linux/drivers/firewire/fw-device.h
Stefan Richter 855c603d61 firewire: fix crash in automatic module unloading
"modprobe firewire-ohci; sleep .1; modprobe -r firewire-ohci" used to
result in crashes like this:

    BUG: unable to handle kernel paging request at ffffffff8807b455
    IP: [<ffffffff8807b455>]
    PGD 203067 PUD 207063 PMD 7c170067 PTE 0
    Oops: 0010 [1] PREEMPT SMP
    CPU 0
    Modules linked in: i915 drm cpufreq_ondemand acpi_cpufreq freq_table applesmc input_polldev led_class coretemp hwmon eeprom snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss button thermal processor sg snd_hda_intel snd_pcm snd_timer snd snd_page_alloc sky2 i2c_i801 rtc [last unloaded: crc_itu_t]
    Pid: 9, comm: events/0 Not tainted 2.6.25-rc2 #3
    RIP: 0010:[<ffffffff8807b455>]  [<ffffffff8807b455>]
    RSP: 0018:ffff81007dcdde88  EFLAGS: 00010246
    RAX: ffff81007dc95040 RBX: ffff81007dee5390 RCX: 0000000000005e13
    RDX: 0000000000008c8b RSI: 0000000000000001 RDI: ffff81007dee5388
    RBP: ffff81007dc5eb40 R08: 0000000000000002 R09: ffffffff8022d05c
    R10: ffffffff8023b34c R11: ffffffff8041a353 R12: ffff81007dee5388
    R13: ffffffff8807b455 R14: ffffffff80593bc0 R15: 0000000000000000
    FS:  0000000000000000(0000) GS:ffffffff8055a000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
    CR2: ffffffff8807b455 CR3: 0000000000201000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process events/0 (pid: 9, threadinfo ffff81007dcdc000, task ffff81007dc95040)
    Stack:  ffffffff8023b396 ffffffff88082524 0000000000000000 ffffffff8807d9ae
    ffff81007dc5eb40 ffff81007dc9dce0 ffff81007dc5eb40 ffff81007dc5eb80
    ffff81007dc9dce0 ffffffffffffffff ffffffff8023be87 0000000000000000
    Call Trace:
    [<ffffffff8023b396>] ? run_workqueue+0xdf/0x1df
    [<ffffffff8023be87>] ? worker_thread+0xd8/0xe3
    [<ffffffff8023e917>] ? autoremove_wake_function+0x0/0x2e
    [<ffffffff8023bdaf>] ? worker_thread+0x0/0xe3
    [<ffffffff8023e813>] ? kthread+0x47/0x74
    [<ffffffff804198e0>] ? trace_hardirqs_on_thunk+0x35/0x3a
    [<ffffffff8020c008>] ? child_rip+0xa/0x12
    [<ffffffff8020b6e3>] ? restore_args+0x0/0x3d
    [<ffffffff8023e68a>] ? kthreadd+0x14c/0x171
    [<ffffffff8023e68a>] ? kthreadd+0x14c/0x171
    [<ffffffff8023e7cc>] ? kthread+0x0/0x74
    [<ffffffff8020bffe>] ? child_rip+0x0/0x12

    Code:  Bad RIP value.
    RIP  [<ffffffff8807b455>]
    RSP <ffff81007dcdde88>
    CR2: ffffffff8807b455
    ---[ end trace c7366c6657fe5bed ]---

Note that this crash happened _after_ firewire-core was unloaded.  The
shared workqueue tried to run firewire-core's device initialization jobs
or similar jobs.

The fix makes sure that firewire-ohci and hence firewire-core is not
unloaded before all device shutdown jobs have been completed.  This is
determined by the count of device initializations minus device releases.

Also skip useless retries in the node initialization job if the node is
to be shut down.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
2008-03-02 12:35:46 +01:00

167 lines
4.1 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 <asm/atomic.h>
enum fw_device_state {
FW_DEVICE_INITIALIZING,
FW_DEVICE_RUNNING,
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.
*/
struct fw_device {
atomic_t state;
struct fw_node *node;
int node_id;
int generation;
unsigned max_speed;
struct fw_card *card;
struct device device;
struct list_head link;
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 int fw_cdev_major;
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);
}
#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 */