From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f171.google.com ([209.85.214.171]:52460 "EHLO mail-ob0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752688AbbAWXIp (ORCPT ); Fri, 23 Jan 2015 18:08:45 -0500 Received: by mail-ob0-f171.google.com with SMTP id va2so179969obc.2 for ; Fri, 23 Jan 2015 15:08:45 -0800 (PST) Date: Fri, 23 Jan 2015 17:08:41 -0600 From: Bjorn Helgaas To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, Rusty Russell , cornelia.huck@de.ibm.com, linux-pci@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org Subject: Re: [PATCH v3 09/16] pci: add pci_iomap_range Message-ID: <20150123230841.GS29776@google.com> References: <1421256142-11512-1-git-send-email-mst@redhat.com> <1421256142-11512-10-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1421256142-11512-10-git-send-email-mst@redhat.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Wed, Jan 14, 2015 at 07:27:54PM +0200, Michael S. Tsirkin wrote: > Virtio drivers should map the part of the BAR they need, not necessarily > all of it. > > Cc: Bjorn Helgaas > Cc: linux-pci@vger.kernel.org > Acked-by: Arnd Bergmann > Signed-off-by: Michael S. Tsirkin > Signed-off-by: Rusty Russell Acked-by: Bjorn Helgaas Sorry it took so long for me to notice these! > --- > > Bjorn, can you please ack this for merging through the virtio tree? > > include/asm-generic/pci_iomap.h | 10 ++++++++++ > lib/pci_iomap.c | 35 ++++++++++++++++++++++++++++++----- > 2 files changed, 40 insertions(+), 5 deletions(-) > > diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h > index ce37349..7389c87 100644 > --- a/include/asm-generic/pci_iomap.h > +++ b/include/asm-generic/pci_iomap.h > @@ -15,6 +15,9 @@ struct pci_dev; > #ifdef CONFIG_PCI > /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */ > extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max); > +extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar, > + unsigned long offset, > + unsigned long maxlen); > /* Create a virtual mapping cookie for a port on a given PCI device. > * Do not call this directly, it exists to make it easier for architectures > * to override */ > @@ -30,6 +33,13 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon > { > return NULL; > } > + > +static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar, > + unsigned long offset, > + unsigned long maxlen) > +{ > + return NULL; > +} > #endif > > #endif /* __ASM_GENERIC_IO_H */ > diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c > index 0d83ea8..bcce5f1 100644 > --- a/lib/pci_iomap.c > +++ b/lib/pci_iomap.c > @@ -10,10 +10,11 @@ > > #ifdef CONFIG_PCI > /** > - * pci_iomap - create a virtual mapping cookie for a PCI BAR > + * pci_iomap_range - create a virtual mapping cookie for a PCI BAR > * @dev: PCI device that owns the BAR > * @bar: BAR number > - * @maxlen: length of the memory to map > + * @offset: map memory at the given offset in BAR > + * @maxlen: max length of the memory to map > * > * Using this function you will get a __iomem address to your device BAR. > * You can access it using ioread*() and iowrite*(). These functions hide > @@ -21,16 +22,21 @@ > * you expect from them in the correct way. > * > * @maxlen specifies the maximum length to map. If you want to get access to > - * the complete BAR without checking for its length first, pass %0 here. > + * the complete BAR from offset to the end, pass %0 here. > * */ > -void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) > +void __iomem *pci_iomap_range(struct pci_dev *dev, > + int bar, > + unsigned long offset, > + unsigned long maxlen) > { > resource_size_t start = pci_resource_start(dev, bar); > resource_size_t len = pci_resource_len(dev, bar); > unsigned long flags = pci_resource_flags(dev, bar); > > - if (!len || !start) > + if (len <= offset || !start) > return NULL; > + len -= offset; > + start += offset; > if (maxlen && len > maxlen) > len = maxlen; > if (flags & IORESOURCE_IO) > @@ -43,6 +49,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) > /* What? */ > return NULL; > } > +EXPORT_SYMBOL(pci_iomap_range); > > +/** > + * pci_iomap - create a virtual mapping cookie for a PCI BAR > + * @dev: PCI device that owns the BAR > + * @bar: BAR number > + * @maxlen: length of the memory to map > + * > + * Using this function you will get a __iomem address to your device BAR. > + * You can access it using ioread*() and iowrite*(). These functions hide > + * the details if this is a MMIO or PIO address space and will just do what > + * you expect from them in the correct way. > + * > + * @maxlen specifies the maximum length to map. If you want to get access to > + * the complete BAR without checking for its length first, pass %0 here. > + * */ > +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); > #endif /* CONFIG_PCI */ > -- > MST >