[RFC 0/3] powerpc/hotplug: Fix affinity assoc for LPAR migration

[RFC 0/3] powerpc/hotplug: Fix affinity assoc for LPAR migration

[Michael Bringmann]

The migration of LPARs across Power systems affects many attributes
including that of the associativity of memory blocks and CPUs.  The
patches in this set execute when a system is coming up fresh upon a
migration target.  They are intended to,

* Recognize changes to the associativity of memory and CPUs recorded
  in internal data structures when compared to the latest copies in
  the device tree (e.g. ibm,dynamic-memory, ibm,dynamic-memory-v2,
  cpus),
* Recognize changes to the associativity mapping (e.g. ibm,
  associativity-lookup-arrays), locate all assigned memory blocks
  corresponding to each changed row, and readd all such blocks.
* Generate calls to other code layers to reset the data structures
  related to associativity of the CPUs and memory.
* Re-register the 'changed' entities into the target system.
  Re-registration of CPUs and memory blocks mostly entails acting as
  if they have been newly hot-added into the target system.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>

Michael Bringmann (3):
  hotplug/mobility: Apply assoc lookup updates for Post Migration Topo
  postmigration/memory: Review assoc lookup array changes
  postmigration/memory: Associativity & 'ibm,dynamic-memory-v2'
---
Changes in RFC:
  -- Rename pseries_update_drconf_cpu to pseries_update_cpu
  -- Simplify code to update CPU nodes during mobility checks.
     Remove functions to generate extra HP_ELOG messages in favor
     of direct function calls to dlpar_cpu_readd_by_index, or
     dlpar_memory_readd_by_index.
  -- Move check for "cpu" node type from pseries_update_cpu to
     pseries_smp_notifier in 'hotplug-cpu.c'
  -- Remove functions 'pseries_memory_readd_by_index' and
     'pseries_cpu_readd_by_index' as no longer needed outside of
     'mobility.c'.
  -- Update patch for recent checkin compatibility
  -- Resubmit as RFC pending further integration with LMB changes
     by Nathan Fontenot

[RFC 1/3] hotplug/mobility: Apply assoc updates for Post Migration Topo

[Michael Bringmann]

hotplug/mobility: Recognize more changes to the associativity of
memory blocks described by the 'ibm,dynamic-memory' and 'cpu'
properties when processing the topology of LPARS in Post Migration
events.  Previous efforts only recognized whether a memory block's
assignment had changed in the property.  Changes here include:

* Checking the aa_index values of the old/new properties and 'readd'
  any block for which the setting has changed.
* Checking for changes in cpu associativity and making 'readd' calls
  when differences are observed.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Simplify code to update CPU nodes during mobility checks.
     Remove functions to generate extra HP_ELOG messages in favor
     of direct function calls to dlpar_cpu_readd_by_index.
  -- Move check for "cpu" node type from pseries_update_cpu to
     pseries_smp_notifier in 'hotplug-cpu.c'
  -- Remove functions 'pseries_memory_readd_by_index' and
     'pseries_cpu_readd_by_index' as no longer needed outside of
     'mobility.c'.
  -- Update patch for recent checkin compatibility
  -- Resubmit as RFC pending further integration with LMB changes
     by Nathan Fontenot
---
 arch/powerpc/platforms/pseries/hotplug-cpu.c    |   69 +++++++++++++++++++++++
 arch/powerpc/platforms/pseries/hotplug-memory.c |    7 ++
 2 files changed, 76 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index a7d14aa7..91ef22a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -636,6 +636,27 @@ 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;
@@ -826,6 +847,9 @@ 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;
@@ -876,12 +900,53 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 
 #endif /* CONFIG_ARCH_CPU_PROBE_RELEASE */
 
+static int pseries_update_cpu(struct of_reconfig_data *pr)
+{
+	u32 old_entries, new_entries;
+	__be32 *p, *old_assoc, *new_assoc;
+	int rc = 0;
+
+	/* So far, we only handle the 'ibm,associativity' property,
+	 * here.
+	 * The first int of the property is the number of domains
+	 * 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))
+			rc = dlpar_cpu_readd_by_index(
+					be32_to_cpu(pr->dn->phandle));
+
+	} else {
+		rc = dlpar_cpu_readd_by_index(
+					be32_to_cpu(pr->dn->phandle));
+	}
+
+	return rc;
+}
+
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *data)
 {
 	struct of_reconfig_data *rd = data;
 	int err = 0;
 
