// SPDX-License-Identifier: GPL-2.0-or-later /* * Device probing and sysfs code. * * Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net> */ #include <linux/bug.h> #include <linux/ctype.h> #include <linux/delay.h> #include <linux/device.h> #include <linux/errno.h> #include <linux/firewire.h> #include <linux/firewire-constants.h> #include <linux/idr.h> #include <linux/jiffies.h> #include <linux/kobject.h> #include <linux/list.h> #include <linux/mod_devicetable.h> #include <linux/module.h> #include <linux/mutex.h> #include <linux/random.h> #include <linux/rwsem.h> #include <linux/slab.h> #include <linux/spinlock.h> #include <linux/string.h> #include <linux/workqueue.h> #include <linux/atomic.h> #include <asm/byteorder.h> #include "core.h" void fw_csr_iterator_init(struct fw_csr_iterator *ci, const u32 *p) { ci->p = p + 1; ci->end = ci->p + (p[0] >> 16); } EXPORT_SYMBOL(fw_csr_iterator_init); int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value) { *key = *ci->p >> 24; *value = *ci->p & 0xffffff; return ci->p++ < ci->end; } EXPORT_SYMBOL(fw_csr_iterator_next); static const u32 *search_leaf(const u32 *directory, int search_key) { struct fw_csr_iterator ci; int last_key = 0, key, value; fw_csr_iterator_init(&ci, directory); while (fw_csr_iterator_next(&ci, &key, &value)) { if (last_key == search_key && key == (CSR_DESCRIPTOR | CSR_LEAF)) return ci.p - 1 + value; last_key = key; } return NULL; } static int textual_leaf_to_string(const u32 *block, char *buf, size_t size) { unsigned int quadlets, i; char c; if (!size || !buf) return -EINVAL; quadlets = min(block[0] >> 16, 256U); if (quadlets < 2) return -ENODATA; if (block[1] != 0 || block[2] != 0) /* unknown language/character set */ return -ENODATA; block += 3; quadlets -= 2; for (i = 0; i < quadlets * 4 && i < size - 1; i++) { c = block[i / 4] >> (24 - 8 * (i % 4)); if (c == '\0') break; buf[i] = c; } buf[i] = '\0'; return i; } /** * fw_csr_string() - reads a string from the configuration ROM * @directory: e.g. root directory or unit directory * @key: the key of the preceding directory entry * @buf: where to put the string * @size: size of @buf, in bytes * * The string is taken from a minimal ASCII text descriptor leaf after * the immediate entry with @key. The string is zero-terminated. * An overlong string is silently truncated such that it and the * zero byte fit into @size. * * Returns strlen(buf) or a negative error code. */ int fw_csr_string(const u32 *directory, int key, char *buf, size_t size) { const u32 *leaf = search_leaf(directory, key); if (!leaf) return -ENOENT; return textual_leaf_to_string(leaf, buf, size); } EXPORT_SYMBOL(fw_csr_string); static void get_ids(const u32 *directory, int *id) { struct fw_csr_iterator ci; int key, value; fw_csr_iterator_init(&ci, directory); while (fw_csr_iterator_next(&ci, &key, &value)) { switch (key) { case CSR_VENDOR: id[0] = value; break; case CSR_MODEL: id[1] = value; break; case CSR_SPECIFIER_ID: id[2] = value; break; case CSR_VERSION: id[3] = value; break; } } } static void get_modalias_ids(struct fw_unit *unit, int *id) { get_ids(&fw_parent_device(unit)->config_rom[5], id); get_ids(unit->directory, id); } static bool match_ids(const struct ieee1394_device_id *id_table, int *id) { int match = 0; if (id[0] == id_table->vendor_id) match |= IEEE1394_MATCH_VENDOR_ID; if (id[1] == id_table->model_id) match |= IEEE1394_MATCH_MODEL_ID; if (id[2] == id_table->specifier_id) match |= IEEE1394_MATCH_SPECIFIER_ID; if (id[3] == id_table->version) match |= IEEE1394_MATCH_VERSION; return (match & id_table->match_flags) == id_table->match_flags; } static const struct ieee1394_device_id *unit_match(struct device *dev, struct device_driver *drv) { const struct ieee1394_device_id *id_table = container_of(drv, struct fw_driver, driver)->id_table; int id[] = {0, 0, 0, 0}; get_modalias_ids(fw_unit(dev), id); for (; id_table->match_flags != 0; id_table++) if (match_ids(id_table, id)) return id_table; return NULL; } static bool