From patchwork Thu Dec 27 11:07:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Garg X-Patchwork-Id: 154568 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp6817074ljp; Thu, 27 Dec 2018 03:08:13 -0800 (PST) X-Google-Smtp-Source: ALg8bN77oIzDUg+nll1DiwDuECUDZtKs8YBu6XQcbdxD2LCEa472W5kRvW+wAZtPbcOcHQ8iKRVJ X-Received: by 2002:a17:902:b48b:: with SMTP id y11mr22561652plr.200.1545908893260; Thu, 27 Dec 2018 03:08:13 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545908893; cv=none; d=google.com; s=arc-20160816; b=hlpAVA5fhvRDj1aKbhwB9InJXGrBHYj6z2D2EpHC95i1FWN+IanPBEOBsaK96AIcQK RLiAHNelabzAoPjXd5O1/y4REitTFQxuiV8awi1Z6zLv6B6zZSFa3s5+mjqb1v13MS6a b8D5ZDtK49vMnukeea6OKEV4Z70qJQDRR7qGZxm1GmEDhRV+oJXDwepRrF70gNqrx4uf pM/zSDhg95FVy1yg3YO5dQlZ92QAnTVnM6MD8WthikPB4NubhaghfB1+5w10ZwnD5w/k QZpSEwnGYeoZOUEonsnKBovZ4fSnMcC7XsNx49pUZ+wmh0MpEl2gq5qJvnVb9z0MENop U4zw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=uuHGIoyqQtttS9xE06KahrWzGw46xmUc9M7qxbxCq40=; b=Lkgy7FYS3qgIdos8W8dCKyHiUx/NK5fsAn7ECNWWQ9f/Zu3vUAW8sOt9bg4N/JVvFB oMuAUgHUN0NQCEQggUpgwDUhc4iE0+gXrEUKYFaZBZFHvs0xljvbon4zB69gJhpRk+8z 3QNLb/RzpAksVbvTHqlR0r5uGDWDkkcLeNiWPCDowPHllnEIFAXlxFKnEVFBC5r4aKFz pfaAQDs/besW5XGw1wodWZ1IOPiZtXQszNaBO/DBaUUbtI0MrrBrqM/+0TId5gxVcrJG 0g+UP9YseF7l220HL1eegpzchBV1m7clD+pD6PcG7BpopBs77OzYqRuzZtsnqU4BvrjV Mk9A== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=OIDPQOoj; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id y123si18083184pfy.18.2018.12.27.03.08.13; Thu, 27 Dec 2018 03:08:13 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=OIDPQOoj; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730412AbeL0LIM (ORCPT + 3 others); Thu, 27 Dec 2018 06:08:12 -0500 Received: from mail-pf1-f194.google.com ([209.85.210.194]:41328 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729577AbeL0LIM (ORCPT ); Thu, 27 Dec 2018 06:08:12 -0500 Received: by mail-pf1-f194.google.com with SMTP id b7so9028635pfi.8 for ; Thu, 27 Dec 2018 03:08:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=uuHGIoyqQtttS9xE06KahrWzGw46xmUc9M7qxbxCq40=; b=OIDPQOojRVw/yysvVtdJuV0+nfjn7i7oEmYq0TbwQMgA8v8gQBUNCFd/7fn7ldPJ5d 942DoOk8Vf078UaJkmYFsZ+Dkz5UnMsk1OqcgCT/y4iLxxJ8ehaix1JlG8E6KTj2nDFG ltS6JJs/i3tb0ZUk9jGIctymRt3js8tBkMIOM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=uuHGIoyqQtttS9xE06KahrWzGw46xmUc9M7qxbxCq40=; b=Qs5V9yhnXIJ1uTHTPTY+DNEexGJUgW6YaKTmyf0glXWsGfPuzjFDouRWTwJpNw4IL2 CsY5v2vQG5BmDExFU0LrVTRr8wvAcu87UJtBjucHAKpEb4xk3do4Gs4q+DKAGWARUwZD K8KpfWY6A+1fSfUWZM8Ana1fEptIXxwbaR+ItimWAuHCnsVru3qhcLH18w0B5suHxD43 qTn9MfcVM1DMnTD02QDB5dTLLkBYVq/RhP5LsBMI0mDN0P+o76Medyyrses56C4cz7H3 KB+H6dqMnrfl5kpd28Vb2k86uM+vGsPXb9OYW0T6ba6HvPIp3+WkGGC7kLLCUqsJ5Um/ ciWg== X-Gm-Message-State: AJcUukdVG73Cp6AZBkAgkKEcM4KfaZ+Ai4Lyps7lePqxeuCDWlaraVoL nBflYyQj3wCBn9tky/ks8/TPYGV2McA= X-Received: by 2002:a63:4246:: with SMTP id p67mr22052895pga.335.1545908891391; Thu, 27 Dec 2018 