[libata] Add ATA transport class

This is a scheleton for libata transport class.
All information is read only, exporting information from libata:
- ata_port class: one per ATA port
- ata_link class: one per ATA port or 15 for SATA Port Multiplier
- ata_device class: up to 2 for PATA link, usually one for SATA.

Signed-off-by: Gwendal Grignou <[e-mail]>
Reviewed-by: Grant Grundler <[e-mail]>
Signed-off-by: Jeff Garzik <[e-mail]>

Documentation/ABI/testing/sysfs-ata

···
+What:		/sys/class/ata_...
+Date:		August 2008
+Contact:	Gwendal Grignou<[e-mail]>
+Description:
+
+Provide a place in sysfs for storing the ATA topology of the system.  This allows
+retrieving various information about ATA objects.
+
+Files under /sys/class/ata_port
+-------------------------------
+
+	For each port, a directory ataX is created where X is the ata_port_id of
+	the port. The device parent is the ata host device.
+
+idle_irq (read)
+
+	Number of IRQ received by the port while idle [some ata HBA only].
+
+nr_pmp_links (read)
+
+	If a SATA Port Multiplier (PM) is connected, number of link behind it.
+
+Files under /sys/class/ata_link
+-------------------------------
+
+	Behind each port, there is a ata_link. If there is a SATA PM in the
+	topology, 15 ata_link objects are created.
+
+	If a link is behind a port, the directory name is linkX, where X is
+	ata_port_id of the port.
+	If a link is behind a PM, its name is linkX.Y where X is ata_port_id
+	of the parent port and Y the PM port.
+
+hw_sata_spd_limit
+
+	Maximum speed supported by the connected SATA device.
+
+sata_spd_limit
+
+	Maximum speed imposed by libata.
+
+sata_spd
+
+	Current speed of the link [1.5, 3Gps,...].
+
+Files under /sys/class/ata_device
+---------------------------------
+
+	Behind each link, up to two ata device are created.
+	The name of the directory is devX[.Y].Z where:
+	- X is ata_port_id of the port where the device is connected,
+	- Y the port of the PM if any, and
+	- Z the device id: for PATA, there is usually 2 devices [0,1],
+	only 1 for SATA.
+
+class
+	Device class. Can be "ata" for disk, "atapi" for packet device,
+	"pmp" for PM, or "none" if no device was found behind the link.
+
+dma_mode
+
+	Transfer modes supported by the device when in DMA mode.
+	Mostly used by PATA device.
+
+pio_mode
+
+	Transfer modes supported by the device when in PIO mode.
+	Mostly used by PATA device.
+
+xfer_mode
+
+	Current transfer mode.
+
+id
+
+	Cached result of IDENTIFY command, as described in ATA8 7.16 and 7.17.
+	Only valid if the device is not a PM.
+
+gscr
+
+	Cached result of the dump of PM GSCR register.
+	Valid registers are:
+	0: 	SATA_PMP_GSCR_PROD_ID,
+	1: 	SATA_PMP_GSCR_REV,
+	2: 	SATA_PMP_GSCR_PORT_INFO,
+	32:	SATA_PMP_GSCR_ERROR,
+	33:	SATA_PMP_GSCR_ERROR_EN,
+	64:	SATA_PMP_GSCR_FEAT,
+	96:	SATA_PMP_GSCR_FEAT_EN,
+	130:	SATA_PMP_GSCR_SII_GPIO
+	Only valid if the device is a PM.
+
+spdn_cnt
+
+	Number of time libata decided to lower the speed of link due to errors.
+
+ering
+
+	Formatted output of the error ring of the device.

drivers/ata/Makefile

···
 # Should be last libata driver
 obj-$(CONFIG_PATA_LEGACY)	+= pata_legacy.o
 
-libata-objs	:= libata-core.o libata-scsi.o libata-eh.o
+libata-objs	:= libata-core.o libata-scsi.o libata-eh.o libata-transport.o
 libata-$(CONFIG_ATA_SFF)	+= libata-sff.o
 libata-$(CONFIG_SATA_PMP)	+= libata-pmp.o
 libata-$(CONFIG_ATA_ACPI)	+= libata-acpi.o

drivers/ata/libata-core.c

···
 #include <linux/ratelimit.h>
 
 #include "libata.h"
-
+#include "libata-transport.h"
 
 /* debounce timing parameters in msecs { interval, duration, timeout } */
 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
···
 	return "<n/a>";
 }
 
-static const char *sata_spd_string(unsigned int spd)
+const char *sata_spd_string(unsigned int spd)
 {
 	static const char * const spd_str[] = {
 		"1.5 Gbps",
···
 	int i;
 
 	/* clear everything except for devices */
-	memset(link, 0, offsetof(struct ata_link, device[0]));
+	memset((void *)link + ATA_LINK_CLEAR_BEGIN, 0,
+	       ATA_LINK_CLEAR_END - ATA_LINK_CLEAR_BEGIN);
 
 	link->ap = ap;
 	link->pmp = pmp;
···
 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
 	if (!ap)
 		return NULL;
-
+	
 	ap->pflags |= ATA_PFLAG_INITIALIZING;
 	ap->lock = &host->lock;
 	ap->print_id = -1;
···
 	for (i = 0; i < host->n_ports; i++)
 		host->ports[i]->print_id = ata_print_id++;
 
