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Merge tag 'rpmsg-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc into next/rpmsg

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* tag 'rpmsg-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/remoteproc:
  remoteproc: s/big switch/lookup table/
  remoteproc: bail out if firmware has different endianess
  remoteproc: don't use virtio's weak barriers
  rpmsg: rename virtqueue_add_buf_gfp to virtqueue_add_buf
  rpmsg: depend on EXPERIMENTAL
  remoteproc: depend on EXPERIMENTAL
  rpmsg: add Kconfig menu
  remoteproc: add Kconfig menu
  remoteproc: look for truncated firmware images
  remoteproc/omap: utilize module_platform_driver
  remoteproc: remove unused resource type
  remoteproc: avoid registering a virtio device if not supported
  remoteproc: do not require an iommu
  samples/rpmsg: add an rpmsg driver sample
  rpmsg: add virtio-based remote processor messaging bus
  remoteproc/omap: add a remoteproc driver for OMAP4
  remoteproc: create rpmsg virtio device
  remoteproc: add debugfs entries
  remoteproc: add framework for controlling remote processors
This commit is contained in:
Arnd Bergmann 2012-02-23 14:11:12 +00:00
commit ab646a24bb
26 changed files with 4833 additions and 1 deletions
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What: /sys/bus/rpmsg/devices/.../name
Date: June 2011
KernelVersion: 3.3
Contact: Ohad Ben-Cohen <ohad@wizery.com>
Description:
Every rpmsg device is a communication channel with a remote
processor. Channels are identified with a (textual) name,
which is maximum 32 bytes long (defined as RPMSG_NAME_SIZE in
rpmsg.h).
This sysfs entry contains the name of this channel.
What: /sys/bus/rpmsg/devices/.../src
Date: June 2011
KernelVersion: 3.3
Contact: Ohad Ben-Cohen <ohad@wizery.com>
Description:
Every rpmsg device is a communication channel with a remote
processor. Channels have a local ("source") rpmsg address,
and remote ("destination") rpmsg address. When an entity
starts listening on one end of a channel, it assigns it with
a unique rpmsg address (a 32 bits integer). This way when
inbound messages arrive to this address, the rpmsg core
dispatches them to the listening entity (a kernel driver).
This sysfs entry contains the src (local) rpmsg address
of this channel. If it contains 0xffffffff, then an address
wasn't assigned (can happen if no driver exists for this
channel).
What: /sys/bus/rpmsg/devices/.../dst
Date: June 2011
KernelVersion: 3.3
Contact: Ohad Ben-Cohen <ohad@wizery.com>
Description:
Every rpmsg device is a communication channel with a remote
processor. Channels have a local ("source") rpmsg address,
and remote ("destination") rpmsg address. When an entity
starts listening on one end of a channel, it assigns it with
a unique rpmsg address (a 32 bits integer). This way when
inbound messages arrive to this address, the rpmsg core
dispatches them to the listening entity.
This sysfs entry contains the dst (remote) rpmsg address
of this channel. If it contains 0xffffffff, then an address
wasn't assigned (can happen if the kernel driver that
is attached to this channel is exposing a service to the
remote processor. This make it a local rpmsg server,
and it is listening for inbound messages that may be sent
from any remote rpmsg client; it is not bound to a single
remote entity).
What: /sys/bus/rpmsg/devices/.../announce
Date: June 2011
KernelVersion: 3.3
Contact: Ohad Ben-Cohen <ohad@wizery.com>
Description:
Every rpmsg device is a communication channel with a remote
processor. Channels are identified by a textual name (see
/sys/bus/rpmsg/devices/.../name above) and have a local
("source") rpmsg address, and remote ("destination") rpmsg
address.
A channel is first created when an entity, whether local
or remote, starts listening on it for messages (and is thus
called an rpmsg server).
When that happens, a "name service" announcement is sent
to the other processor, in order to let it know about the
creation of the channel (this way remote clients know they
can start sending messages).
This sysfs entry tells us whether the channel is a local
server channel that is announced (values are either
true or false).

