Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753325AbaLSONu (ORCPT ); Fri, 19 Dec 2014 09:13:50 -0500 Received: from e06smtp11.uk.ibm.com ([195.75.94.107]:47350 "EHLO e06smtp11.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752750AbaLSONr (ORCPT ); Fri, 19 Dec 2014 09:13:47 -0500 Date: Fri, 19 Dec 2014 15:13:37 +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: <1418679168-1011-3-git-send-email-mst@redhat.com> Message-ID: References: <1418679168-1011-1-git-send-email-mst@redhat.com> <1418679168-1011-3-git-send-email-mst@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: 14121914-0005-0000-0000-00000285D0A2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. > 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 > > 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/