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 __ASSEMBLER__ 15 #include <cdefs.h> 16 #include <stdbool.h> 17 #include <stdint.h> 18 19 #include <lib/utils_def.h> 20 21 /***************************************************************************** 22 * Internal helpers used by the bakery lock implementation. 23 ****************************************************************************/ 24 25 /* Convert a ticket to priority */ bakery_get_priority(unsigned int t,unsigned int pos)26static inline unsigned int bakery_get_priority(unsigned int t, unsigned int pos) 27 { 28 return (t << 8) | pos; 29 } 30 31 #define CHOOSING_TICKET U(0x1) 32 #define CHOSEN_TICKET U(0x0) 33 bakery_is_choosing(unsigned int info)34static inline bool bakery_is_choosing(unsigned int info) 35 { 36 return (info & 1U) == CHOOSING_TICKET; 37 } 38 bakery_ticket_number(unsigned int info)39static inline unsigned int bakery_ticket_number(unsigned int info) 40 { 41 return (info >> 1) & 0x7FFFU; 42 } 43 make_bakery_data(unsigned int choosing,unsigned int num)44static inline uint16_t make_bakery_data(unsigned int choosing, unsigned int num) 45 { 46 unsigned int val = (choosing & 0x1U) | (num << 1); 47 48 return (uint16_t) val; 49 } 50 51 /***************************************************************************** 52 * External bakery lock interface. 53 ****************************************************************************/ 54 #if USE_COHERENT_MEM 55 /* 56 * Bakery locks are stored in coherent memory 57 * 58 * Each lock's data is contiguous and fully allocated by the compiler 59 */ 60 61 typedef struct bakery_lock { 62 /* 63 * The lock_data is a bit-field of 2 members: 64 * Bit[0] : choosing. This field is set when the CPU is 65 * choosing its bakery number. 66 * Bits[1 - 15] : number. This is the bakery number allocated. 67 */ 68 volatile uint16_t lock_data[BAKERY_LOCK_MAX_CPUS]; 69 } bakery_lock_t; 70 71 #else 72 /* 73 * Bakery locks are stored in normal .bss memory 74 * 75 * Each lock's data is spread across multiple cache lines, one per CPU, 76 * but multiple locks can share the same cache line. 77 * The compiler will allocate enough memory for one CPU's bakery locks, 78 * the remaining cache lines are allocated by the linker script 79 */ 80 81 typedef struct bakery_info { 82 /* 83 * The lock_data is a bit-field of 2 members: 84 * Bit[0] : choosing. This field is set when the CPU is 85 * choosing its bakery number. 86 * Bits[1 - 15] : number. This is the bakery number allocated. 87 */ 88 volatile uint16_t lock_data; 89 } bakery_info_t; 90 91 typedef bakery_info_t bakery_lock_t; 92 93 #endif /* __USE_COHERENT_MEM__ */ 94 bakery_lock_init(bakery_lock_t * bakery)95static inline void bakery_lock_init(bakery_lock_t *bakery) {} 96 void bakery_lock_get(bakery_lock_t *bakery); 97 void bakery_lock_release(bakery_lock_t *bakery); 98 99 #define DEFINE_BAKERY_LOCK(_name) bakery_lock_t _name __section("bakery_lock") 100 101 #define DECLARE_BAKERY_LOCK(_name) extern bakery_lock_t _name 102 103 104 #endif /* __ASSEMBLER__ */ 105 #endif /* BAKERY_LOCK_H */ 106