[Intel-gfx] [PATCH 02/14] drm: Hide hw.lock cleanup in filp->release better
Daniel Vetter
daniel.vetter at ffwll.ch
Tue Jun 14 18:50:57 UTC 2016
A few things:
- Rename the cleanup function from drm_master_release to
drm_legacy_lock_release. It doesn't relase any master stuff, but
just the legacy hw lock.
- Hide it in drm_lock.c, which allows us to make a few more functions
static in there. To avoid forward decl we need to shuffle the code a
bit though.
- Push the check for ->master into the function itself.
- Only call this for !DRIVER_MODESET.
End result: Another place that takes struct_mutex gone for good for
modern drivers.
v2: Remove leftover comment.
Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>
---
drivers/gpu/drm/drm_fops.c | 17 +---
drivers/gpu/drm/drm_legacy.h | 8 +-
drivers/gpu/drm/drm_lock.c | 238 ++++++++++++++++++++++---------------------
3 files changed, 126 insertions(+), 137 deletions(-)
diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index a27bc7cda975..2fd4f42b907a 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -338,18 +338,6 @@ out_prime_destroy:
return ret;
}
-static void drm_master_release(struct drm_device *dev, struct file *filp)
-{
- struct drm_file *file_priv = filp->private_data;
-
- if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
- DRM_DEBUG("File %p released, freeing lock for context %d\n",
- filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
- drm_legacy_lock_free(&file_priv->master->lock,
- _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
- }
-}
-
static void drm_events_release(struct drm_file *file_priv)
{
struct drm_device *dev = file_priv->minor->dev;
@@ -468,9 +456,8 @@ int drm_release(struct inode *inode, struct file *filp)
(long)old_encode_dev(file_priv->minor->kdev->devt),
dev->open_count);
- /* if the master has gone away we can't do anything with the lock */
- if (file_priv->minor->master)
- drm_master_release(dev, filp);
+ if (!drm_core_check_feature(dev, DRIVER_MODESET))
+ drm_legacy_lock_release(dev, filp);
if (drm_core_check_feature(dev, DRIVER_HAVE_DMA))
drm_legacy_reclaim_buffers(dev, file_priv);
diff --git a/drivers/gpu/drm/drm_legacy.h b/drivers/gpu/drm/drm_legacy.h
index d3b6ee357a2b..c6f422e879dd 100644
--- a/drivers/gpu/drm/drm_legacy.h
+++ b/drivers/gpu/drm/drm_legacy.h
@@ -88,14 +88,10 @@ struct drm_agp_mem {
struct list_head head;
};
-/*
- * Generic Userspace Locking-API
- */
-
-int drm_legacy_i_have_hw_lock(struct drm_device *d, struct drm_file *f);
+/* drm_lock.c */
int drm_legacy_lock(struct drm_device *d, void *v, struct drm_file *f);
int drm_legacy_unlock(struct drm_device *d, void *v, struct drm_file *f);
-int drm_legacy_lock_free(struct drm_lock_data *lock, unsigned int ctx);
+void drm_legacy_lock_release(struct drm_device *dev, struct file *filp);
/* DMA support */
int drm_legacy_dma_setup(struct drm_device *dev);
diff --git a/drivers/gpu/drm/drm_lock.c b/drivers/gpu/drm/drm_lock.c
index daa2ff12101b..0fb8f9e73486 100644
--- a/drivers/gpu/drm/drm_lock.c
+++ b/drivers/gpu/drm/drm_lock.c
@@ -41,6 +41,110 @@
static int drm_lock_take(struct drm_lock_data *lock_data, unsigned int context);
/**
+ * Take the heavyweight lock.
+ *
+ * \param lock lock pointer.
+ * \param context locking context.
+ * \return one if the lock is held, or zero otherwise.
+ *
+ * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
+ */
+static
+int drm_lock_take(struct drm_lock_data *lock_data,
+ unsigned int context)
+{
+ unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+
+ spin_lock_bh(&lock_data->spinlock);
+ do {
+ old = *lock;
+ if (old & _DRM_LOCK_HELD)
+ new = old | _DRM_LOCK_CONT;
+ else {
+ new = context | _DRM_LOCK_HELD |
+ ((lock_data->user_waiters + lock_data->kernel_waiters > 1) ?