+	
+	/* Create associated sysfs transport objects  */
+	for (i = 0; i < host->n_ports; i++) {
+		rc = ata_tport_add(host->dev,host->ports[i]);
+		if (rc) {
+			goto err_tadd;
+		}
+	}
+
 	rc = ata_scsi_add_hosts(host, sht);
 	if (rc)
-		return rc;
+		goto err_tadd;
 
 	/* associate with ACPI nodes */
 	ata_acpi_associate(host);
···
 	}
 
 	return 0;
+
+ err_tadd:
+	while (--i >= 0) {
+		ata_tport_delete(host->ports[i]);
+	}
+	return rc;
+
 }
 
 /**
···
 	cancel_rearming_delayed_work(&ap->hotplug_task);
 
  skip_eh:
+	if (ap->pmp_link) {
+		int i;
+		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
+			ata_tlink_delete(&ap->pmp_link[i]);
+	}
+	ata_tport_delete(ap);
+
 	/* remove the associated SCSI host */
 	scsi_remove_host(ap->scsi_host);
 }
···
 
 static int __init ata_init(void)
 {
-	int rc = -ENOMEM;
+	int rc;
 
 	ata_parse_force_param();
 
···
 		return rc;
 	}
 
+	libata_transport_init();
+	ata_scsi_transport_template = ata_attach_transport();
+	if (!ata_scsi_transport_template) {
+		ata_sff_exit();
+		rc = -ENOMEM;
+		goto err_out;
+	}		
+
 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
 	return 0;
+
+err_out:
+	return rc;
 }
 
 static void __exit ata_exit(void)
 {
+	ata_release_transport(ata_scsi_transport_template);
+	libata_transport_exit();
 	ata_sff_exit();
 	kfree(ata_force_tbl);
 }

drivers/ata/libata-eh.c

···
 	/* error flags */
 	ATA_EFLAG_IS_IO			= (1 << 0),
 	ATA_EFLAG_DUBIOUS_XFER		= (1 << 1),
+	ATA_EFLAG_OLD_ER                = (1 << 31),
 
 	/* error categories */
 	ATA_ECAT_NONE			= 0,
···
 	return NULL;
 }
 
-static void ata_ering_clear(struct ata_ering *ering)
-{
-	memset(ering, 0, sizeof(*ering));
-}
-
-static int ata_ering_map(struct ata_ering *ering,
-			 int (*map_fn)(struct ata_ering_entry *, void *),
-			 void *arg)
+int ata_ering_map(struct ata_ering *ering,
+		  int (*map_fn)(struct ata_ering_entry *, void *),
+		  void *arg)
 {
 	int idx, rc = 0;
 	struct ata_ering_entry *ent;
···
 	} while (idx != ering->cursor);
 
 	return rc;
+}
+
+int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
+{
+	ent->eflags |= ATA_EFLAG_OLD_ER;
+	return 0;
+}
+
+static void ata_ering_clear(struct ata_ering *ering)
+{
+	ata_ering_map(ering, ata_ering_clear_cb, NULL);
 }
 
 static unsigned int ata_eh_dev_action(struct ata_device *dev)
···
 		int nr_timedout = 0;
 
 		spin_lock_irqsave(ap->lock, flags);
-		
+
 		/* This must occur under the ap->lock as we don't want
 		   a polled recovery to race the real interrupt handler
-		   
+
 		   The lost_interrupt handler checks for any completed but
 		   non-notified command and completes much like an IRQ handler.
-		   
+
 		   We then fall into the error recovery code which will treat
 		   this as if normal completion won the race */
 
 		if (ap->ops->lost_interrupt)
 			ap->ops->lost_interrupt(ap);
-			
+
 		list_for_each_entry_safe(scmd, tmp, &host->eh_cmd_q, eh_entry) {
 			struct ata_queued_cmd *qc;
 
···
 		ap->eh_tries = ATA_EH_MAX_TRIES;
 	} else
 		spin_unlock_wait(ap->lock);
-		
+
 	/* If we timed raced normal completion and there is nothing to
 	   recover nr_timedout == 0 why exactly are we doing error recovery ? */
 
···
 	struct speed_down_verdict_arg *arg = void_arg;
 	int cat;
 
-	if (ent->timestamp < arg->since)
+	if ((ent->eflags & ATA_EFLAG_OLD_ER) || (ent->timestamp < arg->since))
 		return -1;
 
 	cat = ata_eh_categorize_error(ent->eflags, ent->err_mask,

drivers/ata/libata-pmp.c

···
 #include <linux/libata.h>
 #include <linux/slab.h>
 #include "libata.h"
+#include "libata-transport.h"
 
 const struct ata_port_operations sata_pmp_port_ops = {
 	.inherits		= &sata_port_ops,
···
 	return rc;
 }
 
-static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
+static int sata_pmp_init_links (struct ata_port *ap, int nr_ports)
 {
 	struct ata_link *pmp_link = ap->pmp_link;
-	int i;
+	int i, err;
 
 	if (!pmp_link) {
 		pmp_link = kzalloc(sizeof(pmp_link[0]) * SATA_PMP_MAX_PORTS,
···
 			ata_link_init(ap, &pmp_link[i], i);
 
 		ap->pmp_link = pmp_link;
+
+		for (i = 0; i < SATA_PMP_MAX_PORTS; i++) {
+			err = ata_tlink_add(&pmp_link[i]);
+			if (err) {
+				goto err_tlink;
+			}
+		}
 	}
 
 	for (i = 0; i < nr_ports; i++) {
···
 	}
 
 	return 0;
+  err_tlink:
+	while (--i >= 0)
+		ata_tlink_delete(&pmp_link[i]);
+	kfree(pmp_link);
+	ap->pmp_link = NULL;
+	return err;
 }
 
 static void sata_pmp_quirks(struct ata_port *ap)

drivers/ata/libata-scsi.c

···
 #include <asm/unaligned.h>
 
 #include "libata.h"
+#include "libata-transport.h"
 
