From patchwork Wed Sep 2 14:50:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 1355854 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4BhRh56Q01z9sVW; Thu, 3 Sep 2020 00:50:45 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1kDU5y-0003Sg-GV; Wed, 02 Sep 2020 14:50:42 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kDU5v-0003Rl-Su for kernel-team@lists.ubuntu.com; Wed, 02 Sep 2020 14:50:39 +0000 Received: from 3.general.kamal.us.vpn ([10.172.68.53] helo=ascalon) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1kDU5v-0007v2-GY for kernel-team@lists.ubuntu.com; Wed, 02 Sep 2020 14:50:39 +0000 Received: from kamal by ascalon with local (Exim 4.90_1) (envelope-from ) id 1kDU5s-0003c2-K8 for kernel-team@lists.ubuntu.com; Wed, 02 Sep 2020 07:50:36 -0700 From: Kamal Mostafa To: kernel-team@lists.ubuntu.com Subject: [PATCH][AWS-{F, G}] UBUNTU: SAUCE: arm64: Enable PCI write-combine resources under sysfs Date: Wed, 2 Sep 2020 07:50:18 -0700 Message-Id: <20200902145018.13479-3-kamal@canonical.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200902145018.13479-1-kamal@canonical.com> References: <20200902145018.13479-1-kamal@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Clint Sbisa BugLink: https://bugs.launchpad.net/bugs/1893817 Using write-combine is crucial for performance of PCI devices where significant amounts of transactions go over PCI BARs. arm64 supports write-combine PCI mappings, so the appropriate define has been added which will expose write-combine mappings under sysfs for prefetchable PCI resources. Signed-off-by: Clint Sbisa Reference: https://lore.kernel.org/linux-pci/20200831151827.pumm2p54fyj7fz5s@amazon.com/ Signed-off-by: Kamal Mostafa --- arch/arm64/include/asm/pci.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/include/asm/pci.h b/arch/arm64/include/asm/pci.h index 70b323cf8300..b33ca260e3c9 100644 --- a/arch/arm64/include/asm/pci.h +++ b/arch/arm64/include/asm/pci.h @@ -17,6 +17,7 @@ #define pcibios_assign_all_busses() \ (pci_has_flag(PCI_REASSIGN_ALL_BUS)) +#define arch_can_pci_mmap_wc() 1 #define ARCH_GENERIC_PCI_MMAP_RESOURCE 1 extern int isa_dma_bridge_buggy;