[PATCH 1/2] powerpc: introduce pSeries_reconfig_notify()

[PATCH 1/2] powerpc: introduce pSeries_reconfig_notify()

[Akinobu Mita]

This introduces pSeries_reconfig_notify() as a just wrapper of
blocking_notifier_call_chain() for pSeries_reconfig_chain.

This is a preparation to improvement of error code on reconfiguration
notifier failure.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/include/asm/pSeries_reconfig.h |    2 +-
 arch/powerpc/platforms/pseries/dlpar.c      |   10 +++-----
 arch/powerpc/platforms/pseries/reconfig.c   |   30 ++++++++++++++++----------
 3 files changed, 23 insertions(+), 19 deletions(-)

diff --git a/arch/powerpc/include/asm/pSeries_reconfig.h b/arch/powerpc/include/asm/pSeries_reconfig.h
index 89d2f99..23cd6cc 100644
--- a/arch/powerpc/include/asm/pSeries_reconfig.h
+++ b/arch/powerpc/include/asm/pSeries_reconfig.h
@@ -17,7 +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;
+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);
diff --git a/arch/powerpc/platforms/pseries/dlpar.c b/arch/powerpc/platforms/pseries/dlpar.c
index 57ceb92..e9be25b 100644
--- a/arch/powerpc/platforms/pseries/dlpar.c
+++ b/arch/powerpc/platforms/pseries/dlpar.c
@@ -262,12 +262,11 @@ int dlpar_attach_node(struct device_node *dn)
 	if (!dn->parent)
 		return -ENOMEM;
 
-	rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
-					  PSERIES_RECONFIG_ADD, dn);
-	if (rc == NOTIFY_BAD) {
+	rc = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, dn);
+	if (rc) {
 		printk(KERN_ERR "Failed to add device node %s\n",
 		       dn->full_name);
-		return -ENOMEM; /* For now, safe to assume kmalloc failure */
+		return rc;
 	}
 
 	of_attach_node(dn);
@@ -297,8 +296,7 @@ int dlpar_detach_node(struct device_node *dn)
 		remove_proc_entry(dn->pde->name, parent->pde);
 #endif
 
-	blocking_notifier_call_chain(&pSeries_reconfig_chain,
-			    PSERIES_RECONFIG_REMOVE, dn);
+	pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, dn);
 	of_detach_node(dn);
 	of_node_put(dn); /* Must decrement the refcount */
 
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 1de2cbb..286b6af 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -97,7 +97,7 @@ static struct device_node *derive_parent(const char *path)
 	return parent;
 }
 
-BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
+static BLOCKING_NOTIFIER_HEAD(pSeries_reconfig_chain);
 
 int pSeries_reconfig_notifier_register(struct notifier_block *nb)
 {
@@ -109,6 +109,16 @@ void pSeries_reconfig_notifier_unregister(struct notifier_block *nb)
 	blocking_notifier_chain_unregister(&pSeries_reconfig_chain, nb);
 }
 
+int pSeries_reconfig_notify(unsigned long action, void *p)
+{
+	int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
+						action, p);
+
+	if (err == NOTIFY_BAD)
+		return -ENOMEM; /* For now, safe to assume kmalloc failure */
+	return 0;
+}
+
 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
 {
 	struct device_node *np;
@@ -132,11 +142,9 @@ static int pSeries_reconfig_add_node(const char *path, struct property *proplist
 		goto out_err;
 	}
 
-	err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
-				  PSERIES_RECONFIG_ADD, np);
-	if (err == NOTIFY_BAD) {
+	err = pSeries_reconfig_notify(PSERIES_RECONFIG_ADD, np);
+	if (err) {
 		printk(KERN_ERR "Failed to add device node %s\n", path);
-		err = -ENOMEM; /* For now, safe to assume kmalloc failure */
 		goto out_err;
 	}
 
@@ -173,8 +181,7 @@ static int pSeries_reconfig_remove_node(struct device_node *np)
 
 	remove_node_proc_entries(np);
 
-	blocking_notifier_call_chain(&pSeries_reconfig_chain,
-			    PSERIES_RECONFIG_REMOVE, np);
+	pSeries_reconfig_notify(PSERIES_RECONFIG_REMOVE, np);
 	of_detach_node(np);
 
 	of_node_put(parent);
@@ -472,11 +479,10 @@ static int do_update_property(char *buf, size_t bufsize)
 		else
 			action = PSERIES_DRCONF_MEM_REMOVE;
 
-		rc = blocking_notifier_call_chain(&pSeries_reconfig_chain,
-						  action, value);
-		if (rc == NOTIFY_BAD) {
-			rc = prom_update_property(np, oldprop, newprop);
-			return -ENOMEM;
+		rc = pSeries_reconfig_notify(action, value);
+		if (rc) {
+			prom_update_property(np, oldprop, newprop);
+			return rc;
 		}
 	}
 
-- 
1.7.4.4

[PATCH 2/2] powerpc: improve error code on reconfiguration notifier failure

[Akinobu Mita]

Reconfiguration notifier call for device node may fail by several reasons,
but it always assumes kmalloc failures.

