Re: [PATCH v1 3/4] staging: media: tegra-vde: Add IOMMU support
From: Hans Verkuil
Date: Mon Jun 17 2019 - 09:36:02 EST
On 6/2/19 11:37 PM, Dmitry Osipenko wrote:
> All Tegra's could provide memory isolation for the video decoder
> hardware using IOMMU, it is also required for Tegra30+ in order
> to handle sparse dmabuf's which GPU exports in a default kernel
> configuration.
>
> Inspired-by: Thierry Reding <thierry.reding@xxxxxxxxx>
> Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
> ---
> drivers/staging/media/tegra-vde/Kconfig | 1 +
> drivers/staging/media/tegra-vde/Makefile | 1 +
> drivers/staging/media/tegra-vde/iommu.c | 148 ++++++++++++++
> drivers/staging/media/tegra-vde/trace.h | 1 +
> .../media/tegra-vde/{tegra-vde.c => vde.c} | 188 +++++++++---------
> drivers/staging/media/tegra-vde/vde.h | 89 +++++++++
> 6 files changed, 335 insertions(+), 93 deletions(-)
> create mode 100644 drivers/staging/media/tegra-vde/iommu.c
> rename drivers/staging/media/tegra-vde/{tegra-vde.c => vde.c} (91%)
> create mode 100644 drivers/staging/media/tegra-vde/vde.h
>
> diff --git a/drivers/staging/media/tegra-vde/Kconfig b/drivers/staging/media/tegra-vde/Kconfig
> index ff8e846cd15d..2e7f644ae591 100644
> --- a/drivers/staging/media/tegra-vde/Kconfig
> +++ b/drivers/staging/media/tegra-vde/Kconfig
> @@ -3,6 +3,7 @@ config TEGRA_VDE
> tristate "NVIDIA Tegra Video Decoder Engine driver"
> depends on ARCH_TEGRA || COMPILE_TEST
> select DMA_SHARED_BUFFER
> + select IOMMU_IOVA if IOMMU_SUPPORT
> select SRAM
> help
> Say Y here to enable support for the NVIDIA Tegra video decoder
> diff --git a/drivers/staging/media/tegra-vde/Makefile b/drivers/staging/media/tegra-vde/Makefile
> index 7f9020e634f3..c11867e28233 100644
> --- a/drivers/staging/media/tegra-vde/Makefile
> +++ b/drivers/staging/media/tegra-vde/Makefile
> @@ -1,2 +1,3 @@
> # SPDX-License-Identifier: GPL-2.0
> +tegra-vde-y := vde.o iommu.o
> obj-$(CONFIG_TEGRA_VDE) += tegra-vde.o
> diff --git a/drivers/staging/media/tegra-vde/iommu.c b/drivers/staging/media/tegra-vde/iommu.c
> new file mode 100644
> index 000000000000..295c3d7cccd3
> --- /dev/null
> +++ b/drivers/staging/media/tegra-vde/iommu.c
> @@ -0,0 +1,148 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * NVIDIA Tegra Video decoder driver
> + *
> + * Copyright (C) 2016-2019 GRATE-DRIVER project
> + */
> +
> +#include <linux/iommu.h>
> +#include <linux/iova.h>
> +#include <linux/kernel.h>
> +#include <linux/platform_device.h>
> +
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> +#include <asm/dma-iommu.h>
> +#endif
> +
> +#include "vde.h"
> +
> +int tegra_vde_iommu_map(struct tegra_vde *vde,
> + struct sg_table *sgt,
> + struct iova **iovap,
> + dma_addr_t *addrp,
> + size_t size)
> +{
> + struct iova *iova;
> + unsigned long shift;
> + unsigned long end;
> + dma_addr_t addr;
> +
> + end = vde->domain->geometry.aperture_end;
> + size = iova_align(&vde->iova, size);
> + shift = iova_shift(&vde->iova);
> +
> + iova = alloc_iova(&vde->iova, size >> shift, end >> shift, true);
> + if (!iova)
> + return -ENOMEM;
> +
> + addr = iova_dma_addr(&vde->iova, iova);
> +
