* [PATCH RFC 3/5] pci: add pci_iomap_range [not found] <1418326570-9541-1-git-send-email-mst@redhat.com> @ 2014-12-11 19:37 ` Michael S. Tsirkin 2014-12-11 19:37 ` Michael S. Tsirkin 2014-12-11 22:27 ` Arnd Bergmann 0 siblings, 2 replies; 6+ messages in thread From: Michael S. Tsirkin @ 2014-12-11 19:37 UTC (permalink / raw) To: linux-kernel Cc: Rusty Russell, virtualization, cornelia.huck, Michael S Tsirkin, Arnd Bergmann, linux-arch From: Michael S Tsirkin <mst@redhat.com> Virtio drivers should map the part of the range they need, not necessarily all of it. They also need non-cacheable mapping even for prefetchable BARs. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- include/asm-generic/pci_iomap.h | 5 +++++ lib/pci_iomap.c | 46 +++++++++++++++++++++++++++++++++++------ 2 files changed, 45 insertions(+), 6 deletions(-) diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h index ce37349..8777331 100644 --- a/include/asm-generic/pci_iomap.h +++ b/include/asm-generic/pci_iomap.h @@ -15,6 +15,11 @@ 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 offset, + unsigned long minlen, + unsigned long maxlen, + bool force_nocache); /* 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 */ diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c index 0d83ea8..1ac4def 100644 --- a/lib/pci_iomap.c +++ b/lib/pci_iomap.c @@ -10,33 +10,47 @@ #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 + * @minlen: min length of the memory to map + * @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 * the details if this is a MMIO or PIO address space and will just do what * you expect from them in the correct way. * + * @minlen specifies the minimum length to map. We check that BAR is + * large enough. * @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. + * @force_nocache makes the mapping noncacheable even if the BAR + * is prefetcheable. It has no effect otherwise. * */ -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 offset, + unsigned long minlen, + unsigned long maxlen, + bool force_nocache) { 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 (len < minlen) return NULL; if (maxlen && len > maxlen) len = maxlen; if (flags & IORESOURCE_IO) return __pci_ioport_map(dev, start, len); if (flags & IORESOURCE_MEM) { - if (flags & IORESOURCE_CACHEABLE) + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) return ioremap(start, len); return ioremap_nocache(start, len); } @@ -44,5 +58,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) return NULL; } +/** + * 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, 0, maxlen, false); +} + EXPORT_SYMBOL(pci_iomap); +EXPORT_SYMBOL(pci_iomap_range); #endif /* CONFIG_PCI */ -- MST ^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH RFC 3/5] pci: add pci_iomap_range 2014-12-11 19:37 ` [PATCH RFC 3/5] pci: add pci_iomap_range Michael S. Tsirkin @ 2014-12-11 19:37 ` Michael S. Tsirkin 2014-12-11 22:27 ` Arnd Bergmann 1 sibling, 0 replies; 6+ messages in thread From: Michael S. Tsirkin @ 2014-12-11 19:37 UTC (permalink / raw) To: linux-kernel Cc: Rusty Russell, virtualization, cornelia.huck, Michael S Tsirkin, Arnd Bergmann, linux-arch From: Michael S Tsirkin <mst@redhat.com> Virtio drivers should map the part of the range they need, not necessarily all of it. They also need non-cacheable mapping even for prefetchable BARs. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> --- include/asm-generic/pci_iomap.h | 5 +++++ lib/pci_iomap.c | 46 +++++++++++++++++++++++++++++++++++------ 2 files changed, 45 insertions(+), 6 deletions(-) diff --git a/include/asm-generic/pci_iomap.h b/include/asm-generic/pci_iomap.h index ce37349..8777331 100644 --- a/include/asm-generic/pci_iomap.h +++ b/include/asm-generic/pci_iomap.h @@ -15,6 +15,11 @@ 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 offset, + unsigned long minlen, + unsigned long maxlen, + bool force_nocache); /* 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 */ diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c index 0d83ea8..1ac4def 100644 --- a/lib/pci_iomap.c +++ b/lib/pci_iomap.c @@ -10,33 +10,47 @@ #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 + * @minlen: min length of the memory to map + * @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 * the details if this is a MMIO or PIO address space and will just do what * you expect from them in the correct way. * + * @minlen specifies the minimum length to map. We check that BAR is + * large enough. * @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. + * @force_nocache makes the mapping noncacheable even if the BAR + * is prefetcheable. It has no effect otherwise. * */ -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 offset, + unsigned long minlen, + unsigned long maxlen, + bool force_nocache) { 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 (len < minlen) return NULL; if (maxlen && len > maxlen) len = maxlen; if (flags & IORESOURCE_IO) return __pci_ioport_map(dev, start, len); if (flags & IORESOURCE_MEM) { - if (flags & IORESOURCE_CACHEABLE) + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) return ioremap(start, len); return ioremap_nocache(start, len); } @@ -44,5 +58,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) return NULL; } +/** + * 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, 0, maxlen, false); +} + EXPORT_SYMBOL(pci_iomap); +EXPORT_SYMBOL(pci_iomap_range); #endif /* CONFIG_PCI */ -- MST ^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH RFC 3/5] pci: add pci_iomap_range 2014-12-11 19:37 ` [PATCH RFC 3/5] pci: add pci_iomap_range Michael S. Tsirkin 2014-12-11 19:37 ` Michael S. Tsirkin @ 2014-12-11 22:27 ` Arnd Bergmann 2014-12-11 22:27 ` Arnd Bergmann 2014-12-11 23:49 ` Michael S. Tsirkin 1 sibling, 2 replies; 6+ messages in thread From: Arnd Bergmann @ 2014-12-11 22:27 UTC (permalink / raw) To: Michael S. Tsirkin; +Cc: linux-arch, linux-kernel, virtualization On Thursday 11 December 2014 21:37:34 Michael S. Tsirkin wrote: > if (flags & IORESOURCE_MEM) { > - if (flags & IORESOURCE_CACHEABLE) > + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) > return ioremap(start, len); > return ioremap_nocache(start, len); > } > ioremap is the same as ioremap_nocache, so this doesn't really make any sense. IORESOURCE_CACHEABLE is practically only set for ROM bars, which we rarely map. Arnd ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH RFC 3/5] pci: add pci_iomap_range 2014-12-11 22:27 ` Arnd Bergmann @ 2014-12-11 22:27 ` Arnd Bergmann 2014-12-11 23:49 ` Michael S. Tsirkin 1 sibling, 0 replies; 6+ messages in thread From: Arnd Bergmann @ 2014-12-11 22:27 UTC (permalink / raw) To: Michael S. Tsirkin Cc: linux-kernel, Rusty Russell, virtualization, cornelia.huck, linux-arch On Thursday 11 December 2014 21:37:34 Michael S. Tsirkin wrote: > if (flags & IORESOURCE_MEM) { > - if (flags & IORESOURCE_CACHEABLE) > + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) > return ioremap(start, len); > return ioremap_nocache(start, len); > } > ioremap is the same as ioremap_nocache, so this doesn't really make any sense. IORESOURCE_CACHEABLE is practically only set for ROM bars, which we rarely map. Arnd ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH RFC 3/5] pci: add pci_iomap_range 2014-12-11 22:27 ` Arnd Bergmann 2014-12-11 22:27 ` Arnd Bergmann @ 2014-12-11 23:49 ` Michael S. Tsirkin 2014-12-11 23:49 ` Michael S. Tsirkin 1 sibling, 1 reply; 6+ messages in thread From: Michael S. Tsirkin @ 2014-12-11 23:49 UTC (permalink / raw) To: Arnd Bergmann; +Cc: linux-arch, linux-kernel, virtualization On Thu, Dec 11, 2014 at 11:27:54PM +0100, Arnd Bergmann wrote: > On Thursday 11 December 2014 21:37:34 Michael S. Tsirkin wrote: > > if (flags & IORESOURCE_MEM) { > > - if (flags & IORESOURCE_CACHEABLE) > > + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) > > return ioremap(start, len); > > return ioremap_nocache(start, len); > > } > > > > ioremap is the same as ioremap_nocache, so this doesn't really make any > sense. IORESOURCE_CACHEABLE is practically only set for ROM bars, which > we rarely map. > > Arnd Hmm I think you are right. It's an old patch - I think at one point in time we did set it when we now set IORESOURCE_PREFETCH. I'll drop this parameter. -- MST ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH RFC 3/5] pci: add pci_iomap_range 2014-12-11 23:49 ` Michael S. Tsirkin @ 2014-12-11 23:49 ` Michael S. Tsirkin 0 siblings, 0 replies; 6+ messages in thread From: Michael S. Tsirkin @ 2014-12-11 23:49 UTC (permalink / raw) To: Arnd Bergmann Cc: linux-kernel, Rusty Russell, virtualization, cornelia.huck, linux-arch On Thu, Dec 11, 2014 at 11:27:54PM +0100, Arnd Bergmann wrote: > On Thursday 11 December 2014 21:37:34 Michael S. Tsirkin wrote: > > if (flags & IORESOURCE_MEM) { > > - if (flags & IORESOURCE_CACHEABLE) > > + if (!force_nocache && (flags & IORESOURCE_CACHEABLE)) > > return ioremap(start, len); > > return ioremap_nocache(start, len); > > } > > > > ioremap is the same as ioremap_nocache, so this doesn't really make any > sense. IORESOURCE_CACHEABLE is practically only set for ROM bars, which > we rarely map. > > Arnd Hmm I think you are right. It's an old patch - I think at one point in time we did set it when we now set IORESOURCE_PREFETCH. I'll drop this parameter. -- MST ^ permalink raw reply [flat|nested] 6+ messages in thread
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2014-12-11 19:37 ` [PATCH RFC 3/5] pci: add pci_iomap_range Michael S. Tsirkin
2014-12-11 19:37 ` Michael S. Tsirkin
2014-12-11 22:27 ` Arnd Bergmann
2014-12-11 22:27 ` Arnd Bergmann
2014-12-11 23:49 ` Michael S. Tsirkin
2014-12-11 23:49 ` Michael S. Tsirkin
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