+	if (strcmp(rd->dn->type, "cpu"))
+		return notifier_from_errno(err);
+
 	switch (action) {
 	case OF_RECONFIG_ATTACH_NODE:
 		err = pseries_add_processor(rd->dn);
@@ -889,6 +954,10 @@ 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_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..0e2ae20 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1160,6 +1160,13 @@ 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)) {
+			rc = dlpar_memory_readd_by_index(
+				be32_to_cpu(new_drmem[i].drc_index),
+				pr->prop);
 		}
 	}
 	return rc;

[RFC 2/3] postmigration/memory: Review assoc lookup array changes

[Michael Bringmann]

postmigration/memory: In an LPAR migration scenario, the property
"ibm,associativity-lookup-arrays" may change.  In the event that a
row of the array differs, locate all assigned memory blocks with that
'aa_index' and 're-add' them to the system memory block data structures.
In the process of the 're-add', the appropriate entry of the property
'ibm,dynamic-memory' would be updated as well as any other applicable
system data structures.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Simplify code to update memory nodes during mobility checks.
     Remove functions to generate extra HP_ELOG messages in favor
     of direct function calls to dlpar_memory_readd_by_index.
  -- Resubmit as RFC pending further integration with LMB changes
     by Nathan Fontenot
---
 arch/powerpc/platforms/pseries/hotplug-memory.c |  121 +++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 0e2ae20..04208b0 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1172,6 +1172,124 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 	return rc;
 }
 
+struct assoc_arrays {
+	u32 n_arrays;
+	u32 array_sz;
+	const __be32 *arrays;
+};
+
+static int pseries_update_ala_memory_aai(int aa_index,
+					struct property *dmprop)
+{
+	struct of_drconf_cell *drmem;
+	u32 entries;
+	__be32 *p;
+	int i;
+	int rc = 0;
+
+	p = (__be32 *) dmprop->value;
+	if (!p)
+		return -EINVAL;
+
+	/* The first int of the property is the number of lmb's
+	 * described by the property. This is followed by an array
+	 * of of_drconf_cell entries. Get the number of entries
+	 * and skip to the array of of_drconf_cell's.
+	 */
+	entries = be32_to_cpu(*p++);
+	drmem = (struct of_drconf_cell *)p;
+
+	for (i = 0; i < entries; i++) {
+		if ((be32_to_cpu(drmem[i].aa_index) != aa_index) &&
+			(be32_to_cpu(drmem[i].flags) & DRCONF_MEM_ASSIGNED)) {
+			rc = dlpar_memory_readd_by_index(
+				be32_to_cpu(drmem[i].drc_index),
+				dmprop);
+		}
+	}
+
+	return rc;
+}
+
+static int pseries_update_ala_memory(struct of_reconfig_data *pr)
+{
+	struct assoc_arrays new_ala, old_ala;
+	struct device_node *dn;
+	struct property *dmprop;
+	__be32 *p;
+	int i, lim;
+
+	if (rtas_hp_event)
+		return 0;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return -ENODEV;
+
+	dmprop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+	if (!dmprop) {
+		of_node_put(dn);
+		return -ENODEV;
+	}
+
+	/*
+	 * The layout of the ibm,associativity-lookup-arrays
+	 * property is a number N indicating the number of
+	 * associativity arrays, followed by a number M
+	 * indicating the size of each associativity array,
+	 * followed by a list of N associativity arrays.
+	 */
+
+	p = (__be32 *) pr->old_prop->value;
+	if (!p) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+	old_ala.n_arrays = of_read_number(p++, 1);
+	old_ala.array_sz = of_read_number(p++, 1);
+	old_ala.arrays = p;
+
+	p = (__be32 *) pr->prop->value;
+	if (!p) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+	new_ala.n_arrays = of_read_number(p++, 1);
+	new_ala.array_sz = of_read_number(p++, 1);
+	new_ala.arrays = p;
+
+	lim = (new_ala.n_arrays > old_ala.n_arrays) ? old_ala.n_arrays :
+			new_ala.n_arrays;
+
+	if (old_ala.array_sz == new_ala.array_sz) {
+
+		for (i = 0; i < lim; i++) {
+			int index = (i * new_ala.array_sz);
+
+			if (!memcmp(&old_ala.arrays[index],
+						&new_ala.arrays[index],
+						new_ala.array_sz))
+				continue;
+
+			pseries_update_ala_memory_aai(i, dmprop);
+		}
+
+		for (i = lim; i < new_ala.n_arrays; i++)
+			pseries_update_ala_memory_aai(i, dmprop);
+
+	} else {
+		/* Update all entries representing these rows;
+		 * as all rows have different sizes, none can
+		 * have equivalent values.
+		 */
+		for (i = 0; i < lim; i++)
+			pseries_update_ala_memory_aai(i, dmprop);
+	}
+
+	of_node_put(dn);
+	return 0;
+}
+
 static int pseries_memory_notifier(struct notifier_block *nb,
 				   unsigned long action, void *data)
 {
@@ -1188,6 +1306,9 @@ static int pseries_memory_notifier(struct notifier_block *nb,
 	case OF_RECONFIG_UPDATE_PROPERTY:
 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
 			err = pseries_update_drconf_memory(rd);
+		if (!strcmp(rd->prop->name,
+				"ibm,associativity-lookup-arrays"))
+			err = pseries_update_ala_memory(rd);
 		break;
 	}
 	return notifier_from_errno(err);

