libata-link: add PMP links

Add link->pmp, ap->nr_pmp_links, ap->pmp_link[], and implement/update
link helpers.

printk helpers are updated such that port and link are identifed as
'ataP:' if no PMP is attached, while device is identified as
'ataP.DD:'.  If PMP is attached, they become 'ataP:', 'ataP.LL:' and
'ataP.LL' - ie. link and device are identified their PMP number.

If PPM is attached (ap->nr_pmp_links != 0), ata_for_each_link()
iterates over PMP links, while __ata_for_each_link() iterates over the
host link + PMP links.  If PMP is not attached (ap->nr_pmp_links ==
0), both iterate over only the host link.

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

1 files changed, 47 insertions, 6 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index bfa155789993..7a1793bd2371 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -515,6 +515,7 @@ struct ata_acpi_gtm {
 
 struct ata_link {
         struct ata_port         *ap;
+        int                     pmp;            /* port multiplier port # */
 
         unsigned int            active_tag;     /* active tag on this link */
         u32                     sactive;        /* active NCQ commands */
@@ -563,6 +564,9 @@ struct ata_port {
 
         struct ata_link         link;   /* host default link */
 
+        int                     nr_pmp_links;   /* nr of available PMP links */
+        struct ata_link         *pmp_link;      /* array of PMP links */
+
         struct ata_port_stats   stats;
         struct ata_host         *host;
         struct device           *dev;
@@ -926,11 +930,17 @@ extern void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
 #define ata_port_printk(ap, lv, fmt, args...) \
         printk(lv"ata%u: "fmt, (ap)->print_id , ##args)
 
-#define ata_link_printk(link, lv, fmt, args...) \
-        printk(lv"ata%u: "fmt, (link)->ap->print_id , ##args)
+#define ata_link_printk(link, lv, fmt, args...) do { \
+        if ((link)->ap->nr_pmp_links) \
+                printk(lv"ata%u.%02u: "fmt, (link)->ap->print_id, \
+                       (link)->pmp , ##args); \
+        else \
+                printk(lv"ata%u: "fmt, (link)->ap->print_id , ##args); \
+        } while(0)
 
 #define ata_dev_printk(dev, lv, fmt, args...) \
-        printk(lv"ata%u.%02u: "fmt, (dev)->link->ap->print_id, (dev)->devno , ##args)
+        printk(lv"ata%u.%02u: "fmt, (dev)->link->ap->print_id, \
+               (dev)->link->pmp + (dev)->devno , ##args)
 
 /*
  * ata_eh_info helpers
@@ -1039,15 +1049,46 @@ static inline unsigned int ata_dev_absent(const struct ata_device *dev)
 /*
  * link helpers
  */
+static inline int ata_is_host_link(const struct ata_link *link)
+{
+        return link == &link->ap->link;
+}
+
 static inline int ata_link_max_devices(const struct ata_link *link)
 {
-        if (link->ap->flags & ATA_FLAG_SLAVE_POSS)
+        if (ata_is_host_link(link) && link->ap->flags & ATA_FLAG_SLAVE_POSS)
                 return 2;
         return 1;
 }
 
-#define ata_port_for_each_link(lk, ap) \
-        for ((lk) = &(ap)->link; (lk); (lk) = NULL)
+static inline struct ata_link *ata_port_first_link(struct ata_port *ap)
+{
+        if (ap->nr_pmp_links)
+                return ap->pmp_link;
+        return &ap->link;
+}
+
+static inline struct ata_link *ata_port_next_link(struct ata_link *link)
+{
+        struct ata_port *ap = link->ap;
+
+        if (link == &ap->link) {
+                if (!ap->nr_pmp_links)
+                        return NULL;
+                return ap->pmp_link;
+        }
+
+        if (++link - ap->pmp_link < ap->nr_pmp_links)
+                return link;
+        return NULL;
+}
+
+#define __ata_port_for_each_link(lk, ap) \
+        for ((lk) = &(ap)->link; (lk); (lk) = ata_port_next_link(lk))
+
+#define ata_port_for_each_link(link, ap) \
+        for ((link) = ata_port_first_link(ap); (link); \
+             (link) = ata_port_next_link(link))
 
 #define ata_link_for_each_dev(dev, link) \
         for ((dev) = (link)->device; \