kernel/linux.git/arch/s390/include/asm/text-patching.h, branch v6.19.12Linux kernel stable tree (mirror)https://git.radix-linux.su/kernel/linux.git/atom?h=v6.19.122021-10-11T18:55:58+00:00s390: introduce text_poke_sync()2021-10-11T18:55:58+00:00Heiko Carstenshca@linux.ibm.com2021-10-01T10:47:01+00:00urn:sha1:e16d02ee3f348900a0a2cf41931b204e2042f5e3
Introduce a text_poke_sync() similar to what x86 has. This can be
used to execute a serializing instruction on all CPUs (including
the current one).
Note: according to the Principles of Operation an IPI (= interrupt)
will already serialize a CPU, however it is better to be explicit. In
addition on_each_cpu() makes sure that also the current CPU get
serialized - just to make sure that possible preemption can prevent
some theoretical case where a CPU will not be serialized.
Therefore text_poke_sync() has to be used whenever code got modified,
just to avoid to rely on implicit serialization.
Also introduce text_poke_sync_lock() which will also disable CPU
hotplug, to prevent that any CPU is just going online with a
prefetched old version of a modified instruction.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>