[PATCH] drm/mediatek: make imported PRIME buffers contiguous

[PATCH] drm/mediatek: make imported PRIME buffers contiguous

[Alexandre Courbot]

This driver requires imported PRIME buffers to appear contiguously in
its IO address space. Make sure this is the case by setting the maximum
DMA segment size to a better value than the default 64K on the DMA
device, and use said DMA device when importing PRIME buffers.

Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
---
 drivers/gpu/drm/mediatek/mtk_drm_drv.c | 47 ++++++++++++++++++++++++--
 drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
 2 files changed, 46 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
index 95fdbd0fbcac..4ad4770fab13 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
@@ -213,6 +213,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 	struct mtk_drm_private *private = drm->dev_private;
 	struct platform_device *pdev;
 	struct device_node *np;
+	struct device *dma_dev;
 	int ret;
 
 	if (!iommu_present(&platform_bus_type))
@@ -275,7 +276,27 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 		goto err_component_unbind;
 	}
 
-	private->dma_dev = &pdev->dev;
+	dma_dev = &pdev->dev;
+	private->dma_dev = dma_dev;
+
+	/*
+	 * Configure the DMA segment size to make sure we get contiguous IOVA
+	 * when importing PRIME buffers.
+	 */
+	if (!dma_dev->dma_parms) {
+		private->dma_parms_allocated = true;
+		dma_dev->dma_parms =
+			devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
+				     GFP_KERNEL);
+	}
+	if (!dma_dev->dma_parms)
+		goto err_component_unbind;
+
+	ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
+	if (ret) {
+		dev_err(dma_dev, "Failed to set DMA segment size\n");
+		goto err_unset_dma_parms;
+	}
 
 	/*
 	 * We don't use the drm_irq_install() helpers provided by the DRM
@@ -285,13 +306,16 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 	drm->irq_enabled = true;
 	ret = drm_vblank_init(drm, MAX_CRTC);
 	if (ret < 0)
-		goto err_component_unbind;
+		goto err_unset_dma_parms;
 
 	drm_kms_helper_poll_init(drm);
 	drm_mode_config_reset(drm);
 
 	return 0;
 
+err_unset_dma_parms:
+	if (private->dma_parms_allocated)
+		dma_dev->dma_parms = NULL;
 err_component_unbind:
 	component_unbind_all(drm->dev, drm);
 err_config_cleanup:
@@ -302,9 +326,14 @@ static int mtk_drm_kms_init(struct drm_device *drm)
 
 static void mtk_drm_kms_deinit(struct drm_device *drm)
 {
+	struct mtk_drm_private *private = drm->dev_private;
+
 	drm_kms_helper_poll_fini(drm);
 	drm_atomic_helper_shutdown(drm);
 
+	if (private->dma_parms_allocated)
+		private->dma_dev->dma_parms = NULL;
+
 	component_unbind_all(drm->dev, drm);
 	drm_mode_config_cleanup(drm);
 }
@@ -320,6 +349,18 @@ static const struct file_operations mtk_drm_fops = {
 	.compat_ioctl = drm_compat_ioctl,
 };
 
+/*
+ * We need to override this because the device used to import the memory is
+ * not dev->dev, as drm_gem_prime_import() expects.
+ */
+struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
+						struct dma_buf *dma_buf)
+{
+	struct mtk_drm_private *private = dev->dev_private;
+
+	return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
+}
+
 static struct drm_driver mtk_drm_driver = {
 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
 			   DRIVER_ATOMIC,
@@ -331,7 +372,7 @@ static struct drm_driver mtk_drm_driver = {
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_export = drm_gem_prime_export,
-	.gem_prime_import = drm_gem_prime_import,
+	.gem_prime_import = mtk_drm_gem_prime_import,
 	.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
 	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
 	.gem_prime_mmap = mtk_drm_gem_mmap_buf,
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
index 598ff3e70446..e03fea12ff59 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
@@ -51,6 +51,8 @@ struct mtk_drm_private {
 	} commit;
 
 	struct drm_atomic_state *suspend_state;
+
+	bool dma_parms_allocated;
 };
 
 extern struct platform_driver mtk_ddp_driver;
-- 
2.22.0.657.g960e92d24f-goog


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] drm/mediatek: make imported PRIME buffers contiguous

[Tomasz Figa]

On Tue, Jul 23, 2019 at 2:34 PM Alexandre Courbot <acourbot@chromium.org> wrote:
>
> This driver requires imported PRIME buffers to appear contiguously in
> its IO address space. Make sure this is the case by setting the maximum
> DMA segment size to a better value than the default 64K on the DMA
> device, and use said DMA device when importing PRIME buffers.
>
> Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 47 ++++++++++++++++++++++++--
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
>  2 files changed, 46 insertions(+), 3 deletions(-)
>

