linux-stable/drivers/greybus/operation.c
Greg Kroah-Hartman 8465def499 staging: greybus: move the greybus core to drivers/greybus
The Greybus core code has been stable for a long time, and has been
shipping for many years in millions of phones.  With the advent of a
recent Google Summer of Code project, and a number of new devices in the
works from various companies, it is time to get the core greybus code
out of staging as it really is going to be with us for a while.

Cc: Johan Hovold <johan@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: greybus-dev@lists.linaro.org
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Alex Elder <elder@kernel.org>
Link: https://lore.kernel.org/r/20190825055429.18547-9-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-27 19:03:04 +02:00

1264 lines
35 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Greybus operations
*
* Copyright 2014-2015 Google Inc.
* Copyright 2014-2015 Linaro Ltd.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/greybus.h>
#include "greybus_trace.h"
static struct kmem_cache *gb_operation_cache;
static struct kmem_cache *gb_message_cache;
/* Workqueue to handle Greybus operation completions. */
static struct workqueue_struct *gb_operation_completion_wq;
/* Wait queue for synchronous cancellations. */
static DECLARE_WAIT_QUEUE_HEAD(gb_operation_cancellation_queue);
/*
* Protects updates to operation->errno.
*/
static DEFINE_SPINLOCK(gb_operations_lock);
static int gb_operation_response_send(struct gb_operation *operation,
int errno);
/*
* Increment operation active count and add to connection list unless the
* connection is going away.
*
* Caller holds operation reference.
*/
static int gb_operation_get_active(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
unsigned long flags;
spin_lock_irqsave(&connection->lock, flags);
switch (connection->state) {
case GB_CONNECTION_STATE_ENABLED:
break;
case GB_CONNECTION_STATE_ENABLED_TX:
if (gb_operation_is_incoming(operation))
goto err_unlock;
break;
case GB_CONNECTION_STATE_DISCONNECTING:
if (!gb_operation_is_core(operation))
goto err_unlock;
break;
default:
goto err_unlock;
}
if (operation->active++ == 0)
list_add_tail(&operation->links, &connection->operations);
trace_gb_operation_get_active(operation);
spin_unlock_irqrestore(&connection->lock, flags);
return 0;
err_unlock:
spin_unlock_irqrestore(&connection->lock, flags);
return -ENOTCONN;
}
/* Caller holds operation reference. */
static void gb_operation_put_active(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
unsigned long flags;
spin_lock_irqsave(&connection->lock, flags);
trace_gb_operation_put_active(operation);
if (--operation->active == 0) {
list_del(&operation->links);
if (atomic_read(&operation->waiters))
wake_up(&gb_operation_cancellation_queue);
}
spin_unlock_irqrestore(&connection->lock, flags);
}
static bool gb_operation_is_active(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
unsigned long flags;
bool ret;
spin_lock_irqsave(&connection->lock, flags);
ret = operation->active;
spin_unlock_irqrestore(&connection->lock, flags);
return ret;
}
/*
* Set an operation's result.
*
* Initially an outgoing operation's errno value is -EBADR.
* If no error occurs before sending the request message the only
* valid value operation->errno can be set to is -EINPROGRESS,
* indicating the request has been (or rather is about to be) sent.
* At that point nobody should be looking at the result until the
* response arrives.
*
* The first time the result gets set after the request has been
* sent, that result "sticks." That is, if two concurrent threads
* race to set the result, the first one wins. The return value
* tells the caller whether its result was recorded; if not the
* caller has nothing more to do.
*
* The result value -EILSEQ is reserved to signal an implementation
* error; if it's ever observed, the code performing the request has
* done something fundamentally wrong. It is an error to try to set
* the result to -EBADR, and attempts to do so result in a warning,
* and -EILSEQ is used instead. Similarly, the only valid result
* value to set for an operation in initial state is -EINPROGRESS.
* Attempts to do otherwise will also record a (successful) -EILSEQ
* operation result.
*/
static bool gb_operation_result_set(struct gb_operation *operation, int result)
{
unsigned long flags;
int prev;
if (result == -EINPROGRESS) {
/*
* -EINPROGRESS is used to indicate the request is
* in flight. It should be the first result value
* set after the initial -EBADR. Issue a warning
* and record an implementation error if it's
* set at any other time.