 #define SECTOR_SIZE		512
 #define ATA_SCSI_RBUF_SIZE	4096
···
 					const struct scsi_device *scsidev);
 static struct ata_device *ata_scsi_find_dev(struct ata_port *ap,
 					    const struct scsi_device *scsidev);
-static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
-			      unsigned int id, unsigned int lun);
-
 
 #define RW_RECOVERY_MPAGE 0x1
 #define RW_RECOVERY_MPAGE_LEN 12
···
 	0, 0, 0, 0, 0xff, 0xff,
 	0, 30	/* extended self test time, see 05-359r1 */
 };
-
-/*
- * libata transport template.  libata doesn't do real transport stuff.
- * It just needs the eh_timed_out hook.
- */
-static struct scsi_transport_template ata_scsi_transport_template = {
-	.eh_strategy_handler	= ata_scsi_error,
-	.eh_timed_out		= ata_scsi_timed_out,
-	.user_scan		= ata_scsi_user_scan,
-};
-
 
 static const struct {
 	enum link_pm	value;
···
 		*(struct ata_port **)&shost->hostdata[0] = ap;
 		ap->scsi_host = shost;
 
-		shost->transportt = &ata_scsi_transport_template;
+		shost->transportt = ata_scsi_transport_template;
 		shost->unique_id = ap->print_id;
 		shost->max_id = 16;
 		shost->max_lun = 1;
···
  *	RETURNS:
  *	Zero.
  */
-static int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
-			      unsigned int id, unsigned int lun)
+int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
+		       unsigned int id, unsigned int lun)
 {
 	struct ata_port *ap = ata_shost_to_port(shost);
 	unsigned long flags;

