Automatic merge of /spare/repo/linux-2.6/.git branch HEAD
diff --git a/Documentation/DocBook/libata.tmpl b/Documentation/DocBook/libata.tmpl
index cf2fce7..6df1dfd 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 @@
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 @@
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 @@
->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 @@
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 @@
->tf_load(), to be initiated in hardware.
</para>
+ </sect2>
+
+ <sect2><title>Per-cmd ATAPI DMA capabilities filter</title>
<programlisting>
-u8 (*check_status)(struct ata_port *ap);
-void (*dev_select)(struct ata_port *ap, unsigned int device);
+int (*check_atapi_dma) (struct ata_queued_cmd *qc);
</programlisting>
<para>
- Reads the Status ATA shadow register from hardware. On some
- hardware, this has the side effect of clearing the interrupt
- condition.
+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);
+u8 (*check_altstatus)(struct ata_port *ap);
+u8 (*check_err)(struct ata_port *ap);
+ </programlisting>
+
+ <para>
+ 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 @@
<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 @@
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 @@
->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 @@
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 @@
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 @@
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 @@
!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/drivers/scsi/ata_piix.c b/drivers/scsi/ata_piix.c
index 54c5234..3be5464 100644
--- a/drivers/scsi/ata_piix.c
+++ b/drivers/scsi/ata_piix.c
@@ -665,15 +665,6 @@
return ata_pci_init_one(pdev, port_info, n_ports);
}
-/**
- * piix_init -
- *
- * LOCKING:
- *
- * RETURNS:
- *
- */
-
static int __init piix_init(void)
{
int rc;
@@ -689,13 +680,6 @@
return 0;
}
-/**
- * piix_exit -
- *
- * LOCKING:
- *
- */
-
static void __exit piix_exit(void)
{
pci_unregister_driver(&piix_pci_driver);
diff --git a/drivers/scsi/libata-core.c b/drivers/scsi/libata-core.c
index 30a88f0..21d194c 100644
--- a/drivers/scsi/libata-core.c
+++ b/drivers/scsi/libata-core.c
@@ -186,6 +186,28 @@
ata_wait_idle(ap);
}
+
+/**
+ * ata_tf_load - send taskfile registers to host controller
+ * @ap: Port to which output is sent
+ * @tf: ATA taskfile register set
+ *
+ * Outputs ATA taskfile to standard ATA host controller using MMIO
+ * or PIO as indicated by the ATA_FLAG_MMIO flag.
+ * Writes the control, feature, nsect, lbal, lbam, and lbah registers.
+ * Optionally (ATA_TFLAG_LBA48) writes hob_feature, hob_nsect,
+ * hob_lbal, hob_lbam, and hob_lbah.
+ *
+ * This function waits for idle (!BUSY and !DRQ) after writing
+ * registers. If the control register has a new value, this
+ * function also waits for idle after writing control and before
+ * writing the remaining registers.
+ *
+ * May be used as the tf_load() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
void ata_tf_load(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -195,11 +217,11 @@
}
/**
- * ata_exec_command - issue ATA command to host controller
+ * ata_exec_command_pio - issue ATA command to host controller
* @ap: port to which command is being issued
* @tf: ATA taskfile register set
*
- * Issues PIO/MMIO write to ATA command register, with proper
+ * Issues PIO write to ATA command register, with proper
* synchronization with interrupt handler / other threads.
*
* LOCKING:
@@ -235,6 +257,18 @@
ata_pause(ap);
}
+
+/**
+ * ata_exec_command - issue ATA command to host controller
+ * @ap: port to which command is being issued
+ * @tf: ATA taskfile register set
+ *
+ * Issues PIO/MMIO write to ATA command register, with proper
+ * synchronization with interrupt handler / other threads.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_exec_command(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -305,7 +339,7 @@
}
/**
- * ata_tf_read - input device's ATA taskfile shadow registers
+ * ata_tf_read_pio - input device's ATA taskfile shadow registers
* @ap: Port from which input is read
* @tf: ATA taskfile register set for storing input
*
@@ -368,6 +402,23 @@
}
}
+
+/**
+ * ata_tf_read - input device's ATA taskfile shadow registers
+ * @ap: Port from which input is read
+ * @tf: ATA taskfile register set for storing input
+ *
+ * Reads ATA taskfile registers for currently-selected device
+ * into @tf.
