[PATCH v05 0/5] powerpc/migration: Affinity fix for memory

[PATCH v05 0/5] powerpc/migration: Affinity fix for memory

[Michael Bringmann]

The migration of LPARs across Power systems affects many attributes
including that of the associativity of memory blocks.  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 recorded in
  internal data structures when compared to the latest copies in
  the device tree (e.g. ibm,dynamic-memory, ibm,dynamic-memory-v2).
* 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 memory.
* Re-register the 'changed' entities into the target system.
  Re-registration of memory blocks mostly entails acting as if they
  have been newly hot-added into the target system.

This code builds upon features introduced in a previous patch set
that updates CPUs for affinity changes that may occur during LPM.

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

Michael Bringmann (5):
  powerpc/drmem: Export 'dynamic-memory' loader
  powerpc/drmem: Add internal_flags feature
  migration/memory: Add hotplug flags READD_MULTIPLE
  migration/memory: Evaluate LMB assoc changes
  migration/memory: Support 'ibm,dynamic-memory-v2'
---
Changes in v05:
  -- Add walk_drmem_lmbs_pairs to replace macro for_each_pair_lmb
  -- Use walk_drmem_lmbs_pairs and callback instead of local loop
  -- Provide dlpar_memory_readd_helper routine to compress some common code
  -- Move common structure from numa.c + hotplug-memory.c to header file.
  -- Clarify some comments.
Changes in v04:
  -- Move dlpar_memory_readd_multiple() to patch with new ACTION
     constant.
  -- Move init of 'lmb->internal_flags' in init_drmem_v2_lmbs to
     patch with other references to flag.
  -- Correct spacing in one of the patches
Changes in v03:
  -- Change operation to tag changed LMBs in DRMEM array instead of
     queuing a potentially huge number of structures.
  -- Added another hotplug queue event for CPU/memory operations
  -- Added internal_flags feature to DRMEM
  -- Improve the patch description language for the patch set.
  -- Revise patch set to queue worker for memory association
     updates directly to pseries worker queue.

[PATCH v05 1/5] powerpc/drmem: Export 'dynamic-memory' loader

[Michael Bringmann]

powerpc/drmem: Export many of the functions of DRMEM to parse
"ibm,dynamic-memory" and "ibm,dynamic-memory-v2" during hotplug
operations and for Post Migration events.

Also modify the DRMEM initialization code to allow it to,

* Be called after system initialization
* Provide a separate user copy of the LMB array that is produces
* Free the user copy upon request

In addition, a couple of changes were made to make the creation
of additional copies of the LMB array more useful including,

* Add iterator function to work through a pair of drmem_info arrays
  with a callback function to apply specific tests.
* Modify DRMEM code to replace usages of dt_root_addr_cells, and
  dt_mem_next_cell, as these are only available at first boot.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in v05:
  -- Add walk_drmem_lmbs_pairs to replace macro for_each_pair_lmb
---
 arch/powerpc/include/asm/drmem.h |   13 +++++
 arch/powerpc/mm/drmem.c          |   96 ++++++++++++++++++++++++++++++--------
 2 files changed, 89 insertions(+), 20 deletions(-)

diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index 7c1d8e7..cfe8598 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -35,6 +35,11 @@ struct drmem_lmb_info {
 		&drmem_info->lmbs[0],				\
 		&drmem_info->lmbs[drmem_info->n_lmbs - 1])
 
+#define for_each_dinfo_lmb(dinfo, lmb)				\
+	for_each_drmem_lmb_in_range((lmb),			\
+		&dinfo->lmbs[0],				\
+		&dinfo->lmbs[dinfo->n_lmbs - 1])
+
 /*
  * The of_drconf_cell_v1 struct defines the layout of the LMB data
  * specified in the ibm,dynamic-memory device tree property.
@@ -94,6 +99,14 @@ void __init walk_drmem_lmbs(struct device_node *dn,
 			void (*func)(struct drmem_lmb *, const __be32 **));
 int drmem_update_dt(void);
 