*/
spin_lock_irqsave(&gb_operations_lock, flags);
prev = operation->errno;
if (prev == -EBADR)
operation->errno = result;
else
operation->errno = -EILSEQ;
spin_unlock_irqrestore(&gb_operations_lock, flags);
WARN_ON(prev != -EBADR);
return true;
}
/*
* The first result value set after a request has been sent
* will be the final result of the operation. Subsequent
* attempts to set the result are ignored.
*
* Note that -EBADR is a reserved "initial state" result
* value. Attempts to set this value result in a warning,
* and the result code is set to -EILSEQ instead.
*/
if (WARN_ON(result == -EBADR))
result = -EILSEQ; /* Nobody should be setting -EBADR */
spin_lock_irqsave(&gb_operations_lock, flags);
prev = operation->errno;
if (prev == -EINPROGRESS)
operation->errno = result; /* First and final result */
spin_unlock_irqrestore(&gb_operations_lock, flags);
return prev == -EINPROGRESS;
}
int gb_operation_result(struct gb_operation *operation)
{
int result = operation->errno;
WARN_ON(result == -EBADR);
WARN_ON(result == -EINPROGRESS);
return result;
}
EXPORT_SYMBOL_GPL(gb_operation_result);
/*
* Looks up an outgoing operation on a connection and returns a refcounted
* pointer if found, or NULL otherwise.
*/
static struct gb_operation *
gb_operation_find_outgoing(struct gb_connection *connection, u16 operation_id)
{
struct gb_operation *operation;
unsigned long flags;
bool found = false;
spin_lock_irqsave(&connection->lock, flags);
list_for_each_entry(operation, &connection->operations, links)
if (operation->id == operation_id &&
!gb_operation_is_incoming(operation)) {
gb_operation_get(operation);
found = true;
break;
}
spin_unlock_irqrestore(&connection->lock, flags);
return found ? operation : NULL;
}
static int gb_message_send(struct gb_message *message, gfp_t gfp)
{
struct gb_connection *connection = message->operation->connection;
trace_gb_message_send(message);
return connection->hd->driver->message_send(connection->hd,
connection->hd_cport_id,
message,
gfp);
}
/*
* Cancel a message we have passed to the host device layer to be sent.
*/
static void gb_message_cancel(struct gb_message *message)
{
struct gb_host_device *hd = message->operation->connection->hd;
hd->driver->message_cancel(message);
}
static void gb_operation_request_handle(struct gb_operation *operation)
{
struct gb_connection *connection = operation->connection;
int status;
int ret;
if (connection->handler) {
status = connection->handler(operation);
} else {
dev_err(&connection->hd->dev,
"%s: unexpected incoming request of type 0x%02x\n",
connection->name, operation->type);
status = -EPROTONOSUPPORT;
}
ret = gb_operation_response_send(operation, status);
if (ret) {
dev_err(&connection->hd->dev,
"%s: failed to send response %d for type 0x%02x: %d\n",
connection->name, status, operation->type, ret);
return;
}
}
/*
* Process operation work.
*
* For incoming requests, call the protocol request handler. The operation
* result should be -EINPROGRESS at this point.
*
* For outgoing requests, the operation result value should have
* been set before queueing this. The operation callback function
* allows the original requester to know the request has completed
* and its result is available.
*/
static void gb_operation_work(struct work_struct *work)
{
struct gb_operation *operation;
int ret;
operation = container_of(work, struct gb_operation, work);
if (gb_operation_is_incoming(operation)) {
gb_operation_request_handle(operation);
} else {
ret = del_timer_sync(&operation->timer);
if (!ret) {
/* Cancel request message if scheduled by timeout. */
if (gb_operation_result(operation) == -ETIMEDOUT)
gb_message_cancel(operation->request);
}
operation->callback(operation);
}
gb_operation_put_active(operation);
gb_operation_put(operation);
}
static void gb_operation_timeout(struct timer_list *t)
{
struct gb_operation *operation = from_timer(operation, t, timer);
if (gb_operation_result_set(operation, -ETIMEDOUT)) {
/*
* A stuck request message will be cancelled from the
* workqueue.
*/
queue_work(gb_operation_completion_wq, &operation->work);
}
}
static void gb_operation_message_init(struct gb_host_device *hd,
struct gb_message *message,
u16 operation_id,
size_t payload_size, u8 type)
{
struct gb_operation_msg_hdr *header;
header = message->buffer;
message->header = header;
message->payload = payload_size ? header + 1 : NULL;
message->payload_size = payload_size;
/*
* The type supplied for incoming message buffers will be
* GB_REQUEST_TYPE_INVALID. Such buffers will be overwritten by
* arriving data so there's no need to initialize the message header.
