[RFC v7 0/7] powerpc/hotplug: Fix affinity assoc for LPAR migration

[RFC v7 0/7] 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):
  powerpc migration/drmem: Modify DRMEM code to export more features
  powerpc migration/cpu: Associativity & cpu changes
  powerpc migration/memory: Associativity & memory updates
---
Changes in RFC:
  -- Restructure and rearrange content of patches to co-locate
     similar or related modifications
  -- 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.
  -- Revise code order in dlpar_cpu_readd_by_index() to present
     more appropriate error codes from underlying layers of the
     implementation.
  -- Add hotplug device lock around all property updates
  -- Schedule all CPU and memory changes due to device-tree updates /
     LPAR mobility as workqueue operations
  -- Export DRMEM accessor functions to parse 'ibm,dynamic-memory-v2'
  -- Export DRMEM functions to provide user copies of LMB array
  -- Compress code using DRMEM accessor functions.
  -- Split topology timer crash fix into new patch.
  -- Modify DRMEM code to replace usages of dt_root_addr_cells, and
     dt_mem_next_cell, as these are only available at first boot.
  -- Correct a bug in DRC index selection for queued operation.
  -- Rebase to 4.17-rc5 kernel
  -- Various code cleanups and compaction
  -- Correct drc_index for worker fn invocation
  -- Split 'ibm,dynamic-memory-v2' check into separate patch

[RFC v7 1/7] 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

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Separate DRMEM changes into a standalone patch
  -- Do not export excess functions.  Make exported names more explicit.
  -- Add new iterator to work through a pair of drmem_info arrays.
  -- Modify DRMEM code to replace usages of dt_root_addr_cells, and
     dt_mem_next_cell, as these are only available at first boot.
  -- Rebase to 4.17-rc5 kernel
  -- Apply several code and patch cleanups.
---
 arch/powerpc/include/asm/drmem.h |   10 +++++
 arch/powerpc/mm/drmem.c          |   73 ++++++++++++++++++++++++++++----------
 2 files changed, 64 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/drmem.h b/arch/powerpc/include/asm/drmem.h
index ce242b9..e82d254 100644
--- a/arch/powerpc/include/asm/drmem.h
+++ b/arch/powerpc/include/asm/drmem.h
@@ -35,6 +35,13 @@ struct drmem_lmb_info {
 		&drmem_info->lmbs[0],				\
 		&drmem_info->lmbs[drmem_info->n_lmbs - 1])
 
+#define for_each_pair_drmem_lmb(dinfo1, lmb1, dinfo2, lmb2)	\
+	for ((lmb1) = (&dinfo1->lmbs[0]),			\
+	     (lmb2) = (&dinfo2->lmbs[0]);			\
+	     ((lmb1) <= (&dinfo1->lmbs[dinfo1->n_lmbs - 1])) &&	\
+	     ((lmb2) <= (&dinfo2->lmbs[dinfo2->n_lmbs - 1]));	\
+	     (lmb1)++, (lmb2)++)
+
 /*
  * The of_drconf_cell_v1 struct defines the layout of the LMB data
  * specified in the ibm,dynamic-memory device tree property.
@@ -94,6 +101,9 @@ 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);
+
 #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..2bd6a70 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 +359,26 @@ void __init walk_drmem_lmbs(struct device_node *dn,
 	}
 }
 
-static void __init init_drmem_v1_lmbs(const __be32 *prop)
+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)
 		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 +394,12 @@ 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 +410,10 @@ 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 +424,38 @@ 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 +469,11 @@ 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);

