libata: move generic hardreset code from sata_sff_hardreset() to sata_link_hardreset()

sata_sff_hardreset() contains link readiness wait logic which isn't
SFF specific.  Move that part into sata_link_hardreset(), which now
takes two more parameters - @online and @check_ready.  Both are
optional.  The former is out parameter for link onlineness after
reset.  The latter is used to wait for link readiness after hardreset.

Users of sata_link_hardreset() is updated to use new funtionality and
ahci_hardreset() is updated to use sata_link_hardreset() instead of
sata_sff_hardreset().  This doesn't really cause any behavior change.

Signed-off-by: Tejun Heo <htejun@gmail.com>

6 files changed, 92 insertions, 61 deletions

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 7e251a2cbda5..0f553aaa6f79 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1343,10 +1343,12 @@ static int ahci_softreset(struct ata_link *link, unsigned int *class,
 static int ahci_hardreset(struct ata_link *link, unsigned int *class,
                           unsigned long deadline)
 {
+        const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
         struct ata_port *ap = link->ap;
         struct ahci_port_priv *pp = ap->private_data;
         u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
         struct ata_taskfile tf;
+        bool online;
         int rc;
 
         DPRINTK("ENTER\n");
@@ -1358,14 +1360,14 @@ static int ahci_hardreset(struct ata_link *link, unsigned int *class,
         tf.command = 0x80;
         ata_tf_to_fis(&tf, 0, 0, d2h_fis);
 
-        rc = sata_sff_hardreset(link, class, deadline);
+        rc = sata_link_hardreset(link, timing, deadline, &online,
+                                 ahci_check_ready);
 
         ahci_start_engine(ap);
 
-        if (rc == 0 && ata_link_online(link))
+        *class = ATA_DEV_NONE;
+        if (online)
                 *class = ahci_dev_classify(ap);
-        if (rc != -EAGAIN && *class == ATA_DEV_UNKNOWN)
-                *class = ATA_DEV_NONE;
 
         DPRINTK("EXIT, rc=%d, class=%u\n", rc, *class);
         return rc;
@@ -1376,6 +1378,7 @@ static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
 {
         struct ata_port *ap = link->ap;
         u32 serror;
+        bool online;
         int rc;
 
         DPRINTK("ENTER\n");
@@ -1383,7 +1386,7 @@ static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
         ahci_stop_engine(ap);
 
         rc = sata_link_hardreset(link, sata_ehc_deb_timing(&link->eh_context),
-                                 deadline);
+                                 deadline, &online, NULL);
 
         /* vt8251 needs SError cleared for the port to operate */
         ahci_scr_read(ap, SCR_ERROR, &serror);
@@ -1396,7 +1399,8 @@ static int ahci_vt8251_hardreset(struct ata_link *link, unsigned int *class,
         /* vt8251 doesn't clear BSY on signature FIS reception,
          * request follow-up softreset.
          */
-        return rc ?: -EAGAIN;
+        *class = ATA_DEV_NONE;
+        return online ? -EAGAIN : rc;
 }
 
 static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
@@ -1406,6 +1410,7 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
         struct ahci_port_priv *pp = ap->private_data;
         u8 *d2h_fis = pp->rx_fis + RX_FIS_D2H_REG;
         struct ata_taskfile tf;
+        bool online;
         int rc;
 
         ahci_stop_engine(ap);
@@ -1416,13 +1421,10 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
         ata_tf_to_fis(&tf, 0, 0, d2h_fis);
 
         rc = sata_link_hardreset(link, sata_ehc_deb_timing(&link->eh_context),
-                                 deadline);
+                                 deadline, &online, NULL);
 
         ahci_start_engine(ap);
 
-        if (rc || ata_link_offline(link))
-                return rc;
-
         /* The pseudo configuration device on SIMG4726 attached to
          * ASUS P5W-DH Deluxe doesn't send signature FIS after
          * hardreset if no device is attached to the first downstream
@@ -1436,11 +1438,14 @@ static int ahci_p5wdh_hardreset(struct ata_link *link, unsigned int *class,
          * have to be reset again.  For most cases, this should
          * suffice while making probing snappish enough.
          */
-        rc = ata_wait_after_reset(link, jiffies + 2 * HZ, ahci_check_ready);
-        if (rc)
-                ahci_kick_engine(ap, 0);
-
-        return 0;
+        if (online) {
+                rc = ata_wait_after_reset(link, jiffies + 2 * HZ,
+                                          ahci_check_ready);
+                if (rc)
+                        ahci_kick_engine(ap, 0);
+        }
+        *class = ATA_DEV_NONE;
+        return rc;
 }
 
 static void ahci_postreset(struct ata_link *link, unsigned int *class)
diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c
index 7ab76a413cdf..f59a55bfade4 100644
--- a/drivers/ata/ata_piix.c
+++ b/drivers/ata/ata_piix.c
@@ -1022,7 +1022,7 @@ static int piix_sidpr_hardreset(struct ata_link *link, unsigned int *class,
         int rc;
 
