mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-04 04:28:10 -04:00
d460bb6c64
In commitb02002cc4c("s390/pci: Implement ioremap_wc/prot() with MIO") we implemented both ioremap_wc() and ioremap_prot() however until now we had not set HAVE_IOREMAP_PROT in Kconfig, do so now. This also requires implementing pte_pgprot() as this is used in the generic_access_phys() code enabled by CONFIG_HAVE_IOREMAP_PROT. As with ioremap_wc() we need to take the MMIO Write Back bit index into account. Moreover since the pgprot value returned from pte_pgprot() is to be used for mappings into kernel address space we must make sure that it uses appropriate kernel page table protection bits. In particular a pgprot value originally coming from userspace could have the _PAGE_PROTECT bit set to enable fault based dirty bit accounting which would then make the mapping inaccessible when used in kernel address space. Fixes:b02002cc4c("s390/pci: Implement ioremap_wc/prot() with MIO") Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
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.