From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BE750C48BDF for ; Fri, 18 Jun 2021 03:56:05 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 4FF0361351 for ; Fri, 18 Jun 2021 03:56:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FF0361351 Authentication-Results: mail.kernel.org; dmarc=pass (p=none dis=none) header.from=ozlabs.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4G5lTG5Sc0z3c7H for ; Fri, 18 Jun 2021 13:56:02 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=AhTOiHec; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=ozlabs.org (client-ip=2401:3900:2:1::2; helo=ozlabs.org; envelope-from=paulus@ozlabs.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; secure) header.d=ozlabs.org header.i=@ozlabs.org header.a=rsa-sha256 header.s=201707 header.b=AhTOiHec; dkim-atps=neutral Received: from ozlabs.org (bilbo.ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4G5lMP3T2Rz3c1k for ; Fri, 18 Jun 2021 13:50:55 +1000 (AEST) Received: by ozlabs.org (Postfix) id 4G5lML3dQvz9sXL; Fri, 18 Jun 2021 13:50:54 +1000 (AEST) Received: by ozlabs.org (Postfix, from userid 1003) id 4G5lML3HS2z9sfG; Fri, 18 Jun 2021 13:50:54 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ozlabs.org; s=201707; t=1623988254; bh=BuIb8txlo7m7Ua1rdz1ixEJHxyWv5ncIwQS16h/q0BM=; h=Date:From:To:Subject:References:In-Reply-To:From; b=AhTOiHecn4csjmgpPzvyzC4wfsjFwtFolkphrbgoXGV1zC2N9XJTtGw2vfgJsrHfU K38yn+sDiVypWOY+wKhSoERYP1TBFdOzCH2H0ma3jm5hLOkB2gRViLRuyZeEfpVICj SoO5Km6yGRDTQVnSmfh6HDRj2ZrD4PVGJE/Elb48OVV9vCa5Mt5BW8w01sochgjyVn +oNx7MhXfCJZ39VQjWXvKsjdyiIqzEBDtY/y/n/2CF+1dHoHaTiT+6W/cmnLZHEhqY eJLRmx4uayIfCnkV/PLkZlASHSVec1MssLS2CaaCo00kCLsLHvZj3iuslmApN0e5Qp cUBG4wDPI12Ow== Date: Fri, 18 Jun 2021 13:47:08 +1000 From: Paul Mackerras To: linuxppc-dev@ozlabs.org Subject: [PATCH v2 6/9] powerpc/microwatt: Add support for hardware random number generator Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" Microwatt's hardware RNG is accessed using the DARN instruction. Signed-off-by: Paul Mackerras --- arch/powerpc/platforms/microwatt/Kconfig | 1 + arch/powerpc/platforms/microwatt/Makefile | 2 +- arch/powerpc/platforms/microwatt/rng.c | 48 +++++++++++++++++++++++ 3 files changed, 50 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/platforms/microwatt/rng.c diff --git a/arch/powerpc/platforms/microwatt/Kconfig b/arch/powerpc/platforms/microwatt/Kconfig index 50ed0cedb5f1..8f6a81978461 100644 --- a/arch/powerpc/platforms/microwatt/Kconfig +++ b/arch/powerpc/platforms/microwatt/Kconfig @@ -7,6 +7,7 @@ config PPC_MICROWATT select PPC_ICP_NATIVE select PPC_NATIVE select PPC_UDBG_16550 + select ARCH_RANDOM help This option enables support for FPGA-based Microwatt implementations. diff --git a/arch/powerpc/platforms/microwatt/Makefile b/arch/powerpc/platforms/microwatt/Makefile index e6885b3b2ee7..116d6d3ad3f0 100644 --- a/arch/powerpc/platforms/microwatt/Makefile +++ b/arch/powerpc/platforms/microwatt/Makefile @@ -1 +1 @@ -obj-y += setup.o +obj-y += setup.o rng.o diff --git a/arch/powerpc/platforms/microwatt/rng.c b/arch/powerpc/platforms/microwatt/rng.c new file mode 100644 index 000000000000..3d8ee6eb7dad --- /dev/null +++ b/arch/powerpc/platforms/microwatt/rng.c @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Derived from arch/powerpc/platforms/powernv/rng.c, which is: + * Copyright 2013, Michael Ellerman, IBM Corporation. + */ + +#define pr_fmt(fmt) "microwatt-rng: " fmt + +#include +#include +#include +#include +#include + +#define DARN_ERR 0xFFFFFFFFFFFFFFFFul + +int microwatt_get_random_darn(unsigned long *v) +{ + unsigned long val; + + /* Using DARN with L=1 - 64-bit conditioned random number */ + asm volatile(PPC_DARN(%0, 1) : "=r"(val)); + + if (val == DARN_ERR) + return 0; + + *v = val; + + return 1; +} + +static __init int rng_init(void) +{ + unsigned long val; + int i; + + for (i = 0; i < 10; i++) { + if (microwatt_get_random_darn(&val)) { + ppc_md.get_random_seed = microwatt_get_random_darn; + return 0; + } + } + + pr_warn("Unable to use DARN for get_random_seed()\n"); + + return -EIO; +} +machine_subsys_initcall(, rng_init); -- 2.31.1