[RFCv1 PATCH 00/20] vb2: more fixes, add dmabuf/expbuf (PART 2)

[RFCv1 PATCH 00/20] vb2: more fixes, add dmabuf/expbuf (PART 2)

[Hans Verkuil]

Hi all,

This patch series follows on from PART 1: the REVIEWv1 vb2 patch series
just posted.

Patches 1-3 and 11-20 are various code improvements and fixes based
on extensive testing with v4l2-compliance and several test drivers
(vivi and viloop, to be posted later).

Patches 4-10 add support for dmabuf and expbuf to vb2-dma-sg and adds
expbuf support to vmalloc.

This has seen extensive testing as well, but more is needed, in particular
with 'real' hardware as opposed to virtual drivers. I hope to be able to
do some testing for that this week.

Regards,

	Hans

[RFCv1 PATCH 01/20] vb2: stop_streaming should return void

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The vb2 core ignores any return code from the stop_streaming op.
And there really isn't anything it can do anyway in case of an error.
So change the return type to void and update any drivers that implement it.

The int return gave drivers the idea that this operation could actually
fail, but that's really not the case.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/pci/sta2x11/sta2x11_vip.c                  | 3 +--
 drivers/media/platform/blackfin/bfin_capture.c           | 6 +-----
 drivers/media/platform/coda.c                            | 4 +---
 drivers/media/platform/exynos-gsc/gsc-m2m.c              | 4 +---
 drivers/media/platform/exynos4-is/fimc-capture.c         | 6 +++---
 drivers/media/platform/exynos4-is/fimc-lite.c            | 6 +++---
 drivers/media/platform/exynos4-is/fimc-m2m.c             | 3 +--
 drivers/media/platform/marvell-ccic/mcam-core.c          | 7 +++----
 drivers/media/platform/s3c-camif/camif-capture.c         | 4 ++--
 drivers/media/platform/s5p-jpeg/jpeg-core.c              | 4 +---
 drivers/media/platform/s5p-mfc/s5p_mfc_dec.c             | 3 +--
 drivers/media/platform/s5p-mfc/s5p_mfc_enc.c             | 3 +--
 drivers/media/platform/s5p-tv/mixer_video.c              | 3 +--
 drivers/media/platform/soc_camera/atmel-isi.c            | 6 ++----
 drivers/media/platform/soc_camera/mx2_camera.c           | 4 +---
 drivers/media/platform/soc_camera/mx3_camera.c           | 4 +---
 drivers/media/platform/soc_camera/rcar_vin.c             | 4 +---
 drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c | 4 ++--
 drivers/media/platform/vivi.c                            | 3 +--
 drivers/media/platform/vsp1/vsp1_video.c                 | 4 +---
 drivers/media/usb/em28xx/em28xx-v4l.h                    | 2 +-
 drivers/media/usb/em28xx/em28xx-video.c                  | 8 ++------
 drivers/media/usb/pwc/pwc-if.c                           | 6 ++----
 drivers/media/usb/stk1160/stk1160-v4l.c                  | 4 ++--
 drivers/media/usb/usbtv/usbtv-video.c                    | 9 +++------
 drivers/staging/media/davinci_vpfe/vpfe_video.c          | 3 +--
 drivers/staging/media/dt3155v4l/dt3155v4l.c              | 3 +--
 drivers/staging/media/go7007/go7007-v4l2.c               | 3 +--
 drivers/staging/media/msi3101/sdr-msi3101.c              | 6 ++----
 drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c       | 3 +--
 drivers/staging/media/solo6x10/solo6x10-v4l2.c           | 3 +--
 include/media/videobuf2-core.h                           | 2 +-
 32 files changed, 47 insertions(+), 90 deletions(-)

diff --git a/drivers/media/pci/sta2x11/sta2x11_vip.c b/drivers/media/pci/sta2x11/sta2x11_vip.c
index bb11443..7559951 100644
--- a/drivers/media/pci/sta2x11/sta2x11_vip.c
+++ b/drivers/media/pci/sta2x11/sta2x11_vip.c
@@ -357,7 +357,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct sta2x11_vip *vip = vb2_get_drv_priv(vq);
 	struct vip_buffer *vip_buf, *node;
@@ -374,7 +374,6 @@ static int stop_streaming(struct vb2_queue *vq)
 		list_del(&vip_buf->list);
 	}
 	spin_unlock(&vip->lock);
-	return 0;
 }
 
 static struct vb2_ops vip_video_qops = {
diff --git a/drivers/media/platform/blackfin/bfin_capture.c b/drivers/media/platform/blackfin/bfin_capture.c
index 2819165..cf7ceec 100644
--- a/drivers/media/platform/blackfin/bfin_capture.c
+++ b/drivers/media/platform/blackfin/bfin_capture.c
@@ -427,15 +427,12 @@ static int bcap_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return 0;
 }
 
-static int bcap_stop_streaming(struct vb2_queue *vq)
+static void bcap_stop_streaming(struct vb2_queue *vq)
 {
 	struct bcap_device *bcap_dev = vb2_get_drv_priv(vq);
 	struct ppi_if *ppi = bcap_dev->ppi;
 	int ret;
 
-	if (!vb2_is_streaming(vq))
-		return 0;
-
 	bcap_dev->stop = true;
 	wait_for_completion(&bcap_dev->comp);
 	ppi->ops->stop(ppi);
@@ -452,7 +449,6 @@ static int bcap_stop_streaming(struct vb2_queue *vq)
 		list_del(&bcap_dev->cur_frm->list);
 		vb2_buffer_done(&bcap_dev->cur_frm->vb, VB2_BUF_STATE_ERROR);
 	}
-	return 0;
 }
 
 static struct vb2_ops bcap_video_qops = {
diff --git a/drivers/media/platform/coda.c b/drivers/media/platform/coda.c
index 61f3dbc..9e6cf97 100644
--- a/drivers/media/platform/coda.c
+++ b/drivers/media/platform/coda.c
@@ -2269,7 +2269,7 @@ out:
 	return ret;
 }
 
-static int coda_stop_streaming(struct vb2_queue *q)
+static void coda_stop_streaming(struct vb2_queue *q)
 {
 	struct coda_ctx *ctx = vb2_get_drv_priv(q);
 	struct coda_dev *dev = ctx->dev;
@@ -2295,8 +2295,6 @@ static int coda_stop_streaming(struct vb2_queue *q)
 			ctx->bitstream.vaddr, ctx->bitstream.size);
 		ctx->runcounter = 0;
 	}
-
-	return 0;
 }
 
 static struct vb2_ops coda_qops = {
diff --git a/drivers/media/platform/exynos-gsc/gsc-m2m.c b/drivers/media/platform/exynos-gsc/gsc-m2m.c
index 810c3e1..6dbf0ad 100644
--- a/drivers/media/platform/exynos-gsc/gsc-m2m.c
+++ b/drivers/media/platform/exynos-gsc/gsc-m2m.c
@@ -66,15 +66,13 @@ static int gsc_m2m_start_streaming(struct vb2_queue *q, unsigned int count)
 	return ret > 0 ? 0 : ret;
 }
 
-static int gsc_m2m_stop_streaming(struct vb2_queue *q)
+static void gsc_m2m_stop_streaming(struct vb2_queue *q)
 {
 	struct gsc_ctx *ctx = q->drv_priv;
 
 	__gsc_m2m_job_abort(ctx);
 
 	pm_runtime_put(&ctx->gsc_dev->pdev->dev);
-
-	return 0;
 }
 
 void gsc_m2m_job_finish(struct gsc_ctx *ctx, int vb_state)
diff --git a/drivers/media/platform/exynos4-is/fimc-capture.c b/drivers/media/platform/exynos4-is/fimc-capture.c
index 8a712ca..6bfacd0 100644
--- a/drivers/media/platform/exynos4-is/fimc-capture.c
+++ b/drivers/media/platform/exynos4-is/fimc-capture.c
@@ -294,15 +294,15 @@ static int start_streaming(struct vb2_queue *q, unsigned int count)
 	return 0;
 }
 
-static int stop_streaming(struct vb2_queue *q)
+static void stop_streaming(struct vb2_queue *q)
 {
 	struct fimc_ctx *ctx = q->drv_priv;
 	struct fimc_dev *fimc = ctx->fimc_dev;
 
 	if (!fimc_capture_active(fimc))
-		return -EINVAL;
+		return;
 
-	return fimc_stop_capture(fimc, false);
+	fimc_stop_capture(fimc, false);
 }
 
 int fimc_capture_suspend(struct fimc_dev *fimc)
diff --git a/drivers/media/platform/exynos4-is/fimc-lite.c b/drivers/media/platform/exynos4-is/fimc-lite.c
index 1234734..d4b0856 100644
--- a/drivers/media/platform/exynos4-is/fimc-lite.c
+++ b/drivers/media/platform/exynos4-is/fimc-lite.c
@@ -350,14 +350,14 @@ static int start_streaming(struct vb2_queue *q, unsigned int count)
 	return 0;
 }
 
-static int stop_streaming(struct vb2_queue *q)
+static void stop_streaming(struct vb2_queue *q)
 {
 	struct fimc_lite *fimc = q->drv_priv;
 
 	if (!fimc_lite_active(fimc))
-		return -EINVAL;
+		return;
 
-	return fimc_lite_stop_capture(fimc, false);
+	fimc_lite_stop_capture(fimc, false);
 }
 
 static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *pfmt,
diff --git a/drivers/media/platform/exynos4-is/fimc-m2m.c b/drivers/media/platform/exynos4-is/fimc-m2m.c
index 9da95bd..c78c744 100644
--- a/drivers/media/platform/exynos4-is/fimc-m2m.c
+++ b/drivers/media/platform/exynos4-is/fimc-m2m.c
@@ -85,7 +85,7 @@ static int start_streaming(struct vb2_queue *q, unsigned int count)
 	return ret > 0 ? 0 : ret;
 }
 
-static int stop_streaming(struct vb2_queue *q)
+static void stop_streaming(struct vb2_queue *q)
 {
 	struct fimc_ctx *ctx = q->drv_priv;
 	int ret;
@@ -95,7 +95,6 @@ static int stop_streaming(struct vb2_queue *q)
 		fimc_m2m_job_finish(ctx, VB2_BUF_STATE_ERROR);
 
 	pm_runtime_put(&ctx->fimc_dev->pdev->dev);
-	return 0;
 }
 
 static void fimc_device_run(void *priv)
diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 8b34c48..be4b512 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1156,7 +1156,7 @@ static int mcam_vb_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return mcam_read_setup(cam);
 }
 
-static int mcam_vb_stop_streaming(struct vb2_queue *vq)
+static void mcam_vb_stop_streaming(struct vb2_queue *vq)
 {
 	struct mcam_camera *cam = vb2_get_drv_priv(vq);
 	unsigned long flags;
@@ -1164,10 +1164,10 @@ static int mcam_vb_stop_streaming(struct vb2_queue *vq)
 	if (cam->state == S_BUFWAIT) {
 		/* They never gave us buffers */
 		cam->state = S_IDLE;
-		return 0;
+		return;
 	}
 	if (cam->state != S_STREAMING)
-		return -EINVAL;
+		return;
 	mcam_ctlr_stop_dma(cam);
 	/*
 	 * Reset the CCIC PHY after stopping streaming,
@@ -1182,7 +1182,6 @@ static int mcam_vb_stop_streaming(struct vb2_queue *vq)
 	spin_lock_irqsave(&cam->dev_lock, flags);
 	INIT_LIST_HEAD(&cam->buffers);
 	spin_unlock_irqrestore(&cam->dev_lock, flags);
-	return 0;
 }
 
 
diff --git a/drivers/media/platform/s3c-camif/camif-capture.c b/drivers/media/platform/s3c-camif/camif-capture.c
index 5372111..9989491 100644
--- a/drivers/media/platform/s3c-camif/camif-capture.c
+++ b/drivers/media/platform/s3c-camif/camif-capture.c
@@ -435,10 +435,10 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 	return 0;
 }
 
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct camif_vp *vp = vb2_get_drv_priv(vq);
-	return camif_stop_capture(vp);
+	camif_stop_capture(vp);
 }
 
 static int queue_setup(struct vb2_queue *vq, const struct v4l2_format *pfmt,
diff --git a/drivers/media/platform/s5p-jpeg/jpeg-core.c b/drivers/media/platform/s5p-jpeg/jpeg-core.c
index a1c78c8..3722852 100644
--- a/drivers/media/platform/s5p-jpeg/jpeg-core.c
+++ b/drivers/media/platform/s5p-jpeg/jpeg-core.c
@@ -1670,13 +1670,11 @@ static int s5p_jpeg_start_streaming(struct vb2_queue *q, unsigned int count)
 	return ret > 0 ? 0 : ret;
 }
 
-static int s5p_jpeg_stop_streaming(struct vb2_queue *q)
+static void s5p_jpeg_stop_streaming(struct vb2_queue *q)
 {
 	struct s5p_jpeg_ctx *ctx = vb2_get_drv_priv(q);
 
 	pm_runtime_put(ctx->jpeg->dev);
-
-	return 0;
 }
 
 static struct vb2_ops s5p_jpeg_qops = {
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
index 8faf969..58b7bba 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_dec.c
@@ -1027,7 +1027,7 @@ static int s5p_mfc_start_streaming(struct vb2_queue *q, unsigned int count)
 	return 0;
 }
 
-static int s5p_mfc_stop_streaming(struct vb2_queue *q)
+static void s5p_mfc_stop_streaming(struct vb2_queue *q)
 {
 	unsigned long flags;
 	struct s5p_mfc_ctx *ctx = fh_to_ctx(q->drv_priv);
@@ -1071,7 +1071,6 @@ static int s5p_mfc_stop_streaming(struct vb2_queue *q)
 	}
 	if (aborted)
 		ctx->state = MFCINST_RUNNING;
-	return 0;
 }
 
 
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
index 91b6e02..7efd45d 100644
--- a/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
+++ b/drivers/media/platform/s5p-mfc/s5p_mfc_enc.c
@@ -1930,7 +1930,7 @@ static int s5p_mfc_start_streaming(struct vb2_queue *q, unsigned int count)
 	return 0;
 }
 
-static int s5p_mfc_stop_streaming(struct vb2_queue *q)
+static void s5p_mfc_stop_streaming(struct vb2_queue *q)
 {
 	unsigned long flags;
 	struct s5p_mfc_ctx *ctx = fh_to_ctx(q->drv_priv);
@@ -1959,7 +1959,6 @@ static int s5p_mfc_stop_streaming(struct vb2_queue *q)
 		ctx->src_queue_cnt = 0;
 	}
 	spin_unlock_irqrestore(&dev->irqlock, flags);
-	return 0;
 }
 
 static void s5p_mfc_buf_queue(struct vb2_buffer *vb)
diff --git a/drivers/media/platform/s5p-tv/mixer_video.c b/drivers/media/platform/s5p-tv/mixer_video.c
index a1ce55f..9f1e52f 100644
--- a/drivers/media/platform/s5p-tv/mixer_video.c
+++ b/drivers/media/platform/s5p-tv/mixer_video.c
@@ -985,7 +985,7 @@ static void mxr_watchdog(unsigned long arg)
 	spin_unlock_irqrestore(&layer->enq_slock, flags);
 }
 
