viopath.c

linux内核源码

		return;
	if (hvlpevent_is_int(event)) {
		printk(VIOPATH_KERN_WARN
		       "unexpected config request from partition %d",
		       event->xSourceLp);

		if (hvlpevent_need_ack(event)) {
			event->xRc = HvLpEvent_Rc_InvalidSubtype;
			HvCallEvent_ackLpEvent(event);
		}
		return;
	}

	complete((struct completion *)event->xCorrelationToken);
}

/*
 * Initialization of the hosting partition
 */
void vio_set_hostlp(void)
{
	/*
	 * If this has already been set then we DON'T want to either change
	 * it or re-register the proc file system
	 */
	if (viopath_hostLp != HvLpIndexInvalid)
		return;

	/*
	 * Figure out our hosting partition.  This isn't allowed to change
	 * while we're active
	 */
	viopath_ourLp = HvLpConfig_getLpIndex();
	viopath_hostLp = HvLpConfig_getHostingLpIndex(viopath_ourLp);

	if (viopath_hostLp != HvLpIndexInvalid)
		vio_setHandler(viomajorsubtype_config, handleConfig);
}
EXPORT_SYMBOL(vio_set_hostlp);

static void vio_handleEvent(struct HvLpEvent *event)
{
	HvLpIndex remoteLp;
	int subtype = (event->xSubtype & VIOMAJOR_SUBTYPE_MASK)
		>> VIOMAJOR_SUBTYPE_SHIFT;

	if (hvlpevent_is_int(event)) {
		remoteLp = event->xSourceLp;
		/*
		 * The isActive is checked because if the hosting partition
		 * went down and came back up it would not be active but it
		 * would have different source and target instances, in which
		 * case we'd want to reset them.  This case really protects
		 * against an unauthorized active partition sending interrupts
		 * or acks to this linux partition.
		 */
		if (viopathStatus[remoteLp].isActive
		    && (event->xSourceInstanceId !=
			viopathStatus[remoteLp].mTargetInst)) {
			printk(VIOPATH_KERN_WARN
			       "message from invalid partition. "
			       "int msg rcvd, source inst (%d) doesnt match (%d)\n",
			       viopathStatus[remoteLp].mTargetInst,
			       event->xSourceInstanceId);
			return;
		}

		if (viopathStatus[remoteLp].isActive
		    && (event->xTargetInstanceId !=
			viopathStatus[remoteLp].mSourceInst)) {
			printk(VIOPATH_KERN_WARN
			       "message from invalid partition. "
			       "int msg rcvd, target inst (%d) doesnt match (%d)\n",
			       viopathStatus[remoteLp].mSourceInst,
			       event->xTargetInstanceId);
			return;
		}
	} else {
		remoteLp = event->xTargetLp;
		if (event->xSourceInstanceId !=
		    viopathStatus[remoteLp].mSourceInst) {
			printk(VIOPATH_KERN_WARN
			       "message from invalid partition. "
			       "ack msg rcvd, source inst (%d) doesnt match (%d)\n",
			       viopathStatus[remoteLp].mSourceInst,
			       event->xSourceInstanceId);
			return;
		}

		if (event->xTargetInstanceId !=
		    viopathStatus[remoteLp].mTargetInst) {
			printk(VIOPATH_KERN_WARN
			       "message from invalid partition. "
			       "viopath: ack msg rcvd, target inst (%d) doesnt match (%d)\n",
			       viopathStatus[remoteLp].mTargetInst,
			       event->xTargetInstanceId);
			return;
		}
	}

	if (vio_handler[subtype] == NULL) {
		printk(VIOPATH_KERN_WARN
		       "unexpected virtual io event subtype %d from partition %d\n",
		       event->xSubtype, remoteLp);
		/* No handler.  Ack if necessary */
		if (hvlpevent_is_int(event) && hvlpevent_need_ack(event)) {
			event->xRc = HvLpEvent_Rc_InvalidSubtype;
			HvCallEvent_ackLpEvent(event);
		}
		return;
	}