is_fw_unit(struct device *dev); static int fw_unit_match(struct device *dev, struct device_driver *drv) { /* We only allow binding to fw_units. */ return is_fw_unit(dev) && unit_match(dev, drv) != NULL; } static int fw_unit_probe(struct device *dev) { struct fw_driver *driver = container_of(dev->driver, struct fw_driver, driver); return driver->probe(fw_unit(dev), unit_match(dev, dev->driver)); } static int fw_unit_remove(struct device *dev) { struct fw_driver *driver = container_of(dev->driver, struct fw_driver, driver); return driver->remove(fw_unit(dev)), 0; } static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size) { int id[] = {0, 0, 0, 0}; get_modalias_ids(unit, id); return snprintf(buffer, buffer_size, "ieee1394:ven%08Xmo%08Xsp%08Xver%08X", id[0], id[1], id[2], id[3]); } static int fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env) { struct fw_unit *unit = fw_unit(dev); char modalias[64]; get_modalias(unit, modalias, sizeof(modalias)); if (add_uevent_var(env, "MODALIAS=%s", modalias)) return -ENOMEM; return 0; } struct bus_type fw_bus_type = { .name = "firewire", .match = fw_unit_match, .probe = fw_unit_probe, .remove = fw_unit_remove, }; EXPORT_SYMBOL(fw_bus_type); int fw_device_enable_phys_dma(struct fw_device *device) { int generation = device->generation; /* device->node_id, accessed below, must not be older than generation */ smp_rmb(); return device->card->driver->enable_phys_dma(device->card, device->node_id, generation); } EXPORT_SYMBOL(fw_device_enable_phys_dma); struct config_rom_attribute { struct device_attribute attr; u32 key; }; static ssize_t show_immediate(struct device *dev, struct device_attribute *dattr, char *buf) { struct config_rom_attribute *attr = container_of(dattr, struct config_rom_attribute, attr); struct fw_csr_iterator ci; const u32 *dir; int key, value, ret = -ENOENT; down_read(&fw_device_rwsem); if (is_fw_unit(dev)) dir = fw_unit(dev)->directory; else dir = fw_device(dev)->config_rom + 5; fw_csr_iterator_init(&ci, dir); while (fw_csr_iterator_next(&ci, &key, &value)) if (attr->key == key) { ret = snprintf(buf, buf ? PAGE_SIZE : 0, "0x%06x\n", value); break; } up_read(&fw_device_rwsem); return ret; } #define IMMEDIATE_ATTR(name, key) \ { __ATTR(name, S_IRUGO, show_immediate, NULL), key } static ssize_t show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf) { struct config_rom_attribute *attr = container_of(dattr, struct config_rom_attribute, attr); const u32 *dir; size_t bufsize; char dummy_buf[2]; int ret; down_read(&fw_device_rwsem); if (is_fw_unit(dev)) dir = fw_unit(dev)->directory; else dir = fw_device(dev)->config_rom + 5; if (buf) { bufsize = PAGE_SIZE - 1; } else { buf = dummy_buf; bufsize = 1; } ret = fw_csr_string(dir, attr->key, buf, bufsize); if (ret >= 0) { /* Strip trailing whitespace and add newline. */ while (ret > 0 && isspace(buf[ret - 1])) ret--; strcpy(buf + ret, "\n"); ret++; } up_read(&fw_device_rwsem); return ret; } #define TEXT_LEAF_ATTR(name, key) \ { __ATTR(name, S_IRUGO, show_text_leaf, NULL), key } static struct config_rom_attribute config_rom_attributes[] = { IMMEDIATE_ATTR(vendor, CSR_VENDOR), IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION), IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID), IMMEDIATE_ATTR(version, CSR_VERSION), IMMEDIATE_ATTR(model, CSR_MODEL), TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR), TEXT_LEAF_ATTR(model_name, CSR_MODEL), TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION), }; static void init_fw_attribute_group(struct device *dev, struct device_attribute *attrs, struct fw_attribute_group *group) { struct device_attribute *attr; int i, j; for (j = 0; attrs[j].attr.name != NULL; j++) group->attrs[j] = &attrs[j].attr; for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) { attr = &config_rom_attributes[i].attr; if (attr->show(dev, attr, NULL) < 0) continue; group->attrs[j++] = &attr->attr; } group->attrs[j] = NULL; group->groups[0] = &group->group; group->groups[1] = NULL; group->group.attrs = group->attrs; dev->groups = (const struct attribute_group **) group->groups; } static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_unit *unit = fw_unit(dev); int length; length = get_modalias(unit, buf, PAGE_SIZE); strcpy(buf + length, "\n"); return length + 1; } static ssize_t rom_index_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_device *device = fw_device(dev->parent); struct fw_unit *unit = fw_unit(dev); return snprintf(buf, PAGE_SIZE, "%d\n", (int)(unit->directory - device->config_rom)); } static struct device_attribute fw_unit_attributes[] = { __ATTR_RO(modalias), __ATTR_RO(rom_index), __ATTR_NULL, }; static ssize_t config_rom_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_device *device = fw_device(dev); size_t length; down_read(&fw_device_rwsem); length = device->config_rom_length * 4; memcpy(buf, device->config_rom, length); up_read(&fw_device_rwsem); return length; } static ssize_t guid_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_device *device = fw_device(dev); int ret; down_read(&fw_device_rwsem); ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n", device->config_rom[3], device->config_rom[4]); up_read(&fw_device_rwsem); return ret; } static ssize_t is_local_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_device *device = fw_device(dev); return sprintf(buf, "%u\n", device->is_local); } static int units_sprintf(char *buf, const u32 *directory) { struct fw_csr_iterator ci; int key, value; int specifier_id = 0; int version = 0; fw_csr_iterator_init(&ci, directory); while (fw_csr_iterator_next(&ci, &key, &value)) { switch (key) { case CSR_SPECIFIER_ID: specifier_id = value; break; case CSR_VERSION: version = value; break; } } return sprintf(buf, "0x%06x:0x%06x ", specifier_id, version); } static ssize_t units_show(struct device *dev, struct device_attribute *attr, char *buf) { struct fw_device *device = fw_device(dev); struct fw_csr_iterator ci; int key, value, i = 0; down_read(&fw_device_rwsem); fw_csr_iterator_init(&ci, &device->config_rom[5]); while (fw_csr_iterator_next(&ci, &key, &value)) { if (key != (CSR_UNIT | CSR_DIRECTORY)) continue; i += units_sprintf(&buf[i], ci.p + value - 1); if (i >= PAGE_SIZE - (8 + 1 + 8 + 1)) break; } up_read(&fw_device_rwsem); if (i) buf[i - 1] = '\n'; return i; } static struct device_attribute fw_device_attributes[] = { __ATTR_RO(config_rom), __ATTR_RO(guid), __ATTR_RO(is_local), __ATTR_RO(units), __ATTR_NULL, }; static int read_rom(struct fw_device *device, int generation, int index, u32 *data) { u64 offset = (CSR_REGISTER_BASE | CSR_CONFIG_ROM) + index * 4; int i, rcode; /* device->node_id, accessed below, must not be older than generation */ smp_rmb(); for (i = 10; i < 100; i += 10) { rcode = fw_run_transaction(device->card, TCODE_READ_QUADLET_REQUEST, device->node_id, generation, device->max_speed, offset, data, 4); if (rcode != RCODE_BUSY) break; msleep(i); } be32_to_cpus(data); return rcode; } #define MAX_CONFIG_ROM_SIZE 256 /* * Read the bus info block, perform a speed probe, and read all of the rest of * the config ROM. We do all this with a cached bus generation. If the bus * generation changes under us, read_config_rom will fail and get retried. * It's better to start all over in this case because the node from which we * are reading the ROM may have changed the ROM during the reset. * Returns either a result code or a negative error code. */ static int read_config_rom(struct fw_device *device, int generation) { struct fw_card *card = device->card; const u32 *old_rom, *new_rom; u32 *rom, *stack; u32 sp, key; int i, end, length, ret; rom = kmalloc(sizeof(*rom) * MAX_CONFIG_ROM_SIZE + sizeof(*stack) * MAX_CONFIG_ROM_SIZE, GFP_KERNEL); if (rom == NULL) return -ENOMEM; stack = &rom[MAX_CONFIG_ROM_SIZE]; memset(rom, 0, sizeof(*rom) * MAX_CONFIG_ROM_SIZE); device->max_speed = SCODE_100; /* First read the bus info block. */ for (i = 0; i < 5; i++) { ret = read_rom(device, generation, i, &rom[i]); if (ret != RCODE_COMPLETE) goto