*/
if (type != GB_REQUEST_TYPE_INVALID) {
u16 message_size = (u16)(sizeof(*header) + payload_size);
/*
* For a request, the operation id gets filled in
* when the message is sent. For a response, it
* will be copied from the request by the caller.
*
* The result field in a request message must be
* zero. It will be set just prior to sending for
* a response.
*/
header->size = cpu_to_le16(message_size);
header->operation_id = 0;
header->type = type;
header->result = 0;
}
}
/*
* Allocate a message to be used for an operation request or response.
* Both types of message contain a common header. The request message
* for an outgoing operation is outbound, as is the response message
* for an incoming operation. The message header for an outbound
* message is partially initialized here.
*
* The headers for inbound messages don't need to be initialized;
* they'll be filled in by arriving data.
*
* Our message buffers have the following layout:
* message header \_ these combined are
* message payload / the message size
*/
static struct gb_message *
gb_operation_message_alloc(struct gb_host_device *hd, u8 type,
size_t payload_size, gfp_t gfp_flags)
{
struct gb_message *message;
struct gb_operation_msg_hdr *header;
size_t message_size = payload_size + sizeof(*header);
if (message_size > hd->buffer_size_max) {
dev_warn(&hd->dev, "requested message size too big (%zu > %zu)\n",
message_size, hd->buffer_size_max);
return NULL;
}
/* Allocate the message structure and buffer. */
message = kmem_cache_zalloc(gb_message_cache, gfp_flags);
if (!message)
return NULL;
message->buffer = kzalloc(message_size, gfp_flags);
if (!message->buffer)
goto err_free_message;
/* Initialize the message. Operation id is filled in later. */
gb_operation_message_init(hd, message, 0, payload_size, type);
return message;
err_free_message:
kmem_cache_free(gb_message_cache, message);
return NULL;
}
static void gb_operation_message_free(struct gb_message *message)
{
kfree(message->buffer);
kmem_cache_free(gb_message_cache, message);
}
/*
* Map an enum gb_operation_status value (which is represented in a
* message as a single byte) to an appropriate Linux negative errno.
*/
static int gb_operation_status_map(u8 status)
{
switch (status) {
case GB_OP_SUCCESS:
return 0;
case GB_OP_INTERRUPTED:
return -EINTR;
case GB_OP_TIMEOUT:
return -ETIMEDOUT;
case GB_OP_NO_MEMORY:
return -ENOMEM;
case GB_OP_PROTOCOL_BAD:
return -EPROTONOSUPPORT;
case GB_OP_OVERFLOW:
return -EMSGSIZE;
case GB_OP_INVALID:
return -EINVAL;
case GB_OP_RETRY:
return -EAGAIN;
case GB_OP_NONEXISTENT:
return -ENODEV;
case GB_OP_MALFUNCTION:
return -EILSEQ;
case GB_OP_UNKNOWN_ERROR:
default:
return -EIO;
}
}
/*
* Map a Linux errno value (from operation->errno) into the value
* that should represent it in a response message status sent
* over the wire. Returns an enum gb_operation_status value (which
* is represented in a message as a single byte).
*/
static u8 gb_operation_errno_map(int errno)
{
switch (errno) {
case 0:
return GB_OP_SUCCESS;
case -EINTR:
return GB_OP_INTERRUPTED;
case -ETIMEDOUT:
return GB_OP_TIMEOUT;
case -ENOMEM:
return GB_OP_NO_MEMORY;
case -EPROTONOSUPPORT:
return GB_OP_PROTOCOL_BAD;
case -EMSGSIZE:
return GB_OP_OVERFLOW; /* Could be underflow too */
case -EINVAL:
return GB_OP_INVALID;
case -EAGAIN:
return GB_OP_RETRY;
case -EILSEQ:
return GB_OP_MALFUNCTION;
case -ENODEV:
return GB_OP_NONEXISTENT;
case -EIO:
default:
return GB_OP_UNKNOWN_ERROR;
}
}
bool gb_operation_response_alloc(struct gb_operation *operation,
size_t response_size, gfp_t gfp)
{
struct gb_host_device *hd = operation->connection->hd;
struct gb_operation_msg_hdr *request_header;
struct gb_message *response;
u8 type;
type = operation->type | GB_MESSAGE_TYPE_RESPONSE;
response = gb_operation_message_alloc(hd, type, response_size, gfp);
if (!response)
return false;
response->operation = operation;
/*
* Size and type get initialized when the message is
* allocated. The errno will be set before sending. All
* that's left is the operation id, which we copy from the
* request message header (as-is, in little-endian order).