03:08:11 -0800 (PST) Received: from localhost.localdomain ([117.196.233.51]) by smtp.gmail.com with ESMTPSA id v89sm56068526pfk.12.2018.12.27.03.08.05 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 27 Dec 2018 03:08:11 -0800 (PST) From: Sumit Garg To: linux-crypto@vger.kernel.org, devicetree@vger.kernel.org Cc: mpm@selenic.com, herbert@gondor.apana.org.au, robh+dt@kernel.org, mark.rutland@arm.com, arnd@arndb.de, gregkh@linuxfoundation.org, jens.wiklander@linaro.org, daniel.thompson@linaro.org, ard.biesheuvel@linaro.org, bhsharma@redhat.com, tee-dev@lists.linaro.org, Sumit Garg Subject: [PATCH v1 1/2] dt/bindings: add bindings for optional optee rng-uuid property Date: Thu, 27 Dec 2018 16:37:10 +0530 Message-Id: <1545908831-25910-2-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1545908831-25910-1-git-send-email-sumit.garg@linaro.org> References: <1545908831-25910-1-git-send-email-sumit.garg@linaro.org> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Add bindings for OP-TEE based optional hardware random number generator identifier property. It could be used on ARM based devices where entropy source is not accessible to normal world (linux in this case). Signed-off-by: Sumit Garg --- Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt | 4 ++++ 1 file changed, 4 insertions(+) -- 2.7.4 diff --git a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt index d38834c..e3a4c35 100644 --- a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt +++ b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt @@ -20,6 +20,9 @@ the reference implementation maintained by Linaro. "hvc" : HVC #0, with the register assignments specified in drivers/tee/optee/optee_smc.h +- rng-uuid : Optional OP-TEE based RNG service identifier in case + hardware entropy source is not accesible to normal world + (Linux). Example: @@ -27,5 +30,6 @@ Example: optee { compatible = "linaro,optee-tz"; method = "smc"; + rng-uuid = "ab7a617c-b8e7-4d8f-8301-d09b61036b64"; }; }; From patchwork Thu Dec 27 11:07:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Garg X-Patchwork-Id: 154569 Delivered-To: patch@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp6817233ljp; Thu, 27 Dec 2018 03:08:21 -0800 (PST) X-Google-Smtp-Source: ALg8bN7SmxukkVV9w5TJIFi9oowOz1lS5vkkEibaKkXj3xG3mUEyS0jmL3lMBiZumDvM5D2SFP8Z X-Received: by 2002:a17:902:830a:: with SMTP id bd10mr23362196plb.321.1545908901078; Thu, 27 Dec 2018 03:08:21 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545908901; cv=none; d=google.com; s=arc-20160816; b=rC6LVl1EYdsc/kDM23w0mLcVwTpSQrB4bfxiINRpXw4wbM0toOcley2yskWg9J0+hy 79dgYoLQ5A3h4o+2WVNCCgVaDdmhKMEwCARdKCwvQHXhMVhkpnJ/X/8bRvfTlm7j9ty5 ngqrU9Ng1sVwXRPOCf1N1pI7fWmRQmLUfxznhRwOdazOtmFbvfJYOj0I340g2DqnWaOx El5HQ6HQkF904RyMMvVyTJwpw7orqlwjYkLYQOROZpCszNuydzbVclhqKKFoYAno70k2 /H+nshiaTn3nVwOaUIAXer8db2KgxfKG9rqkNo0m8xMuyK25/89TwYoyNYwbXZDQXGA8 