+ *
+ * Reads nsect, lbal, lbam, lbah, and device. If ATA_TFLAG_LBA48
+ * is set, also reads the hob registers.
+ *
+ * May be used as the tf_read() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
void ata_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -381,7 +432,7 @@
* @ap: port where the device is
*
* Reads ATA taskfile status register for currently-selected device
- * and return it's value. This also clears pending interrupts
+ * and return its value. This also clears pending interrupts
* from this device
*
* LOCKING:
@@ -397,7 +448,7 @@
* @ap: port where the device is
*
* Reads ATA taskfile status register for currently-selected device
- * via MMIO and return it's value. This also clears pending interrupts
+ * via MMIO and return its value. This also clears pending interrupts
* from this device
*
* LOCKING:
@@ -408,6 +459,20 @@
return readb((void __iomem *) ap->ioaddr.status_addr);
}
+
+/**
+ * ata_check_status - Read device status reg & clear interrupt
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile status register for currently-selected device
+ * and return its value. This also clears pending interrupts
+ * from this device
+ *
+ * May be used as the check_status() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_check_status(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO)
@@ -415,6 +480,20 @@
return ata_check_status_pio(ap);
}
+
+/**
+ * ata_altstatus - Read device alternate status reg
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile alternate status register for
+ * currently-selected device and return its value.
+ *
+ * Note: may NOT be used as the check_altstatus() entry in
+ * ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_altstatus(struct ata_port *ap)
{
if (ap->ops->check_altstatus)
@@ -425,6 +504,20 @@
return inb(ap->ioaddr.altstatus_addr);
}
+
+/**
+ * ata_chk_err - Read device error reg
+ * @ap: port where the device is
+ *
+ * Reads ATA taskfile error register for
+ * currently-selected device and return its value.
+ *
+ * Note: may NOT be used as the check_err() entry in
+ * ata_port_operations.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
u8 ata_chk_err(struct ata_port *ap)
{
if (ap->ops->check_err)
@@ -873,10 +966,24 @@
}
}
+
+/**
+ * ata_noop_dev_select - Select device 0/1 on ATA bus
+ * @ap: ATA channel to manipulate
+ * @device: ATA device (numbered from zero) to select
+ *
+ * This function performs no actual function.
+ *
+ * May be used as the dev_select() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * caller.
+ */
void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
{
}
+
/**
* ata_std_dev_select - Select device 0/1 on ATA bus
* @ap: ATA channel to manipulate
@@ -884,7 +991,9 @@
*
* Use the method defined in the ATA specification to
* make either device 0, or device 1, active on the
- * ATA channel.
+ * ATA channel. Works with both PIO and MMIO.
+ *
+ * May be used as the dev_select() entry in ata_port_operations.
*
* LOCKING:
* caller.
@@ -1190,7 +1299,12 @@
* 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 +1343,14 @@
}
/**
- * 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)
@@ -1241,10 +1359,15 @@
}
/**
- * __sata_phy_reset -
- * @ap:
+ * __sata_phy_reset - Wake/reset a low-level SATA PHY
+ * @ap: SATA port associated with target SATA PHY.
+ *
+ * This function issues commands to standard SATA Sxxx
+ * PHY registers, to wake up the phy (and device), and
+ * clear any reset condition.
*
* LOCKING:
+ * PCI/etc. bus probe sem.
*
*/
void __sata_phy_reset(struct ata_port *ap)
@@ -1289,10 +1412,14 @@
}
/**
- * __sata_phy_reset -
- * @ap:
+ * sata_phy_reset - Reset SATA bus.
