/arch/powerpc/include/asm/iseries/it_lp_queue.h

 1/*
 2 * Copyright (C) 2001  Mike Corrigan IBM Corporation
 3 *
 4 * This program is free software; you can redistribute it and/or modify
 5 * it under the terms of the GNU General Public License as published by
 6 * the Free Software Foundation; either version 2 of the License, or
 7 * (at your option) any later version.
 8 *
 9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
17 */
18#ifndef _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H
19#define _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H
20
21/*
22 *	This control block defines the simple LP queue structure that is
23 *	shared between the hypervisor (PLIC) and the OS in order to send
24 *	events to an LP.
25 */
26
27#include <asm/types.h>
28#include <asm/ptrace.h>
29
30#define IT_LP_MAX_QUEUES	8
31
32#define IT_LP_NOT_USED		0	/* Queue will not be used by PLIC */
33#define IT_LP_DEDICATED_IO	1	/* Queue dedicated to IO processor specified */
34#define IT_LP_DEDICATED_LP	2	/* Queue dedicated to LP specified */
35#define IT_LP_SHARED		3	/* Queue shared for both IO and LP */
36
37#define IT_LP_EVENT_STACK_SIZE	4096
38#define IT_LP_EVENT_MAX_SIZE	256
39#define IT_LP_EVENT_ALIGN	64
40
41struct hvlpevent_queue {
42/*
43 * The hq_current_event is the pointer to the next event stack entry
44 * that will become valid.  The OS must peek at this entry to determine
45 * if it is valid.  PLIC will set the valid indicator as the very last
46 * store into that entry.
47 *
48 * When the OS has completed processing of the event then it will mark
49 * the event as invalid so that PLIC knows it can store into that event
50 * location again.
51 *
52 * If the event stack fills and there are overflow events, then PLIC
53 * will set the hq_overflow_pending flag in which case the OS will
54 * have to fetch the additional LP events once they have drained the
55 * event stack.
56 *
57 * The first 16-bytes are known by both the OS and PLIC.  The remainder
58 * of the cache line is for use by the OS.
59 */
60	u8		hq_overflow_pending;	/* 0x00 Overflow events are pending */
61	u8		hq_status;		/* 0x01 DedicatedIo or DedicatedLp or NotUsed */
62	u16		hq_proc_index;		/* 0x02 Logical Proc Index for correlation */
63	u8		hq_reserved1[12];	/* 0x04 */
64	char		*hq_current_event;	/* 0x10 */
65	char		*hq_last_event;		/* 0x18 */
66	char		*hq_event_stack;	/* 0x20 */
67	u8		hq_index;		/* 0x28 unique sequential index. */
68	u8		hq_reserved2[3];	/* 0x29-2b */
69	spinlock_t	hq_lock;
70};
71
72extern struct hvlpevent_queue hvlpevent_queue;
73
74extern int hvlpevent_is_pending(void);
75extern void process_hvlpevents(void);
76extern void setup_hvlpevent_queue(void);
77
78#endif /* _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H */