IB/ipath: Driver support for userspace sharing of HW contexts

This allows multiple userspace processes to share a single hardware
context in a master/slave arrangement.  It is backwards binary compatible
with existing userspace.

Signed-off-by: Bryan O'Sullivan <bryan.osullivan@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/ipath/ipath_sysfs.c b/drivers/infiniband/hw/ipath/ipath_sysfs.c
index e299148c4b68..b48ebf62e5dd 100644
--- a/drivers/infiniband/hw/ipath/ipath_sysfs.c
+++ b/drivers/infiniband/hw/ipath/ipath_sysfs.c
@@ -297,6 +297,16 @@ static ssize_t show_nguid(struct device *dev,
         return scnprintf(buf, PAGE_SIZE, "%u\n", dd->ipath_nguid);
 }
 
+static ssize_t show_nports(struct device *dev,
+                           struct device_attribute *attr,
+                           char *buf)
+{
+        struct ipath_devdata *dd = dev_get_drvdata(dev);
+
+        /* Return the number of user ports available. */
+        return scnprintf(buf, PAGE_SIZE, "%u\n", dd->ipath_cfgports - 1);
+}
+
 static ssize_t show_serial(struct device *dev,
                            struct device_attribute *attr,
                            char *buf)
@@ -608,6 +618,7 @@ static DEVICE_ATTR(mlid, S_IWUSR | S_IRUGO, show_mlid, store_mlid);
 static DEVICE_ATTR(mtu, S_IWUSR | S_IRUGO, show_mtu, store_mtu);
 static DEVICE_ATTR(enabled, S_IWUSR | S_IRUGO, show_enabled, store_enabled);
 static DEVICE_ATTR(nguid, S_IRUGO, show_nguid, NULL);
+static DEVICE_ATTR(nports, S_IRUGO, show_nports, NULL);
 static DEVICE_ATTR(reset, S_IWUSR, NULL, store_reset);
 static DEVICE_ATTR(serial, S_IRUGO, show_serial, NULL);
 static DEVICE_ATTR(status, S_IRUGO, show_status, NULL);
@@ -623,6 +634,7 @@ static struct attribute *dev_attributes[] = {
         &dev_attr_mlid.attr,
         &dev_attr_mtu.attr,
         &dev_attr_nguid.attr,
+        &dev_attr_nports.attr,
         &dev_attr_serial.attr,
         &dev_attr_status.attr,
         &dev_attr_status_str.attr,