[09/14] staging: media: tegra-vde: Add IOMMU support
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Message ID 20180813145027.16346-10-thierry.reding@gmail.com
State New
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Series
  • staging: media: tegra-vdea: Add Tegra124 support
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Commit Message

Thierry Reding Aug. 13, 2018, 2:50 p.m. UTC
From: Thierry Reding <treding@nvidia.com>

Implement support for using an IOMMU to map physically discontiguous
buffers into contiguous I/O virtual mappings that the VDE can use. This
allows importing arbitrary DMA-BUFs for use by the VDE.

While at it, make sure that the device is detached from any DMA/IOMMU
mapping that it might have automatically been attached to at boot. If
using the IOMMU API explicitly, detaching from any existing mapping is
required to avoid double mapping of buffers.

Signed-off-by: Thierry Reding <treding@nvidia.com>
---
 drivers/staging/media/tegra-vde/tegra-vde.c | 171 +++++++++++++++++---
 1 file changed, 153 insertions(+), 18 deletions(-)

Comments

Dmitry Osipenko Aug. 18, 2018, 12:50 p.m. UTC | #1
On Monday, 13 August 2018 17:50:22 MSK Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Implement support for using an IOMMU to map physically discontiguous
> buffers into contiguous I/O virtual mappings that the VDE can use. This
> allows importing arbitrary DMA-BUFs for use by the VDE.
> 
> While at it, make sure that the device is detached from any DMA/IOMMU
> mapping that it might have automatically been attached to at boot. If
> using the IOMMU API explicitly, detaching from any existing mapping is
> required to avoid double mapping of buffers.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/staging/media/tegra-vde/tegra-vde.c | 171 +++++++++++++++++---
>  1 file changed, 153 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c
> b/drivers/staging/media/tegra-vde/tegra-vde.c index
> 2496a03fd158..3bc0bfcfe34e 100644
> --- a/drivers/staging/media/tegra-vde/tegra-vde.c
> +++ b/drivers/staging/media/tegra-vde/tegra-vde.c
> @@ -13,7 +13,9 @@
>  #include <linux/dma-buf.h>
>  #include <linux/genalloc.h>
>  #include <linux/interrupt.h>
> +#include <linux/iommu.h>
>  #include <linux/iopoll.h>
> +#include <linux/iova.h>
>  #include <linux/miscdevice.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> @@ -22,6 +24,10 @@
>  #include <linux/slab.h>
>  #include <linux/uaccess.h>
> 
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +#include <asm/dma-iommu.h>
> +#endif
> +
>  #include <soc/tegra/pmc.h>
> 
>  #include <drm/drm_fourcc.h>
> @@ -61,6 +67,11 @@ struct video_frame {
>  	u32 frame_num;
>  	u32 flags;
>  	u64 modifier;
> +
> +	struct iova *y_iova;
> +	struct iova *cb_iova;
> +	struct iova *cr_iova;
> +	struct iova *aux_iova;
>  };
> 
>  struct tegra_vde_soc {
> @@ -93,6 +104,12 @@ struct tegra_vde {
>  	struct clk *clk_bsev;
>  	dma_addr_t iram_lists_addr;
>  	u32 *iram;
> +
> +	struct iommu_domain *domain;
> +	struct iommu_group *group;
> +	struct iova_domain iova;
> +	unsigned long limit;
> +	unsigned int shift;
>  };
> 
>  static void tegra_vde_set_bits(struct tegra_vde *vde,
> @@ -634,12 +651,22 @@ static void tegra_vde_decode_frame(struct tegra_vde
> *vde, VDE_WR(0x20000000 | (macroblocks_nb - 1), vde->sxe + 0x00);
>  }
> 
> -static void tegra_vde_detach_and_put_dmabuf(struct dma_buf_attachment *a,
> +static void tegra_vde_detach_and_put_dmabuf(struct tegra_vde *vde,
> +					    struct dma_buf_attachment *a,
>  					    struct sg_table *sgt,
> +					    struct iova *iova,
>  					    enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf *dmabuf = a->dmabuf;
> 
> +	if (vde->domain) {
> +		unsigned long size = iova_size(iova) << vde->shift;

Let's make it "size = iova_align(&vde->iova, dmabuf->size)" for better 
readability.

> +		dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
> +
> +		iommu_unmap(vde->domain, addr, size);
> +		__free_iova(&vde->iova, iova);
> +	}
> +
>  	dma_buf_unmap_attachment(a, sgt, dma_dir);
>  	dma_buf_detach(dmabuf, a);
>  	dma_buf_put(dmabuf);
> @@ -651,14 +678,16 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde
> *vde, size_t min_size,
>  				   size_t align_size,
>  				   struct dma_buf_attachment **a,
> -				   dma_addr_t *addr,
> +				   dma_addr_t *addrp,
>  				   struct sg_table **s,
> -				   size_t *size,
> +				   struct iova **iovap,
> +				   size_t *sizep,
>  				   enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf_attachment *attachment;
>  	struct dma_buf *dmabuf;
>  	struct sg_table *sgt;
> +	size_t size;
>  	int err;
> 
>  	dmabuf = dma_buf_get(fd);
> @@ -695,18 +724,47 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde
> *vde, goto err_detach;
>  	}
> 
> -	if (sgt->nents != 1) {
> +	if (sgt->nents > 1 && !vde->domain) {
>  		dev_err(vde->dev, "Sparse DMA region is unsupported\n");
>  		err = -EINVAL;
>  		goto err_unmap;
>  	}
> 
> -	*addr = sg_dma_address(sgt->sgl) + offset;
> +	if (vde->domain) {
> +		int prot = IOMMU_READ | IOMMU_WRITE;
> +		struct iova *iova;
> +		dma_addr_t addr;
> +
> +		size = (dmabuf->size - offset) >> vde->shift;

Offset shall not be subtracted and dmabuf size shall be rounded to IOVA 
granule. Also, let's not carry shift within the vde structure as it doesn't 
really worth it.


	shift = iova_shift(&vde->iova);
	size = iova_align(&vde->iova, dmabuf->size) >> shift;

> +
> +		iova = alloc_iova(&vde->iova, size, vde->limit - 1, true);
> +		if (!iova) {
> +			err = -ENOMEM;
> +			goto err_unmap;
> +		}
> +
> +		addr = iova_dma_addr(&vde->iova, iova);
> +
> +		size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
> +				    prot);
> +		if (!size) {
> +			__free_iova(&vde->iova, iova);
> +			err = -ENXIO;
> +			goto err_unmap;
> +		}
> +
> +		*addrp = addr;

Returned address shall point at the beginning of the buffer + offset.

