Merge tag 'for-v4.6-rc/omap-fixes-a' of git://git.kernel.org/pub/scm/linux/kernel/git/pjw/omap-pending into omap-for-v4.6/fixes

ARM: OMAP2+: first hwmod fix for v4.6-rc

Fix a longstanding bug in the hwmod code that could cause
hardware SYSCONFIG register values to not match the kernel's
idea of what they should be, and that could result in lower
performance during IP block idle entry.

Basic build, boot, and PM test logs are available here:

http://www.pwsan.com/omap/testlogs/omap-hwmod-fixes-a-for-v4.6-rc/20160326231727/

1 files changed, 275 insertions, 30 deletions

diff --git a/drivers/gpu/drm/drm_fops.c b/drivers/gpu/drm/drm_fops.c
index 1ea8790e5090..aeef58ed359b 100644
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -1,4 +1,4 @@
-/**
+/*
  * \file drm_fops.c
  * File operations for DRM
  *
@@ -44,6 +44,46 @@
 /* from BKL pushdown */
 DEFINE_MUTEX(drm_global_mutex);
 
+/**
+ * DOC: file operations
+ *
+ * Drivers must define the file operations structure that forms the DRM
+ * userspace API entry point, even though most of those operations are
+ * implemented in the DRM core. The mandatory functions are drm_open(),
+ * drm_read(), drm_ioctl() and drm_compat_ioctl if CONFIG_COMPAT is enabled.
+ * Drivers which implement private ioctls that require 32/64 bit compatibility
+ * support must provided their onw .compat_ioctl() handler that processes
+ * private ioctls and calls drm_compat_ioctl() for core ioctls.
+ *
+ * In addition drm_read() and drm_poll() provide support for DRM events. DRM
+ * events are a generic and extensible means to send asynchronous events to
+ * userspace through the file descriptor. They are used to send vblank event and
+ * page flip completions by the KMS API. But drivers can also use it for their
+ * own needs, e.g. to signal completion of rendering.
+ *
+ * The memory mapping implementation will vary depending on how the driver
+ * manages memory. Legacy drivers will use the deprecated drm_legacy_mmap()
+ * function, modern drivers should use one of the provided memory-manager
+ * specific implementations. For GEM-based drivers this is drm_gem_mmap().
+ *
+ * No other file operations are supported by the DRM userspace API. Overall the
+ * following is an example #file_operations structure:
+ *
+ *     static const example_drm_fops = {
+ *             .owner = THIS_MODULE,
+ *             .open = drm_open,
+ *             .release = drm_release,
+ *             .unlocked_ioctl = drm_ioctl,
+ *     #ifdef CONFIG_COMPAT
+ *             .compat_ioctl = drm_compat_ioctl,
+ *     #endif
+ *             .poll = drm_poll,
+ *             .read = drm_read,
+ *             .llseek = no_llseek,
+ *             .mmap = drm_gem_mmap,
+ *     };
+ */
+
 static int drm_open_helper(struct file *filp, struct drm_minor *minor);
 
 static int drm_setup(struct drm_device * dev)
@@ -67,15 +107,17 @@ static int drm_setup(struct drm_device * dev)
 }
 
 /**
- * Open file.
+ * drm_open - open method for DRM file
+ * @inode: device inode
+ * @filp: file pointer.
  *
- * \param inode device inode
- * \param filp file pointer.
- * \return zero on success or a negative number on failure.
+ * This function must be used by drivers as their .open() #file_operations
+ * method. It looks up the correct DRM device and instantiates all the per-file
+ * resources for it.
+ *
+ * RETURNS:
  *
- * Searches the DRM device with the same minor number, calls open_helper(), and
- * increments the device open count. If the open count was previous at zero,
- * i.e., it's the first that the device is open, then calls setup().
+ * 0 on success or negative errno value on falure.
  */
 int drm_open(struct inode *inode, struct file *filp)
 {
@@ -112,7 +154,7 @@ err_undo:
 }
 EXPORT_SYMBOL(drm_open);
 
