9a69f5087c
The Gasket (Google ASIC Software, Kernel Extensions, and Tools) kernel framework is a generic, flexible system that supports thin kernel drivers. Gasket kernel drivers are expected to handle opening and closing devices, mmap'ing BAR space as requested, a small selection of ioctls, and handling page table translation (covered below). Any other functions should be handled by userspace code. The Gasket common module is not enough to run a device. In order to customize the Gasket code for a given piece of hardware, a device specific module must be created. At a minimum, this module must define a struct gasket_driver_desc containing the device-specific data for use by the framework; in addition, the module must declare an __init function that calls gasket_register_device with the module's gasket_driver_desc struct. Finally, the driver must define an exit function that calls gasket_unregister_device with the module's gasket_driver_desc struct. One of the core assumptions of the Gasket framework is that precisely one process is allowed to have an open write handle to the device node at any given time. (That process may, once it has one write handle, open any number of additional write handles.) This is accomplished by tracking open and close data for each driver instance. Signed-off-by: Rob Springer <rspringer@google.com> Signed-off-by: John Joseph <jnjoseph@google.com> Signed-off-by: Simon Que <sque@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.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.
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.