From patchwork Thu Jan 24 05:54:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Garg X-Patchwork-Id: 156454 Delivered-To: patch@linaro.org Received: by 2002:a02:48:0:0:0:0:0 with SMTP id 69csp1563442jaa; Wed, 23 Jan 2019 21:55:34 -0800 (PST) X-Google-Smtp-Source: ALg8bN4jNeKDV60YQ1bwYw2hAgKqDYb78CJZXTjvQhBf+TRigIMldop1sdQbrmMogP+98Xz5FC72 X-Received: by 2002:a63:c303:: with SMTP id c3mr4771236pgd.268.1548309334619; Wed, 23 Jan 2019 21:55:34 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1548309334; cv=none; d=google.com; s=arc-20160816; b=KaahpEX0atctlrisOe4kQO2nEj9W0XmYWfyGGF9hBGGszPdl6gFo8SYRUtxuEe/g4/ xohEjBojwawcMCN9gcNyDFhW8nf8mX/N1MWFuRtnRCXI9s8lfSuKLNKoJd6xSeacmhCD mc28pjSpXxvTOicIW9duqjQ64VATsSNJaXcMKD3HKHngpihITNReD+BrUMzraeyE0u7J yA3+Qiz9etM4y1s56HlZjPgE3edOVhANqvB+MjEiKF1gGvMgnWQsnTeecF4vjCSppgFF WY3m5qE/zE7CMaElUEh5/9M4ClUoeX/lccjromHp+gjb/aOE2e5FQP5VbauHIi00iJHE pCuQ== 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=UB+824kJL77h2lS4dKLq0h0OL+opJbP1lzg8RMCla+0=; b=SrGC/yp1FJpClY1UVTM5STiHwlMneUx1I/IL/DNBpr/OWMmzOQ0q3FVuImWDhO3h97 D5PHGIroBh+l0//3lKr9uMh8mYHVlxwG+zyfjt+rH5nmU8ADyW66cfZ1M6XtW5j6UufG dgKMS3mF8Foc3ipqMaw7Uv77DdEcJiYfjkaOQnnuYYjicj4R6Ej3uxyQSSB7kOmx5Bg4 +R+f0KOHJD6su+PyjSVGjw+lNfTOS65BUFFip8bk/+e1ddeclCd9JgUzRze1RJ5dz/qc PtzsmwSczJ+9kUE77833iAuYOM2B1sjoitssRbPRioXsF5gPbW4HtCSsO6Vw6s4mr/5C ovQQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=i1+BPS00; 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 q4si21159435pfq.56.2019.01.23.21.55.34; Wed, 23 Jan 2019 21:55:34 -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=i1+BPS00; 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 S1727128AbfAXFzd (ORCPT + 3 others); Thu, 24 Jan 2019 00:55:33 -0500 Received: from mail-pg1-f194.google.com ([209.85.215.194]:45848 "EHLO mail-pg1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726233AbfAXFzd (ORCPT ); Thu, 24 Jan 2019 00:55:33 -0500 Received: by mail-pg1-f194.google.com with SMTP id y4so2175361pgc.12 for ; Wed, 23 Jan 2019 21:55:32 -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=UB+824kJL77h2lS4dKLq0h0OL+opJbP1lzg8RMCla+0=; b=i1+BPS00e2UoU+VZ9Qtxtg1aKiqhEgePjKlQSmkJ6yWx/iiYkHj491z+d4Fe/pJ9VZ cBiPPf7+LaeVsGeozs8p4ufYIRBgkDdQrMHPjOE8/OQopVxQigEyhql/MFZ70bSm1GS0 bRLI31AX1rtUQC4CubMFUuFC55VmduauARyqQ= 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=UB+824kJL77h2lS4dKLq0h0OL+opJbP1lzg8RMCla+0=; b=XxPXdk1SUwljbvHfBzkY6MYvTYDvI7sPnEqsvTKy4sQ+GlE73O+7wID2E6ZCZVpK+M UCSIkMOT9lE+1OXh5oQTwtgQnnbuIm4+MA1T6JgHiNXrcCB00KVnrZ1XeFcHoHgEY2bO uJ8y5dirl7qzV2kHS8689KnhasyWVVICVL+iA/1JViFqn1SKKquF/rGTbzqlFiLU4ixi xxlONi+CIKIWp4ZoDIAowZJ70JynwzLI6klTu0euEEzDJ85iQpgPOwWGJJt33+TJuEsv F5AFHnDfVqwNNSc0VJGksTyonbIBxu+oLe1f5uWEhphT5h3Butqat3gG6xqDinX7UHfa DL9A== X-Gm-Message-State: AJcUukdUiweBZLJC5LTbn3HHEwqrI0tHWr3SgAPmo5LNACtqg4+iUtf+ u0Cpe7MxPczQTRUluZpxE3J6Zg== X-Received: by 2002:a62:cf84:: with SMTP id b126mr5108489pfg.98.1548309332450; Wed, 23 Jan 2019 21:55:32 -0800 (PST) Received: from localhost.localdomain ([117.196.233.31]) by smtp.gmail.com with ESMTPSA id i2sm32297287pfi.66.2019.01.23.21.55.25 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 23 Jan 2019 21:55:31 -0800 (PST) From: Sumit Garg To: jens.wiklander@linaro.org, herbert@gondor.apana.org.au, ard.biesheuvel@linaro.org Cc: linux-arm-kernel@lists.infradead.org, linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org, yamada.masahiro@socionext.com, michal.lkml@markovi.net, mpm@selenic.com, robh+dt@kernel.org, mark.rutland@arm.com, arnd@arndb.de, gregkh@linuxfoundation.org, daniel.thompson@linaro.org, bhsharma@redhat.com, tee-dev@lists.linaro.org, Sumit Garg Subject: [PATCH v5 4/4] hwrng: add OP-TEE based rng driver