-/**
+/*
  * Check whether DRI will run on this CPU.
  *
  * \return non-zero if the DRI will run on this CPU, or zero otherwise.
@@ -125,7 +167,7 @@ static int drm_cpu_valid(void)
 	return 1;
 }
 
-/**
+/*
  * drm_new_set_master - Allocate a new master object and become master for the
  * associated master realm.
  *
@@ -179,7 +221,7 @@ out_err:
 	return ret;
 }
 
-/**
+/*
  * Called whenever a process opens /dev/drm.
  *
  * \param filp file pointer.
@@ -222,6 +264,7 @@ static int drm_open_helper(struct file *filp, struct drm_minor *minor)
 	INIT_LIST_HEAD(&priv->fbs);
 	mutex_init(&priv->fbs_lock);
 	INIT_LIST_HEAD(&priv->blobs);
+	INIT_LIST_HEAD(&priv->pending_event_list);
 	INIT_LIST_HEAD(&priv->event_list);
 	init_waitqueue_head(&priv->event_wait);
 	priv->event_space = 4096; /* set aside 4k for event buffer */
@@ -311,18 +354,16 @@ static void drm_events_release(struct drm_file *file_priv)
 {
 	struct drm_device *dev = file_priv->minor->dev;
 	struct drm_pending_event *e, *et;
-	struct drm_pending_vblank_event *v, *vt;
 	unsigned long flags;
 
 	spin_lock_irqsave(&dev->event_lock, flags);
 
-	/* Remove pending flips */
-	list_for_each_entry_safe(v, vt, &dev->vblank_event_list, base.link)
-		if (v->base.file_priv == file_priv) {
-			list_del(&v->base.link);
-			drm_vblank_put(dev, v->pipe);
-			v->base.destroy(&v->base);
-		}
+	/* Unlink pending events */
+	list_for_each_entry_safe(e, et, &file_priv->pending_event_list,
+				 pending_link) {
+		list_del(&e->pending_link);
+		e->file_priv = NULL;
+	}
 
 	/* Remove unconsumed events */
 	list_for_each_entry_safe(e, et, &file_priv->event_list, link) {
@@ -333,7 +374,7 @@ static void drm_events_release(struct drm_file *file_priv)
 	spin_unlock_irqrestore(&dev->event_lock, flags);
 }
 
-/**
+/*
  * drm_legacy_dev_reinit
  *
  * Reinitializes a legacy/ums drm device in it's lastclose function.
@@ -350,7 +391,7 @@ static void drm_legacy_dev_reinit(struct drm_device *dev)
 	dev->if_version = 0;
 }
 
-/**
+/*
  * Take down the DRM device.
  *
  * \param dev DRM device structure.
@@ -387,16 +428,17 @@ int drm_lastclose(struct drm_device * dev)
 }
 
 /**
- * Release file.
+ * drm_release - release method for DRM file
+ * @inode: device inode
+ * @filp: file pointer.
  *
- * \param inode device inode
- * \param file_priv DRM file private.
- * \return zero on success or a negative number on failure.
+ * This function must be used by drivers as their .release() #file_operations
+ * method. It frees any resources associated with the open file, and if this is
+ * the last open file for the DRM device also proceeds to call drm_lastclose().
  *
- * If the hardware lock is held then free it, and take it again for the kernel
- * context since it's necessary to reclaim buffers. Unlink the file private
- * data from its list and free it. Decreases the open count and if it reaches
- * zero calls drm_lastclose().
+ * RETURNS:
+ *
+ * Always succeeds and returns 0.
  */
 int drm_release(struct inode *inode, struct file *filp)
 {
@@ -451,7 +493,7 @@ int drm_release(struct inode *inode, struct file *filp)
 	if (file_priv->is_master) {
 		struct drm_master *master = file_priv->master;
 