[RFC 3/3] postmigration/memory: Associativity & ibm, dynamic-memory-v2

[Michael Bringmann]

postmigration/memory: Now apply changes to the associativity of memory
blocks described by the 'ibm,dynamic-memory-v2' property regarding
the topology of LPARS in Post Migration events.

* Extend the previous work done for the 'ibm,associativity-lookup-array'
  to apply to either property 'ibm,dynamic-memory' or
  'ibm,dynamic-memory-v2', whichever is present.
* Add new code to parse the 'ibm,dynamic-memory-v2' property looking
  for differences in block 'assignment', associativity indexes per
  block, and any other difference currently known.

When block differences are recognized, the memory block may be removed,
added, or updated depending upon the state of the new device tree
property and differences from the migrated value of the property.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Remove unnecessary spacing changes from patch.
  -- Improve patch description.
  -- Resubmit as RFC pending further integration with LMB changes
     by Nathan Fontenot
---
 arch/powerpc/include/asm/prom.h                 |   12 ++
 arch/powerpc/platforms/pseries/hotplug-memory.c |  171 ++++++++++++++++++++++-
 2 files changed, 174 insertions(+), 9 deletions(-)

diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
index 825bd59..e16ef0f 100644
--- a/arch/powerpc/include/asm/prom.h
+++ b/arch/powerpc/include/asm/prom.h
@@ -92,6 +92,18 @@ struct of_drconf_cell {
 	u32	flags;
 };
 
+/* The of_drconf_cell_v2 struct defines the layout of the LMB array
+ * specified in the device tree property
+ * ibm,dynamic-reconfiguration-memory/ibm,dynamic-memory-v2
+ */
+struct of_drconf_cell_v2 {
+	u32 num_seq_lmbs;
+	u64 base_address;
+	u32 drc_index;
+	u32 aa_index;
+	u32 flags;
+} __attribute__((packed));
+
 #define DRCONF_MEM_ASSIGNED	0x00000008
 #define DRCONF_MEM_AI_INVALID	0x00000040
 #define DRCONF_MEM_RESERVED	0x00000080
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 04208b0..96eaa9a 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1172,14 +1172,112 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 	return rc;
 }
 