+ * @ap: SATA port associated with target SATA PHY.
+ *
+ * This function resets the SATA bus, and then probes
+ * the bus for devices.
*
* LOCKING:
+ * PCI/etc. bus probe sem.
*
*/
void sata_phy_reset(struct ata_port *ap)
@@ -1304,10 +1431,16 @@
}
/**
- * ata_port_disable -
- * @ap:
+ * ata_port_disable - Disable port.
+ * @ap: Port to be disabled.
*
- * LOCKING:
+ * Modify @ap data structure such that the system
+ * thinks that the entire port is disabled, and should
+ * never attempt to probe or communicate with devices
+ * on this port.
+ *
+ * LOCKING: host_set lock, or some other form of
+ * serialization.
*/
void ata_port_disable(struct ata_port *ap)
@@ -1416,7 +1549,10 @@
* ata_set_mode - Program timings and issue SET FEATURES - XFER
* @ap: port on which timings will be programmed
*
+ * Set ATA device disk transfer mode (PIO3, UDMA6, etc.).
+ *
* LOCKING:
+ * PCI/etc. bus probe sem.
*
*/
static void ata_set_mode(struct ata_port *ap)
@@ -1467,7 +1603,10 @@
* @tmout_pat: impatience timeout
* @tmout: overall timeout
*
- * LOCKING:
+ * Sleep until ATA Status register bit BSY clears,
+ * or a timeout occurs.
+ *
+ * LOCKING: None.
*
*/
@@ -1553,10 +1692,14 @@
}
/**
- * 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:
+ * PCI/etc. bus probe sem.
*
*/
@@ -1633,8 +1776,8 @@
* 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.
@@ -1876,7 +2019,11 @@
* @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.
@@ -1909,7 +2056,11 @@
* @ap: Port associated with device @dev
* @dev: Device to which command will be sent
*
+ * Issue SET FEATURES - XFER MODE command to device @dev
+ * on port @ap.
+ *
* LOCKING:
+ * PCI/etc. bus probe sem.
*/
static void ata_dev_set_xfermode(struct ata_port *ap, struct ata_device *dev)
@@ -1947,10 +2098,13 @@
}
/**
- * 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)
@@ -1981,7 +2135,11 @@
* ata_fill_sg - Fill PCI IDE PRD table
* @qc: Metadata associated with taskfile to be transferred
*
+ * Fill PCI IDE PRD (scatter-gather) table with segments
+ * associated with the current disk command.
+ *
* LOCKING:
+ * spin_lock_irqsave(host_set lock)
*
*/
static void ata_fill_sg(struct ata_queued_cmd *qc)
@@ -2028,7 +2186,13 @@
* ata_check_atapi_dma - Check whether ATAPI DMA can be supported
* @qc: Metadata associated with taskfile to check
*
+ * 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.
+ *
* LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ *
* RETURNS: 0 when ATAPI DMA can be used
* nonzero otherwise
*/
@@ -2046,6 +2210,8 @@
* ata_qc_prep - Prepare taskfile for submission
* @qc: Metadata associated with taskfile to be prepared
*
+ * Prepare ATA taskfile for submission.
+ *
* LOCKING:
* spin_lock_irqsave(host_set lock)
*/
@@ -2057,6 +2223,32 @@
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)
+ */
+
+
+
+/**
+ * ata_sg_init_one - Prepare a one-entry scatter-gather list.
+ * @qc: Queued command
+ * @buf: transfer buffer
+ * @buflen: length of buf
+ *
+ * Builds a single-entry scatter-gather list to initiate a
+ * transfer utilizing the specified buffer.