+struct drmem_lmb_info *drmem_lmbs_init(struct property *prop);
+void drmem_lmbs_free(struct drmem_lmb_info *dinfo);
+int walk_drmem_lmbs_pairs(struct drmem_lmb_info *dinfo_oth,
+			  int (*func)(struct drmem_lmb *cnt,
+					struct drmem_lmb *oth,
+					void *data),
+			  void *data);
+
 #ifdef CONFIG_PPC_PSERIES
 void __init walk_drmem_lmbs_early(unsigned long node,
 			void (*func)(struct drmem_lmb *, const __be32 **));
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index 3f18036..ded9dbf 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -20,6 +20,7 @@
 
 static struct drmem_lmb_info __drmem_info;
 struct drmem_lmb_info *drmem_info = &__drmem_info;
+static int n_root_addr_cells;
 
 u64 drmem_lmb_memory_max(void)
 {
@@ -193,12 +194,13 @@ int drmem_update_dt(void)
 	return rc;
 }
 
-static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
+static void read_drconf_v1_cell(struct drmem_lmb *lmb,
 				       const __be32 **prop)
 {
 	const __be32 *p = *prop;
 
-	lmb->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
+	lmb->base_addr = of_read_number(p, n_root_addr_cells);
+	p += n_root_addr_cells;
 	lmb->drc_index = of_read_number(p++, 1);
 
 	p++; /* skip reserved field */
@@ -209,7 +211,7 @@ static void __init read_drconf_v1_cell(struct drmem_lmb *lmb,
 	*prop = p;
 }
 
-static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
+static void __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
 			void (*func)(struct drmem_lmb *, const __be32 **))
 {
 	struct drmem_lmb lmb;
@@ -225,13 +227,14 @@ static void __init __walk_drmem_v1_lmbs(const __be32 *prop, const __be32 *usm,
 	}
 }
 
-static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
+static void read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
 				       const __be32 **prop)
 {
 	const __be32 *p = *prop;
 
 	dr_cell->seq_lmbs = of_read_number(p++, 1);
-	dr_cell->base_addr = dt_mem_next_cell(dt_root_addr_cells, &p);
+	dr_cell->base_addr = of_read_number(p, n_root_addr_cells);
+	p += n_root_addr_cells;
 	dr_cell->drc_index = of_read_number(p++, 1);
 	dr_cell->aa_index = of_read_number(p++, 1);
 	dr_cell->flags = of_read_number(p++, 1);
@@ -239,7 +242,7 @@ static void __init read_drconf_v2_cell(struct of_drconf_cell_v2 *dr_cell,
 	*prop = p;
 }
 
-static void __init __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
+static void __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
 			void (*func)(struct drmem_lmb *, const __be32 **))
 {
 	struct of_drconf_cell_v2 dr_cell;
@@ -275,6 +278,9 @@ void __init walk_drmem_lmbs_early(unsigned long node,
 	const __be32 *prop, *usm;
 	int len;
 
+	if (n_root_addr_cells == 0)
+		n_root_addr_cells = dt_root_addr_cells;
+
 	prop = of_get_flat_dt_prop(node, "ibm,lmb-size", &len);
 	if (!prop || len < dt_root_size_cells * sizeof(__be32))
 		return;
@@ -353,24 +359,47 @@ void __init walk_drmem_lmbs(struct device_node *dn,
 	}
 }
 
-static void __init init_drmem_v1_lmbs(const __be32 *prop)
+int walk_drmem_lmbs_pairs(struct drmem_lmb_info *dinfo_oth,
+			int (*func)(struct drmem_lmb *cnt,
+				     struct drmem_lmb *oth,
+				     void *data),
+			void *data)
+{
+	struct drmem_lmb *lmb1, *lmb2;
+	int rc = 0;
+
+	for ((lmb1) = (&drmem_info->lmbs[0]), (lmb2) = (&dinfo_oth->lmbs[0]);
+		((lmb1) <= (&drmem_info->lmbs[drmem_info->n_lmbs - 1])) &&
+		((lmb2) <= (&dinfo_oth->lmbs[dinfo_oth->n_lmbs - 1]));
+		(lmb1)++, (lmb2)++)
+	{
+		rc = func(lmb1, lmb2, data);
+		if (rc <= 0)
+			break;
+	}
+	return rc;
+}
+
+static void init_drmem_v1_lmbs(const __be32 *prop,
+				struct drmem_lmb_info *dinfo)
 {
 	struct drmem_lmb *lmb;
 
-	drmem_info->n_lmbs = of_read_number(prop++, 1);
-	if (drmem_info->n_lmbs == 0)
+	dinfo->n_lmbs = of_read_number(prop++, 1);
+	if (dinfo->n_lmbs == 0)
 		return;
 
