[3.13.y-ckt stable] Patch "powerpc/pseries: Correct cpu affinity for dlpar added cpus" has been added to staging queue

[Kamal Mostafa]

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

    powerpc/pseries: Correct cpu affinity for dlpar added cpus

to the linux-3.13.y-queue branch of the 3.13.y-ckt extended stable tree 
which can be found at:

    http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11-ckt22.

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

For more information about the 3.13.y-ckt tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From a9560e9884eb2afbc27a19e2b2b9c00dabfca2b0 Mon Sep 17 00:00:00 2001
From: Nathan Fontenot <nfont at linux.vnet.ibm.com>
Date: Wed, 29 Apr 2015 20:42:06 -0500
Subject: powerpc/pseries: Correct cpu affinity for dlpar added cpus

commit f32393c943e297b8ae180c8f83d81a156c7d0412 upstream.

The incorrect ordering of operations during cpu dlpar add results in invalid
affinity for the cpu being added. The ibm,associativity property in the
device tree is populated with all zeroes for the added cpu which results in
invalid affinity mappings and all cpus appear to belong to node 0.

This occurs because rtas configure-connector is called prior to making the
rtas set-indicator calls. Phyp does not assign affinity information
for a cpu until the rtas set-indicator calls are made to set the isolation
and allocation state.

Correct the order of operations to make the rtas set-indicator
calls (done in dlpar_acquire_drc) before calling rtas configure-connector.

Fixes: 1a8061c46c46 ("powerpc/pseries: Add kernel based CPU DLPAR handling")

Signed-off-by: Nathan Fontenot <nfont at linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 arch/powerpc/platforms/pseries/dlpar.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index a8fe5aa..261bf79 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -408,6 +408,10 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 	if (rc)
 		return -EINVAL;

+	rc = dlpar_acquire_drc(drc_index);
+	if (rc)
+		return -EINVAL;
+
 	parent = of_find_node_by_path("/cpus");
 	if (!parent)
 		return -ENODEV;
@@ -418,12 +422,6 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)

 	of_node_put(parent);

-	rc = dlpar_acquire_drc(drc_index);
-	if (rc) {
-		dlpar_free_cc_nodes(dn);
-		return -EINVAL;
-	}
-
 	rc = dlpar_attach_node(dn);
 	if (rc) {
 		dlpar_release_drc(drc_index);
--
1.9.1