libata-link: introduce ata_link

Introduce ata_link.  It abstracts PHY and sits between ata_port and
ata_device.  This new level of abstraction is necessary to support
SATA Port Multiplier, which basically adds a bunch of links (PHYs) to
a ATA host port.  Fields related to command execution, spd_limit and
EH are per-link and thus moved to ata_link.

This patch only defines the host link.  Multiple link handling will be
added later.  Also, a lot of ap->link derefences are added but many of
them will be removed as each part is converted to deal directly with
ata_link instead of ata_port.

This patch introduces no behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 51 insertions, 49 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index ac6ceed4bb60..e2681f56ed44 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -195,7 +195,7 @@ static int ata_ering_map(struct ata_ering *ering,
 
 static unsigned int ata_eh_dev_action(struct ata_device *dev)
 {
-        struct ata_eh_context *ehc = &dev->ap->eh_context;
+        struct ata_eh_context *ehc = &dev->link->eh_context;
 
         return ehc->i.action | ehc->i.dev_action[dev->devno];
 }
@@ -261,7 +261,7 @@ enum scsi_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
 
         ret = EH_HANDLED;
         spin_lock_irqsave(ap->lock, flags);
-        qc = ata_qc_from_tag(ap, ap->active_tag);
+        qc = ata_qc_from_tag(ap, ap->link.active_tag);
         if (qc) {
                 WARN_ON(qc->scsicmd != cmd);
                 qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
@@ -371,9 +371,9 @@ void ata_scsi_error(struct Scsi_Host *host)
                 /* fetch & clear EH info */
                 spin_lock_irqsave(ap->lock, flags);
 
-                memset(&ap->eh_context, 0, sizeof(ap->eh_context));
-                ap->eh_context.i = ap->eh_info;
-                memset(&ap->eh_info, 0, sizeof(ap->eh_info));
+                memset(&ap->link.eh_context, 0, sizeof(ap->link.eh_context));
+                ap->link.eh_context.i = ap->link.eh_info;
+                memset(&ap->link.eh_info, 0, sizeof(ap->link.eh_info));
 
                 ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
                 ap->pflags &= ~ATA_PFLAG_EH_PENDING;
@@ -409,7 +409,7 @@ void ata_scsi_error(struct Scsi_Host *host)
                 }
 
                 /* this run is complete, make sure EH info is clear */
-                memset(&ap->eh_info, 0, sizeof(ap->eh_info));
+                memset(&ap->link.eh_info, 0, sizeof(ap->link.eh_info));
 
                 /* Clear host_eh_scheduled while holding ap->lock such
                  * that if exception occurs after this point but
@@ -420,7 +420,7 @@ void ata_scsi_error(struct Scsi_Host *host)
 
                 spin_unlock_irqrestore(ap->lock, flags);
         } else {
-                WARN_ON(ata_qc_from_tag(ap, ap->active_tag) == NULL);
+                WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
                 ap->ops->eng_timeout(ap);
         }
 
@@ -575,7 +575,7 @@ void ata_eng_timeout(struct ata_port *ap)
 {
         DPRINTK("ENTER\n");
 
-        ata_qc_timeout(ata_qc_from_tag(ap, ap->active_tag));
+        ata_qc_timeout(ata_qc_from_tag(ap, ap->link.active_tag));
 
         DPRINTK("EXIT\n");
 }
@@ -922,7 +922,7 @@ void ata_eh_qc_retry(struct ata_queued_cmd *qc)
  */
 static void ata_eh_detach_dev(struct ata_device *dev)
 {
-        struct ata_port *ap = dev->ap;
+        struct ata_port *ap = dev->link->ap;
         unsigned long flags;
 
         ata_dev_disable(dev);
@@ -937,8 +937,8 @@ static void ata_eh_detach_dev(struct ata_device *dev)
         }
 