-	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
+	dinfo->lmbs = kcalloc(dinfo->n_lmbs, sizeof(*lmb),
 				   GFP_KERNEL);
-	if (!drmem_info->lmbs)
+	if (!dinfo->lmbs)
 		return;
 
-	for_each_drmem_lmb(lmb)
+	for_each_dinfo_lmb(dinfo, lmb)
 		read_drconf_v1_cell(lmb, &prop);
 }
 
-static void __init init_drmem_v2_lmbs(const __be32 *prop)
+static void init_drmem_v2_lmbs(const __be32 *prop,
+				struct drmem_lmb_info *dinfo)
 {
 	struct drmem_lmb *lmb;
 	struct of_drconf_cell_v2 dr_cell;
@@ -386,12 +415,12 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
 	p = prop;
 	for (i = 0; i < lmb_sets; i++) {
 		read_drconf_v2_cell(&dr_cell, &p);
-		drmem_info->n_lmbs += dr_cell.seq_lmbs;
+		dinfo->n_lmbs += dr_cell.seq_lmbs;
 	}
 
-	drmem_info->lmbs = kcalloc(drmem_info->n_lmbs, sizeof(*lmb),
+	dinfo->lmbs = kcalloc(dinfo->n_lmbs, sizeof(*lmb),
 				   GFP_KERNEL);
-	if (!drmem_info->lmbs)
+	if (!dinfo->lmbs)
 		return;
 
 	/* second pass, read in the LMB information */
@@ -402,10 +431,10 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
 		read_drconf_v2_cell(&dr_cell, &p);
 
 		for (j = 0; j < dr_cell.seq_lmbs; j++) {
-			lmb = &drmem_info->lmbs[lmb_index++];
+			lmb = &dinfo->lmbs[lmb_index++];
 
 			lmb->base_addr = dr_cell.base_addr;
-			dr_cell.base_addr += drmem_info->lmb_size;
+			dr_cell.base_addr += dinfo->lmb_size;
 
 			lmb->drc_index = dr_cell.drc_index;
 			dr_cell.drc_index++;
@@ -416,11 +445,38 @@ static void __init init_drmem_v2_lmbs(const __be32 *prop)
 	}
 }
 
+void drmem_lmbs_free(struct drmem_lmb_info *dinfo)
+{
+	if (dinfo) {
+		kfree(dinfo->lmbs);
+		kfree(dinfo);
+	}
+}
+
+struct drmem_lmb_info *drmem_lmbs_init(struct property *prop)
+{
+	struct drmem_lmb_info *dinfo;
+
+	dinfo = kzalloc(sizeof(*dinfo), GFP_KERNEL);
+	if (!dinfo)
+		return NULL;
+
+	if (!strcmp("ibm,dynamic-memory", prop->name))
+		init_drmem_v1_lmbs(prop->value, dinfo);
+	else if (!strcmp("ibm,dynamic-memory-v2", prop->name))
+		init_drmem_v2_lmbs(prop->value, dinfo);
+
+	return dinfo;
+}
+
 static int __init drmem_init(void)
 {
 	struct device_node *dn;
 	const __be32 *prop;
 
+	if (n_root_addr_cells == 0)
+		n_root_addr_cells = dt_root_addr_cells;
+
 	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
 	if (!dn) {
 		pr_info("No dynamic reconfiguration memory found\n");
@@ -434,11 +490,11 @@ static int __init drmem_init(void)
 
 	prop = of_get_property(dn, "ibm,dynamic-memory", NULL);
 	if (prop) {
-		init_drmem_v1_lmbs(prop);
+		init_drmem_v1_lmbs(prop, drmem_info);
 	} else {
 		prop = of_get_property(dn, "ibm,dynamic-memory-v2", NULL);
 		if (prop)
-			init_drmem_v2_lmbs(prop);
+			init_drmem_v2_lmbs(prop, drmem_info);
 	}
 
 	of_node_put(dn);

