Hi all,
This is a rollup of all the patches that I queued up today for
linux-next for the devicetree changeset and overlay work. I'm reposting
these patches because some have been significantly changed since their
first posting. None of the code is actually live yet, but the test cases
are there.
There is one significant functional change which may affect pseries. The
OF_DYNAMIC code has been changed to emit notifiers after applying a
change to the tree instead of before. I think I've got all they users
taken care of correctly, but I'd like to see some testing. I don't have
access to pseries (and I can't get the QEMU pseries model to boot reliably)
Nathan/Tyrel, can you give it a spin? The changes can be found in my git tree:
git://git.secretlab.ca/git/linux devicetree/next
Grant Likely (8):
of/platform: Fix of_platform_device_destroy iteration of devices
of: Move CONFIG_OF_DYNAMIC code into a separate file
of: Make devicetree sysfs update functions consistent.
of: Make sure attached nodes don't carry along extra children
of: Move dynamic node fixups out of powerpc and into common code
of: Reorder device tree changes and notifiers
of: Add todo tasklist for Devicetree
Merge branch 'devicetree/next-overlay' into devicetree/next
Pantelis Antoniou (4):
of: rename of_aliases_mutex to just of_mutex
OF: Utility helper functions for dynamic nodes
of: Create unlocked versions of node and property add/remove functions
of: Transactional DT support.
Documentation/devicetree/changesets.txt | 40 ++
Documentation/devicetree/todo.txt | 11 +
arch/powerpc/kernel/prom.c | 70 ---
arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +-
drivers/crypto/nx/nx-842.c | 30 +-
drivers/of/Makefile | 1 +
drivers/of/base.c | 423 ++++-----------
drivers/of/device.c | 4 +-
drivers/of/dynamic.c | 660 ++++++++++++++++++++++++
drivers/of/of_private.h | 59 ++-
drivers/of/platform.c | 32 +-
drivers/of/selftest.c | 79 +++
drivers/of/testcase-data/testcases.dtsi | 10 +
include/linux/of.h | 80 ++-
include/linux/of_platform.h | 7 +-
15 files changed, 1065 insertions(+), 443 deletions(-)
create mode 100644 Documentation/devicetree/changesets.txt
create mode 100644 Documentation/devicetree/todo.txt
create mode 100644 drivers/of/dynamic.c
of_platform_destroy does not work properly, since the tree
population test was iterating on all devices having as its parent
the given platform device.
The check was intended to check whether any other platform or amba
devices created by of_platform_populate were still populated, but
instead checked for every kind of device. This is wrong, since platform
devices typically create a subsystem regular device and set themselves
as parents.
Instead, go ahead and call the unregister functions for any devices
created with of_platform_populate. The driver core will take care of
unbinding drivers, and drivers are responsible for getting rid of any
child devices that weren't created by of_platform_populate.
Signed-off-by: Grant Likely <[email protected]>
Signed-off-by: Pantelis Antoniou <[email protected]>
---
drivers/of/platform.c | 32 +++++++++-----------------------
include/linux/of.h | 1 +
include/linux/of_platform.h | 7 ++-----
3 files changed, 12 insertions(+), 28 deletions(-)
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 500436f9be7f..0197725e033a 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -422,6 +422,7 @@ static int of_platform_bus_create(struct device_node *bus,
break;
}
}
+ of_node_set_flag(bus, OF_POPULATED_BUS);
return rc;
}
@@ -508,19 +509,13 @@ EXPORT_SYMBOL_GPL(of_platform_populate);
static int of_platform_device_destroy(struct device *dev, void *data)
{
- bool *children_left = data;
-
/* Do not touch devices not populated from the device tree */
- if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED)) {
- *children_left = true;
+ if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
return 0;
- }
- /* Recurse, but don't touch this device if it has any children left */
- if (of_platform_depopulate(dev) != 0) {
- *children_left = true;
- return 0;
- }
+ /* Recurse for any nodes that were treated as busses */
+ if (of_node_check_flag(dev->of_node, OF_POPULATED_BUS))
+ device_for_each_child(dev, NULL, of_platform_device_destroy);
if (dev->bus == &platform_bus_type)
platform_device_unregister(to_platform_device(dev));
@@ -528,19 +523,15 @@ static int of_platform_device_destroy(struct device *dev, void *data)
else if (dev->bus == &amba_bustype)
amba_device_unregister(to_amba_device(dev));
#endif
- else {
- *children_left = true;
- return 0;
- }
of_node_clear_flag(dev->of_node, OF_POPULATED);
-
+ of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
return 0;
}
/**
* of_platform_depopulate() - Remove devices populated from device tree
- * @parent: device which childred will be removed
+ * @parent: device which children will be removed
*
* Complementary to of_platform_populate(), this function removes children
* of the given device (and, recurrently, their children) that have been
@@ -550,14 +541,9 @@ static int of_platform_device_destroy(struct device *dev, void *data)
* Returns 0 when all children devices have been removed or
* -EBUSY when some children remained.
*/
-int of_platform_depopulate(struct device *parent)
+void of_platform_depopulate(struct device *parent)
{
- bool children_left = false;
-
- device_for_each_child(parent, &children_left,
- of_platform_device_destroy);
-
- return children_left ? -EBUSY : 0;
+ device_for_each_child(parent, NULL, of_platform_device_destroy);
}
EXPORT_SYMBOL_GPL(of_platform_depopulate);
diff --git a/include/linux/of.h b/include/linux/of.h
index 196b34c1ef4e..abf829a1f150 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -204,6 +204,7 @@ static inline unsigned long of_read_ulong(const __be32 *cell, int size)
#define OF_DYNAMIC 1 /* node and properties were allocated via kmalloc */
#define OF_DETACHED 2 /* node has been detached from the device tree */
#define OF_POPULATED 3 /* device already created for the node */
+#define OF_POPULATED_BUS 4 /* of_platform_populate recursed to children of this node */
#define OF_IS_DYNAMIC(x) test_bit(OF_DYNAMIC, &x->_flags)
#define OF_MARK_DYNAMIC(x) set_bit(OF_DYNAMIC, &x->_flags)
diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index d96e1badbee0..c2b0627a2317 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -72,7 +72,7 @@ extern int of_platform_populate(struct device_node *root,
const struct of_device_id *matches,
const struct of_dev_auxdata *lookup,
struct device *parent);
-extern int of_platform_depopulate(struct device *parent);
+extern void of_platform_depopulate(struct device *parent);
#else
static inline int of_platform_populate(struct device_node *root,
const struct of_device_id *matches,
@@ -81,10 +81,7 @@ static inline int of_platform_populate(struct device_node *root,
{
return -ENODEV;
}
-static inline int of_platform_depopulate(struct device *parent)
-{
- return -ENODEV;
-}
+static inline void of_platform_depopulate(struct device *parent) { }
#endif
#endif /* _LINUX_OF_PLATFORM_H */
--
1.9.1
Currently, devicetree reconfig notifiers get emitted before the change
is applied to the tree, but that behaviour is problematic if the
receiver wants the determine the new state of the tree. The current
users don't care, but the changeset code to follow will be making
multiple changes at once. Reorder notifiers to get emitted after the
change has been applied to the tree so that callbacks see the new tree
state.
At the same time, fixup the existing callbacks to expect the new order.
There are a few callbacks that compare the old and new values of a
changed property. Put both property pointers into the of_prop_reconfig
structure.
The current notifiers also allow the notifier callback to fail and
cancel the change to the tree, but that feature isn't actually used.
It really isn't valid to ignore a tree modification provided by firmware
anyway, so remove the ability to cancel a change to the tree.
Signed-off-by: Grant Likely <[email protected]>
Cc: Nathan Fontenot <[email protected]>
---
arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +-
drivers/crypto/nx/nx-842.c | 30 +++++++------------------
drivers/of/base.c | 21 ++++++++---------
drivers/of/dynamic.c | 18 +++++++--------
drivers/of/of_private.h | 4 ++--
include/linux/of.h | 1 +
6 files changed, 29 insertions(+), 47 deletions(-)
diff --git a/arch/powerpc/platforms/pseries/hotplug-memory.c b/arch/powerpc/platforms/pseries/hotplug-memory.c
index 7995135170a3..ac01e188faef 100644
--- a/arch/powerpc/platforms/pseries/hotplug-memory.c
+++ b/arch/powerpc/platforms/pseries/hotplug-memory.c
@@ -194,7 +194,7 @@ static int pseries_update_drconf_memory(struct of_prop_reconfig *pr)
if (!memblock_size)
return -EINVAL;
- p = (u32 *)of_get_property(pr->dn, "ibm,dynamic-memory", NULL);
+ p = (u32 *) pr->old_prop->value;
if (!p)
return -EINVAL;
diff --git a/drivers/crypto/nx/nx-842.c b/drivers/crypto/nx/nx-842.c
index 502edf0a2933..c897c3a5ee17 100644
--- a/drivers/crypto/nx/nx-842.c
+++ b/drivers/crypto/nx/nx-842.c
@@ -936,28 +936,14 @@ static int nx842_OF_upd(struct property *new_prop)
goto error_out;
}
- /* Set ptr to new property if provided */
- if (new_prop) {
- /* Single property */
- if (!strncmp(new_prop->name, "status", new_prop->length)) {
- status = new_prop;
-
- } else if (!strncmp(new_prop->name, "ibm,max-sg-len",
- new_prop->length)) {
- maxsglen = new_prop;
-
- } else if (!strncmp(new_prop->name, "ibm,max-sync-cop",
- new_prop->length)) {
- maxsyncop = new_prop;
-
- } else {
- /*
- * Skip the update, the property being updated
- * has no impact.