         /* clear per-dev EH actions */
-        ata_eh_clear_action(dev, &ap->eh_info, ATA_EH_PERDEV_MASK);
-        ata_eh_clear_action(dev, &ap->eh_context.i, ATA_EH_PERDEV_MASK);
+        ata_eh_clear_action(dev, &dev->link->eh_info, ATA_EH_PERDEV_MASK);
+        ata_eh_clear_action(dev, &dev->link->eh_context.i, ATA_EH_PERDEV_MASK);
 
         spin_unlock_irqrestore(ap->lock, flags);
 }
@@ -950,8 +950,8 @@ static void ata_eh_detach_dev(struct ata_device *dev)
  *      @action: action about to be performed
  *
  *      Called just before performing EH actions to clear related bits
- *      in @ap->eh_info such that eh actions are not unnecessarily
- *      repeated.
+ *      in @ap->link.eh_info such that eh actions are not
+ *      unnecessarily repeated.
  *
  *      LOCKING:
  *      None.
@@ -960,8 +960,8 @@ static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
                                unsigned int action)
 {
         unsigned long flags;
-        struct ata_eh_info *ehi = &ap->eh_info;
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_info *ehi = &ap->link.eh_info;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
 
         spin_lock_irqsave(ap->lock, flags);
 
@@ -993,7 +993,7 @@ static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
  *      @action: action just completed
  *
  *      Called right after performing EH actions to clear related bits
- *      in @ap->eh_context.
+ *      in @ap->link.eh_context.
  *
  *      LOCKING:
  *      None.
@@ -1001,13 +1001,15 @@ static void ata_eh_about_to_do(struct ata_port *ap, struct ata_device *dev,
 static void ata_eh_done(struct ata_port *ap, struct ata_device *dev,
                         unsigned int action)
 {
+        struct ata_eh_context *ehc = &ap->link.eh_context;
+
         /* if reset is complete, clear all reset actions & reset modifier */
         if (action & ATA_EH_RESET_MASK) {
                 action |= ATA_EH_RESET_MASK;
-                ap->eh_context.i.flags &= ~ATA_EHI_RESET_MODIFIER_MASK;
+                ehc->i.flags &= ~ATA_EHI_RESET_MODIFIER_MASK;
         }
 
-        ata_eh_clear_action(dev, &ap->eh_context.i, action);
+        ata_eh_clear_action(dev, &ehc->i, action);
 }
 
 /**
@@ -1101,7 +1103,7 @@ static unsigned int ata_read_log_page(struct ata_device *dev,
 static int ata_eh_read_log_10h(struct ata_device *dev,
                                int *tag, struct ata_taskfile *tf)
 {
-        u8 *buf = dev->ap->sector_buf;
+        u8 *buf = dev->link->ap->sector_buf;
         unsigned int err_mask;
         u8 csum;
         int i;
@@ -1155,7 +1157,7 @@ static unsigned int atapi_eh_request_sense(struct ata_queued_cmd *qc)
 {
         struct ata_device *dev = qc->dev;
         unsigned char *sense_buf = qc->scsicmd->sense_buffer;
-        struct ata_port *ap = dev->ap;
+        struct ata_port *ap = dev->link->ap;
         struct ata_taskfile tf;
         u8 cdb[ATAPI_CDB_LEN];
 
@@ -1206,7 +1208,7 @@ static unsigned int atapi_eh_request_sense(struct ata_queued_cmd *qc)
  */
 static void ata_eh_analyze_serror(struct ata_port *ap)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         u32 serror = ehc->i.serror;
         unsigned int err_mask = 0, action = 0;
 
@@ -1248,8 +1250,8 @@ static void ata_eh_analyze_serror(struct ata_port *ap)
  */
 static void ata_eh_analyze_ncq_error(struct ata_port *ap)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
-        struct ata_device *dev = ap->device;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
+        struct ata_device *dev = ap->link.device;
         struct ata_queued_cmd *qc;
         struct ata_taskfile tf;
         int tag, rc;
@@ -1259,7 +1261,7 @@ static void ata_eh_analyze_ncq_error(struct ata_port *ap)
                 return;
 
