Merge tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux

Pull device tree updates from Grant Likely:
 "The branch contains the following device tree changes the v3.17 merge
  window:

  Group changes to the device tree.  In preparation for adding device
  tree overlay support, OF_DYNAMIC is reworked so that a set of device
  tree changes can be prepared and applied to the tree all at once.
  OF_RECONFIG notifiers see the most significant change here so that
  users always get a consistent view of the tree.  Notifiers generation
  is moved from before a change to after it, and notifiers for a group
  of changes are emitted after the entire block of changes have been
  applied

  Automatic console selection from DT.  Console drivers can now use
  of_console_check() to see if the device node is specified as a console
  device.  If so then it gets added as a preferred console.  UART
  devices get this support automatically when uart_add_one_port() is
  called.

  DT unit tests no longer depend on pre-loaded data in the device tree.
  Data is loaded dynamically at the start of unit tests, and then
  unloaded again when the tests have completed.

  Also contains a few bugfixes for reserved regions and early memory
  setup"

* tag 'devicetree-for-linus' of git://git.secretlab.ca/git/linux: (21 commits)
  of: Fixing OF Selftest build error
  drivers: of: add automated assignment of reserved regions to client devices
  of: Use proper types for checking memory overflow
  of: typo fix in __of_prop_dup()
  Adding selftest testdata dynamically into live tree
  of: Add todo tasklist for Devicetree
  of: Transactional DT support.
  of: Reorder device tree changes and notifiers
  of: Move dynamic node fixups out of powerpc and into common code
  of: Make sure attached nodes don't carry along extra children
  of: Make devicetree sysfs update functions consistent.
  of: Create unlocked versions of node and property add/remove functions
  OF: Utility helper functions for dynamic nodes
  of: Move CONFIG_OF_DYNAMIC code into a separate file
  of: rename of_aliases_mutex to just of_mutex
  of/platform: Fix of_platform_device_destroy iteration of devices
  of: Migrate of_find_node_by_name() users to for_each_node_by_name()
  tty: Update hypervisor tty drivers to use core stdout parsing code.
  arm/versatile: Add the uart as the stdout device.
  of: Enable console on serial ports specified by /chosen/stdout-path
  ...

1 files changed, 660 insertions, 0 deletions

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
new file mode 100644
index 000000000000..54fecc49a1fe
--- /dev/null
+++ b/drivers/of/dynamic.c
@@ -0,0 +1,660 @@
+/*
+ * 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);
+
+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)) {
+                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 property *oldprop)
+{
+        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;
+        pr.old_prop = oldprop;
+        return of_reconfig_notify(action, &pr);
+}
+
+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;
+        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.
+ */
+int of_attach_node(struct device_node *np)
+{
+        unsigned long flags;
+
+        mutex_lock(&of_mutex);
+        raw_spin_lock_irqsave(&devtree_lock, flags);
+        __of_attach_node(np);
+        raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+        __of_attach_node_sysfs(np);
+        mutex_unlock(&of_mutex);
+
+        of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
+
+        return 0;
+}
+
+void __of_detach_node(struct device_node *np)
+{
+        struct device_node *parent;
+
+        if (WARN_ON(of_node_check_flag(np, OF_DETACHED)))
+                return;
+
+        parent = np->parent;
+        if (WARN_ON(!parent))
+                return;
+
+        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);
+}
+
+/**
+ * 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;
+
+        mutex_lock(&of_mutex);
+        raw_spin_lock_irqsave(&devtree_lock, flags);
+        __of_detach_node(np);
+        raw_spin_unlock_irqrestore(&devtree_lock, flags);
+
+        __of_detach_node_sysfs(np);
+        mutex_unlock(&of_mutex);
+
+        of_reconfig_notify(OF_RECONFIG_DETACH_NODE, 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);
+}
+
+/**
+ * __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;
+}
+
+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;
+}