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The current ECAM kernel implementation uses ioremap() to map the ECAM configuration space memory region; this is not safe in that on some architectures the ioremap interface provides mappings that allow posted write transactions. This, as highlighted in the PCIe specifications (4.0 - Rev0.3, "Ordering Considerations for the Enhanced Configuration Address Mechanism"), can create ordering issues for software because posted writes transactions on the CPU host bus are non posted in the PCI express fabric. Update the ioremap() interface to use pci_remap_cfgspace() whose mapping attributes guarantee that non-posted writes transactions are issued for memory writes within the ECAM memory mapped address region. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Cc: Jayachandran C <jnair@caviumnetworks.com>
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.