/* * firmware_class.c - Multi purpose firmware loading support * * Copyright (c) 2003 Manuel Estrada Sainz * * Please see Documentation/firmware_class/ for more information. * */ #include <linux/capability.h> #include <linux/device.h> #include <linux/module.h> #include <linux/init.h> #include <linux/timer.h> #include <linux/vmalloc.h> #include <linux/interrupt.h> #include <linux/bitops.h> #include <linux/mutex.h> #include <linux/kthread.h> #include <linux/firmware.h> #include "base.h" #define to_dev(obj) container_of(obj, struct device, kobj) MODULE_AUTHOR("Manuel Estrada Sainz"); MODULE_DESCRIPTION("Multi purpose firmware loading support"); MODULE_LICENSE("GPL"); enum { FW_STATUS_LOADING, FW_STATUS_DONE, FW_STATUS_ABORT, }; static int loading_timeout = 60; /* In seconds */ /* fw_lock could be moved to 'struct firmware_priv' but since it is just * guarding for corner cases a global lock should be OK */ static DEFINE_MUTEX(fw_lock); struct firmware_priv { char fw_id[FIRMWARE_NAME_MAX]; struct completion completion; struct bin_attribute attr_data; struct firmware *fw; unsigned long status; int alloc_size; struct timer_list timeout; }; static void fw_load_abort(struct firmware_priv *fw_priv) { set_bit(FW_STATUS_ABORT, &fw_priv->status); wmb(); complete(&fw_priv->completion); } static ssize_t firmware_timeout_show(struct class *class, char *buf) { return sprintf(buf, "%d\n", loading_timeout); } /** * firmware_timeout_store - set number of seconds to wait for firmware * @class: device class pointer * @buf: buffer to scan for timeout value * @count: number of bytes in @buf * * Sets the number of seconds to wait for the firmware. Once * this expires an error will be returned to the driver and no * firmware will be provided. * * Note: zero means 'wait forever'. **/ static ssize_t firmware_timeout_store(struct class *class, const char *buf, size_t count) { loading_timeout = simple_strtol(buf, NULL, 10); if (loading_timeout < 0) loading_timeout = 0; return count; } static CLASS_ATTR(timeout, 0644, firmware_timeout_show, firmware_timeout_store); static void fw_dev_release(struct device *dev); static int firmware_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) { struct firmware_priv *fw_priv = dev_get_drvdata(dev); int i = 0, len = 0; if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len, "FIRMWARE=%s", fw_priv->fw_id)) return -ENOMEM; if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &len, "TIMEOUT=%i", loading_timeout)) return -ENOMEM; envp[i] = NULL; return 0; } static struct class firmware_class = { .name = "firmware", .dev_uevent = firmware_uevent, .dev_release = fw_dev_release, }; static ssize_t firmware_loading_show(struct device *dev, struct device_attribute *attr, char *buf) { struct firmware_priv *fw_priv = dev_get_drvdata(dev); int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status); return sprintf(buf, "%d\n", loading); } /** * firmware_loading_store - set value in the 'loading' control file * @dev: device pointer * @attr: device attribute pointer * @buf: buffer to scan for loading control value * @count: number of bytes in @buf * * The relevant values are: * * 1: Start a load, discarding any previous partial load. * 0: Conclude the load and hand the data to the driver code. * -1: Conclude the load with an error and discard any written data. **/ static ssize_t firmware_loading_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct firmware_priv *fw_priv = dev_get_drvdata(dev); int loading = simple_strtol(buf, NULL, 10); switch (loading) { case 1: mutex_lock(&fw_lock); if (!fw_priv->fw) { mutex_unlock(&fw_lock); break; } vfree(fw_priv->fw->data); fw_priv->fw->data = NULL; fw_priv->fw->size = 0; fw_priv->alloc_size = 0; set_bit(FW_STATUS_LOADING, &fw_priv->status); mutex_unlock(&fw_lock); break; case 0: if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) { complete(&fw_priv->completion); clear_bit(FW_STATUS_LOADING, &fw_priv->status); break; } /* fallthrough */ default: printk(KERN_ERR "%s: unexpected value (%d)\n", __FUNCTION__, loading); /* fallthrough */ case -1: fw_load_abort(fw_priv); break; } return count; } static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store); static ssize_t firmware_data_read(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = to_dev(kobj); struct firmware_priv *fw_priv = dev_get_drvdata(dev); struct firmware *fw; ssize_t ret_count = count; mutex_lock(&fw_lock); fw = fw_priv->fw; if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { ret_count = -ENODEV; goto