Cancel the operation--not just the request message--if waiting
for a synchronous operation to complete is interrupted. Return
the operation result (which in that case will be -EINTR). The
cancelation will result in the normal operation completion path
being taken before returning.
Make gb_operation_wait() private, since it's only ever used for
for synchronous operations.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
If an operation times out, we need to cancel whatever message it
has in-flight. Do that instead of completing the operation, in the
timeout handler. When the in-flight request message is canceled its
completion function will lead to the proper completion of the
operation.
Change gb_operation_cancel() so it takes the errno that it's
supposed to assign as the result of the operation.
Note that we want to preserve the original -ETIMEDOUT error, so
don't overwrite the operation result value if it has already been
set.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Any time we queue work on the operation work queue we need to have
set the operation errno first.
This patch moves the assignment of that field to be immediately
prior to the queue_work() call in gb_connection_recv_response(),
so it is easier to see at a glance that this has been done.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Grab an extra reference to an operation before sending it. Drop
that reference at the end of its completion handling.
It turns out gb_operation_get() got deleted along the way, so this
re-introduces it. We're assuming we only get a reference when
there's at least one in existence so we don't need a semaphore to
protect it. Emphasize this by *not* returning a pointer to
the referenced operation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The data sent callback can execute in atomic context. If an error
occurred, we shouldn't be completing the operation right then and
there. Instead, hand it off to the operation workqueue to complete
the operation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Change the operation "receive workqueue" to be just the operation
"workqueue". All it does is complete an operation in non-atomic
context. This is all that's required for an outgoing request.
Similarly, ignore any notion that a response will only exist
for outgoing requests in gb_operation_cancel().
I'm doing this in the interest of getting the outgoing request path
verified without the encumbrance of any preconceptions about how
incoming requests need to work. When I finally turn my full
attenion to incoming requests I'll adapt the code as needed.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
An in-core operation structure tracks the progress of an operation.
Currently it holds a result field that was intended to take the
status value that arrives in an operation response message header.
But operations can fail for reasons other than that, and it's
inconvenient to try to represent those using the operation status
codes.
So change the operation->result field to be an int, and switch to
storing negative errno values in it. Rename it "errno" to make
it obvious how to interpret the value.
This patch makes another change, which simplifies the protocol drivers
a lot. It's being done as part of this patch because it affects all
the same code as the above change does. If desired I can split this
into two separate patches.
If a caller makes a synchronous gb_operation_request_send() request
(i.e., no callback function is supplied), and the operation request
and response messages were transferred successfully, have
gb_operation_request_send() return the result of the request (i.e.,
operation->errno). This allows the caller (or more generally, any
caller of gb_request_wait() to avoid having to look at this field
for every successful send.
Any caller that does an asynchronous request will of course need
to look at request->errno in the callback function to see the
result of the operation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Define greybus_data_sent(), which is a callback the host driver
makes when a buffer send request has completed. The main use for
this is to actively detect errors that can occur while sending.
(Something like this existed at one time and was removed.)
This also defines gb_hd_message_find(), which looks up a message
pointer associated with a buffer sent over a given host device.
This is now a pretty trival mapping.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Embed the buffer for message data into the message structure itself.
This allows us to use a single allocation for each message, and
more importantly will allow us to derive the message structure
describing a message from the buffer itself.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Have an operation's request and response messages be dynamically
allocated rather than embedded in an operation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The beginning of an operation message always contains the message
header. Rename the "buffer" field in an operation message to
be "header" to reflect this. Change its type as well.
The size of a message is the combined size of its header and its
payload. Rename the "buffer_size" field in a message header to
be simply "size", so message->size describes exactly that.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rather than having the host driver allocate the buffers that the
Greybus core uses to hold its data for sending or receiving, have
the host driver define what it requires those buffers to look like.
Two constraints define what the host driver requires: the maximum
number of bytes that the host device can send in a single request;
and a statement of the "headroom" that needs to be present for
use by the host device.
The direct description of the headroom is that it's the extra byte
the host device needs at the beginning of the "data" portion of
the buffer so the ES1 driver can insert the destination CPort id.
But more generally, the host driver could put other data in there
as well.
By stating these two parameters, Greybus can allocate the buffers it
uses by itself. The host driver still allocates the buffers it uses
for receiving data--the content of those are copied as needed into
Greybus buffers when data arrives.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
If a response arrives for an operation request and the allotted
buffer isn't big enough we report the error, but we don't finish
processing the response.
Instead, set the operation result, but then finish processing
the response (no different from any other operation error).
This will allow the normal completion handling to occur for
this error case.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Whenever we send a request message we start a timer to ensure the
we don't wait too long for the matching response to arrive.
Currently we set up the timeout *after* sending the message, but
that is subject to a race--the response could arrive (and the
timeout prematurely disabled) before the timeout is even set up.
Set up the timeout before sending the message.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
This is a pervasive change, but not really a big one. However:
============== Pay attention to this ==============
If you're doing any testing with "gbsim" you need to
update that program in sync with this change, because
it changes the protocol used between them.
============== Pay attention to this ==============
The status of a request is now recorded in the header of a response
message. The previous patch put that header status byte in place,
and this one removes the status byte from all the response
messages.
And finally, since we're modifying all these files anyway...
Use gb_operation_status_map() to come up with a return code
to use, given an operation response. Right now most errors
simply result in -EIO getting returned.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Define a common function that maps an operation status value to a
Linux negative errno.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Define a result byte in an operation response message header.
All the protocols now define the mandatory status as the first
byte in their response message. Assume that, for the moment,
and save that value into the header result field (until we can
get the simulator set up to handle the new protocol).
Record the result from the response header as the result of the
overall operation.
Start enforcing the rule that we ignore all response payload (in
fact, the entire message) if we see a non-zero result value.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
When we remove the mandatory status byte from response messages we
will no longer be able to use a zero-sized response to indicate
an operation is to be used for an incoming request.
Define a new function gb_operation_create_incoming() to be used
for incoming operations. Change (and rename) gb_operation_create()
to be a helper that takes a Boolean to indicate which type is to be
created, and use a simple wrapper to expose the outgoing operation
creation routine.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Define two helper functions to break down handling of a received
message. One is used to handle receiving an incoming request
message, the other for a response message.
Three other changes are made:
- We verify message size recorded in the message header does not
exceed the amount of data that's arriving.
- We no longer warn if a request' recorded message size differs
from the number of bytes that have arrived.
- We now record the operation id for an incoming request.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
A message header contains a field "id" that is an operation id.
Since the field doesn't identify the message itself, rename this
field so it's clearer what it's referring to.
Similarly gb_pending_operation_find() has a parameter "id" that
is really an operation id, so rename that as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
We (sort of) maintain the status of each message, but we shouldn't
need to. Right now we're not using it consistently in any case.
If a message fails to send, the caller will know to destroy the
operation that contained it.
If a message has been sent (i.e., handed to the host device layer)
it'll have a non-null cookie pointer.
If a does complete in error, we can update the status of the
operation that contains it. That isn't happening right now but
it will soon.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The only reason gb_operation_message_init() gets its "outbound"
argument is so we can determine what allocation flags to use.
Just pass the flags in directly instead.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
We can derive the destination CPort id of any (outbound) message
from the connection it's operation is associated with. So we don't
need to store that information in every message.
As a result, we no longer need to record it at message initialization
time.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The host device pointer doesn't have to be stored in every message.
It can be derived by following up the chain of pointers back to
the operation's connection.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
All the code has now been adjusted such that we can do away with the
old gbuf structure.
Three unused references remained in "greybus.h", so those are deleted.
Other than that most of the changes were done by simple global
substitution. The gb_message structure incorporates the fields that
were previously found its embedded gbuf structure. A few names have
been changed in the process:
gbuf->transfer_buffer message->buffer
gbuf->transfer_buffer_size message->buffer_size
gbuf->hcd_data; message->cookie
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rework gb_connection_operation_recv() to be more oriented toward an
operation message, and to no longer use a struct gbuf local variable.
Rename it to be a little more wieldy.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rework greybus_kill_gbuf() to be oriented toward an operation
message rather than a gbuf, and rename it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rework greybus_submit_gbuf() to be oriented toward an operation
message rather than a gbuf, and rename it accordingly.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rework gb_opreation_message_init() so it doesn't use a struct gbuf
local variable.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Change the method that sends messages so that it sends "raw" buffers
rather than gbufs. To do this, we supply the host device and
destination CPort when sending. As with other recent patches,
change the name of the method to reflect that we're no longer
dealing with gbufs.
The interface has changed as well. Now this routine will return a
"cookie" value. The cookie is used to represent the outgoing
request, and is supplied by the caller if necessary to cancel a
previously-sent buffer. We'll store the result in gbuf->hcd_data
for now (which produces the same result as before...).
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Change the interface for canceling in-flight buffers to take a magic
cookie value as argument rather than a gbuf. Right now we pass the
gbuf->hcd_data pointer that's assumed to have been set by the submit
routine. But the next patch will change the submit routine to
return the cookie to be used, and the caller will be responsible for
keeping track of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Switch the host driver free routine to take a pointer to the
previously-allocated buffer that should be freed.
Rename the method to reflect it's no longer tied to a gbuf.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
This begins the transition to buffer allocation that does not rely
on the gbuf construct.
The host driver allocation routine will return a pointer to the
buffer to be used, and the caller will be responsible for keeping
track of that pointer, as well as the requested buffer size.
Rename the allocation method to reflect it's no longer tied to a
gbuf.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
For ES1 we need to insert the destination CPort id before the data
to be sent over UniPro. Currently this is done at the time the
buffer is created, but there's no need to do so until we're actually
going to send the content of the buffer.
Move the setting of that destination information into submit_gbuf().
Note that this allows us to defer initializing a few other gbuf
fields until after we know the buffer allocation has succeeded.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
We allocate message buffers with GFP_KERNEL allocation flags if
possible. However when an incoming request message is received we
can be in interrupt context, so we must use GFP_ATOMIC in that case.
The computation of gfp_flags in gb_operation_message_init() is
wrong. It is needlessly using GFP_ATOMIC when allocating outbound
response buffers. Fix the flawed logic.
Change the name of "data_out" to be "outbound" to be consistent with
usage elsewhere. (Data/messages are "inbound" or "outbound";
requests are "incoming" or "outgoing".)
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Only three functions remain in "gbuf.c". Move one of them into
"connection.c" and the other two into "operation.c".
Some more cleanup is coming that will further straighten out gbufs
but for now there's no sense in drawing this out any longer.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Embed the gbuf structures for operation messages into the message
structure rather than pointing to a dynamically allocated one.
Use a null gbuf->transfer_buffer pointer rather than a null gbuf
pointer to indicate an unused gbuf.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Change greybus_alloc_gbuf() so all it does is allocate the gbuf data
structure. Move all of the initialization of the gbuf structure in
the caller. Do the inverse in the caller prior to freeing the gbuf
structure via greybus_free_gbuf(). Use a null gbuf->transfer_buffer
pointer rather than a null gbuf pointer to indicate an unused gbuf.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
This converts some of the operation code to start leveraging the
new gb_message type. Instead of creating the request and response
gbufs, we initialize (and tear down with a new function) the
request and response message structures.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
A Greybus buffer (gbuf) is a generic buffer used for data transfer
over a Greybus interconnect. We only ever use gbufs in operations,
which always involve exactly two of them. The lifetime of a gbuf is
therefore directly connected to the lifetime of an operation, so
there no real need to manage gbufs separate from operations.
This patch begins the process of removing the gbuf abstraction, on
favor of a new data type, gb_message. The purpose of a gb_message
is--like a gbuf--to represent data to be transferred over Greybus.
However a gb_message is oriented toward the more restrictive way
we do Greybus transfers--as operation messages (either a request or
a response).
This patch simply defines the structure in its initial form, and
defines the request and response fields in a Greybus operation
structure as embedded instances of that type. The gbuf pointer
is defined within the gb_message structure, and as a result lots
of code needs to be tweaked to reference the request and response
gbufs as subfields of the request and response structures.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
The only thing we now use the gbuf->operation pointer for is
to get access to its connection's host device.
Record the host device pointer directly in the gbuf, rather
than keeping a pointer to the operation.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Rather than indicating whether a gbuf is intended for outbound data,
record its destination CPort id. That's what's really needed by
the ES1 host driver. Use CPORT_ID_BAD when the buffer is intended
for inbound data.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Add a reference counter to the operations structure. We'll
need this when operations are actually allowed to complete
asynchronously.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
This patch does some cleanup of gb_connection_operation_recv().
- Improve the header comments
- Verify message is big enough for header before interpreting
beginning of the message as a header
- Verify at buffer creation time rather than receive time that
no operation buffer is bigger than the maximum allowed. We
can then compare the incoming data size against the buffer.
- When a response message arrives, record its status in the
operation result, not in the buffer status.
- Record a buffer overflow as an operation error.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
It's possible this function was destined to do something important,
but at this point it's pretty pointless. Get rid of it.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
Move the cancel_delayed_work() call so it's done separate from the
removing the operation from the pending list.
This should have been part of this commit:
d3809f7 greybus: move timeout out of gb_operation_insert()
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Greg Kroah-Hartman <greg@kroah.com>
