Re: [PATCH v6 08/10] optee: support restricted memory allocation

Sumit Garg
2025-03-25T07:07:25Z

On Wed, Mar 05, 2025 at 02:04:14PM +0100, Jens Wiklander wrote:
> Add support in the OP-TEE backend driver for restricted memory
> allocation. The support is limited to only the SMC ABI and for secure
> video buffers.
>
> OP-TEE is probed for the range of restricted physical memory and a
> memory pool allocator is initialized if OP-TEE have support for such
> memory.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> ---
> drivers/tee/optee/core.c | 1 +
> drivers/tee/optee/smc_abi.c | 44 +++++++++++++++++++++++++++++++++++--
> 2 files changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index c75fddc83576..c7fd8040480e 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -181,6 +181,7 @@ void optee_remove_common(struct optee *optee)
> tee_device_unregister(optee->supp_teedev);
> tee_device_unregister(optee->teedev);
>
> + tee_device_unregister_all_dma_heaps(optee->teedev);
> tee_shm_pool_free(optee->pool);
> optee_supp_uninit(&optee->supp);
> mutex_destroy(&optee->call_queue.mutex);
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index cfdae266548b..a14ff0b7d3b3 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -1620,6 +1620,41 @@ static inline int optee_load_fw(struct platform_device *pdev,
> }
> #endif
>
> +static int optee_sdp_pool_init(struct optee *optee)
> +{
> + enum tee_dma_heap_id heap_id = TEE_DMA_HEAP_SECURE_VIDEO_PLAY;
> + struct tee_rstmem_pool *pool;
> + int rc;
> +
> + if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP) {

Is this SDP capability an ABI yet since we haven't supported it in
upstream kernel? If no then can we rename it as
OPTEE_SMC_SEC_CAP_RSTMEM?

> + union {
> + struct arm_smccc_res smccc;
> + struct optee_smc_get_sdp_config_result result;
> + } res;
> +
> + optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0,
> + 0, &res.smccc);
> + if (res.result.status != OPTEE_SMC_RETURN_OK) {
> + pr_err("Secure Data Path service not available\n");
> + return 0;
> + }
> +
> + pool = tee_rstmem_static_pool_alloc(res.result.start,
> + res.result.size);
> + if (IS_ERR(pool))
> + return PTR_ERR(pool);
> +
> + rc = tee_device_register_dma_heap(optee->teedev, heap_id, pool);
> + if (rc)
> + goto err;
> + }
> +
> + return 0;
> +err:
> + pool->ops->destroy_pool(pool);
> + return rc;
> +}
> +
> static int optee_probe(struct platform_device *pdev)
> {
> optee_invoke_fn *invoke_fn;
> @@ -1715,7 +1750,7 @@ static int optee_probe(struct platform_device *pdev)
> optee = kzalloc(sizeof(*optee), GFP_KERNEL);
> if (!optee) {
> rc = -ENOMEM;
> - goto err_free_pool;
> + goto err_free_shm_pool;
> }
>
> optee->ops = &optee_ops;
> @@ -1788,6 +1823,10 @@ static int optee_probe(struct platform_device *pdev)
> pr_info("Asynchronous notifications enabled\n");
> }
>
> + rc = optee_sdp_pool_init(optee);

s/optee_sdp_pool_init/optee_rstmem_pool_init/

-Sumit

> + if (rc)
> + goto err_notif_uninit;
> +
> /*
> * Ensure that there are no pre-existing shm objects before enabling
> * the shm cache so that there's no chance of receiving an invalid
> @@ -1823,6 +1862,7 @@ static int optee_probe(struct platform_device *pdev)
> optee_disable_shm_cache(optee);
> optee_smc_notif_uninit_irq(optee);
> optee_unregister_devices();
> + tee_device_unregister_all_dma_heaps(optee->teedev);
> err_notif_uninit:
> optee_notif_uninit(optee);
> err_close_ctx:
> @@ -1839,7 +1879,7 @@ static int optee_probe(struct platform_device *pdev)
> tee_device_unregister(optee->teedev);
> err_free_optee:
> kfree(optee);
> -err_free_pool:
> +err_free_shm_pool:
> tee_shm_pool_free(pool);
> if (memremaped_shm)
> memunmap(memremaped_shm);
> --
> 2.43.0
>