out; /* * As per IEEE1212 7.2, during initialization, devices can * reply with a 0 for the first quadlet of the config * rom to indicate that they are booting (for example, * if the firmware is on the disk of a external * harddisk). In that case we just fail, and the * retry mechanism will try again later. */ if (i == 0 && rom[i] == 0) { ret = RCODE_BUSY; goto out; } } device->max_speed = device->node->max_speed; /* * Determine the speed of * - devices with link speed less than PHY speed, * - devices with 1394b PHY (unless only connected to 1394a PHYs), * - all devices if there are 1394b repeaters. * Note, we cannot use the bus info block's link_spd as starting point * because some buggy firmwares set it lower than necessary and because * 1394-1995 nodes do not have the field. */ if ((rom[2] & 0x7) < device->max_speed || device->max_speed == SCODE_BETA || card->beta_repeaters_present) { u32 dummy; /* for S1600 and S3200 */ if (device->max_speed == SCODE_BETA) device->max_speed = card->link_speed; while (device->max_speed > SCODE_100) { if (read_rom(device, generation, 0, &dummy) == RCODE_COMPLETE) break; device->max_speed--; } } /* * Now parse the config rom. The config rom is a recursive * directory structure so we parse it using a stack of * references to the blocks that make up the structure. We * push a reference to the root directory on the stack to * start things off. */ length = i; sp = 0; stack[sp++] = 0xc0000005; while (sp > 0) { /* * Pop the next block reference of the stack. The * lower 24 bits is the offset into the config rom, * the upper 8 bits are the type of the reference the * block. */ key = stack[--sp]; i = key & 0xffffff; if (WARN_ON(i >= MAX_CONFIG_ROM_SIZE)) { ret = -ENXIO; goto out; } /* Read header quadlet for the block to get the length. */ ret = read_rom(device, generation, i, &rom[i]); if (ret != RCODE_COMPLETE) goto out; end = i + (rom[i] >> 16) + 1; if (end > MAX_CONFIG_ROM_SIZE) { /* * This block extends outside the config ROM which is * a firmware bug. Ignore this whole block, i.e. * simply set a fake block length of 0. */ fw_err(card, "skipped invalid ROM block %x at %llx\n", rom[i], i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); rom[i] = 0; end = i; } i++; /* * Now read in the block. If this is a directory * block, check the entries as we read them to see if * it references another block, and push it in that case. */ for (; i < end; i++) { ret = read_rom(device, generation, i, &rom[i]); if (ret != RCODE_COMPLETE) goto out; if ((key >> 30) != 3 || (rom[i] >> 30) < 2) continue; /* * Offset points outside the ROM. May be a firmware * bug or an Extended ROM entry (IEEE 1212-2001 clause * 7.7.18). Simply overwrite this pointer here by a * fake immediate entry so that later iterators over * the ROM don't have to check offsets all the time. */ if (i + (rom[i] & 0xffffff) >= MAX_CONFIG_ROM_SIZE) { fw_err(card, "skipped unsupported ROM entry %x at %llx\n", rom[i], i * 4 | CSR_REGISTER_BASE | CSR_CONFIG_ROM); rom[i] = 0; continue; } stack[sp++] = i + rom[i]; } if (length < i) length = i; } old_rom = device->config_rom; new_rom = kmemdup(rom, length * 4, GFP_KERNEL); if (new_rom == NULL) { ret = -ENOMEM; goto out; } down_write(&fw_device_rwsem); device->config_rom = new_rom; device->config_rom_length = length; up_write(&fw_device_rwsem); kfree(old_rom); ret = RCODE_COMPLETE; device->max_rec = rom[2] >> 12 & 0xf; device->cmc = rom[2] >> 30 & 1; device->irmc = rom[2] >> 31 & 1; out: kfree(rom); return ret; } static void fw_unit_release(struct device *dev) { struct fw_unit *unit = fw_unit(dev); fw_device_put(fw_parent_device(unit)); kfree(unit); } static struct device_type fw_unit_type = { .uevent = fw_unit_uevent, .release = fw_unit_release, }; static bool is_fw_unit(struct device *dev) { return dev->type == &fw_unit_type; } static void create_units(struct fw_device *device) { struct fw_csr_iterator ci; struct fw_unit *unit; int key, value, i; i = 0; fw_csr_iterator_init(&ci, &device->config_rom[5]); while (fw_csr_iterator_next(&ci, &key, &value)) { if (key != (CSR_UNIT | CSR_DIRECTORY)) continue; /* * Get the address of the unit directory and try to * match the drivers id_tables against it. */ unit = kzalloc(sizeof(*unit), GFP_KERNEL); if (unit == NULL) continue; unit->directory = ci.p + value - 1; unit->device.bus = &fw_bus_type; unit->device.type = &fw_unit_type; unit->device.parent = &device->device; dev_set_name(&unit->device, "%s.