 @@ static void __ata_qc_complete(struct ata_queued_cmd *qc) * in case something prevents using it. * * LOCKING: + * spin_lock_irqsave(host_set lock) * */ void ata_qc_free(struct ata_queued_cmd *qc) @@ -2825,9 +2890,13 @@ void ata_qc_free(struct ata_queued_cmd *qc) /** * ata_qc_complete - Complete an active ATA command * @qc: Command to complete - * @drv_stat: ATA status register contents + * @drv_stat: ATA Status register contents + * + * Indicate to the mid and upper layers that an ATA + * command has completed, with either an ok or not-ok status. * * LOCKING: + * spin_lock_irqsave(host_set lock) * */ @@ -3234,13 +3303,18 @@ idle_irq: /** * ata_interrupt - Default ATA host interrupt handler - * @irq: irq line - * @dev_instance: pointer to our host information structure + * @irq: irq line (unused) + * @dev_instance: pointer to our ata_host_set information structure * @regs: unused * + * Default interrupt handler for PCI IDE devices. Calls + * ata_host_intr() for each port that is not disabled. + * * LOCKING: + * Obtains host_set lock during operation. * * RETURNS: + * IRQ_NONE or IRQ_HANDLED. * */ @@ -3381,7 +3455,11 @@ static void ata_host_remove(struct ata_port *ap, unsigned int do_unregister) * @ent: Probe information provided by low-level driver * @port_no: Port number associated with this ata_port * + * Initialize a new ata_port structure, and its associated + * scsi_host. + * * LOCKING: + * Inherited from caller. * */ @@ -3436,9 +3514,13 @@ static void ata_host_init(struct ata_port *ap, struct Scsi_Host *host, * @host_set: Collections of ports to which we add * @port_no: Port number associated with this host * + * Attach low-level ATA driver to system. + * * LOCKING: + * PCI/etc. bus probe sem. * * RETURNS: + * New ata_port on success, for NULL on error. * */ @@ -3471,12 +3553,22 @@ err_out: } /** - * ata_device_add - - * @ent: + * ata_device_add - Register hardware device with ATA and SCSI layers + * @ent: Probe information describing hardware device to be registered + * + * This function processes the information provided in the probe + * information struct @ent, allocates the necessary ATA and SCSI + * host information structures, initializes them, and registers + * everything with requisite kernel subsystems. + * + * This function requests irqs, probes the ATA bus, and probes + * the SCSI bus. * * LOCKING: + * PCI/etc. bus probe sem. * * RETURNS: + * Number of ports registered. Zero on error (no ports registered). * */ @@ -3755,6 +3847,7 @@ ata_pci_init_legacy_mode(struct pci_dev *pdev, struct ata_port_info **port, * Inherited from PCI layer (may sleep). * * RETURNS: + * Zero on success, negative on errno-based value on error. * */ @@ -3974,15 +4067,6 @@ int pci_test_config_bits(struct pci_dev *pdev, struct pci_bits *bits) #endif /* CONFIG_PCI */ -/** - * ata_init - - * - * LOCKING: - * - * RETURNS: - * - */ - static int __init ata_init(void) { ata_wq = create_workqueue("ata"); |