From: Nathan Lynch nathanl@linux.ibm.com
[ Upstream commit d4aa219a074a5abaf95a756b9f0d190b5c03a945 ]
Allow external callers to force the cacheinfo code to release all its references to cache nodes, e.g. before processing device tree updates post-migration, and to rebuild the hierarchy afterward.
CPU online/offline must be blocked by callers; enforce this.
Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel") Signed-off-by: Nathan Lynch nathanl@linux.ibm.com Reviewed-by: Gautham R. Shenoy ego@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/powerpc/kernel/cacheinfo.c | 21 +++++++++++++++++++++ arch/powerpc/kernel/cacheinfo.h | 4 ++++ 2 files changed, 25 insertions(+)
diff --git a/arch/powerpc/kernel/cacheinfo.c b/arch/powerpc/kernel/cacheinfo.c index a8f20e5..9edb454 100644 --- a/arch/powerpc/kernel/cacheinfo.c +++ b/arch/powerpc/kernel/cacheinfo.c @@ -865,4 +865,25 @@ void cacheinfo_cpu_offline(unsigned int cpu_id) if (cache) cache_cpu_clear(cache, cpu_id); } + +void cacheinfo_teardown(void) +{ + unsigned int cpu; + + lockdep_assert_cpus_held(); + + for_each_online_cpu(cpu) + cacheinfo_cpu_offline(cpu); +} + +void cacheinfo_rebuild(void) +{ + unsigned int cpu; + + lockdep_assert_cpus_held(); + + for_each_online_cpu(cpu) + cacheinfo_cpu_online(cpu); +} + #endif /* (CONFIG_PPC_PSERIES && CONFIG_SUSPEND) || CONFIG_HOTPLUG_CPU */ diff --git a/arch/powerpc/kernel/cacheinfo.h b/arch/powerpc/kernel/cacheinfo.h index 955f5e9..52bd3fc 100644 --- a/arch/powerpc/kernel/cacheinfo.h +++ b/arch/powerpc/kernel/cacheinfo.h @@ -6,4 +6,8 @@ extern void cacheinfo_cpu_online(unsigned int cpu_id); extern void cacheinfo_cpu_offline(unsigned int cpu_id);
+/* Allow migration/suspend to tear down and rebuild the hierarchy. */ +extern void cacheinfo_teardown(void); +extern void cacheinfo_rebuild(void); + #endif /* _PPC_CACHEINFO_H */