[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 <gwendal@google.com>
Reviewed-by: Grant Grundler <grundler@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

8 files changed, 883 insertions, 40 deletions

diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index d5df04a395ca..ccd461bb5ee4 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -99,7 +99,7 @@ obj-$(CONFIG_ATA_GENERIC)	+= ata_generic.o
 # Should be last libata driver
 obj-$(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
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 932eaee50245..4012b33e8b8a 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -68,7 +68,7 @@
 #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 };
@@ -1017,7 +1017,7 @@ const char *ata_mode_string(unsigned long xfer_mask)
         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",
@@ -5517,7 +5517,8 @@ void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
         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;
@@ -5591,7 +5592,7 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
         ap = kzalloc(sizeof(*ap), GFP_KERNEL);
         if (!ap)
                 return NULL;
-
+        
         ap->pflags |= ATA_PFLAG_INITIALIZING;
         ap->lock = &host->lock;
         ap->print_id = -1;
@@ -6093,9 +6094,18 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
         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);
@@ -6136,6 +6146,13 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
         }
 
         return 0;
+
+ err_tadd:
+        while (--i >= 0) {
+                ata_tport_delete(host->ports[i]);
+        }
+        return rc;
+
 }
 
 /**
@@ -6226,6 +6243,13 @@ static void ata_port_detach(struct ata_port *ap)
         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);
 }
@@ -6542,7 +6566,7 @@ static void __init ata_parse_force_param(void)
 
 static int __init ata_init(void)
 {
-        int rc = -ENOMEM;
+        int rc;
 
         ata_parse_force_param();
 
@@ -6552,12 +6576,25 @@ static int __init ata_init(void)
                 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);
 }
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index e48302eae55f..95838b382231 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -57,6 +57,7 @@ enum {
         /* 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,
@@ -396,14 +397,9 @@ static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
         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;
@@ -422,6 +418,17 @@ static int ata_ering_map(struct ata_ering *ering,
         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)
 {
         struct ata_eh_context *ehc = &dev->link->eh_context;
@@ -572,19 +579,19 @@ void ata_scsi_error(struct Scsi_Host *host)
                 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;
 
@@ -628,7 +635,7 @@ void ata_scsi_error(struct Scsi_Host *host)
                 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 ? */
 
@@ -1755,7 +1762,7 @@ static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
         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,
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index 224faabd7b7e..505470237d79 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -11,6 +11,7 @@
 #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,
@@ -312,10 +313,10 @@ static int sata_pmp_configure(struct ata_device *dev, int print_info)
         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,
@@ -327,6 +328,13 @@ static int sata_pmp_init_links(struct ata_port *ap, int nr_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++) {
@@ -339,6 +347,12 @@ static int sata_pmp_init_links(struct ata_port *ap, int nr_ports)
         }
 
         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)
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index a89172c100f5..c16f5c151735 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -51,6 +51,7 @@
 #include <asm/unaligned.h>
 
 #include "libata.h"
+#include "libata-transport.h"
 
 #define SECTOR_SIZE             512
 #define ATA_SCSI_RBUF_SIZE      4096
@@ -64,9 +65,6 @@ static struct ata_device *__ata_scsi_find_dev(struct ata_port *ap,
                                         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
@@ -106,17 +104,6 @@ static const u8 def_control_mpage[CONTROL_MPAGE_LEN] = {
         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;
         const char      *name;
@@ -3334,7 +3321,7 @@ int ata_scsi_add_hosts(struct ata_host *host, struct scsi_host_template *sht)
                 *(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;
@@ -3616,8 +3603,8 @@ void ata_scsi_hotplug(struct work_struct *work)
  *      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;
diff --git a/drivers/ata/libata-transport.c b/drivers/ata/libata-transport.c
new file mode 100644
index 000000000000..a80860f537e4
--- /dev/null
+++ b/drivers/ata/libata-transport.c
@@ -0,0 +1,773 @@
+/*
+ *  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);
+}
diff --git a/drivers/ata/libata-transport.h b/drivers/ata/libata-transport.h
new file mode 100644
index 000000000000..2820cf864f11
--- /dev/null
+++ b/drivers/ata/libata-transport.h
@@ -0,0 +1,18 @@
+#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
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 9ce1ecc63e39..142102b94df5 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -102,6 +102,7 @@ extern int ata_cmd_ioctl(struct scsi_device *scsidev, void __user *arg);
 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
@@ -137,6 +138,9 @@ extern void ata_scsi_hotplug(struct work_struct *work);
 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);
@@ -164,6 +168,9 @@ extern int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
                           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