[media] vb2-dma-sg: add allocation context to dma-sg

Require that dma-sg also uses an allocation context. This is in preparation
for adding prepare/finish memops to sync the memory between DMA and CPU.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Pawel Osciak <pawel@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

20 files changed, 104 insertions, 10 deletions

diff --git a/drivers/media/pci/cx23885/cx23885-417.c b/drivers/media/pci/cx23885/cx23885-417.c
index 3948db386fb5..d72a3ec348ef 100644
--- a/drivers/media/pci/cx23885/cx23885-417.c
+++ b/drivers/media/pci/cx23885/cx23885-417.c
@@ -1148,6 +1148,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 	dev->ts1.ts_packet_count = mpeglines;
 	*num_planes = 1;
 	sizes[0] = mpeglinesize * mpeglines;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	*num_buffers = mpegbufs;
 	return 0;
 }
diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c
index 331eddac7222..d452b5c076e6 100644
--- a/drivers/media/pci/cx23885/cx23885-core.c
+++ b/drivers/media/pci/cx23885/cx23885-core.c
@@ -1997,9 +1997,14 @@ static int cx23885_initdev(struct pci_dev *pci_dev,
 	if (!pci_dma_supported(pci_dev, 0xffffffff)) {
 		printk("%s/0: Oops: no 32bit PCI DMA ???\n", dev->name);
 		err = -EIO;
-		goto fail_irq;
+		goto fail_context;
 	}
 
+	dev->alloc_ctx = vb2_dma_sg_init_ctx(&pci_dev->dev);
+	if (IS_ERR(dev->alloc_ctx)) {
+		err = PTR_ERR(dev->alloc_ctx);
+		goto fail_context;
+	}
 	err = request_irq(pci_dev->irq, cx23885_irq,
 			  IRQF_SHARED, dev->name, dev);
 	if (err < 0) {
@@ -2028,6 +2033,8 @@ static int cx23885_initdev(struct pci_dev *pci_dev,
 	return 0;
 
 fail_irq:
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
+fail_context:
 	cx23885_dev_unregister(dev);
 fail_ctrl:
 	v4l2_ctrl_handler_free(hdl);
@@ -2053,6 +2060,7 @@ static void cx23885_finidev(struct pci_dev *pci_dev)
 	free_irq(pci_dev->irq, dev);
 
 	cx23885_dev_unregister(dev);
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
 	v4l2_ctrl_handler_free(&dev->ctrl_handler);
 	v4l2_device_unregister(v4l2_dev);
 	kfree(dev);
diff --git a/drivers/media/pci/cx23885/cx23885-dvb.c b/drivers/media/pci/cx23885/cx23885-dvb.c
index 1ed92eeb46d1..44fafba65c6f 100644
--- a/drivers/media/pci/cx23885/cx23885-dvb.c
+++ b/drivers/media/pci/cx23885/cx23885-dvb.c
@@ -102,6 +102,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 	port->ts_packet_count = 32;
 	*num_planes = 1;
 	sizes[0] = port->ts_packet_size * port->ts_packet_count;
+	alloc_ctxs[0] = port->dev->alloc_ctx;
 	*num_buffers = 32;
 	return 0;
 }
diff --git a/drivers/media/pci/cx23885/cx23885-vbi.c b/drivers/media/pci/cx23885/cx23885-vbi.c
index a7c6ef8f3ea3..1d339a69f0c8 100644
--- a/drivers/media/pci/cx23885/cx23885-vbi.c
+++ b/drivers/media/pci/cx23885/cx23885-vbi.c
@@ -132,6 +132,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 		lines = VBI_NTSC_LINE_COUNT;
 	*num_planes = 1;
 	sizes[0] = lines * VBI_LINE_LENGTH * 2;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	return 0;
 }
 