+static inline int pseries_memory_v2_find_drc(u32 drc_index,
+			u64 *base_addr, unsigned long memblock_size,
+			struct of_drconf_cell_v2 **drmem,
+			struct of_drconf_cell_v2 *last_drmem)
+{
+	struct of_drconf_cell_v2 *dm = (*drmem);
+
+	while (dm < last_drmem) {
+		if ((be32_to_cpu(dm->drc_index) <= drc_index) &&
+			(drc_index <= (be32_to_cpu(dm->drc_index)+
+					be32_to_cpu(dm->num_seq_lmbs)-1))) {
+			int offset = drc_index - be32_to_cpu(dm->drc_index);
+			(*base_addr) = be64_to_cpu(dm->base_address) +
+					(offset * memblock_size);
+			break;
+		} else if (drc_index > (be32_to_cpu(dm->drc_index)+
+					be32_to_cpu(dm->num_seq_lmbs)-1)) {
+			dm++;
+			(*drmem) = dm;
+		} else if (be32_to_cpu(dm->drc_index) > drc_index) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static int pseries_update_drconf_memory_v2(struct of_reconfig_data *pr)
+{
+	struct of_drconf_cell_v2 *new_drmem, *old_drmem, *last_old_drmem;
+	unsigned long memblock_size;
+	u32 new_entries, old_entries;
+	u64 old_base_addr;
+	__be32 *p;
+	int i, rc = 0;
+
+	if (rtas_hp_event)
+		return 0;
+
+	memblock_size = pseries_memory_block_size();
+	if (!memblock_size)
+		return -EINVAL;
+
+	/* The first int of the property is the number of lmb's
+	 * described by the property. This is followed by an array
+	 * of of_drconf_cell_v2 entries. Get the number of entries
+	 * and skip to the array of of_drconf_cell_v2's.
+	 */
+	p = (__be32 *) pr->old_prop->value;
+	if (!p)
+		return -EINVAL;
+	old_entries = be32_to_cpu(*p++);
+	old_drmem = (struct of_drconf_cell_v2 *)p;
+	last_old_drmem = old_drmem +
+			(sizeof(struct of_drconf_cell_v2) * old_entries);
+
+	p = (__be32 *)pr->prop->value;
+	new_entries = be32_to_cpu(*p++);
+	new_drmem = (struct of_drconf_cell_v2 *)p;
+
+	for (i = 0; i < new_entries; i++) {
+		int j;
+		u32 new_drc_index = be32_to_cpu(new_drmem->drc_index);
+
+		for (j = 0; j < new_drmem->num_seq_lmbs; j++) {
+			if (!pseries_memory_v2_find_drc(new_drc_index+j,
+							&old_base_addr,
+							memblock_size,
+							&old_drmem,
+							last_old_drmem)) {
+				if ((be32_to_cpu(old_drmem->flags) &
+						DRCONF_MEM_ASSIGNED) &&
+				    (!(be32_to_cpu(new_drmem->flags) &
+						DRCONF_MEM_ASSIGNED))) {
+					rc = pseries_remove_memblock(
+						old_base_addr,
+						memblock_size);
+				} else if ((!(be32_to_cpu(old_drmem->flags) &
+						DRCONF_MEM_ASSIGNED)) &&
+					   (be32_to_cpu(new_drmem->flags) &
+						DRCONF_MEM_ASSIGNED)) {
+					rc = memblock_add(
+						old_base_addr, memblock_size);
+				} else if ((be32_to_cpu(old_drmem->aa_index) !=
+					    be32_to_cpu(new_drmem->aa_index)) &&
+					   (be32_to_cpu(new_drmem->flags) &
+						DRCONF_MEM_ASSIGNED)) {
+					dlpar_memory_readd_by_index(
+						new_drc_index+j,
+						pr->prop);
+				}
+			}
+		}
+	}
+
+	return 0;
+}
+
 struct assoc_arrays {
 	u32 n_arrays;
 	u32 array_sz;
 	const __be32 *arrays;
 };
 
-static int pseries_update_ala_memory_aai(int aa_index,
-					struct property *dmprop)
+static int pseries_update_ala_memory_aai_v1(int aa_index,
+				struct property *dmprop)
 {
 	struct of_drconf_cell *drmem;
 	u32 entries;
@@ -1211,11 +1309,48 @@ static int pseries_update_ala_memory_aai(int aa_index,
 	return rc;
 }
 
