3 * Copyright (C) 2001 Mike Corrigan IBM Corporation
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
11 #include <linux/stddef.h>
12 #include <linux/kernel.h>
13 #include <linux/sched.h>
14 #include <asm/system.h>
16 #include <linux/random.h>
18 #include <asm/iSeries/ItLpQueue.h>
19 #include <asm/iSeries/HvLpEvent.h>
20 #include <asm/iSeries/HvCallEvent.h>
21 #include <asm/iSeries/LparData.h>
23 static __inline__ int set_inUse( struct ItLpQueue * lpQueue )
26 u32 * inUseP = &(lpQueue->xInUseWord);
28 __asm__ __volatile__("\n\
37 : "=&r" (t), "=m" (lpQueue->xInUseWord)
38 : "r" (inUseP), "m" (lpQueue->xInUseWord)
44 static __inline__ void clear_inUse( struct ItLpQueue * lpQueue )
46 lpQueue->xInUseWord = 0;
49 /* Array of LpEvent handler functions */
50 extern LpEventHandler lpEventHandler[HvLpEvent_Type_NumTypes];
51 unsigned long ItLpQueueInProcess = 0;
53 struct HvLpEvent * ItLpQueue_getNextLpEvent( struct ItLpQueue * lpQueue )
55 struct HvLpEvent * nextLpEvent =
56 (struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
57 if ( nextLpEvent->xFlags.xValid ) {
58 /* rmb() needed only for weakly consistent machines (regatta) */
60 /* Set pointer to next potential event */
61 lpQueue->xSlicCurEventPtr += ((nextLpEvent->xSizeMinus1 +
65 /* Wrap to beginning if no room at end */
66 if (lpQueue->xSlicCurEventPtr > lpQueue->xSlicLastValidEventPtr)
67 lpQueue->xSlicCurEventPtr = lpQueue->xSlicEventStackPtr;
75 int ItLpQueue_isLpIntPending( struct ItLpQueue * lpQueue )
78 struct HvLpEvent * nextLpEvent;
80 nextLpEvent = (struct HvLpEvent *)lpQueue->xSlicCurEventPtr;
81 retval = nextLpEvent->xFlags.xValid | lpQueue->xPlicOverflowIntPending;
86 void ItLpQueue_clearValid( struct HvLpEvent * event )
88 /* Clear the valid bit of the event
89 * Also clear bits within this event that might
90 * look like valid bits (on 64-byte boundaries)
92 unsigned extra = (( event->xSizeMinus1 + LpEventAlign ) /
96 ((struct HvLpEvent*)((char*)event+3*LpEventAlign))->xFlags.xValid=0;
98 ((struct HvLpEvent*)((char*)event+2*LpEventAlign))->xFlags.xValid=0;
100 ((struct HvLpEvent*)((char*)event+1*LpEventAlign))->xFlags.xValid=0;
105 event->xFlags.xValid = 0;
108 unsigned ItLpQueue_process( struct ItLpQueue * lpQueue, struct pt_regs *regs )
110 unsigned numIntsProcessed = 0;
111 struct HvLpEvent * nextLpEvent;
113 /* If we have recursed, just return */
114 if ( !set_inUse( lpQueue ) )
117 if (ItLpQueueInProcess == 0)
118 ItLpQueueInProcess = 1;
123 nextLpEvent = ItLpQueue_getNextLpEvent( lpQueue );
125 /* Count events to return to caller
126 * and count processed events in lpQueue
129 lpQueue->xLpIntCount++;
130 /* Call appropriate handler here, passing
131 * a pointer to the LpEvent. The handler
132 * must make a copy of the LpEvent if it
133 * needs it in a bottom half. (perhaps for
136 * Handlers are responsible for ACK processing
138 * The Hypervisor guarantees that LpEvents will
139 * only be delivered with types that we have
140 * registered for, so no type check is necessary
143 if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes )
144 lpQueue->xLpIntCountByType[nextLpEvent->xType]++;
145 if ( nextLpEvent->xType < HvLpEvent_Type_NumTypes &&
146 lpEventHandler[nextLpEvent->xType] )
147 lpEventHandler[nextLpEvent->xType](nextLpEvent, regs);
149 printk(KERN_INFO "Unexpected Lp Event type=%d\n", nextLpEvent->xType );
151 ItLpQueue_clearValid( nextLpEvent );
153 else /* No more valid events
154 * If overflow events are pending
157 if ( lpQueue->xPlicOverflowIntPending ) {
158 HvCallEvent_getOverflowLpEvents(
161 else /* If nothing left then we are done */
165 ItLpQueueInProcess = 0;
167 clear_inUse( lpQueue );
169 get_paca()->lpEvent_count += numIntsProcessed;
171 /* Use LPEvents as a source of randomness. Since there
172 * Isn't an LPEvent Randomness call, pretend these are
173 * mouse events (which is fair since we don't have mice
176 add_mouse_randomness(get_tb());
178 return numIntsProcessed;