From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Nathan Lynch <nathanl@linux.ibm.com>,
"Gautham R . Shenoy" <ego@linux.vnet.ibm.com>,
linuxppc-dev@lists.ozlabs.org, Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.2 060/171] powerpc/pseries/mobility: prevent cpu hotplug during DT update
Date: Thu, 18 Jul 2019 23:54:51 -0400 [thread overview]
Message-ID: <20190719035643.14300-60-sashal@kernel.org> (raw)
In-Reply-To: <20190719035643.14300-1-sashal@kernel.org>
From: Nathan Lynch <nathanl@linux.ibm.com>
[ Upstream commit e59a175faa8df9d674247946f2a5a9c29c835725 ]
CPU online/offline code paths are sensitive to parts of the device
tree (various cpu node properties, cache nodes) that can be changed as
a result of a migration.
Prevent CPU hotplug while the device tree potentially is inconsistent.
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>
---
arch/powerpc/platforms/pseries/mobility.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 0c48c8964783..50e7aee3c7f3 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -6,6 +6,7 @@
* Copyright (C) 2010 IBM Corporation
*/
+#include <linux/cpu.h>
#include <linux/kernel.h>
#include <linux/kobject.h>
#include <linux/smp.h>
@@ -335,11 +336,19 @@ void post_mobility_fixup(void)
if (rc)
printk(KERN_ERR "Post-mobility activate-fw failed: %d\n", rc);
+ /*
+ * We don't want CPUs to go online/offline while the device
+ * tree is being updated.
+ */
+ cpus_read_lock();
+
rc = pseries_devicetree_update(MIGRATION_SCOPE);
if (rc)
printk(KERN_ERR "Post-mobility device tree update "
"failed: %d\n", rc);
+ cpus_read_unlock();
+
/* Possibly switch to a new RFI flush type */
pseries_setup_rfi_flush();
--
2.20.1
next parent reply other threads:[~2019-07-19 4:02 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20190719035643.14300-1-sashal@kernel.org>
2019-07-19 3:54 ` Sasha Levin [this message]
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 077/171] powerpc/pci/of: Fix OF flags parsing for 64bit BARs Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 092/171] powerpc/cacheflush: fix variable set but not used Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 093/171] powerpc/xmon: Fix disabling tracing while in xmon Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 094/171] powerpc/rtas: retry when cpu offline races with suspend/migration Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 105/171] powerpc: silence a -Wcast-function-type warning in dawr_write_file_bool Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 106/171] powerpc/4xx/uic: clear pending interrupt after irq type/pol change Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 107/171] powerpc/mm: mark more tlb functions as __always_inline Sasha Levin
2019-07-19 3:55 ` [PATCH AUTOSEL 5.2 112/171] powerpc/mm: Handle page table allocation failures Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 140/171] powerpc/irq: Don't WARN continuously in arch_local_irq_restore() Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 141/171] powerpc/boot: add {get, put}_unaligned_be32 to xz_config.h Sasha Levin
2019-07-19 3:56 ` [PATCH AUTOSEL 5.2 148/171] powerpc/eeh: Handle hugepages in ioremap space Sasha Levin
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