	*addrp = addr + offset;

Returned size shall represent the leftover size after the offset subtraction, 
like for example it is used for the bitstream_data address counter limit.

	size = dmabuf->size - offset;

> +		*iovap = iova;
> +	} else {
> +		*addrp = sg_dma_address(sgt->sgl) + offset;
> +		size = dmabuf->size - offset;
> +	}
> +
>  	*a = attachment;
>  	*s = sgt;
> 
> -	if (size)
> -		*size = dmabuf->size - offset;
> +	if (sizep)
> +		*sizep = size;
> 
>  	return 0;
> 
> @@ -734,6 +792,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct
> tegra_vde *vde, &frame->y_dmabuf_attachment,
>  				      &frame->y_addr,
>  				      &frame->y_sgt,
> +				      &frame->y_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		return err;
> @@ -743,6 +802,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct
> tegra_vde *vde, &frame->cb_dmabuf_attachment,
>  				      &frame->cb_addr,
>  				      &frame->cb_sgt,
> +				      &frame->cb_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_y;
> @@ -752,6 +812,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct
> tegra_vde *vde, &frame->cr_dmabuf_attachment,
>  				      &frame->cr_addr,
>  				      &frame->cr_sgt,
> +				      &frame->cr_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cb;
> @@ -766,6 +827,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct
> tegra_vde *vde, &frame->aux_dmabuf_attachment,
>  				      &frame->aux_addr,
>  				      &frame->aux_sgt,
> +				      &frame->aux_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cr;
> @@ -774,13 +836,16 @@ static int tegra_vde_attach_dmabufs_to_frame(struct
> tegra_vde *vde,
> 
>  err_release_cr:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
>  err_release_cb:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
>  err_release_y:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
> 
>  	return err;
>  }
> @@ -793,16 +858,20 @@ static void tegra_vde_release_frame_dmabufs(struct
> tegra_vde *vde, if (!baseline_profile)
>  		tegra_vde_detach_and_put_dmabuf(vde,
>  						frame->aux_dmabuf_attachment,
> -						frame->aux_sgt, dma_dir);
> +						frame->aux_sgt,
> +						frame->aux_iova, dma_dir);
> 
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
> 
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
> 
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
>  }
> 
>  static int tegra_vde_validate_frame(struct device *dev,
> @@ -923,6 +992,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde
> *vde, struct sg_table *bitstream_sgt, *secure_sgt;
>  	enum dma_data_direction dma_dir;
>  	dma_addr_t bitstream_data_addr;
> +	struct iova *bitstream_iova;
> +	struct iova *secure_iova;
>  	dma_addr_t secure_addr;
>  	dma_addr_t bsev_ptr;
>  	size_t lsize, csize;
> @@ -948,6 +1019,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde
> *vde, &bitstream_data_dmabuf_attachment,
>  				      &bitstream_data_addr,
>  				      &bitstream_sgt,
> +				      &bitstream_iova,
>  				      &bitstream_data_size,
>  				      DMA_TO_DEVICE);
>  	if (ret)
> @@ -959,6 +1031,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde
> *vde, &secure_attachment,
>  					      &secure_addr,
>  					      &secure_sgt,
> +					      &secure_iova,
>  					      &secure_size,
>  					      DMA_TO_DEVICE);
>  		if (ret)
> @@ -1095,12 +1168,13 @@ static int tegra_vde_ioctl_decode_h264(struct
> tegra_vde *vde, release_bitstream_dmabuf:
>  	if (secure_attachment)
>  		tegra_vde_detach_and_put_dmabuf(vde, secure_attachment,
> -						secure_sgt,
> +						secure_sgt, secure_iova,
>  						DMA_TO_DEVICE);
> 
>  	tegra_vde_detach_and_put_dmabuf(vde,
>  					bitstream_data_dmabuf_attachment,
> -					bitstream_sgt, DMA_TO_DEVICE);
> +					bitstream_sgt, bitstream_iova,
> +					DMA_TO_DEVICE);
> 
>  	return ret;
>  }
> @@ -1193,6 +1267,15 @@ static int tegra_vde_probe(struct platform_device
> *pdev) struct tegra_vde *vde;
>  	int irq, err;
> 
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +	if (dev->archdata.mapping) {
> +		struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> +
> +		arm_iommu_detach_device(dev);
> +		arm_iommu_release_mapping(mapping);
> +	}
> +#endif
> +
>  	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
>  	if (!vde)
>  		return -ENOMEM;
> @@ -1335,6 +1418,37 @@ static int tegra_vde_probe(struct platform_device
> *pdev) return -ENOMEM;
>  	}
> 
> +	vde->group = iommu_group_get(dev);
> +	if (vde->group) {
> +		unsigned long order;
> +
> +		vde->domain = iommu_domain_alloc(&platform_bus_type);
> +		if (!vde->domain) {
> +			iommu_group_put(vde->group);
> +			vde->group = NULL;
> +		} else {
> +			err = iova_cache_get();
> +			if (err < 0)
> +				goto free_domain;
> +
> +			order = __ffs(vde->domain->pgsize_bitmap);
> +
> +			init_iova_domain(&vde->iova, 1UL << order, 0);

The minimum address of IOVA allocations shall be determined by the domains 
aperture start address.


