drm: Convert drm_minors_idr to XArray

Convert a few _irqsave to plain _irq where I can prove it's currently
called from process context with interrupts enabled.

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

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 9d00947ca447fc9555d2abc4194bf95dad799207..c16af0a4473e18e11013c723570d27283dbf9a5e 100644 (file)
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -67,8 +67,7 @@ MODULE_PARM_DESC(debug, "Enable debug output, where each bit enables a debug cat
 "\t\tBit 8 (0x100) will enable DP messages (displayport code)");
 module_param_named(debug, drm_debug, int, 0600);
 
-static DEFINE_SPINLOCK(drm_minor_lock);
-static struct idr drm_minors_idr;
+static DEFINE_XARRAY_FLAGS(drm_minors, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
 
 /*
  * If the drm core fails to init for whatever reason,
@@ -112,7 +111,6 @@ static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
 static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
 {
        struct drm_minor *minor;
-       unsigned long flags;
        int r;
 
        minor = kzalloc(sizeof(*minor), GFP_KERNEL);
@@ -122,21 +120,11 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
        minor->type = type;
        minor->dev = dev;
 
-       idr_preload(GFP_KERNEL);
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       r = idr_alloc(&drm_minors_idr,
-                     NULL,
-                     64 * type,
-                     64 * (type + 1),
-                     GFP_NOWAIT);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
-       idr_preload_end();
-
+       r = xa_alloc_irq(&drm_minors, &minor->index, NULL,
+                       XA_LIMIT(64 * type, 64 * type + 63), GFP_KERNEL);
        if (r < 0)
                goto err_free;
 
-       minor->index = r;
-
        minor->kdev = drm_sysfs_minor_alloc(minor);
        if (IS_ERR(minor->kdev)) {
                r = PTR_ERR(minor->kdev);
@@ -147,9 +135,7 @@ static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
        return 0;
 
 err_index:
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       idr_remove(&drm_minors_idr, minor->index);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
+       xa_erase_irq(&drm_minors, minor->index);
 err_free:
        kfree(minor);
        return r;
@@ -167,9 +153,9 @@ static void drm_minor_free(struct drm_device *dev, unsigned int type)
 
        put_device(minor->kdev);
 
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       idr_remove(&drm_minors_idr, minor->index);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
+       xa_lock_irqsave(&drm_minors, flags);
+       __xa_erase(&drm_minors, minor->index);
+       xa_unlock_irqrestore(&drm_minors, flags);
 
        kfree(minor);
        *slot = NULL;
@@ -178,7 +164,6 @@ static void drm_minor_free(struct drm_device *dev, unsigned int type)
 static int drm_minor_register(struct drm_device *dev, unsigned int type)
 {
        struct drm_minor *minor;
-       unsigned long flags;
        int ret;
 
        DRM_DEBUG("\n");
@@ -198,9 +183,7 @@ static int drm_minor_register(struct drm_device *dev, unsigned int type)
                goto err_debugfs;
 
        /* replace NULL with @minor so lookups will succeed from now on */
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       idr_replace(&drm_minors_idr, minor, minor->index);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
+       xa_store_irq(&drm_minors, minor->index, minor, GFP_KERNEL);
 
        DRM_DEBUG("new minor registered %d\n", minor->index);
        return 0;
@@ -220,9 +203,9 @@ static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
                return;
 
        /* replace @minor with NULL so lookups will fail from now on */
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       idr_replace(&drm_minors_idr, NULL, minor->index);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
+       xa_lock_irqsave(&drm_minors, flags);
+       __xa_store(&drm_minors, minor->index, NULL, 0);
+       xa_unlock_irqrestore(&drm_minors, flags);
 
        device_del(minor->kdev);
        dev_set_drvdata(minor->kdev, NULL); /* safety belt */
@@ -243,11 +226,11 @@ struct drm_minor *drm_minor_acquire(unsigned int minor_id)
        struct drm_minor *minor;
        unsigned long flags;
 
-       spin_lock_irqsave(&drm_minor_lock, flags);
-       minor = idr_find(&drm_minors_idr, minor_id);
+       xa_lock_irqsave(&drm_minors, flags);
+       minor = xa_load(&drm_minors, minor_id);
        if (minor)
                drm_dev_get(minor->dev);
-       spin_unlock_irqrestore(&drm_minor_lock, flags);
+       xa_unlock_irqrestore(&drm_minors, flags);
 
        if (!minor) {
                return ERR_PTR(-ENODEV);
@@ -1134,7 +1117,7 @@ static void drm_core_exit(void)
        unregister_chrdev(DRM_MAJOR, "drm");
        debugfs_remove(drm_debugfs_root);
        drm_sysfs_destroy();
-       idr_destroy(&drm_minors_idr);
+       WARN_ON(!xa_empty(&drm_minors));
        drm_connector_ida_destroy();
 }
 
@@ -1143,7 +1126,6 @@ static int __init drm_core_init(void)
        int ret;
 
        drm_connector_ida_init();
-       idr_init(&drm_minors_idr);
 
        ret = drm_sysfs_init();
        if (ret < 0) {