> + size = iommu_map_sg(vde->domain, addr, sgt->sgl, sgt->nents,
> + IOMMU_READ | IOMMU_WRITE);
> + if (!size) {
> + __free_iova(&vde->iova, iova);
> + return -ENXIO;
> + }
> +
> + *iovap = iova;
> + *addrp = addr;
> +
> + return 0;
> +}
> +
> +void tegra_vde_iommu_unmap(struct tegra_vde *vde, struct iova *iova)
> +{
> + unsigned long shift = iova_shift(&vde->iova);
> + unsigned long size = iova_size(iova) << shift;
> + dma_addr_t addr = iova_dma_addr(&vde->iova, iova);
> +
> + iommu_unmap(vde->domain, addr, size);
> + __free_iova(&vde->iova, iova);
> +}
> +
> +int tegra_vde_iommu_init(struct tegra_vde *vde)
> +{
> + struct iova *iova;
> + unsigned long order;
> + unsigned long shift;
> + int err;
> +
> + vde->group = iommu_group_get(vde->miscdev.parent);
> + if (!vde->group)
> + return 0;
> +
> +#if IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)
> + if (dev->archdata.mapping) {
'dev' doesn't exist, so this fails to compile!
Regards,
Hans
> + struct dma_iommu_mapping *mapping = to_dma_iommu_mapping(dev);
> +
> + arm_iommu_detach_device(dev);
> + arm_iommu_release_mapping(mapping);
> + }
> +#endif
> + vde->domain = iommu_domain_alloc(&platform_bus_type);
> + if (!vde->domain) {
> + err = -ENOMEM;
> + goto put_group;
> + }
> +
> + err = iova_cache_get();
> + if (err)
> + goto free_domain;
> +
> + order = __ffs(vde->domain->pgsize_bitmap);
> + init_iova_domain(&vde->iova, 1UL << order, 0);
> +
> + err = iommu_attach_group(vde->domain, vde->group);
> + if (err)
> + goto put_iova;
> +
> + /*
> + * We're using some static addresses that are not accessible by VDE
> + * to trap invalid memory accesses.
> + */
> + shift = iova_shift(&vde->iova);
> + iova = reserve_iova(&vde->iova, 0x60000000 >> shift,
> + 0x70000000 >> shift);
> + if (!iova) {
> + err = -ENOMEM;
> + goto detach_group;
> + }
> +
> + /*
> + * BSEV's end addresses wraps around due to integer overflow on
> + * hardware context set up if IOVA is allocated at the end of
> + * address space and VDE can't handle that. Hence simply reserve
> + * the last page to avoid the problem.
> + */
> + iova = reserve_iova(&vde->iova, (0xffffffff >> shift) - 1,
> + 0xffffffff >> shift);
> + if (!iova) {
> + err = -ENOMEM;
> + goto detach_group;
> + }
> +
> + return 0;
> +
> +detach_group:
> + iommu_detach_group(vde->domain, vde->group);
> +put_iova:
> + put_iova_domain(&vde->iova);
> + iova_cache_put();
> +free_domain:
> + iommu_domain_free(vde->domain);
> +put_group:
> + iommu_group_put(vde->group);
> +
> + return err;
> +}
> +
> +void tegra_vde_iommu_deinit(struct tegra_vde *vde)
> +{
> + 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);
> + }
> +}
> diff --git a/drivers/staging/media/tegra-vde/trace.h b/drivers/staging/media/tegra-vde/trace.h
> index 85e2f7e2d4d0..c7e7d6f5fd4c 100644
> --- a/drivers/staging/media/tegra-vde/trace.h
> +++ b/drivers/staging/media/tegra-vde/trace.h
> @@ -7,6 +7,7 @@
> #define TEGRA_VDE_TRACE_H
>
> #include <linux/tracepoint.h>
> +#include "vde.h"
>
> DECLARE_EVENT_CLASS(register_access,
> TP_PROTO(struct tegra_vde *vde, void __iomem *base,
