[PATCH v06 2/9] hotplug/cpu: Add operation queuing function

[Michael Bringmann <mwb@linux.vnet.ibm.com>]

migration/dlpar: This patch adds function dlpar_queue_action()
which will queued up information about a CPU/Memory 'readd'
operation according to resource type, action code, and DRC index.
At a subsequent point, the list of operations can be run/played
in series.  Examples of such oprations include 'readd' of CPU
and Memory blocks identified as having changed their associativity
during an LPAR migration event.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in patch:
  -- Correct drc_index before adding to pseries_hp_errorlog struct
  -- Correct text of notice
  -- Revise queuing model to save up all of the DLPAR actions for
     later execution.
  -- Restore list init statement missing from patch
  -- Move call to apply queued operations into 'mobility.c'
  -- Compress some code
  -- Rename some of queueing function APIs
  -- Revise implementation to push execution of queued operations
     to a workqueue task.
  -- Cleanup reference to outdated queuing operation.
---
 arch/powerpc/include/asm/rtas.h           |    2 +
 arch/powerpc/platforms/pseries/dlpar.c    |   61 +++++++++++++++++++++++++++++
 arch/powerpc/platforms/pseries/mobility.c |    4 ++
 arch/powerpc/platforms/pseries/pseries.h  |    2 +
 4 files changed, 69 insertions(+)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 71e393c..4f601c7 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -310,12 +310,14 @@ struct pseries_hp_errorlog {
 		struct { __be32 count, index; } ic;
 		char	drc_name[1];
 	} _drc_u;
+	struct list_head list;
 };
 
 #define PSERIES_HP_ELOG_RESOURCE_CPU	1
 #define PSERIES_HP_ELOG_RESOURCE_MEM	2
 #define PSERIES_HP_ELOG_RESOURCE_SLOT	3
 #define PSERIES_HP_ELOG_RESOURCE_PHB	4
+#define PSERIES_HP_ELOG_RESOURCE_PMT	5
 
 #define PSERIES_HP_ELOG_ACTION_ADD	1
 #define PSERIES_HP_ELOG_ACTION_REMOVE	2
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index a0b20c0..7264b8e 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -25,6 +25,7 @@
 #include <asm/prom.h>
 #include <asm/machdep.h>
 #include <linux/uaccess.h>
+#include <linux/delay.h>
 #include <asm/rtas.h>
 
 static struct workqueue_struct *pseries_hp_wq;
@@ -329,6 +330,8 @@ int dlpar_release_drc(u32 drc_index)
 	return 0;
 }
 
+static int dlpar_pmt(struct pseries_hp_errorlog *work);
+
 static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
 {
 	int rc;
@@ -357,6 +360,9 @@ static int handle_dlpar_errorlog(struct pseries_hp_errorlog *hp_elog)
 	case PSERIES_HP_ELOG_RESOURCE_CPU:
 		rc = dlpar_cpu(hp_elog);
 		break;
+	case PSERIES_HP_ELOG_RESOURCE_PMT:
+		rc = dlpar_pmt(hp_elog);
+		break;
 	default:
 		pr_warn_ratelimited("Invalid resource (%d) specified\n",
 				    hp_elog->resource);
@@ -407,6 +413,61 @@ void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
 	}
 }
 
+LIST_HEAD(dlpar_delayed_list);
+
+int dlpar_queue_action(int resource, int action, u32 drc_index)
+{
+	struct pseries_hp_errorlog *hp_errlog;
+
+	hp_errlog = kmalloc(sizeof(struct pseries_hp_errorlog), GFP_KERNEL);
+	if (!hp_errlog)
+		return -ENOMEM;
+
+	hp_errlog->resource = resource;
+	hp_errlog->action = action;
+	hp_errlog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
+	hp_errlog->_drc_u.drc_index = cpu_to_be32(drc_index);
+
+	list_add_tail(&hp_errlog->list, &dlpar_delayed_list);
+
+	return 0;
+}
+
+static int dlpar_pmt(struct pseries_hp_errorlog *work)
+{
+	struct list_head *pos, *q;
+
+	ssleep(15);
+
+	list_for_each_safe(pos, q, &dlpar_delayed_list) {
+		struct pseries_hp_errorlog *tmp;
+
+		tmp = list_entry(pos, struct pseries_hp_errorlog, list);
+		handle_dlpar_errorlog(tmp);
+
+		list_del(pos);
+		kfree(tmp);
+
+		ssleep(10);
+	}
+
+	return 0;
+}
+
+int dlpar_queued_actions_run(void)
+{
+	if (!list_empty(&dlpar_delayed_list)) {
+		struct pseries_hp_errorlog hp_errlog;
+
+		hp_errlog.resource = PSERIES_HP_ELOG_RESOURCE_PMT;
+		hp_errlog.action = 0;
+		hp_errlog.id_type = 0;
+
+		queue_hotplug_event(&hp_errlog, 0, 0);
+	}
+	return 0;
+}
+
 static int dlpar_parse_resource(char **cmd, struct pseries_hp_errorlog *hp_elog)
 {
 	char *arg;
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index f6364d9..d0d1cae 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -378,6 +378,10 @@ static ssize_t migration_store(struct class *class,
 		return rc;
 
 	post_mobility_fixup();
+
+	/* Apply any necessary changes identified during fixup */
+	dlpar_queued_actions_run();
+
 	return count;
 }
 
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 60db2ee..72ca996 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -61,6 +61,8 @@ extern struct device_node *dlpar_configure_connector(__be32,
 
 void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
 			 struct completion *hotplug_done, int *rc);
+int dlpar_queue_action(int resource, int action, u32 drc_index);
+int dlpar_queued_actions_run(void);
 #ifdef CONFIG_MEMORY_HOTPLUG
 int dlpar_memory(struct pseries_hp_errorlog *hp_elog);
 #else