- */
- goto out;
- }
- }
+ /*
+ * If this is a property update, there are only certain properties that
+ * we care about. Bail if it isn't in the below list
+ */
+ if (new_prop && (strncmp(new_prop->name, "status", new_prop->length) ||
+ strncmp(new_prop->name, "ibm,max-sg-len", new_prop->length) ||
+ strncmp(new_prop->name, "ibm,max-sync-cop", new_prop->length)))
+ goto out;
/* Perform property updates */
ret = nx842_OF_upd_status(new_devdata, status);
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ededf8e33145..a7ad1013edfa 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1674,10 +1674,6 @@ int of_add_property(struct device_node *np, struct property *prop)
unsigned long flags;
int rc;
- rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
- if (rc)
- return rc;
-
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
@@ -1689,6 +1685,9 @@ int of_add_property(struct device_node *np, struct property *prop)
mutex_unlock(&of_mutex);
+ if (!rc)
+ of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
+
return rc;
}
@@ -1731,10 +1730,6 @@ int of_remove_property(struct device_node *np, struct property *prop)
unsigned long flags;
int rc;
- rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
- if (rc)
- return rc;
-
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
@@ -1746,6 +1741,9 @@ int of_remove_property(struct device_node *np, struct property *prop)
mutex_unlock(&of_mutex);
+ if (!rc)
+ of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
+
return rc;
}
@@ -1805,10 +1803,6 @@ int of_update_property(struct device_node *np, struct property *newprop)
if (!newprop->name)
return -EINVAL;
- rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
- if (rc)
- return rc;
-
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
@@ -1820,6 +1814,9 @@ int of_update_property(struct device_node *np, struct property *newprop)
mutex_unlock(&of_mutex);
+ if (!rc)
+ of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
+
return rc;
}
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 7c020b9a3317..7bd5501736a6 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -83,7 +83,7 @@ int of_reconfig_notify(unsigned long action, void *p)
}
int of_property_notify(int action, struct device_node *np,
- struct property *prop)
+ struct property *prop, struct property *oldprop)
{
struct of_prop_reconfig pr;
@@ -93,6 +93,7 @@ int of_property_notify(int action, struct device_node *np,
pr.dn = np;
pr.prop = prop;
+ pr.old_prop = oldprop;
return of_reconfig_notify(action, &pr);
}
@@ -125,11 +126,6 @@ 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;
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
@@ -138,6 +134,9 @@ int of_attach_node(struct device_node *np)
__of_attach_node_sysfs(np);
mutex_unlock(&of_mutex);
+
+ of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+
return 0;
}
@@ -188,10 +187,6 @@ int of_detach_node(struct device_node *np)
unsigned long flags;
int rc = 0;
- rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
- if (rc)
- return rc;
-
mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_detach_node(np);
@@ -199,6 +194,9 @@ int of_detach_node(struct device_node *np)
__of_detach_node_sysfs(np);
mutex_unlock(&of_mutex);
+
+ of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+
return rc;
}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 8129c0e58d70..f69ccb1fa308 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -43,11 +43,11 @@ static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
#if defined(CONFIG_OF_DYNAMIC)
extern int of_property_notify(int action, struct device_node *np,
- struct property *prop);
+ struct property *prop, struct property *old_prop);
extern void of_node_release(struct kobject *kobj);
#else /* CONFIG_OF_DYNAMIC */
static inline int of_property_notify(int action, struct device_node *np,
- struct property *prop)
+ struct property *prop, struct property *old_prop)
{
return 0;
}
diff --git a/include/linux/of.h b/include/linux/of.h
index 705fa12fca7f..400f18cb4fff 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -321,6 +321,7 @@ extern int of_update_property(struct device_node *np, struct property *newprop);
struct of_prop_reconfig {
struct device_node *dn;
struct property *prop;
+ struct property *old_prop;
};
extern int of_reconfig_notifier_register(struct notifier_block *);
--
1.9.1
From: Pantelis Antoniou <[email protected]>
Introducing DT transactional support.
A DT transaction is a method which allows one to apply changes
in the live tree, in such a way that either the full set of changes
take effect, or the state of the tree can be rolled-back to the
state it was before it was attempted. An applied transaction
can be rolled-back at any time.
Documentation is in
Documentation/devicetree/changesets.txt
Signed-off-by: Pantelis Antoniou <[email protected]>
[glikely: Removed device notifiers and reworked to be more consistent]
Signed-off-by: Grant Likely <[email protected]>
---
Documentation/devicetree/changesets.txt | 40 ++++
drivers/of/dynamic.c | 344 ++++++++++++++++++++++++++++++++
drivers/of/of_private.h | 9 +
drivers/of/selftest.c | 51 +++++
drivers/of/testcase-data/testcases.dtsi | 10 +
include/linux/of.h | 76 +++++++
6 files changed, 530 insertions(+)
create mode 100644 Documentation/devicetree/changesets.txt
diff --git a/Documentation/devicetree/changesets.txt b/Documentation/devicetree/changesets.txt
new file mode 100644
index 000000000000..935ba5acc34e
--- /dev/null
+++ b/Documentation/devicetree/changesets.txt
@@ -0,0 +1,40 @@
+A DT changeset is a method which allows one to apply changes
+in the live tree in such a way that either the full set of changes
+will be applied, or none of them will be. If an error occurs partway
+through applying the changeset, then the tree will be rolled back to the
+previous state. A changeset can also be removed after it has been
+applied.
+
+When a changeset is applied, all of the changes get applied to the tree
+at once before emitting OF_RECONFIG notifiers. This is so that the
+receiver sees a complete and consistent state of the tree when it
+receives the notifier.
+
+The sequence of a changeset is as follows.
+
+1. of_changeset_init() - initializes a changeset
+
+2. A number of DT tree change calls, of_changeset_attach_node(),
+of_changeset_detach_node(), of_changeset_add_property(),
+of_changeset_remove_property, of_changeset_update_property() to prepare
+a set of changes. No changes to the active tree are made at this point.
+All the change operations are recorded in the of_changeset 'entries'
+list.
+
+3. mutex_lock(of_mutex) - starts a changeset; The global of_mutex
+ensures there can only be one editor at a time.
+
+4. of_changeset_apply() - Apply the changes to the tree. Either the
+entire changeset will get applied, or if there is an error the tree will
+be restored to the previous state
+
+5. mutex_unlock(of_mutex) - All operations complete, release the mutex
+
+If a successfully applied changeset needs to be removed, it can be done
+with the following sequence.
+
+1. mutex_lock(of_mutex)
+
+2. of_changeset_revert()
+
+3. mutex_unlock(of_mutex)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 7bd5501736a6..c1002b7be786 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -314,3 +314,347 @@ struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags)
kfree(node);
return NULL;
}
+
+static void __of_changeset_entry_destroy(struct of_changeset_entry *ce)
+{
+ of_node_put(ce->np);
+ list_del(&ce->node);
+ kfree(ce);
+}
+
+#ifdef DEBUG
+static void __of_changeset_entry_dump(struct of_changeset_entry *ce)
+{
+ switch (ce->action) {
+ case OF_RECONFIG_ADD_PROPERTY:
+ pr_debug("%p: %s %s/%s\n",
+ ce, "ADD_PROPERTY ", ce->np->full_name,
+ ce->prop->name);
+ break;
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ pr_debug("%p: %s %s/%s\n",
+ ce, "REMOVE_PROPERTY", ce->np->full_name,
+ ce->prop->name);
+ break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ pr_debug("%p: %s %s/%s\n",
+ ce, "UPDATE_PROPERTY", ce->np->full_name,
+ ce->prop->name);
+ break;
+ case OF_RECONFIG_ATTACH_NODE:
+ pr_debug("%p: %s %s\n",
+ ce, "ATTACH_NODE ", ce->np->full_name);
+ break;
+ case OF_RECONFIG_DETACH_NODE:
+ pr_debug("%p: %s %s\n",
+ ce, "DETACH_NODE ", ce->np->full_name);
+ break;
+ }
+}
+#else
+static inline void __of_changeset_entry_dump(struct of_changeset_entry *ce)
+{
+ /* empty */
+}
+#endif
+
+static void __of_changeset_entry_invert(struct of_changeset_entry *ce,
+ struct of_changeset_entry *rce)
+{
+ memcpy(rce, ce, sizeof(*rce));
+
+ switch (ce->action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ rce->action = OF_RECONFIG_DETACH_NODE;
+ break;
+ case OF_RECONFIG_DETACH_NODE:
+ rce->action = OF_RECONFIG_ATTACH_NODE;
+ break;
+ case OF_RECONFIG_ADD_PROPERTY:
+ rce->action = OF_RECONFIG_REMOVE_PROPERTY;
+ break;
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ rce->action = OF_RECONFIG_ADD_PROPERTY;
+ break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ rce->old_prop = ce->prop;
+ rce->prop = ce->old_prop;
+ break;
+ }
+}
+
+static void __of_changeset_entry_notify(struct of_changeset_entry *ce, bool revert)
+{
+ struct of_changeset_entry ce_inverted;
+ int ret;
+
+ if (revert) {
+ __of_changeset_entry_invert(ce, &ce_inverted);
+ ce = &ce_inverted;
+ }
+
+ switch (ce->action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ case OF_RECONFIG_DETACH_NODE:
+ ret = of_reconfig_notify(ce->action, ce->np);
+ break;
+ case OF_RECONFIG_ADD_PROPERTY:
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ ret = of_property_notify(ce->action, ce->np, ce->prop, ce->old_prop);
+ break;
+ default:
+ pr_err("%s: invalid devicetree changeset action: %i\n", __func__,
+ (int)ce->action);
+ return;
+ }
+
+ if (ret)
+ pr_err("%s: notifier error @%s\n", __func__, ce->np->full_name);
+}
+
+static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
+{
+ struct property *old_prop, **propp;
+ unsigned long flags;
+ int ret = 0;
+
+ __of_changeset_entry_dump(ce);
+
+ raw_spin_lock_irqsave(&devtree_lock, flags);
+ switch (ce->action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ __of_attach_node(ce->np);
+ break;
+ case OF_RECONFIG_DETACH_NODE:
+ __of_detach_node(ce->np);
+ break;
+ case OF_RECONFIG_ADD_PROPERTY:
+ /* If the property is in deadprops then it must be removed */
+ for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
+ if (*propp == ce->prop) {
+ *propp = ce->prop->next;
+ ce->prop->next = NULL;
+ break;
+ }
+ }
+
+ ret = __of_add_property(ce->np, ce->prop);
+ if (ret) {
+ pr_err("%s: add_property failed @%s/%s\n",
+ __func__, ce->np->full_name,
+ ce->prop->name);
+ break;
+ }
+ break;
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ ret = __of_remove_property(ce->np, ce->prop);
+ if (ret) {
+ pr_err("%s: remove_property failed @%s/%s\n",
+ __func__, ce->np->full_name,
+ ce->prop->name);
+ break;
+ }
+ break;
+
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ /* If the property is in deadprops then it must be removed */
+ for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
+ if (*propp == ce->prop) {
+ *propp = ce->prop->next;
+ ce->prop->next = NULL;
+ break;
+ }
+ }
+
+ ret = __of_update_property(ce->np, ce->prop, &old_prop);
+ if (ret) {
+ pr_err("%s: update_property failed @%s/%s\n",
+ __func__, ce->np->full_name,
+ ce->prop->name);
+ break;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ }
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+ if (ret)
+ return ret;
+
+ switch (ce->action) {
+ case OF_RECONFIG_ATTACH_NODE:
+ __of_attach_node_sysfs(ce->np);
+ break;
+ case OF_RECONFIG_DETACH_NODE:
+ __of_detach_node_sysfs(ce->np);
+ break;
+ case OF_RECONFIG_ADD_PROPERTY:
+ /* ignore duplicate names */
+ __of_add_property_sysfs(ce->np, ce->prop);
+ break;
+ case OF_RECONFIG_REMOVE_PROPERTY:
+ __of_remove_property_sysfs(ce->np, ce->prop);
+ break;
+ case OF_RECONFIG_UPDATE_PROPERTY:
+ __of_update_property_sysfs(ce->np, ce->prop, ce->old_prop);
+ break;
+ }
+
+ return 0;
+}
+
+static inline int __of_changeset_entry_revert(struct of_changeset_entry *ce)
+{
+ struct of_changeset_entry ce_inverted;
+
+ __of_changeset_entry_invert(ce, &ce_inverted);
+ return __of_changeset_entry_apply(&ce_inverted);
+}
+
+/**
+ * of_changeset_init - Initialize a changeset for use
+ *
+ * @ocs: changeset pointer
+ *
+ * Initialize a changeset structure
+ */
+void of_changeset_init(struct of_changeset *ocs)
+{
+ memset(ocs, 0, sizeof(*ocs));
+ INIT_LIST_HEAD(&ocs->entries);
+}
+
+/**
+ * of_changeset_destroy - Destroy a changeset
+ *
+ * @ocs: changeset pointer
+ *
+ * Destroys a changeset. Note that if a changeset is applied,
+ * its changes to the tree cannot be reverted.