[RFC v7 2/7] powerpc/cpu: Conditionally acquire/release DRC index

[Michael Bringmann]

powerpc/cpu: Modify dlpar_cpu_add and dlpar_cpu_remove to allow the
skipping of DRC index acquire or release operations during the CPU
add or remove operations.  This is intended to support subsequent
changes to provide a 'CPU readd' operation.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Move new validity check added to pseries_smp_notifier
     to another patch
---
 arch/powerpc/platforms/pseries/hotplug-cpu.c |   68 +++++++++++++++-----------
 1 file changed, 39 insertions(+), 29 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index a408217..f78ba5d 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -474,7 +474,7 @@ static bool valid_cpu_drc_index(struct device_node *parent, u32 drc_index)
 				&cdata);
 }
 
-static ssize_t dlpar_cpu_add(u32 drc_index)
+static ssize_t dlpar_cpu_add(u32 drc_index, bool acquire_drc)
 {
 	struct device_node *dn, *parent;
 	int rc, saved_rc;
@@ -499,19 +499,22 @@ static ssize_t dlpar_cpu_add(u32 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;
+	if (acquire_drc) {
+		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);
 	if (!dn) {
 		pr_warn("Failed call to configure-connector, drc index: %x\n",
 			drc_index);
-		dlpar_release_drc(drc_index);
+		if (acquire_drc)
+			dlpar_release_drc(drc_index);
 		of_node_put(parent);
 		return -EINVAL;
 	}
@@ -526,8 +529,9 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
 		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)
+		if (acquire_drc)
+			rc = dlpar_release_drc(drc_index);
+		if (!rc || acquire_drc)
 			dlpar_free_cc_nodes(dn);
 
 		return saved_rc;
@@ -540,7 +544,7 @@ static ssize_t dlpar_cpu_add(u32 drc_index)
 			dn->name, rc, drc_index);
 
 		rc = dlpar_detach_node(dn);
-		if (!rc)
+		if (!rc && acquire_drc)
 			dlpar_release_drc(drc_index);
 
 		return saved_rc;
@@ -608,7 +612,8 @@ static int dlpar_offline_cpu(struct device_node *dn)
 
 }
 
-static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
+static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index,
+				bool release_drc)
 {
 	int rc;
 
@@ -621,12 +626,14 @@ static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
 		return -EINVAL;
 	}
 
-	rc = dlpar_release_drc(drc_index);
-	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;
+	if (release_drc) {
+		rc = dlpar_release_drc(drc_index);
+		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);
@@ -635,7 +642,10 @@ static ssize_t dlpar_cpu_remove(struct device_node *dn, u32 drc_index)
 
 		pr_warn("Failed to detach CPU %s, rc: %d", dn->name, rc);
 
-		rc = dlpar_acquire_drc(drc_index);
+		if (release_drc)
+			rc = dlpar_acquire_drc(drc_index);
+		else
+			rc = 0;
 		if (!rc)
 			dlpar_online_cpu(dn);
 
@@ -664,7 +674,7 @@ static struct device_node *cpu_drc_index_to_dn(u32 drc_index)
 	return dn;
 }
 
-static int dlpar_cpu_remove_by_index(u32 drc_index)
+static int dlpar_cpu_remove_by_index(u32 drc_index, bool release_drc)
 {
 	struct device_node *dn;
 	int rc;
@@ -676,7 +686,7 @@ static int dlpar_cpu_remove_by_index(u32 drc_index)
 		return -ENODEV;
 	}
 
-	rc = dlpar_cpu_remove(dn, drc_index);
+	rc = dlpar_cpu_remove(dn, drc_index, release_drc);
 	of_node_put(dn);
 	return rc;
 }
@@ -741,7 +751,7 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
 	}
 
 	for (i = 0; i < cpus_to_remove; i++) {
-		rc = dlpar_cpu_remove_by_index(cpu_drcs[i]);
+		rc = dlpar_cpu_remove_by_index(cpu_drcs[i], true);
 		if (rc)
 			break;
 
