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-rw-r--r--drivers/staging/greybus/operation.c1264
1 files changed, 0 insertions, 1264 deletions
diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
deleted file mode 100644
index fe268f7b63ed..000000000000
--- a/drivers/staging/greybus/operation.c
+++ /dev/null
@@ -1,1264 +0,0 @@
-// 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 "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;
-}
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.