51337ef07a
kmap_atomic() is being deprecated in favor of kmap_local_page(). Replace the map-memcpy-unmap usage pattern (done using k[un]map_atomic()) with memcpy_from_page(), which internally uses kmap_local_page() and kunmap_local(). This renders the variables 'data' and 'vaddr' unnecessary, and so remove these too. Note that kmap_atomic() disables preemption and page-fault processing, but kmap_local_page() doesn't. When converting uses of kmap_atomic(), one has to check if the code being executed between the map/unmap implicitly depends on page-faults and/or preemption being disabled. If yes, then code to disable page-faults and/or preemption should also be added for functional correctness. That however doesn't appear to be the case here, so just memcpy_from_page() is used. Also note that the page being mapped is not allocated by the driver, and so the driver doesn't know if the page is in normal memory. This is the reason kmap_local_page() is used (via memcpy_from_page()) as opposed to page_address(). I don't have hardware, so this change has only been compile tested. Cc: Ayush Sawal <ayush.sawal@chelsio.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Fabio M. De Francesco <fmdefrancesco@gmail.com> Suggested-by: Fabio M. De Francesco <fmdefrancesco@gmail.com> Signed-off-by: Anirudh Venkataramanan <anirudh.venkataramanan@intel.com> Acked-by: Ayush Sawal <ayush.sawal@chelsio.com> Signed-off-by: David S. Miller <davem@davemloft.net>
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.