qTbw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:references:in-reply-to:message-id:date :subject:cc:to:from:dkim-signature; bh=lEV1sQIjeJ8vtxMw/gLYYroGy1n8/nbUQr7aTOoZJo4=; b=UsuRDpqFIpCC26VMwoKjML1SJR8t9sneYFeXrkuYd1FFOcLCxALwNns6P0H7BdL+ft U/vGs/yWsXrsSORzZHy974+qxaGs7iPm6TnLTlhUEqQAFY1dip8k9iT++zIdbuzlH/dx ht8ICkzYXKuVNIib5kbPJEUHX2fCAPs9K4nBc2nG1hDUgdpd2KXEjF1hgSBsYow27W+V YBUdJsHTzL4MVGrPCgrAyqTR5TfyXMO+/paIbNOEGIMXD+GfBCyFcuddh2nkM0jejrxx UYhUUn4GptloMO5s17nMO1pcmagKjbS8zu1zszByrKiXxFLC+yISF3VwwVmwNRLKB95O 3ECQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=K+txpp+o; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id x2si26287202pgi.152.2018.12.27.03.08.20; Thu, 27 Dec 2018 03:08:21 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=K+txpp+o; spf=pass (google.com: best guess record for domain of linux-crypto-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-crypto-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729577AbeL0LIT (ORCPT + 3 others); Thu, 27 Dec 2018 06:08:19 -0500 Received: from mail-pl1-f195.google.com ([209.85.214.195]:33298 "EHLO mail-pl1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730453AbeL0LIT (ORCPT ); Thu, 27 Dec 2018 06:08:19 -0500 Received: by mail-pl1-f195.google.com with SMTP id z23so8670295plo.0 for ; Thu, 27 Dec 2018 03:08:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=lEV1sQIjeJ8vtxMw/gLYYroGy1n8/nbUQr7aTOoZJo4=; b=K+txpp+oieTB+eznyho3pBiCw/6XVARlyrgEj89j7G5z/h+oFWhob1aaTO+XgfzRHj 5HGZDSfAV/Z6n6L6BwEKLlqCZhGt2aTuTRIV8vxm/1U0aSDPdcu+ob4DJdrbAv4wmOHp cDo/KNzpNWEuaA563XgNnbVrcPkfZb6BgNCAY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=lEV1sQIjeJ8vtxMw/gLYYroGy1n8/nbUQr7aTOoZJo4=; b=U1gLH436GJCbie9aA4+9ffZgCPp7YHwkbjYDQaEW13VkAlOVMxSShjjpl2QO5L5Tcb j475D0hrLS1MT/snIzYdfo3DmsTrTqXxRs7IsDLkva0pIfxj8b4JYuGsKwfYuwH/XDa7 wihYUsp+0MfYfk5zlRDiQNSxxAdgBjS2Jt7zKxHBrXr9BdFYozRRJCnqCEtAWXYDfI4Q ouTc3HIqaGWS3WTIw1BY12tVdcY35jAMefM04AOJUukgjDtyXP7adUAvJu7W7aSLw1LH sMFgBpgq6WWxEodckCOoBES2yYQyAUldNfDwaJuzNCZkiLGAT0OLonnYus/AHOCU7zHR cZMQ== X-Gm-Message-State: AJcUukfUOyCsf/++CpBYD7qpXCTdneZ5zRJZ8tLSfcFjpRb1EZFEhARy VVJ/RmwgadhV2pOagFaeVOr54AK6ZcM= X-Received: by 2002:a17:902:6502:: with SMTP id b2mr22944447plk.44.1545908897959; Thu, 27 Dec 2018 03:08:17 -0800 (PST) Received: from localhost.localdomain ([117.196.233.51]) by smtp.gmail.com with ESMTPSA id v89sm56068526pfk.12.2018.12.27.03.08.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Thu, 27 Dec 2018 03:08:17 -0800 (PST) From: Sumit Garg To: linux-crypto@vger.kernel.org, devicetree@vger.kernel.org Cc: mpm@selenic.com, herbert@gondor.apana.org.au, robh+dt@kernel.org, mark.rutland@arm.com, arnd@arndb.de, gregkh@linuxfoundation.org, jens.wiklander@linaro.org, daniel.thompson@linaro.org, ard.biesheuvel@linaro.org, bhsharma@redhat.com, tee-dev@lists.linaro.org, Sumit Garg Subject: [PATCH v1 2/2] hwrng: add OP-TEE based rng driver Date: Thu, 27 Dec 2018 16:37:11 +0530 