IDR is deprecated, and since XArray manages its own state with internal
locking, it simplifies the locking on DRM side.
Additionally, don't use the IRQ-safe variant, since operating on drm
minor is not done in IRQ context.
Signed-off-by: Michał Winiarski <michal.winiar...@intel.com>
Suggested-by: Matthew Wilcox <wi...@infradead.org>
---
drivers/gpu/drm/drm_drv.c | 49 ++++++++++++++-------------------------
1 file changed, 17 insertions(+), 32 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 8214a0b1ab7f..41799e4d0432 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -34,6 +34,7 @@
#include <linux/pseudo_fs.h>
#include <linux/slab.h>
#include <linux/srcu.h>
+#include <linux/xarray.h>
#include <drm/drm_cache.h>
#include <drm/drm_client.h>
@@ -53,8 +54,7 @@ MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon
Smirl");
MODULE_DESCRIPTION("DRM shared core routines");
MODULE_LICENSE("GPL and additional rights");
-static DEFINE_SPINLOCK(drm_minor_lock);
-static struct idr drm_minors_idr;
+static DEFINE_XARRAY_ALLOC(drm_minors_xa);
/*
* If the drm core fails to init for whatever reason,
@@ -98,21 +98,18 @@ static struct drm_minor **drm_minor_get_slot(struct
drm_device *dev,
static void drm_minor_alloc_release(struct drm_device *dev, void *data)
{
struct drm_minor *minor = data;
- unsigned long flags;
WARN_ON(dev != minor->dev);
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_release(&drm_minors_xa, minor->index);
}
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
- unsigned long flags;
+ u32 id;
int r;
minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
@@ -122,20 +119,12 @@ 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(&drm_minors_xa, &id, NULL,
+ XA_LIMIT(64 * type, 64 * (type + 1) - 1), GFP_KERNEL);
if (r < 0)
return r;
- minor->index = r;
+ minor->index = id;
r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
if (r)
@@ -152,7 +141,7 @@ static int drm_minor_alloc(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;
+ void *entry;
int ret;
DRM_DEBUG("\n");
@@ -172,9 +161,12 @@ 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);
+ entry = xa_store(&drm_minors_xa, minor->index, &minor, GFP_KERNEL);
+ if (xa_is_err(entry)) {
+ ret = xa_err(entry);
+ goto err_debugfs;
+ }
+ WARN_ON(entry);
DRM_DEBUG("new minor registered %d\n", minor->index);
return 0;
@@ -187,16 +179,13 @@ static int drm_minor_register(struct drm_device *dev,
unsigned int type)
static void drm_minor_unregister(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
- unsigned long flags;
minor = *drm_minor_get_slot(dev, type);
if (!minor || !device_is_registered(minor->kdev))
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_erase(&drm_minors_xa, minor->index);
device_del(minor->kdev);
dev_set_drvdata(minor->kdev, NULL); /* safety belt */
@@ -215,13 +204,10 @@ static void drm_minor_unregister(struct drm_device *dev,
unsigned int type)
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);
+ minor = xa_load(&drm_minors_xa, minor_id);
if (minor)
drm_dev_get(minor->dev);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
if (!minor) {
return ERR_PTR(-ENODEV);
@@ -1037,7 +1023,7 @@ static void drm_core_exit(void)
unregister_chrdev(DRM_MAJOR, "drm");
debugfs_remove(drm_debugfs_root);
drm_sysfs_destroy();
- idr_destroy(&drm_minors_idr);
+ xa_destroy(&drm_minors_xa);
drm_connector_ida_destroy();
}
@@ -1046,7 +1032,6 @@ static int __init drm_core_init(void)
int ret;
drm_connector_ida_init();
- idr_init(&drm_minors_idr);
drm_memcpy_init_early();
ret = drm_sysfs_init();
--
2.37.3
