linux/drivers/firewire/core-device.c
Uwe Kleine-König fc7a6209d5 bus: Make remove callback return void
The driver core ignores the return value of this callback because there
is only little it can do when a device disappears.

This is the final bit of a long lasting cleanup quest where several
buses were converted to also return void from their remove callback.
Additionally some resource leaks were fixed that were caused by drivers
returning an error code in the expectation that the driver won't go
away.

With struct bus_type::remove returning void it's prevented that newly
implemented buses return an ignored error code and so don't anticipate
wrong expectations for driver authors.

Reviewed-by: Tom Rix <trix@redhat.com> (For fpga)
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio)
Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts)
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb)
Acked-by: Pali Rohár <pali@kernel.org>
Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media)
Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform)
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Acked-by: Juergen Gross <jgross@suse.com> (For xen)
Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd)
Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb)
Acked-by: Johan Hovold <johan@kernel.org>
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus)
Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio)
Acked-by: Maximilian Luz <luzmaximilian@gmail.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec)
Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack)
Acked-by: Geoff Levand <geoff@infradead.org> (For ps3)
Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt)
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th)
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia)
Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI)
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr)
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid)
Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM)
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa)
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire)
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid)
Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox)
Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss)
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC)
Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Finn Thain <fthain@linux-m68k.org>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-21 11:53:42 +02:00

1316 lines
33 KiB
C

// 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 void fw_unit_remove(struct device *dev)
{
struct fw_driver *driver =
container_of(dev->driver, struct fw_driver, driver);
driver->remove(fw_unit(dev));
}
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;
}
fallthrough; /* 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;
}
}