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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, 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 68A0CC2D0C8 for ; Fri, 13 Dec 2019 00:51:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3D1E522527 for ; Fri, 13 Dec 2019 00:51:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="iJas9yV+" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727491AbfLMAvV (ORCPT ); Thu, 12 Dec 2019 19:51:21 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:38554 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726631AbfLMAvU (ORCPT ); Thu, 12 Dec 2019 19:51:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=U/yCdrBeS8qawSt8fr5/pTCJsSZppXePjAIJbFodjBQ=; b=iJas9yV+XFfPNDfDe0uRBgXIk 5852wR2mDlLu5V3p4b3Qd+Up1xJUaxRvzW6vXlAd+do+YglPFoDxk8vSlh6EDK59S6nKviQWbK5Lc yxjqInJezBx2k1i5Zon1Vf/5r6q+oIvDx/OFCegSTYnzy/AODOI4UuwTNYE2nAEPGLvTc5WPEfE/2 rc1gkljsvGP62aDUII1iUft3deErCXCNL7W6EoM1L6MWkFPqy+2oh5yOD5G7QOJf8uIMvNU2ZILYM qGvqL4bGRwACIYcyEsrZmc4PhP1srYqu8Vp6UEECku4SNqhkWMCY/uhjYl4TuWu4W2SMK/Ghy1dD3 gSud7uyDA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:52224) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ifZAl-0001dm-EJ; Fri, 13 Dec 2019 00:51:11 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1ifZAj-0007Ls-Bb; Fri, 13 Dec 2019 00:51:09 +0000 Date: Fri, 13 Dec 2019 00:51:09 +0000 From: Russell King - ARM Linux admin To: Bjorn Helgaas Cc: Murali Karicheri , Richard Zhu , Lucas Stach , Andrew Murray , linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: imx6 and keystone PCIe abort handling Message-ID: <20191213005109.GP25745@shell.armlinux.org.uk> References: <20191213003236.GA43783@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191213003236.GA43783@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 12, 2019 at 06:32:36PM -0600, Bjorn Helgaas wrote: > Hi folks, > > Why are ks_pcie_fault() and imx6q_pcie_abort_handler() different? I > think they're doing the same thing, and the "instr & 0x0e100090" part > is the same, but only imx6 has the "instr & 0x0c100000" part. And the > return values are different in some cases. Here's the opcodes for the three different types of loads that would be interesting. 0: e5910000 ldr r0, [r1] ; 32-bit 4: e5d10000 ldrb r0, [r1] ; 8-bit 8: e1d100b0 ldrh r0, [r1] ; 16-bit So, (instr & 0x0e100090) == 0x00100090 is trie for the ldrh case. (instr & 0x0c100000) == 0x04100000 is true for the ldr and ldrb case. So, the keystone version only traps ldrh instructions, whereas the imx6 traps them all. > Could/should these be shared somehow? They're both under #ifdef > CONFIG_ARM, so maybe it could be provided by arch/arm? > > static int ks_pcie_fault(unsigned long addr, unsigned int fsr, > struct pt_regs *regs) > { > unsigned long instr = *(unsigned long *) instruction_pointer(regs); > > if ((instr & 0x0e100090) == 0x00100090) { > int reg = (instr >> 12) & 15; > > regs->uregs[reg] = -1; > regs->ARM_pc += 4; > } > > return 0; > } > > static int imx6q_pcie_abort_handler(unsigned long addr, > unsigned int fsr, struct pt_regs *regs) > { > unsigned long pc = instruction_pointer(regs); > unsigned long instr = *(unsigned long *)pc; > int reg = (instr >> 12) & 15; > > /* > * If the instruction being executed was a read, > * make it look like it read all-ones. > */ > if ((instr & 0x0c100000) == 0x04100000) { > unsigned long val; > > if (instr & 0x00400000) > val = 255; > else > val = -1; > > regs->uregs[reg] = val; > regs->ARM_pc += 4; > return 0; > } > > if ((instr & 0x0e100090) == 0x00100090) { > regs->uregs[reg] = -1; > regs->ARM_pc += 4; > return 0; > } > > return 1; > } > > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up