[PATCH v9 12/12] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space
From: Liviu Dudau <Liviu.Dudau@arm.com>
Date: 2014-08-12 16:28:55
Also in:
linux-arch, linux-arm-kernel, linux-pci, lkml
Subsystem:
pci subsystem, the rest · Maintainers:
Bjorn Helgaas, Linus Torvalds
Introduce a default implementation for remapping PCI bus I/O resources onto the CPU address space. Architectures with special needs may provide their own version, but most should be able to use this one. Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rob Herring <robh+dt@kernel.org> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com> --- drivers/pci/pci.c | 33 +++++++++++++++++++++++++++++++++ include/linux/pci.h | 3 +++ 2 files changed, 36 insertions(+)
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 29d1775..76d21b6 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c@@ -2707,6 +2707,39 @@ int pci_request_regions_exclusive(struct pci_dev *pdev, const char *res_name) } EXPORT_SYMBOL(pci_request_regions_exclusive); +/** + * pci_remap_iospace - Remap the memory mapped I/O space + * @res: Resource describing the I/O space + * @phys_addr: physical address where the range will be mapped. + * + * Remap the memory mapped I/O space described by the @res + * into the CPU physical address space. Only architectures + * that have memory mapped IO defined (and hence PCI_IOBASE) + * should call this function. + */ +int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) +{ + int err = -ENODEV; + +#ifdef PCI_IOBASE + if (!(res->flags & IORESOURCE_IO)) + return -EINVAL; + + if (res->end > IO_SPACE_LIMIT) + return -EINVAL; + + err = ioremap_page_range(res->start + (unsigned long)PCI_IOBASE, + res->end + 1 + (unsigned long)PCI_IOBASE, + phys_addr, pgprot_device(PAGE_KERNEL)); +#else + /* this architecture does not have memory mapped I/O space, + so this function should never be called */ + WARN_ON(1); +#endif + + return err; +} + static void __pci_set_master(struct pci_dev *dev, bool enable) { u16 old_cmd, cmd;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index e1e0d80..988c2f5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h@@ -1098,6 +1098,9 @@ int __must_check pci_bus_alloc_resource(struct pci_bus *bus, resource_size_t), void *alignf_data); + +int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr); + static inline dma_addr_t pci_bus_address(struct pci_dev *pdev, int bar) { struct pci_bus_region region;
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2.0.4