diff --git a/drivers/media/pci/cx23885/cx23885-video.c b/drivers/media/pci/cx23885/cx23885-video.c
index 091f5dbe65a8..371eecfe7b32 100644
--- a/drivers/media/pci/cx23885/cx23885-video.c
+++ b/drivers/media/pci/cx23885/cx23885-video.c
@@ -323,6 +323,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 
 	*num_planes = 1;
 	sizes[0] = (dev->fmt->depth * dev->width * dev->height) >> 3;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	return 0;
 }
 
diff --git a/drivers/media/pci/cx23885/cx23885.h b/drivers/media/pci/cx23885/cx23885.h
index cf4efa461ce2..f55cd12da0fd 100644
--- a/drivers/media/pci/cx23885/cx23885.h
+++ b/drivers/media/pci/cx23885/cx23885.h
@@ -425,6 +425,7 @@ struct cx23885_dev {
 	struct vb2_queue           vb2_vidq;
 	struct cx23885_dmaqueue    vbiq;
 	struct vb2_queue           vb2_vbiq;
+	void			   *alloc_ctx;
 
 	spinlock_t                 slock;
 
diff --git a/drivers/media/pci/saa7134/saa7134-core.c b/drivers/media/pci/saa7134/saa7134-core.c
index 236ed725f933..a349e964e0bc 100644
--- a/drivers/media/pci/saa7134/saa7134-core.c
+++ b/drivers/media/pci/saa7134/saa7134-core.c
@@ -1001,13 +1001,18 @@ static int saa7134_initdev(struct pci_dev *pci_dev,
 	saa7134_board_init1(dev);
 	saa7134_hwinit1(dev);
 
+	dev->alloc_ctx = vb2_dma_sg_init_ctx(&pci_dev->dev);
+	if (IS_ERR(dev->alloc_ctx)) {
+		err = PTR_ERR(dev->alloc_ctx);
+		goto fail3;
+	}
 	/* get irq */
 	err = request_irq(pci_dev->irq, saa7134_irq,
 			  IRQF_SHARED, dev->name, dev);
 	if (err < 0) {
 		printk(KERN_ERR "%s: can't get IRQ %d\n",
 		       dev->name,pci_dev->irq);
-		goto fail3;
+		goto fail4;
 	}
 
 	/* wait a bit, register i2c bus */
@@ -1065,7 +1070,7 @@ static int saa7134_initdev(struct pci_dev *pci_dev,
 	if (err < 0) {
 		printk(KERN_INFO "%s: can't register video device\n",
 		       dev->name);
-		goto fail4;
+		goto fail5;
 	}
 	printk(KERN_INFO "%s: registered device %s [v4l2]\n",
 	       dev->name, video_device_node_name(dev->video_dev));
@@ -1078,7 +1083,7 @@ static int saa7134_initdev(struct pci_dev *pci_dev,
 	err = video_register_device(dev->vbi_dev,VFL_TYPE_VBI,
 				    vbi_nr[dev->nr]);
 	if (err < 0)
-		goto fail4;
+		goto fail5;
 	printk(KERN_INFO "%s: registered device %s\n",
 	       dev->name, video_device_node_name(dev->vbi_dev));
 
@@ -1089,7 +1094,7 @@ static int saa7134_initdev(struct pci_dev *pci_dev,
 		err = video_register_device(dev->radio_dev,VFL_TYPE_RADIO,
 					    radio_nr[dev->nr]);
 		if (err < 0)
-			goto fail4;
+			goto fail5;
 		printk(KERN_INFO "%s: registered device %s\n",
 		       dev->name, video_device_node_name(dev->radio_dev));
 	}
@@ -1103,10 +1108,12 @@ static int saa7134_initdev(struct pci_dev *pci_dev,
 	request_submodules(dev);
 	return 0;
 
- fail4:
+ fail5:
 	saa7134_unregister_video(dev);
 	saa7134_i2c_unregister(dev);
 	free_irq(pci_dev->irq, dev);
+ fail4:
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
  fail3:
 	saa7134_hwfini(dev);
 	iounmap(dev->lmmio);
@@ -1173,6 +1180,7 @@ static void saa7134_finidev(struct pci_dev *pci_dev)
 
