forked from Minki/linux
719d1cd867
The hvlpevent_queue (formally ItLpQueue) has a member called xInUseWord which is used for serialising access to the queue. Because it's a word (ie. 32 bit) there's a custom 32-bit version of test_and_set_bit() or thereabouts in ItLpQueue.c. The xInUseWord is not shared with they hypervisor, so we can replace it with a spinlock and remove the custom code. There is also another locking mechanism (ItLpQueueInProcess). This is redundant because it's only manipulated while the lock's held. Remove it. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Acked-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
82 lines
2.8 KiB
C
82 lines
2.8 KiB
C
/*
|
|
* ItLpQueue.h
|
|
* 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.
|
|
*
|
|
* 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. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*/
|
|
#ifndef _ITLPQUEUE_H
|
|
#define _ITLPQUEUE_H
|
|
|
|
/*
|
|
* This control block defines the simple LP queue structure that is
|
|
* shared between the hypervisor (PLIC) and the OS in order to send
|
|
* events to an LP.
|
|
*/
|
|
|
|
#include <asm/types.h>
|
|
#include <asm/ptrace.h>
|
|
|
|
struct HvLpEvent;
|
|
|
|
#define ITMaxLpQueues 8
|
|
|
|
#define NotUsed 0 // Queue will not be used by PLIC
|
|
#define DedicatedIo 1 // Queue dedicated to IO processor specified
|
|
#define DedicatedLp 2 // Queue dedicated to LP specified
|
|
#define Shared 3 // Queue shared for both IO and LP
|
|
|
|
#define LpEventStackSize 4096
|
|
#define LpEventMaxSize 256
|
|
#define LpEventAlign 64
|
|
|
|
struct hvlpevent_queue {
|
|
/*
|
|
* The xSlicCurEventPtr is the pointer to the next event stack entry
|
|
* that will become valid. The OS must peek at this entry to determine
|
|
* if it is valid. PLIC will set the valid indicator as the very last
|
|
* store into that entry.
|
|
*
|
|
* When the OS has completed processing of the event then it will mark
|
|
* the event as invalid so that PLIC knows it can store into that event
|
|
* location again.
|
|
*
|
|
* If the event stack fills and there are overflow events, then PLIC
|
|
* will set the xPlicOverflowIntPending flag in which case the OS will
|
|
* have to fetch the additional LP events once they have drained the
|
|
* event stack.
|
|
*
|
|
* The first 16-bytes are known by both the OS and PLIC. The remainder
|
|
* of the cache line is for use by the OS.
|
|
*/
|
|
u8 xPlicOverflowIntPending;// 0x00 Overflow events are pending
|
|
u8 xPlicStatus; // 0x01 DedicatedIo or DedicatedLp or NotUsed
|
|
u16 xSlicLogicalProcIndex; // 0x02 Logical Proc Index for correlation
|
|
u8 xPlicRsvd[12]; // 0x04
|
|
char *xSlicCurEventPtr; // 0x10
|
|
char *xSlicLastValidEventPtr; // 0x18
|
|
char *xSlicEventStackPtr; // 0x20
|
|
u8 xIndex; // 0x28 unique sequential index.
|
|
u8 xSlicRsvd[3]; // 0x29-2b
|
|
spinlock_t lock;
|
|
};
|
|
|
|
extern struct hvlpevent_queue hvlpevent_queue;
|
|
|
|
extern int hvlpevent_is_pending(void);
|
|
extern void process_hvlpevents(struct pt_regs *);
|
|
extern void setup_hvlpevent_queue(void);
|
|
|
|
#endif /* _ITLPQUEUE_H */
|