> +			vde->shift = iova_shift(&vde->iova);
> +			vde->limit = 1 << (32 - vde->shift);

IOVA limit shall be determined by the domains aperture size. 

	struct iommu_domain_geometry *geometry;

	order = __ffs(vde->domain->pgsize_bitmap);
	geometry = &vde->domain->geometry;

	init_iova_domain(&vde->iova, 1UL << order,
				 geometry->aperture_start >> order);
	vde->iova_end = geometry->aperture_end;

Hence let's replace 'limit' with 'iova_end'.

> +
> +			/*
> +			 * VDE doesn't seem to like accessing the last page of
> +			 * its 32-bit address space.
> +			 */
> +			vde->limit -= 1;

That's probably because some VDE HW address counter is getting wrapped around 
and it can't cope with that due to a HW bug / optimization.

Since this only affects the end of AS, let's check if that adjustment is 
needed:

	if (vde->iova_end == 0xffffffff)
		vde->iova_end -= 1UL << order;

> +
> +			err = iommu_attach_group(vde->domain, vde->group);
> +			if (err < 0)

	goto put_iova;

> +				goto put_cache;
> +		}
> +	}
> +
>  	mutex_init(&vde->lock);
>  	init_completion(&vde->decode_completion);
> 
> @@ -1346,7 +1460,7 @@ static int tegra_vde_probe(struct platform_device
> *pdev) err = misc_register(&vde->miscdev);
>  	if (err) {
>  		dev_err(dev, "Failed to register misc device: %d\n", err);
> -		goto err_gen_free;
> +		goto detach;
>  	}
> 
>  	pm_runtime_enable(dev);
> @@ -1364,7 +1478,21 @@ static int tegra_vde_probe(struct platform_device
> *pdev) err_misc_unreg:
>  	misc_deregister(&vde->miscdev);
> 
> -err_gen_free:

put_iova:
	put_iova_domain(&vde->iova);

> +detach:
> +	if (vde->domain)
> +		iommu_detach_group(vde->domain, vde->group);
> +
> +put_cache:
> +	if (vde->domain)
> +		iova_cache_put();
> +
> +free_domain:
> +	if (vde->domain)
> +		iommu_domain_free(vde->domain);
> +
> +	if (vde->group)
> +		iommu_group_put(vde->group);
> +
>  	gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
>  		      gen_pool_size(vde->iram_pool));
> 
> @@ -1388,6 +1516,13 @@ static int tegra_vde_remove(struct platform_device
> *pdev)
> 
>  	misc_deregister(&vde->miscdev);
> 
> +	if (vde->domain) {
> +		iommu_detach_group(vde->domain, vde->group);

	put_iova_domain(&vde->iova);