 	/* release resources */
 	free_irq(pci_dev->irq, dev);
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
 	iounmap(dev->lmmio);
 	release_mem_region(pci_resource_start(pci_dev,0),
 			   pci_resource_len(pci_dev,0));
diff --git a/drivers/media/pci/saa7134/saa7134-ts.c b/drivers/media/pci/saa7134/saa7134-ts.c
index bd25323bd947..8eff4a7d8ba3 100644
--- a/drivers/media/pci/saa7134/saa7134-ts.c
+++ b/drivers/media/pci/saa7134/saa7134-ts.c
@@ -142,6 +142,7 @@ int saa7134_ts_queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 		*nbuffers = 3;
 	*nplanes = 1;
 	sizes[0] = size;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(saa7134_ts_queue_setup);
diff --git a/drivers/media/pci/saa7134/saa7134-vbi.c b/drivers/media/pci/saa7134/saa7134-vbi.c
index 4f0b1012e4f3..e2cc684a7c12 100644
--- a/drivers/media/pci/saa7134/saa7134-vbi.c
+++ b/drivers/media/pci/saa7134/saa7134-vbi.c
@@ -156,6 +156,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 	*nbuffers = saa7134_buffer_count(size, *nbuffers);
 	*nplanes = 1;
 	sizes[0] = size;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	return 0;
 }
 
diff --git a/drivers/media/pci/saa7134/saa7134-video.c b/drivers/media/pci/saa7134/saa7134-video.c
index fc4a427cb51f..ba029953db9d 100644
--- a/drivers/media/pci/saa7134/saa7134-video.c
+++ b/drivers/media/pci/saa7134/saa7134-video.c
@@ -932,6 +932,7 @@ static int queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 	*nbuffers = saa7134_buffer_count(size, *nbuffers);
 	*nplanes = 1;
 	sizes[0] = size;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	return 0;
 }
 
diff --git a/drivers/media/pci/saa7134/saa7134.h b/drivers/media/pci/saa7134/saa7134.h
index 1a82dd07205b..c644c7da6859 100644
--- a/drivers/media/pci/saa7134/saa7134.h
+++ b/drivers/media/pci/saa7134/saa7134.h
@@ -588,6 +588,7 @@ struct saa7134_dev {
 
 
 	/* video+ts+vbi capture */
+	void			   *alloc_ctx;
 	struct saa7134_dmaqueue    video_q;
 	struct vb2_queue           video_vbq;
 	struct saa7134_dmaqueue    vbi_q;
diff --git a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
index 30e09d935ce1..4f6bfba58065 100644
--- a/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/media/pci/solo6x10/solo6x10-v4l2-enc.c
@@ -718,7 +718,10 @@ static int solo_enc_queue_setup(struct vb2_queue *q,
 				unsigned int *num_planes, unsigned int sizes[],
 				void *alloc_ctxs[])
 {
+	struct solo_enc_dev *solo_enc = vb2_get_drv_priv(q);
+
 	sizes[0] = FRAME_BUF_SIZE;
+	alloc_ctxs[0] = solo_enc->alloc_ctx;
 	*num_planes = 1;
 
 	if (*num_buffers < MIN_VID_BUFFERS)
@@ -1266,6 +1269,11 @@ static struct solo_enc_dev *solo_enc_alloc(struct solo_dev *solo_dev,
 		return ERR_PTR(-ENOMEM);
 
