[PATCH 1/3] hotplug/memory: Apply assoc mem updates Post Migration Topo

[Michael Bringmann]

hotplug/memory: Recognize more changes to the associativity of memory
blocks described by the 'ibm,dynamic-memory' property regarding the
topology of LPARS in Post Migration events.  Previous efforts only
recognized whether a block's assignment had changed in the property.
Topology migration requires us to compare the aa_index values of the
old/new properties and 'readd' any block for which the setting has
changed.

Signed-off-by: Michael Bringmann <mwb@xxxxxxxxxxxxxxxxxx>
---
 arch/powerpc/platforms/pseries/hotplug-cpu.c    |   64 +++++++++++++++++++++++
 arch/powerpc/platforms/pseries/hotplug-memory.c |    6 ++
 arch/powerpc/platforms/pseries/mobility.c       |   47 +++++++++++++----
 arch/powerpc/platforms/pseries/pseries.h        |    2 +
 4 files changed, 109 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index fadb95e..d127c3a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -634,6 +634,27 @@ static int dlpar_cpu_remove_by_index(u32 drc_index)
 	return rc;
 }
 
+static int dlpar_cpu_readd_by_index(u32 drc_index)
+{
+	int rc = 0;
+
+	pr_info("Attempting to update CPU, drc index %x\n", drc_index);
+
+	if (dlpar_cpu_remove_by_index(drc_index))
+		rc = -EINVAL;
+	else if (dlpar_cpu_add(drc_index))
+		rc = -EINVAL;
+
+	if (rc)
+		pr_info("Failed to update cpu at drc_index %lx\n",
+				(unsigned long int)drc_index);
+	else
+		pr_info("CPU at drc_index %lx was updated\n",
+				(unsigned long int)drc_index);
+
+	return rc;
+}
+
 static int find_dlpar_cpus_to_remove(u32 *cpu_drcs, int cpus_to_remove)
 {
 	struct device_node *dn;
@@ -824,6 +845,9 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
 		else
 			rc = -EINVAL;
 		break;
+	case PSERIES_HP_ELOG_ACTION_READD:
+		rc = dlpar_cpu_readd_by_index(drc_index);
+		break;
 	default:
 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
 		rc = -EINVAL;
@@ -874,6 +898,42 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 
 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
 
+static int pseries_update_drconf_cpu(struct of_reconfig_data *pr)
+{
+	u32 old_entries, new_entries;
+	__be32 *p, *old_assoc, *new_assoc;
+
+	if (strcmp(pr->dn->type, "cpu"))
+		return 0;
+
+	/* The first int of the property is the number of domains's
+	 * described.  This is followed by an array of level values.
+	 */
+	p = (__be32 *) pr->old_prop->value;
+	if (!p)
+		return -EINVAL;
+	old_entries = be32_to_cpu(*p++);
+	old_assoc = p;
+
+	p = (__be32 *)pr->prop->value;
+	if (!p)
+		return -EINVAL;
+	new_entries = be32_to_cpu(*p++);
+	new_assoc = p;
+
+	if (old_entries == new_entries) {
+		int sz = old_entries * sizeof(int);
+
+		if (!memcmp(old_assoc, new_assoc, sz))
+			pseries_cpu_readd_by_index(pr->dn->phandle);
+
+	} else {
+		pseries_cpu_readd_by_index(pr->dn->phandle);
+	}
+
+	return 0;
+}
+
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
@@ -887,6 +947,10 @@ static int pseries_smp_notifier(struct notifier_block *nb,
 	case OF_RECONFIG_DETACH_NODE:
 		pseries_remove_processor(rd->dn);
 		break;
+	case OF_RECONFIG_UPDATE_PROPERTY:
+		if (!strcmp(rd->prop->name, "ibm,associativity"))
+			err = pseries_update_drconf_cpu(rd);
+		break;
 	}
 	return notifier_from_errno(err);
 }
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 1d48ab4..c61cfc6 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1160,6 +1160,12 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 					  memblock_size);
 			rc = (rc < 0) ? -EINVAL : 0;
 			break;
+		} else if ((be32_to_cpu(old_drmem[i].aa_index) !=
+					be32_to_cpu(new_drmem[i].aa_index)) &&
+				(be32_to_cpu(new_drmem[i].flags) &
+					DRCONF_MEM_ASSIGNED)) {
+			pseries_memory_readd_by_index(
+				be32_to_cpu(new_drmem[i].drc_index));
 		}
 	}
 	return rc;
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index f7042ad..7c19b23 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -239,9 +239,30 @@ static int add_dt_node(__be32 parent_phandle, __be32 drc_index)
 	return rc;
 }
 
