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

[AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>]

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?)
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);