drivers/ata/libata-transport.c

···
+/*
+ *  Copyright 2008 ioogle, Inc.  All rights reserved.
+ *	Released under GPL v2.
+ *
+ * Libata transport class.
+ *
+ * The ATA transport class contains common code to deal with ATA HBAs,
+ * an approximated representation of ATA topologies in the driver model,
+ * and various sysfs attributes to expose these topologies and management
+ * interfaces to user-space.
+ *
+ * There are 3 objects defined in in this class:
+ * - ata_port
+ * - ata_link
+ * - ata_device
+ * Each port has a link object. Each link can have up to two devices for PATA
+ * and generally one for SATA.
+ * If there is SATA port multiplier [PMP], 15 additional ata_link object are
+ * created.
+ *
+ * These objects are created when the ata host is initialized and when a PMP is
+ * found. They are removed only when the HBA is removed, cleaned before the
+ * error handler runs.
+ */
+
+
+#include <linux/kernel.h>
+#include <linux/blkdev.h>
+#include <linux/spinlock.h>
+#include <scsi/scsi_transport.h>
+#include <linux/libata.h>
+#include <linux/hdreg.h>
+#include <linux/uaccess.h>
+
+#include "libata.h"
+#include "libata-transport.h"
+
+#define ATA_PORT_ATTRS		2
+#define ATA_LINK_ATTRS		3
+#define ATA_DEV_ATTRS		9
+
+struct scsi_transport_template;
+struct scsi_transport_template *ata_scsi_transport_template;
+
+struct ata_internal {
+	struct scsi_transport_template t;
+
+	struct device_attribute private_port_attrs[ATA_PORT_ATTRS];
+	struct device_attribute private_link_attrs[ATA_LINK_ATTRS];
+	struct device_attribute private_dev_attrs[ATA_DEV_ATTRS];
+
+	struct transport_container link_attr_cont;
+	struct transport_container dev_attr_cont;
+
+	/*
+	 * The array of null terminated pointers to attributes
+	 * needed by scsi_sysfs.c
+	 */
+	struct device_attribute *link_attrs[ATA_LINK_ATTRS + 1];
+	struct device_attribute *port_attrs[ATA_PORT_ATTRS + 1];
+	struct device_attribute *dev_attrs[ATA_DEV_ATTRS + 1];
+};
+#define to_ata_internal(tmpl)	container_of(tmpl, struct ata_internal, t)
+
+
+#define tdev_to_device(d)					\
+	container_of((d), struct ata_device, tdev)
+#define transport_class_to_dev(dev)				\
+	tdev_to_device((dev)->parent)
+
+#define tdev_to_link(d)						\
+	container_of((d), struct ata_link, tdev)
+#define transport_class_to_link(dev)				\
+	tdev_to_link((dev)->parent)
+
+#define tdev_to_port(d)						\
+	container_of((d), struct ata_port, tdev)
+#define transport_class_to_port(dev)				\
+	tdev_to_port((dev)->parent)
+
+
+/* Device objects are always created whit link objects */
+static int ata_tdev_add(struct ata_device *dev);
+static void ata_tdev_delete(struct ata_device *dev);
+
+
+/*
+ * Hack to allow attributes of the same name in different objects.
+ */
+#define ATA_DEVICE_ATTR(_prefix,_name,_mode,_show,_store) \
+	struct device_attribute device_attr_##_prefix##_##_name = \
+	__ATTR(_name,_mode,_show,_store)
+
+#define ata_bitfield_name_match(title, table)			\
+static ssize_t							\
+get_ata_##title##_names(u32 table_key, char *buf)		\
+{								\
+	char *prefix = "";					\
+	ssize_t len = 0;					\
+	int i;							\
+								\
+	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
+		if (table[i].value & table_key) {		\
+			len += sprintf(buf + len, "%s%s",	\
+				prefix, table[i].name);		\
+			prefix = ", ";				\
+		}						\
+	}							\
+	len += sprintf(buf + len, "\n");			\
+	return len;						\
+}
+
+#define ata_bitfield_name_search(title, table)			\
+static ssize_t							\
+get_ata_##title##_names(u32 table_key, char *buf)		\
+{								\
+	ssize_t len = 0;					\
+	int i;							\
+								\
+	for (i = 0; i < ARRAY_SIZE(table); i++) {		\
+		if (table[i].value == table_key) {		\
+			len += sprintf(buf + len, "%s",		\
+				table[i].name);			\
+			break;					\
+		}						\
+	}							\
+	len += sprintf(buf + len, "\n");			\
+	return len;						\
+}
+
+static struct {
+	u32		value;
+	char		*name;
+} ata_class_names[] = {
+	{ ATA_DEV_UNKNOWN,		"unknown" },
+	{ ATA_DEV_ATA,			"ata" },
+	{ ATA_DEV_ATA_UNSUP,		"ata" },
+	{ ATA_DEV_ATAPI,		"atapi" },
+	{ ATA_DEV_ATAPI_UNSUP,		"atapi" },
+	{ ATA_DEV_PMP,			"pmp" },
+	{ ATA_DEV_PMP_UNSUP,		"pmp" },
+	{ ATA_DEV_SEMB,			"semb" },
+	{ ATA_DEV_SEMB_UNSUP,		"semb" },
+	{ ATA_DEV_NONE,			"none" }
+};
+ata_bitfield_name_search(class, ata_class_names)
+
+
+static struct {
+	u32		value;
+	char		*name;
+} ata_err_names[] = {
+	{ AC_ERR_DEV,			"DeviceError" },
+	{ AC_ERR_HSM,			"HostStateMachineError" },
+	{ AC_ERR_TIMEOUT,		"Timeout" },
+	{ AC_ERR_MEDIA,			"MediaError" },
+	{ AC_ERR_ATA_BUS,		"BusError" },
+	{ AC_ERR_HOST_BUS,		"HostBusError" },
+	{ AC_ERR_SYSTEM,		"SystemError" },
+	{ AC_ERR_INVALID,		"InvalidArg" },
+	{ AC_ERR_OTHER,			"Unknown" },
+	{ AC_ERR_NODEV_HINT,		"NoDeviceHint" },
+	{ AC_ERR_NCQ,		 	"NCQError" }
+};
+ata_bitfield_name_match(err, ata_err_names)
+
+static struct {
+	u32		value;
+	char		*name;
+} ata_xfer_names[] = {
+	{ XFER_UDMA_7,			"XFER_UDMA_7" },
+	{ XFER_UDMA_6,			"XFER_UDMA_6" },
+	{ XFER_UDMA_5,			"XFER_UDMA_5" },
+	{ XFER_UDMA_4,			"XFER_UDMA_4" },
+	{ XFER_UDMA_3,			"XFER_UDMA_3" },