+ */
+void of_changeset_destroy(struct of_changeset *ocs)
+{
+ struct of_changeset_entry *ce, *cen;
+
+ list_for_each_entry_safe_reverse(ce, cen, &ocs->entries, node)
+ __of_changeset_entry_destroy(ce);
+}
+
+/**
+ * of_changeset_apply - Applies a changeset
+ *
+ * @ocs: changeset pointer
+ *
+ * Applies a changeset to the live tree.
+ * Any side-effects of live tree state changes are applied here on
+ * sucess, like creation/destruction of devices and side-effects
+ * like creation of sysfs properties and directories.
+ * Returns 0 on success, a negative error value in case of an error.
+ * On error the partially applied effects are reverted.
+ */
+int of_changeset_apply(struct of_changeset *ocs)
+{
+ struct of_changeset_entry *ce;
+ int ret;
+
+ /* perform the rest of the work */
+ pr_debug("of_changeset: applying...\n");
+ list_for_each_entry(ce, &ocs->entries, node) {
+ ret = __of_changeset_entry_apply(ce);
+ if (ret) {
+ pr_err("%s: Error applying changeset (%d)\n", __func__, ret);
+ list_for_each_entry_continue_reverse(ce, &ocs->entries, node)
+ __of_changeset_entry_revert(ce);
+ return ret;
+ }
+ }
+ pr_debug("of_changeset: applied, emitting notifiers.\n");
+
+ /* drop the global lock while emitting notifiers */
+ mutex_unlock(&of_mutex);
+ list_for_each_entry(ce, &ocs->entries, node)
+ __of_changeset_entry_notify(ce, 0);
+ mutex_lock(&of_mutex);
+ pr_debug("of_changeset: notifiers sent.\n");
+
+ return 0;
+}
+
+/**
+ * of_changeset_revert - Reverts an applied changeset
+ *
+ * @ocs: changeset pointer
+ *
+ * Reverts a changeset returning the state of the tree to what it
+ * was before the application.
+ * Any side-effects like creation/destruction of devices and
+ * removal of sysfs properties and directories are applied.
+ * Returns 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_revert(struct of_changeset *ocs)
+{
+ struct of_changeset_entry *ce;
+ int ret;
+
+ pr_debug("of_changeset: reverting...\n");
+ list_for_each_entry_reverse(ce, &ocs->entries, node) {
+ ret = __of_changeset_entry_revert(ce);
+ if (ret) {
+ pr_err("%s: Error reverting changeset (%d)\n", __func__, ret);
+ list_for_each_entry_continue(ce, &ocs->entries, node)
+ __of_changeset_entry_apply(ce);
+ return ret;
+ }
+ }
+ pr_debug("of_changeset: reverted, emitting notifiers.\n");
+
+ /* drop the global lock while emitting notifiers */
+ mutex_unlock(&of_mutex);
+ list_for_each_entry_reverse(ce, &ocs->entries, node)
+ __of_changeset_entry_notify(ce, 1);
+ mutex_lock(&of_mutex);
+ pr_debug("of_changeset: notifiers sent.\n");
+
+ return 0;
+}
+
+/**
+ * of_changeset_action - Perform a changeset action
+ *
+ * @ocs: changeset pointer
+ * @action: action to perform
+ * @np: Pointer to device node
+ * @prop: Pointer to property
+ *
+ * On action being one of:
+ * + OF_RECONFIG_ATTACH_NODE
+ * + OF_RECONFIG_DETACH_NODE,
+ * + OF_RECONFIG_ADD_PROPERTY
+ * + OF_RECONFIG_REMOVE_PROPERTY,
+ * + OF_RECONFIG_UPDATE_PROPERTY
+ * Returns 0 on success, a negative error value in case of an error.
+ */
+int of_changeset_action(struct of_changeset *ocs, unsigned long action,
+ struct device_node *np, struct property *prop)
+{
+ struct of_changeset_entry *ce;
+
+ ce = kzalloc(sizeof(*ce), GFP_KERNEL);
+ if (!ce) {
+ pr_err("%s: Failed to allocate\n", __func__);
+ return -ENOMEM;
+ }
+ /* get a reference to the node */
+ ce->action = action;
+ ce->np = of_node_get(np);
+ ce->prop = prop;
+
+ if (action == OF_RECONFIG_UPDATE_PROPERTY && prop)
+ ce->old_prop = of_find_property(np, prop->name, NULL);
+
+ /* add it to the list */
+ list_add_tail(&ce->node, &ocs->entries);
+ return 0;
+}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index f69ccb1fa308..858e0a5d9a11 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -81,4 +81,13 @@ extern int __of_attach_node_sysfs(struct device_node *np);
extern void __of_detach_node(struct device_node *np);
extern void __of_detach_node_sysfs(struct device_node *np);
+/* iterators for transactions, used for overlays */
+/* forward iterator */
+#define for_each_transaction_entry(_oft, _te) \
+ list_for_each_entry(_te, &(_oft)->te_list, node)
+
+/* reverse iterator */
+#define for_each_transaction_entry_reverse(_oft, _te) \
+ list_for_each_entry_reverse(_te, &(_oft)->te_list, node)
+
#endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index ee2166f0f36a..04e39a183e53 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -293,6 +293,56 @@ static void __init of_selftest_property_copy(void)
#endif
}
+static void __init of_selftest_changeset(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+ struct property *ppadd, padd = { .name = "prop-add", .length = 0, .value = "" };
+ struct property *ppupdate, pupdate = { .name = "prop-update", .length = 5, .value = "abcd" };
+ struct property *ppremove;
+ struct device_node *n1, *n2, *n21, *nremove, *parent;
+ struct of_changeset chgset;
+
+ of_changeset_init(&chgset);
+ n1 = __of_node_alloc("/testcase-data/changeset/n1", GFP_KERNEL);
+ selftest(n1, "testcase setup failure\n");
+ n2 = __of_node_alloc("/testcase-data/changeset/n2", GFP_KERNEL);
+ selftest(n2, "testcase setup failure\n");
+ n21 = __of_node_alloc("/testcase-data/changeset/n2/n21", GFP_KERNEL);
+ selftest(n21, "testcase setup failure %p\n", n21);
+ nremove = of_find_node_by_path("/testcase-data/changeset/node-remove");
+ selftest(nremove, "testcase setup failure\n");
+ ppadd = __of_prop_dup(&padd, GFP_KERNEL);
+ selftest(ppadd, "testcase setup failure\n");
+ ppupdate = __of_prop_dup(&pupdate, GFP_KERNEL);
+ selftest(ppupdate, "testcase setup failure\n");
+ parent = nremove->parent;
+ n1->parent = parent;
+ n2->parent = parent;
+ n21->parent = n2;
+ n2->child = n21;
+ ppremove = of_find_property(parent, "prop-remove", NULL);
+ selftest(ppremove, "failed to find removal prop");
+
+ of_changeset_init(&chgset);
+ selftest(!of_changeset_attach_node(&chgset, n1), "fail attach n1\n");
+ selftest(!of_changeset_attach_node(&chgset, n2), "fail attach n2\n");
+ selftest(!of_changeset_detach_node(&chgset, nremove), "fail remove node\n");
+ selftest(!of_changeset_attach_node(&chgset, n21), "fail attach n21\n");
+ selftest(!of_changeset_add_property(&chgset, parent, ppadd), "fail add prop\n");
+ selftest(!of_changeset_update_property(&chgset, parent, ppupdate), "fail update prop\n");
+ selftest(!of_changeset_remove_property(&chgset, parent, ppremove), "fail remove prop\n");
+ mutex_lock(&of_mutex);
+ selftest(!of_changeset_apply(&chgset), "apply failed\n");
+ mutex_unlock(&of_mutex);
+
+ mutex_lock(&of_mutex);
+ selftest(!of_changeset_revert(&chgset), "revert failed\n");
+ mutex_unlock(&of_mutex);
+
+ of_changeset_destroy(&chgset);
+#endif
+}
+
static void __init of_selftest_parse_interrupts(void)
{
struct device_node *np;
@@ -561,6 +611,7 @@ static int __init of_selftest(void)
of_selftest_parse_phandle_with_args();
of_selftest_property_match_string();
of_selftest_property_copy();
+ of_selftest_changeset();
of_selftest_parse_interrupts();
of_selftest_parse_interrupts_extended();
of_selftest_match_node();
diff --git a/drivers/of/testcase-data/testcases.dtsi b/drivers/of/testcase-data/testcases.dtsi
index 6d8d980ac858..669bb07df142 100644
--- a/drivers/of/testcase-data/testcases.dtsi
+++ b/drivers/of/testcase-data/testcases.dtsi
@@ -1,3 +1,13 @@
+/ {
+ testcase-data {
+ changeset {
+ prop-update = "hello";
+ prop-remove = "world";
+ node-remove {
+ };
+ };
+ };
+};
#include "tests-phandle.dtsi"
#include "tests-interrupts.dtsi"
#include "tests-match.dtsi"
diff --git a/include/linux/of.h b/include/linux/of.h
index 400f18cb4fff..bc91fbb13ce8 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -786,4 +786,80 @@ typedef void (*of_init_fn_1)(struct device_node *);
#define OF_DECLARE_2(table, name, compat, fn) \
_OF_DECLARE(table, name, compat, fn, of_init_fn_2)
+/**
+ * struct of_changeset_entry - Holds a changeset entry
+ *
+ * @node: list_head for the log list
+ * @action: notifier action
+ * @np: pointer to the device node affected
+ * @prop: pointer to the property affected
+ * @old_prop: hold a pointer to the original property
+ *
+ * Every modification of the device tree during a changeset
+ * is held in a list of of_changeset_entry structures.
