NTB: Correct debugfs to work with more than 1 NTB Device

Debugfs was setup in NTB to only have a single debugfs directory.  This
resulted in the leaking of debugfs directories and files when multiple
NTB devices were present, due to each device stomping on the variables
containing the previous device's values (thus preventing them from being
freed on cleanup).  Correct this by creating a secondary directory of
the PCI BDF for each device present, and nesting the previously existing
information in those directories.

Signed-off-by: Jon Mason <jon.mason@intel.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/drivers/ntb/ntb_hw.c b/drivers/ntb/ntb_hw.c
index 26b808b4d3a0..b9bf8b551e3c 100644
--- a/drivers/ntb/ntb_hw.c
+++ b/drivers/ntb/ntb_hw.c
@@ -78,6 +78,8 @@ enum {
 	BWD_HW,
 };
 
+static struct dentry *debugfs_dir;
+
 /* Translate memory window 0,1 to BAR 2,4 */
 #define MW_TO_BAR(mw)	(mw * 2 + 2)
 
@@ -998,6 +1000,28 @@ static void ntb_free_callbacks(struct ntb_device *ndev)
 	kfree(ndev->db_cb);
 }
 
+static void ntb_setup_debugfs(struct ntb_device *ndev)
+{
+	if (!debugfs_initialized())
+		return;
+
+	if (!debugfs_dir)
+		debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);
+
+	ndev->debugfs_dir = debugfs_create_dir(pci_name(ndev->pdev),
+					       debugfs_dir);
+}
+
+static void ntb_free_debugfs(struct ntb_device *ndev)
+{
+	debugfs_remove_recursive(ndev->debugfs_dir);
+
+	if (debugfs_dir && simple_empty(debugfs_dir)) {
+		debugfs_remove_recursive(debugfs_dir);
+		debugfs_dir = NULL;
+	}
+}
+
 static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct ntb_device *ndev;
@@ -1010,6 +1034,7 @@ static int ntb_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 	ndev->pdev = pdev;
 	ndev->link_status = NTB_LINK_DOWN;
 	pci_set_drvdata(pdev, ndev);
+	ntb_setup_debugfs(ndev);
 
 	rc = pci_enable_device(pdev);
 	if (rc)
@@ -1106,6 +1131,7 @@ err2:
 err1:
 	pci_disable_device(pdev);
 err:
+	ntb_free_debugfs(ndev);
 	kfree(ndev);
 
 	dev_err(&pdev->dev, "Error loading %s module\n", KBUILD_MODNAME);
@@ -1135,6 +1161,7 @@ static void ntb_pci_remove(struct pci_dev *pdev)
 	iounmap(ndev->reg_base);
 	pci_release_selected_regions(pdev, NTB_BAR_MASK);
 	pci_disable_device(pdev);
+	ntb_free_debugfs(ndev);
 	kfree(ndev);
 }