Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / gpu / drm / exynos / exynos_drm_iommu.c

diff --git a/kernel/drivers/gpu/drm/exynos/exynos_drm_iommu.c b/kernel/drivers/gpu/drm/exynos/exynos_drm_iommu.c
new file mode 100644 (file)
index 0000000..b32b291
--- /dev/null
+++ b/kernel/drivers/gpu/drm/exynos/exynos_drm_iommu.c
@@ -0,0 +1,143 @@
+/* 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;
+
+       mapping = arm_iommu_create_mapping(&platform_bus_type, priv->da_start,
+                                               priv->da_space_size);
+
+       if (IS_ERR(mapping))
+               return PTR_ERR(mapping);
+
+       dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
+                                       GFP_KERNEL);
+       if (!dev->dma_parms)
+               goto error;
+
+       dma_set_max_seg_size(dev, 0xffffffffu);
+       dev->archdata.mapping = mapping;
+
+       return 0;
+error:
+       arm_iommu_release_mapping(mapping);
+       return -ENOMEM;
+}
+
+/*
+ * 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);
+       if (!subdrv_dev->dma_parms)
+               return -ENOMEM;
+
+       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);
+}