 	hdl = &solo_enc->hdl;
+	solo_enc->alloc_ctx = vb2_dma_sg_init_ctx(&solo_dev->pdev->dev);
+	if (IS_ERR(solo_enc->alloc_ctx)) {
+		ret = PTR_ERR(solo_enc->alloc_ctx);
+		goto hdl_free;
+	}
 	v4l2_ctrl_handler_init(hdl, 10);
 	v4l2_ctrl_new_std(hdl, &solo_ctrl_ops,
 			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
@@ -1369,6 +1377,7 @@ pci_free:
 			solo_enc->desc_items, solo_enc->desc_dma);
 hdl_free:
 	v4l2_ctrl_handler_free(hdl);
+	vb2_dma_sg_cleanup_ctx(solo_enc->alloc_ctx);
 	kfree(solo_enc);
 	return ERR_PTR(ret);
 }
@@ -1383,6 +1392,7 @@ static void solo_enc_free(struct solo_enc_dev *solo_enc)
 			solo_enc->desc_items, solo_enc->desc_dma);
 	video_unregister_device(solo_enc->vfd);
 	v4l2_ctrl_handler_free(&solo_enc->hdl);
+	vb2_dma_sg_cleanup_ctx(solo_enc->alloc_ctx);
 	kfree(solo_enc);
 }
 
diff --git a/drivers/media/pci/solo6x10/solo6x10.h b/drivers/media/pci/solo6x10/solo6x10.h
index 72017b7f0a75..bd8edfa319b8 100644
--- a/drivers/media/pci/solo6x10/solo6x10.h
+++ b/drivers/media/pci/solo6x10/solo6x10.h
@@ -180,6 +180,7 @@ struct solo_enc_dev {
 	u32			sequence;
 	struct vb2_queue	vidq;
 	struct list_head	vidq_active;
+	void			*alloc_ctx;
 	int			desc_count;
 	int			desc_nelts;
 	struct solo_p2m_desc	*desc_items;
diff --git a/drivers/media/pci/tw68/tw68-core.c b/drivers/media/pci/tw68/tw68-core.c
index 63f0b64057cb..c135165a8b26 100644
--- a/drivers/media/pci/tw68/tw68-core.c
+++ b/drivers/media/pci/tw68/tw68-core.c
@@ -304,13 +304,19 @@ static int tw68_initdev(struct pci_dev *pci_dev,
 	/* Then do any initialisation wanted before interrupts are on */
 	tw68_hw_init1(dev);
 
+	dev->alloc_ctx = vb2_dma_sg_init_ctx(&pci_dev->dev);
+	if (IS_ERR(dev->alloc_ctx)) {
+		err = PTR_ERR(dev->alloc_ctx);
+		goto fail3;
+	}
+
 	/* get irq */
 	err = devm_request_irq(&pci_dev->dev, pci_dev->irq, tw68_irq,
 			  IRQF_SHARED, dev->name, dev);
 	if (err < 0) {
 		pr_err("%s: can't get IRQ %d\n",
 		       dev->name, pci_dev->irq);
-		goto fail3;
+		goto fail4;
 	}
 
 	/*
@@ -324,7 +330,7 @@ static int tw68_initdev(struct pci_dev *pci_dev,
 	if (err < 0) {
 		pr_err("%s: can't register video device\n",
 		       dev->name);
-		goto fail4;
+		goto fail5;
 	}
 	tw_setl(TW68_INTMASK, dev->pci_irqmask);
 
@@ -333,8 +339,10 @@ static int tw68_initdev(struct pci_dev *pci_dev,
 
 	return 0;
 
-fail4:
+fail5:
 	video_unregister_device(&dev->vdev);
+fail4:
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
 fail3:
 	iounmap(dev->lmmio);
 fail2:
@@ -358,6 +366,7 @@ static void tw68_finidev(struct pci_dev *pci_dev)
 	/* unregister */
 	video_unregister_device(&dev->vdev);
 	v4l2_ctrl_handler_free(&dev->hdl);
+	vb2_dma_sg_cleanup_ctx(dev->alloc_ctx);
 
