1 files changed, 287 insertions, 0 deletions
diff --git a/drivers/gpu/drm/mediatek/mtk_gem.c b/drivers/gpu/drm/mediatek/mtk_gem.c
new file mode 100644
index 000000000000..5a82d7cf3ed0
--- /dev/null
+++ b/drivers/gpu/drm/mediatek/mtk_gem.c
@@ -0,0 +1,287 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ */
+
+#include <linux/dma-buf.h>
+
+#include <drm/drm.h>
+#include <drm/drm_device.h>
+#include <drm/drm_gem.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_prime.h>
+
+#include "mtk_drm_drv.h"
+#include "mtk_gem.h"
+
+static int mtk_gem_object_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma);
+
+static const struct vm_operations_struct vm_ops = {
+	.open = drm_gem_vm_open,
+	.close = drm_gem_vm_close,
+};
+
+static const struct drm_gem_object_funcs mtk_gem_object_funcs = {
+	.free = mtk_gem_free_object,
+	.get_sg_table = mtk_gem_prime_get_sg_table,
+	.vmap = mtk_gem_prime_vmap,
+	.vunmap = mtk_gem_prime_vunmap,
+	.mmap = mtk_gem_object_mmap,
+	.vm_ops = &vm_ops,
+};
+
+static struct mtk_gem_obj *mtk_gem_init(struct drm_device *dev,
+					unsigned long size)
+{
+	struct mtk_gem_obj *mtk_gem_obj;
+	int ret;
+
+	size = round_up(size, PAGE_SIZE);
+
+	if (size == 0)
+		return ERR_PTR(-EINVAL);
+
+	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
+	if (!mtk_gem_obj)
+		return ERR_PTR(-ENOMEM);
+
+	mtk_gem_obj->base.funcs = &mtk_gem_object_funcs;
+
+	ret = drm_gem_object_init(dev, &mtk_gem_obj->base, size);
+	if (ret < 0) {
+		DRM_ERROR("failed to initialize gem object\n");
+		kfree(mtk_gem_obj);
+		return ERR_PTR(ret);
+	}
+
+	return mtk_gem_obj;
+}
+
+struct mtk_gem_obj *mtk_gem_create(struct drm_device *dev,
+				   size_t size, bool alloc_kmap)
+{
+	struct mtk_drm_private *priv = dev->dev_private;
+	struct mtk_gem_obj *mtk_gem;
+	struct drm_gem_object *obj;
+	int ret;
+
+	mtk_gem = mtk_gem_init(dev, size);
+	if (IS_ERR(mtk_gem))
+		return ERR_CAST(mtk_gem);
+
+	obj = &mtk_gem->base;
+
+	mtk_gem->dma_attrs = DMA_ATTR_WRITE_COMBINE;
+
+	if (!alloc_kmap)
+		mtk_gem->dma_attrs |= DMA_ATTR_NO_KERNEL_MAPPING;
+
+	mtk_gem->cookie = dma_alloc_attrs(priv->dma_dev, obj->size,
+					  &mtk_gem->dma_addr, GFP_KERNEL,
+					  mtk_gem->dma_attrs);
+	if (!mtk_gem->cookie) {
+		DRM_ERROR("failed to allocate %zx byte dma buffer", obj->size);
+		ret = -ENOMEM;
+		goto err_gem_free;
+	}
+
+	if (alloc_kmap)
+		mtk_gem->kvaddr = mtk_gem->cookie;
+
+	DRM_DEBUG_DRIVER("cookie = %p dma_addr = %pad size = %zu\n",
+			 mtk_gem->cookie, &mtk_gem->dma_addr,
+			 size);
+
+	return mtk_gem;
+
+err_gem_free:
+	drm_gem_object_release(obj);
+	kfree(mtk_gem);
+	return ERR_PTR(ret);
+}
+
+void mtk_gem_free_object(struct drm_gem_object *obj)
+{
+	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	struct mtk_drm_private *priv = obj->dev->dev_private;
+
+	if (mtk_gem->sg)
+		drm_prime_gem_destroy(obj, mtk_gem->sg);
+	else
+		dma_free_attrs(priv->dma_dev, obj->size, mtk_gem->cookie,
+			       mtk_gem->dma_addr, mtk_gem->dma_attrs);
+
+	/* release file pointer to gem object. */
+	drm_gem_object_release(obj);
+
+	kfree(mtk_gem);
+}
+
+int mtk_gem_dumb_create(struct drm_file *file_priv, struct drm_device *dev,
+			struct drm_mode_create_dumb *args)
+{
+	struct mtk_gem_obj *mtk_gem;
+	int ret;
+
+	args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+
+	/*
+	 * Multiply 2 variables of different types,
+	 * for example: args->size = args->spacing * args->height;
+	 * may cause coverity issue with unintentional overflow.
+	 */
+	args->size = args->pitch;
+	args->size *= args->height;
+
+	mtk_gem = mtk_gem_create(dev, args->size, false);
+	if (IS_ERR(mtk_gem))
+		return PTR_ERR(mtk_gem);
+
+	/*
+	 * allocate a id of idr table where the obj is registered
+	 * and handle has the id what user can see.