+ _DRM_LOCK_CONT : 0);
+ }
+ prev = cmpxchg(lock, old, new);
+ } while (prev != old);
+ spin_unlock_bh(&lock_data->spinlock);
+
+ if (_DRM_LOCKING_CONTEXT(old) == context) {
+ if (old & _DRM_LOCK_HELD) {
+ if (context != DRM_KERNEL_CONTEXT) {
+ DRM_ERROR("%d holds heavyweight lock\n",
+ context);
+ }
+ return 0;
+ }
+ }
+
+ if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) {
+ /* Have lock */
+ return 1;
+ }
+ return 0;
+}
+
+/**
+ * This takes a lock forcibly and hands it to context. Should ONLY be used
+ * inside *_unlock to give lock to kernel before calling *_dma_schedule.
+ *
+ * \param dev DRM device.
+ * \param lock lock pointer.
+ * \param context locking context.
+ * \return always one.
+ *
+ * Resets the lock file pointer.
+ * Marks the lock as held by the given context, via the \p cmpxchg instruction.
+ */
+static int drm_lock_transfer(struct drm_lock_data *lock_data,
+ unsigned int context)
+{
+ unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+
+ lock_data->file_priv = NULL;
+ do {
+ old = *lock;
+ new = context | _DRM_LOCK_HELD;
+ prev = cmpxchg(lock, old, new);
+ } while (prev != old);
+ return 1;
+}
+
+static int drm_legacy_lock_free(struct drm_lock_data *lock_data,
+ unsigned int context)
+{
+ unsigned int old, new, prev;
+ volatile unsigned int *lock = &lock_data->hw_lock->lock;
+
+ spin_lock_bh(&lock_data->spinlock);
+ if (lock_data->kernel_waiters != 0) {
+ drm_lock_transfer(lock_data, 0);
+ lock_data->idle_has_lock = 1;
+ spin_unlock_bh(&lock_data->spinlock);
+ return 1;
+ }
+ spin_unlock_bh(&lock_data->spinlock);
+
+ do {
+ old = *lock;
+ new = _DRM_LOCKING_CONTEXT(old);
+ prev = cmpxchg(lock, old, new);
+ } while (prev != old);
+
+ if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
+ DRM_ERROR("%d freed heavyweight lock held by %d\n",
+ context, _DRM_LOCKING_CONTEXT(old));
+ return 1;
+ }
+ wake_up_interruptible(&lock_data->lock_queue);
+ return 0;
+}
+
+/**
* Lock ioctl.
*
* \param inode device inode.
@@ -165,120 +269,6 @@ int drm_legacy_unlock(struct drm_device *dev, void *data, struct drm_file *file_
}
/**
- * Take the heavyweight lock.
- *
- * \param lock lock pointer.
- * \param context locking context.
- * \return one if the lock is held, or zero otherwise.
- *
- * Attempt to mark the lock as held by the given context, via the \p cmpxchg instruction.
- */
-static
-int drm_lock_take(struct drm_lock_data *lock_data,
- unsigned int context)
-{
- unsigned int old, new, prev;
- volatile unsigned int *lock = &lock_data->hw_lock->lock;
-
- spin_lock_bh(&lock_data->spinlock);
- do {
- old = *lock;
- if (old & _DRM_LOCK_HELD)
- new = old | _DRM_LOCK_CONT;
- else {
- new = context | _DRM_LOCK_HELD |
- ((lock_data->user_waiters + lock_data->kernel_waiters > 1) ?