         /* do hardreset */
-        rc = sata_link_hardreset(link, timing, deadline);
+        rc = sata_link_hardreset(link, timing, deadline, NULL, NULL);
         if (rc) {
                 ata_link_printk(link, KERN_ERR,
                                 "COMRESET failed (errno=%d)\n", rc);
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 3bad6f189190..b607292b6480 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3557,8 +3557,18 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
  *      @link: link to reset
  *      @timing: timing parameters { interval, duratinon, timeout } in msec
  *      @deadline: deadline jiffies for the operation
+ *      @online: optional out parameter indicating link onlineness
+ *      @check_ready: optional callback to check link readiness
  *
  *      SATA phy-reset @link using DET bits of SControl register.
+ *      After hardreset, link readiness is waited upon using
+ *      ata_wait_ready() if @check_ready is specified.  LLDs are
+ *      allowed to not specify @check_ready and wait itself after this
+ *      function returns.  Device classification is LLD's
+ *      responsibility.
+ *
+ *      *@online is set to one iff reset succeeded and @link is online
+ *      after reset.
  *
  *      LOCKING:
  *      Kernel thread context (may sleep)
@@ -3567,13 +3577,17 @@ int ata_std_prereset(struct ata_link *link, unsigned long deadline)
  *      0 on success, -errno otherwise.
  */
 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
-                        unsigned long deadline)
+                        unsigned long deadline,
+                        bool *online, int (*check_ready)(struct ata_link *))
 {
         u32 scontrol;
         int rc;
 
         DPRINTK("ENTER\n");
 
+        if (online)
+                *online = false;
+
         if (sata_set_spd_needed(link)) {
                 /* SATA spec says nothing about how to reconfigure
                  * spd.  To be on the safe side, turn off phy during
@@ -3607,7 +3621,41 @@ int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
 
         /* bring link back */
         rc = sata_link_resume(link, timing, deadline);
+        if (rc)
+                goto out;
+        /* if link is offline nothing more to do */
+        if (ata_link_offline(link))
+                goto out;
+
+        /* Link is online.  From this point, -ENODEV too is an error. */
+        if (online)
+                *online = true;
+
+        if ((link->ap->flags & ATA_FLAG_PMP) && ata_is_host_link(link)) {
+                /* If PMP is supported, we have to do follow-up SRST.
+                 * Some PMPs don't send D2H Reg FIS after hardreset if
+                 * the first port is empty.  Wait only for
+                 * ATA_TMOUT_PMP_SRST_WAIT.
+                 */
+                if (check_ready) {
+                        unsigned long pmp_deadline;
+
+                        pmp_deadline = jiffies + ATA_TMOUT_PMP_SRST_WAIT;
+                        if (time_after(pmp_deadline, deadline))
+                                pmp_deadline = deadline;
+                        ata_wait_ready(link, pmp_deadline, check_ready);
+                }
+                rc = -EAGAIN;
+                goto out;
+        }
+
+        rc = 0;
+        if (check_ready)
+                rc = ata_wait_ready(link, deadline, check_ready);
  out:
+        if (rc && rc != -EAGAIN)
+                ata_link_printk(link, KERN_ERR,
+                                "COMRESET failed (errno=%d)\n", rc);
         DPRINTK("EXIT, rc=%d\n", rc);
         return rc;
 }
diff --git a/drivers/ata/libata-pmp.c b/drivers/ata/libata-pmp.c
index a7cb1498c9b2..7f1a87f01ab2 100644
--- a/drivers/ata/libata-pmp.c
+++ b/drivers/ata/libata-pmp.c
@@ -239,13 +239,14 @@ int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
                            unsigned long deadline)
 {
         const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
+        bool online;
         u32 tmp;
         int rc;
 
         DPRINTK("ENTER\n");
 
