summaryrefslogtreecommitdiff
path: root/drivers/misc/sgi-gru/grukservices.h
blob: eb17e0a3ac61e4a0ff702b2edf8ebf894cb35c0f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
/*
 *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
 *
 *  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 __GRU_KSERVICES_H_
#define __GRU_KSERVICES_H_


/*
 * Message queues using the GRU to send/receive messages.
 *
 * These function allow the user to create a message queue for
 * sending/receiving 1 or 2 cacheline messages using the GRU.
 *
 * Processes SENDING messages will use a kernel CBR/DSR to send
 * the message. This is transparent to the caller.
 *
 * The receiver does not use any GRU resources.
 *
 * The functions support:
 * 	- single receiver
 * 	- multiple senders
 *	- cross partition message
 *
 * Missing features ZZZ:
 * 	- user options for dealing with timeouts, queue full, etc.
 * 	- gru_create_message_queue() needs interrupt vector info
 */

/*
 * Initialize a user allocated chunk of memory to be used as
 * a message queue. The caller must ensure that the queue is
 * in contiguous physical memory and is cacheline aligned.
 *
 * Message queue size is the total number of bytes allocated
 * to the queue including a 2 cacheline header that is used
 * to manage the queue.
 *
 *  Input:
 * 	p	pointer to user allocated memory.
 * 	bytes	size of message queue in bytes
 *
 *  Errors:
 *  	0	OK
 *  	>0	error
 */
extern int gru_create_message_queue(void *p, unsigned int bytes);

/*
 * Send a message to a message queue.
 *
 * Note: The message queue transport mechanism uses the first 32
 * bits of the message. Users should avoid using these bits.
 *
 *
 *   Input:
 * 	xmq	message queue - must be a UV global physical address
 * 	mesg	pointer to message. Must be 64-bit aligned
 * 	bytes	size of message in bytes
 *
 *   Output:
 *      0	message sent
 *     >0	Send failure - see error codes below
 *
 */
extern int gru_send_message_gpa(unsigned long mq_gpa, void *mesg,
						unsigned int bytes);

/* Status values for gru_send_message() */
#define MQE_OK			0	/* message sent successfully */
#define MQE_CONGESTION		1	/* temporary congestion, try again */
#define MQE_QUEUE_FULL		2	/* queue is full */
#define MQE_UNEXPECTED_CB_ERR	3	/* unexpected CB error */
#define MQE_PAGE_OVERFLOW	10	/* BUG - queue overflowed a page */
#define MQE_BUG_NO_RESOURCES	11	/* BUG - could not alloc GRU cb/dsr */

/*
 * Advance the receive pointer for the message queue to the next message.
 * Note: current API requires messages to be gotten & freed in order. Future
 * API extensions may allow for out-of-order freeing.
 *
 *   Input
 * 	mq	message queue
 * 	mesq	message being freed
 */
extern void gru_free_message(void *mq, void *mesq);

/*
 * Get next message from message queue. Returns pointer to
 * message OR NULL if no message present.
 * User must call gru_free_message() after message is processed
 * in order to move the queue pointers to next message.
 *
 *   Input
 * 	mq	message queue
 *
 *   Output:
 *	p	pointer to message
 *	NULL	no message available
 */
extern void *gru_get_next_message(void *mq);


/*
 * Copy data using the GRU. Source or destination can be located in a remote
 * partition.
 *
 *    Input:
 *    	dest_gpa	destination global physical address
 *    	src_gpa		source global physical address
 *    	bytes		number of bytes to copy
 *
 *    Output:
 *	0		OK
 *	>0		error
 */
extern int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
							unsigned int bytes);

#endif 		/* __GRU_KSERVICES_H_ */