Re: [PATCH v11 10/10] PCI: Introduce pci_remap_iospace() for remapping PCI I/O bus resources into CPU space
From: Rob Herring <hidden>
Date: 2014-09-20 00:35:01
Also in:
linux-arch, linux-arm-kernel, linux-pci, lkml
On 09/17/2014 08:30 PM, Liviu Dudau wrote:
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> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
One nit below, otherwise: Reviewed-by: Rob Herring <robh@kernel.org>
quoted hunk ↗ jump to hunk
--- drivers/pci/pci.c | 33 +++++++++++++++++++++++++++++++++ include/asm-generic/pgtable.h | 4 ++++ include/linux/pci.h | 3 +++ 3 files changed, 40 insertions(+)diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 2c9ac70..654b44c 100644 --- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c@@ -2704,6 +2704,39 @@ 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);
Printing what the comment says in the warning would be better than making the user look-up why they got a warning. Rob