- 根目录:
- drivers
- firewire
- core-device.c
/*
* 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/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.
* 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 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) {
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 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.
*/
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;
}
}