 @@ -1,738 +1,743 @@
 /*
  * Copyright © 2008 Intel Corporation
+ *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
+ *
  * The above copyright notice and this permission notice (including the next
  * paragraph) shall be included in all copies or substantial portions of the
  * Software.
+ *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  * IN THE SOFTWARE.
+ *
  * Authors:
  *    Eric Anholt <eric@anholt.net>
+ *
  */
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/uaccess.h>
 #include <linux/fs.h>
 #include <linux/file.h>
 #include <linux/module.h>
 #include <linux/mman.h>
 #include <linux/pagemap.h>
 #include <linux/shmem_fs.h>
 #include <linux/dma-buf.h>
 #include <linux/err.h>
 #include <linux/export.h>
 #include <asm/bug.h>
 #include <drm/drmP.h>
 /** @file drm_gem.c
+ *
  * This file provides some of the base ioctls and library routines for
  * the graphics memory manager implemented by each device driver.
+ *
  * Because various devices have different requirements in terms of
  * synchronization and migration strategies, implementing that is left up to
  * the driver, and all that the general API provides should be generic --
  * allocating objects, reading/writing data with the cpu, freeing objects.
  * Even there, platform-dependent optimizations for reading/writing data with
  * the CPU mean we'll likely hook those out to driver-specific calls.  However,
  * the DRI2 implementation wants to have at least allocate/mmap be generic.
+ *
  * The goal was to have swap-backed object allocation managed through
  * struct file.  However, file descriptors as handles to a struct file have
  * two major failings:
  * - Process limits prevent more than 1024 or so being used at a time by
  *   default.
  * - Inability to allocate high fds will aggravate the X Server's select()
  *   handling, and likely that of many GL client applications as well.
+ *
  * This led to a plan of using our own integer IDs (called handles, following
  * DRM terminology) to mimic fds, and implement the fd syscalls we need as
  * ioctls.  The objects themselves will still include the struct file so
  * that we can transition to fds if the required kernel infrastructure shows
  * up at a later date, and as our interface with shmfs for memory allocation.
  */
 /*
  * We make up offsets for buffer objects so we can recognize them at
  * mmap time.
  */
 /* pgoff in mmap is an unsigned long, so we need to make sure that
  * the faked up offset will fit
  */
 #if BITS_PER_LONG == 64
 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFFUL >> PAGE_SHIFT) + 1)
 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFFUL >> PAGE_SHIFT) * 16)
 #else
 #define DRM_FILE_PAGE_OFFSET_START ((0xFFFFFFFUL >> PAGE_SHIFT) + 1)
 #define DRM_FILE_PAGE_OFFSET_SIZE ((0xFFFFFFFUL >> PAGE_SHIFT) * 16)
 #endif
 /**
  * Initialize the GEM device fields
  */
 int
 drm_gem_init(struct drm_device *dev)
+{
 	struct drm_gem_mm *mm;
 	spin_lock_init(&dev->object_name_lock);
 	idr_init(&dev->object_name_idr);
 	mm = kzalloc(sizeof(struct drm_gem_mm), GFP_KERNEL);
 	if (!mm) {
 		DRM_ERROR("out of memory\n");
 		return -ENOMEM;
+	}
 	dev->mm_private = mm;
 	if (drm_ht_create(&mm->offset_hash, 12)) {
 		kfree(mm);
 		return -ENOMEM;
+	}
 	if (drm_mm_init(&mm->offset_manager, DRM_FILE_PAGE_OFFSET_START,
 			DRM_FILE_PAGE_OFFSET_SIZE)) {
 		drm_ht_remove(&mm->offset_hash);
 		kfree(mm);
 		return -ENOMEM;
+	}
 	return 0;
+}
 void
 drm_gem_destroy(struct drm_device *dev)
+{
 	struct drm_gem_mm *mm = dev->mm_private;
 	drm_mm_takedown(&mm->offset_manager);
 	drm_ht_remove(&mm->offset_hash);
 	kfree(mm);
 	dev->mm_private = NULL;
 #ifdef __NetBSD__
 	idr_destroy(&dev->object_name_idr);
 	spin_lock_destroy(&dev->object_name_lock);
 #endif
+}
 /**
  * Initialize an already allocated GEM object of the specified size with
  * shmfs backing store.