+	{ XFER_UDMA_2,			"XFER_UDMA_2" },
+	{ XFER_UDMA_1,			"XFER_UDMA_1" },
+	{ XFER_UDMA_0,			"XFER_UDMA_0" },
+	{ XFER_MW_DMA_4,		"XFER_MW_DMA_4" },
+	{ XFER_MW_DMA_3,		"XFER_MW_DMA_3" },
+	{ XFER_MW_DMA_2,		"XFER_MW_DMA_2" },
+	{ XFER_MW_DMA_1,		"XFER_MW_DMA_1" },
+	{ XFER_MW_DMA_0,		"XFER_MW_DMA_0" },
+	{ XFER_SW_DMA_2,		"XFER_SW_DMA_2" },
+	{ XFER_SW_DMA_1,		"XFER_SW_DMA_1" },
+	{ XFER_SW_DMA_0,		"XFER_SW_DMA_0" },
+	{ XFER_PIO_6,			"XFER_PIO_6" },
+	{ XFER_PIO_5,			"XFER_PIO_5" },
+	{ XFER_PIO_4,			"XFER_PIO_4" },
+	{ XFER_PIO_3,			"XFER_PIO_3" },
+	{ XFER_PIO_2,			"XFER_PIO_2" },
+	{ XFER_PIO_1,			"XFER_PIO_1" },
+	{ XFER_PIO_0,			"XFER_PIO_0" },
+	{ XFER_PIO_SLOW,		"XFER_PIO_SLOW" }
+};
+ata_bitfield_name_match(xfer,ata_xfer_names)
+
+/*
+ * ATA Port attributes
+ */
+#define ata_port_show_simple(field, name, format_string, cast)		\
+static ssize_t								\
+show_ata_port_##name(struct device *dev,				\
+		     struct device_attribute *attr, char *buf)		\
+{									\
+	struct ata_port *ap = transport_class_to_port(dev);		\
+									\
+	return snprintf(buf, 20, format_string, cast ap->field);	\
+}
+
+#define ata_port_simple_attr(field, name, format_string, type)		\
+	ata_port_show_simple(field, name, format_string, (type))	\
+static DEVICE_ATTR(name, S_IRUGO, show_ata_port_##name, NULL)
+
+ata_port_simple_attr(nr_pmp_links, nr_pmp_links, "%d\n", int);
+ata_port_simple_attr(stats.idle_irq, idle_irq, "%ld\n", unsigned long);
+
+static DECLARE_TRANSPORT_CLASS(ata_port_class,
+			       "ata_port", NULL, NULL, NULL);
+
+static void ata_tport_release(struct device *dev)
+{
+	put_device(dev->parent);
+}
+
+/**
+ * ata_is_port --  check if a struct device represents a ATA port
+ * @dev:	device to check
+ *
+ * Returns:
+ *	%1 if the device represents a ATA Port, %0 else
+ */
+int ata_is_port(const struct device *dev)
+{
+	return dev->release == ata_tport_release;
+}
+
+static int ata_tport_match(struct attribute_container *cont,
+			   struct device *dev)
+{
+	if (!ata_is_port(dev))
+		return 0;
+	return &ata_scsi_transport_template->host_attrs.ac == cont;
+}
+
+/**
+ * ata_tport_delete  --  remove ATA PORT
+ * @port:	ATA PORT to remove
+ *
+ * Removes the specified ATA PORT.  Remove the associated link as well.
+ */
+void ata_tport_delete(struct ata_port *ap)
+{
+	struct device *dev = &ap->tdev;
+
+	ata_tlink_delete(&ap->link);
+
+	transport_remove_device(dev);
+	device_del(dev);
+	transport_destroy_device(dev);
+	put_device(dev);
+}
+
+/** ata_tport_add - initialize a transport ATA port structure
+ *
+ * @parent:	parent device
+ * @ap:		existing ata_port structure
+ *
+ * Initialize a ATA port structure for sysfs.  It will be added to the device
+ * tree below the device specified by @parent which could be a PCI device.
+ *
+ * Returns %0 on success
+ */
+int ata_tport_add(struct device *parent,
+		  struct ata_port *ap)
+{
+	int error;
+	struct device *dev = &ap->tdev;
+
+	device_initialize(dev);
+
+	dev->parent = get_device(parent);
+	dev->release = ata_tport_release;
+	dev_set_name(dev, "ata%d", ap->print_id);
+	transport_setup_device(dev);
+	error = device_add(dev);
+	if (error) {
+		goto tport_err;
+	}
+
+	transport_add_device(dev);
+	transport_configure_device(dev);
+
+	error = ata_tlink_add(&ap->link);
+	if (error) {
+		goto tport_link_err;
+	}
+	return 0;
+
+ tport_link_err:
+	transport_remove_device(dev);
+	device_del(dev);
+
+ tport_err:
+	transport_destroy_device(dev);
+	put_device(dev);
+	return error;
+}
+
+
+/*
+ * ATA link attributes
+ */
+
+
+#define ata_link_show_linkspeed(field)					\
+static ssize_t								\
+show_ata_link_##field(struct device *dev,				\
+		      struct device_attribute *attr, char *buf)		\
+{									\
+	struct ata_link *link = transport_class_to_link(dev);		\
+									\
+	return sprintf(buf,"%s\n", sata_spd_string(fls(link->field)));	\
+}
+
+#define ata_link_linkspeed_attr(field)					\
+	ata_link_show_linkspeed(field)					\
+static DEVICE_ATTR(field, S_IRUGO, show_ata_link_##field, NULL)
+
+ata_link_linkspeed_attr(hw_sata_spd_limit);
+ata_link_linkspeed_attr(sata_spd_limit);
+ata_link_linkspeed_attr(sata_spd);
+
+
+static DECLARE_TRANSPORT_CLASS(ata_link_class,
+		"ata_link", NULL, NULL, NULL);
+
+static void ata_tlink_release(struct device *dev)
+{
+	put_device(dev->parent);
+}
+
+/**
+ * ata_is_link --  check if a struct device represents a ATA link
+ * @dev:	device to check
+ *
+ * Returns:
+ *	%1 if the device represents a ATA link, %0 else
+ */
+int ata_is_link(const struct device *dev)
+{
+	return dev->release == ata_tlink_release;
+}
+
+static int ata_tlink_match(struct attribute_container *cont,
+			   struct device *dev)
+{
+	struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
+	if (!ata_is_link(dev))
+		return 0;
+	return &i->link_attr_cont.ac == cont;
+}
+
+/**
+ * ata_tlink_delete  --  remove ATA LINK
+ * @port:	ATA LINK to remove
+ *
+ * Removes the specified ATA LINK.  remove associated ATA device(s) as well.
+ */
+void ata_tlink_delete(struct ata_link *link)
+{
+	struct device *dev = &link->tdev;
+	struct ata_device *ata_dev;
+
