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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9611CC83F15 for ; Thu, 29 Aug 2024 13:10:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: Message-ID:Date:References:In-Reply-To:Subject:Cc:To:From:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ieTWdV07NbZ9ssB6zICmV4vVPLCi22h5v9KXYRgJRfI=; b=XxUp4iFy8j9fh0MnhbGptvNl9e rQ7dwSfy93RA0x/+dFO+FSBbpPJrB4UABQl6VXEVtN/Kr9l5rCHeMDtrXhgr1eLDlxQTjJTOr5p9A jxKp7voYeZ34wcFUSg3lPA6Jee5/kN467a+bvW4SdhAlQBaYeoCjv8qHHg8aojFP1w9CCSpsISg6Q XxE010649+1Br7346rKIJVscWktLdFVLaWfPLny19EbuIQzqr+fVFDnn2bEV1x6wR3Kfh5O3m6hMk wrXfHiK+fuKgBm8MH1R8SFseSQTTHHSYLhS6K1eWdaDcneEkMqheDDsSAgaqgmjrCuEGfJAkQ5ru3 OW3VE5YQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjeuU-000000025Cc-0wYs; Thu, 29 Aug 2024 13:09:58 +0000 Received: from galois.linutronix.de ([193.142.43.55]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sjetZ-0000000250l-4By1 for linux-arm-kernel@lists.infradead.org; Thu, 29 Aug 2024 13:09:05 +0000 From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1724936937; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ieTWdV07NbZ9ssB6zICmV4vVPLCi22h5v9KXYRgJRfI=; b=y6DKYe1BhMBKW41WL4EOd63wZnaD0fJ1IpF6wrr5Q4Vn1uE4xO4sMCucVnUA/J06x1lmOJ Sjn0tKydI7oN/f0SjMQ1GbD/3Pebu/FCaGg1C2qdGooBYK6j1Xa4K2uCgZR5fuRuR30DHT AXnGpKreUpDsFOtPeNEBp/p4z15HgumgwA1fno/rvX6oLwF5niUdKkQ/4JYtfvy1cczDlv LLhpkmAj5qFoSUS42XTBgX0gGST+c8khK3OWFmP6OOtRVtLHTX+WgLVd8BbIJoD7mpckv4 xp5KDSKSAuOd99pgycNAO47RHs47CPOSqHT1ZZPHyRfE8mgRfrhsb1Rp3wBxEw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1724936937; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=ieTWdV07NbZ9ssB6zICmV4vVPLCi22h5v9KXYRgJRfI=; b=0+ogEiSfY2/9fY30bXDJSxyQ0l/lS2woiv32ZEitRAJVeGgiruE4wgvuBWpYN+84/UpiOs bSrO+tnV8JmgG8AQ== To: Nick Chan , Hector Martin , Sven Peter , Alyssa Rosenzweig , Rob Herring , Krzysztof Kozlowski , Conor Dooley , asahi@lists.linux.dev, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Cc: ~postmarketos/upstreaming@lists.sr.ht, Nick Chan , Konrad Dybcio Subject: Re: [PATCH RESEND 2/3] irqchip/apple-aic: Only access IPI sysregs when use_fast_ipi is true In-Reply-To: <20240829110436.46052-3-towinchenmi@gmail.com> References: <20240829110436.46052-1-towinchenmi@gmail.com> <20240829110436.46052-3-towinchenmi@gmail.com> Date: Thu, 29 Aug 2024 15:08:57 +0200 Message-ID: <87zfova32u.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240829_060902_223078_AF4A93D4 X-CRM114-Status: GOOD ( 18.68 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, Aug 29 2024 at 19:02, Nick Chan wrote: > Starting from the A11 (T8015) SoC, Apple introuced system registers for > fast IPI and UNCORE PMC control. These sysregs do not exist on earlier > A7-A10 SoCs and trying to access them results in an instant crash. > > Restrict sysreg access within the AIC driver to configurations where > use_fast_ipi is true to allow AIC to function properly on A7-A10 SoCs. use_fast_ipi is an implementation detail and does not mean anything here. It's sufficient to say: Only access system registers on SoCs which provide them. Hmm? > While at it, remove the IPI-always-ack path on aic_handle_fiq. It's not while at it. It's part of handling this correctly. > If we are able to reach there, we are on an IPI-capable system and > should be using one of the IPI-capable compatibles, anyway. 'we' can't reach that code ever. https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#changelog > Signed-off-by: Konrad Dybcio > Signed-off-by: Nick Chan This Signed-off-by chain is invalid. If Konrad authored the patch then you need to have a 'From: Konrad ...' line at the top of the change log. If you worked together on this then this needs a Co-developed-by tag. See Documentation/process/... > > - if (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING) { > - if (static_branch_likely(&use_fast_ipi)) { > - aic_handle_ipi(regs); > - } else { > - pr_err_ratelimited("Fast IPI fired. Acking.\n"); > - write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1); > - } > + if (static_branch_likely(&use_fast_ipi) && > + (read_sysreg_s(SYS_IMP_APL_IPI_SR_EL1) & IPI_SR_PENDING)) { > + aic_handle_ipi(regs); > } > > if (TIMER_FIRING(read_sysreg(cntp_ctl_el0))) > @@ -574,8 +571,9 @@ static void __exception_irq_entry aic_handle_fiq(struct pt_regs *regs) > AIC_FIQ_HWIRQ(irq)); > } > > - if (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ && > - (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) & UPMSR_IACT)) { > + if (static_branch_likely(&use_fast_ipi) && > + (FIELD_GET(UPMCR0_IMODE, read_sysreg_s(SYS_IMP_APL_UPMCR0_EL1)) == UPMCR0_IMODE_FIQ) && > + (read_sysreg_s(SYS_IMP_APL_UPMSR_EL1) & UPMSR_IACT)) { > /* Same story with uncore PMCs */ > pr_err_ratelimited("Uncore PMC FIQ fired. Masking.\n"); > sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, > @@ -811,7 +809,8 @@ static int aic_init_cpu(unsigned int cpu) > /* Mask all hard-wired per-CPU IRQ/FIQ sources */ > > /* Pending Fast IPI FIQs */ > - write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1); > + if (static_branch_likely(&use_fast_ipi)) > + write_sysreg_s(IPI_SR_PENDING, SYS_IMP_APL_IPI_SR_EL1); > > /* Timer FIQs */ > sysreg_clear_set(cntp_ctl_el0, 0, ARCH_TIMER_CTRL_IT_MASK); > @@ -832,8 +831,9 @@ static int aic_init_cpu(unsigned int cpu) > FIELD_PREP(PMCR0_IMODE, PMCR0_IMODE_OFF)); > > /* Uncore PMC FIQ */ > - sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, > - FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); > + if (static_branch_likely(&use_fast_ipi)) > + sysreg_clear_set_s(SYS_IMP_APL_UPMCR0_EL1, UPMCR0_IMODE, > + FIELD_PREP(UPMCR0_IMODE, UPMCR0_IMODE_OFF)); Please see the bracket rules in the tip maintainers doc. Thanks, tglx