[Linaro-mm-sig] Re: [PATCH 6/9] dma-buf: heaps: mtk_sec_heap: Add tee service call for buffer allocating/freeing

On 9/11/2023 8:00 AM, Yong Wu wrote:

Add TEE service call for secure memory allocating/freeing.

Signed-off-by: Anan Sun anan.sun@mediatek.com Signed-off-by: Yong Wu yong.wu@mediatek.com

---

drivers/dma-buf/heaps/mtk_secure_heap.c | 69 ++++++++++++++++++++++++- 1 file changed, 68 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/heaps/mtk_secure_heap.c b/drivers/dma-buf/heaps/mtk_secure_heap.c index e3da33a3d083..14c2a16a7164 100644 --- a/drivers/dma-buf/heaps/mtk_secure_heap.c +++ b/drivers/dma-buf/heaps/mtk_secure_heap.c @@ -17,6 +17,9 @@ #define MTK_TEE_PARAM_NUM 4 +#define TZCMD_MEM_SECURECM_UNREF 7 +#define TZCMD_MEM_SECURECM_ZALLOC 15

/*

• MediaTek secure (chunk) memory type

@@ -29,6 +32,8 @@ enum kree_mem_type { struct mtk_secure_heap_buffer { struct dma_heap *heap; size_t size;

• u32 sec_handle;

}; struct mtk_secure_heap { @@ -80,6 +85,63 @@ static int mtk_kree_secure_session_init(struct mtk_secure_heap *sec_heap) return ret; } +static int +mtk_sec_mem_tee_service_call(struct tee_context *tee_ctx, u32 session,

• 	     unsigned int command, struct tee_param *params)
  

+{

• struct tee_ioctl_invoke_arg arg = {0};
• int ret;
• arg.num_params = MTK_TEE_PARAM_NUM;
• arg.session = session;
• arg.func = command;
• ret = tee_client_invoke_func(tee_ctx, &arg, params);
• if (ret < 0 || arg.ret) {

• pr_err("%s: cmd %d ret %d:%x.\n", __func__, command, ret, arg.ret);
  

• ret = -EOPNOTSUPP;
  

• }
• return ret;

+}

+static int mtk_sec_mem_allocate(struct mtk_secure_heap *sec_heap,

• 		struct mtk_secure_heap_buffer *sec_buf)
  

+{

• struct tee_param params[MTK_TEE_PARAM_NUM] = {0};
• u32 mem_session = sec_heap->mem_session;
• int ret;
• params[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
• params[0].u.value.a = SZ_4K; /* alignment */
• params[0].u.value.b = sec_heap->mem_type; /* memory type */
• params[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
• params[1].u.value.a = sec_buf->size;
• params[2].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT;
• /* Always request zeroed buffer */
• ret = mtk_sec_mem_tee_service_call(sec_heap->tee_ctx, mem_session,

• 			   TZCMD_MEM_SECURECM_ZALLOC, params);
  

I see here optee calls are being used to secure memory.

For a secure heap, there can be multiple ways on how we want to secure memory, for eg : by using qcom_scm_assign_mem.

This interface restricts securing memory to only optee calls. can we have a way to choose ops that we want to secure memory ?

Thanks, Vijay

• if (ret)

• return -ENOMEM;
  

• sec_buf->sec_handle = params[2].u.value.a;
• return 0;

+}

+static void mtk_sec_mem_release(struct mtk_secure_heap *sec_heap,

• 		struct mtk_secure_heap_buffer *sec_buf)
  

+{

• struct tee_param params[MTK_TEE_PARAM_NUM] = {0};
• u32 mem_session = sec_heap->mem_session;
• params[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
• params[0].u.value.a = sec_buf->sec_handle;
• params[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
• mtk_sec_mem_tee_service_call(sec_heap->tee_ctx, mem_session,

• 		     TZCMD_MEM_SECURECM_UNREF, params);
  

+}

static struct dma_buf * mtk_sec_heap_allocate(struct dma_heap *heap, size_t size, unsigned long fd_flags, unsigned long heap_flags) @@ -107,6 +169,9 @@ mtk_sec_heap_allocate(struct dma_heap *heap, size_t size, sec_buf->size = size; sec_buf->heap = heap;

• ret = mtk_sec_mem_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;

@@ -115,11 +180,13 @@ mtk_sec_heap_allocate(struct dma_heap *heap, size_t 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:

• mtk_sec_mem_release(sec_heap, sec_buf);

err_free_buf: kfree(sec_buf); return ERR_PTR(ret);