  */
 int drm_gem_object_init(struct drm_device *dev,
 			struct drm_gem_object *obj, size_t size)
+{
 	BUG_ON((size & (PAGE_SIZE - 1)) != 0);
 	obj->dev = dev;
 	obj->filp = shmem_file_setup("drm mm object", size, VM_NORESERVE);
 	if (IS_ERR(obj->filp))
 		return PTR_ERR(obj->filp);
 	kref_init(&obj->refcount);
 	atomic_set(&obj->handle_count, 0);
 	obj->size = size;
 	return 0;
+}
 EXPORT_SYMBOL(drm_gem_object_init);
 /**
  * Initialize an already allocated GEM object of the specified size with
  * no GEM provided backing store. Instead the caller is responsible for
  * backing the object and handling it.
  */
 int drm_gem_private_object_init(struct drm_device *dev,
 			struct drm_gem_object *obj, size_t size)
+{
 	BUG_ON((size & (PAGE_SIZE - 1)) != 0);
 	obj->dev = dev;
 	obj->filp = NULL;
 	kref_init(&obj->refcount);
 	atomic_set(&obj->handle_count, 0);
 	obj->size = size;
 	return 0;
+}
 EXPORT_SYMBOL(drm_gem_private_object_init);
 /**
  * Allocate a GEM object of the specified size with shmfs backing store
  */
 struct drm_gem_object *
 drm_gem_object_alloc(struct drm_device *dev, size_t size)
+{
 	struct drm_gem_object *obj;
 	obj = kzalloc(sizeof(*obj), GFP_KERNEL);
 	if (!obj)
 		goto free;
 	if (drm_gem_object_init(dev, obj, size) != 0)
 		goto free;
 	if (dev->driver->gem_init_object != NULL &&
 	    dev->driver->gem_init_object(obj) != 0) {
 		goto fput;
+	}
 	return obj;
 fput:
 	/* Object_init mangles the global counters - readjust them. */
 	fput(obj->filp);
 free:
 	kfree(obj);
 	return NULL;
+}
 EXPORT_SYMBOL(drm_gem_object_alloc);
 #ifndef __NetBSD__			/* XXX drm prime */
 static void
 drm_gem_remove_prime_handles(struct drm_gem_object *obj, struct drm_file *filp)
+{
 	if (obj->import_attach) {
 		drm_prime_remove_imported_buf_handle(&filp->prime,
 				obj->import_attach->dmabuf);
+	}
 	if (obj->export_dma_buf) {
 		drm_prime_remove_imported_buf_handle(&filp->prime,
 				obj->export_dma_buf);
+	}
+}
 #endif
 /**
  * Removes the mapping from handle to filp for this object.
  */
 int
 drm_gem_handle_delete(struct drm_file *filp, u32 handle)
+{
 	struct drm_device *dev;
 	struct drm_gem_object *obj;
 	/* This is gross. The idr system doesn't let us try a delete and
 	 * return an error code.  It just spews if you fail at deleting.
 	 * So, we have to grab a lock around finding the object and then
 	 * doing the delete on it and dropping the refcount, or the user
 	 * could race us to double-decrement the refcount and cause a
 	 * use-after-free later.  Given the frequency of our handle lookups,
 	 * we may want to use ida for number allocation and a hash table
 	 * for the pointers, anyway.
 	 */
 	spin_lock(&filp->table_lock);
 	/* Check if we currently have a reference on the object */
 	obj = idr_find(&filp->object_idr, handle);
 	if (obj == NULL) {
 		spin_unlock(&filp->table_lock);
 		return -EINVAL;
+	}
 	dev = obj->dev;
 	/* Release reference and decrement refcount. */
 	idr_remove(&filp->object_idr, handle);
 	spin_unlock(&filp->table_lock);
 #ifndef __NetBSD__
 	drm_gem_remove_prime_handles(obj, filp);
 #endif
 	if (dev->driver->gem_close_object)
 		dev->driver->gem_close_object(obj, filp);
 	drm_gem_object_handle_unreference_unlocked(obj);
 	return 0;
+}
 EXPORT_SYMBOL(drm_gem_handle_delete);
 /**
  * Create a handle for this object. This adds a handle reference
  * to the object, which includes a regular reference count. Callers
  * will likely want to dereference the object afterwards.
  */
 int
 drm_gem_handle_create(struct drm_file *file_priv,
 		       struct drm_gem_object *obj,
 		       u32 *handlep)
+{
 	struct drm_device *dev = obj->dev;
 	int ret;
 	/*
 	 * Get the user-visible handle using idr.
