[PATCH AUTOSEL 4.19 415/671] powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild
From: Sasha Levin <sashal@kernel.org>
Date: 2020-01-16 18:51:50
Also in:
linuxppc-dev, stable
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
From: Nathan Lynch <redacted>
[ 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 <redacted>
Reviewed-by: Gautham R. Shenoy <redacted>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 a8f20e5928e1..9edb45430133 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 955f5e999f1b..52bd3fc6642d 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 */
--
2.20.1