@@ -752,7 +762,7 @@ static int dlpar_cpu_remove_by_count(u32 cpus_to_remove)
 		pr_warn("CPU hot-remove failed, adding back removed CPUs\n");
 
 		for (i = 0; i < cpus_removed; i++)
-			dlpar_cpu_add(cpu_drcs[i]);
+			dlpar_cpu_add(cpu_drcs[i], true);
 
 		rc = -EINVAL;
 	} else {
@@ -843,7 +853,7 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add)
 	}
 
 	for (i = 0; i < cpus_to_add; i++) {
-		rc = dlpar_cpu_add(cpu_drcs[i]);
+		rc = dlpar_cpu_add(cpu_drcs[i], true);
 		if (rc)
 			break;
 
@@ -854,7 +864,7 @@ static int dlpar_cpu_add_by_count(u32 cpus_to_add)
 		pr_warn("CPU hot-add failed, removing any added CPUs\n");
 
 		for (i = 0; i < cpus_added; i++)
-			dlpar_cpu_remove_by_index(cpu_drcs[i]);
+			dlpar_cpu_remove_by_index(cpu_drcs[i], true);
 
 		rc = -EINVAL;
 	} else {
@@ -880,7 +890,7 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
 			rc = dlpar_cpu_remove_by_count(count);
 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
-			rc = dlpar_cpu_remove_by_index(drc_index);
+			rc = dlpar_cpu_remove_by_index(drc_index, true);
 		else
 			rc = -EINVAL;
 		break;
@@ -888,7 +898,7 @@ int dlpar_cpu(struct pseries_hp_errorlog *hp_elog)
 		if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_COUNT)
 			rc = dlpar_cpu_add_by_count(count);
 		else if (hp_elog->id_type == PSERIES_HP_ELOG_ID_DRC_INDEX)
-			rc = dlpar_cpu_add(drc_index);
+			rc = dlpar_cpu_add(drc_index, true);
 		else
 			rc = -EINVAL;
 		break;
@@ -913,7 +923,7 @@ static ssize_t dlpar_cpu_probe(const char *buf, size_t count)
 	if (rc)
 		return -EINVAL;
 
-	rc = dlpar_cpu_add(drc_index);
+	rc = dlpar_cpu_add(drc_index, true);
 
 	return rc ? rc : count;
 }
@@ -934,7 +944,7 @@ static ssize_t dlpar_cpu_release(const char *buf, size_t count)
 		return -EINVAL;
 	}
 
-	rc = dlpar_cpu_remove(dn, drc_index);
+	rc = dlpar_cpu_remove(dn, drc_index, true);
 	of_node_put(dn);
 
 	return rc ? rc : count;

[RFC v7 3/7] migration/dlpar: Add operation queuing function

[Michael Bringmann]

migration/dlpar: This patch adds function dlpar_queue_action()
which will queue a worker function to invoke an operation
according to resource type, action code, and DRC index.  Initial
usage is for the 'readd' CPU and Memory blocks identified as
having changed their associativity during a migration event.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Correct drc_index for dlpar_queue_action worker invocation
  -- Correct text of notice
---
 arch/powerpc/platforms/pseries/dlpar.c   |   14 ++++++++++++++
 arch/powerpc/platforms/pseries/pseries.h |    1 +
 2 files changed, 15 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index a0b20c0..1376f50 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -407,6 +407,20 @@ void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
 	}
 }
 
+int dlpar_queue_action(int resource, int action, u32 drc_index)
+{
+	struct pseries_hp_errorlog hp_elog;
+
+	hp_elog.resource = resource;
+	hp_elog.action = action;
+	hp_elog.id_type = PSERIES_HP_ELOG_ID_DRC_INDEX;
+	hp_elog._drc_u.drc_index = cpu_to_be32(drc_index);
+
+	queue_hotplug_event(&hp_elog, NULL, NULL);
+
+	return 0;
+}
+
 static int dlpar_parse_resource(char **cmd, struct pseries_hp_errorlog *hp_elog)
 {
 	char *arg;
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 60db2ee..cb2beb1 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -61,6 +61,7 @@ extern struct device_node *dlpar_configure_connector(__be32,
 
 void queue_hotplug_event(struct pseries_hp_errorlog *hp_errlog,
 			 struct completion *hotplug_done, int *rc);
+extern int dlpar_queue_action(int resource, int action, u32 drc_index);
 #ifdef CONFIG_MEMORY_HOTPLUG
 int dlpar_memory(struct pseries_hp_errorlog *hp_elog);
 #else

