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

Jens Wiklander
2025-03-05T13:07:02Z

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) {
+ 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);
+ 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