+ *
+ * LOCKING:
+ */
void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
{
struct scatterlist *sg;
@@ -2074,6 +2266,32 @@
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)
+ */
+
+
+/**
+ * ata_sg_init - Assign a scatter gather list to a queued command
+ * @qc: Queued command
+ * @sg: Scatter-gather list
+ * @n_elem: length of sg list
+ *
+ * Attaches a scatter-gather list to a queued command.
+ *
+ * LOCKING:
+ */
+
void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
unsigned int n_elem)
{
@@ -2083,14 +2301,16 @@
}
/**
- * 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)
@@ -2115,13 +2335,16 @@
}
/**
- * 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.
*
*/
@@ -2151,6 +2374,7 @@
* @ap:
*
* LOCKING:
+ * None. (executing in kernel thread context)
*
* RETURNS:
*
@@ -2198,6 +2422,7 @@
* @ap:
*
* LOCKING:
+ * None. (executing in kernel thread context)
*/
static void ata_pio_complete (struct ata_port *ap)
@@ -2240,6 +2465,18 @@
ata_qc_complete(qc, drv_stat);
}
+
+/**
+ * swap_buf_le16 -
+ * @buf: Buffer to swap
+ * @buf_words: Number of 16-bit words in buffer.
+ *
+ * Swap halves of 16-bit words if needed to convert from
+ * little-endian byte order to native cpu byte order, or
+ * vice-versa.
+ *
+ * LOCKING:
+ */
void swap_buf_le16(u16 *buf, unsigned int buf_words)
{
#ifdef __BIG_ENDIAN
@@ -2415,6 +2652,7 @@
* @ap:
*
* LOCKING:
+ * None. (executing in kernel thread context)
*/
static void ata_pio_block(struct ata_port *ap)
@@ -2583,6 +2821,7 @@
* transaction completed successfully.
*
* LOCKING:
+ * Inherited from SCSI layer (none, can sleep)
*/
static void ata_qc_timeout(struct ata_queued_cmd *qc)
@@ -2692,6 +2931,7 @@
* @dev: Device from whom we request an available command structure
*
* LOCKING:
+ * None.
*/
static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
@@ -2717,6 +2957,7 @@
* @dev: Device from whom we request an available command structure
*
* LOCKING:
+ * None.
*/
struct ata_queued_cmd *ata_qc_new_init(struct ata_port *ap,
@@ -2781,6 +3022,7 @@
* in case something prevents using it.
*
* LOCKING:
+ * spin_lock_irqsave(host_set lock)
*
*/
void ata_qc_free(struct ata_queued_cmd *qc)
@@ -2794,9 +3036,13 @@
/**
* 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)
*
*/
@@ -2892,6 +3138,7 @@
return -1;
}
+
/**
* ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
* @qc: command to issue to device
@@ -2901,6 +3148,8 @@
* classes called "protocols", and issuing each type of protocol
* is slightly different.
*
+ * May be used as the qc_issue() entry in ata_port_operations.
+ *
* LOCKING:
* spin_lock_irqsave(host_set lock)
*
@@ -2958,7 +3207,7 @@
}
/**
- * ata_bmdma_setup - Set up PCI IDE BMDMA transaction
+ * ata_bmdma_setup_mmio - Set up PCI IDE BMDMA transaction
* @qc: Info associated with this ATA transaction.
*
* LOCKING:
@@ -3065,6 +3314,18 @@
ap->ioaddr.bmdma_addr + ATA_DMA_CMD);
}
+
+/**
+ * ata_bmdma_start - Start a PCI IDE BMDMA transaction
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Writes the ATA_DMA_START flag to the DMA command register.
+ *
+ * May be used as the bmdma_start() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_bmdma_start(struct ata_queued_cmd *qc)
{
if (qc->ap->flags & ATA_FLAG_MMIO)
@@ -3073,6 +3334,20 @@
ata_bmdma_start_pio(qc);
}
+
+/**
+ * ata_bmdma_setup - Set up PCI IDE BMDMA transaction
+ * @qc: Info associated with this ATA transaction.