 	 */
 again:
 	/* ensure there is space available to allocate a handle */
 	if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0)
 		return -ENOMEM;
 	/* do the allocation under our spinlock */
 	spin_lock(&file_priv->table_lock);
 	ret = idr_get_new_above(&file_priv->object_idr, obj, 1, (int *)handlep);
 	spin_unlock(&file_priv->table_lock);
 	if (ret == -EAGAIN)
 		goto again;
 	else if (ret)
 		return ret;
 	drm_gem_object_handle_reference(obj);
 	if (dev->driver->gem_open_object) {
 		ret = dev->driver->gem_open_object(obj, file_priv);
 		if (ret) {
 			drm_gem_handle_delete(file_priv, *handlep);
 			return ret;
+		}
+	}
 	return 0;
+}
 EXPORT_SYMBOL(drm_gem_handle_create);
 /**
  * drm_gem_free_mmap_offset - release a fake mmap offset for an object
  * @obj: obj in question
+ *
  * This routine frees fake offsets allocated by drm_gem_create_mmap_offset().
  */
 void
 drm_gem_free_mmap_offset(struct drm_gem_object *obj)
+{
 	struct drm_device *dev = obj->dev;
 	struct drm_gem_mm *mm = dev->mm_private;
 	struct drm_map_list *list = &obj->map_list;
 	drm_ht_remove_item(&mm->offset_hash, &list->hash);
 	drm_mm_put_block(list->file_offset_node);
 	kfree(list->map);
 	list->map = NULL;
+}
 EXPORT_SYMBOL(drm_gem_free_mmap_offset);
 /**
  * drm_gem_create_mmap_offset - create a fake mmap offset for an object
  * @obj: obj in question
+ *
  * GEM memory mapping works by handing back to userspace a fake mmap offset
  * it can use in a subsequent mmap(2) call.  The DRM core code then looks
  * up the object based on the offset and sets up the various memory mapping
  * structures.
+ *
  * This routine allocates and attaches a fake offset for @obj.
  */
 int
 drm_gem_create_mmap_offset(struct drm_gem_object *obj)
+{
 	struct drm_device *dev = obj->dev;
 	struct drm_gem_mm *mm = dev->mm_private;
 	struct drm_map_list *list;
 	struct drm_local_map *map;
 	int ret;
 	/* Set the object up for mmap'ing */
 	list = &obj->map_list;
 	list->map = kzalloc(sizeof(struct drm_map_list), GFP_KERNEL);
 	if (!list->map)
 		return -ENOMEM;
 	map = list->map;
 	map->type = _DRM_GEM;
 	map->size = obj->size;
 	map->handle = obj;
 	/* Get a DRM GEM mmap offset allocated... */
 	list->file_offset_node = drm_mm_search_free(&mm->offset_manager,
 			obj->size / PAGE_SIZE, 0, false);
 	if (!list->file_offset_node) {
 		DRM_ERROR("failed to allocate offset for bo %d\n", obj->name);
 		ret = -ENOSPC;
 		goto out_free_list;
+	}
 	list->file_offset_node = drm_mm_get_block(list->file_offset_node,
 			obj->size / PAGE_SIZE, 0);
 	if (!list->file_offset_node) {
 		ret = -ENOMEM;
 		goto out_free_list;
+	}
 	list->hash.key = list->file_offset_node->start;
 	ret = drm_ht_insert_item(&mm->offset_hash, &list->hash);
 	if (ret) {
 		DRM_ERROR("failed to add to map hash\n");
 		goto out_free_mm;
+	}
 	return 0;
 out_free_mm:
 	drm_mm_put_block(list->file_offset_node);
 out_free_list:
 	kfree(list->map);
 	list->map = NULL;
 	return ret;
+}
 EXPORT_SYMBOL(drm_gem_create_mmap_offset);
 /** Returns a reference to the object named by the handle. */
 struct drm_gem_object *
 drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
 		      u32 handle)
+{
 	struct drm_gem_object *obj;
 	spin_lock(&filp->table_lock);
 	/* Check if we currently have a reference on the object */
 	obj = idr_find(&filp->object_idr, handle);
 	if (obj == NULL) {
 		spin_unlock(&filp->table_lock);
 		return NULL;
+	}
 	drm_gem_object_reference(obj);
 	spin_unlock(&filp->table_lock);
 	return obj;
+}
 EXPORT_SYMBOL(drm_gem_object_lookup);
 /**
  * Releases the handle to an mm object.
  */
 int
 drm_gem_close_ioctl(struct drm_device *dev, void *data,
 		    struct drm_file *file_priv)
+{
 	struct drm_gem_close *args = data;
 	int ret;
 	if (!(dev->driver->driver_features & DRIVER_GEM))
 		return -ENODEV;
 	ret = drm_gem_handle_delete(file_priv, args->handle);
 	return ret;
+}
 /**
  * Create a global name for an object, returning the name.