*/
request_header = operation->request->header;
response->header->operation_id = request_header->operation_id;
operation->response = response;
return true;
}
EXPORT_SYMBOL_GPL(gb_operation_response_alloc);
/*
* Create a Greybus operation to be sent over the given connection.
* The request buffer will be big enough for a payload of the given
* size.
*
* For outgoing requests, the request message's header will be
* initialized with the type of the request and the message size.
* Outgoing operations must also specify the response buffer size,
* which must be sufficient to hold all expected response data. The
* response message header will eventually be overwritten, so there's
* no need to initialize it here.
*
* Request messages for incoming operations can arrive in interrupt
* context, so they must be allocated with GFP_ATOMIC. In this case
* the request buffer will be immediately overwritten, so there is
* no need to initialize the message header. Responsibility for
* allocating a response buffer lies with the incoming request
* handler for a protocol. So we don't allocate that here.
*
* Returns a pointer to the new operation or a null pointer if an
* error occurs.
*/
static struct gb_operation *
gb_operation_create_common(struct gb_connection *connection, u8 type,
size_t request_size, size_t response_size,
unsigned long op_flags, gfp_t gfp_flags)
{
struct gb_host_device *hd = connection->hd;
struct gb_operation *operation;
operation = kmem_cache_zalloc(gb_operation_cache, gfp_flags);
if (!operation)
return NULL;
operation->connection = connection;
operation->request = gb_operation_message_alloc(hd, type, request_size,
gfp_flags);
if (!operation->request)
goto err_cache;
operation->request->operation = operation;
/* Allocate the response buffer for outgoing operations */
if (!(op_flags & GB_OPERATION_FLAG_INCOMING)) {
if (!gb_operation_response_alloc(operation, response_size,
gfp_flags)) {
goto err_request;
}
timer_setup(&operation->timer, gb_operation_timeout, 0);
}
operation->flags = op_flags;
operation->type = type;
operation->errno = -EBADR; /* Initial value--means "never set" */
INIT_WORK(&operation->work, gb_operation_work);
init_completion(&operation->completion);
kref_init(&operation->kref);
atomic_set(&operation->waiters, 0);
return operation;
err_request:
gb_operation_message_free(operation->request);
err_cache:
kmem_cache_free(gb_operation_cache, operation);
return NULL;
}
/*
* Create a new operation associated with the given connection. The
* request and response sizes provided are the number of bytes
* required to hold the request/response payload only. Both of
* these are allowed to be 0. Note that 0x00 is reserved as an
* invalid operation type for all protocols, and this is enforced
* here.
*/
struct gb_operation *
gb_operation_create_flags(struct gb_connection *connection,
u8 type, size_t request_size,
size_t response_size, unsigned long flags,
gfp_t gfp)
{
struct gb_operation *operation;
if (WARN_ON_ONCE(type == GB_REQUEST_TYPE_INVALID))
return NULL;
if (WARN_ON_ONCE(type & GB_MESSAGE_TYPE_RESPONSE))
type &= ~GB_MESSAGE_TYPE_RESPONSE;
if (WARN_ON_ONCE(flags & ~GB_OPERATION_FLAG_USER_MASK))
flags &= GB_OPERATION_FLAG_USER_MASK;
operation = gb_operation_create_common(connection, type,
request_size, response_size,
flags, gfp);
if (operation)
trace_gb_operation_create(operation);
return operation;
}
EXPORT_SYMBOL_GPL(gb_operation_create_flags);
struct gb_operation *
gb_operation_create_core(struct gb_connection *connection,
u8 type, size_t request_size,
size_t response_size, unsigned long flags,
gfp_t gfp)
{
struct gb_operation *operation;
flags |= GB_OPERATION_FLAG_CORE;
operation = gb_operation_create_common(connection, type,
request_size, response_size,
flags, gfp);
if (operation)
trace_gb_operation_create_core(operation);
return operation;
}
/* Do not export this function. */
size_t gb_operation_get_payload_size_max(struct gb_connection *connection)
{
struct gb_host_device *hd = connection->hd;
return hd->buffer_size_max - sizeof(struct gb_operation_msg_hdr);
}
EXPORT_SYMBOL_GPL(gb_operation_get_payload_size_max);
static struct gb_operation *
gb_operation_create_incoming(struct gb_connection *connection, u16 id,
u8 type, void *data, size_t size)
{
struct gb_operation *operation;
size_t request_size;
unsigned long flags = GB_OPERATION_FLAG_INCOMING;
/* Caller has made sure we at least have a message header. */
request_size = size - sizeof(struct gb_operation_msg_hdr);
if (!id)
flags |= GB_OPERATION_FLAG_UNIDIRECTIONAL;
operation = gb_operation_create_common(connection, type,
request_size,
GB_REQUEST_TYPE_INVALID,
flags, GFP_ATOMIC);
if (!operation)
return NULL;
operation->id = id;
memcpy(operation->request->header, data, size);
trace_gb_operation_create_incoming(operation);
return operation;
}
/*
* Get an additional reference on an operation.
