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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (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 0EF67C433FE for ; Thu, 27 Jan 2022 19:56:44 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.261720.453390 (Exim 4.92) (envelope-from ) id 1nDAsg-00026G-S3; Thu, 27 Jan 2022 19:56:30 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 261720.453390; Thu, 27 Jan 2022 19:56:30 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nDAsg-000269-PB; Thu, 27 Jan 2022 19:56:30 +0000 Received: by outflank-mailman (input) for mailman id 261720; Thu, 27 Jan 2022 19:56:29 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1nDAsf-0001qT-84 for xen-devel@lists.xenproject.org; Thu, 27 Jan 2022 19:56:29 +0000 Received: from mail-lj1-x22b.google.com (mail-lj1-x22b.google.com [2a00:1450:4864:20::22b]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 36c40072-7fab-11ec-8f75-fffcc8bd4f1a; Thu, 27 Jan 2022 20:56:27 +0100 (CET) Received: by mail-lj1-x22b.google.com with SMTP id c7so5392215ljr.13 for ; Thu, 27 Jan 2022 11:56:28 -0800 (PST) Received: from otyshchenko.router ([212.22.223.21]) by smtp.gmail.com with ESMTPSA id j18sm897631lja.26.2022.01.27.11.56.26 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Thu, 27 Jan 2022 11:56:27 -0800 (PST) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 36c40072-7fab-11ec-8f75-fffcc8bd4f1a DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=eo+OIjpWTXwwmP6Pj09KcPNoGuASdj6ZBH9bhBu2VCw=; b=iDUfuS+F3RXhOl1S+NtxvwmywXVfdpg/1suc17SJauTt31SRjVBqOSPkY8HPRZ3yht V5rDuJcBddF2xl3DbceoNuYAQUUSF5qiU0E52+J/aACS257yTq1T6Nn+iPxdZdaE9kDL hf2T1BPiO/T3Sa86kIZztllTb4j+uouEzdxgh0tu6ZzNjiEgvtVjlw7zn91CzZZFcjz7 Sc3dQrctP6ihBiQKEFE7e8XdNr9NhI0fceClfyLTbSsdSxuC0UT5saRMxGnNvELm1Jad QjtHBIJJlYfR5e8F03PVzrDbj4OQvKjuaXZsyB+YTvqlJ8GtE0X8NwZyY5ixxO3wH5XY E68g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=eo+OIjpWTXwwmP6Pj09KcPNoGuASdj6ZBH9bhBu2VCw=; b=LTtVdKlzLSCs+4OXazw/x2pcIVG3MmA420q+U6x3tvugG2ngkekTTnD4kwigxvaFxA 6kVGCJb5FlUEJnuRYcp8HHnxxtB9WCckOj3G/e3fsDV+uZti8WjHLg8YSZGC19jYy5eI LK2/nYBeAK+O1K1SECCDDlrkQd3L+M3CnW6pB7OaPQzlJUZHMqnHXh4/+OPmgxtADkwl UsrTobqukwEiN9lAO4ujOXwNgP2T9JBpAye7sOc7M4hEIEBhM6gm/vC7VpU+/eYTNpN7 DSjycmtkPiZJba6CKTv+eWpR5AzutOXaP3mj2D7WnYPvmGAvyK9tZjPT3pktMbDzVIdX 1HXw== X-Gm-Message-State: AOAM532KGCYVmToaa67mwl3PT/bK82mP+yh9oqbeqyz/4rBuWNKRBKnP lxhT7eqixU7o7bLS2r0K2WA1ARnN9Vk= X-Google-Smtp-Source: ABdhPJyd1lR2ZBeKpiYRAK/LysWfxNy0vopwBbbkjjazDv5ZCPLS4hfEdTurAUDwwUCv2rBBBlQH1Q== X-Received: by 2002:a2e:a786:: with SMTP id c6mr3545836ljf.385.1643313387620; Thu, 27 Jan 2022 11:56:27 -0800 (PST) From: Oleksandr Tyshchenko To: xen-devel@lists.xenproject.org Cc: Oleksandr Tyshchenko , Stefano Stabellini , Julien Grall , Volodymyr Babchuk , Bertrand Marquis , Yoshihiro Shimoda , Oleksandr Andrushchenko Subject: [PATCH V3 1/2] iommu/ipmmu-vmsa: Use refcount for the micro-TLBs Date: Thu, 27 Jan 2022 21:55:51 +0200 Message-Id: <1643313352-29940-2-git-send-email-olekstysh@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1643313352-29940-1-git-send-email-olekstysh@gmail.com> References: <1643313352-29940-1-git-send-email-olekstysh@gmail.com> From: Oleksandr Tyshchenko Reference-count the micro-TLBs as several bus masters can be connected to the same micro-TLB (and drop TODO comment). This wasn't an issue so far, since the platform devices (this driver deals with) get assigned/deassigned together during domain creation/destruction. But, in order to support PCI devices (which are hot-pluggable) in the near future we will need to take care of. Signed-off-by: Oleksandr Tyshchenko Reviewed-by: Yoshihiro Shimoda --- Changes V1 -> V2: - add R-b - add ASSERT() in ipmmu_utlb_disable() Changes V2 -> V3: - add comment to the code --- xen/drivers/passthrough/arm/ipmmu-vmsa.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c b/xen/drivers/passthrough/arm/ipmmu-vmsa.c index 649b9f6..c912120 100644 --- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c +++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c @@ -127,6 +127,7 @@ struct ipmmu_vmsa_device { spinlock_t lock; /* Protects ctx and domains[] */ DECLARE_BITMAP(ctx, IPMMU_CTX_MAX); struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX]; + unsigned int utlb_refcount[IPMMU_UTLB_MAX]; const struct ipmmu_features *features; }; @@ -468,12 +469,17 @@ static int ipmmu_utlb_enable(struct ipmmu_vmsa_domain *domain, } /* - * TODO: Reference-count the micro-TLB as several bus masters can be - * connected to the same micro-TLB. + * Reference-count the micro-TLBs as several bus masters can be connected + * to the same micro-TLB. The platform devices get assigned/deassigned + * together during domain creation/destruction. The PCI devices which use + * the same micro-TLB must also be hot-(un)plugged together. */ - ipmmu_imuasid_write(mmu, utlb, 0); - ipmmu_imuctr_write(mmu, utlb, imuctr | - IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_MMUEN); + if ( mmu->utlb_refcount[utlb]++ == 0 ) + { + ipmmu_imuasid_write(mmu, utlb, 0); + ipmmu_imuctr_write(mmu, utlb, imuctr | + IMUCTR_TTSEL_MMU(domain->context_id) | IMUCTR_MMUEN); + } return 0; } @@ -484,7 +490,10 @@ static void ipmmu_utlb_disable(struct ipmmu_vmsa_domain *domain, { struct ipmmu_vmsa_device *mmu = domain->mmu; - ipmmu_imuctr_write(mmu, utlb, 0); + ASSERT(mmu->utlb_refcount[utlb] > 0); + + if ( --mmu->utlb_refcount[utlb] == 0 ) + ipmmu_imuctr_write(mmu, utlb, 0); } /* Domain/Context Management */ -- 2.7.4