+static int pseries_update_ala_memory_aai_v2(int aa_index,
+				struct property *dmprop)
+{
+	struct of_drconf_cell_v2 *drmem;
+	u32 entries;
+	__be32 *p;
+	int i;
+
+	p = (__be32 *) dmprop->value;
+	if (!p)
+		return -EINVAL;
+
+	/* The first int of the property is the number of lmb's
+	 * described by the property. This is followed by an array
+	 * of of_drconf_cell_v2 entries. Get the number of entries
+	 * and skip to the array of of_drconf_cell_v2's.
+	 */
+	entries = be32_to_cpu(*p++);
+	drmem = (struct of_drconf_cell_v2 *)p;
+
+	for (i = 0; i < entries; i++) {
+		if ((be32_to_cpu(drmem[i].aa_index) != aa_index) &&
+			(be32_to_cpu(drmem[i].flags) & DRCONF_MEM_ASSIGNED)) {
+			int j;
+			int lim = be32_to_cpu(drmem->num_seq_lmbs);
+			u32 drc_index = be32_to_cpu(drmem->drc_index);
+
+			for (j = 0; j < lim; j++)
+				dlpar_memory_readd_by_index(drc_index+j,
+							dmprop);
+		}
+	}
+
+	return 0;
+}
+
 static int pseries_update_ala_memory(struct of_reconfig_data *pr)
 {
 	struct assoc_arrays new_ala, old_ala;
 	struct device_node *dn;
 	struct property *dmprop;
+	bool v1 = true;
 	__be32 *p;
 	int i, lim;
 
@@ -1228,8 +1363,13 @@ static int pseries_update_ala_memory(struct of_reconfig_data *pr)
 
 	dmprop = of_find_property(dn, "ibm,dynamic-memory", NULL);
 	if (!dmprop) {
-		of_node_put(dn);
-		return -ENODEV;
+		v1 = false;
+		dmprop = of_find_property(dn, "ibm,dynamic-memory-v2",
+					NULL);
+		if (!dmprop) {
+			of_node_put(dn);
+			return -ENODEV;
+		}
 	}
 
 	/*
@@ -1271,19 +1411,30 @@ static int pseries_update_ala_memory(struct of_reconfig_data *pr)
 						new_ala.array_sz))
 				continue;
 
-			pseries_update_ala_memory_aai(i, dmprop);
+			if (v1)
+				pseries_update_ala_memory_aai_v1(i, dmprop);
+			else
+				pseries_update_ala_memory_aai_v2(i, dmprop);
 		}
 
-		for (i = lim; i < new_ala.n_arrays; i++)
-			pseries_update_ala_memory_aai(i, dmprop);
+		for (i = lim; i < new_ala.n_arrays; i++) {
+			if (v1)
+				pseries_update_ala_memory_aai_v1(i, dmprop);
+			else
+				pseries_update_ala_memory_aai_v2(i, dmprop);
+		}
 
 	} else {
 		/* Update all entries representing these rows;
 		 * as all rows have different sizes, none can
 		 * have equivalent values.
 		 */
-		for (i = 0; i < lim; i++)
-			pseries_update_ala_memory_aai(i, dmprop);
+		for (i = 0; i < lim; i++) {
+			if (v1)
+				pseries_update_ala_memory_aai_v1(i, dmprop);
+			else
+				pseries_update_ala_memory_aai_v2(i, dmprop);
+		}
 	}
 
 	of_node_put(dn);
@@ -1306,6 +1457,8 @@ static int pseries_memory_notifier(struct notifier_block *nb,
 	case OF_RECONFIG_UPDATE_PROPERTY:
 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
 			err = pseries_update_drconf_memory(rd);
+		if (!strcmp(rd->prop->name, "ibm,dynamic-memory-v2"))
+			err = pseries_update_drconf_memory_v2(rd);
 		if (!strcmp(rd->prop->name,
 				"ibm,associativity-lookup-arrays"))
 			err = pseries_update_ala_memory(rd);

[RFC 2/3] postmigration/memory: Review assoc lookup array changes

[Michael Bringmann]

postmigration/memory: In an LPAR migration scenario, the property
"ibm,associativity-lookup-arrays" may change.  In the event that a
row of the array differs, locate all assigned memory blocks with that
'aa_index' and 're-add' them to the system memory block data structures.
In the process of the 're-add', the appropriate entry of the property
'ibm,dynamic-memory' would be updated as well as any other applicable
system data structures.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Simplify code to update memory nodes during mobility checks.
     Remove functions to generate extra HP_ELOG messages in favor
     of direct function calls to dlpar_memory_readd_by_index.
  -- Resubmit as RFC pending further integration with LMB changes
     by Nathan Fontenot
---
 arch/powerpc/platforms/pseries/hotplug-memory.c |  121 +++++++++++++++++++++++
 1 file changed, 121 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 0e2ae20..04208b0 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1172,6 +1172,124 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 	return rc;
 }
 
