diff options
Diffstat (limited to 'drivers/firewire/core-device.c')
| -rw-r--r-- | drivers/firewire/core-device.c | 1289 |
1 files changed, 1289 insertions, 0 deletions
diff --git a/drivers/firewire/core-device.c b/drivers/firewire/core-device.c new file mode 100644 index 00000000..68109e9b --- /dev/null +++ b/drivers/firewire/core-device.c @@ -0,0 +1,1289 @@ +/* + * Device probing and sysfs code. + * + * Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software Foundation, + * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + */ + +#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/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. + * 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 bool is_fw_unit(struct device *dev); + +static int fw_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}; + + /* We only allow binding to fw_units. */ + if (!is_fw_unit(dev)) + return 0; + + get_modalias_ids(fw_unit(dev), id); + + for (; id_table->match_flags != 0; id_table++) + if (match_ids(id_table, id)) + return 1; + + return 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, +}; +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 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(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. + */ +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 = -1; + + 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++) { + if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE) + goto out; + /* + * As per IEEE1212 7.2, during power-up, 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) + 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)) + goto out; + + /* Read header quadlet for the block to get the length. */ + if (read_rom(device, generation, i, &rom[i]) != 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++) { + if (read_rom(device, generation, i, &rom[i]) != + 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) + 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 = 0; + 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) { + fw_err(device->card, "out of memory for unit\n"); + 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)); + + PREPARE_DELAYED_WORK(&old->work, 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. + */ + + if (read_config_rom(device, device->generation) < 0) { + 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 Config ROM for node id %x\n", + device->node_id); + 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); + ret = idr_pre_get(&fw_device_idr, GFP_KERNEL) ? + idr_get_new(&fw_device_idr, device, &minor) : + -ENOMEM; + up_write(&fw_device_rwsem); + + if (ret < 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 intialization 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) { + PREPARE_DELAYED_WORK(&device->work, 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); + } + + /* + * 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 */ +} + +enum { + REREAD_BIB_ERROR, + REREAD_BIB_GONE, + REREAD_BIB_UNCHANGED, + REREAD_BIB_CHANGED, +}; + +/* Reread and compare bus info block and header of root directory */ +static int reread_config_rom(struct fw_device *device, int generation) +{ + u32 q; + int i; + + for (i = 0; i < 6; i++) { + if (read_rom(device, generation, i, &q) != RCODE_COMPLETE) + return REREAD_BIB_ERROR; + + if (i == 0 && q == 0) + return REREAD_BIB_GONE; + + if (q != device->config_rom[i]) + return REREAD_BIB_CHANGED; + } + + return REREAD_BIB_UNCHANGED; +} + +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 node_id = device->node_id; + + switch (reread_config_rom(device, device->generation)) { + case REREAD_BIB_ERROR: + if (device->config_rom_retries < MAX_RETRIES / 2 && + atomic_read(&device->state) == FW_DEVICE_INITIALIZING) { + device->config_rom_retries++; + fw_schedule_device_work(device, RETRY_DELAY / 2); + + return; + } + goto give_up; + + case REREAD_BIB_GONE: + goto gone; + + case REREAD_BIB_UNCHANGED: + 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; + + case REREAD_BIB_CHANGED: + break; + } + + /* + * 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); + + if (read_config_rom(device, device->generation) < 0) { + 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; + } + goto give_up; + } + + 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; + + give_up: + fw_notice(card, "giving up on refresh of device %s\n", + dev_name(&device->device)); + gone: + atomic_set(&device->state, FW_DEVICE_GONE); + PREPARE_DELAYED_WORK(&device->work, 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); +} + +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 intialization 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. + */ + INIT_DELAYED_WORK(&device->work, fw_device_init); + 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) { + PREPARE_DELAYED_WORK(&device->work, 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) { + PREPARE_DELAYED_WORK(&device->work, 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) { + PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown); + fw_schedule_device_work(device, + list_empty(&card->link) ? 0 : SHUTDOWN_DELAY); + } + break; + } +} |