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 
41 struct 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 
72 extern struct hvlpevent_queue hvlpevent_queue;
73 
74 extern int hvlpevent_is_pending(void);
75 extern void process_hvlpevents(void);
76 extern void setup_hvlpevent_queue(void);
77 
78 #endif /* _ASM_POWERPC_ISERIES_IT_LP_QUEUE_H */
79