+static void pseries_readd_by_index(int resource, __be32 phandle)
+{
+	struct pseries_hp_errorlog hp_elog;
+
+	hp_elog.resource = resource;
+	hp_elog.action = PSERIES_HP_ELOG_ACTION_READD;
+	hp_elog.id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
+	hp_elog._drc_u.drc_index = phandle;
+
+	queue_hotplug_event(&hp_elog, NULL, NULL);
+}
+
+void pseries_memory_readd_by_index(__be32 phandle)
+{
+	pseries_readd_by_index(PSERIES_HP_ELOG_RESOURCE_MEM, phandle);
+}
+
+void pseries_cpu_readd_by_index(__be32 phandle)
+{
+	pseries_readd_by_index(PSERIES_HP_ELOG_RESOURCE_CPU, phandle);
+}
+
 static void prrn_update_node(__be32 phandle)
 {
-	struct pseries_hp_errorlog *hp_elog;
 	struct device_node *dn;
 
 	/*
@@ -254,18 +275,21 @@ static void prrn_update_node(__be32 phandle)
 		return;
 	}
 
-	hp_elog = kzalloc(sizeof(*hp_elog), GFP_KERNEL);
-	if(!hp_elog)
-		return;
+	pseries_memory_readd_by_index(phandle);
+}
 
-	hp_elog->resource = PSERIES_HP_ELOG_RESOURCE_MEM;
-	hp_elog->action = PSERIES_HP_ELOG_ACTION_READD;
-	hp_elog->id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
-	hp_elog->_drc_u.drc_index = phandle;
+static void prrn_update_node_other(s32 scope, __be32 phandle)
+{
+	struct device_node *dn;
+	__be32 drc_index = be32_to_cpu(phandle);
 
-	queue_hotplug_event(hp_elog, NULL, NULL);
+	dn = of_find_node_by_phandle(drc_index);
+	if (dn) {
+		of_node_put(dn);
 
-	kfree(hp_elog);
+		if (!strcmp(dn->type, "cpu"))
+			pseries_cpu_readd_by_index(phandle);
+	}
 }
 
 int pseries_devicetree_update(s32 scope)
@@ -309,6 +333,9 @@ int pseries_devicetree_update(s32 scope)
 
 					if (scope == PRRN_SCOPE)
 						prrn_update_node(phandle);
+					else
+						prrn_update_node_other(
+							scope, phandle);
 
 					break;
 				case ADD_DT_NODE:
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 4470a31..b9a69a6 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -55,6 +55,7 @@ void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
 			 struct completion *hotplug_done, int *rc);
 #ifdef CONFIG_MEMORY_HOTPLUG
 int dlpar_memory(struct pseries_hp_errorlog *hp_elog);
+extern void pseries_memory_readd_by_index(__be32 drc_index);
 #else
 static inline int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 {
@@ -64,6 +65,7 @@ static inline int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 
 #ifdef CONFIG_HOTPLUG_CPU
 int dlpar_cpu(struct pseries_hp_errorlog *hp_elog);
+extern void pseries_cpu_readd_by_index(__be32 drc_index);
 #else
 static inline int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
 {