From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heikki Krogerus Subject: [PATCH v3 03/13] software node: Add support for references Date: Fri, 12 Apr 2019 16:41:12 +0300 Message-ID: <20190412134122.82903-4-heikki.krogerus@linux.intel.com> References: <20190412134122.82903-1-heikki.krogerus@linux.intel.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190412134122.82903-1-heikki.krogerus@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org To: "Rafael J. Wysocki" Cc: Greg Kroah-Hartman , Hans de Goede , Darren Hart , Andy Shevchenko , linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org List-Id: linux-acpi@vger.kernel.org Introducing functions that can be used for adding and removing references to other software nodes. The goal is to support fwnode_property_get_reference_args() also with software nodes, however, get_reference_args fwnode operation callback is not yet implemented in this commit for the software nodes. This commit will only add support for reference addition/removal. The next example shows how to add references to GPIOs using the format described in Documentation/acpi/gpio-properties.txt: /* Array with two GPIOs */ static struct fwnode_reference_args gpioargs[] __initdata = { { .nargs = 3, .args[0]= 19, /* index */ .args[1]= 0, /* pin */ .args[2]= 0, /* active_low */ }, { .nargs = 3, .args[0]= 20, /* index */ .args[1]= 0, /* pin */ .args[2]= 0, /* active_low */ }, { } }; static int myinit(void) { struct software_node_reference *ref; struct fwnode_handle *gpio_node; struct fwnode_handle *my_node; /* Creating the nodes */ gpio_node = fwnode_create_software_node(gpio_props, NULL); ... my_node = fwnode_create_software_node(my_props, NULL); ... /* gpio_node is associated with a GPIO/Pin controller in this example */ ... /* Assigning the actual node references */ gpioargs[0].fwnode = gpio_node; gpioargs[1].fwnode = gpio_node; /* my_node will now have a named ("gpios") reference to the two GPIOs */ ref = fwnode_create_software_node_reference(my_node, "gpios", gpioargs); ... return 0; } Signed-off-by: Heikki Krogerus --- drivers/base/swnode.c | 101 +++++++++++++++++++++++++++++++++++++++ include/linux/property.h | 8 ++++ 2 files changed, 109 insertions(+) diff --git a/drivers/base/swnode.c b/drivers/base/swnode.c index 7b321bf8424c..39b8f8f35cfe 100644 --- a/drivers/base/swnode.c +++ b/drivers/base/swnode.c @@ -11,10 +11,19 @@ #include #include +struct software_node_reference { + struct list_head list; + const char *name; + int nrefs; + struct fwnode_reference_args *args; +}; + struct software_node { int id; struct kobject kobj; struct fwnode_handle fwnode; + struct list_head references; + struct mutex lock; /* node lock */ /* hierarchy */ struct ida child_ids; @@ -598,9 +607,11 @@ fwnode_create_software_node(const struct property_entry *properties, swnode->kobj.kset = swnode_kset; swnode->fwnode.ops = &software_node_ops; + mutex_init(&swnode->lock); ida_init(&swnode->child_ids); INIT_LIST_HEAD(&swnode->entry); INIT_LIST_HEAD(&swnode->children); + INIT_LIST_HEAD(&swnode->references); swnode->parent = p; ret = kobject_init_and_add(&swnode->kobj, &software_node_type, @@ -631,6 +642,11 @@ void fwnode_remove_software_node(struct fwnode_handle *fwnode) if (!swnode) return; + mutex_lock(&swnode->lock); + WARN(!list_empty(&swnode->references), + "\"%s\" has still references", kobject_name(&swnode->kobj)); + mutex_unlock(&swnode->lock); + if (swnode->parent) { ida_simple_remove(&swnode->parent->child_ids, swnode->id); list_del(&swnode->entry); @@ -642,6 +658,91 @@ void fwnode_remove_software_node(struct fwnode_handle *fwnode) } EXPORT_SYMBOL_GPL(fwnode_remove_software_node); +/** + * fwnode_create_software_node_reference - Create named reference description + * @fwnode: The software node to have the references + * @name: Name given to reference description + * @args: Zero terminated array of software node references with arguments + * + * Associates software nodes listed in @args with @fwnode. The association is + * named @name. The reference count is incremented for the nodes in @args. + * + * Returns pointer to software node reference description on success, or ERR_PTR + * on failure. + */ +struct software_node_reference * +fwnode_create_software_node_reference(const struct fwnode_handle *fwnode, + const char *name, + const struct fwnode_reference_args *args) +{ + struct software_node *swnode = to_software_node(fwnode); + struct software_node_reference *ref; + int n; + + if (!swnode) + return ERR_PTR(-EINVAL); + + for (n = 0; args[n].fwnode; n++) + if (!is_software_node(args[n].fwnode)) + return ERR_PTR(-EINVAL); + + ref = kzalloc(sizeof(*ref), GFP_KERNEL); + if (!ref) + return ERR_PTR(-ENOMEM); + + ref->nrefs = n; + + ref->name = kstrdup(name, GFP_KERNEL); + if (!ref->name) { + kfree(ref); + return ERR_PTR(-ENOMEM); + } + + ref->args = kcalloc(ref->nrefs, sizeof(*ref->args), GFP_KERNEL); + if (!ref->args) { + kfree(ref->name); + kfree(ref); + return ERR_PTR(-ENOMEM); + } + + for (n = 0; n < ref->nrefs; n++) { + ref->args[n] = args[n]; + software_node_get(ref->args[n].fwnode); + } + + mutex_lock(&swnode->lock); + list_add_tail(&ref->list, &swnode->references); + mutex_unlock(&swnode->lock); + + return ref; +} +EXPORT_SYMBOL_GPL(fwnode_create_software_node_reference); + +/** + * fwnode_remove_software_node_reference - Remove named reference description + * @ref: Software node reference description + * + * Remove named reference @ref. Decrements the software node reference count of + * each node in @ref, and removes the association that was created in + * fwnode_create_software_node_reference(). + */ +void fwnode_remove_software_node_reference(struct software_node_reference *ref) +{ + int n; + + if (IS_ERR_OR_NULL(ref)) + return; + + for (n = 0; n < ref->nrefs; n++) + kobject_put(&to_software_node(ref->args[n].fwnode)->kobj); + + list_del(&ref->list); + kfree(ref->args); + kfree(ref->name); + kfree(ref); +} +EXPORT_SYMBOL_GPL(fwnode_remove_software_node_reference); + int software_node_notify(struct device *dev, unsigned long action) { struct fwnode_handle *fwnode = dev_fwnode(dev); diff --git a/include/linux/property.h b/include/linux/property.h index 65d3420dd5d1..40e12ca43556 100644 --- a/include/linux/property.h +++ b/include/linux/property.h @@ -314,6 +314,8 @@ int fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode, /* -------------------------------------------------------------------------- */ /* Software fwnode support - when HW description is incomplete or missing */ +struct sofware_node_reference; + bool is_software_node(const struct fwnode_handle *fwnode); int software_node_notify(struct device *dev, unsigned long action); @@ -323,4 +325,10 @@ fwnode_create_software_node(const struct property_entry *properties, const struct fwnode_handle *parent); void fwnode_remove_software_node(struct fwnode_handle *fwnode); +struct software_node_reference * +fwnode_create_software_node_reference(const struct fwnode_handle *fwnode, + const char *name, + const struct fwnode_reference_args *args); +void fwnode_remove_software_node_reference(struct software_node_reference *ref); + #endif /* _LINUX_PROPERTY_H_ */ -- 2.20.1