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct mxr_layer *layer = vb2_get_drv_priv(vq);
 	struct mxr_device *mdev = layer->mdev;
@@ -1031,7 +1031,6 @@ static int stop_streaming(struct vb2_queue *vq)
 	mxr_streamer_put(mdev);
 	/* allow changes in output configuration */
 	mxr_output_put(mdev);
-	return 0;
 }
 
 static struct vb2_ops mxr_video_qops = {
diff --git a/drivers/media/platform/soc_camera/atmel-isi.c b/drivers/media/platform/soc_camera/atmel-isi.c
index 4835173..1d7f60e 100644
--- a/drivers/media/platform/soc_camera/atmel-isi.c
+++ b/drivers/media/platform/soc_camera/atmel-isi.c
@@ -406,7 +406,7 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -433,7 +433,7 @@ static int stop_streaming(struct vb2_queue *vq)
 	if (time_after(jiffies, timeout)) {
 		dev_err(icd->parent,
 			"Timeout waiting for finishing codec request\n");
-		return -ETIMEDOUT;
+		return;
 	}
 
 	/* Disable interrupts */
@@ -444,8 +444,6 @@ static int stop_streaming(struct vb2_queue *vq)
 	ret = atmel_isi_wait_status(isi, WAIT_ISI_DISABLE);
 	if (ret < 0)
 		dev_err(icd->parent, "Disable ISI timed out\n");
-
-	return ret;
 }
 
 static struct vb2_ops isi_video_qops = {
diff --git a/drivers/media/platform/soc_camera/mx2_camera.c b/drivers/media/platform/soc_camera/mx2_camera.c
index d73abca..d88c2d4 100644
--- a/drivers/media/platform/soc_camera/mx2_camera.c
+++ b/drivers/media/platform/soc_camera/mx2_camera.c
@@ -741,7 +741,7 @@ static int mx2_start_streaming(struct vb2_queue *q, unsigned int count)
 	return 0;
 }
 
-static int mx2_stop_streaming(struct vb2_queue *q)
+static void mx2_stop_streaming(struct vb2_queue *q)
 {
 	struct soc_camera_device *icd = soc_camera_from_vb2q(q);
 	struct soc_camera_host *ici =
@@ -773,8 +773,6 @@ static int mx2_stop_streaming(struct vb2_queue *q)
 
 	dma_free_coherent(ici->v4l2_dev.dev,
 			  pcdev->discard_size, b, pcdev->discard_buffer_dma);
-
-	return 0;
 }
 
 static struct vb2_ops mx2_videobuf_ops = {
diff --git a/drivers/media/platform/soc_camera/mx3_camera.c b/drivers/media/platform/soc_camera/mx3_camera.c
index f975b70..4f6d5b67 100644
--- a/drivers/media/platform/soc_camera/mx3_camera.c
+++ b/drivers/media/platform/soc_camera/mx3_camera.c
@@ -406,7 +406,7 @@ static int mx3_videobuf_init(struct vb2_buffer *vb)
 	return 0;
 }
 
-static int mx3_stop_streaming(struct vb2_queue *q)
+static void mx3_stop_streaming(struct vb2_queue *q)
 {
 	struct soc_camera_device *icd = soc_camera_from_vb2q(q);
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -605,8 +605,6 @@ static int mx3_camera_try_bus_param(struct soc_camera_device *icd,
 	} else if (ret != -ENOIOCTLCMD) {
 		return ret;
 	}
-
-	return 0;
 }
 
 static bool chan_filter(struct dma_chan *chan, void *arg)
diff --git a/drivers/media/platform/soc_camera/rcar_vin.c b/drivers/media/platform/soc_camera/rcar_vin.c
index 3b1c05a..16eae33 100644
--- a/drivers/media/platform/soc_camera/rcar_vin.c
+++ b/drivers/media/platform/soc_camera/rcar_vin.c
@@ -505,7 +505,7 @@ static int rcar_vin_videobuf_init(struct vb2_buffer *vb)
 	return 0;
 }
 
-static int rcar_vin_stop_streaming(struct vb2_queue *vq)
+static void rcar_vin_stop_streaming(struct vb2_queue *vq)
 {
 	struct soc_camera_device *icd = soc_camera_from_vb2q(vq);
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -516,8 +516,6 @@ static int rcar_vin_stop_streaming(struct vb2_queue *vq)
 	list_for_each_safe(buf_head, tmp, &priv->capture)
 		list_del_init(buf_head);
 	spin_unlock_irq(&priv->lock);
-
-	return 0;
 }
 
 static struct vb2_ops rcar_vin_vb2_ops = {
diff --git a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
index 150bd4d..abaf736 100644
--- a/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
+++ b/drivers/media/platform/soc_camera/sh_mobile_ceu_camera.c
@@ -471,7 +471,7 @@ static int sh_mobile_ceu_videobuf_init(struct vb2_buffer *vb)
 	return 0;
 }
 
-static int sh_mobile_ceu_stop_streaming(struct vb2_queue *q)
+static void sh_mobile_ceu_stop_streaming(struct vb2_queue *q)
 {
 	struct soc_camera_device *icd = container_of(q, struct soc_camera_device, vb2_vidq);
 	struct soc_camera_host *ici = to_soc_camera_host(icd->parent);
@@ -487,7 +487,7 @@ static int sh_mobile_ceu_stop_streaming(struct vb2_queue *q)
 
 	spin_unlock_irq(&pcdev->lock);
 
-	return sh_mobile_ceu_soft_reset(pcdev);
+	sh_mobile_ceu_soft_reset(pcdev);
 }
 
 static struct vb2_ops sh_mobile_ceu_videobuf_ops = {
diff --git a/drivers/media/platform/vivi.c b/drivers/media/platform/vivi.c
index 643937b..f4ac1f9 100644
--- a/drivers/media/platform/vivi.c
+++ b/drivers/media/platform/vivi.c
@@ -906,12 +906,11 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct vivi_dev *dev = vb2_get_drv_priv(vq);
 	dprintk(dev, 1, "%s\n", __func__);
 	vivi_stop_generating(dev);
-	return 0;
 }
 
 static void vivi_lock(struct vb2_queue *vq)
diff --git a/drivers/media/platform/vsp1/vsp1_video.c b/drivers/media/platform/vsp1/vsp1_video.c
index b4687a8..f86c270 100644
--- a/drivers/media/platform/vsp1/vsp1_video.c
+++ b/drivers/media/platform/vsp1/vsp1_video.c
@@ -720,7 +720,7 @@ static int vsp1_video_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return 0;
 }
 
-static int vsp1_video_stop_streaming(struct vb2_queue *vq)
+static void vsp1_video_stop_streaming(struct vb2_queue *vq)
 {
 	struct vsp1_video *video = vb2_get_drv_priv(vq);
 	struct vsp1_pipeline *pipe = to_vsp1_pipeline(&video->video.entity);
@@ -743,8 +743,6 @@ static int vsp1_video_stop_streaming(struct vb2_queue *vq)
 	spin_lock_irqsave(&video->irqlock, flags);
 	INIT_LIST_HEAD(&video->irqqueue);
 	spin_unlock_irqrestore(&video->irqlock, flags);
-
-	return 0;
 }
 
 static struct vb2_ops vsp1_video_queue_qops = {
diff --git a/drivers/media/usb/em28xx/em28xx-v4l.h b/drivers/media/usb/em28xx/em28xx-v4l.h
index bce4386..432862c 100644
--- a/drivers/media/usb/em28xx/em28xx-v4l.h
+++ b/drivers/media/usb/em28xx/em28xx-v4l.h
@@ -16,5 +16,5 @@
 
 
 int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count);
-int em28xx_stop_vbi_streaming(struct vb2_queue *vq);
+void em28xx_stop_vbi_streaming(struct vb2_queue *vq);
 extern struct vb2_ops em28xx_vbi_qops;
diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index 2775c90..7f91d13 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -937,7 +937,7 @@ int em28xx_start_analog_streaming(struct vb2_queue *vq, unsigned int count)
 	return rc;
 }
 
-static int em28xx_stop_streaming(struct vb2_queue *vq)
+static void em28xx_stop_streaming(struct vb2_queue *vq)
 {
 	struct em28xx *dev = vb2_get_drv_priv(vq);
 	struct em28xx_dmaqueue *vidq = &dev->vidq;
@@ -961,11 +961,9 @@ static int em28xx_stop_streaming(struct vb2_queue *vq)
 	}
 	dev->usb_ctl.vid_buf = NULL;
 	spin_unlock_irqrestore(&dev->slock, flags);
-
-	return 0;
 }
 
-int em28xx_stop_vbi_streaming(struct vb2_queue *vq)
+void em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 {
 	struct em28xx *dev = vb2_get_drv_priv(vq);
 	struct em28xx_dmaqueue *vbiq = &dev->vbiq;
@@ -989,8 +987,6 @@ int em28xx_stop_vbi_streaming(struct vb2_queue *vq)
 	}
 	dev->usb_ctl.vbi_buf = NULL;
 	spin_unlock_irqrestore(&dev->slock, flags);
-
-	return 0;
 }
 
 static void
diff --git a/drivers/media/usb/pwc/pwc-if.c b/drivers/media/usb/pwc/pwc-if.c
index b9c9f10..ed25007 100644
--- a/drivers/media/usb/pwc/pwc-if.c
+++ b/drivers/media/usb/pwc/pwc-if.c
@@ -680,12 +680,12 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 	return r;
 }
 
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct pwc_device *pdev = vb2_get_drv_priv(vq);
 
 	if (mutex_lock_interruptible(&pdev->v4l2_lock))
-		return -ERESTARTSYS;
+		return;
 	if (pdev->udev) {
 		pwc_set_leds(pdev, 0, 0);
 		pwc_camera_power(pdev, 0);
@@ -694,8 +694,6 @@ static int stop_streaming(struct vb2_queue *vq)
 
 	pwc_cleanup_queued_bufs(pdev);
 	mutex_unlock(&pdev->v4l2_lock);
-
-	return 0;
 }
 
 static struct vb2_ops pwc_vb_queue_ops = {
diff --git a/drivers/media/usb/stk1160/stk1160-v4l.c b/drivers/media/usb/stk1160/stk1160-v4l.c
index c45c988..40029e0 100644
--- a/drivers/media/usb/stk1160/stk1160-v4l.c
+++ b/drivers/media/usb/stk1160/stk1160-v4l.c
@@ -583,10 +583,10 @@ static int start_streaming(struct vb2_queue *vq, unsigned int count)
 }
 
 /* abort streaming and wait for last buffer */
-static int stop_streaming(struct vb2_queue *vq)
+static void stop_streaming(struct vb2_queue *vq)
 {
 	struct stk1160 *dev = vb2_get_drv_priv(vq);
-	return stk1160_stop_streaming(dev);
+	stk1160_stop_streaming(dev);
 }
 
 static struct vb2_ops stk1160_video_qops = {
diff --git a/drivers/media/usb/usbtv/usbtv-video.c b/drivers/media/usb/usbtv/usbtv-video.c
index 496bc2e..bc75f42 100644
--- a/drivers/media/usb/usbtv/usbtv-video.c
+++ b/drivers/media/usb/usbtv/usbtv-video.c
@@ -634,15 +634,12 @@ static int usbtv_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return usbtv_start(usbtv);
 }
 
-static int usbtv_stop_streaming(struct vb2_queue *vq)
+static void usbtv_stop_streaming(struct vb2_queue *vq)
 {
 	struct usbtv *usbtv = vb2_get_drv_priv(vq);
 
-	if (usbtv->udev == NULL)
-		return -ENODEV;
-
-	usbtv_stop(usbtv);
-	return 0;
+	if (usbtv->udev)
+		usbtv_stop(usbtv);
 }
 
 struct vb2_ops usbtv_vb2_ops = {
diff --git a/drivers/staging/media/davinci_vpfe/vpfe_video.c b/drivers/staging/media/davinci_vpfe/vpfe_video.c
index 8c101cb..baeceee 100644
--- a/drivers/staging/media/davinci_vpfe/vpfe_video.c
+++ b/drivers/staging/media/davinci_vpfe/vpfe_video.c
@@ -1242,7 +1242,7 @@ static int vpfe_buffer_init(struct vb2_buffer *vb)
 }
 
 /* abort streaming and wait for last buffer */
-static int vpfe_stop_streaming(struct vb2_queue *vq)
+static void vpfe_stop_streaming(struct vb2_queue *vq)
 {
 	struct vpfe_fh *fh = vb2_get_drv_priv(vq);
 	struct vpfe_video_device *video = fh->video;
@@ -1256,7 +1256,6 @@ static int vpfe_stop_streaming(struct vb2_queue *vq)
 		list_del(&video->next_frm->list);
 		vb2_buffer_done(&video->next_frm->vb, VB2_BUF_STATE_ERROR);
 	}
-	return 0;
 }
 
 static void vpfe_buf_cleanup(struct vb2_buffer *vb)
diff --git a/drivers/staging/media/dt3155v4l/dt3155v4l.c b/drivers/staging/media/dt3155v4l/dt3155v4l.c
index e729e52..a57f706 100644
--- a/drivers/staging/media/dt3155v4l/dt3155v4l.c
+++ b/drivers/staging/media/dt3155v4l/dt3155v4l.c
@@ -263,7 +263,7 @@ dt3155_buf_prepare(struct vb2_buffer *vb)
 	return 0;
 }
 
-static int
+static void
 dt3155_stop_streaming(struct vb2_queue *q)
 {
 	struct dt3155_priv *pd = vb2_get_drv_priv(q);
@@ -277,7 +277,6 @@ dt3155_stop_streaming(struct vb2_queue *q)
 	}
 	spin_unlock_irq(&pd->lock);
 	msleep(45); /* irq hendler will stop the hardware */
-	return 0;
 }
 
 static void
diff --git a/drivers/staging/media/go7007/go7007-v4l2.c b/drivers/staging/media/go7007/go7007-v4l2.c
index 3a01576..3965723 100644
--- a/drivers/staging/media/go7007/go7007-v4l2.c
+++ b/drivers/staging/media/go7007/go7007-v4l2.c
@@ -515,7 +515,7 @@ static int go7007_start_streaming(struct vb2_queue *q, unsigned int count)
 	return ret;
 }
 
-static int go7007_stop_streaming(struct vb2_queue *q)
+static void go7007_stop_streaming(struct vb2_queue *q)
 {
 	struct go7007 *go = vb2_get_drv_priv(q);
 	unsigned long flags;
@@ -537,7 +537,6 @@ static int go7007_stop_streaming(struct vb2_queue *q)
 	/* Turn on Capture LED */
 	if (go->board_id == GO7007_BOARDID_ADS_USBAV_709)
 		go7007_write_addr(go, 0x3c82, 0x000d);
-	return 0;
 }
 
 static struct vb2_ops go7007_video_qops = {
diff --git a/drivers/staging/media/msi3101/sdr-msi3101.c b/drivers/staging/media/msi3101/sdr-msi3101.c
index 4c3bf77..e6a1a0a 100644
--- a/drivers/staging/media/msi3101/sdr-msi3101.c
+++ b/drivers/staging/media/msi3101/sdr-msi3101.c
@@ -1577,13 +1577,13 @@ static int msi3101_start_streaming(struct vb2_queue *vq, unsigned int count)
 	return ret;
 }
 