out; } if (offset > fw->size) { ret_count = 0; goto out; } if (offset + ret_count > fw->size) ret_count = fw->size - offset; memcpy(buffer, fw->data + offset, ret_count); out: mutex_unlock(&fw_lock); return ret_count; } static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size) { u8 *new_data; int new_size = fw_priv->alloc_size; if (min_size <= fw_priv->alloc_size) return 0; new_size = ALIGN(min_size, PAGE_SIZE); new_data = vmalloc(new_size); if (!new_data) { printk(KERN_ERR "%s: unable to alloc buffer\n", __FUNCTION__); /* Make sure that we don't keep incomplete data */ fw_load_abort(fw_priv); return -ENOMEM; } fw_priv->alloc_size = new_size; if (fw_priv->fw->data) { memcpy(new_data, fw_priv->fw->data, fw_priv->fw->size); vfree(fw_priv->fw->data); } fw_priv->fw->data = new_data; BUG_ON(min_size > fw_priv->alloc_size); return 0; } /** * firmware_data_write - write method for firmware * @kobj: kobject for the device * @bin_attr: bin_attr structure * @buffer: buffer being written * @offset: buffer offset for write in total data store area * @count: buffer size * * Data written to the 'data' attribute will be later handed to * the driver as a firmware image. **/ static ssize_t firmware_data_write(struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = to_dev(kobj); struct firmware_priv *fw_priv = dev_get_drvdata(dev); struct firmware *fw; ssize_t retval; if (!capable(CAP_SYS_RAWIO)) return -EPERM; mutex_lock(&fw_lock); fw = fw_priv->fw; if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { retval = -ENODEV; goto out; } retval = fw_realloc_buffer(fw_priv, offset + count); if (retval) goto out; memcpy(fw->data + offset, buffer, count); fw->size = max_t(size_t, offset + count, fw->size); retval = count; out: mutex_unlock(&fw_lock); return retval; } static struct bin_attribute firmware_attr_data_tmpl = { .attr = {.name = "data", .mode = 0644}, .size = 0, .read = firmware_data_read, .write = firmware_data_write, }; static void fw_dev_release(struct device *dev) { struct firmware_priv *fw_priv = dev_get_drvdata(dev); kfree(fw_priv); kfree(dev); module_put(THIS_MODULE); } static void firmware_class_timeout(u_long data) { struct firmware_priv *fw_priv = (struct firmware_priv *) data; fw_load_abort(fw_priv); } static inline void fw_setup_device_id(struct device *f_dev, struct device *dev) { /* XXX warning we should watch out for name collisions */ strlcpy(f_dev->bus_id, dev->bus_id, BUS_ID_SIZE); } static int fw_register_device(struct device **dev_p, const char *fw_name, struct device *device) { int retval; struct firmware_priv *fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL); struct device *f_dev = kzalloc(sizeof(*f_dev), GFP_KERNEL); *dev_p = NULL; if (!fw_priv || !f_dev) { printk(KERN_ERR "%s: kmalloc failed\n", __FUNCTION__); retval = -ENOMEM; goto error_kfree; } init_completion(&fw_priv->completion); fw_priv->attr_data = firmware_attr_data_tmpl; strlcpy(fw_priv->fw_id, fw_name, FIRMWARE_NAME_MAX); fw_priv->timeout.function = firmware_class_timeout; fw_priv->timeout.data = (u_long) fw_priv; init_timer(&fw_priv->timeout); fw_setup_device_id(f_dev, device); f_dev->parent = device; f_dev->class = &firmware_class; dev_set_drvdata(f_dev, fw_priv); f_dev->uevent_suppress = 1; retval = device_register(f_dev); if (retval) { printk(KERN_ERR "%s: device_register failed\n", __FUNCTION__); goto error_kfree; } *dev_p = f_dev; return 0; error_kfree: kfree(fw_priv); kfree(f_dev); return retval; } static int fw_setup_device(struct firmware *fw, struct device **dev_p, const char *fw_name, struct device *device, int uevent) { struct device *f_dev; struct firmware_priv *fw_priv; int retval; *dev_p = NULL; retval = fw_register_device(&f_dev, fw_name, device); if (retval) goto out; /* Need to pin this module until class device is destroyed */ __module_get(THIS_MODULE); fw_priv = dev_get_drvdata(f_dev); fw_priv->fw = fw; retval = sysfs_create_bin_file(&f_dev->kobj, &fw_priv->attr_data); if (retval) { printk(KERN_ERR "%s: sysfs_create_bin_file failed\n", __FUNCTION__); goto error_unreg; } retval = device_create_file(f_dev, &dev_attr_loading); if (retval) { printk(KERN_ERR "%s: device_create_file failed\n", __FUNCTION__); goto error_unreg; } if (uevent) f_dev->uevent_suppress = 0; *dev_p = f_dev; goto out; error_unreg: device_unregister(f_dev); out: return retval; } static int _request_firmware(const struct firmware **firmware_p, const char *name, struct device *device, int uevent) { struct device *f_dev; struct firmware_priv *fw_priv; struct