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path: root/drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c
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Diffstat (limited to 'drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c')
-rw-r--r--drivers/gpu/drm/omapdrm/omap_gem_dmabuf.c151
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);
+}