This problem was found on sg2042 server platform with the litmus test.
This patch is based on Guo Ren's patch [1].
[1] c53925298d
riscv: qspinlock: errata: Add ERRATA_THEAD_WRITE_ONCE fixup
The early version of T-Head C9xx cores has a store merge buffer
delay problem. The store merge buffer could improve the store queue
performance by merging multi-store requests, but when there are not
continued store requests, the prior single store request would be
waiting in the store queue for a long time. That would cause
significant problems for communication between multi-cores. This
problem was found on sg2042 & th1520 platforms with the qspinlock
lock torture test.
So appending a fence w.o could immediately flush the store merge
buffer and let other cores see the write result.
This will apply the WRITE_ONCE errata to handle the non-standard
behavior via appending a fence w.o instruction for WRITE_ONCE().
Signed-off-by: haijiao.liu@sophgo.com <haijiao.liu@sophgo.com>
Noisy commit, no functional changes.
Generated with an current upstream clang-format and:
clang-format -i $(find . -name \*.[ch])
Signed-off-by: Olof Johansson <olof@lixom.net>
One of the shortcomings of clang-format is that it doesn't allow
for aligned define tables, which is used for a number of constants.
Add annotation to disable the automatic formatting where needed.
Signed-off-by: Olof Johansson <olof@lixom.net>
This patch updates copyright header in all files as follows:
1. Makes "SPDX-License-Identifier: BSD-2-Clause" as first line
2. Change copyright year to 2019 for Western Digital
Signed-off-by: Anup Patel <anup.patel@wdc.com>
