On Tue, Jun 10, 2025 at 03:13:51PM +0200, 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 <[email protected]> > --- > 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(-)
Reviewed-by: Sumit Garg <[email protected]> -Sumit > > 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)); > + > + 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); > -- > 2.43.0 >
