libata: separate out ata_wait_ready() and implement ata_wait_after_reset()

Factor out waiting logic (which is common to all ATA controllers) from
ata_sff_wait_ready() into ata_wait_ready().  ata_wait_ready() takes
@check_ready function pointer and uses it to poll for readiness.  This
allows non-SFF controllers to use ata_wait_ready() to wait for link
readiness.

This patch also implements ata_wait_after_reset() - generic version of
ata_sff_wait_after_reset() - using ata_wait_ready().

ata_sff_wait_ready() is reimplemented using ata_wait_ready() and
ata_sff_check_ready().  Functionality remains the same.

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

4 files changed, 114 insertions, 50 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index eaead76c9443..3bad6f189190 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -3311,6 +3311,103 @@ int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
 }
 
 /**
+ *      ata_wait_ready - wait for link to become ready
+ *      @link: link to be waited on
+ *      @deadline: deadline jiffies for the operation
+ *      @check_ready: callback to check link readiness
+ *
+ *      Wait for @link to become ready.  @check_ready should return
+ *      positive number if @link is ready, 0 if it isn't, -ENODEV if
+ *      link doesn't seem to be occupied, other errno for other error
+ *      conditions.
+ *
+ *      Transient -ENODEV conditions are allowed for
+ *      ATA_TMOUT_FF_WAIT.
+ *
+ *      LOCKING:
+ *      EH context.
+ *
+ *      RETURNS:
+ *      0 if @linke is ready before @deadline; otherwise, -errno.
+ */
+int ata_wait_ready(struct ata_link *link, unsigned long deadline,
+                   int (*check_ready)(struct ata_link *link))
+{
+        unsigned long start = jiffies;
+        unsigned long nodev_deadline = start + ATA_TMOUT_FF_WAIT;
+        int warned = 0;
+
+        if (time_after(nodev_deadline, deadline))
+                nodev_deadline = deadline;
+
+        while (1) {
+                unsigned long now = jiffies;
+                int ready, tmp;
+
+                ready = tmp = check_ready(link);
+                if (ready > 0)
+                        return 0;
+
+                /* -ENODEV could be transient.  Ignore -ENODEV if link
+                 * is online.  Also, some SATA devices take a long
+                 * time to clear 0xff after reset.  For example,
+                 * HHD424020F7SV00 iVDR needs >= 800ms while Quantum
+                 * GoVault needs even more than that.  Wait for
+                 * ATA_TMOUT_FF_WAIT on -ENODEV if link isn't offline.
+                 *
+                 * Note that some PATA controllers (pata_ali) explode
+                 * if status register is read more than once when
+                 * there's no device attached.
+                 */
+                if (ready == -ENODEV) {
+                        if (ata_link_online(link))
+                                ready = 0;
+                        else if ((link->ap->flags & ATA_FLAG_SATA) &&
+                                 !ata_link_offline(link) &&
+                                 time_before(now, nodev_deadline))
+                                ready = 0;
+                }
+
+                if (ready)
+                        return ready;
+                if (time_after(now, deadline))
+                        return -EBUSY;
+
+                if (!warned && time_after(now, start + 5 * HZ) &&
+                    (deadline - now > 3 * HZ)) {
+                        ata_link_printk(link, KERN_WARNING,
+                                "link is slow to respond, please be patient "
+                                "(ready=%d)\n", tmp);
+                        warned = 1;
+                }
+
+                msleep(50);
+        }
+}
+
+/**
+ *      ata_wait_after_reset - wait for link to become ready after reset
+ *      @link: link to be waited on
+ *      @deadline: deadline jiffies for the operation
+ *      @check_ready: callback to check link readiness
+ *
+ *      Wait for @link to become ready after reset.
+ *
+ *      LOCKING:
+ *      EH context.
+ *
+ *      RETURNS:
+ *      0 if @linke is ready before @deadline; otherwise, -errno.
+ */
+extern int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
+                                int (*check_ready)(struct ata_link *link))
+{
+        msleep(ATA_WAIT_AFTER_RESET_MSECS);
+
+        return ata_wait_ready(link, deadline, check_ready);
+}
+
+/**
  *      sata_link_debounce - debounce SATA phy status
  *      @link: ATA link to debounce SATA phy status for
  *      @params: timing parameters { interval, duratinon, timeout } in msec
@@ -6075,6 +6172,7 @@ EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
 EXPORT_SYMBOL_GPL(ata_port_probe);
 EXPORT_SYMBOL_GPL(ata_dev_disable);
 EXPORT_SYMBOL_GPL(sata_set_spd);
+EXPORT_SYMBOL_GPL(ata_wait_after_reset);
 EXPORT_SYMBOL_GPL(sata_link_debounce);
 EXPORT_SYMBOL_GPL(sata_link_resume);
 EXPORT_SYMBOL_GPL(ata_std_prereset);
diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 6e8de3c1595e..78912c5011ad 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -308,6 +308,17 @@ int ata_sff_busy_sleep(struct ata_port *ap,
         return 0;
 }
 
