From patchwork Mon Dec 28 12:45:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 353110 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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 D87C0C4332B for ; Mon, 28 Dec 2020 16:13:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AC166207FB for ; Mon, 28 Dec 2020 16:13:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733009AbgL1NT7 (ORCPT ); Mon, 28 Dec 2020 08:19:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:48526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733002AbgL1NT7 (ORCPT ); Mon, 28 Dec 2020 08:19:59 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 739C8206ED; Mon, 28 Dec 2020 13:19:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1609161558; bh=iQbz3cXD+jdaNPAAQppX6o8MsPGEkblhEFYCIt2uIsw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rL7w6YIHY5HTDklBC8SBkcqYb95GIIwuTfArRCMKcp6LYJNeHeNkIFdvl6VCGYQm5 1Y5Xn6Azay/6nDgilolk2EfM+XMOzNkQaLwZWdPtN2YGNx3Q7XZRXq9kV7+fkPXRgA sHGqe+XC1WXaCRmNLSmZBNdpkxmim3i1jmaBEDcw= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xu Qiang , Marc Zyngier , Sasha Levin Subject: [PATCH 4.19 011/346] irqchip/gic-v3-its: Unconditionally save/restore the ITS state on suspend Date: Mon, 28 Dec 2020 13:45:30 +0100 Message-Id: <20201228124920.309451207@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201228124919.745526410@linuxfoundation.org> References: <20201228124919.745526410@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xu Qiang [ Upstream commit 74cde1a53368aed4f2b4b54bf7030437f64a534b ] On systems without HW-based collections (i.e. anything except GIC-500), we rely on firmware to perform the ITS save/restore. This doesn't really work, as although FW can properly save everything, it cannot fully restore the state of the command queue (the read-side is reset to the head of the queue). This results in the ITS consuming previously processed commands, potentially corrupting the state. Instead, let's always save the ITS state on suspend, disabling it in the process, and restore the full state on resume. This saves us from broken FW as long as it doesn't enable the ITS by itself (for which we can't do anything). This amounts to simply dropping the ITS_FLAGS_SAVE_SUSPEND_STATE. Signed-off-by: Xu Qiang [maz: added warning on resume, rewrote commit message] Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20201107104226.14282-1-xuqiang36@huawei.com Signed-off-by: Sasha Levin --- drivers/irqchip/irq-gic-v3-its.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index d5cc32e80f5e2..cd58c123f547e 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -49,7 +49,6 @@ #define ITS_FLAGS_CMDQ_NEEDS_FLUSHING (1ULL << 0) #define ITS_FLAGS_WORKAROUND_CAVIUM_22375 (1ULL << 1) #define ITS_FLAGS_WORKAROUND_CAVIUM_23144 (1ULL << 2) -#define ITS_FLAGS_SAVE_SUSPEND_STATE (1ULL << 3) #define RDIST_FLAGS_PROPBASE_NEEDS_FLUSHING (1 << 0) @@ -3240,9 +3239,6 @@ static int its_save_disable(void) list_for_each_entry(its, &its_nodes, entry) { void __iomem *base; - if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE)) - continue; - base = its->base; its->ctlr_save = readl_relaxed(base + GITS_CTLR); err = its_force_quiescent(base); @@ -3261,9 +3257,6 @@ err: list_for_each_entry_continue_reverse(its, &its_nodes, entry) { void __iomem *base; - if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE)) - continue; - base = its->base; writel_relaxed(its->ctlr_save, base + GITS_CTLR); } @@ -3283,9 +3276,6 @@ static void its_restore_enable(void) void __iomem *base; int i; - if (!(its->flags & ITS_FLAGS_SAVE_SUSPEND_STATE)) - continue; - base = its->base; /* @@ -3293,7 +3283,10 @@ static void its_restore_enable(void) * don't restore it since writing to CBASER or BASER * registers is undefined according to the GIC v3 ITS * Specification. + * + * Firmware resuming with the ITS enabled is terminally broken. */ + WARN_ON(readl_relaxed(base + GITS_CTLR) & GITS_CTLR_ENABLE); ret = its_force_quiescent(base); if (ret) { pr_err("ITS@%pa: failed to quiesce on resume: %d\n", @@ -3558,9 +3551,6 @@ static int __init its_probe_one(struct resource *res, ctlr |= GITS_CTLR_ImDe; writel_relaxed(ctlr, its->base + GITS_CTLR); - if (GITS_TYPER_HCC(typer)) - its->flags |= ITS_FLAGS_SAVE_SUSPEND_STATE; - err = its_init_domain(handle, its); if (err) goto out_free_tables;