         /* is it NCQ device error? */
-        if (!ap->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
+        if (!ap->link.sactive || !(ehc->i.err_mask & AC_ERR_DEV))
                 return;
 
         /* has LLDD analyzed already? */
@@ -1281,7 +1283,7 @@ static void ata_eh_analyze_ncq_error(struct ata_port *ap)
                 return;
         }
 
-        if (!(ap->sactive & (1 << tag))) {
+        if (!(ap->link.sactive & (1 << tag))) {
                 ata_port_printk(ap, KERN_ERR, "log page 10h reported "
                                 "inactive tag %d\n", tag);
                 return;
@@ -1497,7 +1499,7 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev, int is_io,
         /* speed down? */
         if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
                 /* speed down SATA link speed if possible */
-                if (sata_down_spd_limit(dev->ap) == 0) {
+                if (sata_down_spd_limit(dev->link->ap) == 0) {
                         action |= ATA_EH_HARDRESET;
                         goto done;
                 }
@@ -1528,7 +1530,7 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev, int is_io,
          * SATA.  Consider it only for PATA.
          */
         if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
-            (dev->ap->cbl != ATA_CBL_SATA) &&
+            (dev->link->ap->cbl != ATA_CBL_SATA) &&
             (dev->xfer_shift != ATA_SHIFT_PIO)) {
                 if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
                         dev->spdn_cnt = 0;
@@ -1557,7 +1559,7 @@ static unsigned int ata_eh_speed_down(struct ata_device *dev, int is_io,
  */
 static void ata_eh_autopsy(struct ata_port *ap)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         unsigned int all_err_mask = 0;
         int tag, is_io = 0;
         u32 serror;
@@ -1656,7 +1658,7 @@ static void ata_eh_autopsy(struct ata_port *ap)
  */
 static void ata_eh_report(struct ata_port *ap)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         const char *frozen, *desc;
         int tag, nr_failed = 0;
 
@@ -1685,15 +1687,15 @@ static void ata_eh_report(struct ata_port *ap)
         if (ehc->i.dev) {
                 ata_dev_printk(ehc->i.dev, KERN_ERR, "exception Emask 0x%x "
                                "SAct 0x%x SErr 0x%x action 0x%x%s\n",
-                               ehc->i.err_mask, ap->sactive, ehc->i.serror,
-                               ehc->i.action, frozen);
+                               ehc->i.err_mask, ap->link.sactive,
+                               ehc->i.serror, ehc->i.action, frozen);
                 if (desc)
                         ata_dev_printk(ehc->i.dev, KERN_ERR, "%s\n", desc);
         } else {
                 ata_port_printk(ap, KERN_ERR, "exception Emask 0x%x "
                                 "SAct 0x%x SErr 0x%x action 0x%x%s\n",
-                                ehc->i.err_mask, ap->sactive, ehc->i.serror,
-                                ehc->i.action, frozen);
+                                ehc->i.err_mask, ap->link.sactive,
+                                ehc->i.serror, ehc->i.action, frozen);
                 if (desc)
                         ata_port_printk(ap, KERN_ERR, "%s\n", desc);
         }
@@ -1775,7 +1777,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                         ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
                         ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         unsigned int *classes = ehc->classes;
         int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
         int try = 0;
@@ -1804,7 +1806,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                         if (rc == -ENOENT) {
                                 ata_port_printk(ap, KERN_DEBUG,
                                                 "port disabled. ignoring.\n");
-                                ap->eh_context.i.action &= ~ATA_EH_RESET_MASK;
+                                ehc->i.action &= ~ATA_EH_RESET_MASK;
 
                                 for (i = 0; i < ATA_MAX_DEVICES; i++)
                                         classes[i] = ATA_DEV_NONE;
@@ -1907,11 +1909,11 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
                  * controller state is undefined.  Record the mode.
                  */
                 for (i = 0; i < ATA_MAX_DEVICES; i++)
-                        ap->device[i].pio_mode = XFER_PIO_0;
+                        ap->link.device[i].pio_mode = XFER_PIO_0;
 
