From: Matthew Wilcox <willy@infradead.org>
Date: Mon, 18 Feb 2019 22:29:10 +0000 (-0500)
Subject: pi433: Convert pi433_idr to XArray
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=19010b309fbd560e7b172878619eeb927824546d;p=users%2Fwilly%2Fxarray.git

pi433: Convert pi433_idr to XArray

Signed-off-by: Matthew Wilcox <willy@infradead.org>
---

diff --git a/drivers/staging/pi433/pi433_if.c b/drivers/staging/pi433/pi433_if.c
index 40c6f4e7632f..a34e684b7445 100644
--- a/drivers/staging/pi433/pi433_if.c
+++ b/drivers/staging/pi433/pi433_if.c
@@ -20,7 +20,6 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/idr.h>
 #include <linux/ioctl.h>
 #include <linux/uaccess.h>
 #include <linux/fs.h>
@@ -37,6 +36,7 @@
 #include <linux/gpio/consumer.h>
 #include <linux/kthread.h>
 #include <linux/wait.h>
+#include <linux/xarray.h>
 #include <linux/spi/spi.h>
 #ifdef CONFIG_COMPAT
 #include <linux/compat.h>
@@ -51,8 +51,7 @@
 #define NUM_DIO			2
 
 static dev_t pi433_dev;
-static DEFINE_IDR(pi433_idr);
-static DEFINE_MUTEX(minor_lock); /* Protect idr accesses */
+static DEFINE_XARRAY_ALLOC(pi433_devs);
 
 static struct class *pi433_class; /* mainly for udev to create /dev/pi433 */
 
@@ -945,9 +944,7 @@ static int pi433_open(struct inode *inode, struct file *filp)
 	struct pi433_device	*device;
 	struct pi433_instance	*instance;
 
-	mutex_lock(&minor_lock);
-	device = idr_find(&pi433_idr, iminor(inode));
-	mutex_unlock(&minor_lock);
+	device = xa_load(&pi433_devs, iminor(inode));
 	if (!device) {
 		pr_debug("device: minor %d unknown.\n", iminor(inode));
 		return -ENODEV;
@@ -1060,26 +1057,21 @@ static void free_gpio(struct pi433_device *device)
 
 static int pi433_get_minor(struct pi433_device *device)
 {
-	int retval = -ENOMEM;
-
-	mutex_lock(&minor_lock);
-	retval = idr_alloc(&pi433_idr, device, 0, N_PI433_MINORS, GFP_KERNEL);
-	if (retval >= 0) {
-		device->minor = retval;
-		retval = 0;
-	} else if (retval == -ENOSPC) {
+	int err;
+
+	err = xa_alloc(&pi433_devs, &device->minor, device,
+			XA_LIMIT(0, N_PI433_MINORS - 1), GFP_KERNEL);
+	if (err == -EBUSY) {
 		dev_err(&device->spi->dev, "too many pi433 devices\n");
-		retval = -EINVAL;
+		err = -EINVAL;
 	}
-	mutex_unlock(&minor_lock);
-	return retval;
+
+	return err;
 }
 
 static void pi433_free_minor(struct pi433_device *dev)
 {
-	mutex_lock(&minor_lock);
-	idr_remove(&pi433_idr, dev->minor);
-	mutex_unlock(&minor_lock);
+	xa_erase(&pi433_devs, dev->minor);
 }
 
 /*-------------------------------------------------------------------------*/