Commit db5d247a "firewire: fix use of multiple AV/C devices, allow
multiple FCP listeners" introduced a regression into 2.6.33-rc3:
The core freed payloads of incoming requests to FCP_Request or
FCP_Response before a userspace driver accessed them.

We need to copy such payloads for each registered userspace client
and free the copies according to the lifetime rules of non-FCP client
request resources.

(This could possibly be optimized by reference counts instead of
copies.)

The presently only kernelspace driver which listens for FCP requests,
firedtv, was not affected because it already copies FCP frames into an
own buffer before returning to firewire-core's FCP handler dispatcher.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

If copy_from_user in an FW_CDEV_IOC_SEND_RESPONSE ioctl failed, the
fw_request pointed to by the inbound_transaction_resource is no
longer referenced and needs to be freed.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Control of more than one AV/C device at once --- e.g. camcorders, tape
decks, audio devices, TV tuners --- failed or worked only unreliably,
depending on driver implementation.  This affected kernelspace and
userspace drivers alike and was caused by firewire-core's inability to
accept multiple registrations of FCP listeners.

The fix allows multiple address handlers to be registered for the FCP
command and response registers.  When a request for these registers is
received, all handlers are invoked, and the Firewire response is
generated by the core and not by any handler.

The cdev API does not change, i.e., userspace is still expected to send
a response for FCP requests; this response is silently ignored.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (changelog, rebased, whitespace)

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
  ieee1394: Use hweight32
  firewire: cdev: reduce stack usage by ioctl_dispatch
  firewire: ohci: 0 may be a valid DMA address
  firewire: core: WARN on wrong usage of core transaction functions
  firewire: core: optimize Topology Map creation
  firewire: core: clarify generate_config_rom usage
  firewire: optimize config ROM creation
  firewire: cdev: normalize variable names
  firewire: normalize style of queue_work wrappers
  firewire: cdev: fix memory leak in an error path

Replace a hardcoded buffer size by a sizeof union {}.  This shrinks the
stack-allocated ioctl argument buffer from 256 to 40 bytes.  (This is
not much, but subsequent stack usage particularly by the queue_iso ioctl
handler adds up.)

The new form is also easier to keep up to date than a hardcoded size if
more ioctls are added.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Unify some names:
  - "e" for pointers to subtypes of struct event,
  - "event" for struct members and pointers to struct event,
  - "r" for pointers to subtypes of struct client_resource,
  - "resource" for struct members and pointers to struct client_resource,
  - other names for struct members and pointers to other types.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

A few stylistic changes to unify some code patterns in the subsystem:

  - The similar queue_delayed_work helpers fw_schedule_bm_work,
    schedule_iso_resource, and sbp2_queue_work now have the same call
    convention.
  - Two conditional calls of schedule_iso_resource are factored into
    another small helper.
  - An sbp2_target_get helper is added as counterpart to
    sbp2_target_put.

Object size of firewire-core is decreased a little bit, object size of
firewire-sbp2 remains unchanged.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

If copy_from_user in an FW_CDEV_IOC_SEND_RESPONSE ioctl failed, an
inbound_transaction_resource instance is no longer referenced and needs
to be freed.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The DMA mapping API cannot map on-stack addresses, as explained in
Documentation/DMA-mapping.txt.  Convert the two cases of on-stack packet
payload buffers in firewire-core (payload of lock requests in the bus
manager work and in iso resource management) to slab-allocated memory.

There are a number on-stack buffers for quadlet write or quadlet read
requests in firewire-core and firewire-sbp2.  These are harmless; they
are copied to/ from card driver internal DMA buffers since quadlet
payloads are inlined with packet headers.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>