> +		iova_cache_put();
> +		iommu_domain_free(vde->domain);
> +		iommu_group_put(vde->group);
> +	}
> +
>  	gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
>  		      gen_pool_size(vde->iram_pool));
Dmitry Osipenko Aug. 18, 2018, 1:07 p.m. UTC | #2
On 13.08.2018 17:50, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Implement support for using an IOMMU to map physically discontiguous
> buffers into contiguous I/O virtual mappings that the VDE can use. This
> allows importing arbitrary DMA-BUFs for use by the VDE.
> 
> While at it, make sure that the device is detached from any DMA/IOMMU
> mapping that it might have automatically been attached to at boot. If
> using the IOMMU API explicitly, detaching from any existing mapping is
> required to avoid double mapping of buffers.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/staging/media/tegra-vde/tegra-vde.c | 171 +++++++++++++++++---
>  1 file changed, 153 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/tegra-vde.c
> index 2496a03fd158..3bc0bfcfe34e 100644
> --- a/drivers/staging/media/tegra-vde/tegra-vde.c
> +++ b/drivers/staging/media/tegra-vde/tegra-vde.c
> @@ -13,7 +13,9 @@
>  #include <linux/dma-buf.h>
>  #include <linux/genalloc.h>
>  #include <linux/interrupt.h>
> +#include <linux/iommu.h>
>  #include <linux/iopoll.h>
> +#include <linux/iova.h>
>  #include <linux/miscdevice.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> @@ -22,6 +24,10 @@
>  #include <linux/slab.h>
>  #include <linux/uaccess.h>
>  
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +#include <asm/dma-iommu.h>
> +#endif
> +
>  #include <soc/tegra/pmc.h>
>  
>  #include <drm/drm_fourcc.h>
> @@ -61,6 +67,11 @@ struct video_frame {
>  	u32 frame_num;
>  	u32 flags;
>  	u64 modifier;
> +
> +	struct iova *y_iova;
> +	struct iova *cb_iova;
> +	struct iova *cr_iova;
> +	struct iova *aux_iova;
>  };
>  
>  struct tegra_vde_soc {
> @@ -93,6 +104,12 @@ struct tegra_vde {
>  	struct clk *clk_bsev;
>  	dma_addr_t iram_lists_addr;
>  	u32 *iram;
> +
> +	struct iommu_domain *domain;
> +	struct iommu_group *group;
> +	struct iova_domain iova;
> +	unsigned long limit;
> +	unsigned int shift;
>  };
>  
>  static void tegra_vde_set_bits(struct tegra_vde *vde,
> @@ -634,12 +651,22 @@ static void tegra_vde_decode_frame(struct tegra_vde *vde,
>  	VDE_WR(0x20000000 | (macroblocks_nb - 1), vde->sxe + 0x00);
>  }
>  
> -static void tegra_vde_detach_and_put_dmabuf(struct dma_buf_attachment *a,
> +static void tegra_vde_detach_and_put_dmabuf(struct tegra_vde *vde,
> +					    struct dma_buf_attachment *a,
>  					    struct sg_table *sgt,
> +					    struct iova *iova,
>  					    enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf *dmabuf = a->dmabuf;
>  
> +	if (vde->domain) {
> +		unsigned long size = iova_size(iova) << vde->shift;
> +		dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
> +
> +		iommu_unmap(vde->domain, addr, size);
> +		__free_iova(&vde->iova, iova);
> +	}
> +
>  	dma_buf_unmap_attachment(a, sgt, dma_dir);
>  	dma_buf_detach(dmabuf, a);
>  	dma_buf_put(dmabuf);
> @@ -651,14 +678,16 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
>  				   size_t min_size,
>  				   size_t align_size,
>  				   struct dma_buf_attachment **a,
> -				   dma_addr_t *addr,
> +				   dma_addr_t *addrp,
>  				   struct sg_table **s,
> -				   size_t *size,
> +				   struct iova **iovap,
> +				   size_t *sizep,
>  				   enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf_attachment *attachment;
>  	struct dma_buf *dmabuf;
>  	struct sg_table *sgt;
> +	size_t size;
>  	int err;
>  
>  	dmabuf = dma_buf_get(fd);
> @@ -695,18 +724,47 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
>  		goto err_detach;
>  	}
>  
> -	if (sgt->nents != 1) {
> +	if (sgt->nents > 1 && !vde->domain) {
>  		dev_err(vde->dev, "Sparse DMA region is unsupported\n");
>  		err = -EINVAL;
>  		goto err_unmap;
>  	}
>  
> -	*addr = sg_dma_address(sgt->sgl) + offset;
> +	if (vde->domain) {
> +		int prot = IOMMU_READ | IOMMU_WRITE;
> +		struct iova *iova;
> +		dma_addr_t addr;
> +
> +		size = (dmabuf->size - offset) >> vde->shift;
> +
> +		iova = alloc_iova(&vde->iova, size, vde->limit - 1, true);
> +		if (!iova) {
> +			err = -ENOMEM;
> +			goto err_unmap;
> +		}
> +
> +		addr = iova_dma_addr(&vde->iova, iova);
> +
> +		size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
> +				    prot);
> +		if (!size) {
> +			__free_iova(&vde->iova, iova);
> +			err = -ENXIO;
> +			goto err_unmap;
> +		}
> +
> +		*addrp = addr;
> +		*iovap = iova;
> +	} else {
> +		*addrp = sg_dma_address(sgt->sgl) + offset;
> +		size = dmabuf->size - offset;
> +	}
> +
>  	*a = attachment;
>  	*s = sgt;
>  
> -	if (size)
> -		*size = dmabuf->size - offset;
> +	if (sizep)
> +		*sizep = size;
>  
>  	return 0;
>  
> @@ -734,6 +792,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->y_dmabuf_attachment,
>  				      &frame->y_addr,
>  				      &frame->y_sgt,
> +				      &frame->y_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		return err;
> @@ -743,6 +802,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->cb_dmabuf_attachment,
>  				      &frame->cb_addr,
>  				      &frame->cb_sgt,
> +				      &frame->cb_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_y;
> @@ -752,6 +812,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->cr_dmabuf_attachment,
>  				      &frame->cr_addr,
>  				      &frame->cr_sgt,
> +				      &frame->cr_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cb;
> @@ -766,6 +827,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->aux_dmabuf_attachment,
>  				      &frame->aux_addr,
>  				      &frame->aux_sgt,
> +				      &frame->aux_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cr;
> @@ -774,13 +836,16 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  
>  err_release_cr:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
>  err_release_cb:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
>  err_release_y:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
>  
>  	return err;
>  }
> @@ -793,16 +858,20 @@ static void tegra_vde_release_frame_dmabufs(struct tegra_vde *vde,
>  	if (!baseline_profile)
>  		tegra_vde_detach_and_put_dmabuf(vde,
>  						frame->aux_dmabuf_attachment,
> -						frame->aux_sgt, dma_dir);
> +						frame->aux_sgt,
> +						frame->aux_iova, dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
>  }
>  
>  static int tegra_vde_validate_frame(struct device *dev,
> @@ -923,6 +992,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  	struct sg_table *bitstream_sgt, *secure_sgt;
>  	enum dma_data_direction dma_dir;
>  	dma_addr_t bitstream_data_addr;
> +	struct iova *bitstream_iova;
> +	struct iova *secure_iova;
>  	dma_addr_t secure_addr;
>  	dma_addr_t bsev_ptr;
>  	size_t lsize, csize;
> @@ -948,6 +1019,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  				      &bitstream_data_dmabuf_attachment,
>  				      &bitstream_data_addr,
>  				      &bitstream_sgt,
> +				      &bitstream_iova,
>  				      &bitstream_data_size,
>  				      DMA_TO_DEVICE);
>  	if (ret)
> @@ -959,6 +1031,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  					      &secure_attachment,
>  					      &secure_addr,
>  					      &secure_sgt,
> +					      &secure_iova,
>  					      &secure_size,
>  					      DMA_TO_DEVICE);
>  		if (ret)
> @@ -1095,12 +1168,13 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  release_bitstream_dmabuf:
>  	if (secure_attachment)
>  		tegra_vde_detach_and_put_dmabuf(vde, secure_attachment,
> -						secure_sgt,
> +						secure_sgt, secure_iova,
>  						DMA_TO_DEVICE);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde,
>  					bitstream_data_dmabuf_attachment,
> -					bitstream_sgt, DMA_TO_DEVICE);
> +					bitstream_sgt, bitstream_iova,
> +					DMA_TO_DEVICE);
>  
>  	return ret;
>  }
> @@ -1193,6 +1267,15 @@ static int tegra_vde_probe(struct platform_device *pdev)
>  	struct tegra_vde *vde;
>  	int irq, err;
>  
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +	if (dev->archdata.mapping) {
> +		struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> +
> +		arm_iommu_detach_device(dev);
> +		arm_iommu_release_mapping(mapping);
> +	}
> +#endif
> +
>  	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
>  	if (!vde)
>  		return -ENOMEM;
> @@ -1335,6 +1418,37 @@ static int tegra_vde_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	}
>  
> +	vde->group = iommu_group_get(dev);
> +	if (vde->group) {
> +		unsigned long order;
> +
> +		vde->domain = iommu_domain_alloc(&platform_bus_type);
> +		if (!vde->domain) {
> +			iommu_group_put(vde->group);
> +			vde->group = NULL;
> +		} else {
> +			err = iova_cache_get();
> +			if (err < 0)
> +				goto free_domain;
> +
> +			order = __ffs(vde->domain->pgsize_bitmap);
> +
> +			init_iova_domain(&vde->iova, 1UL << order, 0);
> +			vde->shift = iova_shift(&vde->iova);
> +			vde->limit = 1 << (32 - vde->shift);
> +
> +			/*
> +			 * VDE doesn't seem to like accessing the last page of
> +			 * its 32-bit address space.
> +			 */
> +			vde->limit -= 1;
> +
> +			err = iommu_attach_group(vde->domain, vde->group);
> +			if (err < 0)
> +				goto put_cache;
> +		}
> +	}
> +