 	/* release resources */
 	iounmap(dev->lmmio);
diff --git a/drivers/media/pci/tw68/tw68-video.c b/drivers/media/pci/tw68/tw68-video.c
index 5c94ac7c88d9..50dcce6251f6 100644
--- a/drivers/media/pci/tw68/tw68-video.c
+++ b/drivers/media/pci/tw68/tw68-video.c
@@ -384,6 +384,7 @@ static int tw68_queue_setup(struct vb2_queue *q, const struct v4l2_format *fmt,
 	unsigned tot_bufs = q->num_buffers + *num_buffers;
 
 	sizes[0] = (dev->fmt->depth * dev->width * dev->height) >> 3;
+	alloc_ctxs[0] = dev->alloc_ctx;
 	/*
 	 * We allow create_bufs, but only if the sizeimage is the same as the
 	 * current sizeimage. The tw68_buffer_count calculation becomes quite
diff --git a/drivers/media/pci/tw68/tw68.h b/drivers/media/pci/tw68/tw68.h
index 2c8abe26b13b..7a7501bd165f 100644
--- a/drivers/media/pci/tw68/tw68.h
+++ b/drivers/media/pci/tw68/tw68.h
@@ -181,6 +181,7 @@ struct tw68_dev {
 	unsigned		field;
 	struct vb2_queue	vidq;
 	struct list_head	active;
+	void			*alloc_ctx;
 
 	/* various v4l controls */
 	const struct tw68_tvnorm *tvnorm;	/* video */
diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index f0eeb6cd262c..c3ff5388aeb3 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1079,6 +1079,8 @@ static int mcam_vb_queue_setup(struct vb2_queue *vq,
 		*nbufs = minbufs;
 	if (cam->buffer_mode == B_DMA_contig)
 		alloc_ctxs[0] = cam->vb_alloc_ctx;
+	else if (cam->buffer_mode == B_DMA_sg)
+		alloc_ctxs[0] = cam->vb_alloc_ctx_sg;
 	return 0;
 }
 
@@ -1286,10 +1288,12 @@ static int mcam_setup_vb2(struct mcam_camera *cam)
 		vq->ops = &mcam_vb2_ops;
 		vq->mem_ops = &vb2_dma_contig_memops;
 		vq->buf_struct_size = sizeof(struct mcam_vb_buffer);
-		cam->vb_alloc_ctx = vb2_dma_contig_init_ctx(cam->dev);
 		vq->io_modes = VB2_MMAP | VB2_USERPTR;
 		cam->dma_setup = mcam_ctlr_dma_contig;
 		cam->frame_complete = mcam_dma_contig_done;
+		cam->vb_alloc_ctx = vb2_dma_contig_init_ctx(cam->dev);
+		if (IS_ERR(cam->vb_alloc_ctx))
+			return PTR_ERR(cam->vb_alloc_ctx);
 #endif
 		break;
 	case B_DMA_sg:
@@ -1300,6 +1304,9 @@ static int mcam_setup_vb2(struct mcam_camera *cam)
 		vq->io_modes = VB2_MMAP | VB2_USERPTR;
 		cam->dma_setup = mcam_ctlr_dma_sg;
 		cam->frame_complete = mcam_dma_sg_done;
+		cam->vb_alloc_ctx_sg = vb2_dma_sg_init_ctx(cam->dev);
+		if (IS_ERR(cam->vb_alloc_ctx_sg))
+			return PTR_ERR(cam->vb_alloc_ctx_sg);
 #endif
 		break;
 	case B_vmalloc:
@@ -1325,6 +1332,10 @@ static void mcam_cleanup_vb2(struct mcam_camera *cam)
 	if (cam->buffer_mode == B_DMA_contig)
 		vb2_dma_contig_cleanup_ctx(cam->vb_alloc_ctx);
 #endif
+#ifdef MCAM_MODE_DMA_SG
+	if (cam->buffer_mode == B_DMA_sg)
+		vb2_dma_sg_cleanup_ctx(cam->vb_alloc_ctx_sg);
+#endif
 }
 
 
diff --git a/drivers/media/platform/marvell-ccic/mcam-core.h b/drivers/media/platform/marvell-ccic/mcam-core.h
index 60a8e1cfeff7..aa0c6eac254a 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.h
+++ b/drivers/media/platform/marvell-ccic/mcam-core.h
@@ -176,6 +176,7 @@ struct mcam_camera {
 	/* DMA buffers - DMA modes */
 	struct mcam_vb_buffer *vb_bufs[MAX_DMA_BUFS];
 	struct vb2_alloc_ctx *vb_alloc_ctx;
+	struct vb2_alloc_ctx *vb_alloc_ctx_sg;
 
