/* Copyright (C) 2010 - 2013 UNISYS CORPORATION
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or (at
* your option) any later version.
*
* 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, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for more
* details.
*/
#include <linux/kernel.h>
#ifdef CONFIG_MODVERSIONS
#include <config/modversions.h>
#endif
#include <linux/module.h>
#include <linux/init.h> /* for module_init and module_exit */
#include <linux/slab.h> /* for memcpy */
#include <linux/types.h>
/* Implementation of exported functions for Supervisor channels */
#include "channel.h"
/*
* Routine Description:
* Tries to insert the prebuilt signal pointed to by pSignal into the nth
* Queue of the Channel pointed to by pChannel
*
* Parameters:
* pChannel: (IN) points to the IO Channel
* Queue: (IN) nth Queue of the IO Channel
* pSignal: (IN) pointer to the signal
*
* Assumptions:
* - pChannel, Queue and pSignal are valid.
* - If insertion fails due to a full queue, the caller will determine the
* retry policy (e.g. wait & try again, report an error, etc.).
*
* Return value:
* 1 if the insertion succeeds, 0 if the queue was full.
*/
unsigned char
visor_signal_insert(CHANNEL_HEADER __iomem *pChannel, U32 Queue, void *pSignal)
{
void __iomem *psignal;
unsigned int head, tail, nof;
SIGNAL_QUEUE_HEADER __iomem *pqhdr =
(SIGNAL_QUEUE_HEADER __iomem *)
((char __iomem *) pChannel + readq(&pChannel->oChannelSpace))
+ Queue;
/* capture current head and tail */
head = readl(&pqhdr->Head);
tail = readl(&pqhdr->Tail);
/* queue is full if (head + 1) % n equals tail */
if (((head + 1) % readl(&pqhdr->MaxSignalSlots)) == tail) {
nof = readq(&pqhdr->NumOverflows) + 1;
writeq(nof, &pqhdr->NumOverflows);
return 0;
}
/* increment the head index */
head = (head + 1) % readl(&pqhdr->MaxSignalSlots);
/* copy signal to the head location from the area pointed to
* by pSignal
*/
psignal = (char __iomem *)pqhdr + readq(&pqhdr->oSignalBase) +
(head * readl(&pqhdr->SignalSize));
MEMCPY_TOIO(psignal, pSignal, readl(&pqhdr->SignalSize));
VolatileBarrier();
writel(head, &pqhdr->Head);
writeq(readq(&pqhdr->NumSignalsSent) + 1, &pqhdr->NumSignalsSent);
return 1;
}
EXPORT_SYMBOL_GPL(visor_signal_insert);
/*
* Routine Description:
* Removes one signal from Channel pChannel's nth Queue at the
* time of the call and copies it into the memory pointed to by
* pSignal.
*
* Parameters:
* pChannel: (IN) points to the IO Channel
* Queue: (IN) nth Queue of the IO Channel
* pSignal: (IN) pointer to where the signals are to be copied
*
* Assumptions:
* - pChannel and Queue are valid.
* - pSignal points to a memory area large enough to hold queue's SignalSize
*
* Return value:
* 1 if the removal succeeds, 0 if the queue was empty.
*/
unsigned char
visor_signal_remove(CHANNEL_HEADER __iomem *pChannel, U32 Queue, void *pSignal)
{
void __iomem *psource;
unsigned int head, tail;
SIGNAL_QUEUE_HEADER __iomem *pqhdr =
(SIGNAL_QUEUE_HEADER __iomem *) ((char __iomem *) pChannel +
readq(&pChannel->oChannelSpace)) + Queue;
/* capture current head and tail */
head = readl(&pqhdr->Head);
tail = readl(&pqhdr->Tail);
/* queue is empty if the head index equals the tail index */
if (head == tail) {
writeq(readq(&pqhdr->NumEmptyCnt) + 1, &pqhdr->NumEmptyCnt);
return 0;
}
/* advance past the 'empty' front slot */
tail = (tail + 1) % readl(&pqhdr->MaxSignalSlots);
/* copy signal from tail location to the area pointed to by pSignal */
psource = (char __iomem *) pqhdr + readq(&pqhdr->oSignalBase) +
(tail * readl(&pqhdr->SignalSize));
MEMCPY_FROMIO(pSignal, psource, readl(&pqhdr->SignalSize));
VolatileBarrier();
writel(tail, &pqhdr->Tail);
writeq(readq(&pqhdr->NumSignalsReceived) + 1,
&pqhdr->NumSignalsReceived);
return 1;
}
EXPORT_SYMBOL_GPL(visor_signal_remove);
/*
* Routine Description:
* Removes all signals present in Channel pChannel's nth Queue at the
* time of the call and copies them into the memory pointed to by
* pSignal. Returns the # of signals copied as the value of the routine.
*
* Parameters:
* pChannel: (IN) points to the IO Channel
* Queue: (IN) nth Queue of the IO Channel
* pSignal: (IN) pointer to where the signals are to be copied
*
* Assumptions:
* - pChannel and Queue are valid.
* - pSignal points to a memory area large enough to hold Queue's MaxSignals
* # of signals, each of which is Queue's SignalSize.
*
* Return value:
* # of signals copied.
*/
unsigned int
SignalRemoveAll(pCHANNEL_HEADER pChannel, U32 Queue, void *pSignal)
{
void *psource;
unsigned int head, tail, signalCount = 0;
pSIGNAL_QUEUE_HEADER pqhdr =
(pSIGNAL_QUEUE_HEADER) ((char *) pChannel +
pChannel->oChannelSpace) + Queue;
/* capture current head and tail */
head = pqhdr->Head;
tail = pqhdr->Tail;
/* queue is empty if the head index equals the tail index */
if (head == tail)
return 0;
while (head != tail) {
/* advance past the 'empty' front slot */
tail = (tail + 1) % pqhdr->MaxSignalSlots;
/* copy signal from tail location to the area pointed
* to by pSignal
*/
psource =
(char *) pqhdr + pqhdr->oSignalBase +
(tail * pqhdr->SignalSize);
MEMCPY((char *) pSignal + (pqhdr->SignalSize * signalCount),
psource, pqhdr->SignalSize);
VolatileBarrier();
pqhdr->Tail = tail;
signalCount++;
pqhdr->NumSignalsReceived++;
}
return signalCount;
}
/*
* Routine Description:
* Determine whether a signal queue is empty.
*
* Parameters:
* pChannel: (IN) points to the IO Channel
* Queue: (IN) nth Queue of the IO Channel
*
* Return value:
* 1 if the signal queue is empty, 0 otherwise.
*/
unsigned char
visor_signalqueue_empty(CHANNEL_HEADER __iomem *pChannel, U32 Queue)
{
SIGNAL_QUEUE_HEADER __iomem *pqhdr =
(SIGNAL_QUEUE_HEADER __iomem *) ((char __iomem *) pChannel +
readq(&pChannel->oChannelSpace)) + Queue;
return readl(&pqhdr->Head) == readl(&pqhdr->Tail);
}
EXPORT_SYMBOL_GPL(visor_signalqueue_empty);