[PATCH v05 2/5] powerpc/drmem: Add internal_flags feature

[Michael Bringmann]

powerpc/drmem: Add internal_flags field to each LMB to allow
marking of kernel software-specific operations that need not
be exported to other users.  For instance, if information about
selected LMBs needs to be maintained for subsequent passes
through the system, it can be encoded into the LMB array itself
without requiring the allocation and maintainance of additional
data structures.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in v04:
  -- Add another initialization of 'lmb->internal_flags' to
     init_drmem_v2_lmbs.
---
 arch/powerpc/include/asm/drmem.h |   18 ++++++++++++++++++
 arch/powerpc/mm/drmem.c          |    3 +++
 2 files changed, 21 insertions(+)

diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index cfe8598..dbb3e6c 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -17,6 +17,7 @@ struct drmem_lmb {
 	u32     drc_index;
 	u32     aa_index;
 	u32     flags;
+	u32     internal_flags;
 };
 
 struct drmem_lmb_info {
@@ -94,6 +95,23 @@ static inline bool drmem_lmb_reserved(struct drmem_lmb *lmb)
 	return lmb->flags & DRMEM_LMB_RESERVED;
 }
 
+#define DRMEM_LMBINT_UPDATE	0x00000001
+
+static inline void drmem_mark_lmb_update(struct drmem_lmb *lmb)
+{
+	lmb->internal_flags |= DRMEM_LMBINT_UPDATE;
+}
+
+static inline void drmem_remove_lmb_update(struct drmem_lmb *lmb)
+{
+	lmb->internal_flags &= ~DRMEM_LMBINT_UPDATE;
+}
+
+static inline bool drmem_lmb_update(struct drmem_lmb *lmb)
+{
+	return lmb->internal_flags & DRMEM_LMBINT_UPDATE;
+}
+
 u64 drmem_lmb_memory_max(void);
 void __init walk_drmem_lmbs(struct device_node *dn,
 			void (*func)(struct drmem_lmb *, const __be32 **));
diff --git a/arch/powerpc/mm/drmem.c b/arch/powerpc/mm/drmem.c
index ded9dbf..f199fe5 100644
--- a/arch/powerpc/mm/drmem.c
+++ b/arch/powerpc/mm/drmem.c
@@ -207,6 +207,7 @@ static void read_drconf_v1_cell(struct drmem_lmb *lmb,
 
 	lmb->aa_index = of_read_number(p++, 1);
 	lmb->flags = of_read_number(p++, 1);
+	lmb->internal_flags = 0;
 
 	*prop = p;
 }
@@ -265,6 +266,7 @@ static void __walk_drmem_v2_lmbs(const __be32 *prop, const __be32 *usm,
 
 			lmb.aa_index = dr_cell.aa_index;
 			lmb.flags = dr_cell.flags;
+			lmb.internal_flags = 0;
 
 			func(&lmb, &usm);
 		}
@@ -441,6 +443,7 @@ static void init_drmem_v2_lmbs(const __be32 *prop,
 
 			lmb->aa_index = dr_cell.aa_index;
 			lmb->flags = dr_cell.flags;
+			lmb->internal_flags = 0;
 		}
 	}
 }

[PATCH v05 3/5] migration/memory: Add hotplug READD_MULTIPLE

[Michael Bringmann]

migration/memory: This patch adds a new pseries hotplug action
for CPU and memory operations, PSERIES_HP_ELOG_ACTION_READD_MULTIPLE.
This is a variant of the READD operation which performs the action
upon multiple instances of the resource at one time.  The operation
is to be triggered by device-tree analysis of updates by RTAS events
analyzed by 'migation_store' during post-migration processing.  It
will be used for memory updates, initially.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in v05:
  -- Provide dlpar_memory_readd_helper routine to compress some common code
Changes in v04:
  -- Move init of 'lmb->internal_flags' in init_drmem_v2_lmbs to
     previous patch.
  -- Pull in implementation of dlpar_memory_readd_multiple() to go
     with operation flag.
---
 arch/powerpc/include/asm/rtas.h                 |    1 +
 arch/powerpc/platforms/pseries/hotplug-memory.c |   44 ++++++++++++++++++++---
 2 files changed, 39 insertions(+), 6 deletions(-)

diff --git a/arch/powerpc/include/asm/rtas.h b/arch/powerpc/include/asm/rtas.h
index 0183e95..cc00451 100644
--- a/arch/powerpc/include/asm/rtas.h
+++ b/arch/powerpc/include/asm/rtas.h
@@ -333,6 +333,7 @@ struct pseries_hp_errorlog {
 #define PSERIES_HP_ELOG_ACTION_ADD	1
 #define PSERIES_HP_ELOG_ACTION_REMOVE	2
 #define PSERIES_HP_ELOG_ACTION_READD	3
+#define PSERIES_HP_ELOG_ACTION_READD_MULTIPLE	4
 
