mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Michael Mueller
c7901a6ebe
This patch prepares a simplification of bit operations between the irq pending mask for emulated interrupts and the Interruption Pending Mask (IPM) which is part of the Guest Interruption State Area (GISA), a feature that allows interrupt delivery to guests by means of the SIE instruction. Without that change, a bit-wise *or* operation on parts of these two masks would either require a look-up table of size 256 bytes to map the IPM to the emulated irq pending mask bit orientation (all bits mirrored at half byte) or a sequence of up to 8 condidional branches to perform tests of single bit positions. Both options are to be rejected either by performance or space utilization reasons. Beyond that this change will be transparent. Signed-off-by: Michael Mueller <mimu@linux.vnet.ibm.com> Reviewed-by: Halil Pasic <pasic@linux.vnet.ibm.com> Reviewed-by: Pierre Morel <pmorel@linux.vnet.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.