%d", dev_name(&device->device), i++); BUILD_BUG_ON(ARRAY_SIZE(unit->attribute_group.attrs) < ARRAY_SIZE(fw_unit_attributes) + ARRAY_SIZE(config_rom_attributes)); init_fw_attribute_group(&unit->device, fw_unit_attributes, &unit->attribute_group); if (device_register(&unit->device) < 0) goto skip_unit; fw_device_get(device); continue; skip_unit: kfree(unit); } } static int shutdown_unit(struct device *device, void *data) { device_unregister(device); return 0; } /* * fw_device_rwsem acts as dual purpose mutex: * - serializes accesses to fw_device_idr, * - serializes accesses to fw_device.config_rom/.config_rom_length and * fw_unit.directory, unless those accesses happen at safe occasions */ DECLARE_RWSEM(fw_device_rwsem); DEFINE_IDR(fw_device_idr); int fw_cdev_major; struct fw_device *fw_device_get_by_devt(dev_t devt) { struct fw_device *device; down_read(&fw_device_rwsem); device = idr_find(&fw_device_idr, MINOR(devt)); if (device) fw_device_get(device); up_read(&fw_device_rwsem); return device; } struct workqueue_struct *fw_workqueue; EXPORT_SYMBOL(fw_workqueue); static void fw_schedule_device_work(struct fw_device *device, unsigned long delay) { queue_delayed_work(fw_workqueue, &device->work, delay); } /* * These defines control the retry behavior for reading the config * rom. It shouldn't be necessary to tweak these; if the device * doesn't respond to a config rom read within 10 seconds, it's not * going to respond at all. As for the initial delay, a lot of * devices will be able to respond within half a second after bus * reset. On the other hand, it's not really worth being more * aggressive than that, since it scales pretty well; if 10 devices * are plugged in, they're all getting read within one second. */ #define MAX_RETRIES 10 #define RETRY_DELAY (3 * HZ) #define INITIAL_DELAY (HZ / 2) #define SHUTDOWN_DELAY (2 * HZ) static void fw_device_shutdown(struct work_struct *work) { struct fw_device *device = container_of(work, struct fw_device, work.work); int minor = MINOR(device->device.devt); if (time_before64(get_jiffies_64(), device->card->reset_jiffies + SHUTDOWN_DELAY) && !list_empty(&device->card->link)) { fw_schedule_device_work(device, SHUTDOWN_DELAY); return; } if (atomic_cmpxchg(&device->state, FW_DEVICE_GONE, FW_DEVICE_SHUTDOWN) != FW_DEVICE_GONE) return; fw_device_cdev_remove(device); device_for_each_child(&device->device, NULL, shutdown_unit); device_unregister(&device->device); down_write(&fw_device_rwsem); idr_remove(&fw_device_idr, minor); up_write(&fw_device_rwsem); fw_device_put(device); } static void fw_device_release(struct device *dev) { struct fw_device *device = fw_device(dev); struct fw_card *card = device->card; unsigned long flags; /* * Take the card lock so we don't set this to NULL while a * FW_NODE_UPDATED callback is being handled or while the * bus manager work looks at this node. */ spin_lock_irqsave(&card->lock, flags); device->node->data = NULL; spin_unlock_irqrestore(&card->lock, flags); fw_node_put(device->node); kfree(device->config_rom); kfree(device); fw_card_put(card); } static struct device_type fw_device_type = { .release = fw_device_release, }; static bool is_fw_device(struct device *dev) { return dev->type == &fw_device_type; } static int update_unit(struct device *dev, void *data) { struct fw_unit *unit = fw_unit(dev); struct fw_driver *driver = (struct fw_driver *)dev->driver; if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) { device_lock(dev); driver->update(unit); device_unlock(dev); } return 0; } static void