*/
void gb_operation_get(struct gb_operation *operation)
{
kref_get(&operation->kref);
}
EXPORT_SYMBOL_GPL(gb_operation_get);
/*
* Destroy a previously created operation.
*/
static void _gb_operation_destroy(struct kref *kref)
{
struct gb_operation *operation;
operation = container_of(kref, struct gb_operation, kref);
trace_gb_operation_destroy(operation);
if (operation->response)
gb_operation_message_free(operation->response);
gb_operation_message_free(operation->request);
kmem_cache_free(gb_operation_cache, operation);
}
/*
* Drop a reference on an operation, and destroy it when the last
* one is gone.
*/
void gb_operation_put(struct gb_operation *operation)
{
if (WARN_ON(!operation))
return;
kref_put(&operation->kref, _gb_operation_destroy);
}
EXPORT_SYMBOL_GPL(gb_operation_put);
/* Tell the requester we're done */
static void gb_operation_sync_callback(struct gb_operation *operation)
{
complete(&operation->completion);
}
/**
* gb_operation_request_send() - send an operation request message
* @operation: the operation to initiate
* @callback: the operation completion callback
* @timeout: operation timeout in milliseconds, or zero for no timeout
* @gfp: the memory flags to use for any allocations
*
* The caller has filled in any payload so the request message is ready to go.
* The callback function supplied will be called when the response message has
* arrived, a unidirectional request has been sent, or the operation is
* cancelled, indicating that the operation is complete. The callback function
* can fetch the result of the operation using gb_operation_result() if
* desired.
*
* Return: 0 if the request was successfully queued in the host-driver queues,
* or a negative errno.
*/
int gb_operation_request_send(struct gb_operation *operation,
gb_operation_callback callback,
unsigned int timeout,
gfp_t gfp)
{
struct gb_connection *connection = operation->connection;
struct gb_operation_msg_hdr *header;
unsigned int cycle;
int ret;
if (gb_connection_is_offloaded(connection))
return -EBUSY;
if (!callback)
return -EINVAL;
/*
* Record the callback function, which is executed in
* non-atomic (workqueue) context when the final result
* of an operation has been set.
*/
operation->callback = callback;
/*
* Assign the operation's id, and store it in the request header.
* Zero is a reserved operation id for unidirectional operations.
*/
if (gb_operation_is_unidirectional(operation)) {
operation->id = 0;
} else {
cycle = (unsigned int)atomic_inc_return(&connection->op_cycle);
operation->id = (u16)(cycle % U16_MAX + 1);
}
header = operation->request->header;
header->operation_id = cpu_to_le16(operation->id);
gb_operation_result_set(operation, -EINPROGRESS);
/*
* Get an extra reference on the operation. It'll be dropped when the
* operation completes.
*/
gb_operation_get(operation);
ret = gb_operation_get_active(operation);
if (ret)
goto err_put;
ret = gb_message_send(operation->request, gfp);
if (ret)
goto err_put_active;
if (timeout) {
operation->timer.expires = jiffies + msecs_to_jiffies(timeout);
add_timer(&operation->timer);
}
return 0;
err_put_active:
gb_operation_put_active(operation);
err_put:
gb_operation_put(operation);
return ret;
}
EXPORT_SYMBOL_GPL(gb_operation_request_send);
/*
* Send a synchronous operation. This function is expected to
* block, returning only when the response has arrived, (or when an
* error is detected. The return value is the result of the
* operation.
