From patchwork Mon Mar 27 09:49:31 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Pieralisi X-Patchwork-Id: 9646013 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id DFF7C602C8 for ; Mon, 27 Mar 2017 09:52:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id BAB6A204C2 for ; Mon, 27 Mar 2017 09:52:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id ACEBF1FFAD; Mon, 27 Mar 2017 09:52:12 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 31A671FFAD for ; Mon, 27 Mar 2017 09:52:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752764AbdC0Jvw (ORCPT ); Mon, 27 Mar 2017 05:51:52 -0400 Received: from foss.arm.com ([217.140.101.70]:59336 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752760AbdC0Jul (ORCPT ); Mon, 27 Mar 2017 05:50:41 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2B1E915AD; Mon, 27 Mar 2017 02:49:57 -0700 (PDT) Received: from red-moon.cambridge.arm.com (red-moon.cambridge.arm.com [10.1.206.55]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6660F3F23B; Mon, 27 Mar 2017 02:49:52 -0700 (PDT) From: Lorenzo Pieralisi To: linux-pci@vger.kernel.org Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lorenzo Pieralisi , Arnd Bergmann , Will Deacon , Bjorn Helgaas , Russell King , Catalin Marinas , Pratyush Anand , Jingoo Han , Mingkai Hu , John Garry , Tanmay Inamdar , Murali Karicheri , Bharat Kumar Gogada , Ray Jui , Wenrui Li , Shawn Lin , Minghuan Lian , Jon Mason , Gabriele Paoloni , Thomas Petazzoni , Joao Pinto , Thierry Reding , Michal Simek , Stanimir Varbanov , Zhou Wang , Roy Zang , "Luis R. Rodriguez" Subject: [PATCH v2 03/22] asm-generic/pgtable.h: introduce pgprot_nonposted remap attribute Date: Mon, 27 Mar 2017 10:49:31 +0100 Message-Id: <20170327094954.7162-4-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20170327094954.7162-1-lorenzo.pieralisi@arm.com> References: <20170327094954.7162-1-lorenzo.pieralisi@arm.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP According to the PCI local bus specifications (Revision 3.0, 3.2.5), I/O Address space transactions are non-posted. On architectures where I/O space is implemented through a chunk of memory mapped space mapped to PCI address space (ie IA64/ARM/ARM64) the memory mapping for the region backing I/O Address Space transactions determines the I/O transactions attributes (before the transactions actually reaches the PCI bus where it is handled according to the PCI specifications). The kernel lacks a pgprot_* attribute to map memory with type generating non-posted writes transactions, which therefore needs to be added. Add a pgprot_nonposted mapping prot to create a memory mapping for memory areas requiring non-posted write transactions; make it default to pgprot_noncached (which should provide a sane default behaviour) but still allowing architectures on which pgprot_noncached results in posted write transactions to override the prot with an arch specific implementation that guarantees non-posted writes transactions. Signed-off-by: Lorenzo Pieralisi Cc: Arnd Bergmann Cc: Will Deacon Cc: Bjorn Helgaas Cc: Russell King Cc: Catalin Marinas --- include/asm-generic/pgtable.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 1fad160..2070172 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -399,6 +399,10 @@ static inline int pud_same(pud_t pud_a, pud_t pud_b) #define pgprot_device pgprot_noncached #endif +#ifndef pgprot_nonposted +#define pgprot_nonposted pgprot_noncached +#endif + #ifndef pgprot_modify #define pgprot_modify pgprot_modify static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)