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Remote Processor Framework
1. Introduction
Modern SoCs typically have heterogeneous remote processor devices in asymmetric
multiprocessing (AMP) configurations, which may be running different instances
of operating system, whether it's Linux or any other flavor of real-time OS.
OMAP4, for example, has dual Cortex-A9, dual Cortex-M3 and a C64x+ DSP.
In a typical configuration, the dual cortex-A9 is running Linux in a SMP
configuration, and each of the other three cores (two M3 cores and a DSP)
is running its own instance of RTOS in an AMP configuration.
The remoteproc framework allows different platforms/architectures to
control (power on, load firmware, power off) those remote processors while
abstracting the hardware differences, so the entire driver doesn't need to be
duplicated. In addition, this framework also adds rpmsg virtio devices
for remote processors that supports this kind of communication. This way,
platform-specific remoteproc drivers only need to provide a few low-level
handlers, and then all rpmsg drivers will then just work
(for more information about the virtio-based rpmsg bus and its drivers,
please read Documentation/rpmsg.txt).
2. User API
int rproc_boot(struct rproc *rproc)
- Boot a remote processor (i.e. load its firmware, power it on, ...).
If the remote processor is already powered on, this function immediately
returns (successfully).
Returns 0 on success, and an appropriate error value otherwise.
Note: to use this function you should already have a valid rproc
handle. There are several ways to achieve that cleanly (devres, pdata,
the way remoteproc_rpmsg.c does this, or, if this becomes prevalent, we
might also consider using dev_archdata for this). See also
rproc_get_by_name() below.
void rproc_shutdown(struct rproc *rproc)
- Power off a remote processor (previously booted with rproc_boot()).
In case @rproc is still being used by an additional user(s), then
this function will just decrement the power refcount and exit,
without really powering off the device.
Every call to rproc_boot() must (eventually) be accompanied by a call
to rproc_shutdown(). Calling rproc_shutdown() redundantly is a bug.
Notes:
- we're not decrementing the rproc's refcount, only the power refcount.
which means that the @rproc handle stays valid even after
rproc_shutdown() returns, and users can still use it with a subsequent
rproc_boot(), if needed.
- don't call rproc_shutdown() to unroll rproc_get_by_name(), exactly
because rproc_shutdown() _does not_ decrement the refcount of @rproc.
To decrement the refcount of @rproc, use rproc_put() (but _only_ if
you acquired @rproc using rproc_get_by_name()).
struct rproc *rproc_get_by_name(const char *name)
- Find an rproc handle using the remote processor's name, and then
boot it. If it's already powered on, then just immediately return
(successfully). Returns the rproc handle on success, and NULL on failure.
This function increments the remote processor's refcount, so always
use rproc_put() to decrement it back once rproc isn't needed anymore.
Note: currently rproc_get_by_name() and rproc_put() are not used anymore
by the rpmsg bus and its drivers. We need to scrutinize the use cases
that still need them, and see if we can migrate them to use the non
name-based boot/shutdown interface.
void rproc_put(struct rproc *rproc)
- Decrement @rproc's power refcount and shut it down if it reaches zero
(essentially by just calling rproc_shutdown), and then decrement @rproc's
validity refcount too.
After this function returns, @rproc may _not_ be used anymore, and its
handle should be considered invalid.
This function should be called _iff_ the @rproc handle was grabbed by
calling rproc_get_by_name().
3. Typical usage
#include <linux/remoteproc.h>
/* in case we were given a valid 'rproc' handle */
int dummy_rproc_example(struct rproc *my_rproc)
{
int ret;
/* let's power on and boot our remote processor */
ret = rproc_boot(my_rproc);
if (ret) {
/*
* something went wrong. handle it and leave.
*/
}
/*
* our remote processor is now powered on... give it some work
*/
/* let's shut it down now */
rproc_shutdown(my_rproc);
}
4. API for implementors
struct rproc *rproc_alloc(struct device *dev, const char *name,
const struct rproc_ops *ops,
const char *firmware, int len)
- Allocate a new remote processor handle, but don't register
it yet. Required parameters are the underlying device, the
name of this remote processor, platform-specific ops handlers,
the name of the firmware to boot this rproc with, and the
length of private data needed by the allocating rproc driver (in bytes).
This function should be used by rproc implementations during
initialization of the remote processor.
After creating an rproc handle using this function, and when ready,
implementations should then call rproc_register() to complete
the registration of the remote processor.
On success, the new rproc is returned, and on failure, NULL.
Note: _never_ directly deallocate @rproc, even if it was not registered
yet. Instead, if you just need to unroll rproc_alloc(), use rproc_free().
void rproc_free(struct rproc *rproc)
- Free an rproc handle that was allocated by rproc_alloc.
This function should _only_ be used if @rproc was only allocated,
but not registered yet.
If @rproc was already successfully registered (by calling
rproc_register()), then use rproc_unregister() instead.
int rproc_register(struct rproc *rproc)
- Register @rproc with the remoteproc framework, after it has been
allocated with rproc_alloc().
This is called by the platform-specific rproc implementation, whenever
a new remote processor device is probed.
Returns 0 on success and an appropriate error code otherwise.
Note: this function initiates an asynchronous firmware loading
context, which will look for virtio devices supported by the rproc's
firmware.
If found, those virtio devices will be created and added, so as a result
of registering this remote processor, additional virtio drivers might get
probed.
Currently, though, we only support a single RPMSG virtio vdev per remote
processor.
int rproc_unregister(struct rproc *rproc)
- Unregister a remote processor, and decrement its refcount.
If its refcount drops to zero, then @rproc will be freed. If not,
it will be freed later once the last reference is dropped.
This function should be called when the platform specific rproc
implementation decides to remove the rproc device. it should
_only_ be called if a previous invocation of rproc_register()
has completed successfully.
After rproc_unregister() returns, @rproc is _not_ valid anymore and
it shouldn't be used. More specifically, don't call rproc_free()
or try to directly free @rproc after rproc_unregister() returns;
none of these are needed, and calling them is a bug.
Returns 0 on success and -EINVAL if @rproc isn't valid.
5. Implementation callbacks
These callbacks should be provided by platform-specific remoteproc
drivers:
/**
* struct rproc_ops - platform-specific device handlers
* @start: power on the device and boot it
* @stop: power off the device
* @kick: kick a virtqueue (virtqueue id given as a parameter)
*/
struct rproc_ops {
int (*start)(struct rproc *rproc);
int (*stop)(struct rproc *rproc);
void (*kick)(struct rproc *rproc, int vqid);
};
Every remoteproc implementation should at least provide the ->start and ->stop
handlers. If rpmsg functionality is also desired, then the ->kick handler
should be provided as well.
The ->start() handler takes an rproc handle and should then power on the
device and boot it (use rproc->priv to access platform-specific private data).
The boot address, in case needed, can be found in rproc->bootaddr (remoteproc
core puts there the ELF entry point).
On success, 0 should be returned, and on failure, an appropriate error code.
The ->stop() handler takes an rproc handle and powers the device down.
On success, 0 is returned, and on failure, an appropriate error code.
The ->kick() handler takes an rproc handle, and an index of a virtqueue
where new message was placed in. Implementations should interrupt the remote
processor and let it know it has pending messages. Notifying remote processors
the exact virtqueue index to look in is optional: it is easy (and not
too expensive) to go through the existing virtqueues and look for new buffers
in the used rings.
6. Binary Firmware Structure
At this point remoteproc only supports ELF32 firmware binaries. However,
it is quite expected that other platforms/devices which we'd want to
support with this framework will be based on different binary formats.
When those use cases show up, we will have to decouple the binary format
from the framework core, so we can support several binary formats without
duplicating common code.
When the firmware is parsed, its various segments are loaded to memory
according to the specified device address (might be a physical address
if the remote processor is accessing memory directly).
In addition to the standard ELF segments, most remote processors would
also include a special section which we call "the resource table".
The resource table contains system resources that the remote processor
requires before it should be powered on, such as allocation of physically
contiguous memory, or iommu mapping of certain on-chip peripherals.
Remotecore will only power up the device after all the resource table's
requirement are met.
In addition to system resources, the resource table may also contain
resource entries that publish the existence of supported features
or configurations by the remote processor, such as trace buffers and
supported virtio devices (and their configurations).
Currently the resource table is just an array of:
/**
* struct fw_resource - describes an entry from the resource section
* @type: resource type
* @id: index number of the resource
* @da: device address of the resource
* @pa: physical address of the resource
* @len: size, in bytes, of the resource
* @flags: properties of the resource, e.g. iommu protection required
* @reserved: must be 0 atm
* @name: name of resource
*/
struct fw_resource {
u32 type;
u32 id;
u64 da;
u64 pa;
u32 len;
u32 flags;
u8 reserved[16];
u8 name[48];
} __packed;
Some resources entries are mere announcements, where the host is informed
of specific remoteproc configuration. Other entries require the host to
do something (e.g. reserve a requested resource) and possibly also reply
by overwriting a member inside 'struct fw_resource' with info about the
allocated resource.
Different resource entries use different members of this struct,
with different meanings. This is pretty limiting and error-prone,
so the plan is to move to variable-length TLV-based resource entries,
where each resource will begin with a type and length fields, followed by
its own specific structure.
Here are the resource types that are currently being used:
/**
* enum fw_resource_type - types of resource entries
*
* @RSC_CARVEOUT: request for allocation of a physically contiguous
* memory region.
* @RSC_DEVMEM: request to iommu_map a memory-based peripheral.
* @RSC_TRACE: announces the availability of a trace buffer into which
* the remote processor will be writing logs. In this case,
* 'da' indicates the device address where logs are written to,
* and 'len' is the size of the trace buffer.
* @RSC_VRING: request for allocation of a virtio vring (address should
* be indicated in 'da', and 'len' should contain the number
* of buffers supported by the vring).
* @RSC_VIRTIO_DEV: announces support for a virtio device, and serves as
* the virtio header. 'da' contains the virtio device
* features, 'pa' holds the virtio guest features (host
* will write them here after they're negotiated), 'len'
* holds the virtio status, and 'flags' holds the virtio
* device id (currently only VIRTIO_ID_RPMSG is supported).
*/
enum fw_resource_type {
RSC_CARVEOUT = 0,
RSC_DEVMEM = 1,
RSC_TRACE = 2,
RSC_VRING = 3,
RSC_VIRTIO_DEV = 4,
RSC_VIRTIO_CFG = 5,
};
Most of the resource entries share the basic idea of address/length
negotiation with the host: the firmware usually asks for memory
of size 'len' bytes, and the host needs to allocate it and provide
the device/physical address (when relevant) in 'da'/'pa' respectively.
If the firmware is compiled with hard coded device addresses, and
can't handle dynamically allocated 'da' values, then the 'da' field
will contain the expected device addresses (today we actually only support
this scheme, as there aren't yet any use cases for dynamically allocated
device addresses).
We also expect that platform-specific resource entries will show up
at some point. When that happens, we could easily add a new RSC_PLAFORM
type, and hand those resources to the platform-specific rproc driver to handle.
7. Virtio and remoteproc
The firmware should provide remoteproc information about virtio devices
that it supports, and their configurations: a RSC_VIRTIO_DEV resource entry
should specify the virtio device id, and subsequent RSC_VRING resource entries
should indicate the vring size (i.e. how many buffers do they support) and
where should they be mapped (i.e. which device address). Note: the alignment
between the consumer and producer parts of the vring is assumed to be 4096.
At this point we only support a single virtio rpmsg device per remote
processor, but the plan is to remove this limitation. In addition, once we
move to TLV-based resource table, the plan is to have a single RSC_VIRTIO
entry per supported virtio device, which will include the virtio header,
the vrings information and the virtio config space.
Of course, RSC_VIRTIO resource entries are only good enough for static
allocation of virtio devices. Dynamic allocations will also be made possible
using the rpmsg bus (similar to how we already do dynamic allocations of
rpmsg channels; read more about it in rpmsg.txt).

