From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752588AbdLHUY2 (ORCPT ); Fri, 8 Dec 2017 15:24:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:43482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750908AbdLHUY0 (ORCPT ); Fri, 8 Dec 2017 15:24:26 -0500 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org AE0B620C01 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=helgaas@kernel.org Date: Fri, 8 Dec 2017 14:24:24 -0600 From: Bjorn Helgaas To: Govinda Tatti Cc: xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, bhelgaas@google.com, boris.ostrovsky@Oracle.COM, jgross@suse.com, JBeulich@suse.com, roger.pau@citrix.com, konrad.wilk@Oracle.COM Subject: Re: [PATCH V3 1/2] Drivers/PCI: Export pcie_has_flr() interface Message-ID: <20171208202424.GC12367@bhelgaas-glaptop.roam.corp.google.com> References: <20171207222145.9769-1-Govinda.Tatti@Oracle.COM> <20171207222145.9769-2-Govinda.Tatti@Oracle.COM> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20171207222145.9769-2-Govinda.Tatti@Oracle.COM> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 07, 2017 at 05:21:44PM -0500, Govinda Tatti wrote: > This patch exports pcie_has_flr() and it is being used by Xen pciback > driver to reset (flr/slot/bus) PCI devices based on 'reset' SysFS > attribute. > > Signed-off-by: Govinda Tatti > --- > v3: -New > > drivers/pci/pci.c | 3 ++- > include/linux/pci.h | 1 + > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 6078dfc..499e922 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -3872,7 +3872,7 @@ static void pci_flr_wait(struct pci_dev *dev) > * Returns true if the device advertises support for PCIe function level > * resets. > */ > -static bool pcie_has_flr(struct pci_dev *dev) > +bool pcie_has_flr(struct pci_dev *dev) > { > u32 cap; > > @@ -3882,6 +3882,7 @@ static bool pcie_has_flr(struct pci_dev *dev) > pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); > return cap & PCI_EXP_DEVCAP_FLR; > } > +EXPORT_SYMBOL_GPL(pcie_has_flr); I'd rather change pcie_flr() so you could *always* call it, and it would return 0, -ENOTTY, or whatever, based on whether FLR is supported. Is that feasible? I don't like the "Can I do this? Ok, do this" style of interfaces. It's racy (not really applicable in this case) and seems clunky. > /** > * pcie_flr - initiate a PCIe function level reset > diff --git a/include/linux/pci.h b/include/linux/pci.h > index d16a7c0..44bf2b5 100644 > --- a/include/linux/pci.h > +++ b/include/linux/pci.h > @@ -1089,6 +1089,7 @@ int pcie_get_mps(struct pci_dev *dev); > int pcie_set_mps(struct pci_dev *dev, int mps); > int pcie_get_minimum_link(struct pci_dev *dev, enum pci_bus_speed *speed, > enum pcie_link_width *width); > +bool pcie_has_flr(struct pci_dev *dev); > void pcie_flr(struct pci_dev *dev); > int __pci_reset_function(struct pci_dev *dev); > int __pci_reset_function_locked(struct pci_dev *dev); > -- > 2.9.5 >