From patchwork Tue Jan 21 10:10:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Courbot X-Patchwork-Id: 3516071 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 3AC5E9F2D6 for ; Tue, 21 Jan 2014 10:12:34 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2F1CE2015A for ; Tue, 21 Jan 2014 10:12:33 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5EBBD20145 for ; Tue, 21 Jan 2014 10:12:31 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1W5YIy-0003M2-FG; Tue, 21 Jan 2014 10:11:36 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1W5YIl-0007pf-AJ; Tue, 21 Jan 2014 10:11:23 +0000 Received: from hqemgate15.nvidia.com ([216.228.121.64]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1W5YIL-0007lf-M5 for linux-arm-kernel@lists.infradead.org; Tue, 21 Jan 2014 10:10:58 +0000 Received: from hqnvupgp08.nvidia.com (Not Verified[216.228.121.13]) by hqemgate15.nvidia.com id ; Tue, 21 Jan 2014 02:10:47 -0800 Received: from hqemhub01.nvidia.com ([172.20.12.94]) by hqnvupgp08.nvidia.com (PGP Universal service); Tue, 21 Jan 2014 02:10:00 -0800 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Tue, 21 Jan 2014 02:10:00 -0800 Received: from percival.nvidia.com (172.20.144.16) by hqemhub01.nvidia.com (172.20.150.30) with Microsoft SMTP Server (TLS) id 8.3.327.1; Tue, 21 Jan 2014 02:10:37 -0800 From: Alexandre Courbot To: Stephen Warren , Thierry Reding , Russell King Subject: [PATCH 2/5] ARM: trusted_foundations: fallback when TF support is missing Date: Tue, 21 Jan 2014 19:10:13 +0900 Message-ID: <1390299016-14105-3-git-send-email-acourbot@nvidia.com> X-Mailer: git-send-email 1.8.5.3 In-Reply-To: <1390299016-14105-1-git-send-email-acourbot@nvidia.com> References: <1390299016-14105-1-git-send-email-acourbot@nvidia.com> X-NVConfidentiality: public MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140121_051057_852950_8C60AE41 X-CRM114-Status: GOOD ( 18.25 ) X-Spam-Score: -2.5 (--) Cc: gnurou@gmail.com, linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, Alexandre Courbot , Olof Johansson , linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When Trusted Foundations is detected as present on the system, but Trusted Foundations support is not built into the kernel, the kernel used to issue a panic very early during boot, leaving little clue to the user as to what is going wrong. It turns out that even without TF support built-in, the kernel can boot on a TF-enabled system provided that SMP and cpuidle are disabled. This patch does this and continue booting on one CPU, leaving the user with a usable (however degraded) system. Signed-off-by: Alexandre Courbot --- arch/arm/include/asm/trusted_foundations.h | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/trusted_foundations.h b/arch/arm/include/asm/trusted_foundations.h index 997862fd5d77..b5f7705abcb0 100644 --- a/arch/arm/include/asm/trusted_foundations.h +++ b/arch/arm/include/asm/trusted_foundations.h @@ -30,6 +30,8 @@ #include #include #include +#include +#include struct trusted_foundations_platform_data { unsigned int version_major; @@ -47,10 +49,13 @@ static inline void register_trusted_foundations( struct trusted_foundations_platform_data *pd) { /* - * If we try to register TF, this means the system needs it to continue. - * Its absence if thus a fatal error. + * If the system requires TF and we cannot provide it, continue booting + * but disable features that cannot be provided. */ - panic("No support for Trusted Foundations, stopping...\n"); + pr_err("No support for Trusted Foundations, continuing in degraded mode.\n"); + pr_err("Secondary processors as well as CPU PM will be disabled.\n"); + setup_max_cpus = 0; + cpu_idle_poll_ctrl(true); } static inline void of_register_trusted_foundations(void)