+	ata_for_each_dev(ata_dev, link, ALL) {
+		ata_tdev_delete(ata_dev);
+	}
+
+	transport_remove_device(dev);
+	device_del(dev);
+	transport_destroy_device(dev);
+	put_device(dev);
+}
+
+/**
+ * ata_tlink_add  --  initialize a transport ATA link structure
+ * @link:	allocated ata_link structure.
+ *
+ * Initialize an ATA LINK structure for sysfs.  It will be added in the
+ * device tree below the ATA PORT it belongs to.
+ *
+ * Returns %0 on success
+ */
+int ata_tlink_add(struct ata_link *link)
+{
+	struct device *dev = &link->tdev;
+	struct ata_port *ap = link->ap;
+	struct ata_device *ata_dev;
+	int error;
+
+	device_initialize(dev);
+	dev->parent = get_device(&ap->tdev);
+	dev->release = ata_tlink_release;
+	if (ata_is_host_link(link))
+		dev_set_name(dev, "link%d", ap->print_id);
+        else
+		dev_set_name(dev, "link%d.%d", ap->print_id, link->pmp);
+
+	transport_setup_device(dev);
+
+	error = device_add(dev);
+	if (error) {
+		goto tlink_err;
+	}
+
+	transport_add_device(dev);
+	transport_configure_device(dev);
+
+	ata_for_each_dev(ata_dev, link, ALL) {
+		error = ata_tdev_add(ata_dev);
+		if (error) {
+			goto tlink_dev_err;
+		}
+	}
+	return 0;
+  tlink_dev_err:
+	while (--ata_dev >= link->device) {
+		ata_tdev_delete(ata_dev);
+	}
+	transport_remove_device(dev);
+	device_del(dev);
+  tlink_err:
+	transport_destroy_device(dev);
+	put_device(dev);
+	return error;
+}
+
+/*
+ * ATA device attributes
+ */
+
+#define ata_dev_show_class(title, field)				\
+static ssize_t								\
+show_ata_dev_##field(struct device *dev,				\
+		     struct device_attribute *attr, char *buf)		\
+{									\
+	struct ata_device *ata_dev = transport_class_to_dev(dev);	\
+									\
+	return get_ata_##title##_names(ata_dev->field, buf);		\
+}
+
+#define ata_dev_attr(title, field)					\
+	ata_dev_show_class(title, field)				\
+static DEVICE_ATTR(field, S_IRUGO, show_ata_dev_##field, NULL)
+
+ata_dev_attr(class, class);
+ata_dev_attr(xfer, pio_mode);
+ata_dev_attr(xfer, dma_mode);
+ata_dev_attr(xfer, xfer_mode);
+
+
+#define ata_dev_show_simple(field, format_string, cast)		\
+static ssize_t								\
+show_ata_dev_##field(struct device *dev,				\
+		     struct device_attribute *attr, char *buf)		\
+{									\
+	struct ata_device *ata_dev = transport_class_to_dev(dev);	\
+									\
+	return snprintf(buf, 20, format_string, cast ata_dev->field);	\
+}
+
+#define ata_dev_simple_attr(field, format_string, type)	\
+	ata_dev_show_simple(field, format_string, (type))	\
+static DEVICE_ATTR(field, S_IRUGO, 			\
+		   show_ata_dev_##field, NULL)
+
+ata_dev_simple_attr(spdn_cnt, "%d\n", int);
+
+struct ata_show_ering_arg {
+	char* buf;
+	int written;
+};
+
+static int ata_show_ering(struct ata_ering_entry *ent, void *void_arg)
+{
+	struct ata_show_ering_arg* arg = void_arg;
+	struct timespec time;
+
+	jiffies_to_timespec(ent->timestamp,&time);
+	arg->written += sprintf(arg->buf + arg->written,
+			       "[%5lu.%06lu]",
+			       time.tv_sec, time.tv_nsec);
+	arg->written += get_ata_err_names(ent->err_mask,
+					  arg->buf + arg->written);
+	return 0;
+}
+
+static ssize_t
+show_ata_dev_ering(struct device *dev,
+		   struct device_attribute *attr, char *buf)
+{
+	struct ata_device *ata_dev = transport_class_to_dev(dev);
+	struct ata_show_ering_arg arg = { buf, 0 };
+
+	ata_ering_map(&ata_dev->ering, ata_show_ering, &arg);
+	return arg.written;
+}
+
+
+static DEVICE_ATTR(ering, S_IRUGO, show_ata_dev_ering, NULL);
+
+static ssize_t
+show_ata_dev_id(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct ata_device *ata_dev = transport_class_to_dev(dev);
+	int written = 0, i = 0;
+
+	if (ata_dev->class == ATA_DEV_PMP)
+		return 0;
+	for(i=0;i<ATA_ID_WORDS;i++)  {
+		written += snprintf(buf+written, 20, "%04x%c",
+				    ata_dev->id[i],
+				    ((i+1) & 7) ? ' ' : '\n');
+	}
+	return written;
+}
+
+static DEVICE_ATTR(id, S_IRUGO, show_ata_dev_id, NULL);
+
+static ssize_t
+show_ata_dev_gscr(struct device *dev,
+		  struct device_attribute *attr, char *buf)
+{
+	struct ata_device *ata_dev = transport_class_to_dev(dev);
+	int written = 0, i = 0;
+
+	if (ata_dev->class != ATA_DEV_PMP)
+		return 0;
+	for(i=0;i<SATA_PMP_GSCR_DWORDS;i++)  {
+		written += snprintf(buf+written, 20, "%08x%c",
+				    ata_dev->gscr[i],
+				    ((i+1) & 3) ? ' ' : '\n');
+	}
+	if (SATA_PMP_GSCR_DWORDS & 3)
+		buf[written-1] = '\n';
+	return written;
+}
+
+static DEVICE_ATTR(gscr, S_IRUGO, show_ata_dev_gscr, NULL);
+
+static DECLARE_TRANSPORT_CLASS(ata_dev_class,
+			       "ata_device", NULL, NULL, NULL);
+
+static void ata_tdev_release(struct device *dev)
+{
+	put_device(dev->parent);
+}
+
+/**
+ * ata_is_ata_dev  --  check if a struct device represents a ATA device
+ * @dev:	device to check
+ *
+ * Returns:
+ *	%1 if the device represents a ATA device, %0 else
+ */
+int ata_is_ata_dev(const struct device *dev)
+{
+	return dev->release == ata_tdev_release;
+}
+
+static int ata_tdev_match(struct attribute_container *cont,
+			  struct device *dev)
+{
+	struct ata_internal* i = to_ata_internal(ata_scsi_transport_template);
+	if (!ata_is_ata_dev(dev))
