[PATCH 3/5] Add of node/property notification chain for adds andremoves

From: Nathan Fontenot
Date: Tue Oct 02 2012 - 22:58:02 EST


This patch moves the notification chain for updates to the device tree
from the powerpc/pseries code to the base OF code. This makes this
functionality available to all architectures.

Additionally the notification chain is updated to allow notifications
for property add/remove/update. To make this work a pointer to a new
struct (of_prop_reconfig) is passed to the routines in the notification chain.
The of_prop_reconfig property contains a pointer to the node containing the
property and a pointer to the property itself. In the case of property
updates, the property pointer refers to the new property.

Signed-off-by: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx>
---
arch/powerpc/include/asm/pSeries_reconfig.h | 32 ----------
arch/powerpc/kernel/prom.c | 6 -
arch/powerpc/platforms/pseries/dlpar.c | 14 ++--
arch/powerpc/platforms/pseries/hotplug-cpu.c | 8 +-
arch/powerpc/platforms/pseries/hotplug-memory.c | 60 +++++++++++++------
arch/powerpc/platforms/pseries/iommu.c | 6 -
arch/powerpc/platforms/pseries/reconfig.c | 65 ---------------------
arch/powerpc/platforms/pseries/setup.c | 6 -
drivers/of/base.c | 74 ++++++++++++++++++++++--
include/linux/of.h | 20 +++++-
10 files changed, 154 insertions(+), 137 deletions(-)

Index: dt-next/arch/powerpc/platforms/pseries/reconfig.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/reconfig.c 2012-10-02 08:40:51.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/reconfig.c 2012-10-02 08:45:12.000000000 -0500
@@ -16,11 +16,11 @@
#include <linux/notifier.h>
#include <linux/proc_fs.h>
#include <linux/slab.h>
+#include <linux/of.h>

#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/uaccess.h>
-#include <asm/pSeries_reconfig.h>
#include <asm/mmu.h>

/**
@@ -55,28 +55,6 @@
return parent;
}

-static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
-
-int pSeries_reconfig_notifier_register(struct notifier_block *nb)
-{
- return blocking_notifier_chain_register(&pSeries_reconfig_chain, nb);
-}
-EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_register);
-
-void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
-{
- blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
-}
-EXPORT_SYMBOL_GPL(pSeries_reconfig_notifier_unregister);
-
-int pSeries_reconfig_notify(unsigned long action, void *p)
-{
- int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
- action, p);
-
- return notifier_to_errno(err);
-}
-
static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
{
struct device_node *np;
@@ -100,13 +78,12 @@
goto out_err;
}

- err = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, np);
+ err = of_attach_node(np);
if (err) {
printk(KERN_ERR "Failed to add device node %s\n", path);
goto out_err;
}

- of_attach_node(np);
of_node_put(np->parent);

return 0;
@@ -134,9 +111,7 @@
return -EBUSY;
}

- pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, np);
of_detach_node(np);
-
of_node_put(parent);
of_node_put(np); /* Must decrement the refcount */
return 0;
@@ -381,7 +356,6 @@
static int do_update_property(char *buf, size_t bufsize)
{
struct device_node *np;
- struct pSeries_reconfig_prop_update upd_value;
unsigned char *value;
char *name, *end, *next_prop;
int rc, length;
@@ -410,41 +384,8 @@
return -ENODEV;
}

- upd_value.node = np;
- upd_value.property = newprop;
- pSeries_reconfig_notify(PSERIES_UPDATE_PROPERTY, &upd_value);
-
rc = prom_update_property(np, newprop, oldprop);
- if (rc)
- return rc;
-
- /* For memory under the ibm,dynamic-reconfiguration-memory node
- * of the device tree, adding and removing memory is just an update
- * to the ibm,dynamic-memory property instead of adding/removing a
- * memory node in the device tree. For these cases we still need to
- * involve the notifier chain.
- */
- if (!strcmp(name, "ibm,dynamic-memory")) {
- int action;
-
- next_prop = parse_next_property(next_prop, end, &name,
- &length, &value);
- if (!next_prop)
- return -EINVAL;
-
- if (!strcmp(name, "add"))
- action = PSERIES_DRCONF_MEM_ADD;
- else
- action = PSERIES_DRCONF_MEM_REMOVE;
-
- rc = pSeries_reconfig_notify(action, value);
- if (rc) {
- prom_update_property(np, oldprop, newprop);
- return rc;
- }
- }
-
- return 0;
+ return rc;
}