Message-Id: <1545908831-25910-3-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1545908831-25910-1-git-send-email-sumit.garg@linaro.org> References: <1545908831-25910-1-git-send-email-sumit.garg@linaro.org> Sender: linux-crypto-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org On ARM SoC's with TrustZone enabled, peripherals like entropy sources might not be accessible to normal world (linux in this case) and rather accessible to secure world (OP-TEE in this case) only. So this driver aims to provides a generic interface to OP-TEE based random number generator service. Signed-off-by: Sumit Garg --- MAINTAINERS | 5 + drivers/char/hw_random/Kconfig | 15 ++ drivers/char/hw_random/Makefile | 1 + drivers/char/hw_random/optee-rng.c | 273 +++++++++++++++++++++++++++++++++++++ 4 files changed, 294 insertions(+) create mode 100644 drivers/char/hw_random/optee-rng.c -- 2.7.4 diff --git a/MAINTAINERS b/MAINTAINERS index 0767f1d..fe0fb74 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11100,6 +11100,11 @@ M: Jens Wiklander S: Maintained F: drivers/tee/optee/ +OP-TEE RANDOM NUMBER GENERATOR (RNG) DRIVER +M: Sumit Garg +S: Maintained +F: drivers/char/hw_random/optee-rng.c + OPA-VNIC DRIVER M: Dennis Dalessandro M: Niranjana Vishwanathapura diff --git a/drivers/char/hw_random/Kconfig b/drivers/char/hw_random/Kconfig index dac895d..25a7d8f 100644 --- a/drivers/char/hw_random/Kconfig +++ b/drivers/char/hw_random/Kconfig @@ -424,6 +424,21 @@ config HW_RANDOM_EXYNOS will be called exynos-trng. If unsure, say Y. + +config HW_RANDOM_OPTEE + tristate "OP-TEE based Random Number Generator support" + depends on OPTEE + default HW_RANDOM + help + This driver provides support for OP-TEE based Random Number + Generator on ARM SoCs where hardware entropy sources are not + accessible to normal world (Linux). + + To compile this driver as a module, choose M here: the module + will be called optee-rng. + + If unsure, say Y. + endif # HW_RANDOM config UML_RANDOM diff --git a/drivers/char/hw_random/Makefile b/drivers/char/hw_random/Makefile index e35ec3c..7c9ef4a 100644 --- a/drivers/char/hw_random/Makefile +++ b/drivers/char/hw_random/Makefile @@ -38,3 +38,4 @@ obj-$(CONFIG_HW_RANDOM_CAVIUM) += cavium-rng.o cavium-rng-vf.o obj-$(CONFIG_HW_RANDOM_MTK) += mtk-rng.o obj-$(CONFIG_HW_RANDOM_S390) += s390-trng.o obj-$(CONFIG_HW_RANDOM_KEYSTONE) += ks-sa-rng.o +obj-$(CONFIG_HW_RANDOM_OPTEE) += optee-rng.o diff --git a/drivers/char/hw_random/optee-rng.c b/drivers/char/hw_random/optee-rng.c new file mode 100644 index 0000000..8c63730 --- /dev/null +++ b/drivers/char/hw_random/optee-rng.c @@ -0,0 +1,273 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Linaro Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001 + +/* + * TA_CMD_GET_ENTROPY - Get Entropy from RNG + * + * param[0] (inout memref) - Entropy buffer memory reference + * param[1] unused + * param[2] unused + * param[3] unused + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + * TEE_ERROR_NOT_SUPPORTED - Requested entropy size greater than size of pool + * TEE_ERROR_HEALTH_TEST_FAIL - Continuous health testing failed + */ +#define TA_CMD_GET_ENTROPY 0x0 + +/* + * TA_CMD_GET_RNG_INFO - Get RNG information + * + * param[0] (out value) - value.a: RNG data-rate in bytes per second + * value.b: Quality/Entropy per 1024 bit of data + * param[1] unused + * param[2] unused + * param[3] unused + * + * Result: + * TEE_SUCCESS - Invoke command success + * TEE_ERROR_BAD_PARAMETERS - Incorrect input param + */ +#define TA_CMD_GET_RNG_INFO 0x1 + +#define MAX_ENTROPY_REQ_SZ (4 * 1024) + +static struct tee_context *ctx; +static struct tee_shm *entropy_shm_pool; +static u32 ta_rng_data_rate; +static u32 ta_rng_seesion_id; + +static size_t get_optee_rng_data(void *buf, size_t req_size) +{ + u32 ret = 0; + u8 *rng_data = NULL; + size_t rng_size = 0; + struct tee_ioctl_invoke_arg inv_arg = {0}; + struct tee_param param[4] = {0}; + + /* Invoke TA_CMD_GET_RNG function of Trusted App */ + inv_arg.func = TA_CMD_GET_ENTROPY; + inv_arg.session = ta_rng_seesion_id; + inv_arg.num_params = 4; + + /* Fill invoke cmd params */ + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT; + param[0].u.memref.shm = entropy_shm_pool; + param[0].u.memref.size = req_size; + param[0].u.memref.shm_offs = 0; + + ret = tee_client_invoke_func(ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + pr_err("TA_CMD_GET_ENTROPY invoke function error: %x\n", + inv_arg.ret); + return 0; + } + + rng_data = tee_shm_get_va(entropy_shm_pool, 0); + if (IS_ERR(rng_data)) { + pr_err("tee_shm_get_va failed\n"); + return 0; + } + + rng_size = param[0].u.memref.size; + memcpy(buf, rng_data, rng_size); + + return rng_size; +} + +static int optee_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) +{ + u8 *data = buf; + size_t read = 0, rng_size = 0; + int timeout = 1; + + if (max > MAX_ENTROPY_REQ_SZ) + max = MAX_ENTROPY_REQ_SZ; + + while (read == 0) { + rng_size = get_optee_rng_data(data, (max - read)); + + data += rng_size; + read += rng_size; + + if (wait) { + if (timeout-- == 0) + return read; + msleep((1000 * (max - read)) / ta_rng_data_rate); + } else { + return read; + } + } + + return read; +} + +static int optee_rng_init(struct hwrng *rng) +{ + entropy_shm_pool = tee_shm_alloc(ctx, MAX_ENTROPY_REQ_SZ, + TEE_SHM_MAPPED | TEE_SHM_DMA_BUF); + if (IS_ERR(entropy_shm_pool)) { + pr_err("tee_shm_alloc failed\n"); + return PTR_ERR(entropy_shm_pool); + } + + return 0; +} + +static void optee_rng_cleanup(struct hwrng *rng) +{ + tee_shm_free(entropy_shm_pool); +} + +static struct hwrng optee_rng = { + .name = "optee-rng", + .init = optee_rng_init, + .cleanup = optee_rng_cleanup, + .read = optee_rng_read, +}; + +static const struct of_device_id optee_match[] = { + { .compatible = "linaro,optee-tz" }, + {}, +}; + +static int