                 /* record current link speed */
                 if (sata_scr_read(ap, SCR_STATUS, &sstatus) == 0)
-                        ap->sata_spd = (sstatus >> 4) & 0xf;
+                        ap->link.sata_spd = (sstatus >> 4) & 0xf;
 
                 if (postreset)
                         postreset(ap, classes);
@@ -1929,7 +1931,7 @@ static int ata_eh_reset(struct ata_port *ap, int classify,
 static int ata_eh_revalidate_and_attach(struct ata_port *ap,
                                         struct ata_device **r_failed_dev)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         struct ata_device *dev;
         unsigned int new_mask = 0;
         unsigned long flags;
@@ -1944,7 +1946,7 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
         for (i = ATA_MAX_DEVICES - 1; i >= 0; i--) {
                 unsigned int action, readid_flags = 0;
 
-                dev = &ap->device[i];
+                dev = &ap->link.device[i];
                 action = ata_eh_dev_action(dev);
 
                 if (ehc->i.flags & ATA_EHI_DID_RESET)
@@ -2004,7 +2006,7 @@ static int ata_eh_revalidate_and_attach(struct ata_port *ap,
          * device detection messages backwards.
          */
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                dev = &ap->device[i];
+                dev = &ap->link.device[i];
 
                 if (!(new_mask & (1 << i)))
                         continue;
@@ -2036,7 +2038,7 @@ static int ata_port_nr_enabled(struct ata_port *ap)
         int i, cnt = 0;
 
         for (i = 0; i < ATA_MAX_DEVICES; i++)
-                if (ata_dev_enabled(&ap->device[i]))
+                if (ata_dev_enabled(&ap->link.device[i]))
                         cnt++;
         return cnt;
 }
@@ -2046,14 +2048,14 @@ static int ata_port_nr_vacant(struct ata_port *ap)
         int i, cnt = 0;
 
         for (i = 0; i < ATA_MAX_DEVICES; i++)
-                if (ap->device[i].class == ATA_DEV_UNKNOWN)
+                if (ap->link.device[i].class == ATA_DEV_UNKNOWN)
                         cnt++;
         return cnt;
 }
 
 static int ata_eh_skip_recovery(struct ata_port *ap)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         int i;
 
         /* thaw frozen port, resume link and recover failed devices */
@@ -2063,7 +2065,7 @@ static int ata_eh_skip_recovery(struct ata_port *ap)
 
         /* skip if class codes for all vacant slots are ATA_DEV_NONE */
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                struct ata_device *dev = &ap->device[i];
+                struct ata_device *dev = &ap->link.device[i];
 
                 if (dev->class == ATA_DEV_UNKNOWN &&
                     ehc->classes[dev->devno] != ATA_DEV_NONE)
@@ -2075,8 +2077,8 @@ static int ata_eh_skip_recovery(struct ata_port *ap)
 
 static void ata_eh_handle_dev_fail(struct ata_device *dev, int err)
 {
-        struct ata_port *ap = dev->ap;
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_port *ap = dev->link->ap;
+        struct ata_eh_context *ehc = &dev->link->eh_context;
 
         ehc->tries[dev->devno]--;
 
@@ -2149,7 +2151,7 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
                           ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
                           ata_postreset_fn_t postreset)
 {
-        struct ata_eh_context *ehc = &ap->eh_context;
+        struct ata_eh_context *ehc = &ap->link.eh_context;
         struct ata_device *dev;
         int i, rc;
 
@@ -2157,7 +2159,7 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
 
         /* prep for recovery */
         for (i = 0; i < ATA_MAX_DEVICES; i++) {
-                dev = &ap->device[i];
+                dev = &ap->link.device[i];
 
                 ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
 
@@ -2240,7 +2242,7 @@ static int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
  out:
         if (rc) {
                 for (i = 0; i < ATA_MAX_DEVICES; i++)
-                        ata_dev_disable(&ap->device[i]);
+                        ata_dev_disable(&ap->link.device[i]);
         }
 
         DPRINTK("EXIT, rc=%d\n", rc);