From: Michael S Tsirkin <[email protected]> Virtio drivers should map the part of the range they need, not necessarily all of it.
Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Rusty Russell <[email protected]> --- include/asm-generic/io.h | 4 ++++ include/asm-generic/iomap.h | 11 +++++++++++ lib/iomap.c | 41 ++++++++++++++++++++++++++++++++++++----- 3 files changed, 51 insertions(+), 5 deletions(-) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index 9120887..3cf1787 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -286,6 +286,10 @@ static inline void writesb(const void __iomem *addr, const void *buf, int len) /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */ struct pci_dev; 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); static inline void pci_iounmap(struct pci_dev *dev, void __iomem *p) { } diff --git a/include/asm-generic/iomap.h b/include/asm-generic/iomap.h index 98dcd76..6f192d4 100644 --- a/include/asm-generic/iomap.h +++ b/include/asm-generic/iomap.h @@ -70,8 +70,19 @@ extern void ioport_unmap(void __iomem *); /* Create a virtual mapping cookie for a PCI BAR (memory or IO) */ struct pci_dev; 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); extern void pci_iounmap(struct pci_dev *dev, void __iomem *); #else +static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar, + unsigned offset, + unsigned long minlen, + unsigned long maxlen) +{ + return NULL; +} struct pci_dev; static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max) { diff --git a/lib/iomap.c b/lib/iomap.c index 5dbcb4b..93ae915 100644 --- a/lib/iomap.c +++ b/lib/iomap.c @@ -243,26 +243,37 @@ EXPORT_SYMBOL(ioport_unmap); #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. * */ -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) { 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; @@ -277,10 +288,30 @@ 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); +} + void pci_iounmap(struct pci_dev *dev, void __iomem * addr) { IO_COND(addr, /* nothing */, iounmap(addr)); } EXPORT_SYMBOL(pci_iomap); +EXPORT_SYMBOL(pci_iomap_range); EXPORT_SYMBOL(pci_iounmap); #endif /* CONFIG_PCI */ _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
