038c5bedbc
Review and extend the low level AP code to be able to deal with asynchronous reported errors on APQNs. The hypervisor and the SE guest may be confronted with an asynchronously reported error at return of an AP instruction. So all places where AP instructions are called need review and may eventually need extensions. However, not all places need rework. As together with the AP status and the enabled asynch bit there is always a response code set. The asynch error reporting comes with new response codes which may be simple handled in the default case of a switch statement. The idea behind this patch is to report asynch errors as -EPERM (read this as "Operation not permitted") which reflects the fact that only a rapq (with F bit enabled) is a valid AP instruction when an asynch error is flagged. The AP queue state machine functions return AP_SM_WAIT_NONE when a asynch error is detected to reflect the fact, that the state machine can't do anything with such an error as long as the queue is reset. Unfortunately the ap bus scan function needed some update as the ap_queue_info() now needs to return 3 states: 1 if an APQN exists and info is available, -1 if it is assumed an APQN does not exist and the new return value 0 without any info values filled. This 0 returncode is handled as "there is an APQN but we currently don't know any more hw info about this, so please use your previous info and try again later". Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Reviewed-by: Holger Dengler <dengler@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.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.