> diff --git a/drivers/staging/media/tegra-vde/tegra-vde.c b/drivers/staging/media/tegra-vde/vde.c
> similarity index 91%
> rename from drivers/staging/media/tegra-vde/tegra-vde.c
> rename to drivers/staging/media/tegra-vde/vde.c
> index cc4244da2705..cbcdbfef072d 100644
> --- a/drivers/staging/media/tegra-vde/tegra-vde.c
> +++ b/drivers/staging/media/tegra-vde/vde.c
> @@ -22,6 +22,10 @@
> #include <soc/tegra/pmc.h>
>
> #include "uapi.h"
> +#include "vde.h"
> +
> +#define CREATE_TRACE_POINTS
> +#include "trace.h"
>
> #define ICMDQUE_WR 0x00
> #define CMDQUE_CONTROL 0x08
> @@ -33,6 +37,10 @@
> #define BSE_DMA_BUSY BIT(23)
>
> struct video_frame {
> + struct iova *y_iova;
> + struct iova *cb_iova;
> + struct iova *cr_iova;
> + struct iova *aux_iova;
> struct dma_buf_attachment *y_dmabuf_attachment;
> struct dma_buf_attachment *cb_dmabuf_attachment;
> struct dma_buf_attachment *cr_dmabuf_attachment;
> @@ -49,63 +57,6 @@ struct video_frame {
> u32 flags;
> };
>
> -struct tegra_vde {
> - void __iomem *sxe;
> - void __iomem *bsev;
> - void __iomem *mbe;
> - void __iomem *ppe;
> - void __iomem *mce;
> - void __iomem *tfe;
> - void __iomem *ppb;
> - void __iomem *vdma;
> - void __iomem *frameid;
> - struct mutex lock;
> - struct miscdevice miscdev;
> - struct reset_control *rst;
> - struct reset_control *rst_mc;
> - struct gen_pool *iram_pool;
> - struct completion decode_completion;
> - struct clk *clk;
> - dma_addr_t iram_lists_addr;
> - u32 *iram;
> -};
> -
> -static __maybe_unused char const *
> -tegra_vde_reg_base_name(struct tegra_vde *vde, void __iomem *base)
> -{
> - if (vde->sxe == base)
> - return "SXE";
> -
> - if (vde->bsev == base)
> - return "BSEV";
> -
> - if (vde->mbe == base)
> - return "MBE";
> -
> - if (vde->ppe == base)
> - return "PPE";
> -
> - if (vde->mce == base)
> - return "MCE";
> -
> - if (vde->tfe == base)
> - return "TFE";
> -
> - if (vde->ppb == base)
> - return "PPB";
> -
> - if (vde->vdma == base)
> - return "VDMA";
> -
> - if (vde->frameid == base)
> - return "FRAMEID";
> -
> - return "???";
> -}
> -
> -#define CREATE_TRACE_POINTS
> -#include "trace.h"
> -
> static void tegra_vde_writel(struct tegra_vde *vde,
> u32 value, void __iomem *base, u32 offset)
> {
> @@ -543,28 +494,35 @@ static void tegra_vde_decode_frame(struct tegra_vde *vde,
> 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,
> + enum dma_data_direction dma_dir,
> + struct dma_buf_attachment *a,
> struct sg_table *sgt,
> - enum dma_data_direction dma_dir)
> + struct iova *iova)
> {
> struct dma_buf *dmabuf = a->dmabuf;
>
> + if (vde->domain)
> + tegra_vde_iommu_unmap(vde, iova);
> +
> dma_buf_unmap_attachment(a, sgt, dma_dir);
> dma_buf_detach(dmabuf, a);
> dma_buf_put(dmabuf);
> }
>
> -static int tegra_vde_attach_dmabuf(struct device *dev,
> +static int tegra_vde_attach_dmabuf(struct tegra_vde *vde,
> int fd,
> unsigned long offset,
> 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,
> + struct iova **iovap,
> size_t *size,
> enum dma_data_direction dma_dir)
> {
> + struct device *dev = vde->miscdev.parent;
> struct dma_buf_attachment *attachment;
> struct dma_buf *dmabuf;
> struct sg_table *sgt;
