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

[Yong Wu (吴勇)]

On Tue, 2023-09-12 at 11:32 +0200, AngeloGioacchino Del Regno wrote:
> Il 12/09/23 08:17, Yong Wu (吴勇) ha scritto:
> > On Mon, 2023-09-11 at 11:29 +0200, AngeloGioacchino Del Regno
> > wrote:
> > > 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@xxxxxxxxxxxx>
> > > > ---
> > > >    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?
> > 
> > Yes. It is the same for all SoCs and all TZ versions currently.
> > 
> 
> That's good news!
> 
> Is this UUID used in any userspace component? (example: Android
> HALs?)

No. Userspace never use it. If userspace would like to allocate this
secure buffer, it can achieve through the existing dmabuf IOCTL via
/dev/dma_heap/mtk_svp node.


> If it is (and I somehow expect that it is), then this definition
> should go
> to a UAPI header, as suggested by Christian.
> 
> Cheers!
> 
> > > 
> > > 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);
> > > 
> > > 
> 
>