From patchwork Tue Dec 18 12:37:30 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Garg X-Patchwork-Id: 154136 Delivered-To: patches@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp3657774ljp; Tue, 18 Dec 2018 04:37:57 -0800 (PST) X-Received: by 2002:a17:902:209:: with SMTP id 9mr16596003plc.288.1545136677001; Tue, 18 Dec 2018 04:37:57 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545136676; cv=none; d=google.com; s=arc-20160816; b=lToRgzjTsFoXAnnGq5e2oodo6mKUIUoGQHt0sIIc4DdXlUuMBANGOs739Y4f3JvlMT 5FKz9517UzEkHxkeGq4L73JcA/w0IdN3QeIgVsUMRZyRrkumUuCUzJ2X5PY1FLKqmrTO shVzQJughzk46YOnTaU7O0cShDx8PHxe7IFdXP+v6p1RhEqMnjOriGhmpp6GCbORciE1 soGOTVdiW30aGuOA5ZF+EXTznBaVd9YNfnzzFM8oiq6hQzam3LV+ae6C2H2ZLvl+QDjM ITmQTo5eeiDAhP6U2ToDl0Uw3eJVjBRmQPZhcRBD0OADK/uS5xLGM9L2kICo7SsSml+O wFQA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=dF7w3Iz4no/GB1OJhGsoU5IeShQF3P1gFHJ0K9wiEq4=; b=sqyD/qkXuVILddcy6EgklufDhrPvRu0tZtI0WqkLt2XHSQZlif/t3ouRQ97IxKoIoP HbS86wqq/83vPMNjnnq4olu69K16/1xgWvalt3KVW5DWVhwbpXfldMY1oQGLuM7JCFOS nuuceNcJsoh6wOxT6WOqEwHMqwpyIWTod0n+7YxV6DfYrhrShloR5wL4M5k4VU0GchVT 6kKeioLKcPm0Fx3MuwMnVi/3KXcnRzVqVWEu2+w0P8poTFOWoXhMBxYNIB1Z24u46bUH dU/njdHFk0pUaUNgbVBSoITEdtCLq36nsg3hxmuc4sRLOE8qKTnErSJC1uE46lCPr8OK x+Iw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=UJrnSvt4; spf=pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=sumit.garg@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id q22sor23117609pll.36.2018.12.18.04.37.56 for (Google Transport Security); Tue, 18 Dec 2018 04:37:56 -0800 (PST) Received-SPF: pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=UJrnSvt4; spf=pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=sumit.garg@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org 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=dF7w3Iz4no/GB1OJhGsoU5IeShQF3P1gFHJ0K9wiEq4=; b=UJrnSvt4VkH8wHFWnwItmgRQuW/pklKLMBtM5/20q0TrTsw91ahUBjUq8WwVxuhif5 k8b3WFaahGZDZDMs9I2pfsUA+VPb2Q6RNhn9KGRA2OWXjOOs1LEgPnC+3fXjL91WHLhQ iDaDmoNSokN1DvsqP0A79cObJGzgtY1w3QObE= 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=dF7w3Iz4no/GB1OJhGsoU5IeShQF3P1gFHJ0K9wiEq4=; b=B2q4P+glF6WxRQKMZ8snW+wt4vAT9xWeNSijShnoVVr+TonsGu5g0yhC/k+kWQc/9R Qj9PUThprdCCcVwhIGRDtQCsU4Oi8KCTfHMwOWAKaS5dyvo6SHndJaMAC1nzU5UbHL/Z 0dv/66Y21UFkdOWLLh2NhbZ6i99Qnk/fcKqU9Dk+NiaA+2vtckmEPlnH7cZ34bWRVqp9 o2TQP63YjP3YZTJRXyrfdtkjCL+agAeuNQGbqp26qbPtTS9r4ECHhGObGEchhDN81ftF +jYi2DaTAE9QEp7IwEh+y2zmUFAMshcj1HPqyuDhWxBXdlsPzAMo8woucDs6eexDsvcA ygMw== X-Gm-Message-State: AA+aEWZgT9r0rCPVrFUvTOJO1J1Ec99Izxhw6GXRvEpEyozSmyZIdb3O rzQJaH7A2nuCNqGHBWgjno1LoUZR X-Google-Smtp-Source: AFSGD/Vut9qi4Jp9mD3dqvH0HavtBUVVbcggDwmjQFsG1PZenVml9SRTSL/YWE1i5VB9OBZ7J0kPdQ== X-Received: by 2002:a17:902:9a02:: with SMTP id v2mr16678806plp.180.1545136676522; Tue, 18 Dec 2018 04:37:56 -0800 (PST) Return-Path: Received: from localhost.localdomain ([117.196.232.175]) by smtp.gmail.com with ESMTPSA id a15sm21880529pgb.1.2018.12.18.04.37.54 