[PATCH 0/5 v2] kernel handling of dynamic logical partitioning

[PATCH 0/5 v2] kernel handling of dynamic logical partitioning

[Nathan Fontenot]

The Dynamic Logical Partitioning (DLPAR) capabilities of the powerpc pseries
platform allows for the addition and removal of resources (i.e. cpus,
memory, pci devices) from a partition. The removal of a resource involves
removing the resource's node from the device tree and then returning the
resource to firmware via the rtas set-indicator call.  To add a resource, it
is first obtained from firmware via the rtas set-indicator call and then a
new device tree node is created using the ibm,configure-connector rtas call
and added to the device tree.

The following set of patches implements the needed infrastructure to have the
kernel handle the DLPAR addition and removal of memory and cpus (other
DLPAR'able items to follow in future patches).  The framework for this is
to create a set of probe/release sysfs files in pseries that will add or
remove the cpu or memory to the system.

The majority of the code is powerpc/pseries specific except for PATCH 3/5, so
I am cc'ing lkml.

Patches include in this set:
1/5 - DLPAR infracstructure for powerpc/pseries platform.
2/5 - Move the of_drconf_cell struct to prom.h
3/5 - Export the memory sysdev class
4/5 - Memory DLPAR handling
5/5 - CPU DLPAR handling

This also includes the following suggested fixes from the first version of the
patches sent out.
- Correct initialization of workarea_lock and reconfig notifier chain.
- Add cc_workarea struct to help understand the work buffer layout.
- Fix memory leak in cpu_probe_store()
- Use strict_strtoul
- Correct checkpatch failures.

-Nathan Fontenot

[PATCH 1/5 v2] dynamic logical partitioning infrastructure

[Nathan Fontenot]

This patch provides the kernel DLPAR infrastructure in a new filed named
dlpar.c.  The functionality provided is for acquiring and releasing a 
resource from firmware and the parsing of information returned from the
ibm,configure-connector rtas call.  Additionally this exports the 
pSeries reconfiguration notifier chain so that it can be invoked when
device tree updates are made.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-09-17 11:32:22.000000000 -0500
@@ -0,0 +1,416 @@
+/*
+ * dlpar.c - support for dynamic reconfiguration (including PCI
+ * Hotplug and Dynamic Logical Partitioning on RPA platforms).
+ *
+ * Copyright (C) 2009 Nathan Fontenot
+ * Copyright (C) 2009 IBM Corporation
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/notifier.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/uaccess.h>
+#include <asm/rtas.h>
+#include <asm/pSeries_reconfig.h>
+
+#define CFG_CONN_WORK_SIZE	4096
+static char workarea[CFG_CONN_WORK_SIZE];
+static DEFINE_SPINLOCK(workarea_lock);
+
+struct cc_workarea {
+	u32	drc_index;
+	u32	zero;
+	u32	name_offset;
+	u32	prop_length;
+	u32	prop_offset;
+};
+
+static struct property *parse_cc_property(char *workarea)
+{
+	struct property *prop;
+	struct cc_workarea *ccwa;
+	char *name;
+	char *value;
+
+	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+	if (!prop)
+		return NULL;
+
+	ccwa = (struct cc_workarea *)workarea;
+	name = workarea + ccwa->name_offset;
+	prop->name = kzalloc(strlen(name) + 1, GFP_KERNEL);
+	if (!prop->name) {
+		kfree(prop);
+		return NULL;
+	}
+
+	strcpy(prop->name, name);
+
+	prop->length = ccwa->prop_length;
+	value = workarea + ccwa->prop_offset;
+	prop->value = kzalloc(prop->length, GFP_KERNEL);
+	if (!prop->value) {
+		kfree(prop->name);
+		kfree(prop);
+		return NULL;
+	}
+
+	memcpy(prop->value, value, prop->length);
+	return prop;
+}
+
+static void free_property(struct property *prop)
+{
+	kfree(prop->name);
+	kfree(prop->value);
+	kfree(prop);
+}
+
+static struct device_node *parse_cc_node(char *work_area)
+{
+	struct device_node *dn;
+	struct cc_workarea *ccwa;
+	char *name;
+
+	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
+	if (!dn)
+		return NULL;
+
+	ccwa = (struct cc_workarea *)work_area;
+	name = work_area + ccwa->name_offset;
+	dn->full_name = kzalloc(strlen(name) + 1, GFP_KERNEL);
+	if (!dn->full_name) {
+		kfree(dn);
+		return NULL;
+	}
+
+	strcpy(dn->full_name, name);
+	return dn;
+}
+
+static void free_one_cc_node(struct device_node *dn)
+{
+	struct property *prop;
+
+	while (dn->properties) {
+		prop = dn->properties;
+		dn->properties = prop->next;
+		free_property(prop);
+	}
+
+	kfree(dn->full_name);
+	kfree(dn);
+}
+
+static void free_cc_nodes(struct device_node *dn)
+{
+	if (dn->child)
+		free_cc_nodes(dn->child);
+
+	if (dn->sibling)
+		free_cc_nodes(dn->sibling);
+
+	free_one_cc_node(dn);
+}
+
+#define NEXT_SIBLING    1
+#define NEXT_CHILD      2
+#define NEXT_PROPERTY   3
+#define PREV_PARENT     4
+#define MORE_MEMORY     5
+#define CALL_AGAIN	-2
+#define ERR_CFG_USE     -9003
+
+struct device_node *configure_connector(u32 drc_index)
+{
+	struct device_node *dn;
+	struct device_node *first_dn = NULL;
+	struct device_node *last_dn = NULL;
+	struct property *property;
+	struct property *last_property = NULL;
+	struct cc_workarea *ccwa;
+	int cc_token;
+	int rc;
+
+	cc_token = rtas_token("ibm,configure-connector");
+	if (cc_token == RTAS_UNKNOWN_SERVICE)
+		return NULL;
+
+	spin_lock(&workarea_lock);
+
+	ccwa = (struct cc_workarea *)&workarea[0];
+	ccwa->drc_index = drc_index;
+	ccwa->zero = 0;
+
+	rc = rtas_call(cc_token, 2, 1, NULL, workarea, NULL);
+	while (rc) {
+		switch (rc) {
+		case NEXT_SIBLING:
+			dn = parse_cc_node(workarea);
+			if (!dn)
+				goto cc_error;
+
+			dn->parent = last_dn->parent;
+			last_dn->sibling = dn;
+			last_dn = dn;
+			break;
+
+		case NEXT_CHILD:
+			dn = parse_cc_node(workarea);
+			if (!dn)
+				goto cc_error;
+
+			if (!first_dn)
+				first_dn = dn;
+			else {
+				dn->parent = last_dn;
+				if (last_dn)
+					last_dn->child = dn;
+			}
+
+			last_dn = dn;
+			break;
+
+		case NEXT_PROPERTY:
+			property = parse_cc_property(workarea);
+			if (!property)
+				goto cc_error;
+
+			if (!last_dn->properties)
+				last_dn->properties = property;
+			else
+				last_property->next = property;
+
+			last_property = property;
+			break;
+
+		case PREV_PARENT:
+			last_dn = last_dn->parent;
+			break;
+
+		case CALL_AGAIN:
+			break;
+
+		case MORE_MEMORY:
+		case ERR_CFG_USE:
+		default:
+			printk(KERN_ERR "Unexpected Error (%d) "
+			       "returned from configure-connector\n", rc);
+			goto cc_error;
+		}
+
+		rc = rtas_call(cc_token, 2, 1, NULL, workarea, NULL);
+	}
+
+	spin_unlock(&workarea_lock);
+	return first_dn;
+
+cc_error:
+	spin_unlock(&workarea_lock);
+
+	if (first_dn)
+		free_cc_nodes(first_dn);
+
+	return NULL;
+}
+
+static struct device_node *derive_parent(const char *path)
+{
+	struct device_node *parent;
+	char parent_path[128];
+	int parent_path_len;
+
+	parent_path_len = strrchr(path, '/') - path + 1;
+	strlcpy(parent_path, path, parent_path_len);
+
+	parent = of_find_node_by_path(parent_path);
+
+	return parent;
+}
+
+static int add_one_node(struct device_node *dn)
+{
+	struct proc_dir_entry *ent;
+	int rc;
+
+	of_node_set_flag(dn, OF_DYNAMIC);
+	kref_init(&dn->kref);
+	dn->parent = derive_parent(dn->full_name);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_RECONFIG_ADD, dn);
+	if (rc == NOTIFY_BAD) {
+		printk(KERN_ERR "Failed to add device node %s\n",
+		       dn->full_name);
+		return -ENOMEM; /* For now, safe to assume kmalloc failure */
+	}
+
+	of_attach_node(dn);
+
+#ifdef CONFIG_PROC_DEVICETREE
+	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
+	if (ent)
+		proc_device_tree_add_node(dn, ent);
+#endif
+
+	of_node_put(dn->parent);
+	return 0;
+}
+
+int add_device_tree_nodes(struct device_node *dn)
+{
+	struct device_node *child = dn->child;
+	struct device_node *sibling = dn->sibling;
+	int rc;
+
+	dn->child = NULL;
+	dn->sibling = NULL;
+	dn->parent = NULL;
+
+	rc = add_one_node(dn);
+	if (rc)
+		return rc;
+
+	if (child) {
+		rc = add_device_tree_nodes(child);
+		if (rc)
+			return rc;
+	}
+
+	if (sibling)
+		rc = add_device_tree_nodes(sibling);
+
+	return rc;
+}
+
+static int remove_one_node(struct device_node *dn)
+{
+	struct device_node *parent = dn->parent;
+	struct property *prop = dn->properties;
+
+#ifdef CONFIG_PROC_DEVICETREE
+	while (prop) {
+		remove_proc_entry(prop->name, dn->pde);
+		prop = prop->next;
+	}
+
+	if (dn->pde)
+		remove_proc_entry(dn->pde->name, parent->pde);
+#endif
+
+	blocking_notifier_call_chain(&pSeries_reconfig_chain,
+			    PSERIES_RECONFIG_REMOVE, dn);
+	of_detach_node(dn);
+
+	of_node_put(parent);
+	of_node_put(dn); /* Must decrement the refcount */
+
+	return 0;
+}
+
+static int _remove_device_tree_nodes(struct device_node *dn)
+{
+	int rc;
+
+	if (dn->child) {
+		rc = _remove_device_tree_nodes(dn->child);
+		if (rc)
+			return rc;
+	}
+
+	if (dn->sibling) {
+		rc = _remove_device_tree_nodes(dn->sibling);
+		if (rc)
+			return rc;
+	}
+
+	rc = remove_one_node(dn);
+	return rc;
+}
+
+int remove_device_tree_nodes(struct device_node *dn)
+{
+	int rc;
+
+	if (dn->child) {
+		rc = _remove_device_tree_nodes(dn->child);
+		if (rc)
+			return rc;
+	}
+
+	rc = remove_one_node(dn);
+	return rc;
+}
+
+#define DR_ENTITY_SENSE		9003
+#define DR_ENTITY_PRESENT	1
+#define DR_ENTITY_UNUSABLE	2
+#define ALLOCATION_STATE	9003
+#define ALLOC_UNUSABLE		0
+#define ALLOC_USABLE		1
+#define ISOLATION_STATE		9001
+#define ISOLATE			0
+#define UNISOLATE		1
+
+int acquire_drc(u32 drc_index)
+{
+	int dr_status, rc;
+
+	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
+		       DR_ENTITY_SENSE, drc_index);
+	if (rc || dr_status != DR_ENTITY_UNUSABLE)
+		return -1;
+
+	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
+	if (rc)
+		return rc;
+
+	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
+	if (rc) {
+		rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
+		return rc;
+	}
+
+	return 0;
+}
+
+int release_drc(u32 drc_index)
+{
+	int dr_status, rc;
+
+	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
+		       DR_ENTITY_SENSE, drc_index);
+	if (rc || dr_status != DR_ENTITY_PRESENT)
+		return -1;
+
+	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
+	if (rc)
+		return rc;
+
+	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
+	if (rc) {
+		rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
+		return rc;
+	}
+
+	return 0;
+}
+
+static int pseries_dlpar_init(void)
+{
+	if (!machine_is(pseries))
+		return 0;
+
+	return 0;
+}
+device_initcall(pseries_dlpar_init);
Index: powerpc/arch/powerpc/platforms/pseries/Makefile
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/Makefile	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/Makefile	2009-09-11 12:51:52.000000000 -0500
@@ -8,7 +8,7 @@
 
 obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
 			   setup.o iommu.o ras.o rtasd.o \
-			   firmware.o power.o
+			   firmware.o power.o dlpar.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_XICS)	+= xics.o
 obj-$(CONFIG_SCANLOG)	+= scanlog.o
Index: powerpc/arch/powerpc/include/asm/pSeries_reconfig.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/pSeries_reconfig.h	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/include/asm/pSeries_reconfig.h	2009-09-11 12:51:52.000000000 -0500
@@ -17,6 +17,7 @@
 #ifdef CONFIG_PPC_PSERIES
 extern int pSeries_reconfig_notifier_register(struct notifier_block *);
 extern void pSeries_reconfig_notifier_unregister(struct notifier_block *);
+extern struct blocking_notifier_head pSeries_reconfig_chain;
 #else /* !CONFIG_PPC_PSERIES */
 static inline int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 {
Index: powerpc/arch/powerpc/platforms/pseries/reconfig.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/reconfig.c	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/reconfig.c	2009-09-15 14:18:38.000000000 -0500
@@ -95,7 +95,7 @@
 	return parent;
 }
 
-static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
+BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 
 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 {

[PATCH 2/5 v2] move of_drconf_cell definition to prom.h

[Nathan Fontenot]

Move the definition of the of_drconf_cell struct from numa.c to prom.h.  This
is needed so that we can parse the ibm,dynamic-memory device-tree property
when DLPAR adding and removing memory.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

Index: powerpc/arch/powerpc/include/asm/prom.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/prom.h	2009-09-15 14:52:14.000000000 -0500
+++ powerpc/arch/powerpc/include/asm/prom.h	2009-09-15 14:53:26.000000000 -0500
@@ -349,6 +349,18 @@
  */
 extern void __iomem *of_iomap(struct device_node *device, int index);
 
+struct of_drconf_cell {
+	u64	base_addr;
+	u32	drc_index;
+	u32	reserved;
+	u32	aa_index;
+	u32	flags;
+};
+
+#define DRCONF_MEM_ASSIGNED	0x00000008
+#define DRCONF_MEM_AI_INVALID	0x00000040
+#define DRCONF_MEM_RESERVED	0x00000080
+
 /*
  * NB:  This is here while we transition from using asm/prom.h
  * to linux/of.h
Index: powerpc/arch/powerpc/mm/numa.c
===================================================================
--- powerpc.orig/arch/powerpc/mm/numa.c	2009-09-15 14:52:14.000000000 -0500
+++ powerpc/arch/powerpc/mm/numa.c	2009-09-15 14:53:26.000000000 -0500
@@ -296,18 +296,6 @@
 	return result;
 }
 
-struct of_drconf_cell {
-	u64	base_addr;
-	u32	drc_index;
-	u32	reserved;
-	u32	aa_index;
-	u32	flags;
-};
-
-#define DRCONF_MEM_ASSIGNED	0x00000008
-#define DRCONF_MEM_AI_INVALID	0x00000040
-#define DRCONF_MEM_RESERVED	0x00000080
-
 /*
  * Read the next lmb list entry from the ibm,dynamic-memory property
  * and return the information in the provided of_drconf_cell structure.

[PATCH 3/5 v2] Export memory_sysdev_class

[Nathan Fontenot]

Export the memory_sysdev_class structure.  This is needed so we can create
a 'release' file in sysfs in addition to the existing 'probe' file in
order to support DLPAR removal of memory on the powerpc/pseries platform.
The new 'release' file will be powerpc/pseries only.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

Index: powerpc/drivers/base/memory.c
===================================================================
--- powerpc.orig/drivers/base/memory.c	2009-09-15 14:52:12.000000000 -0500
+++ powerpc/drivers/base/memory.c	2009-09-15 14:53:32.000000000 -0500
@@ -28,9 +28,10 @@
 
 #define MEMORY_CLASS_NAME	"memory"
 
-static struct sysdev_class memory_sysdev_class = {
+struct sysdev_class memory_sysdev_class = {
 	.name = MEMORY_CLASS_NAME,
 };
+EXPORT_SYMBOL(memory_sysdev_class);
 
 static const char *memory_uevent_name(struct kset *kset, struct kobject *kobj)
 {
Index: powerpc/include/linux/memory_hotplug.h
===================================================================
--- powerpc.orig/include/linux/memory_hotplug.h	2009-09-15 14:52:12.000000000 -0500
+++ powerpc/include/linux/memory_hotplug.h	2009-09-15 14:53:32.000000000 -0500
@@ -12,6 +12,8 @@
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 
+extern struct sysdev_class memory_sysdev_class;
+
 /*
  * Types for free bootmem.
  * The normal smallest mapcount is -1. Here is smaller value than it.

[PATCH 4/5 v2] kernel handling of memory DLPAR

[Nathan Fontenot]

This adds the capability to DLPAR add and remove memory from the kernel.  The
patch extends the powerpc handling of memory_add_physaddr_to_nid(), which is
called from the sysfs memory 'probe' file to first ensure that the memory
has been added to the system.  This is done by creating a platform specific
callout from the routine.  The pseries implementation of this handles the
DLPAR work to add the memory to the system and update the device tree.

The patch also creates a pseries only 'release' sys file,
/sys/devices/system/memory/release.  This file handles the DLPAR release of
memory back to firmware and updating of the device-tree.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-09-17 11:32:22.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-09-17 11:33:00.000000000 -0500
@@ -16,6 +16,10 @@
 #include <linux/notifier.h>
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
+#include <linux/memory_hotplug.h>
+#include <linux/sysdev.h>
+#include <linux/sysfs.h>
+
 
 #include <asm/prom.h>
 #include <asm/machdep.h>
@@ -406,11 +410,163 @@
 	return 0;
 }
 
