accel: Use XArray instead of IDR for minors

Accel minor management is based on DRM (and is also using struct
drm_minor internally), since DRM is using XArray for minors, it makes
sense to also convert accel.
As the two implementations are identical (only difference being the
underlying xarray), move the accel_minor_* functionality to DRM.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Acked-by: James Zhu <James.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240823163048.2676257-3-michal.winiarski@intel.com
Signed-off-by: Christian König <christian.koenig@amd.com>

1 files changed, 7 insertions, 103 deletions

diff --git a/drivers/accel/drm_accel.c b/drivers/accel/drm_accel.c
index 16c3edb8c46e..aa826033b0ce 100644
--- a/drivers/accel/drm_accel.c
+++ b/drivers/accel/drm_accel.c
@@ -8,7 +8,7 @@
 
 #include <linux/debugfs.h>
 #include <linux/device.h>
-#include <linux/idr.h>
+#include <linux/xarray.h>
 
 #include <drm/drm_accel.h>
 #include <drm/drm_auth.h>
@@ -18,8 +18,7 @@
 #include <drm/drm_ioctl.h>
 #include <drm/drm_print.h>
 
-static DEFINE_SPINLOCK(accel_minor_lock);
-static struct idr accel_minors_idr;
+DEFINE_XARRAY_ALLOC(accel_minors_xa);
 
 static struct dentry *accel_debugfs_root;
 
@@ -118,99 +117,6 @@ void accel_set_device_instance_params(struct device *kdev, int index)
 }
 
 /**
- * accel_minor_alloc() - Allocates a new accel minor
- *
- * This function access the accel minors idr and allocates from it
- * a new id to represent a new accel minor
- *
- * Return: A new id on success or error code in case idr_alloc failed
- */
-int accel_minor_alloc(void)
-{
-	unsigned long flags;
-	int r;
-
-	spin_lock_irqsave(&accel_minor_lock, flags);
-	r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT);
-	spin_unlock_irqrestore(&accel_minor_lock, flags);
-
-	return r;
-}
-
-/**
- * accel_minor_remove() - Remove an accel minor
- * @index: The minor id to remove.
- *
- * This function access the accel minors idr and removes from
- * it the member with the id that is passed to this function.
- */
-void accel_minor_remove(int index)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&accel_minor_lock, flags);
-	idr_remove(&accel_minors_idr, index);
-	spin_unlock_irqrestore(&accel_minor_lock, flags);
-}
-
-/**
- * accel_minor_replace() - Replace minor pointer in accel minors idr.
- * @minor: Pointer to the new minor.
- * @index: The minor id to replace.
- *
- * This function access the accel minors idr structure and replaces the pointer
- * that is associated with an existing id. Because the minor pointer can be
- * NULL, we need to explicitly pass the index.
- *
- * Return: 0 for success, negative value for error
- */
-void accel_minor_replace(struct drm_minor *minor, int index)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&accel_minor_lock, flags);
-	idr_replace(&accel_minors_idr, minor, index);
-	spin_unlock_irqrestore(&accel_minor_lock, flags);
-}
-
-/*
- * Looks up the given minor-ID and returns the respective DRM-minor object. The
- * refence-count of the underlying device is increased so you must release this
- * object with accel_minor_release().
- *
- * The object can be only a drm_minor that represents an accel device.
- *
- * As long as you hold this minor, it is guaranteed that the object and the
- * minor->dev pointer will stay valid! However, the device may get unplugged and
- * unregistered while you hold the minor.
- */
-static struct drm_minor *accel_minor_acquire(unsigned int minor_id)
-{
-	struct drm_minor *minor;
-	unsigned long flags;
-
-	spin_lock_irqsave(&accel_minor_lock, flags);
-	minor = idr_find(&accel_minors_idr, minor_id);
-	if (minor)
-		drm_dev_get(minor->dev);
-	spin_unlock_irqrestore(&accel_minor_lock, flags);
-
-	if (!minor) {
-		return ERR_PTR(-ENODEV);
-	} else if (drm_dev_is_unplugged(minor->dev)) {
-		drm_dev_put(minor->dev);
-		return ERR_PTR(-ENODEV);
-	}
-
-	return minor;
-}
-
-static void accel_minor_release(struct drm_minor *minor)
-{
-	drm_dev_put(minor->dev);
-}
-
-/**
  * accel_open - open method for ACCEL file
  * @inode: device inode
  * @filp: file pointer.
@@ -227,7 +133,7 @@ int accel_open(struct inode *inode, struct file *filp)
 	struct drm_minor *minor;
 	int retcode;
 
-	minor = accel_minor_acquire(iminor(inode));
+	minor = drm_minor_acquire(&accel_minors_xa, iminor(inode));
 	if (IS_ERR(minor))
 		return PTR_ERR(minor);
 
@@ -246,7 +152,7 @@ int accel_open(struct inode *inode, struct file *filp)
 
 err_undo:
 	atomic_dec(&dev->open_count);
-	accel_minor_release(minor);
+	drm_minor_release(minor);
 	return retcode;
 }
 EXPORT_SYMBOL_GPL(accel_open);
@@ -257,7 +163,7 @@ static int accel_stub_open(struct inode *inode, struct file *filp)
 	struct drm_minor *minor;
 	int err;
 
-	minor = accel_minor_acquire(iminor(inode));
+	minor = drm_minor_acquire(&accel_minors_xa, iminor(inode));
 	if (IS_ERR(minor))
 		return PTR_ERR(minor);
 
@@ -274,7 +180,7 @@ static int accel_stub_open(struct inode *inode, struct file *filp)
 		err = 0;
 
 out:
-	accel_minor_release(minor);
+	drm_minor_release(minor);
 
 	return err;
 }
@@ -290,15 +196,13 @@ void accel_core_exit(void)
 	unregister_chrdev(ACCEL_MAJOR, "accel");
 	debugfs_remove(accel_debugfs_root);
 	accel_sysfs_destroy();
-	idr_destroy(&accel_minors_idr);
+	WARN_ON(!xa_empty(&accel_minors_xa));
 }
 
 int __init accel_core_init(void)
 {
 	int ret;
 
-	idr_init(&accel_minors_idr);
-
 	ret = accel_sysfs_init();
 	if (ret < 0) {
 		DRM_ERROR("Cannot create ACCEL class: %d\n", ret);