*/
int gb_operation_request_send_sync_timeout(struct gb_operation *operation,
unsigned int timeout)
{
int ret;
ret = gb_operation_request_send(operation, gb_operation_sync_callback,
timeout, GFP_KERNEL);
if (ret)
return ret;
ret = wait_for_completion_interruptible(&operation->completion);
if (ret < 0) {
/* Cancel the operation if interrupted */
gb_operation_cancel(operation, -ECANCELED);
}
return gb_operation_result(operation);
}
EXPORT_SYMBOL_GPL(gb_operation_request_send_sync_timeout);
/*
* Send a response for an incoming operation request. A non-zero
* errno indicates a failed operation.
*
* If there is any response payload, the incoming request handler is
* responsible for allocating the response message. Otherwise the
* it can simply supply the result errno; this function will
* allocate the response message if necessary.
*/
static int gb_operation_response_send(struct gb_operation *operation,
int errno)
{
struct gb_connection *connection = operation->connection;
int ret;
if (!operation->response &&
!gb_operation_is_unidirectional(operation)) {
if (!gb_operation_response_alloc(operation, 0, GFP_KERNEL))
return -ENOMEM;
}
/* Record the result */
if (!gb_operation_result_set(operation, errno)) {
dev_err(&connection->hd->dev, "request result already set\n");
return -EIO; /* Shouldn't happen */
}
/* Sender of request does not care about response. */
if (gb_operation_is_unidirectional(operation))
return 0;
/* Reference will be dropped when message has been sent. */
gb_operation_get(operation);
ret = gb_operation_get_active(operation);
if (ret)
goto err_put;
/* Fill in the response header and send it */
operation->response->header->result = gb_operation_errno_map(errno);
ret = gb_message_send(operation->response, GFP_KERNEL);
if (ret)
goto err_put_active;
return 0;
err_put_active:
gb_operation_put_active(operation);
err_put:
gb_operation_put(operation);
return ret;
}
/*
* This function is called when a message send request has completed.
*/
void greybus_message_sent(struct gb_host_device *hd,
struct gb_message *message, int status)
{
struct gb_operation *operation = message->operation;
struct gb_connection *connection = operation->connection;
/*
* If the message was a response, we just need to drop our
* reference to the operation. If an error occurred, report
* it.
*
* For requests, if there's no error and the operation in not
* unidirectional, there's nothing more to do until the response
* arrives. If an error occurred attempting to send it, or if the
* operation is unidrectional, record the result of the operation and
* schedule its completion.
*/
if (message == operation->response) {
if (status) {
dev_err(&connection->hd->dev,
"%s: error sending response 0x%02x: %d\n",
connection->name, operation->type, status);
}
gb_operation_put_active(operation);
gb_operation_put(operation);
} else if (status || gb_operation_is_unidirectional(operation)) {
if (gb_operation_result_set(operation, status)) {
queue_work(gb_operation_completion_wq,
&operation->work);
}
}
}
EXPORT_SYMBOL_GPL(greybus_message_sent);
/*
* We've received data on a connection, and it doesn't look like a
* response, so we assume it's a request.
*
* This is called in interrupt context, so just copy the incoming
* data into the request buffer and handle the rest via workqueue.
*/
static void gb_connection_recv_request(struct gb_connection *connection,
const struct gb_operation_msg_hdr *header,
void *data, size_t size)
{
struct gb_operation *operation;
u16 operation_id;
u8 type;
int ret;
operation_id = le16_to_cpu(header->operation_id);
type = header->type;
operation = gb_operation_create_incoming(connection, operation_id,
type, data, size);
if (!operation) {
dev_err(&connection->hd->dev,
"%s: can't create incoming operation\n",
connection->name);
return;
}
ret = gb_operation_get_active(operation);
if (ret) {
gb_operation_put(operation);
return;
}
trace_gb_message_recv_request(operation->request);
/*
* The initial reference to the operation will be dropped when the
* request handler returns.
*/
if (gb_operation_result_set(operation, -EINPROGRESS))
queue_work(connection->wq, &operation->work);
}
/*
* We've received data that appears to be an operation response
* message. Look up the operation, and record that we've received
* its response.
*
* This is called in interrupt context, so just copy the incoming
* data into the response buffer and handle the rest via workqueue.
