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Achin Gupta4f6ad662013-10-25 09:08:21 +01001/*
Soby Mathewa0a897d2015-02-19 16:23:51 +00002 * Copyright (c) 2013-2015, ARM Limited and Contributors. All rights reserved.
Achin Gupta4f6ad662013-10-25 09:08:21 +01003 *
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
Dan Handleyed6ff952014-05-14 17:44:19 +010034#include <platform_def.h>
Achin Gupta4f6ad662013-10-25 09:08:21 +010035
36#define BAKERY_LOCK_MAX_CPUS PLATFORM_CORE_COUNT
37
Soby Mathew523d6332015-01-08 18:02:19 +000038#ifndef __ASSEMBLY__
39#include <stdint.h>
40
Soby Mathewa0a897d2015-02-19 16:23:51 +000041/*****************************************************************************
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 ****************************************************************************/
Soby Mathew523d6332015-01-08 18:02:19 +000058#if USE_COHERENT_MEM
Andrew Thoelkee466c9f2015-09-10 11:39:36 +010059/*
60 * Bakery locks are stored in coherent memory
61 *
62 * Each lock's data is contiguous and fully allocated by the compiler
63 */
Soby Mathew523d6332015-01-08 18:02:19 +000064
Dan Handleye2712bc2014-04-10 15:37:22 +010065typedef struct bakery_lock {
Soby Mathewa0a897d2015-02-19 16:23:51 +000066 /*
67 * The lock_data is a bit-field of 2 members:
68 * Bit[0] : choosing. This field is set when the CPU is
69 * choosing its bakery number.
70 * Bits[1 - 15] : number. This is the bakery number allocated.
71 */
72 volatile uint16_t lock_data[BAKERY_LOCK_MAX_CPUS];
Dan Handleye2712bc2014-04-10 15:37:22 +010073} bakery_lock_t;
Achin Gupta4f6ad662013-10-25 09:08:21 +010074
Soby Mathew523d6332015-01-08 18:02:19 +000075#else
Andrew Thoelkee466c9f2015-09-10 11:39:36 +010076/*
77 * Bakery locks are stored in normal .bss memory
78 *
79 * Each lock's data is spread across multiple cache lines, one per CPU,
80 * but multiple locks can share the same cache line.
81 * The compiler will allocate enough memory for one CPU's bakery locks,
82 * the remaining cache lines are allocated by the linker script
83 */
Soby Mathew523d6332015-01-08 18:02:19 +000084
85typedef struct bakery_info {
86 /*
87 * The lock_data is a bit-field of 2 members:
88 * Bit[0] : choosing. This field is set when the CPU is
89 * choosing its bakery number.
90 * Bits[1 - 15] : number. This is the bakery number allocated.
91 */
92 volatile uint16_t lock_data;
93} bakery_info_t;
94
Andrew Thoelkee466c9f2015-09-10 11:39:36 +010095typedef bakery_info_t bakery_lock_t;
Soby Mathew523d6332015-01-08 18:02:19 +000096
97#endif /* __USE_COHERENT_MEM__ */
Andrew Thoelkee466c9f2015-09-10 11:39:36 +010098
99inline void bakery_lock_init(bakery_lock_t *bakery) {}
100void bakery_lock_get(bakery_lock_t *bakery);
101void bakery_lock_release(bakery_lock_t *bakery);
102
103#define DEFINE_BAKERY_LOCK(_name) bakery_lock_t _name \
104 __attribute__ ((section("bakery_lock")))
105
106#define DECLARE_BAKERY_LOCK(_name) extern bakery_lock_t _name
107
108
Soby Mathew523d6332015-01-08 18:02:19 +0000109#endif /* __ASSEMBLY__ */
Achin Gupta4f6ad662013-10-25 09:08:21 +0100110#endif /* __BAKERY_LOCK_H__ */