	/* This innocuous little line is where all the real work happens */
	(*vio_handler[subtype])(event);
}

static void viopath_donealloc(void *parm, int number)
{
	struct alloc_parms *parmsp = parm;

	parmsp->number = number;
	if (parmsp->used_wait_atomic)
		atomic_set(&parmsp->wait_atomic, 0);
	else
		complete(&parmsp->done);
}

static int allocateEvents(HvLpIndex remoteLp, int numEvents)
{
	struct alloc_parms parms;

	if (system_state != SYSTEM_RUNNING) {
		parms.used_wait_atomic = 1;
		atomic_set(&parms.wait_atomic, 1);
	} else {
		parms.used_wait_atomic = 0;
		init_completion(&parms.done);
	}
	mf_allocate_lp_events(remoteLp, HvLpEvent_Type_VirtualIo, 250,	/* It would be nice to put a real number here! */
			    numEvents, &viopath_donealloc, &parms);
	if (system_state != SYSTEM_RUNNING) {
		while (atomic_read(&parms.wait_atomic))
			mb();
	} else
		wait_for_completion(&parms.done);
	return parms.number;
}

int viopath_open(HvLpIndex remoteLp, int subtype, int numReq)
{
	int i;
	unsigned long flags;
	int tempNumAllocated;

	if ((remoteLp >= HVMAXARCHITECTEDLPS) || (remoteLp == HvLpIndexInvalid))
		return -EINVAL;

	subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
	if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
		return -EINVAL;

	spin_lock_irqsave(&statuslock, flags);

	if (!event_buffer_initialised) {
		for (i = 0; i < VIO_MAX_SUBTYPES; i++)
			atomic_set(&event_buffer_available[i], 1);
		event_buffer_initialised = 1;
	}

	viopathStatus[remoteLp].users[subtype]++;

	if (!viopathStatus[remoteLp].isOpen) {
		viopathStatus[remoteLp].isOpen = 1;
		HvCallEvent_openLpEventPath(remoteLp, HvLpEvent_Type_VirtualIo);

		/*
		 * Don't hold the spinlock during an operation that
		 * can sleep.
		 */
		spin_unlock_irqrestore(&statuslock, flags);
		tempNumAllocated = allocateEvents(remoteLp, 1);
		spin_lock_irqsave(&statuslock, flags);

		viopathStatus[remoteLp].numberAllocated += tempNumAllocated;

		if (viopathStatus[remoteLp].numberAllocated == 0) {
			HvCallEvent_closeLpEventPath(remoteLp,
					HvLpEvent_Type_VirtualIo);

			spin_unlock_irqrestore(&statuslock, flags);
			return -ENOMEM;
		}

		viopathStatus[remoteLp].mSourceInst =
			HvCallEvent_getSourceLpInstanceId(remoteLp,
					HvLpEvent_Type_VirtualIo);
		viopathStatus[remoteLp].mTargetInst =
			HvCallEvent_getTargetLpInstanceId(remoteLp,
					HvLpEvent_Type_VirtualIo);
		HvLpEvent_registerHandler(HvLpEvent_Type_VirtualIo,
					  &vio_handleEvent);
		sendMonMsg(remoteLp);
		printk(VIOPATH_KERN_INFO "opening connection to partition %d, "
				"setting sinst %d, tinst %d\n",
				remoteLp, viopathStatus[remoteLp].mSourceInst,
				viopathStatus[remoteLp].mTargetInst);
	}

	spin_unlock_irqrestore(&statuslock, flags);
	tempNumAllocated = allocateEvents(remoteLp, numReq);
	spin_lock_irqsave(&statuslock, flags);
	viopathStatus[remoteLp].numberAllocated += tempNumAllocated;
	spin_unlock_irqrestore(&statuslock, flags);

	return 0;
}
EXPORT_SYMBOL(viopath_open);

int viopath_close(HvLpIndex remoteLp, int subtype, int numReq)
{
	unsigned long flags;
	int i;
	int numOpen;
	struct alloc_parms parms;

