xref: /linux/drivers/misc/sgi-gru/grukservices.h (revision bb9707077b4ee5f77bc9939b057ff8a0d410296f)
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 
44 struct 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  */
74 extern 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  */
94 extern 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  */
114 extern 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  */
130 extern void *gru_get_next_message(struct gru_message_queue_desc *mqd);
131 
132 
133 /*
134  * Read a GRU global GPA. Source can be located in a remote partition.
135  *
136  *    Input:
137  *    	value		memory address where MMR value is returned
138  *    	gpa		source numalink physical address of GPA
139  *
140  *    Output:
141  *	0		OK
142  *	>0		error
143  */
144 int gru_read_gpa(unsigned long *value, unsigned long gpa);
145 
146 
147 /*
148  * Copy data using the GRU. Source or destination can be located in a remote
149  * partition.
150  *
151  *    Input:
152  *    	dest_gpa	destination global physical address
153  *    	src_gpa		source global physical address
154  *    	bytes		number of bytes to copy
155  *
156  *    Output:
157  *	0		OK
158  *	>0		error
159  */
160 extern int gru_copy_gpa(unsigned long dest_gpa, unsigned long src_gpa,
161 							unsigned int bytes);
162 
163 /*
164  * Reserve GRU resources to be used asynchronously.
165  *
166  * 	input:
167  * 		blade_id  - blade on which resources should be reserved
168  * 		cbrs	  - number of CBRs
169  * 		dsr_bytes - number of DSR bytes needed
170  * 		cmp	  - completion structure for waiting for
171  * 			    async completions
172  *	output:
173  *		handle to identify resource
174  *		(0 = no resources)
175  */
176 extern unsigned long gru_reserve_async_resources(int blade_id, int cbrs, int dsr_bytes,
177 				struct completion *cmp);
178 
179 /*
180  * Release async resources previously reserved.
181  *
182  *	input:
183  *		han - handle to identify resources
184  */
185 extern void gru_release_async_resources(unsigned long han);
186 
187 /*
188  * Wait for async GRU instructions to complete.
189  *
190  *	input:
191  *		han - handle to identify resources
192  */
193 extern void gru_wait_async_cbr(unsigned long han);
194 
195 /*
196  * Lock previous reserved async GRU resources
197  *
198  *	input:
199  *		han - handle to identify resources
200  *	output:
201  *		cb  - pointer to first CBR
202  *		dsr - pointer to first DSR
203  */
204 extern void gru_lock_async_resource(unsigned long han,  void **cb, void **dsr);
205 
206 /*
207  * Unlock previous reserved async GRU resources
208  *
209  *	input:
210  *		han - handle to identify resources
211  */
212 extern void gru_unlock_async_resource(unsigned long han);
213 
214 #endif 		/* __GRU_KSERVICES_H_ */
215