diff options
Diffstat (limited to 'drivers/gpu/drm/exynos/exynos_drm_dma.c')
| -rw-r--r-- | drivers/gpu/drm/exynos/exynos_drm_dma.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dma.c b/drivers/gpu/drm/exynos/exynos_drm_dma.c new file mode 100644 index 000000000000..3432c5ee9f0c --- /dev/null +++ b/drivers/gpu/drm/exynos/exynos_drm_dma.c @@ -0,0 +1,157 @@ +// SPDX-License-Identifier: GPL-2.0 +// +// Copyright (c) 2012 Samsung Electronics Co., Ltd. +// Author: Inki Dae <inki.dae@samsung.com> +// Author: Andrzej Hajda <a.hajda@samsung.com> + +#include <drm/drmP.h> +#include <drm/exynos_drm.h> +#include <linux/dma-iommu.h> +#include <linux/dma-mapping.h> +#include <linux/iommu.h> + +#include "exynos_drm_drv.h" + +#if defined(CONFIG_ARM_DMA_USE_IOMMU) +#include <asm/dma-iommu.h> +#else +#define arm_iommu_create_mapping(...) ({ NULL; }) +#define arm_iommu_attach_device(...) ({ -ENODEV; }) +#define arm_iommu_release_mapping(...) ({ }) +#define arm_iommu_detach_device(...) ({ }) +#define to_dma_iommu_mapping(dev) NULL +#endif + +#if !defined(CONFIG_IOMMU_DMA) +#define iommu_dma_init_domain(...) ({ -EINVAL; }) +#endif + +#define EXYNOS_DEV_ADDR_START 0x20000000 +#define EXYNOS_DEV_ADDR_SIZE 0x40000000 + +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_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. + */ +static int drm_iommu_attach_device(struct drm_device *drm_dev, + struct device *subdrv_dev) +{ + struct exynos_drm_private *priv = drm_dev->dev_private; + int ret; + + if (get_dma_ops(priv->dma_dev) != get_dma_ops(subdrv_dev)) { + DRM_ERROR("Device %s lacks support for IOMMU\n", + dev_name(subdrv_dev)); + return -EINVAL; + } + + ret = configure_dma_max_seg_size(subdrv_dev); + if (ret) + return ret; + + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) { + if (to_dma_iommu_mapping(subdrv_dev)) + arm_iommu_detach_device(subdrv_dev); + + ret = arm_iommu_attach_device(subdrv_dev, priv->mapping); + } else if (IS_ENABLED(CONFIG_IOMMU_DMA)) { + ret = iommu_attach_device(priv->mapping, subdrv_dev); + } + + if (ret) + clear_dma_max_seg_size(subdrv_dev); + + 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 + */ +static void drm_iommu_detach_device(struct drm_device *drm_dev, + struct device *subdrv_dev) +{ + struct exynos_drm_private *priv = drm_dev->dev_private; + + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) + arm_iommu_detach_device(subdrv_dev); + else if (IS_ENABLED(CONFIG_IOMMU_DMA)) + iommu_detach_device(priv->mapping, subdrv_dev); + + clear_dma_max_seg_size(subdrv_dev); +} + +int exynos_drm_register_dma(struct drm_device *drm, struct device *dev) +{ + struct exynos_drm_private *priv = drm->dev_private; + + if (!priv->dma_dev) { + priv->dma_dev = dev; + DRM_INFO("Exynos DRM: using %s device for DMA mapping operations\n", + dev_name(dev)); + } + + if (!IS_ENABLED(CONFIG_EXYNOS_IOMMU)) + return 0; + + if (!priv->mapping) { + void *mapping; + + if (IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) + mapping = arm_iommu_create_mapping(&platform_bus_type, + EXYNOS_DEV_ADDR_START, EXYNOS_DEV_ADDR_SIZE); + else if (IS_ENABLED(CONFIG_IOMMU_DMA)) + mapping = iommu_get_domain_for_dev(priv->dma_dev); + + if (IS_ERR(mapping)) + return PTR_ERR(mapping); + priv->mapping = mapping; + } + + return drm_iommu_attach_device(drm, dev); +} + +void exynos_drm_unregister_dma(struct drm_device *drm, struct device *dev) +{ + if (IS_ENABLED(CONFIG_EXYNOS_IOMMU)) + drm_iommu_detach_device(drm, dev); +} + +void exynos_drm_cleanup_dma(struct drm_device *drm) +{ + struct exynos_drm_private *priv = drm->dev_private; + + if (!IS_ENABLED(CONFIG_EXYNOS_IOMMU)) + return; + + arm_iommu_release_mapping(priv->mapping); + priv->mapping = NULL; + priv->dma_dev = NULL; +} |