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author | 2017-10-04 14:09:40 -0500 | |
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committer | 2017-10-16 13:37:38 -0500 | |
commit | b56b5528f5b3c3d47e7c0ca67318c45e980d93f0 (patch) | |
tree | 6c97fc5ee0bb26a4f3c762218a6b351ad3955c8a /drivers/of | |
parent | of: wrap accesses to device_node kobject (diff) | |
download | linux-b56b5528f5b3c3d47e7c0ca67318c45e980d93f0.tar.gz linux-b56b5528f5b3c3d47e7c0ca67318c45e980d93f0.tar.bz2 linux-b56b5528f5b3c3d47e7c0ca67318c45e980d93f0.zip |
of: make kobject and bin_attribute support configurable
Having device_nodes be kobjects is only needed if sysfs or OF_DYNAMIC is
enabled. Otherwise, having a kobject in struct device_node is
unnecessary bloat in minimal kernel configurations.
Likewise, bin_attribute is only needed in struct property when sysfs is
enabled, so we can make it configurable too.
Tested-by: Nicolas Pitre <nico@linaro.org>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/Kconfig | 4 | ||||
-rw-r--r-- | drivers/of/Makefile | 1 | ||||
-rw-r--r-- | drivers/of/base.c | 130 | ||||
-rw-r--r-- | drivers/of/dynamic.c | 22 | ||||
-rw-r--r-- | drivers/of/kobj.c | 164 | ||||
-rw-r--r-- | drivers/of/of_private.h | 23 |
6 files changed, 192 insertions, 152 deletions
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig index ba7b034b2b91..ad9a9578f9c4 100644 --- a/drivers/of/Kconfig +++ b/drivers/of/Kconfig @@ -46,10 +46,14 @@ config OF_EARLY_FLATTREE config OF_PROMTREE bool +config OF_KOBJ + def_bool SYSFS + # Hardly any platforms need this. It is safe to select, but only do so if you # need it. config OF_DYNAMIC bool "Support for dynamic device trees" if OF_UNITTEST + select OF_KOBJ help On some platforms, the device tree can be manipulated at runtime. While this option is selected automatically on such platforms, you diff --git a/drivers/of/Makefile b/drivers/of/Makefile index 97dc01c81438..83d61a7c5e82 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -1,4 +1,5 @@ obj-y = base.o device.o platform.o property.o +obj-$(CONFIG_OF_KOBJ) += kobj.o obj-$(CONFIG_OF_DYNAMIC) += dynamic.o obj-$(CONFIG_OF_FLATTREE) += fdt.o obj-$(CONFIG_OF_EARLY_FLATTREE) += fdt_address.o diff --git a/drivers/of/base.c b/drivers/of/base.c index 9e9bd17121fb..b98f3adffbb0 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -95,105 +95,6 @@ int __weak of_node_to_nid(struct device_node *np) } #endif -#ifndef CONFIG_OF_DYNAMIC -static void of_node_release(struct kobject *kobj) -{ - /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */ -} -#endif /* CONFIG_OF_DYNAMIC */ - -struct kobj_type of_node_ktype = { - .release = of_node_release, -}; - -static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj, - struct bin_attribute *bin_attr, char *buf, - loff_t offset, size_t count) -{ - struct property *pp = container_of(bin_attr, struct property, attr); - return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); -} - -/* always return newly allocated name, caller must free after use */ -static const char *safe_name(struct kobject *kobj, const char *orig_name) -{ - const char *name = orig_name; - struct kernfs_node *kn; - int i = 0; - - /* don't be a hero. After 16 tries give up */ - while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) { - sysfs_put(kn); - if (name != orig_name) - kfree(name); - name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); - } - - if (name == orig_name) { - name = kstrdup(orig_name, GFP_KERNEL); - } else { - pr_warn("Duplicate name in %s, renamed to \"%s\"\n", - kobject_name(kobj), name); - } - return name; -} - -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 (!IS_ENABLED(CONFIG_SYSFS)) - return 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 ? 0400 : 0444; - pp->attr.size = secure ? 0 : pp->length; - pp->attr.read = of_node_property_read; - - rc = sysfs_create_bin_file(&np->kobj, &pp->attr); - WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np); - return rc; -} - -int __of_attach_node_sysfs(struct device_node *np) -{ - const char *name; - struct kobject *parent; - 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 */ - name = safe_name(&of_kset->kobj, "base"); - parent = NULL; - } else { - name = safe_name(&np->parent->kobj, kbasename(np->full_name)); - parent = &np->parent->kobj; - } - if (!name) - return -ENOMEM; - rc = kobject_add(&np->kobj, parent, "%s", name); - kfree(name); - if (rc) - return rc; - - for_each_property_of_node(np, pp) - __of_add_property_sysfs(np, pp); - - return 0; -} - void __init of_core_init(void) { struct device_node *np; @@ -1501,22 +1402,6 @@ int __of_remove_property(struct device_node *np, struct property *prop) return 0; } -void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop) -{ - sysfs_remove_bin_file(&np->kobj, &prop->attr); - kfree(prop->attr.attr.name); -} - -void __of_remove_property_sysfs(struct device_node *np, struct property *prop) -{ - if (!IS_ENABLED(CONFIG_SYSFS)) - return; - - /* at early boot, bail here and defer setup to of_init() */ - if (of_kset && of_node_is_attached(np)) - __of_sysfs_remove_bin_file(np, prop); -} - /** * of_remove_property - Remove a property from a node. * @@ -1576,21 +1461,6 @@ 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) -{ - if (!IS_ENABLED(CONFIG_SYSFS)) - return; - - /* At early boot, bail out and defer setup to