kernel-ark/drivers/firewire/fw-device.h
Stefan Richter 3d36a0df3b firewire: keep highlevel drivers attached during brief connection loss
There are situations when nodes vanish from the bus and come back
quickly thereafter:
  - When certain bus-powered hubs are plugged in,
  - when certain devices are plugged into 6-port hubs,
  - when certain disk enclosures are switched from self-power to bus
    power or vice versa and break the daisy chain during the transition,
  - when the user plugs a cable out and quickly plugs it back in, e.g.
    to reorder a daisy chain (works on Mac OS X if done quickly enough),
  - when certain hubs temporarily malfunction during high bus traffic.

Until now, firewire-core reported affected nodes as lost to the
highlevel drivers (firewire-sbp2 and userspace drivers).  We now delay
the destruction of device representations until after at least two
seconds after the last bus reset.  If a "new" device is detected in this
period whose bus information block and root directory header match that
of a device which is pending for deletion, we resurrect that device and
send update calls to highlevel drivers.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2009-01-20 19:29:52 +01:00

188 lines
4.8 KiB
C

/*
* 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.
*/
#ifndef __fw_device_h
#define __fw_device_h
#include <linux/fs.h>
#include <linux/cdev.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <asm/atomic.h>
enum fw_device_state {
FW_DEVICE_INITIALIZING,
FW_DEVICE_RUNNING,
FW_DEVICE_GONE,
FW_DEVICE_SHUTDOWN,
};
struct fw_attribute_group {
struct attribute_group *groups[2];
struct attribute_group group;
struct attribute *attrs[11];
};
/*
* Note, fw_device.generation always has to be read before fw_device.node_id.
* Use SMP memory barriers to ensure this. Otherwise requests will be sent
* to an outdated node_id if the generation was updated in the meantime due
* to a bus reset.
*
* Likewise, fw-core will take care to update .node_id before .generation so
* that whenever fw_device.generation is current WRT the actual bus generation,
* fw_device.node_id is guaranteed to be current too.
*
* The same applies to fw_device.card->node_id vs. fw_device.generation.
*
* fw_device.config_rom and fw_device.config_rom_length may be accessed during
* the lifetime of any fw_unit belonging to the fw_device, before device_del()
* was called on the last fw_unit. Alternatively, they may be accessed while
* holding fw_device_rwsem.
*/
struct fw_device {
atomic_t state;
struct fw_node *node;
int node_id;
int generation;
unsigned max_speed;
bool cmc;
struct fw_card *card;
struct device device;
struct list_head client_list;
u32 *config_rom;
size_t config_rom_length;
int config_rom_retries;
struct delayed_work work;
struct fw_attribute_group attribute_group;
};
static inline struct fw_device *fw_device(struct device *dev)
{
return container_of(dev, struct fw_device, device);
}
static inline int fw_device_is_shutdown(struct fw_device *device)
{
return atomic_read(&device->state) == FW_DEVICE_SHUTDOWN;
}
static inline struct fw_device *fw_device_get(struct fw_device *device)
{
get_device(&device->device);
return device;
}
static inline void fw_device_put(struct fw_device *device)
{
put_device(&device->device);
}
struct fw_device *fw_device_get_by_devt(dev_t devt);
int fw_device_enable_phys_dma(struct fw_device *device);
void fw_device_cdev_update(struct fw_device *device);
void fw_device_cdev_remove(struct fw_device *device);
extern struct rw_semaphore fw_device_rwsem;
extern struct idr fw_device_idr;
extern int fw_cdev_major;
/*
* fw_unit.directory must not be accessed after device_del(&fw_unit.device).
*/
struct fw_unit {
struct device device;
u32 *directory;
struct fw_attribute_group attribute_group;
};
static inline struct fw_unit *fw_unit(struct device *dev)
{
return container_of(dev, struct fw_unit, device);
}
static inline struct fw_unit *fw_unit_get(struct fw_unit *unit)
{
get_device(&unit->device);
return unit;
}
static inline void fw_unit_put(struct fw_unit *unit)
{
put_device(&unit->device);
}
#define CSR_OFFSET 0x40
#define CSR_LEAF 0x80
#define CSR_DIRECTORY 0xc0
#define CSR_DESCRIPTOR 0x01
#define CSR_VENDOR 0x03
#define CSR_HARDWARE_VERSION 0x04
#define CSR_NODE_CAPABILITIES 0x0c
#define CSR_UNIT 0x11
#define CSR_SPECIFIER_ID 0x12
#define CSR_VERSION 0x13
#define CSR_DEPENDENT_INFO 0x14
#define CSR_MODEL 0x17
#define CSR_INSTANCE 0x18
#define CSR_DIRECTORY_ID 0x20
struct fw_csr_iterator {
u32 *p;
u32 *end;
};
void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 *p);
int fw_csr_iterator_next(struct fw_csr_iterator *ci,
int *key, int *value);
#define FW_MATCH_VENDOR 0x0001
#define FW_MATCH_MODEL 0x0002
#define FW_MATCH_SPECIFIER_ID 0x0004
#define FW_MATCH_VERSION 0x0008
struct fw_device_id {
u32 match_flags;
u32 vendor;
u32 model;
u32 specifier_id;
u32 version;
void *driver_data;
};
struct fw_driver {
struct device_driver driver;
/* Called when the parent device sits through a bus reset. */
void (*update) (struct fw_unit *unit);
const struct fw_device_id *id_table;
};
static inline struct fw_driver *
fw_driver(struct device_driver *drv)
{
return container_of(drv, struct fw_driver, driver);
}
extern const struct file_operations fw_device_ops;
#endif /* __fw_device_h */