Let's factor out IOMMU setup into tegra_vde_init/realease_iommu().
Dmitry Osipenko Aug. 18, 2018, 1:29 p.m. UTC | #3
On 13.08.2018 17:50, Thierry Reding wrote:
> From: Thierry Reding <treding@nvidia.com>
> 
> Implement support for using an IOMMU to map physically discontiguous
> buffers into contiguous I/O virtual mappings that the VDE can use. This
> allows importing arbitrary DMA-BUFs for use by the VDE.
> 
> While at it, make sure that the device is detached from any DMA/IOMMU
> mapping that it might have automatically been attached to at boot. If
> using the IOMMU API explicitly, detaching from any existing mapping is
> required to avoid double mapping of buffers.
> 
> Signed-off-by: Thierry Reding <treding@nvidia.com>
> ---
>  drivers/staging/media/tegra-vde/tegra-vde.c | 171 +++++++++++++++++---
>  1 file changed, 153 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/tegra-vde.c
> index 2496a03fd158..3bc0bfcfe34e 100644
> --- a/drivers/staging/media/tegra-vde/tegra-vde.c
> +++ b/drivers/staging/media/tegra-vde/tegra-vde.c
> @@ -13,7 +13,9 @@
>  #include <linux/dma-buf.h>
>  #include <linux/genalloc.h>
>  #include <linux/interrupt.h>
> +#include <linux/iommu.h>
>  #include <linux/iopoll.h>
> +#include <linux/iova.h>
>  #include <linux/miscdevice.h>
>  #include <linux/module.h>
>  #include <linux/of_device.h>
> @@ -22,6 +24,10 @@
>  #include <linux/slab.h>
>  #include <linux/uaccess.h>
>  
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +#include <asm/dma-iommu.h>
> +#endif
> +
>  #include <soc/tegra/pmc.h>
>  
>  #include <drm/drm_fourcc.h>
> @@ -61,6 +67,11 @@ struct video_frame {
>  	u32 frame_num;
>  	u32 flags;
>  	u64 modifier;
> +
> +	struct iova *y_iova;
> +	struct iova *cb_iova;
> +	struct iova *cr_iova;
> +	struct iova *aux_iova;
>  };
>  
>  struct tegra_vde_soc {
> @@ -93,6 +104,12 @@ struct tegra_vde {
>  	struct clk *clk_bsev;
>  	dma_addr_t iram_lists_addr;
>  	u32 *iram;
> +
> +	struct iommu_domain *domain;
> +	struct iommu_group *group;
> +	struct iova_domain iova;
> +	unsigned long limit;
> +	unsigned int shift;
>  };
>  
>  static void tegra_vde_set_bits(struct tegra_vde *vde,
> @@ -634,12 +651,22 @@ static void tegra_vde_decode_frame(struct tegra_vde *vde,
>  	VDE_WR(0x20000000 | (macroblocks_nb - 1), vde->sxe + 0x00);
>  }
>  
> -static void tegra_vde_detach_and_put_dmabuf(struct dma_buf_attachment *a,
> +static void tegra_vde_detach_and_put_dmabuf(struct tegra_vde *vde,
> +					    struct dma_buf_attachment *a,
>  					    struct sg_table *sgt,
> +					    struct iova *iova,
>  					    enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf *dmabuf = a->dmabuf;
>  
> +	if (vde->domain) {
> +		unsigned long size = iova_size(iova) << vde->shift;
> +		dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
> +
> +		iommu_unmap(vde->domain, addr, size);
> +		__free_iova(&vde->iova, iova);
> +	}
> +
>  	dma_buf_unmap_attachment(a, sgt, dma_dir);
>  	dma_buf_detach(dmabuf, a);
>  	dma_buf_put(dmabuf);
> @@ -651,14 +678,16 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
>  				   size_t min_size,
>  				   size_t align_size,
>  				   struct dma_buf_attachment **a,
> -				   dma_addr_t *addr,
> +				   dma_addr_t *addrp,
>  				   struct sg_table **s,
> -				   size_t *size,
> +				   struct iova **iovap,
> +				   size_t *sizep,
>  				   enum dma_data_direction dma_dir)
>  {
>  	struct dma_buf_attachment *attachment;
>  	struct dma_buf *dmabuf;
>  	struct sg_table *sgt;
> +	size_t size;
>  	int err;
>  
>  	dmabuf = dma_buf_get(fd);
> @@ -695,18 +724,47 @@ static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
>  		goto err_detach;
>  	}
>  
> -	if (sgt->nents != 1) {
> +	if (sgt->nents > 1 && !vde->domain) {
>  		dev_err(vde->dev, "Sparse DMA region is unsupported\n");
>  		err = -EINVAL;
>  		goto err_unmap;
>  	}
>  
> -	*addr = sg_dma_address(sgt->sgl) + offset;
> +	if (vde->domain) {
> +		int prot = IOMMU_READ | IOMMU_WRITE;
> +		struct iova *iova;
> +		dma_addr_t addr;
> +
> +		size = (dmabuf->size - offset) >> vde->shift;
> +
> +		iova = alloc_iova(&vde->iova, size, vde->limit - 1, true);
> +		if (!iova) {
> +			err = -ENOMEM;
> +			goto err_unmap;
> +		}
> +
> +		addr = iova_dma_addr(&vde->iova, iova);
> +
> +		size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
> +				    prot);
> +		if (!size) {
> +			__free_iova(&vde->iova, iova);
> +			err = -ENXIO;
> +			goto err_unmap;
> +		}
> +
> +		*addrp = addr;
> +		*iovap = iova;
> +	} else {
> +		*addrp = sg_dma_address(sgt->sgl) + offset;