This enables reconfiguration notifier call chain to get the actual error
code rather than -ENOMEM by converting all reconfiguration notifier calls
to return encapsulate error code with notifier_from_errno().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: linuxppc-dev@lists.ozlabs.org
---
 arch/powerpc/kernel/prom.c                      |    8 +++-----
 arch/powerpc/platforms/pseries/hotplug-cpu.c    |   10 +++-------
 arch/powerpc/platforms/pseries/hotplug-memory.c |   16 +++++-----------
 arch/powerpc/platforms/pseries/reconfig.c       |    4 +---
 4 files changed, 12 insertions(+), 26 deletions(-)

diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index 8c3112a..86677ba 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -862,16 +862,14 @@ static int prom_reconfig_notifier(struct notifier_block *nb,
 	switch (action) {
 	case PSERIES_RECONFIG_ADD:
 		err = of_finish_dynamic_node(node);
-		if (err < 0) {
+		if (err < 0)
 			printk(KERN_ERR "finish_node returned %d\n", err);
-			err = NOTIFY_BAD;
-		}
 		break;
 	default:
-		err = NOTIFY_DONE;
+		err = 0;
 		break;
 	}
-	return err;
+	return notifier_from_errno(err);
 }
 
 static struct notifier_block prom_reconfig_nb = {
diff --git a/arch/powerpc/platforms/pseries/hotplug-cpu.c b/arch/powerpc/platforms/pseries/hotplug-cpu.c
index 46f13a3..bc02885 100644
--- a/arch/powerpc/platforms/pseries/hotplug-cpu.c
+++ b/arch/powerpc/platforms/pseries/hotplug-cpu.c
@@ -330,21 +330,17 @@ static void pseries_remove_processor(struct device_node *np)
 static int pseries_smp_notifier(struct notifier_block *nb,
 				unsigned long action, void *node)
 {
-	int err = NOTIFY_OK;
+	int err = 0;
 
 	switch (action) {
 	case PSERIES_RECONFIG_ADD:
-		if (pseries_add_processor(node))
-			err = NOTIFY_BAD;
+		err = pseries_add_processor(node);
 		break;
 	case PSERIES_RECONFIG_REMOVE:
 		pseries_remove_processor(node);
 		break;
-	default:
-		err = NOTIFY_DONE;
-		break;
 	}
-	return err;
+	return notifier_from_errno(err);
 }
 
 static struct notifier_block pseries_smp_nb = {
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 33867ec..1eaefd6 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -197,27 +197,21 @@ static int pseries_drconf_memory(unsigned long *base, unsigned int action)
 static int pseries_memory_notifier(struct notifier_block *nb,
 				unsigned long action, void *node)
 {
-	int err = NOTIFY_OK;
+	int err = 0;
 
 	switch (action) {
 	case PSERIES_RECONFIG_ADD:
-		if (pseries_add_memory(node))
-			err = NOTIFY_BAD;
+		err = pseries_add_memory(node);
 		break;
 	case PSERIES_RECONFIG_REMOVE:
-		if (pseries_remove_memory(node))
-			err = NOTIFY_BAD;
+		err = pseries_remove_memory(node);
 		break;
 	case PSERIES_DRCONF_MEM_ADD:
 	case PSERIES_DRCONF_MEM_REMOVE:
-		if (pseries_drconf_memory(node, action))
-			err = NOTIFY_BAD;
-		break;
-	default:
-		err = NOTIFY_DONE;
+		err = pseries_drconf_memory(node, action);
 		break;
 	}
-	return err;
+	return notifier_from_errno(err);
 }
 
 static struct notifier_block pseries_mem_nb = {
diff --git a/arch/powerpc/platforms/pseries/reconfig.c b/arch/powerpc/platforms/pseries/reconfig.c
index 286b6af..168651a 100644
--- a/arch/powerpc/platforms/pseries/reconfig.c
+++ b/arch/powerpc/platforms/pseries/reconfig.c
@@ -114,9 +114,7 @@ int pSeries_reconfig_notify(unsigned long action, void *p)
 	int err = blocking_notifier_call_chain(&pSeries_reconfig_chain,
 						action, p);
 
-	if (err == NOTIFY_BAD)
-		return -ENOMEM; /* For now, safe to assume kmalloc failure */
-	return 0;
+	return notifier_to_errno(err);
 }
 
 static int pSeries_reconfig_add_node(const char *path, struct property *proplist)
-- 
1.7.4.4