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 BFB8EC87FCB for ; Fri, 1 Aug 2025 08:33:10 +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: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-Owner; bh=vY5IloWsNQwsLIRSq+Jk0RbLuNAFATBZvlKueff9YnQ=; b=tMEC9wS4AuyoWSe9giiqDt+s3l fGfIzJM4B2Ptw8YHuXID8nEWbHfY5BBOhOC1Yi9YBa3Ajs8kV8zdS2A90b9vJy4XXAQImqDJoqbtt Z1kmbuyiuVh7s0yJ9TzezpViEkt1WwdvissDwJG6QTd8PGuThu8o45HQkW1EbQiEpWKe6MGe6wpLK 1Bdx5ILIzVyR2vEXeZkJb6PhlYQFLrX8ID0SmCzKENsdJnVS+xYXoSUx8sRQWjz5t3pwEcnsxedk7 zwFx66q86pb8YQmt6V2PYHELM62y6tqAbpJN1mLI4tAImSBeH2AiYhETSXvIIqUP7Q6ajugxDh5kq 4QWgN4+w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uhlCH-00000005G5f-0Xvc; Fri, 01 Aug 2025 08:33:01 +0000 Received: from mail-pl1-x629.google.com ([2607:f8b0:4864:20::629]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1uhkuQ-00000005DqQ-3JWH for linux-arm-kernel@lists.infradead.org; Fri, 01 Aug 2025 08:14:35 +0000 Received: by mail-pl1-x629.google.com with SMTP id d9443c01a7336-24070ef9e2eso119555ad.0 for ; Fri, 01 Aug 2025 01:14:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1754036073; x=1754640873; darn=lists.infradead.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=vY5IloWsNQwsLIRSq+Jk0RbLuNAFATBZvlKueff9YnQ=; b=VgxUrKlD7CMvCO2gqqzdEFrasnsUn50kthBaf3biWVqNKYBY41D1nqOL1H+DeYfxXj zlJGBPPBga1xIg/YMoD0x+kxyjS6ziOsL2JsEDC69AfmtjO46vzhrhurE60ELExgeLxH ErsUDkv6HjU5fOxgYUY+neSs45+/95v4eVMdfyY9j3yFLhS6FSUd+wdrHP1X6X33XbDe O376opFG0lSkwUEwCipQMCU+ou6BgIYbn29hRXeY/lGQSu6vf+uAsC5iy6xj8mLZaCkW hxhmjqIt48ujTcicHeaBNPqRVEglwCVSJg3uAshowq3r2XIMLcVXWmWOqtoikmembnnP Zppw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1754036073; x=1754640873; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=vY5IloWsNQwsLIRSq+Jk0RbLuNAFATBZvlKueff9YnQ=; b=uGO/As7IovpsIRlJdjGcSUDi6ErBlCTnQsaY3ukVyTwHoLNlx9AR9qHUVTeyRqQUCX 8wJXlbO3X8Bw/SbyuzXqRPCsDl9NRi/tT2X1PlaDfYhxtSWRU3TL/otdAiVXflrHpX8N crCdfmVohlu3Pka1FLDt9IcTUXbl6y0xrQBJ1V/vaFEZ9ZjcyCnFZV0Ma31had2ezlsB LTCd+/tqEq3MfbwxmViu9WQFwlZ6v4mzEqkzp9yKVgLJ2U7Bf5dghXrDFd9UuwUN3Nqa ZCzapquQZWDjDH7MHparXyKdqi1yRYqNVqBMQ9sJcwo0RUgpOr1Z4xjwhcMbX2crwjLw hgjQ== X-Forwarded-Encrypted: i=1; AJvYcCUKKDlqtUZID33a9n5YaOfgoTunEfsq3DErKEExeYy/W1IgK6UBbwq/g7sXQp3ZEvEZSFmLQ9/sVCmyBntCsyJm@lists.infradead.org X-Gm-Message-State: AOJu0Yyp97CRW5K0AZzAlkruoAt6wXF9K0dHPLqa/lTPCQJv9ewPB7oV yBD4ru0OiE1oMh9GNz2Efd+tN+q1VsLQNr38MGbAzckvP5DypWoIvqLSbRdBR4FDdA== X-Gm-Gg: ASbGncty4TOcNejR6MrMC48L+ZTP+m2Wym/ZDN01mlxzy6HrsiDwZnNuEEQXQMtGCL5 suTC11zdzvr6YoYtJzeNZF2aVzxIzDeHL7+QHSQMt+6JDdHj0pPjpCglo9+M6o4bVjO7zriPLR7 +Ks+kPMzA2wqu3LUkGcWouWAnOl2YWScWbXIqdCZqikc4DZi3z5mJdYA8pdeSPYkymiYAL3KwKa S7BHl112QUSy53zasgz4b9W1V2hWnGNTjcbpiU83SZd7AFLtAZOtI1nHlkGZFkYQAlyUvpudfIs C4RjYmSTTgKgsgO3wTJ7CwkwiGY2CBWcL3pmx87KrV4m+tcVVcaC5obbYz6IY3k1jeu+gk3UN1q oSR/9PDAUb0u/hDDLnKbSQOSF1pjaqj/qcbjS9v/6tBRnzoqeFh5444FC