firmware *firmware; int retval; if (!firmware_p) return -EINVAL; *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL); if (!firmware) { printk(KERN_ERR "%s: kmalloc(struct firmware) failed\n", __FUNCTION__); retval = -ENOMEM; goto out; } retval = fw_setup_device(firmware, &f_dev, name, device, uevent); if (retval) goto error_kfree_fw; fw_priv = dev_get_drvdata(f_dev); if (uevent) { if (loading_timeout > 0) { fw_priv->timeout.expires = jiffies + loading_timeout * HZ; add_timer(&fw_priv->timeout); } kobject_uevent(&f_dev->kobj, KOBJ_ADD); wait_for_completion(&fw_priv->completion); set_bit(FW_STATUS_DONE, &fw_priv->status); del_timer_sync(&fw_priv->timeout); } else wait_for_completion(&fw_priv->completion); mutex_lock(&fw_lock); if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) { retval = -ENOENT; release_firmware(fw_priv->fw); *firmware_p = NULL; } fw_priv->fw = NULL; mutex_unlock(&fw_lock); device_unregister(f_dev); goto out; error_kfree_fw: kfree(firmware); *firmware_p = NULL; out: return retval; } /** * request_firmware: - send firmware request and wait for it * @firmware_p: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded * * @firmware_p will be used to return a firmware image by the name * of @name for device @device. * * Should be called from user context where sleeping is allowed. * * @name will be used as $FIRMWARE in the uevent environment and * should be distinctive enough not to be confused with any other * firmware image for this or any other device. **/ int request_firmware(const struct firmware **firmware_p, const char *name, struct device *device) { int uevent = 1; return _request_firmware(firmware_p, name, device, uevent); } /** * release_firmware: - release the resource associated with a firmware image * @fw: firmware resource to release **/ void release_firmware(const struct firmware *fw) { if (fw) { vfree(fw->data); kfree(fw); } } /* Async support */ struct firmware_work { struct work_struct work; struct module *module; const char *name; struct device *device; void *context; void (*cont)(const struct firmware *fw, void *context); int uevent; }; static int request_firmware_work_func(void *arg) { struct firmware_work *fw_work = arg; const struct firmware *fw; int ret; if (!arg) { WARN_ON(1); return 0; } ret = _request_firmware(&fw, fw_work->name, fw_work->device, fw_work->uevent); if (ret < 0) fw_work->cont(NULL, fw_work->context); else { fw_work->cont(fw, fw_work->context); release_firmware(fw); } module_put(fw_work->module); kfree(fw_work); return ret; } /** * request_firmware_nowait: asynchronous version of request_firmware * @module: module requesting the firmware * @uevent: sends uevent to copy the firmware image if this flag * is non-zero else the firmware copy must be done manually. * @name: name of firmware file * @device: device for which firmware is being loaded * @context: will be passed over to @cont, and * @fw may be %NULL if firmware request fails. * @cont: function will be called asynchronously when the firmware * request is over. * * Asynchronous variant of request_firmware() for contexts where * it is not possible to sleep. **/ int request_firmware_nowait( struct module *module, int uevent, const char *name, struct device *device, void *context, void (*cont)(const struct firmware *fw, void *context)) { struct task_struct *task; struct firmware_work *fw_work = kmalloc(sizeof (struct firmware_work), GFP_ATOMIC); if (!fw_work) return -ENOMEM; if (!try_module_get(module)) { kfree(fw_work); return -EFAULT; } *fw_work = (struct firmware_work) { .module = module, .name = name, .device = device, .context = context, .cont = cont, .uevent = uevent, }; task = kthread_run(request_firmware_work_func, fw_work, "firmware/%s", name); if (IS_ERR(task)) { fw_work->cont(NULL, fw_work->context); module_put(fw_work->module); kfree(fw_work); return PTR_ERR(task); } return 0; } static int __init firmware_class_init(void) { int error; error = class_register(&firmware_class); if (error) { printk(KERN_ERR "%s: class_register failed\n", __FUNCTION__); return error; } error = class_create_file(&firmware_class, &class_attr_timeout); if (error) { printk(KERN_ERR "%s: class_create_file failed\n", __FUNCTION__); class_unregister(&firmware_class); } return error; } static void __exit firmware_class_exit(void) { class_unregister(&firmware_class); } fs_initcall(firmware_class_init); module_exit(firmware_class_exit); EXPORT_SYMBOL(release_firmware); EXPORT_SYMBOL(request_firmware); EXPORT_SYMBOL(request_firmware_nowait);