1 /* 2 * Copyright (c) 2013-2018, ARM Limited and Contributors. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #ifndef __BAKERY_LOCK_H__ 8 #define __BAKERY_LOCK_H__ 9 10 #include <platform_def.h> 11 12 #define BAKERY_LOCK_MAX_CPUS PLATFORM_CORE_COUNT 13 14 #ifndef __ASSEMBLY__ 15 #include <cdefs.h> 16 #include <stdint.h> 17 18 /***************************************************************************** 19 * Internal helper macros used by the bakery lock implementation. 20 ****************************************************************************/ 21 /* Convert a ticket to priority */ 22 #define PRIORITY(t, pos) (((t) << 8) | (pos)) 23 24 #define CHOOSING_TICKET 0x1 25 #define CHOSEN_TICKET 0x0 26 27 #define bakery_is_choosing(info) (info & 0x1) 28 #define bakery_ticket_number(info) ((info >> 1) & 0x7FFF) 29 #define make_bakery_data(choosing, number) \ 30 (((choosing & 0x1) | (number << 1)) & 0xFFFF) 31 32 /***************************************************************************** 33 * External bakery lock interface. 34 ****************************************************************************/ 35 #if USE_COHERENT_MEM 36 /* 37 * Bakery locks are stored in coherent memory 38 * 39 * Each lock's data is contiguous and fully allocated by the compiler 40 */ 41 42 typedef struct bakery_lock { 43 /* 44 * The lock_data is a bit-field of 2 members: 45 * Bit[0] : choosing. This field is set when the CPU is 46 * choosing its bakery number. 47 * Bits[1 - 15] : number. This is the bakery number allocated. 48 */ 49 volatile uint16_t lock_data[BAKERY_LOCK_MAX_CPUS]; 50 } bakery_lock_t; 51 52 #else 53 /* 54 * Bakery locks are stored in normal .bss memory 55 * 56 * Each lock's data is spread across multiple cache lines, one per CPU, 57 * but multiple locks can share the same cache line. 58 * The compiler will allocate enough memory for one CPU's bakery locks, 59 * the remaining cache lines are allocated by the linker script 60 */ 61 62 typedef struct bakery_info { 63 /* 64 * The lock_data is a bit-field of 2 members: 65 * Bit[0] : choosing. This field is set when the CPU is 66 * choosing its bakery number. 67 * Bits[1 - 15] : number. This is the bakery number allocated. 68 */ 69 volatile uint16_t lock_data; 70 } bakery_info_t; 71 72 typedef bakery_info_t bakery_lock_t; 73 74 #endif /* __USE_COHERENT_MEM__ */ 75 76 static inline void bakery_lock_init(bakery_lock_t *bakery) {} 77 void bakery_lock_get(bakery_lock_t *bakery); 78 void bakery_lock_release(bakery_lock_t *bakery); 79 80 #define DEFINE_BAKERY_LOCK(_name) bakery_lock_t _name __section("bakery_lock") 81 82 #define DECLARE_BAKERY_LOCK(_name) extern bakery_lock_t _name 83 84 85 #endif /* __ASSEMBLY__ */ 86 #endif /* __BAKERY_LOCK_H__ */ 87