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From:   Yong Wu <yong.wu@mediatek.com>
To:     Rob Herring <robh+dt@kernel.org>,
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Subject: [PATCH v3 4/7] dma-buf: heaps: secure_heap: Add dma_ops
Date:   Tue, 12 Dec 2023 10:46:04 +0800
Message-ID: <20231212024607.3681-5-yong.wu@mediatek.com>
In-Reply-To: <20231212024607.3681-1-yong.wu@mediatek.com>
References: <20231212024607.3681-1-yong.wu@mediatek.com>
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Add the dma_ops for this secure heap. For secure buffer, cache_ops/mmap
are not allowed, thus return EPERM for them.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/dma-buf/heaps/secure_heap.c | 103 ++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c
index 925cf8e1c7ce..7cb4db3e55c2 100644
--- a/drivers/dma-buf/heaps/secure_heap.c
+++ b/drivers/dma-buf/heaps/secure_heap.c
@@ -12,6 +12,10 @@
 
 #include "secure_heap.h"
 
+struct secure_heap_attachment {
+	struct sg_table			*table;
+};
+
 static int secure_heap_memory_allocate(struct secure_heap *sec_heap, struct secure_buffer *sec_buf)
 {
 	const struct secure_heap_ops *ops = sec_heap->ops;
@@ -43,6 +47,104 @@ static void secure_heap_memory_free(struct secure_heap *sec_heap, struct secure_
 	ops->memory_free(sec_heap, sec_buf);
 }
 
+static int secure_heap_attach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+	struct secure_buffer *sec_buf = dmabuf->priv;
+	struct secure_heap_attachment *a;
+	struct sg_table *table;
+	int ret;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	table = kzalloc(sizeof(*table), GFP_KERNEL);
+	if (!table) {
+		ret = -ENOMEM;
+		goto err_free_attach;
+	}
+
+	ret = sg_alloc_table(table, 1, GFP_KERNEL);
+	if (ret)
+		goto err_free_sgt;
+	sg_set_page(table->sgl, NULL, sec_buf->size, 0);
+
+	a->table = table;
+	attachment->priv = a;
+
+	return 0;
+
+err_free_sgt:
+	kfree(table);
+err_free_attach:
+	kfree(a);
+	return ret;
+}
+
+static void secure_heap_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attachment)
+{
+	struct secure_heap_attachment *a = attachment->priv;
+
+	sg_free_table(a->table);
+	kfree(a->table);
+	kfree(a);
+}
+
+static struct sg_table *
+secure_heap_map_dma_buf(struct dma_buf_attachment *attachment, enum dma_data_direction direction)
+{
+	struct secure_heap_attachment *a = attachment->priv;
+	struct sg_table *table = a->table;
+
+	return table;
+}
+
+static void
+secure_heap_unmap_dma_buf(struct dma_buf_attachment *attachment, struct sg_table *table,
+			  enum dma_data_direction direction)
+{
+	struct secure_heap_attachment *a = attachment->priv;
+
+	WARN_ON(a->table != table);
+}
+
+static int
+secure_heap_dma_buf_begin_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+	return -EPERM;
+}
+
+static int
+secure_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf, enum dma_data_direction direction)
+{
+	return -EPERM;
+}
+
+static int secure_heap_dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
+{
+	return -EPERM;
+}
+
+static void secure_heap_free(struct dma_buf *dmabuf)
+{
+	struct secure_buffer *sec_buf = dmabuf->priv;
+	struct secure_heap *sec_heap = dma_heap_get_drvdata(sec_buf->heap);
+
+	secure_heap_memory_free(sec_heap, sec_buf);
+	kfree(sec_buf);
+}
+
+static const struct dma_buf_ops sec_heap_buf_ops = {
+	.attach		= secure_heap_attach,
+	.detach		= secure_heap_detach,
+	.map_dma_buf	= secure_heap_map_dma_buf,
+	.unmap_dma_buf	= secure_heap_unmap_dma_buf,
+	.begin_cpu_access = secure_heap_dma_buf_begin_cpu_access,
+	.end_cpu_access	= secure_heap_dma_buf_end_cpu_access,
+	.mmap		= secure_heap_dma_buf_mmap,
+	.release	= secure_heap_free,
+};
+
 static struct dma_buf *
 secure_heap_allocate(struct dma_heap *heap, unsigned long size,
 		     unsigned long fd_flags, unsigned long heap_flags)
@@ -64,6 +166,7 @@ secure_heap_allocate(struct dma_heap *heap, unsigned long size,
 	if (ret)
 		goto err_free_buf;
 	exp_info.exp_name = dma_heap_get_name(heap);
+	exp_info.ops = &sec_heap_buf_ops;
 	exp_info.size = sec_buf->size;
 	exp_info.flags = fd_flags;
 	exp_info.priv = sec_buf;
-- 
2.25.1