- _DRM_LOCK_CONT : 0);
- }
- prev = cmpxchg(lock, old, new);
- } while (prev != old);
- spin_unlock_bh(&lock_data->spinlock);
-
- if (_DRM_LOCKING_CONTEXT(old) == context) {
- if (old & _DRM_LOCK_HELD) {
- if (context != DRM_KERNEL_CONTEXT) {
- DRM_ERROR("%d holds heavyweight lock\n",
- context);
- }
- return 0;
- }
- }
-
- if ((_DRM_LOCKING_CONTEXT(new)) == context && (new & _DRM_LOCK_HELD)) {
- /* Have lock */
- return 1;
- }
- return 0;
-}
-
-/**
- * This takes a lock forcibly and hands it to context. Should ONLY be used
- * inside *_unlock to give lock to kernel before calling *_dma_schedule.
- *
- * \param dev DRM device.
- * \param lock lock pointer.
- * \param context locking context.
- * \return always one.
- *
- * Resets the lock file pointer.
- * Marks the lock as held by the given context, via the \p cmpxchg instruction.
- */
-static int drm_lock_transfer(struct drm_lock_data *lock_data,
- unsigned int context)
-{
- unsigned int old, new, prev;
- volatile unsigned int *lock = &lock_data->hw_lock->lock;
-
- lock_data->file_priv = NULL;
- do {
- old = *lock;
- new = context | _DRM_LOCK_HELD;
- prev = cmpxchg(lock, old, new);
- } while (prev != old);
- return 1;
-}
-
-/**
- * Free lock.
- *
- * \param dev DRM device.
- * \param lock lock.
- * \param context context.
- *
- * Resets the lock file pointer.
- * Marks the lock as not held, via the \p cmpxchg instruction. Wakes any task
- * waiting on the lock queue.
- */
-int drm_legacy_lock_free(struct drm_lock_data *lock_data, unsigned int context)
-{
- unsigned int old, new, prev;
- volatile unsigned int *lock = &lock_data->hw_lock->lock;
-
- spin_lock_bh(&lock_data->spinlock);
- if (lock_data->kernel_waiters != 0) {
- drm_lock_transfer(lock_data, 0);
- lock_data->idle_has_lock = 1;
- spin_unlock_bh(&lock_data->spinlock);
- return 1;
- }
- spin_unlock_bh(&lock_data->spinlock);
-
- do {
- old = *lock;
- new = _DRM_LOCKING_CONTEXT(old);
- prev = cmpxchg(lock, old, new);
- } while (prev != old);
-
- if (_DRM_LOCK_IS_HELD(old) && _DRM_LOCKING_CONTEXT(old) != context) {
- DRM_ERROR("%d freed heavyweight lock held by %d\n",
- context, _DRM_LOCKING_CONTEXT(old));
- return 1;
- }
- wake_up_interruptible(&lock_data->lock_queue);
- return 0;
-}
-
-/**
* This function returns immediately and takes the hw lock
* with the kernel context if it is free, otherwise it gets the highest priority when and if
* it is eventually released.
@@ -330,11 +320,27 @@ void drm_legacy_idlelock_release(struct drm_lock_data *lock_data)
}
EXPORT_SYMBOL(drm_legacy_idlelock_release);
-int drm_legacy_i_have_hw_lock(struct drm_device *dev,
- struct drm_file *file_priv)
+static int drm_legacy_i_have_hw_lock(struct drm_device *dev,
+ struct drm_file *file_priv)
{
struct drm_master *master = file_priv->master;
return (file_priv->lock_count && master->lock.hw_lock &&
_DRM_LOCK_IS_HELD(master->lock.hw_lock->lock) &&
master->lock.file_priv == file_priv);
}
+
+void drm_legacy_lock_release(struct drm_device *dev, struct file *filp)
+{
+ struct drm_file *file_priv = filp->private_data;
+
+ /* if the master has gone away we can't do anything with the lock */
+ if (!file_priv->minor->master)
+ return;
+
+ if (drm_legacy_i_have_hw_lock(dev, file_priv)) {
+ DRM_DEBUG("File %p released, freeing lock for context %d\n",
+ filp, _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
+ drm_legacy_lock_free(&file_priv->master->lock,
+ _DRM_LOCKING_CONTEXT(file_priv->master->lock.hw_lock->lock));
+ }
+}
--
2.8.1
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