xref: /rk3399_ARM-atf/include/lib/bakery_lock.h (revision 7d37aa171158422b5ee7ee6c3cdad58f6aa066b4)
1 /*
2  * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following conditions are met:
6  *
7  * Redistributions of source code must retain the above copyright notice, this
8  * list of conditions and the following disclaimer.
9  *
10  * Redistributions in binary form must reproduce the above copyright notice,
11  * this list of conditions and the following disclaimer in the documentation
12  * and/or other materials provided with the distribution.
13  *
14  * Neither the name of ARM nor the names of its contributors may be used
15  * to endorse or promote products derived from this software without specific
16  * prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28  * POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #ifndef __BAKERY_LOCK_H__
32 #define __BAKERY_LOCK_H__
33 
34 #include <platform_def.h>
35 
36 #define BAKERY_LOCK_MAX_CPUS		PLATFORM_CORE_COUNT
37 
38 #ifndef __ASSEMBLY__
39 #include <stdint.h>
40 
41 /*****************************************************************************
42  * Internal helper macros used by the bakery lock implementation.
43  ****************************************************************************/
44 /* Convert a ticket to priority */
45 #define PRIORITY(t, pos)	(((t) << 8) | (pos))
46 
47 #define CHOOSING_TICKET		0x1
48 #define CHOSEN_TICKET		0x0
49 
50 #define bakery_is_choosing(info)	(info & 0x1)
51 #define bakery_ticket_number(info)	((info >> 1) & 0x7FFF)
52 #define make_bakery_data(choosing, number) \
53 		(((choosing & 0x1) | (number << 1)) & 0xFFFF)
54 
55 /*****************************************************************************
56  * External bakery lock interface.
57  ****************************************************************************/
58 #if USE_COHERENT_MEM
59 
60 typedef struct bakery_lock {
61 	/*
62 	 * The lock_data is a bit-field of 2 members:
63 	 * Bit[0]       : choosing. This field is set when the CPU is
64 	 *                choosing its bakery number.
65 	 * Bits[1 - 15] : number. This is the bakery number allocated.
66 	 */
67 	volatile uint16_t lock_data[BAKERY_LOCK_MAX_CPUS];
68 } bakery_lock_t;
69 
70 void bakery_lock_init(bakery_lock_t *bakery);
71 void bakery_lock_get(bakery_lock_t *bakery);
72 void bakery_lock_release(bakery_lock_t *bakery);
73 int bakery_lock_try(bakery_lock_t *bakery);
74 
75 #else
76 
77 typedef struct bakery_info {
78 	/*
79 	 * The lock_data is a bit-field of 2 members:
80 	 * Bit[0]       : choosing. This field is set when the CPU is
81 	 *                choosing its bakery number.
82 	 * Bits[1 - 15] : number. This is the bakery number allocated.
83 	 */
84 	volatile uint16_t lock_data;
85 } bakery_info_t;
86 
87 void bakery_lock_get(unsigned int id, unsigned int offset);
88 void bakery_lock_release(unsigned int id, unsigned int offset);
89 
90 #endif /* __USE_COHERENT_MEM__ */
91 #endif /* __ASSEMBLY__ */
92 #endif /* __BAKERY_LOCK_H__ */
93