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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 3/7] dma-buf: heaps: secure_heap: Add private heap ops
Date:   Tue, 12 Dec 2023 10:46:03 +0800
Message-ID: <20231212024607.3681-4-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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Precedence: bulk

Add "struct secure_heap_ops". For the secure memory, totally there are
two steps:
a) memory_alloc: Allocate the buffer in kernel;
b) secure_the_memory: Secure/Proect that buffer.
The memory_alloc is mandatory while secure_the_memory is optinal since
it may be part of memory_alloc.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/dma-buf/heaps/secure_heap.c | 39 ++++++++++++++++++++++++++++-
 drivers/dma-buf/heaps/secure_heap.h | 11 ++++++++
 2 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/secure_heap.c b/drivers/dma-buf/heaps/secure_heap.c
index e087da5638aa..925cf8e1c7ce 100644
--- a/drivers/dma-buf/heaps/secure_heap.c
+++ b/drivers/dma-buf/heaps/secure_heap.c
@@ -12,10 +12,42 @@
 
 #include "secure_heap.h"
 
+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;
+	int ret;
+
+	ret = ops->memory_alloc(sec_heap, sec_buf);
+	if (ret)
+		return ret;
+
+	if (ops->secure_the_memory) {
+		ret = ops->secure_the_memory(sec_heap, sec_buf);
+		if (ret)
+			goto sec_memory_free;
+	}
+	return 0;
+
+sec_memory_free:
+	ops->memory_free(sec_heap, sec_buf);
+	return ret;
+}
+
+static void secure_heap_memory_free(struct secure_heap *sec_heap, struct secure_buffer *sec_buf)
+{
+	const struct secure_heap_ops *ops = sec_heap->ops;
+
+	if (ops->unsecure_the_memory)
+		ops->unsecure_the_memory(sec_heap, sec_buf);
+
+	ops->memory_free(sec_heap, sec_buf);
+}
+
 static struct dma_buf *
 secure_heap_allocate(struct dma_heap *heap, unsigned long size,
 		     unsigned long fd_flags, unsigned long heap_flags)
 {
+	struct secure_heap *sec_heap = dma_heap_get_drvdata(heap);
 	struct secure_buffer *sec_buf;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 	struct dma_buf *dmabuf;
@@ -28,6 +60,9 @@ secure_heap_allocate(struct dma_heap *heap, unsigned long size,
 	sec_buf->size = ALIGN(size, PAGE_SIZE);
 	sec_buf->heap = heap;
 
+	ret = secure_heap_memory_allocate(sec_heap, sec_buf);
+	if (ret)
+		goto err_free_buf;
 	exp_info.exp_name = dma_heap_get_name(heap);
 	exp_info.size = sec_buf->size;
 	exp_info.flags = fd_flags;
@@ -36,11 +71,13 @@ secure_heap_allocate(struct dma_heap *heap, unsigned long size,
 	dmabuf = dma_buf_export(&exp_info);
 	if (IS_ERR(dmabuf)) {
 		ret = PTR_ERR(dmabuf);
-		goto err_free_buf;
+		goto err_free_sec_mem;
 	}
 
 	return dmabuf;
 
+err_free_sec_mem:
+	secure_heap_memory_free(sec_heap, sec_buf);
 err_free_buf:
 	kfree(sec_buf);
 	return ERR_PTR(ret);
diff --git a/drivers/dma-buf/heaps/secure_heap.h b/drivers/dma-buf/heaps/secure_heap.h
index 50733dc6d4db..ec5349cd28d0 100644
--- a/drivers/dma-buf/heaps/secure_heap.h
+++ b/drivers/dma-buf/heaps/secure_heap.h
@@ -15,6 +15,17 @@ struct secure_buffer {
 
 struct secure_heap {
 	const char		*name;
+
+	const struct secure_heap_ops *ops;
+};
+
+struct secure_heap_ops {
+	int	(*memory_alloc)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);
+	void	(*memory_free)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);
+
+	/* Protect/unprotect the memory */
+	int	(*secure_the_memory)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);
+	void	(*unsecure_the_memory)(struct secure_heap *sec_heap, struct secure_buffer *sec_buf);
 };
 
 int secure_heap_add(struct secure_heap *sec_heap);
-- 
2.25.1