1 files changed, 217 insertions, 35 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 79e3a8e7a84a..1ee9499bd343 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -163,6 +163,67 @@ MODULE_LICENSE("GPL");
 MODULE_VERSION(DRV_VERSION);
 
 
+/*
+ * Iterator helpers.  Don't use directly.
+ *
+ * LOCKING:
+ * Host lock or EH context.
+ */
+struct ata_link *__ata_port_next_link(struct ata_port *ap,
+                                      struct ata_link *link, bool dev_only)
+{
+        /* NULL link indicates start of iteration */
+        if (!link) {
+                if (dev_only && sata_pmp_attached(ap))
+                        return ap->pmp_link;
+                return &ap->link;
+        }
+
+        /* we just iterated over the host master link, what's next? */
+        if (link == &ap->link) {
+                if (!sata_pmp_attached(ap)) {
+                        if (unlikely(ap->slave_link) && !dev_only)
+                                return ap->slave_link;
+                        return NULL;
+                }
+                return ap->pmp_link;
+        }
+
+        /* slave_link excludes PMP */
+        if (unlikely(link == ap->slave_link))
+                return NULL;
+
+        /* iterate to the next PMP link */
+        if (++link < ap->pmp_link + ap->nr_pmp_links)
+                return link;
+        return NULL;
+}
+
+/**
+ *      ata_dev_phys_link - find physical link for a device
+ *      @dev: ATA device to look up physical link for
+ *
+ *      Look up physical link which @dev is attached to.  Note that
+ *      this is different from @dev->link only when @dev is on slave
+ *      link.  For all other cases, it's the same as @dev->link.
+ *
+ *      LOCKING:
+ *      Don't care.
+ *
+ *      RETURNS:
+ *      Pointer to the found physical link.
+ */
+struct ata_link *ata_dev_phys_link(struct ata_device *dev)
+{
+        struct ata_port *ap = dev->link->ap;
+
+        if (!ap->slave_link)
+                return dev->link;
+        if (!dev->devno)
+                return &ap->link;
+        return ap->slave_link;
+}
+
 /**
  *      ata_force_cbl - force cable type according to libata.force
  *      @ap: ATA port of interest
@@ -206,7 +267,8 @@ void ata_force_cbl(struct ata_port *ap)
  *      the host link and all fan-out ports connected via PMP.  If the
  *      device part is specified as 0 (e.g. 1.00:), it specifies the
  *      first fan-out link not the host link.  Device number 15 always
- *      points to the host link whether PMP is attached or not.
+ *      points to the host link whether PMP is attached or not.  If the
+ *      controller has slave link, device number 16 points to it.
  *
  *      LOCKING:
  *      EH context.
@@ -214,12 +276,11 @@ void ata_force_cbl(struct ata_port *ap)
 static void ata_force_link_limits(struct ata_link *link)
 {
         bool did_spd = false;
-        int linkno, i;
+        int linkno = link->pmp;
+        int i;
 
         if (ata_is_host_link(link))
-                linkno = 15;
-        else
-                linkno = link->pmp;
+                linkno += 15;
 
         for (i = ata_force_tbl_size - 1; i >= 0; i--) {
                 const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -266,9 +327,9 @@ static void ata_force_xfermask(struct ata_device *dev)
         int alt_devno = devno;
         int i;
 
-        /* allow n.15 for the first device attached to host port */
-        if (ata_is_host_link(dev->link) && devno == 0)
-                alt_devno = 15;
+        /* allow n.15/16 for devices attached to host port */
+        if (ata_is_host_link(dev->link))
+                alt_devno += 15;
 
         for (i = ata_force_tbl_size - 1; i >= 0; i--) {
                 const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -320,9 +381,9 @@ static void ata_force_horkage(struct ata_device *dev)
         int alt_devno = devno;
         int i;
 
-        /* allow n.15 for the first device attached to host port */
-        if (ata_is_host_link(dev->link) && devno == 0)
-                alt_devno = 15;
+        /* allow n.15/16 for devices attached to host port */
+        if (ata_is_host_link(dev->link))
+                alt_devno += 15;
 
         for (i = 0; i < ata_force_tbl_size; i++) {
                 const struct ata_force_ent *fe = &ata_force_tbl[i];
@@ -2681,7 +2742,7 @@ static void sata_print_link_status(struct ata_link *link)
                 return;
         sata_scr_read(link, SCR_CONTROL, &scontrol);
 
-        if (ata_link_online(link)) {
+        if (ata_phys_link_online(link)) {
                 tmp = (sstatus >> 4) & 0xf;
                 ata_link_printk(link, KERN_INFO,
                                 "SATA link up %s (SStatus %X SControl %X)\n",
@@ -3372,6 +3433,12 @@ int ata_wait_ready(struct ata_link *link, unsigned long deadline,
         unsigned long nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);
         int warned = 0;
 
+        /* Slave readiness can't be tested separately from master.  On
+         * M/S emulation configuration, this function should be called
+         * only on the master and it will handle both master and slave.
+         */
+        WARN_ON(link == link->ap->slave_link);
+
         if (time_after(nodev_deadline, deadline))
                 nodev_deadline = deadline;
 