Reviewed-by: Tomasz Figa <tfiga@chromium.org>

Best regards,
Tomasz

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] drm/mediatek: make imported PRIME buffers contiguous

[CK Hu]

Hi, Alexandre:

On Tue, 2019-07-23 at 14:34 +0900, Alexandre Courbot wrote:
> This driver requires imported PRIME buffers to appear contiguously in
> its IO address space. Make sure this is the case by setting the maximum
> DMA segment size to a better value than the default 64K on the DMA
> device, and use said DMA device when importing PRIME buffers.
> 
> Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 47 ++++++++++++++++++++++++--
>  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
>  2 files changed, 46 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> index 95fdbd0fbcac..4ad4770fab13 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> @@ -213,6 +213,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  	struct mtk_drm_private *private = drm->dev_private;
>  	struct platform_device *pdev;
>  	struct device_node *np;
> +	struct device *dma_dev;
>  	int ret;
>  
>  	if (!iommu_present(&platform_bus_type))
> @@ -275,7 +276,27 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  		goto err_component_unbind;
>  	}
>  
> -	private->dma_dev = &pdev->dev;
> +	dma_dev = &pdev->dev;
> +	private->dma_dev = dma_dev;
> +
> +	/*
> +	 * Configure the DMA segment size to make sure we get contiguous IOVA
> +	 * when importing PRIME buffers.
> +	 */
> +	if (!dma_dev->dma_parms) {
> +		private->dma_parms_allocated = true;
> +		dma_dev->dma_parms =
> +			devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
> +				     GFP_KERNEL);
> +	}
> +	if (!dma_dev->dma_parms)
> +		goto err_component_unbind;

return with ret = 0?

> +
> +	ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
> +	if (ret) {
> +		dev_err(dma_dev, "Failed to set DMA segment size\n");
> +		goto err_unset_dma_parms;
> +	}
>  
>  	/*
>  	 * We don't use the drm_irq_install() helpers provided by the DRM
> @@ -285,13 +306,16 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  	drm->irq_enabled = true;
>  	ret = drm_vblank_init(drm, MAX_CRTC);
>  	if (ret < 0)
> -		goto err_component_unbind;
> +		goto err_unset_dma_parms;
>  
>  	drm_kms_helper_poll_init(drm);
>  	drm_mode_config_reset(drm);
>  
>  	return 0;
>  
> +err_unset_dma_parms:
> +	if (private->dma_parms_allocated)
> +		dma_dev->dma_parms = NULL;
>  err_component_unbind:
>  	component_unbind_all(drm->dev, drm);
>  err_config_cleanup:
> @@ -302,9 +326,14 @@ static int mtk_drm_kms_init(struct drm_device *drm)
>  
>  static void mtk_drm_kms_deinit(struct drm_device *drm)
>  {
> +	struct mtk_drm_private *private = drm->dev_private;
> +
>  	drm_kms_helper_poll_fini(drm);
>  	drm_atomic_helper_shutdown(drm);
>  
> +	if (private->dma_parms_allocated)
> +		private->dma_dev->dma_parms = NULL;
> +
>  	component_unbind_all(drm->dev, drm);
>  	drm_mode_config_cleanup(drm);
>  }
> @@ -320,6 +349,18 @@ static const struct file_operations mtk_drm_fops = {
>  	.compat_ioctl = drm_compat_ioctl,
>  };
>  
> +/*
> + * We need to override this because the device used to import the memory is
> + * not dev->dev, as drm_gem_prime_import() expects.
> + */
> +struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
> +						struct dma_buf *dma_buf)
> +{
> +	struct mtk_drm_private *private = dev->dev_private;
> +
> +	return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
> +}
> +

I think this part should be an independent patch which fixup
119f5173628aa ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")

Regards,
CK

>  static struct drm_driver mtk_drm_driver = {
>  	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME |
>  			   DRIVER_ATOMIC,
> @@ -331,7 +372,7 @@ static struct drm_driver mtk_drm_driver = {
>  	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
>  	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
>  	.gem_prime_export = drm_gem_prime_export,
> -	.gem_prime_import = drm_gem_prime_import,
> +	.gem_prime_import = mtk_drm_gem_prime_import,
>  	.gem_prime_get_sg_table = mtk_gem_prime_get_sg_table,
>  	.gem_prime_import_sg_table = mtk_gem_prime_import_sg_table,
>  	.gem_prime_mmap = mtk_drm_gem_mmap_buf,
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.h b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> index 598ff3e70446..e03fea12ff59 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.h
> @@ -51,6 +51,8 @@ struct mtk_drm_private {
>  	} commit;
>  
>  	struct drm_atomic_state *suspend_state;
> +
> +	bool dma_parms_allocated;
>  };
>  
>  extern struct platform_driver mtk_ddp_driver;



_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [PATCH] drm/mediatek: make imported PRIME buffers contiguous

[Alexandre Courbot]

