diff options
Diffstat (limited to 'drivers/gpu/drm/exynos/exynos_drm_iommu.c')
| -rw-r--r-- | drivers/gpu/drm/exynos/exynos_drm_iommu.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/drivers/gpu/drm/exynos/exynos_drm_iommu.c new file mode 100644 index 000000000000..3799d5c2b5df --- /dev/null +++ b/drivers/gpu/drm/exynos/exynos_drm_iommu.c @@ -0,0 +1,136 @@ +/* exynos_drm_iommu.c + * + * Copyright (c) 2012 Samsung Electronics Co., Ltd. + * Author: Inki Dae <inki.dae@samsung.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or (at your + * option) any later version. + */ + +#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); +} |