+static struct property *clone_property(struct property *old_prop)
+{
+	struct property *new_prop;
+
+	new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
+	if (!new_prop)
+		return NULL;
+
+	new_prop->name = kzalloc(strlen(old_prop->name) + 1, GFP_KERNEL);
+	new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);
+	if (!new_prop->name || !new_prop->value) {
+		free_property(new_prop);
+		return NULL;
+	}
+
+	strcpy(new_prop->name, old_prop->name);
+	memcpy(new_prop->value, old_prop->value, old_prop->length);
+	new_prop->length = old_prop->length;
+
+	return new_prop;
+}
+
+int platform_probe_memory(u64 phys_addr)
+{
+	struct device_node *dn;
+	struct property *new_prop, *old_prop;
+	struct property *lmb_sz_prop;
+	struct of_drconf_cell *drmem;
+	u64 lmb_size;
+	int num_entries, i, rc;
+
+	if (!phys_addr)
+		return -EINVAL;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return -EINVAL;
+
+	lmb_sz_prop = of_find_property(dn, "ibm,lmb-size", NULL);
+	lmb_size = *(u64 *)lmb_sz_prop->value;
+
+	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+
+	num_entries = *(u32 *)old_prop->value;
+	drmem = (struct of_drconf_cell *)
+				((char *)old_prop->value + sizeof(u32));
+
+	for (i = 0; i < num_entries; i++) {
+		u64 lmb_end_addr = drmem[i].base_addr + lmb_size;
+		if (phys_addr >= drmem[i].base_addr
+		    && phys_addr < lmb_end_addr)
+			break;
+	}
+
+	if (i >= num_entries) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	if (drmem[i].flags & DRCONF_MEM_ASSIGNED) {
+		of_node_put(dn);
+		return 0;
+	}
+
+	rc = acquire_drc(drmem[i].drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return -1;
+	}
+
+	new_prop = clone_property(old_prop);
+	drmem = (struct of_drconf_cell *)
+				((char *)new_prop->value + sizeof(u32));
+
+	drmem[i].flags |= DRCONF_MEM_ASSIGNED;
+	prom_update_property(dn, new_prop, old_prop);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_DRCONF_MEM_ADD,
+					  &drmem[i].base_addr);
+	if (rc == NOTIFY_BAD) {
+		prom_update_property(dn, old_prop, new_prop);
+		release_drc(drmem[i].drc_index);
+	}
+
+	of_node_put(dn);
+	return rc == NOTIFY_BAD ? -1 : 0;
+}
+
+static ssize_t memory_release_store(struct class *class, const char *buf,
+				    size_t count)
+{
+	unsigned long drc_index;
+	struct device_node *dn;
+	struct property *new_prop, *old_prop;
+	struct of_drconf_cell *drmem;
+	int num_entries;
+	int i, rc;
+
+	rc = strict_strtoul(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return 0;
+
+	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+	new_prop = clone_property(old_prop);
+
+	num_entries = *(u32 *)new_prop->value;
+	drmem = (struct of_drconf_cell *)
+				((char *)new_prop->value + sizeof(u32));
+
+	for (i = 0; i < num_entries; i++) {
+		if (drmem[i].drc_index == drc_index)
+			break;
+	}
+
+	if (i >= num_entries) {
+		free_property(new_prop);
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	drmem[i].flags &= ~DRCONF_MEM_ASSIGNED;
+	prom_update_property(dn, new_prop, old_prop);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_DRCONF_MEM_REMOVE,
+					  &drmem[i].base_addr);
+	if (rc != NOTIFY_BAD)
+		rc = release_drc(drc_index);
+
+	if (rc)
+		prom_update_property(dn, old_prop, new_prop);
+
+	of_node_put(dn);
+	return rc ? -1 : count;
+}
+
+static struct class_attribute class_attr_mem_release =
+			__ATTR(release, S_IWUSR, NULL, memory_release_store);
+
 static int pseries_dlpar_init(void)
 {
+	int rc;
+
 	if (!machine_is(pseries))
 		return 0;
 
+	rc = sysfs_create_file(&memory_sysdev_class.kset.kobj,
+			       &class_attr_mem_release.attr);
+	if (rc)
+		printk(KERN_INFO "DLPAR: Could not create sysfs memory "
+		       "release file\n");
+
 	return 0;
 }
 device_initcall(pseries_dlpar_init);
Index: powerpc/arch/powerpc/mm/mem.c
===================================================================
--- powerpc.orig/arch/powerpc/mm/mem.c	2009-09-17 11:17:57.000000000 -0500
+++ powerpc/arch/powerpc/mm/mem.c	2009-09-17 11:33:00.000000000 -0500
@@ -111,8 +111,19 @@
 #ifdef CONFIG_MEMORY_HOTPLUG
 
 #ifdef CONFIG_NUMA
+int __attribute ((weak)) platform_probe_memory(u64 start)
+{
+	return 0;
+}
+
 int memory_add_physaddr_to_nid(u64 start)
 {
+	int rc;
+
+	rc = platform_probe_memory(start);
+	if (rc)
+		return rc;
+
 	return hot_add_scn_to_nid(start);
 }
 #endif

[PATCH 5/5 v2] kernel handling of CPU DLPAR

[Nathan Fontenot]

This adds the capability to DLPAR add and remove CPUs from the kernel. The
creates two new files /sys/devices/system/cpu/probe and
/sys/devices/system/cpu/release to handle the DLPAR addition and removal of
CPUs respectively.

CPU DLPAR add is accomplished by writing the drc-index of the CPU to the
probe file, and removal is done by writing the device-tree path of the cpu
to the release file.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
---

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-09-17 11:33:00.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-09-17 11:33:06.000000000 -0500
@@ -1,11 +1,11 @@
 /*
- * dlpar.c - support for dynamic reconfiguration (including PCI
- * Hotplug and Dynamic Logical Partitioning on RPA platforms).
+ * dlpar.c - support for dynamic reconfiguration (including PCI,
+ * Memory, and CPU Hotplug and Dynamic Logical Partitioning on
+ * PAPR platforms).
  *
  * Copyright (C) 2009 Nathan Fontenot
  * Copyright (C) 2009 IBM Corporation
  *
- *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version
  * 2 as published by the Free Software Foundation.
@@ -19,6 +19,7 @@
 #include <linux/memory_hotplug.h>
 #include <linux/sysdev.h>
 #include <linux/sysfs.h>
+#include <linux/cpu.h>
 
 
 #include <asm/prom.h>
@@ -551,8 +552,85 @@
 	return rc ? -1 : count;
 }
 
+static ssize_t cpu_probe_store(struct class *class, const char *buf,
+			       size_t count)
+{
+	struct device_node *dn;
+	unsigned long drc_index;
+	char *cpu_name;
+	int rc;
+
+	rc = strict_strtoul(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	rc = acquire_drc(drc_index);
+	if (rc)
+		return rc;
+
+	dn = configure_connector(drc_index);
+	if (!dn) {
+		release_drc(drc_index);
+		return rc;
+	}
+
+	/* fixup dn name */
+	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
+			   GFP_KERNEL);
+	if (!cpu_name) {
+		free_cc_nodes(dn);
+		release_drc(drc_index);
+		return -ENOMEM;
+	}
+
+	sprintf(cpu_name, "/cpus/%s", dn->full_name);
+	kfree(dn->full_name);
+	dn->full_name = cpu_name;
+
+	rc = add_device_tree_nodes(dn);
+	if (rc)
+		release_drc(drc_index);
+
+	return rc ? rc : count;
+}
+
+static ssize_t cpu_release_store(struct class *class, const char *buf,
+				 size_t count)
+{
+	struct device_node *dn;
+	u32 *drc_index;
+	int rc;
+
+	dn = of_find_node_by_path(buf);
+	if (!dn)
+		return -EINVAL;
+
+	drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);
+	if (!drc_index) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	rc = release_drc(*drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return rc;
+	}
+
+	rc = remove_device_tree_nodes(dn);
+	if (rc)
+		acquire_drc(*drc_index);
+
+	of_node_put(dn);
+	return rc ? rc : count;
+}
+
 static struct class_attribute class_attr_mem_release =
 			__ATTR(release, S_IWUSR, NULL, memory_release_store);
+static struct class_attribute class_attr_cpu_probe =
+			__ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
+static struct class_attribute class_attr_cpu_release =
+			__ATTR(release, S_IWUSR, NULL, cpu_release_store);
 
 static int pseries_dlpar_init(void)
 {
@@ -567,6 +645,18 @@
 		printk(KERN_INFO "DLPAR: Could not create sysfs memory "
 		       "release file\n");
 
+	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+			       &class_attr_cpu_probe.attr);
+	if (rc)
+		printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+		       "probe file\n");
+
+	rc = sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+			       &class_attr_cpu_release.attr);
+	if (rc)
+		printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+		       "release file\n");
+
 	return 0;
 }
 device_initcall(pseries_dlpar_init);

Re: [PATCH 1/5 v3] dynamic logical partitioning infrastructure

[Nathan Fontenot]

This patch provides the kernel DLPAR infrastructure in a new filed named
dlpar.c.  The functionality provided is for acquiring and releasing a 
resource from firmware and the parsing of information returned from the
ibm,configure-connector rtas call.  Additionally, this exports the pSeries 
reconfiguration notifier chain so that it can be invoked when
device tree updates are made.

Updated to remove an extraneous of_node_put() in the removal of a device
tree node path.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com> 
---