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Remote Processor Messaging (rpmsg) Framework
Note: this document describes the rpmsg bus and how to write rpmsg drivers.
To learn how to add rpmsg support for new platforms, check out remoteproc.txt
(also a resident of Documentation/).
1. Introduction
Modern SoCs typically employ heterogeneous remote processor devices in
asymmetric multiprocessing (AMP) configurations, which may be running
different instances of operating system, whether it's Linux or any other
flavor of real-time OS.
OMAP4, for example, has dual Cortex-A9, dual Cortex-M3 and a C64x+ DSP.
Typically, the dual cortex-A9 is running Linux in a SMP configuration,
and each of the other three cores (two M3 cores and a DSP) is running
its own instance of RTOS in an AMP configuration.
Typically AMP remote processors employ dedicated DSP codecs and multimedia
hardware accelerators, and therefore are often used to offload CPU-intensive
multimedia tasks from the main application processor.
These remote processors could also be used to control latency-sensitive
sensors, drive random hardware blocks, or just perform background tasks
while the main CPU is idling.
Users of those remote processors can either be userland apps (e.g. multimedia
frameworks talking with remote OMX components) or kernel drivers (controlling
hardware accessible only by the remote processor, reserving kernel-controlled
resources on behalf of the remote processor, etc..).
Rpmsg is a virtio-based messaging bus that allows kernel drivers to communicate
with remote processors available on the system. In turn, drivers could then
expose appropriate user space interfaces, if needed.
When writing a driver that exposes rpmsg communication to userland, please
keep in mind that remote processors might have direct access to the
system's physical memory and other sensitive hardware resources (e.g. on
OMAP4, remote cores and hardware accelerators may have direct access to the
physical memory, gpio banks, dma controllers, i2c bus, gptimers, mailbox
devices, hwspinlocks, etc..). Moreover, those remote processors might be
running RTOS where every task can access the entire memory/devices exposed
to the processor. To minimize the risks of rogue (or buggy) userland code
exploiting remote bugs, and by that taking over the system, it is often
desired to limit userland to specific rpmsg channels (see definition below)
it can send messages on, and if possible, minimize how much control
it has over the content of the messages.
Every rpmsg device is a communication channel with a remote processor (thus
rpmsg devices are called channels). Channels are identified by a textual name
and have a local ("source") rpmsg address, and remote ("destination") rpmsg
address.
When a driver starts listening on a channel, its rx callback is bound with
a unique rpmsg local address (a 32-bit integer). This way when inbound messages
arrive, the rpmsg core dispatches them to the appropriate driver according
to their destination address (this is done by invoking the driver's rx handler
with the payload of the inbound message).
2. User API
int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len);
- sends a message across to the remote processor on a given channel.
The caller should specify the channel, the data it wants to send,
and its length (in bytes). The message will be sent on the specified
channel, i.e. its source and destination address fields will be
set to the channel's src and dst addresses.
In case there are no TX buffers available, the function will block until
one becomes available (i.e. until the remote processor consumes
a tx buffer and puts it back on virtio's used descriptor ring),
or a timeout of 15 seconds elapses. When the latter happens,
-ERESTARTSYS is returned.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst);
- sends a message across to the remote processor on a given channel,
to a destination address provided by the caller.
The caller should specify the channel, the data it wants to send,
its length (in bytes), and an explicit destination address.
The message will then be sent to the remote processor to which the
channel belongs, using the channel's src address, and the user-provided
dst address (thus the channel's dst address will be ignored).
In case there are no TX buffers available, the function will block until
one becomes available (i.e. until the remote processor consumes
a tx buffer and puts it back on virtio's used descriptor ring),
or a timeout of 15 seconds elapses. When the latter happens,
-ERESTARTSYS is returned.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
void *data, int len);
- sends a message across to the remote processor, using the src and dst
addresses provided by the user.
The caller should specify the channel, the data it wants to send,
its length (in bytes), and explicit source and destination addresses.
The message will then be sent to the remote processor to which the
channel belongs, but the channel's src and dst addresses will be
ignored (and the user-provided addresses will be used instead).
In case there are no TX buffers available, the function will block until
one becomes available (i.e. until the remote processor consumes
a tx buffer and puts it back on virtio's used descriptor ring),
or a timeout of 15 seconds elapses. When the latter happens,
-ERESTARTSYS is returned.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len);
- sends a message across to the remote processor on a given channel.
The caller should specify the channel, the data it wants to send,
and its length (in bytes). The message will be sent on the specified
channel, i.e. its source and destination address fields will be
set to the channel's src and dst addresses.
In case there are no TX buffers available, the function will immediately
return -ENOMEM without waiting until one becomes available.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
- sends a message across to the remote processor on a given channel,
to a destination address provided by the user.
The user should specify the channel, the data it wants to send,
its length (in bytes), and an explicit destination address.
The message will then be sent to the remote processor to which the
channel belongs, using the channel's src address, and the user-provided
dst address (thus the channel's dst address will be ignored).
In case there are no TX buffers available, the function will immediately
return -ENOMEM without waiting until one becomes available.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
void *data, int len);
- sends a message across to the remote processor, using source and
destination addresses provided by the user.
The user should specify the channel, the data it wants to send,
its length (in bytes), and explicit source and destination addresses.
The message will then be sent to the remote processor to which the
channel belongs, but the channel's src and dst addresses will be
ignored (and the user-provided addresses will be used instead).
In case there are no TX buffers available, the function will immediately
return -ENOMEM without waiting until one becomes available.
The function can only be called from a process context (for now).
Returns 0 on success and an appropriate error value on failure.
struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *rpdev,
void (*cb)(struct rpmsg_channel *, void *, int, void *, u32),
void *priv, u32 addr);
- every rpmsg address in the system is bound to an rx callback (so when
inbound messages arrive, they are dispatched by the rpmsg bus using the
appropriate callback handler) by means of an rpmsg_endpoint struct.
This function allows drivers to create such an endpoint, and by that,
bind a callback, and possibly some private data too, to an rpmsg address
(either one that is known in advance, or one that will be dynamically
assigned for them).
Simple rpmsg drivers need not call rpmsg_create_ept, because an endpoint
is already created for them when they are probed by the rpmsg bus
(using the rx callback they provide when they registered to the rpmsg bus).
So things should just work for simple drivers: they already have an
endpoint, their rx callback is bound to their rpmsg address, and when
relevant inbound messages arrive (i.e. messages which their dst address
equals to the src address of their rpmsg channel), the driver's handler
is invoked to process it.
That said, more complicated drivers might do need to allocate
additional rpmsg addresses, and bind them to different rx callbacks.
To accomplish that, those drivers need to call this function.
Drivers should provide their channel (so the new endpoint would bind
to the same remote processor their channel belongs to), an rx callback
function, an optional private data (which is provided back when the
rx callback is invoked), and an address they want to bind with the
callback. If addr is RPMSG_ADDR_ANY, then rpmsg_create_ept will
dynamically assign them an available rpmsg address (drivers should have
a very good reason why not to always use RPMSG_ADDR_ANY here).
Returns a pointer to the endpoint on success, or NULL on error.
void rpmsg_destroy_ept(struct rpmsg_endpoint *ept);
- destroys an existing rpmsg endpoint. user should provide a pointer
to an rpmsg endpoint that was previously created with rpmsg_create_ept().
int register_rpmsg_driver(struct rpmsg_driver *rpdrv);
- registers an rpmsg driver with the rpmsg bus. user should provide
a pointer to an rpmsg_driver struct, which contains the driver's
->probe() and ->remove() functions, an rx callback, and an id_table
specifying the names of the channels this driver is interested to
be probed with.
void unregister_rpmsg_driver(struct rpmsg_driver *rpdrv);
- unregisters an rpmsg driver from the rpmsg bus. user should provide
a pointer to a previously-registered rpmsg_driver struct.
Returns 0 on success, and an appropriate error value on failure.
3. Typical usage
The following is a simple rpmsg driver, that sends an "hello!" message
on probe(), and whenever it receives an incoming message, it dumps its
content to the console.
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rpmsg.h>
static void rpmsg_sample_cb(struct rpmsg_channel *rpdev, void *data, int len,
void *priv, u32 src)
{
print_hex_dump(KERN_INFO, "incoming message:", DUMP_PREFIX_NONE,
16, 1, data, len, true);
}
static int rpmsg_sample_probe(struct rpmsg_channel *rpdev)
{
int err;
dev_info(&rpdev->dev, "chnl: 0x%x -> 0x%x\n", rpdev->src, rpdev->dst);
/* send a message on our channel */
err = rpmsg_send(rpdev, "hello!", 6);
if (err) {
pr_err("rpmsg_send failed: %d\n", err);
return err;
}
return 0;
}
static void __devexit rpmsg_sample_remove(struct rpmsg_channel *rpdev)
{
dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
}
static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
{ .name = "rpmsg-client-sample" },
{ },
};
MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
static struct rpmsg_driver rpmsg_sample_client = {
.drv.name = KBUILD_MODNAME,
.drv.owner = THIS_MODULE,
.id_table = rpmsg_driver_sample_id_table,
.probe = rpmsg_sample_probe,
.callback = rpmsg_sample_cb,
.remove = __devexit_p(rpmsg_sample_remove),
};
static int __init init(void)
{
return register_rpmsg_driver(&rpmsg_sample_client);
}
module_init(init);
static void __exit fini(void)
{
unregister_rpmsg_driver(&rpmsg_sample_client);
}
module_exit(fini);
Note: a similar sample which can be built and loaded can be found
in samples/rpmsg/.
4. Allocations of rpmsg channels:
At this point we only support dynamic allocations of rpmsg channels.
This is possible only with remote processors that have the VIRTIO_RPMSG_F_NS
virtio device feature set. This feature bit means that the remote
processor supports dynamic name service announcement messages.
When this feature is enabled, creation of rpmsg devices (i.e. channels)
is completely dynamic: the remote processor announces the existence of a
remote rpmsg service by sending a name service message (which contains
the name and rpmsg addr of the remote service, see struct rpmsg_ns_msg).
This message is then handled by the rpmsg bus, which in turn dynamically
creates and registers an rpmsg channel (which represents the remote service).
If/when a relevant rpmsg driver is registered, it will be immediately probed
by the bus, and can then start sending messages to the remote service.
The plan is also to add static creation of rpmsg channels via the virtio
config space, but it's not implemented yet.

7
MAINTAINERS
View File

@ -5550,6 +5550,13 @@ S: Supported
F: drivers/base/regmap/
F: include/linux/regmap.h
REMOTE PROCESSOR (REMOTEPROC) SUBSYSTEM
M: Ohad Ben-Cohen <ohad@wizery.com>
S: Maintained
F: drivers/remoteproc/
F: Documentation/remoteproc.txt
F: include/linux/remoteproc.txt
RFKILL
M: Johannes Berg <johannes@sipsolutions.net>
L: linux-wireless@vger.kernel.org

57
arch/arm/plat-omap/include/plat/remoteproc.h Normal file
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@ -0,0 +1,57 @@
/*
* Remote Processor - omap-specific bits
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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.
*/
#ifndef _PLAT_REMOTEPROC_H
#define _PLAT_REMOTEPROC_H
struct rproc_ops;
struct platform_device;
/*
* struct omap_rproc_pdata - omap remoteproc's platform data
* @name: the remoteproc's name
* @oh_name: omap hwmod device
* @oh_name_opt: optional, secondary omap hwmod device
* @firmware: name of firmware file to load
* @mbox_name: name of omap mailbox device to use with this rproc
* @ops: start/stop rproc handlers
* @device_enable: omap-specific handler for enabling a device
* @device_shutdown: omap-specific handler for shutting down a device
*/
struct omap_rproc_pdata {
const char *name;
const char *oh_name;
const char *oh_name_opt;
const char *firmware;
const char *mbox_name;
const struct rproc_ops *ops;
int (*device_enable) (struct platform_device *pdev);
int (*device_shutdown) (struct platform_device *pdev);
};
#if defined(CONFIG_OMAP_REMOTEPROC) || defined(CONFIG_OMAP_REMOTEPROC_MODULE)
void __init omap_rproc_reserve_cma(void);
#else
void __init omap_rproc_reserve_cma(void)
{
}
#endif
#endif /* _PLAT_REMOTEPROC_H */