+ *
  * Note that the name does not hold a reference; when the object
  * is freed, the name goes away.
  */
 int
 drm_gem_flink_ioctl(struct drm_device *dev, void *data,
 		    struct drm_file *file_priv)
+{
 	struct drm_gem_flink *args = data;
 	struct drm_gem_object *obj;
 	int ret;
 	if (!(dev->driver->driver_features & DRIVER_GEM))
 		return -ENODEV;
 	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
 	if (obj == NULL)
 		return -ENOENT;
 again:
 	if (idr_pre_get(&dev->object_name_idr, GFP_KERNEL) == 0) {
 		ret = -ENOMEM;
 		goto err;
+	}
 	spin_lock(&dev->object_name_lock);
 	if (!obj->name) {
 		ret = idr_get_new_above(&dev->object_name_idr, obj, 1,
 					&obj->name);
 		args->name = (uint64_t) obj->name;
 		spin_unlock(&dev->object_name_lock);
 		if (ret == -EAGAIN)
 			goto again;
 		else if (ret)
 			goto err;
 		/* Allocate a reference for the name table.  */
 		drm_gem_object_reference(obj);
 	} else {
 		args->name = (uint64_t) obj->name;
 		spin_unlock(&dev->object_name_lock);
 		ret = 0;
+	}
 err:
 	drm_gem_object_unreference_unlocked(obj);
 	return ret;
+}
 /**
  * Open an object using the global name, returning a handle and the size.
+ *
  * This handle (of course) holds a reference to the object, so the object
  * will not go away until the handle is deleted.
  */
 int
 drm_gem_open_ioctl(struct drm_device *dev, void *data,
 		   struct drm_file *file_priv)
+{
 	struct drm_gem_open *args = data;
 	struct drm_gem_object *obj;
 	int ret;
 	u32 handle;
 	if (!(dev->driver->driver_features & DRIVER_GEM))
 		return -ENODEV;
 	spin_lock(&dev->object_name_lock);
 	obj = idr_find(&dev->object_name_idr, (int) args->name);
 	if (obj)
 		drm_gem_object_reference(obj);
 	spin_unlock(&dev->object_name_lock);
 	if (!obj)
 		return -ENOENT;
 	ret = drm_gem_handle_create(file_priv, obj, &handle);
 	drm_gem_object_unreference_unlocked(obj);
 	if (ret)
 		return ret;
 	args->handle = handle;
 	args->size = obj->size;
 	return 0;
+}
 /**
  * Called at device open time, sets up the structure for handling refcounting
  * of mm objects.
  */
 void
 drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
+{
 	idr_init(&file_private->object_idr);
 	spin_lock_init(&file_private->table_lock);
+}
 /**
  * Called at device close to release the file's
  * handle references on objects.
  */
 static int
 drm_gem_object_release_handle(int id, void *ptr, void *data)
+{
 	struct drm_file *file_priv = data;
 	struct drm_gem_object *obj = ptr;
 	struct drm_device *dev = obj->dev;
 #ifndef __NetBSD__			/* XXX drm prime */
 	drm_gem_remove_prime_handles(obj, file_priv);
 #endif
 	if (dev->driver->gem_close_object)
 		dev->driver->gem_close_object(obj, file_priv);
 	drm_gem_object_handle_unreference_unlocked(obj);
 	return 0;
+}
 /**
  * Called at close time when the filp is going away.
+ *
  * Releases any remaining references on objects by this filp.
  */
 void
 drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
+{
 	idr_for_each(&file_private->object_idr,
 		     &drm_gem_object_release_handle, file_private);
 	idr_remove_all(&file_private->object_idr);
 	idr_destroy(&file_private->object_idr);
+}
 void
 drm_gem_object_release(struct drm_gem_object *obj)
+{
 	if (obj->filp)
 	    fput(obj->filp);
+}
 EXPORT_SYMBOL(drm_gem_object_release);
 /**
  * Called after the last reference to the object has been lost.