-static int msi3101_stop_streaming(struct vb2_queue *vq)
+static void msi3101_stop_streaming(struct vb2_queue *vq)
 {
 	struct msi3101_state *s = vb2_get_drv_priv(vq);
 	dev_dbg(&s->udev->dev, "%s:\n", __func__);
 
 	if (mutex_lock_interruptible(&s->v4l2_lock))
-		return -ERESTARTSYS;
+		return;
 
 	if (s->udev)
 		msi3101_isoc_cleanup(s);
@@ -1595,8 +1595,6 @@ static int msi3101_stop_streaming(struct vb2_queue *vq)
 	msi3101_ctrl_msg(s, CMD_STOP_STREAMING, 0);
 
 	mutex_unlock(&s->v4l2_lock);
-
-	return 0;
 }
 
 static struct vb2_ops msi3101_vb2_ops = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index ce9e5aa..5008b0f 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -741,14 +741,13 @@ static int solo_enc_start_streaming(struct vb2_queue *q, unsigned int count)
 	return solo_ring_start(solo_enc->solo_dev);
 }
 
-static int solo_enc_stop_streaming(struct vb2_queue *q)
+static void solo_enc_stop_streaming(struct vb2_queue *q)
 {
 	struct solo_enc_dev *solo_enc = vb2_get_drv_priv(q);
 
 	solo_enc_off(solo_enc);
 	INIT_LIST_HEAD(&solo_enc->vidq_active);
 	solo_ring_stop(solo_enc->solo_dev);
-	return 0;
 }
 
 static struct vb2_ops solo_enc_video_qops = {
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2.c b/drivers/staging/media/solo6x10/solo6x10-v4l2.c
index 47e72da..413b0ff 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2.c
@@ -336,13 +336,12 @@ static int solo_start_streaming(struct vb2_queue *q, unsigned int count)
 	return solo_start_thread(solo_dev);
 }
 
-static int solo_stop_streaming(struct vb2_queue *q)
+static void solo_stop_streaming(struct vb2_queue *q)
 {
 	struct solo_dev *solo_dev = vb2_get_drv_priv(q);
 
 	solo_stop_thread(solo_dev);
 	INIT_LIST_HEAD(&solo_dev->vidq_active);
-	return 0;
 }
 
 static void solo_buf_queue(struct vb2_buffer *vb)
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 2ada71b..cb14c1a 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -317,7 +317,7 @@ struct vb2_ops {
 	void (*buf_cleanup)(struct vb2_buffer *vb);
 
 	int (*start_streaming)(struct vb2_queue *q, unsigned int count);
-	int (*stop_streaming)(struct vb2_queue *q);
+	void (*stop_streaming)(struct vb2_queue *q);
 
 	void (*buf_queue)(struct vb2_buffer *vb);
 };
-- 
1.9.0

[RFCv1 PATCH 02/20] vb2: fix handling of data_offset and v4l2_plane.reserved[]

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The videobuf2-core did not zero the reserved array of v4l2_plane as it
should.

More serious is the fact that data_offset was not handled correctly:

- for capture devices it was never zeroed, which meant that it was
  uninitialized. Unless the driver sets it it was a completely random
  number.

- __qbuf_dmabuf had a completely incorrect length check that included
  data_offset.

- in the single-planar case data_offset was never correctly set to 0.
  The single-planar API doesn't support data_offset, so setting it
  to 0 is the right thing to do.

All these issues were found with v4l2-compliance.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 2c3a7f2..f9ced55 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1120,6 +1120,12 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 	unsigned int plane;
 
 	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
+		for (plane = 0; plane < vb->num_planes; ++plane) {
+			memset(v4l2_planes[plane].reserved, 0,
+			       sizeof(v4l2_planes[plane].reserved));
+			v4l2_planes[plane].data_offset = 0;
+		}
+
 		/* Fill in driver-provided information for OUTPUT types */
 		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
 			/*
@@ -1148,8 +1154,6 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 					b->m.planes[plane].m.fd;
 				v4l2_planes[plane].length =
 					b->m.planes[plane].length;
-				v4l2_planes[plane].data_offset =
-					b->m.planes[plane].data_offset;
 			}
 		}
 	} else {
@@ -1159,10 +1163,10 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 		 * In videobuf we use our internal V4l2_planes struct for
 		 * single-planar buffers as well, for simplicity.
 		 */
-		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+		if (V4L2_TYPE_IS_OUTPUT(b->type))
 			v4l2_planes[0].bytesused = b->bytesused;
-			v4l2_planes[0].data_offset = 0;
-		}
+		/* Single-planar buffers never use data_offset */
+		v4l2_planes[0].data_offset = 0;
 
 		if (b->memory == V4L2_MEMORY_USERPTR) {
 			v4l2_planes[0].m.userptr = b->m.userptr;
@@ -1172,9 +1176,7 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 		if (b->memory == V4L2_MEMORY_DMABUF) {
 			v4l2_planes[0].m.fd = b->m.fd;
 			v4l2_planes[0].length = b->length;
-			v4l2_planes[0].data_offset = 0;
 		}
-
 	}
 
 	vb->v4l2_buf.field = b->field;
@@ -1331,8 +1333,7 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		if (planes[plane].length == 0)
 			planes[plane].length = dbuf->size;
 
-		if (planes[plane].length < planes[plane].data_offset +
-		    q->plane_sizes[plane]) {
+		if (planes[plane].length < q->plane_sizes[plane]) {
 			dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
 				plane);
 			ret = -EINVAL;
-- 
1.9.0

[RFCv1 PATCH 03/20] vb2: if bytesused is 0, then fill with output buffer length

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The application should really always fill in bytesused for output
buffers, unfortunately the vb2 framework never checked for that.

So for single planar formats replace a bytesused of 0 by the length
of the buffer, and for multiplanar format do the same if bytesused is
0 for ALL planes.

This seems to be what the user really intended if v4l2_buffer was
just memset to 0.

I'm afraid that just checking for this and returning an error would
break too many applications. Quite a few drivers never check for bytesused
at all and just use the buffer length instead.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 32 +++++++++++++++++++++++++++-----
 1 file changed, 27 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index f9ced55..8070ccc 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1124,19 +1124,35 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 			memset(v4l2_planes[plane].reserved, 0,
 			       sizeof(v4l2_planes[plane].reserved));
 			v4l2_planes[plane].data_offset = 0;
+			v4l2_planes[plane].bytesused = 0;
 		}
 
 		/* Fill in driver-provided information for OUTPUT types */
 		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			bool bytesused_is_used;
+
+			/* Check if bytesused == 0 for all planes */
+			for (plane = 0; plane < vb->num_planes; ++plane)
+				if (b->m.planes[plane].bytesused)
+					break;
+			bytesused_is_used = plane < vb->num_planes;
+
 			/*
 			 * Will have to go up to b->length when API starts
 			 * accepting variable number of planes.
+			 *
+			 * If bytesused_is_used is false, then fall back to the
+			 * full buffer size. In that case userspace clearly
+			 * never bothered to set it and it's a safe assumption
+			 * that they really meant to use the full plane sizes.
 			 */
 			for (plane = 0; plane < vb->num_planes; ++plane) {
-				v4l2_planes[plane].bytesused =
-					b->m.planes[plane].bytesused;
-				v4l2_planes[plane].data_offset =
-					b->m.planes[plane].data_offset;
+				struct v4l2_plane *pdst = &v4l2_planes[plane];
+				struct v4l2_plane *psrc = &b->m.planes[plane];
+
+				pdst->bytesused = bytesused_is_used ?
+					psrc->bytesused : psrc->length;
+				pdst->data_offset = psrc->data_offset;
 			}
 		}
 
@@ -1162,9 +1178,15 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 		 * so fill in relevant v4l2_buffer struct fields instead.
 		 * In videobuf we use our internal V4l2_planes struct for
 		 * single-planar buffers as well, for simplicity.
+		 *
+		 * If bytesused == 0, then fall back to the full buffer size
+		 * as that's a sensible default.
 		 */
 		if (V4L2_TYPE_IS_OUTPUT(b->type))
-			v4l2_planes[0].bytesused = b->bytesused;
+			v4l2_planes[0].bytesused =
+				b->bytesused ? b->bytesused : b->length;
+		else
+			v4l2_planes[0].bytesused = 0;
 		/* Single-planar buffers never use data_offset */
 		v4l2_planes[0].data_offset = 0;
 
-- 
1.9.0

[RFCv1 PATCH 04/20] vb2-dma-sg: add allocation context to dma-sg

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

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>
---
 drivers/media/platform/marvell-ccic/mcam-core.c    |  7 ++++
 drivers/media/platform/marvell-ccic/mcam-core.h    |  1 +
 drivers/media/v4l2-core/videobuf2-core.c           |  3 +-
 drivers/media/v4l2-core/videobuf2-dma-contig.c     |  4 +-
 drivers/media/v4l2-core/videobuf2-dma-sg.c         | 44 +++++++++++++++++++++-
 drivers/media/v4l2-core/videobuf2-vmalloc.c        |  3 +-
 drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c | 10 +++++
 drivers/staging/media/solo6x10/solo6x10.h          |  1 +
 include/media/videobuf2-core.h                     |  3 +-
 include/media/videobuf2-dma-sg.h                   |  3 ++
 10 files changed, 73 insertions(+), 6 deletions(-)

diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index be4b512..99961bf 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1080,6 +1080,8 @@ 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;
 }
 
@@ -1298,6 +1300,7 @@ static int mcam_setup_vb2(struct mcam_camera *cam)
 		vq->ops = &mcam_vb2_sg_ops;
 		vq->mem_ops = &vb2_dma_sg_memops;
 		vq->buf_struct_size = sizeof(struct mcam_vb_buffer);
+		cam->vb_alloc_ctx_sg = vb2_dma_sg_init_ctx(cam->dev);
 		vq->io_modes = VB2_MMAP | VB2_USERPTR;
 		cam->dma_setup = mcam_ctlr_dma_sg;
 		cam->frame_complete = mcam_dma_sg_done;
@@ -1326,6 +1329,10 @@ 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 e0e628c..7b8c201 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-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 8070ccc..bb36fe5 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -102,6 +102,7 @@ module_param(debug, int, 0644);
 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
+	int write = !V4L2_TYPE_IS_OUTPUT(q->type);
 	void *mem_priv;
 	int plane;
 
@@ -113,7 +114,7 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 		unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
 
 		mem_priv = call_memop(vb, alloc, q->alloc_ctx[plane],
-				      size, q->gfp_flags);
+				      size, write, q->gfp_flags);
 		if (IS_ERR_OR_NULL(mem_priv))
 			goto free;
 
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 33d3871d..1e994a9 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -152,7 +152,8 @@ static void vb2_dc_put(void *buf_priv)
 	kfree(buf);
 }
 
-static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
+static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, int write,
+			  gfp_t gfp_flags)
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct device *dev = conf->dev;
@@ -173,6 +174,7 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
 	/* Prevent the device from being released while the buffer is used */
 	buf->dev = get_device(dev);
 	buf->size = size;
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 
 	buf->handler.refcount = &buf->refcount;
 	buf->handler.put = vb2_dc_put;
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index c779f21..92b54fa 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -30,11 +30,17 @@ 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				write;
 	int				offset;
+	enum dma_data_direction		dma_dir;
 	struct sg_table			sg_table;
 	size_t				size;
 	unsigned int			num_pages;
@@ -86,22 +92,27 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
 	return 0;
 }
 
-static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
+static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, int write,
+			      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;
 
 	buf->vaddr = NULL;
-	buf->write = 0;
+	buf->write = write;
 	buf->offset = 0;
 	buf->size = size;
 	/* size is already page aligned */
 	buf->num_pages = size >> PAGE_SHIFT;
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 
 	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
 			     GFP_KERNEL);
@@ -117,6 +128,8 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_fla
 	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;
@@ -152,6 +165,7 @@ 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);
 	}
 }
@@ -164,6 +178,7 @@ static inline int vma_is_io(struct vm_area_struct *vma)
 static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 				    unsigned long size, int write)
 {
+	struct vb2_dma_sg_conf *conf = alloc_ctx;
 	struct vb2_dma_sg_buf *buf;
 	unsigned long first, last;
 	int num_pages_from_user;
@@ -177,6 +192,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->write = write;
 	buf->offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
 
 	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
 	last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
@@ -233,6 +249,8 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 			buf->num_pages, buf->offset, size, 0))
 		goto userptr_fail_alloc_table_from_pages;
 
+	/* Prevent the device from being released while the buffer is used */
+	buf->dev = get_device(conf->dev);
 	return buf;
 
 userptr_fail_alloc_table_from_pages:
@@ -272,6 +290,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 	}
 	kfree(buf->pages);
 	vb2_put_vma(buf->vma);
+	put_device(buf->dev);
 	kfree(buf);
 }
 
@@ -354,6 +373,27 @@ 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/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index 313d977..d77e397 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -35,7 +35,8 @@ struct vb2_vmalloc_buf {
 
 static void vb2_vmalloc_put(void *buf_priv);
 
-static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size, gfp_t gfp_flags)
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size, int write,
+			       gfp_t gfp_flags)
 {
 	struct vb2_vmalloc_buf *buf;
 
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index 5008b0f..efa6772 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -684,7 +684,10 @@ static int solo_enc_queue_setup(struct vb2_queue *q, const struct v4l2_format *f
 			   unsigned int *num_buffers, 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)
@@ -1241,6 +1244,11 @@ 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 = -ENOMEM;
+		goto hdl_free;
+	}
 	v4l2_ctrl_handler_init(hdl, 10);
 	v4l2_ctrl_new_std(hdl, &solo_ctrl_ops,
 			V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
@@ -1340,6 +1348,7 @@ 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);
 }
@@ -1351,6 +1360,7 @@ static void solo_enc_free(struct solo_enc_dev *solo_enc)
 
 	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/staging/media/solo6x10/solo6x10.h b/drivers/staging/media/solo6x10/solo6x10.h
index 8964f8b..06bfee5 100644
--- a/drivers/staging/media/solo6x10/solo6x10.h
+++ b/drivers/staging/media/solo6x10/solo6x10.h
@@ -198,6 +198,7 @@ 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/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index cb14c1a..4b7fed0 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -81,7 +81,8 @@ struct vb2_fileio_data;
  *				  unmap_dmabuf.
  */
 struct vb2_mem_ops {
-	void		*(*alloc)(void *alloc_ctx, unsigned long size, gfp_t gfp_flags);
+	void		*(*alloc)(void *alloc_ctx, unsigned long size, int write,
+				  gfp_t gfp_flags);
 	void		(*put)(void *buf_priv);
 	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
 
diff --git a/include/media/videobuf2-dma-sg.h b/include/media/videobuf2-dma-sg.h
index 7b89852..14ce306 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
-- 
1.9.0

[RFCv1 PATCH 05/20] vb2-dma-sg: add prepare/finish memops

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Now that vb2-dma-sg will sync the buffers for you in the prepare/finish
memops we can drop that from the drivers that use dma-sg.