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-08 11:08:42.000000000 -0500
@@ -0,0 +1,414 @@
+/*
+ * dlpar.c - support for dynamic reconfiguration (including PCI
+ * Hotplug and Dynamic Logical Partitioning on RPA platforms).
+ *
+ * Copyright (C) 2009 Nathan Fontenot
+ * Copyright (C) 2009 IBM Corporation
+ *
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/kref.h>
+#include <linux/notifier.h>
+#include <linux/proc_fs.h>
+#include <linux/spinlock.h>
+
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/uaccess.h>
+#include <asm/rtas.h>
+#include <asm/pSeries_reconfig.h>
+
+#define CFG_CONN_WORK_SIZE	4096
+static char workarea[CFG_CONN_WORK_SIZE];
+static DEFINE_SPINLOCK(workarea_lock);
+
+struct cc_workarea {
+	u32	drc_index;
+	u32	zero;
+	u32	name_offset;
+	u32	prop_length;
+	u32	prop_offset;
+};
+
+static struct property *parse_cc_property(char *workarea)
+{
+	struct property *prop;
+	struct cc_workarea *ccwa;
+	char *name;
+	char *value;
+
+	prop = kzalloc(sizeof(*prop), GFP_KERNEL);
+	if (!prop)
+		return NULL;
+
+	ccwa = (struct cc_workarea *)workarea;
+	name = workarea + ccwa->name_offset;
+	prop->name = kzalloc(strlen(name) + 1, GFP_KERNEL);
+	if (!prop->name) {
+		kfree(prop);
+		return NULL;
+	}
+
+	strcpy(prop->name, name);
+
+	prop->length = ccwa->prop_length;
+	value = workarea + ccwa->prop_offset;
+	prop->value = kzalloc(prop->length, GFP_KERNEL);
+	if (!prop->value) {
+		kfree(prop->name);
+		kfree(prop);
+		return NULL;
+	}
+
+	memcpy(prop->value, value, prop->length);
+	return prop;
+}
+
+static void free_property(struct property *prop)
+{
+	kfree(prop->name);
+	kfree(prop->value);
+	kfree(prop);
+}
+
+static struct device_node *parse_cc_node(char *work_area)
+{
+	struct device_node *dn;
+	struct cc_workarea *ccwa;
+	char *name;
+
+	dn = kzalloc(sizeof(*dn), GFP_KERNEL);
+	if (!dn)
+		return NULL;
+
+	ccwa = (struct cc_workarea *)work_area;
+	name = work_area + ccwa->name_offset;
+	dn->full_name = kzalloc(strlen(name) + 1, GFP_KERNEL);
+	if (!dn->full_name) {
+		kfree(dn);
+		return NULL;
+	}
+
+	strcpy(dn->full_name, name);
+	return dn;
+}
+
+static void free_one_cc_node(struct device_node *dn)
+{
+	struct property *prop;
+
+	while (dn->properties) {
+		prop = dn->properties;
+		dn->properties = prop->next;
+		free_property(prop);
+	}
+
+	kfree(dn->full_name);
+	kfree(dn);
+}
+
+static void free_cc_nodes(struct device_node *dn)
+{
+	if (dn->child)
+		free_cc_nodes(dn->child);
+
+	if (dn->sibling)
+		free_cc_nodes(dn->sibling);
+
+	free_one_cc_node(dn);
+}
+
+#define NEXT_SIBLING    1
+#define NEXT_CHILD      2
+#define NEXT_PROPERTY   3
+#define PREV_PARENT     4
+#define MORE_MEMORY     5
+#define CALL_AGAIN	-2
+#define ERR_CFG_USE     -9003
+
+struct device_node *configure_connector(u32 drc_index)
+{
+	struct device_node *dn;
+	struct device_node *first_dn = NULL;
+	struct device_node *last_dn = NULL;
+	struct property *property;
+	struct property *last_property = NULL;
+	struct cc_workarea *ccwa;
+	int cc_token;
+	int rc;
+
+	cc_token = rtas_token("ibm,configure-connector");
+	if (cc_token == RTAS_UNKNOWN_SERVICE)
+		return NULL;
+
+	spin_lock(&workarea_lock);
+
+	ccwa = (struct cc_workarea *)&workarea[0];
+	ccwa->drc_index = drc_index;
+	ccwa->zero = 0;
+
+	rc = rtas_call(cc_token, 2, 1, NULL, workarea, NULL);
+	while (rc) {
+		switch (rc) {
+		case NEXT_SIBLING:
+			dn = parse_cc_node(workarea);
+			if (!dn)
+				goto cc_error;
+
+			dn->parent = last_dn->parent;
+			last_dn->sibling = dn;
+			last_dn = dn;
+			break;
+
+		case NEXT_CHILD:
+			dn = parse_cc_node(workarea);
+			if (!dn)
+				goto cc_error;
+
+			if (!first_dn)
+				first_dn = dn;
+			else {
+				dn->parent = last_dn;
+				if (last_dn)
+					last_dn->child = dn;
+			}
+
+			last_dn = dn;
+			break;
+
+		case NEXT_PROPERTY:
+			property = parse_cc_property(workarea);
+			if (!property)
+				goto cc_error;
+
+			if (!last_dn->properties)
+				last_dn->properties = property;
+			else
+				last_property->next = property;
+
+			last_property = property;
+			break;
+
+		case PREV_PARENT:
+			last_dn = last_dn->parent;
+			break;
+
+		case CALL_AGAIN:
+			break;
+
+		case MORE_MEMORY:
+		case ERR_CFG_USE:
+		default:
+			printk(KERN_ERR "Unexpected Error (%d) "
+			       "returned from configure-connector\n", rc);
+			goto cc_error;
+		}
+
+		rc = rtas_call(cc_token, 2, 1, NULL, workarea, NULL);
+	}
+
+	spin_unlock(&workarea_lock);
+	return first_dn;
+
+cc_error:
+	spin_unlock(&workarea_lock);
+
+	if (first_dn)
+		free_cc_nodes(first_dn);
+
+	return NULL;
+}
+
+static struct device_node *derive_parent(const char *path)
+{
+	struct device_node *parent;
+	char parent_path[128];
+	int parent_path_len;
+
+	parent_path_len = strrchr(path, '/') - path + 1;
+	strlcpy(parent_path, path, parent_path_len);
+
+	parent = of_find_node_by_path(parent_path);
+
+	return parent;
+}
+
+static int add_one_node(struct device_node *dn)
+{
+	struct proc_dir_entry *ent;
+	int rc;
+
+	of_node_set_flag(dn, OF_DYNAMIC);
+	kref_init(&dn->kref);
+	dn->parent = derive_parent(dn->full_name);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_RECONFIG_ADD, dn);
+	if (rc == NOTIFY_BAD) {
+		printk(KERN_ERR "Failed to add device node %s\n",
+		       dn->full_name);
+		return -ENOMEM; /* For now, safe to assume kmalloc failure */
+	}
+
+	of_attach_node(dn);
+
+#ifdef CONFIG_PROC_DEVICETREE
+	ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
+	if (ent)
+		proc_device_tree_add_node(dn, ent);
+#endif
+
+	of_node_put(dn->parent);
+	return 0;
+}
+
+int add_device_tree_nodes(struct device_node *dn)
+{
+	struct device_node *child = dn->child;
+	struct device_node *sibling = dn->sibling;
+	int rc;
+
+	dn->child = NULL;
+	dn->sibling = NULL;
+	dn->parent = NULL;
+
+	rc = add_one_node(dn);
+	if (rc)
+		return rc;
+
+	if (child) {
+		rc = add_device_tree_nodes(child);
+		if (rc)
+			return rc;
+	}
+
+	if (sibling)
+		rc = add_device_tree_nodes(sibling);
+
+	return rc;
+}
+
+static int remove_one_node(struct device_node *dn)
+{
+	struct device_node *parent = dn->parent;
+	struct property *prop = dn->properties;
+
+#ifdef CONFIG_PROC_DEVICETREE
+	while (prop) {
+		remove_proc_entry(prop->name, dn->pde);
+		prop = prop->next;
+	}
+
+	if (dn->pde)
+		remove_proc_entry(dn->pde->name, parent->pde);
+#endif
+
+	blocking_notifier_call_chain(&pSeries_reconfig_chain,
+			    PSERIES_RECONFIG_REMOVE, dn);
+	of_detach_node(dn);
+	of_node_put(dn); /* Must decrement the refcount */
+
+	return 0;
+}
+
+static int _remove_device_tree_nodes(struct device_node *dn)
+{
+	int rc;
+
+	if (dn->child) {
+		rc = _remove_device_tree_nodes(dn->child);
+		if (rc)
+			return rc;
+	}
+
+	if (dn->sibling) {
+		rc = _remove_device_tree_nodes(dn->sibling);
+		if (rc)
+			return rc;
+	}
+
+	rc = remove_one_node(dn);
+	return rc;
+}
+
+int remove_device_tree_nodes(struct device_node *dn)
+{
+	int rc;
+
+	if (dn->child) {
+		rc = _remove_device_tree_nodes(dn->child);
+		if (rc)
+			return rc;
+	}
+
+	rc = remove_one_node(dn);
+	return rc;
+}
+
+#define DR_ENTITY_SENSE		9003
+#define DR_ENTITY_PRESENT	1
+#define DR_ENTITY_UNUSABLE	2
+#define ALLOCATION_STATE	9003
+#define ALLOC_UNUSABLE		0
+#define ALLOC_USABLE		1
+#define ISOLATION_STATE		9001
+#define ISOLATE			0
+#define UNISOLATE		1
+
+int acquire_drc(u32 drc_index)
+{
+	int dr_status, rc;
+
+	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
+		       DR_ENTITY_SENSE, drc_index);
+	if (rc || dr_status != DR_ENTITY_UNUSABLE)
+		return -1;
+
+	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_USABLE);
+	if (rc)
+		return rc;
+
+	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
+	if (rc) {
+		rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
+		return rc;
+	}
+
+	return 0;
+}
+
+int release_drc(u32 drc_index)
+{
+	int dr_status, rc;
+
+	rc = rtas_call(rtas_token("get-sensor-state"), 2, 2, &dr_status,
+		       DR_ENTITY_SENSE, drc_index);
+	if (rc || dr_status != DR_ENTITY_PRESENT)
+		return -1;
+
+	rc = rtas_set_indicator(ISOLATION_STATE, drc_index, ISOLATE);
+	if (rc)
+		return rc;
+
+	rc = rtas_set_indicator(ALLOCATION_STATE, drc_index, ALLOC_UNUSABLE);
+	if (rc) {
+		rtas_set_indicator(ISOLATION_STATE, drc_index, UNISOLATE);
+		return rc;
+	}
+
+	return 0;
+}
+
+static int pseries_dlpar_init(void)
+{
+	if (!machine_is(pseries))
+		return 0;
+
+	return 0;
+}
+device_initcall(pseries_dlpar_init);
Index: powerpc/arch/powerpc/platforms/pseries/Makefile
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/Makefile	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/Makefile	2009-09-11 12:51:52.000000000 -0500
@@ -8,7 +8,7 @@
 
 obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
 			   setup.o iommu.o ras.o rtasd.o \
-			   firmware.o power.o
+			   firmware.o power.o dlpar.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_XICS)	+= xics.o
 obj-$(CONFIG_SCANLOG)	+= scanlog.o
Index: powerpc/arch/powerpc/include/asm/pSeries_reconfig.h
===================================================================
--- powerpc.orig/arch/powerpc/include/asm/pSeries_reconfig.h	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/include/asm/pSeries_reconfig.h	2009-10-08 09:37:40.000000000 -0500
@@ -17,6 +17,7 @@
 #ifdef CONFIG_PPC_PSERIES
 extern int pSeries_reconfig_notifier_register(struct notifier_block *);
 extern void pSeries_reconfig_notifier_unregister(struct notifier_block *);
+extern struct blocking_notifier_head pSeries_reconfig_chain;
 #else /* !CONFIG_PPC_PSERIES */
 static inline int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 {
Index: powerpc/arch/powerpc/platforms/pseries/reconfig.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/reconfig.c	2009-09-11 12:43:39.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/reconfig.c	2009-10-08 09:37:49.000000000 -0500
@@ -95,7 +95,7 @@
 	return parent;
 }
 
-static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
+BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 
 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 {

Re: [PATCH 4/5 v3] kernel handling of memory DLPAR

[Nathan Fontenot]

This adds the capability to DLPAR add and remove memory from the kernel.  The
patch extends the powerpc handling of memory_add_physaddr_to_nid(), which is
called from the sysfs memory 'probe' file to first ensure that the memory
has been added to the system.  This is done by creating a platform specific
callout from the routine.  The pseries implementation of this handles the
DLPAR work to add the memory to the system and update the device tree.