+	 */
+	ret = drm_gem_handle_create(file_priv, &mtk_gem->base, &args->handle);
+	if (ret)
+		goto err_handle_create;
+
+	/* drop reference from allocate - handle holds it now. */
+	drm_gem_object_put(&mtk_gem->base);
+
+	return 0;
+
+err_handle_create:
+	mtk_gem_free_object(&mtk_gem->base);
+	return ret;
+}
+
+static int mtk_gem_object_mmap(struct drm_gem_object *obj,
+			       struct vm_area_struct *vma)
+
+{
+	int ret;
+	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	struct mtk_drm_private *priv = obj->dev->dev_private;
+
+	/*
+	 * Set vm_pgoff (used as a fake buffer offset by DRM) to 0 and map the
+	 * whole buffer from the start.
+	 */
+	vma->vm_pgoff = 0;
+
+	/*
+	 * dma_alloc_attrs() allocated a struct page table for mtk_gem, so clear
+	 * VM_PFNMAP flag that was set by drm_gem_mmap_obj()/drm_gem_mmap().
+	 */
+	vm_flags_set(vma, VM_IO | VM_DONTEXPAND | VM_DONTDUMP);
+	vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+	vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+
+	ret = dma_mmap_attrs(priv->dma_dev, vma, mtk_gem->cookie,
+			     mtk_gem->dma_addr, obj->size, mtk_gem->dma_attrs);
+
+	return ret;
+}
+
+/*
+ * Allocate a sg_table for this GEM object.
+ * Note: Both the table's contents, and the sg_table itself must be freed by
+ *       the caller.
+ * Returns a pointer to the newly allocated sg_table, or an ERR_PTR() error.
+ */
+struct sg_table *mtk_gem_prime_get_sg_table(struct drm_gem_object *obj)
+{
+	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	struct mtk_drm_private *priv = obj->dev->dev_private;
+	struct sg_table *sgt;
+	int ret;
+
+	sgt = kzalloc(sizeof(*sgt), GFP_KERNEL);
+	if (!sgt)
+		return ERR_PTR(-ENOMEM);
+
+	ret = dma_get_sgtable_attrs(priv->dma_dev, sgt, mtk_gem->cookie,
+				    mtk_gem->dma_addr, obj->size,
+				    mtk_gem->dma_attrs);
+	if (ret) {
+		DRM_ERROR("failed to allocate sgt, %d\n", ret);
+		kfree(sgt);
+		return ERR_PTR(ret);
+	}
+
+	return sgt;
+}
+
+struct drm_gem_object *mtk_gem_prime_import_sg_table(struct drm_device *dev,
+			struct dma_buf_attachment *attach, struct sg_table *sg)
+{
+	struct mtk_gem_obj *mtk_gem;
+
+	/* check if the entries in the sg_table are contiguous */
+	if (drm_prime_get_contiguous_size(sg) < attach->dmabuf->size) {
+		DRM_ERROR("sg_table is not contiguous");
+		return ERR_PTR(-EINVAL);
+	}
+
+	mtk_gem = mtk_gem_init(dev, attach->dmabuf->size);
+	if (IS_ERR(mtk_gem))
+		return ERR_CAST(mtk_gem);
+
+	mtk_gem->dma_addr = sg_dma_address(sg->sgl);
+	mtk_gem->sg = sg;
+
+	return &mtk_gem->base;
+}
+
+int mtk_gem_prime_vmap(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	struct sg_table *sgt = NULL;
+	unsigned int npages;
+
+	if (mtk_gem->kvaddr)
+		goto out;
+
+	sgt = mtk_gem_prime_get_sg_table(obj);
+	if (IS_ERR(sgt))
+		return PTR_ERR(sgt);
+
+	npages = obj->size >> PAGE_SHIFT;
+	mtk_gem->pages = kcalloc(npages, sizeof(*mtk_gem->pages), GFP_KERNEL);
+	if (!mtk_gem->pages) {
+		sg_free_table(sgt);
+		kfree(sgt);
+		return -ENOMEM;
+	}
+
+	drm_prime_sg_to_page_array(sgt, mtk_gem->pages, npages);
+
+	mtk_gem->kvaddr = vmap(mtk_gem->pages, npages, VM_MAP,
+			       pgprot_writecombine(PAGE_KERNEL));
+	if (!mtk_gem->kvaddr) {
+		sg_free_table(sgt);
+		kfree(sgt);
+		kfree(mtk_gem->pages);
+		return -ENOMEM;
+	}
+	sg_free_table(sgt);
+	kfree(sgt);
+
+out:
+	iosys_map_set_vaddr(map, mtk_gem->kvaddr);
+
+	return 0;
+}
+
+void mtk_gem_prime_vunmap(struct drm_gem_object *obj, struct iosys_map *map)
+{
+	struct mtk_gem_obj *mtk_gem = to_mtk_gem_obj(obj);
+	void *vaddr = map->vaddr;
+
+	if (!mtk_gem->pages)
+		return;
+
+	vunmap(vaddr);
+	mtk_gem->kvaddr = NULL;
+	kfree(mtk_gem->pages);
+}