 #define PSERIES_HP_ELOG_ID_DRC_NAME	1
 #define PSERIES_HP_ELOG_ID_DRC_INDEX	2
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 9a15d39..2b12deb 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -512,6 +512,19 @@ static int dlpar_memory_remove_by_index(u32 drc_index)
 	return rc;
 }
 
+static int dlpar_memory_readd_helper(struct drmem_lmb *lmb)
+{
+	int rc;
+
+	rc = dlpar_remove_lmb(lmb);
+	if (!rc) {
+		rc = dlpar_add_lmb(lmb);
+		if (rc)
+			dlpar_release_drc(lmb->drc_index);
+	}
+	return rc;
+}
+
 static int dlpar_memory_readd_by_index(u32 drc_index)
 {
 	struct drmem_lmb *lmb;
@@ -524,12 +537,7 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
 	for_each_drmem_lmb(lmb) {
 		if (lmb->drc_index == drc_index) {
 			lmb_found = 1;
-			rc = dlpar_remove_lmb(lmb);
-			if (!rc) {
-				rc = dlpar_add_lmb(lmb);
-				if (rc)
-					dlpar_release_drc(lmb->drc_index);
-			}
+			rc = dlpar_memory_readd_helper(lmb);
 			break;
 		}
 	}
@@ -546,6 +554,23 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
 	return rc;
 }
 
+static int dlpar_memory_readd_multiple(void)
+{
+	struct drmem_lmb *lmb;
+	int rc;
+
+	pr_info("Attempting to update multiple LMBs\n");
+
+	for_each_drmem_lmb(lmb) {
+		if (drmem_lmb_update(lmb)) {
+			rc = dlpar_memory_readd_helper(lmb);
+			drmem_remove_lmb_update(lmb);
+		}
+	}
+
+	return rc;
+}
+
 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
 {
 	struct drmem_lmb *lmb, *start_lmb, *end_lmb;
@@ -646,6 +671,10 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
 {
 	return -EOPNOTSUPP;
 }
+static int dlpar_memory_readd_multiple(void)
+{
+	return -EOPNOTSUPP;
+}
 
 static int dlpar_memory_remove_by_ic(u32 lmbs_to_remove, u32 drc_index)
 {
@@ -923,6 +952,9 @@ int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 		drc_index = hp_elog->_drc_u.drc_index;
 		rc = dlpar_memory_readd_by_index(drc_index);
 		break;
+	case PSERIES_HP_ELOG_ACTION_READD_MULTIPLE:
+		rc = dlpar_memory_readd_multiple();
+		break;
 	default:
 		pr_err("Invalid action (%d) specified\n", hp_elog->action);
 		rc = -EINVAL;

[PATCH v05 4/5] migration/memory: Evaluate LMB assoc changes

[Michael Bringmann]

migration/memory: This patch adds code that recognizes changes to
the associativity of memory blocks described by the device-tree
properties in order to drive equivalent 'hotplug' operations to
update local and general kernel data structures to reflect those
changes.  These differences may include:

* Evaluate 'ibm,dynamic-memory' properties when processing the
  updated device-tree properties of the system during Post Migration
  events (migration_store).  The new functionality looks for changes
  to the aa_index values for each drc_index/LMB to identify any memory
  blocks that should be readded.

* In an LPAR migration scenario, the "ibm,associativity-lookup-arrays"
  property 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 system routines will update the corresponding entry
  for the memory in the LMB structures and any other relevant kernel
  data structures.

A number of previous extensions made to the DRMEM code for scanning
device-tree properties and creating LMB arrays are used here to
ensure that the resulting code is simpler and more usable:

* Use new paired list iterator for the DRMEM LMB info arrays to find
  differences in old and new versions of properties.
* Use new iterator for copies of the DRMEM info arrays to evaluate
  completely new structures.
* Combine common code for parsing and evaluating memory description
  properties based on the DRMEM LMB array model to greatly simplify
  extension from the older property 'ibm,dynamic-memory' to the new
  property model of 'ibm,dynamic-memory-v2'.

