Due to AV/C protocol extensions, FireDTV devices need a vendor-specific
driver. But their configuration ROM features a vendor ID only in the
root directory, not in the unit directory.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
That way, the new firedtv driver will be able to use a single ID table
in builds against ieee1394 core and/or against firewire core.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This adds the attribute /sys/bus/firewire/devices/fw[0-9]+/units. It
can be used in udev rules like the following ones:
# IIDC devices: industrial cameras and some webcams
SUBSYSTEM=="firewire", ATTR{units}=="*0x00a02d:0x00010?*", GROUP="video"
# AV/C devices: camcorders, set-top boxes, TV sets, audio devices, ...
SUBSYSTEM=="firewire", ATTR{units}=="*0x00a02d:0x010001*", GROUP="video"
Background:
firewire-core manages two device types:
- fw_device is a FireWire node. A character device file is associated
with it.
- fw_unit is a unit directory on a node. Each fw_device may have 0..n
children of type fw_unit. The units tell us what kinds of protocols
a node implements.
We want to set ownership or ACLs or permissions of the character device
file of an fw_device, or/and create symlinks to it, based on available
protocols. Until now udev rules had to look at the fw_unit devices and
then modify their parent's character device file accordingly. This is
problematic for two reasons: 1) It happens sometime after the creation
of the fw_device, 2) an access policy may require that information from
all children is evaluated before a decision about the parent is made.
Problem 1) can ultimately not be avoided since this is the nature of
FireWire nodes: They may add or remove unit directories at any point in
time.
However, we can still help userland a lot by providing the protocol type
information of all units in a summary sysfs attribute directly at the
fw_device. This way,
- the information is immediately available at the affected device
when userspace goes about to handle an ADD or CHANGE event of the
fw_device,
- with most policies, it won't be necessary anymore to dig through
child attributes.
The new attribute is called "units". It contains space-separated tuples
of specifier_id and version of each present unit. The delimiter within
tuples is a colon. Specifier_id and version are printed as 0x%06x.
Here is an example of a node which implements an IPv4 unit and an IPv6
unit: $ cat /sys/bus/firewire/devices/fw2/units
0x00005e:0x000001 0x00005e:0x000002
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
struct fw_attribute_group.attrs.[] must have enough room for all
attributes. This can and should be checked at build time.
Our previous check at run time was a little late and not reliable since
most of the time less than the available attributes are populated.
Furthermore, omit an increment of an index at its last usage.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
My recently added test for a device being local in fw-cdev.c got it
slightly wrong: Comparisons of node IDs are only valid if the
generation is current, which I forgot to check. Normally, serialization
by card->lock takes care of this, but a device in FW_DEVICE_GONE state
will necessarily have a wrong generation and invalid node_id.
The "is it local?" check is made 100% correct and simpler now by means
of a struct fw_device flag which is set at fw_device creation.
Besides the fw-cdev site which was to be fixed, there is another site
which can make use of the new flag, and an RFC-2734 driver will benefit
from it too.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Cache the test result of whether a device implements BROADCAST_CHANNEL.
This minimizes traffic on the bus after each bus reset. A majority of
devices does not implement BROADCAST_CHANNEL.
Remove busy retries; just rely on the hardware to retry requests to busy
responders. Remove unnecessary log messages.
Rename the flag is_irm to broadcast_channel_allocated to better reflect
its meaning. Reset the flag earlier in fw_core_handle_bus_reset.
Pass the generation down as a call parameter; that way generation can't
be newer than card->broadcast_channel_allocated and device->node_id.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Per IEEE 1394 clause 8.4.2.5, bus manager capable nodes which are not
incumbent shall wait at least 125ms before trying to establish
themselves as bus manager.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This changes the as yet unreleased FW_CDEV_IOC_SEND_STREAM_PACKET ioctl
to generate an fw_cdev_event_response event just like the other two
ioctls for asynchronous request transmission do. This way, clients get
feedback on successful or unsuccessful transmission.