+ * That way we can recover from a partial application, or we can
+ * revert the changeset
+ */
+struct of_changeset_entry {
+ struct list_head node;
+ unsigned long action;
+ struct device_node *np;
+ struct property *prop;
+ struct property *old_prop;
+};
+
+/**
+ * struct of_changeset - changeset tracker structure
+ *
+ * @entries: list_head for the changeset entries
+ *
+ * changesets are a convenient way to apply bulk changes to the
+ * live tree. In case of an error, changes are rolled-back.
+ * changesets live on after initial application, and if not
+ * destroyed after use, they can be reverted in one single call.
+ */
+struct of_changeset {
+ struct list_head entries;
+};
+
+#ifdef CONFIG_OF_DYNAMIC
+extern void of_changeset_init(struct of_changeset *ocs);
+extern void of_changeset_destroy(struct of_changeset *ocs);
+extern int of_changeset_apply(struct of_changeset *ocs);
+extern int of_changeset_revert(struct of_changeset *ocs);
+extern int of_changeset_action(struct of_changeset *ocs,
+ unsigned long action, struct device_node *np,
+ struct property *prop);
+
+static inline int of_changeset_attach_node(struct of_changeset *ocs,
+ struct device_node *np)
+{
+ return of_changeset_action(ocs, OF_RECONFIG_ATTACH_NODE, np, NULL);
+}
+
+static inline int of_changeset_detach_node(struct of_changeset *ocs,
+ struct device_node *np)
+{
+ return of_changeset_action(ocs, OF_RECONFIG_DETACH_NODE, np, NULL);
+}
+
+static inline int of_changeset_add_property(struct of_changeset *ocs,
+ struct device_node *np, struct property *prop)
+{
+ return of_changeset_action(ocs, OF_RECONFIG_ADD_PROPERTY, np, prop);
+}
+
+static inline int of_changeset_remove_property(struct of_changeset *ocs,
+ struct device_node *np, struct property *prop)
+{
+ return of_changeset_action(ocs, OF_RECONFIG_REMOVE_PROPERTY, np, prop);
+}
+
+static inline int of_changeset_update_property(struct of_changeset *ocs,
+ struct device_node *np, struct property *prop)
+{
+ return of_changeset_action(ocs, OF_RECONFIG_UPDATE_PROPERTY, np, prop);
+}
+#endif
+
#endif /* _LINUX_OF_H */
--
1.9.1
From: Pantelis Antoniou <[email protected]>
The DT overlay code will need to manipulate nodes and properties while
already holding the devicetree lock, or on nodes that are not yet
attached to the tree, but the current helper functions don't allow that.
Extract the core behaviour from the accessors and create the following
unlocked variants.
The unlocked variants require either the lock to already be held or for
the nodes to be detached from the tree. Changes to live nodes will not
get updated in sysfs, so the caller must arrange for housekeeping to
take place after dropping the lock.
The new functions are: __of_add_property(), __of_remove_property(),
__of_update_property(), __of_attach_node() and __of_detach_node().
Signed-off-by: Pantelis Antoniou <[email protected]>
[Remove unnecessary diff hunks and rewrite commit text]
Signed-off-by: Grant Likely <[email protected]>
---
drivers/of/base.c | 91 +++++++++++++++++++++++++++++--------------------
drivers/of/dynamic.c | 63 ++++++++++++++++++----------------
drivers/of/of_private.h | 8 +++++
3 files changed, 96 insertions(+), 66 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 0d8955605738..b403f9d98461 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -1659,7 +1659,7 @@ EXPORT_SYMBOL(of_count_phandle_with_args);
/**
* __of_add_property - Add a property to a node without lock operations
*/
-static int __of_add_property(struct device_node *np, struct property *prop)
+int __of_add_property(struct device_node *np, struct property *prop)
{
struct property **next;
@@ -1701,6 +1701,25 @@ int of_add_property(struct device_node *np, struct property *prop)
return rc;
}
+int __of_remove_property(struct device_node *np, struct property *prop)
+{
+ struct property **next;
+
+ for (next = &np->properties; *next; next = &(*next)->next) {
+ if (*next == prop)
+ break;
+ }
+ if (*next == NULL)
+ return -ENODEV;
+
+ /* found the node */
+ *next = prop->next;
+ prop->next = np->deadprops;
+ np->deadprops = prop;
+
+ return 0;
+}
+
/**
* of_remove_property - Remove a property from a node.
*
@@ -1711,9 +1730,7 @@ int of_add_property(struct device_node *np, struct property *prop)
*/
int of_remove_property(struct device_node *np, struct property *prop)
{
- struct property **next;
unsigned long flags;
- int found = 0;
int rc;
rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
@@ -1721,22 +1738,11 @@ int of_remove_property(struct device_node *np, struct property *prop)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
- next = &np->properties;
- while (*next) {
- if (*next == prop) {
- /* found the node */
- *next = prop->next;
- prop->next = np->deadprops;
- np->deadprops = prop;
- found = 1;
- break;
- }
- next = &(*next)->next;
- }
+ rc = __of_remove_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- if (!found)
- return -ENODEV;
+ if (rc)
+ return rc;
/* at early boot, bail hear and defer setup to of_init() */
if (!of_kset)
@@ -1747,6 +1753,32 @@ int of_remove_property(struct device_node *np, struct property *prop)
return 0;
}
+int __of_update_property(struct device_node *np, struct property *newprop,
+ struct property **oldpropp)
+{
+ struct property **next, *oldprop;
+
+ for (next = &np->properties; *next; next = &(*next)->next) {
+ if (of_prop_cmp((*next)->name, newprop->name) == 0)
+ break;
+ }
+ *oldpropp = oldprop = *next;
+
+ if (oldprop) {
+ /* replace the node */
+ newprop->next = oldprop->next;
+ *next = newprop;
+ oldprop->next = np->deadprops;
+ np->deadprops = oldprop;
+ } else {
+ /* new node */
+ newprop->next = NULL;
+ *next = newprop;
+ }
+
+ return 0;
+}
+
/*
* of_update_property - Update a property in a node, if the property does
* not exist, add it.
@@ -1758,34 +1790,19 @@ int of_remove_property(struct device_node *np, struct property *prop)
*/
int of_update_property(struct device_node *np, struct property *newprop)
{
- struct property **next, *oldprop;
+ struct property *oldprop;
unsigned long flags;
int rc;
+ if (!newprop->name)
+ return -EINVAL;
+
rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
if (rc)
return rc;
- if (!newprop->name)
- return -EINVAL;
-
raw_spin_lock_irqsave(&devtree_lock, flags);
- next = &np->properties;
- oldprop = __of_find_property(np, newprop->name, NULL);
- if (!oldprop) {
- /* add the new node */
- rc = __of_add_property(np, newprop);
- } else while (*next) {
- /* replace the node */
- if (*next == oldprop) {
- newprop->next = oldprop->next;
- *next = newprop;
- oldprop->next = np->deadprops;
- np->deadprops = oldprop;
- break;
- }
- next = &(*next)->next;
- }
+ rc = __of_update_property(np, newprop, &oldprop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
if (rc)
return rc;
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index e0c4c6e25980..75fcc66fcefd 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -94,6 +94,15 @@ int of_property_notify(int action, struct device_node *np,
return of_reconfig_notify(action, &pr);
}
+void __of_attach_node(struct device_node *np)
+{
+ np->sibling = np->parent->child;
+ np->allnext = np->parent->allnext;
+ np->parent->allnext = np;
+ np->parent->child = np;
+ of_node_clear_flag(np, OF_DETACHED);
+}
+
/**
* of_attach_node() - Plug a device node into the tree and global list.
*/
@@ -107,46 +116,23 @@ int of_attach_node(struct device_node *np)
return rc;
raw_spin_lock_irqsave(&devtree_lock, flags);
- np->sibling = np->parent->child;
- np->allnext = np->parent->allnext;
- np->parent->allnext = np;
- np->parent->child = np;
- of_node_clear_flag(np, OF_DETACHED);
+ __of_attach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_node_add(np);
return 0;
}
-/**
- * of_detach_node() - "Unplug" a node from the device tree.
- *
- * The caller must hold a reference to the node. The memory associated with
- * the node is not freed until its refcount goes to zero.
- */
-int of_detach_node(struct device_node *np)
+void __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;
- raw_spin_lock_irqsave(&devtree_lock, flags);
-
- if (of_node_check_flag(np, OF_DETACHED)) {
- /* someone already detached it */
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
- return rc;
- }
+ if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
+ return;
parent = np->parent;
- if (!parent) {
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
- return rc;
- }
+ if (WARN_ON(!parent))
+ return;
if (of_allnodes == np)
of_allnodes = np->allnext;
@@ -171,6 +157,25 @@ int of_detach_node(struct device_node *np)
}
of_node_set_flag(np, OF_DETACHED);
+}
+
+/**
+ * of_detach_node() - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node. The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+int of_detach_node(struct device_node *np)
+{
+ unsigned long flags;
+ int rc = 0;
+
+ rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
+ if (rc)
+ return rc;
+
+ raw_spin_lock_irqsave(&devtree_lock, flags);
+ __of_detach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
of_node_remove(np);
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 1799ed2b3808..0f6089722af9 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -61,4 +61,12 @@ static inline int of_property_notify(int action, struct device_node *np,
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
+extern int __of_add_property(struct device_node *np, struct property *prop);
+extern int __of_remove_property(struct device_node *np, struct property *prop);
+extern int __of_update_property(struct device_node *np,
+ struct property *newprop, struct property **oldprop);
+
+extern void __of_attach_node(struct device_node *np);
+extern void __of_detach_node(struct device_node *np);
+
#endif /* _LINUX_OF_PRIVATE_H */
--
1.9.1
PowerPC does an odd thing with dynamic nodes. It uses a notifier to
catch new node additions and set some of the values like name and type.
