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From: Yong Wu <yong.wu@mediatek.com>
To: Rob Herring <robh+dt@kernel.org>, Matthias Brugger
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Subject: [PATCH v4 3/7] dma-buf: heaps: restricted_heap: Add private heap ops
Date: Fri, 12 Jan 2024 17:20:10 +0800
Message-ID: <20240112092014.23999-4-yong.wu@mediatek.com>
In-Reply-To: <20240112092014.23999-1-yong.wu@mediatek.com>
References: <20240112092014.23999-1-yong.wu@mediatek.com>
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Add "struct restricted_heap_ops". For the restricted memory, totally there
are two steps:
a) memory_alloc: Allocate the buffer in kernel;
b) memory_restrict: Restrict/Protect/Secure that buffer.
The memory_alloc is mandatory while memory_restrict is optinal since it may
be part of memory_alloc.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
---
 drivers/dma-buf/heaps/restricted_heap.c | 41 ++++++++++++++++++++++++-
 drivers/dma-buf/heaps/restricted_heap.h | 12 ++++++++
 2 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/restricted_heap.c b/drivers/dma-buf/heaps/restricted_heap.c
index fd7c82abd42e..8c266a0f6192 100644
--- a/drivers/dma-buf/heaps/restricted_heap.c
+++ b/drivers/dma-buf/heaps/restricted_heap.c
@@ -12,10 +12,44 @@
 
 #include "restricted_heap.h"
 
+static int
+restricted_heap_memory_allocate(struct restricted_heap *heap, struct restricted_buffer *buf)
+{
+	const struct restricted_heap_ops *ops = heap->ops;
+	int ret;
+
+	ret = ops->memory_alloc(heap, buf);
+	if (ret)
+		return ret;
+
+	if (ops->memory_restrict) {
+		ret = ops->memory_restrict(heap, buf);
+		if (ret)
+			goto memory_free;
+	}
+	return 0;
+
+memory_free:
+	ops->memory_free(heap, buf);
+	return ret;
+}
+
+static void
+restricted_heap_memory_free(struct restricted_heap *heap, struct restricted_buffer *buf)
+{
+	const struct restricted_heap_ops *ops = heap->ops;
+
+	if (ops->memory_unrestrict)
+		ops->memory_unrestrict(heap, buf);
+
+	ops->memory_free(heap, buf);
+}
+
 static struct dma_buf *
 restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
 			 unsigned long fd_flags, unsigned long heap_flags)
 {
+	struct restricted_heap *restricted_heap = dma_heap_get_drvdata(heap);
 	struct restricted_buffer *restricted_buf;
 	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 	struct dma_buf *dmabuf;
@@ -28,6 +62,9 @@ restricted_heap_allocate(struct dma_heap *heap, unsigned long size,
 	restricted_buf->size = ALIGN(size, PAGE_SIZE);
 	restricted_buf->heap = heap;
 
+	ret = restricted_heap_memory_allocate(restricted_heap, restricted_buf);
+	if (ret)
+		goto err_free_buf;
 	exp_info.exp_name = dma_heap_get_name(heap);
 	exp_info.size = restricted_buf->size;
 	exp_info.flags = fd_flags;
@@ -36,11 +73,13 @@ restricted_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_restricted_mem;
 	}
 
 	return dmabuf;
 
+err_free_restricted_mem:
+	restricted_heap_memory_free(restricted_heap, restricted_buf);
 err_free_buf:
 	kfree(restricted_buf);
 	return ERR_PTR(ret);
diff --git a/drivers/dma-buf/heaps/restricted_heap.h b/drivers/dma-buf/heaps/restricted_heap.h
index 443028f6ba3b..ddeaf9805708 100644
--- a/drivers/dma-buf/heaps/restricted_heap.h
+++ b/drivers/dma-buf/heaps/restricted_heap.h
@@ -15,6 +15,18 @@ struct restricted_buffer {
 
 struct restricted_heap {
 	const char		*name;
+
+	const struct restricted_heap_ops *ops;
+};
+
+struct restricted_heap_ops {
+	int	(*heap_init)(struct restricted_heap *heap);
+
+	int	(*memory_alloc)(struct restricted_heap *heap, struct restricted_buffer *buf);
+	void	(*memory_free)(struct restricted_heap *heap, struct restricted_buffer *buf);
+
+	int	(*memory_restrict)(struct restricted_heap *heap, struct restricted_buffer *buf);
+	void	(*memory_unrestrict)(struct restricted_heap *heap, struct restricted_buffer *buf);
 };
 
 int restricted_heap_add(struct restricted_heap *rstrd_heap);
-- 
2.25.1