-		/**
+		/*
 		 * Since the master is disappearing, so is the
 		 * possibility to lock.
 		 */
@@ -508,6 +550,32 @@ int drm_release(struct inode *inode, struct file *filp)
 }
 EXPORT_SYMBOL(drm_release);
 
+/**
+ * drm_read - read method for DRM file
+ * @filp: file pointer
+ * @buffer: userspace destination pointer for the read
+ * @count: count in bytes to read
+ * @offset: offset to read
+ *
+ * This function must be used by drivers as their .read() #file_operations
+ * method iff they use DRM events for asynchronous signalling to userspace.
+ * Since events are used by the KMS API for vblank and page flip completion this
+ * means all modern display drivers must use it.
+ *
+ * @offset is ignore, DRM events are read like a pipe. Therefore drivers also
+ * must set the .llseek() #file_operation to no_llseek(). Polling support is
+ * provided by drm_poll().
+ *
+ * This function will only ever read a full event. Therefore userspace must
+ * supply a big enough buffer to fit any event to ensure forward progress. Since
+ * the maximum event space is currently 4K it's recommended to just use that for
+ * safety.
+ *
+ * RETURNS:
+ *
+ * Number of bytes read (always aligned to full events, and can be 0) or a
+ * negative error code on failure.
+ */
 ssize_t drm_read(struct file *filp, char __user *buffer,
 		 size_t count, loff_t *offset)
 {
@@ -578,6 +646,22 @@ put_back_event:
 }
 EXPORT_SYMBOL(drm_read);
 
