powerpc/pseries: Update CPU hotplug error recovery
Update the cpu dlpar add/remove paths to do better error recovery when
a failure occurs during the add/remove operation.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 6fb28cf..a54aee9 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -18,6 +18,8 @@
* 2 of the License, or (at your option) any later version.
*/
+#define pr_fmt(fmt) "pseries-hotplug-cpu: " fmt
+
#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
@@ -405,38 +407,67 @@
static ssize_t dlpar_cpu_add(u32 drc_index)
{
struct device_node *dn, *parent;
- int rc;
+ int rc, saved_rc;
+
+ pr_debug("Attempting to add CPU, drc index: %x\n", drc_index);
parent = of_find_node_by_path("/cpus");
- if (!parent)
+ if (!parent) {
+ pr_warn("Failed to find CPU root node \"/cpus\"\n");
return -ENODEV;
+ }
if (dlpar_cpu_exists(parent, drc_index)) {
of_node_put(parent);
- printk(KERN_WARNING "CPU with drc index %x already exists\n",
- drc_index);
+ pr_warn("CPU with drc index %x already exists\n", drc_index);
return -EINVAL;
}
rc = dlpar_acquire_drc(drc_index);
if (rc) {
+ pr_warn("Failed to acquire DRC, rc: %d, drc index: %x\n",
+ rc, drc_index);
of_node_put(parent);
return -EINVAL;
}
dn = dlpar_configure_connector(cpu_to_be32(drc_index), parent);
of_node_put(parent);
- if (!dn)
+ if (!dn) {
+ pr_warn("Failed call to configure-connector, drc index: %x\n",
+ drc_index);
+ dlpar_release_drc(drc_index);
return -EINVAL;
+ }
rc = dlpar_attach_node(dn);
if (rc) {
- dlpar_release_drc(drc_index);
- dlpar_free_cc_nodes(dn);
- return rc;
+ saved_rc = rc;
+ pr_warn("Failed to attach node %s, rc: %d, drc index: %x\n",
+ dn->name, rc, drc_index);
+
+ rc = dlpar_release_drc(drc_index);
+ if (!rc)
+ dlpar_free_cc_nodes(dn);
+
+ return saved_rc;
}
rc = dlpar_online_cpu(dn);
+ if (rc) {
+ saved_rc = rc;
+ pr_warn("Failed to online cpu %s, rc: %d, drc index: %x\n",
+ dn->name, rc, drc_index);
+
+ rc = dlpar_detach_node(dn);
+ if (!rc)
+ dlpar_release_drc(drc_index);
+
+ return saved_rc;
+ }
+
+ pr_debug("Successfully added CPU %s, drc index: %x\n", dn->name,
+ drc_index);
return rc;
}
@@ -500,19 +531,38 @@
{
int rc;
+ pr_debug("Attemping to remove CPU %s, drc index: %x\n",
+ dn->name, drc_index);
+
rc = dlpar_offline_cpu(dn);
- if (rc)
+ if (rc) {
+ pr_warn("Failed to offline CPU %s, rc: %d\n", dn->name, rc);
return -EINVAL;
+ }
rc = dlpar_release_drc(drc_index);
- if (rc)
+ if (rc) {
+ pr_warn("Failed to release drc (%x) for CPU %s, rc: %d\n",
+ drc_index, dn->name, rc);
+ dlpar_online_cpu(dn);
return rc;
+ }
rc = dlpar_detach_node(dn);
- if (rc)
- dlpar_acquire_drc(drc_index);
+ if (rc) {
+ int saved_rc = rc;
- return rc;
+ pr_warn("Failed to detach CPU %s, rc: %d", dn->name, rc);
+
+ rc = dlpar_acquire_drc(drc_index);
+ if (!rc)
+ dlpar_online_cpu(dn);
+
+ return saved_rc;
+ }
+
+ pr_debug("Successfully removed CPU, drc index: %x\n", drc_index);
+ return 0;
}
#ifdef CONFIG_ARCH_CPU_PROBE_RELEASE