/**
Index: dt-next/drivers/of/base.c
===================================================================
--- dt-next.orig/drivers/of/base.c 2012-10-02 08:40:51.000000000 -0500
+++ dt-next/drivers/of/base.c 2012-10-02 08:58:55.000000000 -0500
@@ -978,6 +978,24 @@
}
EXPORT_SYMBOL(of_parse_phandle_with_args);

+#if defined(CONFIG_OF_DYNAMIC)
+static int of_property_notify(int action, struct device_node *np,
+ struct property *prop)
+{
+ struct of_prop_reconfig pr;
+
+ pr.dn = np;
+ pr.prop = prop;
+ return of_reconfig_notify(action, &pr);
+}
+#else
+static int of_property_notify(int action, struct device_node *np,
+ struct property *prop)
+{
+ return 0;
+}
+#endif
+
/**
* prom_add_property - Add a property to a node
*/
@@ -985,6 +1003,11 @@
{
struct property **next;
unsigned long flags;
+ int rc;
+
+ rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
+ if (rc)
+ return rc;

prop->next = NULL;
write_lock_irqsave(&devtree_lock, flags);
@@ -1022,6 +1045,11 @@
struct property **next;
unsigned long flags;
int found = 0;
+ int rc;
+
+ rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
+ if (rc)
+ return rc;

write_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
@@ -1064,7 +1092,11 @@
{
struct property **next;
unsigned long flags;
- int found = 0;
+ int rc, found = 0;
+
+ rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
+ if (rc)
+ return rc;

write_lock_irqsave(&devtree_lock, flags);
next = &np->properties;
@@ -1103,6 +1135,26 @@
* device tree nodes.
*/

+static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
+
+int of_reconfig_notifier_register(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_register(&of_reconfig_chain, nb);
+}
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+
+int of_reconfig_notify(unsigned long action, void *p)
+{
+ int rc;
+
+ rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
+ return notifier_to_errno(rc);
+}
+
#ifdef CONFIG_PROC_DEVICETREE
static void of_add_proc_dt_entry(struct device_node *dn)
{
@@ -1122,9 +1174,14 @@
/**
* of_attach_node - Plug a device node into the tree and global list.
*/
-void of_attach_node(struct device_node *np)
+int of_attach_node(struct device_node *np)
{
unsigned long flags;
+ int rc;
+
+ rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+ if (rc)
+ return rc;

write_lock_irqsave(&devtree_lock, flags);
np->sibling = np->parent->child;
@@ -1134,6 +1191,7 @@
write_unlock_irqrestore(&devtree_lock, flags);

of_add_proc_dt_entry(np);
+ return 0;
}

#ifdef CONFIG_PROC_DEVICETREE
@@ -1163,23 +1221,28 @@
* The caller must hold a reference to the node. The memory associated with
* the node is not freed until its refcount goes to zero.
*/
-void of_detach_node(struct device_node *np)
+int of_detach_node(struct device_node *np)
{
struct device_node *parent;
unsigned long flags;
+ int rc = 0;
+
+ rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+ if (rc)
+ return rc;

write_lock_irqsave(&devtree_lock, flags);

if (of_node_check_flag(np, OF_DETACHED)) {
/* someone already detached it */
write_unlock_irqrestore(&devtree_lock, flags);
- return;
+ return rc;
}

parent = np->parent;
if (!parent) {
write_unlock_irqrestore(&devtree_lock, flags);
- return;
+ return rc;
}

if (allnodes == np)
@@ -1208,6 +1271,7 @@
write_unlock_irqrestore(&devtree_lock, flags);

of_remove_proc_dt_entry(np);
+ return rc;
}
#endif /* defined(CONFIG_OF_DYNAMIC) */

Index: dt-next/arch/powerpc/include/asm/pSeries_reconfig.h
===================================================================
--- dt-next.orig/arch/powerpc/include/asm/pSeries_reconfig.h 2012-10-02 08:30:21.000000000 -0500
+++ dt-next/arch/powerpc/include/asm/pSeries_reconfig.h 2012-10-02 08:43:40.000000000 -0500
@@ -2,43 +2,11 @@
#define _PPC64_PSERIES_RECONFIG_H
#ifdef __KERNEL__