+		return 0;
+	return &i->dev_attr_cont.ac == cont;
+}
+
+/**
+ * ata_tdev_free  --  free a ATA LINK
+ * @dev:	ATA PHY to free
+ *
+ * Frees the specified ATA PHY.
+ *
+ * Note:
+ *   This function must only be called on a PHY that has not
+ *   successfully been added using ata_tdev_add().
+ */
+static void ata_tdev_free(struct ata_device *dev)
+{
+	transport_destroy_device(&dev->tdev);
+	put_device(&dev->tdev);
+}
+
+/**
+ * ata_tdev_delete  --  remove ATA device
+ * @port:	ATA PORT to remove
+ *
+ * Removes the specified ATA device.
+ */
+static void ata_tdev_delete(struct ata_device *ata_dev)
+{
+	struct device *dev = &ata_dev->tdev;
+
+	transport_remove_device(dev);
+	device_del(dev);
+	ata_tdev_free(ata_dev);
+}
+
+
+/**
+ * ata_tdev_add  --  initialize a transport ATA device structure.
+ * @ata_dev:	ata_dev structure.
+ *
+ * Initialize an ATA device structure for sysfs.  It will be added in the
+ * device tree below the ATA LINK device it belongs to.
+ *
+ * Returns %0 on success
+ */
+static int ata_tdev_add(struct ata_device *ata_dev)
+{
+	struct device *dev = &ata_dev->tdev;
+	struct ata_link *link = ata_dev->link;
+	struct ata_port *ap = link->ap;
+	int error;
+
+	device_initialize(dev);
+	dev->parent = get_device(&link->tdev);
+	dev->release = ata_tdev_release;
+	if (ata_is_host_link(link))
+		dev_set_name(dev, "dev%d.%d", ap->print_id,ata_dev->devno);
+        else
+		dev_set_name(dev, "dev%d.%d.0", ap->print_id, link->pmp);
+
+	transport_setup_device(dev);
+	error = device_add(dev);
+	if (error) {
+		ata_tdev_free(ata_dev);
+		return error;
+	}
+
+	transport_add_device(dev);
+	transport_configure_device(dev);
+	return 0;
+}
+
+
+/*
+ * Setup / Teardown code
+ */
+
+#define SETUP_TEMPLATE(attrb, field, perm, test)			\
+	i->private_##attrb[count] = dev_attr_##field;		       	\
+	i->private_##attrb[count].attr.mode = perm;			\
+	i->attrb[count] = &i->private_##attrb[count];			\
+	if (test)							\
+		count++
+
+#define SETUP_LINK_ATTRIBUTE(field)					\
+	SETUP_TEMPLATE(link_attrs, field, S_IRUGO, 1)
+
+#define SETUP_PORT_ATTRIBUTE(field)					\
+	SETUP_TEMPLATE(port_attrs, field, S_IRUGO, 1)
+
+#define SETUP_DEV_ATTRIBUTE(field)					\
+	SETUP_TEMPLATE(dev_attrs, field, S_IRUGO, 1)
+
+/**
+ * ata_attach_transport  --  instantiate ATA transport template
+ */
+struct scsi_transport_template *ata_attach_transport(void)
+{
+	struct ata_internal *i;
+	int count;
+
+	i = kzalloc(sizeof(struct ata_internal), GFP_KERNEL);
+	if (!i)
+		return NULL;
+
+	i->t.eh_strategy_handler	= ata_scsi_error;
+	i->t.eh_timed_out		= ata_scsi_timed_out;
+	i->t.user_scan			= ata_scsi_user_scan;
+
+	i->t.host_attrs.ac.attrs = &i->port_attrs[0];
+	i->t.host_attrs.ac.class = &ata_port_class.class;
+	i->t.host_attrs.ac.match = ata_tport_match;
+	transport_container_register(&i->t.host_attrs);
+
+	i->link_attr_cont.ac.class = &ata_link_class.class;
+	i->link_attr_cont.ac.attrs = &i->link_attrs[0];
+	i->link_attr_cont.ac.match = ata_tlink_match;
+	transport_container_register(&i->link_attr_cont);
+
+	i->dev_attr_cont.ac.class = &ata_dev_class.class;
+	i->dev_attr_cont.ac.attrs = &i->dev_attrs[0];
+	i->dev_attr_cont.ac.match = ata_tdev_match;
+	transport_container_register(&i->dev_attr_cont);
+
+	count = 0;
+	SETUP_PORT_ATTRIBUTE(nr_pmp_links);
+	SETUP_PORT_ATTRIBUTE(idle_irq);
+	BUG_ON(count > ATA_PORT_ATTRS);
+	i->port_attrs[count] = NULL;
+
+	count = 0;
+	SETUP_LINK_ATTRIBUTE(hw_sata_spd_limit);
+	SETUP_LINK_ATTRIBUTE(sata_spd_limit);
+	SETUP_LINK_ATTRIBUTE(sata_spd);
+	BUG_ON(count > ATA_LINK_ATTRS);
+	i->link_attrs[count] = NULL;
+
+	count = 0;
+	SETUP_DEV_ATTRIBUTE(class);
+	SETUP_DEV_ATTRIBUTE(pio_mode);
+	SETUP_DEV_ATTRIBUTE(dma_mode);
+	SETUP_DEV_ATTRIBUTE(xfer_mode);
+	SETUP_DEV_ATTRIBUTE(spdn_cnt);
+	SETUP_DEV_ATTRIBUTE(ering);
+	SETUP_DEV_ATTRIBUTE(id);
+	SETUP_DEV_ATTRIBUTE(gscr);
+	BUG_ON(count > ATA_DEV_ATTRS);
+	i->dev_attrs[count] = NULL;
+
+	return &i->t;
+}
+
+/**
+ * ata_release_transport  --  release ATA transport template instance
+ * @t:		transport template instance
+ */
+void ata_release_transport(struct scsi_transport_template *t)
+{
+	struct ata_internal *i = to_ata_internal(t);
+
+	transport_container_unregister(&i->t.host_attrs);
+	transport_container_unregister(&i->link_attr_cont);
+	transport_container_unregister(&i->dev_attr_cont);
+
+	kfree(i);
+}
+
+__init int libata_transport_init(void)
+{
+	int error;
+
+	error = transport_class_register(&ata_link_class);
+	if (error)
+		goto out_unregister_transport;
+	error = transport_class_register(&ata_port_class);
+	if (error)
+		goto out_unregister_link;
+	error = transport_class_register(&ata_dev_class);
+	if (error)
+		goto out_unregister_port;
+	return 0;
+
+ out_unregister_port:
+	transport_class_unregister(&ata_port_class);
+ out_unregister_link:
+	transport_class_unregister(&ata_link_class);
+ out_unregister_transport:
+	return error;
+
+}
+
+void __exit libata_transport_exit(void)
+{
+	transport_class_unregister(&ata_link_class);
+	transport_class_unregister(&ata_port_class);
+	transport_class_unregister(&ata_dev_class);
+}

