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/*
* ItLpQueue.c
* Copyright (C) 2001 Mike Corrigan IBM Corporation
*
* 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.
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/system.h>
#include <asm/paca.h>
#include <asm/iSeries/ItLpQueue.h>
#include <asm/iSeries/HvLpEvent.h>
#include <asm/iSeries/HvCallEvent.h>
static __inline__ int set_inUse( struct ItLpQueue * lpQueue )
{
int t;
u32 * inUseP = &(lpQueue->xInUseWord);
__asm__ __volatile__("\n\
1: lwarx %0,0,%2 \n\
cmpwi 0,%0,0 \n\
li %0,0 \n\
bne- 2f \n\
addi %0,%0,1 \n\
stwcx. %0,0,%2 \n\
bne- 1b \n\
2: eieio"
: "=&r" (t), "=m" (lpQueue->xInUseWord)
: "r" (inUseP), "m" (lpQueue->xInUseWord)
: "cc");
return t;
}
static __inline__ void clear_inUse( struct ItLpQueue * lpQueue )
{
lpQueue->xInUseWord = 0;
}
/* Array of LpEvent handler functions */
extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
unsigned long ItLpQueueInProcess = 0;
struct HvLpEvent * ItLpQueue_getNextLpEvent( struct ItLpQueue * lpQueue )
{
struct HvLpEvent * nextLpEvent =
(struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
if ( nextLpEvent->xFlags.xValid ) {
/* rmb() needed only for weakly consistent machines (regatta) */
rmb();
/* Set pointer to next potential event */
lpQueue->xSlicCurEventPtr += ((nextLpEvent->xSizeMinus1 +
LpEventAlign ) /
LpEventAlign ) *
LpEventAlign;
/* Wrap to beginning if no room at end */
if (lpQueue->xSlicCurEventPtr > lpQueue->xSlicLastValidEventPtr)
lpQueue->xSlicCurEventPtr = lpQueue->xSlicEventStackPtr;
}
else
nextLpEvent = NULL;
return nextLpEvent;
}
static unsigned long spread_lpevents = NR_CPUS;
int ItLpQueue_isLpIntPending( struct ItLpQueue * lpQueue )
{
struct HvLpEvent *next_event;
if (smp_processor_id() >= spread_lpevents)
return 0;
next_event = (struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
return next_event->xFlags.xValid | lpQueue->xPlicOverflowIntPending;
}
void ItLpQueue_clearValid( struct HvLpEvent * event )
{
/* Clear the valid bit of the event
* Also clear bits within this event that might
* look like valid bits (on 64-byte boundaries)
*/
unsigned extra = (( event->xSizeMinus1 + LpEventAlign ) /
LpEventAlign ) - 1;
switch ( extra ) {
case 3:
((struct HvLpEvent*)((char*)event+3*LpEventAlign))->xFlags.xValid=0;
case 2:
((struct HvLpEvent*)((char*)event+2*LpEventAlign))->xFlags.xValid=0;
case 1:
((struct HvLpEvent*)((char*)event+1*LpEventAlign))->xFlags.xValid=0;
case 0:
;
}
mb();
event->xFlags.xValid = 0;
}
unsigned ItLpQueue_process( struct ItLpQueue * lpQueue, struct pt_regs *regs )
{
unsigned numIntsProcessed = 0;
struct HvLpEvent * nextLpEvent;
/* If we have recursed, just return */
if ( !set_inUse( lpQueue ) )
return 0;
if (ItLpQueueInProcess == 0)
ItLpQueueInProcess = 1;
else
BUG();
for (;;) {
nextLpEvent = ItLpQueue_getNextLpEvent( lpQueue );
if ( nextLpEvent ) {
/* Count events to return to caller
* and count processed events in lpQueue
*/
++numIntsProcessed;
lpQueue->xLpIntCount++;
/* Call appropriate handler here, passing
* a pointer to the LpEvent. The handler
* must make a copy of the LpEvent if it
* needs it in a bottom half. (perhaps for
* an ACK)
*
* Handlers are responsible for ACK processing
*
* The Hypervisor guarantees that LpEvents will
* only be delivered with types that we have
* registered for, so no type check is necessary
* here!
*/
if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes )
lpQueue->xLpIntCountByType[nextLpEvent->xType]++;
if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes &&
lpEventHandler[nextLpEvent->xType] )
lpEventHandler[nextLpEvent->xType](nextLpEvent, regs);
else
printk(KERN_INFO "Unexpected Lp Event type=%d\n", nextLpEvent->xType );
ItLpQueue_clearValid( nextLpEvent );
} else if ( lpQueue->xPlicOverflowIntPending )
/*
* No more valid events. If overflow events are
* pending process them
*/
HvCallEvent_getOverflowLpEvents( lpQueue->xIndex);
else
break;
}
ItLpQueueInProcess = 0;
mb();
clear_inUse( lpQueue );
get_paca()->lpevent_count += numIntsProcessed;
return numIntsProcessed;
}
static int set_spread_lpevents(char *str)
{
unsigned long val = simple_strtoul(str, NULL, 0);
/*
* The parameter is the number of processors to share in processing
* lp events.
*/
if (( val > 0) && (val <= NR_CPUS)) {
spread_lpevents = val;
printk("lpevent processing spread over %ld processors\n", val);
} else {
printk("invalid spread_lpevents %ld\n", val);
}
return 1;
}
__setup("spread_lpevents=", set_spread_lpevents);
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