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Date:   Tue, 12 Sep 2023 11:32:23 +0200
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Subject: Re: [PATCH 5/9] dma-buf: heaps: mtk_sec_heap: Initialise tee session
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References: <20230911023038.30649-1-yong.wu@mediatek.com>
 <20230911023038.30649-6-yong.wu@mediatek.com>
 <d0373c02-9b22-661f-9930-ca720053c2a0@collabora.com>
 <a115a2a5d3ac218e6db65ccdb0a1876f9cfca02b.camel@mediatek.com>
From:   AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>
In-Reply-To: <a115a2a5d3ac218e6db65ccdb0a1876f9cfca02b.camel@mediatek.com>
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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@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?
> 
> 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);
>>
>>