Commit 0e32abef authored by Jens Wiklander's avatar Jens Wiklander
Browse files

optee: support protected memory allocation 



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.

Reviewed-by: default avatarSumit Garg <sumit.garg@oss.qualcomm.com>
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent ab09dd6d

drivers/tee/optee/Kconfig

+5 −0
Original line number Diff line number Diff line
@@ -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

drivers/tee/optee/core.c

+7 −0
Original line number Diff line number Diff line
@@ -56,6 +56,13 @@ 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));



	return dma_coerce_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));

drivers/tee/optee/optee_private.h

+2 −0
Original line number Diff line number Diff line
@@ -274,6 +274,8 @@ 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);

drivers/tee/optee/smc_abi.c

+67 −2
Original line number Diff line number Diff line
@@ -1583,6 +1583,68 @@ 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;
@@ -1678,7 +1740,7 @@ 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;
@@ -1751,6 +1813,9 @@ 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
@@ -1802,7 +1867,7 @@ 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);