drivers/ata/libata-transport.h

···
+#ifndef _LIBATA_TRANSPORT_H
+#define _LIBATA_TRANSPORT_H
+
+
+extern struct scsi_transport_template *ata_scsi_transport_template;
+
+int ata_tlink_add(struct ata_link *link);
+void ata_tlink_delete(struct ata_link *link);
+
+int ata_tport_add(struct device *parent, struct ata_port *ap);
+void ata_tport_delete(struct ata_port *ap);
+
+struct scsi_transport_template *ata_attach_transport(void);
+void ata_release_transport(struct scsi_transport_template *t);
+
+__init int libata_transport_init(void);
+void __exit libata_transport_exit(void);
+#endif

drivers/ata/libata.h

···
 extern struct ata_port *ata_port_alloc(struct ata_host *host);
 extern void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy);
 extern void ata_lpm_schedule(struct ata_port *ap, enum link_pm);
+extern const char *sata_spd_string(unsigned int spd);
 
 /* libata-acpi.c */
 #ifdef CONFIG_ATA_ACPI
···
 extern void ata_schedule_scsi_eh(struct Scsi_Host *shost);
 extern void ata_scsi_dev_rescan(struct work_struct *work);
 extern int ata_bus_probe(struct ata_port *ap);
+extern int ata_scsi_user_scan(struct Scsi_Host *shost, unsigned int channel,
+			      unsigned int id, unsigned int lun);
+
 
 /* libata-eh.c */
 extern unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd);
···
 			  ata_postreset_fn_t postreset,
 			  struct ata_link **r_failed_disk);
 extern void ata_eh_finish(struct ata_port *ap);
+extern int ata_ering_map(struct ata_ering *ering,
+			 int (*map_fn)(struct ata_ering_entry *, void *),
+		  	 void *arg);
 
 /* libata-pmp.c */
 #ifdef CONFIG_SATA_PMP

include/linux/libata.h

···
 	union acpi_object	*gtf_cache;
 	unsigned int		gtf_filter;
 #endif
+	struct device		tdev;
 	/* n_sector is CLEAR_BEGIN, read comment above CLEAR_BEGIN */
 	u64			n_sectors;	/* size of device, if ATA */
 	u64			n_native_sectors; /* native size, if ATA */
···
 	struct ata_port		*ap;
 	int			pmp;		/* port multiplier port # */
 
+	struct device		tdev;
 	unsigned int		active_tag;	/* active tag on this link */
 	u32			sactive;	/* active NCQ commands */
 
···
 
 	struct ata_device	device[ATA_MAX_DEVICES];
 };
+#define ATA_LINK_CLEAR_BEGIN		offsetof(struct ata_link, active_tag)
+#define ATA_LINK_CLEAR_END		offsetof(struct ata_link, device[0])
 
 struct ata_port {
 	struct Scsi_Host	*scsi_host; /* our co-allocated scsi host */
···
 	struct ata_port_stats	stats;
 	struct ata_host		*host;
 	struct device 		*dev;
+	struct device		tdev;
 
 	struct mutex		scsi_scan_mutex;
 	struct delayed_work	hotplug_task;