From 8b921acfeffdb0b45085da862fc301a2d25ed2cf Mon Sep 17 00:00:00 2001 From: Liviu Dudau Date: Mon, 29 Sep 2014 15:29:30 +0100 Subject: [PATCH] PCI: Add pci_remap_iospace() to map bus I/O resources Add pci_remap_iospace() to map bus I/O resources into the CPU virtual address space. Architectures with special needs may provide their own version, but most should be able to use this one. This function is useful for PCI host bridge drivers that need to map the PCI I/O resources into virtual memory space. [bhelgaas: phys_addr description, drop temporary "err" variable] Signed-off-by: Liviu Dudau Signed-off-by: Bjorn Helgaas Reviewed-by: Rob Herring Reviewed-by: Catalin Marinas CC: Arnd Bergmann --- drivers/pci/pci.c | 31 +++++++++++++++++++++++++++++++ include/asm-generic/pgtable.h | 4 ++++ include/linux/pci.h | 3 +++ 3 files changed, 38 insertions(+) diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index d36f35ff6c5d..6e994fc077f4 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -2704,6 +2704,37 @@ 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 of range to be mapped + * + * Remap the memory mapped I/O space described by the @res + * and the CPU physical address @phys_addr into virtual address space. + * Only architectures that have memory mapped IO functions defined + * (and the PCI_IOBASE value defined) should call this function. + */ +int __weak pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) +{ +#if defined(PCI_IOBASE) && defined(CONFIG_MMU) + unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; + + if (!(res->flags & IORESOURCE_IO)) + return -EINVAL; + + if (res->end > IO_SPACE_LIMIT) + return -EINVAL; + + return ioremap_page_range(vaddr, vaddr + resource_size(res), 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_ONCE(1, "This architecture does not support memory mapped I/O\n"); + return -ENODEV; +#endif +} + static void __pci_set_master(struct pci_dev *dev, bool enable) { u16 old_cmd, cmd; diff --git a/include/asm-generic/pgtable.h b/include/asm-generic/pgtable.h index 53b2acc38213..977e545a64c3 100644 --- a/include/asm-generic/pgtable.h +++ b/include/asm-generic/pgtable.h @@ -249,6 +249,10 @@ static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b) #define pgprot_writecombine pgprot_noncached #endif +#ifndef pgprot_device +#define pgprot_device pgprot_noncached +#endif + /* * When walking page tables, get the address of the next boundary, * or the end address of the range if that comes earlier. Although no diff --git a/include/linux/pci.h b/include/linux/pci.h index 150da2d644e7..b4995fdfffb1 100644 --- a/include/linux/pci.h +++ b/include/linux/pci.h @@ -1100,6 +1100,9 @@ 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;