 	/* Mode-specific ops, set at open time */
 	void (*dma_setup)(struct mcam_camera *cam);
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 2529b831725b..2bf13dc4df34 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -30,7 +30,12 @@ module_param(debug, int, 0644);
 			printk(KERN_DEBUG "vb2-dma-sg: " fmt, ## arg);	\
 	} while (0)
 
+struct vb2_dma_sg_conf {
+	struct device		*dev;
+};
+
 struct vb2_dma_sg_buf {
+	struct device			*dev;
 	void				*vaddr;
 	struct page			**pages;
 	int				offset;
@@ -89,10 +94,13 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
 static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
 			      enum dma_data_direction dma_dir, gfp_t gfp_flags)
 {
+	struct vb2_dma_sg_conf *conf = alloc_ctx;
 	struct vb2_dma_sg_buf *buf;
 	int ret;
 	int num_pages;
 
+	if (WARN_ON(alloc_ctx == NULL))
+		return NULL;
 	buf = kzalloc(sizeof *buf, GFP_KERNEL);
 	if (!buf)
 		return NULL;
@@ -118,6 +126,8 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size,
 	if (ret)
 		goto fail_table_alloc;
 
+	/* Prevent the device from being released while the buffer is used */
+	buf->dev = get_device(conf->dev);
 	buf->handler.refcount = &buf->refcount;
 	buf->handler.put = vb2_dma_sg_put;
 	buf->handler.arg = buf;
@@ -153,6 +163,7 @@ static void vb2_dma_sg_put(void *buf_priv)
 		while (--i >= 0)
 			__free_page(buf->pages[i]);
 		kfree(buf->pages);
+		put_device(buf->dev);
 		kfree(buf);
 	}
 }
@@ -356,6 +367,27 @@ const struct vb2_mem_ops vb2_dma_sg_memops = {
 };
 EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
 
+void *vb2_dma_sg_init_ctx(struct device *dev)
+{
+	struct vb2_dma_sg_conf *conf;
+
+	conf = kzalloc(sizeof(*conf), GFP_KERNEL);
+	if (!conf)
+		return ERR_PTR(-ENOMEM);
+
+	conf->dev = dev;
+
+	return conf;
+}
+EXPORT_SYMBOL_GPL(vb2_dma_sg_init_ctx);
+
+void vb2_dma_sg_cleanup_ctx(void *alloc_ctx)
+{
+	if (!IS_ERR_OR_NULL(alloc_ctx))
+		kfree(alloc_ctx);
+}
+EXPORT_SYMBOL_GPL(vb2_dma_sg_cleanup_ctx);
+
 MODULE_DESCRIPTION("dma scatter/gather memory handling routines for videobuf2");
 MODULE_AUTHOR("Andrzej Pietrasiewicz");
 MODULE_LICENSE("GPL");
diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
index 7b89852779af..14ce3068b642 100644
--- a/include/media/videobuf2-dma-sg.h
+++ b/include/media/videobuf2-dma-sg.h
@@ -21,6 +21,9 @@ static inline struct sg_table *vb2_dma_sg_plane_desc(
 	return (struct sg_table *)vb2_plane_cookie(vb, plane_no);
 }
 
+void *vb2_dma_sg_init_ctx(struct device *dev);
+void vb2_dma_sg_cleanup_ctx(void *alloc_ctx);
+
 extern const struct vb2_mem_ops vb2_dma_sg_memops;
 
 #endif