C++ drm_gem_object_reference函数代码示例

static int codec_lockbuf(struct dce_file_priv *priv,
		uint32_t codec_handle, int32_t id,
		struct drm_gem_object *y, struct drm_gem_object *uv)
{
	struct dce_codec *codec = &priv->codecs[codec_handle-1];
	int i;

	for (i = 0; i < ARRAY_SIZE(codec->locked_buffers); i++) {
		struct dce_buffer *buf = &codec->locked_buffers[i];
		if (buf->id == 0) {
			dma_addr_t paddr;

			DBG("lock[%d]: y=%p, uv=%p", id, y, uv);

			/* for now, until the codecs support relocated buffers, keep
			 * an extra ref and paddr to keep it pinned
			 */
			drm_gem_object_reference(y);
			omap_gem_get_paddr(y, &paddr, true);

			if (uv) {
				drm_gem_object_reference(uv);
				omap_gem_get_paddr(uv, &paddr, true);
			}

			buf->id = id;
			buf->y = y;
			buf->uv = uv;

			return 0;
		}
	}
	dev_err(priv->dev->dev, "too many locked buffers!\n");
	return -ENOMEM;
}

/**
 * drm_gem_open - implementation of the GEM_OPEN ioctl
 * @dev: drm_device
 * @data: ioctl data
 * @file_priv: drm file-private structure
 *
 * 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 (!drm_core_check_feature(dev, DRIVER_GEM))
		return -ENODEV;

	mutex_lock(&dev->object_name_lock);
	obj = idr_find(&dev->object_name_idr, (int) args->name);
	if (obj) {
		drm_gem_object_reference(obj);
	} else {
		mutex_unlock(&dev->object_name_lock);
		return -ENOENT;
	}

	/* drm_gem_handle_create_tail unlocks dev->object_name_lock. */
	ret = drm_gem_handle_create_tail(file_priv, obj, &handle);
	drm_gem_object_unreference_unlocked(obj);
	if (ret)
		return ret;

	args->handle = handle;
	args->size = obj->size;

	return 0;
}

struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
        struct dma_buf *buffer)
{
    struct drm_gem_object *obj;

    /* is this one of own objects? */
    if (buffer->ops == &omap_dmabuf_ops) {
        obj = buffer->priv;
        /* is it from our device? */
        if (obj->dev == dev) {
            /*
             * Importing dmabuf exported from out own gem increases
             * refcount on gem itself instead of f_count of dmabuf.
             */
            drm_gem_object_reference(obj);
            return obj;
        }
    }

    /*
     * TODO add support for importing buffers from other devices..
     * for now we don't need this but would be nice to add eventually
     */
    return ERR_PTR(-EINVAL);
}

/**
 * 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;
}

/**
 * drm_gem_mmap_obj - memory map a GEM object
 * @obj: the GEM object to map
 * @obj_size: the object size to be mapped, in bytes
 * @vma: VMA for the area to be mapped
 *
 * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
 * provided by the driver. Depending on their requirements, drivers can either
 * provide a fault handler in their gem_vm_ops (in which case any accesses to
 * the object will be trapped, to perform migration, GTT binding, surface
 * register allocation, or performance monitoring), or mmap the buffer memory
 * synchronously after calling drm_gem_mmap_obj.
 *
 * This function is mainly intended to implement the DMABUF mmap operation, when
 * the GEM object is not looked up based on its fake offset. To implement the
 * DRM mmap operation, drivers should use the drm_gem_mmap() function.
 *
 * drm_gem_mmap_obj() assumes the user is granted access to the buffer while
 * drm_gem_mmap() prevents unprivileged users from mapping random objects. So
 * callers must verify access restrictions before calling this helper.
 *
 * Return 0 or success or -EINVAL if the object size is smaller than the VMA
 * size, or if no gem_vm_ops are provided.
 */
int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
		     struct vm_area_struct *vma)
{
	struct drm_device *dev = obj->dev;

	/* Check for valid size. */
	if (obj_size < vma->vm_end - vma->vm_start)
		return -EINVAL;

	if (!dev->driver->gem_vm_ops)
		return -EINVAL;

	vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
	vma->vm_ops = dev->driver->gem_vm_ops;
	vma->vm_private_data = obj;
	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);

	return 0;
}

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;
	}

	/*                       */
	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_RESERVED | VM_IO | VM_PFNMAP | VM_DONTEXPAND;
	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));

	/*                                                             
                                                                    
                                                              
                                                                     
                                                             
  */
	drm_gem_object_reference(obj);

	drm_vm_open_locked(vma);

out_unlock:
	mutex_unlock(&dev->struct_mutex);

	return ret;
}

/**
 * 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;
}

static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
{
	struct tegra_bo *obj = host1x_to_tegra_bo(bo);

	drm_gem_object_reference(&obj->gem);

	return bo;
}

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(vma);
    mutex_unlock(&obj->dev->struct_mutex);
}

static struct host1x_bo *tegra_bo_get(struct host1x_bo *bo)
{
	struct tegra_bo *obj = host1x_to_drm_bo(bo);
	struct drm_device *drm = obj->gem.dev;

	mutex_lock(&drm->struct_mutex);
	drm_gem_object_reference(&obj->gem);
	mutex_unlock(&drm->struct_mutex);

	return bo;
}

struct drm_gem_object *i915_gem_prime_import(struct drm_device *dev,
					     struct dma_buf *dma_buf)
{
	struct dma_buf_attachment *attach;
	struct drm_i915_gem_object *obj;
	int ret;

