libata-transport.c

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/*
 *  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 <linux/slab.h>
#include <scsi/scsi_transport.h>
#include <linux/libata.h>
#include <linux/hdreg.h>
#include <linux/uaccess.h>
#include <linux/pm_runtime.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);
}

static 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;
}

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);
}

int ata_tport_add(struct device *parent,
          struct ata_port *ap)
{
    int error;
    struct device *dev = &ap->tdev;

    device_initialize(dev);
    dev->type = &ata_port_type;

    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;
    }

    device_enable_async_suspend(dev);
    pm_runtime_set_active(dev);
    pm_runtime_enable(dev);
    pm_runtime_forbid(dev);

    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);
}

static 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;
}

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);
}

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);
}

static 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;
}

static void ata_tdev_free(struct ata_device *dev)
{
    transport_destroy_device(&dev->tdev);
    put_device(&dev->tdev);
}

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);
}


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)

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;
}

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);
}