*/
static void gb_connection_recv_response(struct gb_connection *connection,
const struct gb_operation_msg_hdr *header,
void *data, size_t size)
{
struct gb_operation *operation;
struct gb_message *message;
size_t message_size;
u16 operation_id;
int errno;
operation_id = le16_to_cpu(header->operation_id);
if (!operation_id) {
dev_err_ratelimited(&connection->hd->dev,
"%s: invalid response id 0 received\n",
connection->name);
return;
}
operation = gb_operation_find_outgoing(connection, operation_id);
if (!operation) {
dev_err_ratelimited(&connection->hd->dev,
"%s: unexpected response id 0x%04x received\n",
connection->name, operation_id);
return;
}
errno = gb_operation_status_map(header->result);
message = operation->response;
message_size = sizeof(*header) + message->payload_size;
if (!errno && size > message_size) {
dev_err_ratelimited(&connection->hd->dev,
"%s: malformed response 0x%02x received (%zu > %zu)\n",
connection->name, header->type,
size, message_size);
errno = -EMSGSIZE;
} else if (!errno && size < message_size) {
if (gb_operation_short_response_allowed(operation)) {
message->payload_size = size - sizeof(*header);
} else {
dev_err_ratelimited(&connection->hd->dev,
"%s: short response 0x%02x received (%zu < %zu)\n",
connection->name, header->type,
size, message_size);
errno = -EMSGSIZE;
}
}
/* We must ignore the payload if a bad status is returned */
if (errno)
size = sizeof(*header);
/* The rest will be handled in work queue context */
if (gb_operation_result_set(operation, errno)) {
memcpy(message->buffer, data, size);
trace_gb_message_recv_response(message);
queue_work(gb_operation_completion_wq, &operation->work);
}
gb_operation_put(operation);
}
/*
* Handle data arriving on a connection. As soon as we return the
* supplied data buffer will be reused (so unless we do something
* with, it's effectively dropped).
*/
void gb_connection_recv(struct gb_connection *connection,
void *data, size_t size)
{
struct gb_operation_msg_hdr header;
struct device *dev = &connection->hd->dev;
size_t msg_size;
if (connection->state == GB_CONNECTION_STATE_DISABLED ||
gb_connection_is_offloaded(connection)) {
dev_warn_ratelimited(dev, "%s: dropping %zu received bytes\n",
connection->name, size);
return;
}
if (size < sizeof(header)) {
dev_err_ratelimited(dev, "%s: short message received\n",
connection->name);
return;
}
/* Use memcpy as data may be unaligned */
memcpy(&header, data, sizeof(header));
msg_size = le16_to_cpu(header.size);
if (size < msg_size) {
dev_err_ratelimited(dev,
"%s: incomplete message 0x%04x of type 0x%02x received (%zu < %zu)\n",
connection->name,
le16_to_cpu(header.operation_id),
header.type, size, msg_size);
return; /* XXX Should still complete operation */
}
if (header.type & GB_MESSAGE_TYPE_RESPONSE) {
gb_connection_recv_response(connection, &header, data,
msg_size);
} else {
gb_connection_recv_request(connection, &header, data,
msg_size);
}
}
/*
* Cancel an outgoing operation synchronously, and record the given error to
* indicate why.
*/
void gb_operation_cancel(struct gb_operation *operation, int errno)
{
if (WARN_ON(gb_operation_is_incoming(operation)))
return;
if (gb_operation_result_set(operation, errno)) {
gb_message_cancel(operation->request);
queue_work(gb_operation_completion_wq, &operation->work);
}
trace_gb_message_cancel_outgoing(operation->request);
atomic_inc(&operation->waiters);
wait_event(gb_operation_cancellation_queue,
!gb_operation_is_active(operation));
atomic_dec(&operation->waiters);
}
EXPORT_SYMBOL_GPL(gb_operation_cancel);
/*
* Cancel an incoming operation synchronously. Called during connection tear
* down.
*/
void gb_operation_cancel_incoming(struct gb_operation *operation, int errno)
{
if (WARN_ON(!gb_operation_is_incoming(operation)))
return;
if (!gb_operation_is_unidirectional(operation)) {
/*
* Make sure the request handler has submitted the response
* before cancelling it.