+struct assoc_arrays {
+	u32 n_arrays;
+	u32 array_sz;
+	const __be32 *arrays;
+};
+
+static int pseries_update_ala_memory_aai(int aa_index,
+					struct property *dmprop)
+{
+	struct of_drconf_cell *drmem;
+	u32 entries;
+	__be32 *p;
+	int i;
+	int rc = 0;
+
+	p = (__be32 *) dmprop->value;
+	if (!p)
+		return -EINVAL;
+
+	/* The first int of the property is the number of lmb's
+	 * described by the property. This is followed by an array
+	 * of of_drconf_cell entries. Get the number of entries
+	 * and skip to the array of of_drconf_cell's.
+	 */
+	entries = be32_to_cpu(*p++);
+	drmem = (struct of_drconf_cell *)p;
+
+	for (i = 0; i < entries; i++) {
+		if ((be32_to_cpu(drmem[i].aa_index) != aa_index) &&
+			(be32_to_cpu(drmem[i].flags) & DRCONF_MEM_ASSIGNED)) {
+			rc = dlpar_memory_readd_by_index(
+				be32_to_cpu(drmem[i].drc_index),
+				dmprop);
+		}
+	}
+
+	return rc;
+}
+
+static int pseries_update_ala_memory(struct of_reconfig_data *pr)
+{
+	struct assoc_arrays new_ala, old_ala;
+	struct device_node *dn;
+	struct property *dmprop;
+	__be32 *p;
+	int i, lim;
+
+	if (rtas_hp_event)
+		return 0;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return -ENODEV;
+
+	dmprop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+	if (!dmprop) {
+		of_node_put(dn);
+		return -ENODEV;
+	}
+
+	/*
+	 * The layout of the ibm,associativity-lookup-arrays
+	 * property is a number N indicating the number of
+	 * associativity arrays, followed by a number M
+	 * indicating the size of each associativity array,
+	 * followed by a list of N associativity arrays.
+	 */
+
+	p = (__be32 *) pr->old_prop->value;
+	if (!p) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+	old_ala.n_arrays = of_read_number(p++, 1);
+	old_ala.array_sz = of_read_number(p++, 1);
+	old_ala.arrays = p;
+
+	p = (__be32 *) pr->prop->value;
+	if (!p) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+	new_ala.n_arrays = of_read_number(p++, 1);
+	new_ala.array_sz = of_read_number(p++, 1);
+	new_ala.arrays = p;
+
+	lim = (new_ala.n_arrays > old_ala.n_arrays) ? old_ala.n_arrays :
+			new_ala.n_arrays;
+
+	if (old_ala.array_sz == new_ala.array_sz) {
+
+		for (i = 0; i < lim; i++) {
+			int index = (i * new_ala.array_sz);
+
+			if (!memcmp(&old_ala.arrays[index],
+						&new_ala.arrays[index],
+						new_ala.array_sz))
+				continue;
+
+			pseries_update_ala_memory_aai(i, dmprop);
+		}
+
+		for (i = lim; i < new_ala.n_arrays; i++)
+			pseries_update_ala_memory_aai(i, dmprop);
+
+	} else {
+		/* Update all entries representing these rows;
+		 * as all rows have different sizes, none can
+		 * have equivalent values.
+		 */
+		for (i = 0; i < lim; i++)
+			pseries_update_ala_memory_aai(i, dmprop);
+	}
+
+	of_node_put(dn);
+	return 0;
+}
+
 static int pseries_memory_notifier(struct notifier_block *nb,
 				   unsigned long action, void *data)
 {
@@ -1188,6 +1306,9 @@ static int pseries_memory_notifier(struct notifier_block *nb,
 	case OF_RECONFIG_UPDATE_PROPERTY:
 		if (!strcmp(rd->prop->name, "ibm,dynamic-memory"))
 			err = pseries_update_drconf_memory(rd);
+		if (!strcmp(rd->prop->name,
+				"ibm,associativity-lookup-arrays"))
+			err = pseries_update_ala_memory(rd);
 		break;
 	}
 	return notifier_from_errno(err);