> @@ -602,13 +560,23 @@ static int tegra_vde_attach_dmabuf(struct device *dev,
> goto err_detach;
> }
>
> - if (sgt->nents != 1) {
> - dev_err(dev, "Sparse DMA region is unsupported\n");
> + if (!vde->domain && sgt->nents > 1) {
> + dev_err(dev, "Sparse DMA region is unsupported, please enable IOMMU\n");
> err = -EINVAL;
> goto err_unmap;
> }
>
> - *addr = sg_dma_address(sgt->sgl) + offset;
> + if (vde->domain) {
> + err = tegra_vde_iommu_map(vde, sgt, iovap, addrp, dmabuf->size);
> + if (err) {
> + dev_err(dev, "IOMMU mapping failed: %d\n", err);
> + goto err_unmap;
> + }
> + } else {
> + *addrp = sg_dma_address(sgt->sgl);
> + }
> +
> + *addrp = *addrp + offset;
> *a = attachment;
> *s = sgt;
>
> @@ -627,7 +595,7 @@ static int tegra_vde_attach_dmabuf(struct device *dev,
> return err;
> }
>
> -static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
> +static int tegra_vde_attach_dmabufs_to_frame(struct tegra_vde *vde,
> struct video_frame *frame,
> struct tegra_vde_h264_frame *src,
> enum dma_data_direction dma_dir,
> @@ -636,29 +604,32 @@ static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
> {
> int err;
>
> - err = tegra_vde_attach_dmabuf(dev, src->y_fd,
> + err = tegra_vde_attach_dmabuf(vde, src->y_fd,
> src->y_offset, lsize, SZ_256,
> &frame->y_dmabuf_attachment,
> &frame->y_addr,
> &frame->y_sgt,
> + &frame->y_iova,
> NULL, dma_dir);
> if (err)
> return err;
>
> - err = tegra_vde_attach_dmabuf(dev, src->cb_fd,
> + err = tegra_vde_attach_dmabuf(vde, src->cb_fd,
> src->cb_offset, csize, SZ_256,
> &frame->cb_dmabuf_attachment,
> &frame->cb_addr,
> &frame->cb_sgt,
> + &frame->cb_iova,
> NULL, dma_dir);
> if (err)
> goto err_release_y;
>
> - err = tegra_vde_attach_dmabuf(dev, src->cr_fd,
> + err = tegra_vde_attach_dmabuf(vde, src->cr_fd,
> src->cr_offset, csize, SZ_256,
> &frame->cr_dmabuf_attachment,
> &frame->cr_addr,
> &frame->cr_sgt,
> + &frame->cr_iova,
> NULL, dma_dir);
> if (err)
> goto err_release_cb;
> @@ -668,11 +639,12 @@ static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
> return 0;
> }
>
> - err = tegra_vde_attach_dmabuf(dev, src->aux_fd,
> + err = tegra_vde_attach_dmabuf(vde, src->aux_fd,
> src->aux_offset, csize, SZ_256,
> &frame->aux_dmabuf_attachment,
> &frame->aux_addr,
> &frame->aux_sgt,
> + &frame->aux_iova,
> NULL, dma_dir);
> if (err)
> goto err_release_cr;
> @@ -680,34 +652,49 @@ static int tegra_vde_attach_dmabufs_to_frame(struct device *dev,
> return 0;
>
> err_release_cr:
> - tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
> - frame->cr_sgt, dma_dir);
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->cr_dmabuf_attachment,
> + frame->cr_sgt,
> + frame->cr_iova);
> err_release_cb:
> - tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
> - frame->cb_sgt, dma_dir);
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->cb_dmabuf_attachment,
> + frame->cb_sgt,
> + frame->cb_iova);
> err_release_y:
> - tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
> - frame->y_sgt, dma_dir);
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->y_dmabuf_attachment,
> + frame->y_sgt,
> + frame->y_iova);
>
> return err;
> }
>