4
drivers/Kconfig
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@ -132,6 +132,10 @@ source "drivers/clocksource/Kconfig"
source "drivers/iommu/Kconfig"
source "drivers/remoteproc/Kconfig"
source "drivers/rpmsg/Kconfig"
source "drivers/virt/Kconfig"
source "drivers/devfreq/Kconfig"

2
drivers/Makefile
View File

@ -126,6 +126,8 @@ obj-y += clk/
obj-$(CONFIG_HWSPINLOCK) += hwspinlock/
obj-$(CONFIG_NFC) += nfc/
obj-$(CONFIG_IOMMU_SUPPORT) += iommu/
obj-$(CONFIG_REMOTEPROC) += remoteproc/
obj-$(CONFIG_RPMSG) += rpmsg/
# Virtualization drivers
obj-$(CONFIG_VIRT_DRIVERS) += virt/

29
drivers/remoteproc/Kconfig Normal file
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@ -0,0 +1,29 @@
menu "Remoteproc drivers (EXPERIMENTAL)"
# REMOTEPROC gets selected by whoever wants it
config REMOTEPROC
tristate
depends on EXPERIMENTAL
config OMAP_REMOTEPROC
tristate "OMAP remoteproc support"
depends on ARCH_OMAP4
select OMAP_IOMMU
select REMOTEPROC
select OMAP_MBOX_FWK
select RPMSG
default m
help
Say y here to support OMAP's remote processors (dual M3
and DSP on OMAP4) via the remote processor framework.
Currently only supported on OMAP4.
Usually you want to say y here, in order to enable multimedia
use-cases to run on your platform (multimedia codecs are
offloaded to remote DSP processors using this framework).
It's safe to say n here if you're not interested in multimedia
offloading or just want a bare minimum kernel.
endmenu

9
drivers/remoteproc/Makefile Normal file
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@ -0,0 +1,9 @@
#
# Generic framework for controlling remote processors
#
obj-$(CONFIG_REMOTEPROC) += remoteproc.o
remoteproc-y := remoteproc_core.o
remoteproc-y += remoteproc_debugfs.o
remoteproc-y += remoteproc_rpmsg.o
obj-$(CONFIG_OMAP_REMOTEPROC) += omap_remoteproc.o

238
drivers/remoteproc/omap_remoteproc.c Normal file
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@ -0,0 +1,238 @@
/*
* OMAP Remote Processor driver
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
* Fernando Guzman Lugo <fernando.lugo@ti.com>
* Mark Grosen <mgrosen@ti.com>
* Suman Anna <s-anna@ti.com>
* Hari Kanigeri <h-kanigeri2@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/remoteproc.h>
#include <plat/mailbox.h>
#include <plat/remoteproc.h>
#include "omap_remoteproc.h"
#include "remoteproc_internal.h"
/**
* struct omap_rproc - omap remote processor state
* @mbox: omap mailbox handle
* @nb: notifier block that will be invoked on inbound mailbox messages
* @rproc: rproc handle
*/
struct omap_rproc {
struct omap_mbox *mbox;
struct notifier_block nb;
struct rproc *rproc;
};
/**
* omap_rproc_mbox_callback() - inbound mailbox message handler
* @this: notifier block
* @index: unused
* @data: mailbox payload
*
* This handler is invoked by omap's mailbox driver whenever a mailbox
* message is received. Usually, the mailbox payload simply contains
* the index of the virtqueue that is kicked by the remote processor,
* and we let remoteproc core handle it.
*
* In addition to virtqueue indices, we also have some out-of-band values
* that indicates different events. Those values are deliberately very
* big so they don't coincide with virtqueue indices.
*/
static int omap_rproc_mbox_callback(struct notifier_block *this,
unsigned long index, void *data)
{
mbox_msg_t msg = (mbox_msg_t) data;
struct omap_rproc *oproc = container_of(this, struct omap_rproc, nb);
struct device *dev = oproc->rproc->dev;
const char *name = oproc->rproc->name;
dev_dbg(dev, "mbox msg: 0x%x\n", msg);
switch (msg) {
case RP_MBOX_CRASH:
/* just log this for now. later, we'll also do recovery */
dev_err(dev, "omap rproc %s crashed\n", name);
break;
case RP_MBOX_ECHO_REPLY:
dev_info(dev, "received echo reply from %s\n", name);
break;
default:
/* ignore vq indices which are too large to be valid */
if (msg >= 2) {
dev_warn(dev, "invalid mbox msg: 0x%x\n", msg);
break;
}
/*
* At this point, 'msg' contains the index of the vring
* which was just triggered.
*/
if (rproc_vq_interrupt(oproc->rproc, msg) == IRQ_NONE)
dev_dbg(dev, "no message was found in vqid %d\n", msg);
}
return NOTIFY_DONE;
}
/* kick a virtqueue */
static void omap_rproc_kick(struct rproc *rproc, int vqid)
{
struct omap_rproc *oproc = rproc->priv;
int ret;
/* send the index of the triggered virtqueue in the mailbox payload */
ret = omap_mbox_msg_send(oproc->mbox, vqid);
if (ret)
dev_err(rproc->dev, "omap_mbox_msg_send failed: %d\n", ret);
}
/*
* Power up the remote processor.
*
* This function will be invoked only after the firmware for this rproc
* was loaded, parsed successfully, and all of its resource requirements
* were met.
*/
static int omap_rproc_start(struct rproc *rproc)
{
struct omap_rproc *oproc = rproc->priv;
struct platform_device *pdev = to_platform_device(rproc->dev);
struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
int ret;
oproc->nb.notifier_call = omap_rproc_mbox_callback;
/* every omap rproc is assigned a mailbox instance for messaging */
oproc->mbox = omap_mbox_get(pdata->mbox_name, &oproc->nb);
if (IS_ERR(oproc->mbox)) {
ret = PTR_ERR(oproc->mbox);
dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret);
return ret;
}
/*
* Ping the remote processor. this is only for sanity-sake;
* there is no functional effect whatsoever.
*
* Note that the reply will _not_ arrive immediately: this message
* will wait in the mailbox fifo until the remote processor is booted.
*/
ret = omap_mbox_msg_send(oproc->mbox, RP_MBOX_ECHO_REQUEST);
if (ret) {
dev_err(rproc->dev, "omap_mbox_get failed: %d\n", ret);
goto put_mbox;
}
ret = pdata->device_enable(pdev);
if (ret) {
dev_err(rproc->dev, "omap_device_enable failed: %d\n", ret);
goto put_mbox;
}
return 0;
put_mbox:
omap_mbox_put(oproc->mbox, &oproc->nb);
return ret;
}
/* power off the remote processor */
static int omap_rproc_stop(struct rproc *rproc)
{
struct platform_device *pdev = to_platform_device(rproc->dev);
struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
struct omap_rproc *oproc = rproc->priv;
int ret;
ret = pdata->device_shutdown(pdev);
if (ret)
return ret;
omap_mbox_put(oproc->mbox, &oproc->nb);
return 0;
}
static struct rproc_ops omap_rproc_ops = {
.start = omap_rproc_start,
.stop = omap_rproc_stop,
.kick = omap_rproc_kick,
};
static int __devinit omap_rproc_probe(struct platform_device *pdev)
{
struct omap_rproc_pdata *pdata = pdev->dev.platform_data;
struct omap_rproc *oproc;
struct rproc *rproc;
int ret;
ret = dma_set_coherent_mask(&pdev->dev, DMA_BIT_MASK(32));
if (ret) {
dev_err(pdev->dev.parent, "dma_set_coherent_mask: %d\n", ret);
return ret;
}
rproc = rproc_alloc(&pdev->dev, pdata->name, &omap_rproc_ops,
pdata->firmware, sizeof(*oproc));
if (!rproc)
return -ENOMEM;
oproc = rproc->priv;
oproc->rproc = rproc;
platform_set_drvdata(pdev, rproc);
ret = rproc_register(rproc);
if (ret)
goto free_rproc;
return 0;
free_rproc:
rproc_free(rproc);
return ret;
}
static int __devexit omap_rproc_remove(struct platform_device *pdev)
{
struct rproc *rproc = platform_get_drvdata(pdev);
return rproc_unregister(rproc);
}
static struct platform_driver omap_rproc_driver = {
.probe = omap_rproc_probe,
.remove = __devexit_p(omap_rproc_remove),
.driver = {
.name = "omap-rproc",
.owner = THIS_MODULE,
},
};
module_platform_driver(omap_rproc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("OMAP Remote Processor control driver");