This makes no sense since that same code can be put directly into
of_attach_node(). Besides, all dynamic node users need this, not just
powerpc. Fix this problem by moving the logic out of arch/powerpc and
into drivers/of/dynamic.c.
It is also important to remove this notifier because we want to move the
firing of notifiers from before the tree is modified to after so that
the receiver gets a consistent view of the tree, but that is
incompatible with notifiers that modify the node.
Signed-off-by: Grant Likely <[email protected]>
Cc: Nathan Fontenot <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
---
arch/powerpc/kernel/prom.c | 70 ----------------------------------------------
drivers/of/base.c | 4 +--
drivers/of/dynamic.c | 13 +++++++++
drivers/of/of_private.h | 2 ++
4 files changed, 17 insertions(+), 72 deletions(-)
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index b694b0730971..9e8d8a880d6f 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -821,76 +821,6 @@ int cpu_to_chip_id(int cpu)
}
EXPORT_SYMBOL(cpu_to_chip_id);
-#ifdef CONFIG_PPC_PSERIES
-/*
- * Fix up the uninitialized fields in a new device node:
- * name, type and pci-specific fields
- */
-
-static int of_finish_dynamic_node(struct device_node *node)
-{
- struct device_node *parent = of_get_parent(node);
- int err = 0;
- const phandle *ibm_phandle;
-
- node->name = of_get_property(node, "name", NULL);
- node->type = of_get_property(node, "device_type", NULL);
-
- if (!node->name)
- node->name = "<NULL>";
- if (!node->type)
- node->type = "<NULL>";
-
- if (!parent) {
- err = -ENODEV;
- goto out;
- }
-
- /* We don't support that function on PowerMac, at least
- * not yet
- */
- if (machine_is(powermac))
- return -ENODEV;
-
- /* fix up new node's phandle field */
- if ((ibm_phandle = of_get_property(node, "ibm,phandle", NULL)))
- node->phandle = *ibm_phandle;
-
-out:
- of_node_put(parent);
- return err;
-}
-
-static int prom_reconfig_notifier(struct notifier_block *nb,
- unsigned long action, void *node)
-{
- int err;
-
- switch (action) {
- case OF_RECONFIG_ATTACH_NODE:
- err = of_finish_dynamic_node(node);
- if (err < 0)
- printk(KERN_ERR "finish_node returned %d\n", err);
- break;
- default:
- err = 0;
- break;
- }
- return notifier_from_errno(err);
-}
-
-static struct notifier_block prom_reconfig_nb = {
- .notifier_call = prom_reconfig_notifier,
- .priority = 10, /* This one needs to run first */
-};
-
-static int __init prom_reconfig_setup(void)
-{
- return of_reconfig_notifier_register(&prom_reconfig_nb);
-}
-__initcall(prom_reconfig_setup);
-#endif
-
bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
{
return (int)phys_id == get_hard_smp_processor_id(cpu);
diff --git a/drivers/of/base.c b/drivers/of/base.c
index ad4929cbd876..ededf8e33145 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -266,8 +266,8 @@ EXPORT_SYMBOL(of_find_all_nodes);
* Find a property with a given name for a given node
* and return the value.
*/
-static const void *__of_get_property(const struct device_node *np,
- const char *name, int *lenp)
+const void *__of_get_property(const struct device_node *np,
+ const char *name, int *lenp)
{
struct property *pp = __of_find_property(np, name, lenp);
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index b96d83100987..7c020b9a3317 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -98,6 +98,19 @@ int of_property_notify(int action, struct device_node *np,
void __of_attach_node(struct device_node *np)
{
+ const __be32 *phandle;
+ int sz;
+
+ np->name = __of_get_property(np, "name", NULL) ? : "<NULL>";
+ np->type = __of_get_property(np, "device_type", NULL) ? : "<NULL>";
+
+ phandle = __of_get_property(np, "phandle", &sz);
+ if (!phandle)
+ phandle = __of_get_property(np, "linux,phandle", &sz);
+ if (IS_ENABLED(PPC_PSERIES) && !phandle)
+ phandle = __of_get_property(np, "ibm,phandle", &sz);
+ np->phandle = (phandle && (sz >= 4)) ? be32_to_cpup(phandle) : 0;
+
np->child = NULL;
np->sibling = np->parent->child;
np->allnext = np->parent->allnext;
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 0d99ba8caeed..8129c0e58d70 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -63,6 +63,8 @@ static inline int of_property_notify(int action, struct device_node *np,
struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
+extern const void *__of_get_property(const struct device_node *np,
+ const char *name, int *lenp);
extern int __of_add_property(struct device_node *np, struct property *prop);
extern int __of_add_property_sysfs(struct device_node *np,
struct property *prop);
--
1.9.1
The child pointer does not get cleared when attaching new nodes which
could cause the tree to be inconsistent. Clear the child pointer in
__of_attach_node() to be absolutely sure that the structure remains in a
consistent layout.
Signed-off-by: Grant Likely <[email protected]>
---
drivers/of/dynamic.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index c875787fa394..b96d83100987 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -98,6 +98,7 @@ int of_property_notify(int action, struct device_node *np,
void __of_attach_node(struct device_node *np)
{
+ np->child = NULL;
np->sibling = np->parent->child;
np->allnext = np->parent->allnext;
np->parent->allnext = np;
--
1.9.1
All of the DT modification functions are split into two parts, the first
part manipulates the DT data structure, and the second part updates
sysfs, but the code isn't very consistent about how the second half is
called. They don't all enforce the same rules about when it is valid to
update sysfs, and there isn't any clarity on locking.
The transactional DT modification feature that is coming also needs
access to these functions so that it can perform all the structure
changes together, and then all the sysfs updates as a second stage
instead of doing each one at a time.
Fix up the second have by creating a separate __of_*_sysfs() function
for each of the helpers. The new functions have consistent naming (ie.
of_node_add() becomes __of_attach_node_sysfs()) and all of them now
defer if of_init hasn't been called yet.
Callers of the new functions must hold the of_mutex to ensure there are
no race conditions with of_init(). The mutex ensures that there will
only ever be one writer to the tree at any given time. There can still
be any number of readers and the raw_spin_lock is still used to make
sure access to the data structure is still consistent.
Finally, put the function prototypes into of_private.h so they are
accessible to the transaction code.
Signed-off-by: Pantelis Antoniou <[email protected]>
[grant.likely: Changed suffix from _post to _sysfs to match existing code]
[grant.likely: Reorganized to eliminate trivial wrappers]
Signed-off-by: Grant Likely <[email protected]>
---
drivers/of/base.c | 96 +++++++++++++++++++++++++------------------------
drivers/of/dynamic.c | 12 +++++--
drivers/of/of_private.h | 10 ++++++
include/linux/of.h | 2 --
4 files changed, 69 insertions(+), 51 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index b403f9d98461..ad4929cbd876 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -37,10 +37,13 @@ struct device_node *of_chosen;
struct device_node *of_aliases;
static struct device_node *of_stdout;
-static struct kset *of_kset;
+struct kset *of_kset;
/*
- * Used to protect the of_aliases, to hold off addition of nodes to sysfs
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
+ * This mutex must be held whenever modifications are being made to the
+ * device tree. The of_{attach,detach}_node() and
+ * of_{add,remove,update}_property() helpers make sure this happens.
*/
DEFINE_MUTEX(of_mutex);
@@ -127,13 +130,16 @@ static const char *safe_name(struct kobject *kobj, const char *orig_name)
return name;
}
-static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
+int __of_add_property_sysfs(struct device_node *np, struct property *pp)
{
int rc;
/* Important: Don't leak passwords */
bool secure = strncmp(pp->name, "security-", 9) == 0;
+ if (!of_kset || !of_node_is_attached(np))
+ return 0;
+
sysfs_bin_attr_init(&pp->attr);
pp->attr.attr.name = safe_name(&np->kobj, pp->name);
pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
@@ -145,12 +151,15 @@ static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
return rc;
}
-static int __of_node_add(struct device_node *np)
+int __of_attach_node_sysfs(struct device_node *np)
{
const char *name;
struct property *pp;
int rc;
+ if (!of_kset)
+ return 0;
+
np->kobj.kset = of_kset;
if (!np->parent) {
/* Nodes without parents are new top level trees */
@@ -172,26 +181,6 @@ static int __of_node_add(struct device_node *np)
return 0;
}
-int of_node_add(struct device_node *np)
-{
- int rc = 0;
-
- BUG_ON(!of_node_is_initialized(np));
-
- /*
- * Grab the mutex here so that in a race condition between of_init() and
- * of_node_add(), node addition will still be consistent.
- */
- mutex_lock(&of_mutex);
- if (of_kset)
- rc = __of_node_add(np);
- else
- /* This scenario may be perfectly valid, but report it anyway */
- pr_info("of_node_add(%s) before of_init()\n", np->full_name);
- mutex_unlock(&of_mutex);
- return rc;
-}
-
static int __init of_init(void)
{
struct device_node *np;
@@ -204,7 +193,7 @@ static int __init of_init(void)
return -ENOMEM;
}
for_each_of_allnodes(np)
- __of_node_add(np);
+ __of_attach_node_sysfs(np);
mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
@@ -1689,15 +1678,17 @@ int of_add_property(struct device_node *np, struct property *prop)
if (rc)
return rc;
+ mutex_lock(&of_mutex);
+
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_add_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- if (rc)
- return rc;
- if (of_node_is_attached(np))
+ if (!rc)
__of_add_property_sysfs(np, prop);
+ mutex_unlock(&of_mutex);
+
return rc;
}
@@ -1720,6 +1711,13 @@ int __of_remove_property(struct device_node *np, struct property *prop)
return 0;
}
+void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
+{
+ /* at early boot, bail here and defer setup to of_init() */
+ if (of_kset && of_node_is_attached(np))
+ sysfs_remove_bin_file(&np->kobj, &prop->attr);
+}
+
/**
* of_remove_property - Remove a property from a node.