> -static void tegra_vde_release_frame_dmabufs(struct video_frame *frame,
> +static void tegra_vde_release_frame_dmabufs(struct tegra_vde *vde,
> + struct video_frame *frame,
> enum dma_data_direction dma_dir,
> bool baseline_profile)
> {
> if (!baseline_profile)
> - tegra_vde_detach_and_put_dmabuf(frame->aux_dmabuf_attachment,
> - frame->aux_sgt, dma_dir);
> -
> - tegra_vde_detach_and_put_dmabuf(frame->cr_dmabuf_attachment,
> - frame->cr_sgt, dma_dir);
> -
> - tegra_vde_detach_and_put_dmabuf(frame->cb_dmabuf_attachment,
> - frame->cb_sgt, dma_dir);
> -
> - tegra_vde_detach_and_put_dmabuf(frame->y_dmabuf_attachment,
> - frame->y_sgt, dma_dir);
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->aux_dmabuf_attachment,
> + frame->aux_sgt,
> + frame->aux_iova);
> +
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->cr_dmabuf_attachment,
> + frame->cr_sgt,
> + frame->cr_iova);
> +
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->cb_dmabuf_attachment,
> + frame->cb_sgt,
> + frame->cb_iova);
> +
> + tegra_vde_detach_and_put_dmabuf(vde, dma_dir,
> + frame->y_dmabuf_attachment,
> + frame->y_sgt,
> + frame->y_iova);
> }
>
> static int tegra_vde_validate_frame(struct device *dev,
> @@ -800,6 +787,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> struct video_frame *dpb_frames;
> struct dma_buf_attachment *bitstream_data_dmabuf_attachment;
> struct sg_table *bitstream_sgt;
> + struct iova *bitstream_iova;
> enum dma_data_direction dma_dir;
> dma_addr_t bitstream_data_addr;
> dma_addr_t bsev_ptr;
> @@ -819,12 +807,13 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> if (ret)
> return ret;
>
> - ret = tegra_vde_attach_dmabuf(dev, ctx.bitstream_data_fd,
> + ret = tegra_vde_attach_dmabuf(vde, ctx.bitstream_data_fd,
> ctx.bitstream_data_offset,
> SZ_16K, SZ_16K,
> &bitstream_data_dmabuf_attachment,
> &bitstream_data_addr,
> &bitstream_sgt,
> + &bitstream_iova,
> &bitstream_data_size,
> DMA_TO_DEVICE);
> if (ret)
> @@ -866,7 +855,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
>
> dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
>
> - ret = tegra_vde_attach_dmabufs_to_frame(dev, &dpb_frames[i],
> + ret = tegra_vde_attach_dmabufs_to_frame(vde, &dpb_frames[i],
> &frames[i], dma_dir,
> ctx.baseline_profile,
> lsize, csize);
> @@ -954,7 +943,7 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> while (i--) {
> dma_dir = (i == 0) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
>
> - tegra_vde_release_frame_dmabufs(&dpb_frames[i], dma_dir,
> + tegra_vde_release_frame_dmabufs(vde, &dpb_frames[i], dma_dir,
> ctx.baseline_profile);
> }
>
> @@ -965,8 +954,10 @@ static int tegra_vde_ioctl_decode_h264(struct tegra_vde *vde,
> kfree(frames);
>
> release_bitstream_dmabuf:
> - tegra_vde_detach_and_put_dmabuf(bitstream_data_dmabuf_attachment,
> - bitstream_sgt, DMA_TO_DEVICE);
> + tegra_vde_detach_and_put_dmabuf(vde, DMA_TO_DEVICE,
> + bitstream_data_dmabuf_attachment,
> + bitstream_sgt,
> + bitstream_iova);
>
> return ret;
> }
> @@ -1176,10 +1167,16 @@ static int tegra_vde_probe(struct platform_device *pdev)
> vde->miscdev.fops = &tegra_vde_fops;
> vde->miscdev.parent = dev;
>
