From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932075Ab1ILQyt (ORCPT ); Mon, 12 Sep 2011 12:54:49 -0400 Received: from goliath.siemens.de ([192.35.17.28]:29407 "EHLO goliath.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756103Ab1ILQyr (ORCPT ); Mon, 12 Sep 2011 12:54:47 -0400 From: Jan Kiszka To: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Jesse Barnes , "Hans J. Koch" , Greg Kroah-Hartman , "Michael S. Tsirkin" , kvm@vger.kernel.org, Brian King Subject: [PATCH 0/3] PCI: Rework config space locking, add INTx masking services Date: Mon, 12 Sep 2011 18:54:01 +0200 Message-Id: X-Mailer: git-send-email 1.7.3.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This series tries to heal the currently broken locking scheme around PCI config space accesses. We have an interface lock out access via sysfs, but that service wrongly assumes it is only called by one instance at a time for some device. So two loops doing echo 1 > /sys/bus/pci/devices//reset in parallel will trigger a kernel BUG at the moment. Besides synchronizing with user space, we also need to manage config space access of generic PCI drivers. They need to mask legacy interrupt lines while the specific driver runs in user space or a guest OS. The approach taken here is provide mutex-like locking for general access - which still requires a special mechanism due to requirements of the IBM Power RAID SCSI driver. Furthermore, INTx masking is now available via the PCI core and synchronized via the internal pci_lock. Not sure who may want to take this, so I'm CC'ing broadly. CC: Brian King Jan Kiszka (3): pci: Rework config space blocking services pci: Introduce INTx check & mask API uio: Convert uio_generic_pci to new intx masking API drivers/pci/access.c | 76 +++++++++++++++++---------- drivers/pci/iov.c | 12 ++-- drivers/pci/pci.c | 114 ++++++++++++++++++++++++++++++++++++++++- drivers/pci/pci.h | 2 + drivers/scsi/ipr.c | 66 +++++++++++++++++++++--- drivers/scsi/ipr.h | 1 + drivers/uio/uio_pci_generic.c | 82 +++--------------------------- include/linux/pci.h | 17 ++++-- 8 files changed, 248 insertions(+), 122 deletions(-) -- 1.7.3.4