static int optee_shm_register()

in optee/smc_abi.c [434:484]

• 39 lines of code
• 7 McCabe index (conditional complexity)

static int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
			      struct page **pages, size_t num_pages,
			      unsigned long start)
{
	struct optee *optee = tee_get_drvdata(ctx->teedev);
	struct optee_msg_arg *msg_arg;
	struct tee_shm *shm_arg;
	u64 *pages_list;
	int rc;

	if (!num_pages)
		return -EINVAL;

	rc = optee_check_mem_type(start, num_pages);
	if (rc)
		return rc;

	pages_list = optee_allocate_pages_list(num_pages);
	if (!pages_list)
		return -ENOMEM;

	shm_arg = optee_get_msg_arg(ctx, 1, &msg_arg);
	if (IS_ERR(shm_arg)) {
		rc = PTR_ERR(shm_arg);
		goto out;
	}

	optee_fill_pages_list(pages_list, pages, num_pages,
			      tee_shm_get_page_offset(shm));

	msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
	msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
				OPTEE_MSG_ATTR_NONCONTIG;
	msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
	msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
	/*
	 * In the least bits of msg_arg->params->u.tmem.buf_ptr we
	 * store buffer offset from 4k page, as described in OP-TEE ABI.
	 */
	msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
	  (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));

	if (optee->ops->do_call_with_arg(ctx, shm_arg) ||
	    msg_arg->ret != TEEC_SUCCESS)
		rc = -EINVAL;

	tee_shm_free(shm_arg);
out:
	optee_free_pages_list(pages_list, num_pages);
	return rc;
}