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 18 Dec 2018 04:37:56 -0800 (PST) From: Sumit Garg To: daniel.thompson@linaro.org Cc: patches@linaro.org, Sumit Garg Subject: [PATCH 1/2] dt/bindings: add bindings for optional optee hw-rng node Date: Tue, 18 Dec 2018 18:07:30 +0530 Message-Id: <1545136651-25776-2-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1545136651-25776-1-git-send-email-sumit.garg@linaro.org> References: <1545136651-25776-1-git-send-email-sumit.garg@linaro.org> Add bindings for OP-TEE based optional hardware random number generator. 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 --- .../devicetree/bindings/arm/firmware/linaro,optee-tz.txt | 16 ++++++++++++++++ 1 file changed, 16 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..f567566 100644 --- a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt +++ b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.txt @@ -20,12 +20,28 @@ the reference implementation maintained by Linaro. "hvc" : HVC #0, with the register assignments specified in drivers/tee/optee/optee_smc.h +- hw-rng : Optional OP-TEE based hardware RNG in case hardware + entropy source is not accesible to normal world (Linux). + - uuid: Trusted Application identifier which implements + hw-rng + + - data-rate: Hardware RNG data generation rate in bytes per + second + + - quality: Hardware RNG entropy estimation per 1024 bits of + input Example: firmware { optee { compatible = "linaro,optee-tz"; method = "smc"; + + hw-rng { + uuid = "ab7a617c-b8e7-4d8f-8301-d09b61036b64"; + data-rate = <125>; + quality = <999>; + }; }; }; From patchwork Tue Dec 18 12:37:31 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sumit Garg X-Patchwork-Id: 154137 Delivered-To: patches@linaro.org Received: by 2002:a2e:299d:0:0:0:0:0 with SMTP id p29-v6csp3657822ljp; Tue, 18 Dec 2018 04:38:00 -0800 (PST) X-Received: by 2002:a62:4851:: with SMTP id v78mr16642950pfa.97.1545136679922; Tue, 18 Dec 2018 04:37:59 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1545136679; cv=none; d=google.com; s=arc-20160816; b=ebDcqfivetMT0V5AVRPQ4G+mz1VoLtDZD+PMBvGI/47ssoMV4xljOTwJSlAkbDjPsU c6eFse/5Zz7T9MFSGvltPSEgweLc/dXBUjY+uTQJnT+MDMMd4MGvsQrMoOffPyufOIED InwghByxJwbneYSpl94wL7PxeWAND8K7EVxWckuMEqEOU6zGxtM9DQQEkGLduMOrMBrx T4wSrLjaYshcFyOQl1Cc9pjogpHAqcm7NOsh0omp/dm7pUFEfMkz14qu5ByoKpX4R0lm et+z6HyMKdLGAKr+0Ym6eLUhmSzA3H+AnOGkB3lXhB0RVf8ciyVtXWT66BNnXxMWDfQ5 PQQg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=references:in-reply-to:message-id:date:subject:cc:to:from :dkim-signature; bh=0mVQ68tr6t5HR7AtU8Yk+bnG/py0l/sezw1vU5QS+U4=; b=NiFdF24zkAcLPPnYV5oyLv7mmGWx1uBGX+NYiKqV7eMGmmrs81yvNo1B1QBUjLxjnp TMG5+q7jyR9j2N7n2Y0Hcw/hubNzzUnVUlMr0s+nlB2Aejjxmzovg2s5hBwal727Pw50 I5jyldg6WkB5XXD/Vm/GIsKcAOrSd0iDMZ3ROUM6pGacYQ1ms+6tJ9ezFbeCujRfrexN osfbX3pE0w0ojAgPXbBw+Kw8S2WE0mvn3EKkwsQM1uC8eeO0kpH79gOx2g7Tk5vGX51h lUC3hn0sN6G2tJnYoMdzvYVmot+76pnQ+a06D8eVR0Ech6TVGLY0F9BT+a3PYrVOLonj 