@@ -3593,7 +3660,7 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
         }
 
         /* no point in trying softreset on offline link */
-        if (ata_link_offline(link))
+        if (ata_phys_link_offline(link))
                 ehc->i.action &= ~ATA_EH_SOFTRESET;
 
         return 0;
@@ -3671,7 +3738,7 @@ int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
         if (rc)
                 goto out;
         /* if link is offline nothing more to do */
-        if (ata_link_offline(link))
+        if (ata_phys_link_offline(link))
                 goto out;
 
         /* Link is online.  From this point, -ENODEV too is an error. */
@@ -4868,10 +4935,8 @@ int sata_scr_valid(struct ata_link *link)
 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
 {
         if (ata_is_host_link(link)) {
-                struct ata_port *ap = link->ap;
-
                 if (sata_scr_valid(link))
-                        return ap->ops->scr_read(ap, reg, val);
+                        return link->ap->ops->scr_read(link, reg, val);
                 return -EOPNOTSUPP;
         }
 
@@ -4897,10 +4962,8 @@ int sata_scr_read(struct ata_link *link, int reg, u32 *val)
 int sata_scr_write(struct ata_link *link, int reg, u32 val)
 {
         if (ata_is_host_link(link)) {
-                struct ata_port *ap = link->ap;
-
                 if (sata_scr_valid(link))
-                        return ap->ops->scr_write(ap, reg, val);
+                        return link->ap->ops->scr_write(link, reg, val);
                 return -EOPNOTSUPP;
         }
 
@@ -4925,13 +4988,12 @@ int sata_scr_write(struct ata_link *link, int reg, u32 val)
 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 {
         if (ata_is_host_link(link)) {
-                struct ata_port *ap = link->ap;
                 int rc;
 
                 if (sata_scr_valid(link)) {
-                        rc = ap->ops->scr_write(ap, reg, val);
+                        rc = link->ap->ops->scr_write(link, reg, val);
                         if (rc == 0)
-                                rc = ap->ops->scr_read(ap, reg, &val);
+                                rc = link->ap->ops->scr_read(link, reg, &val);
                         return rc;
                 }
                 return -EOPNOTSUPP;
@@ -4941,7 +5003,7 @@ int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
 }
 
 /**
- *      ata_link_online - test whether the given link is online
+ *      ata_phys_link_online - test whether the given link is online
  *      @link: ATA link to test
  *
  *      Test whether @link is online.  Note that this function returns
@@ -4952,20 +5014,20 @@ int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
  *      None.
  *
  *      RETURNS:
- *      1 if the port online status is available and online.
+ *      True if the port online status is available and online.
  */
-int ata_link_online(struct ata_link *link)
+bool ata_phys_link_online(struct ata_link *link)
 {
         u32 sstatus;
 
         if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
             (sstatus & 0xf) == 0x3)
-                return 1;
-        return 0;
+                return true;
+        return false;
 }
 
 /**
- *      ata_link_offline - test whether the given link is offline
+ *      ata_phys_link_offline - test whether the given link is offline
  *      @link: ATA link to test
  *
  *      Test whether @link is offline.  Note that this function
@@ -4976,16 +5038,68 @@ int ata_link_online(struct ata_link *link)
  *      None.
  *
  *      RETURNS:
- *      1 if the port offline status is available and offline.
+ *      True if the port offline status is available and offline.
  */
-int ata_link_offline(struct ata_link *link)
+bool ata_phys_link_offline(struct ata_link *link)
 {
         u32 sstatus;
 
         if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
             (sstatus & 0xf) != 0x3)
-                return 1;
-        return 0;
+                return true;
+        return false;
+}
+
+/**
+ *      ata_link_online - test whether the given link is online
+ *      @link: ATA link to test
+ *
+ *      Test whether @link is online.  This is identical to
+ *      ata_phys_link_online() when there's no slave link.  When
+ *      there's a slave link, this function should only be called on
+ *      the master link and will return true if any of M/S links is
+ *      online.
+ *
+ *      LOCKING:
+ *      None.
+ *
+ *      RETURNS:
+ *      True if the port online status is available and online.
+ */
+bool ata_link_online(struct ata_link *link)
+{
+        struct ata_link *slave = link->ap->slave_link;
+
+        WARN_ON(link == slave); /* shouldn't be called on slave link */
+
+        return ata_phys_link_online(link) ||
+                (slave && ata_phys_link_online(slave));
+}
+
+/**
+ *      ata_link_offline - test whether the given link is offline
+ *      @link: ATA link to test
+ *
+ *      Test whether @link is offline.  This is identical to
+ *      ata_phys_link_offline() when there's no slave link.  When
+ *      there's a slave link, this function should only be called on
+ *      the master link and will return true if both M/S links are
+ *      offline.
+ *
+ *      LOCKING:
+ *      None.
+ *
+ *      RETURNS:
+ *      True if the port offline status is available and offline.
+ */
+bool ata_link_offline(struct ata_link *link)
+{
+        struct ata_link *slave = link->ap->slave_link;
+
+        WARN_ON(link == slave); /* shouldn't be called on slave link */
+
+        return ata_phys_link_offline(link) &&
+                (!slave || ata_phys_link_offline(slave));
 }
 