For support, add a new pseries hotplug action for DLPAR operations,
PSERIES_HP_ELOG_ACTION_READD_MULTIPLE.  It is a variant of the READD
operation which performs the action upon multiple instances of the
resource at one time.  The operation is to be triggered by device-tree
analysis of updates by RTAS events analyzed by 'migation_store' during
post-migration processing.  It will be used for memory updates,
initially.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in v05:
  -- Move common structure from numa.c + hotplug-memory.c to header file.
  -- Clarify some comments.
  -- Use walk_drmem_lmbs_pairs and callback instead of local loop
Changes in v04:
  -- Move dlpar_memory_readd_multiple() function definition and use
     into previous patch along with action constant definition.
  -- Correct spacing in patch
Changes in v03:
  -- Modify the code that parses the memory affinity attributes to
     mark relevant DRMEM LMB array entries using the internal_flags
     mechanism instead of generate unique hotplug actions for each
     memory block to be readded.  The change is intended to both
     simplify the code, and to require fewer resources on systems
     with huge amounts of memory.
  -- Save up notice about any all LMB entries until the end of the
     'migration_store' operation at which point a single action is
     queued to scan the entire DRMEM array.
  -- Add READD_MULTIPLE function for memory that scans the DRMEM
     array to identify multiple entries that were marked previously.
     The corresponding memory blocks are to be readded to the system
     to update relevant data structures outside of the powerpc-
     specific code.
  -- Change dlpar_memory_pmt_changes_action to directly queue worker
     to pseries work queue.
---
 arch/powerpc/include/asm/topology.h             |    7 +
 arch/powerpc/mm/numa.c                          |    6 -
 arch/powerpc/platforms/pseries/hotplug-memory.c |  207 +++++++++++++++++++----
 arch/powerpc/platforms/pseries/mobility.c       |    4 
 arch/powerpc/platforms/pseries/pseries.h        |    4 
 5 files changed, 183 insertions(+), 45 deletions(-)

diff --git a/arch/powerpc/include/asm/topology.h b/arch/powerpc/include/asm/topology.h
index a4a718d..fbe03df 100644
--- a/arch/powerpc/include/asm/topology.h
+++ b/arch/powerpc/include/asm/topology.h
@@ -135,5 +135,12 @@ static inline void shared_proc_topology_init(void) {}
 #endif
 #endif
 
+
+struct assoc_arrays {
+	u32 n_arrays;
+	u32 array_sz;
+	const __be32 *arrays;
+};
+
 #endif /* __KERNEL__ */
 #endif	/* _ASM_POWERPC_TOPOLOGY_H */
diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index b5a71ba..ab881e3 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c
@@ -368,12 +368,6 @@ static unsigned long read_n_cells(int n, const __be32 **buf)
 	return result;
 }
 
-struct assoc_arrays {
-	u32	n_arrays;
-	u32	array_sz;
-	const __be32 *arrays;
-};
-
 /*
  * Retrieve and validate the list of associativity arrays for drconf
  * memory from the ibm,associativity-lookup-arrays property of the
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 2b12deb..6df5722 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -542,8 +542,11 @@ static int dlpar_memory_readd_by_index(u32 drc_index)
 		}
 	}
 
-	if (!lmb_found)
-		rc = -EINVAL;
+	if (!lmb_found) {
+		pr_info("Failed to update memory for drc index %lx\n",
+			(unsigned long) drc_index);
+		return -EINVAL;
+	}
 
 	if (rc)
 		pr_info("Failed to update memory at %llx\n",
@@ -1003,55 +1006,173 @@ static int pseries_add_mem_node(struct device_node *np)
 	return (ret < 0) ? -EINVAL : 0;
 }
 