[RFC v7 4/7] powerpc/dlpar: Provide CPU readd operation

[Michael Bringmann]

powerpc/dlpar: Provide hotplug CPU 'readd by index' operation to
support LPAR Post Migration state updates.  When such changes are
invoked by the PowerPC 'mobility' code, they will be queued up so
that modifications to CPU properties will take place after the new
property value is written to the device-tree.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Add CPU validity check to pseries_smp_notifier
---
 arch/powerpc/platforms/pseries/hotplug-cpu.c |   32 ++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index f78ba5d..ac08d85 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -691,6 +691,26 @@ static int dlpar_cpu_remove_by_index(u32 drc_index, bool release_drc)
 	return rc;
 }
 
+static int dlpar_cpu_readd_by_index(u32 drc_index)
+{
+	int rc = 0;
+
+	pr_info("Attempting to re-add CPU, drc index %x\n", drc_index);
+
+	rc = dlpar_cpu_remove_by_index(drc_index, false);
+	if (!rc)
+		rc = dlpar_cpu_add(drc_index, false);
+
+	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;
@@ -902,6 +922,9 @@ 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;
@@ -958,6 +981,9 @@ static int pseries_smp_notifier(struct notifier_block *nb,
 	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);
@@ -965,6 +991,12 @@ 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"))
+			dlpar_queue_action(PSERIES_HP_ELOG_RESOURCE_CPU,
+					   PSERIES_HP_ELOG_ACTION_READD,
+					   be32_to_cpu(rd->dn->phandle));
+		break;
 	}
 	return notifier_from_errno(err);
 }

[RFC v7 5/7] powerpc/mobility: Add lock/unlock device hotplug

[Michael Bringmann]

powerpc/mobility: Add device lock/unlock to PowerPC 'mobility' operation
to delay the operation of CPU DLPAR work queue operations by the 'readd'
activity until after any changes to the corresponding device-tree
properties have been written.

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

diff --git a/arch/powerpc/platforms/pseries/mobility.c b/arch/powerpc/platforms/pseries/mobility.c
index 8a8033a..6d98f84 100644
--- a/arch/powerpc/platforms/pseries/mobility.c
+++ b/arch/powerpc/platforms/pseries/mobility.c
@@ -283,6 +283,8 @@ int pseries_devicetree_update(s32 scope)
 	if (!rtas_buf)
 		return -ENOMEM;
 
+	lock_device_hotplug();
+
 	do {
 		rc = mobility_rtas_call(update_nodes_token, rtas_buf, scope);
 		if (rc && rc != 1)
@@ -321,6 +323,7 @@ int pseries_devicetree_update(s32 scope)
 	} while (rc == 1);
 
 	kfree(rtas_buf);
+	unlock_device_hotplug();
 	return rc;
 }
 

[RFC v7 6/7] migration/memory: Update memory for assoc changes

[Michael Bringmann]

migration/memory: This patch adds more recognition for changes to
the associativity of memory blocks described by the device-tree
properties and updates local and general kernel data structures to
reflect those changes.  These differences may include:

* Evaluating 'ibm,dynamic-memory' 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 for each drc_index of the old/new LMBs and to 'readd'
  any block for which the setting has changed.

* 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.

