From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kiszka Subject: Re: [RFC] pci: Rework config space blocking services Date: Tue, 06 Sep 2011 10:48:04 +0200 Message-ID: <4E65DE44.5090002@siemens.com> References: <20110829150552.GA6851@redhat.com> <4E5BB358.3060705@siemens.com> <4E5BDEAB.5000405@siemens.com> <20110829191858.GA9415@redhat.com> <4E608A51.70509@siemens.com> <20110906055810.GA13286@redhat.com> <4E65C935.9000803@siemens.com> <20110906080410.GD13286@redhat.com> <4E65D981.7070201@siemens.com> <20110906084728.GA16091@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from david.siemens.de ([192.35.17.14]:18600 "EHLO david.siemens.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753810Ab1IFIsb (ORCPT ); Tue, 6 Sep 2011 04:48:31 -0400 In-Reply-To: <20110906084728.GA16091@redhat.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Michael S. Tsirkin" Cc: Jesse Barnes , Brian King , "James E.J. Bottomley" , "Hans J. Koch" , Greg Kroah-Hartman , "linux-pci@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "kvm@vger.kernel.org" On 2011-09-06 10:47, Michael S. Tsirkin wrote: > On Tue, Sep 06, 2011 at 10:27:45AM +0200, Jan Kiszka wrote: >> On 2011-09-06 10:04, Michael S. Tsirkin wrote: >>> On Tue, Sep 06, 2011 at 09:18:13AM +0200, Jan Kiszka wrote: >>>>>> @@ -401,36 +403,58 @@ int pci_vpd_truncate(struct pci_dev *dev, size_t size) >>>>>> EXPORT_SYMBOL(pci_vpd_truncate); >>>>>> >>>>>> /** >>>>>> - * pci_block_user_cfg_access - Block userspace PCI config reads/writes >>>>>> + * pci_block_cfg_access - Block PCI config reads/writes >>>>> >>>>> This comment seems confusing. We don't in fact block all config >>>>> reads writes. Instead we block userspace accesses and >>>>> concurrent block requests. >>>> >>>> I'm open for a better suggestion that summarize the more verbose (and >>>> hopefully clearer) explanation below. >>> >>> I think the problem is, it doesn't block config access >>> and we call it pci_block_cfg_access. >>> >>> Thinking about it, doesn't this behave somewhat like a lock? >>> How about >>> >>> pci_user_cfg_access_trylock >>> pci_user_cfg_access_lock >>> pci_user_cfg_access_unlock >>> >>> And then: >>> * pci_user_cfg_access_lock - Lock userspace PCI config access >> >> Except that the "userspace" here is still only half of the truth > > It's the name of the lock :) Ah, blind. That has to be change as well of course (pci_cfg_access_*lock). Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux