Add support for polling the status of the write buffer so that user
space can use rpmsg character devices in non-blocking mode.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

This allows rpmsg backends to implement polling of the outgoing buffer,
which provides poll support to user space when using the rpmsg character
device.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Add support for the "label" property, used to give the edge a name other
than the one of the DT node. This allows the implementor to provide
consistently named edges when using the rpmsg character device.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Since commit 4dffed5b ("rpmsg: Name rpmsg devices based on
channel id"), it is no more possible for a firmware to register twice
a service (on different endpoints). rpmsg_register_device function
is failing when calling device_add for the second time as second
device has the same name as first one already register.
It is because name is based only on service name and so is not more
unique. Previously name was unique thanks to the use of rpmsg_dev_index.

This patch adds destination and source endpoint numbers device name to
create an unique identifier.

Fixes: 4dffed5b ("rpmsg: Name rpmsg devices based on channel id")
Acked-by: NPeter Griffin <peter.griffin@linaro.org>
Signed-off-by: NLoic Pallardy <loic.pallardy@st.com>
[bjorn: flipped name and address in device name]
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

qcom_smd_send() should return -EAGAIN for non-blocking channels with
insufficient space, so that we can propagate this event to user space.

Fixes: 53e2822e ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The edge registration functions is to be used from a remoteproc driver
to register and unregister an edge as the remote processor comes and
goes.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

There are two cases of possible uninitialized pointer usage in the API,
either the parameters themselves are invalid or we're trying to jump to
functions not required to be implemented by all backends.
Suggested-by: NLoic Pallardy <loic.pallardy@st.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Some types of rpmsg drivers does not have a primary endpoint to tie
their existence upon, but wishes to create and destroy endpoints
dynamically, e.g. based on user interactions.

Allow rpmsg drivers to omit a driver callback to signal this case and
make the probe path not create a primary endpoint in this case.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Similar to other subsystems it's useful to provide a mechanism to force
a specific driver match on a device, so introduce this.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

SMD channels are created by the remotes in "opening" state, but
sometimes as we close and try to reopen them they linger in closing
state.

Following the search for a matching channel the create_ept() will verify
that the channel is in a suitable state, so we can lax the restrictions
of the search function to work around above difference in behaviour.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The ARM allmodconfig build broke with the addition of the SMD rpmsg
driver that conflicts with the driver its replaces:

WARNING: drivers/soc/qcom/smd: 'qcom_smd_register_edge' exported twice. Previous export was in drivers/rpmsg/qcom_smd.ko
WARNING: drivers/soc/qcom/smd: 'qcom_smd_unregister_edge' exported twice. Previous export was in drivers/rpmsg/qcom_smd.ko

There is already a dependency that is meant to avoid the broken
configuration, but that only prevents the case where at least
one of the two are built-in, but not if both are modules.

This changes the dependency to "=n", to ensure that the new driver
can only be enabled if the other one is completely disabled.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Fixes: 53e2822e ("rpmsg: Introduce Qualcomm SMD backend")
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

This introduces a new rpmsg backend for the Qualcomm SMD system,
allowing communication with various remote processors found in Qualcomm
platforms. The implementation is based on, and intends to replace,
drivers/soc/qcom/smd.c with the necessary adaptions for fitting with the
rpmsg core.

Based on original work by Sricharan R <sricharan@codeaurora.org>

Cc: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Some rpmsg backends support holding on to and redelivering messages upon
failed handling of them, so provide a way for the callback to report and
error and allow the backends to handle this.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Move virtio rpmsg implementation details from the public header file to
the virtio rpmsg implementation.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Create a container struct virtio_rpmsg_channel around the rpmsg_channel
to keep virtio backend information separate from the rpmsg and public
API. This makes the public structures independant of virtio.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Move the device and endpoint indirection tables to the rpmsg internal
header file, to hide them from the public API.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Extract the generic rpmsg core functionality from the virtio rpmsg
implementation, splitting the implementation in a rpmsg core and a
virtio backend.

Based on initial work by Sricharan R <sricharan@codeaurora.org>

Cc: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The tail of create_channel() is common among all rpmsg backends, so
split it off from the virtio specific part to allow it to be extracted
to the rpmsg core.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Extract and move the helper function for finding rpmsg child devices to
the core.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Move the rpmsg_send() and rpmsg_destroy_ept() interface to the rpmsg
core, so that we eventually can hide the rpmsg_endpoint ops from the
public API.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Add indirection table for rpmsg_endpoint related operations and move
virtio implementation behind this, this finishes of the decoupling of
the virtio implementation from the public API.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Extract the now indirect rpmsg_create_ept() interface to a separate
file and start building up a rpmsg core.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

To allow for multiple backend implementations add an indireection table
for rpmsg_device related operations and move the virtio implementation
behind this table.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The rpmsg device representing struct is called rpmsg_channel and the
variable name used throughout is rpdev, with the communication happening
on endpoints it's clearer to just call this a "device" in a public API.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

As we introduce support for additional rpmsg backends, some of these
only supports point-to-point "links" represented by a name. By making
rpmsg_create_ept() take a channel_info struct we allow for these
backends to either be passed a source address, a destination address or
a name identifier.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The rpmsg_send() operations has been taking a rpmsg_device, but this
forces users of secondary rpmsg_endpoints to use the rpmsg_sendto()
interface - by extracting source and destination from the given data
structures. If we instead pass the rpmsg_endpoint to these functions a
service can use rpmsg_sendto() to respond to messages, even on secondary
endpoints.

In addition this would allow us to support operations on multiple
channels in future backends that does not support off-channel
operations.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

By basing rpmsg device names on channel id we end up with human readable
device names in sysfs and debug logs.
Reviewed-by: NSarangdhar Joshi <spjoshi@codeaurora.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Make it possible to match rpmsg devices based on device tree node, in
addition to the id table. In some of these cases the rpmsg driver would
not have a id_table, so make this optional.
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

There are couple of print_hex_dump traces used in rpmsg code which
prints the actual byte messages being transferred between host and
the remote processors. These traces are quiet verbose and affects
performance, if the appropriate trace level is enabled. These hex
dumps are needed rather rarely, but are quite useful when debugging
complex IPC corner cases. So, this patch switches these hex dump
traces to use the dynamic_hex_dump() API.

The hex dump traces are also enabled only when CONFIG_DYNAMIC_DEBUG
is enabled. This switch allows flexibility of controlling these
traces through dynamic debug, instead of removing them completely.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

This patch fixes most of the existing alignment checkpatch check
warnings of the type "Alignment should match open parenthesis"
in the virtio rpmsg bus code. A couple of them have been left as
is to not exceed the 80-char limit.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

The dma_addr_t types can be printed properly using the %pad
printk format-specifier, there is no need to resort to the
unsigned long long type-casting to deal with different possible
type sizes.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

These types of error prints are superfluous. The system will
pick up on OOM issues and let the user know. While at this,
fix the usage of using a structure instead of the actual
variable in one of the allocations.
Signed-off-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

It should never have been there in the first place.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Found with scripts/coccinelle/misc/boolconv.cocci.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

Add register_rpmsg_driver helper macro that adds THIS_MODULE to
rpmsg_driver for the registering driver. We rename and modify
the existing register_rpmsg_driver to enable this.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Acked-by: NSuman Anna <s-anna@ti.com>
Signed-off-by: NBjorn Andersson <bjorn.andersson@linaro.org>

checkpatch.pl wants arrays of strings declared as follows:

  static const char * const names[] = { "vq-1", "vq-2", "vq-3" };

Currently the find_vqs() function takes a const char *names[] argument
so passing checkpatch.pl's const char * const names[] results in a
compiler error due to losing the second const.

This patch adjusts the find_vqs() prototype and updates all virtio
transports.  This makes it possible for virtio_balloon.c, virtio_input.c,
virtgpu_kms.c, and virtio_rpmsg_bus.c to use the checkpatch.pl-friendly
type.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NBjorn Andersson <bjorn.andersson@sonymobile.com>

virtio spec requires that all drivers set DRIVER_OK
before using devices. While rpmsg isn't yet
included in the virtio 1 spec, previous spec versions
also required this.

virtio rpmsg violates this rule: is calls kick
before setting DRIVER_OK.

The fix isn't trivial since simply calling virtio_device_ready earlier
would mean we might get an interrupt in parallel with adding buffers.

Instead, split kick out to prepare+notify calls.  prepare before
virtio_device_ready - when we know we won't get interrupts. notify right
afterwards.
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>
Acked-by: NOhad Ben-Cohen <ohad@wizery.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Adjust the number of rpmsg buffers to rely on the size of the
vring, instead of using the hard coded value of 512 (256 per
direction).

This is needed when small vrings are being used, where 256
buffers are too much to fit in a vring.

While considering the vring size, keep using the 512 hard coded
value as an upper limit to avoid wacky resource tables consuming
unreasonable amount of memory.

NOTE: The number of buffers is already assumed to be symmetrical
in each direction, and that logic is unchanged.
Signed-off-by: NSuman Anna <s-anna@ti.com>
[edit commit message, small code and comment simplification]
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>

Return a negative error code from the error handling case instead of 0, as
returned elsewhere in this function.
Signed-off-by: NWei Yongjun <yongjun_wei@trendmicro.com.cn>
Cc: Ohad Ben-Cohen <ohad@wizery.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix this:
warning: (VIRTIO_PCI && VIRTIO_MMIO && REMOTEPROC && RPMSG) selects VIRTIO which has unmet direct dependencies (VIRTUALIZATION)

Cc: stable@vger.kernel.org
Signed-off-by: NSuman Anna <s-anna@ti.com>
[edit commit log]
Signed-off-by: NOhad Ben-Cohen <ohad@wizery.com>