Date: Thu, 24 Jan 2019 11:24:39 +0530 Message-Id: <1548309279-5281-5-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1548309279-5281-1-git-send-email-sumit.garg@linaro.org> References: <1548309279-5281-1-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. This driver registers on TEE bus to interact with OP-TEE based rng device/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 | 274 +++++++++++++++++++++++++++++++++++++ 4 files changed, 295 insertions(+) create mode 100644 drivers/char/hw_random/optee-rng.c -- 2.7.4 diff --git a/MAINTAINERS b/MAINTAINERS index 51029a4..dcef7e9 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11262,6 +11262,11 @@ 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..4ad0eca --- /dev/null +++ b/drivers/char/hw_random/optee-rng.c @@ -0,0 +1,274 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018-2019 Linaro Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRIVER_NAME "optee-rng" + +#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_session_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_ENTROPY function of Trusted App */ + inv_arg.func = TA_CMD_GET_ENTROPY; + inv_arg.session = ta_rng_session_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 = DRIVER_NAME, + .init = optee_rng_init, + .cleanup = optee_rng_cleanup, + .read = optee_rng_read, +}; + +static int get_optee_rng_info(struct device *dev) +{ + u32 ret = 0; + struct tee_ioctl_invoke_arg inv_arg = {0}; + struct tee_param param[4] = {0}; + + /* Invoke TA_CMD_GET_RNG_INFO function of Trusted App */ + inv_arg.func = TA_CMD_GET_RNG_INFO; + inv_arg.session = ta_rng_session_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)) { + dev_err(dev, "TA_CMD_GET_RNG_INFO invoke func 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 optee_rng_probe(struct device *dev) +{ + struct tee_client_device *rng_device = to_tee_client_device(dev); + int ret = 0, err = -ENODEV; + struct tee_ioctl_open_session_arg sess_arg = {0}; + + /* 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, rng_device->id.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)) { + dev_err(dev, "tee_client_open_session failed, error: %x\n", + sess_arg.ret); + err = -EINVAL; + goto out_ctx; + } + ta_rng_session_id = sess_arg.session; + + err = get_optee_rng_info(dev); + if (err) + goto out_sess; + + err = hwrng_register(&optee_rng); + if (err) { + dev_err(dev, "hwrng registration failed (%d)\n", err); + goto out_sess; + } + + return 0; + +out_sess: + tee_client_close_session(ctx, ta_rng_session_id); +out_ctx: + tee_client_close_context(ctx); + + return err; +} + +static int optee_rng_remove(struct device *dev) +{ + hwrng_unregister(&optee_rng); + tee_client_close_session(ctx, ta_rng_session_id); + tee_client_close_context(ctx); + + return 0; +} + +const struct tee_client_device_id optee_rng_id_table[] = { + {UUID_INIT(0xab7a617c, 0xb8e7, 0x4d8f, + 0x83, 0x01, 0xd0, 0x9b, 0x61, 0x03, 0x6b, 0x64)}, + {} +}; + +MODULE_DEVICE_TABLE(tee, optee_rng_id_table); + +static struct tee_client_driver optee_rng_driver = { + .id_table = optee_rng_id_table, + .driver = { + .name = DRIVER_NAME, + .bus = &tee_bus_type, + .probe = optee_rng_probe, + .remove = optee_rng_remove, + }, +}; + +static int __init optee_rng_mod_init(void) +{ + int rc; + + rc = driver_register(&optee_rng_driver.driver); + if (rc) + pr_warn("driver registration failed, err: %d", rc); + + return rc; +} + +static void __exit optee_rng_mod_exit(void) +{ + driver_unregister(&optee_rng_driver.driver); +} + +module_init(optee_rng_mod_init); +module_exit(optee_rng_mod_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Sumit Garg "); +MODULE_DESCRIPTION("OP-TEE based random number generator driver");