Re: [PATCH v2 03/11] drm/mediatek: Add secure buffer control flow to mtk_drm_gem

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Il 23/10/23 06:45, Jason-JH.Lin ha scritto:
Add secure buffer control flow to mtk_drm_gem.

When user space takes DRM_MTK_GEM_CREATE_ENCRYPTED flag and size
to create a mtk_drm_gem object, mtk_drm_gem will find a matched size
dma buffer from secure dma-heap and bind it to mtk_drm_gem object.

Signed-off-by: Jason-JH.Lin <jason-jh.lin@xxxxxxxxxxxx>
---
  drivers/gpu/drm/mediatek/mtk_drm_gem.c | 84 +++++++++++++++++++++++++-
  drivers/gpu/drm/mediatek/mtk_drm_gem.h |  4 ++
  2 files changed, 87 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
index bcce723f257d..2064ccd7dde0 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
@@ -4,6 +4,8 @@
   */
#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <uapi/linux/dma-heap.h>
  #include <drm/mediatek_drm.h>
#include <drm/drm.h>
@@ -55,6 +57,80 @@ static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
  	return mtk_gem_obj;
  }
+struct mtk_drm_gem_obj *mtk_drm_gem_create_from_heap(struct drm_device *dev,
+						     const char *heap, size_t size)
+{
+	struct mtk_drm_private *priv = dev->dev_private;
+	struct mtk_drm_gem_obj *mtk_gem;
+	struct drm_gem_object *obj;
+	struct dma_heap *dma_heap;
+	struct dma_buf *dma_buf;
+	struct dma_buf_attachment *attach;
+	struct sg_table *sgt;
+	struct iosys_map map = {};
+	int ret;
+
+	mtk_gem = mtk_drm_gem_init(dev, size);
+	if (IS_ERR(mtk_gem))
+		return ERR_CAST(mtk_gem);
+
+	obj = &mtk_gem->base;
+
+	dma_heap = dma_heap_find(heap);
+	if (!dma_heap) {
+		DRM_ERROR("heap find fail\n");
+		goto err_gem_free;
+	}
+	dma_buf = dma_heap_buffer_alloc(dma_heap, size,
+					O_RDWR | O_CLOEXEC, DMA_HEAP_VALID_HEAP_FLAGS);
+	if (IS_ERR(dma_buf)) {
+		DRM_ERROR("buffer alloc fail\n");
+		dma_heap_put(dma_heap);
+		goto err_gem_free;
+	}
+	dma_heap_put(dma_heap);
+
+	attach = dma_buf_attach(dma_buf, priv->dma_dev);
+	if (IS_ERR(attach)) {
+		DRM_ERROR("attach fail, return\n");
+		dma_buf_put(dma_buf);
+		goto err_gem_free;
+	}

blank line here please

+	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
+	if (IS_ERR(sgt)) {
+		DRM_ERROR("map failed, detach and return\n");
+		dma_buf_detach(dma_buf, attach);
+		dma_buf_put(dma_buf);
+		goto err_gem_free;
+	}
+	obj->import_attach = attach;
+	mtk_gem->dma_addr = sg_dma_address(sgt->sgl);
+	mtk_gem->sg = sgt;
+	mtk_gem->size = dma_buf->size;
+
+	if (!strcmp(heap, "mtk_svp") || !strcmp(heap, "mtk_svp_cma")) {
+		/* secure buffer can not be mapped */
+		mtk_gem->sec = true;
+	} else {
+		ret = dma_buf_vmap(dma_buf, &map);
+		mtk_gem->kvaddr = map.vaddr;
+		if (ret) {
+			DRM_ERROR("map failed, ret=%d\n", ret);
+			dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
+			dma_buf_detach(dma_buf, attach);
+			dma_buf_put(dma_buf);
+			mtk_gem->kvaddr = NULL;
+		}
+	}
+
+	return mtk_gem;
+
+err_gem_free:
+	drm_gem_object_release(obj);
+	kfree(mtk_gem);
+	return ERR_PTR(-ENOMEM);
+}
+
  struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev,
  					   size_t size, bool alloc_kmap)
  {
@@ -218,7 +294,9 @@ struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
  	if (IS_ERR(mtk_gem))
  		return ERR_CAST(mtk_gem);
+ mtk_gem->sec = !sg_page(sg->sgl);
  	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
+	mtk_gem->size = attach->dmabuf->size;
  	mtk_gem->sg = sg;
return &mtk_gem->base;
@@ -290,7 +368,11 @@ int mtk_gem_create_ioctl(struct drm_device *dev, void *data,
  	struct drm_mtk_gem_create *args = data;
  	int ret;
- mtk_gem = mtk_drm_gem_create(dev, args->size, false);
+	if (args->flags & DRM_MTK_GEM_CREATE_ENCRYPTED)
+		mtk_gem = mtk_drm_gem_create_from_heap(dev, "mtk_svp_cma", args->size);
+	else
+		mtk_gem = mtk_drm_gem_create(dev, args->size, false);
+
  	if (IS_ERR(mtk_gem))
  		return PTR_ERR(mtk_gem);
diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.h b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
index 90f3d2916ec5..ed4d23e252e9 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_gem.h
+++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.h
@@ -27,9 +27,11 @@ struct mtk_drm_gem_obj {
  	void			*cookie;
  	void			*kvaddr;
  	dma_addr_t		dma_addr;
+	size_t			size;
  	unsigned long		dma_attrs;
  	struct sg_table		*sg;
  	struct page		**pages;
+	bool			sec;

`sec` may be ambiguous. You can call that `secure` or `is_secure_buf`.

  };
#define to_mtk_gem_obj(x) container_of(x, struct mtk_drm_gem_obj, base)
@@ -37,6 +39,8 @@ struct mtk_drm_gem_obj {
  void mtk_drm_gem_free_object(struct drm_gem_object *gem);
  struct mtk_drm_gem_obj *mtk_drm_gem_create(struct drm_device *dev, size_t size,
  					   bool alloc_kmap);
+struct mtk_drm_gem_obj *mtk_drm_gem_create_from_heap(struct drm_device *dev,
+						     const char *heap, size_t size);
  int mtk_drm_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
  			    struct drm_mode_create_dumb *args);
  struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj);






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