69
drivers/remoteproc/omap_remoteproc.h Normal file
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@ -0,0 +1,69 @@
/*
* Remote processor messaging
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name Texas Instruments nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _OMAP_RPMSG_H
#define _OMAP_RPMSG_H
/*
* enum - Predefined Mailbox Messages
*
* @RP_MBOX_READY: informs the M3's that we're up and running. this is
* part of the init sequence sent that the M3 expects to see immediately
* after it is booted.
*
* @RP_MBOX_PENDING_MSG: informs the receiver that there is an inbound
* message waiting in its own receive-side vring. please note that currently
* this message is optional: alternatively, one can explicitly send the index
* of the triggered virtqueue itself. the preferred approach will be decided
* as we progress and experiment with those two different approaches.
*
* @RP_MBOX_CRASH: this message is sent if BIOS crashes
*
* @RP_MBOX_ECHO_REQUEST: a mailbox-level "ping" message.
*
* @RP_MBOX_ECHO_REPLY: a mailbox-level reply to a "ping"
*
* @RP_MBOX_ABORT_REQUEST: a "please crash" request, used for testing the
* recovery mechanism (to some extent).
*/
enum omap_rp_mbox_messages {
RP_MBOX_READY = 0xFFFFFF00,
RP_MBOX_PENDING_MSG = 0xFFFFFF01,
RP_MBOX_CRASH = 0xFFFFFF02,
RP_MBOX_ECHO_REQUEST = 0xFFFFFF03,
RP_MBOX_ECHO_REPLY = 0xFFFFFF04,
RP_MBOX_ABORT_REQUEST = 0xFFFFFF05,
};
#endif /* _OMAP_RPMSG_H */

1450
drivers/remoteproc/remoteproc_core.c Normal file
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File diff suppressed because it is too large Load Diff

179
drivers/remoteproc/remoteproc_debugfs.c Normal file
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@ -0,0 +1,179 @@
/*
* Remote Processor Framework
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Mark Grosen <mgrosen@ti.com>
* Brian Swetland <swetland@google.com>
* Fernando Guzman Lugo <fernando.lugo@ti.com>
* Suman Anna <s-anna@ti.com>
* Robert Tivy <rtivy@ti.com>
* Armando Uribe De Leon <x0095078@ti.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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.
*/
#define pr_fmt(fmt) "%s: " fmt, __func__
#include <linux/kernel.h>
#include <linux/debugfs.h>
#include <linux/remoteproc.h>
#include <linux/device.h>
/* remoteproc debugfs parent dir */
static struct dentry *rproc_dbg;
/*
* Some remote processors may support dumping trace logs into a shared
* memory buffer. We expose this trace buffer using debugfs, so users
* can easily tell what's going on remotely.
*
* We will most probably improve the rproc tracing facilities later on,
* but this kind of lightweight and simple mechanism is always good to have,
* as it provides very early tracing with little to no dependencies at all.
*/
static ssize_t rproc_trace_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct rproc_mem_entry *trace = filp->private_data;
int len = strnlen(trace->va, trace->len);
return simple_read_from_buffer(userbuf, count, ppos, trace->va, len);
}
static int rproc_open_generic(struct inode *inode, struct file *file)
{
file->private_data = inode->i_private;
return 0;
}
static const struct file_operations trace_rproc_ops = {
.read = rproc_trace_read,
.open = rproc_open_generic,
.llseek = generic_file_llseek,
};
/*
* A state-to-string lookup table, for exposing a human readable state
* via debugfs. Always keep in sync with enum rproc_state
*/
static const char * const rproc_state_string[] = {
"offline",
"suspended",
"running",
"crashed",
"invalid",
};
/* expose the state of the remote processor via debugfs */
static ssize_t rproc_state_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct rproc *rproc = filp->private_data;
unsigned int state;
char buf[30];
int i;
state = rproc->state > RPROC_LAST ? RPROC_LAST : rproc->state;
i = snprintf(buf, 30, "%.28s (%d)\n", rproc_state_string[state],
rproc->state);
return simple_read_from_buffer(userbuf, count, ppos, buf, i);
}
static const struct file_operations rproc_state_ops = {
.read = rproc_state_read,
.open = rproc_open_generic,
.llseek = generic_file_llseek,
};
/* expose the name of the remote processor via debugfs */
static ssize_t rproc_name_read(struct file *filp, char __user *userbuf,
size_t count, loff_t *ppos)
{
struct rproc *rproc = filp->private_data;
/* need room for the name, a newline and a terminating null */
char buf[100];
int i;
i = snprintf(buf, sizeof(buf), "%.98s\n", rproc->name);
return simple_read_from_buffer(userbuf, count, ppos, buf, i);
}
static const struct file_operations rproc_name_ops = {
.read = rproc_name_read,
.open = rproc_open_generic,
.llseek = generic_file_llseek,
};
void rproc_remove_trace_file(struct dentry *tfile)
{
debugfs_remove(tfile);
}
struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
struct rproc_mem_entry *trace)
{
struct dentry *tfile;
tfile = debugfs_create_file(name, 0400, rproc->dbg_dir,
trace, &trace_rproc_ops);
if (!tfile) {
dev_err(rproc->dev, "failed to create debugfs trace entry\n");
return NULL;
}
return tfile;
}
void rproc_delete_debug_dir(struct rproc *rproc)
{
if (!rproc->dbg_dir)
return;
debugfs_remove_recursive(rproc->dbg_dir);
}
void rproc_create_debug_dir(struct rproc *rproc)
{
struct device *dev = rproc->dev;
if (!rproc_dbg)
return;
rproc->dbg_dir = debugfs_create_dir(dev_name(dev), rproc_dbg);
if (!rproc->dbg_dir)
return;
debugfs_create_file("name", 0400, rproc->dbg_dir,
rproc, &rproc_name_ops);
debugfs_create_file("state", 0400, rproc->dbg_dir,
rproc, &rproc_state_ops);
}
void __init rproc_init_debugfs(void)
{
if (debugfs_initialized()) {
rproc_dbg = debugfs_create_dir(KBUILD_MODNAME, NULL);
if (!rproc_dbg)
pr_err("can't create debugfs dir\n");
}
}
void __exit rproc_exit_debugfs(void)
{
if (rproc_dbg)
debugfs_remove(rproc_dbg);
}

44
drivers/remoteproc/remoteproc_internal.h Normal file
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@ -0,0 +1,44 @@
/*
* Remote processor framework
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*/
#ifndef REMOTEPROC_INTERNAL_H
#define REMOTEPROC_INTERNAL_H
#include <linux/irqreturn.h>
struct rproc;
/* from remoteproc_core.c */
void rproc_release(struct kref *kref);
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id);
/* from remoteproc_rpmsg.c */
int rproc_add_rpmsg_vdev(struct rproc *);
void rproc_remove_rpmsg_vdev(struct rproc *rproc);
/* from remoteproc_debugfs.c */
void rproc_remove_trace_file(struct dentry *tfile);
struct dentry *rproc_create_trace_file(const char *name, struct rproc *rproc,
struct rproc_mem_entry *trace);
void rproc_delete_debug_dir(struct rproc *rproc);
void rproc_create_debug_dir(struct rproc *rproc);
void rproc_init_debugfs(void);
void rproc_exit_debugfs(void);
#endif /* REMOTEPROC_INTERNAL_H */

