forked from Minki/linux
f43c35966a
This patch changes device pointer provided to all calls to DMA-mapping subsystem from the virtual exynos-drm 'device' to the real device pointer of one of the CRTC devices (decon, fimd or mixer). This way no more hacks will be needed to configure proper DMA-mapping address space on the common virtual exynos-drm device. This change also removes the need for some hacks in IOMMU related code. It also finally solves the problem of Exynos DRM driver not working on ARM64 architecture, which provides noop-based DMA-mapping operations for virtual platform devices. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Inki Dae <inki.dae@samsung.com>
123 lines
2.8 KiB
C
123 lines
2.8 KiB
C
/* exynos_drm_iommu.c
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*
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* Copyright (c) 2012 Samsung Electronics Co., Ltd.
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* Author: Inki Dae <inki.dae@samsung.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version.
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*/
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#include <drm/drmP.h>
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#include <drm/exynos_drm.h>
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#include <linux/dma-mapping.h>
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#include <linux/iommu.h>
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#include <linux/kref.h>
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#include <asm/dma-iommu.h>
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#include "exynos_drm_drv.h"
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#include "exynos_drm_iommu.h"
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/*
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* drm_create_iommu_mapping - create a mapping structure
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*
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* @drm_dev: DRM device
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*/
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int drm_create_iommu_mapping(struct drm_device *drm_dev)
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{
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struct dma_iommu_mapping *mapping = NULL;
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struct exynos_drm_private *priv = drm_dev->dev_private;
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if (!priv->da_start)
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priv->da_start = EXYNOS_DEV_ADDR_START;
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if (!priv->da_space_size)
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priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
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mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
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priv->da_space_size);
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if (IS_ERR(mapping))
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return PTR_ERR(mapping);
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priv->mapping = mapping;
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return 0;
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}
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/*
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* drm_release_iommu_mapping - release iommu mapping structure
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*
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* @drm_dev: DRM device
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*
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* if mapping->kref becomes 0 then all things related to iommu mapping
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* will be released
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*/
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void drm_release_iommu_mapping(struct drm_device *drm_dev)
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{
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struct exynos_drm_private *priv = drm_dev->dev_private;
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arm_iommu_release_mapping(priv->mapping);
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}
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/*
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* drm_iommu_attach_device- attach device to iommu mapping
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*
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* @drm_dev: DRM device
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* @subdrv_dev: device to be attach
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*
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* This function should be called by sub drivers to attach it to iommu
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* mapping.
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*/
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int drm_iommu_attach_device(struct drm_device *drm_dev,
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struct device *subdrv_dev)
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{
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struct exynos_drm_private *priv = drm_dev->dev_private;
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int ret;
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if (!priv->mapping)
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return 0;
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subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
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sizeof(*subdrv_dev->dma_parms),
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GFP_KERNEL);
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if (!subdrv_dev->dma_parms)
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return -ENOMEM;
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dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
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if (subdrv_dev->archdata.mapping)
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arm_iommu_detach_device(subdrv_dev);
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ret = arm_iommu_attach_device(subdrv_dev, priv->mapping);
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if (ret < 0) {
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DRM_DEBUG_KMS("failed iommu attach.\n");
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return ret;
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}
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return 0;
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}
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/*
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* drm_iommu_detach_device -detach device address space mapping from device
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*
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* @drm_dev: DRM device
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* @subdrv_dev: device to be detached
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*
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* This function should be called by sub drivers to detach it from iommu
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* mapping
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*/
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void drm_iommu_detach_device(struct drm_device *drm_dev,
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struct device *subdrv_dev)
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{
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struct exynos_drm_private *priv = drm_dev->dev_private;
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struct dma_iommu_mapping *mapping = priv->mapping;
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if (!mapping || !mapping->domain)
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return;
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arm_iommu_detach_device(subdrv_dev);
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}
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