Hi Amir,

On Tue, Jun 24, 2025 at 8:54 AM Amirreza Zarrabi amirreza.zarrabi@oss.qualcomm.com wrote:

Hi Jens,

On 6/10/2025 11:13 PM, Jens Wiklander wrote:

...

Add support in the OP-TEE backend driver for protected memory allocation. The support is limited to only the SMC ABI and for secure video buffers.

OP-TEE is probed for the range of protected 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/Kconfig | 5 +++ drivers/tee/optee/core.c | 10 +++++ drivers/tee/optee/optee_private.h | 2 + drivers/tee/optee/smc_abi.c | 70 ++++++++++++++++++++++++++++++- 4 files changed, 85 insertions(+), 2 deletions(-)

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig index 7bb7990d0b07..50d2051f7f20 100644 --- a/drivers/tee/optee/Kconfig +++ b/drivers/tee/optee/Kconfig @@ -25,3 +25,8 @@ config OPTEE_INSECURE_LOAD_IMAGE

    Additional documentation on kernel security risks are at
    Documentation/tee/op-tee.rst.

+config OPTEE_STATIC_PROTMEM_POOL

• bool
  

• depends on HAS_IOMEM && TEE_DMABUF_HEAPS
  

• default y
  

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index c75fddc83576..4b14a7ac56f9 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -56,6 +56,15 @@ int optee_rpmb_intf_rdev(struct notifier_block *intf, unsigned long action, return 0; }

+int optee_set_dma_mask(struct optee *optee, u_int pa_width) +{

• u64 mask = DMA_BIT_MASK(min(64, pa_width));
  

nit: Why not dma_coerce_mask_and_coherent() instead of bellow?

Good point, I'll update in the next version.

Thanks, Jens

• Amir

...

• optee->teedev->dev.dma_mask = &optee->teedev->dev.coherent_dma_mask;
  

• return dma_set_mask_and_coherent(&optee->teedev->dev, mask);
  

+}

static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); @@ -181,6 +190,7 @@ 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/optee_private.h b/drivers/tee/optee/optee_private.h index dc0f355ef72a..5e3c34802121 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -272,6 +272,8 @@ struct optee_call_ctx {

extern struct blocking_notifier_head optee_rpmb_intf_added;

+int optee_set_dma_mask(struct optee *optee, u_int pa_width);

int optee_notif_init(struct optee *optee, u_int max_key); void optee_notif_uninit(struct optee *optee); int optee_notif_wait(struct optee *optee, u_int key, u32 timeout); diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index f0c3ac1103bb..cf106d15e64e 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1584,6 +1584,68 @@ static inline int optee_load_fw(struct platform_device *pdev, } #endif

+static struct tee_protmem_pool *static_protmem_pool_init(struct optee *optee) +{ +#if IS_ENABLED(CONFIG_OPTEE_STATIC_PROTMEM_POOL)

• union {
  

•         struct arm_smccc_res smccc;
  

•         struct optee_smc_get_protmem_config_result result;
  

• } res;
  

• struct tee_protmem_pool *pool;
  

• void *p;
  

• int rc;
  

• optee->smc.invoke_fn(OPTEE_SMC_GET_PROTMEM_CONFIG, 0, 0, 0, 0,
  

•                      0, 0, 0, &res.smccc);
  

• if (res.result.status != OPTEE_SMC_RETURN_OK)
  

•         return ERR_PTR(-EINVAL);
  

• rc = optee_set_dma_mask(optee, res.result.pa_width);
  

• if (rc)
  

•         return ERR_PTR(rc);
  

• /*
  

•  * Map the memory as uncached to make sure the kernel can work with
  

•  * __pfn_to_page() and friends since that's needed when passing the
  

•  * protected DMA-buf to a device. The memory should otherwise not
  

•  * be touched by the kernel since it's likely to cause an external
  

•  * abort due to the protection status.
  

•  */
  

• p = devm_memremap(&optee->teedev->dev, res.result.start,
  

•                   res.result.size, MEMREMAP_WC);
  

• if (IS_ERR(p))
  

•         return p;
  

• pool = tee_protmem_static_pool_alloc(res.result.start, res.result.size);
  

• if (IS_ERR(pool))
  

•         devm_memunmap(&optee->teedev->dev, p);
  

• return pool;
  

+#else

• return ERR_PTR(-EINVAL);
  

+#endif +}

+static int optee_protmem_pool_init(struct optee *optee) +{

• enum tee_dma_heap_id heap_id = TEE_DMA_HEAP_SECURE_VIDEO_PLAY;
  

• struct tee_protmem_pool *pool = ERR_PTR(-EINVAL);
  

• int rc;
  

• if (!(optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_PROTMEM))
  

•         return 0;
  

• pool = static_protmem_pool_init(optee);
  

• if (IS_ERR(pool))
  

•         return PTR_ERR(pool);
  

• rc = tee_device_register_dma_heap(optee->teedev, heap_id, pool);
  

• if (rc)
  

•         pool->ops->destroy_pool(pool);
  

• return rc;
  

+}

static int optee_probe(struct platform_device *pdev) { optee_invoke_fn *invoke_fn; @@ -1679,7 +1741,7 @@ 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;
  

@@ -1752,6 +1814,9 @@ static int optee_probe(struct platform_device *pdev) pr_info("Asynchronous notifications enabled\n"); }

• if (optee_protmem_pool_init(optee))
  

•         pr_info("Protected memory service not available\n");
  

• /*
   * Ensure that there are no pre-existing shm objects before enabling
   * the shm cache so that there's no chance of receiving an invalid
  

@@ -1787,6 +1852,7 @@ 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: @@ -1803,7 +1869,7 @@ 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);