For the solo6x10 driver that was a bit more involved because it needs to
copy JPEG or MPEG headers to the buffer before returning it to userspace,
and that cannot be done in the old place since the buffer there is still
setup for DMA access, not for CPU access. However, the buf_finish op is
the ideal place to do this. By the time buf_finish is called the buffer
is available for CPU access, so copying to the buffer is fine.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/platform/marvell-ccic/mcam-core.c    | 18 +-------
 drivers/media/v4l2-core/videobuf2-dma-sg.c         | 18 ++++++++
 drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c | 48 ++++++++++------------
 3 files changed, 41 insertions(+), 43 deletions(-)

diff --git a/drivers/media/platform/marvell-ccic/mcam-core.c b/drivers/media/platform/marvell-ccic/mcam-core.c
index 99961bf..a21f291 100644
--- a/drivers/media/platform/marvell-ccic/mcam-core.c
+++ b/drivers/media/platform/marvell-ccic/mcam-core.c
@@ -1221,17 +1221,12 @@ static int mcam_vb_sg_buf_init(struct vb2_buffer *vb)
 static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 {
 	struct mcam_vb_buffer *mvb = vb_to_mvb(vb);
-	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
 	struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
 	struct mcam_dma_desc *desc = mvb->dma_desc;
 	struct scatterlist *sg;
 	int i;
 
-	mvb->dma_desc_nent = dma_map_sg(cam->dev, sg_table->sgl,
-			sg_table->nents, DMA_FROM_DEVICE);
-	if (mvb->dma_desc_nent <= 0)
-		return -EIO;  /* Not sure what's right here */
-	for_each_sg(sg_table->sgl, sg, mvb->dma_desc_nent, i) {
+	for_each_sg(sg_table->sgl, sg, sg_table->nents, i) {
 		desc->dma_addr = sg_dma_address(sg);
 		desc->segment_len = sg_dma_len(sg);
 		desc++;
@@ -1239,16 +1234,6 @@ static int mcam_vb_sg_buf_prepare(struct vb2_buffer *vb)
 	return 0;
 }
 
-static void mcam_vb_sg_buf_finish(struct vb2_buffer *vb)
-{
-	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
-	struct sg_table *sg_table = vb2_dma_sg_plane_desc(vb, 0);
-
-	if (sg_table)
-		dma_unmap_sg(cam->dev, sg_table->sgl,
-				sg_table->nents, DMA_FROM_DEVICE);
-}
-
 static void mcam_vb_sg_buf_cleanup(struct vb2_buffer *vb)
 {
 	struct mcam_camera *cam = vb2_get_drv_priv(vb->vb2_queue);
@@ -1265,7 +1250,6 @@ static const struct vb2_ops mcam_vb2_sg_ops = {
 	.buf_init		= mcam_vb_sg_buf_init,
 	.buf_prepare		= mcam_vb_sg_buf_prepare,
 	.buf_queue		= mcam_vb_buf_queue,
-	.buf_finish		= mcam_vb_sg_buf_finish,
 	.buf_cleanup		= mcam_vb_sg_buf_cleanup,
 	.start_streaming	= mcam_vb_start_streaming,
 	.stop_streaming		= mcam_vb_stop_streaming,
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 92b54fa..c7e0eca 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -170,6 +170,22 @@ static void vb2_dma_sg_put(void *buf_priv)
 	}
 }
 
+static void vb2_dma_sg_prepare(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = &buf->sg_table;
+
+	dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
+static void vb2_dma_sg_finish(void *buf_priv)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct sg_table *sgt = &buf->sg_table;
+
+	dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+}
+
 static inline int vma_is_io(struct vm_area_struct *vma)
 {
 	return !!(vma->vm_flags & (VM_IO | VM_PFNMAP));
@@ -366,6 +382,8 @@ const struct vb2_mem_ops vb2_dma_sg_memops = {
 	.put		= vb2_dma_sg_put,
 	.get_userptr	= vb2_dma_sg_get_userptr,
 	.put_userptr	= vb2_dma_sg_put_userptr,
+	.prepare	= vb2_dma_sg_prepare,
+	.finish		= vb2_dma_sg_finish,
 	.vaddr		= vb2_dma_sg_vaddr,
 	.mmap		= vb2_dma_sg_mmap,
 	.num_users	= vb2_dma_sg_num_users,
diff --git a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
index efa6772..0361f28 100644
--- a/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
+++ b/drivers/staging/media/solo6x10/solo6x10-v4l2-enc.c
@@ -465,7 +465,6 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
 	struct solo_dev *solo_dev = solo_enc->solo_dev;
 	struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
 	int frame_size;
-	int ret;
 
 	vb->v4l2_buf.flags |= V4L2_BUF_FLAG_KEYFRAME;
 
@@ -476,21 +475,10 @@ static int solo_fill_jpeg(struct solo_enc_dev *solo_enc,
 		& ~(DMA_ALIGN - 1);
 	vb2_set_plane_payload(vb, 0, vop_jpeg_size(vh) + solo_enc->jpeg_len);
 
-	/* may discard all previous data in vbuf->sgl */
-	dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
-			DMA_FROM_DEVICE);
-	ret = solo_send_desc(solo_enc, solo_enc->jpeg_len, vbuf,
+	return solo_send_desc(solo_enc, solo_enc->jpeg_len, vbuf,
 			     vop_jpeg_offset(vh) - SOLO_JPEG_EXT_ADDR(solo_dev),
 			     frame_size, SOLO_JPEG_EXT_ADDR(solo_dev),
 			     SOLO_JPEG_EXT_SIZE(solo_dev));
-	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
-			DMA_FROM_DEVICE);
-
-	/* add the header only after dma_unmap_sg() */
-	sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
-			    solo_enc->jpeg_header, solo_enc->jpeg_len);
-
-	return ret;
 }
 
 static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
@@ -500,7 +488,6 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 	struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
 	int frame_off, frame_size;
 	int skip = 0;
-	int ret;
 
 	if (vb2_plane_size(vb, 0) < vop_mpeg_size(vh))
 		return -EIO;
@@ -522,20 +509,9 @@ static int solo_fill_mpeg(struct solo_enc_dev *solo_enc,
 	frame_size = (vop_mpeg_size(vh) + skip + (DMA_ALIGN - 1))
 		& ~(DMA_ALIGN - 1);
 
-	/* may discard all previous data in vbuf->sgl */
-	dma_map_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
-			DMA_FROM_DEVICE);
-	ret = solo_send_desc(solo_enc, skip, vbuf, frame_off, frame_size,
+	return solo_send_desc(solo_enc, skip, vbuf, frame_off, frame_size,
 			SOLO_MP4E_EXT_ADDR(solo_dev),
 			SOLO_MP4E_EXT_SIZE(solo_dev));
-	dma_unmap_sg(&solo_dev->pdev->dev, vbuf->sgl, vbuf->nents,
-			DMA_FROM_DEVICE);
-
-	/* add the header only after dma_unmap_sg() */
-	if (!vop_type(vh))
-		sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
-				    solo_enc->vop, solo_enc->vop_len);
-	return ret;
 }
 
 static int solo_enc_fillbuf(struct solo_enc_dev *solo_enc,
@@ -753,9 +729,29 @@ static void solo_enc_stop_streaming(struct vb2_queue *q)
 	solo_ring_stop(solo_enc->solo_dev);
 }
 
+static void solo_enc_buf_finish(struct vb2_buffer *vb)
+{
+	struct solo_enc_dev *solo_enc = vb2_get_drv_priv(vb->vb2_queue);
+	struct sg_table *vbuf = vb2_dma_sg_plane_desc(vb, 0);
+
+	switch (solo_enc->fmt) {
+	case V4L2_PIX_FMT_MPEG4:
+	case V4L2_PIX_FMT_H264:
+		if (vb->v4l2_buf.flags & V4L2_BUF_FLAG_KEYFRAME)
+			sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
+					solo_enc->vop, solo_enc->vop_len);
+		break;
+	default: /* V4L2_PIX_FMT_MJPEG */
+		sg_copy_from_buffer(vbuf->sgl, vbuf->nents,
+				solo_enc->jpeg_header, solo_enc->jpeg_len);
+		break;
+	}
+}
+
 static struct vb2_ops solo_enc_video_qops = {
 	.queue_setup	= solo_enc_queue_setup,
 	.buf_queue	= solo_enc_buf_queue,
+	.buf_finish     = solo_enc_buf_finish,
 	.start_streaming = solo_enc_start_streaming,
 	.stop_streaming = solo_enc_stop_streaming,
 	.wait_prepare	= vb2_ops_wait_prepare,
-- 
1.9.0

[RFCv1 PATCH 06/20] vb2: memop prepare: return errors

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

For vb2-dma-sg the dma_map_sg function can return an error. This means that
the prepare memop also needs to change so an error can be returned.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 5 +++--
 drivers/media/v4l2-core/videobuf2-dma-sg.c     | 4 ++--
 include/media/videobuf2-core.h                 | 2 +-
 3 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 1e994a9..604f2f4 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -108,16 +108,17 @@ static unsigned int vb2_dc_num_users(void *buf_priv)
 	return atomic_read(&buf->refcount);
 }
 
-static void vb2_dc_prepare(void *buf_priv)
+static int vb2_dc_prepare(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
 	struct sg_table *sgt = buf->dma_sgt;
 
 	/* DMABUF exporter will flush the cache for us */
 	if (!sgt || buf->db_attach)
-		return;
+		return 0;
 
 	dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	return 0;
 }
 
 static void vb2_dc_finish(void *buf_priv)
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index c7e0eca..c54df54 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -170,12 +170,12 @@ static void vb2_dma_sg_put(void *buf_priv)
 	}
 }
 
-static void vb2_dma_sg_prepare(void *buf_priv)
+static int vb2_dma_sg_prepare(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
 	struct sg_table *sgt = &buf->sg_table;
 
-	dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
+	return dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir) ? 0 : -EIO;
 }
 
 static void vb2_dma_sg_finish(void *buf_priv)
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 4b7fed0..a0dedc1 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -90,7 +90,7 @@ struct vb2_mem_ops {
 					unsigned long size, int write);
 	void		(*put_userptr)(void *buf_priv);
 
-	void		(*prepare)(void *buf_priv);
+	int		(*prepare)(void *buf_priv);
 	void		(*finish)(void *buf_priv);
 
 	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
-- 
1.9.0

[RFCv1 PATCH 07/20] vb2: call memop prepare before the buf_prepare op is called

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The prepare memop now returns an error, so we need to be able to handle that.
In addition, prepare has to be called before buf_prepare since in the dma-sg
case buf_prepare expects that the dma memory is mapped and it can use the
sg_table.

So call the prepare memop before calling buf_prepare and clean up the memory
in case of an error.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 67 +++++++++++++++++++++++++++++---
 1 file changed, 61 insertions(+), 6 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index bb36fe5..0e0d2a8 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1207,6 +1207,39 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 	vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
 }
 
+/*
+ * __buf_prepare_memory() - prepare (sync) a vb2_buffer so it can be enqueued
+ */
+static int __buf_prepare_memory(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+	int err;
+
+	/* sync buffers */
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		err = call_memop(vb, prepare, vb->planes[plane].mem_priv);
+		if (err) {
+			fail_memop(vb, prepare);
+			for (; plane; plane--)
+				call_memop(vb, finish, vb->planes[plane - 1].mem_priv);
+			return err;
+		}
+	}
+	return 0;
+}
+
+/*
+ * __buf_finish_memory() - finish (unsync) a vb2_buffer
+ */
+static void __buf_finish_memory(struct vb2_buffer *vb)
+{
+	unsigned int plane;
+
+	/* unsync buffers */
+	for (plane = 0; plane < vb->num_planes; ++plane)
+		call_memop(vb, finish, vb->planes[plane].mem_priv);
+}
+
 /**
  * __qbuf_userptr() - handle qbuf of a USERPTR buffer
  */
@@ -1290,10 +1323,18 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		}
 	}
 
+	ret = __buf_prepare_memory(vb);
+	if (ret) {
+		call_vb_qop(vb, buf_cleanup, vb);
+		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		goto err;
+	}
+
 	ret = call_vb_qop(vb, buf_prepare, vb);
 	if (ret) {
 		dprintk(1, "qbuf: buffer preparation failed\n");
 		fail_vb_qop(vb, buf_prepare);
+		__buf_finish_memory(vb);
 		call_vb_qop(vb, buf_cleanup, vb);
 		goto err;
 	}
@@ -1320,9 +1361,20 @@ static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	int ret;
 
 	__fill_vb2_buffer(vb, b, vb->v4l2_planes);
+
+	ret = __buf_prepare_memory(vb);
+	if (ret) {
+		call_vb_qop(vb, buf_cleanup, vb);
+		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		return ret;
+	}
+
 	ret = call_vb_qop(vb, buf_prepare, vb);
-	if (ret)
+	if (ret) {
+		dprintk(1, "%s: buffer preparation failed\n", __func__);
 		fail_vb_qop(vb, buf_prepare);
+		__buf_finish_memory(vb);
+	}
 	return ret;
 }
 
@@ -1431,10 +1483,18 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		}
 	}
 
+	ret = __buf_prepare_memory(vb);
+	if (ret) {
+		call_vb_qop(vb, buf_cleanup, vb);
+		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		goto err;
+	}
+
 	ret = call_vb_qop(vb, buf_prepare, vb);
 	if (ret) {
 		dprintk(1, "qbuf: buffer preparation failed\n");
 		fail_vb_qop(vb, buf_prepare);
+		__buf_finish_memory(vb);
 		call_vb_qop(vb, buf_cleanup, vb);
 		goto err;
 	}
@@ -1453,15 +1513,10 @@ err:
 static void __enqueue_in_driver(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
-	unsigned int plane;
 
 	vb->state = VB2_BUF_STATE_ACTIVE;
 	atomic_inc(&q->owned_by_drv_count);
 
-	/* sync buffers */
-	for (plane = 0; plane < vb->num_planes; ++plane)
-		call_memop(vb, prepare, vb->planes[plane].mem_priv);
-
 	call_vb_qop(vb, buf_queue, vb);
 }
 
-- 
1.9.0

[RFCv1 PATCH 08/20] vb2-dma-sg: add dmabuf import support

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Add support for dmabuf to vb2-dma-sg.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-dma-sg.c | 125 +++++++++++++++++++++++++++--
 1 file changed, 118 insertions(+), 7 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index c54df54..075acbe 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -42,11 +42,15 @@ struct vb2_dma_sg_buf {
 	int				offset;
 	enum dma_data_direction		dma_dir;
 	struct sg_table			sg_table;
+	struct sg_table			*dma_sgt;
 	size_t				size;
 	unsigned int			num_pages;
 	atomic_t			refcount;
 	struct vb2_vmarea_handler	handler;
 	struct vm_area_struct		*vma;
+
+	/* DMABUF related */
+	struct dma_buf_attachment	*db_attach;
 };
 
 static void vb2_dma_sg_put(void *buf_priv);
@@ -113,6 +117,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, int write,
 	/* size is already page aligned */
 	buf->num_pages = size >> PAGE_SHIFT;
 	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_sgt = &buf->sg_table;
 
 	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
 			     GFP_KERNEL);
@@ -123,7 +128,7 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, int write,
 	if (ret)
 		goto fail_pages_alloc;
 