On Wed, Jul 24, 2019 at 2:49 PM CK Hu <ck.hu@mediatek.com> wrote:
>
> Hi, Alexandre:
>
> On Tue, 2019-07-23 at 14:34 +0900, Alexandre Courbot wrote:
> > This driver requires imported PRIME buffers to appear contiguously in
> > its IO address space. Make sure this is the case by setting the maximum
> > DMA segment size to a better value than the default 64K on the DMA
> > device, and use said DMA device when importing PRIME buffers.
> >
> > Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
> > ---
> >  drivers/gpu/drm/mediatek/mtk_drm_drv.c | 47 ++++++++++++++++++++++++--
> >  drivers/gpu/drm/mediatek/mtk_drm_drv.h |  2 ++
> >  2 files changed, 46 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/mediatek/mtk_drm_drv.c b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > index 95fdbd0fbcac..4ad4770fab13 100644
> > --- a/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > +++ b/drivers/gpu/drm/mediatek/mtk_drm_drv.c
> > @@ -213,6 +213,7 @@ static int mtk_drm_kms_init(struct drm_device *drm)
> >       struct mtk_drm_private *private = drm->dev_private;
> >       struct platform_device *pdev;
> >       struct device_node *np;
> > +     struct device *dma_dev;
> >       int ret;
> >
> >       if (!iommu_present(&platform_bus_type))
> > @@ -275,7 +276,27 @@ static int mtk_drm_kms_init(struct drm_device *drm)
> >               goto err_component_unbind;
> >       }
> >
> > -     private->dma_dev = &pdev->dev;
> > +     dma_dev = &pdev->dev;
> > +     private->dma_dev = dma_dev;
> > +
> > +     /*
> > +      * Configure the DMA segment size to make sure we get contiguous IOVA
> > +      * when importing PRIME buffers.
> > +      */
> > +     if (!dma_dev->dma_parms) {
> > +             private->dma_parms_allocated = true;
> > +             dma_dev->dma_parms =
> > +                     devm_kzalloc(drm->dev, sizeof(*dma_dev->dma_parms),
> > +                                  GFP_KERNEL);
> > +     }
> > +     if (!dma_dev->dma_parms)
> > +             goto err_component_unbind;
>
> return with ret = 0?

Oops, indeed.

>
> > +
> > +     ret = dma_set_max_seg_size(dma_dev, (unsigned int)DMA_BIT_MASK(32));
> > +     if (ret) {
> > +             dev_err(dma_dev, "Failed to set DMA segment size\n");
> > +             goto err_unset_dma_parms;
> > +     }
> >
> >       /*
> >        * We don't use the drm_irq_install() helpers provided by the DRM
> > @@ -285,13 +306,16 @@ static int mtk_drm_kms_init(struct drm_device *drm)
> >       drm->irq_enabled = true;
> >       ret = drm_vblank_init(drm, MAX_CRTC);
> >       if (ret < 0)
> > -             goto err_component_unbind;
> > +             goto err_unset_dma_parms;
> >
> >       drm_kms_helper_poll_init(drm);
> >       drm_mode_config_reset(drm);
> >
> >       return 0;
> >
> > +err_unset_dma_parms:
> > +     if (private->dma_parms_allocated)
> > +             dma_dev->dma_parms = NULL;
> >  err_component_unbind:
> >       component_unbind_all(drm->dev, drm);
> >  err_config_cleanup:
> > @@ -302,9 +326,14 @@ static int mtk_drm_kms_init(struct drm_device *drm)
> >
> >  static void mtk_drm_kms_deinit(struct drm_device *drm)
> >  {
> > +     struct mtk_drm_private *private = drm->dev_private;
> > +
> >       drm_kms_helper_poll_fini(drm);
> >       drm_atomic_helper_shutdown(drm);
> >
> > +     if (private->dma_parms_allocated)
> > +             private->dma_dev->dma_parms = NULL;
> > +
> >       component_unbind_all(drm->dev, drm);
> >       drm_mode_config_cleanup(drm);
> >  }
> > @@ -320,6 +349,18 @@ static const struct file_operations mtk_drm_fops = {
> >       .compat_ioctl = drm_compat_ioctl,
> >  };
> >
> > +/*
> > + * We need to override this because the device used to import the memory is
> > + * not dev->dev, as drm_gem_prime_import() expects.
> > + */
> > +struct drm_gem_object *mtk_drm_gem_prime_import(struct drm_device *dev,
> > +                                             struct dma_buf *dma_buf)
> > +{
> > +     struct mtk_drm_private *private = dev->dev_private;
> > +
> > +     return drm_gem_prime_import_dev(dev, dma_buf, private->dma_dev);
> > +}
> > +
>
> I think this part should be an independent patch which fixup
> 119f5173628aa ("drm/mediatek: Add DRM Driver for Mediatek SoC MT8173.")

I have split this patch and sent a v2.

Thanks,
Alex.

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel