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

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