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authorMarek Szyprowski <m.szyprowski@samsung.com>2016-06-17 10:54:23 +0300
committerInki Dae <daeinki@gmail.com>2016-07-13 17:06:04 +0300
commitf7c72773de88fa3d4b51d4eb2bd2a89b746aaf54 (patch)
tree05a40dbdf33237547e0d2703027533a65fc12ca7 /drivers/gpu/drm/exynos
parent5dd0775e502b26b44e5bcb5f504a977a565f2f3e (diff)
downloadlinux-f7c72773de88fa3d4b51d4eb2bd2a89b746aaf54.tar.xz
drm/exynos: iommu: move dma_params configuration code to separate functions
Move code for managing DMA max segment size parameter to separate functions. This patch also replaces devm_kzalloc() with kzalloc() and adds proper kfree call. devm_kzalloc() cannot be used for dma_params structure, because it will be freed on driver remove not on device release. This means in case of Exynos DRM being compiled as module and loaded 2 times, a user-after-free issue will happen. Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Inki Dae <inki.dae@samsung.com>
Diffstat (limited to 'drivers/gpu/drm/exynos')
-rw-r--r--drivers/gpu/drm/exynos/exynos_drm_iommu.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
index 7ca09ee19656..1e82529e0c41 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_iommu.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -21,6 +21,23 @@
#include "exynos_drm_drv.h"
#include "exynos_drm_iommu.h"
+static inline int configure_dma_max_seg_size(struct device *dev)
+{
+ if (!dev->dma_parms)
+ dev->dma_parms = kzalloc(sizeof(*dev->dma_parms), GFP_KERNEL);
+ if (!dev->dma_parms)
+ return -ENOMEM;
+
+ dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
+ return 0;
+}
+
+static inline void clear_dma_max_seg_size(struct device *dev)
+{
+ kfree(dev->dma_parms);
+ dev->dma_parms = NULL;
+}
+
/*
* drm_create_iommu_mapping - create a mapping structure
*
@@ -80,13 +97,10 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
if (!priv->mapping)
return 0;
- subdrv_dev->dma_parms = devm_kzalloc(subdrv_dev,
- sizeof(*subdrv_dev->dma_parms),
- GFP_KERNEL);
- if (!subdrv_dev->dma_parms)
- return -ENOMEM;
- dma_set_max_seg_size(subdrv_dev, 0xffffffffu);
+ ret = configure_dma_max_seg_size(subdrv_dev);
+ if (ret)
+ return ret;
if (subdrv_dev->archdata.mapping)
arm_iommu_detach_device(subdrv_dev);
@@ -94,6 +108,7 @@ int drm_iommu_attach_device(struct drm_device *drm_dev,
ret = arm_iommu_attach_device(subdrv_dev, priv->mapping);
if (ret < 0) {
DRM_DEBUG_KMS("failed iommu attach.\n");
+ clear_dma_max_seg_size(subdrv_dev);
return ret;
}
@@ -119,4 +134,5 @@ void drm_iommu_detach_device(struct drm_device *drm_dev,
return;
arm_iommu_detach_device(subdrv_dev);
+ clear_dma_max_seg_size(subdrv_dev);
}