299
drivers/remoteproc/remoteproc_rpmsg.c Normal file
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@ -0,0 +1,299 @@
/*
* Remote processor messaging transport (OMAP platform-specific bits)
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*/
#include <linux/export.h>
#include <linux/remoteproc.h>
#include <linux/rpmsg.h>
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_ring.h>
#include <linux/err.h>
#include <linux/kref.h>
#include <linux/slab.h>
#include "remoteproc_internal.h"
/**
* struct rproc_virtio_vq_info - virtqueue state
* @vq_id: a unique index of this virtqueue (unique for this @rproc)
* @rproc: handle to the remote processor
*
* Such a struct will be maintained for every virtqueue we're
* using to communicate with the remote processor
*/
struct rproc_virtio_vq_info {
__u16 vq_id;
struct rproc *rproc;
};
/* kick the remote processor, and let it know which virtqueue to poke at */
static void rproc_virtio_notify(struct virtqueue *vq)
{
struct rproc_virtio_vq_info *rpvq = vq->priv;
struct rproc *rproc = rpvq->rproc;
dev_dbg(rproc->dev, "kicking vq id: %d\n", rpvq->vq_id);
rproc->ops->kick(rproc, rpvq->vq_id);
}
/**
* rproc_vq_interrupt() - tell remoteproc that a virtqueue is interrupted
* @rproc: handle to the remote processor
* @vq_id: index of the signalled virtqueue
*
* This function should be called by the platform-specific rproc driver,
* when the remote processor signals that a specific virtqueue has pending
* messages available.
*
* Returns IRQ_NONE if no message was found in the @vq_id virtqueue,
* and otherwise returns IRQ_HANDLED.
*/
irqreturn_t rproc_vq_interrupt(struct rproc *rproc, int vq_id)
{
return vring_interrupt(0, rproc->rvdev->vq[vq_id]);
}
EXPORT_SYMBOL(rproc_vq_interrupt);
static struct virtqueue *rp_find_vq(struct virtio_device *vdev,
unsigned id,
void (*callback)(struct virtqueue *vq),
const char *name)
{
struct rproc *rproc = vdev_to_rproc(vdev);
struct rproc_vdev *rvdev = rproc->rvdev;
struct rproc_virtio_vq_info *rpvq;
struct virtqueue *vq;
void *addr;
int ret, len;
rpvq = kmalloc(sizeof(*rpvq), GFP_KERNEL);
if (!rpvq)
return ERR_PTR(-ENOMEM);
rpvq->rproc = rproc;
rpvq->vq_id = id;
addr = rvdev->vring[id].va;
len = rvdev->vring[id].len;
dev_dbg(rproc->dev, "vring%d: va %p qsz %d\n", id, addr, len);
/*
* Create the new vq, and tell virtio we're not interested in
* the 'weak' smp barriers, since we're talking with a real device.
*/
vq = vring_new_virtqueue(len, AMP_VRING_ALIGN, vdev, false, addr,
rproc_virtio_notify, callback, name);
if (!vq) {
dev_err(rproc->dev, "vring_new_virtqueue %s failed\n", name);
ret = -ENOMEM;
goto free_rpvq;
}
rvdev->vq[id] = vq;
vq->priv = rpvq;
return vq;
free_rpvq:
kfree(rpvq);
return ERR_PTR(ret);
}
static void rproc_virtio_del_vqs(struct virtio_device *vdev)
{
struct virtqueue *vq, *n;
struct rproc *rproc = vdev_to_rproc(vdev);
list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
struct rproc_virtio_vq_info *rpvq = vq->priv;
vring_del_virtqueue(vq);
kfree(rpvq);
}
/* power down the remote processor */
rproc_shutdown(rproc);
}
static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct virtqueue *vqs[],
vq_callback_t *callbacks[],
const char *names[])
{
struct rproc *rproc = vdev_to_rproc(vdev);
int i, ret;
/* we maintain two virtqueues per remote processor (for RX and TX) */
if (nvqs != 2)
return -EINVAL;
/* boot the remote processor */
ret = rproc_boot(rproc);
if (ret) {
dev_err(rproc->dev, "rproc_boot() failed %d\n", ret);
goto error;
}
for (i = 0; i < nvqs; ++i) {
vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i]);
if (IS_ERR(vqs[i])) {
ret = PTR_ERR(vqs[i]);
goto error;
}
}
return 0;
error:
rproc_virtio_del_vqs(vdev);
return ret;
}
/*
* We don't support yet real virtio status semantics.
*
* The plan is to provide this via the VIRTIO HDR resource entry
* which is part of the firmware: this way the remote processor
* will be able to access the status values as set by us.
*/
static u8 rproc_virtio_get_status(struct virtio_device *vdev)
{
return 0;
}
static void rproc_virtio_set_status(struct virtio_device *vdev, u8 status)
{
dev_dbg(&vdev->dev, "new status: %d\n", status);
}
static void rproc_virtio_reset(struct virtio_device *vdev)
{
dev_dbg(&vdev->dev, "reset !\n");
}
/* provide the vdev features as retrieved from the firmware */
static u32 rproc_virtio_get_features(struct virtio_device *vdev)
{
struct rproc *rproc = vdev_to_rproc(vdev);
/* we only support a single vdev device for now */
return rproc->rvdev->dfeatures;
}
static void rproc_virtio_finalize_features(struct virtio_device *vdev)
{
struct rproc *rproc = vdev_to_rproc(vdev);
/* Give virtio_ring a chance to accept features */
vring_transport_features(vdev);
/*
* Remember the finalized features of our vdev, and provide it
* to the remote processor once it is powered on.
*
* Similarly to the status field, we don't expose yet the negotiated
* features to the remote processors at this point. This will be
* fixed as part of a small resource table overhaul and then an
* extension of the virtio resource entries.
*/
rproc->rvdev->gfeatures = vdev->features[0];
}
static struct virtio_config_ops rproc_virtio_config_ops = {
.get_features = rproc_virtio_get_features,
.finalize_features = rproc_virtio_finalize_features,
.find_vqs = rproc_virtio_find_vqs,
.del_vqs = rproc_virtio_del_vqs,
.reset = rproc_virtio_reset,
.set_status = rproc_virtio_set_status,
.get_status = rproc_virtio_get_status,
};
/*
* This function is called whenever vdev is released, and is responsible
* to decrement the remote processor's refcount taken when vdev was
* added.
*
* Never call this function directly; it will be called by the driver
* core when needed.
*/
static void rproc_vdev_release(struct device *dev)
{
struct virtio_device *vdev = dev_to_virtio(dev);
struct rproc *rproc = vdev_to_rproc(vdev);
kref_put(&rproc->refcount, rproc_release);
}
/**
* rproc_add_rpmsg_vdev() - create an rpmsg virtio device
* @rproc: the rproc handle
*
* This function is called if virtio rpmsg support was found in the
* firmware of the remote processor.
*
* Today we only support creating a single rpmsg vdev (virtio device),
* but the plan is to remove this limitation. At that point this interface
* will be revised/extended.
*/
int rproc_add_rpmsg_vdev(struct rproc *rproc)
{
struct device *dev = rproc->dev;
struct rproc_vdev *rvdev = rproc->rvdev;
int ret;
rvdev->vdev.id.device = VIRTIO_ID_RPMSG,
rvdev->vdev.config = &rproc_virtio_config_ops,
rvdev->vdev.dev.parent = dev;
rvdev->vdev.dev.release = rproc_vdev_release;
/*
* We're indirectly making a non-temporary copy of the rproc pointer
* here, because drivers probed with this vdev will indirectly
* access the wrapping rproc.
*
* Therefore we must increment the rproc refcount here, and decrement
* it _only_ when the vdev is released.
*/
kref_get(&rproc->refcount);
ret = register_virtio_device(&rvdev->vdev);
if (ret) {
kref_put(&rproc->refcount, rproc_release);
dev_err(dev, "failed to register vdev: %d\n", ret);
}
return ret;
}
/**
* rproc_remove_rpmsg_vdev() - remove an rpmsg vdev device
* @rproc: the rproc handle
*
* This function is called whenever @rproc is removed _iff_ an rpmsg
* vdev was created beforehand.
*/
void rproc_remove_rpmsg_vdev(struct rproc *rproc)
{
struct rproc_vdev *rvdev = rproc->rvdev;
unregister_virtio_device(&rvdev->vdev);
}

10
drivers/rpmsg/Kconfig Normal file
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@ -0,0 +1,10 @@
menu "Rpmsg drivers (EXPERIMENTAL)"
# RPMSG always gets selected by whoever wants it
config RPMSG
tristate
select VIRTIO
select VIRTIO_RING
depends on EXPERIMENTAL
endmenu

1
drivers/rpmsg/Makefile Normal file
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@ -0,0 +1 @@
obj-$(CONFIG_RPMSG) += virtio_rpmsg_bus.o

1026
drivers/rpmsg/virtio_rpmsg_bus.c Normal file
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File diff suppressed because it is too large Load Diff

9
include/linux/mod_devicetable.h
View File

@ -414,6 +414,15 @@ struct hv_vmbus_device_id {
__attribute__((aligned(sizeof(kernel_ulong_t))));
};
/* rpmsg */
#define RPMSG_NAME_SIZE 32
#define RPMSG_DEVICE_MODALIAS_FMT "rpmsg:%s"
struct rpmsg_device_id {
char name[RPMSG_NAME_SIZE];
};
/* i2c */
#define I2C_NAME_SIZE 20