get_optee_rng_uuid(uuid_t *ta_rng_uuid) +{ + struct device_node *fw_np; + struct device_node *np; + const char *uuid; + + /* Node is supposed to be below /firmware */ + fw_np = of_find_node_by_name(NULL, "firmware"); + if (!fw_np) + return -ENODEV; + + np = of_find_matching_node(fw_np, optee_match); + if (!np || !of_device_is_available(np)) + return -ENODEV; + + if (of_property_read_string(np, "rng-uuid", &uuid)) { + pr_warn("missing \"uuid\" property\n"); + return -ENXIO; + } + + if (uuid_parse(uuid, ta_rng_uuid)) { + pr_warn("incorrect rng ta uuid\n"); + return -EINVAL; + } + + return 0; +} + +static int get_optee_rng_info(void) +{ + u32 ret = 0; + struct tee_ioctl_invoke_arg inv_arg = {0}; + struct tee_param param[4] = {0}; + + /* Invoke TA_CMD_GET_RNG function of Trusted App */ + inv_arg.func = TA_CMD_GET_RNG_INFO; + inv_arg.session = ta_rng_seesion_id; + inv_arg.num_params = 4; + + /* Fill invoke cmd params */ + param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT; + + ret = tee_client_invoke_func(ctx, &inv_arg, param); + if ((ret < 0) || (inv_arg.ret != 0)) { + pr_err("TA_CMD_GET_RNG_INFO invoke function error: %x\n", + inv_arg.ret); + return -EINVAL; + } + + ta_rng_data_rate = param[0].u.value.a; + optee_rng.quality = param[0].u.value.b; + + return 0; +} + +static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) +{ + if (ver->impl_id == TEE_IMPL_ID_OPTEE) + return 1; + else + return 0; +} + +static int __init mod_init(void) +{ + int ret = 0, err = -ENODEV; + struct tee_ioctl_open_session_arg sess_arg = {0}; + uuid_t ta_rng_uuid = {0}; + + err = get_optee_rng_uuid(&ta_rng_uuid); + if (err) + return err; + + /* Open context with TEE driver */ + ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL); + if (IS_ERR(ctx)) + return -ENODEV; + + /* Open session with hwrng Trusted App */ + memcpy(sess_arg.uuid, ta_rng_uuid.b, TEE_IOCTL_UUID_LEN); + sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC; + sess_arg.num_params = 0; + + ret = tee_client_open_session(ctx, &sess_arg, NULL); + if ((ret < 0) || (sess_arg.ret != 0)) { + pr_err("tee_client_open_session failed, error: %x\n", + sess_arg.ret); + err = -EINVAL; + goto out_ctx; + } + ta_rng_seesion_id = sess_arg.session; + + err = get_optee_rng_info(); + if (err) + goto out_sess; + + err = hwrng_register(&optee_rng); + if (err) { + pr_err("registering failed (%d)\n", err); + goto out_sess; + } + + return 0; + +out_sess: + tee_client_close_session(ctx, ta_rng_seesion_id); +out_ctx: + tee_client_close_context(ctx); + + return err; +} + +static void __exit mod_exit(void) +{ + tee_client_close_session(ctx, ta_rng_seesion_id); + tee_client_close_context(ctx); + hwrng_unregister(&optee_rng); +} + +module_init(mod_init); +module_exit(mod_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Sumit Garg "); +MODULE_DESCRIPTION("OP-TEE based random number generator driver"); +MODULE_SOFTDEP("pre: optee");