-	ret = sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+	ret = sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
 			buf->num_pages, 0, size, gfp_flags);
 	if (ret)
 		goto fail_table_alloc;
@@ -161,7 +166,7 @@ static void vb2_dma_sg_put(void *buf_priv)
 			buf->num_pages);
 		if (buf->vaddr)
 			vm_unmap_ram(buf->vaddr, buf->num_pages);
-		sg_free_table(&buf->sg_table);
+		sg_free_table(buf->dma_sgt);
 		while (--i >= 0)
 			__free_page(buf->pages[i]);
 		kfree(buf->pages);
@@ -173,7 +178,11 @@ static void vb2_dma_sg_put(void *buf_priv)
 static int vb2_dma_sg_prepare(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	struct sg_table *sgt = &buf->sg_table;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	/* DMABUF exporter will flush the cache for us */
+	if (buf->db_attach)
+		return 0;
 
 	return dma_map_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir) ? 0 : -EIO;
 }
@@ -181,7 +190,11 @@ static int vb2_dma_sg_prepare(void *buf_priv)
 static void vb2_dma_sg_finish(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
-	struct sg_table *sgt = &buf->sg_table;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	/* DMABUF exporter will flush the cache for us */
+	if (buf->db_attach)
+		return;
 
 	dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
 }
@@ -209,6 +222,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	buf->offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
 	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_sgt = &buf->sg_table;
 
 	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
 	last  = ((vaddr + size - 1) & PAGE_MASK) >> PAGE_SHIFT;
@@ -261,7 +275,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	if (num_pages_from_user != buf->num_pages)
 		goto userptr_fail_get_user_pages;
 
-	if (sg_alloc_table_from_pages(&buf->sg_table, buf->pages,
+	if (sg_alloc_table_from_pages(buf->dma_sgt, buf->pages,
 			buf->num_pages, buf->offset, size, 0))
 		goto userptr_fail_alloc_table_from_pages;
 
@@ -297,7 +311,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 	       __func__, buf->num_pages);
 	if (buf->vaddr)
 		vm_unmap_ram(buf->vaddr, buf->num_pages);
-	sg_free_table(&buf->sg_table);
+	sg_free_table(buf->dma_sgt);
 	while (--i >= 0) {
 		if (buf->write)
 			set_page_dirty_lock(buf->pages[i]);
@@ -370,11 +384,104 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
 	return 0;
 }
 
+/*********************************************/
+/*       callbacks for DMABUF buffers        */
+/*********************************************/
+
+static int vb2_dma_sg_map_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+	struct sg_table *sgt;
+
+	if (WARN_ON(!buf->db_attach)) {
+		pr_err("trying to pin a non attached buffer\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(buf->dma_sgt)) {
+		pr_err("dmabuf buffer is already pinned\n");
+		return 0;
+	}
+
+	/* get the associated scatterlist for this buffer */
+	sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir);
+	if (IS_ERR_OR_NULL(sgt)) {
+		pr_err("Error getting dmabuf scatterlist\n");
+		return -EINVAL;
+	}
+
+	buf->dma_sgt = sgt;
+	return 0;
+}
+
+static void vb2_dma_sg_unmap_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+	struct sg_table *sgt = buf->dma_sgt;
+
+	if (WARN_ON(!buf->db_attach)) {
+		pr_err("trying to unpin a not attached buffer\n");
+		return;
+	}
+
+	if (WARN_ON(!sgt)) {
+		pr_err("dmabuf buffer is already unpinned\n");
+		return;
+	}
+
+	dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir);
+
+	buf->dma_sgt = NULL;
+}
+
+static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
+{
+	struct vb2_dma_sg_buf *buf = mem_priv;
+
+	/* if vb2 works correctly you should never detach mapped buffer */
+	if (WARN_ON(buf->dma_sgt))
+		vb2_dma_sg_unmap_dmabuf(buf);
+
+	/* detach this attachment */
+	dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach);
+	kfree(buf);
+}
+
+static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
+	unsigned long size, int write)
+{
+	struct vb2_dma_sg_conf *conf = alloc_ctx;
+	struct vb2_dma_sg_buf *buf;
+	struct dma_buf_attachment *dba;
+
+	if (dbuf->size < size)
+		return ERR_PTR(-EFAULT);
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return ERR_PTR(-ENOMEM);
+
+	buf->dev = conf->dev;
+	/* create attachment for the dmabuf with the user device */
+	dba = dma_buf_attach(dbuf, buf->dev);
+	if (IS_ERR(dba)) {
+		pr_err("failed to attach dmabuf\n");
+		kfree(buf);
+		return dba;
+	}
+
+	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->size = size;
+	buf->db_attach = dba;
+
+	return buf;
+}
+
 static void *vb2_dma_sg_cookie(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
 
-	return &buf->sg_table;
+	return buf->dma_sgt;
 }
 
 const struct vb2_mem_ops vb2_dma_sg_memops = {
@@ -387,6 +494,10 @@ const struct vb2_mem_ops vb2_dma_sg_memops = {
 	.vaddr		= vb2_dma_sg_vaddr,
 	.mmap		= vb2_dma_sg_mmap,
 	.num_users	= vb2_dma_sg_num_users,
+	.map_dmabuf	= vb2_dma_sg_map_dmabuf,
+	.unmap_dmabuf	= vb2_dma_sg_unmap_dmabuf,
+	.attach_dmabuf	= vb2_dma_sg_attach_dmabuf,
+	.detach_dmabuf	= vb2_dma_sg_detach_dmabuf,
 	.cookie		= vb2_dma_sg_cookie,
 };
 EXPORT_SYMBOL_GPL(vb2_dma_sg_memops);
-- 
1.9.0

[RFCv1 PATCH 09/20] vb2-dma-sg: add get_dmabuf

[Hans Verkuil]

From: Hans Verkuil <hansverk@cisco.com>

Add DMABUF export support to vb2-dma-sg.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-dma-sg.c | 170 +++++++++++++++++++++++++++++
 1 file changed, 170 insertions(+)

diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 075acbe..3efa27c 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -385,6 +385,175 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
 }
 
 /*********************************************/
+/*         DMABUF ops for exporters          */
+/*********************************************/
+
+struct vb2_dma_sg_attachment {
+	struct sg_table sgt;
+	enum dma_data_direction dir;
+};
+
+static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
+	struct dma_buf_attachment *dbuf_attach)
+{
+	struct vb2_dma_sg_attachment *attach;
+	unsigned int i;
+	struct scatterlist *rd, *wr;
+	struct sg_table *sgt;
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+	int ret;
+
+	attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+	if (!attach)
+		return -ENOMEM;
+
+	sgt = &attach->sgt;
+	/* Copy the buf->base_sgt scatter list to the attachment, as we can't
+	 * map the same scatter list to multiple attachments at the same time.
+	 */
+	ret = sg_alloc_table(sgt, buf->dma_sgt->orig_nents, GFP_KERNEL);
+	if (ret) {
+		kfree(attach);
+		return -ENOMEM;
+	}
+
+	rd = buf->dma_sgt->sgl;
+	wr = sgt->sgl;
+	for (i = 0; i < sgt->orig_nents; ++i) {
+		sg_set_page(wr, sg_page(rd), rd->length, rd->offset);
+		rd = sg_next(rd);
+		wr = sg_next(wr);
+	}
+
+	attach->dir = DMA_NONE;
+	dbuf_attach->priv = attach;
+
+	return 0;
+}
+
+static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
+	struct dma_buf_attachment *db_attach)
+{
+	struct vb2_dma_sg_attachment *attach = db_attach->priv;
+	struct sg_table *sgt;
+
+	if (!attach)
+		return;
+
+	sgt = &attach->sgt;
+
+	/* release the scatterlist cache */
+	if (attach->dir != DMA_NONE)
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dir);
+	sg_free_table(sgt);
+	kfree(attach);
+	db_attach->priv = NULL;
+}
+
+static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
+	struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+{
+	struct vb2_dma_sg_attachment *attach = db_attach->priv;
+	/* stealing dmabuf mutex to serialize map/unmap operations */
+	struct mutex *lock = &db_attach->dmabuf->lock;
+	struct sg_table *sgt;
+	int ret;
+
+	mutex_lock(lock);
+
+	sgt = &attach->sgt;
+	/* return previously mapped sg table */
+	if (attach->dir == dir) {
+		mutex_unlock(lock);
+		return sgt;
+	}
+
+	/* release any previous cache */
+	if (attach->dir != DMA_NONE) {
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dir);
+		attach->dir = DMA_NONE;
+	}
+
+	/* mapping to the client with new direction */
+	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dir);
+	if (ret <= 0) {
+		pr_err("failed to map scatterlist\n");
+		mutex_unlock(lock);
+		return ERR_PTR(-EIO);
+	}
+
+	attach->dir = dir;
+
+	mutex_unlock(lock);
+
+	return sgt;
+}
+
+static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+	struct sg_table *sgt, enum dma_data_direction dir)
+{
+	/* nothing to be done here */
+}
+
+static void vb2_dma_sg_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+	/* drop reference obtained in vb2_dma_sg_get_dmabuf */
+	vb2_dma_sg_put(dbuf->priv);
+}
+
+static void *vb2_dma_sg_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
+{
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+	return buf->vaddr + pgnum * PAGE_SIZE;
+}
+
+static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
+{
+	struct vb2_dma_sg_buf *buf = dbuf->priv;
+
+	return vb2_dma_sg_vaddr(buf);
+}
+
+static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
+	struct vm_area_struct *vma)
+{
+	return vb2_dma_sg_mmap(dbuf->priv, vma);
+}
+
+static struct dma_buf_ops vb2_dma_sg_dmabuf_ops = {
+	.attach = vb2_dma_sg_dmabuf_ops_attach,
+	.detach = vb2_dma_sg_dmabuf_ops_detach,
+	.map_dma_buf = vb2_dma_sg_dmabuf_ops_map,
+	.unmap_dma_buf = vb2_dma_sg_dmabuf_ops_unmap,
+	.kmap = vb2_dma_sg_dmabuf_ops_kmap,
+	.kmap_atomic = vb2_dma_sg_dmabuf_ops_kmap,
+	.vmap = vb2_dma_sg_dmabuf_ops_vmap,
+	.mmap = vb2_dma_sg_dmabuf_ops_mmap,
+	.release = vb2_dma_sg_dmabuf_ops_release,
+};
+
+static struct dma_buf *vb2_dma_sg_get_dmabuf(void *buf_priv, unsigned long flags)
+{
+	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct dma_buf *dbuf;
+
+	if (WARN_ON(!buf->dma_sgt))
+		return NULL;
+
+	dbuf = dma_buf_export(buf, &vb2_dma_sg_dmabuf_ops, buf->size, flags);
+	if (IS_ERR(dbuf))
+		return NULL;
+
+	/* dmabuf keeps reference to vb2 buffer */
+	atomic_inc(&buf->refcount);
+
+	return dbuf;
+}
+
+/*********************************************/
 /*       callbacks for DMABUF buffers        */
 /*********************************************/
 
@@ -494,6 +663,7 @@ const struct vb2_mem_ops vb2_dma_sg_memops = {
 	.vaddr		= vb2_dma_sg_vaddr,
 	.mmap		= vb2_dma_sg_mmap,
 	.num_users	= vb2_dma_sg_num_users,
+	.get_dmabuf	= vb2_dma_sg_get_dmabuf,
 	.map_dmabuf	= vb2_dma_sg_map_dmabuf,
 	.unmap_dmabuf	= vb2_dma_sg_unmap_dmabuf,
 	.attach_dmabuf	= vb2_dma_sg_attach_dmabuf,
-- 
1.9.0

[RFCv1 PATCH 10/20] vb2-vmalloc: add get_dmabuf support

[Hans Verkuil]

From: Hans Verkuil <hansverk@cisco.com>

Add support for DMABUF exporting to the vb2-vmalloc implementation.

All memory models now have support for both importing and exporting of DMABUFs.

Signed-off-by: Hans Verkuil <hansverk@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-vmalloc.c | 174 ++++++++++++++++++++++++++++
 1 file changed, 174 insertions(+)

diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index d77e397..4baa11a 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -31,6 +31,9 @@ struct vb2_vmalloc_buf {
 	atomic_t			refcount;
 	struct vb2_vmarea_handler	handler;
 	struct dma_buf			*dbuf;
+
+	/* DMABUF related */
+	struct dma_buf_attachment	*db_attach;
 };
 
 static void vb2_vmalloc_put(void *buf_priv);
@@ -210,6 +213,176 @@ static int vb2_vmalloc_mmap(void *buf_priv, struct vm_area_struct *vma)
 }
 
 /*********************************************/
+/*         DMABUF ops for exporters          */
+/*********************************************/
+
+struct vb2_vmalloc_attachment {
+	struct sg_table sgt;
+	enum dma_data_direction dir;
+};
+
+static int vb2_vmalloc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
+	struct dma_buf_attachment *dbuf_attach)
+{
+	struct vb2_vmalloc_attachment *attach;
+	struct vb2_vmalloc_buf *buf = dbuf->priv;
+	int num_pages = PAGE_ALIGN(buf->size) / PAGE_SIZE;
+	struct sg_table *sgt;
+	struct scatterlist *sg;
+	void *vaddr = buf->vaddr;
+	int ret;
+	int i;
+
+	attach = kzalloc(sizeof(*attach), GFP_KERNEL);
+	if (!attach)
+		return -ENOMEM;
+
+	sgt = &attach->sgt;
+	ret = sg_alloc_table(sgt, num_pages, GFP_KERNEL);
+	if (ret) {
+		kfree(attach);
+		return ret;
+	}
+	for_each_sg(sgt->sgl, sg, sgt->nents, i) {
+		struct page *page = vmalloc_to_page(vaddr);
+
+		if (!page) {
+			sg_free_table(sgt);
+			kfree(attach);
+			return -ENOMEM;
+		}
+		sg_set_page(sg, page, PAGE_SIZE, 0);
+		vaddr += PAGE_SIZE;
+	}
+
+	attach->dir = DMA_NONE;
+	dbuf_attach->priv = attach;
+	return 0;
+}
+
+static void vb2_vmalloc_dmabuf_ops_detach(struct dma_buf *dbuf,
+	struct dma_buf_attachment *db_attach)
+{
+	struct vb2_vmalloc_attachment *attach = db_attach->priv;
+	struct sg_table *sgt;
+
+	if (!attach)
+		return;
+
+	sgt = &attach->sgt;
+
+	/* release the scatterlist cache */
+	if (attach->dir != DMA_NONE)
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dir);
+	sg_free_table(sgt);
+	kfree(attach);
+	db_attach->priv = NULL;
+}
+
+static struct sg_table *vb2_vmalloc_dmabuf_ops_map(
+	struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+{
+	struct vb2_vmalloc_attachment *attach = db_attach->priv;
+	/* stealing dmabuf mutex to serialize map/unmap operations */
+	struct mutex *lock = &db_attach->dmabuf->lock;
+	struct sg_table *sgt;
+	int ret;
+
+	mutex_lock(lock);
+
+	sgt = &attach->sgt;
+	/* return previously mapped sg table */
+	if (attach->dir == dir) {
+		mutex_unlock(lock);
+		return sgt;
+	}
+
+	/* release any previous cache */
+	if (attach->dir != DMA_NONE) {
+		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
+			attach->dir);
+		attach->dir = DMA_NONE;
+	}
+
+	/* mapping to the client with new direction */
+	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dir);
+	if (ret <= 0) {
+		pr_err("failed to map scatterlist\n");
+		mutex_unlock(lock);
+		return ERR_PTR(-EIO);
+	}
+
+	attach->dir = dir;
+
+	mutex_unlock(lock);
+
+	return sgt;
+}
+
+static void vb2_vmalloc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
+	struct sg_table *sgt, enum dma_data_direction dir)
+{
+	/* nothing to be done here */
+}
+
+static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
+{
+	/* drop reference obtained in vb2_vmalloc_get_dmabuf */
+	vb2_vmalloc_put(dbuf->priv);
+}
+
+static void *vb2_vmalloc_dmabuf_ops_kmap(struct dma_buf *dbuf, unsigned long pgnum)
+{
+	struct vb2_vmalloc_buf *buf = dbuf->priv;
+
+	return buf->vaddr + pgnum * PAGE_SIZE;
+}
+
+static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
+{
+	struct vb2_vmalloc_buf *buf = dbuf->priv;
+
+	return buf->vaddr;
+}
+
+static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
+	struct vm_area_struct *vma)
+{
+	return vb2_vmalloc_mmap(dbuf->priv, vma);
+}
+
+static struct dma_buf_ops vb2_vmalloc_dmabuf_ops = {
+	.attach = vb2_vmalloc_dmabuf_ops_attach,
+	.detach = vb2_vmalloc_dmabuf_ops_detach,
+	.map_dma_buf = vb2_vmalloc_dmabuf_ops_map,
+	.unmap_dma_buf = vb2_vmalloc_dmabuf_ops_unmap,
+	.kmap = vb2_vmalloc_dmabuf_ops_kmap,
+	.kmap_atomic = vb2_vmalloc_dmabuf_ops_kmap,
+	.vmap = vb2_vmalloc_dmabuf_ops_vmap,
+	.mmap = vb2_vmalloc_dmabuf_ops_mmap,
+	.release = vb2_vmalloc_dmabuf_ops_release,
+};
+
+static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flags)
+{
+	struct vb2_vmalloc_buf *buf = buf_priv;
+	struct dma_buf *dbuf;
+
+	if (WARN_ON(!buf->vaddr))
+		return NULL;
+
+	dbuf = dma_buf_export(buf, &vb2_vmalloc_dmabuf_ops, buf->size, flags);
+	if (IS_ERR(dbuf))
+		return NULL;
+
+	/* dmabuf keeps reference to vb2 buffer */
+	atomic_inc(&buf->refcount);
+
+	return dbuf;
+}
+
+/*********************************************/
 /*       callbacks for DMABUF buffers        */
 /*********************************************/
 