fw_device_update(struct work_struct *work) { struct fw_device *device = container_of(work, struct fw_device, work.work); fw_device_cdev_update(device); device_for_each_child(&device->device, NULL, update_unit); } /* * If a device was pending for deletion because its node went away but its * bus info block and root directory header matches that of a newly discovered * device, revive the existing fw_device. * The newly allocated fw_device becomes obsolete instead. */ static int lookup_existing_device(struct device *dev, void *data) { struct fw_device *old = fw_device(dev); struct fw_device *new = data; struct fw_card *card = new->card; int match = 0; if (!is_fw_device(dev)) return 0; down_read(&fw_device_rwsem); /* serialize config_rom access */ spin_lock_irq(&card->lock); /* serialize node access */ if (memcmp(old->config_rom, new->config_rom, 6 * 4) == 0 && atomic_cmpxchg(&old->state, FW_DEVICE_GONE, FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { struct fw_node *current_node = new->node; struct fw_node *obsolete_node = old->node; new->node = obsolete_node; new->node->data = new; old->node = current_node; old->node->data = old; old->max_speed = new->max_speed; old->node_id = current_node->node_id; smp_wmb(); /* update node_id before generation */ old->generation = card->generation; old->config_rom_retries = 0; fw_notice(card, "rediscovered device %s\n", dev_name(dev)); old->workfn = fw_device_update; fw_schedule_device_work(old, 0); if (current_node == card->root_node) fw_schedule_bm_work(card, 0); match = 1; } spin_unlock_irq(&card->lock); up_read(&fw_device_rwsem); return match; } enum { BC_UNKNOWN = 0, BC_UNIMPLEMENTED, BC_IMPLEMENTED, }; static void set_broadcast_channel(struct fw_device *device, int generation) { struct fw_card *card = device->card; __be32 data; int rcode; if (!card->broadcast_channel_allocated) return; /* * The Broadcast_Channel Valid bit is required by nodes which want to * transmit on this channel. Such transmissions are practically * exclusive to IP over 1394 (RFC 2734). IP capable nodes are required * to be IRM capable and have a max_rec of 8 or more. We use this fact * to narrow down to which nodes we send Broadcast_Channel updates. */ if (!device->irmc || device->max_rec < 8) return; /* * Some 1394-1995 nodes crash if this 1394a-2000 register is written. * Perform a read test first. */ if (device->bc_implemented == BC_UNKNOWN) { rcode = fw_run_transaction(card, TCODE_READ_QUADLET_REQUEST, device->node_id, generation, device->max_speed, CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, &data, 4); switch (rcode) { case RCODE_COMPLETE: if (data & cpu_to_be32(1 << 31)) { device->bc_implemented = BC_IMPLEMENTED; break; } /* else, fall through - to case address error */ case RCODE_ADDRESS_ERROR: device->bc_implemented = BC_UNIMPLEMENTED; } } if (device->bc_implemented == BC_IMPLEMENTED) { data = cpu_to_be32(BROADCAST_CHANNEL_INITIAL | BROADCAST_CHANNEL_VALID); fw_run_transaction(card, TCODE_WRITE_QUADLET_REQUEST, device->node_id, generation, device->max_speed, CSR_REGISTER_BASE + CSR_BROADCAST_CHANNEL, &data, 4); } } int fw_device_set_broadcast_channel(struct device *dev, void *gen) { if (is_fw_device(dev)) set_broadcast_channel(fw_device(dev), (long)gen); return 0; } static void fw_device_init(struct work_struct *work) { struct fw_device *device = container_of(work, struct fw_device, work.work); struct fw_card *card = device->card; struct device *revived_dev; int minor, ret; /* * All failure paths here set node->data to NULL, so that we * don't try to do device_for_each_child() on a kfree()'d * device. */ ret = read_config_rom(device, device->generation); if (ret != RCODE_COMPLETE) { if (device->config_rom_retries < MAX_RETRIES && atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { device->config_rom_retries++; fw_schedule_device_work(device, RETRY_DELAY); } else { if (device->node->link_on) fw_notice(card, "giving up on node %x: reading config rom failed: %s\n", device->node_id, fw_rcode_string(ret)); if (device->node == card->root_node) fw_schedule_bm_work(card, 0); fw_device_release(&device->device); } return; } revived_dev = device_find_child(card->device, device, lookup_existing_device); if (revived_dev) { put_device(revived_dev); fw_device_release(&device->device); return; } device_initialize(&device->device); fw_device_get(device); down_write(&fw_device_rwsem); minor = idr_alloc(&fw_device_idr, device, 0, 1 << MINORBITS, GFP_KERNEL); up_write(&fw_device_rwsem); if (minor < 0) goto error; device->device.bus = &fw_bus_type; device->device.type = &fw_device_type; device->device.parent = card->device; device->device.devt = MKDEV(fw_cdev_major, minor); dev_set_name(&device->device, "fw%d", minor); BUILD_BUG_ON(ARRAY_SIZE(device->attribute_group.attrs) < ARRAY_SIZE(fw_device_attributes) + ARRAY_SIZE(config_rom_attributes)); init_fw_attribute_group(&device->device, fw_device_attributes, &device->attribute_group); if (device_add(&device->device)) { fw_err(card, "failed to add device\n"); goto error_with_cdev; } create_units(device); /* * Transition the device to running state. If it got pulled * out from under us while we did the initialization work, we * have to shut down the device again here. Normally, though, * fw_node_event will be responsible for shutting it down when * necessary. We have to use the atomic cmpxchg here to avoid * racing with the FW_NODE_DESTROYED case in * fw_node_event(). */ if (atomic_cmpxchg(&device->state, FW_DEVICE_INITIALIZING, FW_DEVICE_RUNNING) == FW_DEVICE_GONE) { device->workfn = fw_device_shutdown; fw_schedule_device_work(device, SHUTDOWN_DELAY); } else { fw_notice(card, "created device %s: GUID %08x%08x, S%d00\n", dev_name(&device->device), device->config_rom[3], device->config_rom[4], 1 << device->max_speed); device->config_rom_retries = 0; set_broadcast_channel(device, device->generation); add_device_randomness(&device->config_rom[3], 8); } /* * Reschedule the IRM work if we just finished reading the * root node config rom. If this races with a bus reset we * just end up running the IRM work a couple of extra times - * pretty harmless. */ if (device->node == card->root_node) fw_schedule_bm_work(card, 0); return; error_with_cdev: down_write(&fw_device_rwsem); idr_remove(&fw_device_idr, minor); up_write(&fw_device_rwsem); error: fw_device_put(device); /* fw_device_idr's reference */ put_device(&device->device); /* our reference */ } /* Reread and compare bus info block and header of root directory */ static int reread_config_rom(struct fw_device *device, int generation, bool *changed) { u32 q; int i, rcode; for (i = 0; i < 6; i++) { rcode = read_rom(device, generation, i, &q); if (rcode != RCODE_COMPLETE) return rcode; if (i == 0 && q == 0) /* inaccessible (see read_config_rom); retry later */ return RCODE_BUSY; if (q != device->config_rom[i]) { *changed = true; return RCODE_COMPLETE; } } *changed = false; return RCODE_COMPLETE; } static void fw_device_refresh(struct work_struct *work) { struct fw_device *device = container_of(work, struct fw_device, work.work); struct fw_card *card = device->card; int ret, node_id = device->node_id; bool changed; ret = reread_config_rom(device, device->generation, &changed); if (ret != RCODE_COMPLETE) goto failed_config_rom; if (!changed) { if (atomic_cmpxchg(&device->state, FW_DEVICE_INITIALIZING, FW_DEVICE_RUNNING) == FW_DEVICE_GONE) goto gone; fw_device_update(work); device->config_rom_retries = 0; goto out; } /* * Something changed. We keep things simple and don't investigate * further. We just destroy all previous units and create new ones. */ device_for_each_child(&device->device, NULL, shutdown_unit); ret = read_config_rom(device, device->generation); if (ret != RCODE_COMPLETE) goto failed_config_rom; fw_device_cdev_update(device); create_units(device); /* Userspace may want to re-read attributes. */ kobject_uevent(&device->device.kobj, KOBJ_CHANGE); if (atomic_cmpxchg(&device->state, FW_DEVICE_INITIALIZING, FW_DEVICE_RUNNING) == FW_DEVICE_GONE) goto