-#include <linux/notifier.h>
-
-/*
- * Use this API if your code needs to know about OF device nodes being
- * added or removed on pSeries systems.
- */
-
-#define PSERIES_RECONFIG_ADD 0x0001
-#define PSERIES_RECONFIG_REMOVE 0x0002
-#define PSERIES_DRCONF_MEM_ADD 0x0003
-#define PSERIES_DRCONF_MEM_REMOVE 0x0004
-#define PSERIES_UPDATE_PROPERTY 0x0005
-
-/**
- * pSeries_reconfig_notify - Notifier value structure for OFDT property updates
- *
- * @node: Device tree node which owns the property being updated
- * @property: Updated property
- */
-struct pSeries_reconfig_prop_update {
- struct device_node *node;
- struct property *property;
-};
-
#ifdef CONFIG_PPC_PSERIES
-extern int pSeries_reconfig_notifier_register(struct notifier_block *);
-extern void pSeries_reconfig_notifier_unregister(struct notifier_block *);
-extern int pSeries_reconfig_notify(unsigned long action, void *p);
/* Not the best place to put this, will be fixed when we move some
* of the rtas suspend-me stuff to pseries */
extern void pSeries_coalesce_init(void);
#else /* !CONFIG_PPC_PSERIES */
-static inline int pSeries_reconfig_notifier_register(struct notifier_block *nb)
-{
- return 0;
-}
-static inline void pSeries_reconfig_notifier_unregister(struct notifier_block *nb) { }
static inline void pSeries_coalesce_init(void) { }
#endif /* CONFIG_PPC_PSERIES */

Index: dt-next/arch/powerpc/platforms/pseries/hotplug-cpu.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/hotplug-cpu.c 2012-10-02 08:30:23.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/hotplug-cpu.c 2012-10-02 08:43:40.000000000 -0500
@@ -23,12 +23,12 @@
#include <linux/delay.h>
#include <linux/sched.h> /* for idle_task_exit */
#include <linux/cpu.h>
+#include <linux/of.h>
#include <asm/prom.h>
#include <asm/rtas.h>
#include <asm/firmware.h>
#include <asm/machdep.h>
#include <asm/vdso_datapage.h>
-#include <asm/pSeries_reconfig.h>
#include <asm/xics.h>
#include "plpar_wrappers.h"
#include "offline_states.h"
@@ -333,10 +333,10 @@
int err = 0;

switch (action) {
- case PSERIES_RECONFIG_ADD:
+ case OF_RECONFIG_ATTACH_NODE:
err = pseries_add_processor(node);
break;
- case PSERIES_RECONFIG_REMOVE:
+ case OF_RECONFIG_DETACH_NODE:
pseries_remove_processor(node);
break;
}
@@ -399,7 +399,7 @@

/* Processors can be added/removed only on LPAR */
if (firmware_has_feature(FW_FEATURE_LPAR)) {
- pSeries_reconfig_notifier_register(&pseries_smp_nb);
+ of_reconfig_notifier_register(&pseries_smp_nb);
cpu_maps_update_begin();
if (cede_offline_enabled && parse_cede_parameters() == 0) {
default_offline_state = CPU_STATE_INACTIVE;
Index: dt-next/arch/powerpc/platforms/pseries/hotplug-memory.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-02 08:30:04.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/hotplug-memory.c 2012-10-02 08:43:40.000000000 -0500
@@ -16,7 +16,6 @@

#include <asm/firmware.h>
#include <asm/machdep.h>
-#include <asm/pSeries_reconfig.h>
#include <asm/sparsemem.h>

static unsigned long get_memblock_size(void)
@@ -181,42 +180,69 @@
return (ret < 0) ? -EINVAL : 0;
}

-static int pseries_drconf_memory(unsigned long *base, unsigned int action)
+static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
{
+ struct of_drconf_cell *new_drmem, *old_drmem;
unsigned long memblock_size;
- int rc;
+ u32 entries;
+ u32 *p;
+ int i, rc = -EINVAL;

memblock_size = get_memblock_size();
if (!memblock_size)
return -EINVAL;

- if (action == PSERIES_DRCONF_MEM_ADD) {
- rc = memblock_add(*base, memblock_size);
- rc = (rc < 0) ? -EINVAL : 0;
- } else if (action == PSERIES_DRCONF_MEM_REMOVE) {
- rc = pseries_remove_memblock(*base, memblock_size);
- } else {
- rc = -EINVAL;
+ p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL);
+ if (!p)
+ return -EINVAL;
+
+ /* The first int of the property is the number of lmb's described
+ * by the property. This is followed by an array of of_drconf_cell
+ * entries. Get the niumber of entries and skip to the array of
+ * of_drconf_cell's.
+ */
+ entries = *p++;
+ old_drmem = (struct of_drconf_cell *)p;
+
+ p = (u32 *)pr->prop->value;
+ p++;
+ new_drmem = (struct of_drconf_cell *)p;
+
+ for (i = 0; i < entries; i++) {
+ if ((old_drmem[i].flags & DRCONF_MEM_ASSIGNED) &&
+ (!(new_drmem[i].flags & DRCONF_MEM_ASSIGNED))) {
+ rc = pseries_remove_memblock(old_drmem[i].base_addr,
+ memblock_size);
+ break;
+ } else if ((!(old_drmem[i].flags & DRCONF_MEM_ASSIGNED)) &&
+ (new_drmem[i].flags & DRCONF_MEM_ASSIGNED)) {
+ rc = memblock_add(old_drmem[i].base_addr,
+ memblock_size);
+ rc = (rc < 0) ? -EINVAL : 0;
+ break;
+ }
}

