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=-2.2 required=3.0 tests=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 EF442C432C0 for ; Tue, 19 Nov 2019 19:07:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C207A22432 for ; Tue, 19 Nov 2019 19:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727362AbfKSTHZ (ORCPT ); Tue, 19 Nov 2019 14:07:25 -0500 Received: from muru.com ([72.249.23.125]:42954 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727007AbfKSTHZ (ORCPT ); Tue, 19 Nov 2019 14:07:25 -0500 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id CDE20809B; Tue, 19 Nov 2019 19:08:01 +0000 (UTC) Date: Tue, 19 Nov 2019 11:07:21 -0800 From: Tony Lindgren To: "Andrew F. Davis" Cc: Mark Rutland , linux-omap@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] ARM: OMAP: Use ARM SMC Calling Convention when OP-TEE is available Message-ID: <20191119190721.GO35479@atomide.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.2 (2019-09-21) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * 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. 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 :) Regards, Tony