*
@@ -1737,20 +1735,18 @@ int of_remove_property(struct device_node *np, struct property *prop)
if (rc)
return rc;
+ mutex_lock(&of_mutex);
+
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_remove_property(np, prop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- if (rc)
- return rc;
-
- /* at early boot, bail hear and defer setup to of_init() */
- if (!of_kset)
- return 0;
+ if (!rc)
+ __of_remove_property_sysfs(np, prop);
- sysfs_remove_bin_file(&np->kobj, &prop->attr);
+ mutex_unlock(&of_mutex);
- return 0;
+ return rc;
}
int __of_update_property(struct device_node *np, struct property *newprop,
@@ -1779,6 +1775,18 @@ int __of_update_property(struct device_node *np, struct property *newprop,
return 0;
}
+void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
+ struct property *oldprop)
+{
+ /* At early boot, bail out and defer setup to of_init() */
+ if (!of_kset)
+ return;
+
+ if (oldprop)
+ sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
+ __of_add_property_sysfs(np, newprop);
+}
+
/*
* of_update_property - Update a property in a node, if the property does
* not exist, add it.
@@ -1801,22 +1809,18 @@ int of_update_property(struct device_node *np, struct property *newprop)
if (rc)
return rc;
+ mutex_lock(&of_mutex);
+
raw_spin_lock_irqsave(&devtree_lock, flags);
rc = __of_update_property(np, newprop, &oldprop);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- if (rc)
- return rc;
- /* At early boot, bail out and defer setup to of_init() */
- if (!of_kset)
- return 0;
+ if (!rc)
+ __of_update_property_sysfs(np, newprop, oldprop);
- /* Update the sysfs attribute */
- if (oldprop)
- sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
- __of_add_property_sysfs(np, newprop);
+ mutex_unlock(&of_mutex);
- return 0;
+ return rc;
}
static void of_alias_add(struct alias_prop *ap, struct device_node *np,
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 75fcc66fcefd..c875787fa394 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -41,11 +41,13 @@ void of_node_put(struct device_node *node)
}
EXPORT_SYMBOL(of_node_put);
-static void of_node_remove(struct device_node *np)
+void __of_detach_node_sysfs(struct device_node *np)
{
struct property *pp;
BUG_ON(!of_node_is_initialized(np));
+ if (!of_kset)
+ return;
/* only remove properties if on sysfs */
if (of_node_is_attached(np)) {
@@ -115,11 +117,13 @@ int of_attach_node(struct device_node *np)
if (rc)
return rc;
+ mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_attach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- of_node_add(np);
+ __of_attach_node_sysfs(np);
+ mutex_unlock(&of_mutex);
return 0;
}
@@ -174,11 +178,13 @@ int of_detach_node(struct device_node *np)
if (rc)
return rc;
+ mutex_lock(&of_mutex);
raw_spin_lock_irqsave(&devtree_lock, flags);
__of_detach_node(np);
raw_spin_unlock_irqrestore(&devtree_lock, flags);
- of_node_remove(np);
+ __of_detach_node_sysfs(np);
+ mutex_unlock(&of_mutex);
return rc;
}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index 0f6089722af9..0d99ba8caeed 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -33,6 +33,8 @@ struct alias_prop {
extern struct mutex of_mutex;
extern struct list_head aliases_lookup;
+extern struct kset *of_kset;
+
static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
{
@@ -62,11 +64,19 @@ struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
extern int __of_add_property(struct device_node *np, struct property *prop);
+extern int __of_add_property_sysfs(struct device_node *np,
+ struct property *prop);
extern int __of_remove_property(struct device_node *np, struct property *prop);
+extern void __of_remove_property_sysfs(struct device_node *np,
+ struct property *prop);
extern int __of_update_property(struct device_node *np,
struct property *newprop, struct property **oldprop);
+extern void __of_update_property_sysfs(struct device_node *np,
+ struct property *newprop, struct property *oldprop);
extern void __of_attach_node(struct device_node *np);
+extern int __of_attach_node_sysfs(struct device_node *np);
extern void __of_detach_node(struct device_node *np);
+extern void __of_detach_node_sysfs(struct device_node *np);
#endif /* _LINUX_OF_PRIVATE_H */
diff --git a/include/linux/of.h b/include/linux/of.h
index abf829a1f150..705fa12fca7f 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -74,8 +74,6 @@ struct of_phandle_args {
uint32_t args[MAX_PHANDLE_ARGS];
};
-extern int of_node_add(struct device_node *node);
-
/* initialize a node */
extern struct kobj_type of_node_ktype;
static inline void of_node_init(struct device_node *node)
--
1.9.1
Split the dynamic device tree code into a separate file to make it
really clear what features CONFIF_OF_DYNAMIC add to the kernel. Without
CONFIG_OF_DYNAMIC only properties can be changed, and notifiers do not
get sent. Enabling it turns on reference counting, notifiers and the
ability to add and remove nodes.
v2: Moved of_node_release() into dynamic.c
Signed-off-by: Grant Likely <[email protected]>
Signed-off-by: Pantelis Antoniou <[email protected]>
Cc: Rob Herring <[email protected]>
---
drivers/of/Makefile | 1 +
drivers/of/base.c | 230 +-----------------------------------------------
drivers/of/dynamic.c | 216 +++++++++++++++++++++++++++++++++++++++++++++
drivers/of/of_private.h | 18 ++++
4 files changed, 236 insertions(+), 229 deletions(-)
create mode 100644 drivers/of/dynamic.c
diff --git a/drivers/of/Makefile b/drivers/of/Makefile
index 099b1fb00af4..08e6c0f79806 100644
--- a/drivers/of/Makefile
+++ b/drivers/of/Makefile
@@ -1,4 +1,5 @@
obj-y = base.o device.o platform.o
+obj-$(CONFIG_OF_DYNAMIC) += dynamic.o
obj-$(CONFIG_OF_FLATTREE) += fdt.o
obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o
obj-$(CONFIG_OF_PROMTREE) += pdt.o
diff --git a/drivers/of/base.c b/drivers/of/base.c
index e48a1b90a392..0d8955605738 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -88,79 +88,7 @@ int __weak of_node_to_nid(struct device_node *np)
}
#endif
-#if defined(CONFIG_OF_DYNAMIC)
-/**
- * of_node_get - Increment refcount of a node
- * @node: Node to inc refcount, NULL is supported to
- * simplify writing of callers
- *
- * Returns node.
- */
-struct device_node *of_node_get(struct device_node *node)
-{
- if (node)
- kobject_get(&node->kobj);
- return node;
-}
-EXPORT_SYMBOL(of_node_get);
-
-static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
-{
- return container_of(kobj, struct device_node, kobj);
-}
-
-/**
- * of_node_release - release a dynamically allocated node
- * @kref: kref element of the node to be released
- *
- * In of_node_put() this function is passed to kref_put()
- * as the destructor.
- */
-static void of_node_release(struct kobject *kobj)
-{
- struct device_node *node = kobj_to_device_node(kobj);
- struct property *prop = node->properties;
-
- /* We should never be releasing nodes that haven't been detached. */
- if (!of_node_check_flag(node, OF_DETACHED)) {
- pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
- dump_stack();
- return;
- }
-
- if (!of_node_check_flag(node, OF_DYNAMIC))
- return;
-
- while (prop) {
- struct property *next = prop->next;
- kfree(prop->name);
- kfree(prop->value);
- kfree(prop);
- prop = next;
-
- if (!prop) {
- prop = node->deadprops;
- node->deadprops = NULL;
- }
- }
- kfree(node->full_name);
- kfree(node->data);
- kfree(node);
-}
-
-/**
- * of_node_put - Decrement refcount of a node
- * @node: Node to dec refcount, NULL is supported to
- * simplify writing of callers
- *
- */
-void of_node_put(struct device_node *node)
-{
- if (node)
- kobject_put(&node->kobj);
-}
-EXPORT_SYMBOL(of_node_put);
-#else
+#ifndef CONFIG_OF_DYNAMIC
static void of_node_release(struct kobject *kobj)
{
/* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
@@ -264,25 +192,6 @@ int of_node_add(struct device_node *np)
return rc;
}
-#if defined(CONFIG_OF_DYNAMIC)
-static void of_node_remove(struct device_node *np)
-{
- struct property *pp;
-
- BUG_ON(!of_node_is_initialized(np));
-
- /* only remove properties if on sysfs */
- if (of_node_is_attached(np)) {
- for_each_property_of_node(np, pp)
- sysfs_remove_bin_file(&np->kobj, &pp->attr);
- kobject_del(&np->kobj);
- }
-
- /* finally remove the kobj_init ref */
- of_node_put(np);
-}
-#endif
-
static int __init of_init(void)
{
struct device_node *np;
@@ -1747,28 +1656,6 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
}
EXPORT_SYMBOL(of_count_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;
-
- /* only call notifiers if the node is attached */
- if (!of_node_is_attached(np))
- return 0;
-
- 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
-
/**
* __of_add_property - Add a property to a node without lock operations
*/
@@ -1915,121 +1802,6 @@ int of_update_property(struct device_node *np, struct property *newprop)
return 0;
}
-#if defined(CONFIG_OF_DYNAMIC)
-/*
- * Support for dynamic device trees.
- *
- * On some platforms, the device tree can be manipulated at runtime.
- * The routines in this section support adding, removing and changing
- * 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);
-}
-EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
-
-int of_reconfig_notifier_unregister(struct notifier_block *nb)
-{
- return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
-}
-EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
-
-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);
-}
-
-/**
- * of_attach_node - Plug a device node into the tree and global list.
- */
-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;
-
- raw_spin_lock_irqsave(&devtree_lock, flags);
- np->sibling = np->parent->child;
- np->allnext = np->parent->allnext;
- np->parent->allnext = np;
- np->parent->child = np;
- of_node_clear_flag(np, OF_DETACHED);
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
- of_node_add(np);
- return 0;
-}
-
-/**
- * of_detach_node - "Unplug" a node from the device tree.