The patch also creates a pseries only 'release' sys file,
/sys/devices/system/memory/release.  This file handles the DLPAR release of
memory back to firmware and updating of the device-tree.

Updated to add #ifdef CONFIG_MEMORY_HOTPLUG around the memory hotplug specific
updates.  This allows the file to be built without CONFIG_MEMORY_HOTPLUG
defined.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
--- 

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-08 11:08:42.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
@@ -16,6 +16,10 @@
 #include <linux/notifier.h>
 #include <linux/proc_fs.h>
 #include <linux/spinlock.h>
+#include <linux/memory_hotplug.h>
+#include <linux/sysdev.h>
+#include <linux/sysfs.h>
+
 
 #include <asm/prom.h>
 #include <asm/machdep.h>
@@ -404,11 +408,165 @@
 	return 0;
 }
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+
+static struct property *clone_property(struct property *old_prop)
+{
+	struct property *new_prop;
+
+	new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
+	if (!new_prop)
+		return NULL;
+
+	new_prop->name = kzalloc(strlen(old_prop->name) + 1, GFP_KERNEL);
+	new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);
+	if (!new_prop->name || !new_prop->value) {
+		free_property(new_prop);
+		return NULL;
+	}
+
+	strcpy(new_prop->name, old_prop->name);
+	memcpy(new_prop->value, old_prop->value, old_prop->length);
+	new_prop->length = old_prop->length;
+
+	return new_prop;
+}
+
+int platform_probe_memory(u64 phys_addr)
+{
+	struct device_node *dn;
+	struct property *new_prop, *old_prop;
+	struct property *lmb_sz_prop;
+	struct of_drconf_cell *drmem;
+	u64 lmb_size;
+	int num_entries, i, rc;
+
+	if (!phys_addr)
+		return -EINVAL;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return -EINVAL;
+
+	lmb_sz_prop = of_find_property(dn, "ibm,lmb-size", NULL);
+	lmb_size = *(u64 *)lmb_sz_prop->value;
+
+	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+
+	num_entries = *(u32 *)old_prop->value;
+	drmem = (struct of_drconf_cell *)
+				((char *)old_prop->value + sizeof(u32));
+
+	for (i = 0; i < num_entries; i++) {
+		u64 lmb_end_addr = drmem[i].base_addr + lmb_size;
+		if (phys_addr >= drmem[i].base_addr
+		    && phys_addr < lmb_end_addr)
+			break;
+	}
+
+	if (i >= num_entries) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	if (drmem[i].flags & DRCONF_MEM_ASSIGNED) {
+		of_node_put(dn);
+		return 0;
+	}
+
+	rc = acquire_drc(drmem[i].drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return -1;
+	}
+
+	new_prop = clone_property(old_prop);
+	drmem = (struct of_drconf_cell *)
+				((char *)new_prop->value + sizeof(u32));
+
+	drmem[i].flags |= DRCONF_MEM_ASSIGNED;
+	prom_update_property(dn, new_prop, old_prop);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_DRCONF_MEM_ADD,
+					  &drmem[i].base_addr);
+	if (rc == NOTIFY_BAD) {
+		prom_update_property(dn, old_prop, new_prop);
+		release_drc(drmem[i].drc_index);
+	}
+
+	of_node_put(dn);
+	return rc == NOTIFY_BAD ? -1 : 0;
+}
+
+static ssize_t memory_release_store(struct class *class, const char *buf,
+				    size_t count)
+{
+	unsigned long drc_index;
+	struct device_node *dn;
+	struct property *new_prop, *old_prop;
+	struct of_drconf_cell *drmem;
+	int num_entries;
+	int i, rc;
+
+	rc = strict_strtoul(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
+	if (!dn)
+		return 0;
+
+	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
+	new_prop = clone_property(old_prop);
+
+	num_entries = *(u32 *)new_prop->value;
+	drmem = (struct of_drconf_cell *)
+				((char *)new_prop->value + sizeof(u32));
+
+	for (i = 0; i < num_entries; i++) {
+		if (drmem[i].drc_index == drc_index)
+			break;
+	}
+
+	if (i >= num_entries) {
+		free_property(new_prop);
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	drmem[i].flags &= ~DRCONF_MEM_ASSIGNED;
+	prom_update_property(dn, new_prop, old_prop);
+
+	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+					  PSERIES_DRCONF_MEM_REMOVE,
+					  &drmem[i].base_addr);
+	if (rc != NOTIFY_BAD)
+		rc = release_drc(drc_index);
+
+	if (rc)
+		prom_update_property(dn, old_prop, new_prop);
+
+	of_node_put(dn);
+	return rc ? -1 : count;
+}
+
+static struct class_attribute class_attr_mem_release =
+			__ATTR(release, S_IWUSR, NULL, memory_release_store);
+#endif
+
 static int pseries_dlpar_init(void)
 {
 	if (!machine_is(pseries))
 		return 0;
 
+#ifdef CONFIG_MEMORY_HOTPLUG
+	if (sysfs_create_file(&memory_sysdev_class.kset.kobj,
+			      &class_attr_mem_release.attr))
+		printk(KERN_INFO "DLPAR: Could not create sysfs memory "
+		       "release file\n");
+#endif
+
 	return 0;
 }
 device_initcall(pseries_dlpar_init);
Index: powerpc/arch/powerpc/mm/mem.c
===================================================================
--- powerpc.orig/arch/powerpc/mm/mem.c	2009-10-08 11:07:45.000000000 -0500
+++ powerpc/arch/powerpc/mm/mem.c	2009-10-08 11:08:54.000000000 -0500
@@ -111,8 +111,19 @@
 #ifdef CONFIG_MEMORY_HOTPLUG
 
 #ifdef CONFIG_NUMA
+int __attribute ((weak)) platform_probe_memory(u64 start)
+{
+	return 0;
+}
+
 int memory_add_physaddr_to_nid(u64 start)
 {
+	int rc;
+
+	rc = platform_probe_memory(start);
+	if (rc)
+		return rc;
+
 	return hot_add_scn_to_nid(start);
 }
 #endif

Re: [PATCH 5/5 v2] kernel handling of CPU DLPAR

[Nathan Fontenot]

This adds the capability to DLPAR add and remove CPUs from the kernel. The
creates two new files /sys/devices/system/cpu/probe and
/sys/devices/system/cpu/release to handle the DLPAR addition and removal of
CPUs respectively.

CPU DLPAR add is accomplished by writing the drc-index of the CPU to the
probe file, and removal is done by writing the device-tree path of the cpu
to the release file.

Updated to include #ifdef CONFIG_HOTPLUG_CPU around the cpu hotplug specific
bits so that it will build without CONFIG_HOTPLUG_CPU defined.

Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
--- 

Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
+++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:09:00.000000000 -0500
@@ -1,11 +1,11 @@
 /*
- * dlpar.c - support for dynamic reconfiguration (including PCI
- * Hotplug and Dynamic Logical Partitioning on RPA platforms).
+ * dlpar.c - support for dynamic reconfiguration (including PCI,
+ * Memory, and CPU Hotplug and Dynamic Logical Partitioning on
+ * PAPR platforms).
  *
  * Copyright (C) 2009 Nathan Fontenot
  * Copyright (C) 2009 IBM Corporation
  *
- *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License version
  * 2 as published by the Free Software Foundation.
@@ -19,6 +19,7 @@
 #include <linux/memory_hotplug.h>
 #include <linux/sysdev.h>
 #include <linux/sysfs.h>
+#include <linux/cpu.h>
 
 
 #include <asm/prom.h>
@@ -408,6 +409,82 @@
 	return 0;
 }
 
+#ifdef CONFIG_HOTPLUG_CPU
+static ssize_t cpu_probe_store(struct class *class, const char *buf,
+			       size_t count)
+{
+	struct device_node *dn;
+	unsigned long drc_index;
+	char *cpu_name;
+	int rc;
+
+	rc = strict_strtoul(buf, 0, &drc_index);
+	if (rc)
+		return -EINVAL;
+
+	rc = acquire_drc(drc_index);
+	if (rc)
+		return rc;
+
+	dn = configure_connector(drc_index);
+	if (!dn) {
+		release_drc(drc_index);
+		return rc;
+	}
+
+	/* fixup dn name */
+	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
+			   GFP_KERNEL);
+	if (!cpu_name) {
+		free_cc_nodes(dn);
+		release_drc(drc_index);
+		return -ENOMEM;
+	}
+
+	sprintf(cpu_name, "/cpus/%s", dn->full_name);
+	kfree(dn->full_name);
+	dn->full_name = cpu_name;
+
+	rc = add_device_tree_nodes(dn);
+	if (rc)
+		release_drc(drc_index);
+
+	return rc ? rc : count;
+}
+
+static ssize_t cpu_release_store(struct class *class, const char *buf,
+				 size_t count)
+{
+	struct device_node *dn;
+	u32 *drc_index;
+	int rc;
+
+	dn = of_find_node_by_path(buf);
+	if (!dn)
+		return -EINVAL;
+
+	drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);
+	if (!drc_index) {
+		of_node_put(dn);
+		return -EINVAL;
+	}
+
+	rc = release_drc(*drc_index);
+	if (rc) {
+		of_node_put(dn);
+		return rc;
+	}
+
+	rc = remove_device_tree_nodes(dn);
+	if (rc)
+		acquire_drc(*drc_index);
+
+	of_node_put(dn);
+	return rc ? rc : count;
+}
+
+#endif /* CONFIG_HOTPLUG_CPU */
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 
 static struct property *clone_property(struct property *old_prop)
@@ -553,6 +630,13 @@
 
 static struct class_attribute class_attr_mem_release =
 			__ATTR(release, S_IWUSR, NULL, memory_release_store);
+#endif /* CONFIG_MEMORY_HOTPLUG */
+
+#ifdef CONFIG_HOTPLUG_CPU
+static struct class_attribute class_attr_cpu_probe =
+			__ATTR(probe, S_IWUSR, NULL, cpu_probe_store);
+static struct class_attribute class_attr_cpu_release =
+			__ATTR(release, S_IWUSR, NULL, cpu_release_store);
 #endif
 
 static int pseries_dlpar_init(void)
@@ -567,6 +651,18 @@
 		       "release file\n");
 #endif
 