> +		size = dmabuf->size - offset;
> +	}
> +
>  	*a = attachment;
>  	*s = sgt;
>  
> -	if (size)
> -		*size = dmabuf->size - offset;
> +	if (sizep)
> +		*sizep = size;
>  
>  	return 0;
>  
> @@ -734,6 +792,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->y_dmabuf_attachment,
>  				      &frame->y_addr,
>  				      &frame->y_sgt,
> +				      &frame->y_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		return err;
> @@ -743,6 +802,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->cb_dmabuf_attachment,
>  				      &frame->cb_addr,
>  				      &frame->cb_sgt,
> +				      &frame->cb_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_y;
> @@ -752,6 +812,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->cr_dmabuf_attachment,
>  				      &frame->cr_addr,
>  				      &frame->cr_sgt,
> +				      &frame->cr_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cb;
> @@ -766,6 +827,7 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  				      &frame->aux_dmabuf_attachment,
>  				      &frame->aux_addr,
>  				      &frame->aux_sgt,
> +				      &frame->aux_iova,
>  				      NULL, dma_dir);
>  	if (err)
>  		goto err_release_cr;
> @@ -774,13 +836,16 @@ static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
>  
>  err_release_cr:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
>  err_release_cb:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
>  err_release_y:
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
>  
>  	return err;
>  }
> @@ -793,16 +858,20 @@ static void tegra_vde_release_frame_dmabufs(struct tegra_vde *vde,
>  	if (!baseline_profile)
>  		tegra_vde_detach_and_put_dmabuf(vde,
>  						frame->aux_dmabuf_attachment,
> -						frame->aux_sgt, dma_dir);
> +						frame->aux_sgt,
> +						frame->aux_iova, dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
> -					frame->cr_sgt, dma_dir);
> +					frame->cr_sgt, frame->cr_iova,
> +					dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
> -					frame->cb_sgt, dma_dir);
> +					frame->cb_sgt, frame->cb_iova,
> +					dma_dir);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
> -					frame->y_sgt, dma_dir);
> +					frame->y_sgt, frame->y_iova,
> +					dma_dir);
>  }
>  
>  static int tegra_vde_validate_frame(struct device *dev,
> @@ -923,6 +992,8 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  	struct sg_table *bitstream_sgt, *secure_sgt;
>  	enum dma_data_direction dma_dir;
>  	dma_addr_t bitstream_data_addr;
> +	struct iova *bitstream_iova;
> +	struct iova *secure_iova;
>  	dma_addr_t secure_addr;
>  	dma_addr_t bsev_ptr;
>  	size_t lsize, csize;
> @@ -948,6 +1019,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  				      &bitstream_data_dmabuf_attachment,
>  				      &bitstream_data_addr,
>  				      &bitstream_sgt,
> +				      &bitstream_iova,
>  				      &bitstream_data_size,
>  				      DMA_TO_DEVICE);
>  	if (ret)
> @@ -959,6 +1031,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  					      &secure_attachment,
>  					      &secure_addr,
>  					      &secure_sgt,
> +					      &secure_iova,
>  					      &secure_size,
>  					      DMA_TO_DEVICE);
>  		if (ret)
> @@ -1095,12 +1168,13 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>  release_bitstream_dmabuf:
>  	if (secure_attachment)
>  		tegra_vde_detach_and_put_dmabuf(vde, secure_attachment,
> -						secure_sgt,
> +						secure_sgt, secure_iova,
>  						DMA_TO_DEVICE);
>  
>  	tegra_vde_detach_and_put_dmabuf(vde,
>  					bitstream_data_dmabuf_attachment,
> -					bitstream_sgt, DMA_TO_DEVICE);
> +					bitstream_sgt, bitstream_iova,
> +					DMA_TO_DEVICE);
>  
>  	return ret;
>  }
> @@ -1193,6 +1267,15 @@ static int tegra_vde_probe(struct platform_device *pdev)
>  	struct tegra_vde *vde;
>  	int irq, err;
>  
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +	if (dev->archdata.mapping) {
> +		struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> +
> +		arm_iommu_detach_device(dev);
> +		arm_iommu_release_mapping(mapping);
> +	}
> +#endif
> +
>  	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
>  	if (!vde)
>  		return -ENOMEM;
> @@ -1335,6 +1418,37 @@ static int tegra_vde_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  	}
>  
> +	vde->group = iommu_group_get(dev);
> +	if (vde->group) {
> +		unsigned long order;
> +
> +		vde->domain = iommu_domain_alloc(&platform_bus_type);
> +		if (!vde->domain) {
> +			iommu_group_put(vde->group);
> +			vde->group = NULL;
> +		} else {
> +			err = iova_cache_get();
> +			if (err < 0)

