Re: [PATCH 5/9] dma-buf: heaps: mtk_sec_heap: Initialise tee session

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

Il 11/09/23 04:30, Yong Wu ha scritto:
> The TEE probe later than dma-buf heap, and PROBE_DEDER doesn't work
> here since this is not a platform driver, therefore initialise the TEE
> context/session while we allocate the first secure buffer.
> 
> Signed-off-by: Yong Wu <yong.wu@mediatek.com>
> ---
>   drivers/dma-buf/heaps/mtk_secure_heap.c | 61 +++++++++++++++++++++++++
>   1 file changed, 61 insertions(+)
> 
> diff --git a/drivers/dma-buf/heaps/mtk_secure_heap.c b/drivers/dma-buf/heaps/mtk_secure_heap.c
> index bbf1c8dce23e..e3da33a3d083 100644
> --- a/drivers/dma-buf/heaps/mtk_secure_heap.c
> +++ b/drivers/dma-buf/heaps/mtk_secure_heap.c
> @@ -10,6 +10,12 @@
>   #include <linux/err.h>
>   #include <linux/module.h>
>   #include <linux/slab.h>
> +#include <linux/tee_drv.h>
> +#include <linux/uuid.h>
> +
> +#define TZ_TA_MEM_UUID		"4477588a-8476-11e2-ad15-e41f1390d676"
> +

Is this UUID the same for all SoCs and all TZ versions?

Thanks,
Angelo


> +#define MTK_TEE_PARAM_NUM		4
>   
>   /*
>    * MediaTek secure (chunk) memory type
> @@ -28,17 +34,72 @@ struct mtk_secure_heap_buffer {
>   struct mtk_secure_heap {
>   	const char		*name;
>   	const enum kree_mem_type mem_type;
> +	u32			 mem_session;
> +	struct tee_context	*tee_ctx;
>   };
>   
> +static int mtk_optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
> +{
> +	return ver->impl_id == TEE_IMPL_ID_OPTEE;
> +}
> +
> +static int mtk_kree_secure_session_init(struct mtk_secure_heap *sec_heap)
> +{
> +	struct tee_param t_param[MTK_TEE_PARAM_NUM] = {0};
> +	struct tee_ioctl_open_session_arg arg = {0};
> +	uuid_t ta_mem_uuid;
> +	int ret;
> +
> +	sec_heap->tee_ctx = tee_client_open_context(NULL, mtk_optee_ctx_match,
> +						    NULL, NULL);
> +	if (IS_ERR(sec_heap->tee_ctx)) {
> +		pr_err("%s: open context failed, ret=%ld\n", sec_heap->name,
> +		       PTR_ERR(sec_heap->tee_ctx));
> +		return -ENODEV;
> +	}
> +
> +	arg.num_params = MTK_TEE_PARAM_NUM;
> +	arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
> +	ret = uuid_parse(TZ_TA_MEM_UUID, &ta_mem_uuid);
> +	if (ret)
> +		goto close_context;
> +	memcpy(&arg.uuid, &ta_mem_uuid.b, sizeof(ta_mem_uuid));
> +
> +	ret = tee_client_open_session(sec_heap->tee_ctx, &arg, t_param);
> +	if (ret < 0 || arg.ret) {
> +		pr_err("%s: open session failed, ret=%d:%d\n",
> +		       sec_heap->name, ret, arg.ret);
> +		ret = -EINVAL;
> +		goto close_context;
> +	}
> +	sec_heap->mem_session = arg.session;
> +	return 0;
> +
> +close_context:
> +	tee_client_close_context(sec_heap->tee_ctx);
> +	return ret;
> +}
> +
>   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 *sec_heap = dma_heap_get_drvdata(heap);
>   	struct mtk_secure_heap_buffer *sec_buf;
>   	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
>   	struct dma_buf *dmabuf;
>   	int ret;
>   
> +	/*
> +	 * TEE probe may be late. Initialise the secure session in the first
> +	 * allocating secure buffer.
> +	 */
> +	if (!sec_heap->mem_session) {
> +		ret = mtk_kree_secure_session_init(sec_heap);
> +		if (ret)
> +			return ERR_PTR(ret);
> +	}
> +
>   	sec_buf = kzalloc(sizeof(*sec_buf), GFP_KERNEL);
>   	if (!sec_buf)
>   		return ERR_PTR(-ENOMEM);