- *
- * The caller must hold a reference to the node. The memory associated with
- * the node is not freed until its refcount goes to zero.
- */
-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;
-
- raw_spin_lock_irqsave(&devtree_lock, flags);
-
- if (of_node_check_flag(np, OF_DETACHED)) {
- /* someone already detached it */
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
- return rc;
- }
-
- parent = np->parent;
- if (!parent) {
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
- return rc;
- }
-
- if (of_allnodes == np)
- of_allnodes = np->allnext;
- else {
- struct device_node *prev;
- for (prev = of_allnodes;
- prev->allnext != np;
- prev = prev->allnext)
- ;
- prev->allnext = np->allnext;
- }
-
- if (parent->child == np)
- parent->child = np->sibling;
- else {
- struct device_node *prevsib;
- for (prevsib = np->parent->child;
- prevsib->sibling != np;
- prevsib = prevsib->sibling)
- ;
- prevsib->sibling = np->sibling;
- }
-
- of_node_set_flag(np, OF_DETACHED);
- raw_spin_unlock_irqrestore(&devtree_lock, flags);
-
- of_node_remove(np);
- return rc;
-}
-#endif /* defined(CONFIG_OF_DYNAMIC) */
-
static void of_alias_add(struct alias_prop *ap, struct device_node *np,
int id, const char *stem, int stem_len)
{
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
new file mode 100644
index 000000000000..125994330437
--- /dev/null
+++ b/drivers/of/dynamic.c
@@ -0,0 +1,216 @@
+/*
+ * Support for dynamic device trees.
+ *
+ * On some platforms, the device tree can be manipulated at runtime.
+ * The routines in this section support adding, removing and changing
+ * device tree nodes.
+ */
+
+#include <linux/of.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/proc_fs.h>
+
+#include "of_private.h"
+
+/**
+ * of_node_get() - Increment refcount of a node
+ * @node: Node to inc refcount, NULL is supported to simplify writing of
+ * callers
+ *
+ * Returns node.
+ */
+struct device_node *of_node_get(struct device_node *node)
+{
+ if (node)
+ kobject_get(&node->kobj);
+ return node;
+}
+EXPORT_SYMBOL(of_node_get);
+
+/**
+ * of_node_put() - Decrement refcount of a node
+ * @node: Node to dec refcount, NULL is supported to simplify writing of
+ * callers
+ */
+void of_node_put(struct device_node *node)
+{
+ if (node)
+ kobject_put(&node->kobj);
+}
+EXPORT_SYMBOL(of_node_put);
+
+static void of_node_remove(struct device_node *np)
+{
+ struct property *pp;
+
+ BUG_ON(!of_node_is_initialized(np));
+
+ /* only remove properties if on sysfs */
+ if (of_node_is_attached(np)) {
+ for_each_property_of_node(np, pp)
+ sysfs_remove_bin_file(&np->kobj, &pp->attr);
+ kobject_del(&np->kobj);
+ }
+
+ /* finally remove the kobj_init ref */
+ of_node_put(np);
+}
+
+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);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
+
+int of_reconfig_notifier_unregister(struct notifier_block *nb)
+{
+ return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
+}
+EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
+
+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);
+}
+
+int of_property_notify(int action, struct device_node *np,
+ struct property *prop)
+{
+ struct of_prop_reconfig pr;
+
+ /* only call notifiers if the node is attached */
+ if (!of_node_is_attached(np))
+ return 0;
+
+ pr.dn = np;
+ pr.prop = prop;
+ return of_reconfig_notify(action, &pr);
+}
+
+/**
+ * of_attach_node() - Plug a device node into the tree and global list.
+ */
+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;
+
+ raw_spin_lock_irqsave(&devtree_lock, flags);
+ np->sibling = np->parent->child;
+ np->allnext = np->parent->allnext;
+ np->parent->allnext = np;
+ np->parent->child = np;
+ of_node_clear_flag(np, OF_DETACHED);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+ of_node_add(np);
+ return 0;
+}
+
+/**
+ * of_detach_node() - "Unplug" a node from the device tree.
+ *
+ * The caller must hold a reference to the node. The memory associated with
+ * the node is not freed until its refcount goes to zero.
+ */
+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;
+
+ raw_spin_lock_irqsave(&devtree_lock, flags);
+
+ if (of_node_check_flag(np, OF_DETACHED)) {
+ /* someone already detached it */
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+ return rc;
+ }
+
+ parent = np->parent;
+ if (!parent) {
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+ return rc;
+ }
+
+ if (of_allnodes == np)
+ of_allnodes = np->allnext;
+ else {
+ struct device_node *prev;
+ for (prev = of_allnodes;
+ prev->allnext != np;
+ prev = prev->allnext)
+ ;
+ prev->allnext = np->allnext;
+ }
+
+ if (parent->child == np)
+ parent->child = np->sibling;
+ else {
+ struct device_node *prevsib;
+ for (prevsib = np->parent->child;
+ prevsib->sibling != np;
+ prevsib = prevsib->sibling)
+ ;
+ prevsib->sibling = np->sibling;
+ }
+
+ of_node_set_flag(np, OF_DETACHED);
+ raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+ of_node_remove(np);
+ return rc;
+}
+
+/**
+ * of_node_release() - release a dynamically allocated node
+ * @kref: kref element of the node to be released
+ *
+ * In of_node_put() this function is passed to kref_put() as the destructor.
+ */
+void of_node_release(struct kobject *kobj)
+{
+ struct device_node *node = kobj_to_device_node(kobj);
+ struct property *prop = node->properties;
+
+ /* We should never be releasing nodes that haven't been detached. */
+ if (!of_node_check_flag(node, OF_DETACHED)) {
+ pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
+ dump_stack();
+ return;
+ }
+
+ if (!of_node_check_flag(node, OF_DYNAMIC))
+ return;
+
+ while (prop) {
+ struct property *next = prop->next;
+ kfree(prop->name);
+ kfree(prop->value);
+ kfree(prop);
+ prop = next;
+
+ if (!prop) {
+ prop = node->deadprops;
+ node->deadprops = NULL;
+ }
+ }
+ kfree(node->full_name);
+ kfree(node->data);
+ kfree(node);
+}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index fcc70e74dfe0..c270f2037779 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -33,4 +33,22 @@ struct alias_prop {
extern struct mutex of_mutex;
extern struct list_head aliases_lookup;
+
+static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
+{
+ return container_of(kobj, struct device_node, kobj);
+}
+
+#if defined(CONFIG_OF_DYNAMIC)
+extern int of_property_notify(int action, struct device_node *np,
+ struct property *prop);
+extern void of_node_release(struct kobject *kobj);
+#else /* CONFIG_OF_DYNAMIC */
+static inline int of_property_notify(int action, struct device_node *np,
+ struct property *prop)
+{
+ return 0;
+}
+#endif /* CONFIG_OF_DYNAMIC */
+
#endif /* _LINUX_OF_PRIVATE_H */
--
1.9.1
From: Pantelis Antoniou <[email protected]>
Introduce helper functions for working with the live DT tree,
all of them related to dynamically adding/removing nodes and
properties.
__of_prop_dup() copies a property dynamically
__of_node_alloc() creates an empty node
Bug fix about prop->len == 0 by Ionut Nicu <[email protected]>
Signed-off-by: Pantelis Antoniou <[email protected]>
[glikely: Added unittest for of_copy_property and dropped fine-grained allocations]
[glikely: removed name, type and phandle arguments from __of_node_alloc]
Signed-off-by: Grant Likely <[email protected]>
---
drivers/of/dynamic.c | 77 +++++++++++++++++++++++++++++++++++++++++++++++++
drivers/of/of_private.h | 10 +++++++
drivers/of/selftest.c | 28 ++++++++++++++++++
3 files changed, 115 insertions(+)
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 125994330437..e0c4c6e25980 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -214,3 +214,80 @@ void of_node_release(struct kobject *kobj)
kfree(node->data);
kfree(node);
}
+
+/**
+ * __of_prop_dup - Copy a property dynamically.
+ * @prop: Property to copy
+ * @allocflags: Allocation flags (typically pass GFP_KERNEL)
+ *
+ * Copy a property by dynamically allocating the memory of both the
+ * property stucture and the property name & contents. The property's
+ * flags have the OF_DYNAMIC bit set so that we can differentiate between
+ * dynamically allocated properties and not.
+ * Returns the newly allocated property or NULL on out of memory error.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags)
+{
+ struct property *new;
+
+ new = kzalloc(sizeof(*new), allocflags);
+ if (!new)
+ return NULL;
+
+ /*
+ * NOTE: There is no check for zero length value.
+ * In case of a boolean property This will allocate a value
+ * of zero bytes. We do this to work around the use
+ * of of_get_property() calls on boolean values.
+ */
+ new->name = kstrdup(prop->name, allocflags);
+ new->value = kmemdup(prop->value, prop->length, allocflags);
+ new->length = prop->length;
+ if (!new->name || !new->value)
+ goto err_free;
+
+ /* mark the property as dynamic */
+ of_property_set_flag(new, OF_DYNAMIC);
+
+ return new;
+
+ err_free:
+ kfree(new->name);
+ kfree(new->value);
+ kfree(new);
+ return NULL;
+}
+
+/**
+ * __of_node_alloc() - Create an empty device node dynamically.
+ * @full_name: Full name of the new device node
+ * @allocflags: Allocation flags (typically pass GFP_KERNEL)
+ *
+ * Create an empty device tree node, suitable for further modification.
+ * The node data are dynamically allocated and all the node flags
+ * have the OF_DYNAMIC & OF_DETACHED bits set.
+ * Returns the newly allocated node or NULL on out of memory error.
+ */
+struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags)
+{
+ struct device_node *node;
+
+ node = kzalloc(sizeof(*node), allocflags);
+ if (!node)
+ return NULL;
+
+ node->full_name = kstrdup(full_name, allocflags);
+ of_node_set_flag(node, OF_DYNAMIC);
+ of_node_set_flag(node, OF_DETACHED);
+ if (!node->full_name)
+ goto err_free;
+
+ of_node_init(node);
+
+ return node;
+
+ err_free:
+ kfree(node->full_name);
+ kfree(node);
+ return NULL;
+}
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index c270f2037779..1799ed2b3808 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -51,4 +51,14 @@ static inline int of_property_notify(int action, struct device_node *np,
}
#endif /* CONFIG_OF_DYNAMIC */
+/**
+ * General utilities for working with live trees.