iova_cache_get() returns only 0 on success, let's check for the 0 like in the
rest of the code for consistency,

> +				goto free_domain;
> +
> +			order = __ffs(vde->domain->pgsize_bitmap);
> +
> +			init_iova_domain(&vde->iova, 1UL << order, 0);
> +			vde->shift = iova_shift(&vde->iova);
> +			vde->limit = 1 << (32 - vde->shift);
> +
> +			/*
> +			 * VDE doesn't seem to like accessing the last page of
> +			 * its 32-bit address space.
> +			 */
> +			vde->limit -= 1;
> +
> +			err = iommu_attach_group(vde->domain, vde->group);
> +			if (err < 0)

Same as above.

> +				goto put_cache;
> +		}
> +	}

Patch
diff mbox series

diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/tegra-vde.c
index 2496a03fd158..3bc0bfcfe34e 100644
--- a/drivers/staging/media/tegra-vde/tegra-vde.c
+++ b/drivers/staging/media/tegra-vde/tegra-vde.c
@@ -13,7 +13,9 @@ 
 #include <linux/dma-buf.h>
 #include <linux/genalloc.h>
 #include <linux/interrupt.h>
+#include <linux/iommu.h>
 #include <linux/iopoll.h>
+#include <linux/iova.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
@@ -22,6 +24,10 @@ 
 #include <linux/slab.h>
 #include <linux/uaccess.h>
 
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+#include <asm/dma-iommu.h>
+#endif
+
 #include <soc/tegra/pmc.h>
 
 #include <drm/drm_fourcc.h>
@@ -61,6 +67,11 @@  struct video_frame {
 	u32 frame_num;
 	u32 flags;
 	u64 modifier;
+
+	struct iova *y_iova;
+	struct iova *cb_iova;
+	struct iova *cr_iova;
+	struct iova *aux_iova;
 };
 
 struct tegra_vde_soc {
@@ -93,6 +104,12 @@  struct tegra_vde {
 	struct clk *clk_bsev;
 	dma_addr_t iram_lists_addr;
 	u32 *iram;
+
+	struct iommu_domain *domain;
+	struct iommu_group *group;
+	struct iova_domain iova;
+	unsigned long limit;
+	unsigned int shift;
 };
 
 static void tegra_vde_set_bits(struct tegra_vde *vde,
@@ -634,12 +651,22 @@  static void tegra_vde_decode_frame(struct tegra_vde *vde,
 	VDE_WR(0x20000000 | (macroblocks_nb - 1), vde->sxe + 0x00);
 }
 
-static void tegra_vde_detach_and_put_dmabuf(struct dma_buf_attachment *a,
+static void tegra_vde_detach_and_put_dmabuf(struct tegra_vde *vde,
+					    struct dma_buf_attachment *a,
 					    struct sg_table *sgt,
+					    struct iova *iova,
 					    enum dma_data_direction dma_dir)
 {
 	struct dma_buf *dmabuf = a->dmabuf;
 
+	if (vde->domain) {
+		unsigned long size = iova_size(iova) << vde->shift;
+		dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
+
+		iommu_unmap(vde->domain, addr, size);
+		__free_iova(&vde->iova, iova);
+	}
+
 	dma_buf_unmap_attachment(a, sgt, dma_dir);
 	dma_buf_detach(dmabuf, a);
 	dma_buf_put(dmabuf);
@@ -651,14 +678,16 @@  static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
 				   size_t min_size,
 				   size_t align_size,
 				   struct dma_buf_attachment **a,
-				   dma_addr_t *addr,
+				   dma_addr_t *addrp,
 				   struct sg_table **s,
-				   size_t *size,
+				   struct iova **iovap,
+				   size_t *sizep,
 				   enum dma_data_direction dma_dir)
 {
 	struct dma_buf_attachment *attachment;
 	struct dma_buf *dmabuf;
 	struct sg_table *sgt;
+	size_t size;
 	int err;
 
 	dmabuf = dma_buf_get(fd);
@@ -695,18 +724,47 @@  static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
 		goto err_detach;
 	}
 
-	if (sgt->nents != 1) {
+	if (sgt->nents > 1 && !vde->domain) {
 		dev_err(vde->dev, "Sparse DMA region is unsupported\n");
 		err = -EINVAL;
 		goto err_unmap;
 	}
 
-	*addr = sg_dma_address(sgt->sgl) + offset;
+	if (vde->domain) {
+		int prot = IOMMU_READ | IOMMU_WRITE;
+		struct iova *iova;
+		dma_addr_t addr;
+
+		size = (dmabuf->size - offset) >> vde->shift;
+
+		iova = alloc_iova(&vde->iova, size, vde->limit - 1, true);
+		if (!iova) {
+			err = -ENOMEM;
+			goto err_unmap;
+		}
+
+		addr = iova_dma_addr(&vde->iova, iova);
+
+		size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
+				    prot);
+		if (!size) {
+			__free_iova(&vde->iova, iova);
+			err = -ENXIO;
+			goto err_unmap;
+		}
+
+		*addrp = addr;
+		*iovap = iova;
+	} else {
+		*addrp = sg_dma_address(sgt->sgl) + offset;
+		size = dmabuf->size - offset;
+	}
+
 	*a = attachment;
 	*s = sgt;
 
-	if (size)
-		*size = dmabuf->size - offset;
+	if (sizep)
+		*sizep = size;
 
 	return 0;
 
@@ -734,6 +792,7 @@  static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
 				      &frame->y_dmabuf_attachment,
 				      &frame->y_addr,
 				      &frame->y_sgt,
+				      &frame->y_iova,
 				      NULL, dma_dir);
 	if (err)
 		return err;
@@ -743,6 +802,7 @@  static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
 				      &frame->cb_dmabuf_attachment,
 				      &frame->cb_addr,
 				      &frame->cb_sgt,
+				      &frame->cb_iova,
 				      NULL, dma_dir);
 	if (err)
 		goto err_release_y;
@@ -752,6 +812,7 @@  static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
 				      &frame->cr_dmabuf_attachment,
 				      &frame->cr_addr,
 				      &frame->cr_sgt,
+				      &frame->cr_iova,
 				      NULL, dma_dir);
 	if (err)
 		goto err_release_cb;
@@ -766,6 +827,7 @@  static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
 				      &frame->aux_dmabuf_attachment,
 				      &frame->aux_addr,
 				      &frame->aux_sgt,
+				      &frame->aux_iova,
 				      NULL, dma_dir);
 	if (err)
 		goto err_release_cr;
@@ -774,13 +836,16 @@  static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
 
 err_release_cr:
 	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
-					frame->cr_sgt, dma_dir);
+					frame->cr_sgt, frame->cr_iova,
+					dma_dir);
 err_release_cb:
 	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
-					frame->cb_sgt, dma_dir);
+					frame->cb_sgt, frame->cb_iova,
+					dma_dir);
 err_release_y:
 	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
-					frame->y_sgt, dma_dir);
+					frame->y_sgt, frame->y_iova,
+					dma_dir);
 