         /* do hardreset */
-        rc = sata_link_hardreset(link, timing, deadline);
+        rc = sata_link_hardreset(link, timing, deadline, &online, NULL);
         if (rc) {
                 ata_link_printk(link, KERN_ERR,
                                 "COMRESET failed (errno=%d)\n", rc);
@@ -261,7 +262,7 @@ int sata_pmp_std_hardreset(struct ata_link *link, unsigned int *class,
         }
 
         /* if device is present, follow up with srst to wait for !BSY */
-        if (ata_link_online(link))
+        if (online)
                 rc = -EAGAIN;
  out:
         /* if SCR isn't accessible, we need to reset the PMP */
@@ -916,7 +917,7 @@ static int sata_pmp_eh_handle_disabled_links(struct ata_port *ap)
                  * SError.N working.
                  */
                 sata_link_hardreset(link, sata_deb_timing_normal,
-                                    jiffies + ATA_TMOUT_INTERNAL_QUICK);
+                                jiffies + ATA_TMOUT_INTERNAL_QUICK, NULL, NULL);
 
                 /* unconditionally clear SError.N */
                 rc = sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 78912c5011ad..0b97e84d3af6 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -1921,50 +1921,19 @@ int ata_sff_softreset(struct ata_link *link, unsigned int *classes,
 int sata_sff_hardreset(struct ata_link *link, unsigned int *class,
                        unsigned long deadline)
 {
-        struct ata_port *ap = link->ap;
-        const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
+        struct ata_eh_context *ehc = &link->eh_context;
+        const unsigned long *timing = sata_ehc_deb_timing(ehc);
+        bool online;
         int rc;
 
-        DPRINTK("ENTER\n");
-
-        /* do hardreset */
-        rc = sata_link_hardreset(link, timing, deadline);
-        if (rc) {
-                ata_link_printk(link, KERN_ERR,
-                                "COMRESET failed (errno=%d)\n", rc);
-                return rc;
-        }
-
-        /* TODO: phy layer with polling, timeouts, etc. */
-        if (ata_link_offline(link)) {
-                *class = ATA_DEV_NONE;
-                DPRINTK("EXIT, link offline\n");
-                return 0;
-        }
-
-        /* If PMP is supported, we have to do follow-up SRST.  Note
-         * that some PMPs don't send D2H Reg FIS after hardreset at
-         * all if the first port is empty.  Wait for it just for a
-         * second and request follow-up SRST.
-         */
-        if (ap->flags & ATA_FLAG_PMP) {
-                ata_sff_wait_after_reset(link, 1, jiffies + HZ);
-                return -EAGAIN;
-        }
-
-        /* wait for the link to become online */
-        rc = ata_sff_wait_after_reset(link, 1, deadline);
-        /* link occupied, -ENODEV too is an error */
-        if (rc) {
-                ata_link_printk(link, KERN_ERR,
-                                "COMRESET failed (errno=%d)\n", rc);
-                return rc;
-        }
-
-        *class = ata_sff_dev_classify(link->device, 1, NULL);
+        rc = sata_link_hardreset(link, timing, deadline, &online,
+                                 ata_sff_check_ready);
+        *class = ATA_DEV_NONE;
+        if (online)
+                *class = ata_sff_dev_classify(link->device, 1, NULL);
 
         DPRINTK("EXIT, class=%u\n", *class);
-        return 0;
+        return rc;
 }
 
 /**
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 4bbf2524e473..d9ebce2bf5e7 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -261,6 +261,13 @@ enum {
          */
         ATA_WAIT_AFTER_RESET_MSECS = 150,
 
+        /* If PMP is supported, we have to do follow-up SRST.  As some
+         * PMPs don't send D2H Reg FIS after hardreset, LLDs are
+         * advised to wait only for the following duration before
+         * doing SRST.
+         */
+        ATA_TMOUT_PMP_SRST_WAIT = 1 * HZ,
+
         /* ATA bus states */
         BUS_UNKNOWN             = 0,
         BUS_DMA                 = 1,
@@ -844,7 +851,8 @@ extern int sata_link_debounce(struct ata_link *link,
 extern int sata_link_resume(struct ata_link *link, const unsigned long *params,
                             unsigned long deadline);
 extern int sata_link_hardreset(struct ata_link *link,
-                        const unsigned long *timing, unsigned long deadline);
+                        const unsigned long *timing, unsigned long deadline,
+                        bool *online, int (*check_ready)(struct ata_link *));
 extern void ata_std_postreset(struct ata_link *link, unsigned int *classes);
 extern void ata_port_disable(struct ata_port *);