Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752526AbaLSO2s (ORCPT ); Fri, 19 Dec 2014 09:28:48 -0500 Received: from mx1.redhat.com ([209.132.183.28]:53671 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751886AbaLSO2q (ORCPT ); Fri, 19 Dec 2014 09:28:46 -0500 Date: Fri, 19 Dec 2014 16:28:29 +0200 From: "Michael S. Tsirkin" To: Sebastian Ott 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 Message-ID: <20141219142829.GA13440@redhat.com> References: <1418679168-1011-1-git-send-email-mst@redhat.com> <1418679168-1011-3-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? > > 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? > > > > 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/