gone; fw_notice(card, "refreshed device %s\n", dev_name(&device->device)); device->config_rom_retries = 0; goto out; failed_config_rom: if (device->config_rom_retries < MAX_RETRIES && atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { device->config_rom_retries++; fw_schedule_device_work(device, RETRY_DELAY); return; } fw_notice(card, "giving up on refresh of device %s: %s\n", dev_name(&device->device), fw_rcode_string(ret)); gone: atomic_set(&device->state, FW_DEVICE_GONE); device->workfn = fw_device_shutdown; fw_schedule_device_work(device, SHUTDOWN_DELAY); out: if (node_id == card->root_node->node_id) fw_schedule_bm_work(card, 0); } static void fw_device_workfn(struct work_struct *work) { struct fw_device *device = container_of(to_delayed_work(work), struct fw_device, work); device->workfn(work); } void fw_node_event(struct fw_card *card, struct fw_node *node, int event) { struct fw_device *device; switch (event) { case FW_NODE_CREATED: /* * Attempt to scan the node, regardless whether its self ID has * the L (link active) flag set or not. Some broken devices * send L=0 but have an up-and-running link; others send L=1 * without actually having a link. */ create: device = kzalloc(sizeof(*device), GFP_ATOMIC); if (device == NULL) break; /* * Do minimal initialization of the device here, the * rest will happen in fw_device_init(). * * Attention: A lot of things, even fw_device_get(), * cannot be done before fw_device_init() finished! * You can basically just check device->state and * schedule work until then, but only while holding * card->lock. */ atomic_set(&device->state, FW_DEVICE_INITIALIZING); device->card = fw_card_get(card); device->node = fw_node_get(node); device->node_id = node->node_id; device->generation = card->generation; device->is_local = node == card->local_node; mutex_init(&device->client_list_mutex); INIT_LIST_HEAD(&device->client_list); /* * Set the node data to point back to this device so * FW_NODE_UPDATED callbacks can update the node_id * and generation for the device. */ node->data = device; /* * Many devices are slow to respond after bus resets, * especially if they are bus powered and go through * power-up after getting plugged in. We schedule the * first config rom scan half a second after bus reset. */ device->workfn = fw_device_init; INIT_DELAYED_WORK(&device->work, fw_device_workfn); fw_schedule_device_work(device, INITIAL_DELAY); break; case FW_NODE_INITIATED_RESET: case FW_NODE_LINK_ON: device = node->data; if (device == NULL) goto create; device->node_id = node->node_id; smp_wmb(); /* update node_id before generation */ device->generation = card->generation; if (atomic_cmpxchg(&device->state, FW_DEVICE_RUNNING, FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) { device->workfn = fw_device_refresh; fw_schedule_device_work(device, device->is_local ? 0 : INITIAL_DELAY); } break; case FW_NODE_UPDATED: device = node->data; if (device == NULL) break; device->node_id = node->node_id; smp_wmb(); /* update node_id before generation */ device->generation = card->generation; if (atomic_read(&device->state) == FW_DEVICE_RUNNING) { device->workfn = fw_device_update; fw_schedule_device_work(device, 0); } break; case FW_NODE_DESTROYED: case FW_NODE_LINK_OFF: if (!node->data) break; /* * Destroy the device associated with the node. There * are two cases here: either the device is fully * initialized (FW_DEVICE_RUNNING) or we're in the * process of reading its config rom * (FW_DEVICE_INITIALIZING). If it is fully * initialized we can reuse device->work to schedule a * full fw_device_shutdown(). If not, there's work * scheduled to read it's config rom, and we just put * the device in shutdown state to have that code fail * to create the device. */ device = node->data; if (atomic_xchg(&device->state, FW_DEVICE_GONE) == FW_DEVICE_RUNNING) { device->workfn = fw_device_shutdown; fw_schedule_device_work(device, list_empty(&card->link) ? 0 : SHUTDOWN_DELAY); } break; } }