linux/drivers/gpu/drm/exynos/exynos_drm_iommu.c
Wei Yongjun a0e41b562b drm/exynos/iommu: fix return value check in drm_create_iommu_mapping()
In case of error, function arm_iommu_create_mapping() returns
ERR_PTR() and never returns NULL. The NULL test in the return
value check should be replaced with IS_ERR().

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
2012-12-13 06:05:45 -08:00

151 lines
4.3 KiB
C

/* exynos_drm_iommu.c
*
* Copyright (c) 2012 Samsung Electronics Co., Ltd.
* Author: Inki Dae <inki.dae@samsung.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <drmP.h>
#include <drm/exynos_drm.h>
#include <linux/dma-mapping.h>
#include <linux/iommu.h>
#include <linux/kref.h>
#include <asm/dma-iommu.h>
#include "exynos_drm_drv.h"
#include "exynos_drm_iommu.h"
/*
* drm_create_iommu_mapping - create a mapping structure
*
* @drm_dev: DRM device
*/
int drm_create_iommu_mapping(struct drm_device *drm_dev)
{
struct dma_iommu_mapping *mapping = NULL;
struct exynos_drm_private *priv = drm_dev->dev_private;
struct device *dev = drm_dev->dev;
if (!priv->da_start)
priv->da_start = EXYNOS_DEV_ADDR_START;
if (!priv->da_space_size)
priv->da_space_size = EXYNOS_DEV_ADDR_SIZE;
if (!priv->da_space_order)
priv->da_space_order = EXYNOS_DEV_ADDR_ORDER;
mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
priv->da_space_size,
priv->da_space_order);
if (IS_ERR(mapping))
return PTR_ERR(mapping);
dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
GFP_KERNEL);
dma_set_max_seg_size(dev, 0xffffffffu);
dev->archdata.mapping = mapping;
return 0;
}
/*
* drm_release_iommu_mapping - release iommu mapping structure
*
* @drm_dev: DRM device
*
* if mapping->kref becomes 0 then all things related to iommu mapping
* will be released
*/
void drm_release_iommu_mapping(struct drm_device *drm_dev)
{
struct device *dev = drm_dev->dev;
arm_iommu_release_mapping(dev->archdata.mapping);
}
/*
* drm_iommu_attach_device- attach device to iommu mapping
*
* @drm_dev: DRM device
* @subdrv_dev: device to be attach
*
* This function should be called by sub drivers to attach it to iommu
* mapping.
*/
int drm_iommu_attach_device(struct drm_device *drm_dev,
struct device *subdrv_dev)
{
struct device *dev = drm_dev->dev;
int ret;
if (!dev->archdata.mapping) {
DRM_ERROR("iommu_mapping is null.\n");
return -EFAULT;
}
subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
sizeof(*subdrv_dev->dma_parms),
GFP_KERNEL);
dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
ret = arm_iommu_attach_device(subdrv_dev, dev->archdata.mapping);
if (ret < 0) {
DRM_DEBUG_KMS("failed iommu attach.\n");
return ret;
}
/*
* Set dma_ops to drm_device just one time.
*
* The dma mapping api needs device object and the api is used
* to allocate physial memory and map it with iommu table.
* If iommu attach succeeded, the sub driver would have dma_ops
* for iommu and also all sub drivers have same dma_ops.
*/
if (!dev->archdata.dma_ops)
dev->archdata.dma_ops = subdrv_dev->archdata.dma_ops;
return 0;
}
/*
* drm_iommu_detach_device -detach device address space mapping from device
*
* @drm_dev: DRM device
* @subdrv_dev: device to be detached
*
* This function should be called by sub drivers to detach it from iommu
* mapping
*/
void drm_iommu_detach_device(struct drm_device *drm_dev,
struct device *subdrv_dev)
{
struct device *dev = drm_dev->dev;
struct dma_iommu_mapping *mapping = dev->archdata.mapping;
if (!mapping || !mapping->domain)
return;
iommu_detach_device(mapping->domain, subdrv_dev);
drm_release_iommu_mapping(drm_dev);
}