1 files changed, 151 insertions, 0 deletions
diff --git a/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
new file mode 100644
index 000000000..393f82e26
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
@@ -0,0 +1,151 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
+ * Author: Rob Clark <rob.clark@linaro.org>
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/highmem.h>
+
+#include <drm/drm_prime.h>
+
+#include "omap_drv.h"
+
+MODULE_IMPORT_NS(DMA_BUF);
+
+/* -----------------------------------------------------------------------------
+ * DMABUF Export
+ */
+
+static struct sg_table *omap_gem_map_dma_buf(
+		struct dma_buf_attachment *attachment,
+		enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = attachment->dmabuf->priv;
+	struct sg_table *sg;
+	sg = omap_gem_get_sg(obj, dir);
+	if (IS_ERR(sg))
+		return sg;
+
+	return sg;
+}
+
+static void omap_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
+		struct sg_table *sg, enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = attachment->dmabuf->priv;
+	omap_gem_put_sg(obj, sg);
+}
+
+static int omap_gem_dmabuf_begin_cpu_access(struct dma_buf *buffer,
+		enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = buffer->priv;
+	struct page **pages;
+	if (omap_gem_flags(obj) & OMAP_BO_TILED_MASK) {
+		/* TODO we would need to pin at least part of the buffer to
+		 * get de-tiled view.  For now just reject it.
+		 */
+		return -ENOMEM;
+	}
+	/* make sure we have the pages: */
+	return omap_gem_get_pages(obj, &pages, true);
+}
+
+static int omap_gem_dmabuf_end_cpu_access(struct dma_buf *buffer,
+					  enum dma_data_direction dir)
+{
+	struct drm_gem_object *obj = buffer->priv;
+	omap_gem_put_pages(obj);
+	return 0;
+}
+
+static int omap_gem_dmabuf_mmap(struct dma_buf *buffer,
+		struct vm_area_struct *vma)
+{
+	struct drm_gem_object *obj = buffer->priv;
+	int ret = 0;
+
+	ret = drm_gem_mmap_obj(obj, omap_gem_mmap_size(obj), vma);
+	if (ret < 0)
+		return ret;
+
+	return omap_gem_mmap_obj(obj, vma);
+}
+
+static const struct dma_buf_ops omap_dmabuf_ops = {
+	.map_dma_buf = omap_gem_map_dma_buf,
+	.unmap_dma_buf = omap_gem_unmap_dma_buf,
+	.release = drm_gem_dmabuf_release,
+	.begin_cpu_access = omap_gem_dmabuf_begin_cpu_access,
+	.end_cpu_access = omap_gem_dmabuf_end_cpu_access,
+	.mmap = omap_gem_dmabuf_mmap,
+};
+
+struct dma_buf *omap_gem_prime_export(struct drm_gem_object *obj, int flags)
+{
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+
+	exp_info.ops = &omap_dmabuf_ops;
+	exp_info.size = omap_gem_mmap_size(obj);
+	exp_info.flags = flags;
+	exp_info.priv = obj;
+	exp_info.resv = obj->resv;
+
+	return drm_gem_dmabuf_export(obj->dev, &exp_info);
+}
+
+/* -----------------------------------------------------------------------------
+ * DMABUF Import
+ */
+
+struct drm_gem_object *omap_gem_prime_import(struct drm_device *dev,
+					     struct dma_buf *dma_buf)
+{
+	struct dma_buf_attachment *attach;
+	struct drm_gem_object *obj;
+	struct sg_table *sgt;
+	int ret;
+
+	if (dma_buf->ops == &omap_dmabuf_ops) {
+		obj = dma_buf->priv;
+		if (obj->dev == dev) {
+			/*
+			 * Importing dmabuf exported from out own gem increases
+			 * refcount on gem itself instead of f_count of dmabuf.
+			 */
+			drm_gem_object_get(obj);
+			return obj;
+		}
+	}
+
+	attach = dma_buf_attach(dma_buf, dev->dev);
+	if (IS_ERR(attach))
+		return ERR_CAST(attach);
+
+	get_dma_buf(dma_buf);
+
+	sgt = dma_buf_map_attachment(attach, DMA_TO_DEVICE);
+	if (IS_ERR(sgt)) {
+		ret = PTR_ERR(sgt);
+		goto fail_detach;
+	}
+
+	obj = omap_gem_new_dmabuf(dev, dma_buf->size, sgt);
+	if (IS_ERR(obj)) {
+		ret = PTR_ERR(obj);
+		goto fail_unmap;
+	}
+
+	obj->import_attach = attach;
+
+	return obj;
+
+fail_unmap:
+	dma_buf_unmap_attachment(attach, sgt, DMA_TO_DEVICE);
+fail_detach:
+	dma_buf_detach(dma_buf, attach);
+	dma_buf_put(dma_buf);
+
+	return ERR_PTR(ret);
+}