145 lines
3.8 KiB
C
145 lines
3.8 KiB
C
// SPDX-License-Identifier: GPL-2.0
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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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// Author: Andrzej Hajda <a.hajda@samsung.com>
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#include <linux/dma-iommu.h>
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#include <linux/dma-map-ops.h>
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#include <linux/iommu.h>
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#include <linux/platform_device.h>
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#include <drm/drm_print.h>
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#include <drm/exynos_drm.h>
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#include "exynos_drm_drv.h"
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#if defined(CONFIG_ARM_DMA_USE_IOMMU)
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#include <asm/dma-iommu.h>
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#else
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#define arm_iommu_create_mapping(...) ({ NULL; })
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#define arm_iommu_attach_device(...) ({ -ENODEV; })
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#define arm_iommu_release_mapping(...) ({ })
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#define arm_iommu_detach_device(...) ({ })
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#define to_dma_iommu_mapping(dev) NULL
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#endif
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#if !defined(CONFIG_IOMMU_DMA)
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#define iommu_dma_init_domain(...) ({ -EINVAL; })
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#endif
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#define EXYNOS_DEV_ADDR_START 0x20000000
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#define EXYNOS_DEV_ADDR_SIZE 0x40000000
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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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static int drm_iommu_attach_device(struct drm_device *drm_dev,
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struct device *subdrv_dev, void **dma_priv)
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{
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struct exynos_drm_private *priv = drm_dev->dev_private;
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int ret = 0;
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if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) {
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DRM_DEV_ERROR(subdrv_dev, "Device %s lacks support for IOMMU\n",
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dev_name(subdrv_dev));
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return -EINVAL;
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}
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dma_set_max_seg_size(subdrv_dev, DMA_BIT_MASK(32));
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if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
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/*
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* Keep the original DMA mapping of the sub-device and
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* restore it on Exynos DRM detach, otherwise the DMA
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* framework considers it as IOMMU-less during the next
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* probe (in case of deferred probe or modular build)
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*/
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*dma_priv = to_dma_iommu_mapping(subdrv_dev);
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if (*dma_priv)
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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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} else if (IS_ENABLED(CONFIG_IOMMU_DMA)) {
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ret = iommu_attach_device(priv->mapping, subdrv_dev);
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}
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return ret;
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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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static void drm_iommu_detach_device(struct drm_device *drm_dev,
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struct device *subdrv_dev, void **dma_priv)
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{
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struct exynos_drm_private *priv = drm_dev->dev_private;
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if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) {
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arm_iommu_detach_device(subdrv_dev);
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arm_iommu_attach_device(subdrv_dev, *dma_priv);
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} else if (IS_ENABLED(CONFIG_IOMMU_DMA))
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iommu_detach_device(priv->mapping, subdrv_dev);
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}
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int exynos_drm_register_dma(struct drm_device *drm, struct device *dev,
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void **dma_priv)
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{
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struct exynos_drm_private *priv = drm->dev_private;
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if (!priv->dma_dev) {
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priv->dma_dev = dev;
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DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n",
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dev_name(dev));
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}
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if (!IS_ENABLED(CONFIG_EXYNOS_IOMMU))
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return 0;
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if (!priv->mapping) {
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void *mapping;
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if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
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mapping = arm_iommu_create_mapping(&platform_bus_type,
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EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE);
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else if (IS_ENABLED(CONFIG_IOMMU_DMA))
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mapping = iommu_get_domain_for_dev(priv->dma_dev);
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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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}
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return drm_iommu_attach_device(drm, dev, dma_priv);
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}
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void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev,
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void **dma_priv)
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{
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if (IS_ENABLED(CONFIG_EXYNOS_IOMMU))
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drm_iommu_detach_device(drm, dev, dma_priv);
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}
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void exynos_drm_cleanup_dma(struct drm_device *drm)
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{
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struct exynos_drm_private *priv = drm->dev_private;
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if (!IS_ENABLED(CONFIG_EXYNOS_IOMMU))
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return;
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arm_iommu_release_mapping(priv->mapping);
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priv->mapping = NULL;
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priv->dma_dev = NULL;
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}
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