-static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
+static int pmt_changes = 0;
+
+void dlpar_memory_pmt_changes_set(void)
+{
+	pmt_changes = 1;
+}
+
+void dlpar_memory_pmt_changes_clear(void)
 {
-	struct of_drconf_cell_v1 *new_drmem, *old_drmem;
+	pmt_changes = 0;
+}
+
+int dlpar_memory_pmt_changes(void)
+{
+	return pmt_changes;
+}
+
+void dlpar_memory_pmt_changes_action(void)
+{
+	if (dlpar_memory_pmt_changes()) {
+		struct pseries_hp_errorlog hp_errlog;
+
+		hp_errlog.resource = PSERIES_HP_ELOG_RESOURCE_MEM;
+		hp_errlog.action = PSERIES_HP_ELOG_ACTION_READD_MULTIPLE;
+		hp_errlog.id_type = 0;
+
+		queue_hotplug_event(&hp_errlog);
+
+		dlpar_memory_pmt_changes_clear();
+	}
+}
+
+struct dlpar_memory_lmb_chk_affinity_data {
 	unsigned long memblock_size;
-	u32 entries;
-	__be32 *p;
-	int i, rc = -EINVAL;
+};
+
+int dlpar_memory_lmb_chk_affinity(struct drmem_lmb *old_lmb,
+				  struct drmem_lmb *new_lmb,
+				  void *data)
+{
+	struct dlpar_memory_lmb_chk_affinity_data *ldata = data;
+	int rc = 1;
+
+	if (new_lmb->drc_index != old_lmb->drc_index)
+		return rc;
+
+	if ((old_lmb->flags & DRCONF_MEM_ASSIGNED) &&
+	    (!(new_lmb->flags & DRCONF_MEM_ASSIGNED))) {
+		rc = pseries_remove_memblock(
+				old_lmb->base_addr,
+				ldata->memblock_size);
+	} else if ((!(old_lmb->flags & DRCONF_MEM_ASSIGNED)) &&
+			(new_lmb->flags & DRCONF_MEM_ASSIGNED)) {
+		rc = memblock_add(old_lmb->base_addr,
+				ldata->memblock_size);
+		rc = (rc < 0) ? -EINVAL : 0;
+	} else if ((old_lmb->aa_index != new_lmb->aa_index) &&
+			(new_lmb->flags & DRCONF_MEM_ASSIGNED)) {
+		drmem_mark_lmb_update(old_lmb);
+		dlpar_memory_pmt_changes_set();
+	}
+
+	return rc;
+}
+
+static int pseries_update_drconf_memory(struct drmem_lmb_info *new_dinfo)
+{
+	struct dlpar_memory_lmb_chk_affinity_data data;
+	int rc = 0;
 
 	if (rtas_hp_event)
 		return 0;
 
-	memblock_size = pseries_memory_block_size();
-	if (!memblock_size)
+	data.memblock_size = pseries_memory_block_size();
+	if (!data.memblock_size)
 		return -EINVAL;
 
+	/* Arrays should have the same size and DRC indexes */
+	rc = walk_drmem_lmbs_pairs(new_dinfo,
+			dlpar_memory_lmb_chk_affinity, &data);
+	return rc;
+}
+
+static void pseries_update_ala_memory_aai(int aa_index)
+{
+	struct drmem_lmb *lmb;
+
+	/* Readd all LMBs which were previously using the
+	 * specified aa_index value.
+	 */
+	for_each_drmem_lmb(lmb) {
+		if ((lmb->aa_index == aa_index) &&
+			(lmb->flags & DRCONF_MEM_ASSIGNED)) {
+			drmem_mark_lmb_update(lmb);
+			dlpar_memory_pmt_changes_set();
+		}
+	}
+}
+
+static int pseries_update_ala_memory(struct of_reconfig_data *pr)
+{
+	struct assoc_arrays new_ala, old_ala;
+	__be32 *p;
+	int i, lim;
+
+	if (rtas_hp_event)
+		return 0;
+
+	/*
+	 * 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)
 		return -EINVAL;
+	old_ala.n_arrays = of_read_number(p++, 1);
+	old_ala.array_sz = of_read_number(p++, 1);
+	old_ala.arrays = p;
 
-	/* 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++);
-	old_drmem = (struct of_drconf_cell_v1 *)p;
-
-	p = (__be32 *)pr->prop->value;
-	p++;
-	new_drmem = (struct of_drconf_cell_v1 *)p;
-
-	for (i = 0; i < entries; i++) {
-		if ((be32_to_cpu(old_drmem[i].flags) & DRCONF_MEM_ASSIGNED) &&
-		    (!(be32_to_cpu(new_drmem[i].flags) & DRCONF_MEM_ASSIGNED))) {
-			rc = pseries_remove_memblock(
-				be64_to_cpu(old_drmem[i].base_addr),
-						     memblock_size);
-			break;
-		} else if ((!(be32_to_cpu(old_drmem[i].flags) &
-			    DRCONF_MEM_ASSIGNED)) &&
-			    (be32_to_cpu(new_drmem[i].flags) &
-			    DRCONF_MEM_ASSIGNED)) {
-			rc = memblock_add(be64_to_cpu(old_drmem[i].base_addr),
-					  memblock_size);
-			rc = (rc < 0) ? -EINVAL : 0;
-			break;
+	p = (__be32 *) pr->prop->value;
+	if (!p)
+		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) {
+
+		/* Iterate comparing rows of the old and new
+		 * ibm,associativity-lookup-arrays looking for
+		 * changes.  If a row has changed, then mark all
+		 * memory blocks using that index for readd.
+		 */
+		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);
 		}
+
+		/* Reset any entries representing the extra rows.
+		 * There shouldn't be any, but just in case ...
+		 */
+		for (i = lim; i < new_ala.n_arrays; i++)
+			pseries_update_ala_memory_aai(i);
+
+	} 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);
 	}
-	return rc;
+
+	return 0;
 }
 
