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The PCI bus specification (rev 3.0, 3.2.5 "Transaction Ordering and Posting") defines rules for PCI configuration space transactions ordering and posting, that state that configuration writes have to be non-posted transactions. Current ioremap interface on ARM provides mapping functions that provide "bufferable" writes transactions (ie ioremap uses MT_DEVICE memory type) aka posted writes, so PCI host controller drivers have no arch interface to remap PCI configuration space with memory attributes that comply with the PCI specifications for configuration space. Implement an ARM specific pci_remap_cfgspace() interface that allows to map PCI config memory regions with MT_UNCACHED memory type (ie strongly ordered - non-posted writes), providing a remap function that complies with PCI specifications for config space transactions. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@armlinux.org.uk>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.