7ZWQ== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=iJOM4jcl; spf=pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=sumit.garg@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Return-Path: Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id d27sor25408827pgm.9.2018.12.18.04.37.59 for (Google Transport Security); Tue, 18 Dec 2018 04:37:59 -0800 (PST) Received-SPF: pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=iJOM4jcl; spf=pass (google.com: domain of sumit.garg@linaro.org designates 209.85.220.65 as permitted sender) smtp.mailfrom=sumit.garg@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org 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=0mVQ68tr6t5HR7AtU8Yk+bnG/py0l/sezw1vU5QS+U4=; b=iJOM4jclTZMPqMuXyddR/tGWtnbQazc3ZiFmaG9QuB0aPVwoKERnuM07tRm/1mcQVQ KQ9ebLcd3uvfdDu4B7y1sVIjwynabqp87cCQZlbVMKI3VsdXJ7VvEGD9MVojPhsby+jk xHn/BOh92bEoDX+tOjrJDa5x+JeznkYVZn+Lc= 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=0mVQ68tr6t5HR7AtU8Yk+bnG/py0l/sezw1vU5QS+U4=; b=cKNAsTsMaoJs9SVhJDRKJ19jD26QvEo9as5Hc1eeXKD6NWk7UNYASknCE0eGPAGoKt iXNZOPGeV+TP3m8ysHWlbzecv0ScPh9NJABYA3X8mRg4WlSlcuPD13lNNojGwCD5cpnt nQBnrBSci/3VsjAz0rt0L4tBbqV3LU3lTBf9ZN7AgEJFH0PlqCq7KKxNLNiozWWqRcRr hn4qiifg4KECRgR92hTi1yxjTNd0nB/N2T/BlVg/CYjWvtXCiG/iUJhb9oYYRwczrGhg UR08Xj144j/Fr/6UMgOUJ0gmzOdonlERPoRXeyLMe9ZNsHyc7/BH3yAzND+vU2jPZB/D 6IXQ== X-Gm-Message-State: AA+aEWbCbQgQztCf+KslSjEENnQeQQs29Wsx6CahLmufLeLg1oOZAcLv dMPQB0V1/ZfF+ik7hwNNpGR5taUx X-Google-Smtp-Source: AFSGD/V2RZhpCY4gcJZOrIRRrlUjyd1I9qcLVAYrIhIl+kCHwhSjSw0fkD1mNEWN6Noqz9xcX1V/XA== X-Received: by 2002:a63:f94c:: with SMTP id q12mr15457954pgk.91.1545136679320; Tue, 18 Dec 2018 04:37:59 -0800 (PST) Return-Path: Received: from localhost.localdomain ([117.196.232.175]) by smtp.gmail.com with ESMTPSA id a15sm21880529pgb.1.2018.12.18.04.37.56 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 18 Dec 2018 04:37:58 -0800 (PST) From: Sumit Garg To: daniel.thompson@linaro.org Cc: patches@linaro.org, Sumit Garg Subject: [PATCH 2/2] hwrng: add OP-TEE based rng driver Date: Tue, 18 Dec 2018 18:07:31 +0530 Message-Id: <1545136651-25776-3-git-send-email-sumit.garg@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1545136651-25776-1-git-send-email-sumit.garg@linaro.org> References: <1545136651-25776-1-git-send-email-sumit.garg@linaro.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 | 236 +++++++++++++++++++++++++++++++++++++ 4 files changed, 257 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..e2c1368 --- /dev/null +++ b/drivers/char/hw_random/optee-rng.c @@ -0,0 +1,236 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2018 Linaro Ltd. + */ + +#include +#include +#include +#include +#include +#include +#include + +#define PFX KBUILD_MODNAME ": " + +#define TEE_ERROR_HEALTH_TEST_FAIL 0x00000001 + +/* + * TA_CMD_GET_ENTROPY - Get Entropy from RNG using Thermal Sensor + * + * 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 + +#define