17.06.2019 16:31, Hans Verkuil пишет:

On 6/2/19 11:37 PM, Dmitry Osipenko wrote:

quoted

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 [off-list ref]
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
 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!

Oh, indeed! I actually didn't even try to compile with CONFIG_ARM_DMA_USE_IOMMU. Will
fix it in v2, thanks!