mainlining shenanigans
ee03b9b447
Although it is often possible to recover a CPU that was interrupted from OPAL with a system reset NMI, it's undesirable to interrupt them for a few reasons. Firstly because dump/debug code itself needs to call firmware, so it could hang on a lock or possibly corrupt a per-cpu data structure if it or another CPU was interrupted from OPAL. Secondly, the kexec crash dump code will not return from interrupt to unwind the OPAL call. Call OPAL_QUIESCE with QUIESCE_HOLD before sending an NMI IPI to another CPU, which wait for it to leave firmware (or time out) to avoid this problem in normal conditions. Firmware bugs may still result in a timeout and interrupting OPAL, but that is the best option (stops the CPU, and possibly allows firmware to be debugged). Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> |
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arch | ||
block | ||
certs | ||
crypto | ||
Documentation | ||
drivers | ||
firmware | ||
fs | ||
include | ||
init | ||
ipc | ||
kernel | ||
lib | ||
LICENSES | ||
mm | ||
net | ||
samples | ||
scripts | ||
security | ||
sound | ||
tools | ||
usr | ||
virt | ||
.clang-format | ||
.cocciconfig | ||
.get_maintainer.ignore | ||
.gitattributes | ||
.gitignore | ||
.mailmap | ||
COPYING | ||
CREDITS | ||
Kbuild | ||
Kconfig | ||
MAINTAINERS | ||
Makefile | ||
README |
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.