+static int ata_sff_check_ready(struct ata_link *link)
+{
+        u8 status = link->ap->ops->sff_check_status(link->ap);
+
+        if (!(status & ATA_BUSY))
+                return 1;
+        if (status == 0xff)
+                return -ENODEV;
+        return 0;
+}
+
 /**
  *      ata_sff_wait_ready - sleep until BSY clears, or timeout
  *      @link: SFF link to wait ready status for
@@ -324,56 +335,7 @@ int ata_sff_busy_sleep(struct ata_port *ap,
  */
 int ata_sff_wait_ready(struct ata_link *link, unsigned long deadline)
 {
-        struct ata_port *ap = link->ap;
-        unsigned long start = jiffies;
-        unsigned long nodev_deadline = start + ATA_TMOUT_FF_WAIT;
-        int warned = 0;
-
-        if (time_after(nodev_deadline, deadline))
-                nodev_deadline = deadline;
-
-        while (1) {
-                u8 status = ap->ops->sff_check_status(ap);
-                unsigned long now = jiffies;
-
-                if (!(status & ATA_BUSY))
-                        return 0;
-
-                /* No device status could be transient.  Ignore it if
-                 * link is online.  Also, some SATA devices take a
-                 * long time to clear 0xff after reset.  For example,
-                 * HHD424020F7SV00 iVDR needs >= 800ms while Quantum
-                 * GoVault needs even more than that.  Wait for
-                 * ATA_TMOUT_FF_WAIT on -ENODEV if link isn't offline.
-                 *
-                 * Note that some PATA controllers (pata_ali) explode
-                 * if status register is read more than once when
-                 * there's no device attached.
-                 */
-                if (status == 0xff) {
-                        if (ata_link_online(link))
-                                status = ATA_BUSY;
-                        else if ((link->ap->flags & ATA_FLAG_SATA) &&
-                                 !ata_link_offline(link) &&
-                                 time_before(now, nodev_deadline))
-                                status = ATA_BUSY;
-                        if (status == 0xff)
-                                return -ENODEV;
-                }
-
-                if (time_after(now, deadline))
-                        return -EBUSY;
-
-                if (!warned && time_after(now, start + 5 * HZ) &&
-                    (deadline - now > 3 * HZ)) {
-                        ata_link_printk(link, KERN_WARNING,
-                                "link is slow to respond, please be patient "
-                                "(Status 0x%x)\n", status);
-                        warned = 1;
-                }
-
-                msleep(50);
-        }
+        return ata_wait_ready(link, deadline, ata_sff_check_ready);
 }
 
 /**
diff --git a/drivers/ata/libata.h b/drivers/ata/libata.h
index 11b5f67a19d4..08af43e2c081 100644
--- a/drivers/ata/libata.h
+++ b/drivers/ata/libata.h
@@ -81,6 +81,8 @@ extern unsigned ata_exec_internal_sg(struct ata_device *dev,
                                      int dma_dir, struct scatterlist *sg,
                                      unsigned int n_elem, unsigned long timeout);
 extern unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd);
+extern int ata_wait_ready(struct ata_link *link, unsigned long deadline,
+                          int (*check_ready)(struct ata_link *link));
 extern int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
                            unsigned int flags, u16 *id);
 extern int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags);
diff --git a/include/linux/libata.h b/include/linux/libata.h
index da5560244787..4bbf2524e473 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -837,6 +837,8 @@ extern void sata_print_link_status(struct ata_link *link);
 extern void ata_port_probe(struct ata_port *);
 extern int sata_set_spd(struct ata_link *link);
 extern int ata_std_prereset(struct ata_link *link, unsigned long deadline);
+extern int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
+                                int (*check_ready)(struct ata_link *link));
 extern int sata_link_debounce(struct ata_link *link,
                         const unsigned long *params, unsigned long deadline);
 extern int sata_link_resume(struct ata_link *link, const unsigned long *params,