return rc;
}

static int pseries_memory_notifier(struct notifier_block *nb,
- unsigned long action, void *node)
+ unsigned long action, void *node)
{
+ struct of_prop_reconfig *pr;
int err = 0;

switch (action) {
- case PSERIES_RECONFIG_ADD:
+ case OF_RECONFIG_ATTACH_NODE:
err = pseries_add_memory(node);
break;
- case PSERIES_RECONFIG_REMOVE:
+ case OF_RECONFIG_DETACH_NODE:
err = pseries_remove_memory(node);
break;
- case PSERIES_DRCONF_MEM_ADD:
- case PSERIES_DRCONF_MEM_REMOVE:
- err = pseries_drconf_memory(node, action);
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ pr = (struct of_prop_reconfig *)node;
+ if (!strcmp(pr->prop->name, "ibm,dynamic-memory"))
+ err = pseries_update_drconf_memory(pr);
break;
}
return notifier_from_errno(err);
@@ -229,7 +255,7 @@
static int __init pseries_memory_hotplug_init(void)
{
if (firmware_has_feature(FW_FEATURE_LPAR))
- pSeries_reconfig_notifier_register(&pseries_mem_nb);
+ of_reconfig_notifier_register(&pseries_mem_nb);

return 0;
}
Index: dt-next/include/linux/of.h
===================================================================
--- dt-next.orig/include/linux/of.h 2012-10-02 08:31:08.000000000 -0500
+++ dt-next/include/linux/of.h 2012-10-02 08:50:22.000000000 -0500
@@ -21,6 +21,7 @@
#include <linux/kref.h>
#include <linux/mod_devicetable.h>
#include <linux/spinlock.h>
+#include <linux/notifier.h>

#include <asm/byteorder.h>
#include <asm/errno.h>
@@ -270,8 +271,23 @@

#if defined(CONFIG_OF_DYNAMIC)
/* For updating the device tree at runtime */
-extern void of_attach_node(struct device_node *);
-extern void of_detach_node(struct device_node *);
+#define OF_RECONFIG_ATTACH_NODE 0x0001
+#define OF_RECONFIG_DETACH_NODE 0x0002
+#define OF_RECONFIG_ADD_PROPERTY 0x0003
+#define OF_RECONFIG_REMOVE_PROPERTY 0x0004
+#define OF_RECONFIG_UPDATE_PROPERTY 0x0005
+
+struct of_prop_reconfig {
+ struct device_node *dn;
+ struct property *prop;
+};
+
+extern int of_reconfig_notifier_register(struct notifier_block *);
+extern int of_reconfig_notifier_unregister(struct notifier_block *);
+extern int of_reconfig_notify(unsigned long, void *);
+
+extern int of_attach_node(struct device_node *);
+extern int of_detach_node(struct device_node *);
#endif

#define of_match_ptr(_ptr) (_ptr)
Index: dt-next/arch/powerpc/kernel/prom.c
===================================================================
--- dt-next.orig/arch/powerpc/kernel/prom.c 2012-10-02 08:30:22.000000000 -0500
+++ dt-next/arch/powerpc/kernel/prom.c 2012-10-02 08:43:40.000000000 -0500
@@ -32,6 +32,7 @@
#include <linux/debugfs.h>
#include <linux/irq.h>
#include <linux/memblock.h>
+#include <linux/of.h>