MAX_ENTROPY_REQ_SZ (4 * 1024) + +static struct tee_context *ctx; +static struct tee_shm *entropy_shm_pool; +static uuid_t ta_rng_uuid = {0}; +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(PFX "tee_client_invoke_func failed, 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(PFX "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 = max / MAX_ENTROPY_REQ_SZ + 1; + + /* New random numbers are generated approximately 1byte per 2ms */ + while (read < max) { + if ((max - read) < MAX_ENTROPY_REQ_SZ) + rng_size = get_optee_rng_data(data, (max - read)); + else + rng_size = get_optee_rng_data(data, MAX_ENTROPY_REQ_SZ); + + data += rng_size; + read += rng_size; + + if (wait) { + if (timeout-- == 0) + return read; + if ((max - read) < MAX_ENTROPY_REQ_SZ) + msleep((1000 * (max - read)) / + ta_rng_data_rate); + else + msleep((1000 * MAX_ENTROPY_REQ_SZ) / + ta_rng_data_rate); + } else { + return read; + } + } + + return read; +} + +static int optee_rng_init(struct hwrng *rng) +{ + int ret = 0, err = 0; + struct tee_ioctl_open_session_arg sess_arg = {0}; + + /* 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(PFX "tee_client_open_session failed, error: %x\n", + sess_arg.ret); + err = -EINVAL; + goto out_ctx; + } + ta_rng_seesion_id = sess_arg.session; + + 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(PFX "tee_shm_alloc failed\n"); + err = PTR_ERR(entropy_shm_pool); + 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 optee_rng_cleanup(struct hwrng *rng) +{ + tee_shm_free(entropy_shm_pool); + tee_client_close_session(ctx, ta_rng_seesion_id); +} + +static struct hwrng optee_rng = { + .name = "optee-rng", + .init = optee_rng_init, + .cleanup = optee_rng_cleanup, + .read = optee_rng_read, +}; + +static int get_optee_hwrng_params(void) +{ + struct device_node *np; + const char *uuid; + u32 quality; + + /* Node is supposed to be below /firmware/optee */ + np = of_find_node_by_path("/firmware/optee/hw-rng"); + if (!np) + return -ENODEV; + + if (of_property_read_string(np, "uuid", &uuid)) { + pr_warn(PFX "missing \"uuid\" property\n"); + return -ENXIO; + } + + if (uuid_parse(uuid, &ta_rng_uuid)) { + pr_warn(PFX "incorrect rng ta uuid\n"); + return -EINVAL; + } + + if (of_property_read_u32(np, "data-rate", &ta_rng_data_rate)) { + pr_warn(PFX "missing \"data-rate\" property\n"); + return -ENXIO; + } + + if (!of_property_read_u32(np, "quality", &quality)) + optee_rng.quality = quality; + + return 0; +} + +static int tee_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 err = -ENODEV; + + err = get_optee_hwrng_params(); + if (err) + return err; + + /* Open context with TEE driver */ + ctx = tee_client_open_context(NULL, tee_match, NULL, NULL); + if (IS_ERR(ctx)) + return -ENODEV; + + err = hwrng_register(&optee_rng); + if (err) { + pr_err(PFX " registering failed (%d)\n", err); + return err; + } + + return 0; +} + +static void __exit mod_exit(void) +{ + 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");