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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no 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 F3ADAC432C0 for ; Tue, 19 Nov 2019 19:12:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CD8B422440 for ; Tue, 19 Nov 2019 19:12:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="ERuGxb56" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727082AbfKSTMe (ORCPT ); Tue, 19 Nov 2019 14:12:34 -0500 Received: from lelv0143.ext.ti.com ([198.47.23.248]:47660 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726711AbfKSTMe (ORCPT ); Tue, 19 Nov 2019 14:12:34 -0500 Received: from lelv0266.itg.ti.com ([10.180.67.225]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id xAJJCOlE049841; Tue, 19 Nov 2019 13:12:24 -0600 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1574190744; bh=OAVQNrmkwx9aXRike52bpwLCdj/ux8+UBWHSi3lRntE=; h=Subject:To:CC:References:From:Date:In-Reply-To; b=ERuGxb56ndQhxCTx24hcknxZk5Gdg4K7tdNvYdbKOlXuXWUiZidk56FWQwoI3Qv2Z IgIxIYmsQyPIJ8ABbCnJzxsr5Jb0/XsYww1SYyYQecxYTjPNqZvbWGCu83ZZ/XlRaA 7BDJfh4T+S02C9TFNOLbfzEHOmEHoBvMFskHABOA= Received: from DFLE113.ent.ti.com (dfle113.ent.ti.com [10.64.6.34]) by lelv0266.itg.ti.com (8.15.2/8.15.2) with ESMTPS id xAJJCOga114678 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 19 Nov 2019 13:12:24 -0600 Received: from DFLE108.ent.ti.com (10.64.6.29) by DFLE113.ent.ti.com (10.64.6.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Tue, 19 Nov 2019 13:12:24 -0600 Received: from lelv0327.itg.ti.com (10.180.67.183) by DFLE108.ent.ti.com (10.64.6.29) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Tue, 19 Nov 2019 13:12:24 -0600 Received: from [10.250.45.147] (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0327.itg.ti.com (8.15.2/8.15.2) with ESMTP id xAJJCO7d115048; Tue, 19 Nov 2019 13:12:24 -0600 Subject: Re: [PATCH] ARM: OMAP: Use ARM SMC Calling Convention when OP-TEE is available To: Tony Lindgren CC: Mark Rutland , , References: <20191118223128.GE35479@atomide.com> <29db708e-119e-8a89-7d43-e38e2a10dc07@ti.com> <20191119162157.GJ35479@atomide.com> <6e009ae3-6aa2-409b-749f-4947303940d8@ti.com> <20191119164227.GL35479@atomide.com> <20191119180546.GM35479@atomide.com> <9e15c170-c9fa-778c-d998-bd1111a6390d@ti.com> <20191119183247.GN35479@atomide.com> <20191119190721.GO35479@atomide.com> From: "Andrew F. Davis" Message-ID: <7fa11037-8d33-2274-c8cc-80e9630b38b0@ti.com> Date: Tue, 19 Nov 2019 14:12:18 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191119190721.GO35479@atomide.com> Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/19/19 2:07 PM, Tony Lindgren wrote: > * Andrew F. Davis [191119 18:51]: >> On 11/19/19 1:32 PM, Tony Lindgren wrote: >>> It would allow us to completely change over to using >>> arm_smccc_smc() and forget the custom calls. >> >> We would need more than just the r12 quirk to replace all our custom SMC >> handlers, we would need quirks for omap_smc2 which puts process ID in r1 >> and puts #0xff in r6, and omap_smc3 that uses smc #1. All of our legacy >> SMC calls also trash r4-r11, that is very non SMCCC complaint as only >> r4-r7 need be caller saved. I don't see arm_smccc_smc() working with >> legacy ROM no matter how much we hack at it :( > > We would just have omap_smc2() call arm_smccc_smc() and in that > case. And omap_smc2() would still deal with saving and restoring > the registers. > Then why call arm_smccc_smc()? omap_smc2() is already an assembly function, all it needs to do after loading the registers and saving the right ones is issue an "smc #0" instruction, why would we want to instead call into some other function to re-save registers and issue the exact same instruction? > Certainly the wrapper functions calling arm_smccc_smc() can deal > with r12 too if the r12-quirk version and the plain version are > never needed the same time on a booted SoC. > > Are they ever needed the same time on a booted SoC or not? > >> I can make OP-TEE also compatible with the r12 quirk, which is what I >> used to do. That way we didn't need to do any detection. The issue was >> that non-standard SMC calls should not go through the common SMCCC >> handler (unless you are QCOM for some reason..). > > Sounds like for optee nothing must be done for r12 :) > Unless all our calls use the r12 hack, then we would need to fixup OP-TEE to accept that also. Andrew > Regards, > > Tony >