+ *
+ * All functions with two leading underscores operate
+ * without taking node references, so you either have to
+ * own the devtree lock or work on detached trees only.
+ */
+struct property *__of_prop_dup(const struct property *prop, gfp_t allocflags);
+struct device_node *__of_node_alloc(const char *full_name, gfp_t allocflags);
+
#endif /* _LINUX_OF_PRIVATE_H */
diff --git a/drivers/of/selftest.c b/drivers/of/selftest.c
index 077314eebb95..ee2166f0f36a 100644
--- a/drivers/of/selftest.c
+++ b/drivers/of/selftest.c
@@ -16,6 +16,8 @@
#include <linux/slab.h>
#include <linux/device.h>
+#include "of_private.h"
+
static struct selftest_results {
int passed;
int failed;
@@ -266,6 +268,31 @@ static void __init of_selftest_property_match_string(void)
selftest(rc == -EILSEQ, "unterminated string; rc=%i", rc);
}
+#define propcmp(p1, p2) (((p1)->length == (p2)->length) && \
+ (p1)->value && (p2)->value && \
+ !memcmp((p1)->value, (p2)->value, (p1)->length) && \
+ !strcmp((p1)->name, (p2)->name))
+static void __init of_selftest_property_copy(void)
+{
+#ifdef CONFIG_OF_DYNAMIC
+ struct property p1 = { .name = "p1", .length = 0, .value = "" };
+ struct property p2 = { .name = "p2", .length = 5, .value = "abcd" };
+ struct property *new;
+
+ new = __of_prop_dup(&p1, GFP_KERNEL);
+ selftest(new && propcmp(&p1, new), "empty property didn't copy correctly\n");
+ kfree(new->value);
+ kfree(new->name);
+ kfree(new);
+
+ new = __of_prop_dup(&p2, GFP_KERNEL);
+ selftest(new && propcmp(&p2, new), "non-empty property didn't copy correctly\n");
+ kfree(new->value);
+ kfree(new->name);
+ kfree(new);
+#endif
+}
+
static void __init of_selftest_parse_interrupts(void)
{
struct device_node *np;
@@ -533,6 +560,7 @@ static int __init of_selftest(void)
of_selftest_dynamic();
of_selftest_parse_phandle_with_args();
of_selftest_property_match_string();
+ of_selftest_property_copy();
of_selftest_parse_interrupts();
of_selftest_parse_interrupts_extended();
of_selftest_match_node();
--
1.9.1
From: Pantelis Antoniou <[email protected]>
We're overloading usage of of_aliases_mutex for sysfs changes,
so rename to something that is more generic.
Signed-off-by: Pantelis Antoniou <[email protected]>
Signed-off-by: Grant Likely <[email protected]>
---
drivers/of/base.c | 19 +++++++++----------
drivers/of/device.c | 4 ++--
drivers/of/of_private.h | 2 +-
3 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/of/base.c b/drivers/of/base.c
index b9864806e9b8..e48a1b90a392 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -40,10 +40,9 @@ static struct device_node *of_stdout;
static struct kset *of_kset;
/*
- * Used to protect the of_aliases; but also overloaded to hold off addition of
- * nodes to sysfs
+ * Used to protect the of_aliases, to hold off addition of nodes to sysfs
*/
-DEFINE_MUTEX(of_aliases_mutex);
+DEFINE_MUTEX(of_mutex);
/* use when traversing tree through the allnext, child, sibling,
* or parent members of struct device_node.
@@ -255,13 +254,13 @@ int of_node_add(struct device_node *np)
* Grab the mutex here so that in a race condition between of_init() and
* of_node_add(), node addition will still be consistent.
*/
- mutex_lock(&of_aliases_mutex);
+ mutex_lock(&of_mutex);
if (of_kset)
rc = __of_node_add(np);
else
/* This scenario may be perfectly valid, but report it anyway */
pr_info("of_node_add(%s) before of_init()\n", np->full_name);
- mutex_unlock(&of_aliases_mutex);
+ mutex_unlock(&of_mutex);
return rc;
}
@@ -289,15 +288,15 @@ static int __init of_init(void)
struct device_node *np;
/* Create the kset, and register existing nodes */
- mutex_lock(&of_aliases_mutex);
+ mutex_lock(&of_mutex);
of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
if (!of_kset) {
- mutex_unlock(&of_aliases_mutex);
+ mutex_unlock(&of_mutex);
return -ENOMEM;
}
for_each_of_allnodes(np)
__of_node_add(np);
- mutex_unlock(&of_aliases_mutex);
+ mutex_unlock(&of_mutex);
/* Symlink in /proc as required by userspace ABI */
if (of_allnodes)
@@ -2122,7 +2121,7 @@ int of_alias_get_id(struct device_node *np, const char *stem)
struct alias_prop *app;
int id = -ENODEV;
- mutex_lock(&of_aliases_mutex);
+ mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (strcmp(app->stem, stem) != 0)
continue;
@@ -2132,7 +2131,7 @@ int of_alias_get_id(struct device_node *np, const char *stem)
break;
}
}
- mutex_unlock(&of_aliases_mutex);
+ mutex_unlock(&of_mutex);
return id;
}
diff --git a/drivers/of/device.c b/drivers/of/device.c
index dafb9736ab9b..46d6c75c1404 100644
--- a/drivers/of/device.c
+++ b/drivers/of/device.c
@@ -160,7 +160,7 @@ void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
seen = 0;
- mutex_lock(&of_aliases_mutex);
+ mutex_lock(&of_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (dev->of_node == app->np) {
add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
@@ -168,7 +168,7 @@ void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
seen++;
}
}
- mutex_unlock(&of_aliases_mutex);
+ mutex_unlock(&of_mutex);
}
int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h
index ff350c8fa7ac..fcc70e74dfe0 100644
--- a/drivers/of/of_private.h
+++ b/drivers/of/of_private.h
@@ -31,6 +31,6 @@ struct alias_prop {
char stem[0];
};
-extern struct mutex of_aliases_mutex;
+extern struct mutex of_mutex;
extern struct list_head aliases_lookup;
#endif /* _LINUX_OF_PRIVATE_H */
--
1.9.1
On 07/23/2014 06:44 PM, Grant Likely wrote:
> Hi all,
>
> This is a rollup of all the patches that I queued up today for
> linux-next for the devicetree changeset and overlay work. I'm reposting
> these patches because some have been significantly changed since their
> first posting. None of the code is actually live yet, but the test cases
> are there.
>
> There is one significant functional change which may affect pseries. The
> OF_DYNAMIC code has been changed to emit notifiers after applying a
> change to the tree instead of before. I think I've got all they users
> taken care of correctly, but I'd like to see some testing. I don't have
> access to pseries (and I can't get the QEMU pseries model to boot reliably)
>
> Nathan/Tyrel, can you give it a spin? The changes can be found in my git tree:
Grant,
I was able to do some sniff testing by adding/removing memory, cpus, and pci
devices and it appears that all device tree nodes and properties were updated
properly.
I would still like to try doing live partition migration where we can update
many pieces of the device tree. I'll be out next week, will try to get
on that when I return.
-Nathan
>
> git://git.secretlab.ca/git/linux devicetree/next
>
> Grant Likely (8):
> of/platform: Fix of_platform_device_destroy iteration of devices
> of: Move CONFIG_OF_DYNAMIC code into a separate file
> of: Make devicetree sysfs update functions consistent.
> of: Make sure attached nodes don't carry along extra children
> of: Move dynamic node fixups out of powerpc and into common code
> of: Reorder device tree changes and notifiers
> of: Add todo tasklist for Devicetree
> Merge branch 'devicetree/next-overlay' into devicetree/next
>
> Pantelis Antoniou (4):
> of: rename of_aliases_mutex to just of_mutex
> OF: Utility helper functions for dynamic nodes
> of: Create unlocked versions of node and property add/remove functions
> of: Transactional DT support.
>
> Documentation/devicetree/changesets.txt | 40 ++
> Documentation/devicetree/todo.txt | 11 +
> arch/powerpc/kernel/prom.c | 70 ---
> arch/powerpc/platforms/pseries/hotplug-memory.c | 2 +-
> drivers/crypto/nx/nx-842.c | 30 +-
> drivers/of/Makefile | 1 +
> drivers/of/base.c | 423 ++++-----------
> drivers/of/device.c | 4 +-
> drivers/of/dynamic.c | 660 ++++++++++++++++++++++++
> drivers/of/of_private.h | 59 ++-
> drivers/of/platform.c | 32 +-
> drivers/of/selftest.c | 79 +++
> drivers/of/testcase-data/testcases.dtsi | 10 +
> include/linux/of.h | 80 ++-
> include/linux/of_platform.h | 7 +-
> 15 files changed, 1065 insertions(+), 443 deletions(-)
> create mode 100644 Documentation/devicetree/changesets.txt
> create mode 100644 Documentation/devicetree/todo.txt
> create mode 100644 drivers/of/dynamic.c
>
On Fri, 25 Jul 2014 13:10:15 -0500, Nathan Fontenot <[email protected]> wrote:
> On 07/23/2014 06:44 PM, Grant Likely wrote:
> > Hi all,
> >
> > This is a rollup of all the patches that I queued up today for
> > linux-next for the devicetree changeset and overlay work. I'm reposting
> > these patches because some have been significantly changed since their
> > first posting. None of the code is actually live yet, but the test cases
> > are there.
> >
> > There is one significant functional change which may affect pseries. The
> > OF_DYNAMIC code has been changed to emit notifiers after applying a
> > change to the tree instead of before. I think I've got all they users
> > taken care of correctly, but I'd like to see some testing. I don't have
> > access to pseries (and I can't get the QEMU pseries model to boot reliably)
> >
> > Nathan/Tyrel, can you give it a spin? The changes can be found in my git tree:
>
> Grant,
>
> I was able to do some sniff testing by adding/removing memory, cpus, and pci
> devices and it appears that all device tree nodes and properties were updated
> properly.
>
> I would still like to try doing live partition migration where we can update
> many pieces of the device tree. I'll be out next week, will try to get
> on that when I return.
Thanks Nathan,
In the mean time, all this stuff is in Linux next. I would really like
to merge it for v3.17. I expect the merge window will open next weekend.
Let me know once you've been able to do the migration test. I can hold
off sending Linus a pull request until wk2 of the merge window if you
need the extra time.
g.