From patchwork Thu Feb 2 14:50:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Zijlstra X-Patchwork-Id: 649764 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 57321C636D4 for ; Thu, 2 Feb 2023 15:31:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233157AbjBBPb2 (ORCPT ); Thu, 2 Feb 2023 10:31:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233008AbjBBPbX (ORCPT ); Thu, 2 Feb 2023 10:31:23 -0500 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AA1D4975F; Thu, 2 Feb 2023 07:30:44 -0800 (PST) DKIM-Signature: v=1; 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Thu, 2 Feb 2023 16:28:45 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 0) id 96E8D23F31FB6; Thu, 2 Feb 2023 16:28:40 +0100 (CET) Message-ID: <20230202152655.564329626@infradead.org> User-Agent: quilt/0.66 Date: Thu, 02 Feb 2023 15:50:36 +0100 From: Peter Zijlstra To: torvalds@linux-foundation.org Cc: corbet@lwn.net, will@kernel.org, peterz@infradead.org, boqun.feng@gmail.com, mark.rutland@arm.com, catalin.marinas@arm.com, dennis@kernel.org, tj@kernel.org, cl@linux.com, hca@linux.ibm.com, gor@linux.ibm.com, agordeev@linux.ibm.com, borntraeger@linux.ibm.com, svens@linux.ibm.com, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, joro@8bytes.org, suravee.suthikulpanit@amd.com, robin.murphy@arm.com, dwmw2@infradead.org, baolu.lu@linux.intel.com, Arnd Bergmann , Herbert Xu , davem@davemloft.net, penberg@kernel.org, rientjes@google.com, iamjoonsoo.kim@lge.com, Andrew Morton , vbabka@suse.cz, roman.gushchin@linux.dev, 42.hyeyoo@gmail.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-s390@vger.kernel.org, iommu@lists.linux.dev, linux-arch@vger.kernel.org, linux-crypto@vger.kernel.org, Vasant Hegde Subject: [PATCH v2 06/10] x86,amd_iommu: Replace cmpxchg_double() References: <20230202145030.223740842@infradead.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-crypto@vger.kernel.org Signed-off-by: Peter Zijlstra (Intel) Tested-by: Vasant Hegde --- drivers/iommu/amd/amd_iommu_types.h | 9 +++++++-- drivers/iommu/amd/iommu.c | 10 ++++------ 2 files changed, 11 insertions(+), 8 deletions(-) --- a/drivers/iommu/amd/amd_iommu_types.h +++ b/drivers/iommu/amd/amd_iommu_types.h @@ -979,8 +979,13 @@ union irte_ga_hi { }; struct irte_ga { - union irte_ga_lo lo; - union irte_ga_hi hi; + union { + struct { + union irte_ga_lo lo; + union irte_ga_hi hi; + }; + u128 irte; + }; }; struct irq_2_irte { --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2992,10 +2992,10 @@ static int alloc_irq_index(struct amd_io static int modify_irte_ga(struct amd_iommu *iommu, u16 devid, int index, struct irte_ga *irte, struct amd_ir_data *data) { - bool ret; struct irq_remap_table *table; - unsigned long flags; struct irte_ga *entry; + unsigned long flags; + u128 old; table = get_irq_table(iommu, devid); if (!table) @@ -3006,16 +3006,14 @@ static int modify_irte_ga(struct amd_iom entry = (struct irte_ga *)table->table; entry = &entry[index]; - ret = cmpxchg_double(&entry->lo.val, &entry->hi.val, - entry->lo.val, entry->hi.val, - irte->lo.val, irte->hi.val); /* * We use cmpxchg16 to atomically update the 128-bit IRTE, * and it cannot be updated by the hardware or other processors * behind us, so the return value of cmpxchg16 should be the * same as the old value. */ - WARN_ON(!ret); + old = entry->irte; + WARN_ON(!try_cmpxchg128(&entry->irte, &old, irte->irte)); if (data) data->ref = entry;