From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Sean O. Stalley" Subject: Re: [PATCH v2 0/2] PCI: Add support for PCI Enhanced Allocation "BARs" Date: Wed, 23 Sep 2015 16:51:09 -0700 Message-ID: <20150923235109.GA4384@sean.stalley.intel.com> References: <1443047264-4003-1-git-send-email-sean.stalley@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-pci-owner@vger.kernel.org To: Yinghai Lu Cc: Bjorn Helgaas , Rajat Jain , "Michael S. Tsirkin" , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , "gong.chen@linux.intel.com" , "linux-pci@vger.kernel.org" , Linux Kernel Mailing List , linux-api@vger.kernel.org List-Id: linux-api@vger.kernel.org On Wed, Sep 23, 2015 at 04:26:56PM -0700, Yinghai Lu wrote: > On Wed, Sep 23, 2015 at 3:27 PM, Sean O. Stalley wrote: > > PCI Enhanced Allocation is a new method of allocating MMIO & IO > > resources for PCI devices & bridges. It can be used instead > > of the traditional PCI method of using BARs. > > > > EA entries are hardware-initialized to a fixed address. > > Unlike BARs, regions described by EA are cannot be moved. > > Because of this, only devices which are permanently connected to > > the PCI bus can use EA. A removable PCI card must not use EA. > > As it is fixed, can you put IORESOURCE_PCI_FIXED in the res->flags? > > Thanks > > Yinghai IORESOURCE_PCI_FIXED is set in pci_ea_set_flags(): +static unsigned long pci_ea_set_flags(struct pci_dev *dev, u8 prop) +{ + unsigned long flags = IORESOURCE_PCI_FIXED; + + Which is called in pci_ea_read(), and passed to res->flags (if there aren't any errors): + + /* Try to use primary properties, otherwise fall back to secondary */ + flags = pci_ea_set_flags(dev, PCI_EA_PP(dw0)); + if (!flags) + flags = pci_ea_set_flags(dev, PCI_EA_SP(dw0)); + ... + res->flags = flags; -Sean