#include <asm/prom.h>
#include <asm/rtas.h>
@@ -49,7 +50,6 @@
#include <asm/btext.h>
#include <asm/sections.h>
#include <asm/machdep.h>
-#include <asm/pSeries_reconfig.h>
#include <asm/pci-bridge.h>
#include <asm/kexec.h>
#include <asm/opal.h>
@@ -802,7 +802,7 @@
int err;

switch (action) {
- case PSERIES_RECONFIG_ADD:
+ case OF_RECONFIG_ATTACH_NODE:
err = of_finish_dynamic_node(node);
if (err < 0)
printk(KERN_ERR "finish_node returned %d\n", err);
@@ -821,7 +821,7 @@

static int __init prom_reconfig_setup(void)
{
- return pSeries_reconfig_notifier_register(&prom_reconfig_nb);
+ return of_reconfig_notifier_register(&prom_reconfig_nb);
}
__initcall(prom_reconfig_setup);
#endif
Index: dt-next/arch/powerpc/platforms/pseries/iommu.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/iommu.c 2012-10-02 08:30:23.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/iommu.c 2012-10-02 08:43:40.000000000 -0500
@@ -35,6 +35,7 @@
#include <linux/dma-mapping.h>
#include <linux/crash_dump.h>
#include <linux/memory.h>
+#include <linux/of.h>
#include <asm/io.h>
#include <asm/prom.h>
#include <asm/rtas.h>
@@ -42,7 +43,6 @@
#include <asm/pci-bridge.h>
#include <asm/machdep.h>
#include <asm/abs_addr.h>
-#include <asm/pSeries_reconfig.h>
#include <asm/firmware.h>
#include <asm/tce.h>
#include <asm/ppc-pci.h>
@@ -1211,7 +1211,7 @@
struct direct_window *window;

switch (action) {
- case PSERIES_RECONFIG_REMOVE:
+ case OF_RECONFIG_DETACH_NODE:
if (pci && pci->iommu_table)
iommu_free_table(pci->iommu_table, np->full_name);

@@ -1274,7 +1274,7 @@
}


- pSeries_reconfig_notifier_register(&iommu_reconfig_nb);
+ of_reconfig_notifier_register(&iommu_reconfig_nb);
register_memory_notifier(&iommu_mem_nb);

set_pci_dma_ops(&dma_iommu_ops);
Index: dt-next/arch/powerpc/platforms/pseries/setup.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/setup.c 2012-10-02 08:30:23.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/setup.c 2012-10-02 08:43:40.000000000 -0500
@@ -40,6 +40,7 @@
#include <linux/seq_file.h>
#include <linux/root_dev.h>
#include <linux/cpuidle.h>
+#include <linux/of.h>

#include <asm/mmu.h>
#include <asm/processor.h>
@@ -63,7 +64,6 @@
#include <asm/smp.h>
#include <asm/firmware.h>
#include <asm/eeh.h>
-#include <asm/pSeries_reconfig.h>

#include "plpar_wrappers.h"
#include "pseries.h"
@@ -258,7 +258,7 @@
int err = NOTIFY_OK;

switch (action) {
- case PSERIES_RECONFIG_ADD:
+ case OF_RECONFIG_ATTACH_NODE:
pci = np->parent->data;
if (pci) {
update_dn_pci_info(np, pci->phb);
@@ -390,7 +390,7 @@
init_pci_config_tokens();
eeh_pseries_init();
find_and_init_phbs();
- pSeries_reconfig_notifier_register(&pci_dn_reconfig_nb);
+ of_reconfig_notifier_register(&pci_dn_reconfig_nb);
eeh_init();

pSeries_nvram_init();
Index: dt-next/arch/powerpc/platforms/pseries/dlpar.c
===================================================================
--- dt-next.orig/arch/powerpc/platforms/pseries/dlpar.c 2012-10-02 08:40:51.000000000 -0500
+++ dt-next/arch/powerpc/platforms/pseries/dlpar.c 2012-10-02 08:43:40.000000000 -0500
@@ -16,13 +16,13 @@
#include <linux/spinlock.h>
#include <linux/cpu.h>
#include <linux/slab.h>
+#include <linux/of.h>
#include "offline_states.h"

#include <asm/prom.h>
#include <asm/machdep.h>
#include <asm/uaccess.h>
#include <asm/rtas.h>
-#include <asm/pSeries_reconfig.h>

struct cc_workarea {
u32 drc_index;
@@ -262,24 +262,26 @@
if (!dn->parent)
return -ENOMEM;

- rc = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, dn);
+ rc = of_attach_node(dn);
if (rc) {
printk(KERN_ERR "Failed to add device node %s\n",
dn->full_name);
return rc;
}

- of_attach_node(dn);
of_node_put(dn->parent);
return 0;
}

int dlpar_detach_node(struct device_node *dn)
{
- pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, dn);
- of_detach_node(dn);
- of_node_put(dn); /* Must decrement the refcount */
+ int rc;

+ rc = of_detach_node(dn);
+ if (rc)
+ return rc;
+
+ of_node_put(dn); /* Must decrement the refcount */
return 0;
}


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