  * Must be called holding struct_ mutex
+ *
  * Frees the object
  */
 void
 drm_gem_object_free(struct kref *kref)
+{
 	struct drm_gem_object *obj = (struct drm_gem_object *) kref;
 	struct drm_device *dev = obj->dev;
 	BUG_ON(!mutex_is_locked(&dev->struct_mutex));
 	if (dev->driver->gem_free_object != NULL)
 		dev->driver->gem_free_object(obj);
+}
 EXPORT_SYMBOL(drm_gem_object_free);
 static void drm_gem_object_ref_bug(struct kref *list_kref)
+{
 	BUG();
+}
 /**
  * Called after the last handle to the object has been closed
+ *
  * Removes any name for the object. Note that this must be
  * called before drm_gem_object_free or we'll be touching
  * freed memory
  */
 void drm_gem_object_handle_free(struct drm_gem_object *obj)
+{
 	struct drm_device *dev = obj->dev;
 	/* Remove any name for this object */
 	spin_lock(&dev->object_name_lock);
 	if (obj->name) {
 		idr_remove(&dev->object_name_idr, obj->name);
 		obj->name = 0;
 		spin_unlock(&dev->object_name_lock);
 		/*
 		 * The object name held a reference to this object, drop
 		 * that now.
+		*
 		* This cannot be the last reference, since the handle holds one too.
 		 */
 		kref_put(&obj->refcount, drm_gem_object_ref_bug);
 	} else
 		spin_unlock(&dev->object_name_lock);
+}
 EXPORT_SYMBOL(drm_gem_object_handle_free);
 void drm_gem_vm_open(struct vm_area_struct *vma)
+{
 	struct drm_gem_object *obj = vma->vm_private_data;
 	drm_gem_object_reference(obj);
 	mutex_lock(&obj->dev->struct_mutex);
 	drm_vm_open_locked(obj->dev, vma);
 	mutex_unlock(&obj->dev->struct_mutex);
+}
 EXPORT_SYMBOL(drm_gem_vm_open);
 void drm_gem_vm_close(struct vm_area_struct *vma)
+{
 	struct drm_gem_object *obj = vma->vm_private_data;
 	struct drm_device *dev = obj->dev;
 	mutex_lock(&dev->struct_mutex);
 	drm_vm_close_locked(obj->dev, vma);
 	drm_gem_object_unreference(obj);
 	mutex_unlock(&dev->struct_mutex);
+}
 EXPORT_SYMBOL(drm_gem_vm_close);
 /**
  * drm_gem_mmap - memory map routine for GEM objects
  * @filp: DRM file pointer
  * @vma: VMA for the area to be mapped
+ *
  * If a driver supports GEM object mapping, mmap calls on the DRM file
  * descriptor will end up here.
+ *
  * If we find the object based on the offset passed in (vma->vm_pgoff will
  * contain the fake offset we created when the GTT map ioctl was called on
  * the object), we set up the driver fault handler so that any accesses
  * to the object can be trapped, to perform migration, GTT binding, surface
  * register allocation, or performance monitoring.
  */
 int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
 	struct drm_file *priv = filp->private_data;
 	struct drm_device *dev = priv->minor->dev;
 	struct drm_gem_mm *mm = dev->mm_private;
 	struct drm_local_map *map = NULL;
 	struct drm_gem_object *obj;
 	struct drm_hash_item *hash;
 	int ret = 0;
 	if (drm_device_is_unplugged(dev))
 		return -ENODEV;
 	mutex_lock(&dev->struct_mutex);
 	if (drm_ht_find_item(&mm->offset_hash, vma->vm_pgoff, &hash)) {
 		mutex_unlock(&dev->struct_mutex);
 		return drm_mmap(filp, vma);
+	}
 	map = drm_hash_entry(hash, struct drm_map_list, hash)->map;
 	if (!map ||
 	    ((map->flags & _DRM_RESTRICTED) && !capable(CAP_SYS_ADMIN))) {
 		ret =  -EPERM;
 		goto out_unlock;
+	}
 	/* Check for valid size. */
 	if (map->size < vma->vm_end - vma->vm_start) {
 		ret = -EINVAL;
 		goto out_unlock;
+	}
 	obj = map->handle;
 	if (!obj->dev->driver->gem_vm_ops) {
 		ret = -EINVAL;
 		goto out_unlock;
+	}
 	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
 	vma->vm_ops = obj->dev->driver->gem_vm_ops;
 	vma->vm_private_data = map->handle;
 	vma->vm_page_prot =  pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
 	/* Take a ref for this mapping of the object, so that the fault
 	 * handler can dereference the mmap offset's pointer to the object.
 	 * This reference is cleaned up by the corresponding vm_close
 	 * (which should happen whether the vma was created by this call, or
 	 * by a vm_open due to mremap or partial unmap or whatever).
 	 */
 	drm_gem_object_reference(obj);
 	drm_vm_open_locked(dev, vma);
 out_unlock:
 	mutex_unlock(&dev->struct_mutex);
 	return ret;
+}
 EXPORT_SYMBOL(drm_gem_mmap);