	if ((remoteLp >= HVMAXARCHITECTEDLPS) || (remoteLp == HvLpIndexInvalid))
		return -EINVAL;

	subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
	if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
		return -EINVAL;

	spin_lock_irqsave(&statuslock, flags);
	/*
	 * If the viopath_close somehow gets called before a
	 * viopath_open it could decrement to -1 which is a non
	 * recoverable state so we'll prevent this from
	 * happening.
	 */
	if (viopathStatus[remoteLp].users[subtype] > 0)
		viopathStatus[remoteLp].users[subtype]--;

	spin_unlock_irqrestore(&statuslock, flags);

	parms.used_wait_atomic = 0;
	init_completion(&parms.done);
	mf_deallocate_lp_events(remoteLp, HvLpEvent_Type_VirtualIo,
			      numReq, &viopath_donealloc, &parms);
	wait_for_completion(&parms.done);

	spin_lock_irqsave(&statuslock, flags);
	for (i = 0, numOpen = 0; i < VIO_MAX_SUBTYPES; i++)
		numOpen += viopathStatus[remoteLp].users[i];

	if ((viopathStatus[remoteLp].isOpen) && (numOpen == 0)) {
		printk(VIOPATH_KERN_INFO "closing connection to partition %d\n",
				remoteLp);

		HvCallEvent_closeLpEventPath(remoteLp,
					     HvLpEvent_Type_VirtualIo);
		viopathStatus[remoteLp].isOpen = 0;
		viopathStatus[remoteLp].isActive = 0;

		for (i = 0; i < VIO_MAX_SUBTYPES; i++)
			atomic_set(&event_buffer_available[i], 0);
		event_buffer_initialised = 0;
	}
	spin_unlock_irqrestore(&statuslock, flags);
	return 0;
}
EXPORT_SYMBOL(viopath_close);

void *vio_get_event_buffer(int subtype)
{
	subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
	if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES))
		return NULL;

	if (atomic_dec_if_positive(&event_buffer_available[subtype]) == 0)
		return &event_buffer[subtype * 256];
	else
		return NULL;
}
EXPORT_SYMBOL(vio_get_event_buffer);

void vio_free_event_buffer(int subtype, void *buffer)
{
	subtype = subtype >> VIOMAJOR_SUBTYPE_SHIFT;
	if ((subtype < 0) || (subtype >= VIO_MAX_SUBTYPES)) {
		printk(VIOPATH_KERN_WARN
		       "unexpected subtype %d freeing event buffer\n", subtype);
		return;
	}

	if (atomic_read(&event_buffer_available[subtype]) != 0) {
		printk(VIOPATH_KERN_WARN
		       "freeing unallocated event buffer, subtype %d\n",
		       subtype);
		return;
	}

	if (buffer != &event_buffer[subtype * 256]) {
		printk(VIOPATH_KERN_WARN
		       "freeing invalid event buffer, subtype %d\n", subtype);
	}

	atomic_set(&event_buffer_available[subtype], 1);
}
EXPORT_SYMBOL(vio_free_event_buffer);

static const struct vio_error_entry vio_no_error =
    { 0, 0, "Non-VIO Error" };
static const struct vio_error_entry vio_unknown_error =
    { 0, EIO, "Unknown Error" };

static const struct vio_error_entry vio_default_errors[] = {
	{0x0001, EIO, "No Connection"},
	{0x0002, EIO, "No Receiver"},
	{0x0003, EIO, "No Buffer Available"},
	{0x0004, EBADRQC, "Invalid Message Type"},
	{0x0000, 0, NULL},
};

const struct vio_error_entry *vio_lookup_rc(
		const struct vio_error_entry *local_table, u16 rc)
{
	const struct vio_error_entry *cur;

	if (!rc)
		return &vio_no_error;
	if (local_table)
		for (cur = local_table; cur->rc; ++cur)
			if (cur->rc == rc)
				return cur;
	for (cur = vio_default_errors; cur->rc; ++cur)
		if (cur->rc == rc)
			return cur;
	return &vio_unknown_error;
}
EXPORT_SYMBOL(vio_lookup_rc);