289e1c8921
The cited commit describes that when using writel(), explicit wmb()
is not needed. wmb() is an expensive barrier. writel() uses the needed
platform specific barrier instead of wmb().
writeX() section of "KERNEL I/O BARRIER EFFECTS" already describes
ordering of I/O accessors with MMIO writes.
Hence add the comment for pseudo code of writel() and remove confusing
text around writel() and wmb().
commit 5846581e3563 ("locking/memory-barriers.txt: Fix broken DMA vs. MMIO ordering example")
Co-developed-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
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.