271
include/linux/remoteproc.h Normal file
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@ -0,0 +1,271 @@
/*
* Remote Processor Framework
*
* Copyright(c) 2011 Texas Instruments, Inc.
* Copyright(c) 2011 Google, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name Texas Instruments nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef REMOTEPROC_H
#define REMOTEPROC_H
#include <linux/types.h>
#include <linux/kref.h>
#include <linux/klist.h>
#include <linux/mutex.h>
#include <linux/virtio.h>
#include <linux/completion.h>
/*
* The alignment between the consumer and producer parts of the vring.
* Note: this is part of the "wire" protocol. If you change this, you need
* to update your peers too.
*/
#define AMP_VRING_ALIGN (4096)
/**
* struct fw_resource - describes an entry from the resource section
* @type: resource type
* @id: index number of the resource
* @da: device address of the resource
* @pa: physical address of the resource
* @len: size, in bytes, of the resource
* @flags: properties of the resource, e.g. iommu protection required
* @reserved: must be 0 atm
* @name: name of resource
*
* The remote processor firmware should contain a "resource table":
* array of 'struct fw_resource' entries.
*
* Some resources entries are mere announcements, where the host is informed
* of specific remoteproc configuration. Other entries require the host to
* do something (e.g. reserve a requested resource) and possibly also reply
* by overwriting a member inside 'struct fw_resource' with info about the
* allocated resource.
*
* Different resource entries use different members of this struct,
* with different meanings. This is pretty limiting and error-prone,
* so the plan is to move to variable-length TLV-based resource entries,
* where each resource type will have its own structure.
*/
struct fw_resource {
u32 type;
u32 id;
u64 da;
u64 pa;
u32 len;
u32 flags;
u8 reserved[16];
u8 name[48];
} __packed;
/**
* enum fw_resource_type - types of resource entries
*
* @RSC_CARVEOUT: request for allocation of a physically contiguous
* memory region.
* @RSC_DEVMEM: request to iommu_map a memory-based peripheral.
* @RSC_TRACE: announces the availability of a trace buffer into which
* the remote processor will be writing logs. In this case,
* 'da' indicates the device address where logs are written to,
* and 'len' is the size of the trace buffer.
* @RSC_VRING: request for allocation of a virtio vring (address should
* be indicated in 'da', and 'len' should contain the number
* of buffers supported by the vring).
* @RSC_VIRTIO_DEV: this entry declares about support for a virtio device,
* and serves as the virtio header. 'da' holds the
* the virtio device features, 'pa' holds the virtio guest
* features, 'len' holds the virtio status, and 'flags' holds
* the virtio id (currently only VIRTIO_ID_RPMSG is supported).
* @RSC_LAST: just keep this one at the end
*
* Most of the resource entries share the basic idea of address/length
* negotiation with the host: the firmware usually asks (on behalf of the
* remote processor that will soon be booted with it) for memory
* of size 'len' bytes, and the host needs to allocate it and provide
* the device/physical address (when relevant) in 'da'/'pa' respectively.
*
* If the firmware is compiled with hard coded device addresses, and
* can't handle dynamically allocated 'da' values, then the 'da' field
* will contain the expected device addresses (today we actually only support
* this scheme, as there aren't yet any use cases for dynamically allocated
* device addresses).
*
* Please note that these values are used as indices to the rproc_handle_rsc
* lookup table, so please keep them sane. Moreover, @RSC_LAST is used to
* check the validity of an index before the lookup table is accessed, so
* please update it as needed.
*/
enum fw_resource_type {
RSC_CARVEOUT = 0,
RSC_DEVMEM = 1,
RSC_TRACE = 2,
RSC_VRING = 3,
RSC_VIRTIO_DEV = 4,
RSC_LAST = 5,
};
/**
* struct rproc_mem_entry - memory entry descriptor
* @va: virtual address
* @dma: dma address
* @len: length, in bytes
* @da: device address
* @priv: associated data
* @node: list node
*/
struct rproc_mem_entry {
void *va;
dma_addr_t dma;
int len;
u64 da;
void *priv;
struct list_head node;
};
struct rproc;
/**
* struct rproc_ops - platform-specific device handlers
* @start: power on the device and boot it
* @stop: power off the device
* @kick: kick a virtqueue (virtqueue id given as a parameter)
*/
struct rproc_ops {
int (*start)(struct rproc *rproc);
int (*stop)(struct rproc *rproc);
void (*kick)(struct rproc *rproc, int vqid);
};
/**
* enum rproc_state - remote processor states
* @RPROC_OFFLINE: device is powered off
* @RPROC_SUSPENDED: device is suspended; needs to be woken up to receive
* a message.
* @RPROC_RUNNING: device is up and running
* @RPROC_CRASHED: device has crashed; need to start recovery
* @RPROC_LAST: just keep this one at the end
*
* Please note that the values of these states are used as indices
* to rproc_state_string, a state-to-name lookup table,
* so please keep the two synchronized. @RPROC_LAST is used to check
* the validity of an index before the lookup table is accessed, so
* please update it as needed too.
*/
enum rproc_state {
RPROC_OFFLINE = 0,
RPROC_SUSPENDED = 1,
RPROC_RUNNING = 2,
RPROC_CRASHED = 3,
RPROC_LAST = 4,
};
/**
* struct rproc - represents a physical remote processor device
* @node: klist node of this rproc object
* @domain: iommu domain
* @name: human readable name of the rproc
* @firmware: name of firmware file to be loaded
* @priv: private data which belongs to the platform-specific rproc module
* @ops: platform-specific start/stop rproc handlers
* @dev: underlying device
* @refcount: refcount of users that have a valid pointer to this rproc
* @power: refcount of users who need this rproc powered up
* @state: state of the device
* @lock: lock which protects concurrent manipulations of the rproc
* @dbg_dir: debugfs directory of this rproc device
* @traces: list of trace buffers
* @num_traces: number of trace buffers
* @carveouts: list of physically contiguous memory allocations
* @mappings: list of iommu mappings we initiated, needed on shutdown
* @firmware_loading_complete: marks e/o asynchronous firmware loading
* @bootaddr: address of first instruction to boot rproc with (optional)
* @rvdev: virtio device (we only support a single rpmsg virtio device for now)
*/
struct rproc {
struct klist_node node;
struct iommu_domain *domain;
const char *name;
const char *firmware;
void *priv;
const struct rproc_ops *ops;
struct device *dev;
struct kref refcount;
atomic_t power;
unsigned int state;
struct mutex lock;
struct dentry *dbg_dir;
struct list_head traces;
int num_traces;
struct list_head carveouts;
struct list_head mappings;
struct completion firmware_loading_complete;
u64 bootaddr;
struct rproc_vdev *rvdev;
};
/**
* struct rproc_vdev - remoteproc state for a supported virtio device
* @rproc: the rproc handle
* @vdev: the virio device
* @vq: the virtqueues for this vdev
* @vring: the vrings for this vdev
* @dfeatures: virtio device features
* @gfeatures: virtio guest features
*/
struct rproc_vdev {
struct rproc *rproc;
struct virtio_device vdev;
struct virtqueue *vq[2];
struct rproc_mem_entry vring[2];
unsigned long dfeatures;
unsigned long gfeatures;
};
struct rproc *rproc_get_by_name(const char *name);
void rproc_put(struct rproc *rproc);
struct rproc *rproc_alloc(struct device *dev, const char *name,
const struct rproc_ops *ops,
const char *firmware, int len);
void rproc_free(struct rproc *rproc);
int rproc_register(struct rproc *rproc);
int rproc_unregister(struct rproc *rproc);
int rproc_boot(struct rproc *rproc);
void rproc_shutdown(struct rproc *rproc);
static inline struct rproc *vdev_to_rproc(struct virtio_device *vdev)
{
struct rproc_vdev *rvdev = container_of(vdev, struct rproc_vdev, vdev);
return rvdev->rproc;
}
#endif /* REMOTEPROC_H */