+ *
+ * Writes address of PRD table to device's PRD Table Address
+ * register, sets the DMA control register, and calls
+ * ops->exec_command() to start the transfer.
+ *
+ * May be used as the bmdma_setup() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
void ata_bmdma_setup(struct ata_queued_cmd *qc)
{
if (qc->ap->flags & ATA_FLAG_MMIO)
@@ -3081,6 +3356,19 @@
ata_bmdma_setup_pio(qc);
}
+
+/**
+ * ata_bmdma_irq_clear - Clear PCI IDE BMDMA interrupt.
+ * @ap: Port associated with this ATA transaction.
+ *
+ * Clear interrupt and error flags in DMA status register.
+ *
+ * May be used as the irq_clear() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
void ata_bmdma_irq_clear(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO) {
@@ -3093,6 +3381,19 @@
}
+
+/**
+ * ata_bmdma_status - Read PCI IDE BMDMA status
+ * @ap: Port associated with this ATA transaction.
+ *
+ * Read and return BMDMA status register.
+ *
+ * May be used as the bmdma_status() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
u8 ata_bmdma_status(struct ata_port *ap)
{
u8 host_stat;
@@ -3104,6 +3405,19 @@
return host_stat;
}
+
+/**
+ * ata_bmdma_stop - Stop PCI IDE BMDMA transfer
+ * @ap: Port associated with this ATA transaction.
+ *
+ * Clears the ATA_DMA_START flag in the dma control register
+ *
+ * May be used as the bmdma_stop() entry in ata_port_operations.
+ *
+ * LOCKING:
+ * spin_lock_irqsave(host_set lock)
+ */
+
void ata_bmdma_stop(struct ata_port *ap)
{
if (ap->flags & ATA_FLAG_MMIO) {
@@ -3203,13 +3517,18 @@
/**
* 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.
*
*/
@@ -3302,6 +3621,19 @@
ata_qc_complete(qc, ATA_ERR);
}
+
+/**
+ * ata_port_start - Set port up for dma.
+ * @ap: Port to initialize
+ *
+ * Called just after data structures for each port are
+ * initialized. Allocates space for PRD table.
+ *
+ * May be used as the port_start() entry in ata_port_operations.
+ *
+ * LOCKING:
+ */
+
int ata_port_start (struct ata_port *ap)
{
struct device *dev = ap->host_set->dev;
@@ -3315,6 +3647,18 @@
return 0;
}
+
+/**
+ * ata_port_stop - Undo ata_port_start()
+ * @ap: Port to shut down
+ *
+ * Frees the PRD table.
+ *
+ * May be used as the port_stop() entry in ata_port_operations.
+ *
+ * LOCKING:
+ */
+
void ata_port_stop (struct ata_port *ap)
{
struct device *dev = ap->host_set->dev;
@@ -3357,7 +3701,11 @@
* @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.
*
*/
@@ -3412,9 +3760,13 @@
* @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.
*
*/
@@ -3447,12 +3799,22 @@
}
/**
- * 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).
*
*/
@@ -3604,7 +3966,15 @@
/**
* ata_std_ports - initialize ioaddr with standard port offsets.
* @ioaddr: IO address structure to be initialized
+ *
+ * Utility function which initializes data_addr, error_addr,
+ * feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
+ * device_addr, status_addr, and command_addr to standard offsets
+ * relative to cmd_addr.
+ *
+ * Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
*/
+
void ata_std_ports(struct ata_ioports *ioaddr)
{
ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
@@ -3646,6 +4016,20 @@
return probe_ent;
}
+
+
+/**
+ * ata_pci_init_native_mode - Initialize native-mode driver
+ * @pdev: pci device to be initialized
+ * @port: array[2] of pointers to port info structures.
+ *
+ * Utility function which allocates and initializes an
+ * ata_probe_ent structure for a standard dual-port
+ * PIO-based IDE controller. The returned ata_probe_ent
+ * structure can be passed to ata_device_add(). The returned
+ * ata_probe_ent structure should then be freed with kfree().
