grukservices.h revision 6f2584f47474d29ce829604bfc8b56c10b352fdb 
1
2/*
3 *  Copyright (c) 2008 Silicon Graphics, Inc.  All Rights Reserved.
4 *
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.
9 *
10 *  This program is distributed in the hope that it will be useful,
11 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13 *  GNU General Public License for more details.
14 *
15 *  You should have received a copy of the GNU General Public License
16 *  along with this program; if not, write to the Free Software
17 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
18 */
19#ifndef __GRU_KSERVICES_H_
20#define __GRU_KSERVICES_H_
21
22
23/*
24 * Message queues using the GRU to send/receive messages.
25 *
26 * These function allow the user to create a message queue for
27 * sending/receiving 1 or 2 cacheline messages using the GRU.
28 *
29 * Processes SENDING messages will use a kernel CBR/DSR to send
30 * the message. This is transparent to the caller.
31 *
32 * The receiver does not use any GRU resources.
33 *
34 * The functions support:
35 * 	- single receiver
36 * 	- multiple senders
37 *	- cross partition message
38 *
39 * Missing features ZZZ:
40 * 	- user options for dealing with timeouts, queue full, etc.
41 * 	- gru_create_message_queue() needs interrupt vector info
42 */
43
44struct gru_message_queue_desc {
45	void		*mq;			/* message queue vaddress */
46	unsigned long	mq_gpa;			/* global address of mq */
47	int		qlines;			/* queue size in CL */
48	int		interrupt_vector;	/* interrupt vector */
49	int		interrupt_pnode;	/* pnode for interrupt */
50	int		interrupt_apicid;	/* lapicid for interrupt */
51};
52
53/*
54 * Initialize a user allocated chunk of memory to be used as
55 * a message queue. The caller must ensure that the queue is
56 * in contiguous physical memory and is cacheline aligned.
57 *
58 * Message queue size is the total number of bytes allocated
59 * to the queue including a 2 cacheline header that is used
60 * to manage the queue.
61 *
62 *  Input:
63 * 	mqd	pointer to message queue descriptor
64 * 	p	pointer to user allocated mesq memory.
65 * 	bytes	size of message queue in bytes
66 *      vector	interrupt vector (zero if no interrupts)
67 *      nasid	nasid of blade where interrupt is delivered
68 *      apicid	apicid of cpu for interrupt
69 *
70 *  Errors:
71 *  	0	OK
72 *  	>0	error
73 */
74extern int gru_create_message_queue(struct gru_message_queue_desc *mqd,
75		void *p, unsigned int bytes, int nasid, int vector, int apicid);
76
77/*
78 * Send a message to a message queue.
79 *
80 * Note: The message queue transport mechanism uses the first 32
81 * bits of the message. Users should avoid using these bits.
82 *
83 *
84 *   Input:
85 * 	mqd	pointer to message queue descriptor
86 * 	mesg	pointer to message. Must be 64-bit aligned
87 * 	bytes	size of message in bytes
88 *
89 *   Output:
90 *      0	message sent
91 *     >0	Send failure - see error codes below
92 *
93 */
94extern int gru_send_message_gpa(struct gru_message_queue_desc *mqd,
95			void *mesg, unsigned int bytes);
96
97/* Status values for gru_send_message() */
98#define MQE_OK			0	/* message sent successfully */
99#define MQE_CONGESTION		1	/* temporary congestion, try again */
100#define MQE_QUEUE_FULL		2	/* queue is full */
101#define MQE_UNEXPECTED_CB_ERR	3	/* unexpected CB error */
102#define MQE_PAGE_OVERFLOW	10	/* BUG - queue overflowed a page */
103#define MQE_BUG_NO_RESOURCES	11	/* BUG - could not alloc GRU cb/dsr */
104
105/*
106 * Advance the receive pointer for the message queue to the next message.
107 * Note: current API requires messages to be gotten & freed in order. Future
108 * API extensions may allow for out-of-order freeing.
109 *
110 *   Input
111 * 	mqd	pointer to message queue descriptor
112 * 	mesq	message being freed
113 */
114extern void gru_free_message(struct gru_message_queue_desc *mqd,
115			     void *mesq);
116
117/*
118 * Get next message from message queue. Returns pointer to
119 * message OR NULL if no message present.
120 * User must call gru_free_message() after message is processed
121 * in order to move the queue pointers to next message.
122 *
123 *   Input
124 * 	mqd	pointer to message queue descriptor
125 *
126 *   Output:
127 *	p	pointer to message
128 *	NULL	no message available
129 */
130extern void *gru_get_next_message(struct gru_message_queue_desc *mqd);
131
132
133/*
134 * Copy data using the GRU. Source or destination can be located in a remote
135 * partition.
136 *
137 *    Input:
138 *    	dest_gpa	destination global physical address
139 *    	src_gpa		source global physical address
140 *    	bytes		number of bytes to copy
141 *
142 *    Output:
143 *	0		OK
144 *	>0		error
145 */
146extern int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
147							unsigned int bytes);
148
149#endif 		/* __GRU_KSERVICES_H_ */
150