@@ -265,6 +438,7 @@ const struct vb2_mem_ops vb2_vmalloc_memops = {
 	.put		= vb2_vmalloc_put,
 	.get_userptr	= vb2_vmalloc_get_userptr,
 	.put_userptr	= vb2_vmalloc_put_userptr,
+	.get_dmabuf	= vb2_vmalloc_get_dmabuf,
 	.map_dmabuf	= vb2_vmalloc_map_dmabuf,
 	.unmap_dmabuf	= vb2_vmalloc_unmap_dmabuf,
 	.attach_dmabuf	= vb2_vmalloc_attach_dmabuf,
-- 
1.9.0

[RFCv1 PATCH 11/20] vb2: improve buf_prepare/finish comments

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Clarify in the buf_prepare/finish ops what the dma mapping status is of
the provided buffer.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 include/media/videobuf2-core.h | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index a0dedc1..169e111 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -274,12 +274,14 @@ struct vb2_buffer {
  *			operation in this callback; drivers that support
  *			VIDIOC_CREATE_BUFS must also validate the buffer size;
  *			if an error is returned, the buffer will not be queued
- *			in driver; optional.
+ *			in driver; any necessary DMA mapping action will have
+ *			been done before this is called; optional.
  * @buf_finish:		called before every dequeue of the buffer back to
  *			userspace; drivers may perform any operations required
- *			before userspace accesses the buffer; optional. Note:
- *			this op can be called as well when vb2_is_streaming()
- *			returns false!
+ *			before userspace accesses the buffer; any necessary DMA
+ *			unmapping action will have been done before this is
+ *			called; optional. Note: this op can be called as well
+ *			when vb2_is_streaming() returns false!
  * @buf_cleanup:	called once before the buffer is freed; drivers may
  *			perform any additional cleanup; optional.
  * @start_streaming:	called once to enter 'streaming' state; the driver may
-- 
1.9.0

[RFCv1 PATCH 12/20] vb2: use correct prefix

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The __qbuf_mmap/userptr/dmabuf all uses similar dprintk's, all using the same
'qbuf' prefix. Replace this by the actual function name so I can see which
dprintk is actually executed.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 48 +++++++++++++++++---------------
 1 file changed, 25 insertions(+), 23 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 0e0d2a8..1f8ab7b 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1263,15 +1263,14 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		    && vb->v4l2_planes[plane].length == planes[plane].length)
 			continue;
 
-		dprintk(3, "qbuf: userspace address for plane %d changed, "
-				"reacquiring memory\n", plane);
+		dprintk(3, "%s: userspace address for plane %d changed, reacquiring memory\n",
+			__func__, plane);
 
 		/* Check if the provided plane buffer is large enough */
 		if (planes[plane].length < q->plane_sizes[plane]) {
-			dprintk(1, "qbuf: provided buffer size %u is less than "
-						"setup size %u for plane %d\n",
-						planes[plane].length,
-						q->plane_sizes[plane], plane);
+			dprintk(1, "%s: provided buffer size %u is less than setup size %u for plane %d\n",
+				__func__, planes[plane].length,
+				q->plane_sizes[plane], plane);
 			ret = -EINVAL;
 			goto err;
 		}
@@ -1293,8 +1292,8 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 				      planes[plane].m.userptr,
 				      planes[plane].length, write);
 		if (IS_ERR_OR_NULL(mem_priv)) {
-			dprintk(1, "qbuf: failed acquiring userspace "
-						"memory for plane %d\n", plane);
+			dprintk(1, "%s: failed acquiring userspace memory for plane %d\n",
+				__func__, plane);
 			fail_memop(vb, get_userptr);
 			ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
 			goto err;
@@ -1317,7 +1316,8 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		 */
 		ret = call_vb_qop(vb, buf_init, vb);
 		if (ret) {
-			dprintk(1, "qbuf: buffer initialization failed\n");
+			dprintk(1, "%s: buffer initialization failed\n",
+				__func__);
 			fail_vb_qop(vb, buf_init);
 			goto err;
 		}
@@ -1326,13 +1326,13 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	ret = __buf_prepare_memory(vb);
 	if (ret) {
 		call_vb_qop(vb, buf_cleanup, vb);
-		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		dprintk(1, "%s: buffer memory preparation failed\n", __func__);
 		goto err;
 	}
 
 	ret = call_vb_qop(vb, buf_prepare, vb);
 	if (ret) {
-		dprintk(1, "qbuf: buffer preparation failed\n");
+		dprintk(1, "%s: buffer preparation failed\n", __func__);
 		fail_vb_qop(vb, buf_prepare);
 		__buf_finish_memory(vb);
 		call_vb_qop(vb, buf_cleanup, vb);
@@ -1365,7 +1365,7 @@ static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	ret = __buf_prepare_memory(vb);
 	if (ret) {
 		call_vb_qop(vb, buf_cleanup, vb);
-		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		dprintk(1, "%s: buffer memory preparation failed\n", __func__);
 		return ret;
 	}
 
@@ -1398,8 +1398,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
 
 		if (IS_ERR_OR_NULL(dbuf)) {
-			dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
-				plane);
+			dprintk(1, "%s: invalid dmabuf fd for plane %d\n",
+				__func__, plane);
 			ret = -EINVAL;
 			goto err;
 		}
@@ -1409,8 +1409,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 			planes[plane].length = dbuf->size;
 
 		if (planes[plane].length < q->plane_sizes[plane]) {
-			dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
-				plane);
+			dprintk(1, "%s: invalid dmabuf length for plane %d\n",
+				__func__, plane);
 			ret = -EINVAL;
 			goto err;
 		}
@@ -1422,7 +1422,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 			continue;
 		}
 
-		dprintk(1, "qbuf: buffer for plane %d changed\n", plane);
+		dprintk(1, "%s: buffer for plane %d changed\n",
+			__func__, plane);
 
 		if (!reacquired) {
 			reacquired = true;
@@ -1437,7 +1438,7 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		mem_priv = call_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
 			dbuf, planes[plane].length, write);
 		if (IS_ERR(mem_priv)) {
-			dprintk(1, "qbuf: failed to attach dmabuf\n");
+			dprintk(1, "%s: failed to attach dmabuf\n", __func__);
 			fail_memop(vb, attach_dmabuf);
 			ret = PTR_ERR(mem_priv);
 			dma_buf_put(dbuf);
@@ -1455,8 +1456,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	for (plane = 0; plane < vb->num_planes; ++plane) {
 		ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv);
 		if (ret) {
-			dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
-				plane);
+			dprintk(1, "%s: failed to map dmabuf for plane %d\n",
+				__func__, plane);
 			fail_memop(vb, map_dmabuf);
 			goto err;
 		}
@@ -1477,7 +1478,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		 */
 		ret = call_vb_qop(vb, buf_init, vb);
 		if (ret) {
-			dprintk(1, "qbuf: buffer initialization failed\n");
+			dprintk(1, "%s: buffer initialization failed\n",
+				__func__);
 			fail_vb_qop(vb, buf_init);
 			goto err;
 		}
@@ -1486,13 +1488,13 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	ret = __buf_prepare_memory(vb);
 	if (ret) {
 		call_vb_qop(vb, buf_cleanup, vb);
-		dprintk(1, "qbuf: buffer memory preparation failed\n");
+		dprintk(1, "%s: buffer memory preparation failed\n", __func__);
 		goto err;
 	}
 
 	ret = call_vb_qop(vb, buf_prepare, vb);
 	if (ret) {
-		dprintk(1, "qbuf: buffer preparation failed\n");
+		dprintk(1, "%s: buffer preparation failed\n", __func__);
 		fail_vb_qop(vb, buf_prepare);
 		__buf_finish_memory(vb);
 		call_vb_qop(vb, buf_cleanup, vb);
-- 
1.9.0

[RFCv1 PATCH 13/20] vb2: move __qbuf_mmap before __qbuf_userptr

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

__qbuf_mmap was sort of hidden in between the much larger __qbuf_userptr
and __qbuf_dmabuf functions. Move it before __qbuf_userptr which is
also conform the usual order these memory models are implemented: first
mmap, then userptr, then dmabuf.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 50 ++++++++++++++++----------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 1f8ab7b..1dc1db8 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1241,6 +1241,31 @@ static void __buf_finish_memory(struct vb2_buffer *vb)
 }
 
 /**
+ * __qbuf_mmap() - handle qbuf of an MMAP buffer
+ */
+static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
+{
+	int ret;
+
+	__fill_vb2_buffer(vb, b, vb->v4l2_planes);
+
+	ret = __buf_prepare_memory(vb);
+	if (ret) {
+		call_vb_qop(vb, buf_cleanup, vb);
+		dprintk(1, "%s: buffer memory preparation failed\n", __func__);
+		return ret;
+	}
+
+	ret = call_vb_qop(vb, buf_prepare, vb);
+	if (ret) {
+		dprintk(1, "%s: buffer preparation failed\n", __func__);
+		fail_vb_qop(vb, buf_prepare);
+		__buf_finish_memory(vb);
+	}
+	return ret;
+}
+
+/**
  * __qbuf_userptr() - handle qbuf of a USERPTR buffer
  */
 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
@@ -1354,31 +1379,6 @@ err:
 }
 
 /**
- * __qbuf_mmap() - handle qbuf of an MMAP buffer
- */
-static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
-{
-	int ret;
-
-	__fill_vb2_buffer(vb, b, vb->v4l2_planes);
-
-	ret = __buf_prepare_memory(vb);
-	if (ret) {
-		call_vb_qop(vb, buf_cleanup, vb);
-		dprintk(1, "%s: buffer memory preparation failed\n", __func__);
-		return ret;
-	}
-
-	ret = call_vb_qop(vb, buf_prepare, vb);
-	if (ret) {
-		dprintk(1, "%s: buffer preparation failed\n", __func__);
-		fail_vb_qop(vb, buf_prepare);
-		__buf_finish_memory(vb);
-	}
-	return ret;
-}
-
-/**
  * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
  */
 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
-- 
1.9.0

[RFCv1 PATCH 14/20] vb2: allow read/write as long as the format is single planar

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

It was impossible to read() or write() a frame if the queue type was multiplanar.
Even if the current format is single planar. Change this to just check whether
the number of planes is 1 or more.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 1dc1db8..52f38d0 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -576,6 +576,7 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
 		 * for it. The caller has already verified memory and size.
 		 */
 		b->length = vb->num_planes;
+		b->bytesused = 0;
 		memcpy(b->m.planes, vb->v4l2_planes,
 			b->length * sizeof(struct v4l2_plane));
 	} else {
@@ -2589,6 +2590,7 @@ struct vb2_fileio_buf {
  */
 struct vb2_fileio_data {
 	struct v4l2_requestbuffers req;
+	struct v4l2_plane p;
 	struct v4l2_buffer b;
 	struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
 	unsigned int cur_index;
@@ -2683,8 +2685,16 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 		 */
 		for (i = 0; i < q->num_buffers; i++) {
 			struct v4l2_buffer *b = &fileio->b;
+
 			memset(b, 0, sizeof(*b));
 			b->type = q->type;
+			if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
+				struct v4l2_plane *p = &fileio->p;
+
+				memset(p, 0, sizeof(*p));
+				b->m.planes = p;
+				b->length = 1;
+			}
 			b->memory = q->memory;
 			b->index = i;
 			ret = vb2_qbuf(q, b);
@@ -2784,6 +2794,11 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 		memset(&fileio->b, 0, sizeof(fileio->b));
 		fileio->b.type = q->type;
 		fileio->b.memory = q->memory;
+		if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
+			memset(&fileio->p, 0, sizeof(fileio->p));
+			fileio->b.m.planes = &fileio->p;
+			fileio->b.length = 1;
+		}
 		ret = vb2_internal_dqbuf(q, &fileio->b, nonblock);
 		dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
 		if (ret)
@@ -2854,6 +2869,12 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 		fileio->b.memory = q->memory;
 		fileio->b.index = index;
 		fileio->b.bytesused = buf->pos;
+		if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
+			memset(&fileio->p, 0, sizeof(fileio->p));
+			fileio->p.bytesused = buf->pos;
+			fileio->b.m.planes = &fileio->p;
+			fileio->b.length = 1;
+		}
 		ret = vb2_internal_qbuf(q, &fileio->b);
 		dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
 		if (ret)
-- 
1.9.0

[RFCv1 PATCH 15/20] vb2: replace 'write' by 'dma_dir'

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

The 'write' argument is very ambiguous. I first assumed that if it is 1,
then we're doing video output but instead it meant the reverse.