+#ifdef CONFIG_HOTPLUG_CPU
+	if (sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+			      &class_attr_cpu_probe.attr))
+		printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+		       "probe file\n");
+
+	if (sysfs_create_file(&cpu_sysdev_class.kset.kobj,
+			      &class_attr_cpu_release.attr))
+		printk(KERN_INFO "DLPAR: Could not create sysfs cpu "
+		       "release file\n");
+#endif
+
 	return 0;
 }
 device_initcall(pseries_dlpar_init);

Re: [PATCH 5/5 v2] kernel handling of CPU DLPAR

[Michael Ellerman]

[-- Attachment #1: Type: text/plain, Size: 3511 bytes --]

On Tue, 2009-10-13 at 13:14 -0500, Nathan Fontenot wrote:
> This adds the capability to DLPAR add and remove CPUs from the kernel. The
> creates two new files /sys/devices/system/cpu/probe and
> /sys/devices/system/cpu/release to handle the DLPAR addition and removal of
> CPUs respectively.

How does this relate to the existing cpu hotplug mechanism? Or is this
making the cpu exist (possible), vs marking it as online?

Is some other platform going to want to do the same? ie. should the
probe/release part be in generic code?

> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
> ===================================================================
> --- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:09:00.000000000 -0500
> @@ -1,11 +1,11 @@
>  /*
> - * dlpar.c - support for dynamic reconfiguration (including PCI
> - * Hotplug and Dynamic Logical Partitioning on RPA platforms).
> + * dlpar.c - support for dynamic reconfiguration (including PCI,

We know it's dlpar.c :)

> + * Memory, and CPU Hotplug and Dynamic Logical Partitioning on
> + * PAPR platforms).
>   *
>   * Copyright (C) 2009 Nathan Fontenot
>   * Copyright (C) 2009 IBM Corporation
>   *
> - *
>   * This program is free software; you can redistribute it and/or
>   * modify it under the terms of the GNU General Public License version
>   * 2 as published by the Free Software Foundation.
> @@ -19,6 +19,7 @@
>  #include <linux/memory_hotplug.h>
>  #include <linux/sysdev.h>
>  #include <linux/sysfs.h>
> +#include <linux/cpu.h>
>  
> 
>  #include <asm/prom.h>
> @@ -408,6 +409,82 @@
>  	return 0;
>  }
>  
> +#ifdef CONFIG_HOTPLUG_CPU
> +static ssize_t cpu_probe_store(struct class *class, const char *buf,
> +			       size_t count)
> +{
> +	struct device_node *dn;
> +	unsigned long drc_index;
> +	char *cpu_name;
> +	int rc;
> +
> +	rc = strict_strtoul(buf, 0, &drc_index);
> +	if (rc)
> +		return -EINVAL;
> +
> +	rc = acquire_drc(drc_index);
> +	if (rc)
> +		return rc;
> +
> +	dn = configure_connector(drc_index);
> +	if (!dn) {
> +		release_drc(drc_index);
> +		return rc;
> +	}
> +
> +	/* fixup dn name */
> +	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
> +			   GFP_KERNEL);
> +	if (!cpu_name) {
> +		free_cc_nodes(dn);
> +		release_drc(drc_index);
> +		return -ENOMEM;
> +	}
> +
> +	sprintf(cpu_name, "/cpus/%s", dn->full_name);
> +	kfree(dn->full_name);
> +	dn->full_name = cpu_name;

What was all that? Firmware gives us a bogus full name? But the parent
is right?

> +	rc = add_device_tree_nodes(dn);
> +	if (rc)
> +		release_drc(drc_index);
> +
> +	return rc ? rc : count;

You're sure rc is < 0.

> +}
> +
> +static ssize_t cpu_release_store(struct class *class, const char *buf,
> +				 size_t count)
> +{
> +	struct device_node *dn;
> +	u32 *drc_index;
> +	int rc;
> +
> +	dn = of_find_node_by_path(buf);
> +	if (!dn)
> +		return -EINVAL;
> +
> +	drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);

No cast required.

> +	if (!drc_index) {
> +		of_node_put(dn);
> +		return -EINVAL;
> +	}
> +
> +	rc = release_drc(*drc_index);
> +	if (rc) {
> +		of_node_put(dn);
> +		return rc;
> +	}
> +
> +	rc = remove_device_tree_nodes(dn);
> +	if (rc)
> +		acquire_drc(*drc_index);
> +
> +	of_node_put(dn);
> +	return rc ? rc : count;
> +}


cheers

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 197 bytes --]

Re: [PATCH 4/5 v3] kernel handling of memory DLPAR

[Michael Ellerman]

[-- Attachment #1: Type: text/plain, Size: 6749 bytes --]

On Tue, 2009-10-13 at 13:13 -0500, Nathan Fontenot wrote:
> This adds the capability to DLPAR add and remove memory from the kernel.  The

Hi Nathan,

Sorry to only get around to reviewing version 3, time is a commodity in
short supply :)

> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
> ===================================================================
> --- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-08 11:08:42.000000000 -0500
> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
> @@ -16,6 +16,10 @@
>  #include <linux/notifier.h>
>  #include <linux/proc_fs.h>
>  #include <linux/spinlock.h>
> +#include <linux/memory_hotplug.h>
> +#include <linux/sysdev.h>
> +#include <linux/sysfs.h>
> +
>  
>  #include <asm/prom.h>
>  #include <asm/machdep.h>
> @@ -404,11 +408,165 @@
>  	return 0;
>  }
>  
> +#ifdef CONFIG_MEMORY_HOTPLUG
> +
> +static struct property *clone_property(struct property *old_prop)
> +{
> +	struct property *new_prop;
> +
> +	new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
> +	if (!new_prop)
> +		return NULL;
> +
> +	new_prop->name = kzalloc(strlen(old_prop->name) + 1, GFP_KERNEL);

kstrdup()?

> +	new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);
> +	if (!new_prop->name || !new_prop->value) {
> +		free_property(new_prop);
> +		return NULL;
> +	}
> +
> +	strcpy(new_prop->name, old_prop->name);
> +	memcpy(new_prop->value, old_prop->value, old_prop->length);
> +	new_prop->length = old_prop->length;
> +
> +	return new_prop;
> +}
> +
> +int platform_probe_memory(u64 phys_addr)
> +{
> +	struct device_node *dn;
> +	struct property *new_prop, *old_prop;
> +	struct property *lmb_sz_prop;
> +	struct of_drconf_cell *drmem;
> +	u64 lmb_size;
> +	int num_entries, i, rc;
> +
> +	if (!phys_addr)
> +		return -EINVAL;
> +
> +	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
> +	if (!dn)
> +		return -EINVAL;
> +
> +	lmb_sz_prop = of_find_property(dn, "ibm,lmb-size", NULL);
> +	lmb_size = *(u64 *)lmb_sz_prop->value;

of_get_property() ?
> +
> +	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);

I know we should never fail to find these properties, but it would be
nice to check just in case.

> +
> +	num_entries = *(u32 *)old_prop->value;
> +	drmem = (struct of_drconf_cell *)
> +				((char *)old_prop->value + sizeof(u32));

You do this dance twice (see below), a struct might make it cleaner.

> +	for (i = 0; i < num_entries; i++) {
> +		u64 lmb_end_addr = drmem[i].base_addr + lmb_size;
> +		if (phys_addr >= drmem[i].base_addr
> +		    && phys_addr < lmb_end_addr)
> +			break;
> +	}
> +
> +	if (i >= num_entries) {
> +		of_node_put(dn);
> +		return -EINVAL;
> +	}
> +
> +	if (drmem[i].flags & DRCONF_MEM_ASSIGNED) {
> +		of_node_put(dn);
> +		return 0;

This is the already added case?

> +	}
> +
> +	rc = acquire_drc(drmem[i].drc_index);
> +	if (rc) {
> +		of_node_put(dn);
> +		return -1;

-1 ?

> +	}
> +
> +	new_prop = clone_property(old_prop);
> +	drmem = (struct of_drconf_cell *)
> +				((char *)new_prop->value + sizeof(u32));
> +
> +	drmem[i].flags |= DRCONF_MEM_ASSIGNED;
> +	prom_update_property(dn, new_prop, old_prop);
> +
> +	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
> +					  PSERIES_DRCONF_MEM_ADD,
> +					  &drmem[i].base_addr);
> +	if (rc == NOTIFY_BAD) {
> +		prom_update_property(dn, old_prop, new_prop);
> +		release_drc(drmem[i].drc_index);
> +	}
> +
> +	of_node_put(dn);
> +	return rc == NOTIFY_BAD ? -1 : 0;

-1 ?