 static int pseries_memory_notifier(struct notifier_block *nb,
@@ -1068,8 +1189,16 @@ static int pseries_memory_notifier(struct notifier_block *nb,
 		err = pseries_remove_mem_node(rd->dn);
 		break;
 	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")) {
+			struct drmem_lmb_info *dinfo =
+				drmem_lmbs_init(rd->prop);
+			if (!dinfo)
+				return -EINVAL;
+			err = pseries_update_drconf_memory(dinfo);
+			drmem_lmbs_free(dinfo);
+		} else if (!strcmp(rd->prop->name,
+				"ibm,associativity-lookup-arrays"))
+			err = pseries_update_ala_memory(rd);
 		break;
 	}
 	return notifier_from_errno(err);
diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 2f0f512..0df0171 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -377,6 +377,10 @@ static ssize_t migration_store(struct class *class,
 		return rc;
 
 	post_mobility_fixup();
+
+	/* Apply any necessary changes identified during fixup */
+	dlpar_memory_pmt_changes_action();
+
 	return count;
 }
 
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 72c0b89..3352f90 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -71,6 +71,10 @@ static inline int dlpar_memory(struct pseries_hp_errorlog *hp_elog)
 	return -EOPNOTSUPP;
 }
 #endif
+void dlpar_memory_pmt_changes_set(void);
+void dlpar_memory_pmt_changes_clear(void);
+int dlpar_memory_pmt_changes(void);
+void dlpar_memory_pmt_changes_action(void);
 
 #ifdef CONFIG_HOTPLUG_CPU
 int dlpar_cpu(struct pseries_hp_errorlog *hp_elog);

Re: [PATCH v05 4/5] migration/memory: Evaluate LMB assoc changes

[kbuild test robot]

[-- Attachment #1: Type: text/plain, Size: 1310 bytes --]

Hi Michael,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on powerpc/next]
[also build test ERROR on v4.19-rc7 next-20181012]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Michael-Bringmann/powerpc-migration-Affinity-fix-for-memory/20181014-130402
base:   https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git next
config: powerpc-defconfig (attached as .config)
compiler: powerpc64-linux-gnu-gcc (Debian 7.2.0-11) 7.2.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        GCC_VERSION=7.2.0 make.cross ARCH=powerpc 

All errors (new ones prefixed by >>):

   powerpc64-linux-gnu-ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'.
   arch/powerpc/platforms/pseries/mobility.o: In function `.migration_store':
>> mobility.c:(.text+0x944): undefined reference to `.dlpar_memory_pmt_changes_action'

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

[-- Attachment #2: .config.gz --]
[-- Type: application/gzip, Size: 23972 bytes --]

[PATCH v05 5/5] migration/memory: Support 'ibm,dynamic-memory-v2'

[Michael Bringmann]

migration/memory: This patch adds recognition for changes to the
associativity of memory blocks described by 'ibm,dynamic-memory-v2'.
If the associativity of an LMB has changed, it should be readded to
the system in order to update local and general kernel data structures.
This patch builds upon previous enhancements that scan the device-tree
"ibm,dynamic-memory" properties using the base LMB array, and a copy
derived from the updated properties.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
 arch/powerpc/platforms/pseries/hotplug-memory.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 6df5722..75c2118 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1189,7 +1189,8 @@ static int pseries_memory_notifier(struct notifier_block *nb,
 		err = pseries_remove_mem_node(rd->dn);
 		break;
 	case OF_RECONFIG_UPDATE_PROPERTY:
-		if (!strcmp(rd->prop->name, "ibm,dynamic-memory")) {
+		if (!strcmp(rd->prop->name, "ibm,dynamic-memory") ||
+		    !strcmp(rd->prop->name, "ibm,dynamic-memory-v2")) {
 			struct drmem_lmb_info *dinfo =
 				drmem_lmbs_init(rd->prop);
 			if (!dinfo)