Since it is used to setup the dma_dir value anyway it is now replaced by
the correct dma_dir value which is unambiguous.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c       | 15 +++++----
 drivers/media/v4l2-core/videobuf2-dma-contig.c | 46 ++++++++++++++------------
 drivers/media/v4l2-core/videobuf2-dma-sg.c     | 46 ++++++++++++--------------
 drivers/media/v4l2-core/videobuf2-vmalloc.c    | 20 ++++++-----
 include/media/videobuf2-core.h                 | 11 +++---
 5 files changed, 73 insertions(+), 65 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 52f38d0..b0d1ed9 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -102,7 +102,8 @@ module_param(debug, int, 0644);
 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
-	int write = !V4L2_TYPE_IS_OUTPUT(q->type);
+	enum dma_data_direction dma_dir =
+		V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	void *mem_priv;
 	int plane;
 
@@ -114,7 +115,7 @@ static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
 		unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
 
 		mem_priv = call_memop(vb, alloc, q->alloc_ctx[plane],
-				      size, write, q->gfp_flags);
+				      size, dma_dir, q->gfp_flags);
 		if (IS_ERR_OR_NULL(mem_priv))
 			goto free;
 
@@ -1276,7 +1277,8 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	void *mem_priv;
 	unsigned int plane;
 	int ret;
-	int write = !V4L2_TYPE_IS_OUTPUT(q->type);
+	enum dma_data_direction dma_dir =
+		V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	bool reacquired = vb->planes[0].mem_priv == NULL;
 
 	/* Copy relevant information provided by the userspace */
@@ -1316,7 +1318,7 @@ static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 		/* Acquire each plane's memory */
 		mem_priv = call_memop(vb, get_userptr, q->alloc_ctx[plane],
 				      planes[plane].m.userptr,
-				      planes[plane].length, write);
+				      planes[plane].length, dma_dir);
 		if (IS_ERR_OR_NULL(mem_priv)) {
 			dprintk(1, "%s: failed acquiring userspace memory for plane %d\n",
 				__func__, plane);
@@ -1389,7 +1391,8 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	void *mem_priv;
 	unsigned int plane;
 	int ret;
-	int write = !V4L2_TYPE_IS_OUTPUT(q->type);
+	enum dma_data_direction dma_dir =
+		V4L2_TYPE_IS_OUTPUT(q->type) ? DMA_TO_DEVICE : DMA_FROM_DEVICE;
 	bool reacquired = vb->planes[0].mem_priv == NULL;
 
 	/* Copy relevant information provided by the userspace */
@@ -1437,7 +1440,7 @@ static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 
 		/* Acquire each plane's memory */
 		mem_priv = call_memop(vb, attach_dmabuf, q->alloc_ctx[plane],
-			dbuf, planes[plane].length, write);
+			dbuf, planes[plane].length, dma_dir);
 		if (IS_ERR(mem_priv)) {
 			dprintk(1, "%s: failed to attach dmabuf\n", __func__);
 			fail_memop(vb, attach_dmabuf);
diff --git a/drivers/media/v4l2-core/videobuf2-dma-contig.c b/drivers/media/v4l2-core/videobuf2-dma-contig.c
index 604f2f4..e52a1bc 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-contig.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-contig.c
@@ -153,8 +153,8 @@ static void vb2_dc_put(void *buf_priv)
 	kfree(buf);
 }
 
-static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, int write,
-			  gfp_t gfp_flags)
+static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size,
+			  enum dma_data_direction dma_dir, gfp_t gfp_flags)
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct device *dev = conf->dev;
@@ -175,7 +175,7 @@ static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size, int write,
 	/* Prevent the device from being released while the buffer is used */
 	buf->dev = get_device(dev);
 	buf->size = size;
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 
 	buf->handler.refcount = &buf->refcount;
 	buf->handler.put = vb2_dc_put;
@@ -229,7 +229,7 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 
 struct vb2_dc_attachment {
 	struct sg_table sgt;
-	enum dma_data_direction dir;
+	enum dma_data_direction dma_dir;
 };
 
 static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
@@ -264,7 +264,7 @@ static int vb2_dc_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
 		wr = sg_next(wr);
 	}
 
-	attach->dir = DMA_NONE;
+	attach->dma_dir = DMA_NONE;
 	dbuf_attach->priv = attach;
 
 	return 0;
@@ -282,16 +282,16 @@ static void vb2_dc_dmabuf_ops_detach(struct dma_buf *dbuf,
 	sgt = &attach->sgt;
 
 	/* release the scatterlist cache */
-	if (attach->dir != DMA_NONE)
+	if (attach->dma_dir != DMA_NONE)
 		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dir);
+			attach->dma_dir);
 	sg_free_table(sgt);
 	kfree(attach);
 	db_attach->priv = NULL;
 }
 
 static struct sg_table *vb2_dc_dmabuf_ops_map(
-	struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 {
 	struct vb2_dc_attachment *attach = db_attach->priv;
 	/* stealing dmabuf mutex to serialize map/unmap operations */
@@ -303,27 +303,27 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 
 	sgt = &attach->sgt;
 	/* return previously mapped sg table */
-	if (attach->dir == dir) {
+	if (attach->dma_dir == dma_dir) {
 		mutex_unlock(lock);
 		return sgt;
 	}
 
 	/* release any previous cache */
-	if (attach->dir != DMA_NONE) {
+	if (attach->dma_dir != DMA_NONE) {
 		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dir);
-		attach->dir = DMA_NONE;
+			attach->dma_dir);
+		attach->dma_dir = DMA_NONE;
 	}
 
 	/* mapping to the client with new direction */
-	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dir);
+	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir);
 	if (ret <= 0) {
 		pr_err("failed to map scatterlist\n");
 		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
 	}
 
-	attach->dir = dir;
+	attach->dma_dir = dma_dir;
 
 	mutex_unlock(lock);
 
@@ -331,7 +331,7 @@ static struct sg_table *vb2_dc_dmabuf_ops_map(
 }
 
 static void vb2_dc_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
-	struct sg_table *sgt, enum dma_data_direction dir)
+	struct sg_table *sgt, enum dma_data_direction dma_dir)
 {
 	/* nothing to be done here */
 }
@@ -460,7 +460,8 @@ static int vb2_dc_get_user_pfn(unsigned long start, int n_pages,
 }
 
 static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
-	int n_pages, struct vm_area_struct *vma, int write)
+	int n_pages, struct vm_area_struct *vma,
+	enum dma_data_direction dma_dir)
 {
 	if (vma_is_io(vma)) {
 		unsigned int i;
@@ -482,7 +483,7 @@ static int vb2_dc_get_user_pages(unsigned long start, struct page **pages,
 		int n;
 
 		n = get_user_pages(current, current->mm, start & PAGE_MASK,
-			n_pages, write, 1, pages, NULL);
+			n_pages, dma_dir == DMA_FROM_DEVICE, 1, pages, NULL);
 		/* negative error means that no page was pinned */
 		n = max(n, 0);
 		if (n != n_pages) {
@@ -551,7 +552,7 @@ static inline dma_addr_t vb2_dc_pfn_to_dma(struct device *dev, unsigned long pfn
 #endif
 
 static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
-	unsigned long size, int write)
+	unsigned long size, enum dma_data_direction dma_dir)
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct vb2_dc_buf *buf;
@@ -582,7 +583,7 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		return ERR_PTR(-ENOMEM);
 
 	buf->dev = conf->dev;
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 
 	start = vaddr & PAGE_MASK;
 	offset = vaddr & ~PAGE_MASK;
@@ -618,7 +619,8 @@ static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	}
 
 	/* extract page list from userspace mapping */
-	ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, write);
+	ret = vb2_dc_get_user_pages(start, pages, n_pages, vma,
+				    dma_dir == DMA_FROM_DEVICE);
 	if (ret) {
 		unsigned long pfn;
 		if (vb2_dc_get_user_pfn(start, n_pages, vma, &pfn) == 0) {
@@ -777,7 +779,7 @@ static void vb2_dc_detach_dmabuf(void *mem_priv)
 }
 
 static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
-	unsigned long size, int write)
+	unsigned long size, enum dma_data_direction dma_dir)
 {
 	struct vb2_dc_conf *conf = alloc_ctx;
 	struct vb2_dc_buf *buf;
@@ -799,7 +801,7 @@ static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
 		return dba;
 	}
 
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 	buf->size = size;
 	buf->db_attach = dba;
 
diff --git a/drivers/media/v4l2-core/videobuf2-dma-sg.c b/drivers/media/v4l2-core/videobuf2-dma-sg.c
index 3efa27c..9afe8e0 100644
--- a/drivers/media/v4l2-core/videobuf2-dma-sg.c
+++ b/drivers/media/v4l2-core/videobuf2-dma-sg.c
@@ -38,7 +38,6 @@ struct vb2_dma_sg_buf {
 	struct device			*dev;
 	void				*vaddr;
 	struct page			**pages;
-	int				write;
 	int				offset;
 	enum dma_data_direction		dma_dir;
 	struct sg_table			sg_table;
@@ -96,8 +95,8 @@ static int vb2_dma_sg_alloc_compacted(struct vb2_dma_sg_buf *buf,
 	return 0;
 }
 
-static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, int write,
-			      gfp_t gfp_flags)
+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;
@@ -111,12 +110,11 @@ static void *vb2_dma_sg_alloc(void *alloc_ctx, unsigned long size, int write,
 		return NULL;
 
 	buf->vaddr = NULL;
-	buf->write = write;
 	buf->offset = 0;
 	buf->size = size;
 	/* size is already page aligned */
 	buf->num_pages = size >> PAGE_SHIFT;
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 	buf->dma_sgt = &buf->sg_table;
 
 	buf->pages = kzalloc(buf->num_pages * sizeof(struct page *),
@@ -205,7 +203,8 @@ static inline int vma_is_io(struct vm_area_struct *vma)
 }
 
 static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
-				    unsigned long size, int write)
+				    unsigned long size,
+				    enum dma_data_direction dma_dir)
 {
 	struct vb2_dma_sg_conf *conf = alloc_ctx;
 	struct vb2_dma_sg_buf *buf;
@@ -218,10 +217,9 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		return NULL;
 
 	buf->vaddr = NULL;
-	buf->write = write;
 	buf->offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 	buf->dma_sgt = &buf->sg_table;
 
 	first = (vaddr           & PAGE_MASK) >> PAGE_SHIFT;
@@ -267,7 +265,7 @@ static void *vb2_dma_sg_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		num_pages_from_user = get_user_pages(current, current->mm,
 					     vaddr & PAGE_MASK,
 					     buf->num_pages,
-					     write,
+					     buf->dma_dir == DMA_FROM_DEVICE,
 					     1, /* force */
 					     buf->pages,
 					     NULL);
@@ -313,7 +311,7 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 		vm_unmap_ram(buf->vaddr, buf->num_pages);
 	sg_free_table(buf->dma_sgt);
 	while (--i >= 0) {
-		if (buf->write)
+		if (buf->dma_dir == DMA_FROM_DEVICE)
 			set_page_dirty_lock(buf->pages[i]);
 		if (!vma_is_io(buf->vma))
 			put_page(buf->pages[i]);
@@ -390,7 +388,7 @@ static int vb2_dma_sg_mmap(void *buf_priv, struct vm_area_struct *vma)
 
 struct vb2_dma_sg_attachment {
 	struct sg_table sgt;
-	enum dma_data_direction dir;
+	enum dma_data_direction dma_dir;
 };
 
 static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev,
@@ -425,7 +423,7 @@ static int vb2_dma_sg_dmabuf_ops_attach(struct dma_buf *dbuf, struct device *dev
 		wr = sg_next(wr);
 	}
 
-	attach->dir = DMA_NONE;
+	attach->dma_dir = DMA_NONE;
 	dbuf_attach->priv = attach;
 
 	return 0;
@@ -443,16 +441,16 @@ static void vb2_dma_sg_dmabuf_ops_detach(struct dma_buf *dbuf,
 	sgt = &attach->sgt;
 
 	/* release the scatterlist cache */
-	if (attach->dir != DMA_NONE)
+	if (attach->dma_dir != DMA_NONE)
 		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dir);
+			attach->dma_dir);
 	sg_free_table(sgt);
 	kfree(attach);
 	db_attach->priv = NULL;
 }
 
 static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
-	struct dma_buf_attachment *db_attach, enum dma_data_direction dir)
+	struct dma_buf_attachment *db_attach, enum dma_data_direction dma_dir)
 {
 	struct vb2_dma_sg_attachment *attach = db_attach->priv;
 	/* stealing dmabuf mutex to serialize map/unmap operations */
@@ -464,27 +462,27 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 
 	sgt = &attach->sgt;
 	/* return previously mapped sg table */
-	if (attach->dir == dir) {
+	if (attach->dma_dir == dma_dir) {
 		mutex_unlock(lock);
 		return sgt;
 	}
 
 	/* release any previous cache */
-	if (attach->dir != DMA_NONE) {
+	if (attach->dma_dir != DMA_NONE) {
 		dma_unmap_sg(db_attach->dev, sgt->sgl, sgt->orig_nents,
-			attach->dir);
-		attach->dir = DMA_NONE;
+			attach->dma_dir);
+		attach->dma_dir = DMA_NONE;
 	}
 
 	/* mapping to the client with new direction */
-	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dir);
+	ret = dma_map_sg(db_attach->dev, sgt->sgl, sgt->orig_nents, dma_dir);
 	if (ret <= 0) {
 		pr_err("failed to map scatterlist\n");
 		mutex_unlock(lock);
 		return ERR_PTR(-EIO);
 	}
 
-	attach->dir = dir;
+	attach->dma_dir = dma_dir;
 
 	mutex_unlock(lock);
 
@@ -492,7 +490,7 @@ static struct sg_table *vb2_dma_sg_dmabuf_ops_map(
 }
 
 static void vb2_dma_sg_dmabuf_ops_unmap(struct dma_buf_attachment *db_attach,
-	struct sg_table *sgt, enum dma_data_direction dir)
+	struct sg_table *sgt, enum dma_data_direction dma_dir)
 {
 	/* nothing to be done here */
 }
@@ -617,7 +615,7 @@ static void vb2_dma_sg_detach_dmabuf(void *mem_priv)
 }
 
 static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
-	unsigned long size, int write)
+	unsigned long size, enum dma_data_direction dma_dir)
 {
 	struct vb2_dma_sg_conf *conf = alloc_ctx;
 	struct vb2_dma_sg_buf *buf;
@@ -639,7 +637,7 @@ static void *vb2_dma_sg_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
 		return dba;
 	}
 
-	buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+	buf->dma_dir = dma_dir;
 	buf->size = size;
 	buf->db_attach = dba;
 
diff --git a/drivers/media/v4l2-core/videobuf2-vmalloc.c b/drivers/media/v4l2-core/videobuf2-vmalloc.c
index 4baa11a..daf7779 100644
--- a/drivers/media/v4l2-core/videobuf2-vmalloc.c
+++ b/drivers/media/v4l2-core/videobuf2-vmalloc.c
@@ -25,7 +25,7 @@ struct vb2_vmalloc_buf {
 	void				*vaddr;
 	struct page			**pages;
 	struct vm_area_struct		*vma;
-	int				write;
+	enum dma_data_direction		dma_dir;
 	unsigned long			size;
 	unsigned int			n_pages;
 	atomic_t			refcount;
@@ -38,8 +38,8 @@ struct vb2_vmalloc_buf {
 
 static void vb2_vmalloc_put(void *buf_priv);
 
-static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size, int write,
-			       gfp_t gfp_flags)
+static void *vb2_vmalloc_alloc(void *alloc_ctx, unsigned long size,
+			       enum dma_data_direction dma_dir, gfp_t gfp_flags)
 {
 	struct vb2_vmalloc_buf *buf;
 
@@ -74,7 +74,8 @@ static void vb2_vmalloc_put(void *buf_priv)
 }
 
 static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
-				     unsigned long size, int write)
+				     unsigned long size,
+				     enum dma_data_direction dma_dir)
 {
 	struct vb2_vmalloc_buf *buf;
 	unsigned long first, last;
@@ -86,7 +87,7 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 	if (!buf)
 		return NULL;
 