> +}
> +
> +static ssize_t memory_release_store(struct class *class, const char *buf,
> +				    size_t count)
> +{
> +	unsigned long drc_index;
> +	struct device_node *dn;
> +	struct property *new_prop, *old_prop;
> +	struct of_drconf_cell *drmem;
> +	int num_entries;
> +	int i, rc;
> +
> +	rc = strict_strtoul(buf, 0, &drc_index);
> +	if (rc)
> +		return -EINVAL;
> +
> +	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
> +	if (!dn)
> +		return 0;

0 really?

> +
> +	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
> +	new_prop = clone_property(old_prop);
> +
> +	num_entries = *(u32 *)new_prop->value;
> +	drmem = (struct of_drconf_cell *)
> +				((char *)new_prop->value + sizeof(u32));
> +
> +	for (i = 0; i < num_entries; i++) {
> +		if (drmem[i].drc_index == drc_index)
> +			break;
> +	}
> +
> +	if (i >= num_entries) {
> +		free_property(new_prop);
> +		of_node_put(dn);
> +		return -EINVAL;
> +	}

Couldn't use old_prop up until here? They're identical aren't they, so
you can do the clone here and you can avoid the free in the above error
case.

> +	drmem[i].flags &= ~DRCONF_MEM_ASSIGNED;
> +	prom_update_property(dn, new_prop, old_prop);
> +
> +	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
> +					  PSERIES_DRCONF_MEM_REMOVE,
> +					  &drmem[i].base_addr);
> +	if (rc != NOTIFY_BAD)
> +		rc = release_drc(drc_index);
> +
> +	if (rc)
> +		prom_update_property(dn, old_prop, new_prop);
> +
> +	of_node_put(dn);
> +	return rc ? -1 : count;

-1, EPERM?

> +}
> +
> +static struct class_attribute class_attr_mem_release =
> +			__ATTR(release, S_IWUSR, NULL, memory_release_store);
> +#endif
> +
>  static int pseries_dlpar_init(void)
>  {
>  	if (!machine_is(pseries))
>  		return 0;
>  
> +#ifdef CONFIG_MEMORY_HOTPLUG
> +	if (sysfs_create_file(&memory_sysdev_class.kset.kobj,
> +			      &class_attr_mem_release.attr))
> +		printk(KERN_INFO "DLPAR: Could not create sysfs memory "
> +		       "release file\n");
> +#endif
> +
>  	return 0;
>  }
>  device_initcall(pseries_dlpar_init);
> Index: powerpc/arch/powerpc/mm/mem.c
> ===================================================================
> --- powerpc.orig/arch/powerpc/mm/mem.c	2009-10-08 11:07:45.000000000 -0500
> +++ powerpc/arch/powerpc/mm/mem.c	2009-10-08 11:08:54.000000000 -0500
> @@ -111,8 +111,19 @@
>  #ifdef CONFIG_MEMORY_HOTPLUG
>  
>  #ifdef CONFIG_NUMA
> +int __attribute ((weak)) platform_probe_memory(u64 start)

__weak

Though be careful, I think this is vulnerable to a bug in some
toolchains where the compiler will inline this version. See the comment
around early_irq_init() in kernel/softirq.c for example.

This will need to be a ppc_md hook as soon as another platform supports
memory hotplug, though that may be never :)

> +{
> +	return 0;
> +}
> +
>  int memory_add_physaddr_to_nid(u64 start)
>  {
> +	int rc;
> +
> +	rc = platform_probe_memory(start);
> +	if (rc)
> +		return rc;
> +
>  	return hot_add_scn_to_nid(start);
>  }
>  #endif

cheers


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Re: [PATCH 4/5 v3] kernel handling of memory DLPAR

[Nathan Fontenot]

Michael Ellerman wrote:
> On Tue, 2009-10-13 at 13:13 -0500, Nathan Fontenot wrote:
>> This adds the capability to DLPAR add and remove memory from the kernel.  The
> 
> Hi Nathan,
> 
> Sorry to only get around to reviewing version 3, time is a commodity in
> short supply :)
> 
>> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
>> ===================================================================
>> --- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-08 11:08:42.000000000 -0500
>> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
>> @@ -16,6 +16,10 @@
>>  #include <linux/notifier.h>
>>  #include <linux/proc_fs.h>
>>  #include <linux/spinlock.h>
>> +#include <linux/memory_hotplug.h>
>> +#include <linux/sysdev.h>
>> +#include <linux/sysfs.h>
>> +
>>  
>>  #include <asm/prom.h>
>>  #include <asm/machdep.h>
>> @@ -404,11 +408,165 @@
>>  	return 0;
>>  }
>>  
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> +
>> +static struct property *clone_property(struct property *old_prop)
>> +{
>> +	struct property *new_prop;
>> +
>> +	new_prop = kzalloc((sizeof *new_prop), GFP_KERNEL);
>> +	if (!new_prop)
>> +		return NULL;
>> +
>> +	new_prop->name = kzalloc(strlen(old_prop->name) + 1, GFP_KERNEL);
> 
> kstrdup()?

Ahhh.. I did not know of kstrdup().  I will update to use this instead.

> 
>> +	new_prop->value = kzalloc(old_prop->length + 1, GFP_KERNEL);
>> +	if (!new_prop->name || !new_prop->value) {
>> +		free_property(new_prop);
>> +		return NULL;
>> +	}
>> +
>> +	strcpy(new_prop->name, old_prop->name);
>> +	memcpy(new_prop->value, old_prop->value, old_prop->length);
>> +	new_prop->length = old_prop->length;
>> +
>> +	return new_prop;
>> +}
>> +
>> +int platform_probe_memory(u64 phys_addr)
>> +{
>> +	struct device_node *dn;
>> +	struct property *new_prop, *old_prop;
>> +	struct property *lmb_sz_prop;
>> +	struct of_drconf_cell *drmem;
>> +	u64 lmb_size;
>> +	int num_entries, i, rc;
>> +
>> +	if (!phys_addr)
>> +		return -EINVAL;
>> +
>> +	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
>> +	if (!dn)
>> +		return -EINVAL;
>> +
>> +	lmb_sz_prop = of_find_property(dn, "ibm,lmb-size", NULL);
>> +	lmb_size = *(u64 *)lmb_sz_prop->value;
> 
> of_get_property() ?

ok, will switch to of_find_property()

>> +
>> +	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
> 
> I know we should never fail to find these properties, but it would be
> nice to check just in case.
> 

yes, will update.

>> +
>> +	num_entries = *(u32 *)old_prop->value;
>> +	drmem = (struct of_drconf_cell *)
>> +				((char *)old_prop->value + sizeof(u32));
> 
> You do this dance twice (see below), a struct might make it cleaner.

Agreed.  I think I will make this update in a separate patch.  Updating
this to use a of_drconf struct would benefit this code as well as the code
in powerpc/numa.c that also deals with manipulating this property.

> 
>> +	for (i = 0; i < num_entries; i++) {
>> +		u64 lmb_end_addr = drmem[i].base_addr + lmb_size;
>> +		if (phys_addr >= drmem[i].base_addr
>> +		    && phys_addr < lmb_end_addr)
>> +			break;
>> +	}
>> +
>> +	if (i >= num_entries) {
>> +		of_node_put(dn);
>> +		return -EINVAL;
>> +	}
>> +
>> +	if (drmem[i].flags & DRCONF_MEM_ASSIGNED) {
>> +		of_node_put(dn);
>> +		return 0;
> 
> This is the already added case?

Yes.  In this case the lmb is already assigned to the system.

> 
>> +	}
>> +
>> +	rc = acquire_drc(drmem[i].drc_index);
>> +	if (rc) {
>> +		of_node_put(dn);
>> +		return -1;
> 
> -1 ?

Yeah, bad choice.

> 
>> +	}
>> +
>> +	new_prop = clone_property(old_prop);
>> +	drmem = (struct of_drconf_cell *)
>> +				((char *)new_prop->value + sizeof(u32));
>> +
>> +	drmem[i].flags |= DRCONF_MEM_ASSIGNED;
>> +	prom_update_property(dn, new_prop, old_prop);
>> +
>> +	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
>> +					  PSERIES_DRCONF_MEM_ADD,
>> +					  &drmem[i].base_addr);
>> +	if (rc == NOTIFY_BAD) {
>> +		prom_update_property(dn, old_prop, new_prop);
>> +		release_drc(drmem[i].drc_index);
>> +	}
>> +
>> +	of_node_put(dn);
>> +	return rc == NOTIFY_BAD ? -1 : 0;
> 
> -1 ?

Another bad return code choice.

> 
>> +}
>> +
>> +static ssize_t memory_release_store(struct class *class, const char *buf,
>> +				    size_t count)
>> +{
>> +	unsigned long drc_index;
>> +	struct device_node *dn;
>> +	struct property *new_prop, *old_prop;
>> +	struct of_drconf_cell *drmem;
>> +	int num_entries;
>> +	int i, rc;
>> +
>> +	rc = strict_strtoul(buf, 0, &drc_index);
>> +	if (rc)
>> +		return -EINVAL;
>> +
>> +	dn = of_find_node_by_path("/ibm,dynamic-reconfiguration-memory");
>> +	if (!dn)
>> +		return 0;
> 
> 0 really?

... and again...

> 
>> +
>> +	old_prop = of_find_property(dn, "ibm,dynamic-memory", NULL);
>> +	new_prop = clone_property(old_prop);
>> +
>> +	num_entries = *(u32 *)new_prop->value;
>> +	drmem = (struct of_drconf_cell *)
>> +				((char *)new_prop->value + sizeof(u32));
>> +
>> +	for (i = 0; i < num_entries; i++) {
>> +		if (drmem[i].drc_index == drc_index)
>> +			break;
>> +	}
>> +
>> +	if (i >= num_entries) {
>> +		free_property(new_prop);
>> +		of_node_put(dn);
>> +		return -EINVAL;
>> +	}
> 
> Couldn't use old_prop up until here? They're identical aren't they, so
> you can do the clone here and you can avoid the free in the above error
> case.
> 

Yes, this is possible.  I will clean this up.

>> +	drmem[i].flags &= ~DRCONF_MEM_ASSIGNED;
>> +	prom_update_property(dn, new_prop, old_prop);
>> +
>> +	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
>> +					  PSERIES_DRCONF_MEM_REMOVE,
>> +					  &drmem[i].base_addr);
>> +	if (rc != NOTIFY_BAD)
>> +		rc = release_drc(drc_index);
>> +
>> +	if (rc)
>> +		prom_update_property(dn, old_prop, new_prop);
>> +
>> +	of_node_put(dn);
>> +	return rc ? -1 : count;
> 
> -1, EPERM?

EPERM.

> 
>> +}
>> +
>> +static struct class_attribute class_attr_mem_release =
>> +			__ATTR(release, S_IWUSR, NULL, memory_release_store);
>> +#endif
>> +
>>  static int pseries_dlpar_init(void)
>>  {
>>  	if (!machine_is(pseries))
>>  		return 0;
>>  
>> +#ifdef CONFIG_MEMORY_HOTPLUG
>> +	if (sysfs_create_file(&memory_sysdev_class.kset.kobj,
>> +			      &class_attr_mem_release.attr))
>> +		printk(KERN_INFO "DLPAR: Could not create sysfs memory "
>> +		       "release file\n");
>> +#endif
>> +
>>  	return 0;
>>  }
>>  device_initcall(pseries_dlpar_init);
>> Index: powerpc/arch/powerpc/mm/mem.c
>> ===================================================================
>> --- powerpc.orig/arch/powerpc/mm/mem.c	2009-10-08 11:07:45.000000000 -0500
>> +++ powerpc/arch/powerpc/mm/mem.c	2009-10-08 11:08:54.000000000 -0500
>> @@ -111,8 +111,19 @@
>>  #ifdef CONFIG_MEMORY_HOTPLUG
>>  
>>  #ifdef CONFIG_NUMA
>> +int __attribute ((weak)) platform_probe_memory(u64 start)
> 
> __weak
> 
> Though be careful, I think this is vulnerable to a bug in some
> toolchains where the compiler will inline this version. See the comment
> around early_irq_init() in kernel/softirq.c for example.
> 
> This will need to be a ppc_md hook as soon as another platform supports
> memory hotplug, though that may be never :)
> 

I didn't know any other way to implement this.  If using a weak symbol is ok
I will leave it.  I am open to suggestions if there is a better way to do this.

thanks for reviewing the patch.

-Nathan

>> +{
>> +	return 0;
>> +}
>> +
>>  int memory_add_physaddr_to_nid(u64 start)
>>  {
>> +	int rc;
>> +
>> +	rc = platform_probe_memory(start);
>> +	if (rc)
>> +		return rc;
>> +
>>  	return hot_add_scn_to_nid(start);
>>  }
>>  #endif
> 
> cheers
> 

Re: [PATCH 5/5 v2] kernel handling of CPU DLPAR

[Nathan Fontenot]

Michael Ellerman wrote:
> On Tue, 2009-10-13 at 13:14 -0500, Nathan Fontenot wrote:
>> This adds the capability to DLPAR add and remove CPUs from the kernel. The
>> creates two new files /sys/devices/system/cpu/probe and
>> /sys/devices/system/cpu/release to handle the DLPAR addition and removal of
>> CPUs respectively.
> 
> How does this relate to the existing cpu hotplug mechanism? Or is this
> making the cpu exist (possible), vs marking it as online?

This update makes the cpu exist, it does not mark the cpu online.

> 
> Is some other platform going to want to do the same? ie. should the
> probe/release part be in generic code?

I thought about making this generic code, perhaps a follow-on patch to move
the creation of the probe/release files to generic code to see what the
community thinks.  I would assume there would still need to be a arch and/or
platforms specific callout to do the real work.

> 
>> Index: powerpc/arch/powerpc/platforms/pseries/dlpar.c
>> ===================================================================
>> --- powerpc.orig/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:08:22.000000000 -0500
>> +++ powerpc/arch/powerpc/platforms/pseries/dlpar.c	2009-10-13 13:09:00.000000000 -0500
>> @@ -1,11 +1,11 @@
>>  /*
>> - * dlpar.c - support for dynamic reconfiguration (including PCI
>> - * Hotplug and Dynamic Logical Partitioning on RPA platforms).
>> + * dlpar.c - support for dynamic reconfiguration (including PCI,
> 
> We know it's dlpar.c :)

heh! good point.  Consider it gone.

> 
>> + * Memory, and CPU Hotplug and Dynamic Logical Partitioning on
>> + * PAPR platforms).
>>   *
>>   * Copyright (C) 2009 Nathan Fontenot
>>   * Copyright (C) 2009 IBM Corporation
>>   *
>> - *
>>   * This program is free software; you can redistribute it and/or
>>   * modify it under the terms of the GNU General Public License version
>>   * 2 as published by the Free Software Foundation.
>> @@ -19,6 +19,7 @@
>>  #include <linux/memory_hotplug.h>
>>  #include <linux/sysdev.h>
>>  #include <linux/sysfs.h>
>> +#include <linux/cpu.h>
>>  
>>
>>  #include <asm/prom.h>
>> @@ -408,6 +409,82 @@
>>  	return 0;
>>  }
>>  
>> +#ifdef CONFIG_HOTPLUG_CPU
>> +static ssize_t cpu_probe_store(struct class *class, const char *buf,
>> +			       size_t count)
>> +{
>> +	struct device_node *dn;
>> +	unsigned long drc_index;
>> +	char *cpu_name;
>> +	int rc;
>> +
>> +	rc = strict_strtoul(buf, 0, &drc_index);
>> +	if (rc)
>> +		return -EINVAL;
>> +
>> +	rc = acquire_drc(drc_index);
>> +	if (rc)
>> +		return rc;
>> +
>> +	dn = configure_connector(drc_index);
>> +	if (!dn) {
>> +		release_drc(drc_index);
>> +		return rc;
>> +	}
>> +
>> +	/* fixup dn name */
>> +	cpu_name = kzalloc(strlen(dn->full_name) + strlen("/cpus/") + 1,
>> +			   GFP_KERNEL);
>> +	if (!cpu_name) {
>> +		free_cc_nodes(dn);
>> +		release_drc(drc_index);
>> +		return -ENOMEM;
>> +	}
>> +
>> +	sprintf(cpu_name, "/cpus/%s", dn->full_name);
>> +	kfree(dn->full_name);
>> +	dn->full_name = cpu_name;
> 
> What was all that? Firmware gives us a bogus full name? But the parent
> is right?

Yeah, this has always been an oddity to me.  The name that is given to us
from firmware puts the cpu node in the root of the device tree as opposed
to /cpus.  Since cpu nodes are in /cpus, the name is fixed up to reflect this.

This name fixup has always been done by the drmgr userspace command, which is
where this functionality is being imported from.

> 
>> +	rc = add_device_tree_nodes(dn);
>> +	if (rc)
>> +		release_drc(drc_index);
>> +
>> +	return rc ? rc : count;
> 
> You're sure rc is < 0.
> 
Oh, good catch.

>> +}
>> +
>> +static ssize_t cpu_release_store(struct class *class, const char *buf,
>> +				 size_t count)
>> +{
>> +	struct device_node *dn;
>> +	u32 *drc_index;
>> +	int rc;
>> +
>> +	dn = of_find_node_by_path(buf);
>> +	if (!dn)
>> +		return -EINVAL;
>> +
>> +	drc_index = (u32 *)of_get_property(dn, "ibm,my-drc-index", NULL);
> 
> No cast required.

ok.

thanks for the review.

-Nathan

> 
>> +	if (!drc_index) {
>> +		of_node_put(dn);
>> +		return -EINVAL;
>> +	}
>> +
>> +	rc = release_drc(*drc_index);
>> +	if (rc) {
>> +		of_node_put(dn);
>> +		return rc;
>> +	}
>> +
>> +	rc = remove_device_tree_nodes(dn);
>> +	if (rc)
>> +		acquire_drc(*drc_index);
>> +
>> +	of_node_put(dn);
>> +	return rc ? rc : count;
>> +}
> 
> 
> cheers

Re: [PATCH 5/5 v2] kernel handling of CPU DLPAR

[Michael Ellerman]

[-- Attachment #1: Type: text/plain, Size: 1410 bytes --]

On Thu, 2009-10-15 at 10:40 -0500, Nathan Fontenot wrote:
> Michael Ellerman wrote:
> > On Tue, 2009-10-13 at 13:14 -0500, Nathan Fontenot wrote:
> >> This adds the capability to DLPAR add and remove CPUs from the kernel. The
> >> creates two new files /sys/devices/system/cpu/probe and
> >> /sys/devices/system/cpu/release to handle the DLPAR addition and removal of
> >> CPUs respectively.
> > 
> > How does this relate to the existing cpu hotplug mechanism? Or is this
> > making the cpu exist (possible), vs marking it as online?
> 
> This update makes the cpu exist, it does not mark the cpu online.
> 
> > 
> > Is some other platform going to want to do the same? ie. should the
> > probe/release part be in generic code?
> 
> I thought about making this generic code, perhaps a follow-on patch to move
> the creation of the probe/release files to generic code to see what the
> community thinks.  I would assume there would still need to be a arch and/or
> platforms specific callout to do the real work.

I'm not so worried about the code being generic, there's not much that
would be generic. More the mechanism. We don't want to add probe/release
to powerpc, and then have a different mechanism get added later by some
other platform, or generically.

But I guess you CC'ed lkml and there's not much more to do, I don't know
specifically who'd care about it.

cheers


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