This also adds input validation for length, tag, channel, sy, speed.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This changes the ioctl() return value of FW_CDEV_IOC_SEND_REQUEST and of
the as yet unreleased FW_CDEV_IOC_SEND_BROADCAST_REQUEST. They used to
return
sizeof(struct fw_cdev_send_request *) + data_length
which is obviously a failed attempt to emulate the return value of
raw1394's respective interface which uses write() instead of ioctl().
However, the first summand, as size of a kernel pointer, is entirely
meaningless to clients and the second summand is already known to
clients. And the result does not resemble raw1394's write() return
code anyway.
So simplify it to a constant non-negative value, i.e. 0. The only
dangers here would be that future client implementations check for error
by ret != 0 instead of ret < 0 when running on top of an old kernel; or
that current clients interpret ret = 0 or more as failure. But both are
hypothetical cases which don't justify to return irritating values.
While we touch this code, also remove "& 0x1f" from tcode in the call of
fw_send_request. The tcode cannot be bigger than 0x1f at this point.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The bus reset handler concurrently frees client->device->node. Use
device->node_id instead. This is equivalent to device->node->node_id
while device->generation is current.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The access permissions and ownership or ACL of /dev/fw* character device
files will typically be set based on the device type of the respective
nodes, as obtained by firewire-core from descriptors in the device's
configuration ROM. An example policy is to deny write permission by
default but grant write permission to files of AV/C video and audio
devices and IIDC video devices.
The FW_CDEV_IOC_ADD_DESCRIPTOR ioctl could be used to partly subvert
such a policy: Find a device file with relaxed permissions, use the
ioctl to add a descriptor with AV/C marker to the local node's ROM, thus
gain access to the local node's character device file. (This is only
possible if there are udev scripts installed which actively relax
permissions for known device types and if there is a device of such a
type connected.)
Accessibility of the local node's device file is relevant to host
security if the host contains two or more IEEE 1394 link layer
controllers which are plugged into a single bus.
Therefore change the ABI to deny FW_CDEV_IOC_ADD_DESCRIPTOR if the file
belongs to a remote node. (This change has no impact on known
implementers of the ABI: None of them uses the ioctl yet.)
Also clarify the documentation: The ioctl affects all local nodes, not
just one local node.
Cc: stable@kernel.org
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The as yet unreleased FW_CDEV_IOC_GET_SPEED ioctl puts only a single
integer into the parameter buffer. We can use ioctl()'s return value
instead.
(Also: Some whitespace change in firewire-cdev.h.)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This patch adds the ISO broadcast channel support that is required of a
1394a IRM. In specific, if the local device the IRM, it allocates ISO
channel 31 and sets the broadcast channel register of all devices on the
local bus to BROADCAST_CHANNEL_INITIAL | BROADCAST_CHANNEL_VALID to indicate
that channel 31 can be use for broadcast messages.
One minor complication is that on startup the local device may become IRM
before all the devices on the bus have been enumerated by the stack. Therefore
we have to keep a "the local device is IRM" flag and possibly set the
broadcast channel register of new devices at enumeration time.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Allow userspace and other firewire drivers (fw-ipv4 I'm looking at
you!) to send Asynchronous Transmit Streams as described in 7.8.3 of
release 1.1 of the 1394 Open Host Controller Interface Specification.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (tweaks)
Standardize on if (err)
handle_error;
and if (ret < 0)
handle_error;
Don't call a variable err if we store values in it which mean success.
Also, offset some return statements by a blank line since this how we do
it in drivers/firewire.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
reread_bus_info_block() only gets to see devices whose config_rom_length
is at least 6 (ROM header, bus info block, root directory header).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The kernel API documentation says that queue_delayed_work() returns 0
(only) if the work was already queued. The return codes of
schedule_delayed_work() are not documented but the same.
In init_iso_resource(), the work has never been queued yet, hence we
can assume schedule_delayed_work() to be a guaranteed success there.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Some fixes:
- Remove stale documentation.
- Fix a != vs. == thinko that got in the way of channel management.
- Try bandwidth deallocation even if channel deallocation failed.
A simplification:
- fw_cdev_allocate_iso_resource.channels is now ordered like
libdc1394's dc1394_iso_allocate_channel() channels_allowed
argument.
