[PATCH 4/9] dma-buf: heaps: Initialise MediaTek secure heap

[Yong Wu]

Initialise a mtk_svp heap. Currently just add a null heap, Prepare for
the later patches.

Signed-off-by: Yong Wu <yong.wu@xxxxxxxxxxxx>
---
 drivers/dma-buf/heaps/Kconfig           |  8 ++
 drivers/dma-buf/heaps/Makefile          |  1 +
 drivers/dma-buf/heaps/mtk_secure_heap.c | 99 +++++++++++++++++++++++++
 3 files changed, 108 insertions(+)
 create mode 100644 drivers/dma-buf/heaps/mtk_secure_heap.c

diff --git a/drivers/dma-buf/heaps/Kconfig b/drivers/dma-buf/heaps/Kconfig
index a5eef06c4226..729c0cf3eb7c 100644
--- a/drivers/dma-buf/heaps/Kconfig
+++ b/drivers/dma-buf/heaps/Kconfig
@@ -12,3 +12,11 @@ config DMABUF_HEAPS_CMA
 	  Choose this option to enable dma-buf CMA heap. This heap is backed
 	  by the Contiguous Memory Allocator (CMA). If your system has these
 	  regions, you should say Y here.
+
+config DMABUF_HEAPS_MTK_SECURE
+	bool "DMA-BUF MediaTek Secure Heap"
+	depends on DMABUF_HEAPS && TEE
+	help
+	  Choose this option to enable dma-buf MediaTek secure heap for Secure
+	  Video Path. This heap is backed by TEE client interfaces. If in
+	  doubt, say N.
diff --git a/drivers/dma-buf/heaps/Makefile b/drivers/dma-buf/heaps/Makefile
index 974467791032..df559dbe33fe 100644
--- a/drivers/dma-buf/heaps/Makefile
+++ b/drivers/dma-buf/heaps/Makefile
@@ -1,3 +1,4 @@
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_DMABUF_HEAPS_SYSTEM)	+= system_heap.o
 obj-$(CONFIG_DMABUF_HEAPS_CMA)		+= cma_heap.o
+obj-$(CONFIG_DMABUF_HEAPS_MTK_SECURE)	+= mtk_secure_heap.o
diff --git a/drivers/dma-buf/heaps/mtk_secure_heap.c b/drivers/dma-buf/heaps/mtk_secure_heap.c
new file mode 100644
index 000000000000..bbf1c8dce23e
--- /dev/null
+++ b/drivers/dma-buf/heaps/mtk_secure_heap.c
@@ -0,0 +1,99 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DMABUF mtk_secure_heap exporter
+ *
+ * Copyright (C) 2023 MediaTek Inc.
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+/*
+ * MediaTek secure (chunk) memory type
+ *
+ * @KREE_MEM_SEC_CM_TZ: static chunk memory carved out for trustzone.
+ */
+enum kree_mem_type {
+	KREE_MEM_SEC_CM_TZ = 1,
+};
+
+struct mtk_secure_heap_buffer {
+	struct dma_heap		*heap;
+	size_t			size;
+};
+
+struct mtk_secure_heap {
+	const char		*name;
+	const enum kree_mem_type mem_type;
+};
+
+static struct dma_buf *
+mtk_sec_heap_allocate(struct dma_heap *heap, size_t size,
+		      unsigned long fd_flags, unsigned long heap_flags)
+{
+	struct mtk_secure_heap_buffer *sec_buf;
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct dma_buf *dmabuf;
+	int ret;
+
+	sec_buf = kzalloc(sizeof(*sec_buf), GFP_KERNEL);
+	if (!sec_buf)
+		return ERR_PTR(-ENOMEM);
+
+	sec_buf->size = size;
+	sec_buf->heap = heap;
+
+	exp_info.exp_name = dma_heap_get_name(heap);
+	exp_info.size = sec_buf->size;
+	exp_info.flags = fd_flags;
+	exp_info.priv = sec_buf;
+
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf)) {
+		ret = PTR_ERR(dmabuf);
+		goto err_free_buf;
+	}
+
+	return dmabuf;
+
+err_free_buf:
+	kfree(sec_buf);
+	return ERR_PTR(ret);
+}
+
+static const struct dma_heap_ops mtk_sec_heap_ops = {
+	.allocate	= mtk_sec_heap_allocate,
+};
+
+static struct mtk_secure_heap mtk_sec_heap[] = {
+	{
+		.name		= "mtk_svp",
+		.mem_type	= KREE_MEM_SEC_CM_TZ,
+	},
+};
+
+static int mtk_sec_heap_init(void)
+{
+	struct mtk_secure_heap *sec_heap = mtk_sec_heap;
+	struct dma_heap_export_info exp_info;
+	struct dma_heap *heap;
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(mtk_sec_heap); i++, sec_heap++) {
+		exp_info.name = sec_heap->name;
+		exp_info.ops = &mtk_sec_heap_ops;
+		exp_info.priv = (void *)sec_heap;
+
+		heap = dma_heap_add(&exp_info);
+		if (IS_ERR(heap))
+			return PTR_ERR(heap);
+	}
+	return 0;
+}
+
+module_init(mtk_sec_heap_init);
+MODULE_DESCRIPTION("MediaTek Secure Heap Driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1