> + err = tegra_vde_iommu_init(vde);
> + if (err) {
> + dev_err(dev, "Failed to initialize IOMMU: %d\n", err);
> + goto err_gen_free;
> + }
> +
> err = misc_register(&vde->miscdev);
> if (err) {
> dev_err(dev, "Failed to register misc device: %d\n", err);
> - goto err_gen_free;
> + goto err_deinit_iommu;
> }
>
> pm_runtime_enable(dev);
> @@ -1197,6 +1194,9 @@ static int tegra_vde_probe(struct platform_device *pdev)
> err_misc_unreg:
> misc_deregister(&vde->miscdev);
>
> +err_deinit_iommu:
> + tegra_vde_iommu_deinit(vde);
> +
> err_gen_free:
> gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
> gen_pool_size(vde->iram_pool));
> @@ -1221,6 +1221,8 @@ static int tegra_vde_remove(struct platform_device *pdev)
>
> misc_deregister(&vde->miscdev);
>
> + tegra_vde_iommu_deinit(vde);
> +
> gen_pool_free(vde->iram_pool, (unsigned long)vde->iram,
> gen_pool_size(vde->iram_pool));
>
> diff --git a/drivers/staging/media/tegra-vde/vde.h b/drivers/staging/media/tegra-vde/vde.h
> new file mode 100644
> index 000000000000..37414b7fdee1
> --- /dev/null
> +++ b/drivers/staging/media/tegra-vde/vde.h
> @@ -0,0 +1,89 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * NVIDIA Tegra Video decoder driver
> + *
> + * Copyright (C) 2016-2019 GRATE-DRIVER project
> + */
> +
> +#ifndef TEGRA_VDE_H
> +#define TEGRA_VDE_H
> +
> +#include <linux/completion.h>
> +#include <linux/miscdevice.h>
> +#include <linux/mutex.h>
> +#include <linux/types.h>
> +#include <linux/iova.h>
> +
> +struct clk;
> +struct gen_pool;
> +struct iommu_group;
> +struct iommu_domain;
> +struct reset_control;
> +
> +struct tegra_vde {
> + void __iomem *sxe;
> + void __iomem *bsev;
> + void __iomem *mbe;
> + void __iomem *ppe;
> + void __iomem *mce;
> + void __iomem *tfe;
> + void __iomem *ppb;
> + void __iomem *vdma;
> + void __iomem *frameid;
> + struct mutex lock;
> + struct miscdevice miscdev;
> + struct reset_control *rst;
> + struct reset_control *rst_mc;
> + struct gen_pool *iram_pool;
> + struct completion decode_completion;
> + struct clk *clk;
> + struct iommu_domain *domain;
> + struct iommu_group *group;
> + struct iova_domain iova;
> + dma_addr_t iram_lists_addr;
> + u32 *iram;
> +};
> +
> +int tegra_vde_iommu_init(struct tegra_vde *vde);
> +void tegra_vde_iommu_deinit(struct tegra_vde *vde);
> +int tegra_vde_iommu_map(struct tegra_vde *vde,
> + struct sg_table *sgt,
> + struct iova **iovap,
> + dma_addr_t *addrp,
> + size_t size);
> +void tegra_vde_iommu_unmap(struct tegra_vde *vde, struct iova *iova);
> +
> +static __maybe_unused char const *
> +tegra_vde_reg_base_name(struct tegra_vde *vde, void __iomem *base)
> +{
> + if (vde->sxe == base)
> + return "SXE";
> +
> + if (vde->bsev == base)
> + return "BSEV";
> +
> + if (vde->mbe == base)
> + return "MBE";
> +
> + if (vde->ppe == base)
> + return "PPE";
> +
> + if (vde->mce == base)
> + return "MCE";
> +
> + if (vde->tfe == base)
> + return "TFE";
> +
> + if (vde->ppb == base)
> + return "PPB";
> +
> + if (vde->vdma == base)
> + return "VDMA";
> +
> + if (vde->frameid == base)
> + return "FRAMEID";
> +
> + return "???";
> +}
> +
> +#endif /* TEGRA_VDE_H */
>