By the way, I looked closer at cards from NEC, TI, and VIA, and noticed
that they all don't implement IEEE 1394a behaviour which is meant to
deviate from IEEE 1212's notion of lock compare-swap. This means that
we have to do two lock transactions instead of one in many cases where
one transaction would already succeed on a fully 1394a compliant IRM.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
DMA must be halted before we DMA-unmap and free the DMA buffer. Since
we cannot rely on the client to stop the context before it closes the
fd, we have to reorder fw_iso_buffer_destroy vs. fw_iso_context_destroy.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
All of these functions are entered with IRQs enabled.
Hence the unconditional spin_unlock_irq can be used.
Function: Caller context:
dequeue_event() client process, via read(2)
fill_bus_reset_event() fw-device.c update worqueue job
release_client_resource() client process, via ioctl(2)
fw_device_op_release() client process, via close(2)
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Make the size check of ioctl_send_request and
ioctl_send_broadcast_request speed dependent. Also change the error
return code from -EINVAL to -EIO to distinguish this from other errors
concerning the ioctl parameters.
Another payload size limit for which we don't check here though is the
remote node's Bus_Info_Block.max_rec.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
We don't want random users write to Memory Space (e.g. PCs with physical
DMA filters down) or to core CSRs like Reset_Start.
This does not protect SBP-2 target CSRs. But properly behaving SBP-2
targets ignore broadcast write requests to these registers, and the
maximum damage which can happen with laxer targets is DOS. But there
are ways to create DOS situations anyway if there are devices with weak
device file permissions (like audio/video devices) present at the same
bus as an SBP-2 target.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Write transactions to the broadcast node ID are a convenient way to
trigger functions of multiple nodes at once. IIDC is a protocol which
can make use of this if multiple cameras with same command_regs_base are
connected at the same bus.
Based on
Date: Wed, 10 Sep 2008 11:32:16 -0400
From: Jay Fenlason <fenlason@redhat.com>
Subject: [patch] SEND_BROADCAST_REQUEST
Changes: ioctl_send_request() and ioctl_send_broadcast_request() now
share code. Broadcast speed corrected to S100. Check for proper tcode.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
While the speed of asynchronous transactions is automatically chosen by
the kernel, the speed of isochronous streams has to be chosen by the
initiating client.
In case of 1394a bus topologies, the maximum possible speed could be
figured out with some effort by evaluation of the remote node's link
speed field in the config ROM, the local node's link speed field, and
the PHY speeds and topologic information in the local node's or IRM's
topology map CSR. However, this does not work in case of 1394b buses.
Hence add an ioctl to export the maximum speed which the kernel already
determined.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This adds ioctls for allocation and deallocation of a channel or/and
bandwidth without auto-reallocation and without auto-deallocation.
The benefit of these ioctls is that libraw1394-style isochronous
resource management can be implemented without write access to the IRM's
character device file.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Based on
Date: Tue, 18 Nov 2008 11:41:27 -0500
From: Jay Fenlason <fenlason@redhat.com>
Subject: [Patch V4] Add ISO resource management support
with several changes to the ABI and implementation. Only the part of
the ABI which enables auto-reallocation and auto-deallocation is
included here.
This implements ioctls for kernel-assisted allocation of isochronous
channels and isochronous bandwidth. The benefits are:
- The client does not have to have write access to the /dev/fw* device
corresponding to the IRM.
- The client does not have to perform reallocation after bus resets.
- Channel and bandwidth are deallocated by the kernel if the file is
closed before the client deallocated the resources. Thus resources
are released even if the client crashes.
It is anticipated that future in-kernel code (firewire-core IRM code;
the firewire port of firedtv), will use the fw-iso.c portions of this
code too.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Tested-by: David Moore <dcm@acm.org>
to indicate that they are specializations of struct event or of struct
client_resource, respectively.
struct response was both an event and a client_resource; it is now split
into struct outbound_transaction_resource and ~_event in order to
document more explicitly which types of client resources exist.
struct request and struct_request_event are renamed to struct
inbound_transaction_resource and ~_event because requests and responses
occur in outbound and in inbound transactions.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The lifetime of struct client instances must be longer than the lifetime
of any client resource.
