From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752921AbcFISUP (ORCPT ); Thu, 9 Jun 2016 14:20:15 -0400 Received: from mail.kernel.org ([198.145.29.136]:58754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751172AbcFISUN (ORCPT ); Thu, 9 Jun 2016 14:20:13 -0400 Subject: [PATCH v1 0/3] PCI: Clean up write combining usage for user mmap To: Yinghai Lu , Benjamin Herrenschmidt , Michal Simek , Paul Mackerras , Michael Ellerman From: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Date: Thu, 09 Jun 2016 13:20:08 -0500 Message-ID: <20160609181102.13455.33593.stgit@bhelgaas-glaptop2.roam.corp.google.com> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org These patches: - Enforce a "no write combining on I/O port space mapping" policy. This seems like an obviously good thing but was previously enforced only by powerpc. - Stop giving powerpc users write combining mappings of prefetchable memory they ask for write combining with the procfs PCIIOC_WRITE_COMBINE ioctl or a sysfs "resourceN_wc" file. - Clean up arch-specific code that related to the above. Ben, I'm particularly interested in your thoughts about the powerpc change. It should "only" affect performance of users who aren't actually requesting write combining. I don't know how many of those users there might be. Yinghai, I added your sign-off to the powerpc part, since you posted that exact patch. Let me know if you don't want that. These are on my pci/resource branch. --- Bjorn Helgaas (2): PCI: Ignore write combining when mapping I/O port space microblaze/PCI: Remove useless __pci_mmap_set_pgprot() Yinghai Lu (1): powerpc/pci: Remove __pci_mmap_set_pgprot() arch/microblaze/pci/pci-common.c | 31 +------------------------------ arch/powerpc/kernel/pci-common.c | 37 ++++--------------------------------- drivers/pci/proc.c | 9 ++++++--- 3 files changed, 11 insertions(+), 66 deletions(-)