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 * Bakery locks are stored in coherent memory 61 * 62 * Each lock's data is contiguous and fully allocated by the compiler 63 */ 64 65 typedef struct bakery_lock { 66 /* 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]; 73 } bakery_lock_t; 74 75 #else 76 /* 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 */ 84 85 typedef 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 95 typedef bakery_info_t bakery_lock_t; 96 97 #endif /* __USE_COHERENT_MEM__ */ 98 99 inline void bakery_lock_init(bakery_lock_t *bakery) {} 100 void bakery_lock_get(bakery_lock_t *bakery); 101 void bakery_lock_release(bakery_lock_t *bakery); 102 103 #define DEFINE_BAKERY_LOCK(_name) bakery_lock_t _name __section("bakery_lock") 104 105 #define DECLARE_BAKERY_LOCK(_name) extern bakery_lock_t _name 106 107 108 #endif /* __ASSEMBLY__ */ 109 #endif /* __BAKERY_LOCK_H__ */ 110