 #ifdef CONFIG_PM
@@ -5127,11 +5241,11 @@ int ata_port_start(struct ata_port *ap)
  */
 void ata_dev_init(struct ata_device *dev)
 {
-        struct ata_link *link = dev->link;
+        struct ata_link *link = ata_dev_phys_link(dev);
         struct ata_port *ap = link->ap;
         unsigned long flags;
 
-        /* SATA spd limit is bound to the first device */
+        /* SATA spd limit is bound to the attached device, reset together */
         link->sata_spd_limit = link->hw_sata_spd_limit;
         link->sata_spd = 0;
 
@@ -5264,6 +5378,7 @@ struct ata_port *ata_port_alloc(struct ata_host *host)
         INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
         INIT_LIST_HEAD(&ap->eh_done_q);
         init_waitqueue_head(&ap->eh_wait_q);
+        init_completion(&ap->park_req_pending);
         init_timer_deferrable(&ap->fastdrain_timer);
         ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
         ap->fastdrain_timer.data = (unsigned long)ap;
@@ -5294,6 +5409,7 @@ static void ata_host_release(struct device *gendev, void *res)
                         scsi_host_put(ap->scsi_host);
 
                 kfree(ap->pmp_link);
+                kfree(ap->slave_link);
                 kfree(ap);
                 host->ports[i] = NULL;
         }
@@ -5414,6 +5530,68 @@ struct ata_host *ata_host_alloc_pinfo(struct device *dev,
         return host;
 }
 
+/**
+ *      ata_slave_link_init - initialize slave link
+ *      @ap: port to initialize slave link for
+ *
+ *      Create and initialize slave link for @ap.  This enables slave
+ *      link handling on the port.
+ *
+ *      In libata, a port contains links and a link contains devices.
+ *      There is single host link but if a PMP is attached to it,
+ *      there can be multiple fan-out links.  On SATA, there's usually
+ *      a single device connected to a link but PATA and SATA
+ *      controllers emulating TF based interface can have two - master
+ *      and slave.
+ *
+ *      However, there are a few controllers which don't fit into this
+ *      abstraction too well - SATA controllers which emulate TF
+ *      interface with both master and slave devices but also have
+ *      separate SCR register sets for each device.  These controllers
+ *      need separate links for physical link handling
+ *      (e.g. onlineness, link speed) but should be treated like a
+ *      traditional M/S controller for everything else (e.g. command
+ *      issue, softreset).
+ *
+ *      slave_link is libata's way of handling this class of
+ *      controllers without impacting core layer too much.  For
+ *      anything other than physical link handling, the default host
+ *      link is used for both master and slave.  For physical link
+ *      handling, separate @ap->slave_link is used.  All dirty details
+ *      are implemented inside libata core layer.  From LLD's POV, the
+ *      only difference is that prereset, hardreset and postreset are
+ *      called once more for the slave link, so the reset sequence
+ *      looks like the following.
+ *
+ *      prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
+ *      softreset(M) -> postreset(M) -> postreset(S)
+ *
+ *      Note that softreset is called only for the master.  Softreset
+ *      resets both M/S by definition, so SRST on master should handle
+ *      both (the standard method will work just fine).
+ *
+ *      LOCKING:
+ *      Should be called before host is registered.
+ *
+ *      RETURNS:
+ *      0 on success, -errno on failure.
+ */
+int ata_slave_link_init(struct ata_port *ap)
+{
+        struct ata_link *link;
+
+        WARN_ON(ap->slave_link);
+        WARN_ON(ap->flags & ATA_FLAG_PMP);
+
+        link = kzalloc(sizeof(*link), GFP_KERNEL);
+        if (!link)
+                return -ENOMEM;
+
+        ata_link_init(ap, link, 1);
+        ap->slave_link = link;
+        return 0;
+}
+
 static void ata_host_stop(struct device *gendev, void *res)
 {
         struct ata_host *host = dev_get_drvdata(gendev);
@@ -5640,6 +5818,8 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
 
                 /* init sata_spd_limit to the current value */
                 sata_link_init_spd(&ap->link);
+                if (ap->slave_link)
+                        sata_link_init_spd(ap->slave_link);
 
                 /* print per-port info to dmesg */
                 xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
@@ -6260,10 +6440,12 @@ EXPORT_SYMBOL_GPL(ata_base_port_ops);
 EXPORT_SYMBOL_GPL(sata_port_ops);
 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
+EXPORT_SYMBOL_GPL(__ata_port_next_link);
 EXPORT_SYMBOL_GPL(ata_std_bios_param);
 EXPORT_SYMBOL_GPL(ata_host_init);
 EXPORT_SYMBOL_GPL(ata_host_alloc);
 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
+EXPORT_SYMBOL_GPL(ata_slave_link_init);
 EXPORT_SYMBOL_GPL(ata_host_start);
 EXPORT_SYMBOL_GPL(ata_host_register);
 EXPORT_SYMBOL_GPL(ata_host_activate);