-	buf->write = write;
+	buf->dma_dir = dma_dir;
 	offset = vaddr & ~PAGE_MASK;
 	buf->size = size;
 
@@ -111,7 +112,8 @@ static void *vb2_vmalloc_get_userptr(void *alloc_ctx, unsigned long vaddr,
 		/* current->mm->mmap_sem is taken by videobuf2 core */
 		n_pages = get_user_pages(current, current->mm,
 					 vaddr & PAGE_MASK, buf->n_pages,
-					 write, 1, /* force */
+					 dma_dir == DMA_FROM_DEVICE,
+					 1, /* force */
 					 buf->pages, NULL);
 		if (n_pages != buf->n_pages)
 			goto fail_get_user_pages;
@@ -148,7 +150,7 @@ static void vb2_vmalloc_put_userptr(void *buf_priv)
 		if (vaddr)
 			vm_unmap_ram((void *)vaddr, buf->n_pages);
 		for (i = 0; i < buf->n_pages; ++i) {
-			if (buf->write)
+			if (buf->dma_dir == DMA_FROM_DEVICE)
 				set_page_dirty_lock(buf->pages[i]);
 			put_page(buf->pages[i]);
 		}
@@ -414,7 +416,7 @@ static void vb2_vmalloc_detach_dmabuf(void *mem_priv)
 }
 
 static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
-	unsigned long size, int write)
+	unsigned long size, enum dma_data_direction dma_dir)
 {
 	struct vb2_vmalloc_buf *buf;
 
@@ -426,7 +428,7 @@ static void *vb2_vmalloc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
 		return ERR_PTR(-ENOMEM);
 
 	buf->dbuf = dbuf;
-	buf->write = write;
+	buf->dma_dir = dma_dir;
 	buf->size = size;
 
 	return buf;
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 169e111..df5e75a 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -81,20 +81,23 @@ struct vb2_fileio_data;
  *				  unmap_dmabuf.
  */
 struct vb2_mem_ops {
-	void		*(*alloc)(void *alloc_ctx, unsigned long size, int write,
-				  gfp_t gfp_flags);
+	void		*(*alloc)(void *alloc_ctx, unsigned long size,
+				enum dma_data_direction dma_dir,
+				gfp_t gfp_flags);
 	void		(*put)(void *buf_priv);
 	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
 
 	void		*(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
-					unsigned long size, int write);
+					unsigned long size,
+					enum dma_data_direction dma_dir);
 	void		(*put_userptr)(void *buf_priv);
 
 	int		(*prepare)(void *buf_priv);
 	void		(*finish)(void *buf_priv);
 
 	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
-				unsigned long size, int write);
+					  unsigned long size,
+					  enum dma_data_direction dma_dir);
 	void		(*detach_dmabuf)(void *buf_priv);
 	int		(*map_dmabuf)(void *buf_priv);
 	void		(*unmap_dmabuf)(void *buf_priv);
-- 
1.9.0

[RFCv1 PATCH 16/20] vb2: fix timecode and flags handling for output buffers

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

When sending a buffer to a video output device some of the fields need
to be copied so they arrive in the driver. These are the KEY/P/BFRAME
flags and the TIMECODE flag, and, if that flag is set, the timecode field
itself.

There are a number of functions involved in this: the __fill_vb2_buffer()
is called while preparing a buffer. For output buffers the buffer contains
the video data, so any meta data associated with that (KEY/P/BFRAME and
the field information) should be stored at that point.

The timecode, timecode flag and timestamp information is not part of that,
that information will have to be set when vb2_internal_qbuf() is called to
actually queue the buffer to the driver. Usually VIDIOC_QBUF will do the
prepare as well, but you can call PREPARE_BUF first and only later VIDIOC_QBUF.
You most likely will want to set the timestamp and timecode when you actually
queue the buffer, not when you prepare it.

Finally, in buf_prepare() make sure the timestamp and sequence fields are
actually cleared so that when you do a QUERYBUF of a prepared-but-not-yet-queued
buffer you will not see stale timestamp/sequence data.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 35 ++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index b0d1ed9..2ac98ff 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -91,10 +91,14 @@ module_param(debug, int, 0644);
 
 #endif
 
+/* Flags that are set by the vb2 core */
 #define V4L2_BUFFER_MASK_FLAGS	(V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
 				 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
 				 V4L2_BUF_FLAG_PREPARED | \
 				 V4L2_BUF_FLAG_TIMESTAMP_MASK)
+/* Output buffer flags that should be passed on to the driver */
+#define V4L2_BUFFER_OUT_FLAGS	(V4L2_BUF_FLAG_PFRAME | V4L2_BUF_FLAG_BFRAME | \
+				 V4L2_BUF_FLAG_KEYFRAME | V4L2_BUF_FLAG_TIMECODE)
 
 /**
  * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
@@ -1204,9 +1208,21 @@ static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b
 		}
 	}
 
-	vb->v4l2_buf.field = b->field;
-	vb->v4l2_buf.timestamp = b->timestamp;
+	/* Zero flags that the vb2 core handles */
 	vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
+	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+		/*
+		 * For output buffers mask out the timecode flag:
+		 * this will be handled later in vb2_internal_qbuf().
+		 * The 'field' is valid metadata for this output buffer
+		 * and so that needs to be copied here.
+		 */
+		vb->v4l2_buf.flags &= ~V4L2_BUF_FLAG_TIMECODE;
+		vb->v4l2_buf.field = b->field;
+	} else {
+		/* Zero any output buffer flags as this is a capture buffer */
+		vb->v4l2_buf.flags &= ~V4L2_BUFFER_OUT_FLAGS;
+	}
 }
 
 /*
@@ -1540,6 +1556,10 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 	}
 
 	vb->state = VB2_BUF_STATE_PREPARING;
+	vb->v4l2_buf.timestamp.tv_sec = 0;
+	vb->v4l2_buf.timestamp.tv_usec = 0;
+	vb->v4l2_buf.sequence = 0;
+
 	switch (q->memory) {
 	case V4L2_MEMORY_MMAP:
 		ret = __qbuf_mmap(vb, b);
@@ -1739,6 +1759,17 @@ static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
 	list_add_tail(&vb->queued_entry, &q->queued_list);
 	q->queued_count++;
 	vb->state = VB2_BUF_STATE_QUEUED;
+	if (V4L2_TYPE_IS_OUTPUT(q->type)) {
+		/*
+		 * For output buffers copy the timestamp if needed,
+		 * and the timecode field and flag if needed.
+		 */
+		if (q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_COPY)
+			vb->v4l2_buf.timestamp = b->timestamp;
+		vb->v4l2_buf.flags |= b->flags & V4L2_BUF_FLAG_TIMECODE;
+		if (b->flags & V4L2_BUF_FLAG_TIMECODE)
+			vb->v4l2_buf.timecode = b->timecode;
+	}
 
 	/*
 	 * If already streaming, give the buffer to driver for processing.
-- 
1.9.0

[RFCv1 PATCH 17/20] vb2: set timestamp when using write()

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

When using write() to write data to an output video node the vb2 core
should set timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody
else is able to provide this information with the write() operation.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 2ac98ff..db95dcb 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -22,6 +22,7 @@
 #include <media/v4l2-dev.h>
 #include <media/v4l2-fh.h>
 #include <media/v4l2-event.h>
+#include <media/v4l2-common.h>
 #include <media/videobuf2-core.h>
 
 static int debug;
@@ -2797,6 +2798,8 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 {
 	struct vb2_fileio_data *fileio;
 	struct vb2_fileio_buf *buf;
+	bool set_timestamp = !read &&
+		q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_COPY;
 	int ret, index;
 
 	dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
@@ -2909,6 +2912,8 @@ static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_
 			fileio->b.m.planes = &fileio->p;
 			fileio->b.length = 1;
 		}
+		if (set_timestamp)
+			v4l2_get_timestamp(&fileio->b.timestamp);
 		ret = vb2_internal_qbuf(q, &fileio->b);
 		dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
 		if (ret)
-- 
1.9.0

[RFCv1 PATCH 18/20] vb2: reject output buffers with V4L2_FIELD_ALTERNATE

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

This is not allowed by the spec and does in fact not make any sense.
Return -EINVAL if this is the case.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index db95dcb..face6e9 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1555,6 +1555,15 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
 			__func__, ret);
 		return ret;
 	}
+	if (V4L2_TYPE_IS_OUTPUT(q->type) && b->field == V4L2_FIELD_ALTERNATE) {
+		/*
+		 * If field is ALTERNATE, then we return an error.
+		 * If the format's field is ALTERNATE, then the buffer's field
+		 * should be either TOP or BOTTOM, but using ALTERNATE here as
+		 * well makes no sense.
+		 */
+		return -EINVAL;
+	}
 
 	vb->state = VB2_BUF_STATE_PREPARING;
 	vb->v4l2_buf.timestamp.tv_sec = 0;
-- 
1.9.0

[RFCv1 PATCH 19/20] vb2: add vb2_fileio_is_active and check it more often

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

Added a vb2_fileio_is_active inline function that returns true if fileio
is in progress. Use it in the source. Check for this too in mmap() (you
don't want apps mmap()ing buffers used by fileio) and expbuf() (same reason).

In addition drivers should be able to check for this in queue_setup() to
return an error if an attempt is made to read() or write() with
V4L2_FIELD_ALTERNATE being configured. This is illegal (there is no way
to pass the TOP/BOTTOM information around using file I/O).

However, in order to be able to check for this the init_fileio function
needs to set q->fileio early on, before the buffers are allocated. So switch
to using internal functions (__reqbufs, vb2_internal_qbuf and
vb2_internal_streamon) to skip the fileio check. Well, that's why the internal
functions were created...

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 35 ++++++++++++++++++++------------
 include/media/videobuf2-core.h           | 17 ++++++++++++++++
 2 files changed, 39 insertions(+), 13 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index face6e9..8ea78d6 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -747,7 +747,7 @@ static int __verify_memory_type(struct vb2_queue *q,
 	 * create_bufs is called with count == 0, but count == 0 should still
 	 * do the memory and type validation.
 	 */
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "reqbufs: file io in progress\n");
 		return -EBUSY;
 	}
@@ -1658,7 +1658,7 @@ int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
 	struct vb2_buffer *vb;
 	int ret;
 
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "%s(): file io in progress\n", __func__);
 		return -EBUSY;
 	}
@@ -1827,7 +1827,7 @@ static int vb2_internal_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
  */
 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
 {
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "%s(): file io in progress\n", __func__);
 		return -EBUSY;
 	}
@@ -2047,7 +2047,7 @@ static int vb2_internal_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool n
  */
 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
 {
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "dqbuf: file io in progress\n");
 		return -EBUSY;
 	}
@@ -2173,7 +2173,7 @@ static int vb2_internal_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
  */
 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
 {
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "streamon: file io in progress\n");
 		return -EBUSY;
 	}
@@ -2220,7 +2220,7 @@ static int vb2_internal_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
  */
 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
 {
-	if (q->fileio) {
+	if (vb2_fileio_is_active(q)) {
 		dprintk(1, "streamoff: file io in progress\n");
 		return -EBUSY;
 	}
@@ -2305,6 +2305,11 @@ int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
 		return -EINVAL;
 	}
 
+	if (vb2_fileio_is_active(q)) {
+		dprintk(1, "expbuf: file io in progress\n");
+		return -EBUSY;
+	}
+
 	vb_plane = &vb->planes[eb->plane];
 
 	dbuf = call_memop(vb, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
@@ -2381,6 +2386,10 @@ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
 			return -EINVAL;
 		}
 	}
+	if (vb2_fileio_is_active(q)) {
+		dprintk(1, "mmap: file io in progress\n");
+		return -EBUSY;
+	}
 
 	/*
 	 * Find the plane corresponding to the offset passed by userspace.
@@ -2695,7 +2704,8 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 	fileio->req.count = count;
 	fileio->req.memory = V4L2_MEMORY_MMAP;
 	fileio->req.type = q->type;
-	ret = vb2_reqbufs(q, &fileio->req);
+	q->fileio = fileio;
+	ret = __reqbufs(q, &fileio->req);
 	if (ret)
 		goto err_kfree;
 
@@ -2741,7 +2751,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 			}
 			b->memory = q->memory;
 			b->index = i;
-			ret = vb2_qbuf(q, b);
+			ret = vb2_internal_qbuf(q, b);
 			if (ret)
 				goto err_reqbufs;
 			fileio->bufs[i].queued = 1;
@@ -2757,19 +2767,18 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
 	/*
 	 * Start streaming.
 	 */
-	ret = vb2_streamon(q, q->type);
+	ret = vb2_internal_streamon(q, q->type);
 	if (ret)
 		goto err_reqbufs;
 
-	q->fileio = fileio;
-
 	return ret;
 
 err_reqbufs:
 	fileio->req.count = 0;
-	vb2_reqbufs(q, &fileio->req);
+	__reqbufs(q, &fileio->req);
 
 err_kfree:
+	q->fileio = NULL;
 	kfree(fileio);
 	return ret;
 }
@@ -3200,7 +3209,7 @@ unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
 
 	/* Try to be smart: only lock if polling might start fileio,
 	   otherwise locking will only introduce unwanted delays. */
-	if (q->num_buffers == 0 && q->fileio == NULL) {
+	if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) {
 		if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
 				(req_events & (POLLIN | POLLRDNORM)))
 			must_lock = true;
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index df5e75a..e242f35 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -470,6 +470,23 @@ static inline bool vb2_is_streaming(struct vb2_queue *q)
 }
 
 /**
+ * vb2_fileio_is_active() - return true if fileio is active.
+ * @q:		videobuf queue
+ *
+ * This returns true if read() or write() is used to stream the data
+ * as opposed to stream I/O. This is almost never an important distinction,
+ * except in rare cases. One such case is that using read() or write() to
+ * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
+ * is no way you can pass the field information of each buffer to/from
+ * userspace. A driver that supports this field format should check for
+ * this in the queue_setup op and reject it if this function returns true.
+ */
+static inline bool vb2_fileio_is_active(struct vb2_queue *q)
+{
+	return q->fileio;
+}
+
+/**
  * vb2_is_busy() - return busy status of the queue
  * @q:		videobuf queue
  *
-- 
1.9.0

[RFCv1 PATCH 20/20] vb2: simplify a confusing condition.

[Hans Verkuil]

From: Hans Verkuil <hans.verkuil@cisco.com>

q->start_streaming_called is always true, so the WARN_ON check against
it being false can be dropped.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 drivers/media/v4l2-core/videobuf2-core.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c
index 8ea78d6..0e40c8d 100644
--- a/drivers/media/v4l2-core/videobuf2-core.c
+++ b/drivers/media/v4l2-core/videobuf2-core.c
@@ -1081,9 +1081,8 @@ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
 	if (!q->start_streaming_called) {
 		if (WARN_ON(state != VB2_BUF_STATE_QUEUED))
 			state = VB2_BUF_STATE_QUEUED;
-	} else if (!WARN_ON(!q->start_streaming_called)) {
-		if (WARN_ON(state != VB2_BUF_STATE_DONE &&
-			    state != VB2_BUF_STATE_ERROR))
+	} else if (WARN_ON(state != VB2_BUF_STATE_DONE &&
+			   state != VB2_BUF_STATE_ERROR)) {
 			state = VB2_BUF_STATE_ERROR;
 	}
 
-- 
1.9.0