of_init() */ - if (!of_kset) - return; - - if (oldprop) - __of_sysfs_remove_bin_file(np, oldprop); - __of_add_property_sysfs(np, newprop); -} - /* * of_update_property - Update a property in a node, if the property does * not exist, add it. diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 9d6ba18c529f..39e8cf731764 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -48,28 +48,6 @@ void of_node_put(struct device_node *node) } EXPORT_SYMBOL(of_node_put); -void __of_detach_node_sysfs(struct device_node *np) -{ - struct property *pp; - - if (!IS_ENABLED(CONFIG_SYSFS)) - return; - - 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) - __of_sysfs_remove_bin_file(np, pp); - 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) diff --git a/drivers/of/kobj.c b/drivers/of/kobj.c new file mode 100644 index 000000000000..250fc7bb550f --- /dev/null +++ b/drivers/of/kobj.c @@ -0,0 +1,164 @@ +#include <linux/of.h> +#include <linux/slab.h> + +#include "of_private.h" + +/* true when node is initialized */ +static int of_node_is_initialized(struct device_node *node) +{ + return node && node->kobj.state_initialized; +} + +/* true when node is attached (i.e. present on sysfs) */ +int of_node_is_attached(struct device_node *node) +{ + return node && node->kobj.state_in_sysfs; +} + + +#ifndef CONFIG_OF_DYNAMIC +static void of_node_release(struct kobject *kobj) +{ + /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */ +} +#endif /* CONFIG_OF_DYNAMIC */ + +struct kobj_type of_node_ktype = { + .release = of_node_release, +}; + +static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t offset, size_t count) +{ + struct property *pp = container_of(bin_attr, struct property, attr); + return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length); +} + +/* always return newly allocated name, caller must free after use */ +static const char *safe_name(struct kobject *kobj, const char *orig_name) +{ + const char *name = orig_name; + struct kernfs_node *kn; + int i = 0; + + /* don't be a hero. After 16 tries give up */ + while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) { + sysfs_put(kn); + if (name != orig_name) + kfree(name); + name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i); + } + + if (name == orig_name) { + name = kstrdup(orig_name, GFP_KERNEL); + } else { + pr_warn("Duplicate name in %s, renamed to \"%s\"\n", + kobject_name(kobj), name); + } + return name; +} + +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 (!IS_ENABLED(CONFIG_SYSFS)) + return 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 ? 0400 : 0444; + pp->attr.size = secure ? 0 : pp->length; + pp->attr.read = of_node_property_read; + + rc = sysfs_create_bin_file(&np->kobj, &pp->attr); + WARN(rc, "error adding attribute %s to node %pOF\n", pp->name, np); + return rc; +} + +void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop) +{ + if (!IS_ENABLED(CONFIG_SYSFS)) + return; + + sysfs_remove_bin_file(&np->kobj, &prop->attr); + kfree(prop->attr.attr.name); +} + +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)) + __of_sysfs_remove_bin_file(np, prop); +} + +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) + __of_sysfs_remove_bin_file(np, oldprop); + __of_add_property_sysfs(np, newprop); +} + +int __of_attach_node_sysfs(struct device_node *np) +{ + const char *name; + struct kobject *parent; + 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 */ + name = safe_name(&of_kset->kobj, "base"); + parent = NULL; + } else { + name = safe_name(&np->parent->kobj, kbasename(np->full_name)); + parent = &np->parent->kobj; + } + if (!name) + return -ENOMEM; + rc = kobject_add(&np->kobj, parent, "%s", name); + kfree(name); + if (rc) + return rc; + + for_each_property_of_node(np, pp) + __of_add_property_sysfs(np, pp); + + return 0; +} + +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) + __of_sysfs_remove_bin_file(np, pp); + kobject_del(&np->kobj); + } + + /* finally remove the kobj_init ref */ + of_node_put(np); +} + diff --git a/drivers/of/of_private.h b/drivers/of/of_private.h index cc86a974f35f..43df14f0cbce 100644 --- a/drivers/of/of_private.h +++ b/drivers/of/of_private.h @@ -49,6 +49,29 @@ static inline int of_property_notify(int action, struct device_node *np, } #endif /* CONFIG_OF_DYNAMIC */ +#if defined(CONFIG_OF_KOBJ) +int of_node_is_attached(struct device_node *node); +int __of_add_property_sysfs(struct device_node *np, struct property *pp); +void __of_remove_property_sysfs(struct device_node *np, struct property *prop); +void __of_update_property_sysfs(struct device_node *np, struct property *newprop, + struct property *oldprop); +int __of_attach_node_sysfs(struct device_node *np); +void __of_detach_node_sysfs(struct device_node *np); +#else +static inline int __of_add_property_sysfs(struct device_node *np, struct property *pp) +{ + return 0; +} +static inline void __of_remove_property_sysfs(struct device_node *np, struct property *prop) {} +static inline void __of_update_property_sysfs(struct device_node *np, + struct property *newprop, struct property *oldprop) {} +static inline int __of_attach_node_sysfs(struct device_node *np) +{ + return 0; +} +static inline void __of_detach_node_sysfs(struct device_node *np) {} +#endif + #if defined(CONFIG_OF_UNITTEST) && defined(CONFIG_OF_OVERLAY) extern void __init unittest_unflatten_overlay_base(void); #else |