Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751927AbaLSPNl (ORCPT ); Fri, 19 Dec 2014 10:13:41 -0500 Received: from e06smtp10.uk.ibm.com ([195.75.94.106]:46908 "EHLO e06smtp10.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751382AbaLSPNj (ORCPT ); Fri, 19 Dec 2014 10:13:39 -0500 Date: Fri, 19 Dec 2014 16:13:29 +0100 (CET) From: Sebastian Ott X-X-Sender: sebott@denkbrett To: "Michael S. Tsirkin" cc: linux-kernel@vger.kernel.org, Rusty Russell , virtualization@lists.linux-foundation.org, linux-sh@vger.kernel.org, Cornelia Huck , Martin Schwidefsky , Heiko Carstens , linux390@de.ibm.com, Gerald Schaefer , linux-s390@vger.kernel.org Subject: Re: [PATCH RFC 2/5] s390: add pci_iomap_range In-Reply-To: <20141219142829.GA13440@redhat.com> Message-ID: References: <1418679168-1011-1-git-send-email-mst@redhat.com> <1418679168-1011-3-git-send-email-mst@redhat.com> <20141219142829.GA13440@redhat.com> User-Agent: Alpine 2.11 (LFD 23 2013-08-11) Organization: =?ISO-8859-15?Q?=22IBM_Deutschland_Research_&_Development_GmbH_=2F_Vorsitzende_des_Aufsichtsrats=3A_Martina_Koederitz_Gesch=E4ftsf=FChrung=3A_Dirk_Wittkopp_Sitz_der_Gesellschaft=3A_B=F6blingen_=2F_Registergericht?= =?ISO-8859-15?Q?=3A_Amtsgericht_Stuttgart=2C_HRB_243294=22?= MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 14121915-0041-0000-0000-000002894166 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Dec 2014, Michael S. Tsirkin wrote: > On Fri, Dec 19, 2014 at 03:13:37PM +0100, Sebastian Ott wrote: > > On Mon, 15 Dec 2014, Michael S. Tsirkin wrote: > > > From: Michael S Tsirkin > > > > > > Virtio drivers should map the part of the range they need, not > > > necessarily all of it. > > > To this end, support mapping ranges within BAR on s390. > > > Since multiple ranges can now be mapped within a BAR, we keep track of > > > the number of mappings created, and only clear out the mapping for a BAR > > > when this number reaches 0. > > > > > > > I can't say much about the users of this interface but in principle I'm > > OK with such a change. > > I don't have an s390 system with pci for testing - could you help me out > by testing this and confirming it doesn't break things? I did some minor tests and nothing broke... > > > > Signed-off-by: Michael S. Tsirkin > > > --- > > > arch/s390/include/asm/pci_io.h | 1 + > > > arch/s390/pci/pci.c | 34 +++++++++++++++++++++++++++------- > > > 2 files changed, 28 insertions(+), 7 deletions(-) > > > > > > diff --git a/arch/s390/include/asm/pci_io.h b/arch/s390/include/asm/pci_io.h > > > index d194d54..25228b3 100644 > > > --- a/arch/s390/include/asm/pci_io.h > > > +++ b/arch/s390/include/asm/pci_io.h > > > @@ -16,6 +16,7 @@ > > > struct zpci_iomap_entry { > > > u32 fh; > > > u8 bar; > > > + u16 count; > > > }; > > > > > > extern struct zpci_iomap_entry *zpci_iomap_start; > > > diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c > > > index 2fa7b14..51cb653 100644 > > > --- a/arch/s390/pci/pci.c > > > +++ b/arch/s390/pci/pci.c > > > @@ -259,7 +259,10 @@ void __iowrite64_copy(void __iomem *to, const void *from, size_t count) > > > } > > > > > > /* Create a virtual mapping cookie for a PCI BAR */ > > > -void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max) > > > +void __iomem *pci_iomap_range(struct pci_dev *pdev, > > > + int bar, > > > + unsigned long offset, > > > + unsigned long max) > > > { > > > struct zpci_dev *zdev = get_zdev(pdev); > > > u64 addr; > > > @@ -270,14 +273,27 @@ void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max) > > > > > > idx = zdev->bars[bar].map_idx; > > > spin_lock(&zpci_iomap_lock); > > > - zpci_iomap_start[idx].fh = zdev->fh; > > > - zpci_iomap_start[idx].bar = bar; > > > + if (zpci_iomap_start[idx].count++) { > > > + BUG_ON(zpci_iomap_start[idx].fh != zdev->fh || > > > + zpci_iomap_start[idx].bar != bar); > > > + } else { > > > + zpci_iomap_start[idx].fh = zdev->fh; > > > + zpci_iomap_start[idx].bar = bar; > > > + } > > > + /* Detect overrun */ > > > + BUG_ON(!zpci_iomap_start[idx].count); > > > spin_unlock(&zpci_iomap_lock); > > > > > > addr = ZPCI_IOMAP_ADDR_BASE | ((u64) idx << 48); > > > - return (void __iomem *) addr; > > > + return (void __iomem *) addr + offset; > > > } > > > -EXPORT_SYMBOL_GPL(pci_iomap); > > > +EXPORT_SYMBOL_GPL(pci_iomap_range); > > > + > > > +void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) > > > +{ > > > + return pci_iomap_range(dev, bar, 0, maxlen); > > > +} > > > +EXPORT_SYMBOL(pci_iomap); > > > > This was EXPORT_SYMBOL_GPL. I guess, for this patch, it should stay that > > way. ...Hm, everyone else has this stuff as EXPORT_SYMBOL looks like we > > should use that too. > > > > Regards, > > Sebastian > > OK, so you want two patches: one with new functionality, > one switching to EXPORT_SYMBOL? Either that or at least add a note in the patch description. Regards, Sebastian > > > > > > > > void pci_iounmap(struct pci_dev *pdev, void __iomem *addr) > > > { > > > @@ -285,8 +301,12 @@ void pci_iounmap(struct pci_dev *pdev, void __iomem *addr) > > > > > > idx = (((__force u64) addr) & ~ZPCI_IOMAP_ADDR_BASE) >> 48; > > > spin_lock(&zpci_iomap_lock); > > > - zpci_iomap_start[idx].fh = 0; > > > - zpci_iomap_start[idx].bar = 0; > > > + /* Detect underrun */ > > > + BUG_ON(!zpci_iomap_start[idx].count); > > > + if (!--zpci_iomap_start[idx].count) { > > > + zpci_iomap_start[idx].fh = 0; > > > + zpci_iomap_start[idx].bar = 0; > > > + } > > > spin_unlock(&zpci_iomap_lock); > > > } > > > EXPORT_SYMBOL_GPL(pci_iounmap); > > > -- > > > MST > > > > > > > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/