This fixes a possible race between fw_device_op_release and transaction
completions. It also prepares for new ioctls for isochronous resource
management which will involve delayed processing of client resources.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Reviewed-by: David Moore <dcm@acm.org>
OHCI-1394 1.1 clause 10.4.3 says: "If more than one IR DMA context
specifies receives for packets from the same isochronous channel, the
context destination for that channel's packets is undefined."
Any userspace client and in the future also kernelspace clients can
allocate IR DMA contexts for any channel. We don't want them to
interfere with each other, hence it is preferable to return -EBUSY if
allocation of a second context for a channel is attempted.
Notes:
- This limitation is OHCI-1394 specific, therefore its proper place of
implementation is down in the low-level driver.
- Since the <linux/firewire-cdev.h> ABI simply maps one userspace iso
client context to one hardware iso context, this OHCI-1394
limitation alas requires userspace to implement its own multiplexing
of iso reception from the same channel and card to multiple clients
when needed.
- The limitation is independent of channel allocation at the IRM; the
latter is really only important for the initiation of iso
transmission but not of iso reception.
- We don't need to do the same for IT DMA because OHCI-1394 does not
have any ties between IT contexts and channels. Only the voluntary
channel allocation protocol via the IRM, globally to the FireWire
bus, can ensure proper isochronous transmit behaviour anyway.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Like before my commit 1415d9189e,
fw_core_add_address_handler() does not align the address region now.
Instead the caller is required to pass valid parameters.
Since one of the callers of fw_core_add_address_handler() is the cdev
userspace interface, we now check for valid input. If the client is
buggy, we give it a hint with -EINVAL.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The current code uses a linked list and a counter for storing
resources and the corresponding handle numbers. By changing to an idr
we can be safe from counter wrap-around giving two resources the same
handle.
Furthermore, the deallocation ioctls now check whether the resource to
be freed is of the intended type.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Some rework by Stefan R:
- The idr API documentation says we get an ID within 0...0x7fffffff.
Hence we can rest assured that idr handles fit into cdev handles.
- Fix some races. Add a client->in_shutdown flag for this purpose.
- Add allocation retry to add_client_resource().
- It is possible to use idr_for_each() in fw_device_op_release().
- Fix ioctl_send_response() regression.
- Small style changes.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Unlink the client from the fw_device earlier in order to prevent bus
reset events being added to client->event_list during shutdown.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
The behaviour of fw-transaction.c::fw_send_request is ill-defined for
any other tcodes than read/ write/ lock request tcodes. Therefore
prevent requests with wrong tcodes from entering the transaction layer.
Maybe fw_send_request should check them itself, but I am not inclined to
change it and fw_fill_request from void-valued functions to ones which
return error codes and pass those up. Besides, maybe fw_send_request is
going to support one more tcode than ioctl_send_request in the future
(TCODE_STREAM_DATA).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This adds a client_list_lock, which only protects the device's
client_list, so that future versions of the driver can call code that
takes the card->lock while holding the client_list_lock. Adding this
lock is much simpler than adding __ versions of all the functions that
the future version may need. The one ordering issue is to make sure
code never takes the client_list_lock with card->lock held. Since
client_list_lock is only used in three places, that isn't hard.
Signed-off-by: Jay Fenlason <fenlason@redhat.com>
Update fill_bus_reset_event() accordingly. Include linux/spinlock.h.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Previously, when an iso context had header_size > 4, the iso header
(len/tag/channel/tcode/sy) was passed to userspace followed by quadlets
stripped from the payload. This patch changes the behavior:
header_size = 8 now passes the header quadlet followed by the timestamp
quadlet. When header_size > 8, quadlets are stripped from the payload.
The header_size = 4 case remains identical.
Since this alters the semantics of the API, the firewire API version
needs to be bumped concurrently with this change.
This change also refactors the header copying code slightly to be much
easier to read.
Signed-off-by: David Moore <dcm@acm.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
After a controller initialization failure, addition of another card got
stuck due to card_list corruption.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
