[3.16.y-ckt stable] Patch "powerpc: use device_online/offline() instead of cpu_up/down()" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    powerpc: use device_online/offline() instead of cpu_up/down()

to the linux-3.16.y-queue branch of the 3.16.y-ckt extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.16.y-queue

This patch is scheduled to be released in version 3.16.7-ckt2.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.16.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From c3e9182213960db3a85849d707717d84c5aa2bf5 Mon Sep 17 00:00:00 2001
From: Dan Streetman <ddstreet at ieee.org>
Date: Fri, 31 Oct 2014 15:41:34 -0400
Subject: powerpc: use device_online/offline() instead of cpu_up/down()

commit 10ccaf178b2b961d8bca252d647ed7ed8aae2a20 upstream.

In powerpc pseries platform dlpar operations, use device_online() and
device_offline() instead of cpu_up() and cpu_down().

Calling cpu_up/down() directly does not update the cpu device offline
field, which is used to online/offline a cpu from sysfs. Calling
device_online/offline() instead keeps the sysfs cpu online value
correct. The hotplug lock, which is required to be held when calling
device_online/offline(), is already held when dlpar_online/offline_cpu()
are called, since they are called only from cpu_probe|release_store().

This patch fixes errors on phyp (PowerVM) systems that have cpu(s)
added/removed using dlpar operations; without this patch, the
/sys/devices/system/cpu/cpuN/online nodes do not correctly show the
online state of added/removed cpus.

Signed-off-by: Dan Streetman <ddstreet at ieee.org>
Cc: Nathan Fontenot <nfont at linux.vnet.ibm.com>
Fixes: 0902a9044fa5 ("Driver core: Use generic offline/online for CPU offline/online")
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 arch/powerpc/platforms/pseries/dlpar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index 2d0b4d68a40a..c89787d43dd1 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -379,7 +379,7 @@ static int dlpar_online_cpu(struct device_node *dn)
 			BUG_ON(get_cpu_current_state(cpu)
 					!= CPU_STATE_OFFLINE);
 			cpu_maps_update_done();
-			rc = cpu_up(cpu);
+			rc = device_online(get_cpu_device(cpu));
 			if (rc)
 				goto out;
 			cpu_maps_update_begin();
@@ -462,7 +462,7 @@ static int dlpar_offline_cpu(struct device_node *dn)
 			if (get_cpu_current_state(cpu) == CPU_STATE_ONLINE) {
 				set_preferred_offline_state(cpu, CPU_STATE_OFFLINE);
 				cpu_maps_update_done();
-				rc = cpu_down(cpu);
+				rc = device_offline(get_cpu_device(cpu));
 				if (rc)
 					goto out;
 				cpu_maps_update_begin();
--
2.1.0