X-Google-Smtp-Source: AGHT+IGXJ0oDUg8x3lalK0qa+IS9YcsVUdYwosMrUSgYdRWE/44m5WMnRi51aRiN1cRnb1G5Gn4Zxw== X-Received: by 2002:a17:902:d490:b0:240:48f4:40fd with SMTP id d9443c01a7336-2422a435a05mr2506505ad.19.1754036073034; Fri, 01 Aug 2025 01:14:33 -0700 (PDT) Received: from google.com (232.98.126.34.bc.googleusercontent.com. [34.126.98.232]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-241d1f1efe8sm36422045ad.69.2025.08.01.01.14.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 01 Aug 2025 01:14:32 -0700 (PDT) Date: Fri, 1 Aug 2025 08:14:27 +0000 From: Pranjal Shrivastava To: Nicolin Chen Cc: jgg@nvidia.com, will@kernel.org, joro@8bytes.org, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH rc] iommu/arm-smmu-v3: Fix smmu_domain->nr_ats_masters decrement Message-ID: References: <20250801030127.2006979-1-nicolinc@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250801030127.2006979-1-nicolinc@nvidia.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250801_011434_835445_147A7B7D X-CRM114-Status: GOOD ( 23.11 ) 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, Jul 31, 2025 at 08:01:27PM -0700, Nicolin Chen wrote: > The arm_smmu_attach_commit() updates master->ats_enabled before calling > arm_smmu_remove_master_domain() that is supposed to clean up everything > in the old domain, including the old domain's nr_ats_masters. So, it is > supposed to use the old ats_enabled state of the device, not an updated > state. > > This isn't a problem if switching between two domains where: > - old ats_enabled = false; new ats_enabled = false > - old ats_enabled = true; new ats_enabled = true > but can fail cases where: > - old ats_enabled = false; new ats_enabled = true > (old domain should keep the counter but incorrectly decreased it) > - old ats_enabled = true; new ats_enabled = false > (old domain needed to decrease the counter but incorrectly missed it) > > Update master->ats_enabled after arm_smmu_remove_master_domain() to fix > this. > > Fixes: 7497f4211f4f ("iommu/arm-smmu-v3: Make changing domains be hitless for ATS") > Cc: stable@vger.kernel.org > Signed-off-by: Nicolin Chen arm_smmu_remove_master_domain() needs to see the old ats_enabled state for the cleanup. Reviewed-by: Pranjal Shrivastava Thanks, Praan > --- > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index 312bc31d7e8eb..3c81139faecae 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -2997,9 +2997,9 @@ void arm_smmu_attach_commit(struct arm_smmu_attach_state *state) > /* ATS is being switched off, invalidate the entire ATC */ > arm_smmu_atc_inv_master(master, IOMMU_NO_PASID); > } > - master->ats_enabled = state->ats_enabled; > > arm_smmu_remove_master_domain(master, state->old_domain, state->ssid); > + master->ats_enabled = state->ats_enabled; > } > > static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) > -- > 2.43.0 > >