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![Sachin Kamat](/assets/img/avatar_default.png)
devm_kzalloc can fail. Hence check the pointer to avoid NULL pointer dereferencing. Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org> Signed-off-by: Inki Dae <inki.dae@samsung.com>
145 lines
3.6 KiB
C
145 lines
3.6 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 <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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struct device *dev = drm_dev->dev;
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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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if (!priv->da_space_order)
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priv->da_space_order = EXYNOS_DEV_ADDR_ORDER;
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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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priv->da_space_order);
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if (IS_ERR(mapping))
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return PTR_ERR(mapping);
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dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
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GFP_KERNEL);
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if (!dev->dma_parms)
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goto error;
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dma_set_max_seg_size(dev, 0xffffffffu);
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dev->archdata.mapping = mapping;
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return 0;
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error:
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arm_iommu_release_mapping(mapping);
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return -ENOMEM;
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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 device *dev = drm_dev->dev;
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arm_iommu_release_mapping(dev->archdata.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 device *dev = drm_dev->dev;
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int ret;
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if (!dev->archdata.mapping) {
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DRM_ERROR("iommu_mapping is null.\n");
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return -EFAULT;
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}
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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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ret = arm_iommu_attach_device(subdrv_dev, dev->archdata.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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/*
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* Set dma_ops to drm_device just one time.
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*
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* The dma mapping api needs device object and the api is used
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* to allocate physial memory and map it with iommu table.
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* If iommu attach succeeded, the sub driver would have dma_ops
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* for iommu and also all sub drivers have same dma_ops.
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*/
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if (!dev->archdata.dma_ops)
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dev->archdata.dma_ops = subdrv_dev->archdata.dma_ops;
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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 device *dev = drm_dev->dev;
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struct dma_iommu_mapping *mapping = dev->archdata.mapping;
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if (!mapping || !mapping->domain)
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return;
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iommu_detach_device(mapping->domain, subdrv_dev);
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drm_release_iommu_mapping(drm_dev);
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}
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