Operating on drm minor is not done in IRQ context, which means that we
could safely downgrade to regular non-irq spinlock.
But we can also go further and drop the idr_preload tricks by just using
a mutex.
Signed-off-by: Michał Winiarski <michal.winiar...@intel.com>
---
drivers/gpu/drm/drm_drv.c | 31 ++++++++++++-------------------
1 file changed, 12 insertions(+), 19 deletions(-)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 0dab1ef8a98d..b31497e28e6a 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -53,7 +53,7 @@ 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 DEFINE_MUTEX(drm_minor_lock);
static struct idr drm_minors_idr;
/*
@@ -98,21 +98,19 @@ 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);
+ mutex_lock(&drm_minor_lock);
idr_remove(&drm_minors_idr, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ mutex_unlock(&drm_minor_lock);
}
static int drm_minor_alloc(struct drm_device *dev, unsigned int type)
{
struct drm_minor *minor;
- unsigned long flags;
int r, start, end;
minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
@@ -126,11 +124,9 @@ static int drm_minor_alloc(struct drm_device *dev,
unsigned int type)
end = 128 * (type + 1);
do {
- idr_preload(GFP_KERNEL);
- spin_lock_irqsave(&drm_minor_lock, flags);
- r = idr_alloc(&drm_minors_idr, NULL, start, end, GFP_NOWAIT);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
- idr_preload_end();
+ mutex_lock(&drm_minor_lock);
+ r = idr_alloc(&drm_minors_idr, NULL, start, end, GFP_KERNEL);
+ mutex_unlock(&drm_minor_lock);
start += 256;
end += 256;
@@ -156,7 +152,6 @@ 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;
int ret;
DRM_DEBUG("\n");
@@ -176,9 +171,9 @@ 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);
+ mutex_lock(&drm_minor_lock);
idr_replace(&drm_minors_idr, minor, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ mutex_unlock(&drm_minor_lock);
DRM_DEBUG("new minor registered %d\n", minor->index);
return 0;
@@ -191,16 +186,15 @@ 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);
+ mutex_lock(&drm_minor_lock);
idr_replace(&drm_minors_idr, NULL, minor->index);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ mutex_unlock(&drm_minor_lock);
device_del(minor->kdev);
dev_set_drvdata(minor->kdev, NULL); /* safety belt */
@@ -219,13 +213,12 @@ 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);
+ mutex_lock(&drm_minor_lock);
minor = idr_find(&drm_minors_idr, minor_id);
if (minor)
drm_dev_get(minor->dev);
- spin_unlock_irqrestore(&drm_minor_lock, flags);
+ mutex_unlock(&drm_minor_lock);
if (!minor) {
return ERR_PTR(-ENODEV);
--
2.37.2