	/* is this one of own objects? */
	if (dma_buf->ops == &i915_dmabuf_ops) {
		obj = dma_buf_to_obj(dma_buf);
		/* is it from our device? */
		if (obj->base.dev == dev) {
			/*
			 * Importing dmabuf exported from out own gem increases
			 * refcount on gem itself instead of f_count of dmabuf.
			 */
			drm_gem_object_reference(&obj->base);
			return &obj->base;
		}
	}

	/* need to attach */
	attach = dma_buf_attach(dma_buf, dev->dev);
	if (IS_ERR(attach))
		return ERR_CAST(attach);

	get_dma_buf(dma_buf);

	obj = i915_gem_object_alloc(dev);
	if (obj == NULL) {
		ret = -ENOMEM;
		goto fail_detach;
	}

	ret = drm_gem_private_object_init(dev, &obj->base, dma_buf->size);
	if (ret) {
		i915_gem_object_free(obj);
		goto fail_detach;
	}

	i915_gem_object_init(obj, &i915_gem_object_dmabuf_ops);
	obj->base.import_attach = attach;

	return &obj->base;

fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);

	return ERR_PTR(ret);
}

struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
					     struct dma_buf *dma_buf)
{
	struct dma_buf_attachment *attach;
	struct drm_gem_object *obj;
	struct sg_table *sgt;
	int ret;

	if (dma_buf->ops == &omap_dmabuf_ops) {
		obj = dma_buf->priv;
		if (obj->dev == dev) {
			/*
			 * Importing dmabuf exported from out own gem increases
			 * refcount on gem itself instead of f_count of dmabuf.
			 */
			drm_gem_object_reference(obj);
			return obj;
		}
	}

	attach = dma_buf_attach(dma_buf, dev->dev);
	if (IS_ERR(attach))
		return ERR_CAST(attach);

	get_dma_buf(dma_buf);

	sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
	if (IS_ERR(sgt)) {
		ret = PTR_ERR(sgt);
		goto fail_detach;
	}

	obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
	if (IS_ERR(obj)) {
		ret = PTR_ERR(obj);
		goto fail_unmap;
	}

	obj->import_attach = attach;

	return obj;

fail_unmap:
	dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
fail_detach:
	dma_buf_detach(dma_buf, attach);
	dma_buf_put(dma_buf);

	return ERR_PTR(ret);
}

static void unpin(void *arg, struct drm_gem_object *bo)
{
	struct drm_plane *plane = arg;
	struct omap_plane *omap_plane = to_omap_plane(plane);

	if (kfifo_put(&omap_plane->unpin_fifo,
			(const struct drm_gem_object **)&bo)) {
		/* also hold a ref so it isn't free'd while pinned */
		drm_gem_object_reference(bo);
	} else {
		dev_err(plane->dev->dev, "unpin fifo full!\n");
		omap_gem_put_paddr(bo);
	}
}

/**
 * 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 -EBADF;

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;

		if (ret != 0)
			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:
	mutex_lock(&dev->struct_mutex);
	drm_gem_object_unreference(obj);
	mutex_unlock(&dev->struct_mutex);
	return ret;
}

/* called from IRQ to update cursor related registers (if needed).  The
 * cursor registers, other than x/y position, appear not to be double
 * buffered, and changing them other than from vblank seems to trigger
 * underflow.
 */
static void update_cursor(struct drm_crtc *crtc)
{
	struct mdp4_crtc *mdp4_crtc = to_mdp4_crtc(crtc);
	struct mdp4_kms *mdp4_kms = get_kms(crtc);
	enum mdp4_dma dma = mdp4_crtc->dma;
	unsigned long flags;

	spin_lock_irqsave(&mdp4_crtc->cursor.lock, flags);
	if (mdp4_crtc->cursor.stale) {
		struct drm_gem_object *next_bo = mdp4_crtc->cursor.next_bo;
		struct drm_gem_object *prev_bo = mdp4_crtc->cursor.scanout_bo;
		uint32_t iova = mdp4_crtc->cursor.next_iova;

		if (next_bo) {
			/* take a obj ref + iova ref when we start scanning out: */
			drm_gem_object_reference(next_bo);
			msm_gem_get_iova_locked(next_bo, mdp4_kms->id, &iova);

			/* enable cursor: */
			mdp4_write(mdp4_kms, REG_MDP4_DMA_CURSOR_SIZE(dma),
					MDP4_DMA_CURSOR_SIZE_WIDTH(mdp4_crtc->cursor.width) |
					MDP4_DMA_CURSOR_SIZE_HEIGHT(mdp4_crtc->cursor.height));
			mdp4_write(mdp4_kms, REG_MDP4_DMA_CURSOR_BASE(dma), iova);
			mdp4_write(mdp4_kms, REG_MDP4_DMA_CURSOR_BLEND_CONFIG(dma),
					MDP4_DMA_CURSOR_BLEND_CONFIG_FORMAT(CURSOR_ARGB) |
					MDP4_DMA_CURSOR_BLEND_CONFIG_CURSOR_EN);
		} else {
			/* disable cursor: */
			mdp4_write(mdp4_kms, REG_MDP4_DMA_CURSOR_BASE(dma),
					mdp4_kms->blank_cursor_iova);
		}

		/* and drop the iova ref + obj rev when done scanning out: */
		if (prev_bo)
			drm_flip_work_queue(&mdp4_crtc->unref_cursor_work, prev_bo);

		mdp4_crtc->cursor.scanout_bo = next_bo;
		mdp4_crtc->cursor.stale = false;
	}

	mdp4_write(mdp4_kms, REG_MDP4_DMA_CURSOR_POS(dma),
			MDP4_DMA_CURSOR_POS_X(mdp4_crtc->cursor.x) |
			MDP4_DMA_CURSOR_POS_Y(mdp4_crtc->cursor.y));

	spin_unlock_irqrestore(&mdp4_crtc->cursor.lock, flags);
}