*/
flush_work(&operation->work);
if (!gb_operation_result_set(operation, errno))
gb_message_cancel(operation->response);
}
trace_gb_message_cancel_incoming(operation->response);
atomic_inc(&operation->waiters);
wait_event(gb_operation_cancellation_queue,
!gb_operation_is_active(operation));
atomic_dec(&operation->waiters);
}
/**
* gb_operation_sync_timeout() - implement a "simple" synchronous operation
* @connection: the Greybus connection to send this to
* @type: the type of operation to send
* @request: pointer to a memory buffer to copy the request from
* @request_size: size of @request
* @response: pointer to a memory buffer to copy the response to
* @response_size: the size of @response.
* @timeout: operation timeout in milliseconds
*
* This function implements a simple synchronous Greybus operation. It sends
* the provided operation request and waits (sleeps) until the corresponding
* operation response message has been successfully received, or an error
* occurs. @request and @response are buffers to hold the request and response
* data respectively, and if they are not NULL, their size must be specified in
* @request_size and @response_size.
*
* If a response payload is to come back, and @response is not NULL,
* @response_size number of bytes will be copied into @response if the operation
* is successful.
*
* If there is an error, the response buffer is left alone.
*/
int gb_operation_sync_timeout(struct gb_connection *connection, int type,
void *request, int request_size,
void *response, int response_size,
unsigned int timeout)
{
struct gb_operation *operation;
int ret;
if ((response_size && !response) ||
(request_size && !request))
return -EINVAL;
operation = gb_operation_create(connection, type,
request_size, response_size,
GFP_KERNEL);
if (!operation)
return -ENOMEM;
if (request_size)
memcpy(operation->request->payload, request, request_size);
ret = gb_operation_request_send_sync_timeout(operation, timeout);
if (ret) {
dev_err(&connection->hd->dev,
"%s: synchronous operation id 0x%04x of type 0x%02x failed: %d\n",
connection->name, operation->id, type, ret);
} else {
if (response_size) {
memcpy(response, operation->response->payload,
response_size);
}
}
gb_operation_put(operation);
return ret;
}
EXPORT_SYMBOL_GPL(gb_operation_sync_timeout);
/**
* gb_operation_unidirectional_timeout() - initiate a unidirectional operation
* @connection: connection to use
* @type: type of operation to send
* @request: memory buffer to copy the request from
* @request_size: size of @request
* @timeout: send timeout in milliseconds
*
* Initiate a unidirectional operation by sending a request message and
* waiting for it to be acknowledged as sent by the host device.
*
* Note that successful send of a unidirectional operation does not imply that
* the request as actually reached the remote end of the connection.
*/
int gb_operation_unidirectional_timeout(struct gb_connection *connection,
int type, void *request,
int request_size,
unsigned int timeout)
{
struct gb_operation *operation;
int ret;
if (request_size && !request)
return -EINVAL;
operation = gb_operation_create_flags(connection, type,
request_size, 0,
GB_OPERATION_FLAG_UNIDIRECTIONAL,
GFP_KERNEL);
if (!operation)
return -ENOMEM;
if (request_size)
memcpy(operation->request->payload, request, request_size);
ret = gb_operation_request_send_sync_timeout(operation, timeout);
if (ret) {
dev_err(&connection->hd->dev,
"%s: unidirectional operation of type 0x%02x failed: %d\n",
connection->name, type, ret);
}
gb_operation_put(operation);
return ret;
}
EXPORT_SYMBOL_GPL(gb_operation_unidirectional_timeout);
int __init gb_operation_init(void)
{
gb_message_cache = kmem_cache_create("gb_message_cache",
sizeof(struct gb_message), 0, 0,
NULL);
if (!gb_message_cache)
return -ENOMEM;
gb_operation_cache = kmem_cache_create("gb_operation_cache",
sizeof(struct gb_operation), 0,
0, NULL);
if (!gb_operation_cache)
goto err_destroy_message_cache;
gb_operation_completion_wq = alloc_workqueue("greybus_completion",
0, 0);
if (!gb_operation_completion_wq)
goto err_destroy_operation_cache;
return 0;
err_destroy_operation_cache:
kmem_cache_destroy(gb_operation_cache);
gb_operation_cache = NULL;
err_destroy_message_cache:
kmem_cache_destroy(gb_message_cache);
gb_message_cache = NULL;
return -ENOMEM;
}
void gb_operation_exit(void)
{
destroy_workqueue(gb_operation_completion_wq);
gb_operation_completion_wq = NULL;
kmem_cache_destroy(gb_operation_cache);
gb_operation_cache = NULL;
kmem_cache_destroy(gb_message_cache);
gb_message_cache = NULL;
}