[SCSI] scsi_transport_sas: support link error attributes

For now supporting the ->get_linkerrors method is mandatory.  I'll
probably be beaten to implement the .show_foo variables and different
types of attributes soon..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

2 files changed, 49 insertions, 5 deletions

diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 1d145d2f9a38..63445f90097e 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -34,7 +34,7 @@
 
 
 #define SAS_HOST_ATTRS          0
-#define SAS_PORT_ATTRS          11
+#define SAS_PORT_ATTRS          15
 #define SAS_RPORT_ATTRS         5
 
 struct sas_internal {
@@ -257,6 +257,26 @@ show_sas_phy_##field(struct class_device *cdev, char *buf)		\
         sas_phy_show_linkspeed(field)                                   \
 static CLASS_DEVICE_ATTR(field, S_IRUGO, show_sas_phy_##field, NULL)
 
+#define sas_phy_show_linkerror(field)                                   \
+static ssize_t                                                          \
+show_sas_phy_##field(struct class_device *cdev, char *buf)              \
+{                                                                       \
+        struct sas_phy *phy = transport_class_to_phy(cdev);             \
+        struct Scsi_Host *shost = dev_to_shost(phy->dev.parent);        \
+        struct sas_internal *i = to_sas_internal(shost->transportt);    \
+        int error;                                                      \
+                                                                        \
+        error = i->f->get_linkerrors(phy);                              \
+        if (error)                                                      \
+                return error;                                           \
+        return snprintf(buf, 20, "%u\n", phy->field);                   \
+}
+
+#define sas_phy_linkerror_attr(field)                                   \
+        sas_phy_show_linkerror(field)                                   \
+static CLASS_DEVICE_ATTR(field, S_IRUGO, show_sas_phy_##field, NULL)
+
+
 static ssize_t
 show_sas_device_type(struct class_device *cdev, char *buf)
 {
@@ -282,6 +302,10 @@ sas_phy_linkspeed_attr(minimum_linkrate_hw);
 sas_phy_linkspeed_attr(minimum_linkrate);
 sas_phy_linkspeed_attr(maximum_linkrate_hw);
 sas_phy_linkspeed_attr(maximum_linkrate);
+sas_phy_linkerror_attr(invalid_dword_count);
+sas_phy_linkerror_attr(running_disparity_error_count);
+sas_phy_linkerror_attr(loss_of_dword_sync_count);
+sas_phy_linkerror_attr(phy_reset_problem_count);
 
 
 static DECLARE_TRANSPORT_CLASS(sas_phy_class,
@@ -749,6 +773,11 @@ sas_attach_transport(struct sas_function_template *ft)
         SETUP_PORT_ATTRIBUTE(minimum_linkrate);
         SETUP_PORT_ATTRIBUTE(maximum_linkrate_hw);
         SETUP_PORT_ATTRIBUTE(maximum_linkrate);
+
+        SETUP_PORT_ATTRIBUTE(invalid_dword_count);
+        SETUP_PORT_ATTRIBUTE(running_disparity_error_count);
+        SETUP_PORT_ATTRIBUTE(loss_of_dword_sync_count);
+        SETUP_PORT_ATTRIBUTE(phy_reset_problem_count);
         i->phy_attrs[count] = NULL;
 
         count = 0;
diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index bc4aeb660dd3..38389d8dd56e 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -41,20 +41,28 @@ struct sas_identify {
         u8                      phy_identifier;
 };
 
-/* The functions by which the transport class and the driver communicate */
-struct sas_function_template {
-};
-
 struct sas_phy {
         struct device           dev;
         int                     number;
+
+        /* phy identification */
         struct sas_identify     identify;
+
+        /* phy attributes */
         enum sas_linkrate       negotiated_linkrate;
         enum sas_linkrate       minimum_linkrate_hw;
         enum sas_linkrate       minimum_linkrate;
         enum sas_linkrate       maximum_linkrate_hw;
         enum sas_linkrate       maximum_linkrate;
         u8                      port_identifier;
+
+        /* link error statistics */
+        u32                     invalid_dword_count;
+        u32                     running_disparity_error_count;
+        u32                     loss_of_dword_sync_count;
+        u32                     phy_reset_problem_count;
+
+        /* the other end of the link */
         struct sas_rphy         *rphy;
 };
 
@@ -79,6 +87,13 @@ struct sas_rphy {
 #define rphy_to_shost(rphy) \
         dev_to_shost((rphy)->dev.parent)
 
+
+/* The functions by which the transport class and the driver communicate */
+struct sas_function_template {
+        int (*get_linkerrors)(struct sas_phy *);
+};
+
+
 extern void sas_remove_host(struct Scsi_Host *);
 
 extern struct sas_phy *sas_phy_alloc(struct device *, int);