9401911f2d
Currently phram always uses ioremap(), but this is unnecessary when normal memory is used. If the reserved-memory node does not specify the no-map property, indicating it should be mapped as system RAM and ioremap() cannot be used on it, use a cached mapping using memremap(MEMREMAP_WB) instead. On one of my systems this improves read performance by ~70%. (Note that this driver has always used normal memcpy/memset functions on memory obtained from ioremap(), which sparse doesn't like. There is no memremap() variant which maps exactly to ioremap() on all architectures, so that behaviour of the driver is not changed to avoid affecting existing users, but the sparse warnings are suppressed in the moved code with __force.) Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com> Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com> Link: https://lore.kernel.org/linux-mtd/20220510151822.1809278-1-vincent.whitchurch@axis.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.