 	return err;
 }
@@ -793,16 +858,20 @@  static void tegra_vde_release_frame_dmabufs(struct tegra_vde *vde,
 	if (!baseline_profile)
 		tegra_vde_detach_and_put_dmabuf(vde,
 						frame->aux_dmabuf_attachment,
-						frame->aux_sgt, dma_dir);
+						frame->aux_sgt,
+						frame->aux_iova, dma_dir);
 
 	tegra_vde_detach_and_put_dmabuf(vde, frame->cr_dmabuf_attachment,
-					frame->cr_sgt, dma_dir);
+					frame->cr_sgt, frame->cr_iova,
+					dma_dir);
 
 	tegra_vde_detach_and_put_dmabuf(vde, frame->cb_dmabuf_attachment,
-					frame->cb_sgt, dma_dir);
+					frame->cb_sgt, frame->cb_iova,
+					dma_dir);
 
 	tegra_vde_detach_and_put_dmabuf(vde, frame->y_dmabuf_attachment,
-					frame->y_sgt, dma_dir);
+					frame->y_sgt, frame->y_iova,
+					dma_dir);
 }
 
 static int tegra_vde_validate_frame(struct device *dev,
@@ -923,6 +992,8 @@  static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 	struct sg_table *bitstream_sgt, *secure_sgt;
 	enum dma_data_direction dma_dir;
 	dma_addr_t bitstream_data_addr;
+	struct iova *bitstream_iova;
+	struct iova *secure_iova;
 	dma_addr_t secure_addr;
 	dma_addr_t bsev_ptr;
 	size_t lsize, csize;
@@ -948,6 +1019,7 @@  static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 				      &bitstream_data_dmabuf_attachment,
 				      &bitstream_data_addr,
 				      &bitstream_sgt,
+				      &bitstream_iova,
 				      &bitstream_data_size,
 				      DMA_TO_DEVICE);
 	if (ret)
@@ -959,6 +1031,7 @@  static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 					      &secure_attachment,
 					      &secure_addr,
 					      &secure_sgt,
+					      &secure_iova,
 					      &secure_size,
 					      DMA_TO_DEVICE);
 		if (ret)
@@ -1095,12 +1168,13 @@  static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
 release_bitstream_dmabuf:
 	if (secure_attachment)
 		tegra_vde_detach_and_put_dmabuf(vde, secure_attachment,
-						secure_sgt,
+						secure_sgt, secure_iova,
 						DMA_TO_DEVICE);
 
 	tegra_vde_detach_and_put_dmabuf(vde,
 					bitstream_data_dmabuf_attachment,
-					bitstream_sgt, DMA_TO_DEVICE);
+					bitstream_sgt, bitstream_iova,
+					DMA_TO_DEVICE);
 
 	return ret;
 }
@@ -1193,6 +1267,15 @@  static int tegra_vde_probe(struct platform_device *pdev)
 	struct tegra_vde *vde;
 	int irq, err;
 
+#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
+	if (dev->archdata.mapping) {
+		struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
+
+		arm_iommu_detach_device(dev);
+		arm_iommu_release_mapping(mapping);
+	}
+#endif
+
 	vde = devm_kzalloc(dev, sizeof(*vde), GFP_KERNEL);
 	if (!vde)
 		return -ENOMEM;
@@ -1335,6 +1418,37 @@  static int tegra_vde_probe(struct platform_device *pdev)
 		return -ENOMEM;
 	}
 
+	vde->group = iommu_group_get(dev);
+	if (vde->group) {
+		unsigned long order;
+
+		vde->domain = iommu_domain_alloc(&platform_bus_type);
+		if (!vde->domain) {
+			iommu_group_put(vde->group);
+			vde->group = NULL;
+		} else {
+			err = iova_cache_get();
+			if (err < 0)
+				goto free_domain;
+
+			order = __ffs(vde->domain->pgsize_bitmap);
+
+			init_iova_domain(&vde->iova, 1UL << order, 0);
+			vde->shift = iova_shift(&vde->iova);
+			vde->limit = 1 << (32 - vde->shift);
+
+			/*
+			 * VDE doesn't seem to like accessing the last page of
+			 * its 32-bit address space.
+			 */
+			vde->limit -= 1;
+
+			err = iommu_attach_group(vde->domain, vde->group);
+			if (err < 0)
+				goto put_cache;
+		}
+	}
+
 	mutex_init(&vde->lock);
 	init_completion(&vde->decode_completion);
 
@@ -1346,7 +1460,7 @@  static int tegra_vde_probe(struct platform_device *pdev)
 	err = misc_register(&vde->miscdev);
 	if (err) {
 		dev_err(dev, "Failed to register misc device: %d\n", err);
-		goto err_gen_free;
+		goto detach;
 	}
 
 	pm_runtime_enable(dev);
@@ -1364,7 +1478,21 @@  static int tegra_vde_probe(struct platform_device *pdev)
 err_misc_unreg:
 	misc_deregister(&vde->miscdev);
 
-err_gen_free:
+detach:
+	if (vde->domain)
+		iommu_detach_group(vde->domain, vde->group);
+
+put_cache:
+	if (vde->domain)
+		iova_cache_put();
+
+free_domain:
+	if (vde->domain)
+		iommu_domain_free(vde->domain);
+
+	if (vde->group)
+		iommu_group_put(vde->group);
+
 	gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
 		      gen_pool_size(vde->iram_pool));
 
@@ -1388,6 +1516,13 @@  static int tegra_vde_remove(struct platform_device *pdev)
 
 	misc_deregister(&vde->miscdev);
 
+	if (vde->domain) {
+		iommu_detach_group(vde->domain, vde->group);
+		iova_cache_put();
+		iommu_domain_free(vde->domain);
+		iommu_group_put(vde->group);
+	}
+
 	gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
 		      gen_pool_size(vde->iram_pool));