326
include/linux/rpmsg.h Normal file
View File

@ -0,0 +1,326 @@
/*
* Remote processor messaging
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name Texas Instruments nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef _LINUX_RPMSG_H
#define _LINUX_RPMSG_H
#include <linux/types.h>
#include <linux/device.h>
#include <linux/mod_devicetable.h>
/* The feature bitmap for virtio rpmsg */
#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
/**
* struct rpmsg_hdr - common header for all rpmsg messages
* @src: source address
* @dst: destination address
* @reserved: reserved for future use
* @len: length of payload (in bytes)
* @flags: message flags
* @data: @len bytes of message payload data
*
* Every message sent(/received) on the rpmsg bus begins with this header.
*/
struct rpmsg_hdr {
u32 src;
u32 dst;
u32 reserved;
u16 len;
u16 flags;
u8 data[0];
} __packed;
/**
* struct rpmsg_ns_msg - dynamic name service announcement message
* @name: name of remote service that is published
* @addr: address of remote service that is published
* @flags: indicates whether service is created or destroyed
*
* This message is sent across to publish a new service, or announce
* about its removal. When we receive these messages, an appropriate
* rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
* or ->remove() handler of the appropriate rpmsg driver will be invoked
* (if/as-soon-as one is registered).
*/
struct rpmsg_ns_msg {
char name[RPMSG_NAME_SIZE];
u32 addr;
u32 flags;
} __packed;
/**
* enum rpmsg_ns_flags - dynamic name service announcement flags
*
* @RPMSG_NS_CREATE: a new remote service was just created
* @RPMSG_NS_DESTROY: a known remote service was just destroyed
*/
enum rpmsg_ns_flags {
RPMSG_NS_CREATE = 0,
RPMSG_NS_DESTROY = 1,
};
#define RPMSG_ADDR_ANY 0xFFFFFFFF
struct virtproc_info;
/**
* rpmsg_channel - devices that belong to the rpmsg bus are called channels
* @vrp: the remote processor this channel belongs to
* @dev: the device struct
* @id: device id (used to match between rpmsg drivers and devices)
* @src: local address
* @dst: destination address
* @ept: the rpmsg endpoint of this channel
* @announce: if set, rpmsg will announce the creation/removal of this channel
*/
struct rpmsg_channel {
struct virtproc_info *vrp;
struct device dev;
struct rpmsg_device_id id;
u32 src;
u32 dst;
struct rpmsg_endpoint *ept;
bool announce;
};
typedef void (*rpmsg_rx_cb_t)(struct rpmsg_channel *, void *, int, void *, u32);
/**
* struct rpmsg_endpoint - binds a local rpmsg address to its user
* @rpdev: rpmsg channel device
* @cb: rx callback handler
* @addr: local rpmsg address
* @priv: private data for the driver's use
*
* In essence, an rpmsg endpoint represents a listener on the rpmsg bus, as
* it binds an rpmsg address with an rx callback handler.
*
* Simple rpmsg drivers shouldn't use this struct directly, because
* things just work: every rpmsg driver provides an rx callback upon
* registering to the bus, and that callback is then bound to its rpmsg
* address when the driver is probed. When relevant inbound messages arrive
* (i.e. messages which their dst address equals to the src address of
* the rpmsg channel), the driver's handler is invoked to process it.
*
* More complicated drivers though, that do need to allocate additional rpmsg
* addresses, and bind them to different rx callbacks, must explicitly
* create additional endpoints by themselves (see rpmsg_create_ept()).
*/
struct rpmsg_endpoint {
struct rpmsg_channel *rpdev;
rpmsg_rx_cb_t cb;
u32 addr;
void *priv;
};
/**
* struct rpmsg_driver - rpmsg driver struct
* @drv: underlying device driver
* @id_table: rpmsg ids serviced by this driver
* @probe: invoked when a matching rpmsg channel (i.e. device) is found
* @remove: invoked when the rpmsg channel is removed
* @callback: invoked when an inbound message is received on the channel
*/
struct rpmsg_driver {
struct device_driver drv;
const struct rpmsg_device_id *id_table;
int (*probe)(struct rpmsg_channel *dev);
void (*remove)(struct rpmsg_channel *dev);
void (*callback)(struct rpmsg_channel *, void *, int, void *, u32);
};
int register_rpmsg_device(struct rpmsg_channel *dev);
void unregister_rpmsg_device(struct rpmsg_channel *dev);
int register_rpmsg_driver(struct rpmsg_driver *drv);
void unregister_rpmsg_driver(struct rpmsg_driver *drv);
void rpmsg_destroy_ept(struct rpmsg_endpoint *);
struct rpmsg_endpoint *rpmsg_create_ept(struct rpmsg_channel *,
rpmsg_rx_cb_t cb, void *priv, u32 addr);
int
rpmsg_send_offchannel_raw(struct rpmsg_channel *, u32, u32, void *, int, bool);
/**
* rpmsg_send() - send a message across to the remote processor
* @rpdev: the rpmsg channel
* @data: payload of message
* @len: length of payload
*
* This function sends @data of length @len on the @rpdev channel.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to, using @rpdev's source and destination addresses.
* In case there are no TX buffers available, the function will block until
* one becomes available, or a timeout of 15 seconds elapses. When the latter
* happens, -ERESTARTSYS is returned.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline int rpmsg_send(struct rpmsg_channel *rpdev, void *data, int len)
{
u32 src = rpdev->src, dst = rpdev->dst;
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
}
/**
* rpmsg_sendto() - send a message across to the remote processor, specify dst
* @rpdev: the rpmsg channel
* @data: payload of message
* @len: length of payload
* @dst: destination address
*
* This function sends @data of length @len to the remote @dst address.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to, using @rpdev's source address.
* In case there are no TX buffers available, the function will block until
* one becomes available, or a timeout of 15 seconds elapses. When the latter
* happens, -ERESTARTSYS is returned.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline
int rpmsg_sendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
{
u32 src = rpdev->src;
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
}
/**
* rpmsg_send_offchannel() - send a message using explicit src/dst addresses
* @rpdev: the rpmsg channel
* @src: source address
* @dst: destination address
* @data: payload of message
* @len: length of payload
*
* This function sends @data of length @len to the remote @dst address,
* and uses @src as the source address.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to.
* In case there are no TX buffers available, the function will block until
* one becomes available, or a timeout of 15 seconds elapses. When the latter
* happens, -ERESTARTSYS is returned.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline
int rpmsg_send_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
void *data, int len)
{
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, true);
}
/**
* rpmsg_send() - send a message across to the remote processor
* @rpdev: the rpmsg channel
* @data: payload of message
* @len: length of payload
*
* This function sends @data of length @len on the @rpdev channel.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to, using @rpdev's source and destination addresses.
* In case there are no TX buffers available, the function will immediately
* return -ENOMEM without waiting until one becomes available.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline
int rpmsg_trysend(struct rpmsg_channel *rpdev, void *data, int len)
{
u32 src = rpdev->src, dst = rpdev->dst;
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
}
/**
* rpmsg_sendto() - send a message across to the remote processor, specify dst
* @rpdev: the rpmsg channel
* @data: payload of message
* @len: length of payload
* @dst: destination address
*
* This function sends @data of length @len to the remote @dst address.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to, using @rpdev's source address.
* In case there are no TX buffers available, the function will immediately
* return -ENOMEM without waiting until one becomes available.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline
int rpmsg_trysendto(struct rpmsg_channel *rpdev, void *data, int len, u32 dst)
{
u32 src = rpdev->src;
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
}
/**
* rpmsg_send_offchannel() - send a message using explicit src/dst addresses
* @rpdev: the rpmsg channel
* @src: source address
* @dst: destination address
* @data: payload of message
* @len: length of payload
*
* This function sends @data of length @len to the remote @dst address,
* and uses @src as the source address.
* The message will be sent to the remote processor which the @rpdev
* channel belongs to.
* In case there are no TX buffers available, the function will immediately
* return -ENOMEM without waiting until one becomes available.
*
* Can only be called from process context (for now).
*
* Returns 0 on success and an appropriate error value on failure.
*/
static inline
int rpmsg_trysend_offchannel(struct rpmsg_channel *rpdev, u32 src, u32 dst,
void *data, int len)
{
return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);
}
#endif /* _LINUX_RPMSG_H */

1
include/linux/virtio_ids.h
View File

@ -34,6 +34,7 @@
#define VIRTIO_ID_CONSOLE 3 /* virtio console */
#define VIRTIO_ID_RNG 4 /* virtio ring */
#define VIRTIO_ID_BALLOON 5 /* virtio balloon */
#define VIRTIO_ID_RPMSG 7 /* virtio remote processor messaging */
#define VIRTIO_ID_9P 9 /* 9p virtio console */
#endif /* _LINUX_VIRTIO_IDS_H */

8
samples/Kconfig
View File

@ -61,4 +61,12 @@ config SAMPLE_KDB
Build an example of how to dynamically add the hello
command to the kdb shell.
config SAMPLE_RPMSG_CLIENT
tristate "Build rpmsg client sample -- loadable modules only"
depends on RPMSG && m
help
Build an rpmsg client sample driver, which demonstrates how
to communicate with an AMP-configured remote processor over
the rpmsg bus.
endif # SAMPLES

2
samples/Makefile
View File

@ -1,4 +1,4 @@
# Makefile for Linux samples code
obj-$(CONFIG_SAMPLES) += kobject/ kprobes/ tracepoints/ trace_events/ \
hw_breakpoint/ kfifo/ kdb/ hidraw/
hw_breakpoint/ kfifo/ kdb/ hidraw/ rpmsg/

1
samples/rpmsg/Makefile Normal file
View File

@ -0,0 +1 @@
obj-$(CONFIG_SAMPLE_RPMSG_CLIENT) += rpmsg_client_sample.o

100
samples/rpmsg/rpmsg_client_sample.c Normal file
View File

@ -0,0 +1,100 @@
/*
* Remote processor messaging - sample client driver
*
* Copyright (C) 2011 Texas Instruments, Inc.
* Copyright (C) 2011 Google, Inc.
*
* Ohad Ben-Cohen <ohad@wizery.com>
* Brian Swetland <swetland@google.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rpmsg.h>
#define MSG "hello world!"
#define MSG_LIMIT 100
static void rpmsg_sample_cb(struct rpmsg_channel *rpdev, void *data, int len,
void *priv, u32 src)
{
int ret;
static int rx_count;
dev_info(&rpdev->dev, "incoming msg %d (src: 0x%x)\n", ++rx_count, src);
print_hex_dump(KERN_DEBUG, __func__, DUMP_PREFIX_NONE, 16, 1,
data, len, true);
/* samples should not live forever */
if (rx_count >= MSG_LIMIT) {
dev_info(&rpdev->dev, "goodbye!\n");
return;
}
/* send a new message now */
ret = rpmsg_send(rpdev, MSG, strlen(MSG));
if (ret)
dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
}
static int rpmsg_sample_probe(struct rpmsg_channel *rpdev)
{
int ret;
dev_info(&rpdev->dev, "new channel: 0x%x -> 0x%x!\n",
rpdev->src, rpdev->dst);
/* send a message to our remote processor */
ret = rpmsg_send(rpdev, MSG, strlen(MSG));
if (ret) {
dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
return ret;
}
return 0;
}
static void __devexit rpmsg_sample_remove(struct rpmsg_channel *rpdev)
{
dev_info(&rpdev->dev, "rpmsg sample client driver is removed\n");
}
static struct rpmsg_device_id rpmsg_driver_sample_id_table[] = {
{ .name = "rpmsg-client-sample" },
{ },
};
MODULE_DEVICE_TABLE(rpmsg, rpmsg_driver_sample_id_table);
static struct rpmsg_driver rpmsg_sample_client = {
.drv.name = KBUILD_MODNAME,
.drv.owner = THIS_MODULE,
.id_table = rpmsg_driver_sample_id_table,
.probe = rpmsg_sample_probe,
.callback = rpmsg_sample_cb,
.remove = __devexit_p(rpmsg_sample_remove),
};
static int __init rpmsg_client_sample_init(void)
{
return register_rpmsg_driver(&rpmsg_sample_client);
}
module_init(rpmsg_client_sample_init);
static void __exit rpmsg_client_sample_fini(void)
{
unregister_rpmsg_driver(&rpmsg_sample_client);
}
module_exit(rpmsg_client_sample_fini);
MODULE_DESCRIPTION("Remote processor messaging sample client driver");
MODULE_LICENSE("GPL v2");