[PATCH] xilinx_sdfec: Convert to IDA

[Matthew Wilcox]

From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

This driver does not use the lookup abilities of the IDR, so convert it
to the more space-efficient IDA.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
 drivers/misc/xilinx_sdfec.c | 25 ++++++-------------------
 1 file changed, 6 insertions(+), 19 deletions(-)

diff --git a/drivers/misc/xilinx_sdfec.c b/drivers/misc/xilinx_sdfec.c
index f257d3812110..071b26a8c6a9 100644
--- a/drivers/misc/xilinx_sdfec.c
+++ b/drivers/misc/xilinx_sdfec.c
@@ -22,8 +22,7 @@
 
 #define DEV_NAME_LEN 12
 
-static struct idr dev_idr;
-static struct mutex dev_idr_lock;
+static DEFINE_IDA(dev_nrs);
 
 /**
  * struct xsdfec_clks - For managing SD-FEC clocks
@@ -227,13 +226,6 @@ static void xsdfec_disable_all_clks(struct xsdfec_clks *clks)
 	clk_disable_unprepare(clks->axi_clk);
 }
 
-static void xsdfec_idr_remove(struct xsdfec_dev *xsdfec)
-{
-	mutex_lock(&dev_idr_lock);
-	idr_remove(&dev_idr, xsdfec->dev_id);
-	mutex_unlock(&dev_idr_lock);
-}
-
 static int xsdfec_probe(struct platform_device *pdev)
 {
 	struct xsdfec_dev *xsdfec;
@@ -263,9 +255,7 @@ static int xsdfec_probe(struct platform_device *pdev)
 	/* Save driver private data */
 	platform_set_drvdata(pdev, xsdfec);
 
-	mutex_lock(&dev_idr_lock);
-	err = idr_alloc(&dev_idr, xsdfec->dev_name, 0, 0, GFP_KERNEL);
-	mutex_unlock(&dev_idr_lock);
+	err = ida_alloc(&dev_nrs, GFP_KERNEL);
 	if (err < 0)
 		goto err_xsdfec_dev;
 	xsdfec->dev_id = err;
@@ -278,12 +268,12 @@ static int xsdfec_probe(struct platform_device *pdev)
 	err = misc_register(&xsdfec->miscdev);
 	if (err) {
 		dev_err(dev, "error:%d. Unable to register device", err);
-		goto err_xsdfec_idr;
+		goto err_xsdfec_ida;
 	}
 	return 0;
 
-err_xsdfec_idr:
-	xsdfec_idr_remove(xsdfec);
+err_xsdfec_ida:
+	ida_free(&dev_nrs, xsdfec->dev_id);
 err_xsdfec_dev:
 	xsdfec_disable_all_clks(&xsdfec->clks);
 	return err;
@@ -295,7 +285,7 @@ static int xsdfec_remove(struct platform_device *pdev)
 
 	xsdfec = platform_get_drvdata(pdev);
 	misc_deregister(&xsdfec->miscdev);
-	xsdfec_idr_remove(xsdfec);
+	ida_free(&dev_nrs, xsdfec->dev_id);
 	xsdfec_disable_all_clks(&xsdfec->clks);
 	return 0;
 }
@@ -321,8 +311,6 @@ static int __init xsdfec_init(void)
 {
 	int err;
 
-	mutex_init(&dev_idr_lock);
-	idr_init(&dev_idr);
 	err = platform_driver_register(&xsdfec_driver);
 	if (err < 0) {
 		pr_err("%s Unabled to register SDFEC driver", __func__);
@@ -334,7 +322,6 @@ static int __init xsdfec_init(void)
 static void __exit xsdfec_exit(void)
 {
 	platform_driver_unregister(&xsdfec_driver);
-	idr_destroy(&dev_idr);
 }
 
 module_init(xsdfec_init);
-- 
2.20.1