[PATCH] rapidio: use is_visible() to hide switch-specific attributes

[Dmitry Torokhov]

Instead of creating switch-specific attributes by hand, implement
is_visible() method of attribute group and hide them when dealing with
non-switch devices. This will ensure that all attributes are created
together, before userspace gets notified of new device.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---

Not tested on hardware, compiled only.

 drivers/rapidio/rio-sysfs.c | 76 ++++++++++++++++++++-------------------------
 drivers/rapidio/rio.c       |  3 --
 drivers/rapidio/rio.h       |  2 --
 3 files changed, 33 insertions(+), 48 deletions(-)

diff --git a/drivers/rapidio/rio-sysfs.c b/drivers/rapidio/rio-sysfs.c
index eda41563d06d..73e4b407f162 100644
--- a/drivers/rapidio/rio-sysfs.c
+++ b/drivers/rapidio/rio-sysfs.c
@@ -108,15 +108,11 @@ static struct attribute *rio_dev_attrs[] = {
 	&dev_attr_lprev.attr,
 	&dev_attr_destid.attr,
 	&dev_attr_modalias.attr,
-	NULL,
-};
 
-static const struct attribute_group rio_dev_group = {
-	.attrs = rio_dev_attrs,
-};
-
-const struct attribute_group *rio_dev_groups[] = {
-	&rio_dev_group,
+	/* Switch-only attributes */
+	&dev_attr_routes.attr,
+	&dev_attr_lnext.attr,
+	&dev_attr_hopcount.attr,
 	NULL,
 };
 
@@ -259,46 +255,40 @@ static struct bin_attribute rio_config_attr = {
 	.write = rio_write_config,
 };
 
-/**
- * rio_create_sysfs_dev_files - create RIO specific sysfs files
- * @rdev: device whose entries should be created
- *
- * Create files when @rdev is added to sysfs.
- */
-int rio_create_sysfs_dev_files(struct rio_dev *rdev)
-{
-	int err = 0;
-
-	err = device_create_bin_file(&rdev->dev, &rio_config_attr);
+static struct bin_attribute *rio_dev_bin_attrs[] = {
+	&rio_config_attr,
+	NULL,
+};
 
-	if (!err && (rdev->pef & RIO_PEF_SWITCH)) {
-		err |= device_create_file(&rdev->dev, &dev_attr_routes);
-		err |= device_create_file(&rdev->dev, &dev_attr_lnext);
-		err |= device_create_file(&rdev->dev, &dev_attr_hopcount);
+static umode_t rio_dev_is_attr_visible(struct kobject *kobj,
+				       struct attribute *attr, int n)
+{
+	struct rio_dev *rdev = to_rio_dev(kobj_to_dev(kobj));
+	umode_t mode = attr->mode;
+
+	if (!(rdev->pef & RIO_PEF_SWITCH) &&
+	    (attr == &dev_attr_routes.attr ||
+	     attr == &dev_attr_lnext.attr ||
+	     attr == &dev_attr_hopcount.attr)) {
+		/*
+		 * Hide switch-specific attributes for a non-switch device.
+		 */
+		mode = 0;
 	}
 
-	if (err)
-		pr_warning("RIO: Failed to create attribute file(s) for %s\n",
-			   rio_name(rdev));
-
-	return err;
+	return mode;
 }
 
-/**
- * rio_remove_sysfs_dev_files - cleanup RIO specific sysfs files
- * @rdev: device whose entries we should free
- *
- * Cleanup when @rdev is removed from sysfs.
- */
-void rio_remove_sysfs_dev_files(struct rio_dev *rdev)
-{
-	device_remove_bin_file(&rdev->dev, &rio_config_attr);
-	if (rdev->pef & RIO_PEF_SWITCH) {
-		device_remove_file(&rdev->dev, &dev_attr_routes);
-		device_remove_file(&rdev->dev, &dev_attr_lnext);
-		device_remove_file(&rdev->dev, &dev_attr_hopcount);
-	}
-}
+static const struct attribute_group rio_dev_group = {
+	.attrs		= rio_dev_attrs,
+	.is_visible	= rio_dev_is_attr_visible,
+	.bin_attrs	= rio_dev_bin_attrs,
+};
+
+const struct attribute_group *rio_dev_groups[] = {
+	&rio_dev_group,
+	NULL,
+};
 
 static ssize_t bus_scan_store(struct bus_type *bus, const char *buf,
 				size_t count)
diff --git a/drivers/rapidio/rio.c b/drivers/rapidio/rio.c
index 37042858c2db..38d949405618 100644
--- a/drivers/rapidio/rio.c
+++ b/drivers/rapidio/rio.c
@@ -192,8 +192,6 @@ int rio_add_device(struct rio_dev *rdev)
 	}
 	spin_unlock(&rio_global_list_lock);
 
-	rio_create_sysfs_dev_files(rdev);
-
 	return 0;
 }
 EXPORT_SYMBOL_GPL(rio_add_device);
@@ -220,7 +218,6 @@ void rio_del_device(struct rio_dev *rdev, enum rio_device_state state)
 		}
 	}
 	spin_unlock(&rio_global_list_lock);
-	rio_remove_sysfs_dev_files(rdev);
 	device_unregister(&rdev->dev);
 }
 EXPORT_SYMBOL_GPL(rio_del_device);
diff --git a/drivers/rapidio/rio.h b/drivers/rapidio/rio.h
index 9796b3fee70d..b2abf8576397 100644
--- a/drivers/rapidio/rio.h
+++ b/drivers/rapidio/rio.h
@@ -27,8 +27,6 @@ extern u32 rio_mport_get_efb(struct rio_mport *port, int local, u16 destid,
 			     u8 hopcount, u32 from);
 extern int rio_mport_chk_dev_access(struct rio_mport *mport, u16 destid,
 				    u8 hopcount);
-extern int rio_create_sysfs_dev_files(struct rio_dev *rdev);
-extern void rio_remove_sysfs_dev_files(struct rio_dev *rdev);
 extern int rio_lock_device(struct rio_mport *port, u16 destid,
 			u8 hopcount, int wait_ms);
 extern int rio_unlock_device(struct rio_mport *port, u16 destid, u8 hopcount);
-- 
2.11.0.483.g087da7b7c-goog


-- 
Dmitry