Signed-off-by: Michael Bringmann <mwb@linux.vnet.ibm.com>
---
Changes in RFC:
  -- Simplify code to update memory nodes during mobility checks.
  -- Reuse code from DRMEM changes to scan for LMBs when updating
     aa_index
  -- Combine common code for properties 'ibm,dynamic-memory' and
     'ibm,dynamic-memory-v2' after integrating DRMEM features.
  -- Rearrange patches to co-locate memory property-related changes.
  -- Use new paired list iterator for the drmem info arrays.
  -- Use direct calls to add/remove memory from the update drconf
     function as those operations are only intended for user DLPAR
     ops, and should not occur during Migration reconfig notifier
     changes.
  -- Correct processing bug in processing of ibm,associativity-lookup-arrays
  -- Rebase to 4.17-rc5 kernel
  -- Apply minor code cleanups
---
 arch/powerpc/platforms/pseries/hotplug-memory.c |  152 ++++++++++++++++++-----
 1 file changed, 120 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index c1578f5..cdceb3e 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -994,13 +994,11 @@ 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 pseries_update_drconf_memory(struct drmem_lmb_info *new_dinfo)
 {
-	struct of_drconf_cell_v1 *new_drmem, *old_drmem;
+	struct drmem_lmb *old_lmb, *new_lmb;
 	unsigned long memblock_size;
-	u32 entries;
-	__be32 *p;
-	int i, rc = -EINVAL;
+	int rc = 0;
 
 	if (rtas_hp_event)
 		return 0;
@@ -1009,42 +1007,124 @@ static int pseries_update_drconf_memory(struct of_reconfig_data *pr)
 	if (!memblock_size)
 		return -EINVAL;
 
-	p = (__be32 *) pr->old_prop->value;
-	if (!p)
-		return -EINVAL;
+	/* Arrays should have the same size and DRC indexes */
+	for_each_pair_drmem_lmb(drmem_info, old_lmb, new_dinfo, new_lmb) {
 
-	/* 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;
+		if (new_lmb->drc_index != old_lmb->drc_index)
+			continue;
 
-	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))) {
+		if ((old_lmb->flags & DRCONF_MEM_ASSIGNED) &&
+		    (!(new_lmb->flags & DRCONF_MEM_ASSIGNED))) {
 			rc = pseries_remove_memblock(
-				be64_to_cpu(old_drmem[i].base_addr),
-						     memblock_size);
+				old_lmb->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);
+		} else if ((!(old_lmb->flags & DRCONF_MEM_ASSIGNED)) &&
+			   (new_lmb->flags & DRCONF_MEM_ASSIGNED)) {
+			rc = memblock_add(old_lmb->base_addr,
+					memblock_size);
 			rc = (rc < 0) ? -EINVAL : 0;
 			break;
+		} else if ((old_lmb->aa_index != new_lmb->aa_index) &&
+			   (new_lmb->flags & DRCONF_MEM_ASSIGNED)) {
+			dlpar_queue_action(PSERIES_HP_ELOG_RESOURCE_MEM,
+					   PSERIES_HP_ELOG_ACTION_READD,
+					   new_lmb->drc_index);
 		}
 	}
 	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)) {
+			dlpar_queue_action(PSERIES_HP_ELOG_RESOURCE_MEM,
+					   PSERIES_HP_ELOG_ACTION_READD,
+					   lmb->drc_index);
+		}
+	}
+}
+
+struct assoc_arrays {
+	u32 n_arrays;
+	u32 array_sz;
+	const __be32 *arrays;
+};
+
+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;
+
+	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) {
+
+		/* Reset any entries where the old and new rows
+		 * the array have changed.
+		 */
+		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 0;
+}
+
 static int pseries_memory_notifier(struct notifier_block *nb,
 				   unsigned long action, void *data)
 {
@@ -1059,8 +1139,16 @@ 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);

[RFC v5 7/7] 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'
in order to update local and general kernel data structures to
reflect those changes.  Support builds upon previous patches to
check for associativity changes in 'ibm,dynamic-memory'.

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 cdceb3e..ac329aa 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -1139,7 +1139,8 @@ 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)