+/**
+ * drm_poll - poll method for DRM file
+ * @filp: file pointer
+ * @wait: poll waiter table
+ *
+ * This function must be used by drivers as their .read() #file_operations
+ * method iff they use DRM events for asynchronous signalling to userspace.
+ * Since events are used by the KMS API for vblank and page flip completion this
+ * means all modern display drivers must use it.
+ *
+ * See also drm_read().
+ *
+ * RETURNS:
+ *
+ * Mask of POLL flags indicating the current status of the file.
+ */
 unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 {
 	struct drm_file *file_priv = filp->private_data;
@@ -591,3 +675,164 @@ unsigned int drm_poll(struct file *filp, struct poll_table_struct *wait)
 	return mask;
 }
 EXPORT_SYMBOL(drm_poll);
+
+/**
+ * drm_event_reserve_init_locked - init a DRM event and reserve space for it
+ * @dev: DRM device
+ * @file_priv: DRM file private data
+ * @p: tracking structure for the pending event
+ * @e: actual event data to deliver to userspace
+ *
+ * This function prepares the passed in event for eventual delivery. If the event
+ * doesn't get delivered (because the IOCTL fails later on, before queuing up
+ * anything) then the even must be cancelled and freed using
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
+ *
+ * If callers embedded @p into a larger structure it must be allocated with
+ * kmalloc and @p must be the first member element.
+ *
+ * This is the locked version of drm_event_reserve_init() for callers which
+ * already hold dev->event_lock.
+ *
+ * RETURNS:
+ *
+ * 0 on success or a negative error code on failure.
+ */
+int drm_event_reserve_init_locked(struct drm_device *dev,
+				  struct drm_file *file_priv,
+				  struct drm_pending_event *p,
+				  struct drm_event *e)
+{
+	if (file_priv->event_space < e->length)
+		return -ENOMEM;
+
+	file_priv->event_space -= e->length;
+
+	p->event = e;
+	list_add(&p->pending_link, &file_priv->pending_event_list);
+	p->file_priv = file_priv;
+
+	/* we *could* pass this in as arg, but everyone uses kfree: */
+	p->destroy = (void (*) (struct drm_pending_event *)) kfree;
+
+	return 0;
+}
+EXPORT_SYMBOL(drm_event_reserve_init_locked);
+
+/**
+ * drm_event_reserve_init - init a DRM event and reserve space for it
+ * @dev: DRM device
+ * @file_priv: DRM file private data
+ * @p: tracking structure for the pending event
+ * @e: actual event data to deliver to userspace
+ *
+ * This function prepares the passed in event for eventual delivery. If the event
+ * doesn't get delivered (because the IOCTL fails later on, before queuing up
+ * anything) then the even must be cancelled and freed using
+ * drm_event_cancel_free(). Successfully initialized events should be sent out
+ * using drm_send_event() or drm_send_event_locked() to signal completion of the
+ * asynchronous event to userspace.
+ *
+ * If callers embedded @p into a larger structure it must be allocated with
+ * kmalloc and @p must be the first member element.
+ *
+ * Callers which already hold dev->event_lock should use
+ * drm_event_reserve_init() instead.
+ *
+ * RETURNS:
+ *
+ * 0 on success or a negative error code on failure.
+ */
+int drm_event_reserve_init(struct drm_device *dev,
+			   struct drm_file *file_priv,
+			   struct drm_pending_event *p,
+			   struct drm_event *e)
+{
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&dev->event_lock, flags);
+	ret = drm_event_reserve_init_locked(dev, file_priv, p, e);
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(drm_event_reserve_init);
+
+/**
+ * drm_event_cancel_free - free a DRM event and release it's space
+ * @dev: DRM device
+ * @p: tracking structure for the pending event
+ *
+ * This function frees the event @p initialized with drm_event_reserve_init()
+ * and releases any allocated space.
+ */
+void drm_event_cancel_free(struct drm_device *dev,
+			   struct drm_pending_event *p)
+{
+	unsigned long flags;
+	spin_lock_irqsave(&dev->event_lock, flags);
+	if (p->file_priv) {
+		p->file_priv->event_space += p->event->length;
+		list_del(&p->pending_link);
+	}
+	spin_unlock_irqrestore(&dev->event_lock, flags);
+	p->destroy(p);
+}
+EXPORT_SYMBOL(drm_event_cancel_free);
+
+/**
+ * drm_send_event_locked - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. Callers must already hold
+ * dev->event_lock, see drm_send_event() for the unlocked version.
+ *
+ * Note that the core will take care of unlinking and disarming events when the
+ * corresponding DRM file is closed. Drivers need not worry about whether the
+ * DRM file for this event still exists and can call this function upon
+ * completion of the asynchronous work unconditionally.
+ */
+void drm_send_event_locked(struct drm_device *dev, struct drm_pending_event *e)
+{
+	assert_spin_locked(&dev->event_lock);
+
+	if (!e->file_priv) {
+		e->destroy(e);
+		return;
+	}
+
+	list_del(&e->pending_link);
+	list_add_tail(&e->link,
+		      &e->file_priv->event_list);
+	wake_up_interruptible(&e->file_priv->event_wait);
+}
+EXPORT_SYMBOL(drm_send_event_locked);
+
+/**
+ * drm_send_event - send DRM event to file descriptor
+ * @dev: DRM device
+ * @e: DRM event to deliver
+ *
+ * This function sends the event @e, initialized with drm_event_reserve_init(),
+ * to its associated userspace DRM file. This function acquires dev->event_lock,
+ * see drm_send_event_locked() for callers which already hold this lock.
+ *
+ * Note that the core will take care of unlinking and disarming events when the
+ * corresponding DRM file is closed. Drivers need not worry about whether the
+ * DRM file for this event still exists and can call this function upon
+ * completion of the asynchronous work unconditionally.
+ */
+void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
+{
+	unsigned long irqflags;
+
+	spin_lock_irqsave(&dev->event_lock, irqflags);
+	drm_send_event_locked(dev, e);
+	spin_unlock_irqrestore(&dev->event_lock, irqflags);
+}
+EXPORT_SYMBOL(drm_send_event);