+ */
+
#ifdef CONFIG_PCI
struct ata_probe_ent *
ata_pci_init_native_mode(struct pci_dev *pdev, struct ata_port_info **port)
@@ -3727,10 +4111,19 @@
* @port_info: Information from low-level host driver
* @n_ports: Number of ports attached to host controller
*
+ * This is a helper function which can be called from a driver's
+ * xxx_init_one() probe function if the hardware uses traditional
+ * IDE taskfile registers.
+ *
+ * This function calls pci_enable_device(), reserves its register
+ * regions, sets the dma mask, enables bus master mode, and calls
+ * ata_device_add()
+ *
* LOCKING:
* Inherited from PCI layer (may sleep).
*
* RETURNS:
+ * Zero on success, negative on errno-based value on error.
*
*/
@@ -3949,15 +4342,6 @@
#endif /* CONFIG_PCI */
-/**
- * ata_init -
- *
- * LOCKING:
- *
- * RETURNS:
- *
- */
-
static int __init ata_init(void)
{
ata_wq = create_workqueue("ata");
diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 416ba67..7a4adc4 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -947,7 +947,7 @@
}
/**
- * ata_scsiop_noop -
+ * ata_scsiop_noop - Command handler that simply returns success.
* @args: device IDENTIFY data / SCSI command of interest.
* @rbuf: Response buffer, to which simulated SCSI cmd output is sent.
* @buflen: Response buffer length.
diff --git a/include/linux/libata.h b/include/linux/libata.h
index e74f301..b009f80 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -467,12 +467,34 @@
return ap->ops->check_status(ap);
}
+
+/**
+ * ata_pause - Flush writes and pause 400 nanoseconds.
+ * @ap: Port to wait for.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
static inline void ata_pause(struct ata_port *ap)
{
ata_altstatus(ap);
ndelay(400);
}
+
+/**
+ * ata_busy_wait - Wait for a port status register
+ * @ap: Port to wait for.
+ *
+ * Waits up to max*10 microseconds for the selected bits in the port's
+ * status register to be cleared.
+ * Returns final value of status register.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
static inline u8 ata_busy_wait(struct ata_port *ap, unsigned int bits,
unsigned int max)
{
@@ -487,6 +509,18 @@
return status;
}
+
+/**
+ * ata_wait_idle - Wait for a port to be idle.
+ * @ap: Port to wait for.
+ *
+ * Waits up to 10ms for port's BUSY and DRQ signals to clear.
+ * Returns final value of status register.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
static inline u8 ata_wait_idle(struct ata_port *ap)
{
u8 status = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 1000);
@@ -525,6 +559,18 @@
tf->device = ATA_DEVICE_OBS | ATA_DEV1;
}
+
+/**
+ * ata_irq_on - Enable interrupts on a port.
+ * @ap: Port on which interrupts are enabled.
+ *
+ * Enable interrupts on a legacy IDE device using MMIO or PIO,
+ * wait for idle, clear any pending interrupts.
+ *
+ * LOCKING:
+ * Inherited from caller.
+ */
+
static inline u8 ata_irq_on(struct ata_port *ap)
{
struct ata_ioports *ioaddr = &ap->ioaddr;
@@ -544,6 +590,18 @@
return tmp;
}
+
+/**
+ * ata_irq_ack - Acknowledge a device interrupt.
+ * @ap: Port on which interrupts are enabled.
+ *
+ * Wait up to 10 ms for legacy IDE device to become idle (BUSY
+ * or BUSY+DRQ clear). Obtain dma status and port status from
+ * device. Clear the interrupt. Return port status.
+ *
+ * LOCKING:
+ */
+
static inline u8 ata_irq_ack(struct ata_port *ap, unsigned int chk_drq)
{
unsigned int bits = chk_drq ? ATA_BUSY | ATA_DRQ : ATA_BUSY;